Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Gram-positive transposon Tn916 was introduced into two strains of Haemophilus paragallinarum by electroporation of the suicide plasmid pAM120 (pGL101::Tn916). Tetracycline resistant mutants of H. paragallinarum strains Tw-1 and 221 were recovered at frequencies of 2.1 x 10(-6) and 4.5 x 10(-7) per viable cell electroporated, respectively. Tn916 generates stable single insertions within different sites of the H. paragallinarum chromosome. One Tw-1::Tn916 mutant had the Tn916 insertion in the cryptic plasmid p250. This study indicates the potential use of Tn916 as a genetic tool for insertional mutagenesis of H. paragallinarum.
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PMID:Transposon mutagenesis of Haemophilus paragallinarum with Tn916. 905 24

The full sequence of plasmid p250, isolated from Haemophilus paragallinarum strain HP250, has been obtained. The plasmid contains seven ORFs: a putative integrase, a putative replication protein (repB) and five ORFs similar to those from the haemocin (bacteriocin) hmcDCBAI operon from Haemophilus influenzae. Of 19 other non-plasmid-containing H. paragallinarum strains screened (11 serovar reference strains and 8 field isolates), 17 strains produced haemocin and were resistant to killing by strain HP250. These strains, unlike strain HP250, have a chromosomally encoded haemocin operon. A number of other members of the family Pasteurellaceae were tested for haemocin sensitivity. Pasteurella avium, Pasteurella volantium and Pasteurella species A, all non-pathogenic bacteria found in the respiratory tract of chickens suffering from respiratory diseases, were sensitive to H. paragallinarum haemocin. However, amongst the pathogenic Pasteurellaceae, 50 % of P. multocida isolates and all five isolates of Pasteurella haemolytica tested were sensitive to the haemocin. Given the prevalence of haemocin production in H. paragallinarum strains, it may play a role in aiding colonization by inhibiting other Gram-negative bacteria that are associated with the respiratory tract in chickens. The origin of replication from plasmid p250 has been used to generate an Escherichia coli-H. paragallinarum shuttle vector which may be useful in genetically manipulating H. paragallinarum.
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PMID:Genetic analysis of a plasmid encoding haemocin production in Haemophilus paragallinarum. 1460 Feb 29