RESUMO
The aim of this study was to determine the frequency of enterotoxigenic and enteroaggregative strains of Escherichia coli in chicken carcasses by polymerase chain reaction [PCR]. In this study 63 strains of E. coli were isolated from 110 samples of chicken carcasses during processing after chilling in the poultry slaughter house of Shahrekord. Polymerase chain reaction assays were used to detect the presence of the genes encoding heat-stable enterotoxin a [STa], heat-stable enterotoxin b [STb], heat labile toxin [LT] and Enteroaggregative heat-stable toxin 1 [EAST1]. Sixty three out of 110 [57.27%] carcasses were contaminated with E. coli. Six out of 63 [9.52%] harbored the gene for LT, 1 [1.58%] STb, 21 [33.3%] EAST1 and 8 [12.69%] contain both LT and EAST1 genes. None of the strains contain the STa gene. The results indicated that contamination of the chicken carcasses with E. coli in such a level could be a potential hazard for consumers
RESUMO
Staphylococci isolated from 98 mastitic cow's milk samples were analyzed for the production of alpha, beta and delta-hemolysin on sheep, bovine and horse red blood cells and in vitro susceptibility to several antimicrobial agents. Out of a total of 18 isolated strains, 100% demonstrated hemolytic activity either alone or in combined forms. Among 8 isolates of S. aureus 3 isolates produced alpha / beta and 5 produced alpha / beta / delta hemolysins. From 10 isolates of coagulase-negative staphylococci [CNS], 2 alpha, 2 delta, 2 alpha / delta and 4 alpha / beta / delta hemolysins producing isolates were confirmed. S. aureus isolates were resistant to cloxacillin [100%], penicillin [87%] and ampicillin [62.5%]. CNSs showed resistance only to amoxicillin [60%]. The results suggest that a cow's infected mammary glands are an important reservoir of hemolytic staphylococci. A high degree of S. aureus antimicrobial resistances was detected