Distribution of virulence profiles related to new toxins and putative adhesins in Shiga toxin-producing Escherichia coli isolated from diverse sources in Brazil

• Published in: FEMS microbiology letters 2007-09, Vol.274 (2), p.329-334
• Main Authors: Cergole-Novella, Maria Cecília, Nishimura, Lucília S., Dos Santos, Luis Fernando, Irino, Kinue, Vaz, Tânia Mara I., Bergamini, Alzira M.M., Guth, Beatriz Ernestina C.
• Format: Article
• Language: English
• Subjects: Adhesins; Adhesins, Escherichia coli - biosynthesis; Adhesins, Escherichia coli - genetics; Adhesins, Escherichia coli - metabolism; Adhesion; Animals; Bacteria; Bacteriology; Beef cattle; Biological and medical sciences; Brazil; Cattle; Cytolethal distending toxin; E coli; Escherichia coli; Escherichia coli - chemistry; Escherichia coli - classification; Escherichia coli - isolation & purification; Escherichia coli - pathogenicity; Escherichia coli Infections - epidemiology; Escherichia coli Infections - microbiology; Escherichia coli Infections - veterinary; Escherichia coli Proteins - metabolism; Fundamental and applied biological sciences. Psychology; Genetics; Meat; Microbiology; Pili; serotypes; Shiga toxin; Shiga Toxins - biosynthesis; Shiga toxin‐producing Escherichia coli; Subtilase; Toxins; Virulence; Virulence - genetics; Virulence Factors; virulence markers
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2007.00856.x

Abstract The distribution of virulence markers related to cytolethal distending toxin-V (CDT-V), subtilase cytotoxin (SubAB), the enterohemorrhagic Escherichia coli factor for adherence (Efa1), the adhesin similar to IrgA (Iha), the long polar fimbriae (LpfO113), the autoagglutinating adhesin (Saa), and the protein required for full expression of adherence of O157:H7 Sakai strain (ToxB) was investigated in 121 Shiga toxin-producing E. coli (STEC) strains isolated in Brazil. STEC strains were isolated from human infections (n=49), cattle (n=68) and ground meat samples (n=4). Overall, the lpfAO113, iha, efa, saa, and toxB sequences were observed in 89.2%, 87.6%, 47.1%, 43%, and 13.2% of the strains, respectively. The genes efa1 (96.6%) and toxB (27%) were only identified among eae-positive strains, while saa (83.8%), cdt-V (12.9%), and subAB (48.4%) just occurred in eae-negative STEC strains. STEC strains harboring cdt-V and subAB were for the first time described in the South American subcontinent. In addition, the simultaneous presence of cdt-V and subAB has not been previously reported, nor the presence of subAB in STEC O77, O79, O105, O174, and O178 serogroups. A diversity of virulence profiles was observed among the STEC strains studied. The most prevalent profile observed among eae-positive STEC strains mainly isolated from humans was eae efa1 iha lpfAO113, whereas iha lpfAO113 saa ehxA subAB prevailed among eae-negative STEC strains, mostly isolated from cattle and foods.