Identification and Phylogenetic Diversity of Parvovirus Circulating in Commercial Chicken and Turkey Flocks in Croatia

Detection and molecular characterization of chicken parvovirus and chicken megrivirus in layer breeders affected by intestinal dilatation syndrome

RESEARCH HIGHLIGHTS

IDS presented pathognomonic dilatation of the jejunum up to Meckel's diverticulum.IDS caused weight loss, decreased egg production, and increased culling and mortality.Chicken parvovirus (ChPV) was consistently detected through PCR assays.Chicken megrivirus (ChMV) was consistently detected through viral metagenomics.

Molecular Characterization of the Chicken Parvovirus Based on VP1 Gene Circulating in Brazilian Chicken Flocks

Parvovirus infection affects several animal species, especially young animals. In birds, parvovirus infection has been described in Muscovy ducks, turkeys, and chickens, all of which had enteric diseases characterized by diarrhea. Chicken parvovirus (ChPV) has been detected in poultry around the world in animals affected by enteric problems, showing dwarfism, cloacal pasting, and diarrhea. In Brazil, ChPV was detected in chickens affected by diarrhea fifteen years ago. However, the genetic characteristics of ChPV circulating in chicken flocks were not determined. Therefore, the aim of the present investigation was to determine the genetic characteristics of the VP1 gene from ChPV detected in chickens affected by enteric diseases in Brazil. For this purpose, a molecular approach was used. Specific primers were designed to flank the complete VP1 gene of ChPV and amplify it using PCR. The amplified products from samples of chickens with enteric diseases were sequenced, and 22 complete CDs of the VP1 gene were obtained. These samples, compared to the ABU-P1 sequence, showed 17 sequences with high nucleotide (NT) similarity of 92.7-97.4% and amino acid (AA) similarity of 94.8-99.5% associated with Runting and Stunting syndrome (RSS); there were also five samples associated with hens with diarrhea with unusual jejunal dilatation (JD) that had less similarity than the RSS sequences (NT of 86.5% and AA of 93-93.1%). The phylogenetic analysis determined four groups. Group I had sequences from Korea. The second group included sequences from Korea, China, and Brazil (not included in this work). The third group had studied RSS sequences grouped with the ABU-P1 strain and sequences from China and the United States. Finally, the sequences from JD were clustered in a separate group with a bootstrap of 100%, a group that was denoted as group IV, and included sequences from China. RDP4 and SimPlot analysis showed one point of recombination with the sequences of group III ChPV in the JD sequences. Herein, we show that circulating strains of ChPV exhibit genetic differences in the VP1 gene in Brazilian chicken flocks. Nevertheless, more studies are needed to determine the probability of a new genetic group of ChPV based on the analysis of the complete genome.

Detection and Molecular Characterization of Enteric Viruses in Poultry Flocks in Hebei Province, China

Simple Summary

Enteric viruses act as etiological agents for a series of health disturbances that pose a threat to commercial chickens worldwide. The affected chickens exhibit stunted growth, low feed conversion, etc. On a global scale, research on enteric virus diversity has been performed in countries such as India, South Korea and Brazil, yet at present, there have been no conclusive reports of avian enteric viruses in China. In the present study, the virus species, infection types, clinical symptoms, and relationships among the virus species were studied in 145 positive enteric virus samples. Additionally, the evolutionary relationship and recombination of the viruses were also further studied. The results of this study can be used to define the distribution and infection type of enteric viruses in poultry, and to analyze the classification of and evolutionary relationship between certain viruses.

Abstract

Enteric viruses, as a potential pathogen, have been found to be vital causes of economic losses in poultry industry worldwide. The enteric viruses widely studied to date mainly include avian nephritis virus (ANV), avian reovirus (ARe), chicken astrovirus (CAstV), chicken parvovirus (ChPV), fowl adenovirus group I (FAdV-1), infectious bronchitis virus (IBV), and avian rotavirus (ARoV). This paper aimed to identify single and multiple infections of the seven enteric viruses using the data obtained from positive 145 enteric virus samples in poultry flocks from different areas in Hebei Province, throughout the period from 2019 to 2021. Next, the correlation between bird age and clinical signs was investigated using PCR and RT-PCR techniques. Furthermore, the whole genomes of seven parvovirus strains and open reading frame 2 (ORF2) of six CAstV strains and eight ANV strains were sequenced for phylogenetic analysis and recombination analysis, to characterize the viruses and evaluate species correlation and geographic patterns. A total of 11 profiles of virus combinations were detected; 191 viruses were detected in 145 samples; 106 single infections were reported in 73.1% of the samples; and multiple infections were detected in the remaining 26.9%. For viruses, 69% of ChPV was correlated with single infection, while ANV (61.4%) and CAstV (56.1%) were correlated with multiple infections. However, IBV and ARe were not detected in any of the samples. Recombination events were reported in parvovirus, and all CAstV sequences investigated in this paper were included within genotype Bii. The eight ANV strains pertained to different subtypes with significant differences. The above results revealed for the first time the complexity of enteric viruses over the past several years, thus contributing to disease prevention and control in the future.

Small but mighty: old and new parvoviruses of veterinary significance

In line with the Latin expression "sed parva forti" meaning "small but mighty," the family Parvoviridae contains many of the smallest known viruses, some of which result in fatal or debilitating infections. In recent years, advances in metagenomic viral discovery techniques have dramatically increased the identification of novel parvoviruses in both diseased and healthy individuals. While some of these discoveries have solved etiologic mysteries of well-described diseases in animals, many of the newly discovered parvoviruses appear to cause mild or no disease, or disease associations remain to be established. With the increased use of animal parvoviruses as vectors for gene therapy and oncolytic treatments in humans, it becomes all the more important to understand the diversity, pathogenic potential, and evolution of this diverse family of viruses. In this review, we discuss parvoviruses infecting vertebrate animals, with a special focus on pathogens of veterinary significance and viruses discovered within the last four years.

Detection and characterization of chicken astrovirus associated with hatchery disease in commercial day-old turkeys in southwestern Nigeria

Infectious diseases are a major obstacle to profitable poultry production in Nigeria due to the mortality and severe economic losses they cause. In particular, they are a potent threat to attainment of the food security goals of government and national self-sufficiency in food production. Thus, there is a need for continuous monitoring of the nation’s poultry population for these diseases. As part of an ongoing investigation of enteric viruses associated with poor performance or hatchery diseases in commercial poultry in southwestern Nigeria, intestinal contents from 97 condemned or runted day-old commercial turkey poults were examined for turkey astroviruses, infectious bronchitis virus, chicken astrovirus (CAstV), avian nephritis virus, avian rotavirus, avian reovirus, fowl adenovirus, and chicken parvovirus by virus isolation, electron microscopy (EM), polymerase chain reaction (PCR), and reverse transcription PCR. The samples were collected from five commercial hatcheries and five farms located in southwestern Nigeria. While all samples tested negative for other viruses, CAstV was detected in the majority (83.5%) of the birds, although some pleomorphic virus-like particles with surface projections that appeared fringed or fimbriated were observed in five of the cell culture samples by EM. Phylogenetic analysis revealed these CAstV strains belonged to the Bi clade. These findings not only implicate CAstV as the major cause of hatchery condemnations in commercial turkeys in southwestern Nigeria but also highlight the need for experimental studies to further establish its role in this disease condition.

Runting and Stunting Syndrome in Broiler Chickens: Histopathology and Association With a Novel Picornavirus

Runting stunting syndrome (RSS) in commercial chickens has been reported worldwide, and although several studies have attempted to clarify the cause and describe the lesions, there are gaps in knowledge of the epidemiology, pathogenesis, and etiology. The study objective was to use commercial chicks naturally affected by RSS to describe the histologic changes of RSS in all segments of the small intestine in chicks of different ages and to identify viral gene sequences in affected chicks and their association with histologic lesions. Chicks lacking clinical signs but from the same houses and from unaffected houses were used as controls. The average weight of affected chicks was significantly lower than expected for their flocks. Macroscopically, the small intestines had paler serosa, with watery, mucoid, or foamy contents and poorly digested food. Histologic lesions were characterized by necrotic crypts, crypt dilation, and flattening of the crypt epithelium. Histomorphometry of the intestines revealed villous atrophy especially in the jejunum and ileum. Histologic changes in other organs were not observed. Random next-generation sequencing of total RNA extracted from formalin-fixed paraffin-embedded tissues detected avian nephritis virus, avian rotavirus, and picornavirus in jejunal segments from 7-day-old chicks. No viruses were detected in the jejunum of 1-day-old chicks. Detection of picornaviral reads was significantly associated (P < .05) with histologic lesions of RSS. Sequence analysis of the picornavirus revealed genetic similarity with the genus Gallivirus. Using in situ hybridization for galliviral nucleic acid sequences, the signal was associated with crypt lesion severity, although signal was detected both in chicks with and without RSS.

Epidemiological Surveillance of Parvoviruses in Commercial Chicken and Turkey Farms in Guangxi, Southern China, During 2014-2019

A previously unidentified chicken parvovirus (ChPV) and turkey parvovirus (TuPV) strain, associated with runting-stunting syndrome (RSS) and poultry enteritis and mortality syndrome (PEMS) in turkeys, is now prevalent among chickens in China. In this study, a large-scale surveillance of parvoviruses in chickens and turkeys using conserved PCR assays was performed. We assessed the prevalence of ChPV/TuPV in commercial chicken and turkey farms in China between 2014 and 2019. Parvoviruses were prevalent in 51.73% (1,795/3,470) of commercial chicken and turkey farms in Guangxi, China. The highest frequency of ChPV positive samples tested by PCR occurred in chickens that were broiler chickens 64.18% (1,041/1,622) compared with breeder chickens 38.75% (572/1,476) and layer hens 38.89% (112/288), and TuPV was detected in 70/84 (83.33%). Native and exotic chicken species were both prevalent in commercial farms in southern China, and exotic broiler chickens had a higher positive rate with 88.10% (148/168), while native chickens were 50.00% (1,465/2,930). The environmental samples from poultry houses tested positive for ChPV and TuPV were 47.05% (415/874). Samples from open house flocks had higher prevalence rates of ChPV than those of closed house flocks (Table 5), among which those from the open house showed 84.16% (85/101) positivity, those from litter showed 62.86% (44/70) positivity, and those from drinking water showed 50.00% (56/112) positivity, whereas those from the closed house litter were 53.57% (60/112), those from swabs were 50.18% (138/275), and those from drinking water were 15.69% (32/204). Samples collected during spring were more frequently ChPV/ TuPV positive than those collected during other seasons. This study is the first report regarding the epidemiological surveillance of ChPV and TuPV in chicken/turkey flocks in Guangxi, China. Our results suggest that ChPV and TuPV are widely distributed in commercial fowl in Guangxi. These findings highlight the need for further epidemiological and genetic research on ChPV and TuPV in this area.

Complete Coding Sequences of Three Chicken Parvovirus Isolates from the United States

Parvoviruses are commonly found in U.S. poultry and are associated with clinical disease. Here, we report the complete coding sequences of three chicken parvoviruses from broiler chickens from commercial farms in the state of Georgia.

Parvoviruses are commonly found in U.S. poultry and are associated with clinical disease. Here, we report the complete coding sequences of three chicken parvoviruses from broiler chickens from commercial farms in the state of Georgia.

Molecular Characterization and Pathogenicity of Chicken Parvovirus (ChPV) in Specific Pathogen-Free Chicks Infected Experimentally

Chicken parvovirus (ChPV) is an agent frequently associated with runting stunting syndrome (RSS). This syndrome has been reported in association with ChPV in many countries, including Brazil; however, studies characterizing the virus on a molecular level are scarce, and ChPV pathogenicity in day-old chicks remains unclear. The aim of the present work was to establish the molecular characteristics of ChPV, determine the pathogenicity of ChPV in SPF chicks and detect and quantify ChPV by qPCR in several tissues and chicks of different ages. The experimental challenge was performed at one day of age, and daily and weekly observations were performed and five birds from each experimental group (mock and infected birds) were euthanized to perform the different analysis. ChPV genome copies were detected and quantified by qPCR in gut, spleen, thymus, kidney, pancreas, proventriculus and bursa. Clinically, the infected group presented with diarrhea 24 h post-infection, which persisted until 42 days of age. The small intestine was distended, and its contents were aqueous and foamy. Enteritis and dilated crypts with cyst shapes were observed in intestinal segments. Acute pancreatitis associated with lymphocytic nodules, infiltrating lymphocytes and plasma cells between the pancreatic acinus was observed. Koch’s postulate was demonstrated and the genetic characterization of the VP1 gene showed that the Brazilian ChPV isolate belongs to the ChPV II group.

Molecular Characterization of Parvovirus Strain GX-Tu-PV-1, Isolated from a Guangxi Turkey

The aim of the current study was to determine the genomic sequence of parvovirus strain GX-Tu-PV-1, which was isolated from a turkey in Guangxi Province, South China. The analysis showed that the genome sequence of GX-Tu-PV-1 was 81.3% to ∼99.3% similar to those of other turkey parvoviruses (TuPVs) and 79.8% to ∼92.1% related to chicken parvovirus (ChPV). This study will help in understanding the epidemiology and molecular characteristics of parvovirus in turkeys.

The aim of the current study was to determine the genomic sequence of parvovirus strain GX-Tu-PV-1, which was isolated from a turkey in Guangxi Province, South China. The analysis showed that the genome sequence of GX-Tu-PV-1 was 81.3% to ∼99.3% similar to those of other turkey parvoviruses (TuPVs) and 79.8% to ∼92.1% related to chicken parvovirus (ChPV). This study will help in understanding the epidemiology and molecular characteristics of parvovirus in turkeys.

Investigation of Enteric Viruses Associated With Runting and Stunting in Day-Old Chicks and Older Broilers in Southwest Nigeria

Enteric viruses are known to have significant economic impact on poultry, especially broiler chicken flocks, because of production losses attributable to poor feed conversion and weight gain. To sustain the Nigerian poultry industry that contributes significantly to the livestock sector of the economy, there is a need to investigate commercial broiler flocks in the country for the presence of enteric viruses causing runting and stunting, growth retardation, and hatchery diseases. Gut contents were collected from 158 day-old and six 14-week old runted/stunted broiler chickens in commercial farms (ten) and hatcheries (six) located in Southwest Nigeria. The samples were examined for the presence of chicken astrovirus (CAstV), avian nephritis virus (ANV), avian rotavirus (AvRV), chicken parvovirus (ChPV), and turkey astroviruses (TAstV-1 and−2) by polymerase chain reaction (PCR) and reverse transcriptase-PCR (RT-PCR) whereas avian reovirus (ARV) and fowl adenovirus (FAdV) by virus isolation (VI), RT-PCR, and PCR. While CAstV was detected in all the birds (100%), sporadic detection of ANV (5%), and ChPV (5%) was observed in day-old and/or older birds. Four isolates were obtained by VI with one isolate being ARV positive and other three FAdV positive by RT-PCR and PCR, respectively. These findings strongly suggest CAstV as a major cause of runting and stunting as well as hatchery condemnations in commercial broilers in Southwest Nigeria, although co-infections with ANV, FAdV, ARV, and ChPV cannot be ruled out. In addition, the possible vertical and horizontal transmissions of these viruses are discussed.

Avian parvovirus: classification, phylogeny, pathogenesis and diagnosis

Poultry parvoviruses identified during the early 1980s are found worldwide in intestines from young birds with enteric disease syndromes as well as healthy birds. The chicken parvovirus (ChPV) and turkey parvovirus (TuPV) belong to the Aveparvovirus genus within the subfamily Parvovirinae. Poultry parvoviruses are small, non-enveloped, single-stranded DNA viruses consisting of three open reading frames, the first two encoding the non-structural protein (NS) and nuclear phosphoprotein (NP) and the third encoding the viral capsid proteins 1 (VP1 and VP2). In contrast to other parvoviruses, the VP1-unique region does not contain the phospholipase A2 sequence motif. Recent experimental studies suggested the parvoviruses to be the candidate pathogens in cases of enteric disease syndrome. Current diagnostic methods for poultry parvovirus detection include PCR, real-time PCR, enzyme linked immunosorbent assay using recombinant VP2 or VP1 capsid proteins. Moreover, sequence-independent amplification techniques combined with next-generation sequencing platforms have allowed rapid and simultaneous detection of the parvovirus from affected and healthy birds. There is no commercial vaccine; hence, the development of an effective vaccine to control the spread of infection should be of primary importance. This review presents the current knowledge on poultry parvoviruses with emphasis on taxonomy, phylogenetic relationship, genomic analysis, epidemiology, pathogenesis and diagnostic methods.

Genetic and phylogenetic analysis of a novel parvovirus isolated from chickens in Guangxi, China

A previously unidentified chicken parvovirus (ChPV) strain, associated with runting-stunting syndrome (RSS), is now endemic among chickens in China. To explore the genetic diversity of ChPV strains, we determined the first complete genome sequence of a novel ChPV isolate (GX-CH-PV-7) identified in chickens in Guang Xi, China, and showed moderate genome sequence similarity to reference strains. Analysis showed that the viral genome sequence is 86.4 %-93.9 % identical to those of other ChPVs. Genetic and phylogenetic analyses showed that this newly emergent GX-CH-PV-7 is closely related to Gallus gallus enteric parvovirus isolate ChPV 798 from the USA, indicating that they may share a common ancestor. The complete DNA sequence is 4612 bp long with an A+T content of 56.66 %. We determined the first complete genome sequence of a previously unidentified ChPV strain to elucidate its origin and evolutionary status.

Molecular detection of chicken parvovirus in broilers with enteric disorders presenting curving of duodenal loop, pancreatic atrophy, and mesenteritis

Enteric disorders are an important cause of economic losses in broiler chickens worldwide. Several agents have been associated with enteric problems, such as viruses, bacteria, and parasites. In this study, broiler chickens showing signs of enteric disorders were subjected to molecular diagnosis for several viral agents and also for pathological examination for elucidating this problem. Thus, the chickens were screened for avian nephritis virus (ANV), chicken astrovirus (CAstV), avian rotavirus (ArtV), avian reovirus (AReoV), infectious bronchitis virus (IBV), fowl adenovirus group I (FAdV-1), and chicken parvovirus (ChPV). Postmortem examinations revealed a curving of the duodenal loop (J-like appearance) and intestines filled with liquid and gaseous content. Histopathological analysis of the duodenal loop showed pancreatic atrophy, acute mesenteritis, and enteritis. PCR results showed that ChPV was the sole viral agent detected in samples with lesions such as the curved duodenal loop and pancreatic atrophy. Molecular characterization of the nucleotide and deduced amino acid sequences revealed a high similarity with other strains of ChPV from Brazil, Canada, United States, Europe, and Asia. These findings suggest an association between ChPV and the development of enteritis, pancreatitis, and pancreatic atrophy, which may lead to curling of the duodenal loop. Together, these alterations may disrupt the normal functioning of the digestive system, diminishing digestion and the absorption of dietary nutrients and consequently leading to reduced weight gain, flock impairment, dwarfism, and an elevated feed conversion rate.

Isolation and molecular characterisation of chicken parvovirus from Brazilian flocks with enteric disorders

1. The presence of parvovirus in chickens with enteric disease was investigated in commercial flocks in Brazil. 2. The intestinal contents of chickens exhibiting clinical signs of diarrhoea, weight loss or mortality were examined, and chicken parvovirus (chPV) was identified using a polymerase chain reaction (PCR) assay. The samples were sequenced and inoculated into specific-pathogen-free (SPF) embryonated eggs to isolate the virus. 3. Necropsies showed that the embryos were dwarfish, haemorrhagic and oedematous. The presence of chPV was confirmed by PCR and DNA sequencing. 4. The molecular characterisation of chPV strains circulating in the Brazilian flocks showed that they were genetically related to sequences from North America, Europe and Asia. Phylogenetic analyses clustered the Brazilian chPV sequences with those from Europe (Croatia, Hungary) and Asia (South Korea). 5. This study is the first report of the molecular characterisation of chPV circulating in the commercial flocks in Brazil and indicates high genetic similarity with chPV sequences from around the world.

Genetic characterization of three novel chicken parvovirus strains based on analysis of their coding sequences

Chicken parvovirus (ChPV) is one of the causative agents of viral enteritis. Recently, the genome of the ABU-P1 strain of ChPV was fully sequenced and determined to have a distinct genomic composition compared with that of vertebrate parvoviruses. However, no comparative sequence analysis of coding regions of ChPVs was possible because of the lack of other sequence information. In this study, we obtained the nucleotide sequences of all genomic coding regions of three ChPVs by polymerase chain reaction using 13 primer sets, and deduced the amino acid sequences from the nucleotide sequences. The non-structural protein 1 (NS1) gene of the three ChPVs showed 95.0 to 95.5% nucleotide sequence identity and 96.5 to 98.1% amino acid sequence identity to those of NS1 from the ABU-P1 strain, respectively, and even higher nucleotide and amino acid similarities to one another. The viral proteins (VP) gene was more divergent between the three ChPV Korean strains and ABU-P1, with 88.1 to 88.3% nucleotide identity and 93.0% amino acid identity. Analysis of the putative tertiary structure of the ChPV VP2 protein showed that variable regions with less than 80% nucleotide similarity between the three Korean strains and ABU-P1 occurred in large loops of the VP2 protein believed to be involved in antigenicity, pathogenicity, and tissue tropism in other parvoviruses. Based on our analysis of full-length coding sequences, we discovered greater variation in ChPV strains than reported previously, especially in partial regions of the VP2 protein.

Molecular survey of enteric viruses in commercial chicken farms in Korea with a history of enteritis

Several enteric viruses have increasingly received attention as potential causative agents of runting-stunting syndrome (RSS) in chickens. A molecular survey was performed to determine the presence of a broad range of enteric viruses, namely chicken astrovirus (CAstV), avian nephritis virus (ANV), chicken parvovirus (ChPV), infectious bronchitis virus (IBV), avian rotavirus (AvRV), avian reovirus (ARV), and fowl adenovirus (FAdV), in intestinal samples derived from 34 commercial chicken flocks that experienced enteritis outbreaks between 2010 and 2012. Using techniques such as PCR and reverse-transcription PCR, enteric viruses were identified in a total of 85.3% of investigated commercial chicken flocks in Korea. Furthermore, diverse combinations of 2 or more enteric viruses were simultaneously identified in 51.7% of chicken farms positive for enteric viruses. The rank order of positivity for enteric viruses was as follows: ANV (44.1%), CAstV (38.2%), ChPV (26.5%), IBV (20.6%), ARV (8.8%), AvRV (5.9%), and FAdV (2.9%). Additionally, other pathogens such as Escherichia coli, Salmonella spp., Eimeria spp., and FAdV were detected in 79% of chicken flocks positive for enteric viruses using PCR, bacterial isolation, and microscopic examination. The results of our study indicate the presence of several enteric viruses with various combinations in commercial chicken farms that experienced enteritis outbreaks. Experimental studies are required to further understand the roles of enteric viruses in RSS in commercial chickens.

Chicken parvovirus-induced runting-stunting syndrome in young broilers

Previously we identified a novel parvovirus from enteric contents of chickens that were affected by enteric diseases. Comparative sequence analysis showed that the chicken parvovirus (ChPV) represented a new member in the Parvoviridae family. Here, we describe some of the pathogenic characteristics of ChPV in young broilers. Following experimental infection, 2-day-old broiler chickens showed characteristic signs of enteric disease. Runting-stunting syndrome (RSS) was observed in four of five experimental groups with significant growth retardation between 7 and 28 days postinoculation (DPI). Viral growth in small intestine and shedding was detected at early times postinoculation, which was followed by viremia and generalization of infection. ChPV could be detected in most of the major tissues for 3 to 4 wk postinoculation. Immunohistochemistry staining revealed parvovirus-positive cells in the duodenum of inoculated birds at 7 and 14 DPI. Our data indicate that ChPV alone induces RSS in broilers and is important determinant in the complex etiology of enteric diseases of poultry.

Quantification of human and animal viruses to differentiate the origin of the fecal contamination present in environmental samples

Many different viruses are excreted by humans and animals and are frequently detected in fecal contaminated waters causing public health concerns. Classical bacterial indicator such as E. coli and enterococci could fail to predict the risk for waterborne pathogens such as viruses. Moreover, the presence and levels of bacterial indicators do not always correlate with the presence and concentration of viruses, especially when these indicators are present in low concentrations. Our research group has proposed new viral indicators and methodologies for determining the presence of fecal pollution in environmental samples as well as for tracing the origin of this fecal contamination (microbial source tracking). In this paper, we examine to what extent have these indicators been applied by the scientific community. Recently, quantitative assays for quantification of poultry and ovine viruses have also been described. Overall, quantification by qPCR of human adenoviruses and human polyomavirus JC, porcine adenoviruses, bovine polyomaviruses, chicken/turkey parvoviruses, and ovine polyomaviruses is suggested as a toolbox for the identification of human, porcine, bovine, poultry, and ovine fecal pollution in environmental samples.

Genetic characterization of parvoviruses circulating in turkey and chicken flocks in Poland

Between 2008 and 2011, commercial turkey and chicken flocks in Poland were examined for the presence of turkey parvovirus (TuPV) and chicken parvovirus (ChPV). Clinical samples (10 individual faecal swabs/flock) from 197 turkey flocks (turkeys aged 1 to 19 weeks) and 45 chicken flocks (chickens aged 3 to 17 weeks) were collected in different regions of the country and tested using a PCR assay that targeted the NS1 gene (3’ORF). The prevalence of TuPV was 29.4 % in the flocks tested, while ChPV infections were found in 22.2 % of the studied flocks. Phylogenetic analysis revealed a clear division into three groups: ChPV-like, TuPV-like and a third, previously unrecognized and distinct subgroup, TuPV-LUB, containing exclusively three Polish isolates from turkeys. The isolates from the novel group showed as little as 50.6-64.5 % of nucleotide sequence identity to the prototype chicken and turkey parvovirus strains. Genetic analysis of a ChPV isolate that was classified in the TuPV group strongly suggests a recombination event between chicken and turkey parvoviruses.

A novel tool for specific detection and quantification of chicken/turkey parvoviruses to trace poultry fecal contamination in the environment

Poultry farming may introduce pathogens into the environment and food chains. High concentrations of chicken/turkey parvoviruses were detected in chicken stools and slaughterhouse and downstream urban wastewaters by applying new PCR-based specific detection and quantification techniques. Our results confirm that chicken/turkey parvoviruses may be useful viral indicators of poultry fecal contamination.