Ferrous iron-binding protein Omb of Salmonella enterica serovar Choleraesuis promotes resistance to hydrophobic antibiotics and contributes to its virulence.

Salmonella enterica serovar Choleraesuis (SC) is an important enteric pathogen that causes serious systemic infections in swine and humans. To identify the genes required for resistance to antimicrobial peptides, we constructed a bank of SC transposon mutants and screened them for hypersensitivity to the cationic peptide polymyxin B. Here we report one isolated polymyxin B-susceptible mutant that also exhibited increased sensitivity toward human neutrophil peptide alpha-defensin 1 (HNP-1) and hydrophobic antibiotics including erythromycin and novobiocin.

Cloning and characterization of the lipase and lipase activator protein from Vibrio vulnificus CKM-1.

The gene (lipA) encoding the extracellular lipase and its downstream gene (lipB) from Vibrio vulnificus CKM-1 were cloned and sequenced. Nucleotide sequence analysis and alignments of amino acid sequences suggest that Lip Ais a member of bacterial lipase family I.1 and that LipB is a lipase activator of LipA.

Cloning of a gene encoding a unique haemolysin from Klebsiella pneumoniae and its potential use as a species-specific gene probe.

A gene, designated khe, that encodes a haemolysin of Klebsiella pneumoniae CMC-1 has been cloned and sequenced. When expressed in Escherichia coli, a unique peptide of approximately 20kDa was identified. Nucleotide sequence analysis predicted a single open reading frame (ORF) of 486bp encoding a 162 amino acid polypeptide with an estimated pI of 6.

Molecular analysis and expression of the extracellular lipase of Aeromonas hydrophila MCC-2.

The structural gene encoding the extracellular lipase of Aeromonas hydrophila MCC-2 was cloned and found to be expressed in Escherichia coli using its own promoter. When the cloned gene (lip) was expressed in E. coli minicells, an 80 kDa protein was identified.