Spatio-Temporal Distribution of Norovirus GII Accumulated in Oyster at A Cultivating Area in Northeastern Japan

ERMAYA EKA C, Dr. Ir. Retno Indrati, M. Sc.

2017 | Skripsi | S1 TEKNOLOGI PANGAN DAN HASIL PERTANIAN

Norovirus diketahui menjadi penyebab kasus gastroenteritis di berbagai tempat. Kasus tersebut dikaitkan dengan konsumsi kerang tiram mentah. Kerang tiram sebagai pembawa virus dibudidayakan di zona interdal yang mempunyai pasang-surut ombak yang tinggi dan faktor lingkungan di area yang sempit dapat sangat berbeda. Perbedaan dari titik kultivasi dapat berpengaruh terhadap kontaminasi virus dan keadaan biologis kerang tiram. Analisis spatio-temporal dilakukan untuk menyelidiki apakah terdapat pola akumulasi virus dalam kerang tiram pada titik kultivasi yang berbeda saat musim dingin. Setidaknya ada 4 titik kultivasi (Station A, B, C, dan D) yang diamati. Station A yang terjauh dan Station D yang terdekat dari muara sungai. Real-time quantitative PCR (RT-qPCR) dilakukan untuk mengatahui konsentrasi Norovirus GII di dalam kerang tiram. Hasil akan dibandingkan antara station, bulan dan kedalaman yang berbeda. Sekitar 87% sampel kerang tiram dinyatakan positif Norovirus GII di musim dingin 2014/2015. Puncak akumulasi Norovirus terjadi di bulan February 2015 pada seluruh titik kultivasi. Kerang tiram yang dibudidayakan dekat muara sungai yang diketahui mendapat pengaruh dari tempat pengolahan air limbah tingkat kontaminasi Norovirus GII cenderung tinggi namun tidak signifikan dengan titik lain. Berat kerang tiram pada titik terdekat dengan muara signifikan lebih kecil dari titik lain. Kerang tiram yang yang diambil dari permukaan atas cenderung memiliki konsentrasi virus yang rendah dibandingkan dari tengah dan bawah.

Norovirus is one of causative agent of acute gastroenteritis outbreak worldwide. Outbreaks have been associated with oyster without sufficient cooking. Oyster as an outbreak vehicle is cultivated in the intertidal zone, which have a high range of tidal wave and environmental factors could be very different in the narrow area. The differences of site cultivation might impact the virus contamination and oyster biology. Spatio-temporal analysis was performed to investigate trend of accumulation virus within oyster at an oyster cultivation area in winter month. There are four site cultivation observed (named as Station A, B, C, D). Station A is the furthest and Station D is the nearest station counted from river mouth. Real-time quantitative PCR (RT-qPCR) was performed to determine the concentration of Norovirus genogroup II (GII). Results were compared among different stations, months and water depth (layer). Approximately 87% of the samples were positive in Norovirus GII in winter month 2014/2015. The peak of Norovirus concentration in oyster, which showed in February 2015, observed almost in all site cultivations. The oysters cultivated in seawater near wastewater treatment plant trend to have a higher concentration of Norovirus GII but not significant among different stations. Oyster weight from nearest station was significantly smaller than other stations. Oysters are taken from top layer of sea water showed lower concentration than middle layer and bottom layer.

Kata Kunci : spatio-temporal distribution, norovirus, oyster