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Evaluation of a live avirulent Escherichia coli vaccine for K88+, LT+ enterotoxigenic colibacillosis in weaned pigs.
1991
Francis D.H. | Willgohs J.A.
Live, avirulent Escherichia coli vaccine strains were constructed and tested for efficacy in preventing colibacillosis in 4-week-old pigs. Either or both of 2 plasmids were inserted into avirulent E coli strain G58-1 (0101:NM). These plasmids were pPMC4, which encodes for LTb subunits of heat-labile enterotoxin, and pDHF1, which encodes for K88ac fimbriae. Litter- and weight-matched pigs were removed from sows when they were 10 days old and vaccinated orally with the constructed strains or with G58-1 (negative control vaccine) when they were 2 weeks old and 5 days later. All pigs were challenge-inoculated with virulent E coli strain 3030-2 (0157:K88, LT+, STb+) 2 weeks after the first vaccination. Only 1 pig vaccinated with G58-1/pPMC4/pDHF1 developed diarrhea and none died following challenge inoculation. Seventeen of 31 control pigs developed diarrhea and 11 died. Of 18 pigs vaccinated with G58-1/pDHF1 then challenge-inoculated with the virulent strain, 5 developed diarrhea and 2 died. Fifteen of 18 litter- and weight-matched controls developed diarrhea and 8 died. When compared with G58-1 (negative control), G58-1/pPMC4 afforded no protection to pigs challenge-inoculated with 3030-2.
Afficher plus [+] Moins [-]Linkage of serum resistance, aerobactin production, and resistance to antimicrobial agents on conjugal plasmids in some strains of Escherichia coli isolated from septic foals.
1993
Hirsh D.C. | Kirkham C. | Wilson W.D.
Fifteen isolates of Escherichia coli obtained from the blood and tissues of septic foals had plasmid DNA of size ranging from 2.5 to 93 megadaltons. These isolates grew in normal equine serum (serum resistant), a trait previously documented to be expressed by isolates obtained from blood and tissues of septic foals, but not by isolates obtained from the feces of clinically normal horses. Of these isolates, 3 contained conjugal plasmids that encoded resistance to multiple antimicrobial agents linked to serum resistance and, in 1 isolate, to production of aerobactin as well. Serum resistance and production of aerobactin are related to virulence of septicemic E coli from non-equine sources.
Afficher plus [+] Moins [-]Association between the effacing (eae) gene and the Shiga-like toxin-encoding genes in Escherichia coli isolates from cattle.
1993
Mainil J.G. | Jacquemin E.R. | Kaeckenbeeck A.E. | Pohl P.H.
Two hundred ninety-six Eschericbia coli isolates from feces or intestines of calves with diarrhea were hybridized with 7 gene probes. One probe (the eae probe) was derived from the eae gene coding for a protein involved in the effacement of the enterocyte microvilli by the group of bacteria called attaching and effacing E coli (AEEC), and 2 probes were derived from genes coding for the Shiga-like toxins (SLT) 1 and 2 produced by the verocytotoxic E coli (VTEC). The other 4 probes were derived from DNA sequences associated with the adhesive properties of enteroadherent E coli (EAEC) to cultured cells (the EAF probe for the localized adherence pattern, probes F1845 and AIDA-1 for the diffuse adherence pattern, and the Agg probe for the aggregative adherence pattern). Hybridization results for the eae probe were in agreement, for all but 1 of the 8 isolates, with previously published phenotypic results of microvilli effacement. The latter was previously reported as effacing the microvilli of calf enterocytes, but was eae probe-negative. Two classes of isolates hybridized with the eae probe. Members of a first class (60 isolates) additionally produced a positive signal with 1 or both of the SLT probes (VTEC-AEEC isolates). Isolates hy- bridizing with the eae and the SLT1 probes were the most frequent: 56 isolates (ie, 93% of all VTEC-AEEC). Members of the second class (10 isolates) failed to hybridize with either SLT probe (non-VTEC-AEEC isolates). Most isolates of these 2 classes belong to only 4 serogroups: O5, O26, O111, and O118. In addition to these 2 AEEC classes, a VTEC class (20 isolates) was observed. Such isolates were positive with 1 or both SLT probes, but were negative with the eae probe. All but 1 isolate belonged to serogroups not found among the AEEC isolates. Only 7 of all AEEC and VTEC isolates were positive with the EAF, the F1845, or the AIDA-1 probe, and none were positive with the Agg probe. On the other hand, 32 non-VTEC, non-AEEC isolates were po.
Afficher plus [+] Moins [-]Genetic properties of R plasmids in Salmonella isolates of swine and bovine origin in Korea., 2; incompatibility and profile of R plasmid.
1989
Choi W.P. | Lee H.S. | Yeo S.G. | Lee H.J. | Jung S.C.
This paper deals with the genetic properties of R plasmids in Salmonella originated from pigs and cattle. The plasmid DNA was examined for incompatibility, stability and fertility inhibition (F1), and gel electrophoresis was performed for isolation of plasmid DNA. Among the 66 conjugative R plasmids from 44 pigs and 22 cattle, 61 R plasmids (92.4 %) were Fi-, whereas the remainder were Fi+. The Inc groups of 66 R plasmids were determined with 7 standard plasmids. Twenty-six R plasmids were classified into Inc group Ialpha, H1, H2 or F1, 40 R plasmids being not classified with standard plasmids used, and the Inc group Ialpha (57.7 %) was most frequent. 3. Inc groups Ialpha H1, and F1 were identified in strains from swine, Inc groups H2 and F1 from cattle. The plasmid DNA profiles in 16 Salmonella isolated from pigs and cattle were confirmed as being 1 to 10 fragments by the gel eletrophoresis. Their molecular weight ranged 1.0 to 90 megadalton. The molecular weight of conjugative plasmids ranged 1.0 to 80 megadalton in 4 Salmonella (P-4, P-5, P-7 and P-8) isolated from pigs.
Afficher plus [+] Moins [-]Genetic properties of R plasmids in Shigella isolates of swine origin in Korea.
1989
Choi W.P. | Kwon H.B. | Jung S.C.
This paper dealt wih the distribution of Shigella spp. on 5 piggeries in Taegu and Kyongbuk during the period from August to October 1987. Isolated Shigella were examined for serogrouping, antimicrobial drug resistance and detection of R plasmid. Genetic properties of R plasmid in Shigella were examined for fertility inhibition (F1) and gel electrophoresis was performed for the isolation of plasmid DNA. Of total 2,978 samples from 5 piggeries, 82 strains (2.8 %) of Shigella spp. were isolated from 82 samples. The isolated strains were identified as S. dysenteriae (60 strains), S. flexneri (20 strains) and S. sonnei (2 strains). Of the 82 strains examined 67 (95.1 %) were resistant to one or more antibiotics, such as ampicillin (Am), chloramphenicol (Cm), kanamycin (Km), nalidixic acid (Na), rifampicin (Rf), streptomycin (Sm), sulfademethoxine (Su), and tetracycline (Tc) and higher resistance to Su (90.2 %), Sm (63.4 %) and Tc (63.4 %). Of the 78 resistant Shigella strains 26 (33.3 %) harbored conjugative R plasmids and the transfer frequency of Sm (50.0 %), Cm (33.3 %) resistance was much higher than that of the other drug resistance. The most common resistant patterns were SmSuTc, Su and AmSmSuTc. Out of the 26 Shigella R plasmids examined for Fi, 14 (53.8 % were Fi + and the remainder were Fi-. The plasmid DNA profiles in Shigella spp. (9 strains) isolated from pigs were confirmed as being 2 to 9 fragments by the gel electrophoresis. Their molecular size ranged 2.17 to 87.62 kilobase (Kb). All strains of Shigella spp. consisted in 15.4 Kb plasmids.
Afficher plus [+] Moins [-]Genetic properties of R plasmids in Salmonella isolates of swine and bovine origin in Korea, 1. Distribution and drug resistance of Salmonella isolated from dairy cow.
1988
Choi W.P. | Lee H.S. | Chae T.C. | Yeo S.G. | Lee H.J.
This paper deals with the distribution of Salmonella (S) infection on 4 herds in Kyungju and Taegu during the period from May to October 1986. Isolated Salmonella were examined for serotypes, antimicrobial drug resistance and detection of R plasmid. From 4 herds, 67 Salmonella were isolated from 51 samples (1.1%), and their serovar strains were S. typhimurium 6, S. derby 5, S. infantis 4, S. bareilly 4, S. dublin 3, S. anatum 2, S. montevideo 2 and untypable 41. In 4 herds, the incidence of drug resistance was 57.7-100% and transfer frequency of conjugative R plasmid was 96.1-100%.
Afficher plus [+] Moins [-]Development of a real-time TaqMan PCR assay for the detection of porcine circovirus 4 Texte intégral
2022
Chen, Wanting | Jiang, Dike | Xiao, Lü | Zhang, Pengfei | Luo, Yan | Yang, Zexiao | Yao, Xueping | Wang, Yin | Wu, Xulong
Development of a real-time TaqMan PCR assay for the detection of porcine circovirus 4 Texte intégral
2022
Chen, Wanting | Jiang, Dike | Xiao, Lü | Zhang, Pengfei | Luo, Yan | Yang, Zexiao | Yao, Xueping | Wang, Yin | Wu, Xulong
Porcine circovirus 4 (PCV4) was first discovered in 2019 in a herd of pigs with porcine respiratory disease, dermatitis and nephropathy syndrome in Hunan Province, China. It has subsequently been detected in other provinces and in South Korea. In consideration of the potential of the virus to cause an epidemic, rapid, sensitive, and specific detection of PCV4 is needed, as is the facilitation of further epidemiological research through elucidation of the whole genome of PCV4. This study had those two aims. Fifty-five blood samples, two pig tissue samples, nine saliva swabs and one semen sample which all originated from Sichuan province pig farms were analysed. The virus’ genome of 1,770 bp was synthesised artificially based on a Chinese reference strain and primers and probes for the ORF2 gene were designed. Then, the amplified target fragment was cloned into the pMD19-T vector and a series of diluted recombinant plasmids were used to generate a standard curve. An optimised real-time TaqMan PCR method was established. The results of this study showed that the established method is specific for PCV4 but not for other viruses, and has amplification efficiency of 99.6%, a regression squared value (R²) of 1.000 and a detection limit of 2.2×10 DNA copies. This method was shown to be analytically specific and sensitive with a low intra- and inter-assay coefficient of variation (<1.67 %). Of a total of 67 clinical samples tested using the established method, three were shown to be positive (4%). This study confirms the existence of PCV4 in Sichuan and provides a promising alternative tool for rapid detection of PCV4.
Afficher plus [+] Moins [-]Development of a real-time TaqMan PCR assay for the detection of porcine circovirus 4 Texte intégral
2022
Chen Wanting | Jiang Dike | Xiao Lu | Zhang Pengfei | Luo Yan | Yang Zexiao | Yao Xueping | Wang Yin | Wu Xulong
Porcine circovirus 4 (PCV4) was first discovered in 2019 in a herd of pigs with porcine respiratory disease, dermatitis and nephropathy syndrome in Hunan Province, China. It has subsequently been detected in other provinces and in South Korea. In consideration of the potential of the virus to cause an epidemic, rapid, sensitive, and specific detection of PCV4 is needed, as is the facilitation of further epidemiological research through elucidation of the whole genome of PCV4. This study had those two aims.
Afficher plus [+] Moins [-]In vitro evaluation of chitosan-DNA plasmid complex encoding Jembrana disease virus Env-TM protein as a vaccine candidate Texte intégral
2019
Ishak, Januar | Unsunnidhal, Lalu | Martien, Ronny | Kusumawati, Asmarani
In vitro evaluation of chitosan-DNA plasmid complex encoding Jembrana disease virus Env-TM protein as a vaccine candidate Texte intégral
2019
Ishak, Januar | Unsunnidhal, Lalu | Martien, Ronny | Kusumawati, Asmarani
Introduction: The development of Jembrana disease vaccine is an important effort to prevent losses in the Bali cattle industry in Indonesia. This study aims to prepare a Jembrana DNA vaccine encoding the transmembrane portion of the envelope protein in pEGFP-C1 and test the success of its delivery in culture cells using a chitosan-DNA complex. Material and Methods: Cloning of the DNA vaccine was successfully performed on E. coli DH5α and confirmed by colony PCR, restriction analysis and sequencing. The plasmids were prepared as a chitosan complex using the complex coacervation method and physicochemically characterised using a particle size analyser. A transfection assay was performed in HeLa cells with 4 h exposure, and mRNA expression was assessed at 24 h post transfection. Results: With a 1:2 (wt./wt.) ratio of DNA and chitosan, the complexes have a mean diameter of 236 nm, zeta potential value of + 17.9 mV, and showed no high toxicity potential in the HeLa cells. This complex successfully delivered the DNA into cells, as shown by the presence of a specific RT-PCR product (336 bp). However, the real-time PCR analysis showed that the delivery with chitosan complex resulted in lower target mRNA expression when compared with a commercial transfecting agent. Conclusion: pEGFP-env-tm JDV as a candidate vaccine can be delivered as the chitosan-DNA complex and be expressed at the transcription level in vitro. This initial study will be used for further improvement and evaluation in vivo.
Afficher plus [+] Moins [-]In vitro evaluation of chitosan-DNA plasmid complex encoding Jembrana disease virus Env-TM protein as a vaccine candidate Texte intégral
2019
Ishak Januar | Unsunnidhal Lalu | Martien Ronny | Kusumawati Asmarani
Introduction: The development of Jembrana disease vaccine is an important effort to prevent losses in the Bali cattle industry in Indonesia. This study aims to prepare a Jembrana DNA vaccine encoding the transmembrane portion of the envelope protein in pEGFP-C1 and test the success of its delivery in culture cells using a chitosan-DNA complex.
Afficher plus [+] Moins [-]Evaluation of real-time PCR based on SYBR Green I fluorescent dye for detection of Bacillus anthracis strains in biological samples Texte intégral
2018
Kędrak-Jabłońska, Agnieszka | Budniak, Sylwia | Szczawińska, Anna | Reksa, Monika | Krupa, Marek | Szulowski, Krzysztof
Evaluation of real-time PCR based on SYBR Green I fluorescent dye for detection of Bacillus anthracis strains in biological samples Texte intégral
2018
Kędrak-Jabłońska, Agnieszka | Budniak, Sylwia | Szczawińska, Anna | Reksa, Monika | Krupa, Marek | Szulowski, Krzysztof
Introduction: The aim of the study was the application and evaluation of real-time PCRs based on the fluorescence of SYBR Green I intercalating dye for the detection of three Bacillus anthracis genes in contaminated liver and blood samples. The goals for detection were rpoB gene as a chromosomal marker, pag gene located on plasmid pXO1, and capC gene located on plasmid pXO2. Material and Methods: Five B. anthracis strains were used for the experiments. Additionally, single strains of other species of the genus Bacillus, i.e. B. cereus, B. brevis, B. subtilis, and B. megaterium, and strains of six other species were used for evaluation of the specificity of the tests. Three SYBR Green I real-time PCRs were conducted allowing confirmation of B. anthracis in the biological samples. Results: The observation of amplification curves in real-time PCRs enabled the detection of the chromosomally encoded rpoB gene, pag gene, and capC gene of B. anthracis. The specificity of the tests was confirmed by estimation of the melting temperature of the PCR products. The sensitivity and linearity of the reactions were determined using regression coefficients. Strains of other microbial species did not reveal real-time PCR products. Conclusion: All real-time PCRs for the detection of B. anthracis in biological samples demonstrated a significant sensitivity and high specificity.
Afficher plus [+] Moins [-]Evaluation of real-time PCR based on SYBR Green I fluorescent dye for detection of Bacillus anthracis strains in biological samples Texte intégral
2018
Kędrak-Jabłońska Agnieszka | Budniak Sylwia | Szczawińska Anna | Reksa Monika | Krupa Marek | Szulowski Krzysztof
Introduction: The aim of the study was the application and evaluation of real-time PCRs based on the fluorescence of SYBR Green I intercalating dye for the detection of three Bacillus anthracis genes in contaminated liver and blood samples. The goals for detection were rpoB gene as a chromosomal marker, pag gene located on plasmid pXO1, and capC gene located on plasmid pXO2.
Afficher plus [+] Moins [-]Isolation and characterisation of peroxiredoxin 6 promoter from sheep (Ovis aries) Texte intégral
2016
Liu, Nan-Nan | Liu, Zeng-Shan | Lu, Shi-Ying | Hu, Pan | Zhang, Ying | Fu, Bao-Quan | Li, Yan-Song | Zhou, Yu | Zhang, Yu | Ren, Hong-Lin
Isolation and characterisation of peroxiredoxin 6 promoter from sheep (Ovis aries) Texte intégral
2016
Liu, Nan-Nan | Liu, Zeng-Shan | Lu, Shi-Ying | Hu, Pan | Zhang, Ying | Fu, Bao-Quan | Li, Yan-Song | Zhou, Yu | Zhang, Yu | Ren, Hong-Lin
Introduction: Peroxiredoxin 6 (Prdx6) is a bifunctional protein and a unique 1-Cys Prdx of the peroxiredoxin family. The expression and regulation of Prdx6 are implicated in numerous physiological and pathological processes.Material and Methods: Eight stepwise truncated DNA fragments obtained from the 5′-flank region of the Prdx6 gene were prepared and subcloned into the pSEAP2-Enhancer vectors. To investigate the transcriptional activity of the truncated DNA fragments, the recombinant plasmids were transfected into the COS-1 cells and the transcriptional activity was measured via assaying the expression of the reporter gene of the secreted alkaline phosphatase.Results: A 3.4 kb 5′-upstream flank region of the Prdx6 gene was cloned and sequenced. The region from −108 nt to −36 nt of the 5′-flanking region of the Prdx6 gene contained basal transcriptional activity.Conclusion: This result provides the basis for further studies on the gene regulation of the Prdx6-mediated biological processes and on screening for the transacting factors that interact with cis-acting elements of the Prdx6 gene promoter.
Afficher plus [+] Moins [-]Isolation and characterisation of peroxiredoxin 6 promoter from sheep (Ovis aries) Texte intégral
2016
Liu Nan-Nan | Liu Zeng-Shan | Lu Shi-Ying | Hu Pan | Zhang Ying | Fu Bao-Quan | Li Yan-Song | Zhou Yu | Zhang Yu | Ren Hong-Lin
Introduction: Peroxiredoxin 6 (Prdx6) is a bifunctional protein and a unique 1-Cys Prdx of the peroxiredoxin family. The expression and regulation of Prdx6 are implicated in numerous physiological and pathological processes.
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