Molecular Epidemiology of Carbapenem-Resistant Acinetobacter baumannii From Khartoum State, Sudan

Abstract

Carbapenem resistant Acinetobacter baumannii (CRAb) is an important global pathogen contributing to increased morbidity and mortality in hospitalized patients, due to limited alternative treatment options. Nine international clonal (IC) lineages have been identified in many countries worldwide, however, data still lacks from some parts of the world, particularly in Africa. We hereby present the molecular epidemiology of MDR A. baumannii from four hospitals in Khartoum, Sudan, collected from 2017 to 2018. Forty-two isolates were whole-genome sequenced, and subsequent molecular epidemiology was determined by core genome MLST (cgMLST), and their resistomes identified. All isolates had an array of diverse antibiotic resistance mechanisms conferring resistance to multiple classes of antibiotics. We found a predominance (88%) of IC2 (with the intrinsic OXA-66 and acquired OXA-23), and some with NDM-1. IC2 isolates were sub-divided into 4 STs separated by 5 to 431 allelic differences, and with evidence of seven transmission clusters. Isolates belonging to IC1, IC5, and IC9 were also identified. These data illustrate that MDR IC2 A. baumannii are widely distributed in Khartoum hospitals and are in possession of multiple antibiotic resistance determinants.

Keywords: NDM-1; OXA; Sudan; antibiotic resistance; cgMLST; international clones.

TABLE 2

Resistome data for all isolates.

FIGURE 1

Ridom SeqSphere+ minimum spanning tree (MST) for 42 samples based on 2,390 alleles. Isolates grouped by color indicating the different STs (Pasteur scheme). Eight different STs were identified, belonging to IC1, IC2, IC5, IC9, and a singleton. Numbers between the nodes indicate the number of allelic differences. Shaded nodes represent transmission clusters (TC), and are numbered TC1-7.