Departamento de Microbiologia, REQUIMTE, Faculdade Farmácia Universidade Porto, Rua Jorge Viterbo Ferreira n° 228, 4050-313 Porto, Porto, Portugal.
BMC Microbiol. 2013 Jun 21;13:144. doi: 10.1186/1471-2180-13-144.
Phylogenetic group D Escherichia coli clones (ST69, ST393, ST405) are increasingly reported as multidrug resistant strains causing extra-intestinal infections. We aim to characterize inter- and intraclonal diversity of a broad sample (isolates from different geographic locations and origins with variable antibiotic resistance profiles, 1980-2010) and their ability to adhere and form biofilm by both a modified quantitative biofilm producing assay and Field Emission Scanning Electron Microscopy (FESEM).
High virulence scores were observed among ST69 (median 14/range 9-15) and ST393 (median 14/range 8-15) clones, particularly enriched in pap alleles, iha, kpsMTII-K5 and ompT, in contrast with ST405 (median 6/range 2-14) isolates, exhibiting frequently fyuA, malX and traT. All ST69 and ST393 and only two ST405 isolates were classified as ExPEC. Biofilm production was detected in two non-clinical ST69 and three ST393 isolates from different origins showing variable virulence profiles. Within each clonal group, and despite the high diversity of PFGE-types observed, isolates from different countries and recovered over large periods of time were clustered in a few groups sharing common virulence gene profiles among ST69 (n = 10 isolates) and ST393 (n = 9 isolates) (fimH-iha-iutA-kpsMTII-K5-(traT)-sat-(ompT)-papA-papEF-papGII-papC) or ST405 (n = 6 isolates) (fimH-traT-fyuA-malX).
This study highlights the circulation of highly transmissible ST69, ST393 and ST405 variants among different settings. Biofilm production seems not to be directly correlated with their epidemiological success.
进化枝 D 型大肠埃希菌克隆（ST69、ST393、ST405）越来越多地被报道为引起肠道外感染的多药耐药株。我们旨在对广泛样本（来自不同地理位置和起源的分离株，具有不同的抗生素耐药谱，1980-2010 年）的种内和种间多样性进行特征描述，并通过改良的定量产菌生物膜测定法和场发射扫描电子显微镜（FESEM）来研究它们的粘附和形成生物膜的能力。
ST69（中位数 14/范围 9-15）和 ST393（中位数 14/范围 8-15）克隆的毒力评分较高，尤其是富含 pap 等位基因、iha、kpsMTII-K5 和 ompT，而 ST405（中位数 6/范围 2-14）分离株则富含 fyuA、malX 和 traT。所有 ST69 和 ST393 以及仅 2 株 ST405 分离株被归类为 ExPEC。从不同来源的 2 株非临床 ST69 和 3 株 ST393 分离株中检测到生物膜产生，这些分离株表现出不同的毒力谱。在每个克隆群内，尽管观察到 PFGE 型的多样性很高，但来自不同国家并在较长时间内恢复的分离株聚集在少数几个组中，这些组在 ST69（n=10 株）和 ST393（n=9 株）（fimH-iha-iutA-kpsMTII-K5-（traT）-sat-（ompT）-papA-papEF-papGII-papC）或 ST405（n=6 株）（fimH-traT-fyuA-malX）中共享共同的毒力基因谱。
本研究强调了高传播性 ST69、ST393 和 ST405 变体在不同环境中的传播。生物膜的产生似乎与它们的流行病学成功没有直接关系。
