• Korean Journal of Veterinary Service
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• v.16 no.2
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• pp.157-165
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• 1993

The present study was conducted to investigate biochemical properties, antimicrobial drug susceptibilities and epidemiology of 71 stranins of Salmonella pullorum isolated from about 110 diseased chickens of 23 poultry farms located in Cheongjoo, Cheongweon and Koesan county, Chungbuk province, from August 1991 to March 1993. The isolates were identified as S. pullorum by serological and biochemical means. S. pullorum were mostly isolated in chicken under 3weeks of age, and also isolated in 58, 72 days and 23 weeks of age. According to breeds, most of the cultures were isolated in colored broiler chicken (14 to 23 cases), and also variously isolated in native chicken, white broiler chicken, black bone chicken and laying hen. According to organs of diseased chickens, most of the cultures were isolated in liver (37 to 71 strains), and also variously isolated in spleen, lungs, blood, heart, oviduct and brain. According to media used for primary culture from organs, most of the cultures were isolated purely with SS and BHI medium. The majority of biochemical properties of S. pullorum isolated from diseased chickens were identical to those of the standard strains, but in the properties of rhamnose, and arabinose fermentation, some isolates were negative in spite of positive in those of standard S. pullorum. All the isolates were highly susceptible to colistin, amikacin, kanamycin, gentamicin, carbenicillin, ampicillin, sulfamethxazole, cephalothin, tetracycline and piperacillin regardless of isolated years, but no susceptible to penicillin, erythromycin, vancomycin, tylosin and novobiocin.

• Korean Journal of Veterinary Service
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• v.17 no.2
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• pp.83-88
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• 1994

The studies were carried out to diagnose of disease chickens that were raised at the chicken farms located in Chung -nam province and evaluated potential of mold growth inhibition of antifungal agent, Mold-X. The diseased 25 chickens that were shown clinical sign such as anorexia, respiratory symptoms, were suspected aspergillosis. The results obtained were summarized as follows ; 1. The diseased thickens were diagnosed aspergillosis according to clinical sign, pathological finding, isolation of etiological agent. 2. The growth of mold was conciderable inhibited by the Mold-X of 300 ppm level.

• Korean Journal of Veterinary Research
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• v.49 no.3
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• pp.195-200
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• 2009

Avian pathogenic Escherichia coli (APEC) is an important bacterial pathogen of chickens and causes colibacillosis such as airsacculitis, perihepatitis, omphalitis, peritonitis, salpingitis, and pericarditis. As the transfer of antibiotic resistance from animal to humans can be possible, surveillance on antibiotic resistance of APEC is very important. A total 34 APEC isolates from diseased chickens during the period from 2007 to 2009 were obtained. The susceptibility of the isolates to 13 antibiotics was determined by disc diffusion assay. Resistance to erythromycin was found in 97.1% of APEC isolated, followed by resistance to tetracycline (85.3%), doxycycline (82.3%), ampicillin (73.5%), sulfisoxazole (67.6%), enrofloxacin (67.6%), ciprofloxacin (64.7%), norfloxacin (61.7%) trimethoprim/sulfamethoxazole (52.9%), gentamycin (26.5%), amoxicillin (8.8%), colistin (5.9%), and amikacin (2.9%). The blaTEM genes were detected in 25 (100%) of the 25 ampicillin-resistant APEC isolates. Among the 29 tetracycline-resistant APEC isolates, tetA and tetB genes were detected in 18 (62.1%) and 9 (31%) isolates, respectively. Twenty six (76.5%) isolates were multiresistant to at least 6 antibiotics and seven (20.1%) isolates were multiresistant to at least 10 antibiotics. This results indicated that multiple antibiotic-resistant APEC is widespread in chicken flocks in Korea.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.137-146
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• 1997

About Clostridium perfringens causing clinically necrotic enteritis or isolated from the intestinal contens of healthy chicken, We examined the usefulness of a rapid identification method by gas-liquid chromatography as well as the types of toxins. For this study, there were used 169 chickens including 116 broilers, 27 layers and 26 breeders which collected from 9 healty flock and 21 diseased flock showing necrotic enteritis. Among them, Cl perfringens was isolated from 30 chickens(17.8%) including 7 breeders(26.9%), 5 layers(18.5%) and 18 broilers(15.5%). Isolation of Cl perfringens was mainly from ceca (100%) and followed by small intestines(70.0%) and livers(16.7%), respectively. Average concentration of the pathogen in intestinal contents was $10^{3.8}CFU/g$ in cases occuring necrotic enteritis and on the contrary $10^{3.8}CFU/g$ in healthy cases. All isolates tested showed the same characterstics in biochemical tests compared to those in standard strain. Analysis of gas-liquid chromatography to volatile fatty acids produced by Cl perfringens in PYG broth showed the typical peaks of acetic and butyric acids compatible with the standard chromogram and was confirmed as a effective and reliable tool for rapid identification of the bacteria. Toxin types of 30 strains were mostly classified in A type(26 isolates) and the rest in C type(2 isolates) and unidentifed type(2 isolates). All the isolates were highly susceptible to amphicillin, amoxicillin and cephalothin.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.359-365
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• 1997

Staphylococcus hyicus subsp. hyicus strains isolated from pigs, chickens and cattle were examined for the production of staphylokinase after inhibition of staphylococcal proteases by two procedures with EDTA(disodium). In one, EDTA was added to the bovine fibrin-dog plasminogen agar medium in concentration of 0.07% and paper strips soaked in 2mg/ml soy bean trypsin inhibitor were then applied on the agar plates. In the other, paper strips soaked in 5% EDTA solution were applied on the bovine fibrin-dog plasminogen agar plates and the strains to be tested were then streaked at right angles with the strip. By these procedures, staphylokinase activity was detected in 8(88.9%) of 9 strains from diseased pigs and in 57(80.3%) of 71 strains from skin of healthy pigs, but not in any strains from skin of healthy chickens and milk samples of mastitic cattle. Additionally kinase activity in 9 Staphylococcus species and subspecies isolated from bovine intramammary infections was also tested by these procedures. Staphylokinase activity was detected in 74.2% of Staph aureus strains and in 25% of Staph xylosus strains.

• Korean Journal of Veterinary Service
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• v.33 no.1
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• pp.7-12
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• 2010

There are several immunosuppressive viral diseases in chickens such as avian adenovirus (AAV), chicken anemia virus (CAV), infectious bursal disease (IBD) and Marek's disease (MD). In this study, we have investigated two broiler chicken farms suffered from high mortality in Jeonbuk in July to August 2009. Clinically high fever and growth retardation were observed in the diseased chicken. In necropsy, the hemorrhages in thigh leg and thymus, hemorrhages and enlargement of liver, kidney and proventriculus, and yellowish fluid in heart were seen. Histologically, necrotic foci and basophilic intranuclear inclusion bodies of hepatocytes, hemorrhages and infiltrated lymphocytes in kidney and proventriculus were observed. By using polymerase chain reaction (PCR), the genes of avian adenovirus, CAV and ND virus were detected in specimens. We suggested that these coinfection cases with high mortality were due to primarily infection of immunosuppressive diseases such as avian adenovirus, CAV, followed by secondary infection of Newcastle disease (ND) virus.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.161-166
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• 1997

From January of 1991 to December of 1992, 42 chickens collected from 21 poultry farms and also diagnosed as necrotic enteritis(NE) was examined clinical signs, gross and histopathological findings. Main clinical signs were characterized by decreased appetite, mild to severe depression, reductance to move, ruffled feathers, greenish to yellow-browinish diarrhea sometimes including blood. As progressed, diseased chickens showed feces mixed with necrotic debris which detached from the intestinal mucosa and mostly resulted in the death. In chronic cases, there were dirty feathers around cloaca due to diarrhea and notably retarded growth. Principle gross lesions were usually confined to the jejunum and ileum, especially toward the lower part of Meckel's diverticulum. The part of small intestine was frequently distended with gas, and also showed mucosal congestion and hemorrhages with varying degrees. Sometimes, the intestinal mucosa was thickened, and also covered with fibronecrotic psuedomembrane. In addition, there were focal necrosis and severely multifocal ulcreation in the mucosa of small intestine. Major histopathological findings included villous necrosis and erosion of the small intestine covering with lots of bacterial colonies, inflammatory cell infiltration in the lamina propria, and dilatation and hyperplasia of crypts. Luminal exudate contained bacterial colonies, fibrin, erythrocytes, and desquamated epithelium. Thirteen(61.9%) out of 21 NE-occurring farms were complicated with intestinal coccidiosis.

• Korean Journal of Poultry Science
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• v.46 no.2
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• pp.127-136
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• 2019

Three strains of infectious bronchitis viruses (IBVs), designated VNUA3, VNUA8 and VNUA11, were isolated from diseased/infected chickens in Hanoi, Thainguyen, and Haiphong provinces of Vietnam. These birds had received a live IBV vaccination but still suffered from infectious bronchitis. VNUA3, VNUA8 and VNUA11 harbor cleavage sites (RRTGR, HRRRR, and HRRKR, respectively) within the S protein. A BLASTN search revealed that the S gene of VNUA3, VNUA8, and VNUA11 showed the highest nucleotide identity with those of IBV strains CK/Italy/I2022/13, CK/CH/LHLJ/08-6, and GX-NN120084, respectively. Phylogenetic analyses based on the S gene nucleotide sequences revealed that VNUA3, VNUA8 and VNUA11 clustered with Q1-like, QX-like and TC07-2-like genotypes, respectively, and were closely related to reference IBV strains from China. However, the Vietnam IBVs showed high divergence from vaccine strains 4/91 and Ma5, which are used in the Vietnamese farms from which the isolates were obtained. Taken together, these results indicate that at least three genotypes of IBV are circulating among chickens in North Vietnam. This is the first report of the molecular epidemiology of IBV in Vietnam.