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Species identification and cow risks of non-aureus staphylococci from South African dairy herds
2022
Inge-Marie Petzer | Christiaan Labuschagne | Lufuno Phophi | Joanne Karzis
Detailed information on specific species of non-aureus staphylococci (NAS) has become a necessity for effective udder health control programs in South Africa. The main objective of this preliminary study was to identify the different NAS species and strains present in dairy herds in South Africa using a cost-effective method. A further objective was to investigate the effects of cow risk factors and farming systems on the NAS isolates identified. A total of 214 NAS, isolated from milk collected from 17 South African dairy herds, were identified using three diagnostic tests (API Staph test, MALDI-TOF and 16s rRNA). There was a good observed agreement between the MALDI-TOF and 16S rRNA sequencing (92.2%) and a poor observed agreement between the MALDI-TOF and API Staph (25.7%). The genetic relatedness within species was investigated in 128 of these isolates using random polymorphic amplified deoxyribonucleic acid (DNA) (RAPD), verified by multilocus sequence typing (MLST), and phylogenetic analysis and cow risk factors were investigated on species level. The main NAS species isolated were Staphylococcus chromogenes (75.2%), Staphylococcus epidermidis (9.4%) and Staphylococcus haemolyticus (8.9%). The RAPD test identified 34 Staphylococcus chromogenes, 13 Staphylococcus epidermidis and nine Staphylococcus haemolyticus strains, indicating genetic diversity amongst strains and herds. The presence of NAS intramammary infections was found to be significantly related to the farming systems, composite cow milk somatic cell count (SCC), parity and days in milk (DIM). Significantly more NAS were isolated from primiparous and from older cows. This knowledge could assist with the management of NAS on dairy farms.
Show more [+] Less [-]Antibody response to Raboral VR-G® oral rabies vaccine in captive and free-ranging black-backed jackals (Canis mesomelas)
2022
Katja N. Koeppel | Peter Geertsma | Brian F. Kuhn | Ockert L. van Schalkwyk | Peter N. Thompson
Rabies is a zoonotic disease that remains endemic in large parts of southern Africa because of its persistence in wildlife and domestic dog vectors. The black-backed jackals (Canis mesomelas) is primarily the wildlife vector responsible for rabies outbreaks in northern parts of South Africa. Two trials were carried out to investigate antibody responses to the oral rabies vaccine Raboral V-RG® in black-backed jackals under captive and free-ranging conditions. In captive jackals 10/12 (83%; 95% confidence interval [CI]: 52% – 98%), seroconverted after single oral vaccination. Nine captive jackals had protective antibody titres ( 0.5 IU/mL) at 4 weeks (median: 2.1 IU/mL; inter quartile range [IQR]: 0.6–5.7) and 10 jackals had at 12 weeks (median: 3.5 IU/mL; IQR: 1.5–8.3) and three maintained antibody titres for up to 48 weeks (median: 3.4 IU/mL; IQR: 2.0–6.3). Four sites were baited with Raboral V-RG® vaccine for wild jackals, using fishmeal polymer and chicken heads. Baits were distributed by hand or from vehicle at three sites in north-eastern South Africa, with an average baiting density of 4.4 baits/km2 and at one site in central South Africa, at 0.12 baits/km2. This resulted in protective antibody titres in 3/11 jackals (27%; 95% Cl: 6–61) trapped between 3 and 12 months after baiting in north-eastern South Africa, compared with 4/7 jackals (57%; 95% Cl: 18–90) trapped after 3–18 months in central South Africa. This study shows the potential utility of oral rabies vaccination for the control of wildlife-associated rabies in north-eastern and central South Africa, but extensive studies with wider distribution of bait are needed to assess its potential impact on rabies control in wild jackals.
Show more [+] Less [-]Propagation of avian influenza virus in embryonated ostrich eggs
2022
Agnes T. Laleye | Modupeore Adeyemi | Celia Abolnik
Influenza A viruses (IAVs) are typically isolated and cultured by successive passages using 9- to 11-day-old embryonated chicken eggs (ECEs) and in 14-day old ECEs for virus mutational studies. Real-time reverse transcription-polymerase chain reaction tests (RT-PCRs) are commonly used for IAV diagnosis, but virus isolation remains invaluable in terms of its high sensitivity, providing viable isolates for further studies and the ability to distinguish between viable and nonviable virus. Efforts at isolating ostrich-origin IAVs from RT-PCR positive specimens using ECEs have often been unsuccessful, raising the possibility of a species bottleneck, whereby ostrich-adapted IAVs may not readily infect and replicate in ECEs, yet the capacity of an ostrich embryo to support the replication of influenza viruses has not been previously demonstrated. This study describes an optimised method for H5 and H7 subtype IAV isolation and propagation in 28-day old embryonated ostrich eggs (EOEs), the biological equivalent of 14-day old ECEs. The viability of EOEs transported from breeding sites could be maximised by pre-incubating the eggs for 12 to 14 days prior to long-distance transportation. This method applied to studies for ostrich-adapted virus isolation and in ovo studies will enable better understanding of the virus-host interaction in ostriches and the emergence of potentially zoonotic diseases.
Show more [+] Less [-]Table of Contents Vol 89, No 1 (2022)
2022
Editorial Office
No abstract available.
Show more [+] Less [-]Image quality assessments of focal spot size on radiographic images in dogs
2022
Park, S.J. | Hwang, T.S. | Lee, H.C.
The aim of this prospective study was to investigate the effects of focal spot size of X-ray tube on sharpness of clinical radiographic images of dogs and cats. Radiographic images of 24 stifle joints, 15 carpi, 18 lumbar spines, 61 thoraxes, and 47 abdomens of 102 dogs and 4 cats were obtained in the present study, using 2 X-ray tubes with nominal focal spots of 2.0 mm and 0.6 mm, respectively. The sharpness of specific anatomical structures in all the images of 5 projections was assessed. The radiographic sharpness of various anatomical structures of lumbar spine and cortex of stifle with fine focal spot was increased significantly compared with broad focal spot images. In addition, the blurred motion was significantly higher in the fine focal spot images of thorax. In conclusion, our study suggests that a selective use of fine foci for imaging of lumbar spine or cortex of stifle enhanced radiographic sharpness.
Show more [+] Less [-]Risk factors for repeat breeder dairy cows and their impacts on reproductive performance
2022
Jeong, J.K. | Kim, I.H.
The objective of this study was to identify risk factors for repeat breeder dairy cows and their impact on reproductive performance. The characteristics of 1,504 cows, including their peripartum health, nutrition, production, and reproduction, were collected. Cows with metabolic disorder were significantly more likely (odds ratio [OR], 2.47; p less than 0.001) and cows with clinical endometritis tended to be more likely (OR, 1.35; p less than 0.1) to become repeat breeders than cows without metabolic disorder and clinical endometritis, respectively. Cows initially inseminated more than 80 days after calving were less likely (OR, 0.78; p less than 0.05) to become repeat breeders than cows initially inseminated ≤ 80 days after calving. As a result, repeat breeding in dairy cows resulted in a 90 day longer (p less than 0.0001) mean interval from calving to pregnancy. In conclusion, postpartum metabolic disorder, clinical endometritis, and a short interval from calving to initial insemination were risk factors for repeat breeder dairy cows, resulting in a severely impaired reproductive performance.
Show more [+] Less [-]Non-epitheliotropic Cutaneous T-cell lymphoma in a cat: a case report
2022
Jeon, Y.S. | Bae, H.A. | Shin, S.W. | Cho, A.R. | Kim, Y.J. | Hwang, T.S. | Lee, H.C. | Hyun, J.E. | Cho, K.W. | Jung, D.I. | Kim, D.Y. | Yu, D.H.
Cutaneous lymphoma is rare in cats. An 11-year-old spayed female Persian cat presented with crust, ulceration, and multiple nodules on the shoulder and forelimb for 2 months. Computed tomography revealed a diffuse, irregularly margined lesion in the dorsal cutis extending from cervical to thoracic vertebrae. Cytological evaluation predominantly revealed large round cells with multilobulated nuclei and basophilic cytoplasm. Histopathological examination confirmed round CD3+/PAX5- cells packed in the dermis. Thus, the diagnosis of non-epitheliotropic cutaneous lymphoma with a diffuse large T-cell type was made. The disease progressed rapidly for the next 2 weeks, and the owner elected humane euthanasia.
Show more [+] Less [-]Pseudohyperkalemia after total splenectomy in a dog: a case report
2022
Moon, C.H. | Lee, J.H. | Jeong, Y.J. | Kwon, Y.S. | Lee, H.B. | Kim, D.H. | Jeong, S.M.
A 16-year-old, 7.4 kg, castrated male Cocker Spaniel presenting anorexia and weight loss was referred due to a splenic mass, and total splenectomy was performed to resolve clinical signs. Following surgery, the dog developed mild hyperkalemia (6.27 mmol/L) without any clinical symptoms. Further investigations were conducted to determine the cause of hyperkalemia. The serum-plasma potassium difference was measured (1.05 mmol/L), and pseudohyperkalemia was diagnosed. The cause of pseudohyperkalemia was considered as thrombocytosis after splenectomy. The dog did not receive any specific treatment to lower blood potassium. To our knowledge, we report the first case of post-splenectomy pseudohyperkalemia in a dog.
Show more [+] Less [-]Computed tomographic diagnosis of broncholithiasis in a cat
2022
Kim, R.H. | An, S.Y. | Hwang, G.H. | Ryu, J.M. | Kim, M.J. | Yoon, J.W. | Noh, S.A. | Yu, D.H. | Lee, H.C. | Hwang, T.S.
A 5-year-old castrated male domestic shorthair cat was referred for further investigation of pulmonary nodules incidentally detected on thoracic radiographs. Thoracic radiographs identified ill-defined soft tissue opacity nodules with small faint mineral opacity. Thoracic computed tomography (CT) revealed that bronchial dilation and bronchial wall thickening in bilateral cranial and accessory lung lobes. Round to ellipsoid mineralized concretions were found embedded in the intrabronchial soft tissue attenuation material. Based on radiography, CT, and cytology, the patient was tentatively diagnosed as having broncholithiasis with chronic bronchitis. This report described the CT diagnosis of broncholithiasis, which has been rarely reported in a cat.
Show more [+] Less [-]Neuronal ceroid lipofuscinosis in a Border Collie: a case report
2022
Seo, M.S. | Koo, Y.H. | Choi, D.J. | Kim, S.G. | Yun, T.S. | Chae, Y. | Lee, D.H. | Kim, H.H. | Yang, M.P. | Kim, S.C. | Kang, B.T.
A 2-year-old spayed female Border Collie presented with visual deficits and behavioral changes. Neurological examination revealed bilateral menace response deficit with a normal pupil light reflex. Cerebral cortical thinning, cerebral sulci and cerebellar fissure widening, ventriculomegaly, and cerebral atrophy were observed on magnetic resonance imaging (MRI). Histopathology revealed fluorescent lipopigment accumulation in the cerebrum, and the dog was diagnosed with neuronal ceroid lipofuscinosis. This is the first case report describing the changes in clinical signs, MRI findings, and histopathologic changes in neuronal ceroid lipofuscinosis in Korea.
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