Vibrio cholerae and Vibrio parahaemolyticus detected in seafood products from Senegal.

The detection of pathogenic Vibrio in seafood from Senegal has generated five food alerts in the European Union. To investigate the presence and abundance Vibrio cholerae and Vibrio parahaemolyticus in seafood and coastal and estuarine waters, 123 seafood samples and 52 water samples were collected during 2007-2009 from two large seafood markets in Dakar, and from different oceanic and estuarine areas of the country. V. parahaemolyticus was detected in 30.1% of seafood samples, whereas presence of V. cholerae was only found in 1.6%. In water samples, V. parahaemolyticus and V. cholerae were detected in 28.8% and 5.7% of the samples, respectively. Abundance of V. parahaemolyticus in seafood from the fishing areas ranged from <0.3 to 7.5 most probable number (MPN) per gram. In samples from markets, densities of V. parahaemolyticus showed higher values ranging from 0.61 to >110 MPN/g. Densities of V. cholerae in the two positive seafood samples reached values of 0.36 and 0.61 MPN/g, repectively. V. parahaemolyticus strains were found to possess tlh, but not tdh and trh by polymerase chain reaction, and all the strains of V. cholerae were non-O1 or non-O139. These results suggest that the prevalence of high salinities in coastal and estuarine environments of Senegal limits the occurrence of V. parahaemolyticus and V. cholerae, despite warmer temperatures prevailing in seawater environments throughout the year. Furthermore, temperature abuse driven by a deficient cold chain over the distribution and retail sales may represent a major risk due to the postharvest multiplication of these Vibrio pathogens.

Analysis of microbiological and chemical quality of poultry meat in the vicinity of the Mbeubeuss landfill in Malika (Senegal).

A total of 100 samples of poultry meat were collected in poultry farms in the vicinity of the Mbeubeuss landfill in the Niayes (Senegal) for microbiological and chemical analysis. Fifty-four (54) samples were collected in farms located less than 1 km from the landfill and 46 samples were collected in farms located a bit further (more than 1 km from the landfill). Microbiological quality was determined using techniques recommended by Association Française de Normalisation (AFNOR). Lead and cadmium concentration in poultry meat was measured by flame spectrometry while total mercury was determined by atomic absorption spectrometry. Three percent (3%) of the samples' quality were unsatisfactory for E. coli, 1% for Staphylococci and 7% for Salmonella spp. Poor meat quality was found either in farms located less than 1 km of the landfill or in farms located at more than 1 km of the landfill. Except for Salmonella, only meat samples from poultry receiving drinking water from well showed unsatisfactory microbiological quality. The samples were free of cadmium and lead but were contaminated by mercury. Sixty-eight percent (68%) of the samples contained mercury with a high contamination level (>0.011 mg/kg) in 20% of the samples. No significant difference was found between the farms that were nearest to and further away from the landfill while the source of drinking water seemed to be the main cause of contamination of poultry meat by mercury.

Antimicrobial resistance of Salmonella isolated from poultry carcasses in Dakar (Senegal)

This study was undertaken to estimate the antimicrobial resistance of Salmonella isolated from raw chicken. From November 2003 to April 2004 a total of 120 chicken carcasses were collected from 36 randomly selected sale points (supermarkets, traditional market, poultry slaughter house, flocks) in the urban and periurban zones of Dakar, Sénégal, and examined for the presence of Salmonella. Salmonella was isolated from 75 (62.5 percent) of the examined samples. Out of the 90 Salmonella isolates obtained, twenty one serotypes were identified, from which the most prevalent were S. Kentuchy 30 percent, S. Muenster (13.3 percent), S. Brancaster (8.8 percent), S. Enteritidis and S. Hadar (6.6 percent). All Salmonella isolates were tested for their susceptibility to 16 selected antimicrobial agents by the agar diffusion method. Seventy one (78.9 percent) isolates were resistant to one or more antimicrobials. Out of 71 resistant Salmonella isolates, 33 (46.5 percent) showed multiple resistance to five or more different antimicrobials. Resistance to ampicillin, trimethoprim, trimethoprim-sulphamethoxazole, tetracyclin and sulphonamides was the most frequent. We found 36 different patterns of multiresistant strains. The high level of antibiotic resistance of foodborne Salmonella isolates in the present study is an indication of indiscriminate and continuous use of subtherapeutic doses of antibiotics in animals. Furthermore, the results showed the possible significance of chicken meat as a source of multiple antimicrobial-resistant Salmonella for human infections and suggest the need for detailed epidemiological study.

O presente estudo foi realizado com o propósito de aviliar a resistência aos antibióticos dos sorovares da Salmonella isolados da carne de frango crua. De novembro de 2003 até abril de 2004, um total de 120 carcaças de frango foram compradas em 13 pontos de venda e 23 centros de criação de frangos. As Salmonella foram isoladas a partir de 75 (62,2 por cento) carcaças analisadas. Vinte e um (21) sorotipos diferentes foram identificados, sendo os mais freqüentes S. Kentucky (30 por cento), S. Muenster (13,3 por cento), S. Brancaster (8,8 por cento), S. Enteritidis e S. Hadar (6,6 por cento). Todos os sorovares de salmonela foram examinados a fim de determinar a resistência à 16 antibióticos. Setenta e quatro (79,6 por cento) foram resistentes à um antibiotico ou mais, das quais 33 (45,6 por cento) mostraram resistência múltipla a cinco antibióticos (ampicilina, trimetoprim, trimetoprim-sulfametoxazol, tetraciclina e sulfonamidas). Foram encontrados 36 perfis diferentes de resistência múltipla. O nível elevado de resistência dos isolados de Salmonella encontrados na carne do presente estudo, é um indicador do uso indevido e contínuo de doses subterapêuticas de antibióticos nos animais. Por outro lado, os resultados do estudo demonstram a importância da carne de frango como fonte potencial de sorovares de Salmonella multiresistentes transmissíveis ao homem e sugerem um estudo epidemiólogico detalhado.