SLIME PRODUCTION AND DNase ACTIVITY OF STAPHYLOCOCCI ISOLATED FROM RAW MILK

In this study, 851 Staphylococci isolates isolated from 38 raw milk samples were investigated for DNase activity and slime production. The 851 Staphylococci isolates were identified as 704 Staphylococcus aureus and 147 coagulase-negative staphylococci. Coagulase – negative staphylococci isolates were classified as 32.7% S. cohnii, 19.7% S. hominis, 19.1% S. xylosus, 12.9% S. epidermidis, 8.2% S. capitis, 4.8% S. haemolyticus, 1.4% S. simulans and 1.4% S. saprophyticus by using Dichotomous scheme. DNase agar was used to investigate for DNase activity. DNase activity was found in 93.6% of 704 S. aureus and 10.2% of 147 coagulase – negative staphylococci. DNase activity was positive in 42.9% of S. haemolyticus, 20.7% of S. hominis, 17.9% of S. xylosus and 2.1% of S. cohnii isolates. No DNase activity was found in S. epidermidis, S. capitis, S. simulans and S. saprophyticus isolates. Slime production of S. aureus and coagulase – negative staphylococci from raw milk samples was investigated by using Congo Red Agar method. Slime production was positive in 5.1% of S. aureus and 42.2% of 147 coagulase – negative staphylococci. Slime production was positive in 100% of S. simulans, 68.4% of S. epidermidis, 50% of S. cohnii, 50% of S. saprophyticus, 37.9% of S. hominis, 32.1% of S. xylosus and 16.7% of S. capitis isolates. None of the 7 S. haemolyticus isolates had slime production. In conclusion, slime production and DNase activity are important virulence factors to identify pathogenic staphylococci.     

THE OCCURRENCE, HEMOLYTIC ACTIVITY AND ANTIBIOTIC SUSCEPTIBILITY OF MOTILE AEROMONAS SPP. ISOLATED FROM MEAT AND MILK SAMPLES IN TURKEY

Research was carried out to detect the incidence of motile Aeromonas species (A. hydrophila, A. caviae, A. sobria) in a variety of raw meat products (minced meat and chicken) and milk samples (raw and pasteurized) commonly consumed in Ankara. Motile Aeromonas species were isolated from 51.8% of samples detected; these were 40 (67.7%) of the 59 samples of minced meat, 20 (86.9%) of the 23 samples of chicken, 75 (47.7%) of the 157 samples of raw milk and 5 (16.0%) of the 31 samples of pasteurized milk. The dominant species were A.hydrophila and A.sobria in the meat samples, while A. hydrophila was the only isolated species in the milk samples. The strains identified as A. sobria or A. hydrophila were the stronger producers of hemolysin, whereas the A. caviae strains were nonhemolytic. The resistance of isolates to eight antibiotics was determined using the Kirby Bauer disc diffusion assay (Ciprofloxacin, Ceftazidime, Ampicillin, Cefixime, Cefoperazone, Erythromycin, Trimethoprim/sulfamethoxazole, Ceftriaxone). All aeromonads isolates (100%) were susceptible to ciprofloxacin but resistant to (100%) ampicillin and erythromycin. We found out that motile Aeromonas species are commonly present in milk and meat samples investigated in Turkey, which may pose a health problem to consumer. In addition, ciprofloxacin, cefoperozone, and ceftriaxone are suitable drugs that can be used in the treatment of Aeromonas-associated infections, particularly in the immunocompromised, elderly people and young children.