Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Feb 11:8:31.
doi: 10.1186/s13756-019-0491-9. eCollection 2019.

Phenotypic and molecular characterisations of carbapenem-resistant Acinetobacter baumannii strains isolated in Madagascar

Pierrette Landrie Simo Tchuinte #  1 , Mamitiana Alain Noah Rabenandrasana #  1 , Carole Kowalewicz  1 , Volasoa Herilalaina Andrianoelina  1 , Andriniaina Rakotondrasoa  1 , Zafitsara Zo Andrianirina  2 , Vincent Enouf  3 , Elisoa Hariniaina Ratsima  1 , Frédérique Randrianirina  1 , Jean-Marc Collard  1
Affiliations

Phenotypic and molecular characterisations of carbapenem-resistant Acinetobacter baumannii strains isolated in Madagascar

Pierrette Landrie Simo Tchuinte et al. Antimicrob Resist Infect Control. .

Abstract

Background: The present study aimed to perform a deep phenotypic and genotypic analysis of 15 clinical carbapenem-resistant Acinetobacter baumannii (CRAb) strains isolated in Madagascar between 2008 and 2016 from diverse sources.

Methods: CRAb isolates collected from the Clinical Biology Centre of the Institut Pasteur of Madagascar, from the neonatal unit of Antananarivo military hospital, and from intensive care units of Mahajanga Androva and Antananarivo Joseph Ravoahangy Andrianavalona (HJRA) hospitals were subjected to susceptibility testing. Whole-genome sequencing allowed us to assess the presence of antibiotic-resistance determinants, insertion sequences, integrons, genomic islands and potential virulence factors in all strains. The structure of the carO porin gene and deduced protein (CarO) were also assessed in CRAb isolates.

Results: All isolates were found to be multidrug-resistant strains. Antibiotic-resistance genes against six classes of antimicrobial agents were described. The four carbapenem-resistance genes: blaOXA-51 like , blaOXA-23 , blaOXA-24 , and blaOXA-58 genes were detected in 100, 53.3, 13.3, and 6.6% of the isolates, respectively. Additionally, an ISAba1 located upstream of blaOXA-23 and blaADC-like genes was observed in 53.3 and 66.7% of isolates, respectively. Further, Tn2006 and Tn2008 were found associated to the ISAba1-blaOXA-23 structure. An 8051-bp mobilizable plasmid harbouring the blaOXA-24 gene was isolated in two strains. In addition, 46.7% of isolates were positive for class 1 integrons. Overall, five sequences types (STs), with predominantly ST2, were detected. Several virulence genes were found in the CRAb isolates, among which two genes, epsA and ptk, responsible for the capsule-positive phenotype, were involved in A. baumannii pathogenesis.

Conclusions: This study revealed the presence of high-level carbapenem resistance in A. baumannii with the first description of OXA-24 and OXA-58 carbapenemases in Madagascar. This highlights the importance of better monitoring and controlling CRAb in Madagascan hospitals to avoid their spread.

Keywords: Acinetobacter baumannii; Antimicrobial resistance; Carbapenem-resistance.

PubMed Disclaimer

Conflict of interest statement

Not applicable.Not applicable.Not applicable.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
a and b Schematic representation of two transposons described in this study: (a) Tn2006; (b) Tn2008 and their genetic environment. The nine-bp target site duplication of Tn2006 and Tn2008 are represented underlined. Insertion elements are represented by ISAba1 and ISAba2. Pout: ISAba1 promoter; orf1: orf encoding for a hypothetical protein; ATPase: gene encoding the putative AAA ATPase; DEAD, gene encoding the putative DEAD helicase
Fig. 2
Fig. 2
Circular map of the pOXA-24_AB334 plasmid. The two mobilization genes are represented by mobL and mobS. orf1, orf2 and orf3: genes encoding for hypothetical proteins
Fig. 3
Fig. 3
Phylogenetic analysis of 15 A. baumannii isolates. The phylogenetic tree was constructed with the Harverst suite for core genome alignment and visualization
See this image and copyright information in PMC

References

    1. Molina L, Udaondo Z, Duque E, Fernández M, Molina-Santiago C, Roca A, et al. Antibiotic resistance determinants in a Pseudomonas putida strain isolated from a hospital. PLoS One. 2014;9(1):e81604. doi: 10.1371/journal.pone.0081604. - DOI - PMC - PubMed
    1. Vijayakumar S, S BA, Kanthan K, Veeraraghavan B. Whole-genome shotgun sequences of seven colistin-resistant Acinetobacter baumannii isolates from bacteraemia. J Glob Antimicrob Resist. 2018;12:155–156. doi: 10.1016/j.jgar.2018.01.012. - DOI - PubMed
    1. Hujer KM, Hujer AM, Endimiani A, Thomson JM, Adams MD, Goglin K, et al. Rapid determination of quinolone resistance in Acinetobacter spp. J Clin Microbiol. 2009;47(5):1436–1442. doi: 10.1128/JCM.02380-08. - DOI - PMC - PubMed
    1. Horii T, Muramatsu H, Iinuma Y. Mechanisms of resistance to fluoroquinolones and carbapenems in Pseudomonas putida. J Antimicrob Chemother. 2005;56(4):643–647. doi: 10.1093/jac/dki254. - DOI - PubMed
    1. Mugnier PD, Poirel L, Naas T, Nordmann P. Worldwide dissemination of the blaOXA-23 Carbapenemase gene of Acinetobacter baumannii. Emerg Infect Dis. 2010;16(1):35–40. doi: 10.3201/eid1601.090852. - DOI - PMC - PubMed

Publication types

MeSH terms