1.Actinobacillus pleuropneumoniaein Korea (2015-2025): serovar distribution, toxin gene profiles, antimicrobial resistance, and identification of an apxIICA-deficient serovar 15 profile
Da-Yun BAE ; Eun Ju KANG ; Yun-Chae CHO ; Yujoon LIM ; Sung-Hyun MOON ; Won-Il KIM ; Yeonsu OH ; Ho-Seong CHO
Journal of Veterinary Science 2026;27(3):e39-
Objective:
To provide a decade-long molecular and phenotypic characterization of APP isolates from Korean pig farms, focusing on the serovar distribution, apx-based toxingene profiles, and antimicrobial susceptibility.
Methods:
Between 2015 and 2025, 1,215 pneumonic lung samples from 965 pig farms yielded 132 APP isolates. The species identity was confirmed by 16S rRNA sequencing. The serovars were determined using capsule polysaccharide (CPS) gene-based multiplex polymerase chain reaction (PCR). Toxin genes (apxIA–apxIVA) were profiled, and the antimicrobial susceptibility to 29 agents was assessed by broth microdilution according to the Clinical and Laboratory Standards Institute guidelines.
Results:
Serovar 1 was predominant (66.7%), followed by serovars 5 (17.4%) and 2 (6.8%).CPS multiplex PCR identified three isolates (2.3%) as serovar 15, which displayed heterogeneous toxin gene profiles, including apxIICA-deficient profiles. Most isolates exhibited classical repeats-in-toxin operon arrangements, suggesting ongoing diversification of toxin gene profiles. High resistance rates were observed for oxytetracycline (90.9%) and florfenicol (50.8%), and recurrent multidrug-resistant combinations were frequently detected.
Conclusions
and Relevance: Serovar 1 is dominant in Korea, but the emergence of atypical toxin gene profiles in serovar 15 may carry immunological implications. Persistent resistance to older drug classes underscores the necessity for long-term molecular surveillance, evaluation of vaccine coverage against evolving strains, and enhanced antimicrobial stewardship to strengthen the control efforts for porcine pleuropneumonia in Korea.
2.Clinical validation of the 3-dimensional double-echo steady-state with water excitation sequence of MR neurography for preoperative facial and lingual nerve identification
Dohyun KWON ; Chena LEE ; YeonSu CHAE ; Ik Jae KWON ; Soung Min KIM ; Jong-Ho LEE
Imaging Science in Dentistry 2022;52(3):259-266
Purpose:
This study aimed to evaluate the clinical usefulness of magnetic resonance (MR) neurography using the 3-dimensional double-echo steady-state with water excitation (3D-DESS-WE) sequence for the preoperative delineation of the facial and lingual nerves.
Materials and Methods:
Patients underwent MR neurography for a tumor in the parotid gland area or lingual neuropathy from January 2020 to December 2021 were reviewed. Preoperative MR neurography using the 3D-DESS-WE sequence was evaluated. The visibility of the facial nerve and lingual nerve was scored on a 5-point scale, with poor visibility as 1 point and excellent as 5 points. The facial nerve course relative to the tumor wasidentified as superficial, deep, or encased. This was compared to the actual nerve course identified during surgery. The operative findings in lingual nerve surgery were also described.
Results:
Ten patients with parotid tumors and 3 patients with lingual neuropathy were included. Among 10 parotid tumor patients, 8 were diagnosed with benign tumors and 2 with malignant tumors. The median facial nerve visibility score was 4.5 points. The distribution of scores was as follows: 5 points in 5 cases, 4 points in 1 case, 3 points in 2 cases, and 2 points in 2 cases. The lingual nerve continuity score in the affected area was lower than in the unaffected area in all 3 patients. The average visibility score of the lingual nerve was 2.67 on the affected side and 4 on the unaffected side.
Conclusion
This study confirmed that the preoperative localization of the facial and lingual nerves using MR neurography with the 3D-DESS-WE sequence was feasible and contributed to surgical planning for the parotid area and lingual nerve.

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