A Study of Activities of Cefdinir and Other Antibacterial Agents in Vitro Against Normal Respiratory Tract Pathogens in Community-acquired Infections

Objective:To test the antibacterial activity of cefdinir in vitro against the common clinical pathogens of community acquired respiratory infection and compare with those of cefuroxime,cefaclor,azithromycin and ampicillin.Methods:MIC values of antibacterial agents were determined with agar dilution method.Results:Two hundred strains were tested and results showed that the susceptibility rate of cefdinir against methicillin sensitive Staphylococcus aureus(MSSA)was 100%,and the activity of cefdinir against MSSA,which was similar to those of cefuroxime and cefaclor,was more active than that of azithromycin;The susceptibility rate of Penicillin sensitive Streptococcus pneumoniae(PSSP) to those three cephalosprins was 100%,and the MIC_ 90 of cefdinir was 025mg/L,which was similar to that of cefuroxime.The activity of cefdinir against Gram-negative bacteria was excellent and with the MIC_ 90 of 025,1,0,25mg/L respectively when against ESBLs-negative-Klebsiella pneumoniae,Haemophilus influenzae and Moraxella catarrhalis,the susceptibility rate was up to 972%～100%.Haemophilus influenzae was resistant to ampicillin and its susceptibility was only 861%,but the lowest MIC_ 50 could be 006mg/L.Methicillin resistant Staphylococcus aureus(MRSA),Penicillin resistant Streptococcus pneumoniae(PRSP) and ESBLs Producing Klebsiella pneumoniae were all resistant to those four antiboitics.The activity of cefdinir against Penicillin intermediate Streptococcus pneumoniae(PISP) was more active than second generation cephalosprins and azithromycin.Conclusions:Cefdinir has an ideal3 antibacterial activity in vitro against Gram-positive coccus and Gram-negative bacteria,and can be a good choice for the treatment of community acquired respiratory infection.