Molecular Epidemiology, Antimicrobial Resistance and Characterization of Extended-Spectrum Beta-Lactamases of Salmonella enterica Serotype Paratyphi B Clinical Isolates

2014 ◽  
Vol 48 (2) ◽  
pp. 191-200 ◽  
Author(s):  
Gülçin BAYRAMOĞLU ◽  
Osman Birol ÖZGÜMÜŞ ◽  
Fetiye KOLAYLI ◽  
Ahu KAMBUROĞLU ◽  
Yeşim BEŞLİ ◽  
...  
Chemotherapy ◽  
2015 ◽  
Vol 61 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Bamidele T. Odumosu ◽  
Bola A. Adeniyi ◽  
Ram Chandra

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.


2018 ◽  
Vol 1 (2) ◽  
pp. 74-78
Author(s):  
Ram Prasad Adhikari ◽  
Subha Shrestha ◽  
Junu Richhinbung Rai ◽  
Ritu Amatya

Introduction: Multidrug resistance among Enterobacteriaceae is in increasing trend these days. The objective of this study was to determine the antibiogram of clinical isolates of Enterobacteriaceae with special reference to multidrug resistance and  extended spectrum beta-lactamases production.Materials and Methods: A descriptive cross sectional study was conducted over a period of six months (February -July, 2017) in the microbiology laboratory of Nepal Medical College Teaching Hospital, Kathmandu, Nepal. A total of 936 bacterial isolates of Enterobacteriaceae from clinical specimens were processed for antimicrobial susceptibility testing and screened for multidrug resistance. ESBL production was detected among potential isolates by combination disk diffusion test.Results: The rate of multidrug resistance and extended spectrum beta-lactamases production was 54.2% and 23.8% respectively. Of the total ESBL producers 92.4% were multidrug resistance. The rate of multidrug resistance and extended spectrum beta-lactamases production were higher in organisms isolated from clinical samples collected from inpatients. High rate of multidrug resistance and extended spectrum beta-lactamases production was seen in E. coli (54.4% & 27.7%), Klebsiella spp. (67.1% & 28.2%) and Citrobacter spp. (70.3% & 10.9%). The antimicrobial resistance rate was highest against ampicillin (76.7%) followed by cefixime (54. 0%), ceftazidime (51.5%), ceftriaxone (51.0%), cotrimoxazole (48.7%), ciprofloxacin (43.9%) and ofloxacin (41.1%).Conclusions:  Multidrug resistance is common among Enterobacteriaceae. These bacteria have high rate of resistance against commonly used groups of antibiotics like cephalosporins and quinolones. Continuous monitoring, surveillance of antimicrobial resistance, proper infection control and practices are important to combat with these issues.


2021 ◽  
Vol 25 (2) ◽  
pp. 234-245
Author(s):  
A. V. Bardasheva ◽  
N. V. Fomenko ◽  
T. V. Kalymbetova ◽  
I. V. Babkin ◽  
S. O. Chretien ◽  
...  

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.


1992 ◽  
Vol 36 (11) ◽  
pp. 2536-2538 ◽  
Author(s):  
A Fernandez-Rodriguez ◽  
R Canton ◽  
J C Perez-Diaz ◽  
J Martinez-Beltran ◽  
J J Picazo ◽  
...  

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