High occurrence of shiga-like toxin-producing strains among diarrheagenic Escherichia coli isolated from raw beef products in Rio de Janeiro City, Brazil

被引:27
作者
Cerqueira, AMF
Tibana, A
Guth, BEC
机构
[1] FED UNIV RIO DE JANEIRO, INST MICROBIOL, RIO DE JANEIRO, BRAZIL
[2] UNIV FED SAO PAULO, ESCOLA PAULISTA MED, DISCIPLINA MICROBIOL, SAO PAULO, BRAZIL
关键词
beef products; diarrheagenic Escherichia coli; Shiga like toxin; serotypes;
D O I
10.4315/0362-028X-60.2.177
中图分类号
Q81 [生物工程学(生物技术)]; Q93 [微生物学];
学科分类号
071005 ; 0836 ; 090102 ; 100705 ;
摘要
Raw beef samples (n=105) were examined for diarrheagenic Escherichia coli (DEC) using standard methods. The isolates obtained (n=1,066) were screened for Shiga-like toxins (SLT-I and SLT-II), cytolethal distending toxin (CLDT), enterotoxins (LT-I and STa), and classical enteropathogenic (EPEC) and enteroinvasive (EIEC) serogroups. Seventy-three (6.8%) DEC isolates representing 42 strains isolated from 34 (32.4%) beef samples were detected. SLT-producing E. coli (SLTEC) was the most frequent DEC category found and corresponded to 21 (50%) of the 42 DEC strains. Several serotypes were detected among the SLTEC and some of them have been found previously in animal and human isolates, but E. coli O157:H7 was not isolated. Other virulence markers found in DEC strains included enterotoxin production (38.1%), CLDT (7.1%), and EPEC serogroups (4.3%). This is the first report of CLDT-producing E. coli (CLDTEC) isolated from food samples in Brazil. Production of both SLT-I and LT-I was found in one E. coli isolate, and 3 beef samples harbored both SLTEC and ETEC strains. Although a high frequency of DEC groups was found in commercial beef samples in Rio de Janeiro City, Brazil, the significance of these strains as agents of human diarrhea remains to be established.
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页码:177 / 180
页数:4
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