Phenotypic and genotypic characterization of Actinobacillus suis sensu stricto isolated from a dairy calf.

The species of the genus Actinobacillus have so far been associated with specific animal hosts, and A. suis sensu stricto, an opportunistic pathogen of swine, is rarely isolated from ruminants. We describe here the isolation of A.

Isolation and molecular characterization of a urease-negative Actinobacillus pleuropneumoniae mutant.

An atypical urease-negative mutant of Actinobacillus pleuropneumoniae serovar 2 was isolated in Japan. Nucleotide sequence analysis of the urease gene cluster revealed that the insertion of a short DNA sequence into the cbiM gene was responsible for the urease-negative activity of the mutant. Veterinary diagnostic laboratories should be watchful for the presence of aberrant urease-negative A.

Heparan Sulfate and Heparin Promote Faithful Prion Replication in Vitro by Binding to Normal and Abnormal Prion Proteins in Protein Misfolding Cyclic Amplification.

The precise mechanism underlying the conversion of normal prion protein (PrP) into abnormal prion protein (PrP) remains unclear. Protein misfolding cyclic amplification (PMCA), an in vitro technique used for amplifying PrP, results in PrP replication that preserves the strain-specific characteristics of the input PrP; thus, PMCA mimics the process of in vivo PrP replication. Previous work has demonstrated that in PMCA, nucleic acids are critical for PrP amplification, but little information has been reported on glycosaminoglycan (GAG) participation in PrP replication in vitro Here, we investigated whether GAGs play a role in the faithful replication of PrP by using a modified PMCA performed with baculovirus-derived recombinant PrP (Bac-PrP) as a substrate.

Nucleotide sequence analysis of a DNA region involved in capsular polysaccharide biosynthesis reveals the molecular basis of the nontypeability of two Actinobacillus pleuropneumoniae isolates.

The aim of our study was to reveal the molecular basis of the serologic nontypeability of 2 Actinobacillus pleuropneumoniae field isolates. Nine field strains of A. pleuropneumoniae, the causative agent of porcine pleuropneumonia, were isolated from pigs raised on the same farm and sent to our diagnostic laboratory for serotyping.