1. A genus of small, gram-negative bacteria that require blood factors for growth, commonly found in the respiratory tract of humans and animals.
Usage: medical/scientific term; often used in microbiology and clinical contexts; also spelled 'hemophilus' in U.S. English
2. Any bacterium of the genus Haemophilus, especially Haemophilus influenzae, which can cause respiratory infections and meningitis.
Usage: medical/clinical usage

Examples

• Haemophilus influenzae is a common cause of ear infections in children.
• The laboratory identified haemophilus bacteria in the patient's sputum sample.
• Vaccination against haemophilus influenzae type b has significantly reduced serious infections.
• Haemophilus species require X and V factors present in blood for optimal growth.
• The antibiotic resistance of haemophilus strains has become a growing clinical concern.