• Title, Summary, Keyword: Verotoxin

Search Result 20, Processing Time 0.053 seconds

Isolation of Escherichia coli O157:H7 from animal feces and biochemical characteristics of Verotoxin-2 produced by these strains I. Study on the phages related to production of Verotoxin-2, and Isolation of Escherichia coli O157:H7 from feces of cattle and pigs (동물분변에서 Escherichia coli O157:H7의 분리 및 이들 균이 생산하는 Verotoxin-2의 생물화학적 특성 I. 소와 돼지의 분변에서 E coli O157:H7의 분리 및 Verotoxin-2 생산에 관여하여 파아지의 분리에 관하여)

  • Cha, In-ho;Kim, Yong-hwan
    • Korean Journal of Veterinary Research
    • /
    • v.36 no.2
    • /
    • pp.371-378
    • /
    • 1996
  • Three and 2 strains of E coli O157 were isolated from fecal materials of cattle (390) and pigs (420) in Korea, respectively. One strain of O157:H7 isolated from cattle and 2 strains of O157:H7 isolated from pigs were identified as verotoxin-1 (VT-1) produing strains and 2 strains (O157:H7 and O157:H-) isolated from cattle were identified as verotoxin-2 (VT-2) producing strains by neutralization test on HeLa and Vero cells. Culture supernatants of the isolates were cytotoxic to HeLa and Vero cells. The levels of cytotoxin produced by isolates were $10^2{\sim}10^4$ cytotoxic dose($CD_{50}$)/ml. Also, VT-2-converting bacteriophage was isolated from KSC109 strain which had been isolated from cattle. Molecular weight of the phage DNA was determined as approximately 45 Kb in 0.8% agarose gel electrophoresis, and morphology of the phage stained with phosphotungstic acid was observed by transmissible electron microscopy.

  • PDF

Characteristics of verotoxin non-producing Escherichia coli O157 and verotoxin-producing E coli isolated from healthy cattle (정상 소 분변에서 분리한 verotoxin을 산생하지 않는 Escherichia coli O157과 verotoxin을 산생하는 E coli의 특성 조사)

  • Jung, Byeong-yeal;Jung, Suk-chan;Park, Hong-je;Cho, Gil-jae;Kim, Bong-hwan
    • Korean Journal of Veterinary Research
    • /
    • v.40 no.3
    • /
    • pp.525-531
    • /
    • 2000
  • Verotoxin non-producing E coli O157 strains have been isolated from cattle feces and compared in particular regard to biochemical properties and genotypes with verotoxin-producing E coli (VTEC). E coli O157 : nonH7 strains had different phenotypes in sorbitol fermentation and ${\beta}-glucuronidase$ activity from E coli O157 : H7. Regardless of verotoxin production ability of E coli O157 : H7, uidA gene was uniquely detected from sorbitol and ${\beta}-glucuronidase$ negative E coli O157 : H7. Forty five fecal samples from 6 dairy farms were obtained and VTEC was detected as 15.6% (7 strains) of the samples. Most VTEC isolates were positive for sorbitol fermentation and ${\beta}-glucuronidase$ activity but negative for eaeA gene. This study suggested that cattle could be a reservior for VTEC. However, absence of eaeA gene in VTEC isolates from most of healthy cattle suggested that they might be less virulent than eaeA-positive E coli against human health.

  • PDF

Isolation of Escherichia coli O157:H7 from animal feces and biochemical characteristics of Verotoxin-2 produced by these strains II. Purification and characterization of Verotoxin-2 Produced by Escherichia coli O157:H7 Isolated from animal feces (동물분변에서 Escherichia coli O157:H7의 분리 및 이들 균이 생산하는 Verotoxin-2의 생물화학적 특성 II. 동물분변에서 분리한 Escherichia coli O157:H7으로부터 Verotoxin-2의 정제 및 특성)

  • Cha, In-ho;Kim, Yong-hwan
    • Korean Journal of Veterinary Research
    • /
    • v.36 no.2
    • /
    • pp.379-387
    • /
    • 1996
  • The objects of the present study were to establish the method of purification, subunit dissociation of verotoxin-2 (VT2) produced by Escherichia coli O157:H7, and to investigate the characteristics of purified verotoxin-2 such as molecular weight and composition of amino acid. The results were summerized as follows; Verotoxin-2 was extracted by addition of polymyxin B sulfate into bacterial cell lysate prepared from Escherichia coli O157:H7(KSC109). As an initial step, the bacterial cell lysate was precipitated with 30% saturated ammonium sulfate. The precipitated crude toxin was then subjected to anion-exchange, chromatofocusing and cation-exchange chromatography. Using this scheme, we obtained highly purified toxin with a specific activity of $1.1{\times}10^9$ $CD_{50}/mg$. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) for purified VT2 showed two protein bands. The upper band, approximately 32 Kd, was supposed as A subunit and the lower band, approximately 7.7 Kd, was supposed as B subunit. When the toxin was separated in the subunit-dissociating solution, two peaks emerged with retention times of 15 and 28 min by HPLC. These peaks represented A subunit and B subunit, respectively. The amino acid composition of purified VT2 were made up in order of glutamic acid, histamine, asparaginic acid, histidine, lysine, alanine and leucine etc. The largest amount among the amino acid composing VT2 was methionine.

  • PDF

Year-round Monitoring of Verotoxin-producing Escherichia coli from Feces of Dairy Cattle

  • Kobayashi, Y.;El-Sawy, H.B.I.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.20 no.5
    • /
    • pp.789-794
    • /
    • 2007
  • A PCR-aided monitoring of verotoxin-producing Escherichia coli (VTEC) was performed over the period of 12 months by using fresh feces collected monthly from 5 dairy cows that had been identified as VTEC carriers. The PCR products were confirmed to be verotoxin genes by Southern hybridization using a gene fragment of verotoxin 2 as a probe. Although seasonal variation of VTEC shedding seemed to depend on each cow, several factors may have influenced the frequency of detection. Shedding of VTEC tended to be reduced during grazing from the middle of May up to the beginning of October. Only one cow was positive for VTEC in August. Dry-off was also suggested to have a depressive effect on VTEC shedding, i.e. 3 of 4 dry cows showed no shedding of VTEC. Contrary to these factors, winter or indoor rearing tended to increase VTEC with only 5/24 samples being negative during the period from November to April. Total VFA concentration was higher (p<0.05) in VTEC-positive feces than in VTEC-negative feces, while fecal pH and VFA proportions were not different. Partial sequences of verotoxin genes from feces of 4 VTEC-positive cows were nearly identical (99-100%), suggesting that gut bacteria sharing the same gene were distributed among the cows. The present results indicate that grazing and dry-off could be factors which reduce VTEC shedding, while winter/indoor rearing may be a factor which increases the shedding, possibly through on-farm interactions.

Charaterization of an Escherichia coli O157:H7 Strain Producing Verotoxin 2Isolated from a Patient in Korea

  • Park, Wan;Sohn, Chang-Kyu;Wan Huh;Kim, Byung-Chun
    • Journal of Microbiology
    • /
    • v.38 no.2
    • /
    • pp.93-98
    • /
    • 2000
  • Nine hundred patients diagnosed with diarrhea or hemorrhagic uremic syndrome in the Kyungpook Province, Korea, were examined from November 1998 to February 2000. One patient in Kumi appeared to possess the Escherichia coli O157:H7 strain, which is very important in clinical decision making and public health action. The isolated strain, an E. coli O157:H7 KM, contained a 60 MDa plasmid and typical virulence genes including the verotoxin 2 gene, ehxA gene (encoding enterohemorrhagic hemolysin), and eae (encoding attaching and effacing protein-intimin) gene. This strain produced only verotoxin 2. Pulsed field gel electrophoretic analysis showed that the genomic organization of the E. coli O157:H7 KM strain may differ greatly from those of representative strains previously reported in the United States and Japan.

  • PDF

Characteristics and antimicrobial susceptibility of Escherichia coli isolated from horse (말에서 분리한 Escherichia coli의 특성 및 항생제 감수성)

  • Yun, Sung-Wook;Kwon, Do-Yeon;Choi, Seong-kyoon;Lee, Hee-Soo;Cho, Gil-Jae
    • Korean Journal of Veterinary Research
    • /
    • v.50 no.3
    • /
    • pp.231-237
    • /
    • 2010
  • This study was conducted to investigate characteristics and antimicrobial susceptibility of Escherichia (E.) coli isolates isolated from vaginal mucosa and clitorial fossa of 105 Thoroughbred mares suspicious of the genital disease in Korea during the period from March 2006 to July 2007. Ninety six E. coli isolates were identified as standard biochemical properties and using BIOLOG system. Fifty three isolates (55.2%) could be classified into a total of 21 O serotypes and forty three isolates (44.8%) were non-typeable with 51 O antisera used in this study. The verotoxin 1 (VT 1) and verotoxin 2 genes were analyzed by multiplex PCR. Among them, one isolate was detected VT 1 gene (130 bp). Most of isolates showed a high susceptibility in ciprofloxacin (100%), enrofloxacin (100%), norfloxacin (100%), cefoxitin (96.9%), gentamicin (96.9%), sulphamethoxazole (96.9%), nitrofurantoin (94.8%), amikacin (93.8%), nalidixic acid (92.7%) and tetracycline (90.6%). These results may provide the basic information to establish strategies for the treatment and prevention of reproductive disease in Thoroughbred mares in Korea.

Characterization of Verotoxin-producing Escherichia coli Isolated from Domestic Foods (국내 유통식품에서 분리된 Verotoxin 생성 Escherichia coli의 특성)

  • Kwak, Hyo-Shun;Cha, Jin;Kwang, Kil-Jin;Kim, Hun;Park, Sun-Hee;Kim, Chang-Min
    • Journal of Food Hygiene and Safety
    • /
    • v.15 no.3
    • /
    • pp.241-247
    • /
    • 2000
  • The incidence of verotoxin-producing Escherichia coli(VTEC) was surveyed in domestic foods including hamburger, raw meats and vegetables from 1997 to 1999. The molecular biological characteristics of the isolates were analyzed. Three VTEC strain were isolated from 1,700 samples. Serotypes of those isolates were 0157 : H7, 026 H4, and 056 : Hl2, respectively. Serotype O26 : H4 produced VT I and VT II, and 055 Hl2 isolate produced VT I, however the 60 MDa plasmid DNA and eae gene were not found from both strains. One 0157 : H7 isolate produced VT II and harbour 60 MDa plasmid DNA, however eae gene was not found in the strain. Although they produced VT, it seemed that the virulence of two strains were relatively weak because of the lack of the eae gene. In addition, the serotype O157 : H7 isolate resistant to ampicillin and streptomycin, while isolates of serotype O26 : H4 and O55 : Hl2 were multi-resistant to antibiotics including ampicillin, carbenicillin , cephalothin, trimethoprim/sulfamethoxazole and tetracycline. Supernatants of cultures of all three isolates were showed cytotoxic effect to vero and HeLa cell

  • PDF

Molecular Detection of Verotoxigenic Escherichia coli (VTEC) from Animal Feces for Screening VTEC-shedders

  • Kobayashi, Y.;Sato, M.;Taguchi, H.;Koike, S.;Nakatsuji, H.;Tanaka, K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.17 no.3
    • /
    • pp.423-427
    • /
    • 2004
  • Seventy-six animals including cattle, sheep, horses, 6 species of zoo animals were employed for collection of fresh feces in order to detect verotoxigenic Esherichia coli (VTEC) by safe, quick and sensitive PCR-based molecular methods. Bacterial cell disruption with bead-beating followed by bacterial DNA purification with hydroxyapatide chromatography and gel filtration allowed DNA preparation from animal feces with high recovery and purity. A mountain goat was firstly shown by PCR and sequencing to shed verotoxin 2 gene (vt2) that was used to generate vt2 probe and second primer set for nested PCR to attempt more sensitive detection. Most sensitive nested PCR revealed that 45% of tested cattle and 47% of tested zoo animals were VTEC-positive, while least sensitive normal PCR detected VTEC from none of these animals except a mountain goat. Moderately sensitive detection by PCR in combination with hybridization suggested that the VTEC density varied between the VTEC-positive cattle.

Phenotypic characteristics and antimicrobial susceptibility of verotoxin -producing E coli from slaughtered cattle

  • Byun Jae-Won;Kim Kyoung-Ho;Lee Sung-Mo;Hwang Hyun-Soon;Kim Yong-Hee
    • Korean Journal of Veterinary Service
    • /
    • v.28 no.4
    • /
    • pp.407-412
    • /
    • 2005
  • Ten isolates of Verotoxin-producing Escherichia coli (VTEC) were detected in slaughtered cattle and investigated their phenotypic characteristics and antimicrobial susceptibility. None of the isolates was positive for eae gene. Only one isolate was positive for uidA gene. Eight out of ten isolates of VTEC were originated from broker's cattle. Thus microbiological monitoring for broker farms should be performed to minimize VTEC contamination. In the antimicrobial susceptibility test, all the isolates were highly resistant to bacitracin and lincomycin whilst they are susceptible to apramycin and neomycin.