The serologically and structurally related Eschrichia coli capsular polysaccharides (K antigens) K13, K20, and K23 were found to be depolymerized by the bacteriophages phi K13 and phi K20 to almost similar oligomer profiles as shown by polyacrylamide gel electrophoresis. The phage-polysaccharide interactions were followed by an increase of reducing 2-keto-3-deoxyoctulosonic acid due to a phage-associated glycanase that catalyzed the hydrolytic cleavage of common beta-ketopyranosidic 2-keto-3-deoxyoctulosonic acid linkages. The related E. coli K antigens K18, K22, and K100 as well as the Haemophilus influenzae type b capsular polysaccharide were degraded by bacteriophage phi K100 with different efficacy. It is suggested that phi K100 enzymatically cleaves ribitol-5-phosphate bonds as the only structural feature present in all the polysaccharides investigated.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/j.1574-6968.1997.tb10470.x | DOI Listing |
Int J Mol Sci
November 2024
Master Program in Biomedical Sciences, School of Medicine, Tzu Chi University, No. 701, Sec. 3, Zhongyang Road, Hualien 97004, Taiwan.
Bacteriophages are viruses that have the potential to combat bacterial infections caused by antimicrobial-resistant bacterial strains. In this study, we investigated a novel lytic bacteriophage, vB_EcoS_JSSK01, isolated from sewage in Hualien, Taiwan, which effectively combats multidrug-resistant (MDR) of the K1 capsular type. K1 is a major cause of severe extraintestinal infections, such as neonatal meningitis and urinary tract infections.
View Article and Find Full Text PDFMicrob Pathog
December 2024
Department of Clinical Analysis, School of Pharmacy, University of São Paulo, São Paulo, Brazil; One Health Brazilian Resistance Project (OneBR), Brazil; Department of Internal Medicine, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil. Electronic address:
Escherichia coli is a Gram-negative ubiquitous bacteria occurring in a diversity of environments including water, soil, and the gastrointestinal tract of humans and warm-blooded animals, being classified into commensal and pathogenic strains. While empirical antibiotic therapy with fluoroquinolones, such a ciprofloxacin and norfloxacin, has been a common practice, resistance to broad-spectrum cephalosporins, mediated by extended-spectrum β-lactamases (ESBLs), has been alerted as a critical priority by the World Health Organization. Additionally, the convergence of virulence and resistance has been observed in some E.
View Article and Find Full Text PDFUnlabelled: The capsular polysaccharide synthesis ( ) locus of is implicated in invasive meningococcal disease. The synthesis ( ) and transport ( ) operons are transcribed in opposite directions from a common intergenic region and expression is negatively regulated by the bacterial two-component system and thermosensitive RNA folding. However, these mechanisms do not fully explain the stationary phase responses and the cis-acting elements remain to be fully characterized.
View Article and Find Full Text PDFMicrob Pathog
December 2024
ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Post Box No. 6450, Yelahanka, Bengaluru, 560064, Karnataka, India. Electronic address:
A total of 52 Pasteurella multocida strains of capsular serogroups (A, B and D) were screened for anti-quorum sensing activity against Chromobacterium violaceum. Of which, 12 strains of serogroups A were found to possess anti-quorum sensing activity. Inhibition activity was highest for strain NIVEDIPm9 and lowest for strain NIVEDIPm30 based on zone of pigment inhibition.
View Article and Find Full Text PDFFluoroquinolone-resistant sequence type (ST)1193 is a profound, emerging lineage associated with systemic, urinary tract and neonatal infections. Humans, companion animals and the environment are reservoirs for ST1193, which has been disseminated globally. Following its detection in 2007, ST1193 has been identified repeatedly amongst fluoroquinolone-resistant clones in Australia.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!