Distribution of classical enterotoxin genes in staphylococci from milk of cows with- and without mastitis and the cowshed environment.

The aim of this study was to analyze by PCR 185 isolates of Staphylococcus from milk of cows with- and without mastitis and from the cowsheds environment for their potential ability to produce five classical staphylococcal enterotoxins. Among S. aureus isolates 8 (32%) carried enterotoxin genes and only 2 of them had more than one gene. The enterotoxin genes were detected in 22 (13.7%) coagulase-negative staphylococci (CNS) isolates, among them in 9 (11.4%) isolates of S. xylosus, 5 (16.7%) S. sciuri, 3 (10.3%) S. epidermidis and in 5 (22.7%) Staphylococcus spp. In some CNS 2 or 3 genes were detected simultaneously. Among the investigated enterotoxin genes, sec was the most prevalent (70%). The genes encoding enterotoxin B and D were detected in 5 (16.7%) and 6 (20%) isolates, respectively. The lowest number of isolates had sea and see genes. The genes encoding enterotoxins were often identified in staphylococci from milk of cows with mastitis (73.4% of detected genes), while only 6 (20%) isolates from milk of cows without mastitis and 2 (6.6%) isolates from cowshed environment were positive for enterotoxin genes. The results showed that CNS from bovine milk, like S. aureus, carried enterotoxin genes and may pose a risk for public health.

[Occurrence of beta-lactamase type ESBL and IBL in Pseudomonas aeruginosa rods]. / Wystepowanie beta-laktamaz typu esbl i ibl u paleczek Pseudomonas aeruginosa.

The aim of the study was to determine extended spectrum beta-lactamases (ESBL) and inducible beta-lactamases (IBL) among Pseudomonas aeruginosa strains. A total of 43 strains isolated from humans (6), hospital sink (1), fish (15), cattle (5), swine (5), dog (1), redder (1) fur animals (9) were studied. ESBL-producing strains were detected with double disc diffusion test according to Jarlier et al. (8). Clavulonate and tazobactam were used as the inhibitors of ESBL. Inducible beta-lactamases were determined using double disc method according to Sanders (15). Cefoxitin was the inductor of these beta-lactamases. The susceptibility study was carried out using the disc diffusion method according to NCCLS standards. A total of 8 ESBL (18.6% of all strains) and 31 (72%) IBL producing strains were detected. The obtained results indicate the necessity of monitoring of ESBL- and IBL-producing strains of Pseudomonas aeruginosa.