First Detection of OXA-10 Extended-Spectrum Beta-Lactamases and the Occurrence of mexR and nfxB in Clinical Isolates of Pseudomonas aeruginosa from Nigeria

Chemotherapy ◽  
2015 ◽  
Vol 61 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Bamidele T. Odumosu ◽  
Bola A. Adeniyi ◽  
Ram Chandra
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Clinical Isolates ◽  
Beta Lactamases ◽  
First Report ◽  
Extended Spectrum ◽  
Pcr Rflp ◽  
Extended Spectrum Beta Lactamases ◽  
Regulator Genes

Background: The characterization of β-lactamase production in Pseudomonasaeruginosa is rarely reported in Nigeria. The objective of this study was to investigate the occurrence and characterize the different β-lactamases as well as mechanisms of fluoroquinolones resistance among P. aeruginosa isolated from various clinical sources from Nigeria. Materials and Method: Isolates were investigated using PCR, RFLP and sequencing for the detection of various β-lactamases and efflux pump regulator genes. Result: The prevalence of OXA-10, AmpC, CTX-M and SHV in P. aeruginosa was 80, 70, 5 and 5%, respectively. The coexistence of blaOXA-10 with blaAmpC, blaSHV and blaCTX-M was reported in 40, 5 and 5% of isolates, respectively. The efflux pump regulator genes mexR and nfxB were both amplified in 45% of the OXA-10-positive isolates. Conclusion: This is the first report of the characterization of OXA-10 extended-spectrum β-lactamases and occurrence of mexR and nfxB efflux regulator genes in clinical isolates of P. aeruginosa in Nigeria.

scholarly journals Extremely Drug-Resistant Pseudomonas aeruginosa ST309 Harboring Tandem GES Enzymes: A Newly Emerging Threat in the United States

2019 ◽  
Author(s):  
Ayesha Khan ◽  
Truc T. Tran ◽  
Rafael Rios ◽  
Blake Hanson ◽  
William C. Shropshire ◽  
...  
Keyword(s):  
United States ◽  
Pseudomonas Aeruginosa ◽  
Phylogenetic Analysis ◽  
The United States ◽  
Clinical Isolates ◽  
Drug Resistant ◽  
Beta Lactamases ◽  
Extended Spectrum ◽  
Extended Spectrum Beta Lactamases ◽  
Lactamase Inhibitor

AbstractTwo ST309 Pseudomonas aeruginosa clinical isolates resistant to carbapenems and newer β-lactam/β-lactamase inhibitor combinations were found to harbor the extended spectrum beta-lactamases GES 19 and 26 genetically clustered in tandem. The combination of ceftazidime/avibactam plus aztreonam achieved cure in one patient. Phylogenetic analysis suggests that ST309 P. aeruginosa carrying tandem GES are an emerging lineage in the United States.

scholarly journals Genetic characterization of clinical Klebsiella isolates circulating in Novosibirsk

2021 ◽  
Vol 25 (2) ◽  
pp. 234-245
Author(s):  
A. V. Bardasheva ◽  
N. V. Fomenko ◽  
T. V. Kalymbetova ◽  
I. V. Babkin ◽  
S. O. Chretien ◽  
...  
Keyword(s):  
Beta Lactam ◽  
Genetic Determinants ◽  
Aminoglycoside Resistance ◽  
Beta Lactamases ◽  
Phenotypic Resistance ◽  
Molecular Serotyping ◽  
Extended Spectrum ◽  
Extended Spectrum Beta Lactamases ◽  
Aminoglycoside Resistance Genes

72 clinical strains of Klebsiella spp. isolated from samples obtained from humans in Novosibirsk, Russia, were analyzed. Species identification of strains was performed using 16S rRNA and rpoB gene sequences. It was revealed that Klebsiella pneumoniae strains were dominant in the population (57 strains), while the remaining 15 strains were K. grimontii, K. aerogenes, K. oxytoca and K. quasipneumoniae. By molecular serotyping using the wzi gene sequence, K. pneumoniae strains were assigned to twenty-one K-serotypes with a high proportion of virulent K1- and K2-serotypes. It was found that K. pneumoniae strains isolated from the hospitalized patients had a higher resistance to antibiotics compared to the other Klebsiella species. Real-time PCR revealed that the population contained genes of the blaSHV, blaTEM, blaCTX families and the blaOXA-48 gene, which are the genetic determinants of beta-lactam resistance. It has been shown that the presence of the blaCTX sequence correlated with the production of extended-spectrum beta-lactamases, and phenotypic resistance to car-bapenems is due to the presence of the blaOXA-48 gene. At the same time, the carbapenemase genes vim, ndm, kpc, imp were not detected. Among the aminoglycoside resistance genes studied, the aph(6)-Id and aadA genes were found, but their presence did not always coincide with phenotypic resistance. Resistance to fluoroquinolones in the vast majority of strains was accompanied by the presence of the aac(6’)-IB-cr, oqxA, oqxB, qnrB, and qnrS genes in various combinations, while the presence of the oqxA and/or oqxB genes alone did not correlate with resistance to fluoroquinolones. Thus, the detection of blaCTX and blaOXA-48 can be used to quickly predict the production of extended-spectrum beta-lactamases and to determine the resistance of Klebsiella to carbapenems. The detection of the aac(6’)-Ib-cr and/or qnrB/qnrS genes can be used to quickly determine resistance to fluoroquinolones.

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