Unknown

Dataset Information

0

Identification and characterization of a DNA region involved in the export of capsular polysaccharide by Actinobacillus pleuropneumoniae serotype 5a.


ABSTRACT: Actinobacillus pleuropneumoniae synthesizes a serotype-specific capsular polysaccharide that acts as a protective barrier to phagocytosis and complement-mediated killing. To begin understanding the role of A. pleuropneumoniae capsule in virulence, we sought to identify the genes involved in capsular polysaccharide export and biosynthesis. A 5.3-kb XbaI fragment of A. pleuropneumoniae serotype 5a J45 genomic DNA that hybridized with DNA probes specific for the Haemophilus influenzae type b cap export region was cloned and sequenced. This A. pleuropneumoniae DNA fragment encoded four open reading frames, designated cpxDCBA. The nucleotide and predicted amino acid sequences of cpxDCBA contained a high degree of homology to the capsule export genes of H. influenzae type b bexDCBA, Neisseria meningitidis group B ctrABCD, and, to a lesser extent, Escherichia coli K1 and K5 kpsE and kpsMT. When present in trans, the cpxDCBA gene cluster complemented kpsM::TnphoA or kpsT::TnphoA mutations, determined by enzyme immunoassay and by restored sensitivity to a K5-specific bacteriophage. A cpxCB probe hybridized to genomic DNA from all A. pleuropneumoniae serotypes tested, indicating that this DNA was conserved among serotypes. These data suggest that A. pleuropneumoniae produces a group II family capsule similar to those of related mucosal pathogens.

SUBMITTER: Ward CK 

PROVIDER: S-EPMC175351 | BioStudies | 1997-01-01T00:00:00Z

SECONDARY ACCESSION(S): U36397

REPOSITORIES: biostudies

Similar Datasets

2004-01-01 | S-EPMC516343 | BioStudies
1998-01-01 | S-EPMC104904 | BioStudies
2009-01-01 | S-EPMC2705073 | BioStudies
1000-01-01 | S-EPMC173541 | BioStudies
1000-01-01 | S-EPMC173100 | BioStudies
2014-01-01 | S-EPMC4064151 | BioStudies
1998-01-01 | S-EPMC108349 | BioStudies
2015-01-01 | S-EPMC4478738 | BioStudies
2017-01-01 | S-EPMC5496888 | BioStudies
2020-01-01 | S-EPMC7321687 | BioStudies