S.-K. Ha

Prevalence of a Gene Encoding Adhesin Involved in Diffuse Adherence among Escherichia Coli Isolates in Pigs with Postweaning Diarrhea or Edema Disease

A total of 604 Escherichia coli strains isolated from weaned pigs with diarrhea or edema disease on 653 swine farms were screened for the presence of the adhesin involved in diffuse adherence (AIDA) gene by polymerase chain reaction (PCR). Escherichia coli isolates that carried AIDA genes were also tested by PCR for the detection of 5 fimbriae (F4, F5, F6, F18, and F41), 3 heat-stable (STa, STb, and EAST1) and 1 heat-labile (LT) enterotoxin, and Shiga toxin 2e (Stx2e) genes. Forty-five (7.5%) of the 604 E. coli isolates carried the gene for AIDA. Of these 45 isolates, 5 (11.1%) carried EAST1 genes only, 1 (2.2%) carried genes for at least one of the fimbrial adhesins, 12 (26.7%) carried genes for at least one of the toxins, and 27 (60%) carried genes for at least one of the fimbrial adhesins and toxins. Fifty-one percent of strains that carried AIDA genes carried Stx2e genes, and 40% of strains that carried AIDA genes carried F18ab. The isolation rate of enterotoxigenic E. coli strain carrying genes for AIDA was 87%, and the isolation rate of Shiga toxin-producing E. coli strain carrying genes for AIDA was 49%. AIDA may represent an important virulence determinant in pigs with postweaning diarrhea or edema disease.

Role of AMP-activated Protein Kinase and Adiponectin during Development of Hepatic Steatosis in High-fat Diet-induced Obesity in Rats

Obesity, an abnormal condition of adipose tissue, has recently been recognized as a major cause of metabolic syndromes, especially non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to examine the possible involvement of adipokines in the development of fatty liver. Sprague-Dawley (SD) rats fed a high-fat (HF) diet for 15 weeks developed increased hepatocellular vacuolation, hepatic triglyceride (TG) content and serum TG, total cholesterol and free fatty acid levels, with increases in adipose tissue mass. The serum concentration of adiponectin decreased slightly in these animals. Western blotting analysis demonstrated a decrease in the levels of AMP-activated protein kinase (AMPK) and phosphorylated-AMPK in the livers of these rats. These results indicate similarities between the diet-induced obesity rat model of NAFLD and human NAFLD, thus making the rat a useful model for the further study of NAFLD, including the interactions between adipokines and hepatic fat metabolism.

Detection and isolation of H1N1 influenza virus from pigs in Korea

neoplastic mesothelial cells and macrophages was not possible cytomorphologically. In this report, ultrasonography proved to be a useful tool for diagnosis as well as prognosis. The ascites and nodular lesions could be clearly imaged and, together with the results of abdominocentesis, allowed a tentative diagnosis of neoplasia. Non-inflammatory ascites due to other disorders (Braun 1997, Milne and others 2001), such as right-sided cardiac insufficiency, thrombosis of the caudal vena cava and portal hypertension, could be ruled out in this case based on the results of the clinical and ultrasonographic findings. The differential diagnosis also included other tumours, such as carcinoma and sarcoma (Barker 1993), serosal tuberculosis and fat necrosis. The diagnosis could easily have been confirmed intra vitam by means of transcutaneous ultrasoundguided biopsy of the nodules; however, the condition and prognosis of the cow precluded this procedure.

Identification of porcine circovirus type 2 in retrospective cases of pigs naturally infected with porcine epidemic diarrhoea virus

Abstract The identification of porcine circovirus type 2 (PCV2) was studied in fresh intestinal tissues by polymerase chain reaction (PCR) and in formalin-fixed, paraffin-wax-embedded intestinal tissues by in situ hybridisation. The tissues came from pigs naturally infected with porcine epidemic diarrhoea virus (PEDV). A total of 35 (32.7%) of 107 small intestinal samples from pigs naturally infected with PEDV were found to be positive using PCR. Positive signals for PCV2 were detected in 32 (29.9%) of 107 small intestinal samples from pigs naturally infected with PEDV by in situ hybridisation. The distribution of positive cells in the jejunum and ileum was multifocal or patchy. Distinct positive labelling was found throughout the lamina propria in the small intestines. The results of this study indicate that PCV2 is highly prevalent in pigs naturally infected with PEDV.

Development of an optimized protocol for the detection of classical swine fever virus in formalin-fixed, paraffin-embedded tissues by seminested reverse transcription-polymerase chain reaction and comparison with in situ hybridization

Abstract An optimized protocol was developed for the detection of classical swine fever virus (CSFV) in formalin-fixed, paraffin-embedded tissues obtained from experimentally and naturally infected pigs by seminested reverse transcription-polymerase chain reaction (RT-PCR). The results for seminested RT-PCR were compared with those determined by in situ hybridization. The results obtained show that the use of deparaffinization with xylene, digestion with proteinase K, extraction with Trizol LS, followed by seminested RT-PCR is a reliable detection method. An increase in sensitivity was observed as amplicon size decreased. The highest sensitivity for RT-PCR on formalin-fixed, paraffin-embedded tissues RNA was obtained with amplicon sizes less than approximately 200 base pairs. An hybridization signal for CSFV was detected in lymph nodes from 12 experimentally and 12 naturally infected pigs. The sensitivity of seminested RT-PCR compared with in situ hybridization was 100% for CSFV. When only formalin-fixed tissues are available, seminested RT-PCR and in situ hybridization would be useful diagnostic methods for the detection of CSFV nucleic acid.

Polymerase Chain Reaction Analysis of Eae Gene Subtypes Present in Attaching and Effacing Escherichia Coli Isolated from Pigs with Diarrhea

In this study the subtype of eae gene was determined by polymerase chain reaction for a total of 59 attaching and effacing Escherichia coli isolated from preweaned (38 isolates) and postweaned (21 isolates) pigs. The eae β gene detected in 19 E. coli from preweaned pigs and 10 E. coli from postweaned pigs was found to be the most common subtype, followed by eae γ, eaeε, and eae ζ genes. Subtypes were not determined for 7 E. coli isolates. No other subtype of the eae gene was detected in eae + E. coli evaluated in this study.

Prevalence of tir gene subtypes in Escherichia coli isolates from pigs

ATTACHING and effacing Escherichia coli (aeec) are characterised by their capacity to infect intestinal epithelial cells, resulting in attaching and effacing (ae) lesions. ae histopathology is characterised by intimate adherence of the bacteria to enterocytes and disruption of the underlying