Hepatitis E is an infectious disease caused by a small RNA virus (Hepatitis E Virus, HEV), which can cause acute hepatitis in humans. Four mammalian HEV genotypes are known, among which g3 and g4 are considered zoonotic. In Italy, g3 strains have been detected in swine, in both farms and slaughterhouses. Food-borne transmission of HEV was reported frequently in sporadic and clustered human cases associate to consumption of raw meat or liver of boar, swine and deer. In this study, we investigated the presence of HEV in liver sausage, which is often consumed raw or undercooked in Italy. Methods: In 2012, 8 packages of pork liver both fresh and dry sausages were bought at a butcher shop in Rome. Each sausages (n° 29) were chopped in three slices (250 mg each, obtaining of 45 and 42 slices for fresh and dry liver sausages) and spiked with Murine Norovirus (MNV-1). After RNA extraction, samples were analyzed by RT-qPCR for MNV detection (extraction process control). Samples confirmed positive for MNV were then analyzed for HEV and Porcine Adenovirus (PAdV, as index virus of swine fecal contamination) by RT-qPCR and Real-Time PCR, respectively. No process control signal was obtained from 19 of 42 dry liver sausages tested. Conversely, the HEV genome was detected in both raw (10 out of 45 slices, 22.2%) and dry (1/23 slices, 4.3%) liver sausages by RTqPCR. RNAs resulting positive for the process control MNV-1 were further analyzed by conventional RT-PCR and PCR assays for HEV and PAdV, respectively. All slices were negative for PAdV, suggesting the absence of swine fecal contamination. On the contrary, three out of 11 RT-qPCR HEV-positive slices of sausages were also positive by at least one of the two conventional RT-PCR performed, which amplify the MTase and RdRp. Sequences were correlated to genotype 3 HEV strains detected in swine in Italy. Since different sequenced regions are currently available from human and swine Italian strains, few conclusions can be drawn on possible correlation of the HEV from sausage characterized with human strains. Although HEV infectivity was not confirmed, this pilot study fosters more investigations on HEV presence in pork-derived food, to assess the possible risk for the consumers.
Detection of Hepatitis E virus in pork liver sausages
OSTANELLO, FABIO;
2014
Abstract
Hepatitis E is an infectious disease caused by a small RNA virus (Hepatitis E Virus, HEV), which can cause acute hepatitis in humans. Four mammalian HEV genotypes are known, among which g3 and g4 are considered zoonotic. In Italy, g3 strains have been detected in swine, in both farms and slaughterhouses. Food-borne transmission of HEV was reported frequently in sporadic and clustered human cases associate to consumption of raw meat or liver of boar, swine and deer. In this study, we investigated the presence of HEV in liver sausage, which is often consumed raw or undercooked in Italy. Methods: In 2012, 8 packages of pork liver both fresh and dry sausages were bought at a butcher shop in Rome. Each sausages (n° 29) were chopped in three slices (250 mg each, obtaining of 45 and 42 slices for fresh and dry liver sausages) and spiked with Murine Norovirus (MNV-1). After RNA extraction, samples were analyzed by RT-qPCR for MNV detection (extraction process control). Samples confirmed positive for MNV were then analyzed for HEV and Porcine Adenovirus (PAdV, as index virus of swine fecal contamination) by RT-qPCR and Real-Time PCR, respectively. No process control signal was obtained from 19 of 42 dry liver sausages tested. Conversely, the HEV genome was detected in both raw (10 out of 45 slices, 22.2%) and dry (1/23 slices, 4.3%) liver sausages by RTqPCR. RNAs resulting positive for the process control MNV-1 were further analyzed by conventional RT-PCR and PCR assays for HEV and PAdV, respectively. All slices were negative for PAdV, suggesting the absence of swine fecal contamination. On the contrary, three out of 11 RT-qPCR HEV-positive slices of sausages were also positive by at least one of the two conventional RT-PCR performed, which amplify the MTase and RdRp. Sequences were correlated to genotype 3 HEV strains detected in swine in Italy. Since different sequenced regions are currently available from human and swine Italian strains, few conclusions can be drawn on possible correlation of the HEV from sausage characterized with human strains. Although HEV infectivity was not confirmed, this pilot study fosters more investigations on HEV presence in pork-derived food, to assess the possible risk for the consumers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
