Campylobacter, Salmonella, Shigella and Escherichia coli in live and dressed poultry from metropolitan accra

This study on the microbiology of chicken assessed a total of 97 live birds from three selected farms and 87 carcasses/chicken parts from two supermarkets, two open markets and one wholesale outlet (cold store) in the Accra metropolis. Campylobacter spp. were isolated from 14 (14.4%) gut contents of live birds from three farms. None of the frozen birds were positive for Campylobacter spp. These isolates were sensitive to most common antibiotics but not to ampicillin and tetracyclines. Salmonella spp. were isolated from 7 (7.2%) gut contents and 13 (6.8%) carcasses and were resistant to erythromycin. cefotiam, penicillin, ampicillin and cefadroxil. Samonella spp. had varied susceptibilities to nalidixic acid, chloramphenicol and minocyclin. No Shigella spp. was isolated from any of the live birds but 6 (6.9%) of imported chicken samples from the cold store and two markets were positive. Fosfomycin and chloramphenicol were the only antibiotics effective against these isolates. Twelve different Escherichia coli serovars were identified from the total of 21 positive samples. These, in order of magnitude isolated, are E. coli 0158 (14.3%), 0125 (14.3%), 025 (9.5%), 028ac (9.5%), 0159 (9.5%). 015 (9.5%), 0126 (9.5%), 063 (4.8%), 0143 (4.8%), 026 (4.8%), 078 (4.8%), 0164 (4.8%). Cefadroxil, ampicillin, penicillin, cefotiam, tetracycline and erythromycin were ineffective against all strains of E. coli isolated. Minocyclin was effective against all strains with the exception of E. coli 0159, 025, 0164 and 063, which were moderately susceptible. All strains with exception of E. coli 0164 were susceptible to fosfomycin. Nalidixic acid, chloramphenicol, kanamaycin, ceftrioxone and amoxycillin all showed varied effectiveness against the strains isolated. It is concluded that imported and locally produced chicken is a potential source of multiple-antibiotic-resistant enteropathogenic bacteria. Measures to improve the microbial quality of chicken are discussed.

The effects of fermentation and/or vacuum flask storage on the presence of coliforms in complementary foods prepared for Ghanaian children

Microbial contamination of complementary foods is a major cause of childhood diarrhoea. In a community-based study in Ghana, we evaluated whether fermentation of maize porridge or storage of porridge in vacuum flasks reduces coliform contamination. The complementary food examined, Weanimix, consisted of, on a dry weight basis, toasted maize (75%), peanuts (10%), and soybeans (15%) milled into flour. The fermented food was Weanimix made with drum-dried, previously fermented maize. Fifty women with infants 6-18 months of age participated. A repeated measures cross-over design was used. Each mother participated in all four treatments (1 week per treatment, in random order): (a) non-fermented Weanimix (W), (b) fermented Weanimix (F), (c) non-fermented Weanimix stored in a vacuum flask (WV), and (d) fermented Weanimix stored in a vacuum flask (FV). Each week, mothers were supplied with the appropriate food, and asked to prepare a porridge each morning by boiling the dry mix in water. Samples were collected in the evenings and immediately plated onto 3 M Petrifilm. Contamination was defined as > or = 100 colony-forming units of coliforms per ml. Contamination rates (95% confidence intervals) were W = 48% (38-58%), F = 25% (17-34%), WV = 42% (32-52%), and FV = 13% (6-20%). All pairwise comparisons were significant (P < 0.05) except for W vs WV. Within the WV treatment, contamination rates were 85% when the sample temperature fell below 50 degrees C (N = 41) vs 12% when it remained > 50 degrees C (N = 59) (P < 0.001). These results indicate that contamination is reduced by fermentation, and further reduced by vacuum flask storage of fermented foods. For non-fermented foods, vacuum flask-storage was protective only when the temperature was maintained at > 50 degrees C; at < or = 50 degrees C vacuum flask storage increased the risk of contamination.