Pseudomonas putida KT2440 is a chloramphenicol-resistant bacterium that is able to grow in the presence of this antibiotic at a concentration of up to 25 μg/ml. Transcriptomic analyses revealed that the expression profile of 102 genes changed in response to this concentration of chloramphenicol in the culture medium. The genes that showed altered expression include those involved in general metabolism, cellular stress response, gene regulation, efflux pump transporters, and protein biosynthesis. Analysis of a genome-wide collection of mutants showed that survival of a knockout mutant in the TtgABC resistance-nodulation-division (RND) efflux pump and mutants in the biosynthesis of pyrroloquinoline (PQQ) were compromised in the presence of chloramphenicol. The analysis also revealed that an ABC extrusion system (PP2669/PP2668/PP2667) and the AgmR regulator (PP2665) were needed for full resistance toward chloramphenicol. Transcriptional arrays revealed that AgmR controls the expression of the pqq genes and the operon encoding the ABC extrusion pump from the promoter upstream of open reading frame (ORF) PP2669.
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http://dx.doi.org/10.1128/AAC.05398-11 | DOI Listing |
Sci Rep
January 2025
Microbiology Division, ICMR-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar, 751023, Odisha, India.
This research delves into the evolving dynamics of antibiogram trends, the diversity of antibiotic resistance genes and antibiotic efficacy against Vibrio cholerae strains that triggered the cholera outbreak 2022 in Odisha, India. The study will provide valuable insights managing antimicrobial resistance during cholera outbreaks. Eighty V.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Normal University, Xi'an 710119, P. R. China.
High expression of drug efflux pump makes antibiotics ineffective against bacteria, leading to drug-resistant strains and even the emergence of "superbugs". Herein, we design and synthesize a dual functional o-nitrobenzene (NB)-modified conjugated oligo-polyfluorene vinylene (OPFV) photosensitizer, OPFV-NB, which can depress efflux pump activity and also possesses photodynamic therapy (PDT) for synergistically overcoming drug-resistant bacteria. Upon light irradiation, the OPFV-NB can produce aldehyde active groups to covalently bind outer membrane proteins, such as tolerant colicin (TolC), blocking drug efflux of bacteria.
View Article and Find Full Text PDFJ Poult Sci
January 2025
College of Veterinary Medicine & Institute for Veterinary Biomedical Science, Kyungpook National University, Daegu 41556, Republic of Korea.
Farm biosecurity is valuable for reducing the indiscriminate use of antimicrobials. However, its relationship with antimicrobial usage can be difficult to assess because of multiple factors. This study evaluated the impact of biosecurity practices on productivity, frequency of antimicrobial use, and development of antimicrobial resistance.
View Article and Find Full Text PDFMicroorganisms
December 2024
Department of Food and Nutrition, Dongduk Women's University, Seoul 02748, Republic of Korea.
Antibiotic susceptibilities, hemolytic activities, and technological properties of 46 isolates from kimchi were evaluated to select starter candidates. All strains were susceptible to clindamycin and erythromycin, while some exhibited resistance to ampicillin, chloramphenicol, gentamicin, streptomycin, and tetracycline; all were resistant to kanamycin based on the EFSA breakpoint values for species. PCR analysis did not detect resistance genes for these six antibiotics in any strain.
View Article and Find Full Text PDFMicroorganisms
December 2024
Research and Development Center, Insilicogen Inc., 13, Yongin-si 16954, Republic of Korea.
, a significant cause of gastroenteritis and a growing public health concern, has become increasingly prevalent owing to the rise in ocean temperatures driven by climate change. This study aimed to characterize the genetic diversity, pathogenic potential, and antimicrobial resistance (AMR) profiles of strains isolated from the southern coastal region of Korea. Using whole genome sequencing (WGS) and advanced bioinformatics tools, we identified novel sequence types through multilocus sequence typing and serotyped isolates using the VPsero database.
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