Principal Germs Causing Clinical Mastitis in Dairy Cattle Farms in Governorate of Blida (Algeria)

This study focused on characterizing the germs causing the intra-mammary infections in the dairy farms of governorate of Blida (Algeria), by making use of the Speed Mam Test as screening method and conventional bacteriological methods. Out of 78 milk samples originating from quarters with clinical mastitis, we obtained 06 negative cultures (7.69%) and 72 positive cultures distributed in pure cultures (64 or 82.05%) and mixed cultures (08 or 10.25%, of which 7 described 2 germs and 1 was considered contaminated as it described 3 germs). The characterization of the 81 isolated strains revealed the prevalence of the Enterobacteria (25.93%) with high proportion of Escherichia coli (12.34%), followed by Coagulase-Negative Staphylococci (CNS; 20.99%) and Coagulase Positive Staphylococci (CPS; 19.75%), in this case occurring a reversal of the staphylococci prevalence trend (CNS vs CPS) in intra-mammary infections. Streptococci are present at a rate of 9.88% and are being represented by Str. uberis and Str. dysgalactiae. There have also been isolated Enterococcus faecium and Pseudomonas sp. Of all isolated strains, 12 (14.81%) have not been identified, as they did not belong to the researched families and genders. The interpretation of the results as per reservoir type show that the percentage of germs located in the environmental reservoir (Escherichia coli, Klebsiella ornithinolytica; odorifera Serratia, Proteus and Aeromonas hydrophila, Str. Uberis and Enterococcus faecium; 39.49%) is twice as big as opposed to those germs located in the mammary gland reservoir (S. aureus and Str. dysgalactiae; 20.98%). The health condition of the udder at the level of the explored dairy farms point out the prevalence of the clinical mastitis caused by environmental factors over the mammary reservoir (particularly, S. aureus).