WYSTĘPOWANIE I ZRÓŻNICOWANIE GENÓW ODPOWIEDZIALNYCH ZA OPORNOŚĆ NA TETRACYKLINĘ SZCZEPÓW ENTEROCOCCUS FAECALIS IZOLOWANYCH W REGIONIE GDAŃSKIM
[THE PREVALANCE OF TETRACYCLINE RESISTANCE GENES IN CLINICAL AND COMMENSAL STRAINS OF ENTEROCOCCUS FAECALIS ISOLATED IN GDAŃSK]

Streszczenie.

Porównano częstość występowania u E. faecalis genów tet(M) i tet(S) oraz transpozonów Tn916 i Tn5397, na których najczęściej zlokalizowane są powyższe geny. Stwierdzono istotne różnice w częstości występowania transpozonów i genu tet(S) w izolatach klinicznych oraz komensalnych. Filogenetyczna analiza genu tet(M), wykazała podobieństwa genetyczne niezależne od pochodzenia szczepu, co może wskazywać na swobodne rozprzestrzenianie się genu tet(M) pomiędzy szczepami.

Abstract.

The common use of antibiotics is responsible for selecting of drug resistance not only in pathogenic, clinical bacteria but also in commensal, not pathogenic strains which could cause the rapid dissemination of the resistance to these antibacterial agents. However, information regarding the antibiotic resistance of commensal bacteria is very scarce, and the data is based mostly on phenotypical
research. Therefore the use of genotyping methods for detection of tetracycline resistance genes, in
commensal and medical isolates of bacteria, is essential, for understnding the spread of antibiotic resistance.
In this study 24 commensal and 27 clinical isolates of Enterococcus faecalis has been screened by
PCR methods for tet(M), tet(S) genes and Tn916 and Tn5397 transpozons. Subsequently, the tet(M)
gene amplicones were sequenced and phylogenetic analysis was performed. We have found that the
prevalence of tet(S) gene varied significantly between commensal and clinical strains. Moreover, the frequency of transpozons in clinical isolates was much higher comparing to strains isolated from healthy individuals. The phylogenetic analysis did not show significant differences between clinical and commensal strains but it could suggest that the genetic similarity between these two groups could be favourable factor for broad range spread of tet(M) gene.