在校学生鼻腔携带耐甲氧西林凝固酶阴性葡萄球菌的分子特征

Molecular Characteristics of Nasal Carriage Methicillin-Resistant Coagulase Negative Staphylococci in School Students.

作者信息

Iravani Mohammad Abadi Mohammad, Moniri Rezvan, Khorshidi Ahmad, Piroozmand Ahmad, Mousavi Seyed Gholam Abbas, Dastehgoli Kamran, Mirzaei Ghazikalayeh Hamed

机构信息

Department of Microbiology and Immunology, Kashan University of Medical Sciences, Kashan, IR Iran.

Trauma Research Center, Kashan University of Medical Sciences, Kashan, IR Iran.

出版信息

Jundishapur J Microbiol. 2015 Jun 27;8(6):e18591. doi: 10.5812/jjm.18591v2. eCollection 2015 Jun.

DOI:10.5812/jjm.18591v2

PMID:26301061

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4541167/

Abstract

BACKGROUND

Coagulase-negative staphylococci (CoNS) are opportunistic pathogens. Methicillin resistance is common in CoNS and may play an important role as reservoir of staphylococcal cassette chromosome mec (SCCmec) for Staphylococcus aureus.

OBJECTIVES

The aim of this study was to determine molecular characteristics of nasal carriage of methicillin-resistant coagulase negative staphylococci among students.

MATERIALS AND METHODS

MR-CoNS from both nares of students were collected. Resistance to methicillin was determined by cefoxitin (30μg) disk diffusion test. SCCmec typing was performed using multiplex PCR by mec complex classes and ccr genes. Antimicrobial susceptibility profiles were determined on Mueller-Hinton agar according to CLSI.

RESULTS

A total of 600 consecutive students were enrolled in this study; 430 of whom (71.7%) had CoNS. Seventy-two MR-CoNS strains, 21 (29.2%) S. lugdunensis, 17 (23.6%) S. haemolyticus, 17 (23.6%) S. saprophyticus, 9 (12.5%) S. epidermidis and 8 (11.1%) S. schleiferi were isolated. MR-CoNS rate in nasal carriage was 16.7%. All strains were susceptible to vancomycin. Forty-eight (66.7%) had a single SCCmec type including types I (n = 5), II (n = 4), III (n = 7), IV (n = 19) and V (n = 13), whereas 5 (6.9%) had two types including III + IV (n = 2), III + V (n = 1) and IV + V (n = 2). Nineteen strains (26.4%) were non-typeable for their SCCmec and ccr. Types IV and V SCCmec were associated with S. lugdunensis and S. haemolyticus, respectively.

CONCLUSIONS

SCCmec types IV and V were prevalent in MR-CoNS and few isolates could harbor more than one type.

摘要

背景

凝固酶阴性葡萄球菌（CoNS）是机会致病菌。耐甲氧西林在CoNS中很常见，并且可能作为金黄色葡萄球菌葡萄球菌盒式染色体mec（SCCmec）的储存库发挥重要作用。

目的

本研究的目的是确定学生中耐甲氧西林凝固酶阴性葡萄球菌鼻腔携带的分子特征。

材料与方法

收集学生双侧鼻腔的耐甲氧西林CoNS。采用头孢西丁（30μg）纸片扩散试验测定对甲氧西林的耐药性。使用多重PCR通过mec复合类和ccr基因进行SCCmec分型。根据CLSI在Mueller-Hinton琼脂上测定抗菌药物敏感性谱。

结果

本研究共纳入600名连续的学生；其中430名（71.7%）携带CoNS。分离出72株耐甲氧西林CoNS菌株，21株（29.2%）路邓葡萄球菌、17株（23.6%）溶血葡萄球菌、17株（23.6%）腐生葡萄球菌、9株（12.5%）表皮葡萄球菌和8株（11.1%）施氏葡萄球菌。鼻腔携带耐甲氧西林CoNS的比例为16.7%。所有菌株对万古霉素敏感。48株（66.7%）具有单一的SCCmec类型，包括I型（n = 5）、II型（n = 4）、III型（n = 7）、IV型（n = 19）和V型（n = 13），而5株（6.9%）具有两种类型，包括III + IV型（n = 2）、III + V型（n = 块）和IV + V型（n = 2）。19株（26.4%）的SCCmec和ccr无法分型。IV型和V型SCCmec分别与路邓葡萄球菌和溶血葡萄球菌相关。