Prevalence of Shiga toxin-producing Escherichia coli and Salmonellae and some associated hematologic and biochemical profile alterations in lambs

Lamb enteritis constitutes an economic burden on sheep production worldwide. We aimed to estimate the prevalence of Shiga toxin-producing Escherichia coli (STEC) and Salmonellae among diarrheic lambs at Kafrelsheikh Governorate, Egypt and to detect the associated clinical, hematologic, biochemical, and antioxidant parameters. Fifty diarrheic and twenty apparently healthy control lambs were examined clinically, and hematologically. Diarrheic lambs had a significant elevated body temperature, respiratory and pulse rate, most of hemogram para-meters, total proteins and albumin, oxidative stress markers malonaldiahyde and nitric oxide levels, liver enzymes, urea and creatinine than control group. On the other hand, these diarrheic lambs had significant reduction in total leukocyte count and lymphocytes, antioxidant biomarkers super oxide dismutase activities and reduced glutathione than control lambs. E. coli and Salmonella spp. were isolated from ۳۲.۰۰% and ۱۶.۰۰% of diseased lambs, respectively. Serotyping and biochemical tests of examined samples identified ۱۶ E. coli isolates belonged to ۱۰ different serotypes; O۶, O۸, O۲۶:H۱۱, O۷۵, O۸۴:H۲۱, O۱۰۳:H۲, O۱۱۴:H۴, O۱۲۱:H۷, O۱۲۸:H۲ and O۱۶۳:H۲. All isolates are STEC as they harbor either Shiga-toxin ۱ or Shiga-toxin ۲ genes or both. One isolate carries intimin gene (eaeA) and classified as EHEC; O۲۶:H۱۱. The obtained nine isolates of Salmonella carry enterotoxin (Stn) genes, eight of them carry hyper-invasive locus (hilA) gene, all isolates belonged to six serotypes; S. Enteritidis, S. Heidelberg, S. Tsevie, S. Typhimurium, S. Essen, and S. Infantis. Lamb diarrhea was prevalent in the studied area and might constitute a veterinary and public health threat. Alteration in hemato-biochemical para-meters and oxidative–anti-oxidant balance could help adopt appropriate treatment regimens.

Keywords:

Escherichia coli , Hemato-biochemical profile , Lamb enteritis , Virulence genes , Salmonella