Resistance to macrolides and tetracyclines is increasing among streptococci and co-occurs as their resistance determinants are carried on the same mobile element. We developed a multiplex PCR to facilitate simultaneous and specific detection of resistance determinants for both macrolides [erm(A), erm(B), and mef(A/E)] and tetracyclines [tet(M), tet(O), tet(K), and tet(L)] in streptococci.

The activity of tigecycline, 9-(t-butylglycylamido)-minocycline, against Escherichia coli KAM3 (acrB) strains harboring plasmids encoding various tetracycline-specific efflux transporter genes, tet(B), tet(C), and tet(K), and multidrug transporter genes, acrAB, acrEF, and bcr, was examined. Tigecycline showed potent activity against all three Tet-expressing, tetracycline-resistant strains, with...

BACKGROUND Campylobacter is one of the leading bacterial species causing foodborne illnesses in humans. Antimicrobial agents have been extensively used for treatment of Campylobacter infections; but in the recent years, both animal and human isolates of this bacterium have shown resistance to several antibiotics such as tetracycline. OBJECTIVES The aim of this study was to investigate the pre...

A Neisseria meningitidis strain, NIID129, with high-level resistance to tetracycline (Tet) was isolated from a Japanese woman’s nasopharynx; the MIC of tetracycline (Pfizer Pharmaceuticals Inc.) was 32 g/ml on Muller-Hinton agar (Difco) as determined by the microdilution method performed in accordance with NCCLS guidelines (6) and 24 g/ml when measured by the Etest (AB Biodisk). In order to det...

From 1996 to 2001 a total of 467 Staphylococcus hyicus isolates from exudative epidermitis (EE) in pigs in Denmark were examined for susceptibility to 13 different antimicrobial agents. The presence of selected genes encoding macrolide (erm(A), erm(B) and erm(C)), penicillin (blaZ), streptogramin (vat, vga, vga(B), vat(B), vat(D) and vat(E)), streptomycin (aadE) and tetracycline resistance (tet...

The presence of the tet(M) determinant and conjugative transposons related to Tn1545 in urogenital pathogens, Bacteroides ureolyticus (10 strains), Neisseria gonorrhoeae (37 strains) and Ureaplasma urealyticum (81 strains), was studied by PCR analysis and hybridization assay. All tetracycline-resistant strains that hybridized with a probe specific for tet(M) gave the expected fragment when thei...

Be it the B class, or another class of tetracycline (tet) repressor, the utility and specificity of transcriptional regulators based on this family of prokaryotic DNA binding proteins is unparalleled. A method for regulating gene expression at will in mammalian cells has long been the holy grail. Transfections of uncontrolled numbers of plasmids and unregulated gene expression were breakthrough...

Oxytetracycline-resistant bacteria were isolated from a mariculture farm in China, and accounted for 32.23% and 5.63% of the total culturable microbes of the sea cucumber and the sea urchin rearing waters respectively. Marine vibrios, especially strains related to Vibrio splendidus or V. tasmaniensis, were the most abundant resistant isolates. For oxytetracycline resistance, tet(A), tet(B) and ...

This study examined differences in antibiotic-resistant soil bacteria and the presence and quantity of resistance genes in soils with a range of management histories. We analyzed four soils from agricultural systems that were amended with manure from animals treated with erythromycin and exposed to streptomycin and/or oxytetracycline, as well as non-manure-amended compost and forest soil. Low c...

A randomized controlled field trial was conducted to evaluate the effects of two sets of treatment strategies on ceftiofur and tetracycline resistance in feedlot cattle. The strategies consisted of ceftiofur crystalline-free acid (CCFA) administered to either one or all of the steers within a pen, followed by feeding or not feeding a therapeutic dose of chlortetracycline (CTC). Eighty-eight ste...