scholarly journals Multidrug-resistant genes of aminoglycoside-modifying enzymes and 16S rRNA methylases in Acinetobacter baumannii strains

2014 ◽  
Vol 13 (2) ◽  
pp. 3842-3849 ◽  
Author(s):  
J.-T. Wen ◽  
Y. Zhou ◽  
L. Yang ◽  
Y. Xu
Keyword(s):  
16S Rrna ◽  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Resistant Genes

Whole genome analysis of extensively drug-resistant Acinetobacter bau-mannii clinical isolates in Thailand

2020 ◽  
Vol 20 ◽  
Author(s):  
Peechanika Chopjitt ◽  
Anusak Kerdsin ◽  
Dan Takeuchi ◽  
Rujirat Hatrongjit ◽  
Parichart Boueroy ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Acinetobacter Baumannii ◽  
Genome Sequencing ◽  
Efflux Pump ◽  
Multidrug Resistant ◽  
Whole Genome ◽  
Drug Resistant ◽  
Resistant Genes ◽  
Extensively Drug Resistant ◽  
Antibiotic Efflux

Background:: Acinetobacter baumannii is recognized as a majority opportunistic nosocomial pathogen and caus-ing hospital-acquired infection worldwide. The increasing prevalence of extensively drug-resistant Acinetobacter baumannii (XDRAB) has become a rising concern in healthcare facilities and has impeded public health due to limitation of therapeutic options and are associated with high morbidity and mortality as well as longer hospitalization. Whole-genome sequencing of highly multidrug resistant A. baumannii will increase understanding of resistant mechanisms, the emergence of novel re-sistance, genetic relationships among the isolates, source tracking, and treatment decisions in selected patients. Objective:: This study revealed the genomic analysis to explore blaOXA-23 harboring XDRAB isolates in Thailand. Methods:: Whole-genome sequencing of the two XDRAB isolates was carried out on a HiSeq2000 Illumina platform and susceptibility on antimicrobials was conducted. Results:: Both isolates revealed sequence types of international, clone II-carrying, multiple antimicrobial-resistant genes—ST195 and ST451. They were resistant to antimicrobial agents in all drug classes tested for Acinetobacter spp. They carried 18 antimicrobial-resistant genes comprising of 4 -lactamase genes (blaOXA-23, blaOXA-66, blaTEM-1D, blaADC-25), 4 aminogly-coside-resistant genes (armA, aph(3')-Ia, aph(3'')-Ib, aph(6)-Id), 3 macrolide-resistant genes (amvA, mphE, msrE), 1 sulfon-amide-resistant gene (sul-2), 2 tetracycline-resistant genes (tetB, tetR), 1 resistant-nodulation-cell division (RND) antibiotic efflux pump gene cluster, 2 major facilitator superfamily (MFS) antibiotic efflux pump genes (abaF, abaQ), and 1 small multidrug-resistant (SMR) antibiotic efflux pump gene (abeS). Mutation of gyrA (S81L) occurred in both isolates. Conclusions:: Whole-genome sequencing revealed both blaOXA-23 harboring XDRAB isolates were clustered under interna-tional clone II with difference STs and carrying multiple antimicrobial-resistant genes conferred their resistance to antimi-crobial agents. Inactivation of antimicrobials and target modification by enzymes, and pumping antibiotics by efflux pump are mainly resistance mechanism of the XDRAB in this study.

Emergence and spread of a multidrug-resistant Acinetobacter baumannii clone producing both the carbapenemase OXA-23 and the 16S rRNA methylase ArmA

2012 ◽  
Vol 61 (5) ◽  
pp. 653-661 ◽  
Author(s):  
Gioconda Brigante ◽  
Roberta Migliavacca ◽  
Simone Bramati ◽  
Eleonora Motta ◽  
Elisabetta Nucleo ◽  
...  
Keyword(s):  
16S Rrna ◽  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
16S Rrna Methylase

Co-existence of bla OXA-23 and armA in multidrug-resistant Acinetobacter baumannii isolated from a hospital in South Korea

2013 ◽  
Vol 62 (6) ◽  
pp. 836-844 ◽  
Author(s):  
Seung Bok Hong ◽  
Kyeong Seob Shin ◽  
Jungsu Ha ◽  
Kyudong Han
Keyword(s):  
16S Rrna ◽  
South Korea ◽  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Pcr Assay ◽  
Clonal Relatedness ◽  
Multiplex Pcr Assay ◽  
Ciprofloxacin Resistance ◽  
Methylase Gene ◽  
16S Rrna Methylase

The co-existence of carbapenemase, 16S rRNA methylase and mutated quinolone resistance-determining regions (QRDRs) can cause serious difficulty in treating infections with multidrug-resistant Acinetobacter baumannii. In this study, we aimed to determine the mechanisms of imipenem, amikacin and ciprofloxacin resistance in A. baumannii isolates with resistance to these antibiotics. A total of 31 non-duplicate isolates of amikacin- and ciprofloxacin-resistant Acinetobacter isolates were identified from April to August 2010 from a single hospital in South Korea. To assess the clonal relatedness of the 31 Acinetobacter isolates, multilocus sequence typing, network phylogenetic analysis and enterobacterial repetitive intergenic consensus-PCR were utilized. Detection of OXA-type carbapenemase and 16S rRNA methylase was conducted using a multiplex PCR assay. The QRDRs of the gyrA and parC genes were amplified and sequenced. The result showed that 30/31 isolates harboured the bla OXA-23-like carbapenemase, which made them resistant to imipenem (MICs ≥16 µg ml−1). Twenty-eight of the 31 isolates were found to possess armA, a 16S rRNA methylase gene, and showed resistance to amikacin, arbekacin, gentamicin and tobramycin (MICs >256 µg ml−1). All of the isolates were determined to carry QRDR mutations in both gyrA and parC: a Ser83Leu substitution in gyrA and a Ser80Leu substitution in parC, causing a ciprofloxacin MIC ≥64 µg ml−1. In conclusion, A. baumannii with co-existence of carbapenemase, 16S rRNA methylase and mutated QRDRs are extremely prevalent in South Korea, which may cause serious problems in the treatment of A. baumannii infections using carbapenem, amikacin and ciprofloxacin.

scholarly journals Epidemiological Analysis of Multidrug-Resistant Acinetobacter baumannii Isolates in a Tertiary Hospital Over a 12-Year Period in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Meijie Jiang ◽  
Xia Chen ◽  
Shuang Liu ◽  
Zhijun Zhang ◽  
Ning Li ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Genetic Relatedness ◽  
Tertiary Hospital ◽  
Multidrug Resistant ◽  
Epidemiological Surveillance ◽  
Genetic Evolution ◽  
Detection Rates ◽  
Integrase Gene ◽  
The Past ◽  
Resistant Genes

Acinetobacter baumannii is an important nosocomial pathogen, which is multidrug resistant (MDR). Acinetobacter baumannii has become a major threat to public health worldwide due to its ability to easily acquire resistant genes. In order to analyze its epidemiology characteristics and the genetic evolution, A. baumannii isolates obtained from a Chinese tertiary hospital in the past 12 years (2008–2019), 295 isolates of non-repetitive A. baumannii, were recovered from patients and wards environments. The resistance genes were analyzed using antimicrobial susceptibility testing. The genetic relatedness of 295 isolates was identified by multilocus sequence typing (MLST) and eBURST analysis. It was found that the antibiotic-resistant and carbapenemase-resistant genes of all the 295 MDR A. baumannii in the hospital have not changed significantly over the past 12 years; all of them were resistant to multiple antibiotics except the polymyxin E and tigecycline. The results of drug-resistant genes showed that the detection rates of carbapenemase-resistant genes blaOXA−23, blaTEM−1, and blaOXA−66 were 97.6, 75.3, and 71.9%, respectively, which were detected almost every year from 2008 to 2019. Additionally, 16s rRNA methylation enzyme gene armA, aminoglycoside-resistant gene ant(3")-I, and class I integrase gene could also have a high positive rate. By MLST, these isolates were assigned to 12 sequence types (STs), including ST369, ST208, ST195, ST191, ST368, ST530, ST469, ST451, ST229, ST381, ST543, and ST1176. eBURST analysis showed that 9 STs with ST208 as the founder genotype belonged to Group 1 except for ST229, ST530, and ST1176. Therefore, most MDR A. baumannii isolates had a relatively close genetic relationship. Notably, the predominant ST208 and ST369 at the early stage changed to ST451 in 2019, indicating that the complex and diverse genetic background of the prevalence of A. baumannii isolates in the hospital. Overall, further epidemiological surveillance and genetic evolution analysis of A. baumannii are required, which can provide new strategies for the prevention and control of A. baumannii infections.

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