• Korean Journal of Veterinary Research
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• v.52 no.4
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• pp.239-252
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• 2012

The circulation and infection of avian influenza virus (AIV) in zoos and backyard flocks has not been systematically investigated. In the present study, we surveyed the birds including those in live bird markets (LBMs) and evaluated co-circulation of AIVs among them. Overall, 26 H9N2 AIVs and one H6N2 AIV were isolated from backyard flocks and LBMs, but no AIVs were isolated from zoo birds. Genetic analysis of the HA and NA genes indicated that most of the H9N2 AIVs showed higher similarities to AIVs circulating in domestic poultry than to those in wild birds, while the H6N2 AIV isolate from an LBM did to AIVs circulating in migratory wild birds. In serological tests, 15% (391/2619) of the collected sera tested positive for AIVs by competitive-ELISA. Among them, 34% (131/391) of the sera tested positive for AIV H9 antigen by HI test, but only one zoo sample was H9 positive. Although AIVs were not isolated from zoo birds, the serological results indicated that infection of AIVs might occur in zoos. It was also confirmed that H9N2 AIVs continue to circulate and evolve between backyard flocks and LBMs. Therefore, continuous surveillance and monitoring of these flocks should be conducted to control further epidemics.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.19-25
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• 1999

A total of 137 strains of Staphylococcus aureus were isolated from dairy cow's milk with subclinical mastitis from 33 herds in 5 provinces and 36 strains of S aureus from clinical mastitis from 4 herds where the mastitis were severe problem. Arbitrary primed polymerase chain reactions with 10 bp oligonucleotide primer were performed and the PCR products were analysed with image analyzer, The S aureus strains were genotyped into 20 distinct DNA fingerprinting profiles. The size of PCR products ranged from 163 to 2,479 bp and PCR products of 506, 770, 784 and 2,479 bp were the most prevailing bands. Genotype 3 was founded in all 5 provinces. The various genotypes were identified in newly founded dairy herds, however, only one or two genotypes were identified in the closed herds. In clinical mastitis, only a limited number of different S aureus genotype was founded in each of the herds in comparision with subclinical mastitis. The results demonstrated that PCR-based DNA fingerprinting analysis of S aureus strain can be used to study epidemiology of mastitis, in addition, common genotype in geographic region can be useful for the development of an effective S aureus bacterin.

• Journal of Veterinary Clinics
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• v.34 no.3
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• pp.185-188
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• 2017

This study assessed the seroprevalence of Babesia gibsoni in companion dogs in Korea by enzyme linked immunosorbent assay using recombinant BgTRAP antigen. Dogs were randomly selected from those admitted for various reasons to local private veterinary hospitals and the Animal Medical Center of Chonbuk National University. With the owners' permission, extra blood was drawn from each dog for serological assays. Of the 188 selected dogs, seven (3.72%) were positive for B. gibsoni, including six of 167 (3.59%) indoor and one of 12 (8.33%) outdoor dogs. Of the seven dogs positive for B. gibsoni, four were aged > 10 years, two were < 1 year, and one was between 1 and 10 years; and two were Yorkshires and one each was Shih-tzu, Maltese, Pekinese, beagle and mixed. Concurrent diseases or chief complaints were anemia in two dogs, both of which had a history of confirmed babesiosis by polymerase chain reaction, and non-anemic diseases in five. Geographically, four dogs were from Jeonbuk/Jeonju, and one each from Seoul, Gyounggi-do, and Jeonnam/Gwangju. To our knowledge, this is the first report of companion dogs in Korea being seropositive for B. gibsoni. Serologic screening of subclinical or carrier dogs can detect this potentially dangerous disease and assess its epidemiology.

• Journal of Veterinary Clinics
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• v.25 no.6
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• pp.476-481
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• 2008

A retrospective study of 17 dogs with hyperadrenocorticism (HAC) was performed to evaluate the clinical and clinicopathological outcomes in dogs with pituitary-dependent HAC or adrenal gland-dependent HAC. Sixteen dogs were monitored at day 10, 30 and 90 then every 3 month after first presentation. In each examination, physical examination and ACTH stimulation test and client questionnaire were performed. In 17 cases, eight dogs were successfully treated with mitotane therapy (median dose 16.7 mg/kg; range 5.3 to 50 mg/kg, SID); another one dog showed favorable response, but the clients declined to further treatment before the full control of the disease had been achieved; four dogs showed poor response to treatment. One dog was euthanized due to septicemia. These results showed canine HAC can be medically managed successfully without side effects at the doses used in this study.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.859-866
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• 1998

This study was carried out to investigate the prevalence of Neopsora (N) caninum infection in Korean dairy herds. To determine the prevalence of antibodies to N caninum in Korean dairy cattle, a total of 1,688 sera including 895 sera taken from 30 herds having recent high abortion rate and 793 sera selected randomly from 168 herds with no history of recent abortion problem, respectively, collected nationwide during a designated period were analyzed by indirect fluorescent antibody (IFA) test. Mean nationwide seropositive rate of the sera tested in herds and individual cattle tested were 53.5% and 35.6%, respectively. However mean seropositive rate of the samples from herds having abortion problem was approximately two and half times higher than those in herds with no recent abortion history. Regional seropositive rates of the samples from the herds with abortion problem were 48.6%, 51.6%, 44.4% and 71.4% at Kyunggi, Kangwon, Kyungbuk and Jeonnam province, respetively. Regional seropositive rates of the samples from the herds with no recent abortion problem were 35.6%, 18.3%, 16.5%, 37.5%, 19.4%, 33.3%, 32.1%, 3.8% and 0.0% at Kyunggi, Kangwon, Chungbuk, Chungnam, Kyungbuk, Kyungnam, Jeonbuk, Jeonnam and Jeju province, respectively. The results of this study suggested that N caninum infection was widespread and considerably associated with bovine abortion in Korea.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.125-131
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• 2010

Bacterial contamination is an unavoidable finding of the semen collection process in boar and can lead in deleterious effects on semen quality and longevity if left uncontrolled. The purpose of this study is to identify the bacteria in extended boar semen and to select the effective antimicrobials to control of the contaminants. Of 116 extended boar semen samples submitted from eight AI centers in Korea, 39 (33.6%) samples were positive for bacterial contamination. Among 39 contaminated semen, most of them (84.6%) were contaminated with one or two bacterial species and there was no significant difference between two age groups $(\leq\;24\;and\;>\;24\;month\;old).$ Stenotrophomonas maltophilia (n = 18) was the most predominant bacterium followed by Elizabethkingia meningoseptica (n = 12), Sphingomonas paucimobilis (n = 12), Myroides spp. (n = 5), Ochrobactrum anthropi (n = 3), and so on. Enrofloxacin (72.9%), florfenicol (72.9%), bacitracin (49.2%) and tylosin (49.2%) showed higher sensitivity compared with penicillin (13.6%) or aminoglycosides (6.8%-18.6%). Brucella spp., Leptospira spp., Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, Mycobacterium tuberculosis complex were not detected in semen by PCR.

• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.181-190
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• 2024

Bovine mastitis-associated Escherichia coli (BMEC) is considered the main causative agent of significant financial losses in the dairy industry worldwide, as it alters both the quantity and quality of milk produced and increases the rate of culling. This creates a variety of challenges for researchers, veterinarians, and farmers in understanding and determining the most effective therapies and diagnostic techniques. Subclinical mastitis is particularly concerning, as infected bovines exhibit no obvious symptoms and continue to secrete apparently normal milk over an extended period, allowing the causative pathogen, E. coli, to spread within the herd. For effective prevention, understanding the pathogenesis of mastitis through three stages invasion, infection, and inflammation is essential. To date, no clear correlation has been found between virulence factors and pathogenicity contributing to the clinical severity of BMEC. Multidrug-resistant E. coli and the evolution of novel resistance mechanisms have become concerns owing to the extensive use of antibiotics to treat mastitis. Therefore, it is vital to explore alternative controls to enhance the efficacy of BMEC treatment. Over the past 30 years, various genetic typing techniques have been used to examine the subspecies-level epidemiology of bovine mastitis. These studies have advanced our understanding of the origin, transmission pathway, population structure, and evolutionary relatedness of BMEC strains. In this review we provide an overview of BMEC, including insights into its etiology, genetic relationship, pathogenesis, and management of the disease, as well as new therapy options.

• Journal of Veterinary Science
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• v.21 no.3
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• pp.36.1-36.9
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• 2020

Background: Pseudorabies, also known as Aujeszky's disease, is caused by the pseudorabies virus (PRV) and has been recognized as a critical disease affecting the pig industry and a wide range of animals around the world, resulting in great economic losses each year. Shandong province, one of the most vital food animal-breeding regions in China, has a very dense pig population, within which pseudorabies infections were detected in recent years. The data, however, on PRV epidemiology and coinfection rates of PRV with other major swine diseases is sparse. Objectives: This study aimed to investigate the PRV epidemiology in Shandong and analyze the current control measures. Methods: In this study, a total number of 16,457 serum samples and 1,638 tissue samples, which were collected from 362 intensive pig farms (≥ 300 sows/farm) covered all cities in Shandong, were tested by performing enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). Results: Overall, 52.7% and 91.5% of the serum samples were positive for PRV-gE and -gB, respectively, based on ELISA results. In addition, 15.7% of the tissue samples were PCR positive for PRV. The coinfection rates of PRV with porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus, and classical swine fever virus were measured; coinfection with PCV2 was 35.0%, higher than those of the other two viruses. Macroscopic and microscopic lesions were observed in various tissues during histopathological examination. Conclusions: The results demonstrate the PRV prevalence and its coinfection rates in Shandong province and indicate that pseudorabies is endemic in pig farms in this region. This study provides epidemiological data that can be useful in the prevention and control of pseudorabies in Shandong, China.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.665-673
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• 2014

We compared standard culture methods as well as conventional PCR and real-time PCR for the detection of Listeria monocytogenes (L. monocytogenes) in milk, cheese, fresh-cut vegetables, and raw beef that have different levels of background microflora. No statistical differences were observed in sensitivity between the two selective media in all foods. In total, real-time PCR assay exhibited statistically excellent detection sensitivity (p<0.05) and was less time consuming and laborious as compared with standard culture methods. Conventional culture methods showed poor performance in detecting L. monocytogenes in food with high levels of background microflora, generating numerous false negative results. While the detection of L. monocytogenes in fresh cut vegetable by culture methods was hindered only by L. innocua, various background microflora, such as L. innocua, L. welshimeri, L. grayi, and Enterococcus faecalis appeared on the two selective media as presumptive positive colonies in raw beef indicating the necessity of improvement of current selective media. It appears that real-time PCR is an effective and sensitive presumptive screening tool for L. monocytogenes in various types of foods, especially foods samples with high levels of background microflora, thus complementing standard culture methodologies.

• Journal of Veterinary Clinics
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• v.26 no.4
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• pp.340-343
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• 2009

A 3-year-old, intact female Poong-san dog was presented with a 4-month history of erosive, erythematous dermatitis unresponsive to systemic antibiotics and glucocorticoids. Crust, erosion, and alopecia were noted on the ear pinnae, bridge of nose, and forelimb. Cytological evaluation of intact pustules showed isolated free-floating rounded acantholytic keratinocytes admixed with non-degenerated neutrophils and eosinophils. Results of histopathologic examination revealed the intra-epidermal pustules with predominant neutrophils, less eosinophils, and isolated and clustered acantholytic cells. A diagnosis of pemphigus foliaceus (PF) was made based on the history, clinical, cytological and histopathological results. The skin lesions had improved after systemic cyclosporine therapy. This case report demonstrates that cyclosporine, an immunosuppressive agent, can be used in the management of PF in dogs.