Serovars and biochemical characterization of Escherichia coli isolated from colibacillosis cases and dead-in-shell embryos in poultry in Zaria-Nigeria

This study was designed to determine the isolation rate, serovars and biochemical profiles of e. coli from cases of colibacillosis and dead-in-shell embryos in Zaria-Northern Nigeria. The isolation rate of e. coli from hatcheries studied were 4.67% and 7.50% from farms of Simtu Agricultural Company and National Animal Production Research Institute (NAPRI) Shika Zaria, Nigeria respectively. Twenty e. coli isolates from clinical cases of colibacillosis were also used for this study. The Simtu farm e. coli isolates showed 97.5% motility, while isolates from both NAPRI and clinical colibacillosis cases were 100% motile. The results of carbohydrate fermentation are variable without specific character, except for e. coli isolates from clinical cases of colibaccillosis that showed 100% fermentation especially for lactose, ducitol, rhamnose and xylose. The major serovars recorded from clinical cases of colibacillosis were serovars O8:K50 and O9:K30. Serovars from the dead-in-shell embryos were O78:K80, O8:K50, O9:K30, and O26:K60. Untypable isolates made up the greatest percentage of serogroup of e. coli studied. The antibiotic susceptibility testing indicated that many of the isolates were resistant to more than one antibiotic. Ciprofloxacin was the antibiotic to which majority of isolates were sensitive (85% of the clinical cases and 100% of both the Simtu and the NAPRI farms’ isolates). It is concluded that other methods for controlling e. coli should be evaluated, so that the emergence of resistant isolates be limited and the cost involved in prophylactic and therapeutic treatment programs be reduced.