Motallebirad Tahereh, Fazeli Hossein, Jalalifar Saba, Shokri Darioush, Moghim Sharareh, Nasr Esfahani Bahram
Department of Bacteriology and Virology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Department of Microbiology, Faculty of Biological Sciences and Technology, Shahid Ashrafi Esfahani University, Isfahan, Iran.
Adv Biomed Res. 2020 Sep 30;9:44. doi: 10.4103/abr.abr_25_20. eCollection 2020.
The increasing incidence of Group B Streptococcus (GBS) infection among nonpregnant adults has become of growing clinical and public health concern. The current study investigated the distribution of important virulence determinants and antibiotic susceptibility of GBS isolates causing community acquired (CA) and hospital acquired (HA) infections among nonpregnant adults.
A total of 62 GBS, including 31 CA GBS and 31 HA GBS, were collected from a teaching hospital in Isfahan, Iran. Capsular polysaccharide genotypes (CPS), PI 1, PI 2a, PI 2b, and hypervirulent GBS adhesin (hvgA) virulence genes and antibiotic resistance profiling were determined.
There were 19 (30.6%) cases of underlying disease that diabetes mellitus (20.9%) was most common. The rate of multidrug resistant GBS strains was accounted for 29%. Distribution of macrolide resistant phenotypes was as follows: constitutive macrolides, lincosamides, and streptogramin B (MLSB) (15 isolates); inducible resistance to MLSB; and L phenotype (each 5 isolates) and M phenotype (1 isolate). V and Ia serotypes were the most predominant capsular type in HA GBS and CA GBS isolates, respectively. The most frequent pilus types were PI 1, PI 1+PI 2a, PI 1+PI 2b, and PI 2a. PI 1 and PI 1+PI 2a had significantly different distributions between CA and HA GBS isolates. Three CA GBS isolates (9.6%) were positive for hvgA gene that belonged to clonal complex 17/sequence type 17/CPS III/PI 1+PI 2b lineage.
There was a significant difference in the distribution of PIs among CA GBS and HA GBS isolates in our region.
B族链球菌（GBS）在非孕成年人中的感染发生率不断上升，已引起越来越多的临床和公共卫生关注。本研究调查了导致非孕成年人社区获得性（CA）和医院获得性（HA）感染的GBS分离株中重要毒力决定因素的分布及抗生素敏感性。
从伊朗伊斯法罕的一家教学医院收集了总共62株GBS，其中包括31株CA GBS和31株HA GBS。测定了荚膜多糖基因型（CPS）、PI 1、PI 2a、PI 2b和高毒力GBS黏附素（hvgA）毒力基因以及抗生素耐药谱。
有19例（30.6%）存在基础疾病，其中糖尿病（20.9%）最为常见。多重耐药GBS菌株的比例为29%。大环内酯类耐药表型的分布如下：组成型大环内酯类、林可酰胺类和链阳菌素B（MLSB）（15株分离株）；对MLSB的诱导性耐药；以及L表型（各5株分离株）和M表型（1株分离株）。V型和Ia型血清型分别是HA GBS和CA GBS分离株中最主要的荚膜类型。最常见的菌毛类型为PI 1、PI 1+PI 2a、PI 1+PI 2b和PI 2a。PI 1和PI 1+PI 2a在CA GBS和HA GBS分离株之间的分布有显著差异。3株CA GBS分离株（9.6%）的hvgA基因呈阳性，属于克隆复合体17/序列型17/CPS III/PI 1+PI 2b谱系。
在我们地区，CA GBS和HA GBS分离株中PI的分布存在显著差异。
