Prevalence and distribution of staphylococcal enterotoxin genes among Staphylococcus aureus isolates from chicken and turkey carcasses in Algeria

This study is aimed to determine the prevalence of staphylococcus aureus (S.aureus) by biochemical tests in poultry carcasses. It is also intend to detect the distribution of genes for classical staphylococcal enterotoxins A, B, C, D and E (sea, seb, sec, sed and see) and for gene femA, specific for S. aureus species, using multiplex PCR. A total of 385 samples of neck skins from fresh poultry carcasses were collected during the period 2012-2013 from 16 different slaughterhouses located in the region of Algiers, Algeria. The overall prevalence of S.aureus in freshly slaughtered poultry carcasses was 41.56%, with an individual prevalence of 40.63% and 45.71% for chicken and turkey respectively. From the 95 strains of S.aureus identified by biochemical tests. 82 (86.32%) isolates were femA positive using multiplex PCR. The investigation has also revealed the presence of both enterotoxins B and D, with a predominance of seb (13.33%) followed by sed (1.67%), in the chicken carcasses while in turkey only sed was detected (4.55%) It has been found that strains of S.aureus of poultry origin can be enterotoxigenic with the predominance of genes encoding for enterotoxins seb in chicken and sed in turkey. As enterotoxins can be produced in adequate amounts to induce foodborne illnesses, these potential dangers must be considered in terms of a real risk to public health

Prevalence and distribuion of staphylococcal enterotoxin genes among Staphylococcus aureus isolates from chicken and turkey carcasses in Algeria

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗThis study is aimed to determine the prevalence of staphylococcus aureus (S.aureus) by biochemical tests in poultry carcasses. It is also intend to detect the distribution of genes for classical staphylococcal enterotoxins A, B, C, D and E (sea, seb, sec, sed and see) and for gene femA, specific for S.aureus species, using multiplex PCR. A total of 385 samples of neck skins from fresh poultry carcasses were collected during the period 2012-2013 from 16 different slaughterhouses located in the region of Algiers, Algeria. The overall prevalence of S.aureus in freshly slaughtered poultry carcasses was 41.56%, with an individual prevalence of 40.63% and 45.71% for chicken and turkey respectively. From the 95 strains of S.aureus identified by biochemical tests, 82 (86.32%) isolates were femA positive using multiplex PCR. The investigation has also revealed the presence of both enterotoxins B and D, with a predominance of seb (13.33%) followed by sed (1.67%), in the chicken carcasses while in turkey only sed was detected (4.55%) It has been found that strains of S.aureus of poultry origin can be enterotoxigenic with the predominance of genes encoding for enterotoxins seb in chicken and sed in turkey. As enterotoxins can be produced in adequate amounts to induce foodborne illnesses, these potential dangers must be considered in terms of a real risk to public health

Effect of feed on the milk protein and fat composition

Abstract. Feed is considered the most important factor affecting the composition of cow’s milk of which the quality can be evaluated, essentially, through two parameters, the fat and protein content, because of their industrial interest. This study aims to evaluate the impact of seven different rations (R1-R7) on the protein and fat content of Prim’holstein cow milk in a cattle farm in Algiers. The results showed that the dry matter (DM) content of forages and concentrate was 72.74% (62.94% - 81.49%) and 27.25% (18.51% - 37.06%), respectively. The forage unit milk (FUM) and the digestible nitrogen matter (DNM) contents of forage were 60.50% (51.37% - 72.08%) and 61.15% (46.73% - 74.63%), respectively. In concentrate, the FUM and DNM contents were 39.50% (24.85 - 51.5%) and 38.85% (25.37 - 52.39%), respectively (Table 3). The forages showed significantly higher DM, FUM and DNM contents than the concentrate (p<0.0001). The type of ration showed a highly significant effect on the quantity of milk produced per day, protein content and defatted dry matter. However, no significant influence was observed for the fat content. The highest milk production (ranging from 17.31 to 19.64 liters/day) and the highest defatted dry matter (87.03 and 87.92 g/l) were recorded in cows which received rations R2, R3, R4 and R5 (p<0.0001). The highest protein content values (32.87 and 33.20 g/l) were observed in the milk of cows that were fed with rations R2, R3 and R4. The lowest levels were observed for rations R6 (31.80 g/l) and R7 (31.22 g/l) (p<0.0001). Protein to fat content ratio ranged from 0.79 to 0.84 and fat to protein content ratio ranged from 1.19 to 1.27. Good management of the diet and feeding practices of the dairy cows allow having an adequate protein and fat content in the milk. A diet composed of forages with an adequate supplementation in concentrate leads to the optimal results. Further studies are important to evaluate the effect of the physical form of the diet on the physicochemical quality of the milk