Massot Méril, Daubié Anne-Sophie, Clermont Olivier, Jauréguy Françoise, Couffignal Camille, Dahbi Ghizlane, Mora Azucena, Blanco Jorge, Branger Catherine, Mentré France, Eddi Alain, Picard Bertrand, Denamur Erick
INSERM, IAME, UMR1137, Paris, France.
Univ Paris Diderot, IAME, UMR1137, Sorbonne Paris Cité, Paris, France.
Microbiology (Reading). 2016 Apr;162(4):642-650. doi: 10.1099/mic.0.000242. Epub 2016 Jan 28.
It is important to study commensal populations of Escherichia coli because they appear to be the reservoir of both extra-intestinal pathogenic E. coli and antibiotic resistant strains of E. coli. We studied 279 dominant faecal strains of E. coli from 243 adults living in the community in the Paris area in 2010. The phylogenetic group and subgroup [sequence type complex (STc)] of the isolates and the presence of 20 virulence genes were determined by PCR assays. The O-types and resistance to 18 antibiotics were assessed phenotypically. The B2 group was the most frequently recovered (34.0 %), followed by the A group (28.7 %), and other groups were more rare. The most prevalent B2 subgroups were II (STc73), IV (STc141), IX (STc95) and I (STc131), with 22.1, 21.1, 16.8 and 13.7 %, respectively, of the B2 group strains. Virulence factors (VFs) were more common in B2 group than other strains. One or more resistances were found in 125 strains (44.8 % of the collection) but only six (2.2 % of the collection) were multiresistant; no extended-spectrum beta-lactamase-producing strain was isolated. The C phylogroup and clonal group A strains were the most resistant. No trade-off between virulence and resistance was evidenced. We compared these strains with collections of strains gathered under the same conditions 30 and 10 years ago. There has been a parallel and linked increase in the frequency of B2 group strains (from 9.4 % in 1980, to 22.7 % in 2000 and 34.0 % in 2010) and of VFs. Antibiotic resistance also increased, from 22.6 % of strains resistant to at least one antibiotic in 1980, to 31.8 % in 2000 and 44.8 % in 2010; resistance to streptomycin, however, remained stable. Commensal human E. coli populations have clearly evolved substantially over time, presumably reflecting changes in human practices, and particularly increasing antibiotic use.
研究大肠杆菌的共生菌群很重要,因为它们似乎是肠外致病性大肠杆菌和大肠杆菌耐药菌株的储存库。2010年,我们对来自巴黎地区243名社区成年人的279株优势粪便大肠杆菌菌株进行了研究。通过PCR检测确定了分离株的系统发育组和亚组[序列类型复合体(STc)]以及20种毒力基因的存在情况。通过表型评估了O型和对18种抗生素的耐药性。B2组是最常分离到的(34.0%),其次是A组(28.7%),其他组则较为少见。最常见的B2亚组是II(STc73)、IV(STc141)、IX(STc95)和I(STc131),分别占B2组菌株的22.1%、21.1%、16.8%和13.7%。毒力因子(VFs)在B2组中比其他菌株更常见。在125株菌株(占收集菌株的44.8%)中发现了一种或多种耐药性,但只有6株(占收集菌株的2.2%)是多重耐药的;未分离到产超广谱β-内酰胺酶的菌株。C系统发育组和克隆组A菌株的耐药性最强。未发现毒力和耐药性之间存在权衡。我们将这些菌株与30年和10年前在相同条件下收集的菌株进行了比较。B2组菌株的频率(从1980年的9.4%增加到2000年的22.7%和2010年的34.0%)和VFs频率呈平行且相关的增加。抗生素耐药性也有所增加,从1980年至少对一种抗生素耐药的菌株的22.6%增加到2000年的31.8%和2010年的44.8%;然而,对链霉素的耐药性保持稳定。人类大肠杆菌共生菌群显然随着时间的推移发生了显著进化,大概反映了人类行为的变化,尤其是抗生素使用的增加。