BACKGROUND Antimicrobial usage is considered the most important factor promoting the emergence, selection and dissemination of antimicrobial-resistant microorganisms in both veterinary and human medicine. The aim of this study was to investigate the prevalence and genetic basis of tetracycline resistance in faecal Escherichia coli isolates from healthy broiler chickens and compare these data wi...

The Pseudomonas R factor RP1 determines an inducible tetracycline resistance similar to that described for Escherichia coli R factors. The level of RP1-determined resistance measured by minimal inhibitory concentration testing is dependent on the host bacteria and corresponds to the magnitude of decrease in tetracycline accumulation by RPl-containing organisms. The tetracycline resistance mecha...

One of the two major mechanisms of tetracycline resistance is ribosomal protection. Of this resistance type, tet(M) is the best characterized. Although the mechanism of tet(M) resistance has not yet been fully elucidated, it has been demonstrated that ribosomes isolated from a tet(M) strain are resistant to inhibition of protein synthesis by tetracycline. A new generation of tetracycline compou...

The present study was done to evaluate the presence of antibiotic resistance genes in Lactococcus garvieae isolated from cultured rainbow trout, West Iran.The isolates were examined for antimicrobial resistance using disc diffusion method. Of the 24 strains tested, 21 were resistant to ampicillin (87.5%), 9 to erythromycin (37.5%) and 19 to tetracycline (79.1%). Fourteen strains were resistant ...

Most Helicobacter pylori strains are susceptible to tetracycline, an antibiotic commonly used for the eradication of H. pylori. However, an increase in incidence of tetracycline resistance in H. pylori has recently been reported. Here the mechanism of tetracycline resistance of the first Dutch tetracycline-resistant (Tet(r)) H. pylori isolate (strain 181) is investigated. Twelve genes were sele...

We found that naturally occurring tetracycline resistance in streptococci is encoded by more than one genetic determinant. Two of these distinct determinants were cloned, and the regions that are necessary and sufficient for expression of tetracycline resistance were defined by deletion analysis. These cloned determinants were further characterized by DNA-DNA hybridization experiments which als...

The Pseudomonas R factor RP1 determines an inducible tetracycline resistance similar to that described for Escherichia coli R factors. The level of RP1-determined resistance measured by minimal inhibitory concentration testing is dependent on the host bacteria and corresponds to the magnitude of decrease in tetracycline accumulation by RP1-containing organisms. The tetracycline resistance mecha...

Like animals and people, insects can serve as both collectors and disseminators of antibiotic resistance genes, as exquisitely demonstrated by a recent study (B. Tian, N. H. Fadhil, J. E. Powell, W. K. Kwong, and N. A. Moran, mBio 3[6]:e00377-12, doi:10.1128/mBio.00377-12, 2012). Notably, the relatively confined ecosystem of the honeybee gut demonstrates a large propensity for harboring a diver...