s The Spectrum of Cefditoren for Lower Respiratory Tract Infections (LRTIs) in Surabaya

Background: Empirical antibiotics among outpatients with Lower Respiratory Tract Infections (LRTIs) are scarcely allocated in Indonesia. The study aims to evaluate the pathogens causing LRTIs, drug sensitivity test and the minimum inhibitory concentrations of 90% (MIC90) of Cefditoren, Azithromycin, Amoxicillin-Clavulanic Acid, and Cefixime. Methods: The study was performed in adult outpatients with LRTI that can be expectorated. Patients with diabetes mellitus, HIV, lung tuberculosis, renal or hepatic failure, and hemoptysis were excluded. We performed bacterial culture, antibiotic sensitivity, and MIC measurement of four antibiotics. Results: There were 126 patients with LRTIs, and 61 patients were eligible for the study. We identified 69 bacteria. We found Klebsiella pneumonia (n=16; 26.23%), Staphylococcus aureus (n=11; 18%), Pseudomonas aeruginosa (n=8; 13.11%), Acinetobacter baumanii complex (n= 4; 6.55%), Streptococcus pneumonia (n=3; 4.9%) and others bacteria as causes of LRTI. Testing MIC90 of Cefditoren and three empiric antibiotics on LRTI found that Cefditoren has a lower MIC of 90 for K. pneumonia (0.97(2.04) μg.mL^-1) and S. pneumonia (0.06(0.00)μg.mL^-1) than other antibiotics, but almost the same as Cefixime ((0.05(0.16)μg.mL-1) and (0.38(0.17)μg.mL-1). MIC90 Cefditoren for S.aureus (3.18(3.54)μg.mL-1) and P.aeruginosa (9.2(3.53)μg.mL-1) is lower than Cefixime but higher than Azithromycin and Amoxicillin-Clavulanic acid. Reference data MIC90 of Cefditoren for LRTI bacteria is lower than the other three oral empirical antibiotics. Conclusion : In vitro studies of an outpatient LRTI in Surabaya found gram-negative bacteria dominant. Cefditoren can inhibit K.pneumonia and S.pneumonia has a lower MIC90 compared to other antibiotics. Cefditoren can inhibit gram-negative and positive bacteria causing LRTI.