Evaluation of Fecal Colonization with Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae and Risk Factors among Cancer Patients in Eastern Iran

This research aimed to estimate the prevalence of extended-spectrum b-lactamase-producing Enterobacteriaceae (ESBL-PE) in stool samples of patients with different types of cancer.

Stool samples or deep rectal swabs were collected from cancer cases from January 2017 to December 2018. After species identification, in order to detect ESBL-PE, double-disk synergy test (DD test) was used. Disk diffusion procedure was conducted to determine the susceptibility of bacteria to antimicrobials. Lastly, antibiotic resistance genes including bla genes were characterized via polymerase chain reaction (PCR).

Among 100 patients enrolled in this study, 50 (50%) were ESBL carriers. Escherichia coli was the most prevalent bacterium isolated (85%). Genotyping of EBSL-PE encoding genes using PCR showed that the prevalence rates of blaCTX-M and blaCTX-M-15 genes were 94 (47 of 50) and 90% (45 of 50), respectively, which were higher than those of blaTEM (80%, 40 of 50) and blaSHV genes (34%, 17of 50). There was no significant association between ESBL-PE fecal carriage and age (p= .68), sex (p = .49), time of diagnosis (p= .21), antibiotic therapy for the past three months (p= .77), and history of chemotherapy (p= .49). Finally, it was determined that cancer type was an associated risk factor for ESBL-PE fecal carriage in cancer patients. 

This research emphasizes regular bacterial monitoring, and that antibiotic stewardship plans ought to be performed among cancer patients to prohibit further spread of ESBL-PE with confined therapeutic options.