a total of 711 beta-hemolytic streptococci were isolated from throat cultures of patients during 1970-73. these strains were grouped in parallel by the precipitin and bacitracin paper disk method. the former method was estab­lished as the standard by which the bacitracin technique was compared. the difference in results was about 5.67%. the greatest error (5.4%) was seen with non-group a strain...

in a clinical trial a new pyrrolidonyl-β-naphthylamide (pyr) hydrolysis test was compared with the bacitracin disk susceptibility test for accuracy in the presumptive identification of group a streptococci (gas). among 128 isolates of beta-hemolytic streptococci 93 group a isolates were found. the sensitivity of the pyr and bacitracin tests were similar (98.9%), but the bacitracin test had a lo...

Bacitracin susceptibility was evaluated as a laboratory method to differentiate staphylococci from micrococci. A total of 317 staphylococcal isolates and 108 micrococcal isolates were each tested for susceptibility to bacitracin by a disk-diffusion method using disks of three different potencies (0.04, 2.0, and 10.0 U) and a broth dilution method to obtain MICs. When a growth inhibition zone di...

In a clinical trial a new pyrrolidonyl-β-naphthylamide (PYR) hydrolysis test was compared with the bacitracin disk susceptibility test for accuracy in the presumptive identification of group A streptococci (GAS). Among 128 isolates of beta-hemolytic streptococci 93 group A isolates were found. The sensitivity of the PYR and bacitracin tests were similar (98.9%), but the bacitracin test had ...

In the first study, selective sulfamethoxazole-trimethoprim blood agar (SXT-BA) and conventional blood agar (BA) plates incubated under CO2 and anaerobically were compared for their ability to recover group A streptococci from throat cultures. Recovery rates were: SXT-BA (anaerobic), 100%; SXT-BA (CO2), 98%; BA (anaerobic), 89.2%; and BA (CO2), 76.5%. Primary plate bacitracin test results could...

In a clinical trial, Strep-A-Chek (a 10-min chromogenic test) was compared with the bacitracin disk susceptibility test for accuracy and turnaround time in the presumptive identification of Streptococcus pyogenes. Among 461 isolates of beta-hemolytic streptococci (344 throat isolates and 117 isolates from other sites), 303 group A S. pyogenes isolates were found. The sensitivities of the Strep-...

The aim of the study was to establish the in vitro sensitivity of S. agalactiae (126 strains), S. dysgalactiae (82 strains), S. uberis (419 strains), and Enterococcus sp. (136 strains) isolated from mastitis in cows to 13 antibiotics. Bacteriological examinations of quarter milk samples were conducted with the recommendations of the IDF. Sensitivity to antibiotics was tested by disk diffusion m...

The purpose of the study was determining the in vitro sensitivity of Streptococcus agalactiae, other Streptococcus sp., Staphylococcus aureus, coagulase-negative staphylococci, Escherichia coli, and Arcanobacterium pyogenes strains to antibiotics commonly used in veterinary praxis. These pathogens were isolated from cows with clinical or subclinical mastitis in 2006–2007. The activity of 10–14 ...