Abstract

OCCURRENCE OF STAPHYLOCOCCUS SPP. AND STREPTOCOCCUS SPP. IN RAW MILK AND THEIR RESISTANCE TO ANTIBIOTICS

Zigo F.*, Veszelits Lakticová K. and Vargová M.

ABSTRACT

The aim of this study was to evaluate the prevalence and effectiveness of different antibiotics against mastitis causing microorganisms at the two herds of dairy cows and sheep. The diagnosis of mastitis was performed on the basis of clinical examination of the udder, macroscopic evaluation of milk and bacteriological examination of raw milk samples. All isolated pathogens were tested by in vitro test on Mueller-Hinton agar by disc methods on resistance to 12 types of antibiotics. From total 1120 quarter cow’s milk samples were 22.3% positive to California mastitis test (CMT) and from 15.2% samples were isolated pathogens microorganisms caused intramammary infection (IMI) of which accounted for most subclinical mastitis forms 11.3% mainly caused of coagulase-negative staphylococci (CNS), Str. uberis and coliform bacteria. From total 820 half sheep’s milk samples were 11.5% positive to pathogens microorganisms caused IMI mainly of Stap. aureus, Str. agalactiae and CNS. From all tested bacteria which cause mastitis in cows and sheep were observed higher sensitivity against tetradelta (100% of Strep. agalactiae and Strep. uberis, CNS), (94.4% of Stap. aureus) with highest number of bacterial isolates, followed by cefalexin + kanamycin amoxicillin plus clavulanat acid and ceftiotur (100% of Strep. agalactiae and Strep. uberis). Resistance was observed against penicillin (22.2% of Stap. aureus) amoxicillin (22.2% of Stap. aureus and 10.5% of Strep. uberis) and streptomycin (22.2% of Stap. aureus and 52.7% of Strep. uberis). The use of antibiotics in treatment of mastitis and other diseases in dairy ruminants can have a negative impact on public health through the increase in resistant bacteria or bacteria producing resistant genes that pass into the organism of people directly or indirectly.

Keywords: Cows, sheep, mastitis, resistance, coagulase-negative staphylococci.