국내 연안 자연해수에서 급성간췌장괴사병(AHPND) 관련 PirA 유전자의 모니터링 및 수온과 검출 간의 관련성 분석 = Monitoring of the acute hepatopancreatic necrosis disease (AHPND) associated PirA gene in Korean coastal seawater and its association with water temperature

다국어 초록 (Multilingual Abstract)

Acute hepatopancreatic necrosis disease (AHPND) is an important bacterial disease in shrimp aquaculture. This study investigated detection patterns of the AHPND-associated PirA gene in Korean coastal seawater and evaluated its association with environmental factors, particularly water temperature. Sampling stations were selected based on whiteleg shrimp farm distribution, previous AHPND occurrence, coastal accessibility, and environmental characteristics. Coastal seawater monitoring was conducted from April to October between 2022 and 2025. Seawater samples were concentrated and analyzed using conventional PCR and qPCR. Conventional PCR was used as a supplementary confirmation method, whereas final detection was determined by qPCR targeting the PirA gene. Environmental factors were analyzed using correlation analysis, ROC curve analysis, and multivariable logistic regression. A total of 210, 225, 225, and 235 samples were analyzed in 2022, 2023, 2024, and 2025, respectively. Positive samples were 38 (18.1%), 64 (28.4%), 74 (32.9%), and 103 (43.8%), respectively. Detection was concentrated in July and August. Water temperature showed a significant but weak positive correlation with detection (r=0.293, P<0.001). ROC analysis yielded an AUC of 0.684 and an optimal cut-off value of 25.35℃, with 62.0% sensitivity and 65.9% specificity. In multivariable logistic regression, water temperature remained significantly associated with detection after adjustment for salinity, pH, and dissolved oxygen. Detection odds increased 1.179-fold for every 1℃ increase in water temperature (95% CI, 1.121–1.241; P<0.001). These findings suggest that water temperature may serve as a supplementary indicator for identifying periods with a relatively higher probability of detecting the AHPND-associated PirA gene.