Bovine Parainfluenza Type Research Articles

Bovine parainfluenza type 3 virus induces incomplete autophagy to promote viral replication by activated beclin1 in vitro

Bovine Parainfluenza virus Type 3 (BPIV3) is one of the most important pathogens in cattle, capable of causing severe respiratory symptoms. Numerous studies have shown that autophagy plays a diverse role in the infection process of various pathogens. The influence of autophagy machinery on BPIV3 infection has not yet been confirmed. In the present study, we initially demonstrated that the expression of LC3 was significantly increased and exhibited a notable increase in double or single-membrane vesicles under a transmission electron microscope during BPIV3 infection. These observations unequivocally establish the induction of steady-state autophagy in vitro consequent to BPIV3 infection. Furthermore, quantification of autophagic flux substantiates the induction of an incomplete autophagic process during BPIV3 infection. Additionally, through targeted interventions, we demonstrate the regulatory impact of pharmacological agents influencing autophagy and RNA interference targeting an autophagy-associated protein on viral replication. Intriguingly, our data revealed that BPIV3 infection enhanced the phosphorylation of rapamycin kinase (mTOR). This result demonstrated that mTOR does not operate as a counteractive regulator of BPIV3-induced autophagy. Instead, we discern an augmentation in the expression of Beclin1, a key autophagy initiator, which complexes with Vps34, constituting a Class III phosphatidylinositol 3-kinase. This phenomenon serves as a hallmark in the inaugural phase of autophagy initiation during BPIV3 infection. Collectively, these discernments underscore that BPIV3 infection actively stimulates autophagy, thereby enhancing viral replication through the activation of Beclin1, independently of the mTOR signaling pathway. This nuanced comprehension significantly contributes to unraveling the intricate molecular mechanisms governing BPIV3-induced autophagy.

Molecular and genetic characterization of bovine parainfluenza type 3 European field and vaccine strains.

Bovine Parainfluenza Type 3 virus (BPIV-3) is an enveloped, non-segmented single-stranded, negative-sense RNA virus belonging to the Paramyxoviridae family (genus Respirovirus) with a well-known role in Bovine Respiratory Disease (BRD) onset. Being isolated for the first time in 1959, BPIV-3 currently circulates worldwide in cattle herds and is routinely tested in suspected BRD cases. Different commercial vaccines are available to prevent infection and/or to reduce the clinical signs associated with BPIV-3 infection, which are essential to prevent secondary infections. Despite years of molecular surveillance, a very limited number of complete genome sequences were made publicly available, preventing thus the understanding of the genetic diversity of the circulating strains in the field. In addition, no data about the genetic identity between field and vaccine strains is currently available. In this study, we sequenced the full-genome and genetically characterized BPIV-3 strains isolated from animals displaying respiratory illness in France and Sweden, as well as the vaccine strains contained in three different commercialized vaccines. Our results show that the sequences from France and Sweden belong to genotype C. However, a third sequence from Sweden from 2017 clustered within genotype A. The sequencing of vaccine strains revealed that two of the vaccine strains clustered within genotype C, whereas the third vaccine strain belonged to genotype A. Altogether, our findings suggest that both genotypes A and C circulate in Europe and that BPIV-3 field and vaccine strains are genetically divergent. Our sequencing results could be useful to better understand the genetic differences between the circulating field and vaccine BPIV-3 strains. This is crucial for a correct interpretation of diagnostic findings and for the assessment of BPIV-3 prevalence in cattle population.

Effect of on-arrival bovine respiratory disease vaccination on ultrasound-confirmed pneumonia and production parameters in male dairy calves: A randomized clinical trial

The high degree of commingling and accumulation of stressors during and after transport makes prevention of bovine respiratory disease (BRD) extremely challenging in the veal and dairy beef industry. Upon arrival, vaccination for agents involved in BRD is practically most achievable, but its efficacy under such conditions in dairy veal calves is unknown. Given the high prevalence of subclinical pneumonia in these settings, the primary objective of the present study was to determine the effect of 2 vaccination protocols administered upon arrival against bovine respiratory syncytial virus (BRSV), bovine parainfluenza type 3 virus (BPI-3), and Mannheimia haemolytica on clinical BRD and lung ultrasonographic findings in dairy veal calves. In addition, the effects of vaccination on average daily live weight gain and cold carcass weight were determined. In this randomized clinical trial, 443 male dairy calves were assigned to one of 3 groups: a negative, placebo-controlled group (n = 151), a vaccination group with 2 subcutaneous injections 4 wk apart with an inactivated vaccine containing BRSV, BPI-3, and M. haemolytica (parenteral [PE] group; n = 149) and a second vaccination group receiving an intranasal live-attenuated vaccine containing BRSV and BPI-3 and 2 subcutaneous vaccinations with the same inactivated vaccine as the PE vaccination group (intranasal-parenteral [IN-PE] group; n = 143). Clinical scoring and quick thoracic ultrasonography (qTUS) were performed on all calves on arrival (wk 0), at the peak of respiratory disease (outbreak; wk 1), at the end of the first antimicrobial group treatment (wk 3), and at a long-term evaluation point (wk 10). Culture and nanopore sequencing on nonendoscopic bronchoalveolar lavage (nBAL) samples were used to identify pathogens involved in the outbreak. Upon arrival, 15.1% of the calves had lung consolidation ≥1cm and incidence quickly rose to 42.8% during the outbreak. In both the PE and IN-PE group, the odds of pneumonia in wk 10 were reduced by 62% (odds ratio [OR] = 0.38; 95% confidence interval [CI] = 0.23-0.64) and 41% (OR = 0.59; 95% CI = 0.37-0.96), respectively. Short-term cure rate (50.3%), as determined immediately after the first group antimicrobial treatment, was not influenced by vaccination. In contrast, long-term cure rate, determined at wk 10, was affected by vaccination with higher cure in the PE group compared with the control group (69.4% vs. 51.2%; OR = 2.2; 95% CI = 1.1-5.0). Average daily gain in the first 10 wk of production was not affected by vaccination. Vaccination resulted in an increase in cold carcass weight of 3.5 and 4.3 kg in the PE (95% CI = -0.9-7.9) and IN-PE group (95% CI = -0.17-8.7), respectively. In conclusion, under the conditions of the present study, vaccination upon arrival resulted in a reduced prevalence of pneumonia at wk 10 of production, likely caused both by an improved cure rate of secondary infections and a reduced incidence of new cases between outbreak and long-term evaluation. The present protocol, using qTUS for pneumonia detection and nBAL diagnostics for pathogen identification adds a new dimension to randomized clinical trials on respiratory disease in calves.

The effect of neonatal vaccination for bovine respiratory disease in the face of a dual challenge with bovine viral diarrhea virus and Mannheimia hemolytica.

Bovine respiratory disease is the greatest threat to calf health. In this study, colostrum-fed dairyXbeef calves were vaccinated at ∼30days of age with an adjuvanted parenteral vaccine containing modified live bovine viral diarrhea virus (BVDV) type 1 and type 2, bovine herpesvirus 1 (BHV-1), bovine parainfluenza type 3 virus (PI3V) and bovine respiratory syncytial virus (BRSV) andM. haemolyticatoxoid (Group 1), or intranasal temperature-sensitive BHV-1, BRSV and PI3V concurrently witha parenteral vaccine containing modified live BVDV type 1 and type 2 andM. haemolyticatoxoid (Group 2) or a placebo (Group 3). The calves were challenged ∼150days post vaccination intranasally with BVDV 1b and then 7days later intratracheally withM. haemolytica. The calves wereeuthanized 6days after theM. haemolyticachallenge. Clinical signs following BVDV infection were similar in all groups. There was increased rectal temperatures in the Groups 2 and 3 on day 3 and in Group 3 on days 8-13. Group 1 animals had a slight leukopenia following BVDV infection while Groups 2 and 3 had greater leukopenia. BVDV type 1 and 2 serum titers increased in Group 1 following vaccination while these titers waned in Groups 2 and 3. There were higher levels of BVDV in the buffy coats and nasal samples in Group 2 and Group 3 versus Group 1 (p<0.01). Interferon-gamma response was higher (p<0.01) in Group 1 animals than Groups 2 and 3. Group 1 had the lowest percent pneumonic tissue (1.6%) while Group 2 vaccinates had 3.7% and the control Group 3 was 5.3%. Vaccination in the face of maternal antibody with a parenteral adjuvanted vaccine resulted in better protection than the regimen of an intranasal vaccine anda parenteral adjuvanted BVDV andM haemolyticacombination vaccine in a BVDV-M. haemolyticadual challenge.

Vaccination of calves at day of birth with attenuated vaccines against bovine respiratory syncytial virus, bovine parainfluenza type 3 virus and respiratory bovine coronavirus

Vaccination of calves at day of birth with attenuated vaccines against bovine respiratory syncytial virus, bovine parainfluenza type 3 virus and respiratory bovine coronavirus

Early Activation of the Innate Immunity and Specific Cellular Immune Pathways after Vaccination with a Live Intranasal Viral Vaccine and Challenge with Bovine Parainfluenza Type 3 Virus.

Bovine parainfluenza type 3 (BPIV3) and bovine respiratory syncytial virus (BRSV) may cause bovine respiratory disease (BRD) in very young calves, and therefore vaccination should induce protection at the youngest age and as quickly as possible. This can be achieved by intranasal vaccination with a vaccine containing live attenuated BRSV and BPIV3 virus strains. The objective of this study was to measure gene expression levels by means of RT-qPCR of proteins involved in the innate and adaptive immune response in the nasopharyngeal mucosae after administration of the above-mentioned vaccine and after challenge with BPIV3. Gene expression profiles were different between (i) vaccinated, (ii) nonvaccinated-challenged, and (iii) vaccinated-challenged animals. In nonvaccinated-challenged animals, expression of genes involved in development of disease symptoms and pathology were increased, however, this was not the case after vaccination. Moreover, gene expression patterns of vaccinated animals reflected induction of the antiviral and innate immune pathways as well as an initial Th1 (cytotoxic) cellular response. After challenge with BPIV3, the vaccinated animals were protected against nasal shedding of the challenge virus and clinical symptoms, and in parallel the expression levels of the investigated genes had returned to values that were found before vaccination. In conclusion, in comparison to the virulent wild-type field isolates, the two virus strains in the vaccine have lost their capacity to evade the immune response, resulting in the induction of an antiviral state followed by a very early activation of innate immune and antiviral responses as well as induction of specific cellular immune pathways, resulting in protection. The exact changes in the genomes of these vaccine strains leading to attenuation have not been identified. These data represent the real-life situation and can serve as a basis for further detailed research. This is the first report describing the effects on immune gene expression profiles in the nasal mucosae induced by intranasal vaccination with a bivalent, live BRSV-BPI3V vaccine formulation in comparison to wild-type infection with a virulent BPI3V strain.

Indirect detection of respiratory viruses responsible for respiratory disease in sheep

Respiratory disease in sheep is an important disease in sheep flocks, in which viruses are categorized as primary etiological agents. It is responsible for elevated economic losses in sheep production and new data about its occurrence and the etiological agents are necessary to understand its situation in Brazilian flocks. This research aimed to detect antibodies against Bovine Viral Diarrhea Virus, Bovine Herpesvirus type 1, Bovine Respiratory Syncytial Virus (BRSV) and Bovine Parainfluenza type 3 (bPI-3) virus in healthy and pneumonic sheep in relation to clinical signs of respiratory disease. Ninety-nine male and female sheep from the states of São Paulo (SP) and Rio de Janeiro (RJ) were enrolled in this study. They were classified as healthy and pneumonic using physical examination. Serum samples were obtained, and they were used to determine the presence of antibodies against respiratory viruses using serum neutralization test. The association between the microorganisms, clinical status, and clinical signs of respiratory disease in sheep was evaluated. Antibodies against Bovine Parainfluenza type 3 virus were mainly detected (52.5%), followed by Bovine Respiratory Syncytial Virus (48.5%). Data analysis did not reveal any association between the presence of antibodies and clinical signs of respiratory disease in sheep. Respiratory disease is an important issue in sheep production in which different bacterial and viral etiologic agents may be involved in its development. BRSV and bPI-3 are circulating in sheep flocks from São Paulo and Rio de Janeiro.

Seropositivity of Bovine Herpes Virus Type 1, Parainfluenza Type 3 Virus and Bovine Respiratory Syncytial Virus in Healthy and Pneumonic Cattle

Seropositivity of bovine herpes virus type 1, bovine respiratory syncytial virus and bovine parainfluenza type 3 viruses was determined in 41 cattle presented to large animal hospital, GADVASU with respiratory diseases and 25 cattle were kept as control animals. The seropositivity of BoHV-1, BRSV and BPIV-3 in control and diseased group was 16.0 Vs 41.5, 28.0 Vs 51.2 and 36.0 Vs 65.8 per cent, respectively. There was statistically significant difference (p

Pathological description of naturally occurring Mycoplasma bovis associated pneumonia in bovine calves

Mycoplasma bovis is an important etiologic agent of bovine respiratory infection and predominantly causing chronic pneumonic lesion. The present study encompassed standardized pathological, immunohistological and molecular technique for diagnosing natural bovine pneumonic cases with Mycoplasma bovis associated lesions. During the study, examination of 87 carcasses putatively died of pneumonia where Mycoplasma bovis was ascertained in two bovine female calves by immunohistological staining and Polymerase chain reaction. The specific pathological lesions were noted as chronic bronchopneumonia with mild to moderate caseonecrotic lesion and suppurative bronchopneumonia typical of Pasteurella infection. The other bacterial organism associated with these cases was found to be of Pasteurella multocida detected on isolation. No viral etiological association was detected in immunohistological examination in respect of bovine parainfluenza type 3, bovine respiratory syncytial virus and infectious bovine rhinotracheitis virus. The result also revealed that M bovis infection may develop into a severe necrosuppurative bronchopneumonia when associated with high numbers of intralesional organism and into mild catarrhal bronchointerstitial pneumonia when associated with low numbers of organism.

Evaluation of bovine Parainfluenza type-3 virus and Influenza virus D participation in bovine respiratory disease of calves from Brazilian family farming

Bovine respiratory disease (BRD) is responsible for great economic losses in bovine production with major impact on family farming. Among all possible causes of bovine respiratory disease, viruses are commonly categorized as primary etiological agents. The present study aimed to identify the presence of bovine parainfluenza type 3 virus and Influenza virus D (IVD) in tracheobronchial fluid samples of healthy calves and calves showing clinical signs of bovine respiratory disease. Samples were collected from 42 family farming farms in Sao Paulo State, Brazil. A total of 141 tracheobronchial fluid samples from healthy calves (n=100) and calves showing clinical signs of bovine respiratory disease (n=41) were enrolled in this study. No sample was positive for both viruses after Real-Time PCR. Serum neutralization for bovine Parainfluenza type 3 virus (bPI-3v) was performed using 88 randomly selected serum samples and antibodies were detected in 45.45% (40/88) samples. Serum reactive samples were detected in both healthy (46.8%; 22/47) and BRD calves (43.9%; 18/41). Regarding antibody titer, numerical differences were detected between healthy (3%) and BRD calves (9%) for titers 128-512 (P > 0.05). The present research was the first that aimed to study the presence of bPI-3V and IVD in family farming herds from Sao Paulo State, Brazil. This research revealed that bPI-3v is circulating in the region studied and is possibly involved in some BRD cases. On the other hand, IVD was not detected.

Seroprevalence and risk factors for selected respiratory and reproductive tract pathogen exposure in European bison (Bison bonasus) in Poland

After the complete extinction from the wild of European bison (Bison bonasus) at the beginning of the twentieth century, the worldwide species population was restored to approximately 5500 individuals, with the species however remaining endangered. Despite numerous studies on the ecology and genetics of European bison, the threats of infectious diseases have been largely unexamined. The aim of this study was to screen the exposure of the world’s largest population of European bison to the pathogens, which may influence the condition and development of the endangered species. A total of 240 free-ranging and captive European bison from eight main Polish populations sampled were tested for the presence of specific antibodies against ten different viruses, bacteria or protozoan. The samples were collected from chemically immobilized, selectively culled or found dead animals. Based on serology, the exposure to bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BoHV-1), Mycoplasma and Brucella spp. was determined as rather accidental. Using gamma-interferon assay followed by Mycobacterium tuberculosis subs. caprae detection in tissues, diagnosis of bovine tuberculosis was made for 6 out of 78 (7.7%) bison from one captive herd. The highest seroprevalence was found for bovine adenovirus type 3 (BAdV-3) −60.2% and bovine parainfluenza type 3 (PIV-3) −34.0%, while the antibodies against bovine respiratory syncytial virus (BRSV), Toxoplasma gondii and Leptospira spp. were found in 10.4%, 10.4% and 8.7% of samples, respectively. In the multivariable statistical analysis using generalized linear mixed models (GLMMS), the risk factors for PIV-3 seropositivity included population type (free-living/captive), age and health status (apparently healthy/eliminated due to the poor condition). Higher risk of BAdV-3 seropositive result was observed in free-living female European bison. The high BAdV-3 and PIV-3 seroprevalences may suggest involvement of these pathogens in the most frequently observed respiratory disorders in European bison. Moreover, this is the first study demonstrating BAdV-3 exposure in the species.

Comparison of interferon and bovine herpesvirus-1-specific IgA levels in nasal secretions of dairy cattle administered an intranasal modified live viral vaccine prior to calving or on the day of calving

Thirty-two Holstein cows were allocated to receive intranasal vaccination with modified live bovine herpesvirus-1 (BHV-1), bovine respiratory syncytial virus (BRSV) and parainfluenza type 3 virus (PI3V) vaccine either two weeks prior to their projected calving date, or within 24h after calving. Nasal secretions were collected twice at a 12-h interval on the day prior to vaccination (day 0) and at 2, 4, 7, 10 and 14days post vaccination to measure interferon (IFN) alpha, IFN-beta, IFN-gamma, and BHV-1-specific IgA by ELISA. Serum neutralizing antibody titers to BHV-1 and BRSV were measured on days 0, 7, and 14.There was a significant treatment effect (p<0.0004) and interaction (p<0.05) on nasal BHV-1 IgA levels, with higher IgA levels in cows vaccinated within 24h after calving. There was a significant treatment effect on nasal IFN-gamma concentration (p<0.05) and on nasal total IFN concentration (p<0.05), with higher IFN-gamma and total IFN concentrations seen in cows vaccinated within 24h after calving. There was no significant treatment or interaction effect on nasal IFN-alpha or IFN-beta concentrations, or on serum neutralizing titers to BRSV.In spite of prior viral vaccination during the previous lactation, cows vaccinated on the day of calving responded to an intranasal viral vaccination with increased concentrations of IFN-gamma and increased titers of IgA following vaccination which was significantly higher than cows vaccinated precalving. This study is the first to examine respiratory mucosal responses in immunologically mature dairy cattle vaccinated intranasally before and after calving.

Experimental Infection with bovine parainfluenza type 3 virus in mice

Four weeks old mice were used for experimental infection with isolated bovine parainfluenza type 3 virus. Mice were divided into three groups: The first group was infected by intracerebral route, the second group was infected by intranasal route and the third group was a control group. Experimental infection with isolated bovine parainfluenza type 3 virus in mice revealed that the isolated BPIV-3 was unable to kill 4 weeks old mice within 65 days when inoculated by intracerebral route, but isolated BPIV-3 was shown to kill (5 out of 10) 4 weeks old mice within 65 days when inoculated by intranasal route. There was no mortality in the control group within the same period. Two weeks old mice were used for experimental infection with isolated bovine parainfluenza type 3 virus and histopathological examination of infected organs was performed. Experimental infection of 2 weeks old mice by isolated BPIV-3 revealed that isolated BPIV-3 induced hydrocephalus after intracerebral inoculation. Histopathological examination for collected organs of BPIV-3 infected 2 weeks old mice (brain and lung) indicated histopathological changes were detected in comparison to non-infected collected organs. Virus was reisolated from infected brains of experimentally infected mice with locally isolated BPIV-3.

Identification and genome characterization of genotype B and genotype C bovine parainfluenza type 3 viruses isolated in the United States.

BackgroundBovine parainfluenza 3 viruses (BPI3V) are respiratory pathogens of cattle that cause disease singly but are often associated with bovine respiratory disease complex (BRDC) in conjunction with other viral and bacterial agents. Bovine vaccines currently contain BPI3V to provide protection against the virus, but there is no current information regarding the BPI3V strains that are circulating in the U.S.ResultsA project was initiated to sequence archival BPI3V isolates to study viral evolution over time. This was done with a deep sequencing protocol that generated sequences of multiple RNA virus genomes simultaneously. Analysis of the BPI3V sequences revealed that, in addition to the genotype A (BPI3Va) viruses previously described in the United States, there were two additional genotypes of BPI3V circulating that had been described only in Australia (BPI3Vb) and Asia (BPI3Vc). The U.S. BPI3Vb and BPI3Vc isolates showed some divergence from the Australian and Asian strains; the BPI3Vb were 93 % similar to the Australian Q5592 strain and the BPI3Vc viruses were 98 % similar to the 12Q061 strain that was described in South Korea. Overall, the three genotypes were 82 to 84 % identical to each other and 80 % identical to the most similar human PI3V. Cross-neutralization studies using an APHIS/NVSL BPI3V reference serum showed that neutralization titers against the genotype B and C viruses were 4- to ≥16-fold less then the titer against the APHIS BPI3Va reference strain, SF-4.ConclusionsThis study clearly demonstrated that BPI3Vb and BPI3Vc strains, previously thought to be foreign to the U.S., are indeed circulating in domestic livestock herds. Based on virus neutralization using polyclonal antisera, there were antigenic differences between viruses from these genotypes and the BPI3Va viruses that are included in currently marketed bovine vaccines. Further study of these viruses is warranted to determine pathogenic potential and cross-protection afforded by vaccination.

Effect of ambient temperature on viral replication and serologic titers following administration of a commercial intranasal modified-live IBR/ PI-3 vaccine in beef cattle housed in high and low ambient temperature environments

The impact of ambient temperature at the time of vaccine administration on viral replication and calf immune response is not well defined. The research objective was to compare serologic response and viral replication following intranasal administration of a modified-live infectious bovine rhinotracheitis (IBR) and parainfluenza type 3 (PI3) vaccine (N asalgen IP, Merck Animal Health) to beef heifers during periods of high (summer) and moderate ambient temperatures.

Seroprevalence of some bovine viral respiratory diseases among non vaccinated cattle in Saudi Arabia

Aim: Four viral pathogens, bovine viral diarrhea virus (BVDV), and bovine herpes virus type 1 (BHV-1), bovine parainfluenza type 3 virus (PI-3V), bovine respiratory syncytial virus (BRSV) are mainly associated with bovine respiratory diseases that cause major economic losses in the dairy cattle industry. This study aimed to document exposure of cattle in Saudi Arabia to infectious BVDV, BHV-1, PI-3V and BRSV viruses in non vaccinated cattle in order to obtain epidemiological and immunological information. Materials and Methods: In the present study, 460 random serum samples obtained from non vaccinated cattle in five districts (Riyadh, Eastern Province, Jizan, Najran, Asir) of Saudi Arabia between January to March 2011. These samples were tested for presence of antibodies against BVDV, BHV-1, BRSV and PIV-3 by commercial indirect ELISA kits. Results: Our findings displayed that Seropositivity rates were 26 % for BVD, 17.4 % for BHV-1, 69.1 % for PI-3V and 75.6 % for BRSV in the sampled population. In addition, coinfections with more than one virus were considerably common among non-vaccinated dairy cattle. Conclusion: These results indicate that exposure to these agents is common within the study areas. Preventive and control measures against these infectious agents should therefore be adopted.

Recent developments with live‐attenuated recombinant paramyxovirus vaccines

There is no vaccine currently approved for paramyxovirus-induced respiratory diseases in humans, despite their major clinical importance. We review the development and evaluation of new vaccine strategies based on live-attenuated chimeric and recombinant vaccines against human respiratory syncytial virus, human metapneumovirus and human parainfluenza viruses types 1 to 3, which are significant causes of upper and lower tract respiratory diseases. Most promising strategies are based on virus attenuation through (i) mutations in key genes involved in replication; (ii) deletion of accessory genes; or (iii) the use of a corresponding animal viral vector, such as bovine parainfluenza type 3 and Sendai virus, as a background for the expression of a viral glycoprotein. Indeed, the fusion (F), or attachment (HN/H/G) glycoproteins are the most immunogenic antigens in paramyxoviruses. For each strategy, we will review the immunogenicity (increase in neutralising antibody titres) and the protection conferred by the most promising recombinant vectored vaccines and list ongoing clinical trials. We will conclude by discussing the most important challenges regarding the introduction of such vaccines into immunisation programmes.

Detection of bovine parainfluenza type 3 virus in Iraq

This study is considered the first study in our country to isolate bovine parainfluenzatype 3 virus (BPIV-3) from naturally infected calves. BPIV-3 virus was isolated from nasalswabs collected from calves with respiratory disease. The virus was isolated and titrated insecondary embryonic bovine kidney (SEBK) cell culture; other cell cultures (secondary sheeptestis and chicken embryos fibroblast cell cultures) were used for propagation of isolatedvirus. Examination of infected cell culture revealed giant cell formation and intracytoplasmicinclusions. The isolated virus agglutinated guinea pig’s erythrocytes and produces clearheamadsorption of guinea pig’s erythrocyte in infected SEBK cell culture. Virus titer was2×102TCID50/0.1ml in the sixth passage and became 2×104.5TCID 50/0.1ml in the ninthpassage. The new isolated virus was identified as BPIV-3 by heamagglutination inhibitiontest, serum neutralization test and indirect immunoflurescent technique, by using specificmonoclonal and polyclonal antibody. The virus was sensitive to ether. High titer of BPIV-3antibodies was detected in sera of infected animals during convalescent period by ELISA test

Prevalence of Pasteurella multocida and other respiratory pathogens in the nasal tract of Scottish calves

The prevalence of Pasteurella multocida, a cause of bovine respiratory disease, was studied in a random sample of beef suckler and dairy farms throughout Scotland, by means of a cross-sectional...

Field efficacy of combination vaccines against bovine respiratory pathogens in calves

The efficacy of an inactivated bovine respiratory syncytial virus (BRSV)--bovine parainfluenza type 3 (PI3)--Mannheimia haemolytica (Mh) combination vaccine was examined in two field studies. Calves were vaccinated (i) with the inactivated vaccine, (ii) a modified live/killed viral combination vaccine, or (iii) left unvaccinated. The efficacy of the vaccines was judged by the (i) number of treated animals, (ii) number of individual antibiotic treatments per calf and (iii) mortality rates. After vaccination with the inactivated vaccine, the number of calves requiring antibiotic treatment was significantly lower than in the unvaccinated group (odds ratios: 0.26 first study and 0.53 second study), but differences between vaccination with live/killed combination vaccines and controls were not significant (odds ratios: 0.56 and 0.90, respectively). In both studies, a number of unvaccinated controls died due to respiratory disease (4.6% first and 6.7% second study). By contrast, none of the animals vaccinated with the inactivated vaccine died in the first study and only 3.3% in the second study. The mortality rates for the groups vaccinated with the live vaccine (1.3% and 7.8%) were similar to the unvaccinated controls. In summary, these data demonstrate the efficacy of the inactivated vaccine under field conditions.