scholarly journals Molecular epidemiological study and detection of multi-drug resistant Acinetobacter baumannii -related resistance genes

2013 ◽  
Vol 7 (48) ◽  
pp. 5496-5502 ◽  
Author(s):  
J Jiang M ◽  
P Zhao Sh ◽  
M Li J ◽  
S Zhang F
Keyword(s):  
Acinetobacter Baumannii ◽  
Epidemiological Study ◽  
Resistance Genes ◽  
Drug Resistant ◽  
Molecular Epidemiological Study

scholarly journals Whole-genome sequence analysis reveals evolution of antimicrobial resistance in a Ugandan colistin resistant Acinetobacter baumannii

2020 ◽  
Author(s):  
Dickson Aruhomukama ◽  
Ivan Sserwadda ◽  
Gerald Mboowa
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Mobile Genetic Element ◽  
Whole Genome Sequence ◽  
Broad Host Range ◽  
Insertion Sequences ◽  
Drug Resistant ◽  
Genetic Element ◽  
Resistance Evolution

AbstractIn recent times, pan-drug resistant Acinetobacter baumannii have emerged and continue to spread among critically ill patients, this poses an urgent risk to global and local human health. This study sought to provide the first genomic analysis of a pan-drug resistant Acinetobacter baumannii from Uganda and Africa, and to tell a story of mobile genetic element-mediated antibiotic resistance evolution in the isolate. It was an in-silico study in which intrinsic and acquired antibiotic resistance genes, and/or chromosomal resistance mutations were identified using PATRIC, CARD, NDARO and ResFinder. Screening for insertion sequences was done using ISfinder. Also, plasmid screening, phylogenetic analysis and sequence typing were performed using PlasmidFinder, PATRIC and Gubbin, and MLST respectively.The isolate belonged to the Sequence type 136, belonging to Clonal complex 208 and Global complex 2. This isolate shared close homology with strains from Tanzania. Resistance in the isolate was chromosomally and mobile genetic element-mediated by Acinetobacter-derived cephalosporinases and carbapenem hydrolyzing class D β-lactamses, blaOXA-2, 51, 5 88, 317, blaADC-2, 25. Colistin resistance was associated with previously documented mutants, lpxA and lpxC. Other key resistance genes identified were: aph(3”)-lb, aph(6)-ld, aph(3’)-la, aac(3)-lld, aac(3)-lla, aph(3’)-l, aph(3”)-l, aph(6)-lc, aph(6)-ld, aac(3)-II, III, IV, VI, VIII, IX, X, macA, macB, tetA, tetB, tetR, dfrA, and those of the floR family. RSF1010 like IncQ broad-host-range plasmids and features of pACICU1, pACICU2, and p3ABAYE Acinetobacter baumannii plasmids namely partitioning proteins ParA and B were present. Insertion sequences present included IS3, IS5, IS66 and those of the ISLre2 families.The study described for the first time a pan-drug resistant Acinetobacter baumannii from Uganda, and told a story of mobile genetic element-mediated antibiotic resistance evolution in the isolate despite being limited by pan-drug resistance phenotypic data. It provides a basis to track trends in antibiotic resistance and identification of emerging resistance patterns in Acinetobacter baumannii in Uganda.

scholarly journals Genomic Characterization of Extensively Drug-Resistant NDM-Producing Acinetobacter baumannii Clinical Isolates With the Emergence of Novel blaADC-257

2021 ◽  
Vol 12 ◽  
Author(s):  
Mai M. Zafer ◽  
Amira F. A. Hussein ◽  
Mohamed H. Al-Agamy ◽  
Hesham H. Radwan ◽  
Samira M. Hamed
Keyword(s):  
Antimicrobial Resistance ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Strong Association ◽  
Carbapenem Resistance ◽  
Clinical Isolates ◽  
Drug Resistant ◽  
Missense Mutations ◽  
Extensively Drug Resistant ◽  
Susceptibility Profiles

Acinetobacter baumannii has become a major challenge to clinicians worldwide due to its high epidemic potential and acquisition of antimicrobial resistance. This work aimed at investigating antimicrobial resistance determinants and their context in four extensively drug-resistant (XDR) NDM-producing A. baumannii clinical isolates collected between July and October 2020 from Kasr Al-Ainy Hospital, Cairo, Egypt. A total of 20 A. baumannii were collected and screened for acquired carbapenemases (blaNDM, blaVIM and blaIMP) using PCR. Four NDM producer A. baumannii isolates were identified and selected for whole-genome sequencing, in silico multilocus sequence typing, and resistome analysis. Antimicrobial susceptibility profiles were determined using disk diffusion and broth microdilution tests. All blaNDM-positive A. baumannii isolates were XDR. Three isolates belonged to high-risk international clones (IC), namely, IC2 corresponding to ST570Pas/1701Oxf (M20) and IC9 corresponding to ST85Pas/ST1089Oxf (M02 and M11). For the first time, we report blaNDM-1 gene on the chromosome of an A. baumannii strain that belongs to sequence type ST164Pas/ST1418Oxf. Together with AphA6, blaNDM-1 was bracketed by two copies of ISAba14 in ST85Pas isolates possibly facilitating co-transfer of amikacin and carbapenem resistance. A novel blaADC allele (blaADC-257) with an upstream ISAba1 element was identified in M19 (ST/CC164Pas and ST1418Oxf/CC234Oxf). blaADC genes harbored by M02 and M11 were uniquely interrupted by IS1008. Tn2006-associated blaOXA-23 was carried by M20. blaOXA-94 genes were preceded by ISAba1 element in M02 and M11. AbGRI3 was carried by M20 hosting the resistance genes aph(3`)-Ia, aac(6`)-Ib`, catB8, ant(3``)-Ia, sul1, armA, msr(E), and mph(E). Nonsynonymous mutations were identified in the quinolone resistance determining regions (gyrA and parC) of all isolates. Resistance to colistin in M19 was accompanied by missense mutations in lpxACD and pmrABC genes. The current study provided an insight into the genomic background of XDR phenotype in A. baumannii recovered from patients in Egypt. WGS revealed strong association between resistance genes and diverse mobile genetic elements with novel insertion sites and genetic organizations.

Extensively Drug Resistant Acinetobacter baumannii ST369 Infection in Emergency Intensive Care Unit in Shandong Province, China

2020 ◽  
Author(s):  
Meijie Jiang ◽  
Lin Li ◽  
Shuang Liu ◽  
Zhijun Zhang ◽  
Ning Li ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Molecular Epidemiology ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Susceptibility Testing ◽  
Control Measures ◽  
Pulse Field ◽  
Drug Resistant ◽  
Aminoglycoside Resistance ◽  
Extensively Drug Resistant

Abstract Background: Acinetobacter baumannii is a significant nosocomial infectious pathogen worldwide. The aim of this study is to characterize the molecular epidemiology of Acinetobacter baumannii isolated from the clinical infection, providing the epidemiology data for prevention and control. Four patients hospitalized in EICU on January 31st, 2014, and then Acinetobacter baumannii infection was observed. Antimicrobial resistance and resistance genes were analyzed by antimicrobial susceptibility testing and PCR sequencing. Pulse field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to analyze these strains’ clonal relatedness. Results: Sixteen strains were recovered, of which 4 strains were isolated from 4 patients, and others were from environment in EICU, such as air, phone and ventilator. All strains belonged to clonal pulsotype A and ST369. Sixteen antibiotics were used to perform the susceptibility testing, and all strains were extensively drug resistant (XDR) Acinetobacter baumannii, they were only susceptible to tigecycline and polymyxin B, but resistant to others, including carbapenems and aminoglycoside antibiotics. Furthermore, all strains carried blaOXA-23-like carbapenemases gene with ISAba1 insertion sequence in the upstream, aminoglycoside resistance genes ant(3″)-I, 16S rRNA methylase gene armA and disinfectant resistant gene qacE△1, which were mainly responsible for the spread of antimicrobial resistance. Fortunately, enhanced control measures were immediately implemented after this infection, and new strains were no longer detected for consecutive three months. Conclusions: molecular epidemiology of blaOXA-23-like carbapenemase-producing Acinetobacter baumannii ST369 in EICU of a hospital was characterized. Routine monitoring should be strengthen to prevent outbreaks of this disease.

Identification of Antibiotic Resistance Genes in Multi-Drug Resistant Acinetobacter Baumannii Clinical Isolates of Iraqi Patients (Zq Strains), Using Whole-Genome Sequencing

2019 ◽  
Vol 10 (04) ◽  
pp. 670-680
Author(s):  
Zainab J Qasim ◽  
Haider Sabah Kadhim ◽  
Ahmed Sahib Abdulamir
Keyword(s):  
Antimicrobial Resistance ◽  
Acinetobacter Baumannii ◽  
Genome Sequence ◽  
Resistance Genes ◽  
Genetic Material ◽  
Whole Genome ◽  
Drug Resistant ◽  
Intrinsic Resistance ◽  
Antimicrobial Resistance Genes ◽  
Recent Emergence

Background: The recent emergence of multidrug resistance (MDR) in Acinetobacter baumannii (A. baumannii ) has raised concern in health care settings in Iraq. This is the first report of the whole genome sequence of A. baumannii ZQ isolated from Iraqi patients. To better comprehend the repertoire of MDR genetic elements and organization, we compared the genome sequences of eight extended drug-resistant (XDR) and two less drug-resistant A. baumannii ZQ strains with that of other completely sequenced A. baumannii from divergent worldwide distributed isolates.Results: In consistence with their phenotypic antimicrobial resistance profiles, ZQ genomes harbors high to moderate numbers of genetic determinants, including β-lactamases, aminoglycoside-modifying enzymes, efflux pumps, modifications of target sites. Several strains showed nearly identical genome sequence, frequent structural variation was detected even between the closely related strains.Conclusion: In general, the shorter the genetic distance among strains, the less insertion/deletion events proceed. However, frequent genomic changes was observed even inside the closely related strains of A. baumannii. Antimicrobial resistance genes are likely to be the target accumulating such variations, suggesting that the resistance elements respond actively to the selection pressure in the hospital setting. Besides the lateral acquisition of genetic material from resistant bacterial strains, the drastic issues is associated with continuous presence of intrinsic resistance genes in the genome of A. baumannii, which are ready to be boosted by exposure to sub-inhibitory levels of the antibiotics in the environment and might also play an important role in the evolution of resistance to the new derivatives of different antibiotic classes.

Decreased carO gene expression and OXA-type carbapenemases among extensively drug-resistant Acinetobacter baumannii strains isolated from burn patients in Tehran, Iran

2020 ◽  
Author(s):  
Elham Abbasi ◽  
Hossein Goudarzi ◽  
Ali Hashemi ◽  
Alireza Salimi Chirani ◽  
Abdollah Ardebili ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acinetobacter Baumannii ◽  
High Rate ◽  
Burn Patients ◽  
Drug Resistant ◽  
Disc Diffusion ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant ◽  
Sds Page ◽  
Extensively Drug Resistance

AbstractA major challenge in the treatment of infections has been the rise of extensively drug resistance (XDR) and multidrug resistance (MDR) in Acinetobacter baumannii. The goals of this study were to determine the pattern of antimicrobial susceptibility, blaOXA and carO genes among burn-isolated A. baumannii strains. In this study, 100 A. baumannii strains were isolated from burn patients and their susceptibilities to different antibiotics were determined using disc diffusion testing and broth microdilution. Presence of carO gene and OXA-type carbapenemase genes was tested by PCR and sequencing. SDS-PAGE was done to survey CarO porin and the expression level of carO gene was evaluated by Real-Time PCR. A high rate of resistance to meropenem (98%), imipenem (98%) and doripenem (98%) was detected. All tested A. baumannii strains were susceptible to colistin. The results indicated that 84.9% were XDR and 97.9% of strains were MDR. In addition, all strains bore blaOXA-51 like and blaOXA-23 like and carO genes. Nonetheless, blaOXA-58 like and blaOXA-24 like genes were harbored by 0 percent and 76 percent of strains, respectively. The relative expression levels of the carO gene ranged from 0.06 to 35.01 fold lower than that of carbapenem-susceptible A. baumannii ATCC19606 and SDS – PAGE analysis of the outer membrane protein showed that all 100 isolates produced CarO. The results of current study revealed prevalence of blaOXA genes and changes in carO gene expression in carbapenem resistant A.baumannii.

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