Background: Production of Bla OXA-23, OXA-24, OXA-58 and hyperexpression of OXA-51 due to ISAba1 insertion sequence are the leading causes of carbapenem resistance in Acinetobacter baumannii. The loss of OprD transmembrane protein and the overexpression of some effl ux pumps are considered to be the main factors for carbapenem resistance in Pseudomonas aeruginosa whereas metallo-enzymes' production has a secondary role.
Aim: Тo examine the carbapenem resistance due to carbapenemase production among clinically signifi cant Gram-negative non-fermenters from St George University hospital, Plovdiv: A. baumannii and P. aeruginosa.
Materials And Methods: Forty three A. baumannii and 43 P. aeruginosa isolates, resistant or with intermediate resistance to imipenem and/or meropenem were included in the study. They were collected from patients admitted in 14 various hospital wards between 2010 and 2014. Both phenotypic and genetic methods were used for identifi cation and antimicrobial susceptibility testing.
Results: All A. baumannii demonstrated carbapenemase production determined by a modifi ed Hodge test whereas P. aeruginosa isolates did not show this phenomenon. OXA-23 genes were determined in 97.7% (42 out of 43) of A. baumannii isolates indistinguishable from the sequence of the classical ARI-1 gene. OXA-24, OXA-58 and overexpression of OXA-51 were not registered in any of the isolates. All P. aeruginosa were negative for blaVIM and blaIMP genes.
Conclusion: The leading cause of carbapenem resistance in A. baumannii isolates from our hospital is the carbapenemase production due to the expression of OXA- 23 gene, whereas in P. aeruginosa - the loss of transmembrane OprD protein and the effl ux pumps' hyperexpression are suspected to be the main mechanisms.
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http://dx.doi.org/10.1515/folmed-2017-0060 | DOI Listing |
J Antibiot (Tokyo)
January 2025
Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Metallo-beta-lactamase-producing Pseudomonas aeruginosa (P. aeruginosa) is a major pathogen in burn wounds, often exhibiting high levels of antibiotic resistance, which complicates treatment strategies. This study deals with the validity of the modified Carbapenem Inactivation Method (mCIM) and the simplified Carbapenem Inactivation Method (sCIM) phenotypic tests for screening metallo-beta-lactamase (MBL) production by P.
View Article and Find Full Text PDFBMC Infect Dis
January 2025
Department of Microbiology, Immunology and Parasitology, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
Background: Escherichia coli (E. coli) O157:H7, associated with diarrhea, poses a global health risk. In Ethiopia, where diarrhea is common, there is limited knowledge about these resistant strains and a lack of data on Extended-Spectrum β-Lactamase (ESBL) and carbapenemase production.
View Article and Find Full Text PDFJ Microbiol Methods
January 2025
Faculdade de Farmácia, Universidade Federal do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil; Laboratório de Pesquisa em Resistência Bacteriana (LABRESIS), Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas (PPGCF), Faculdade de Farmácia, Universidade Federal do Rio Grande Do Sul (UFRGS), Porto Alegre, RS, Brazil. Electronic address:
Carbapenemase-producing Enterobacterales are a growing concern in public health. In order to rapidly determine the antimicrobial profile, the MALDI Biotyper - antibiotic susceptibility test rapid assay (MBT-ASTRA) was developed, based on the relative growth of bacteria in the presence of antibiotics. In this study, we added carbapenemase enzymatic inhibitors to the MBT-ASTRA and developed an adapted method named MALDI Biotyper - Phenotypic Identification Test Rapid Assay (MBT-PITRA) in order to perform a rapid and cost-effective phenotypic test to detect Klebsiella pneumoniae carbapenemase (KPC) and New Delhi metallo-beta-lactamase (NDM), including co-producers, in Enterobacterales.
View Article and Find Full Text PDFZhonghua Yu Fang Yi Xue Za Zhi
January 2025
Department of Reproductive Medicine, Henan Province Hospital of Traditional Chinese Medicine, Zhengzhou450002, China.
To analyze the epidemiological characteristics of drug resistance genes of carbapenemase-producing Escherichia coli (CPECO) in Henan Province Hospital of Traditional Chinese Medicine from 2021 to 2023, providing data support and theoretical basis for controlling nosocomial infections of CPECO. Using a cross-sectional study, 30 carbapenem-resistant Escherichia coli (CRECO) strains confirmed by VITEK-2 Compact identification and drug sensitivity test in the Clinical Microbiology Laboratory of Henan Province Hospital of Traditional Chinese Medicine from 2021 to 2023 were tested, using carbapenemase inhibitor enhancement test to conduct preliminary screening of carbapenemases, and colloidal gold immunochromatography and polymerase chain reaction (PCR) were used to determine the phenotypes and genotypes of common carbapenemases () respectively, and the genotypes () of common extended Spectrum beta-lactamases (ESBL) were confirmed using PCR. The PCR amplification products of carbapenemase and ESBL positive strains were Sanger-sequenced, and the sequencing products were compared on the Blast website to determine the exact carbapenemase and ESBL genotypes.
View Article and Find Full Text PDFJ Glob Antimicrob Resist
January 2025
Infection Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton Victoria, Australia; Centre to Impact AMR, Monash University, Clayton, Victoria, Australia; Department of Infectious Diseases, Alfred Health and School of Translational Medicine, Monash University, Melbourne, Victoria, Australia. Electronic address:
Objective: The IMP-4 carbapenemase is an endemic cause of carbapenem resistance in the Asia-Pacific region. Our aim was to determine the dissemination mechanism of the bla gene.
Methods: Twelve representative Australian IMP-4 clinical isolates from The Alfred Hospital, were characterised using antimicrobial susceptibility testing and genome and plasmid assemblies analysed.
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