Prevalence of antibiotic-resistant bacteria colonized in neutropenic patients at Siriraj Hospital.

ABSTRACT

Objective: To determine prevalence of antibiotic-resistant bacteria colonized in throat and gastrointestinal tract of neutropenic patients at Siriraj Hospital. Methods: Adult patients who had recent neutropenia (absolute neutrophils <500) without any evidence of infections were recruited from January 2006 to March 2007 at Hematology Clinic and Department of Medicine, Siriraj Hospital. The throat swabs and stool samples or peri-anal swabs collected from the patients were sent for bacterial culture and antibiotic susceptibility testing. Results: There were 140 patients. 75 (53.6%) were females. The mean age was 49.3 years. The major underlying diseases were leukemia (53.6%) and lymphoma (33.3%). The main causes of neutropenia were chemotherapy-induced (84.3%) and the underlying diseases (15.7%). The bacteria commonly recovered from the stools or throat swabs of the patients were E.coli (77.9%), Klebsiella pneumoniae (46.4%), Enterobacter sp (20%) and Enterococcus sp. (45.7%). ESBL-producing gram negatives, Pseudomonas aeruginosa, Acinetobacter sp. and MRSA were found in 13.6%, 8.6%, 5% and 1.4% respectively. The susceptibility rate of E.coli, Klebsiella pneumoniae and Enterobacter sp. to co-trimoxazole, co-amoxiclav and ciprofloxacin was 51.5%, 73.2% and 74.8% respectively. Less than 50% of ESBL-producing gram negatives, Pseudomonas aeruginosa and Acinetobacter sp. were susceptible to the aforementioned oral antibiotics. Conclusion: Ciprofloxacin or co-amoxiclav seems to be a suitable oral antibiotic for preventing gram negative bacterial infection in ambulatory neutropenic patients in Thailand. However, the patients receiving such antibiotics still have more than 25% risk of carrying gram negatives resistant to both antibiotics.