Bacterial co-infections in cancer patients with COVID-19: predictors and antimicrobial resistance trends.

Introduction: Within the context of the coronavirus disease 2019 (COVID-19) pandemic, this study investigated the multifaceted challenges of bacterial infections in cancer patients with COVID-19. It focuses on clinical predictors, resistance patterns, and microbiological characteristics.

Methodology: Over 18 months, 112 adult cancer patients with coronavirus infection confirmed by reverse transcription polymerase chain reaction (RT-PCR) were enrolled. Bloodstream and respiratory samples were evaluated for bacterial infection using the Phoenix automation system for definitive species identification. In vitro susceptibility testing followed the Clinical Laboratory Standards Institute (CLSI) M100-Ed30 guidelines.

Results: Bacterial infections affected 25.0% of patients, encompassing bacteremia (21.4%) and respiratory tract infections (8.0%). Multivariable analysis identified hypertension, age < 60, and critical COVID-19 as significant predictors for bacterial infections (p-values = 0.024, 0.029, and 0.039, respectively). Most patients received antimicrobial therapy (93.8%), including last-resort carbapenems (52.7%) and colistin (8.9%). Thirty-three bacterial isolates were identified, with secondary infections doubling co-infection rates. Escherichia coli, Klebsiella species, and Staphylococcus aureus were the most common co-infecting species, while Klebsiella, Acinetobacter, and Pseudomonas species were more frequently associated with secondary infections. Alarmingly, 84.8% of isolates displayed high resistance patterns. All isolated S. aureus species were methicillin-resistant, and 62.5% of Gram-negative bacteria were exclusively sensitive to colistin.

Conclusions: The dominance of highly transmissible hospital-acquired bacterial species, with increased resistance and extensive antibiotic use in COVID-19 patients, necessitates strict infection control and antimicrobial stewardship. Developing customized antimicrobial strategies for cancer patients with COVID-19 is crucial to managing bacterial infections effectively and improving patient outcomes.