Johnson J R, Stapleton A E, Russo T A, Scheutz F, Brown J J, Maslow J N
VA Medical Center, and Department of Medicine, University of Minnesota, Minneapolis 55417, USA.
Infect Immun. 1997 Jun;65(6):2153-9. doi: 10.1128/iai.65.6.2153-2159.1997.
The recent discovery of a geographically dispersed clonal group of Escherichia coli O4:H5 that includes prototypic uropathogenic strain J96 prompted us to determine the prevalence of J96-like strains within serogroup O4 and to further assess the characteristics of such strains. We used O:K:H;F serotyping, PCR-based genomic fingerprinting, pulsed-field gel electrophoresis (PFGE), multilocus enzyme electrophoresis (MLEE), and PCR detection of the three papG alleles and of the cytotoxic necrotizing factor 1 (cnf1) and aerobactin (aer) gene sequences to characterize the 15 O4 strains among 336 E. coli isolates from three clinical collections (187 from mixed-source bacteremia, 75 from urosepsis, and 74 from acute cystitis). J96-like strains constituted approximately half of the O4 strains, or 2% of the total population. In contrast to other O4 strains, the J96-like strains characteristically exhibited specific group III capsular antigens, the H5 flagellar and F13 fimbrial antigens, a distinctive PCR genomic fingerprint, the class III papG allele (plus, in 50% of strains, the enigmatic class I papG allele), and cnf1 but lacked aer. A subset of these strains was remarkably homogeneous with respect to all these characteristics and exhibited a distinctive PFGE fingerprint and MLEE pattern. These findings clarify the epidemiological relevance of J96 as a model extraintestinal pathogen, provide further evidence of the class I papG allele outside of strain J96, and offer insights into the evolution of E. coli serogroup O4.
最近发现了一个地理分布广泛的大肠杆菌O4:H5克隆群，其中包括原型尿路致病性菌株J96，这促使我们确定血清群O4中J96样菌株的流行率，并进一步评估此类菌株的特征。我们使用O:K:H;F血清分型、基于PCR的基因组指纹分析、脉冲场凝胶电泳（PFGE）、多位点酶电泳（MLEE），以及对三种papG等位基因、细胞毒性坏死因子1（cnf1）和气杆菌素（aer）基因序列进行PCR检测，以对来自三个临床样本（187份混合源菌血症样本、75份泌尿道脓毒症样本和74份急性膀胱炎样本）的336株大肠杆菌分离株中的15株O4菌株进行特征分析。J96样菌株约占O4菌株的一半，占总菌株数的2%。与其他O4菌株相比，J96样菌株的特征是具有特定的III类荚膜抗原、H5鞭毛和F13菌毛抗原、独特的PCR基因组指纹、III类papG等位基因（另外，50%的菌株中还有神秘的I类papG等位基因），以及cnf1，但缺乏aer。这些菌株中的一部分在所有这些特征方面非常一致，表现出独特的PFGE指纹和MLEE模式。这些发现阐明了J96作为一种典型的肠外病原体的流行病学相关性，为J96菌株之外的I类papG等位基因提供了进一步的证据，并为大肠杆菌血清群O4的进化提供了见解。
