Heterogeneity of methicillin-sensitive Staphylococcus pseudintermedius strains isolated from diseased dogs.

Thirty nine canine S. pseudintermedius strains were examined for antibiotic susceptibility and genetic polymorphisms. All strains were methicillin-sensitive S. pseudintermedius (MSSP). Resistance to penicillin was most prevalent (66.6%), followed by resistance to neomycin (56.4%), erythromycin (53.8%), clindamycin (48.7%), chloramphenicol (48.7%), and tetracycline (46.2%). Pulsed-field electrophoresis (PFGE) showed a high genetic polymorphism in the investigated strains.

Screening of Staphylococcus aureus nasal strains isolated from medical students for toxin genes.

Three hundred twenty-one students (156 students with no clinical exposure and 165 students with clinical exposure) were screened for nasal colonization by Staphylococcus aureus; 20.9% of students were S. aureus nasal carriers, and 40.3% of S. aureus isolates harbored toxin genes. The most prevalent genes were tst (15.0 %) and sec (13.4 %). Isolates with multiple genes were only found among clinical students (p = 0.045). Six of 11 PFGE clones were positive for toxin genes. Methicillin-resistant (MRSA) isolates were only detected in the clinical students (4.5 %). The exposure of students to the hospital environment neither radically increased S. aureus nasal carriage, nor the frequency of clinically important toxin gene presence, but it could have influenced the positive selection of toxigenic MRSA strains.

[Drug resistance of group B streptococci]. / Lekoopornosc paciorkowców grupy B.

The group B streptococci (GBS) are one of the main infections' factors in neonates. The source of the infection is mother and the infection follows during childbirth. In many countries various methods of prophylaxis in reference to mother and neonate are introduced. Thus far the widest application have found a method of giving to pregnant women penicillins or cephalosporins. The purpose of the present work was to study how the drug-resistant of the GBS forms in our country and if using antibiotics in prophylactic purposes without doing any antibiograms is burdened with risk, resulted from the possibility of meeting resistant strains. 365 strains of the GBS, derived from colonised neonates, pregnant women and clinical materials were put to the scientific research. 120 animal strains isolated from events of mastitis in cows, represented the second group. The GBS, derived from pregnant women were sensitive to every examined antibiotics except lincomycin (5.9%). Amid the streptococcus isolated from neonates there were some strains resistant to every examined antibiotic (1.9-4.4%). More often resistant strains were isolated from clinical materials (3.9-9.0%). The highest percentage of the resistant strains was identified in animals (7.5-20.0%). The GBS as a rule were insensitive to cotrimoxasolum. As follows from our scientific researches, the GBS derived from people as a rule are sensitive to used antibiotics. But there were some strains resistant even to several antibiotics. Possibility of meeting these strains should be taken into consideration as in prophylaxis as in treatment of the infections. Amid the animal strains of the GBS the phenomenon of the resistance to antibiotics is more often met than in human ones.

[Biochemical typing as a method of differentiating group B streptococcus]. / Typowanie biochemiczne jako metoda róznicowania paciorkowców grupy B.

In epidemiological studies on the group B streptococcus the serological typing is used. The paper present the results of a study on usefulness of biochemical typing for differentiation of the group B streptococcus. For that purpose, 210 strains descended from colonized infants and pregnant women were put to typing with both of mentioned methods. We showed that each of the method distinguishes similar number of biotypes and serotypes. However, ought to be marked that significant number of strains (93.8%) belonged to the three out of eight biochemical types. Similar results were achieved in serological typing, three of the most numerous serotypes contained 81.4% strains. Analysis of the relationship between serological and biochemical types did not reveal statistical association because the strains belonged to various serotypes. Obtained results show that both methods of typing--biochemical and serological, have similar value in differentiation of the strains. The method of biochemical typing is quite simple and can be used in laboratory conditions.