Abstract：
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.
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.
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.
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.
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.
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.
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.
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.
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.
摘要：
背景：金黄色葡萄球菌是人类广泛感染的主要原因，Panton-Valentine杀白细胞素（PVL）的表达与严重的临床综合征有关。
目的：本研究旨在调查从巴西南部某教学医院侵袭性感染住院患者临床样本中分离出的金黄色葡萄球菌中PVL编码基因的流行情况。此外，分析了细菌分离株的表型和基因型特征。
方法：对从不同身体部位回收的98株金黄色葡萄球菌进行了抗菌药物敏感性分析。耐甲氧西林和SCCmec分型，遗传相关性和毒力编码基因的发生，比如icaA,lukS-PV/lukF-PV，还有tst.
结果：68个（69.4％）分离株被归类为耐甲氧西林，其中,四个（5.9％）没有携带mecA基因。将携带mecA的耐甲氧西林金黄色葡萄球菌（MRSA）分离株分为SCCmecI型（6.3％），II（64.1%），III（6.3%），IV（15.6%），V（4.7%），和VI（1.6%）。一种分离物(1.6%)被分类为不可分型(NT)。70株(71.4%)被归类为多重耐药。毒力编码基因的总体患病率如下：icaA，99.0%；tst，27.5%；和lukS-PV/lukF-PV，50.0%。与MRSA分离株相比，甲氧西林敏感的金黄色葡萄球菌（MSSA）中tst基因的存在明显更高（p<0.001）。
结论：本研究报告在侵袭性感染中携带lukS-PV/lukF-PV和tst基因的多药耐药金黄色葡萄球菌的患病率很高。金黄色葡萄球菌的抗菌药物敏感性和毒力的连续监测是控制由该细菌引起的感染的重要措施。
目的：本研究旨在调查从巴西南部某教学医院侵袭性感染住院患者临床样本中分离出的金黄色葡萄球菌中PVL编码基因的流行情况。此外，分析了细菌分离株的表型和基因型特征。
方法：对从不同身体部位回收的98株金黄色葡萄球菌进行了抗菌药物敏感性分析。耐甲氧西林和SCCmec分型，遗传相关性和毒力编码基因的发生，比如icaA,lukS-PV/lukF-PV，还有tst.
结果：68个（69.4％）分离株被归类为耐甲氧西林，其中,四个（5.9％）没有携带mecA基因。将携带mecA的耐甲氧西林金黄色葡萄球菌（MRSA）分离株分为SCCmecI型（6.3％），II（64.1%），III（6.3%），IV（15.6%），V（4.7%），和VI（1.6%）。一种分离物(1.6%)被分类为不可分型(NT)。70株(71.4%)被归类为多重耐药。毒力编码基因的总体患病率如下：icaA，99.0%；tst，27.5%；和lukS-PV/lukF-PV，50.0%。与MRSA分离株相比，甲氧西林敏感的金黄色葡萄球菌（MSSA）中tst基因的存在明显更高（p<0.001）。
结论：本研究报告在侵袭性感染中携带lukS-PV/lukF-PV和tst基因的多药耐药金黄色葡萄球菌的患病率很高。金黄色葡萄球菌的抗菌药物敏感性和毒力的连续监测是控制由该细菌引起的感染的重要措施。
