Annual change of ampicillin susceptibility of H. influenzae and the clinical efficacy of penicillins in bronchopulmonary infections caused by β-lactamase negative

Abstract

The clinical efficacy of penicillins for 43 episodes of bronchopulmonary infections due to β-lactamase negative H. influenzae with an ampicillin (ABPC)-MIC of 2μg/ml isolated from washed sputum was evaluated. Oral administration of amoxicillin (AMPC) and parenteral administration of ABPC proved effective for bronchopulmonary infections caused by β -lactamase negative H . influenzae with an ABPC-MIC of 2μg/ml.
Frequent use of new oral cephems entails the problem of increase in β -lactamase nagative ampicillin resistant H. influenzae (BLNAR) and penicillin-G resistant S. pneumoniae (PRSP), which become multiple drug resistant with mutation of penicillin-binding proteins (PBPs). Oral administration of AMPC with good mobility to the airway is better than β-lactamase stable neworal cephem preparations which is easy to cause the mutation of PBPs.
It is necessary to keep in mind the suitable antimicronbial chemotherapy that a resistant strains seldom appears, paying attention to the trend of BLNAR.