Tetracycline Resistance Genes of Ureaplasmas

There is limited information in the medical setting on antimicrobial susceptibilities and resistance development in ureaplasmas. The study investigated tetracycline and doxycycline resistance in clinical isolates of Ureaplasma parvum and Ureaplasma urealyticum. Culture with species PCR confirmatory techniques were applied to 191 endocervical specimens collected during the period January-March 2006. MIC determinations were performed by microbroth dilution with tetM resistance and int-Tn genes characterised employing PCR and sequencing. Sixty-six Ureaplasma cultures (35 U. parvum; 9 U. urealyticum; 22 U. parvum + U. urealyticum) were obtained. On screening the Ureaplasma cultures; tetM gene regions were demonstrated from both tetracycline-susceptible and -resistant ureaplasmas. Seven isolates [U. parvum (6); U. urealyticum (1)] were resistant to tetracycline with dual doxycycline resistance observed in three strains. Int-Tn gene characterisation of the seven tetracycline-resistant strains revealed three types were present indicating transposons from different origins had integrated into Ureaplasma genomes. TetM sequences of five tetracycline-resistant strains were seen to be highly mosaic in structure. The finding of transposon and/or tetM regions in all Ureaplasma cultures investigated with or without full expression of tetracycline resistance; in conjunction with tetM and int-Tn gene mosaic/diversity; verifies that ureaplasmas undergo extensive genetic exchange of transposon/resistance genes with concomitant genomic remodelling

Fourteen days oral administration of therapeutic dosage of some antibiotics reduced serum testosterone in male rats

Fourteen days oral administration of therapeutic dose of Ampicillin (4mg/100g/day); Cloxacillin (6mg/100g/day) and Tetracycline (12mg/100g/day) separately to healthy adult male albino rats significantly reduced their serum testosterone level as assessed by enzyme immunoassay. The control group received equal volume of the vehicle (Normal saline) throughout the period of the treatment. A significant reduction (P0 .05) in testicular and epididymal weight was also produced by Cloxacillin; Cloxacillin and Tetracycline respectively. Ampicillin administration on the other hand significantly reduced (P0 .05) prostrate gland weight. After subjecting the treated animals to a recovery period ranging from 1-2 weeks; during which the drug administration was discontinued; all the animals recovered fully from the antifertility effect of these antibiotics on the serum testosterone level by the end of the second week. A significant recovery in the epididymal; testicular and prostrate gland weight was also recorded in the Cloxacillin and Tetracycline; Cloxacillin; and Ampicillin treated animals respectively. The result suggests that the reversible antifertility effects of these antibiotics were produced via the disruption of testosterone hormone production process. This was also accompanied by reduction in the weight of some of the male reproductive organs

Fourteen Days Oral Administration of Therapeutic Dosage of some Antibiotics Reduced Serum Testosterone in Male Rats

Fourteen days oral administration of therapeutic dose of Ampicillin (4mg/100g/day); Cloxacillin (6mg/100g/day) and Tetracycline (12mg/100g/day) separately to healthy adult male albino rats significantly reduced their serum testosterone level as assessed by enzyme immunoassay. The control group received equal volume of the vehicle (Normal saline) throughout the period of the treatment. A significant reduction (P0 .05) in testicular and epididymal weight was also produced by Cloxacillin; Cloxacillin and Tetracycline respectively. Ampicillin administration on the other hand significantly reduced (P0 .05) prostrate gland weight. After subjecting the treated animals to a recovery period ranging from 1-2 weeks; during which the drug administration was discontinued; all the animals recovered fully from the antifertility effect of these antibiotics on the serum testosterone level by the end of the second week. A significant recovery in the epididymal; testicular and prostrate gland weight was also recorded in the Cloxacillin and Tetracycline; Cloxacillin; and Ampicillin treated animals respectively. The result suggests that the reversible antifertility effects of these antibiotics were produced via the disruption of testosterone hormone production process. This was also accompanied by reduction in the weight of some of the male reproductive organs

Tetracycline resistance genes in salmonella tyhimurium in a hospital in Kenya

Tetracyclines have been among the most widely used antibiotics worldwide. Plasmid-mediated tetracycline resistance among hospital strains of bacteria has increased through the many years of usage. The major concern has been the transfer of resistance to pathogenic organisms. Bacteraemia due to S. typhimurium has been a major cause of morbidity at Kenyatta National Hospital (KNH); hence the need to study drug resistance patten of this organism and to characterize the tetracycline resistance genes using oligonucleotide probes. 97 S. typhimurium strains isolated from patients at KNH were used. Agar dilution method was used todetermine minimum inhibitory concentration (MIC). Plasmids were isolated from each strain and the different plasmid profiles were grouped by their molecular weights into 6 plasmid profile groups. Tetracycline resistance genes were characterized using oligonucleotide probes. 87 out of 97 (88) strains were resistant. MIC ranged from 1 ug/ml to 128 ug/ml. Genes encoding for tetracycline resistance were located on plasmids of molecular weights 65 MDa; 5.2 or both. Salmonellosis is a public health problem in Kenya especially bacteraemia due to S. typhimurium. Plasmid-encoded natimicrobial resistance is likely to spread to other pathogenic organisms; reduce our ability to treat the infection and increase cost and duration of treatment

Integrons in enteric bacteria isolated in Senegal

In this lecture the molecular mechanisms of antibiotics resistance and the molecular mechanisms of transmission of resistance genes are described in enteric bacteria isolated in Senegal