Molecular characterization of extended spectrum beta-lactamase-producing Enterobacterales from urinary tract infections in Burundi.

BACKGROUND

The production of β-lactamases by the Enterobacterales family is currently the leading cause of antibiotic resistance. Urinary tract infections (UTIs) account for 25% of all infections, and UTIs caused by extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) constitute a serious public health concern in children and adult patients. The aim of this study was to describe the antimicrobial susceptibility profiles and molecular characteristics of ESBL-PE isolates from UTIs in Burundi.

METHODS

A laboratory-based cross-sectional study involving 247 isolates of Enterobacterales was carried out at six selected hospital sites in Burundi. The bacterial isolates, which were collected over a nine-month period, were randomly selected from the biobank of isolated and identified enteric gram-negative bacteria from urine samples from UTI patients. The clinical and demographic characteristics of the UTI patients were extracted from the OpenClinic GA Information System via a structured data collection sheet. The ESBL-PEs were confirmed via a double-disk synergy test and PCR methods. The chi-square test was used to determine the relationship between epidemiological and microbiological variables; as well as the presence of ESBL-PE isolates.

RESULTS

Among the 247 Enterobacterales isolates, Escherichia coli (72.4%) and Klebsiella pneumoniae (14.5%) predominated. Among the isolates, 28.74% were phenotypically positive for ESBL production. The high percentage of resistant isolates to antibiotics were observed for tetracycline (91.5%), amoxycillin-clavulanic acid (72.6%) and cotrimoxazole (65.6%). There was no resistance to either meropenem or imipenem. The most effective antibiotics were nitrofurantoin (91.1%) and amikacin (71.7%). The majority of the blaCTX-M genes (80.28%) were found in ESBL-PE isolates from UTI patients. The percentages of blaTEM and blaSHV genes were 53.52% and 25.35%, respectively. The blaCTX-M and blaTEM genes were the most prevalent coexisting resistance genes (26.8%), followed by the group of blaCTX-M, blaTEM, and blaSHV genes (18.3%). The blaTEM and blaSHV genes did not coexist in this study.

CONCLUSION

The blaCTX-M gene is predominant in UTIs, which are caused primarily by the ESBL-PE strains acquired in hospital and community settings. Amikacin, nitrofurantoin, imipenem and meropenem could be the drugs of choice for treating ESBL-PE in Burundi. On the basis of these findings, we suggest the development of infection prevention and control interventions, antibiotic stewardship policies and the establishment of routine surveillance of ESBL-PE in Burundi. The transmission dynamics of TEM- and CTX-M-type ESBL-PE need to be further understood in Burundian hospital and community settings.