Absence of Escherichia coli O157 in a survey of wildlife from Trinidad andTobago

Fecal, cloacal, or rectal swabs of free-ranging and captive mamalian and av ian wildlife in Trinidad and Tobago were cultured for non-sorbitol fermenti ng Escherichia coli and tested for O157:H7 strains. Ability of E. coli stra ins to produce hemolysin and mucoid colonies also was investigated. Of 271 free-ranging mammals tested, 158 (58%) yielded E. coli; only one (<1%) bact erial isolate was a non-sorbitol fermenter which was not agglutinated by O1 57 antiserum. All isolates were negative for hemolysin production and mucoi d colonial growth. Two hundred and sixty-three (90%) of 293 free-flying bir ds were positive for E. coli and all isolates were sorbitol fermenters and negative for production of hemolysin and mucoid growth. Of 175 captive wild animals from individual backyard farms and a government demonstration farm , 145 (83%) yielded E, coli with four (2%) non-sorbitol fermenters; all wer e negative for O157 strains, hemolysin production, and mucoid colonial grow th. Of 373 animals in a zoo, 250 (67%) were positive for E. coli with only two (0.5%) non-sorbitol fermenters. All strains were non-hemolytic and non- mucoid farms. It appears that free-ranging and captive avian and mammalian wildlife are not important reservoirs of O157:H7 strains of E. coli in Trin idad and Tobago.