Background: Bacterial infection is a frequent complication in cancer and immunocompromised patients. The emergence of antibiotic resistance is a significant health problem and cancer patients are at risk of repeated infections with drug-resistant bacteria.

Objective: This investigation aimed to identify predictors of repeat infections of Escherichia coli and Klebsiella pneumoniae and drug resistance in cancer patients admitted to the intensive care unit (ICU) in Upper Egypt.

Methods: Blood, urine, sputum, pus, and mouth and nose swabs were collected form patients at the Pediatric Oncology and Medical Oncology ICUs during the period from February 2017 to May 2018. The samples were assessed by antibiotic susceptibility test and further evaluated by genetic testing for the temoniera (TEM) gene of β-lactamase. Samples positive for K. pneumoniae and E. coli were included and isolates positive for other microorganisms were excluded.

Results: The study included 107 patients with malignant neoplasms and 136 samples. Repeated infection with K. pneumoniae and E. coli occurred in 31% and 22.45% of patients, respectively. Patients stayed for a longer period in the ICU were more likely to have repeated infections (OR 1.25, 95%CI 1.10-1.44, p=0.001) after control of other confounding factors. The type of malignant neoplasm whether it was hematologic or solid tumor (OR 7.46, 95% CI 2.56-21.7, p=0.0002) and a longer prior stay in the ICU (OR 1.14, 95% CI 1.02-1.28, p=0.025) remained the independent predictors for the drug resistance in the last infection. The TEM type of β-lactamase was encoded in 48.68% and 66.67% of K. pneumoniae and E. coli, respectively.

Conclusion: Reinfection with K. pneumoniae and E. coli in patients with cancer can occur as the number of days in the hospital increases. Total prior days spent in the ICU by cancer patients were independently associated with both repeated infections and drug resistance. Samples from patients with hematologic neoplasms were associated with drug resistance.