Novel mechanisms of resistance to β-lactam antibiotics in Haemophilus parainfluenzae: β-lactamase-negative ampicillin resistance and inhibitor-resistant TEM β-lactamases

Abstract

Clinical isolates of H. parainfluenzae express a variety of aminopenicillin resistance mechanisms, either alone or in combination, including PBP3 modifications, blaTEM-1 and IRT β-lactamase production.