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Objective To understand the pathogen composition of viral diarrhea in Chongqing, and to provide reference for the prevention and control of viral diarrhea. Methods Real-time fluorescent RT-PCR was used to detect the nucleic acids of rotavirus, norovirus, sapovirus, astrovirus, and enteric adenovirus collected from diarrhea outpatient cases from 2018 to 2019, and the positive nucleic acid samples were sequenced. Results Among the 398 cases of diarrhea, 184 cases were detected positive, with the positive detection rate of 46.23%. Norovirus infection was the main infection, accounting for 29.40%. The G/P genotype of group A rotavirus was mainly G9P8, accounting for 90.32%. The genotype of norovirus was mainly GII.2[P16], accounting for 33.91%. The genotype of sapovirus was mainly GI.2, accounting for 55.56%. The genotype of astrovirus was HAstV-4, accounting for 100%. The genotype of enteric adenovirus was F41, accounting for 100%. The diarrhea cases were mainly distributed in the fourth quarter, with the positive detection rate of 70.42%, among which norovirus had the highest detection rate, accounting for 53.99%. Conclusion High incidence of viral diarrhea is in winter in Chongqing. The main pathogen of viral diarrhea is norovirus, and the genotypes of norovirus show diversity. It is necessary to prevent the outbreak and epidemic caused by norovirus in winter. In the future, the surveillance of viral diarrhea should be strengthened, and the viral diarrhea gene database should be improved to provide a scientific basis for epidemic prevention and control.
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@#Objective To culture human sapovirus(HuSaV) GⅠ.1 in vitro and prepare polyclonal antibody against the capsid protein VP1.Methods HuSaV GⅠ.1 positive stool specimens preserved in diarrhea department of National Institute for Viral Disease Control and Prevention were inoculated with HuTu-80 cells supplemented with different bile acid salts[glycine chenodeoxycholic acid(GCDCA) and glycine cholic acid(GCA)],and the infection,proliferation and passage of the virus were determined by PCR and RT-qPCR.The VP1 gene was amplified by PCR and cloned into prokaryotic expression vector pGEX-6P-1.The constructed recombinant expression plasmid pGEX-6P-1-VP1 was transformed into E.coli BL21(DE3) and induced by IPTG.Two female New Zealand white rabbits were immunized with the purified recombinant VP1 protein for 4 times.The blood samples were collected 18,28,38 and 48 d after immunization,and the serum titers were detected by ELISA.Results HuTu-80 cells were effectively infected by HuSaV GⅠ.1 in the presence of bile acid salt GCA,and the proliferated virus were stably and continuously transmitted for three generations in HuTu-80 cells.The expressed recom-binant GST-VP1 protein showed a relative molecular mass of about 86 000,and about 60 000 after purification(GST tag excision).The titer of polyclonal antibody against HuSaV VP1 protein was over 1:12 800.Conclusion HuSaV was successfully isolated and cultured in vitro using HuTu-80 cells supplemented with bile acid salt,and polyclonal antibody with high titer against HuSaV VP1 protein was prepared,which laid a foundation of in-depth research of HuSaV identification,infection and pathogenesis.
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Objective:To analyze the epidemiological characteristics of an aggregational gastroenteritis and determine the genotypes of sapovirus， and to provide scientific basis for formulating effective control strategies. Methods:Unified case definition， active case search and descriptive epidemiology were used to analyze the epidemic. Feces or anal swabs of untreated students， teachers， canteen staff as well as canteen environment samples were collected. Norovirus and sapovirus nucleic acid tests were conducted by real-time fluorescent RT-PCR， and sapovirus nucleic acid was amplified by conventional RT-PCR. The gene region of capsid protein was analyzed by MEGA7.0 software and phylogenetic tree was constructed. Results:A total of 12 cases were reported in the epidemic， and the incidence rate was 44.44%. All reported cases， with vomiting symptoms， were found in the same class. The epidemic showed a point-based outbreak. The first case became the source of infection in class， and the epidemic lasted for 8 days. Real-time fluorescent RT-PCR assay confirmed that five children's feces were positive for sapovirus nucleic acid， and the first-episode children's feces were positive for sapovirus and GII norovirus nucleic acid. Sequence alignment result showed that the sapovirus strains belonged to GI.1 type with homologous genes. Conclusion:Based on the clinical manifestations， field epidemiological investigation and laboratory test results， we confirm that the first case of the epidemic in class is caused by GI.1 sapovirus infection. The epidemic is effectively controlled by comprehensive measures such as case isolation and disinfection.
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Objective To investigate the characteristics of outbreaks of acute gastroenteritis caused by sapovirus infection among primary school students in Yangzhou. Methods An on-site epidemiological investigation was carried out to analyze the clinical symptoms and risk factors of epidemic transmission. Samples of patients were collected for nucleic acid detection of sapovirus. Follow-up observations were carried out on cases with positive detection to explore the duration of intestinal detoxification of sapovirus infection. Samples of close contacts without clinical symptoms were collected to analyze recessive infection status. Results A total of 30 cases were reported from two outbreaks of sapovirus infection. As a main symptom, the incidence rate of vomiting was 93.33%. The duration of intestinal detoxification of the cases was 3 to 19 days, with an average of 11.12 days. The rate of recessive infection was 26.32%. The risk factor for sapovirus infection was exposure to vomit or feces within 1 meter (OR=12.94, 95%CI 1.19-140.37), and the protective factor was washing hands before eating (OR=0.064, 95%CI 0.007-0.56). Conclusion The main symptom of sapovirus infection was vomiting, with a high rate of recessive infection and a long detoxification period. It is easy to cause an outbreak in primary schools. Exposure to vomit or feces within 1 meter could increase the risk of sapovirus infection. Washing hands before eating could reduce the risk of sapovirus infection.
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Objective To understand the epidemiological and etiological characteristics of outbreaks on acute gastroenteritis caused by sapovirus (SaⅤ) worldwide.Methods Literature about the outbreaks on acute gastroenteritis caused by SaⅤ were retrieved from the databases including WanFang,CNKI,PubMed and Web of Science after evaluation.Time,geography,setting and population distributions of outbreaks,transmission mode,SaⅤ genotype and clinical characteristics of the patients were analyzed.Results A total of 34 papers about SaⅤ were included,involving 146 outbreaks occurred between October 1976 and April 2016.In these papers,138 outbreaks were reported on the related months.All these outbreaks occurred in northern hemisphere.SaⅤ outbreaks occurred all year around,but mainly in cold season,the incidence was highest in December (25 outbreaks) and lowest in in August (2 outbreaks).Most outbreaks were reported by Japan,followed by Canada,the United States of America and the Netherlands.There were 141 outbreaks for which the occurring settings were reported,child-care settings were most commonly reported setting (48/141,34.04％),followed by long-term care facility (41/141,29.08％) and hospital (16/141,11.35％).Clinical symptoms of 1 704 cases in 31 outbreaks were reported,with the most common symptom was diarrhea (1 331/1 704,78.12％),followed by nausea (829/1 198,69.20％),abdominal pain (840/1 328,63.25％),vomiting (824/1 704,48.36％) and fever (529/1 531,34.53％).Genotypes of SaⅤ were determined for 119 outbreaks.GⅠ (51/119,42.86％) and GⅣ (45/119,37.82％) were predominant.The outbreaks of G Ⅳ SaⅤ increased suddenly in 2007,and the outbreaks of G Ⅰ SaⅤ mainly occurred in 2008 and during 2011-2013.Conclusions SaⅤ outbreaks were reported mainly by developed countries,with most outbreaks occurred in cold season,in child-care settings and long term care facility.G Ⅰ and GⅣ were the most common genotypes of SaⅤ.Prevention and control of SaⅤ outbreak in China seemed relatively weak,and it is necessary to conduct related training and to strengthen the SaⅤ outbreak surveillance in areas where service is in need.
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Objective To understand the epidemiological and etiological characteristics of outbreaks on acute gastroenteritis caused by sapovirus (SaⅤ) worldwide.Methods Literature about the outbreaks on acute gastroenteritis caused by SaⅤ were retrieved from the databases including WanFang,CNKI,PubMed and Web of Science after evaluation.Time,geography,setting and population distributions of outbreaks,transmission mode,SaⅤ genotype and clinical characteristics of the patients were analyzed.Results A total of 34 papers about SaⅤ were included,involving 146 outbreaks occurred between October 1976 and April 2016.In these papers,138 outbreaks were reported on the related months.All these outbreaks occurred in northern hemisphere.SaⅤ outbreaks occurred all year around,but mainly in cold season,the incidence was highest in December (25 outbreaks) and lowest in in August (2 outbreaks).Most outbreaks were reported by Japan,followed by Canada,the United States of America and the Netherlands.There were 141 outbreaks for which the occurring settings were reported,child-care settings were most commonly reported setting (48/141,34.04％),followed by long-term care facility (41/141,29.08％) and hospital (16/141,11.35％).Clinical symptoms of 1 704 cases in 31 outbreaks were reported,with the most common symptom was diarrhea (1 331/1 704,78.12％),followed by nausea (829/1 198,69.20％),abdominal pain (840/1 328,63.25％),vomiting (824/1 704,48.36％) and fever (529/1 531,34.53％).Genotypes of SaⅤ were determined for 119 outbreaks.GⅠ (51/119,42.86％) and GⅣ (45/119,37.82％) were predominant.The outbreaks of G Ⅳ SaⅤ increased suddenly in 2007,and the outbreaks of G Ⅰ SaⅤ mainly occurred in 2008 and during 2011-2013.Conclusions SaⅤ outbreaks were reported mainly by developed countries,with most outbreaks occurred in cold season,in child-care settings and long term care facility.G Ⅰ and GⅣ were the most common genotypes of SaⅤ.Prevention and control of SaⅤ outbreak in China seemed relatively weak,and it is necessary to conduct related training and to strengthen the SaⅤ outbreak surveillance in areas where service is in need.
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Human sapoviruses (HSaV) are considered important causative agents of acute gastroenteritis in humans worldwide. However, knowledge of the genetic characteristics of the whole genome of HSaV in Brazil is limited. Here we report the complete genome sequences of six HSaVs GI.2 and two GI.3 strains obtained from children with acute gastroenteritis in the Northern region of Brazil. Next generation sequencing was used to obtain the full genome and molecular characterization of the genome was performed. Phylogenetic analysis of the genome was also performed. Only one complete HSaV GI.2 genome characterization in the country precedes that of the present study. This is the first complete genome sequence of genotype GI.3 in Brazil. The data obtained in this investigation can contribute to the augmentation of the database on the molecular diversity of HSaVs strains circulating in Brazil, and to the improvement of current typing protocols.
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Humans , Child , Caliciviridae Infections/virology , Sapovirus/genetics , Gastroenteritis/virology , Phylogeny , Brazil , Acute Disease , Sequence Analysis, DNA , High-Throughput Nucleotide Sequencing , GenotypeABSTRACT
BACKGROUND: Diarrhea has been the second leading cause of death among children under the age of five, and the rapid and accurate pathogen diagnosis in patients with diarrhea is crucial for reducing morbidity and mortality. A newly developed one-step multiplex real-time PCR assay, the Allplex GI-Virus Assay, was evaluated for its ability to detect six diarrhea-causing viruses (rotavirus, norovirus genogroup I (GI) and genogroup II (GII), enteric adenovirus, astrovirus, and sapovirus) in stool samples. METHODS: The performance of the Allplex assay was compared with those of another multiplex PCR assay (Seeplex Diarrhea-V Ace Detection) and genotyping by sequencing, using 446 stool samples from patients with acute gastroenteritis. RESULTS: The overall agreement rates between the results of the Allplex and Seeplex assays were 98.7% for rotavirus, 99.1% for norovirus GI, 93.3% for norovirus GII, 98.0% for adenovirus, and 99.6% for astrovirus. The overall agreement rates between the Allplex assay and genotyping were 99.1% for rotavirus, 99.1% for norovirus GI, 98.7% for norovirus GII, 89.7% for adenovirus, 98.2% for astrovirus, and 99.8% for sapovirus. In addition, eight rotavirus genotypes, three norovirus GI genotypes, four norovirus GII genotypes, eight adenovirus genotypes, two astrovirus genotypes, and two sapovirus genotypes were detected. CONCLUSIONS: The Allplex assay showed high agreement with Seeplex and genotyping results, and was able to additionally detect sapoviruses. The Allplex assay could be useful in identifying viral gastrointestinal infections in patients with acute gastroenteritis symptoms.
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Child , Humans , Adenoviridae , Cause of Death , Diagnosis , Diarrhea , Gastroenteritis , Genotype , Mortality , Multiplex Polymerase Chain Reaction , Norovirus , Real-Time Polymerase Chain Reaction , Rotavirus , SapovirusABSTRACT
Abstract INTRODUCTION: Acute gastroenteritis (AGE) is one of the most common causes of morbidity and mortality, especially among children from developing countries. Human adenovirus (HAdV) and sapovirus (SaV) are among the agents that cause AGE. The present study aimed to detect and genotype HAdV and SaV in 172 fecal samples from children with AGE, collected during a surveillance study carried out in a low-income community in Belém, Pará, between 1990 and 1992. METHODS: HAdV was detected by nested PCR, using primers Hex1deg/Hex2deg and NeHex3deg/NeHex4deg. SaV was assayed by reverse transcription PCR (RT-PCR), nested PCR, and quantitative PCR. The nucleotide sequence was determined by direct cycle sequencing. RESULTS: Overall, 43% (74/172) of samples were positive for HAdV, of which 70.3% (52/74) were sequenced and classified as belonging to five different species, mostly A and F. For SaV, positivity was 5.2% (9/172) and genotypes GI.1, GI.7, GII.1, and GV.2 were detected. CONCLUSIONS: The present results reinforce the need for further studies to obtain epidemiological data about the circulation of these viruses in Brazil, especially in the Amazon Region, where data from the early 1990's are scarce. Furthermore, the study describes for the first time the detection of SaV genotypes GI.7 and GV.2 in Brazil, showing that these types circulated in the region more than 25 years ago.
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Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Brazil/epidemiology , Adenoviruses, Human/isolation & purification , Caliciviridae Infections/virology , Sapovirus/isolation & purification , Gastroenteritis/virology , Genotype , Phylogeny , Time Factors , Base Sequence , Adenovirus Infections, Human/epidemiology , Adenovirus Infections, Human/virology , Adenoviruses, Human/genetics , Polymerase Chain Reaction , Prevalence , Prospective Studies , Age Distribution , Caliciviridae Infections/epidemiology , Sapovirus/genetics , Genotyping Techniques/methods , Gastroenteritis/enzymology , Genes, ViralABSTRACT
Objective@#To understand the potential viral pathogens other than enteroviruses existing in samples of hand foot and mouth disease (HFMD) patient and study their molecular feature and genotype.@*Methods@#The deep sequencing analysis of a fecal specimen collected from HFMD patient was conducted by metagenomics and bioinformatics.@*Results@#Enterovirus A71 and sapovirus mixed infection was found in this case. The nucleic acid of sapovirus was confirmed positive by RT-PCR and the 7 429 bp complete genome sequence of sapovirus was obtained by assembling sequencing reads which consisted of 3 open reading frames. Phylogenetic analysis revealed that this strain of virus should belong to the genotype 1 of sapovirus having a homology of 99.4% with sapovirus Hu/G1/Zhejiang1/China/2014 strain, which is a currently predominant genotype circulating in China.@*Conclusions@#The sapovirus, which is a predominant strain circulating in China, was a mixed infected causative agent existing in HFMD sample identified by deep sequencing. This study will serve as a reference for pathogen detection of HFMD and diarrheal related diseases, as well as provide a sequence reference for molecular feature study of sapovirus in China in the future.
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ABSTRACT Gastroenteritis is one of the most common diseases during childhood, with norovirus (NoV) and sapovirus (SaV) being two of its main causes. This study reports for the first time the incidence of these viruses in hospitalized children with and without gastroenteritis in São Luís, Maranhão. A total of 136 fecal samples were tested by enzyme immunoassays (EIA) for the detection of NoV and by reverse transcription-polymerase chain reaction (RT-PCR) for detection of both NoV and SaV. Positive samples for both agents were subjected to sequencing. The overall frequency of NoV as detected by EIA and RT-PCR was 17.6% (24/136) and 32.6% (15/46), respectively in diarrheic patients and 10.0% (9/90) in non-diarrheic patients (p < 0.01). Of the diarrheic patients, 17% had fever, vomiting and anorexia, and 13% developed fever, vomiting and abdominal pain. Of the 24 NoV-positive samples, 50% (12/24) were sequenced and classified as genotypes GII.3 (n = 1), GII.4 (6), GII.5 (1), GII.7 (2), GII.12 (1) and GII.16 (1). SaV frequency was 9.8% (11/112), with 22.6% (7/31) in diarrheic patients and 4.9% (4/81) in nondiarrheic (p = 0.04) ones. In diarrheic cases, 27.3% had fever, vomiting and anorexia, whereas 18.2% had fever, anorexia and abdominal pain. One SaV-positive sample was sequenced and classified as GII.1. These results show a high genetic diversity of NoV and higher prevalence of NoV compared to SaV. Our data highlight the importance of NoV and SaV as enteropathogens in São Luís, Maranhão.
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Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , History, 20th Century , Young Adult , Caliciviridae/classification , Cross Infection , Caliciviridae Infections/epidemiology , Caliciviridae Infections/virology , Phylogeny , Brazil , Caliciviridae/genetics , Incidence , Caliciviridae Infections/diagnosis , Caliciviridae Infections/history , Evolution, Molecular , Norovirus/classification , Norovirus/genetics , Sapovirus/classification , Sapovirus/genetics , Gastroenteritis/history , Gastroenteritis/epidemiology , Gastroenteritis/virology , GenotypeABSTRACT
Objective To investigate the epidemiology of adults acute viral gastroenteritis in Shanghai Changning district. Methods All of 1 554 stool specimens of adults acute gastroenteritis in Shanghai Changning district from June 2010 to December 2013, and the enzyme-linked immunosorbent assay and multiple polymerase chain reaction was used to detecte different viruses. Results In all of 1 554 cases, the average age was (46.19 ± 15.59) years. Among them, 691 persons were male, 863 persons were female. Virus infection was detected in 407 cases, and the detection rate was 26.19%. Among them, 395 cases (97.05%) were single virus infection, and 12 cases (2.95%) were mixed infection. The peak of epidemic was from every November to next February. The incidence of watery diarrhea, vomiting and fever in virus positive group was significantly higher than that in virus negative group:95.09%(387/407) vs. 88.14%(1 011/1 147), 31.20%(127/407) vs. 18.83%(216/1 147), and 11.06%(45/407) vs. 7.59%(87/1147), P<0.01 or<0.05. Conclusions Rotavirus infection is common in adults with acute viral gastroenteritis. Patients with positive virus infection had a higher incidence of watery diarrhea, vomiting and fever. The peak of epidemic is winter.
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Background & objectives: Due to limited availability of data on viral aetiology of acute gastroenteritis in north India, the present study was planned to detect rotavirus, norovirus, sapovirus and astrovirus in stool samples of both in hospitalized and non-hospitalized children less than five years of age presenting with acute gastroenteritis. Methods: A total of 278 stool samples from equal number of children were tested for rotavirus antigen using ELISA and for norovirus, sapovirus and astroviruses by reverse transcription (RT)-PCR. Results: Of the 169 samples from hospitalized patients, rotavirus, norovirus, sapovirus and astrovirus were detected in 19.5, 2.3, 3.5 and 2.9 per cent samples, respectively. Of the 109 samples collected from the non-hospitalized patients, frequency of rotavirus and sapovirus detection was 9.1 and 1.8 per cent, respectively while norovirus and astrovirus were not detected. Interpretation & conclusions: Rotavirus was the most frequent cause of viral gastroenteritis in both hospitalized and non-hospitalized children. Maximum positivity of the viruses was seen in children less than two years of age.
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Objective To analyze the distribution and clinical characteristics of gastrointestinal virus infection in infants with acute diarrhea.Methods Stool samples and clinical data were collected from 900 infants (≤5 years old) with acute diarrhea in outpatient department of Beilun District People' s Hospital during July 2012 and July 2013.Specimens were tested for 5 gastrointestinal virus including group A/B/C rotavirus (RV),adenovirus (AdV),astrovirus (AstV),sapovirus (SV) and norovirus (NV) by the multiplex PCR assay.Chi-square test was performed to compare the positive rates of virus infection among children with different genders and ages.Results Among 900 stool samples,369 were positive of gastrointestinal virus,of which 291 were positive for single virus and 78 for mixed virus.In single virus infection,NV was detected with the highest positive rate of 19.4％ (4.9％ for G Ⅰ and 14.6％ for G Ⅱ),followed by RV-A (8.2％),SV (2.9％),AstV (1.0％) and AdV (0.8％).RV-B and C type were not found.In 78 cases with mixed infections,RV-A plus NV infection was the most common one with a prevalent rate of 5.8％.The positive rate in age group ≤2 years old was 51.0％,which was significantly higher than that of age group ＞ 2-5 years old (22.1％,x2 =70.404,P ＜ 0.01).In 369 children with positive gastrointestinal virus,fever was present in 24.1％,and vomit in 35.2％ of children.Fever,vomit and fever plus vomit was more common symptoms in children with mixed infections (x2 =17.878,21.869 and 14.155,P ＜ 0.01).Conclusion NV and RV-A are the most common pathogens in infants with acute diarrhea in Beilun district,especially in children younger than 2 years old.
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Objective To investigate the molecular-epidemiologic characteristics and genotypes of human calicivirus (HuCVs) in acute diarrhea patients in Hangzhou from 2009 to 2010.Methods Epidemiologic data and fecal specimens were collected from patients with acute diarrhea.HuCVs of 920 specimens were detected by PCR.PCR products of several positive samples were randomly selected and sequenced.All the sequences were analyzed,phylogenetically.Results 201HuCVs positive cases were identified from 920 facal specimens (21.8％).25 isolates would include norovims G Ⅰ -type,G Ⅱ -type for 170 strains and sapovirus for 1 1 strains.Norovirus G Ⅰ -type and G Ⅱ -type were detected in four specimens at the same time.Other specimens were mixed infection with norovirus G Ⅱ -type and sapovirus.Genotypes of HuCVs showed that norovirus G Ⅰ subtypes were G Ⅰ -1 (3 strains) and G Ⅰ -2 (1 strain).Norovirus G Ⅱ subtypes were G Ⅱ -4/2006b variant strains (7 strains),GⅡ-2 (1 strain),G Ⅱ -7 (1 strain) and G Ⅱ -4/2008 variant strains (2 strains) ;Sapovirus subtypes were G Ⅰ -2 (5 strains),G Ⅰ -1 (4 strains) and G Ⅱ-1 ( 1 strain).The prevalence rates of HuCVs were different in seasons and age groups.Conclusion HuCVs were one of the major pathogens causing acute diarrhea.Both multiple viruses and genotypes of HuCVs were found in the specimens.G Ⅱ-4/2006b variant and similar strains were identified,probably as the prevalent strains from 2009 to 2010 in Hangzhou,Zhejiang province.
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Acute gastroenteritis caused by viruses is one of the leading causes of infantile morbidity. The aim of the present study was to investigate the presence of human caliciviruses of the genera norovirus and sapovirus in children up to 3 years of age with acute gastroenteritis from low-income communities in the city of Salvador, Brazil. This study is an extension of previous work carried out to establish the profile of the most prevalent enteric pathogens present in these communities. In this report, 139 fecal samples, collected from July 2001 to January 2002 were analyzed by RT-PCR and 13 (9 percent) were positive for human caliciviruses. By sequencing, seven isolates were characterized as norovirus genogroup GII and one as sapovirus genotype GII/1. Sequencing of the previously detected group-A rotaviruses and human astroviruses was also performed and revealed the circulation of rotavirus group A genotypes G1P[8] and G9P[8], and human astrovirus genotypes 6, 7, and 8. No mixed infection was observed. Community-based studies provide geographically representative information on disease burden. However, there are only a few reports in developing countries concerning the genotypes of the most important gastroenteric viruses detected in such communities. The present findings demonstrate the wide diversity of genotypes of the most important viruses responsible for acute gastroenteritis circulating in low-income communities.
Subject(s)
Child, Preschool , Humans , Caliciviridae Infections/virology , Gastroenteritis/virology , Norovirus/genetics , Sapovirus/genetics , Acute Disease , Brazil/epidemiology , Caliciviridae Infections/diagnosis , Caliciviridae Infections/epidemiology , Feces/virology , Genotype , Gastroenteritis/diagnosis , Gastroenteritis/epidemiology , Molecular Sequence Data , Norovirus/isolation & purification , Phylogeny , Reverse Transcriptase Polymerase Chain Reaction , RNA, Viral/analysis , Sapovirus/isolation & purification , Urban PopulationABSTRACT
A total of 189 stool samples from swine with diarrhea, collected in various porcine farms in the central region of China were tested for porcine enteric caliciviruses (PEC) member porcine sapoviruses (SaV) by reverse transcription polymerase chain reaction (RT-PCR) amplification using primers designed to detect porcine SaV. Selected amplicons were sequenced to establish phylogenetic relationships with reference strains. Porcine SaV were detected in 12.70% (24/189) of the samples. Phylogenetic studies based on partial RNA polymerase gene sequences indicated that the field strains of viruses isolated in China were closely related (75.6 88.3% identity) to the porcine SaV Cowden reference strain. These results provide evidence that caliciviruses of the genus sapovirus circulate in piglets in China, but further studies are needed to clarify their importance as cause of diarrhea. This is the first report of PEC in China.
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Sapovirus of the Caliciviridae family is an important agent of acute gastroenteritis in children and piglets. The Sapovirus genus is divided into seven genogroups (G), and strains from the GIII, GVI and GVII are associated with infections in swine. Despite the high prevalence in some countries, there are no studies related to the presence of porcine enteric sapovirus infections in piglets in Brazil. In the present study, 18 fecal specimens from piglets up to 28 days were examined to determine the presence of sapovirus genome by RT-PCR assay, using primers designed to amplify a 331 bp segment of the RNA polymerase gene. In 44.4 percent (8/18) of fecal samples, an amplified DNA fragment was obtained. One of these fragments was sequenced and submitted to molecular and phylogenetic analysis. This analysis revealed high similarity, with nucleotides (87 percent) and amino acids (97.8 percent), to the Cowden strain, the GIII prototype of porcine enteric calicivirus. This is the first description of sapovirus in Brazilian swine herds.
O sapovírus classificado na família Caliciviridae é um importante causador de gastroenterite aguda em crianças e leitões. O gênero Sapovirus é dividido em sete genogrupos (G), sendo que as estirpes dos GIII, GVI e GVII estão associadas com infecção em suínos. Apesar da alta prevalência da infecção em alguns países, ainda não existem estudos referentes à presença do calicivírus entérico suíno nos rebanhos brasileiros. No presente estudo 18 amostras de fezes de leitões com até 28 dias foram avaliadas pela RT-PCR para a presença do genoma do sapovírus, utilizando os primers desenvolvidos para amplificar um segmento de 331 pb do gene da RNA polimerase viral. Em 44,4 por cento (8/18) das amostras foi amplificado um fragmento de DNA. Um desses amplicons foi seqüenciado e pela análise molecular e filogenética foi verificada similaridade de 87 por cento em nucleotídeos e 97,8 por cento em aminoácidos com a estirpe Cowden, protótipo do GIII. Esta é a primeira descrição do sapovírus em rebanhos suínos brasileiros.