The ribosome and protein synthesis are major targets within the cell for inhibition by antibiotics, such as the tetracyclines. The tetracycline family of antibiotics represent a large and diverse group of compounds, ranging from the naturally produced chlortetracycline, introduced into medical usage in the 1940s, to second and third generation semi-synthetic derivatives of tetracycline, such as...

Of 15 Peptostreptococcus sp. strains isolated between 1975 and 1984, 13 hybridized with the Tet K, Tet M, or Tet O determinant. A donor Peptostreptococcus anaerobius strain carrying the three determinants could transfer Tet M to P. anaerobius and Fusobacterium nucleatum recipients but not to an Enterococcus faecalis recipient, while neither Tet K nor Tet O was transferred.

PenB is the third resistance determinant in the stepwise acquisition of multiple resistance genes in chromosomally mediated resistant Neisseria gonorrhoeae (CMRNG). Alterations in por(IB), one of two alleles at the por locus that encodes the outer membrane protein porin IB (PIB), were recently reported to be responsible for the increased resistance to penicillin and tetracycline conferred by pe...

We have characterized a transferable tetracycline resistance (Tcr) element from a Streptococcus intermedius isolate. The gene responsible for this resistance was identified by PCR and Southern hybridization as tet(S). Furthermore, the genetic support for this determinant was shown to be a conjugative transposon closely related to Tn916. This element has been designated Tn916S.

First reported in 2003, mosaic tetracycline resistance genes are a subgroup of the genes encoding ribosomal protection proteins (RPPs). They are formed when two or more RPP-encoding genes recombine resulting in a functional chimera. To date, the majority of mosaic genes are derived from sections of three RPP genes, tet(O), tet(W) and tet(32), with others comprising tet(M) and tet(S). In this fi...

There are no examples of stable tetracycline resistance in clinical strains of Chlamydia trachomatis. However, the swine pathogen Chlamydia suis is commonly tetracycline resistant, both in America and in Europe. In tested U.S. strains, this resistance is mediated by a genomic island carrying a tet(C) allele. In the present study, the ability of C. suis to mobilize tet(C) into other chlamydial s...

We conducted a retrospective study of Escherichia coli isolates recovered from human and food animal samples during 1950-2002 to assess historical changes in antimicrobial drug resistance. A total of 1,729 E. coli isolates (983 from humans, 323 from cattle, 138 from chickens, and 285 from pigs) were tested for susceptibility to 15 antimicrobial drugs. A significant upward trend in resistance wa...

Using a rapid screening method, we investigated the prevalence of fecal carriage of antimicrobial drug-resistant Escherichia coli in 3,174 healthy children from 4 urban settings in Peru and Bolivia. High resistance rates were observed for ampicillin (95%), trimethoprim-sulfamethoxazole (94%), tetracycline (93%), streptomycin (82%), and chloramphenicol (70%). Lower resistance rates were observed...

A study was conducted to understand the descriptive and molecular epidemiology of antimicrobial-resistant gram-negative enteric bacteria in the feces of healthy lactating dairy cattle. Gram-negative enteric bacteria resistant to ampicillin, florfenicol, spectinomycin, and tetracycline were isolated from the feces of 35, 8, 5, and 42% of 213 lactating cattle on 74, 39, 9, 26, and 82% of 23 farms...