Molecular Epidemiology of Carbapenem-Resistant Acinetobacter baumannii Strains Isolated at the German Military Field Laboratory in Mazar-e Sharif, Afghanistan.

Paul G Higgins,Sandra Rojak,Holger Rohde,Meret Kniel,Ralf Matthias Hagen,Carsten Balczun,Hagen Frickmann

doi:10.3390/microorganisms9112229

Abstract

The study was performed to provide an overview of the molecular epidemiology of carbapenem-resistant Acinetobacter baumannii in Afghanistan isolated by the German military medical service during the Afghanistan conflict. A total of 18 isolates were collected between 2012 and 2018 at the microbiological laboratory of the field hospital in Camp Marmal near Mazar-e Sharif, Afghanistan, from Afghan patients. The isolates were subjected to phenotypic and genotypic differentiation and antimicrobial susceptibility testing as well as to a core genome multi-locus sequence typing (cgMLST) approach based on whole-genome next-generation sequence (wgNGS) data. Next to several sporadic isolates, four transmission clusters comprising strains from the international clonal lineages IC1, IC2, and IC9 were identified. Acquired carbapenem resistance was due to blaOXA-23 in 17/18 isolates, while genes mediating resistance against sulfonamides, macrolides, tetracyclines, and aminoglycosides were frequently identified as well. In conclusion, the assessment confirmed both the frequent occurrence of A. baumannii associated with outbreak events and a variety of different clones in Afghanistan. The fact that acquired carbapenem resistance was almost exclusively associated with blaOXA-23 may facilitate molecular resistance screening based on rapid molecular assays targeting this resistance determinant.

Highlights

Carbapenem-resistant Acinetobacter baumannii has been identified as a considerable menace for traumatic wounds associated with international wars and crises [1,2]
The core genome multi-locus sequence typing (cgMLST) analysis indicated four transmission clusters, comprising six, four, two, and two isolates, respectively (Figure 1). Three out of those four transmission clusters could be attributed to the international clones (IC) international clone 1 (IC1), IC2, and IC9, while the other cluster was genetically distinct from the international clonal lineages
Of 11 were singletons, three of them clustered within the international clonal lineages but without sufficient genomic similarity to suggest nosocomial transmission (Figure 1)

Summary

Introduction

Carbapenem-resistant Acinetobacter baumannii has been identified as a considerable menace for traumatic wounds associated with international wars and crises [1,2]. This applies to the recent military conflict in Afghanistan, in which German soldiers participated for nearly 20 years, from 2002 until 2021. Most reports on war trauma-associated A. baumannii infections or colonization from the recent Afghanistan conflict were, provided by the medical services of the 4.0/). In 2008, the US Armed Forces Medical Service reported an increased frequency of A. baumannii isolates associated with osteomyelitis in war-injured soldiers fighting for the OEF mission [6], and in the same year, an increased acquisition risk of resistant A. baumannii isolates at OEF deployment sites was documented [7]. As reported in 2011, the colonization rate with A. baumannii was highest at the beginning of the mission and declined in the following years [9]

Methods

Results

Discussion

Conclusion