We investigated hypermutability in Klebsiella pneumoniae and its association with ciprofloxacin resistance and mutations in the quinolone resistance-determining region (QRDR). Sixty-four strains of K. pneumoniae isolated in London, UK, between 1995 and 2002 with widely differing ciprofloxacin minimum inhibitory concentrations (MICs) and known gyrA and parC sequences were tested for mutation frequencies by selection with rifampicin. Only three hypermutable (frequency >or=10(-6)) strains were identified, with ciprofloxacin MICs of 0.25 microg/mL, 8 microg/mL and 64 microg/mL. There was no relationship between hypermutation and the ciprofloxacin MIC or QRDR mutations. Screening selected strains with streptomycin did not reveal any hypermutators, and screening with ciprofloxacin identified only two of the three hypermutators identified by rifampicin. Hypermutation in K. pneumoniae is uncommon and does not contribute to accumulation of QRDR mutations or directly to ciprofloxacin resistance.
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http://dx.doi.org/10.1016/j.ijantimicag.2010.04.010 | DOI Listing |
Int J Microbiol
January 2025
Department of Biochemistry, Faculty of Science, Université de Dschang, Dschang, Cameroon.
Cases of antibiotic-resistant () infections are becoming increasingly frequent and represent a major threat to our ability to treat cancer patients. The emergence of antimicrobial resistance threatens the treatment of infections. In this study, the antimicrobial profiles, virulent genes, and the frequency of extended-spectrum beta-lactamase (ESBL) gene carriage in fecal isolates from cancer patients at the Laquintinie Hospital in Douala (Cameroon) were determined.
View Article and Find Full Text PDFEnviron Toxicol Chem
January 2025
Laboratorio de Ecotoxicología, Facultad de Humanidades y Ciencias, Universidad Nacional del Litoral (UNL), Santa Fe, Argentina.
The combination of silver nanoparticles (AgNPs) and ciprofloxacin (CIP) can be considered an alternative to combat multidrug-resistant microbial infections. However, knowledge about their combined toxicity is scarce after being released in an aquatic environment. The present study evaluated the individual toxicity of AgNPs and CIP and their combined toxicity on the unicellular green microalga Chlorella vulgaris, evaluating cellular responses and conducting metabolomic analysis.
View Article and Find Full Text PDFPLOS Glob Public Health
January 2025
Department of Global Health Security, Infectious Diseases Institute, Makerere University, Kampala, Uganda.
Infections with multi-drug-resistant (MDR) pathogens in food-animals threaten public health and food security. However, the epidemiology and factors associated with MDR Escherichia coli (MDR E. coli) on Ugandan farms are not well known.
View Article and Find Full Text PDFBackground: The transmission of Salmonella spp. to human through the consumption of contaminated food products of animal origin, mainly poultry is a significant global public health concern. The emerging multidrug resistant (MDR) clones of non-typhoidal Salmonella (NTS) serovars, have spread rapidly worldwide both in humans and in the food chain.
View Article and Find Full Text PDFHeliyon
July 2024
Department of Medicine, Faculty of Veterinary, Animal and Biomedical Sciences, Sylhet Agricultural University, Sylhet, Bangladesh.
Subclinical mastitis (SCM), a silent threat in the dairy sector of Bangladesh poses a significant economic impact and serves as a potential source of infection for healthy cows, hindering efforts to achieve milk self-sufficiency. Despite the importance of this issue, limited research has been conducted on mastitis in Sylhet region of Bangladesh. This study aimed to investigate the molecular prevalence, antimicrobial susceptibility profile and resistant genes detection on pathogens ( and causing SCM.
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