Genetic Diversity of Rotavirus Strains Circulating in Environmental Water and Bivalve Shellfish in Thailand

Abstract

Rotavirus is a common cause of acute diarrhea in young children worldwide. This study investigated the prevalence and molecular characterization of rotavirus in environmental water and oyster samples in Thailand. A total of 114 water samples and 110 oyster samples were collected and tested for group A rotavirus using RT-nested PCR. Rotavirus genotype was identified by phylogenetic analysis of the VP7 genetic sequences. Group A rotavirus was detected in 21 water samples (18.4%) and six oyster samples (5.4%). Twenty five rotavirus strains were successfully sequenced and classified into four genotypes; G1, G2, G3, and G9. Rotavirus G1 (three strains), G2 (three strains), and G9 (two strains) demonstrated the genetic sequences similar to human strains (90%–99% nucleotide identity), whereas G3 (17 strains) was closely related to animal strains (84%–98% nucleotide identity). G1 strains belonged to lineages I (sub-lineage c) and II. G2 strains belonged to lineage II. G9 strains belonged to lineages III (sub-lineage b) and IV. G3 strains belonged to lineages I, III (sub-lineage c), and IV with a predominance of lineage I. The present study provides important information on the rotavirus strains circulating in the environment.

Improving the efficacy of sewage treatment decreases norovirus contamination in oysters

“…This may be partly explained by the specific binding of HuNoV to the oyster digestive tract through an A-like carbohydrate structure (which is indistinguishable from human blood group A antigen), other ligands such as sialic acids, and also through ionic bonding (Di Girolamo et al, 1977;Le Guyader et al, 2006;Tian et al, 2007). To avoid the marketing of virus-contaminated shellfish, end-product testing using molecular methods is one risk management option (ISO/TS 15216-1, 2017), however this approach is difficult, because in addition to HuNoV's, there may be a variety of other human enteric viruses present in the shellfish, such as hepatitis A virus, enterovirus, rotavirus or sapovirus ( Boxman et al, 2016;Kittigul et al, 2014;McLeod et al, 2009;Polo et al, 2015;Ueki et al, 2010) -testing for such a diversity of viruses presents both logistic and economic challenges. The plethora of viruses detected in shellfish is linked to the high diversity of viruses in human sewage, reflecting the microbiome of the local population, and thereby potentially favoring the dispersion of emerging viruses (Bisseux et al, 2018;Geoghegan et al,2016;Newton et al, 2015).…”

Weekly Variation of Rotavirus A Concentrations in Sewage and Oysters in Japan, 2014–2016

“…Approximately 62.2% (46 of 74 weeks) of sewage and 57.8% (37 of 64 weeks) of oyster samples were positive for rotavirus, which is much higher than the positivity rates reported in previous studies. In Thailand, rotavirus was detected in 27.1% (16 of 59), 9.1% (5 of 55), and 5.4% (5 of 110) of river water, irrigation canal water, and cultured oyster samples, respectively [10]. A wide range of positivity rates for rotavirus has been reported in oysters from different regions.…”

“…While norovirus has been well recognized to contaminate oysters, causing high levels of gastroenteritis in temperate regions during winter months, rotavirus was also detected in 0.3% to 16.7% of cases with oyster-associated gastroenteritis [8,9]. Although rotavirus has been detected in farmed oysters at rates of 3.3%–44.4% [9,10,11], information about their level of contamination in the environment and its seasonal variation remains limited. In this study, we performed long-term weekly monitoring of oysters at a cultivation site in Japan, tracking changes in viral loads across different seasons.…”

Rotavirus and Astrovirus

“…RVA and HAstV are transmitted by the fecal-oral route and quickly spread through person-to-person contact (Estes & Greenberg, 2013), airborne droplets and fomites (Estes & Greenberg, 2013). Transmission is also observed by ingestion of contaminated water and food and cases of RVA-and HAstV-associated waterborne disease have been reported (Gallay et al, 2006;Martinelli et al, 2007;Moreno et al, 2009;Koroglu et al, 2011, Villena et al, 2013Kittigul et al, 2014;Mellou et al, 2014;Quiroz-Santiago et al, 2014;El-Senousy et al, 2015).…”

“…In Italy, RVA was found in 25.5% (35/113) of the molluscan shellfish from 62 samples collected for environmental monitoring and from 67 for sale, including mussels, clams and oysters obtained from Greece, France, and Italy (Gabrieli et al, 2007). In Thailand, 110 oyster samples were collected and RVA was detected 5.4% (6/110) of the samples analyzed (Kittigul et al, 2014). In another study that used specific, sensitive and high-throughput gene chip technology RVA were detected in 6.2% of shellfish samples from the main coastal cities of China (Ming et al, 2014).…”