Some observations on the faecal carriage of mesophilicAeromonasspecies in cows and pigs

Abstract

SUMMARY: Replicate faecal samples from healthy individual pigs and cows were examined for the presence ofAeromonassp. over a 12-month period. Aeromonads were found to be minor components of the faecal flora, only 8·8 % of 520 samples from pigs and 4·6% of 481 samples from cows proving positive. Isolation rates in both groups of animals were seasonal.A. hydrophila(62% of the isolates) was the predominant species in cows, followed byA. caviae(32%) andA. sobria(15%). This pattern was also recorded in the natural waters that the animals drank from during the period when the faecal carriage rate was at its highest. In pigs,A. caviae(59%) was more common thanA. hydrophila(41%).A. sobriawas not found in any of the pig-associated samples. It seems that cattle acquire their faecal aeromonads from drinking water. The source of the organisms in pigs is less clear.