Molecular screening and risk factors of enterotoxigenic Escherichia coli and Salmonella spp. in diarrheic neonatal calves in Egypt.
ABSTRACT The aim of the present study was to carry out molecular epidemiological investigation on enterotoxigenic Escherichia coli (ETEC) K99 and Salmonella spp. in diarrheic neonatal calves. Fecal samples were obtained from 220 diarrheic calves at 9 farms related to four governorates in central and northern Egypt. E. coli and Salmonella spp. isolates were examined for E. coli K99 and Salmonella spp. using PCR. ETEC K99 was recovered from 20 (10.36 %) out of 193 isolates, whereas Salmonella spp. was recovered from nine calves (4.09%). Multivariable logistic regression was used to evaluate the risk factors associated with both infections. ETEC K99 was significantly affected by age (P<0.01; OR: 1.812; CI 95%: 0.566-1.769), colostrum feeding practice (P<0.01; OR: 5.525; CI 95%: 2.025-15.076), rotavirus infection (P<0.001; OR: 2.220; CI 95%: 0.273-1.251), vaccination of pregnant dams with combined vaccine against rotavirus, coronavirus and E. coli (K99) (P<0.001; OR: 4.753; CI 95%: 2.124-10.641), and vitamin E and selenium administration to the pregnant dam (P<0.01; OR: 3.933; CI 95%: 0.703-1.248). Infection with Salmonella spp. was found to be significantly affected by the animal age (P<0.05; OR: 0.376; CI 95%: 0.511-1.369), Hygiene (P<0.05; OR: 0.628; CI 95%: 1.729-5.612), and region (P<0. 01; OR: 0.970; CI 95%: 0.841-1.624). The results of the present study indicate the importance of PCR as rapid, effective and reliable tool for screening of ETEC and Salmonella spp. when confronted with cases of undifferentiated calf diarrhea. Moreover, identification of the risk factors associated with the spreading of bacteria causing diarrhea may be helpful for construction of suitable methods for prevention and control.
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ABSTRACT: Calf diarrhea is a major economic concern in bovine industry all around the world. This study was carried out in order to investigate distribution of virulence genes, pathotypes, serogroups and antibiotic resistance properties of Escherichia coli isolated from diarrheic calves.Biological research. 01/2014; 47(1):28.
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ABSTRACT: Enterotoxigenic Escherichia coli (ETEC) is one of the major causes of neonatal calf diarrhea. Almost all ETEC bacteria are known to adhere to receptors on the small intestinal epithelium via their fimbriae, (F5 (K99) and F41).This study was undertaken to investigate the phenotypic and genotypic screening of virulence genes in E. coli K99 and F41. During January 2008 to December 2009, 298 diarrheic neonatal calves at 1–30 days old were studied by multiplex PCR, isolation, and serological grouping. Of the 298 diarrheic samples, 268 E. coli were isolated, of which 16 samples (5.3%) were positive for having the F5 (K99) fimbrial gene by PCR while all of the E. coli isolates also carried F41 fimbrial genes. Twenty-five percent of the isolates were proven not to be toxigenic as they did not possess the STa enterotoxin gene.Comparative Clinical Pathology 01/2010;
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ABSTRACT: This study was conducted to determine the prevalence and characteristics of pathogenic Escherichia coli strains from diarrhoeic calves in Iran. A total of 156 E. coli isolates obtained from 180 diarrhoeic calves were evaluated with two multiplex PCR protocols for the detection of the K99, F41, Sta, Stx1, Stx2 and eaeA genes. Of these 156 isolates, 32 (20.5%) carried at least one virulent gene, 22 (14.1%) possessed enterotoxigenic E. coli (ETEC) virulent genes and 10 (6.4%) possessed shiga toxin genes, virulence factors of shiga toxin-producing E. coli (STEC). None of the isolates carried eaeA gene. All ETEC but one were isolated from 1- to 4-day-old calves (95.4%), and one was isolated from a 6-day-old calf. All STEC were isolated from 7- to 28-day-old calves. All ETEC carried both K99 and F41 fimbriae and possessed Sta enterotoxin gene.Comparative Clinical Pathology 05/2012; 22(3).