All strains of Bifidobacterium animalis subsp. lactis described to date show medium level resistance to tetracycline. Screening of 26 strains from a variety of sources revealed the presence of tet(W) in all isolates. A transposase gene upstream of tet(W) was found in all strains, and both genes were cotranscribed in strain IPLAIC4. Mutants with increased tetracycline resistance as well as tetra...

A new Tn10-based transposon has been constructed and used to isolate insertion mutations with tetracycline-conditional phenotypes. Classes of mutants include conditional lethal mutations, conditional auxotrophs, and conditional mutants of the eut (ethanolamine utilization) operon. The described mutations were made with a new derivative of Tn10dTet that we have called Tn10d(T-POP). Others have n...

The triple-base-pair 16S rDNA mutation AGA(926-928)-->TTC mediates high-level tetracycline resistance in Helicobacter pylori. In contrast, single- and double-base-pair mutations mediated only low-level tetracycline resistance and decreased growth rates in the presence of tetracycline, explaining the preference for the TTC mutation in tetracycline-resistant H. pylori isolates.

Sensitivity testing on Vibrio cholerae isolates during an epidemic in 1998 in Kelantan identified strains resistant to tetracycline. This prompted a change in the usual management of cholera in Kelantan. The antibiotic of choice was changed from tetracycline to erythromycin.

Subgingival plaque samples and root canal samples were collected from 2,839 marginal periodontitis (MP) patients and 21 apical periodontitis (AP) patients. Enterococcus species were identified by a series of phenotypic and genotypic tests. Antimicrobial susceptibility assays were performed by an agar disk diffusion test. Multilocus sequence typing (MLST), eBURST, and minimum spanning tree were ...

Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation. Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher th...

objective(s):to date, the most important genes responsible for tetracycline resistance among acinetobacter baumannii isolates have been identified as tet a and tet b. this study was carried out to determine the rate of resistance to tetracycline and related antibiotics, and mechanisms of resistance.  materials and methods: during the years 2010 and 2011, a total of 100 a. baumannii isolates wer...

Mechanisms for tetracycline and macrolide resistance in 54 isolates of erythromycin-resistant Streptococcus agalactiae were analyzed by PCR. The erm(B), erm(A), and mef(A) genes, either alone or in combination, were detected in all the erythromycin-resistant isolates. The tet(M) and tet(O) genes were responsible for tetracycline resistance. Random amplification of polymorphic DNA indicated diff...