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Updated: Oct 14, 2025

Author Spotlight: Development of an Enhanced Protocol for Rapid and Accurate Isolation of Campylobacter from Food Products
Published on: February 23, 2024
Identification of Campylobacter jejuni and Chlamydia psittaci from cockatiel (Nymphicus hollandicus) using
Si-Hyeon Kim1, Yong-Kuk Kwon1, Choi-Kyu Park2
1Avian Disease Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gyeongsangbuk-do, 39660, Gimcheon-si, Republic of Korea.
Background:
In July 2015, the carcasses of 11 cockatiels were submitted for disease diagnosis to the Avian Disease Division of the Animal and Plant Quarantine Agency of Korea. The cockatiels, which appeared dehydrated and underweight, had exhibited severe diarrhea and 22 % mortality over 2 weeks. Traditional diagnosis did not reveal the causes of these symptoms.
Methods:
We conducted metagenomics analysis on intestines and livers from the dead cockatiels using Illumina high-throughput sequencing. To obtain more accurate and longer contigs, which are required for further genetic characterization, we compared the results of three de novo assembly tools (metaSPAdes, MEGAHIT, and IDBA-UD).
Results:
Sequence reads of Campylobacter jejuni (C. jejuni) and Chlamydia psittaci (C. psittaci) were present in most of the cockatiel samples. Either of these bacteria could cause the reported symptoms in psittaciformes. metaSPAdes (ver.3.14.1) identified the 1152 bp flaA gene of C. jejuni and the 1096 bp ompA gene of C. psittaci. Genetic analysis revealed that flaA of C. jejuni was recombinant between C. jejuni and Campylobacter coli, and that ompA of C. psittaci isolated from cockatiel was closely related to strains isolated from humans.
Conclusions:
C. jejuni and C. psittaci were detected in cockatiels in the Republic of Korea using metagenomic analysis. This approach is useful for understanding pathogens of pet birds. Three de novo assemblers were compared to obtain accurate contigs from large quantities of reads, and sequences of C. jejuni and C. psittaci generated by metaSPAdes were analyzed.

