Characterization of a Novel Porcine Parvovirus Tentatively Designated PPV5

A new porcine parvovirus (PPV), provisionally designated as PPV5, was identified in U.S. pigs. Cloning and sequencing from a circular or head-to-tail concatemeric array revealed that the PPV5 possesses the typical genomic organization of parvoviruses with two major predicted open reading frames (ORF1 and ORF2), and is most closely related to PPV4 with overall genomic identities of 64.1–67.3%. The amino acid identities between PPV5 and PPV4 were 84.6%–85.1% for ORF1 and 54.0%–54.3% for ORF2. Unlike PPV4, but similar to bovine parvovirus 2 (BPV2), PPV5 lacks the additional ORF3 and has a much longer ORF2. Moreover, the amino acid sequences of ORF1 and ORF2 of BPV2 showed higher homologies to PPV5 than to PPV4. The conserved motifs of the Ca²⁺ binding loop (YXGXG) and the catalytic center (HDXXY) of phospholipase A₂ (PLA₂) were identified in VP1 (ORF2) of PPV5, as well as in BPV2, but were not present in PPV4. Phylogenetic analyses revealed that PPV5, PPV4 and BPV2 form a separate clade different from the genera Parvovirus and Bocavirus. Further epidemiologic investigations of PPV4 and PPV5 in U.S. pigs of different ages indicated a slightly higher prevalence for PPV5 (6.6%; 32/483) compared to PPV4 (4.1%; 20/483), with detection of concurrent PPV4 and PPV5 in 15.6% (7/45) of lungs of infected pigs. Evidence for potential vertical transmission or association with reproductive failure was minimal for both PPV4 and PPV5. The high similarity to PPV4 and the lack of ORF3 may suggest PPV5 is an intermediate of PPV4 during the evolution of parvoviruses in pigs.     

A retrospective study of DNA prevalence of porcine parvoviruses in Mexico and its relationship with porcine circovirus associated disease

Worldwide, many emerging porcine parvoviruses (PPVs) have been linked to porcine circovirus-2 (PCV2) associated disease (PCVAD), which includes post-weaning multi-systemic wasting syndrome (PMWS), PCV2-related reproductive failure (PCV2-RF), as well as other syndromes. To determine the DNA prevalence of PPVs and their relationship with PMWS and PCV2-RF in Mexico, 170 formalin-fixed paraffin-embedded tissues were selected from archival collections to detect PPVs using a nested polymerase chain reaction. The tissues were composed of 50 PMWS cases, 20 age-matched tissues from healthy pigs, 56 PCV2-related reproductive failure (PCV2⁺-RF) cases, and 44 PCV2^--RF cases. Overall, PPV2 and PPV6 were the most prevalent species (90.0% and 74.7%, respectively). In 8–11 week old pigs, the highest prevalence was for PPV6 and PPV3. Concerning reproductive failure, the PCV2-affected farms had a significantly higher prevalence for PPV6 (61.6%) and PPV5 (36.4%) than the PCV2-unaffected farms (35.0% and 5.0%, respectively). The concurrent infection rate was high, being significant for PPV2/PPV4 and PPV1/PPV5 within the PMWS cases and for PPV6/PPV5 among the PCV2⁺-RF tissues. PPV5 showed a significant relationship with PMWS, whereas PPV5 and PPV6 were significant for PCVAD. The prevalence and coinfection rate of PPVs in Mexico were markedly higher than that described in other countries, denoting that PPV5 and PPV6 might have a potential role in PCVAD in Mexico. It is concluded that it is likely that the density population of pigs in Mexico is contributing to high PPV inter-species and PCV2 coinfections which might lead to a different pathogenic outcome.     

Coexistence of multiple strains of porcine parvovirus 2 in pig farms

The porcine parvovirus 2 (PPV2) genome was first identified in 2001 in Myanmar. Recently, the PPV2 genome has been found in several other countries. In this study, the prevalence of PPV2 in Japanese domestic pigs was investigated and found to be 58% (69/120) in healthy domestic pigs and 100% (69/69) in sick domestic pigs. Sequencing and phylogenetic analysis of the PCR products of the VP1 gene and an almost full length PPV2 clone indicated that diverged PPV2 strains exist in Japan. Clearly distinct strains of PPV2 were detected in 7 of the 10 pig farms.     

Capsid protein evolution and comparative phylogeny of novel porcine parvoviruses

In addition to the well known “classical” porcine parvovirus (PPV1; responsible for reproductive failure of susceptible sows) several new porcine parvoviruses have been recognized (PPV2, PPV3 and PPV4) in recent years. The genetic variation, characteristics and evolutionary factors shaping these novel PPVs were studied by comparing the complete capsid (cap) genes of PPVs from domestic pigs and wild boars. Using Bayesian coalescent methods we estimated the rate of nucleotide substitution for PPV2, PPV3 and PPV4 to be of the order of 3.86 × 10^?4–8.23 × 10^?4 subs site^?1 year^?1, similar to those commonly measured for RNA viruses, although this rate in case of PPV2 is probably influenced by frequent recombination events. Given such rapid evolutionary dynamics, it is likely that novel PPVs will continue to improve their capacity to spread among Suidae hosts worldwide. The mean time to the most recent common ancestor for the sampled genetic diversity of the newly discovered porcine parvoviruses was estimated. The results indicated that novel PPVs originated within approximately the last 70 years. Incongruent phylogenetic relationships of several strains suggested recombination events supported by several recombination-detecting methods and by split-decomposition phylogenetic networks. Analyses of the selective constraints acting on each codon suggest that some regions of PPV cap genes were under positive selection. This study showed that inter- and intraspecies recombination and diversifying selection pressures are prevalent across the cap genes of novel PPVs, and beside host switching and gene flow are important driving forces of their evolution and may be significant factors in the emergence of new viral variants.     

Prevalence of antibodies to selected viral pathogens in wild boars (Sus scrofa) in Croatia in 2005-06 and 2009-10

We determined prevalence of antibody to selected viral pathogens important for domestic pigs and livestock in 556 wild boar (Sus scrofa) sera collected during 2005-06 and 2009-10 in four counties in Croatia. These counties account for an important part of the Croatian commercial pig production and have a high density of wild boars. Samples were tested for antibodies to porcine parvovirus (PPV), Aujeszky's disease virus (ADV), porcine circovirus type 2 (PCV2), swine influenza virus, porcine respiratory and reproductive syndrome virus (PRRSV), porcine respiratory coronavirus (PRCV), transmissible gastroenteritis virus, and swine vesicular disease virus (SVDV). Antibodies to all of the infectious pathogens except SVDV were detected. There was a statistically significant difference in prevalence between the two periods for PPV, ADV, PCV2, PRRSV, and PRCV, with a higher prevalence of PPV and ADV in the 2009-10 period (P<0.05). During the same period, the prevalence of PCV2, PRRSV, and PRCV was lower (P<0.05). Our results provide information on the current disease exposure and health status of wild boars in Croatia and suggest that wild boars may act as a reservoir for several pathogens and a source of infection for domestic pigs and other livestock as well as humans, especially for ADV.     

LuIII parvovirus selectively and efficiently targets, replicates in, and kills human glioma cells

Because productive infection by parvoviruses requires cell division and is enhanced by oncogenic transformation, some parvoviruses may have potential utility in killing cancer cells. To identify the parvovirus(es) with the optimal oncolytic effect against human glioblastomas, we screened 12 parvoviruses at a high multiplicity of infection (MOI). MVMi, MVMc, MVM-G17, tumor virus X (TVX), canine parvovirus (CPV), porcine parvovirus (PPV), rat parvovirus 1A (RPV1A), and H-3 were relatively ineffective. The four viruses with the greatest oncolytic activity, LuIII, H-1, MVMp, and MVM-G52, were tested for the ability, at a low MOI, to progressively infect the culture over time, causing cell death at a rate higher than that of cell proliferation. LuIII alone was effective in all five human glioblastomas tested. H-1 progressively infected only two of five; MVMp and MVM-G52 were ineffective in all five. To investigate the underlying mechanism of LuIII's phenotype, we used recombinant parvoviruses with the LuIII capsid replacing the MVMp capsid or with molecular alteration of the P4 promoter. The LuIII capsid enhanced efficient replication and oncolysis in MO59J gliomas cells; other gliomas tested required the entire LuIII genome to exhibit enhanced infection. LuIII selectively infected glioma cells over normal glial cells in vitro. In mouse models, human glioblastoma xenografts were selectively infected by LuIII when administered intratumorally; LuIII reduced tumor growth by 75%. LuIII also had the capacity to selectively infect subcutaneous or intracranial gliomas after intravenous inoculation. Intravenous or intracranial LuIII caused no adverse effects. Intracranial LuIII caused no infection of mature mouse neurons or glia in vivo but showed a modest infection of developing neurons.     

Two novel parvoviruses in frugivorous New and Old World bats

Bats, a globally distributed group of mammals with high ecological importance, are increasingly recognized as natural reservoir hosts for viral agents of significance to human and animal health. In the present study, we evaluated pools of blood samples obtained from two phylogenetically distant bat families, in particular from flying foxes (Pteropodidae), Eidolon helvum in West Africa, and from two species of New World leaf-nosed fruit bats (Phyllostomidae), Artibeus jamaicensis and Artibeus lituratus in Central America. A sequence-independent virus discovery technique (VIDISCA) was used in combination with high throughput sequencing to detect two novel parvoviruses: a PARV4-like virus named Eh-BtPV-1 in Eidolon helvum from Ghana and the first member of a putative new genus in Artibeus jamaicensis from Panama (Aj-BtPV-1). Those viruses were circulating in the corresponding bat colony at rates of 7-8%. Aj-BtPV-1 was also found in Artibeus lituratus (5.5%). Both viruses were detected in the blood of infected animals at high concentrations: up to 10E8 and to 10E10 copies/ml for Aj-BtPV-1 and Eh-BtPV-1 respectively. Eh-BtPV-1 was additionally detected in all organs collected from bats (brain, lungs, liver, spleen, kidneys and intestine) and spleen and kidneys were identified as the most likely sites where viral replication takes place. Our study shows that bat parvoviruses share common ancestors with known parvoviruses of humans and livestock. We also provide evidence that a variety of Parvovirinae are able to cause active infection in bats and that they are widely distributed in these animals with different geographic origin, ecologies and climatic ranges.     

猪圆环病毒2型与猪细小病毒共感染对猪肺泡巨噬细胞吞噬功能及其干扰素表达水平的影响

【目的】分析猪圆环病毒2型(PCV2)与猪细小病毒(PPV)共感染对猪肺泡巨噬细胞(PAM)吞噬功能及其干扰素表达水平的影响,为进一步阐明猪断奶后多系统衰减综合征的发病机制提供实验依据。【方法】将48头5周龄健康仔猪随机分为PCV2组、PPV组、PCV2/PPV组和对照组,每组12头。PCV2和PPV组经口鼻途径分别接种PCV2或PPV,PCV2/PPV组同时接种PCV2和PPV,对照组接种细胞营养液。感染后3、7、14和35d(dpi)从每组随机选择3头剖杀,检测PAM的存活率、吞噬活性及其α1型干扰素(IFN-α1)、γ干扰素(IFN-γ)mRNA的表达水平。【结果】PCV2组和PCV2/PPV组PAM的存活率于3、7、14dpi均低于对照组,35dpi均与对照组PAM的存活率接近,PCV2与PCV2/PPV两组之间差异不显著(P>0.05);3个病毒感染组PAM的吞噬功能均显著下降(P<0.01),其中PCV2/PPV组的吞噬功能低于PCV2组(P<0.05);PCV2/PPV组PAM中IFN-α1和IFN-γ mRNA的水平持续低于PCV2、PPV组和对照组的水平(P<0.01)。【结论】PCV2与PPV共感染没有引起PAM的活力进一步下降,但导致其吞噬功能及IFN-α1和IFN-γmRNA的表达水平持续降低。     

猪圆环病毒2型的PCR检测方法应用

本研究登录Genbank对猪圆环病毒2型基因的序列进行分析,用Primer 5.0设计了ORF2基因的扩增引物,试图选择一种比较合理的PCR方法检查PCV2感染的病原,以期这种PCR方法可以有效分析猪综合征障碍病毒(PRRSV)、猪细小病毒(PPV)、猪瘟病毒的扩增(HCV)、猪伪狂犬病毒(PRV)等比较常见的病原。研究结果表明,在PCV2进行扩增阳性样品检测中,发现一条异常447 bp的DNA条带,对产物测序结果进行扩增分析,证明其是PCV ORF2基因序列。敏感性检验分析表明检测样本DNA浓度时达到了9.8×10^-4ng/μL。PCR实验具有良好的稳定性和重复性。根据对66例临床病猪的分析表明,在PCV2的检测中阳性感染率是27.26%,这可能受到HCV、PRRSV、PRV、PPV等多种病毒的感染,其中混合感染的比例达到了72.23%。     

High prevalence of human parvovirus 4 infection in HBV and HCV infected individuals in shanghai

Human parvovirus 4 (PARV4) has been detected in blood and diverse tissues samples from HIV/AIDS patients who are injecting drug users. Although B19 virus, the best characterized human parvovirus, has been shown to co-infect patients with hepatitis B or hepatitis C virus (HBV, HCV) infection, the association of PARV4 with HBV or HCV infections is still unknown.The aim of this study was to characterise the association of viruses belonging to PARV4 genotype 1 and 2 with chronic HBV and HCV infection in Shanghai.Serum samples of healthy controls, HCV infected subjects and HBV infected subjects were retrieved from Shanghai Center for Disease Control and Prevention (SCDC) Sample Bank. Parvovirus-specific nested-PCR was performed and results confirmed by sequencing. Sequences were compared with reference sequences obtained from Genbank to derive phylogeny trees.The frequency of parvovirus molecular detection was 16-22%, 33% and 41% in healthy controls, HCV infected and HBV infected subjects respectively, with PARV4 being the only parvovirus detected. HCV infected and HBV infected subjects had a significantly higher PARV4 prevalence than the healthy population. No statistical difference was found in PARV4 prevalence between HBV or HCV infected subjects. PARV4 sequence divergence within study groups was similar in healthy subjects, HBV or HCV infected subjects.Our data clearly demonstrate that PARV4 infection is strongly associated with HCV and HBV infection in Shanghai but may not cause increased disease severity.     

Evaluation of virus decontamination techniques for porcine embryos produced in vitro

The objective of this study was to explore approaches to decontaminate embryos either contaminated naturally or under experimental conditions with different viruses. Embryos were obtained from in vitro maturation and fertilisation of porcine oocytes. After 7 days of development, morula and blastocyst stages were exposed for 1 h to the following viruses: encephalomyocarditis virus (EMCV), porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus (PRRSV), and bovine viral diarrhea virus (BVDV) at an infectivity of 100 TCID50/mL. Embryos samples were treated with different washing procedures, which all included the following standard washing solutions: PBS+0.4% BSA (five times for 10 s), Hank's+0.25% trypsin (two times for 60-90 or 120-150 s, or one time of 5 min), Hank's+0.1 mg/mL DNase 1+20 U/mL RNase One (one time of 30 min) and PBS+0.4% BSA again (five times for 10s). Two new approaches were used to improve trypsin treatment, 0.1% hyaluronidase (one time for 5 min) instead of trypsin and a pre-incubation with oviductal cells. Therefore, in the first experiment, oocytes received standard maturation treatments and in the second, they were also co-incubated with oviductal cells for the last 3 h of maturation. The effectiveness of the different washing techniques in removing viruses was evaluated by polymerase chain reaction (PCR) analysis. In the first experiment, trypsin treatment did not eliminate PRRSV, PPV, PCV, and EMCV from contaminated embryos. Surprisingly, treatment with hyaluronidase eliminated all tested viruses. In the second experiment, all viruses tested were removed from the oocytes following the different enzymatic treatments. In conclusion, in vitro embryo decontamination was more effective following exposure to oviductal secretions and hyaluronidase eliminated more virions than trypsin in washing techniques.     

Identification and nearly full-length genome characterization of novel porcine bocaviruses

The genus bocavirus includes bovine parvovirus (BPV), minute virus of canines (MVC), and a group of human bocaviruses (HBoV1-4). Using sequence-independent single primer amplification (SISPA), a novel bocavirus group was discovered with high prevalence (12.59%) in piglet stool samples. Two nearly full-length genome sequences were obtained, which were approximately 5,100 nucleotides in length. Multiple alignments revealed that they share 28.7-56.8% DNA sequence identity with other members of Parvovirinae. Phylogenetic analyses indicated their closest neighbors were members of the genus bocavirus. The new viruses had a putative non-structural NP1 protein, which was unique to bocaviruses. They were provisionally named porcine bocavirus 1 and 2 (PBoV1, PBoV2). PBoV1 and PBoV2 shared 94.2% nucleotide identity in NS1 gene sequence, suggesting that they represented two different bocavirus species. Two additional samples (6V, 7V) were amplified for 2,407 bp and 2,434 bp products, respectively, including a partial NP1 gene and the complete VP1 gene; Phylogenetic analysis indicated that 6Vand 7V grouped with PBoV1 and PBoV2 in the genus of bocavirus, but were in the separate clusters. Like other parvoviruses, PBoV1, PBoV2, 6Vand 7V also contained a putative secretory phospholipase A(2) (sPLA(2)) motif in the VP1 unique region, with a conserved HDXXY motif in the catalytic center. The conserved motif YXGXF of the Ca(2+)-binding loop of sPLA2 identified in human bocavirus was also found in porcine bocavirus, which differs from the YXGXG motif carried by most other parvoviruses. The observation of PBoV and potentially other new bocavirus genus members may aid in molecular and functional characterization of the genus bocavirus.     

High Prevalence and Widespread Distribution of Zoonotic Enterocytozoon bieneusi Genotypes in Swine in Northeast China: Implications for Public Health

This study analyzed 563 fecal specimens of asymptomatic pigs from five cities of northeast China for the prevalence and genetic characteristics of Enterocytozoon bieneusi. The parasite was detected in 267 of 563 (47.4%) pigs by nested PCR of the ribosomal internal transcribed spacer (ITS). The differences in prevalence between preweaned (58.0%, 94/162) and growing pigs (39.6%, 114/288) and between weaned (52.2%, 59/113) and growing pigs are significant (p < 0.05). Genotypic typing and phylogenetic analysis facilitated identification of six human‐pathogenic genotypes EbpC, O, CS‐4, EbpA, Henan‐IV, and PigEBITS5 and six potentially zoonotic genotypes EbpB, CC‐1, CS‐1, CS‐3, CHN7, and CS‐10. Genotypes CS‐4 (32/35) and EbpC (3/35) from Harbin and Henan‐IV (5/64) from Qiqihar determined in pigs herein represented the main causative agents of human microsporidiosis in Harbin. The most dominant genotype EbpC found in pigs from Daqing (35/65) and Qiqihar (a close neighbor to Daqing) (47/64) contributed significantly to human infections in Daqing. Genotype EbpC was also a leading E. bieneusi pathogen in humans, drinking water, and wastewater in central China. This study provided robust evidence that pigs could be an outstanding source of human microsporidiosis and water contamination in China.     

Use of oxfendazole to control porcine cysticercosis in a high-endemic area of Mozambique

A randomized controlled field trial to evaluate the effectiveness of a single oral dose of 30 mg/kg of oxfendazole (OFZ) treatment for control of porcine cysticercosis was conducted in 4 rural villages of Angónia district, north-western Mozambique. Two hundred and sixteen piglets aged 4 months were selected and assigned randomly to OFZ treatment or control groups. Fifty-four piglets were treated at 4 months of age (T1), while another 54 piglets were treated at 9 months of age (T2) and these were matched with 108 control pigs from the same litters and raised under the same conditions. Baseline data were collected on the prevalence of porcine cysticercosis using antigen ELISA (Ag-ELISA), as well as knowledge and practices related to Taenia solium transmission based on questionnaire interviews and observations. All animals were followed and re-tested for porcine cysticercosis by Ag-ELISA at 9 and 12 months of age when the study was terminated. Overall prevalence at baseline was 5.1% with no significant difference between groups. At the end of the study, 66.7% of the controls were found positive, whereas 21.4% of the T1 and 9.1% of the T2 pigs were positive, respectively. Incidence rates of porcine cysticercosis were lower in treated pigs as compared to controls. Necropsy of 30 randomly selected animals revealed that viable cysts were present in none (0/8) of T2 pigs, 12.5% (1/8) of T1 pigs and 42.8% (6/14) of control pigs. There was a significant reduction in the risk of T. solium cysticercosis if pigs were treated with OFZ either at 4 months (OR = 0.14; 95% CI: 0.05–0.36) or at 9 months of age (OR = 0.05; 95% CI: 0.02–0.16). Strategic treatment of pigs in endemic areas should be further explored as a means to control T. solium cysticercosis/taeniosis.     

No Evidence of Presence of Parvovirus 4 in a Swedish Cohort of Severely Immunocompromised Children and Adults

The recently discovered human parvovirus 4 (PARV4) has been associated with seropositivity for human immunodeficiency virus, hepatitis B virus and hepatitis C virus. High prevalence is seen especially in intravenous drug users. The virus has been detected in blood products and persons who have been repeatedly transfused have shown to be a risk-group. Furthermore, reports from different parts of the world suggesting a prevalence ranging from zero to one third of the healthy population and the virus is thought to cause a latent or persistent infection. We investigated the presence of PARV4 DNA and parvovirus B19 (B19) DNA in serum from 231 severely immunocompromised cancer patients that have been exposed for blood products. Compared to B19, which was found in 3.9% of the patients, we found no evidence of PARV4. Our results may indicate a very low prevalence of the virus in Sweden, and it would be useful to measure the real PARV4 exposure of the healthy population as well as individuals with known risk factors by serology.     

猪细小病毒LDR-PCR检测方法的建立和应用

为准确特异灵敏地检测猪细小病毒(PPV),建立一种新的LDR-PCR方法。首先在病毒的保守区内设计一对LDR探针,LDR探针两端各连有一段引物对应序列,以连接产物为模板进行PCR,琼脂糖凝胶电泳检测结果。以标准质粒为模板,通过对LDR反应的退火温度、连接酶浓度及探针浓度等反应条件进行优化,确定了LDR最佳的反应体系,并建立了LDR-PCR方法。结果表明,可以特异地检测PPV,与猪繁殖与呼吸障碍综合征病毒(PRRSV)、猪瘟病毒(CSFV)、伪狂犬病毒(PRV)、猪圆环病毒(PCV)、猪传染性胃肠炎病毒(TGEV)、猪流行性腹泻病毒(PEDV)无交叉反应;最低检测限为102个拷贝。利用建立的方法对41例临床样本进行检测,14份样品PPV阳性,与普通PCR检测结果符合率为97.6%。     

Antibodies to selected pathogens in wild boar (Sus scrofa) from Catalonia (NE Spain)

From 2004 to 2007, blood samples from 273 healthy wild boars (Sus scrofa), culled during the hunting season, were obtained in three areas of Catalonia (NE Spain): Pyrenees, Sant Llorenç del Munt i l’Obac Natural Park (SLM), and Ports de Tortosa i Beseit National Hunting Reserve (PTB). We investigated the presence of antibodies against classical swine fever virus (CSFV), African swine fever virus (ASFV), porcine vesicular disease virus (PVDV), porcine respiratory and reproductive syndrome virus (PRRSV), Aujeszky’s disease virus (ADV), porcine influenza A virus (PIV), porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), Mycoplasma hyopneumoniae, Erysipelothrix rhusiopathiae, Salmonella spp., and Toxoplasma gondii. Four wild boars were suspicious for CSFV, but the infection was discarded with a virus neutralization test, and infection with a border disease virus was confirmed. Negative results were obtained against ASFV and PVDV. Antibodies were detected against PRRSV (3%), ADV (0.8%), PIV (6.4%), PCV2 (64.6%), PPV (54.7%), M. hyopneumoniae (26.6%), E. rhusiopathiae (5.3%), Salmonella spp. (11.3%), and T. gondii (43.5%). In SLM, we detected a higher seroprevalence for PIV and M. hyopneumoniae and a lower seroprevalence for E. rhusiopathiae than in the other two areas. In PTB, seroprevalence was higher for PPV, Salmonella spp., and PCV2. Adult wild boar displayed higher seroprevalence for PPV, PIV, and M. hyopneumoniae, whereas presence of antibodies for Salmonella spp. was higher in juveniles compared with adults and piglets.

     

Risk factors of porcine cysticercosis in the Eastern Cape Province, South Africa

There is a high prevalence of Taenia solium taeniosis/cysticercosis in humans and pigs in the Eastern Cape Province (ECP) of South Africa. The objective of this study was to identify risk factors of porcine cysticercosis in select districts of the ECP. Data were collected in 2003 by interviewing 217 pig producers from the area. Blood samples were collected from 261 of their pigs, which were tested using two enzyme-linked immunosorbent assays (ELISA) for the presence of antibodies to cysticercosis. Frequencies of both owner- and pig-level characteristics were determined. For pig-level analysis, all bivariable and multivariable associations were determined using the surveylogistic procedure of the SAS/STAT? software to accommodate for the intraclass correlation that exists for clusters of pigs within one owner and for clusters of owners within a district. All tests for significance were performed at the α?=?0.05 level, and adjusted odds ratios (aOR) and 95% confidence intervals (CI) were determined. Among the respondents, 48% of their households lacked a latrine, 98% slaughtered pigs at home, and 99% indicated that meat inspection services were not available. On bivariable analysis, there was a significant association between porcine infection and district (p?=?0.003), breed (p?=?0.041) and the absence of a latrine (p?=?0.006). On multivariable analysis, the absence of a latrine was the only variable significantly associated with porcine infection (aOR?=?1.89; 95% CI?=?1.07, 3.35) (p?=?0.028). The increased odds of porcine infection with households lacking a latrine contributes to our understanding of the transmission of this parasite in the ECP. Determining and addressing the risk factors for T. solium infection can potentially lower the very high prevalence in humans and pigs in this endemic area.     

CpG Distribution and Methylation Pattern in Porcine Parvovirus

Based on GC content and the observed/expected CpG ratio (oCpGr), we found three major groups among the members of subfamily Parvovirinae: Group I parvoviruses with low GC content and low oCpGr values, Group II with low GC content and high oCpGr values and Group III with high GC content and high oCpGr values. Porcine parvovirus belongs to Group I and it features an ascendant CpG distribution by position in its coding regions similarly to the majority of the parvoviruses. The entire PPV genome remains hypomethylated during the viral lifecycle independently from the tissue of origin. In vitro CpG methylation of the genome has a modest inhibitory effect on PPV replication. The in vitro hypermethylation disappears from the replicating PPV genome suggesting that beside the maintenance DNMT1 the de novo DNMT3a and DNMT3b DNA methyltransferases can’t methylate replicating PPV DNA effectively either, despite that the PPV infection does not seem to influence the expression, translation or localization of the DNA methylases. SNP analysis revealed high mutability of the CpG sites in the PPV genome, while introduction of 29 extra CpG sites into the genome has no significant biological effects on PPV replication in vitro. These experiments raise the possibility that beyond natural selection mutational pressure may also significantly contribute to the low level of the CpG sites in the PPV genome.     

Antibodies to selected viral and bacterial pathogens in European wild boars from southcentral Spain

Serum samples from 78 European wild boars (Sus scrofa) harvested during the 1999-2000 hunting season were tested for antibodies to Brucella spp., classical swine fever virus, Erysipelothrix rhusiopathiae, Haemophilus parasuis, Leptospira interrogans serovar pomona, Mycoplasma hyopneumoniae, pseudorabies virus (PRV), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus, Salmonella serogroups B, C, and D, Streptococcus suis, and swine influenza virus (SIV) serotypes H1N1 and H3N2. Samples were collected from Sierra Morena and Montes de Toledo in southcentral Spain. Antibodies were detected to PRV (36%), L. interrogans serovar pomona (12%), PPV (10%), E. rhusiopathiae (5%), SIV serotype H1N1 (4%), Salmonella serogroup B (4%), and Salmonella serogroup C (3%). Our results suggest that more research is needed to describe the epidemiology of infectious diseases of Spanish wild boars.