Dataset Information

Molecular Detection of Carbapenemase-Encoding Genes in Multidrug-Resistant Acinetobacter baumannii Clinical Isolates in South Africa.

ABSTRACT:

Introduction

Carbapenem-resistant Acinetobacter baumannii has been responsible for an increasing number of hospital-acquired infections globally. The study investigated the prevalence of carbapenemase-encoding genes in clinical multidrug-resistant A. baumannii strains.

Materials and methods

A total of 100 nonduplicate multidrug-resistant A. baumannii strains were cultured from clinical samples obtained from healthcare facilities in the O. R. Tambo district. The strains were confirmed by detecting the intrinsic bla _OXA-51-like gene. Antimicrobial susceptibility testing was performed by VITEK^® 2 and autoSCAN-4 systems. The MIC of imipenem and meropenem was rechecked by E-test. Colistin MIC was confirmed by the broth microdilution method. Real-time PCR was performed to investigate the presence of carbapenemase-encoding genes.

Results

Most strains showed high resistance rates (>80%) to the antibiotics tested. Resistance to amikacin, tetracycline, and tigecycline were 50%, 64%, and 48%, respectively. All strains were fully susceptible to colistin. The bla _OXA-51-like was detected in all strains whilst bla _OXA-23-like, bla _OXA-58-like, bla _OXA-24-like, bla _IMP-1, bla _VIM, and bla _NDM-1 were found in 70%, 8%, 5%, 4%, 3%, and 2% of strains, respectively. None of the tested strains harboured the genes bla _SIM and bla _AmpC. The coexistence of bla _OXA-23-like, and bla _IMP-1 or bla _OXA-58-like was detected in 1% and 2% strains, respectively. A distinct feature of our findings was the coharbouring of the genes bla _OXA-23-like, bla _OXA-58-like, and bla _IMP-1 in 2% strains, and this is the first report in the Eastern Cape Province, South Africa. The intI1 was carried in 80% of tested strains whilst ISAba1/bla _OXA-51-like and ISAba1/bla _OXA-23-like were detected in 15% and 40% of the strains, respectively. The detection of bla _OXA-23-like, ISAba1/bla _OXA-51-like, ISAba1/bla _OXA-23-like, and bla _OXA-23-like, bla _OXA-58-like, and bla _IMP-1 carbapenemases in strains had a significant effect on both imipenem and meropenem MICs.

Conclusions

Results showed a high level of oxacillinases producing A. baumannii circulating in our study setting, highlighting the need for local molecular surveillance to inform appropriate management and prevention strategies.

SUBMITTER: Anane YA

PROVIDER: S-EPMC7306865 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Publications

Molecular Detection of Carbapenemase-Encoding Genes in Multidrug-Resistant <i>Acinetobacter baumannii</i> Clinical Isolates in South Africa.

Anane Yaw Adjei YA Apalata Teke T Vasaikar Sandeep S Okuthe Grace Emily GE Songca Sandile S

International journal of microbiology 20200613

<h4>Introduction</h4>Carbapenem-resistant <i>Acinetobacter baumannii</i> has been responsible for an increasing number of hospital-acquired infections globally. The study investigated the prevalence of carbapenemase-encoding genes in clinical multidrug-resistant <i>A. baumannii</i> strains.<h4>Materials and methods</h4>A total of 100 nonduplicate multidrug-resistant <i>A. baumannii</i> strains were cultured from clinical samples obtained from healthcare facilities in the O. R. Tambo district. Th ...[more]

PMID: 32612659

Similar Datasets

Project description:Carbapenem resistant Acinetobacter baumannii is a major global concern, especially in countries of the Middle East and North Africa, where the antibiotic resistance rates are on the rise. The aim of this study was to study the genomic characteristics and antimicrobial susceptibility profile of thirty-six multidrug resistant A. baumannii clinical isolates obtained in hospitals from Alexandria, Egypt. Antibiotic resistance rates were estimated by determination of Minimum Inhibitory Concentrations. Carbapenemase genes, other antibiotic resistance genes and virulence factors were then screened by the use of Whole Genome Sequencing. Isolates were also subjected to Multi Locus Sequence Typing (MLST) using the Pasteur Scheme and to core genome MLST to study their clonal relatedness. In addition, plasmid analysis was performed by the use of a commercial kit and S1- Pulsed Field Gel Electrophoresis, and Hybridization experiments with DIG-labeled DNA probes for bla NDM-1, blaPER-7 and bla GES-like were performed to locate these genes. The majority of isolates were resistant to β-lactams (including carbapenems), fluoroquinolones, aminoglycosides and trimethoprim; and some showed resistance to cefiderocol and minocycline. We identified 8 different bla OXA-51-like variants including bla OXA-51, bla OXA-64, bla OXA-65, bla OXA-66, bla OXA-68, bla OXA-91, bla OXA-94 and bla OXA-336; bla OXA-23, bla NDM-1, bla PER-7, bla GES-like and bla ADC-like and other antibiotic resistance genes, some of these genes were within transposons or class 1 integrons. Multiple virulence factors responsible for adherence, biofilm production, type II and type VI secretion systems, exotoxins, exoenzymes, immune modulation and iron uptake were observed and 34 out of 36 isolates showed motility. Thirty-five out of 36 isolates clustered with International Clones 2, 4, 5, 7, 8 and 9; and 9 STs were identified including ST570, ST2, ST600, ST15, ST113, ST613, ST85, ST158, ST164. Plasmids ranging in size from 1.7 to 70 kb were found; bla NDM-1 and blaPER-7 genes were located in the chromosome and bla GES-like genes were simultaneously located in the chromosome and in a plasmid of 70kb. In conclusion, this study revealed a wide spectrum of antibiotic resistance genes and a variety of lineages among A. baumannii isolated in hospitals from Alexandria, and highlights the importance of investigating the molecular epidemiology to control the spread of multi-drug resistant isolates.