The fate of bacteria in human urine was studied after inoculation of small numbers of Escherichia coli and other bacterial strains commonly implicated in urinary tract infection. Urine from normal individuals was often inhibitory and sometimes bactericidal for growth of these organisms. Antibacterial activity of urine was not related to lack of nutrient material as addition of broth did not dec...

The objective of this study was to compare quinolone resistance and gyrA mutations in clinical isolates of Klebsiella pneumoniae and Escherichia coli from Chinese adults who used quinolone in the preceding month and children without any known history of quinolone administration. The antimicrobial susceptibilities of 61 isolates from children and 79 isolates from adults were determined. The muta...

Quinolone resistance is caused mainly by chromosomal mutations in gram negative bacteria. In 1998, plasmid-mediated resistance to quinolones in clinical isolates was first reported in a Klebsiella pneumoniae strain. Locus qnr (quinolone resistance) was responsible of the quinolone resistance in this plasmid. qnr codes a protein whose function is protect both DNA-girase and topoisomerase IV from...

The use of light-activated bactericidal agents—photobactericides—is suggested in local infection in order to conserve conventional antibacterials for more systemic disease. Local administration of a photobactericide such as methylene blue coupled with locally-targeted red light illumination ensures the production of non-specific reactive oxygen species and thus a rapid and localised antibacteri...

Silkworm larvae at the 5th instar were injected with lipopolysaccharide from Escherichia coli and inducible polypeptides were examined within a pI range of 3-10 and a size range of 14-97 kDa by proteomics, including peptide mass fingerprinting. No polypeptides were induced in the midgut. FB1 and H1-4 polypeptides were significantly induced in fat body and hemolymph, respectively. FB1 and H1 wer...

Polyphenols are plant-derived natural products with well-documented health benefits to human beings, such as antibacterial activities. However, the antibacterial activities of polyphenols under hyperglycemic conditions have been rarely studied, which could be relevant to their antibacterial efficacy in disease conditions, such as in diabetic patients. Herein, the antibacterial activities of 38 ...

A novel antibacterial peptide that shows antibacterial activity against Staphylococcus aureus was isolated from the hemolymph of the silkworm, Bombyx mori. The novel peptide consisted of 42 amino acids and was highly basic. This peptide indicated no significant similarity with other antibacterial peptides. The peptide showed antibacterial activity against several Gram-negative and -positive bac...

This study was carried out to evaluate the antibacterial activity of aqueous and organic extracts of Thymus capitatus L. (Lamiaceae) leaves and stems. Dried ground powder leaves and stems were extracted with water (aqueous extracts), ethanol, dichloromethane and hexane (Soxhlet extracts). The antibacterial activity of these extracts was evaluated against bacteria using disc diffusion method. Th...

Quinolone resistance normally arises by mutations in the chromosomal genes for type II topoisomerases and by changes in the expression of proteins that control the accumulation of quinolones inside bacteria. A novel mechanism of plasmid-mediated quinolone resistance was recently reported that involves DNA gyrase protection by a pentapeptide repeat family member called Qnr. This family includes ...

qnrE1, found in a clinical Klebsiella pneumoniae isolate, was undetectable by PCR assays used for the six qnr families. qnrE1 was located on a conjugative plasmid (ca. 185 kb) and differed from qnrB alleles by 25%. Phylogenetic reconstructions of qnr genes and proteins and analysis of the qnrE1 surroundings showed that this gene belongs to a new qnr family and was likely mobilized by ISEcp1 fro...