Minarini Luciene A R, Camargo Ilana L B C, Pitondo-Silva André, Darini Ana Lúcia C
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, USP, Ribeirão Preto, SP, 14040-903, Brazil.
Curr Microbiol. 2007 Dec;55(6):524-9. doi: 10.1007/s00284-007-9026-3. Epub 2007 Sep 25.
In the present study, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) and polymerase chain reaction detection of three resistance genes were combined to characterize seven uropathogenic E. coli isolated from outpatients. Selected portions of seven housekeeping and three antibiotic-resistance genes of the isolates were sequenced. The seven isolates were classified into four different sequence types (STs) by MLST and five PGFE types. Three isolates had a novel allelic profile representing a new ST designated as ST528 and showed the same PFGE and resistance genes. Two isolates, both characterized as ST359, were differentiated by PFGE and shared only one of the antibiotic-resistance genes studied. Comparison of MLST results with those of PFGE and resistance genes demonstrated that Escherichia coli had acquired different antibiotic-resistance genes and DNA rearrangements, causing alterations in PFGE patterns but maintaining the same ST. Furthermore, this article also reports the first detection of a CTX-M-2 ESBL E. coli and SHV-5 in a Brazilian community.
在本研究中，将多位点序列分型（MLST）、脉冲场凝胶电泳（PFGE）以及对三个耐药基因的聚合酶链反应检测相结合，以对从门诊患者中分离出的7株尿路致病性大肠杆菌进行特征分析。对分离株的7个管家基因和3个抗生素耐药基因的选定部分进行了测序。通过MLST将这7株分离株分为4种不同的序列类型（STs），通过PFGE分为5种类型。3株分离株具有代表新ST（命名为ST528）的新等位基因谱，并显示出相同的PFGE和耐药基因。2株均被鉴定为ST359的分离株通过PFGE得以区分，并且仅共享所研究的一个抗生素耐药基因。将MLST结果与PFGE和耐药基因的结果进行比较表明，大肠杆菌获得了不同的抗生素耐药基因和DNA重排，导致PFGE模式发生改变，但ST保持相同。此外，本文还报道了在巴西社区首次检测到CTX-M-2型超广谱β-内酰胺酶大肠杆菌和SHV-5。
