Case Presentation: We present a case of a 29-year-old lady who sustained severe burn injuries after a gas explosion at home. She was admitted to the United Arab Emirates (UAE) National Burns Unit and required several episodes of surgical debridement. She developed S. paucimobilis bloodstream infection whilst being treated with Piperacillin-tazobactam. She was subsequently treated with Meropenem for a total of 7 days after removing the source of infection, an infected central line. The S. paucimobilis isolate showed intermediate resistance to Piperacillin-tazobactam.

Conclusion: Numerous case reports indicate high morbidity in patients with life-threatening S. paucimobilis infections, immunocompromised patients, and patients with underlying medical comorbidity; however, this is the first reported case from the UAE.

Methods: PubMed/MEDLINE was searched from database inception until January 2024, pairing Non-bacterial Thrombotic Endocarditis (NBTE) and related terms with “Lung Cancer (LC)”. Reports were included if patients had both NBTE and lung cancer. The risk of bias was assessed using Mixed Methods Analysis Testing (MMAT).

Results and Discussion: 32 patients with an average age of 59y +/- 11.6 were included from 31 peer-reviewed publications, with significant findings as below:

• The majority (47%) of patients were admitted with stroke.

• The most commonly affected valve was aortic (51%), followed by mitral (43%), and tricuspid (5%).

• At diagnosis of NBTE, 86% of patients had stage IV cancer.

• Multi-organ infarct was common (61%), with the brain most often affected (40%).

• Treatment of NBTE included antibiotics (86%), anticoagulation (50%), and cardiac surgery (6%).

• Treatment of LC included traditional chemotherapy (30.7%), radiation (16%), tyrosine kinase inhibitors (11.5%), lobectomy (6%), and immunotherapy (3.8%).

• Overall mortality rate was 77%.

• Mortality rate was 38% in patients treated with chemotherapy and 91% in patients who did not receive chemotherapy.

• Mortality rate stratified by anticoagulant: unfractionated heparin (85.7%), DOAC (75%), and LMWH (20%).

Conclusion: High clinical suspicion for NBTE in patients presenting with LC and thromboembolic phenomena can lead to changes in treatment and improved clinical outcomes.

Case Representation: We present a case of SBE resulting in an isolated ruptured mycotic mitral valve aneurysm in a patient on dialysis. Mycotic mitral valve aneurysm is an uncommon and serious complication of infective endocarditis, particularly subacute endocarditis.

Conclusion: In order to diagnose this complication, there should be clinical suspicion in the presence of severe regurgitation without any cause, and a detailed echocardiography should be performed.

Objective: Evaluate the activity of Brevinin2 HYba5 against S. aureus and E. faecalis mixed biofilm.

Methods: The anti-biofilm activity of peptide 29 was tested by Crystal violet assay, Confocal laser scanning Microscopy (CLSM) and MTT Assay. Cytotoxicity of the peptide was tested in RBC and L929 fibroblast cell line. Biofilm inhibitory activity of the peptide was evaluated at different temperatures, pH, serum and plasma concentrations. The antibiofilm potential of the peptide was tested against polymicrobial biofilm by Fluorescent in situ hybridisation (FISH) and plate counting on HiCrome^TM UTI Agar media.

Results: The peptide 29 could inhibit biofilm formation of S. aureus and E. faecalis individually as well as in polymicrobial biofilm at 75 μM concentration. The peptide maintained its antibiofilm potential at different temperatures, serum and plasma concentrations. Activity of the peptide was high at acidic and neutral pH but found to get reduced towards alkaline pH. The peptide is nonhemolytic and does not exhibit significant cytotoxicity against the L929 fibroblast cell line (92.80% cell viability).

Conclusion: The biofilm inhibition property makes peptide 29 a promising candidate for the management of S. aureus and E. faecalis biofilm, especially in catheter-associated devices to prevent the initial colonization and thus can ease the burden of pathogenic biofilm-associated infections.

Case: A 56-year-old female presented with fever and abdominal pain. Bile aspirated during the ERCP was received in our laboratory. The gram stain of the bile sample revealed abundant polymorphonuclear leucocytes along with gram-positive diplococci. The organism failed to grow on MacConkey agar. On blood agar, non-hemolytic colonies grew. The organism was identified as E. hirae by MALDI-TOF MS. The antibiotic susceptibility performed using VITEK2 revealed it to be resistant to high-level gentamicin and susceptible to all remaining drugs. She was successfully treated with oral ciprofloxacin for the infection.

Discussion: Bile is colonized with bacteria due to obstruction in the biliary tree, leading to cholangitis. This causes bacterial proliferation and translocation of bacteria into the systemic circulation. Our case was resistant to high-level gentamicin, while all previously reported cases were susceptible. The resistant isolates of E. hirae being isolated from cattle and their surroundings amidst the rampant use of antibiotics in livestock can pose a difficult situation for humans. Thus, there should be regulations on antibiotic usage in livestock. Cases like these should be reported and recognized for their potential to cause outbreaks if they remain unreported.

Conclusion: Thus, E. hirae, when encountered, should not be ignored but considered a pathogen and reported. The presence of drug-resistant organisms in cattle and their surroundings, their zoonotic potential to cause infections in humans, and the uncontrolled usage of antibiotics in livestock are causes for concern. Thus, we need to be more vigilant regarding it in the future.

This review aims at a compilation of a comprehensive study on literature reporting the microbiological characteristics of NVS species, their detection, and treatment strategies with an emphasis on large-scale research experimentations.

According to the literature, the classification of these Streptococci has changed several times, interpreting the scientific literature of Abiotrophia and Granulicatella spp. NVS strains exhibit pleomorphic cellular morphologies, and they can be distinguished from other streptococci by their biochemical reactions and molecular tests. They have been isolated from clinical specimens including pus, synovial fluid, and blood, in addition to their involvement in endocarditis. Treatment of NVS is challenging due to its difficult nature and the complexity of antimicrobial susceptibility testing.

Early diagnosis is critical for initiating proper therapy and avoiding fatal consequences. Microbiologists and clinicians ought to be cautious of these isolates, which are easy to overlook due to their difficult nature and the challenges in retrieving from clinical samples. Hence largescale research is required to identify additional detection techniques, infrastructure, and treatment options.

Objectives: The present study aimed to investigate the prevalence of PVL-encoding genes in S. aureus isolated from clinical samples of inpatients with invasive infections in a teaching hospital in Southern Brazil. Furthermore, phenotypic and genotypic characteristics of bacterial isolates were analyzed.

Methods: A total of 98 S. aureus isolates recovered from different body sites were characterized according to their antimicrobial susceptibility profile, methicillin-resistance and SCCmec typing, genetic relatedness and occurrence of virulence-encoding genes, such as icaA, lukS-PV/lukF-PV, and tst.

Results: Sixty-eight (69.4%) isolates were classified as methicillin-resistant, and among them, four (5.9%) did not harbor the mecA gene. The mecA-harboring methicillin-resistant S. aureus (MRSA) isolates were grouped into SCCmec types I (6.3%), II (64.1%), III (6.3%), IV (15.6%), V (4.7%), and VI (1.6%). One isolate (1.6%) was classified as non-typeable (NT). Seventy isolates (71.4%) were classified as multidrug-resistant. The overall prevalence of virulence-encoding genes was as follows: icaA, 99.0%; tst, 27.5%; and lukS-PV/lukF-PV, 50.0%. The presence of tst gene was significantly higher (p < 0.001) in methicillin-susceptible S. aureus (MSSA) compared to MRSA isolates.

Conclusion: The present study reports a high prevalence of multidrug-resistant S. aureus harboring lukS-PV/lukF-PV and tst genes in invasive infections. The continuous monitoring of the antimicrobial susceptibility profile and virulence of S. aureus is an important measure for the control of infections caused by this bacterium.

Objective: Therefore, this study was conducted to evaluate the antifungal activity of AgNPs on Candida albicans, Candida dubliniensis, and Candida guilliermondii.

Methodology: Antifungal activity of AgNPs on Candida albicans, Candida dubliniensis, and Candida guilliermondii was assessed by agar and macrodilution diffusion methods in an in-vitro investigation. Structural changes were investigated by scanning electron microscope (SEM). Then, the obtained data were evaluated by SPSS statistical software.

Results: Based on the results, the mean diameter of growth inhibition halos by AgNPs was equal to 20, 20.2, and 40.7mm for Candida albicans, Candida dubliniensis, and Candida guilliermondii, respectively. The minimum inhibitory concentrations (MIC) equal 62.50, 31.25, and 15.62 mg/ml for Candida albicans, Candida dubliniensis, and Candida guilliermondii, respectively. The minimum fungicidal concentrations (MFC) were equal to 125, 62.50, and 31.25 mg/ml for Candida albicans, Candida dubliniensis, and Candida guilliermondii, respectively.

Conclusion: Our results revealed that AgNPs inhibit the growth of Candida albicans, Candida dubliniensis, and Candida guilliermondii. SEM observations also showed that NPs disrupted cell membrane/wall. Changes in yeast levels from smooth to uneven were also observed.

Objective: In this study, we investigated the microbial epidemiology and resistance pattern of enterococcal bacteremia.

Methods: This study was a cross-sectional study that investigated all cases of positive blood cultures with Enterococcus spp. at a tertiary referral colligates hospital in Tehran in 2018.

Results: Enterococcus spp. was isolated from blood cultures of a total of 73 patients. Most of the patients were male i.e: 42 (57.7%). The mean age of the patients was 58.8 (±18.8) years. Hospital- acquired infection was the most prevalent type of infection involving enterococcal bacteremia (80.8%) compared with community-acquired (6.7%) and the health care-associated one (12.3%). Renal failure and cancer were the most underlying disease in E. faecalis and E. faecium, respectively. Mortality for Vancomycin-resistant enterococci (VRE) was approximately two times more than the sensitive ones. Between the dead/alive groups, the following items were significantly different (P.Value<0.05): Vancomycin resistance for enterococcus isolated, immunodeficiency as an underlying disease, Mechanical ventilation, hospitalization period, and the empiric regimen.

Conclusion: Increased antibiotic-resistant strains, especially Vancomycin-resistant enterococci (VRE), pose a serious threat to the general public, especially hospitalized patients, causing an increase in mortality. Surveillance of microorganisms and antimicrobial resistance is a crucial part of an efficient health care system.

Methods: The nanoparticles were synthesized by the co-precipitation method and characterized by DLS, UV-Vis spectrophotometer, FT-IR, XRD, FEG-TEM, and VSM analysis.

Results and Discussion: The results showed that the synthesized SPIONs were having a size range of 8-12nm with magnetic property. Bacteria removal efficiency and antibacterial activity of SPIONs were assessed in sterile distilled water by adding different concentrations of SPIONs viz. 0, 6.25, 12.5, 25, 50, 100, 200, 500, and 1000μM with different initial bacterial loads viz. 1×10³, 1×10⁴, 1×10⁵, 1×10⁶, and 1×10⁷ CFU mL−1 at different time intervals 15, 30, 45, and 60 min. At low bacterial load (1×10³ to 1×10⁵ CFU mL−1), 95 to 99.99% of bacteria were removed by low SPIONs concentration (6.25-100μM) by 15min which was increased up to 100% by 30min. However, at high bacterial load (1×10⁶ to 1×10⁷ CFU mL⁻¹), more than 87 to 95% of bacteria were removed by the highest SPIONs concentration (1000μM) by 15min, which was increased above 93 to 99.99% by increasing the exposure time to 60min. At low bacterial load (1×10³ to1×10⁵ CFU mL⁻¹), the effective concentration was 3.21 to 6.42μM at 15-60 min intervals. Meanwhile, the effective concentration at high bacterial load was 267.81 μM at 15min, which was decreased to 104.09 μM with increasing exposure time to 60min.

Conclusion: Based on the results, it is concluded that the antibacterial effect against A. hydrophila depends on the concentration as well as the exposure time of SPIONs. A low concentration of SPIONs is sufficient to remove 100% of bacterial load in lower exposure time and increasing concentration of SPIONs increases the antibacterial effect. However, further research requires to find the safe concentration of SPIONs for using it as a novel antibacterial agent for the treatment of aeromonads disease in aquaculture.]]> https://www.benthamscience.comarticle/118466 https://www.benthamscience.comarticle/119131 https://www.benthamscience.comarticle/116164Background: Brucellosis is a zoonotic disease that causes serious economic losses due to factors, such as miscarriages and decreased milk yield in animals. Existing live vaccines have some disadvantages, so effective vaccines need to be developed with new technological approaches.

Objective: The primary objectives of this study were the expression and purification of recombinant Omp25 fusion protein from B. abortus, and the evaluation of the effect of the Omp25 protein on cell viability and inflammatory response.

Methods: The omp25 gene region was amplified by a polymerase chain reaction and cloned into a Pet102/D-TOPO expression vector. The protein expression was carried out using the prokaryotic expression system. The recombinant Omp25 protein was purified with affinity chromatography followed by GPC (Gel Permeation Chromatography). The MTS assay and cytokine-release measurements were carried out to evaluate cell viability and inflammatory response, respectively.

Results: It was determined that doses of the recombinant Omp25 protein greater than 0.1 μg/mL are toxic to RAW cells. Doses of 1 μg/mL and lower significantly increased inflammation due to Nitric Oxide (NO) levels. ELISA results showed that IFN-γ was produced in stimulated RAW 264.7 cells at a dose that did not affect the viability (0.05 μg/mL). However, IL-12, which is known to have a dual role in the activation of macrophages, did not show a statistically significant difference at the same dose.

Conclusion: Studies on cell viability and Th1-related cytokine release suggest Omp25 protein to be a promising candidate molecule for vaccine development.

Objective: In this review, we summarize drug resistance exhibited by S. aureus, lacunae in current anti-staphylococcal therapy and nanoparticles as an alternative therapeutic modality. The focus lies on various green synthesized nanoparticles, their mode of action, and their application as potent antibacterial compounds against S. aureus.

Conclusion: The use of nanoparticles as anti-bacterial drugs has gained momentum in the recent past, and green synthesized nanoparticles, which involve microorganisms and plants or their byproducts for the synthesis of nanoparticles, offer a potent, as well as environment friendly solution in warfare against MDR bacteria.

Methods: A systematic overview was conducted by searching PubMed, Oxford academic, and Cochrane library up to June 2020. Study selection and data extraction: All English- language clinical trials, in vitro studies, and case reports related to the synergistic drug therapy for MRSAB.

Results: In the case of MRSAB infections, we examined two different in vitro studies that showed effective synergism with DAP and CFT. The Minimum Inhibitory Concentration (MIC) range observed for each is as follow: DAP 0.125-1 mg/L, CFT 0.38-1 mg/L, DAP + CFT 0.094-0.5 mg/L, vancomycin (VAN) 0.75-2 mg/L, VAN + CFT 0.25-2 mg/L. DAP + CFT combination displayed the most efficacy with the lowest MIC. The statistical analysis performed showed that DAP + CFT obtained significantly lower fractional inhibitory concentration (FIC) values (0.941 ± 0.328) compared with VAN + CFT. In vitro activities of regimens tested on DAP non-susceptibility and VAN intermediate after 96 hours showed DAP 8.29 ± 0.03^a log₁₀ CFU/mL, VAN 6.82 ± 0.04^a log₁₀ Colony Forming Unit (CFU)/mL, CFT 4.63 ± 0.19^a log₁₀ CFU/mL, DAP + CFT 1.15 ± 0.20^b log₁₀ CFU/mL, VAN + CFT 3.18 ± 0.49^a log₁₀ CFU/mL. (^a meaning significantly different than DAP plus CFT, P< equal to 0.001^b meaning therapeutic enhancement combination was defined as ≥ 2 log₁₀ CFU/ml reduction over the most active single agent). Based on these results, although DAP was not susceptible, the Colony Forming Unit (CFU) for DAP and CFT had the best therapeutic results.

Conclusion: In vitro studies have shown that a combination DAP and CFT is more efficacious than the combination of VAN and CFT in MRSA bacteremia infections. The synergic effects of DAP (bactericidal) and CFT (bactericidal) is statistically significant, in recent trials, warranting promising evidence for its use in complicated bacteremia infection.

The multidrug resistance (MDR) and antibiotics losing efficacy, esp. in methicillin resistance Staphylococcus aureus (MRSA) urge for novel antimicrobial agents. The MRSA strains are resistant to the entire class of β-lactam antibiotics and limit effective treatment, leading to still spread of staphylococcal infections. MRSA also exhibits resistance to cephalosporins, macrolides, fluoroquinolones, aminoglycosides, and glycopeptides (teicoplanine and vancomycin), leading to resistant strains-glycopeptide resistant strain (GRSA) and glycopeptide intermediate (GISA) S. aureus. In this review, chemical constituents responsible for the anti-MRSA activity of tea are explored.

Methods: The antimicrobial analysis of the extracts of leaves, roots and stems of C. borivilianum is based on the agar well diffusion method and Minimum Inhibitory Concentration (MIC). The phytochemical screening and characterization of saponin on the basis of structural and antimicrobial activity present in C. borivilianum were analyzed by different spectrophotometric methods such as HPLC, UV-visible, IR, NMR, LC-ESI-MS and pharmacophore modeling.

Results: The results revealed that the methanolic leaf, stem and root extracts have inhibitory potential against the growth of K. pneumonia, B. subtilis, M. tuberculosis, E coli and S. aureus in case of bacteria and C. albicans, A. fumigatus and Tricoderma in case of fungus. The MIC values of leaf, stem and root extracts were found in the range of 1 mg/ml to 0.125 mg/ml. Moreover, the purified saponins indicated MIC in the range of 0.5 mg/ml to 0.0625 mg/ml against the selected microbial pathogens. Saponins act as one of the major phytocomponents present in C. borivilianum. The antimicrobial and structural analysis of purified saponins of C. borivilianum was also performed using different spectral analysis methods.

Conclusion: The anti-microbial results showed that the extract from the leaf and stems had higher anti-pathogenic activity as compared to the roots. The MIC results showed that the purified saponin also possessed the anti-microbial activity and oleanolic acid content, as detected by spectral analysis the fundamental structure of the extracted saponin.

Objective: The authors proposed to cover relevant literature, published following the review article written by Rani et al., illustrating chemical structures and antibacterial activity of some imidazole derivatives.

Method: Approximately 100 scientific articles presenting more than 150 compounds have been reviewed. The most relevant data have been extracted and systematically arranged in figures and tables.

Results: The reviewed studies used a broad number of bacterial strains, however Staphylococcus aureus as Gram-positive, and Escherichia coli as Gram-negative bacterial strains were most frequently used to assess the activity of these compounds.

Conclusion: Some of the compounds showed promising results against both Gram-positive and Gram-negative bacterial strains, thus further analysis should be performed in terms of toxicity, pharmacokinetics and pharmacodynamics. Additional screening of these imidazole derivatives could lead to useful compounds with potential broad-spectrum antibacterial activity against resistant pathogens.

Methods:^99mTc-Vancomycin scintigraphy was evaluated for its accumulation in IE with Staphylococcus aureus performed in an experimental rat model. Serial planar scintigraphic and biodistribution analysis of infected vegetations are compared to rats with sterile vegetations. The heart was identified as an infected organ, the liver was identified as a non-infected organ and the heart/liver uptake ratio (T / NT ratio) was compared between infective endocarditis and sterile endocarditis groups.

Results: Planar scintigrams (in vivo measurements) showed more uptake in the heart of rats in the infective endocarditis group compared to the uptake in the heart of rats in the sterile endocarditis group, but this difference was not statistically significant (p>0.05). From the ex vivo measurements, the ^99mTc-Vancomycin heart uptake increased significantly (p = 0.016), liver uptake was significantly decreased (p = 0.045) and the T/NT ratio was significantly higher (p = 0.014) in the infective endocarditis group compared to the sterile endocarditis group.

Conclusion: In this experimental study, ^99mTc-Vancomycin scintigraphy ensured the detection of ex vivo infected tissue in a rat model of IE. In addition, the absence of significant ^99mTc-Vancomycin uptake in the sterile endocarditis group indicates that this agent targeted the infected tissue instead of the sterile inflammatory tissue. Finally, this agent should also be evaluated with animal- specific imaging devices.

Objective: Due to the high similarity among genera and species of pathogens, it is sometimes difficult for microbiologists to differentiate between them. Their automatic classification using deeplearning models can help in gaining reliable and accurate outcomes.

Methods: Deep-learning models, namely; AlexNet, GoogleNet, ResNet101, and InceptionV3 are used with numerous variations including training model from scratch, fine-tuning without pre-trained weights, fine-tuning along with freezing weights of initial layers, fine-tuning along with adjusting weights of all layers and augmenting the dataset by random translation and reflection. Moreover, as the dataset is small, fine-tuning and data augmentation strategies are applied to avoid overfitting and produce a generalized model. A merged feature vector is produced using two best-performing models and accuracy is calculated by xgboost algorithm on the feature vector by applying cross-validation.

Results: Fine-tuned models where augmentation is applied produces the best results. Out of these, two-best-performing deep models i.e. (ResNet101, and InceptionV3) selected for feature fusion, produced a similar validation accuracy of 95.83 with a loss of 0.0213 and 0.1066, and testing accuracy of 97.92 and 93.75, respectively. The proposed model used xgboost to attain a classification accuracy of 98.17% by using 35-folds cross-validation.

Conclusion: The automatic classification using these models can help experts in the correct identification of pathogens. Consequently, they can help in controlling epidemics and thereby minimizing the socio-economic impact on the community.

Methods: In this study, marine sponge samples were screened for potent fibrinolytic producing bacteria. The primary screening was done for protease production, and clot lysis activity. The secondary screening was done for casein plasminogen activity and fibrinolytic activity. The strain which had potent fibrinolytic activity among them was further subjected to morphological, biochemical and molecular characterization. Media optimization was carried out to enhance enzyme production. The enzyme produced was subjected to purification using ammonium sulfate precipitation, gel filtration and characterized using HPLC and FTIR analysis.

Results: Sponge was identified to be Desmapsamma anchorata. Thirteen bacterial isolates were isolated from the sponge sample. The 16S rRNA sequencing revealed that the potential strain had 99% similarity with Bacillus licheniformis. Amongst the isolates, most were found to be morphologically identical to the Bacillus genus. Gram’s staining and SEM analysis of the potent isolate were performed to identify the spore formation and rod-shaped morphology of the bacteria. The optimal temperature and pH for the production of the enzyme were 37°C and 8, respectively. The carbon source maltose and nitrogen sources were malt extract and yeast extract that were found to be optimal. The optimum incubation time was found to be 4 to 5 days. The crude supernatant was purified with ammonium sulfate precipitation and gel filtration chromatography. The retention time of 11.3 min and the presence of functional groups show the purity of the enzyme. The partially purified enzyme showed 96.4% clot lysis in artificial clot lysis activity.

Conclusion: Although the secretion of fibrinolytic enzymes from Bacillus species is not new, based on our investigation, there are no reports regarding Bacillus licheniformis being isolated from marine sponges. However, there are reports of Bacillus licheniformis secreting fibrinolytic enzymes isolated from fermented food samples. This study identifies the marine environment as a potential source of new exploration for drug discovery.

Methods: This present study was carried out from July 2018 to December 2018 on all the pus and body fluid samples that were received in the Department of Microbiology. Samples were processed as per the standard Microbiological guidelines and also were analyzed for their antimicrobial susceptibility profile as per Clinical Laboratory Standards Institute.

Results: Out of 8425 samples received, 2140 were culture positive, amongst which 19 samples (0.89%) were positive for Providencia species (9) and Morganella morganii(10). The male : female ratio of these 19 patients was 2.8 : 1 and maximum patients (13) belonged to 20-60 years. As far as risk factors are concerned, maximum patients were diabetics (7) followed by abnormal liver function tests (6), concomitant UTI (6), history of invasive procedure (5), prior exposure to antibiotics (5) and urinary catheterization (4). About 6 were polymicrobial infections. Antibiotic susceptibility patterns revealed that Providencia strains were sensitive to ampicillin- sulbactum (77.7%) and amikacin (77.7%), while all Morganella strains were 100% sensitive to tobramycin and piperacillintazobactam.

Conclusion: This study heralds in need for more research in this area as infections caused by these two pathogens are on the rise. Moreover, resistance to antimicrobials is also an increasingly common problem thus delaying the treatment and prognosis of the disease.

Objective: This study aimed to investigate the potential of α-pinene as an efflux pump inhibitor in species of S. aureus carrying the TetK and MrsA proteins.

Methods: The minimum inhibitory concentrations (MIC) of α-pinene and other efflux pump inhibitors were assessed using serial dilutions of each compound at an initial concentration above 1024 μg/mL. Solutions containing culture medium and bacterial inoculums were prepared in test tubes and subsequently transferred to 96-well microdilution plates. The modulation of ethidium bromide (EtBr) and antibiotics (tetracycline and erythromycin) was investigated through analysis of the modification in their MICs in the presence of a subinhibitory concentration of α-pinene (MIC/8). Wells containing only culture medium and bacterial inoculums were used as negative control. Carbonyl cyanide m-chlorophenylhydrazone (CCCP) was used as a positive control.

Results: The MIC of ethidium bromide against S. aureus strains RN-4220 and IS-58 was reduced by association with α-pinene. This monoterpene potentiated the effect of tetracycline against the IS-58 strain but failed in modulating the antibacterial effect of erythromycin against RN-4220, suggesting a selective inhibitory effect on the TetK EP by α- pinene.

Conclusion: In conclusion, α-pinene has promising effects against S.aureus strains, which should be useful in the combat of antibacterial resistance associated with EP expression. Nevertheless, further research is required to fully characterize its molecular mechanism of action as an EP inhibitor.

Methods: Aiming to control and solve these problems, our study sought to evaluate the action of 1,2,3- triazoles against a Staphylococcus aureus isolate in planktonic and in the biofilm form, evaluating the activity of this triazole through Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. We have also performed cytotoxic evaluation and Scanning Electron Microscopy (SEM) of the biofilms under the treatment of the compound. The 1,2,3-triazole DAN 49 showed bacteriostatic and bactericidal activity (MIC and MBC 128 μg/mL). In addition, its presence interfered with the biofilm formation stage (1/2 MIC, p <0.000001) and demonstrated an effect on young preformed biofilm (2 MICs, p <0.05).

Results: Scanning Electron Microscopy images showed a reduction in the cell population and the appearance of deformations on the surface of some bacteria in the biofilm under treatment with the compound.

Conclusion: Therefore, it was possible to conclude the promising anti-biofilm potential of 1,2,3-triazole, demonstrating the importance of the synthesis of new compounds with biological activity.

Methods: In this work, the toxins were downloaded from the Protein DataBank database and energies were minimized using KoBaMIN server. Forty flavonoids compounds were identified by pubchem compound database through extensive literature study and their 3D structures were obtained by submitting SMILES to CORINA tool. Based on Lipinski’s rule of five, the molecules were filtered that resulted in 27 compounds. Molecular docking was performed for identifying the binding and interaction sites of flavonoids with the toxins using Autodock 4.

Results and Conclusion: The docked complexes were then subjected to molecular dynamics simulation using Gromacs. The analysis revealed the stability of the complexes as indicated by three hydrogen bonds formed during the simulation time period of 20 ns.

From ancient times, herbs and spices have been used to preserve foods, and their antimicrobial, anti-biofilm and anti-quorum sensing properties are well known. Moreover, phytochemicals exert their anti-biofilm properties at sub-inhibitory concentrations without providing the opportunity for the emergence of resistant bacteria or harming the host microbiota.

With increasing scientific attention to natural phytotherapeutic agents, numerous experimental investigations have been conducted in recent years. The present paper aims to review the articles published in the last decade in order to summarize a) our current understanding of AMR in correlation with biofilm formation and b) the evidence of phytotherapeutic agents against bacterial biofilms and their mechanisms of action. The main focus has been put on herbal anti-biofilm compounds tested to date in association with Staphylococcus aureus, Pseudomonas aeruginosa and food-borne pathogens (Salmonella spp., Campylobacter spp., Listeria monocytogenes and Escherichia coli).

Methods: ZnS NPs were synthesized through a co-precipitation method using polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA) and polyethylene glycol (PEG-4000). The size and morphology of the synthesized ZnS NPs were determined by a scanning electron microscope (SEM) and it was found that the average size of the applied NPs was about 70 nm. In order to evaluate the antibacterial effect of the synthesized ZnS NPs, various concentrations (50μg/mL, 100 μg/mL and 150 μg/mL) of ZnS NPs were prepared. Antibacterial assessments were performed through the disc diffusion method in Mueller Hinton Agar (MHA) culture medium and also the optical density (OD) method was performed by a UV-Vis spectrophotometer in Trypticase™ Soy Broth (TSB) medium. Then, in order to compare the antibacterial effects of the applied NPs, several commercial antibiotics including penicillin, amikacin, ceftazidime and primaxin were used.

Results: The achieved results indicated that the antibacterial effects of ZnS NPs had a direct relation along with the concentrations and the concentration of 150 μg/mL showed the highest antibacterial effect in comparison with others. In addition, the ZnS NPs were more effective on Acinetobacter baumannii.

Conclusion: The findings of this research suggest a novel approach against antibiotic resistance.

Methods: We prospectively studied patients who received aminoglycosides, vancomycin, amphotericin, or calcineurin inhibitors, and collected their serial urine while on therapy. Patients who developed drug-induced AKI (fulfilling KDIGO criteria) were matched with non-AKI controls in a 1:2 ratio. Their urine samples were batch-analyzed at time-intervals leading up to AKI onset; the latter benchmarked against the final day of nephrotoxic therapy in non- AKI controls. Biomarkers examined include clusterin, beta-2-microglobulin, KIM1, MCP1, cystatin-C, trefoil-factor- 3, NGAL, interleukin-18, GST-Pi, calbindin, and osteopontin; biomarkers were normalized with corresponding urine creatinine.

Results: Nine of 84 (11%) patients developed drug-induced AKI. Biomarkers from 7 AKI cases with pre-AKI samples were compared with those from 14 non-AKI controls. Corresponding mean ages were 55(±17) and 52(±16) years; baseline eGFR were 99(±21) and 101(±24) mL/min/1.73m2 (all p=NS). Most biomarker levels peaked before the onset of AKI. Median levels of 5 biomarkers were significantly higher in AKI cases than controls at 1-3 days before AKI onset (all µg/mmol): clusterin [58(8-411) versus 7(3-17)], beta-2-microglobulin [1632(913-3823) versus 253(61-791)], KIM1 [0.16(0.13-0.76) versus 0.07(0.05-0.15)], MCP1 [0.40(0.16-1.90) versus 0.07(0.04-0.17)], and cystatin-C [33(27-2990) versus 11(7-19)], all p<0.05; their AUROC for AKI prediction were >0.80 (confidence intervals >0.50), with average accuracy highest for clusterin (86%), followed by beta-2-microglobulin, cystatin-C, MCP1, and KIM1 (57%) after cross-validation.

Conclusion: Serial surveillance of these biomarkers could improve the lead time for nephrotoxicity detection by days.

Methods: The identification of phytochemical compounds in both plants was performed by Highperformance liquid chromatography (HPLC), headspace-solid-phase microextraction (HS-SPME) and Fourier-transform infrared spectroscopy (FTIR). To investigate microbial susceptibility, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and disc diffusion method (DAD) were used. Finally, the results of the study were compared with methicillin.

Results: Of the 42 combinations of O. vulgare, carvacrol (48%) and of the 38 combinations of H. perforatum, hypericin (46.2%) were the most abundant. The MIC, MBC and DAD of O. vulgare and H. perforatum, carvacrol, hypericin and methicillin were 625, 625, 312.5, 78.12 and 384 µg/mL, 10000, 10000, 2500, 2500 and 384 µg/mL, and 15.66 ± 4.49, 12.66 ± 0.47 and 22 ± 0.81 mm, respectively.

Conclusion: Due to the significant effects of O. vulgare and H. perforatum and their active components against S. aureus, it is expected that in the future, hypericin, carvacrol and their derivatives can be used as effective antibacterial agents against S. aureus.

Objective: The aim of the work was to present the latest data about tubular and glomerular biomarkers of acute kidney injury in newborns.

Methods: We undertook a structured search of bibliographic databases for peer-reviewed research literature by using focused review topics. According to the conceptual framework, the main idea of research literature has been summarized and presented in this study.

Results: The concentrations of some novel biomarkers are higher in serum and/or urine of term and preterm newborns with AKI, especially in the course of perinatal asphyxia.

Conclusion: In this systematic review of the literature, we have highlighted the usefulness of biomarkers in predicting tubular and/or glomerular injury in newborns. However, novel biomarkers need to prove their clinical applicability, accuracy, and cost-effectiveness prior to their implementation in clinical practice.

Discussion: A storm of pro-inflammatory cytokines and reactive oxygen species accounts for the systemic inflammatory response syndrome. In this phase, bacterial clearance may be associated with a severe organ failure development. Tolerance or compensatory anti-inflammatory response syndrome (CARS) depends on the production of anti-inflammatory mediators, such as interleukin-10, secreted by T regulatory cells. However, once triggered, CARS, if prolonged, may also be detrimental to the host, thus reducing bacterial clearance.

Conclusion: In this review, the description of pathogenic mechanisms of sepsis is propaedeutic to the illustration of novel therapeutic attempts for the prevention or attenuation of experimental sepsis as well as of clinical trials. In this direction, inhibitors of NF-κB pathway, cell therapy and use of dietary products in sepsis will be described in detail.

Objective: This study aimed at evaluating anti-virulence potential of Herboheal formulation against S. aureus in vitro as well as in vivo, followed by studying its effect on target bacterium’s gene expression at the whole transcriptome level.

Methods: In vitro efficacy of the test formulation was evaluated using broth dilution assay, whereas in vivo efficacy was assayed employing the nematode Caenorhabditis elegans as the model host. Molecular targets of the test formulation in S. aureus were elucidated through whole transcriptome analysis.

Results: This formulation could exert inhibitory effect on bacterial growth and quorum sensingregulated pigment (staphyloxanthin) production at ≥ 0.025% v/v. It not only could inhibit S. aureus biofilm formation, but also eradicated pre-formed biofilm effectively. This formulation could modulate antibiotic susceptibility of S. aureus, enhanced its susceptibility to human serum heavily, while compromising its haemolytic potential. Herboheal-treated bacteria expressed notably lesser virulence towards the nematode worm Caenorhabditis elegans. Even repeated exposure of S. aureus to this polyherbal formulation did not give rise to resistant phenotype. Whole transcriptome analysis revealed genes associated with hemolysis, virulence, enzyme activity, transport, basic cellular processes, quorum sensing, and transcriptional regulators as the major targets of Herboheal in S. aureus.

Conclusion: This study validates the traditional use of Herboheal formulation in wound-care by demonstrating its efficacy against one of the pathogenic bacteria most commonly involved in wound infections.

Objectives: We sought to understand the role of oral health in pregnancy.

Methods: We identified major articles of interest in the field of oral health in pregnancy and drafted a mini-symposium based on relevant information.

Conclusion: Regular dental visits and cognizant efforts to sustain a healthy oral environment can help women in the prevention and treatment of dental issues during pregnancy. The paper highlights the common oral manifestations during pregnancy and their local and systemic impact on the body during pregnancy. Furthermore, it also emphasizes the importance of good oral health practices to counteract the oral complications and the significance of oral health awareness in pregnant women.

Objective: Pseudomonas aeruginosa is an emerging pathogen that has been associated with IE. However, it is not known whether P. aeruginosa can bind and interact with HAECs. The aim of this study was to determine whether P. aeruginosa can bind and colonize HAECs.

Methods: The invasion of HAECs by P. aeruginosa was assessed by gentamicin protection assay. Cytokine levels were determined by enzyme-linked Immunosorbent Assay (ELISA) kits. Cell damage was determined by Lactate Dehydrogenase (LDH) assay.

Results: P. aeruginosa can bind and invade HAECs. Infection of HAECs with P. aeruginosa induces TNF-α IL-1β, IL-6 and IL-8 cytokine production leading to the generation of inflammatory milieu that can cause tissue damage as observed in human clinical cases of IE. We also observed that P. aeruginosa induces cell damage in HAECs.

Conclusion: In this study, we demonstrate for first time that P. aeruginosa can invade and survive inside HAECs. This cell culture model can be of immense importance to determine the efficacy of drug targets against IE.]]> https://www.benthamscience.comarticle/91871

Objectives: We investigated the role of oxidative stress and inflammatory factors in valve disease whether this relates to cell death.

Methods: Blood samples were taken from 24 patients with valve disease before surgery and the results were compared with those from blood samples from 30 control healthy subjects. Myocardial biopsies from patients with valve disease were also collected before cannulation of the right atrial appendage. NF-κB activities in atrial and mononuclear cells nuclear extracts were determined by electrophoretic mobility shift assay.

Results: Nuclear factor kappaB activities were significantly greater in mononuclear cells from AVD patients compared with healthy controls and the antigens were detectable in atrial tissues valve disease patients. Plasma C-reactive protein, B-natriuretic peptides, plasma tumor necrosis factor alpha and soluble tumor necrosis factor receptor 1 and 3-nitrotyrosine levels were significantly higher in valve disease patients. Inducible nitric oxide and 3-nitrotyrosine antigens and cells expressing CD45 antigens were detected within atrial tissues obtained from valve disease patients suggesting oxidative stress originated from in situ leukocytes.

Conclusion: The findings suggest that oxidative stress originating from in situ leukocytes within the atrial myocardium may be the potential trigger for excessive transcriptional activities and apoptotic cell death within the atrial myocardium of valve disease patients. This represents a potential therapeutic target.]]> https://www.benthamscience.comarticle/95734 https://www.benthamscience.comarticle/93977

Objective: This review aims to elucidate the case studies where PPIs involved in various human diseases have been proven or validated with computational techniques, and also to elucidate how small molecule inhibitors of PPIs have been designed computationally to act as effective therapeutic measures against certain diseases.

Results: Computational techniques to predict PPIs are emerging rapidly in the modern day. They not only help in predicting new PPIs, but also generate outputs that substantiate the experimentally determined results. Moreover, computation has aided in the designing of novel inhibitor molecules disrupting the PPIs. Some of them are already being tested in the clinical trials.

Conclusion: This review delineated the classification of computational tools that are essential to investigate PPIs. Furthermore, the review shed light on how indispensable computational tools have become in the field of medicine to analyze the interaction networks and to design novel inhibitors efficiently against dreadful diseases in a shorter time span.]]> https://www.benthamscience.comarticle/92090

Objective: The study aimed at developing and validating a Liquid Chromatography-Mass Spectrometry (LC-MS) method for simultaneous determination and therapeutic drug monitoring of vancomycin and teicoplanin in patients with severe infection.

Method: Plasma was processed by protein precipitation extraction. The analytes were separated on a C18 column by gradient elution with 0.1% formic acid and acetonitrile as mobile phase and measured by electrospray ionization source in positive selective ion monitoring mode at m/z 724.7 (vancomycin), 940.7 (teicoplanin) and 329.0 (bergenin). The plasma samples (104) were obtained from patients who were taking vancomycin or teicoplanin for further analysis.

Results: The calibration curves were linear within the range of 0.25–40 µg/mL for vancomycin, and 0.5-40 µg/mL for teicoplanin. Either inter- or intra-day precision was less than 10.01 %. The extraction recoveries ranged from 89.99 to 94.29% for vancomycin and from 39.83 to 40.16 % for teicoplanin. Vancomycin and teicoplanin in plasma were stable at various storage conditions. The measured mean trough concentrations were 12.313 µg/mL for vancomycin and 8.765 µg/mL for teicoplanin.

Conclusion: This method was successfully applied to therapeutic drug monitoring of vancomycin and teicoplanin in patients. It is with great clinic value for monitoring and predicting the individual response of patients under treatment.]]> https://www.benthamscience.comarticle/91204

Objective: To provide an update on the evaluation, diagnosis, and treatment of community-acquired pneumonia in children.

Methods: A PubMed search was completed in Clinical Queries using the key term “communityacquired pneumonia”. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. Patents were searched using the key term “community-acquired pneumonia” from www.google.com/patents, http://espacenet.com, and www. freepatentsonline.com.

Results: Generally, viruses, notably respiratory syncytial virus, are the most common cause of community- acquired pneumonia in children younger than 5 years. Streptococcus pneumoniae is the most common bacterial cause across all age groups. Other important bacterial causes in children younger than 5 years include Haemophilus influenzae, Streptococcus pyogenes, Staphylococcus aureus, and Moraxella catarrhalis. In children 5 years or older, in addition to S. pneumoniae, other important bacterial causes include Mycoplasma pneumoniae and Chlamydophila pneumonia. In the majority of cases, bacterial and viral pneumonia cannot be reliably distinguished from each other on clinical grounds. In practice, most children with pneumonia are treated empirically with antibiotics; the choice of which depends on the patient’s age and most likely pathogen. Recent patents related to the management of community-acquired pneumonia are discussed.

Conclusion: In previously healthy children under the age of 5 years, high dose amoxicillin is the treatment of choice. For those with type 1 hypersensitivity to penicillin, clindamycin, azithromycin, clarithromycin, and levofloxacin are reasonable alternatives. For children with a non-type 1 hypersensitivity to penicillin, cephalosporins such as cefixime, cefprozil, cefdinir, cefpodoxime, and cefuroxime should be considered. In previously healthy children over the age of 5 years, macrolides such as azithromycin and clarithromycin are the drugs of choice.]]> https://www.benthamscience.comarticle/90526 https://www.benthamscience.comarticle/88834 https://www.benthamscience.comarticle/83658 https://www.benthamscience.comarticle/86266 https://www.benthamscience.comarticle/79977

Objective: In this review we specifically highlight several major virulence factors produced by S. aureus for which recent advances in antivirulence approaches may hold promise as an alternative means to treating diseases caused by this pathogen. Strategies to inhibit virulence factors can range from small molecule inhibitors, to antibodies, to mutant and toxoid forms of the virulence proteins.

Conclusion: The major prevalence of antibiotic resistant strains of S. aureus combined with the lack of new antibiotic discoveries highlight the need for vigorous research into alternative strategies to combat diseases caused by this highly successful pathogen. Current efforts to develop specific antivirulence strategies, vaccine approaches, and alternative therapies for treating severe disease caused by S. aureus have the potential to stem the tide against the limitations that we face in the post-antibiotic era.]]> https://www.benthamscience.comarticle/81235 https://www.benthamscience.comarticle/85306

Objective: To describe the variability in current practice and review recently published evidence in three key areas: inflammatory markers were used as a tool for risk stratification, impact of viral testing, and optimal observation time on antibiotics.

Method: Articles were identified using PubMed, Scopus, and Cochrane databases and via experts. Abstracts were screened and potential articles underwent full review if they focused on febrile infants 0- 90 days with fever without a source and outcomes for key topics.

Results: Thirty-two articles were included. Recent studies show that variability exists for most aspects of evaluation and management. C reactive protein and procalcitonin (PCT) perform poorly for identification of serious bacterial infections (SBIs). However, PCT has good diagnostic accuracy for detection of invasive bacterial infections (IBIs), such as bacteremia and meningitis. When PCT is combined with urinalysis and clinical appearance in the Step-by-Step method, the sensitivity for detection of IBI is 92% for infants > 21 days of age. Infants with lab-confirmed viral infection were found to have reduced risk for SBI. Blood culture yield for true pathogens was the highest in the first 12-36 hours after incubation.

Conclusion: Recent studies suggest viral testing and inflammatory markers (specifically PCT) can help better stratify young febrile infants at risk for IBIs. Infants who are deemed low risk may benefit from shorter observation times and tailored or discontinued antibiotic therapy.]]> https://www.benthamscience.comarticle/76967

Objective: Given that cardiac tumors exhibit some nonspecific symptoms compared with other heart diseases, clinical diagnosis of cardiac tumors is rather challenging. Thus we will try to review the classification and pathogenesis of cardiac tumors.

Conclusion: Current evidence revealed that 75% of cardiac tumors are considered benign (myxoma, fibromas, lipomas, rhabdomyomas, hemangiomas, teratomas, papillary fibroelastomas, pericardial cysts or cystic tumor of atrioventricular node). Clinical differential diagnosis of cardiac tumors is mainly based on imaging techniques including transthoracic and transesophageal echocardiograms, computed tomography (CT) scans and magnetic resonance imaging (MRIs). This mini-review tries to summarize recent understanding of the pathogenesis and therapeutics of cardiac tumors.]]> https://www.benthamscience.comarticle/82132

Objective: In this study, we investigate the antimicrobial effect of Modified Citrus Pectin (MCP) against Staphylococcus aureus, a pathogen showing increasing rates of antimicrobial resistance worldwide.

Method: Forty-three clinical isolates of S. aureus were obtained from a hospital in North Lebanon. Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs) were determined using MCP after determining its optimum pH activity. The combination between MCP and cefotaxime was then investigated for S. aureus isolates using the checkerboard technique.

Results and Discussion: The optimum pH for the activity of MCP was 6.0. MIC and MBC values against S. aureus ranged between 0.39-50 µg/µl and 3.13-50 µg/µl, respectively. These values are promising for using MCP in the inhibition of some S. aureus isolates at relatively low concentrations. Combination experiments showed an additive effect in most S. aureus strains between MCP and cefotaxime, and a synergistic effect in two strains. These preliminary findings open the way for further investigation into the therapeutic potential of MCP in the treatment of S. aureus infections.

Conclusion: MCP demonstrates in vitro antimicrobial activity alone and in combination with cefotaxime against S. aureus.]]> https://www.benthamscience.comarticle/81800

Methods: Nosocomial pneumonias, specifically ventilator associated pneumonias have become a major health care issue. The implication of oral care in hospital presents challenges that can prevent or reduce the risk of nosocomial pneumonias in ICU. In this review article, we reviewed the most important nosocomial pathogens which colonize the oral cavity and causes severe infections during hospitalization in ICU.

Conclusion: Finally, we discuss that the prevention strategies against oral colonization of nosocomial pathogens include classical methods and novel methods such as Photodynamic therapy, NO based therapy, anti-virulence therapy and other new under investigation antimicrobial strategies.]]> https://www.benthamscience.comarticle/81357

Methods: Considering that antimicrobial resistance can vary according to geographical location, we investigated the status of antibiotic resistance in Ilam province from 2008 to 2013.

Results: The results of our study showed that antibiotic resistance rates to aztreonam, cefotaxime, ceftazidime and ceftriaxone were 38%, 39%, 43% and 48% respectively.

Conclusion: Antibiotic resistance had increased (except for aztreonam) during the period from 2008 to 2013.]]> https://www.benthamscience.comarticle/82987 https://www.benthamscience.comarticle/83780

Objectives: This review first briefly discusses the physico-chemical properties, biosynthesis, occurrence, in vivo localization and roles of the different Chl pigments. Then we provide a detailed overview of their potential applications in the food industry and medicine. These include the use of Chls and their derivatives (different chlorophyllins) as food colorants (identified as E140 and E141 in the European Union). Different sources used for industrial extraction as well as different factors influencing pigment stability during processing are also critically reviewed. The problems surrounding the nomenclature, the production and the composition of different chlorophyllin mixtures are also discussed. Finally, a comprehensive overview of the health benefits and potential medicinal applications of these pigments and the future directions of research in these fields are provided.]]> https://www.benthamscience.comarticle/80708 https://www.benthamscience.comarticle/79592 https://www.benthamscience.comarticle/82222

Antimicrobial peptides (AMPs) are considered an interesting class of antibacterial molecules. Many new AMPs have been discovered and some are being evaluated for the development of new antibacterial therapeutics. Since the development of new antibacterial drugs has been neglected for decades, we are now faced with extreme medical need combined with a lack of technical experimental progress in setting up efficient models of antibacterial activity in animals. Here we review experiments with AMPs in animal models of sepsis, pneumonia and skin infection caused by bacteria. Animal models of infection have been of enormous predictive value in antibacterial drug discovery, both for elucidating AMP efficacy in the treatment of experimentally induced infection and for comparing the effectiveness of two or more antibiotics. ]]> https://www.benthamscience.comarticle/77051 https://www.benthamscience.comarticle/78018 https://www.benthamscience.comarticle/78139 https://www.benthamscience.comarticle/7761699mTc) is widely used as a radionuclide for labeling of biomolecules in nuclear medicine practice. 6-hydrazinopyridine-3-carboxylic acid namely HYNIC is one of the best bifunctional chelating agents for attachment of ^99mTc to the biomolecules such as peptides and proteins. Since HYNIC can only occupy one or two coordination sites of ^99mTc, co-ligands are needed to complete the coordination sphere of the technetium. Selection of co-ligands can be impressive on the stability, lipophilicity and biodistribution of ^99mTc-HYNIC conjugated peptides. The aim of this review was to explain the chemical and biological effects of various co-ligands on characteristics of ^99mTc-HYNIC conjugates for tumor or diseases imaging.]]> https://www.benthamscience.comarticle/77934

Objective: As a part of our ongoing studies toward the development of novel antibacterial agents, the synthesis and antibacterial activity of a series of (Z)-5-((3-phenyl-1H-pyrazol-4-yl)methylene)-2-thioxothiazolidin-4-one derivatives will be discussed in this study.

Method: (Z)-5-((3-phenyl-1H-pyrazol-4-yl)methylene)-2-thioxothiazolidin-4-one derivatives were designed, synthesized and evaluated for antibacterial activity. The structures were confirmed by IR, 1H NMR, 13C NMR and mass spectrometry. All of the synthesized compounds were evaluated in vitro using a 96-well microtiter plate and a serial dilution method to obtain their minimum inhibitory concentration (MIC) values against a variety of different strains, including multidrug-resistant clinical isolates.

Results: The antibacterial test in-vitro showed that most compounds in series 7 and 9 exhibited significant inhibitory activities against anaerobic bacteria (Streptococcus mutans) strains with a MIC value of 1 µg/mL. Compounds 7c and 9c showed the most potent activity against MRSA (3167 and 3506) with a minimum inhibitory concentration (MIC) value of 1 µg/mL, which is equivalent to moxifloxacin and greater than gatifloxacin, oxacillin and norfloxacin. Additionally, compound 9c showed potent antibacterial activity against Bacillus subtilis (aerobic bacteria) with a MIC value of 2 µg/mL.

Conclusion: The work suggests that these type of rhodanine compounds had a better potent activity against MRSA compared with other perviously reported rhodanine derivatives, which might provide a valuable information for the development of new antibacterial agents against multidrug-resistant clinical isolates MRSA.]]>