title: Virulence profiles of enterotoxigenic, shiga toxin and enteroaggregative Escherichia coli in South African pigs.
abstract: Enterotoxigenic Escherichia coli (ETEC) and shiga toxin E. coli (STEC) are important causes of colibacillosis in piglets. Recently, enteroaggregative E. coli heat-stable enterotoxin 1 (EAST-1) has been implicated in pig diarrhoea. This study investigated the prevalence of enterotoxin [heat-labile toxins (LT), heat-stable toxin a (STa), heat-stable toxin b (STb)], shiga toxins (Stx1, Stx2, Stx2e), enteroaggregative heat-stable E. coli (EAST-1), associated fimbriae (F4, F5, F6, F41, F18ab, F18ac) and non-fimbrial adhesins [adhesin involved in diffuse adherence 1 (AIDA-1), attaching and effacing factor, porcine attaching- and effacing-associated factor] in South African pigs. A total of 263 E. coli strains were isolated from Landrace (n = 24), Large White (n = 126), Duroc (n = 28) and indigenous (n = 85) breeds of piglets aged between 9 and 136 days. PCR was used in the analysis. Virulent genes were detected in 40.3% of the isolates, of which 18.6, 0.4 and 17.5% were classified as ETEC, STEC and enteroaggregative E. coli (EAEC), respectively. Individual genes were found in the following proportions: STb (19.01%), LT (0.4%), STa (3.4%), St2xe (1.1%) and EAST-1 (20.2%) toxins. None of the tested fimbriae were detected in ETEC and STEC isolates. About one third of the ETEC and STEC isolates was tested negative for both fimbrial and non-fimbrial adhesins. Twenty-five pathotypes from ETEC-, EAEC- and STEC-positive strains were identified. Pathotypes EAST-1 (30.2%), STb (13.2%) and STb/AIDA-1 (10.4%) were most prevalent. The study provided insight on possible causes of colibacillosis in South African pigs.
authors: Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, Pietermaritzburg, South Africa.
authors: Ramadimetja Prescilla
authors: RP
authors: Mohlatlole
authors: Evelyn
authors: E
authors: Madoroba
authors: Farai Catherine
authors: FC
authors: Muchadeyi
authors: Michael
authors: M
authors: Chimonyo
authors: Arnold Tapera
authors: AT
authors: Kanengoni
authors: Edgar Farai
authors: EF
authors: Dzomba
mesh_terms: D000818:Animals; D054307:Enterotoxigenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D010861:Fimbriae, Bacterial / Q000235:genetics* / Q000382:microbiology; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015995:Prevalence; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D013019:South Africa / Q000453:epidemiology; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D037521:Virulence Factors