CTX-M, TEM, and SHV Genes in , and Isolated from Hematologic Cancer Patients with Bacteremia in Uganda.

Purpose: We determined the phenotypic resistance to third-generation cephalosporins, phenotypic extended spectrum beta-lactamase (ESBL) prevalence, and genotypic prevalence of ESBL-encoding genes and in isolated from hematologic cancer patients with febrile neutropenia and bacteremia at the Uganda Cancer Institute (UCI).

Patients And Methods: Blood cultures from hematologic cancer patients with febrile neutropenia were processed in BACTEC 9120. and . isolates were identified using conventional biochemical methods. Antimicrobial susceptibility tests, phenotypic ESBL characterization, and genotypic characterization of the ESBL-encoding genes , and were determined for pure isolates of and .

Results: Two hundred and two patients were included in the study. Median age of patients was 19 years (IQR: 10-30 years). Majority (N=119, 59%) were male patients. Sixty (30%) of the participants had at least one febrile episode due to Enterobacteriaceae. Eighty-three organisms were isolated with being predominant (45, 54%). Seventy-nine (95%) Enterobacteriaceae were multidrug resistant. The ESBL phenotype was detected in 54/73 (74%) of Enterobacteriaceae that were resistant to third-generation cephalosporins. A higher proportion of Enterobacteriaceae with ESBL-positive phenotype were resistant to piperacillin-tazobactam (p=0.024), gentamicin (p=0.000), ciprofloxacin (p=0.000), and cotrimoxazole (p=0.000) compared to Enterobacteriaceae, which were sensitive to third-generation cephalosporins. The organisms were more susceptible to carbapenems and chloramphenicol than resistant. ESBL-encoding genes ( and ) were detected in 55 (75%) of the 73 Enterobacteriaceae that were resistant to third-generation cephalosporins. , was the most common ESBL-encoding gene identified with 50 (91%).

Conclusion: ESBL-producing Enterobacteriaceae are a predominant cause of bacteremia in hematologic cancer patients at UCI. The most common ESBL-encoding gene identified in the ESBL-PE was . Resistance to imipenem and meropenem was low.