Performance of selective media for E. coli O157, using non-sorbitol fermenting strains and physiological characters of shiga-toxin producing species isolated in Côte d'Ivoire

Performance of three selective media, tmperature and pH effects on growth of E. coli O157:H7 isolated in Ivory Coast were investigated. Thirty-eight (38) non-sorbitol fermenting E. coli were characterized by serotyping, detection of shiga-toxin gene (PCR) and plating on SMAC, VRMUG and BCMtm media for Performance evaluation. Temperature and pH effects on E. coli O157:H7 were measured in varied culture conditions. All culture media were sensitive (100%) for the growth of E. coli O157. Their specificities were 97.3, 94.7 and 50.7% respectively for VRMUG, BCMtm and SMAC media. Predictive value for VR-MUG medium was 66%, whereas that for SMAC medium was only 5.4%. Serotype O157:H7 E. coli population grew slightly at 42 °C and didn’t grow under acid conditions (pH 4.5, 3.5). The performance of the culture media evaluatedand the physiological data obtained for E. coli O157:H7 during this study would contribute to improve both isolation and identification methods of the pathovars.© 2010 International Formulae Group. All rights reserved.Keywords: E. coli O157H7, performance, culture medium, shiga-toxin, pH, temperatur

Analyse des risques microbiens du lait cru local à Abidjan (Côte d’Ivoire)

The hygiene practices during milking, the microbiological and chemical quality of cow raw milk from production to sale were studied in 15 small dairies in Abidjan. The analysis of raw milk quality showed that 81.5% of raw milk taken udders of cow were of good quality, against 35.30% for raw milk on sale. The average of Coliforms was 8.7.103 cfu/ml for raw milk taken cow’s udder, 3.2.105 cfu/ml for raw milk in tank and 9.9.105 cfu/ml for raw milk sales. The udders of cows, hands of milkers were identified as primary sources of milk contamination. The utensils (farmer, vendor) and environment were identified as major sources of secondary contamination. In addition, 24.7% of milk contained antibiotics and 50% of raw milk on sale were wet with water. The occurrence of food borne diseases is significantly related to the behavior of consumption of unpasteurized raw milk (P<0.05) with a relative risk of 2.81 (95%CI: 1.17 – 6.78). The zootechnical management of actors and popularization of good hygiene practices throughout the production chain are necessary for improvement of local milk quality

Bacterial risk assessment in informally produced milk consumption in Côte d’Ivoire

BACKGROUND: Fifteen dairy farms from five zones of Abidjan, Côte d’Ivoire, were characterized to assess the conditions of raw milk production and marketing, and detect whether Bacillus cereus presented a risk to the consumer. METHODS: In total, 119 udder milk, 113 udder skin swabs, 22 hand swabs of farmers, 14 mixture milk of shepherd, 14 utensils rinse water, 16 environment samples and water used to rinse material for milking in 5 farms were sampled. Three informal markets in these zones were visited and 17 retailer pooled milk samples were collected and analyzed. The isolated strains were characterized and their virulence genes were detected by polymerase chain reaction (PCR). Milk quality was determined by comparing the average count of B. cereus to the limits of acceptability. To assess the impact of the consumption of raw milk, a consumer survey was conducted on 188 clients selected randomly at informal markets. RESULTS: 26.6% (32/119) of raw milk samples taken directly from the cow’s udders, 28.6% (4/14) mixture milk of shepherd and 41.2% (7/17) of retailer pooled milk were contaminated by B. cereus. Regarding limits of acceptability, 28.6% (2/7) of retailer pooled milk samples met the standards, 28.6% (2/7) presented a potential risk of disease and 42.8% (3/7) posed a real risk of foodborne poisoning. The sources of contamination of milk by B. cereus were, by decreasing order of importance, the udder (73/113), the water (3/5), the environment (9/16), the milk vendor containers (7/17), the hands of the milker(s) (9/22) and the utensils (4/14). All B.cereus strains (88 strains) isolated were virulent and harbored at least one of the virulence genes hblA, hblC, hblD, nheA, nheB, nheC, bceT and cytK-2. The most frequent virulence genes were hblD (79/88), cytK-2 (79/88), nheC (65/88) and hblC (60/88), all involved in the aetiology of diarrheal syndromes. Among milk consumer’s respondents, 12.8% (24/188) reported episodes of symptoms including diarrhea (19/37), fever (5/37), bloating stomach (4/37), vomiting (3/37) and nausea (1/37). Severe cases requiring a stay of one to three days in hospital were reported by 12.5% (3/24) of those infected. SUMMARY: The probability of consuming milk contaminated by B. cereus was 22.2%. The occurrence of foodborne diseases was significantly related (p < 0.05) to the consumption of unpasteurized milk (Relative Risk (RR): 2.6, 95% CI 1.07 - 6.22). Milk quality could be improved by the introduction of good hygiene practices such as water quality, utensil washing and milk pasteurization. Awareness of stakeholders in the informal dairy sector is also crucial to reduce the risk of infection for the consumer

Evaluation De La Performance Nutritionnelle D\'une Farine Infantile Composée Chez De Jeunes Rats

Une farine composée à base de maïs, de niébé et de manioc a été obtenue à partir de fermentation associée et soumise au jeune rat mâle Wistar, comme aliment de complément. Cette farine fermentée (FF) est mieux consommée par les rats (8,0 0,6 g-1j-1) que la farine composée non fermentée (FNF) témoin (5 0,4 g-1j-1). L\'efficacité alimentaire de la farine fermentée est 2 fois plus élevée (0,22 g j-1 g-1) que celle du témoin (0,1 g g-1 / j-1). Par ailleurs, la digestibilité in vitro révèle une meilleure sensibilité de l\'amidon de la farine fermentée (82 %) par rapport à celui de la farine non fermentée (48 %). Ces farines produisent in vivo, essentiellement de l\'hydrogène et des acides gras à chaînes courtes caractéristiques d\'un métabolisme fermentaire des fibres et de l\'amidon résistant par la flore microbienne du cæcum. La performance alimentaire observée serait la conséquence de l\'élimination par la fermentation, de certains facteurs antinutritionnels et de l\'amélioration de la digestibilité in vivo de la farine fermentée.The maize, coopea and cassava bean flour was obtained from associated fementation and given to young male rat wistar as food supplement. The fermented flour was more accepted by the rats (8,0 0,6g-1j-1) than the non fermented composed flour controle (5 0,04 g-1j-1). The food efficiency of the fermented flower two was tinaes higher (0,22 g -1j-1g-1) than that of the control (0,1g-1j-1g-1). Morever, in vitro starch digestibility was found to fermented flower as compared 82 % in to that of non fermented composed flower (48 %). These flours produced in vivo essentially hydrogen and short chain fatty acid characteristic of a fermentation metabolism linked to the microbian flora of the caecum. The food performance observed could be the consequence of the elimination of some anti-nutritional factors and the improvement of the in vivo digestibility of flower by fermentation. Keywords: keydigestibilité, efficacité, flatulence, fermentation, Côte d'Ivoire; digestibility, food efficiency, flatulence, fermentation, Côte d'Ivoire.Agronomie Africaine Vol. 15 (2) 2003: pp. 67-7

Prévalence de Escherichia coli entéropathogènes dans le lait non pasteurisé produit à Abidjan, Côte d’Ivoire

L’objectif de cette étude était de déterminer la prévalence de Escherichia coli entéropathogènes (ECEP) dans le lait non pasteurisé. Un total de 207 échantillons ont été analysés pour l’identification de E. coli. Les souches ont été caractérisées par réaction de polymérisation en chaîne (PCR) pour la détection des gènes eaeA et bfp et un test a été effectué sur lignée cellulaire Hep-2 pour la détermination des phénotypes d’adhésion caractéristiques. La prévalence des E. coli présentant des gènes de virulence dans le lait non Pasteurisé est de 3,4% (7 souches). La fréquence des ECEP typiques (eaeA, bfp) est de 1,2%. Les ECEP atypiques (eaeA+, bfp-) ont été révélés dans 1,6% des souches. Une adhésion localisée aux cellules Hep-2 a été observée chez 3 (43%) des souches possédant des facteurs de virulence. Le lait non Pasteurisé représente un facteur de risque de développement d’infection à ECEP chez les enfants consommateurs.© 2010 International Formulae Group. All rights reserved.Mots clés: Escherichia coli, ECEP, virulence, adhésion, cellules Hep-2

Contamination of raw milk with Bacillus cereus from farm to retail in Abidjan, Côte d'Ivoire and possible health implications

In Africa, milk and dairy products play an important role in human nutrition but could represent a risk to human health, due to poor hygiene throughout the production chain. This study aimed firstly to assess the contamination of raw milk produced in traditional dairy farms in Abidjan with Bacillus cereus from farm to retail and secondly to assess the associated health risk for consumers in informal markets using a participatory approach. In total, 320 samples including 150 milk samples were collected in 15 purposively selected traditional dairy farms from four sites of Abidjan and analysed according to EN ISO 7932:2004 with slight modification. In addition, a survey was conducted in the three informal markets with 188 individuals who bought milk. B. cereus was found in 27% of the udder milk samples while 41% of the samples taken from seller’s pooled milk contained B. cereus. Out of the 183 milk consumers, 14% reported daily consumption of unheated milk, indicating the high probability of exposure to B. cereus and other foodborne illnesses. After milk consumption, 13% of consumers reported that they contracted a foodborne illness. In conclusion, milk produced and sold in informal markets in Abidjan represents a risk for consumers’ health and B. cereus is one possible cause. Milk quality could be improved by good hygiene practices, strengthening and targeting educational interventions and effective monitoring throughout the production and delivery chain