PDF(Pubmed)
Abstract：
Methicillin-resistant (MR) Staphylococcus aureus (SA) and others, except for Staphylococcus aureus (SOSA), are common in healthcare-associated infections. SOSA encompass largely coagulase-negative staphylococci, including coagulase-positive staphylococcal species. Biofilm formation is encoded by the icaADBC operon and is involved in virulence. mecA encodes an additional penicillin-binding protein (PBP), PBP2a, that avoids the arrival of β-lactams at the target, found in the staphylococcal cassette chromosome mec (SCCmec). This work aims to detect mecA, the bap gene, the icaADBC operon, and types of SCCmec associated to biofilm in MRSA and SOSA strains. A total of 46% (37/80) of the strains were S. aureus, 44% (35/80) S. epidermidis, 5% (4/80) S. haemolyticus, 2.5% (2/80) S. hominis, 1.25% (1/80) S. intermedius, and 1.25% (1/80) S. saprophyticus. A total of 85% were MR, of which 95.5% showed mecA and 86.7% β-lactamase producers; thus, Staphylococcus may have more than one resistance mechanism. Healthcare-associated infection strains codified type I-III genes of SCCmec; types IV and V were associated to community-acquired strains (CA). Type II prevailed in MRSA mecA strains and type II and III in MRSOSA (methicillin-resistant staphylococci other than Staphylococcus aureus). The operon icaADBC was found in 24% of SA and 14% of SOSA; probably the arrangement of the operon, fork formation, and mutations influenced the variation. Methicillin resistance was mainly mediated by the mecA gene; however, there may be other mechanisms that also participate, since biofilm production is related to genes of the icaADBC operon and methicillin resistance was not associated with biofilm production. Therefore, it is necessary to strengthen surveillance to prevent the spread of these outbreaks both in the nosocomial environment and in the community.
摘要：
耐甲氧西林（MR）金黄色葡萄球菌（SA）等，除金黄色葡萄球菌（SOSA）外，在医疗保健相关感染中很常见。SOSA主要包括凝固酶阴性葡萄球菌，包括凝固酶阳性葡萄球菌。生物膜形成由icaADBC操纵子编码，并参与毒力。mecA编码额外的青霉素结合蛋白（PBP），PBP2a,这避免了β-内酰胺到达目标，在葡萄球菌盒染色体mec（SCCmec）中发现。这项工作旨在检测mecA，bap基因,icaADBC操纵子,以及MRSA和SOSA菌株中与生物膜相关的SCCmec类型。总计46%(37/80)的菌株为金黄色葡萄球菌,44%（35/80）表皮葡萄球菌，5%（4/80）溶血链球菌，2.5%(2/80)人源链球菌，1.25%（1/80）S.intermedius，和1.25%（1/80）腐生链球菌。总共85%是MR，其中95.5%为mecA生产者，86.7%为β-内酰胺酶生产者；因此，葡萄球菌可能具有多种耐药机制。医疗保健相关感染菌株编码了SCCmec的I-III型基因；IV和V型与社区获得性菌株（CA）相关。在MRSAmecA菌株中流行II型，在MRSOSA（金黄色葡萄球菌以外的耐甲氧西林葡萄球菌）中流行II型和III型。操纵子icaADBC在24%的SA和14%的SOSA中发现；可能是操纵子的排列，叉形,突变影响了变异。甲氧西林抗性主要由mecA基因介导;然而,可能还有其他机制也参与其中，由于生物膜的产生与icaADBC操纵子的基因有关，而甲氧西林抗性与生物膜的产生无关。因此,有必要加强监测，以防止这些疫情在医院环境和社区中传播。
