Subclinical mastitis on the raw milk as a risk factor for the transmission of Staphylococcus.aureus and coagulase-negative staphylococci, multidrug resistance in Sidi Bel Abbes, Algeria

Abstract

In Algeria, the milk is consumed directly, generally in the raw state thus escaping any quality control. The subclinical mastitis becomes a problem of food security. Our hypothesis is that consumption of the raw milk of the cows with subclinical mastitis is a tool for transmission of antibiotic resistant staphylococci, which can pass unobserved to man. A total of 981 raw milk samples were obtained from 250 cow’s quarters. The California Mastitis test (CMT) has been performed to diagnose the presence of subclinical mastitis. Milk samples were subjected to a bacteriological study and presumptive colonies were confirmed by biochemical characterization using the API-Staph-20 system. The sensitivity tests were performed by disc diffusion method on Muller-Hinton agar, for 13 antibiotics commonly used in veterinary medicine in Algeria, and the VITEK 2 system is used for the determination of the minimum inhibitory concentrations (MIC) for the strains confirmed as S. aureus. The biochemical identification showed that 73.75% of the isolates are CoNS, and that 26.25% are S.aureus. Resistance to penicillin G touches 61.02% of the strains of CoNS that with the tetracycline is of 74.58%. For S. aureus, we found a high resistance to penicillin G 80.95% and with the tetracycline 71.43%. According to our results, 02 (9.52%) isolate is S. aureus resistant to the methicillin , with modified penicillin-binding proteins , identified by the test of the disk of the oxacillin with a diameter of: R≤10 mm, and confirmed by one MIC ≥ 4 μg / l. The MIC of the vancomycin has proved that one strain is a VRSA with one MIC ≥ 32 μg / ml, and a second strain is a hetero-VISA with one MIC ˃ 1 μg / ml. We noted that for the 21 strains of S. aureus, 11 different phenotypes of resistances dominated by resistance to “penicillin G”. Our results indicated that there's a multi-resistant staphylococci passage in raw milk consumed in the western region of Algeria, harmful for the health and the security of the consumer, with a higher prevalence of coagulase negative staphylococci compared with S.aureus. Despite unknown pathogenicity of the species, organisms may be the tanks of the resistant to antibiotics; which requires periodic monitoring of antimicrobial resistance of staphylococci in order to control their spread.

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Cite this paper

@inproceedings{Belmamoun2016SubclinicalMO, title={Subclinical mastitis on the raw milk as a risk factor for the transmission of Staphylococcus.aureus and coagulase-negative staphylococci, multidrug resistance in Sidi Bel Abbes, Algeria}, author={Ahmed Reda Belmamoun and Karima Bereksi Reguig and Sofiane Bouazza and Mustapha Mahmoud Dif}, year={2016} }