RESUMO
Food borne Salmonella infection is an important cause of morbidity and mortality. A total of 200 food samples commonly sold in Lagos, Nigeria comprising raw and cooked meat as well as meat products and spoilt meat were analysed for the presence of Salmonella spp using REVEAL serology kit, culture methods employing RPVA (Rappaport Vassiliadis agar), SSA (Salmonella-Shigella agar) and BSA (brilliant sulphite agar) and PCR method for direct detection from samples using primer salm3/4 and ST11/ST15 sets. Using the REVEAL serology kit, 74% of the samples were positive for Salmonella spp, while culture methods showed only 19% to be Salmonella spp. The PCR method revealed that Salmonella spp was present in 62% and 54% of the samples using primer set salm3/4 and ST11/ST15, respectively. However, the primer set ST11/ST15 was more reliable in the identification of Salmonella spp directly from food samples. These tools should prove useful in the continuous monitoring and control strategies especially for ready-to-eat foods, as well as in retail meat outlets, slaughter houses, fast food restaurants for the prevention and reduction of this pathogen that is of significant importance in the food industry.
Assuntos
Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/genética , Doenças Transmitidas por Alimentos/microbiologia , Carne/microbiologia , Salmonella/genética , Salmonella/isolamento & purificação , Primers do DNA , Doenças Transmitidas por Alimentos/epidemiologia , Genes Bacterianos , Humanos , Nigéria/epidemiologia , Reação em Cadeia da Polimerase , Intoxicação Alimentar por Salmonella/epidemiologiaRESUMO
A total of 61 isolates of Salmonella spp (made up of 26 clinical isolates and 20 food handler and 15 animal isolates) were typed by RAPD-PCR for the purpose of screening for epidemiologically related isolates. The RAPD -PCR typing method used comprised six primers namely 787, 797, 784, 1254, RAPD 1 and RAPD 2 but 784 and 1254 did not produce discriminatory patterns and so were dropped. From the 61 strains, RAPD fingerprinting with primers RAPD 1, 2 produced 22 and 24 fingerprint patterns respectively. RAPD fingerprinting with primers 787, 797 produced 17, 11 fingerprinting patterns respectively. Combinations of the two RAPD 1 and 2 primers increased the discrimination of Salmonella strains to 32 patterns rather than the other primers used. Primer 797 was the least discriminatory. This study showed that the RAPD 1 and 2 primers would be useful for epidemiological typing of the Salmonella spp in Nigeria.