On the assumption of the theory that the sulfone of a penam derivative should effectively act as a suicide substrate against beta-lactamases to which the parent compound is a poor substrate, the action of cloxacillin sulfone on four different types of beta-lactamases was studied. As we expected, cloxacillin sulfone showed strong mechanism-based irreversible inactivation against type Ib penicill...

BACKGROUND AND PURPOSE Salmonella enterica is one of the most common enteric pathogens worldwide. Conventional methods of isolation of Salmonella strains take 4-7 days to complete, are laborious and require substantial manpower. We devised a polymerase chain reaction (PCR) method that simultaneously uses three pairs of specific primers to detect inv, spv, and via genes of Salmonella. METHODS ...

We investigated the role of commensals at the peak of infection with the colonic mouse pathogen Citrobacter rodentium. Bioluminescent and kanamycin (Kan)-resistant C. rodentium persisted avirulently in the cecal lumen of mice continuously treated with Kan. A single Kan treatment was sufficient to displace C. rodentium from the colonic mucosa, a phenomenon not observed following treatment with v...

Tracking disease progression in vivo is essential for the development of treatments against bacterial infection. Optical imaging has become a central tool for in vivo tracking of bacterial population development and therapeutic response. For a precise understanding of in vivo imaging results in terms of disease mechanisms derived from detailed postmortem observations, however, a link between th...

The mouse enteric pathogen Citrobacter rodentium, like its human counterpart, enteropathogenic Escherichia coli, causes attaching and effacing lesions in the intestinal epithelium of its host. This phenotype requires virulence factors encoded by the locus for enterocyte effacement (LEE) pathogenicity island. For timely expression of these virulence determinants at the site of infection and for ...

We have isolated mutants of Citrobacter freundii that can grow on melibiose. Inducible alpha-galactosidase activity and melibiose transport activity were detected in the mutant cells but not in the wild-type cells. We detected a DNA region which hybridized with melB (the gene for the melibiose transporter) DNA of Escherichia coli in the chromosomal DNA of wild-type C. freundii. Protons, but not...

The discharge of untreated detergent-bearing waste introduces linear alklcylbenzene sulfonates (LAS) to the aquatic environment. The surfactant persists in some streams and rivers in Nigeria, some is adsorbed to suspended materials and end in the sediment of the receiving water bodies. In this study, bacteria isolated from sediments of some tropical detergent-effluent-polluted streams were test...

BACKGROUND Citrobacter amalonaticus Y19 is a good biocatalyst for production of hydrogen (H2) from oxidation of carbon monoxide (CO) via the so-called water-gas-shift reaction (WGSR). It has a high H2-production activity (23.83 mmol H2 g-1 cell h-1) from CO, and can grow well to a high density on various sugars. However, its H2-production activity is expressed only when CO is present as an indu...