Prevalence and molecular characterization of bovine Cryptosporidium isolates in India

A survey based on PCR assay of 18S SSU rRNA gene revealed a 30.2% infection with Cryptosporidium spp., out of 457 faecal samples collected from neonatal bovine calves across three different regions of India. The PCR-RFLP pattern of the gene in all the positive cases established the species as Cryptosporidium parvum. Highest prevalence was recorded in the monsoon months (37.3%) and in the calves showing acute diarrhoea (32.3%). The calves below 15 days of age were mostly affected (45.1%). The infection was more prevalent in the northern parts (35.4%) of the country than in the eastern or southern parts. Results indicated that C. parvum was the only species of Cryptosporidium prevalent in bovine calves in three different geographical regions of India.     

Prevalence of porcine circovirus type 2 in aborted fetuses and stillborn piglets

A retrospective study of natural cases of abortion, recorded between October 2000 and September 2002, was made to determine the prevalence of abortions associated with porcine circovirus type 2 (PCV-2). The virus was detected by PCR, immunohistochemistry and in situ hybridisation. A total of 46 (13.1 per cent) of 350 aborted fetuses and stillborn piglets were positive for PCV-2 by PCR, and the virus was detected in fetuses at all stages of gestation. Viral antigen was detected in macrophages from the aborted fetuses and stillborn piglets by immunohistochemistry, and viral DNA was detected by in situ hybridisation.     

Detection and molecular characterization of porcine circovirus type 2 (PCV2) from piglets with exudative epidermitis in Uruguay

Porcine circovirus type 2 (PCV2) is an economically important emerging pathogen associated with distinct syndromes and diseases in swine, collectively known as porcine circovirus associated diseases (PCVAD). The main purpose of this study was to investigate the presence of PCV2 in piglets affected with exudative epidermitis (EE) in Uruguay. In addition we aimed to analyze the phylogenetic relationships of the isolated strains. In June 2011 an outbreak of EE detected in a small herd was reported. Piglets presented skin lesions compatible with EE and symptoms associated with postweaning multisystemic wasting syndrome (PMWS) were also observed. Sera from affected and healthy animals were tested for the presence of viral DNA. Exclusively, diseased piglets were infected with PCV2. Phylogenetic analysis showed that PCV2 isolates belonged to PCV2b genotype. We report the detection and molecular characterization of PCV2 strains for the first time in Uruguay.     

Picobirnavirus detection in bovine and buffalo calves from foothills of Himalaya and Central India

The present study describes detection of picobirnavirus (PBV) in faecal samples from bovine and buffalo calves employing the polyacrylamide gel electrophoresis (PAGE). A total of 136 faecal samples from buffalo (n = 122) and cow calves (n = 14) exhibiting clinical signs of diarrhoea and from healthy calves were collected during 2007–2010 from subtropical (central India) and tarai area of western temperate Himalayan foothills (Uttarakhand). The dsRNA nature of the virus was confirmed by nuclease treatment (RNase A, RNaseT1 and DNase 1). PAGE results confirmed 3.67% (5/136) positivity for PBV, showing a typical genomic migration pattern with two discrete bands with size of approximately 2.4 and 1.7 kbps for the larger and smaller segments, respectively. Among the five PBV samples identified, three were from buffalo calves and one from cow calf exhibiting clinical signs of acute diarrhoea, while one sample from non-diarrhoeic buffalo calf also showed the presence of PBV. None of the samples showed dual infection of rotavirus and PBV. The preliminary findings indicate sporadic incidences of PBV in bovine calves and emphasize the need for the development of better diagnostics for early detection and genetic characterization of these emerging isolates of farm animals of economic significance.     

Seroprevalence and molecular detection of porcine sapovirus in symptomatic suckling piglets in Guangdong Province,China

The seroprevalence and genetic identification of sapovirus (SaV) in symptomatic suckling piglets were investigated in Guangdong Province, China, between November 2011 and April 2013. Serum (n?=?960) and diarrheic fecal (n?=?101) samples collected from symptomatic suckling piglets in Guangdong Province were evaluated for antibodies against SaV using indirect enzyme-linked immunosorbent assay (iELISA). The overall seroprevalence of SaV in symptomatic suckling piglets was 61.9 % (594/960). Positive animals were found in all regions with seroprevalence ranging from 52 to 67.8 %, but the difference was not statistically significant (P?>?0.05). In addition, RNA of SaV was extracted from diarrheic fecal samples, and the partial polymerase gene was amplified by RT-PCR and then sequenced. Seven of 101 (6.9 %) samples were found to contain porcine SaV. Phylogenetic analysis showed that all the porcine SaV isolates belong to the porcine SaV genogroup III (GIII). This is the first report of SaV seroprevalence in symptomatic pigs in China.     

Prevalence and molecular characterization of Giardia duodenalis in dogs in Israel

Three hundred and two stool samples were collected from municipal shelters and owned dogs in different geographical locations in Israel from December 2016 to September 2017 and examined for Giardia and assemblage type by PCR targeting the 18S rRNA and β-giardin genes. Overall Giardia prevalence was 24.5 % (74/30). Giardia prevalence was 1.9-fold higher in dogs ≤ 6 months old compared to > 6 ≤ 12 months old and older dogs [25/61 (41 %), 18/73 (24.6 %) and 31/166 (18.7 %), respectively, (p = 0.001)], 2.3-fold higher in winter [32/90 (35.5 %)] compared to its prevalence during autumn [15/60 (25 %)], spring [10/62 (16.1 %)] and summer [17/89 (19.1 %), p = 0.003)], and 2.7-fold more frequent among diarrheic dogs [23/43 (53.4 %)] compared to those with formed stools [51/253 (20.1 %)], (p = 0.001)]. The Giardia sp. assemblages detected were C and D. Higher infection rates in young, diarrheic dogs, sampled during winter, and housed in municipal shelters, indicates the need for targeted preventive measures.     

Prevalence of porcine reproductive and respiratory syndrome virus and porcine circovirus type 2 in piglets after weaning on a commercial pig farm in Japan

To investigate the transition in concentration of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) and antibody for these viruses in serum, serum samples were collected from 29 pigs on weaning day and at 7, 14, 21, 28, 53, 84, and 120 days after weaning. The concentration of circulated PRRSV and PCV2 in serum was measured by real-time RT-PCR and real-time PCR, respectively. The specific antibody for PRRSV and PCV2 was measured using ELISA. PRRSV was not detected on 0 days post-weaning (dpw). The specific antibody for PRRSV began to increase as the concentration of PRRSV in serum increased, and the level of PRRSV then tended to decrease. PCV2 was detected in 12 of 28 pigs on 0 dpw. The concentration of PCV2 and the specific antibody for PCV2 showed a similar tendency to those of PRRSV. The correlation analysis suggests that a decline in the daily weight gain coincided with an increase in the PRRSV concentration. Pigs with a higher antibody titer against PRRSV or PCV2 on 0 dpw showed the lower level of PRRSV or PCV2, respectively.     

Identification and genotypic characterization of porcine teschovirus from selected pig populations in India

Tropical Animal Health and Production - Porcine teschovirus (PTV) previously classified as porcine enteroviruses in the family Picornaviridae are associated with a wide range of illnesses in swine...     

Hemoprotozoa of domestic animals in France: Prevalence and molecular characterization

Very limited information is available on epizootiology of haematozoan infections in French domestic animals. In an attempt to address this issue, prevalence of piroplasmida was studied in carnivores and ruminants, whereas prevalence of Hepatozoon spp. was only investigated in carnivores. In total, 383 animals were included in the survey (namely 116 cats, 108 dogs, 91 sheep and 68 cows). Parasite diagnosis was carried out using molecular methods such as PCR and sequencing of the 18S rRNA gene. In addition, ruminant samples were analyzed with the reverse line blotting technique (RLB). Results of RLB and PCR plus sequencing were in total agreement.     

Detection and molecular characterization of porcine group C rotaviruses in South Korea

Group C rotaviruses (GCRVs) cause acute diarrhea in humans and animals worldwide and the evidence for a possible zoonotic role of GCRVs has been recently provided. However, there is little evidence of porcine GCRV infections or of their genetic diversity in South Korea. We examined 137 diarrheic fecal specimens from 55 farms collected from six provinces. RT-PCR utilizing primer pairs specific for the GCRV VP6 gene detected GCRV-positive reactions in 36 (26.2%) diarrheic fecal samples. Of these, 17 samples (12.4%) tested positive for porcine GCRVs alone and 19 samples (13.8%) were also positive for other pathogens. Other enteric pathogens except for GCRV were detected in 64 feces samples (46.7%) and no enteric pathogens were evident in 37 feces samples (27.0%). Phylogenetic and sequence homology analyses of GCRV partial VP6 gene between 23 Korean and other known porcine GCRVs demonstrated that Korean strains belonged to the porcine lineage. Furthermore, one Korean porcine strain shared the highest nucleotide (89.7–89.0%) and deduced amino acid sequence (92.9–93.9%) identities with bovine GCRV strains and was placed in the bovine GCRV lineage indicative of bovine origin. In conclusion, porcine GCRV infections are widespread in piglets with diarrhea in South Korea. The infecting porcine GCRVs mostly belong to the porcine lineage with the exception of one bovine-like GCRV, which possibly originated from bovine GCRV due to interspecies transmission.     

Detection and molecular characterization of porcine type 3 orthoreoviruses circulating in South Korea

Orthoreoviruses infect virtually all mammalian species, causing systemic infections including mild gastrointestinal and respiratory illnesses. However, little is known about the prevalence or genetic diversity of porcine orthoreoviruses in South Korea. We examined 237 diarrheic fecal samples collected from 78 pig farms around the country. RT-PCR utilizing primers specific for the L1 gene of mammalian orthoreoviruses showed that 45 (19.0%) samples were positive. The 10 strains isolated from orthoreovirus-positive samples formed typical perinuclear cytoplasmic inclusion bodies and had an atypical hemagglutination pattern; these are characteristics of type 3 orthoreovirus. Phylogenetic analysis of the S1 gene in these 10 Korean and other strains showed that type 3 orthoreoviruses could be divided into four lineages; the 10 Korean strains were included in porcine lineage IV, along with T3/porcine/Sichuan/2006. Sequence analysis showed that strains in lineage IV had nucleotide identities of 97.0-98.1% and deduced amino acid identities of 96.4-98.2%. Sequence analysis of the σ1 protein, a viral attachment protein, revealed that the amino acid sequences associated with neurotropism (amino acids 198-204, 249I, 350D, and 419E) were highly conserved among the Korean strains, confirming that neural tropism was present. In conclusion, our findings suggest that porcine orthoreovirus infections are endemic in pig farms in South Korea and that the 10 novel Korean porcine orthoreoviruses belong to porcine lineage IV of type 3 orthoreovirus. In addition, sequence analysis of S1 genes encoding the σ1 protein showed that the 9 of 10 Korean porcine orthoreoviruses exhibited neural tropism.     

High prevalence of porcine circovirus viremia in newborn piglets in five clinically normal swine breeding herds in North America

Porcine circovirus type 2 (PCV2) can be vertically transmitted resulting in fetal infection with or without clinical signs and lesions. The primary objective of this study was to assess the prevalence of intrauterine PCV2 infection in clinically normal newborn piglets in conventional pork production facilities. Five commercial breeding herds located in the U.S. and Mexico were included in the study. A total of 125 sows and 3-5 neonatal piglets per sow were arbitrarily selected. Blood and colostrum samples were collected from sows. Blood was collected from piglets prior to suckling. All samples were analyzed for the presence of anti-PCV2 IgG antibodies and presence and amount of PCV2 DNA. In addition, PCV2 DNA positive samples were further subtyped into PCV2a and PCV2b. All (125/125) sow colostrum samples and 96.8% (121/125) of the sow serum samples and 21.4% (107/499) of the piglet pre-suckle serum samples were positive for anti-PCV2 IgG antibody. The overall PCV2 DNA prevalence was 47.2% (59/125) in sow serum, 40.8% (51/125) in sow colostrum, and 39.9% (199/499) in pre-suckle piglet serum. In the PCV2 DNA positive samples, PCV2b was detected at a higher frequency (69.5% for sow serum, 84.3% for sow colostrum, and 74.4% for piglet serum) compared to PCV2a (18.6% for sow serum, 9.8% for sow colostrum, and 15.6% for piglet serum). Concurrent PCV2a and PCV2b infection was detected in 11.9% of the sow serum, in 5.9% of the colostrum samples, and in 10.0% of the piglet serum samples. In conclusion, an unexpectedly high prevalence of PCV2 viremia was detected in healthy sows (serum and colostrum) and their pre-suckle piglets in the five breeding herds investigated and PCV2b was more prevalent than PCV2a. This information adds to the knowledge of PCV2 infection in breeding herds.     

Validation of rt-PCR assays for molecular characterization of porcine teschoviruses and enteroviruses

Porcine enteroviruses (PEVs) and teschoviruses (PTVs) are described as causative agents of neurological disorders, fertility disorders and dermal lesions of swine. Difficulties in the serological detection of these viruses may lead to a significant underestimation of infections with clinical symptoms. With the recent availability of genome sequence data for all the serotypes, molecular diagnosis is a possibility. The present study describes a new approach to molecular 'serotyping' of PTVs and PEV-B viruses, involving the amplification and sequencing of a genomic fragment of the VP1 coding region. A molecular characterization of Italian entero-teschovirus isolates was performed using a set of previously published and newly designed polymerase chain reaction primers. A total of 33 porcine isolates and 10 reference strains were analysed. Porcine enterovirus-B samples were first diagnosed as positive for enterovirus by amplification of the 5'-non-translated region. Samples were then typed by amplification and sequencing of a portion of the VP1 coding region. Porcine enterovirus-A and PTVs were detected by a published assay in the 5'-NC region that allows them to be differentiated according to the size of amplification product, using the same set of primers. For serotype characterization of PTV, we evaluated four different regions: the N terminus of the capsid protein VP2, the region encoding for RNA-dependent RNA polymerase, and the capsid VP1 and VP4 regions. The newly designed primers in the VP1 region was proved to be broad in range and suitable for serotype assessment and therefore constitute a useful diagnostic tool for molecular diagnosis of porcine teschovirus/enterovirus strains and for the study of molecular epidemiology and evolution of these viruses.     

Prevalence and molecular characterization of Babesia in pet dogs in Shenzhen,China

Canine babesiosis is an important global tick-borne infectious disease of domestic dogs and wild canids. B. gibsoni and B. vogeli are the most widespread species mainly endemic in dog population in southern and eastern regions of China. In this study, 272 blood samples were collected from pet dogs in five districts of Shenzhen, China. Babesia DNA was detected in 30 samples with an overall prevalence of 11.0 % in pet dogs in Shenzhen. The difference in the positive rate between female and male pet dogs, among different breed, and among the five sampling sites was not significant, while the age and health status of pet dogs significantly influence the positive rate of Babesia spp. infection. Sequencing results showed the presence of only B. vogeli in all of the samples tested. Sequence comparison and phylogenetic analysis revealed that all 30 strains of Babesia identified in this study shared the highest identity with B. vogeli. In sum, all results of this study showed a considerable high infection rate of Babesia spp. in pet dogs, and B. vogeli was the only Babesia species infecting pet dogs in Shenzhen city. Such information is necessary to help to elucidate the epidemiology of canine babesiosis in Shenzhen, and it is necessary to actively monitor this disease in pet dogs.     

Prevalence and antimicrobial resistance of porcine O157 and non-O157 Shiga toxin-producing Escherichia coli from India

The aims of this study were to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) strains in pigs as a possible STEC reservoir in India as well as to characterize the STEC strains and to determine the antimicrobial resistance pattern of the strains. A total of 782 E. coli isolates from clinically healthy (n?=?473) and diarrhoeic piglets (309) belonging to major pig-producing states of India were screened by the polymerase chain reaction (PCR) assay for the presence of virulence genes characteristic for STEC, that is, Shiga toxin-producing gene(s) (stx1, stx2), intimin (eae), enterohemolysin (hlyA) and STEC autoagglutinating adhesin (Saa). Overall STEC were detected in 113 (14.4 %) piglets, and the prevalence of E. coli O157 and non-O157 STEC were 4 (0.5 %) and 109 (13.9 %), respectively. None of the O157 STEC isolates carried gene encoding for H7 antigen (fliCh7). The various combinations of virulence genes present in the strains studied were stx1 in 4.6 %, stx1 in combination with stx2 gene in 5.1 %, stx1 in combination with stx2 and ehxA in 0.6 %, stx1 in combination with stx2 and eae in 0.2 % and stx2 alone in 3.7 %. All STEC isolates were found negative for STEC autoagglutinating adhesin (Saa). The number of STEC isolates which showed resistance to antimicrobials such as ampicillin, tetracycline, streptomycin, lincomycin, nalidixic acid, sulfadiazine, penicillin, gentamicin, kanamycin and ceftriaxone were 100, 99, 98, 97, 95, 94, 92, 88, 85 and 85, respectively. Ninety-seven isolates showed resistance to more than 2 antimicrobials, and 8 resistance groups (R1 to R8) were observed. This study demonstrates that pigs in India harbour both O157 and non-O157 STEC, and this may pose serious public health problems in future.     

Prevalence and molecular characterization of Cryptosporidium and Giardia species and genotypes in sheep in Maryland

In the United Kingdom and Australia sheep have been implicated as sources of Cryptosporidium and Giardia that infect humans, but no such studies have been conducted in North America. Therefore, a study was undertaken to investigate the prevalence of these parasites in sheep on a farm in Maryland. Feces were collected from 32 pregnant ewes 1, 2, and 3 days after parturition and from each of their lambs 7, 14, and 21 days after birth. The presence of Cryptosporidium oocysts and Giardia cysts was determined by both immunofluorescence microscopy and PCR/gene sequence analysis. PCR was consistently more sensitive than microscopy. The prevalence, by PCR, of Cryptosporidium in ewes and lambs was 25 and 77.4%, respectively. Three species/genotypes of Cryptosporidium were identified: C. parvum, a novel C. bovis-like genotype, and Cryptosporidium cervine genotype. Cryptosporidium parvum and the cervine genotype have been reported worldwide in human infections. The novel C. bovis-like genotype is reported here for the first time. The prevalence of Giardia in ewes and lambs was 12 and 4%, respectively. Most infections were Assemblage E which is not zoonotic; however, one ewe was infected with zoonotic Assemblage A. The identification of only two lambs infected with C. parvum and one ewe infected with G. duodenalis Assemblage A suggests a low prevalence of these zoonoses. However, the high prevalence of the zoonotic cervine genotype indicates that sheep should be considered a potential environmental source of this human pathogen.     

猪圆环病毒和猪繁殖与呼吸综合征病毒混合感染对仔猪致病性的评估

本研究通过猪圆环病毒2型(Porcine circovirus type 2,PCV2)和猪繁殖与呼吸综合征(Porcine reproductive and respiratory syndrome virus,PRRSV)强毒共感染3周龄健康仔猪来评价其致病性。试验动物随机分为3组,空白对照组(n=3头),PRRSV单独感染组(n=3头),PCV2和PRRSV共感染组(n=6头),从而比较相互之间的差异。通过临床症状、病理学变化、病原学和血清学检查,对二者混合感染仔猪的致病性进行了研究。结果表明PCV2和PRRSV共同感染能引起仔猪断奶后多系统消耗性综合征,表现为淋巴组织肿大、出血,肉芽肿性炎症,坏死性肝炎,仔猪消瘦、生长缓慢等特征性病变;混合感染能加重PRRSV对仔猪引起的间质性肺炎的严重程度。混合感染可以出现支气管肺炎和明显的肝病变,淋巴结多呈界限明显的块状出血等典型病变。