Characterization of Staphylococci Isolated from Raw Milk

Abstract

Characterization of staphylococci isolated from raw milk. Appl. Microbiol. 13:167-170. 1965.-To evaluate the pathogenicity of staphylococci from bovine raw milk, the general characteristics of 775 strains isolated from 798 samples of milk were studied. The coagulase test was performed by use of rabbit plasma. Chromogenesis, mannitol fermentation, and gelatin liquefaction were investigated on Chapman's Medium 110, after 48 hr of incubation. Production of ,-hemolysin, which has been considered indicative of pathogenic staphylococci of animal origin, was determined by streaking different strains on sheep blood-agar plates in the presence of a strain of Lancefield group B streptococci. Plates were incubated at 37 C for 24 hr, and strong hemolysis was produced in the zone of interaction of j3-hemolysin and some substance liberated by streptococcus (CAMP test). Of 404 strains found to be coagulase-positive, 95.8% exhibited a deep-orange pigment, 76.5% produced ,-hemolysin, 91.8% fermented mannitol, and

Safety Evaluation of Oral Care Probiotics Weissella cibaria CMU and CMS1 by Phenotypic and Genotypic Analysis

“…Bacterial pathogenicity is often dependent on cell penetration ability, and cell invasion requires protein degradation ability [40]. In this study, we investigated the degradability of proteins by determining whether a gelatin liquefaction phenomenon existed.…”

“…The activity of β-glucuronidase was detected by measuring the changed color using a 0.1 M p -nitrophenyl-β- d -glucuronide as a substrate [40]. The bacterial culture was concentrated and washed with sodium phosphate buffer (pH 7.0) until OD 600 = 4.…”

“…Bacteria were inoculated in the tubes and incubated at 37 °C for 24 h. P. aeruginosa was used as a positive control. When a liquefaction reaction occurred at 4 °C, it was regarded as a positive reaction [40].…”