Rahman A, Hosaain M A, Mahmud C, Paul S K, Sultana S, Haque N, Kabir M R, Kubayashi N
Department of Microbiology, Community Based Medical College, Mymensingh, Bangladesh.
Mymensingh Med J. 2012 Apr;21(2):195-9.
Staphylococci are Gram positive, non motile, asporogenous bacteria that characteristically divide in more than one plane to form irregular cluster. Species are classified as coagulase-positive Staphylococcus aureus and coagulase-negative staphylococci. Coagulase-negative staphylococci (CoNS) are reported to be the third causative agent of nosocomial infections and the most frequent cause of nosocomial bloodstream infections. Strains of CoNS those are resistant to methicillin referred to as Methicillin Resistant Coagulase Negative Staphylococci (MRCoNS). Now a days, MRCoNS has been increasing as a serious nosocomial pathogen having the property of multi drug resistance. The present study was conducted to see the species distribution, antibiotic resistance patterns and some virulence factors of CoNS isolated from different clinical specimens. This cross sectional descriptive study was carried out in the Department of Microbiology, Mymensingh Medical College during the period from July 2009 to May 2011. A total of 300 clinical specimens were collected for this study of which 240 were found culture positive as single isolate. Among them 110 were from surgical wound, 80 from pus of skin infections, 30 from burn ulcer exudates and 20 from diabetic ulcer exudates. A total of 80 strains of CoNS were isolated from them. Besides CoNS other isolated bacteria were S. aureus, Pseudomonas spp and Escherichia coli. The CoNS were initially detected by coagulase test. All the strains that were either slide or tube coagulase negative were further identified by different biochemical tests using a commercial kit HiStaph™ Identification Kit (HiMedia Laboratories Ltd) which comprise a set of 12 standard biochemical tests. A total of 16 species were identified. These were S. epidermidis, S. saprophyticus, S. caprae, S. haemolyticus, S. simulans, S. xylosus, S. hyicus, S. hominis, S. warneri, S. auricularis, S. lugdunensis, S. felis, S. capitis, S. chromogenes, S. carnosus and S. gallinarum. Of them S. epidermidis was the most prevalent (17%) followed by S. saprophyticus (15%), S. caprae (11%), S. haemolyticus (9%).
葡萄球菌是革兰氏阳性、无运动性、不产芽孢的细菌，其特征是在多个平面上分裂形成不规则的簇。葡萄球菌种类分为凝固酶阳性的金黄色葡萄球菌和凝固酶阴性葡萄球菌。据报道，凝固酶阴性葡萄球菌（CoNS）是医院感染的第三大病原体，也是医院血流感染最常见的原因。对甲氧西林耐药的CoNS菌株被称为耐甲氧西林凝固酶阴性葡萄球菌（MRCoNS）。如今，MRCoNS作为一种具有多重耐药性的严重医院病原体，其数量一直在增加。本研究旨在观察从不同临床标本中分离出的CoNS的菌种分布、抗生素耐药模式和一些毒力因子。这项横断面描述性研究于2009年7月至2011年5月期间在迈门辛医学院微生物学系进行。本研究共收集了300份临床标本，其中240份培养为单一分离株阳性。其中110份来自手术伤口，80份来自皮肤感染脓液，30份来自烧伤溃疡渗出液，20份来自糖尿病溃疡渗出液。共从中分离出80株CoNS。除CoNS外，其他分离出的细菌有金黄色葡萄球菌、假单胞菌属和大肠杆菌。CoNS最初通过凝固酶试验检测。所有玻片或试管凝固酶阴性的菌株进一步使用HiStaph™鉴定试剂盒（HiMedia Laboratories Ltd）通过不同的生化试验进行鉴定，该试剂盒包含一组12项标准生化试验。共鉴定出16个菌种。它们是表皮葡萄球菌、腐生葡萄球菌、山羊葡萄球菌、溶血葡萄球菌、模仿葡萄球菌、木糖葡萄球菌、猪葡萄球菌、人葡萄球菌、沃氏葡萄球菌、耳葡萄球菌、路邓葡萄球菌、猫葡萄球菌、头葡萄球菌、产色葡萄球菌、肉葡萄球菌和鸡葡萄球菌。其中表皮葡萄球菌最为常见（17%），其次是腐生葡萄球菌（15%）、山羊葡萄球菌（11%）、溶血葡萄球菌（9%）。
