Title:High Prevalence of Panton-valentine Leukocidin-encoding Genes in
Methicillin-resistant Staphylococcus aureus Isolated from Inpatients with
Invasive Infections at a University Hospital in Southern Brazil
Volume: 23
Issue: 2
Author(s): Raquel Soares da Silva, Felipe Crepaldi Duarte, Tiago Danelli, Anna Paula Silva Olak, Gerusa Luciana Gomes Magalhães, Marsileni Pelisson, Stefani Lino Cardim, Guilherme Bartolomeu Gonçalves, Eliana Carolina Vespero, Eliandro Reis Tavares, Lucy Megumi Yamauchi, Marcia Regina Eches Perugini and Sueli Fumie Yamada-Ogatta*
Affiliation:
- Departamento de Patologia, Análises Clínicas e Toxicológicas, Programa de Pós-graduação em Fisiopatologia
Clínica e Laboratorial, Centro de Ciências da Saúde, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Departamento de Microbiologia, Programa de
Pós-graduação em Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina,
Paraná, Brazil
Keywords:
Multidrug-resistance, SCCmec typing, rep-PCR fingerprinting, toxic shock syndrome toxin, intercellular adhesion locus, S. aureus.
Abstract:
Background: Staphylococcus aureus is a major cause of a wide diversity of infections in
humans, and the expression of Panton-Valentine Leukocidin (PVL) has been associated with severe
clinical syndromes.
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.