Characterization of an atypical Actinobacillus pleuropneumoniae serovar 2 isolate with a rough-type lipopolysaccharide

• Published in: Journal of Veterinary Medical Science Vol. 85; no. 2; pp. 157 - 162
• Main Authors: TO, Ho, AKAIKE, Yuta, KON, Michiha, KOIKE, Fumiko, SHIBUYA, Kazumoto, SASAKAWA, Chihiro, NAGAI, Shinya
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 2023; Japan Science and Technology Agency; The Japanese Society of Veterinary Science
• Subjects: Actinobacillus Infections - veterinary; Actinobacillus pleuropneumoniae; Actinobacillus pleuropneumoniae - genetics; Animals; atypical; Bacteriology; Biosynthesis; C-Terminus; Capsular polysaccharides; Gene clusters; Gene deletion; Lipopolysaccharides; Nucleotide sequence; Polysaccharides; rough-type lipopolysaccharide; Sequence analysis; Serogroup; Serotyping - veterinary; Swine; Swine Diseases; wcaJ; swine; wcaJ; rough-type lipopolysaccharide; Actinobacillus pleuropneumoniae; atypical
• ISSN: 0916-7250; 1347-7439
• DOI: 10.1292/jvms.22-0258

We describe phenotypic and genetic characterization of an atypical Japanese Actinobacillus pleuropneumoniae isolate OT761. Nucleotide sequence analysis revealed that gene clusters involved in capsular polysaccharide and O-polysaccharide (O-PS) biosynthesis of the isolate were nearly identical to those of serovar 2 reference strain. The main difference found between the O-PS loci is the shortening of 31 amino acids from the C terminus of WcaJ in the atypical isolate due to a 93 bp deletion at the 3' end of wcaJ gene. Immunoblot analysis revealed that this isolate could not produce O-PS. Taken together, our results showed that the C-terminal domain of the A. pleuropneumoniae WcaJ plays a critical role in enzyme function of WcaJ involved in the biosynthesis of O-PS.