Haemophili in the human oarl cavity.

Abstract

For the purpose of clarifing their ecology, Haemophili which inhabit the upper respiratory tracts, were isolated from saliva and dental plaque of 38 heahhy human adults. The isolates were then classified by biochemical properties, and were also tested for their sensitivity to antibiotics.

The average counts of Haemophilus in the saliva and that in dental plaque were 6.6×10⁶/ml and 6.0x10⁵/g, raspectively.

Three hundred sixteen isolates were analyzed by biochemical properties. Eleven were identified as H. influenzae which were found only in saliva and then belonged to biotypes I~V, but not to Vl. Two hundred twenty-nine isolates were identified as H. parainfluenzae. Of those biotype I and Ⅲ were found in both saliva and dental plaque, but biotype Ⅱ was found only in saliva. Sixty four H. paraphrophilus were isolated from both saliva and dental plaque. Five isolates H. aphrophilus were found only in dental plaque, and 7 H. parahaemolyticus only in saliva.

One hundred one strains comprising H. influenzae, H. parainfluenzae, H. aphrophilus, H. paraphrophilus and H. parahaemolyticus were tested for using different 20 antibiotics. Among 6 penicillins, PCG showed weak antibacterial activity, however PIPC, APPC, MZPC exerted very strong antibacterial activity. Among 8 cepharosporins CZX exhibited strong antibacterial activity and its peak minimum inhibitory concentration (MIC) was 0.5μg/ml.

Some isolates showed high resistance to PCG, ABPC, SBPC, CXM, CZX, CEX or CCL (their MIC being≧100μg/ml), The penicillin-resistance strains produced β-lactamase.