Cloning of the haemocin locus of Haemophilus influenzae type b and assessment of the role of haemocin in virulence.
The bacteriocin haemocin (HMC) is produced by most type b strains of Haemophilus influenzae, including strains determined to be genetically diverse, and is toxic to virtually all non-type b strains of H. influenzae, both encapsulated and non-encapsulated. Examination of the deduced amino acid sequences of several genes upstream of the previously identified HMC immunity gene (hmcI) revealed several features common to class II bacteriocins of certain Gram-positive bacteria. Mutagenesis of the open reading frame immediately upstream of hmcI resulted in a loss of the HMC production phenotype. When an HMC-producing strai of H. influenzae and the HMC-deficient isogenic mutant were compared for invasion on the infant-rat model, the HMC-producing strain was found to invade significantly earlier; however, a significantly higher number of rats infected with the isogenic mutant became bacteraemic as compared with those infected with the HMC-producing parent.
Departments of Microbiology/Immunology and Allegheny University of the Health Sciences, and St Christopher's Hospital for ChildrenPA 19129USA.
Yvette M
YM
Murley
Departments of Microbiology/Immunology and Allegheny University of the Health Sciences, and St Christopher's Hospital for ChildrenPA 19129USA.
Thomas D
TD
Edlind
Departments of Microbiology/Immunology and Allegheny University of the Health Sciences, and St Christopher's Hospital for ChildrenPA 19129USA.
P Artur
PA
Plett
Departments of Microbiology/Immunology and Allegheny University of the Health Sciences, and St Christopher's Hospital for ChildrenPA 19129USA.|Departments of PhiladelphiaPA 19129USA.|Departments of Pediatrics,Allegheny University of the Health Sciences, and St Christopher's Hospital for Children,PA 19129USA.
John J
JJ
LiPuma
D000595:Amino Acid Sequence; D000818:Animals; D016470:Bacteremia / Q000209:etiology; D001430:Bacteriocins / Q000235:genetics*; D002460:Cell Line; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003588:Cytopathogenic Effect, Viral; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006192:Haemophilus Infections / Q000209:etiology; D019741:Haemophilus influenzae type b / Q000235:genetics* / Q000472:pathogenicity*; D006801:Humans; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016366:Open Reading Frames; D010641:Phenotype; D051381:Rats; D017207:Rats, Sprague-Dawley; D014774:Virulence / Q000235:genetics
D001430:Bacteriocins; D004269:DNA, Bacterial; C030520:haemocin