Factors responsible for subclinical mastitis in cows caused by Staphylococcus chromogenes and its susceptibility to antibiotics based on bap, fnbA, eno, mecA, tetK, and ermA genes.

The aim of this study was to recognize selected factors of virulence determining the adhesion of Staphylococcus chromogenes to cows' udder tissues in subclinical mastitis and to evaluate the susceptibility of this pathogen to antibiotics. The subjects of the study were 38 isolates of Staph. chromogenes from 335 samples of milk from cows with subclinical coagulase-negative staphylococci mastitis. Somatic cell count ranged between 216,000 and 568,000/mL of milk (average 356,000/mL of milk). We confirmed the ability to produce slime in 24 isolates (63.2%), and the ability to produce protease in 29 isolates (76.3%). In each slime-producing isolate, the bap gene was not found, and the fnbA and eno genes were not detected. In vitro tests showed that ceftiofur had the highest effectiveness against Staph. chromogenes (89.5% of susceptible isolates). Minimum inhibitory concentrations ranged from 0.06 to 2µg/mL for susceptible isolates. The minimum concentrations required to inhibit growth of 90 and 50% of the isolates for ceftiofur were at or below the cutoffs recommended by the Clinical and Laboratory Standards Institute (2 and 0.06µg/mL, respectively). A significant percentage of the isolates were susceptible to other ß-lactam antibiotics: amoxicillin with clavulanic acid (84.2%) and ampicillin (81.6%). The lowest effectiveness among ß-lactams was for penicillin (73.7% of susceptible isolates), and the minimum inhibitory concentration for penicillin ranged from <0.06 to 8µg/mL. None of the examined isolates had the mecA gene, but ß-lactamase was detected in 4 isolates (10.5%). Erythromycin and oxytetracycline exhibited the lowest activity against Staph. chromogenes (71.1 and 63.2% of susceptible isolates, respectively). The genes tetK (6 isolates) and ermA (1 isolate) were also detected.

Diagnosis of the Encephalitozoon cuniculi infections in pet rabbits with neurological symptoms.

The purpose of the study was the in vivo diagnosing of E. cuniculi invasions in pet rabbits with neurological symptoms using the Real-Time PCR, and determination of the rate of invasion, in this group of animals. The study involved 103 pet rabbits with neurological symptoms. Parasitic invasions were diagnosed using Real-Time PCR. The DNA of the parasites for molecular tests was isolated from the urine of the diseased animals. Out of the 103 tested DNA samples, the presence of the E. cuniculi genetic material was detected in 27 samples (26.21%). The melting temperature (Tm) of all products was 77.5 degrees C. The presence of parasitic DNA in the urine of 26.21% of examined animals indicates that E. cuniculi infections occur widely in pet rabbits in Poland and are a significant cause of neurological disorders in those animals.

Detection of Borrelia burgdorferi sensu lato DNA in the blood of wild bison from Bialowieza primeval forest in eastern Poland.

The aim of the present study was to investigate the occurrence of Borrelia burgdorferi sensu lato DNA in a group of 120 wild bison (Bison bonasus) from the Bialowieza Primeval Forest in eastern Poland. The PCR technique revealed the presence of 16S RNA of Borrelia burgdorferi sensu lato in the blood of 16 out of 120 examined animals. DNA amplification by means of primers SC1 and SC2 gave a product with a size of 300-bp. The sequences of the PCR products obtained showed 100% homology with each other and 100% homology with B. burgdorferi s.1. 16S RNA gene DQ111061. Results of this study suggest that wild bison are important in maintaining agents of Lyme borreliosis, and that studies of reservoir competence of this species are indicated.