Detection and virulence gene characterization of Shiga toxigenic E. coli from buffalo meat samples

Abstract

Shiga-toxigenic Escherichia coli (STEC) are causative agents of bloody diarrhoea, haemorrhagic colitis (HC) and haemolytic uraemic syndrome (HUS). Humans acquire infections primarily through contaminated beef. In India, STEC has not been implicated as a major cause of diarrhoea. The study was carried out to know the prevalence of shiga toxin (ST) producing Escherichia coli (STEC) and virulence genes characterization from buffalo meat samples sold at various retail meat shops at Anand, India. In the present investigation 70 isolates of Escherichia coli isolated from 150 retail market buffalo meat samples, were screened for STEC, using conventional culture methods, serotyping and polymerase chain reaction (PCR). Out of 70 E. coli isolates 11 different 'O' serogroups were recorded in 44 isolates. While 19 isolates were untypable and seven were rough isolates. Out of the 70 E. coli tested 56 isolates (80%) were positive for stx genes: of which 51 (72.85%) harboured stx2 genes and 2 isolates (2.85%) were positive for stx1 gene only. Moreover, 3 E. coli isolates (4.28%) harboured both stx1 and stx2. About 66 (94.28%) isolates were positive for eaeA gene. While out of 70 E. coli isolates tested, 3 (4.28%) were found to be positive for rfb O157 gene. Presence of STEC and other virulence factors in buffalo meat samples appeared to be matter of concern and threat to public health.

Diversity of antibiotic‐resistant Shiga toxin‐producing Escherichia coli serogroups in foodstuffs of animal origin in northern India

“…Raw beef had more non‐O157 STEC isolates compared to all other types of foodstuffs (45%) ( χ 2 , p < .1), that was expected given that bovines are the main environmental reservoir of various STEC serogroups, both O157 and non‐O157 serogroups (Karmali et al, ; Synge, ). Our findings agrees with reports obtained from India and the rest of the world indicating that foodstuffs of bovine origin were found to carry higher numbers of STEC, including non‐O157 serogroups (Bai et al, ; Hazarika et al, ; Manna et al, ; Sinha et al, ; Xia et al, ).…”

“…STEC O101 and STEC O132 detected in raw fish and raw chicken, respectively, were also reported from the same types of samples in other regions in India (Manna et al, 2010). A total of ONT STEC isolates from various samples were also found to harbor Shiga toxin, ONT STEC isolates have been commonly reported in food samples in India and the rest of the world (Bai et al, 2016;Hazarika et al, 2007;Manna et al, 2010;Sinha et al, 2015;Xia et al, 2010).…”

“…The diversity of E. coli serogroups in foodstuffs samples showed the prevalence of serogroup O60 (19, n = 158) as the first most prevalent serogroup, particularly in food of bovine origin (raw beef, milk, and beef kebab). Serogroup O60 was detected in food of bovine origin and cattle feces with various degrees of predominance in India (Manna et al, ; Sinha et al, ). Another two serogroups that were exclusively of bovine origin in this study were O8 (7, n = 158) and O68 (7, n = 158), these two serogroups were also commonly reported in food of bovine origin and cattle feces in India and worldwide (Blanco et al, ; Manna et al, ; Orden et al, ; Sinha et al, ).…”

“…The diversity of non‐O157 STEC serogroups in all food samples showed that raw fish and chicken samples were contaminated with more non‐O157 STEC serogroups (six different serogroups each), while foodstuffs of bovine origin carried the most prevalent non‐O157 STEC serogroups. Notably, STEC serogroups O60, O8, and O68 were more predominant among all STEC‐producing serogroups, and were exclusively of bovine origin, these three serogroups were isolated from foodstuffs of bovine origin in other regions in India (Hazarika et al, ; Manna et al, ; Sinha et al, ). STEC O101 and STEC O132 detected in raw fish and raw chicken, respectively, were also reported from the same types of samples in other regions in India (Manna et al, ).…”

“…STEC O101 and STEC O132 detected in raw fish and raw chicken, respectively, were also reported from the same types of samples in other regions in India (Manna et al, ). A total of ONT STEC isolates from various samples were also found to harbor Shiga toxin, ONT STEC isolates have been commonly reported in food samples in India and the rest of the world (Bai et al, ; Hazarika et al, ; Manna et al, ; Sinha et al, ; Xia et al, ). Overall, it was suggested that the prevalence of STEC serogroups, including non‐O157 serogroups in food of animal origin may varies and the factors attributing to this variation is related to the settings of geographic locations of where the investigation is conducted (Bosilevac & Koohmaraie, ).…”