Related Experiment Video
Updated: May 4, 2026
Antigen-Capture Enzyme-Linked Immunosorbent Assay for Specific Detection of Mycoplasma pneumoniae
Published on: February 24, 2023
Isolation of atypical genotype Actinobacillus pleuropneumoniae serotype 6 in Japan
Hiroya Ito1, Kiyohito Katsuragi, Shunsuke Akama
1National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan.
Abstract:
We describe here isolation of genetically atypical serotype 6 Actinobacillus pleuropneumoniae in Japan indistinguishable by the multiplex PCR that can discriminate between immunologically cross-reactive serotypes 3, 6 and 8. Nucleotide sequence analysis of capsular export and biosynthesis genes revealed that the atypical isolates have capsular polysaccharide export and synthesis gene sequences that are distinct from those of the serotype 6 reference strain. The atypical strains contain a sequence that is identical with both serotype 3- and 6-specific primers, which causes cross-reactions in multiplex PCR.
Insights
Genetically atypical Actinobacillus pleuropneumoniae serotype 6 strains were found in Japan. These strains cause cross-reactions in multiplex PCR tests, complicating diagnosis.
Area of Science:
- Veterinary Microbiology
- Bacterial Genetics
- Molecular Diagnostics
Background:
- Actinobacillus pleuropneumoniae causes significant respiratory disease in swine.
- Accurate serotyping is crucial for disease control and epidemiological surveillance.
- Existing diagnostic methods, like multiplex PCR, can misidentify certain strains.
Purpose of the Study:
- To report the isolation and characterization of genetically atypical serotype 6 Actinobacillus pleuropneumoniae in Japan.
- To investigate the genetic basis for the atypicality and its impact on diagnostic assays.
Main Methods:
- Isolation and identification of bacterial strains from swine in Japan.
- Multiplex PCR for serotype discrimination.
- Nucleotide sequence analysis of capsular polysaccharide export and biosynthesis genes.
Main Results:
- Isolation of genetically atypical serotype 6 Actinobacillus pleuropneumoniae.
- These atypical strains were indistinguishable from other serotypes using standard multiplex PCR.
- Sequence analysis revealed distinct capsular gene sequences compared to the serotype 6 reference strain.
- A specific genetic sequence in atypical strains caused cross-reactivity with serotype 3 and 6 specific primers.
Conclusions:
- The genetic distinctiveness of these atypical strains poses a challenge for accurate diagnosis using current multiplex PCR methods.
- Further refinement of diagnostic tools is needed to reliably differentiate these atypical strains.
- Understanding the genetic basis of serotype variation is important for controlling Actinobacillus pleuropneumoniae infections.
