Evidence for tetracycline resistance determinant tet(M) allele replacement in a Streptococcus pneumoniae population of limited geographical origin.
A collection of 185 Streptococcus pneumoniae isolates was tested for their susceptibility to antipneumococcal drugs, with a focus on the distribution of tetracycline resistance determinants tet(M) and tet(O). Resistance patterns were compared with established correlates of multidrug resistance, and tetracycline-resistant isolates were tested for clonality and allelic variation within tet(M). Resistance to tetracyclines, penicillins and macrolides were all strongly related to multidrug resistance. Over one-quarter of the strains were tetracycline resistant, all via the tet(M)-mediated mechanism. Restriction fragment length polymorphism analysis revealed a high degree of allelic variation within tet(M) and gave evidence of a clonal and horizontal spread of selected alleles. A tet(M) variant that emerged with the onset of epidemic multidrug-resistant strains was replacing old alleles in the population.
Dzierzanowska-Fangrat
Katarzyna
K
Department of Clinical Microbiology and Immunology, Children's Memorial Health Institute, Aleja Dzieci Polskich 20, 04-736 Warszawa, Poland.
Semczuk
Katarzyna
K
Górska
Paulina
P
Giedrys-Kalemba
Stefania
S
Kochman
Maria
M
Samet
Alfred
A
Tyski
Stefan
S
Dzierzanowska
Danuta
D
Trzciński
Krzysztof
K
D000483:Alleles; D005798:Genes, Bacterial; D006801:Humans; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000382:microbiology; D011044:Poland; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D013753:Tetracycline Resistance / Q000235:genetics*