Bergal A, Loucif L, Benouareth D E, Bentorki A A, Abat C, Rolain J-M
Facultés de Médecine et de Pharmacie, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63 CNRS 7278 IRD 198 INSERM U1905, IHU Méditerranée Infection, Marseille, France.
Département d'Écologie et Génie de l'Environnement, Faculté des Sciences de la Nature et de la Vie et Sciences de la Terre et de l'Univers, Université 8 Mai 1945, Guelma, Algeria.
Eur J Clin Microbiol Infect Dis. 2015 Dec;34(12):2339-48. doi: 10.1007/s10096-015-2487-6. Epub 2015 Sep 28.
This study describes, for the first time, the genetic and phenotypic diversity among 93 Streptococcus agalactiae (group B Streptococcus, GBS) isolates collected from Guelma, Algeria and Marseille, France. All strains were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The molecular support of antibiotic resistance and serotyping were investigated by polymerase chain reaction (PCR). The phylogenetic lineage of each GBS isolate was determined by multilocus sequence typing (MLST) and grouped into clonal complexes (CCs) using eBURST. The isolates represented 37 sequence types (STs), 16 of which were novel, grouped into five CCs, and belonging to seven serotypes. Serotype V was the most prevalent serotype in our collection (44.1%). GBS isolates of each serotype were distributed among multiple CCs, including cps III/CC19, cps V/CC1, cps Ia/CC23, cps II/CC10, and cps III/CC17. All isolates presented susceptibility to penicillin, whereas resistance to erythromycin was detected in 40% and tetracycline in 82.2% of isolates. Of the 37 erythromycin-resistant isolates, 75.7% showed the macrolide-lincosamide-streptogramin B (MLSB)-resistant phenotype and 24.3% exhibited the macrolide (M)-resistant phenotype. Constitutive MLSB resistance (46%) mediated by the ermB gene was significantly associated with the Guelma isolates, whereas the M resistance phenotype (24.3%) mediated by the mefA/E gene dominated among the Marseille isolates and belonged to ST-23. Tetracycline resistance was predominantly due to tetM, which was detected alone (95.1%) or associated with tetO (3.7%). These results provide epidemiological data in these regions that establish a basis for monitoring increased resistance to erythromycin and also provide insight into correlations among clones, serotypes, and resistance genes.
本研究首次描述了从阿尔及利亚盖勒马和法国马赛收集的93株无乳链球菌（B组链球菌，GBS）分离株的遗传和表型多样性。所有菌株均通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）进行鉴定。通过聚合酶链反应（PCR）研究抗生素耐药性和血清分型的分子支持。通过多位点序列分型（MLST）确定每个GBS分离株的系统发育谱系，并使用eBURST将其分组为克隆复合体（CCs）。这些分离株代表37种序列类型（STs），其中16种为新类型，分为五个CCs，属于七种血清型。血清型V是我们收集样本中最常见的血清型（44.1%）。每种血清型的GBS分离株分布在多个CCs中，包括cps III/CC19、cps V/CC1、cps Ia/CC23、cps II/CC10和cps III/CC17。所有分离株对青霉素均敏感，而40%的分离株对红霉素耐药，82.2%的分离株对四环素耐药。在37株红霉素耐药分离株中，75.7%表现出大环内酯-林可酰胺-链阳菌素B（MLSB）耐药表型，24.3%表现出大环内酯（M）耐药表型。由ermB基因介导的组成型MLSB耐药（46%）与盖勒马分离株显著相关，而由mefA/E基因介导的M耐药表型（24.3%）在马赛分离株中占主导地位，且属于ST-23。四环素耐药主要归因于tetM，其单独检测到（95.1%）或与tetO相关（3.7%）。这些结果提供了这些地区的流行病学数据，为监测红霉素耐药性增加奠定了基础，同时也深入了解了克隆、血清型和耐药基因之间的相关性。
