Is it acceptable to select antibiotics for the treatment of community-acquired acute cystitis based on the antibiotics susceptibility results for uropathogens from community-acquired acute pyelonephritis in Korea?

Background: Uncomplicated acute cystitis (CA-UAC) is one of the most common infections treated with antibiotics in the community. However, few data on etiology of CA-UAC and its susceptibility to antibiotics are available, primarily because, in Korea, insurance does not allow reimbursement for microbiological evaluation of CA-UAC. However, microbiologic data on community-acquired uncomplicated acute pyelonephritis (CA-UAPN) are available. The objective of the study was to evaluate the question of whether microbiologic data on CA-UAPN can be used for treatment of CA-UAC; therefore, etiology and antimicrobial susceptibility were compared between pathogens of CA-UAC and those of CA-UAPN. Materials and Methods: During 2008, 538 CA-UACs and 1,265 CA-UAPNs were recruited retrospectively from 14 hospitals (UTI research group). Microbiologic data on etiology and susceptibility to antibiotics were collected retrospectively. Results: Urine culture was positive in 131 CA-UACs (131/469, 27.9%) and 719 CA-UAPNs (719/1249, 57.6%). Escherichia coli was the most common pathogen in both groups [83.2% (109/131) in CA-UAC vs. 91.9% (661/719) in CA-UAPN]. Susceptibility to common UTI regimens, such as ciprofloxacin, extended-spectrum cephalosporins, and trimethoprim/sulfamethoxazole did not differ between urinary pathogens of CA-UACs and CA-UAPNs, however, a significant difference was observed in rates of resistance to ampicillin/sulbactam (16.5% vs. 42.9%, P<0.001, respectively). Conclusions: Rates of resistance of E. coli from CA-UAC and CA-UAPN to most antibiotics did not differ. For proper treatment, further microbiological evaluation for CA-UAC is mandatory.