| serial propagation of porcine enteric calicivirus in a continuous cell line. effect of medium supplementation with intestinal contents or enzymes. | a porcine enteric calicivirus (pec) was adapted to serial propagation in a continuous porcine kidney cell line (llc-pk) by inclusion of an intestinal contents preparation (icp), derived from uninfected gnotobiotic pigs, in the maintenance medium. infected cells were detected by immunofluorescent staining of cell monolayers. attempts to propagate pec in the presence of various intestinal enzymes of porcine origin, bacterial protease, bovine icp, avian icp or without medium supplementation were un ... | 1991 | 1929875 |
| biochemical characterization of porcine enteric calicivirus: analysis of structural and nonstructural viral proteins. | in this report, the molecular weight and antigenicity of the proteins of a porcine enteric calicivirus (pec) were characterized. the pec virions were purified from intestinal contents of infected pigs and from infected cell culture lysates. the average buoyant density of the purified virus was 1.37 gm/cm3 in cesium chloride. one major structural protein with a molecular weight of approximately 58 k was found in the gut and cell culture-passaged pec using sodium dodecyl sulfate polyacrylamide gel ... | 1990 | 2369321 |
| serial propagation of porcine enteric calicivirus-like virus in primary porcine kidney cell cultures. | a porcine enteric calicivirus-like virus was adapted to serial propagation in primary porcine kidney cell cultures. attempts to propagate this virus in primary porcine kidney cells in the presence of trypsin or pancreatin or without medium supplementation were unsuccessful. a low-ph medium (ph 6.8) was also ineffective in virus propagation. successful serial propagation of the virus required the presence of an intestinal-content preparation, derived from uninfected gnotobiotic pigs, in the cell ... | 1988 | 2830305 |
| pathogenesis of porcine enteric calicivirus-like virus in four-day-old gnotobiotic pigs. | eighteen 4-day-old gnotobiotic pigs were orally inoculated with porcine enteric calicivirus-like virus (c strain). seven additional gnotobiotic pigs served as noninoculated controls. mild diarrhea developed in all inoculated pigs by postinoculation day (pid) 3 and persisted for 3 to 7 days. severe diarrhea developed in 2 inoculated pigs between pid 4 and 5. twelve inoculated and 7 control pigs were euthanatized over a 7-day period. small intestinal mucosal smears were stained with a fluorescein- ... | 1988 | 2840841 |
| molecular characterization of a porcine enteric calicivirus genetically related to sapporo-like human caliciviruses. | porcine enteric calicivirus (pec) is associated with diarrhea in pigs, and to date it is the only cultivable enteric calicivirus (tissue culture-adapted [tc] pec/cowden). based on sequence analysis of cdna clones and reverse transcription-pcr products, tc pec/cowden has an rna genome of 7,320 bp, excluding its 3' poly(a)(+) tail. the genome is organized in two open reading frames (orfs), similar to the organizations of the human sapporo-like viruses (slvs) and the lagoviruses. orf1 encodes the p ... | 1999 | 10516074 |
| expression and self-assembly in baculovirus of porcine enteric calicivirus capsids into virus-like particles and their use in an enzyme-linked immunosorbent assay for antibody detection in swine. | porcine enteric calicivirus (pec) causes diarrhea and intestinal lesions in pigs. pec strain cowden grows to low to moderate titers in cell culture but only with the addition of intestinal contents from uninfected gnotobiotic pigs (w. t. flynn and l. j. saif, j. clin. microbiol. 26:206--212, 1988; a. v. parwani, w. t. flynn, k. l. gadfield, and l. j. saif, arch. virol. 120:115--122, 1991). cloning and sequence analysis of the pec cowden full-length genome revealed that it is most closely related ... | 2001 | 11283075 |
| detection and molecular characterization of cultivable caliciviruses from clinically normal mink and enteric caliciviruses associated with diarrhea in mink. | enteric caliciviruses are emerging pathogens responsible for diarrhea or gastroenteritis in their respective hosts. in this report, mink enteric caliciviruses (mec) were detected in feces from diarrheic mink by both immune electron microscopy (iem) and rt-pcr using a broadly reactive primer pair (p289/290) targeting the highly conserved rna polymerase regions of the enteric caliciviruses, norwalk-like viruses (nlvs) and sapporo-like viruses (slvs). the mec possess classical caliciviral morpholog ... | 2001 | 11338385 |
| comparative pathogenesis of tissue culture-adapted and wild-type cowden porcine enteric calicivirus (pec) in gnotobiotic pigs and induction of diarrhea by intravenous inoculation of wild-type pec. | porcine enteric calicivirus (pec/cowden) causes diarrhea in pigs, grows in cell culture, and is morphologically and genetically similar to the sapporo-like human caliciviruses. genetic analysis revealed that the tissue culture-adapted (tc) cowden pec has one distant and three clustered amino acid substitutions in the capsid region and 2 amino acid changes in the rna polymerase region compared to wild-type (wt) pec (m. guo, k.-o. chang, m. e. hardy, q. zhang, a. v. parwani, and l. j. saif, j. vir ... | 2001 | 11533186 |
| cell-culture propagation of porcine enteric calicivirus mediated by intestinal contents is dependent on the cyclic amp signaling pathway. | enteric caliciviruses are emerging pathogens in humans and animals, but they do not replicate in cell culture except for the porcine enteric calicivirus (pec) cowden strain. the pec cowden strain grows in pig kidney (llc-pk) cells, but only in the presence of intestinal contents (ic) from uninfected gnotobiotic pigs in the medium. in this study, we investigated the relationship between ic and growth of cowden pec. pretreatment of cells or the virus with ic or transfection of viral rna into cells ... | 2002 | 12504571 |
| bile acids are essential for porcine enteric calicivirus replication in association with down-regulation of signal transducer and activator of transcription 1. | a porcine enteric calicivirus (pec), strain cowden in the family caliciviridae (genus sapovirus), can be propagated in a continuous cell line, llc-pk cells, but only in the presence of an intestinal content fluid filtrate from gnotobiotic pigs. this cell culture system is presently the only in vitro model among caliciviruses that cause gastrointestinal disease, including members of the genera sapovirus and norovirus. we report here the identification of bile acids as active factors in intestinal ... | 2004 | 15161971 |
| genetic diversity among sapoviruses. | norovirus and sapovirus are two genera of the family caliciviridae that contain viruses that can cause acute gastroenteritis in humans. noroviruses (nor) are genetically highly diverse but limited studies of the genetic diversity of sapoviruses (sap) have been reported. in this study we characterized twenty-five sap detected in our laboratory from outbreaks or sporadic cases of acute gastroenteritis in children from different geographical locations and in adults involved in a cruise ship outbrea ... | 2004 | 15221533 |
| reverse genetics system for porcine enteric calicivirus, a prototype sapovirus in the caliciviridae. | a porcine enteric calicivirus (pec), strain cowden in the genus sapovirus of the caliciviridae family, can be propagated in a porcine kidney continuous cell line (llc-pk) in the presence of bile acids in the cell culture medium. a full-length cdna copy of the cowden pec genome was cloned into a plasmid vector directly downstream from the t7 rna polymerase promoter, and capped rna transcripts derived from this clone were infectious when transfected into llc-pk cells. the recovery of pec after tra ... | 2005 | 15650167 |
| detection and molecular characterization of porcine enteric calicivirus in korea, genetically related to sapoviruses. | porcine enteric calicivirus (pecv) shares morphological and genetical similarities with sapoviruses (svs), which are the leading cause of epidemic, non-bacterial gastroenteritis in children worldwide. the aim of this study was to identify the prevalence of pecv infection in pig farms in korea, and to compare the evolutionary inter-relationships between korean pecvs and other caliciviruses. among 102 diarrhoeic faecal samples of sucking (n = 50) and weaned (n = 52) piglets from 31 different farms ... | 2006 | 16629981 |
| molecular detection of porcine enteric caliciviruses in venezuelan farms. | caliciviruses are a well-established cause of respiratory, vesicular and hemorrhagic diseases in animals. in addition, these viruses are an important cause of enteric diseases in humans. recently, molecular analysis of several porcine enteric caliciviruses indicated that they are closely related to human enteric caliciviruses. the objective of this work was to determine the frequency, age distribution, and association with diarrhea of enteric calicivirus infections in piglets and to partially ch ... | 2006 | 16701967 |
| porcine enteric caliciviruses: genetic and antigenic relatedness to human caliciviruses, diagnosis and epidemiology. | porcine enteric caliciviruses include sapoviruses and noroviruses. porcine sapoviruses infect pigs of all ages and cause diarrhea in young pigs, whereas porcine noroviruses were detected exclusively from adult pigs without clinical signs. importantly, certain porcine norovirus strains were genetically and antigenically related to human noroviruses. this raises public health concerns that pigs may be reservoirs for emergence of epidemic human norovirus strains. this article reviews the discovery ... | 2007 | 17234307 |
| bile acids promote the expression of hepatitis c virus in replicon-harboring cells. | hepatitis c virus (hcv) is a cause of chronic liver disease, with more than 170 million persistently infected individuals worldwide. although the combination therapy of alpha interferon (ifn-alpha) and ribavirin is effective for chronic hcv infection, around half of all patients infected with hcv genotype 1 fail to show sustained virologic responses and remain chronically infected. previously, we demonstrated that bile acids were essential for growth of porcine enteric calicivirus in cell cultur ... | 2007 | 17609266 |
| enhancement of genotype 1 hepatitis c virus replication by bile acids through fxr. | hepatitis c virus (hcv) infected patients with high serum levels of bile acids (bas) usually fail to respond to antiviral therapy. besides, bas are essential factors for replication of the porcine enteric calicivirus by inhibiting interferon signaling. the role of bas on hcv rna replication was thus assessed. | 2008 | 18096266 |
| genetic heterogeneity of porcine enteric caliciviruses identified from diarrhoeic piglets. | enteric caliciviruses (noroviruses and sapoviruses) are responsible for the majority of non-bacterial gastroenteritis in humans of all age groups. analysis of the polymerase and capsid genes has provided evidence for a huge genetic diversity, but the understanding of their ecology is limited. in this study, we investigated the presence of porcine enteric caliciviruses in the faeces of piglets with diarrhoea. a total of 209 samples from 118 herds were analysed and calicivirus rna was detected by ... | 2008 | 18204823 |
| noroviruses and sapoviruses in pigs in belgium. | porcine noroviruses and sapoviruses belong to the family caliciviridae and are rarely reported in european countries. in this study, swine stools from a region representative of northern europe were screened for these viruses by rt-pcr. both porcine noroviruses and sapoviruses were detected, showing their circulation in this region. the porcine norovirus strains were genetically related to genotype 19 strains in the genogroup ii of the genus norovirus. the porcine sapovirus strains were genetica ... | 2008 | 18777158 |
| porcine noroviruses and sapoviruses on korean swine farms. | porcine noroviruses (novs) and sapoviruses (savs), which belong to the family caliciviridae, have been considered potential zoonotic agents for human infection, and several cases have been reported in asian countries. in this study, a total of 537 porcine fecal samples collected from 64 swine farms in korea were tested. among 537 samples, porcine novs were detected by semi-nested rt-pcr in ten samples (1.9%), and porcine savs were detected by rt-pcr in 60 samples (11.2%), showing their circulati ... | 2009 | 19812890 |
| genetic diversity of porcine enteric caliciviruses in pigs raised in rio de janeiro state, brazil. | porcine enteric caliciviruses (pec) belong to the genera norovirus and sapovirus within the family caliciviridae. they are enteric pathogens and are considered potential zoonotic agents. in this study, the circulation of pec was evaluated by rt-pcr of stool samples and intestinal contents of pigs raised in rio de janeiro state, brazil. both porcine norovirus (ponov) and porcine sapovirus (posav) were detected. the ponov strains were classified as genogroup ii, genotypes 11, 18 and 19. the posav ... | 2010 | 20526786 |
| seroepidemiology of porcine enteric sapovirus in pig farms in venezuela. | porcine enteric sapovirus (pes) has been shown to cause diarrhea under experimental conditions in gnotobiotic piglets. however, the role of pes as enteric pathogens in porcine farms remains unclear. to further understand the pes-host interactions under field conditions, a serological survey was carried out. to this end the capsid gene of a pes isolate was cloned in the baculovirus expression system and an elisa was developed based on virus-like particles from the baculovirus-expressed pes capsid ... | 2010 | 20621364 |
| diagnostic investigation of porcine periweaning failure-to-thrive syndrome: lack of compelling evidence linking to common porcine pathogens. | porcine periweaning failure-to-thrive syndrome (pfts), an increasingly recognized syndrome in the swine industry of north america, is characterized by the anorexia of nursery pigs noticeable within 1 week of weaning, and progressive loss of body condition and lethargy during the next 1-2 weeks. morbidity caused by pfts is moderate, but case fatality is high. the etiology of pfts is presently unknown and may include infectious agent(s), noninfectious factors, or both. pfts was identified in a hig ... | 2011 | 22362939 |
| ceramide formation mediated by acid sphingomyelinase facilitates endosomal escape of caliciviruses. | our recent results demonstrated that bile acids facilitate virus escape from the endosomes into the cytoplasm for successful replication of porcine enteric calicivirus (pec). we report a novel finding that bile acids can be substituted by cold treatment for endosomal escape and virus replication. this endosomal escape by cold treatment or bile acids is associated with ceramide formation by acid sphingomyelinase (asm). asm catalyzes hydrolysis of sphingomyelin into ceramide, which is known to des ... | 2015 | 25985440 |
| comprehensive comparison of cultivable norovirus surrogates in response to different inactivation and disinfection treatments. | human norovirus is the leading cause of epidemic and sporadic acute gastroenteritis. since no cell culture method for human norovirus exists, cultivable surrogate viruses (csv), including feline calicivirus (fcv), murine norovirus (mnv), porcine enteric calicivirus (pec), and tulane virus (tuv), have been used to study responses to inactivation and disinfection methods. we compared the levels of reduction in infectivities of csv and aichi virus (aiv) after exposure to extreme phs, 56°c heating, ... | 2014 | 25015883 |
| factors affecting detection of hepatitis e virus on canadian retail pork chops and pork livers assayed using real-time rt-pcr. | we collected 599 canadian retail pork chops and 283 pork livers routinely (usually weekly) from april 2011 to march 2012 using the canadian integrated program for antimicrobial resistance surveillance (cipars) retail sampling platform. samples were assayed using validated real-time (q) reverse transcriptase polymerase chain reaction (rt-pcr) and nested classical rt-pcr for the detection of hepatitis e virus (hev), porcine enteric calicivirus (pec) and rotavirus (rv). the presence of escherichia ... | 2016 | 26192650 |
| endosomal acidification and cathepsin l activity is required for calicivirus replication. | the role of cellular proteases and endosome maturation in the entry of caliciviruses including porcine enteric calicivirus (pec), murine norovirus (mnv)-1 and feline calicivirus (fcv) were investigated. treatment with chloroquine or cathepsin l inhibitors, but not cathepsin b inhibitors, significantly reduced the replication of pec, mnv and fcv. when concentrated pec, mnv or fcv were incubated with recombinant cathepsin l, the minor capsid protein vp2 of pec and the major capsid protein vp1 of m ... | 2014 | 25108379 |
| farm-level prevalence and risk factors for detection of hepatitis e virus, porcine enteric calicivirus, and rotavirus in canadian finisher pigs. | hepatitis e virus (hev), norovirus (nov), and rotavirus (rv) are all hypothesized to infect humans zoonotically via exposure through swine and pork. our study objectives were to estimate canadian farm-level prevalence of hev, nov [specifically porcine enteric calicivirus (pec)], and rv in finisher pigs, and to study risk factors for farm level viral detection. farms were recruited using the canadian integrated program for antimicrobial resistance surveillance (cipars) and foodnet canada on-farm ... | 2016 | 27127336 |
| first detection and molecular characterization of sapoviruses and noroviruses with zoonotic potential in swine in ethiopia. | noroviruses (novs) and sapoviruses (savs), which belong to the family caliciviridae, are important human and animal enteric pathogens with zoonotic potential. in ethiopia, no study has been done on the epidemiology of animal novs and savs. the aim of this study was to detect and characterize novs and savs from swine of various ages. swine fecal samples (n = 117) were collected from commercial farms in ethiopia. the samples were screened for caliciviruses by reverse transcription polymerase chain ... | 2016 | 27424025 |
| age distribution of porcine sapovirus asymptomatic infection and molecular evidence of genogroups giii and gix? circulation in distinct brazilian pig production systems. | this study aimed to evaluate the natural infection by sav in pigs of different categories of production cycle in an important brazilian pig-producing region. faecal samples (n = 169) of suckling, post-weaning, finisher and breeder pig categories were analysed. animals were from five farrow-to-weaning and nine grower-to-finish commercial pig farms. the rt-pcr assay was performed targeting the partial rna-dependent rna polymerase (rdrp) gene of porcine sav genome. the virus was detected in 23.7% ( ... | 2016 | 26385461 |
| the crucial role of bile acids in the entry of porcine enteric calicivirus. | replication of porcine enteric calicivirus (pec) in llc-pk cells is dependent on the presence of bile acids in the medium. however, the mechanism of bile acid-dependent pec replication is unknown. understanding of bile acid-mediated pec replication may provide insight into cultivating related human noroviruses, currently uncultivable, which are the major cause of viral gastroenteritis outbreaks in humans. our results demonstrated that while uptake of pec into the endosomes does not require bile ... | 2014 | 24889246 |
| frequency of hepatitis e virus, rotavirus and porcine enteric calicivirus at various stages of pork carcass processing in two pork processing plants. | hepatitis e virus (hev), rotavirus (rv), and porcine enteric calicivirus (pec) infections are common in swine and raises concerns about the potential for zoonotic transmission through undercooked meat products. enteric viruses can potentially contaminate carcasses during meat processing operations. there is a lack of information on the prevalence and control of enteric viruses in the pork processing chain. this study compared the incidence and levels of contamination of hog carcasses with hev, r ... | 2017 | 28783534 |
| prevalence and molecular characterization of porcine enteric caliciviruses and first detection of porcine kobuviruses in us swine. | the prevalence of porcine sapoviruses (savs) and noroviruses (novs) in nursing piglets on three pig farms in ohio was studied. fecal samples (n = 139) were collected from individual pigs and screened for caliciviruses by rt-pcr. phylogenetic analysis was conducted using partial sequences of the rna polymerase region. three different sav genogroups, including a newly emerging one (do19 korea-like) were detected. no novs were detected. kobuviruses, emerging members of the family picornaviridae, we ... | 2013 | 23456421 |