Abstract:ObjectiveTo realize the isolation status of fastidious bacteria causing respiratory tract infection and antimicrobial susceptibility of fastidious bacteria to cefditoren pivoxil as well as the other 9 antimicrobial agents, so as to provide reference for clinical treatment.Methods Fastidious bacteria isolated from sputum of patients with respiratory tract infection during the year of 2005, 2007, 2008, and JanuaryJune in 2010 were collected. Antimicrobial susceptibility of fastidious bacteria were tested with KirbyBauer method recommended by Clinical and Laboratory Standards Institute (CLSI). ResultsA total of 462 isolates were isolated from 438 patients, βlactamaseproducing rate was as follows: Haemophilus influenzae (HI) 23.62% (30/127), Haemophilus parainfluenzae (HP) 2.51%(5/199), Moraxella catarrhalis (MC) 41.58% (42/101), penicillinresistant Streptococcus pneumoniae (SP) isolates was not found. The susceptibility rate (SR) of HI, HP, MC, and SP to cefditoren pivoxil was 96.30%, 94.36%, 100.00%, and 100.00%, respectively;The SR of HI and HP to cefotaxime, cefuroxime, cefaclor and cefazolin was 83.59%-93.33%, SR to amoxicillin/clavulanic acid was 91.67% and 88.21% respectively; SR of MC and SP to amoxicillin / clavulanic acid was 100.00%; SR of HI to clarithromycin was 87.96%,SR of HP, SP and MC to clarithromycin was 34.29%-59.00%; SR of 4 kinds of fastidious bacteria to tetracycline was 22.86%-63.00%; The resistant rate of HI,HP and MC to trimethoprim/sulfamethoxazole was 54.63%-3.33%.ConclusionCefditoren pivoxil has strong activity against fastidious bacteria causing respiratory tract infection; in order to reduce the emergence of drugresistant strain, clinicians should choose antimicrobial agents according to antimicrobial susceptibility test results.