Direct Fluorescent Antibody Technique Research Articles

Acute Respiratory Distress Syndrome Secondary to Rabies: A Case Report and Review of the Literature

Introduction: Introduction: Rabies is a zoonotic viral infection with a worldwide distribution, primarily found in Asia and Africa, leading to an annual mortality rate of approximately 60 000 cases. The rabies virus is an RNA virus primarily transmitted through mucosal surfaces or contact with compromised skin. In this study, we present a case of rabies associated with acute respiratory distress syndrome (ARDS). Case Presentation: A 64-year-old male who had been bitten by a dog three weeks prior to admission presented to our emergency department with restlessness. A lung CT scan revealed nearly complete opacification of both lungs, indicative of ARDS. Unfortunately, the patient passed away within 5 hours of admission. An autopsy was conducted, and brain samples tested positive for rabies using the direct fluorescent antibody technique. Conclusions: ARDS is a rare but fatal extra-neural complication of rabies, potentially linked to cytokine storms and nitric oxide as etiological factors. Nevertheless, further investigations are warranted to gain a more precise understanding of the pathogenesis.

Development of a Recombinant Pichinde Virus-Vectored Vaccine against Turkey Arthritis Reovirus and Its Immunological Response Characterization in Vaccinated Animals.

Vaccination may be an effective way to reduce turkey arthritis reovirus (TARV)-induced lameness in turkey flocks. However, there are currently no commercial vaccines available against TARV infection. Here, we describe the use of reverse genetics technology to generate a recombinant Pichinde virus (PICV) that expresses the Sigma C and/or Sigma B proteins of TARV as antigens. Nine recombinant PICV-based TARV vaccines were developed carrying the wild-type S1 (Sigma C) and/or S3 (Sigma B) genes from three different TARV strains. In addition, three recombinant PICV-based TARV vaccines were produced carrying codon-optimized S1 and/or S3 genes of a TARV strain. The S1 and S3 genes and antigens were found to be expressed in virus-infected cells via reverse transcriptase polymerase chain reaction (RT-PCR) and the direct fluorescent antibody (DFA) technique, respectively. Turkey poults inoculated with the recombinant PICV-based TARV vaccine expressing the bivalent TARV S1 and S3 antigens developed high anti-TARV antibody titers, indicating the immunogenicity (and safety) of this vaccine. Future in vivo challenge studies using a turkey reovirus infection model will determine the optimum dose and protective efficacy of this recombinant virus-vectored candidate vaccine.

The Impact of Storms on Legionella pneumophila in Cooling Tower Water, Implications for Human Health.

At the U.S. Department of Energy’s Savannah River Site (SRS) in Aiken, SC, cooling tower water is routinely monitored for Legionella pneumophila concentrations using a direct fluorescent antibody (DFA) technique. Historically, 25–30 operating SRS cooling towers have varying concentrations of Legionella in all seasons of the year, with patterns that are unpredictable. Legionellosis, or Legionnaires’ disease (LD), is a pneumonia caused by Legionella bacteria that thrive both in man-made water distribution systems and natural surface waters including lakes, streams, and wet soil. Legionnaires’ disease is typically contracted by inhaling L. pneumophila, most often in aerosolized mists that contain the bacteria. At the SRS, L. pneumophila is typically found in cooling towers ranging from non-detectable up to 108 cells/L in cooling tower water systems. Extreme weather conditions contributed to elevations in L. pneumophila to 107–108 cells/L in SRS cooling tower water systems in July–August 2017. L. pneumophila concentrations in Cooling Tower 785-A/2A located in SRS A-Area, stayed in the 108 cells/L range despite biocide addition. During this time, other SRS cooling towers did not demonstrate this L. pneumophila increase. No significant difference was observed in the mean L. pneumophila mean concentrations for the towers (p < 0.05). There was a significant variance observed in the 285-2A/A Tower L. pneumophila results (p < 0.05). Looking to see if we could find “effects” led to model development by analyzing 13 months of water chemistry and microbial data for the main factors influencing the L. pneumophila concentrations in five cooling towers for this year. It indicated chlorine and dissolved oxygen had a significant impact (p < 0.0002) on cooling tower 785A/2A. Thus, while the variation in the log count data for the A-area tower is statistically greater than that of the other four towers, the average of the log count data for the A-Area tower was in line with that of the other towers. It was also observed that the location of 785A/2A and basin resulted in more debris entering the system during storm events. Our results suggest that future analyses should evaluate the impact of environmental conditions and cooling tower design on L. pneumophila water concentrations and human health.

Retrospective study of dog bites and cases of rabies virus infected dogs in slaughter houses in Makurdi, Nigeria

This study was carried out to obtain a 16-year retrospective data on dog bites/suspected dog rabies cases and to determine the prevalence of rabies antigen in the brains of dogs slaughtered for human consumption in Makurdi, Benue State. Data for retrospective studies (2003 - 2018) of dog bite/suspected rabies cases was collected from both government and private veterinary clinics in Makurdi while dog brain samples were collected from the dog slaughter slab at the mammy market in Makurdi. A total of 139 dog bite/suspected rabies cases were reported between January, 2003 and December, 2018 in the veterinary clinics with majority (55.3%) of the victims being children less than 16-years old. Only 18 (12.2%) of the offending dogs were quarantined at the time of bite, 11 of which died in quarantine. Five samples from the dogs that died in quarantine were later confirmed positive for rabies at the National Veterinary Research Institute Vom, Nigeria. Of the 464 brain samples collected from the slaughter slab, 52 (11.2%) tested positive for rabies antigen through the direct fluorescent antibody technique. The presence of rabies antigen in apparently healthy dogs may serve as a source of spread of the virus to the public as most people do not regard bites from healthy dogs as possible exposures. There is need for public health awareness on the health challenges posed by dog bites especially on the possibility of developing rabies from such bites, and the need to promptly report every bite so that proper medical attention can be given. With the world looking at eliminating canine mediated rabies by the year 2030, mass enlightenment programmes regarding rabies and its prevention in Makurdi is strongly recommended to help achieve this goal.&#x0D; Keywords: Bites, Dogs, Rabies, Makurdi, Nigeria, Retrospective

Cattle rabies: the effect of clinical evolution, viral genetic lineage, and viral load on the severity of histological lesions

ABSTRACT: Our objective was the characterization and staging of histological lesions in different anatomical sites of the central nervous system (CNS) of rabid cattle. The severity of the lesions was compared with the clinical stages of the disease, the variants of viral isolates, and with the load of virus. Thirty-one spontaneously affected rabid cattle the state of Santa Catarina underwent clinical follow-up and were eventually necropsied. CNS tissues were sampled and submitted to direct fluorescent antibody technique (DFAT), immunohistochemistry (IHC), routine histopathology with hematoxylin and eosin stain (HE), reverse transcriptase polymerase chain reaction (RT-PCR), and polymerase chain reaction in quantitative reverse transcriptase in real time (qRT-PCR). Affected cattle were allotted in four groups according to their clinical stage when euthanized: G1, euthanized while standing; G2, euthanized when in sternal recumbence; G3, euthanized when in lateral recumbence; and G4, affected cattle with natural death. In order to evaluate the degree of severity of the lesions and the presence of Negri bodies (NBs), the brain was sectioned at 9 sites. Additionally, spinal cord and trigeminal ganglion sections were examined. The intensity of the lesions was graded as either absent, mild, moderate, or marked, and the presence or absence of the NBs was noted. Histological lesions were characterized by lymphocytic and monocytic meningoencephalitis with NBs in 28 cases. In all analyzed groups, intensities of histological lesions ranging from mild to severe were observed. Brain regions with the highest inflammatory lesion intensity were the medulla at the level of obex, followed by the colliculus and thalamus. NBs were observed in a higher percentage in the cerebellum, followed by medulla at the obex level, striatum complex, and frontal telencephalon. The duration of the clinical course of the disease did not influence the intensity of the inflammatory lesion, but it did influence the presence of NBs, with a higher percentage of these inclusions in cattle that died naturally than in euthanized cattle. All isolated rhabdovirus included in this study were genetically compatible with samples from hematophagous bats Desmodus rotundus. The evaluation by qRT-PCR did not demonstrate a correlation between lesion intensity and the amount of virus.

Concurrent detection of bovine viral diarrhoea virus and bovine herpesvirus-1 in bulls’ semen and their effect on semen quality

ABSTRACT Reproductive diseases may have destructive effects on the fertility of cattle. Bovine viral diarrhoea virus (BVDV) and bovine herpes virus-1 (BoHV-1) are potent viral pathogens linked to reproduction. Thus, the aim of this study was to utilize raw semen samples for conventional and molecular detection of BVDV and BoHV-1, simultaneously. Additionally, the effect of virus infection on the semen quality of naturally infected bulls has been investigated. Therefore, 40 bulls were employed for semen collection, evaluation and testing for both viruses by virus isolation, direct fluorescent antibody technique (FAT) and SYBR Green real-time PCR assay. In virus isolation results, no cytopathic effect (CPE) was observed for BVDV on cell culture whereas, eight (20%) samples displayed characteristic grape-like clusters of cells for BoHV-1. By direct FAT, 12 (30%) positive BVDV and 8 (20%) positive BoHV-1 samples were confirmed. SYBR Green real-time PCR analysis using 48 h inoculated semen samples revealed 14 (35%) and 8 (20%) positive samples for BVDV and BoHV-1, respectively. Statistical analysis of semen evaluation parameters showed a significant difference between viral-infected and free groups represented by increased sperm abnormalities and decreased sperm motility, liveability and concentration. However, there was no significant difference among BVDV, BoHV-1 and mixed-infected groups. The study concluded that BVDV and/or BoHV- 1 infected bulls expressed low semen quality. Real-time PCR was confirmed to be the ideal laboratory assay for detection of both viruses in semen.

Prevalence of the bovine adenovirus type 3 by using direct fluorescent antibody technique in calves in Nineveh province

Prevalence of the bovine adenovirus type 3 by using direct fluorescent antibody technique in calves in Nineveh province

Application and Comparative Evaluation of Fluorescent Antibody, Immunohistochemistry and Reverse Transcription Polymerase Chain Reaction Tests for the Detection of Rabies Virus Antigen or Nucleic Acid in Brain Samples of Animals Suspected of Rabies in India.

Accurate and early diagnosis of animal rabies is critical for undertaking public health measures. Whereas the direct fluorescent antibody (DFA) technique is the recommended test, the more convenient, direct rapid immunochemistry test (dRIT), as well as the more sensitive, reverse transcription polymerase chain reaction (RT-PCR), have recently been employed for the laboratory diagnosis of rabies. We compared the three methods on brain samples from domestic (dog, cat, cattle, buffalo, horse, pig and goat) and wild (leopard, wolf and jackal) animals from various parts of India. Of the 257 samples tested, 167 were positive by all the three tests; in addition, 35 of the 36 decomposed samples were positive by RT-PCR. This is the first study in which such large number of animal samples have been subjected to the three tests simultaneously. The results confirm 100% corroboration between DFA and dRIT, buttress the applicability of dRIT in the simple and rapid diagnosis of rabies in animals, and reaffirm the suitability of RT-PCR for samples unfit for testing either by DFA or dRIT.

Evaluation of patients with dry eye disease for conjunctival Chlamydia trachomatis and Ureaplasma urealyticum.

To determine the possibility of the development of dry eye disease (DED) as a result of persistent infection with Chlamydia trachomatis and Ureaplasma urealyticum in the conjunctiva of patients. This study was conducted on 58 patients of age range 20-50y, diagnosed with DED confirmed by Schirmer I test and tear breakup time. The non-dry eye control group included 27 subjects of the same age. Ocular specimens were collected as conjunctival scrapings and swabs divided into three groups: the first used for bacterial culture, the second and third taken to detect Chlamydia trachomatis and Ureaplasma urealyticum by direct fluorescent antibody (DFA) assay and polymerase chain reaction (PCR) method. Chlamydia trachomatis was detected in 65.5% and 76% of DED patients by DFA and PCR methods respectively. Ureaplasma urealyticum was found in 44.8% of DED infected patients using the PCR method. Both organisms were identified in only 37.9% of DED patients found to be infected. Control subjects had a 22% detection rate of Chlamydia trachomatis by DFA assay versus a 7% detection rate by PCR; while Ureaplasma urealyticum was detected in 3.7% of the controls by PCR method. The conjunctival culture revealed that gram positive microorganisms represented 75% of isolates with coagulase negative Staphylococci the most common (50%) followed by Staphylococcus aureus (20%), whereas gram negative microorganisms occurred in 25% of cases, isolating Moraxella spp. as the most frequent organism. Our results tend to point out that Chlamydia trachomatis and Ureaplasma urealyticum were detected in a moderate percentage of patients with DED, and could be a fair possibility for its development. PCR is more reliable in detecting Chlamydia trachomatis than DFA technique. The presence of isolated conjunctival bacterial microflora can be of some potential value.

Role of nitric oxide in the regulation of immune responses during rabies virus infection in mice.

Rabies virus (RABV) stimulates nitric oxide (NO) production, which either triggers T cell differentiation or suppresses T cell function depending on its concentration. Herein, we assessed the potential role of NO in regulation of immune responses during RABV infection in mice model. The experimental animals were divided into four groups and 100LD50 of challenge virus standard (CVS) strain of RABV was inoculated intracerebrally on day 0 and subsequently aminoguanidine (AG; inducible nitric oxide synthase inhibitor) was injected intraperitoneally twice a day, up to 6days. The samples were collected at 2, 4, 6, 8, 9, 10 and 12days post infection (DPI). The immune cells including CD4+, CD8+ T lymphocytes and natural killer (NK) cells were estimated from peripheral blood mononuclear cells (PBMCs) and splenocytes. Serum total NO concentration, histopathology, immunohistochemistry, direct fluorescent antibody technique and TUNEL assay was performed. Infection with CVS resulted in significant early increase in CD4+, CD8+ and NK cells in blood and spleen until 2DPI. From 4DPI onwards significant reduction was noticed in these parameters which coincided with increased NO on 4 DPI, rising to maximum on 8DPI, until their death on 10DPI. Conversely, the CVS-AG treated group showed lower levels of NO and increased number of CD4+, CD8+ and NK cells. Increased number of cells in blood and spleen coincided with increased survival time, delayed development of clinical signs, reduced viral load and less apoptotic cells. NO played important role in regulation of immune responses during RABV infection. The findings of present study confirmed the role of NO and/or iNOS using iNOS inhibitor (aminoguanidine) in immune response during RABV infection, which would further help in understanding the virus immunopathogenesis with adoption of newer antiviral strategies to counter the progression of disease.

Role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh.

In Bangladesh, cholera is endemic and maintains a regular seasonal pattern. The role of phytoplankton in maintaining endemicity and seasonality of cholera was monitored in Matlab, Bangladesh. Phytoplankton and water samples were collected from two ponds bi-weekly for 1 year. The association of Vibrio cholerae O1 with phytoplankton was studied by culture and direct fluorescent antibody techniques. The bio-physicochemical parameters of water were measured and data for cases of cholera were collected from the records of Matlab hospital. The correlation of cholera cases with levels of phytoplankton, V. cholerae and bio-physicochemical parameters of water was carried out using Pearson's correlation coefficients. V. cholerae O1 survived for 48 days in association with Anabaena variabilis in a culturable state, but survived for a year in a viable but non-culturable (VBNC) state. V. cholerae survived for 12 and 32 days in a culturable state in control water (without algae) and water with algae, respectively. There was a significant correlation between changing levels of cholera cases in the community and the blue green algae and total phytoplankton in the aquatic environment. A significant correlation was also found between the cholera cases and chlorophyll-a and VBNC V. cholerae O1 in the aquatic environment. This study demonstrated the role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh.

Identification and genetic characterization of rabies virus from Egyptian water buffaloes (Bubalus bubalis) bitten by a fox.

Rabies is caused by negative strand RNA-virus classified in the genus Lyssavirus, family Rhabdoviridae of the order Mononegavirales. The aim of the present study was to identify and analyze nucleotides sequence of nucleoprotein (N) gene of rabies virus (RABV) from two cases of water buffaloes (Bubalus bubalis) bitten by a fox in Egypt, 2013. The diseased buffaloes showed nervous manifestations with fever. Specimens from brains of the buffaloes with suspected rabies were collected. RABV in collected samples was identified using direct fluorescent antibody (dFA) technique, histopathological examination and reverse transcription-polymerase chain reaction (RT-PCR). Also, nucleotides sequence of partially amplified nucleoprotein (N) gene was compared with the other street strains of RABV available on GenBank. The results revealed that RABV antigen was identified in the brains of diseased buffaloes by dFA technique and the characteristic intracytoplasmic inclusions (Negri bodies) and RABV nucleic acid were detected by histopathology and RT-PCR, respectively. The identified virus showed close genetic relationship with street strains identified previously from dogs in different Governorates in Egypt and with strains identified in Israel and Jordan indicating transmission of the virus between Egyptian Governorates with a potential transmission from and/or to our neighboring countries.

Some Studies on Prevalence and Effect of Thieleria Infection on Erythrocytes Profile in Camel in Some Localities at New-Valley, Governorate, Egypt

Theileria spp is protozoan parasites infecting wild and domestic animals throughout the world and affected the healthy state of the infected animals for that this study was carried to evaluate the effects of natural infection of camels with Theileria spp on blood picture and efficacy of indirect fluorescent antibody technique in diagnosis this infection, where blood samples were obtained from125 apparently healthy dromedary camels aged 1-9 years ,held in some localities in New-Valley governorate and classified into two groups, the first group (100 camels) as infected group and the rest number 25 as a control group where all of them examined by direct smear and indirect fluorescent antibody technique. Direct smear revealed 9 out 100 camel are positive for Theileria spp in ratio of 9% while indirect fluorescent antibody technique revealed 11out of 100 camels are positive (11%), with one sample as false negative and 3 samples as false positive so we can consider the indirect fluorescent technique remain the most convenient test for theileria spp diagnosis in camels. Hematological analysis revealed significant decrease in PCV, HB, RBCs count with significant increase in MCV, MCH and MCHC in infected group than control one. The frequency of theileriosis in camels is considerable and Theileria spp do not seem to induce significant alteration in clinical signs in naturally-infected dromedary camels but laboratory seem to induce significant decrease in hematological parameters which translated to anemia.

Rabies and dog bites cases in lagos state Nigeria: a prevalence and retrospective studies (2006-2011).

This study was carried out to determine the prevalence of rabies antigen in brain of dogs slaughtered for consumption and those that died in veterinary clinics as well as to obtain a 6-year retrospective data on dog bites/suspected dog rabies cases in Lagos State. Dog brain samples were collected from dog slaughter slabs and veterinary clinics (for dogs that died in clinics) across the Lagos state while data for retrospective studies (2006-2011) of dog bite/suspected rabies cases were collected from public (government owned) and private veterinary clinics across the state. Out of the 444 brain samples collected and tested for presence of rabies antigen using the direct fluorescent antibody technique (DFAT) only 7 (1.58%) were positive for the rabies antigen. A total of 196 dog bites/suspected rabies cases were encountered between January 2006 and December, 2011 in the veterinary clinics with adults been the major (55.61%) victims. Majority (96.43%) of the offending dogs were not quarantined at the time of bite and only one out of the quarantined dogs died and was confirmed positive for rabies antigen. The result of this study indicates that rabies antigen is present among dogs slaughtered in Lagos State and may pose a threat to public health. Though, available records showed that provocation of dogs was the major cause of dog bites and both children and adults fell victim of dog bites, there was a poor record keeping practice in the veterinary clinics across the state.

Bench‐top validation testing of selected immunological and molecular Renibacterium salmoninarum diagnostic assays by comparison with quantitative bacteriological culture

No gold standard assay exhibiting error-free classification of results has been identified for detection of Renibacterium salmoninarum, the causative agent of salmonid bacterial kidney disease. Validation of diagnostic assays for R.salmoninarum has been hindered by its unique characteristics and biology, and difficulties in locating suitable populations of reference test animals. Infection status of fish in test populations is often unknown, and it is commonly assumed that the assay yielding the most positive results has the highest diagnostic accuracy, without consideration of misclassification of results. In this research, quantification of R.salmoninarum in samples by bacteriological culture provided a standardized measure of viable bacteria to evaluate analytical performance characteristics (sensitivity, specificity and repeatability) of non-culture assays in three matrices (phosphate-buffered saline, ovarian fluid and kidney tissue). Non-culture assays included polyclonal enzyme-linked immunosorbent assay (ELISA), direct smear fluorescent antibody technique (FAT), membrane-filtration FAT, nested polymerase chain reaction (nested PCR) and three real-time quantitative PCR assays. Injection challenge of specific pathogen-free Chinook salmon, Oncorhynchus tshawytscha (Walbaum), with R.salmoninarum was used to estimate diagnostic sensitivity and specificity. Results did not identify a single assay demonstrating the highest analytical and diagnostic performance characteristics, but revealed strengths and weaknesses of each test.

Molecular epidemiology of animal rabies in the semiarid region of Paraíba, Northeastern Brazil

In the semiarid of the state of Paraíba, the anti-rabies vaccination is not common, most of the local inhabitants who deal with the animals do not know the incidence of the disease in the region. In this study, samples of foxes (Pseudalopex vetulus), insectivorous bats (Molossus molossus), raccoons (Procyon cancrivorous) and domestic animals brains were submitted to the diagnosis of rabies, by using the direct fluorescent antibody technique (d-FAT) and mouse inoculation test (MIT). Of the 581 examined materials, 50 (8.60 %) were positive for d-FAT and 47 (8.09 %) for MIT. From the positive samples for rabies, RNAs were extracted and transformed to cDNA, at the Laboratory of Rabies/Faculdade de Medicina Veterinária e Zootecnia/USP, SP. The phylogenetic characterization of the N gene was performed at the Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Medicina Veterinária Preventiva e Saúde Animal, Universidade Nihon, Faculdade de Ciências Bioresource, Fujisawa, Kanagawa, Japão. Based on the results of genotyping and phylogenetic analyzes, it is concluded that the epidemiology of rabies is complex in the semiarid of Paraíba, with different viral variants being maintained in domestic dogs, foxes, insectivorous bats and vampire bats. All the isolates examined belong to the genotype I of the genus Lyssavirus and it is possible to state that in the region, foxes are important sylvatic reservoirs of the rabies virus.

ISOLATION AND MOLECULAR IDENTIFICATION OF BHV-1 FROM CATTLE SUFFERING FROM RESPIRATORY SIGNS

A total of 93 ocular, 50 nasal swabs and 10 lung tissue were collected from 2-3 years old cattles affected with respiratory manifestation, and 145 serum samples from in contact apparently healthy cattles distributed in 4 different Governorates of Egypt (Ismalia, Qalioubia, Kafr El-Sheikh, and EL-Fayoum). Swabs and lung tissue samples were subjected to Bovine Herpes Virus (BHV-1) isolation on tissue culture Medin –Darby Bovine Kidney (MDBK) cell line and isolates were identified by direct fluorescent antibody technique (FAT) and polymerase chain reaction (PCR) by using primers complementary to the sequence of BHV-1 glycoprotein gB gene, as a rapid and more sensitive technique. From the results of virus isolation and identification were confirmed the more sensitivity of virus isolation than FAT and the most sensitivity and rapidity of PCR technique with confirmation and agreement of its results with the conventional methods. BHV-1 specific antibodies was detected in serum samples collected from the same 4 different Governorate, because of virus latency is a normal sequel to BHV-1 infection, by using the most suitable, sensitive, rapid, and specific techniques are ELISA and serum neutralization test (SNT), it is clear that the highest percentage of positive BHV-1 serum reactors was, in Kafr El-Sheikh followed by Ismalia, and Qalioubia and the lowest percentage was in EL-Fayoum. By the detection and identification of BHV-1 in collected samples and presence of positive reactors in serum samples this was a good indication for the circulation of BHV-1 in cattles of Egypt.

Prevalence of parainfluenza type 3 virus antigens in pneumonic caprine lungs by direct immunofluorescence and immunoperoxidase techniques

The purpose of this study was to determine the prevalence of Parainfluenza type 3 (PI-3) virus antigens using direct fluorescent antibody technique (DFAT) and immunoperoxidase (IP) staining of frozen and formalin-fixed paraffin-embedded tissues in pneumonic lungs of goats. An abattoir survey for prevalence of pneumonia in goats was carried out between January and June 2011 in Elazig region. A total of 889 goat lungs were grossly examined, and pneumonic apical and cardiac lobes were detected in only 152 lungs (17.10%). The severity of lesions in apical and cardiac lobes was scored according to the extent of consolidation. The tissues were stained with hematoxylin and eosin. IP and DFAT methods were only performed in tissues with 106 interstitial or fibrinous chronic bronchopneumonia. In conclusion, PI-3 viral antigens were identified at the rate of 44.40% by DFAT and 28.30% by IP in cases of natural chronic bronchopneumonia in goats in Elazig region, and the virus was suggested as one of the important etiological agents in chronic bronchopneumonia in goats.

Real-world comparison of two molecular methods for detection of respiratory viruses

BackgroundMolecular polymerase chain reaction (PCR) based assays are increasingly used to diagnose viral respiratory infections and conduct epidemiology studies. Molecular assays have generally been evaluated by comparing them to conventional direct fluorescent antibody (DFA) or viral culture techniques, with few published direct comparisons between molecular methods or between institutions. We sought to perform a real-world comparison of two molecular respiratory viral diagnostic methods between two experienced respiratory virus research laboratories.MethodsWe tested nasal and throat swab specimens obtained from 225 infants with respiratory illness for 11 common respiratory viruses using both a multiplex assay (Respiratory MultiCode-PLx Assay [RMA]) and individual real-time RT-PCR (RT-rtPCR).ResultsBoth assays detected viruses in more than 70% of specimens, but there was discordance. The RMA assay detected significantly more human metapneumovirus (HMPV) and respiratory syncytial virus (RSV), while RT-rtPCR detected significantly more influenza A. We speculated that primer differences accounted for these discrepancies and redesigned the primers and probes for influenza A in the RMA assay, and for HMPV and RSV in the RT-rtPCR assay. The tests were then repeated and again compared. The new primers led to improved detection of HMPV and RSV by RT-rtPCR assay, but the RMA assay remained similar in terms of influenza detection.ConclusionsGiven the absence of a gold standard, clinical and research laboratories should regularly correlate the results of molecular assays with other PCR based assays, other laboratories, and with standard virologic methods to ensure consistency and accuracy.

VIROLOGIC, SEROLOGIC AND PATHOLOGIC STUDIES INTO BORDER DISEASE VIRUS (BDV) INFECTION IN A GOAT HERD IN SAUDIA ARABIA

In this study, border disease virus (BDV) infection was suspected in a goat herd in Riyadh province, KSA. The outbreak was unusual in that the typical clinical signs of border disease, i.e., tremor and/or fleece changes were not present; manifestations of disease were restricted to abortion and the birth of small weak kids. The diagnosis was confirmed by virus detection from dead-born fetuses, seroprevalence and pathology. Impression smears from internal organs of aborted feti with suspected border disease (BD) were stained with the direct fluorescent antibody technique and examined by fluorescent microscopy, as well as prepared samples were assessed by antigen ELISA, where the two assays indicated the existence of BDV antigen. In addition; the serological investigation performed to determine the prevalence of (BDV) antibodies using ELISA revealed concurrent infection of BDV among this goat herd. Histopathological changes were confined to the brain, spinal cord and liver. Lesions were especially pronounced in the white matter of the cerebrum and the cerebellum. This is the first study that shows the presence of BDV and serologically positive animals to BDV in KSA. Further studies are needed in order to determine the prevalence of the disease in the other goat and sheep populations and the strains of the virus may be present in KSA.