The phenotypic and clinical characterisation of tigecycline coresistant carbapenem-resistant Enterobacterales observed at Inkosi Albert Luthuli Central Hospital, Durban, South Africa.

Abstract

Background Rising rates of carbapenem-resistant Enterobacterales (CRE) and limited therapeutic options have resulted in clinical dependence on tigecycline with subsequent emergence of tigecycline coresistant CRE (TGC Co-R CRE). Characterisation of TGC Co-R CRE is imperative to limiting its propagation. Objective We sought to determine the frequency, clinical implication, and microbiologic characteristics of TGC Co-R CRE at Inkosi Albert Luthuli Central Hospital from 2017 to 2019. Methodology We undertook a retrospective descriptive study. Data sources comprised the laboratory and hospital information systems. The frequency of TGC Co-R CRE was calculated. Specimen type, species, antimicrobial resistance, infection onset, antimicrobial exposure, age, sex, comorbidities, ward, and clinical outcome were characterised. Results The frequency of TGC Co-R CRE was 2/53 (3.8%) in 2017, 0/90 (0.0%) in 2018 and 4/123 (3.3%) in 2019. The decrease was not significant (p = 0.148). Six isolates were recorded. Acquisition was uniformly healthcare associated. Most cases (5/6; 83,3%) were female and two-thirds (4/6; 66.7%) were paediatric. Most cases were ICU patients (5/6; 83,3%). Most cases (5/6; 83.3%) were carbapenem-exposed. None were tigecycline-exposed. Comorbidities included HIV (2/6; 33.3%), SLE (1/6; 16.7%), burns (1/6; 16.7%) and surgery (2/6; 33.3%). Half the patients (3/6; 50.0%) demised. Specimens comprised peritoneal dialysis fluid (1/6; 16.7%), blood culture (1/6; 16.7%), endotracheal aspirate (2/6; 33.3%), catheter urine (1/6; 16.7%) and wound swab (1/6; 16.7%). Species comprised Klebsiella pneumoniae (3/6; 50.0%), Enterobacter cloacae (2/6; 33.3%) and Serratia species (1/6; 16.7%). All isolates were multidrug-resistant (MDR). Conclusion The advent of TGC Co-R CRE is a phenomenon warranting further research into prevalence, resistance mechanisms and acquisitional risk factors. The results of this study are of hypothesisgenerating value for subsequent research.