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Spores from a number of different Bacillus species are currently being used as human and animal probiotics, although their mechanisms of action remain poorly understood. Here we describe the isolation of 237 presumptive gut-associated Bacillus spp. isolates that were obtained by heat and ethanol treatment of fecal material from organically reared broilers(More)
OBJECTIVES To examine 397 strains of Salmonella enterica of human and animal origin comprising 35 serotypes for the presence of aadB, aphAI-IAB, aadA1, aadA2, bla(Carb(2)) or pse1, bla(Tem), cat1, cat2, dhfr1, floR, strA, sul1, sul2, tetA(A), tetA(B) and tetA(G) genes, the presence of class 1 integrons and the relationship of resistance genes to integrons(More)
OBJECTIVES To study how disinfectants affect antimicrobial susceptibility and phenotype of Salmonella enterica serovar Typhimurium SL1,344. METHODS Wild-type strain SL1,344 and its isogenic gyrA mutant were passaged daily for 7 days in subinhibitory concentrations, and separately for 16 days in gradually increasing concentrations of a quaternary ammonium(More)
In cellular immunology the critical balance between effector and regulatory mechanisms is highlighted by serious immunopathologies attributable to mutations in Foxp3, a transcription factor required for a major subset of regulatory T (Tr) cells. Thus, many studies have focused on the developmental origin of Tr cells, with the prevailing view that they(More)
OBJECTIVE To determine the effect of growth of five strains of Salmonella enterica and their isogenic multiply antibiotic-resistant (MAR) derivatives with a phenolic farm disinfectant or triclosan (biocides) upon the frequency of mutation to resistance to antibiotics or cyclohexane. METHODS Strains were grown in broth with or without the biocides and then(More)
Enterohaemorrhagic Escherichia coli O157 : H7 is a bacterial pathogen that can cause haemorrhagic colitis and haemolytic uremic syndrome. In the primary reservoir host, cattle, the terminal rectum is the principal site of E. coli O157 colonization. In this study, bovine terminal rectal primary epithelial cells were used to examine the role of H7 flagella in(More)
OBJECTIVES Multiply antibiotic-resistant (MAR) mutants of Escherichia coli and Salmonella enterica are characterized by reduced susceptibility to several unrelated antibiotics, biocides and other xenobiotics. Porin loss and/or active efflux have been identified as a key mechanisms of MAR. A single rapid test was developed for MAR. METHODS The(More)
Intestinal colonization by enteropathogenic and enterohemorrhagic Escherichia coli requires the locus of enterocyte effacement-encoded type III secretion system. We report that NleC and NleD are translocated into host cells via this system. Deletion mutants induced attaching and effacing lesions in vitro, while infection of calves or lambs showed that(More)
OBJECTIVES The aim of this study was to characterize the mechanisms of resistance to triclosan in Salmonella enterica serovar Typhimurium. METHODS Mutants resistant to triclosan were selected from nine S. enterica serovar Typhimurium strains. Mutants were characterized by genotyping, mutagenesis and complementation of fabI and analysis of efflux activity.(More)
In previous work, Salmonella enterica serovar Typhimurium strain SL1344 was exposed to sublethal concentrations of three widely used farm disinfectants in daily serial passages for 7 days in an attempt to investigate possible links between the use of disinfectants and antimicrobial resistance. Stable variants OXCR1, QACFGR2, and TOPR2 were obtained(More)