Evaluation of in vitro antibacterial potencies of oral antibiotics against sputum isolates

• Published in: Japanese journal of antibiotics Vol. 36; no. 8; pp. 2103 - 2108
• Main Authors: Yamada, H, Nakanishi, H, Yamaguchi, M, Nagasawa, Z
• Format: Journal Article
• Language: Japanese
• Published: Japan 01.08.1983
• Subjects: Administration, Oral; Anti-Bacterial Agents - pharmacology; Drug Resistance, Microbial; Escherichia coli - drug effects; Haemophilus influenzae - drug effects; Humans; Klebsiella pneumoniae - drug effects; Respiratory Tract Infections - microbiology; Sputum - microbiology; Staphylococcus aureus - drug effects; Streptococcus pneumoniae - drug effects
• ISSN: 0368-2781

Susceptibility of 162 sputum isolates to oral antibiotics was measured by an agar dilution method. The sputum isolates included S. pneumoniae 25 strains, S. aureus 30 strains, H. influenzae 37 strains, K. pneumoniae 51 strains and E. coli 19 strains. Minimal inhibitory concentration (MIC) values of cefaclor (CCL), cephalexin (CEX), ampicillin (ABPC) and minocycline (MINO) were measured for each strains. Eighty percent of S. pneumoniae strains were inhibited at 0.024 to 0.05 micrograms/ml of ABPC, 0.39 to 0.78 micrograms/ml of CCL, and 1.56 to 3.13 micrograms/ml of CEX and MINO. ABPC, CCL and CEX were considered to be effective clinically when they were used with the usual dosage. However, about 30% of strains were resistant to the usual dosage of orally administrated MINO. Eighty percent of S. aureus strains were inhibited at 0.20 to 0.39 microgram/ml of MINO and 3.13 to 6.25 micrograms/ml of the other 3 drugs. MINO is the most effective with the usual dosage. Twenty to 40% of strains showed resistance to CCL, CEX and ABPC. Eighty percent of H. influenzae strains were inhibited at 0.39 micrograms/ml of ABPC, 0.78 to 1.56 micrograms/ml of MINO, 3.13 micrograms/ml of CCL and 12.5 to 25 micrograms/ml of CEX. ABPC should be selected as the first choice antibiotic. However, there were 2 ABPC-resistant strains that were highly susceptible to CCL. Eighty percent of K. pneumoniae strains were inhibited at 0.39 to 0.78 micrograms/ml of CCL, 3.13 to 6.25 micrograms/ml of MINO and CEX, and 12.5 to 25 micrograms/ml of ABPC. CCL seemed to be only effective oral antibiotic for K. pneumoniae infection.(ABSTRACT TRUNCATED AT 250 WORDS)