A total of 23,322 specimens collected between 2014 and 2017, froma total of 2,592 cases, were received in Veterinary Research Institute, Ipoh (VRI) from various states in Malaysia and testedfor common bacterial, viral, and parasitic diseases in pigs. The highest occurrence of isolated bacteria from 771 samples whichtested positive were Salmonella (47.38%) and Escherichia coli (15.68%), followed by Staphylococcus (6.62%), Streptococcus (5.57%), Klebsiella pneumonia (4.88%), Pseudomona (3.38%), Acinetobacter (3.14%), Aeromonas (2.79%), Enterobacter (2.44%), one each of Bacillus and Pasteurella multocida (1.74%), Enterococcus (1.39%) and Corynebacterium (1.05%). 1.74% of each bacteria detected were Moxarella, Aspergillus, Burkholderia andChromobacterium. Positive samples tested by ELISA was Japanese encephalitis virus (JEV) (9.15%), Aujezsky disease virus (ADV)(5.37%), porcine cirvo-virus-2 (PCV2) (5.09%) and porcine reproductive and respiratory syndrome virus (PRRSV) (4.52%). Positive amples tested by the molecular test wasPCV2 (1.62%), PRRSV (1.32%) and classical swine fever virus (CSFV) (0.4%). Serology tests were conducted on 11,305 samplesand reported positive for Brucella suis (15.32%), Brucella abortus (0.62%), Brucella melitensis (0.85%), and melioidosis (0.05%). Parasitology analyses on 99 samples. revealed presence of 10.1% coccidia and 1% each of helminths and Sarcocystis. Within the 4-year period, there were no positive samples for porcine parvovirus (PPV), Nipah virus, swine influenza virus (SIV), and bacteria of Johne’s disease and leptospirosis. Continuous assessment is required to establish a comprehensive baseline data of swine diseases in Malaysia.

Sequential histologic, immunologic, and virologic features of herpesvirus-induced keratitis were studied in 18 experimentally infected cats. Histologic changes were assessed by use of light microscopy, and the presence of viral antigen, B lymphocytes, and T lymphocytes was verified immunohistochemically. Flow cytometry was used to monitor changes in blood T lymphocytes (CD4 and CD8 homologues) and B lymphocytes. Cellular immunity was assessed by use of the lymphocyte proliferation assay. Development of stromal keratitis was preceded by prolonged absence of corneal epithelium, decreased numbers of circulating lymphocyte subsets, decreased mitogen responses, and acquisition of viral antigen by the corneal stroma. Return to normal of circulating lymphocyte numbers and function was temporally associated with the arrival of neutrophils and B and T lymphocytes in the corneal stroma. Sequelae to stromal inflammation were fibrosis and scarring. Findings suggest that suppression of local immune responses allows virus access to the corneal stroma, and that subsequent keratitis is mediated by an immune response to viral antigen.

A virologic survey was conducted on calves with diarrhea associated with bovine rotavirus (BRV) on a closed dairy farm. The BRV was detected from 32 of 219 (14.6%) fecal specimens repeatedly collected from 56 calves born during the years 1992-1993, regardless of whether they had diarrhea. Most of the 32 strains were isolated from fecal specimens obtained from 2-to 6-week-old calves. After electrophoresis of doublestranded viral RNA from the 32 strains, genomic RNA migration patterns were similar to those of the predominant BRV strains isolated at the same farm during the years 1990-1991. All representative strains were identified as G serotype 6 (G6) and P type 5 (P5) by results of the virus-neutralization test and polymerase chain reaction procedure. Thus, BRV had no change in genomic RNA electropherotypes and serologic antigenicities in a closed dairy herd over a period of several years.

Bovine immunodeficiency virus (BIV) is prevalent in beef and dairy cattle, yet the mode(s) of BIV transmission are undefined. Using polymerase chain reaction, which specifically targeted a 235-bp, highly conserved region of the BIV pol gene, BIV-infected leukocytes were detected in the blood and milk of BIV-seropositive cows. These data confirm the presence of BIV in milk and identify the potential for lactogenic transmission of this virus.

To evaluate economic effects and health and performance of the general cattle population after exposure to cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) in a feedlot. 21,743 high-risk calves from the southeastern United States. PI status was determined by use of an antigen-capture ELISA (ACE) and confirmed by use of a second ACE, reverse transcriptase-PCR assay of sera, immunohistochemical analysis, and virus isolation from sera. Groups with various amounts of exposure to BVDV PI cattle were used. After being placed in the feedlot, identified PI cattle were removed from 1 section, but PI cattle remained in another section of the feedlot. Exposure groups for cattle lots arriving without PI animals were determined by spatial association to cattle lots, with PI animals remaining or removed from the lot. 15,348 cattle maintained their exposure group. Performance outcomes improved slightly among the 5 exposure groups as the risk for exposure to BVDV PI cattle decreased. Health outcomes had an association with exposure risk that depended on the exposure group. Comparing cattle lots with direct exposure with those without direct exposure revealed significant improvements in all performance outcomes and in first relapse percentage and mortality percentage in the health outcomes. Economic analysis revealed that fatalities accounted for losses of $5.26/animal and performance losses were $88.26/animal. This study provided evidence that exposure of the general population of feedlot cattle to BVDV PI animals resulted in substantial costs attributable to negative effects on performance and increased fatalities.

Objective-To analyze the 7a7b genes of the feline coronavirus (FCoV) of cheetahs, which are believed to play a role in virulence of this virus. Sample Population-Biologic samples collected during a 4-year period from 5 cheetahs at the same institution and at 1 time point from 4 cheetahs at different institutions. Procedures-Samples were first screened for FCoV via a reverse transcription-PCR procedure involving primers that encompassed the 3'-untranslated region. Samples that yielded positive assay results were analyzed by use of primers that targeted the 7a7b open reading frames. The nucleotide sequences of the 7a7b amplification products were determined and analyzed. Results-In most isolates, substantial deletional mutations in the 7a gene were detected that would result in aberrant or no expression of the 7a product because of altered reading frames. Although the 7b gene was also found to contain mutations, these were primarily point mutations resulting in minor amino acid changes. The coronavirus associated with 1 cheetah with feline infectious peritonitis had intact 7a and 7b genes. Conclusions and Clinical Relevance-The data suggest that mutations arise readily in the 7a region and may remain stable in FCoV of cheetahs. In contrast, an intact 7b gene may be necessary for in vivo virus infection and replication. Persistent infection with FCoV in a cheetah population results in continued virus circulation and may lead to a quasispecies of virus variants.

Six pregnant gilts were purchased from a high health herd and were found to be serologically positive for swine influenza virus (SIV) subtype H3N2. Three of the gilts, at 80 to 82 days of gestation, were experimentally exposed a second time to the same SIV subtype --- H3N2. No clinical signs resulted from the second exposure to SIV and hemagglutination-inhibition (HI) titers for SIV at 4 weeks postexposure were unchanged suggesting that the gilts had not been reinfected. However, the second exposure to SIV affected the number of pigs born alive. Each of the 3 litters from the twice exposed gilts suffered 2 or 3 stillborn piglets per litter. In contrast the 3 matched, sero-positive gilts that were not exposed to SIV (controls) had no stillborn piglets. These differences were statistically significant using a t-test for unequal variances (P = 0.0086). Sera from 2 of the stillborn piglets were negative for HI antibodies and there was no indication from the pigs born alive that the H3N2 virus had crossed the placenta.

Field infectious bursal disease viruses 9IBDVs) were isolated from IBDV-suspected commercial chickens. The variable region in VP2 gene of six Korean IBDV isolates (K-IBDVs) and IBD vaccines was examined using the reverse transcriptase/polymerase chain reaction-restriction fragment length polymorphism (RT/PCR-RFLP) assay. With all K-IBDVs and vaccine IBDVs, a 474-bp fragment of the VP2 gene was amplified and tested with various restriction enzymes. Resseriction enzymes BstNI and StyI differentiated K-IBDV isolates and IBD vaccines into four groups. Reseriction enzyme profiles of K-IBDV isolates were different from them of IBD vaccines. K-IBDV isolates except for 310 isolate had specific SspI and TaqI recognition sites, which were recognized in highly virulent IBDVs, but IBD vaccines had no those sites. This study showed that RT/PCR-RFLP assay was thought to be valuable tool for differentiation of IBDVs and identification of highly virulent IBDV.

Bovine immunodeficiency virus (BIV), a lentivirus, is prevalent in dairy and beef cattle in southeastern United States and may be associated with a lymphoproliferative disease. The mode(s) of BIV transmission are undefined. Because artificial insemination is a common practice in dairy production, contaminated stud semen could serve as an important source of infection if the virus is harbored in seminal fluids. To evaluate this possibility, we procured 11 cryopreserved semen specimens from a stud semen repository. Leukocytes were purified from the specimens, and the leukocyte DNA was used as template in a polymerase chain reaction procedure that targeted a 235-base pair, highly conserved domain of the BIV pol gene. The target sequence was amplified from the seminal leukocyte DNA of 9 of the specimens (82%), and nucleotide sequencing confirmed the BIV specificity of the fragment. This finding provides evidence that stud bull semen may serve as an important reservoir of BIV, suggesting the possibility that artificial insemination of dairy cows may have a major role in transmission and wide-spread dissemination of this bovine lentivirus.

Porcine fetuses were exposed in utero to porcine reproductive and respiratory syndrome virus (PRRSV) at stages of gestation ranging from 34 to 85 days and examined 17 to 31 days later to determine the effect of gestational age on fetal susceptibility. For each of the 8 litters tested during the study, all of the fetuses of 1 horn of the uterus were exposed to virus by intraamniotic injection; those of the other horn were exposed similarly to a sham inoculum that consisted of sterile cell culture medium. Viral infectivity titers associated with fetal tissues collected at necropsy indicated that, regardless of gestational age, the virus had replicated in fetuses exposed intraamniotically. In addition, virus had also spread and replicated in sham-inoculated littermates in 3 litters. On the basis of these findings it appears that there may be little or no temporal difference in fetal susceptibility to infection with PRRSV. If so, the lack of early fetal death as a commonly recognized feature of naturally occurring cases of PRRS may be due to a greater resistance of early gestational fetuses to the lethal effects of PRRSV, as suggested by this study, and/or a greater likelihood of transplacental infection during late gestation.