The mechanisms by which viruses modulate the immune system include changes in host genomic methylation. 5-hydroxymethylcytosine (5hmC) is the catalytic product of the Tet (Ten-11 translocation) family of enzymes and may serve as an intermediate of DNA demethylation. Recent reports suggest that 5hmC may confer consequences on cellular events including the pathogenesis of disease; in order to exp...

Avian pathogenic Escherichia coli (APEC) causes extensive mortality in poultry flocks, leading to extensive economic losses. To date, little information is available on the molecular basis of antimicrobial resistance in APEC in Africa. Therefore, the objective of this study was to characterize the virulence and antimicrobial resistance of multidrug-resistant APEC isolated from septicemic broile...

To make a comprehensive study of tetracycline resistance determinant distribution in the genus Shigella, a collection of 577 clinical isolates of Shigella spp. and enteroinvasive Escherichia coli (EIEC) from a variety of geographical locations was screened to identify tetracycline-resistant strains. The 459 tetracycline-resistant isolates identified were then screened by PCR analysis to determi...

The mechanisms of antimicrobial resistance were characterized in 90 Salmonella enterica isolates either resistant or with intermediate resistance to amoxicillin/clavulanate (AMC(R/I)) or resistant to third-generation cephalosporins (C3G(R)). These isolates were recovered in three Spanish hospitals during 2007-2009. The C3G(R) phenotype was expressed by three isolates that carried the following ...

Vancomycin-resistant Enterococcus faecalis, E. faecium and E. durans isolates with the genotype vanA were detected in 7 of 118 faecal samples (5.9%) of natural gilthead seabream recovered off the coast of Portugal, and one vancomycin-resistant isolate/sample was further characterized. The genes erm(B), tet(L), tet(M), aac(6')-aph(2"), aph(3')-IIIa and/or ant(6)-Ia were identified in most of the...

The minimum inhibitory concentrations (MICs) of 6 different antibiotics (chloramphenicol, clindamycin, erythromycin, streptomycin, tetracycline and vancomycin) were determined for 143 strains of lactic acid bacteria and bifidobacteria using the Etest. Different MICs were found for different species and strains. Based on the distribution of these MIC values, most of the strains were either susce...

The distribution of tetracycline resistance in commensal E. coli strains, isolated from pigs at different stages of production system was investigated in four Bulgarian swine farms. The prevalence of antibiotic resistance and particularly tetracycline resistance, as well as two tetracycline resistance genes were evaluated in Escherichia coli isolates from swine faeces and manure lagoons. A tota...

We sought to determine the genetic and phenotypic antimicrobial resistance (AMR) profiles of commensal Klebsiella spp. circulating in Kenya by testing human stool isolates of 87 K. pneumoniae and three K. oxytoca collected at eight locations. Over one-third of the isolates were resistant to ≥3 categories of antimicrobials and were considered multidrug-resistant (MDR). We then compared the resis...

Tetracycline-resistant Tet M-negative isolates of Actinomyces viscosus, Eubacterium lentum, Mobiluncus curtisii, and Mobiluncus mulieris were screened with the Tet K, Tet L, and Tet O DNA probes. Ten (71%) of the resistant Mobiluncus strains hybridized with the Tet O probe, two of the three E. lentum strains hybridized with the Tet K probe, and the A. viscosus isolate hybridized with the Tet L ...

BENCHMARKS Conditional gene expression using the Tet system is well established in eukaryotes (1). The tetracycline-controlled transactivator (tTA) binds to P tet-1 in the absence of an effector and stimulates transcription of the successive target gene (2). Effector tet-racyclines abolish activation by tTA (Tet-Off). The reverse transactivator rtTA2 S-M2 contains a mutated tetR al-lele and act...