Microbial quality of "doubles" sold in Trinidad

ABSTRACT

A cross-sectional study was conducted to determine the prevalence and characteristics of Escherichia coli, Staphylococcus aureus, Bacillus spp. and Salmonella spp. in "bara", "channa", condiments/spices and ready-to-eat "doubles" sold by vendors in the St. George and Caroni counties of Trinidad. Of 196 samples of each of "bara", "channa", condiments/spices and ready-to-eat "doubles" examined, E. coli was detected in 0 (0.0 per cent), 14 (7.1 per cent), 96 (49.0 per cent) and 67 (34.2 per cent), respectively; Staphylococci were isolated from 104 (53.1 per cent), 71 (36.2 per cent), 129 (65.8 per cent) and 123 (62.8 per cent) samples, respectively; and Bacillus spp. were recovered from 22 (11.2 per cent), 85 (43.4 per cent), 100 (51.0 per cent) and 88 (44.9 per cent) samples, respectively. Salmonella spp. were not isolated from any sample. Of the 177 isolates of E. coli recovered from all sources, 9 (5.1 per cent), 7 (4.0 per cent) and 47 (26.6 per cent) were mucoid, haemolytic and non-sorbitol fermenters (NSF), respectively, but none agglutinated with O157 antiserum. Of 427 staphylococcal isolates, 130 (30.4 per cent) were confirmed as S. aureus of which 20 (15.4 per cent) were haemolytic and 84 (64.6 per cent) pigmented, while 17 (20.7 per cent) of 82 strains of S. aureus tested produced enterotoxins. Ready-to-eat "doubles", a popular food in Trinidad, therefore pose a potential health risk to consumers due to the high level of contamination with bacteria.