Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twenty-one Escherichia coli O157:H7 strains isolated in northern Italy from sporadic cases of hemolytic-uremic syndrome and from cattle and food were characterized by virulence gene analysis, pulsed-field gel electrophoresis (PFGE) of XbaI-digested DNA, enterobacterial repetitive intergenic consensus (ERIC) sequence-based PCR (ERIC-PCR), and antibiotic resistance patterns and compared to 18 strains isolated in France from human cases of diarrhea, cattle, and the environment. Strains isolated in Sicily (southern Italy) from a local farm (one strain) and from calves just imported from France (11 strains) and Spain (six strains) were also typed. Whereas the eae and hlyA genes were always detected, Shiga toxin gene (stx) analysis showed some differences related to geographic areas. Isolates from northern Italy showed a high frequency of stx(1) and stx(2), while strains isolated in France and from French and Spanish calves imported to Sicily more frequently possessed the stx(2c) gene. The majority of the strains isolated in northern Italy were also resistant to one or more antibiotics, while most of the strains isolated in France and Sicily were fully susceptible. ERIC-PCR analysis was not able to differentiate the strains. PFGE typing after XbaI DNA digestion produced a total of 54 distinct restriction endonuclease digestion profiles (REDPs) among the 57 strains. Phylogenetic analysis was unable to cluster REDPs according to geographic origin. All epidemiologically related isolates showed either identical or >/=91% similar REDPs. Our findings suggest a peculiar circulation of antibiotic-resistant, genetically unrelated strains in northern Italy.
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PMID:Characterization of Shiga toxin-producing Escherichia coli O157:H7 isolated in Italy and in France. 1245 62

A structure sequence and a DNA fragment including the signal peptide sequence and structure sequence of Shiga-like toxin II variant B subunit gene were amplified from E. coli strain O138 by PCR. After digested with restriction endonuclease EcoRI and BamHI, the two genes were orientally inserted into the polycloning site of expression vector pYA3334 (asd+) respectively. Recombinant plasmids pB0 and pB1 were constructed and amplified in E. coli X6212 (asd-). pB0 and pB1 were then introduced into avirulent Salmonella typhimurium vaccine strain X4550 (asd-) by serial transformation through intermediate strain X3730 (asd-) to construct recombinant SLT-IIvB strain. Results of nucleotide sequencing of the cloned fragments in pB0 and pB1 revealed that they were in correct ORF of SLT-IIvB. The results of SDS-PAGE and Western-blot showed that 7.6 kD protein of SLT-IIvB antigen was expressed at pretty high level in recombinant strain X4550(pB0). The results of mice immunization indicated X4550(pB0) could initiate the host to produce specific antibodies to SLT-IIvB and LPS-O antigen of X4550. So the recombinant strain X4550 (pB0) is worth considering as a candidate vaccine strain against porcine edema disease and Salmonella typhimurium infections.
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PMID:[Cloning and expression of Shiga-like toxin type II variant B gene of E. coli]. 1254 52

Of 220 Shiga toxin-producing Escherichia coli (STEC) strains collected in central France from healthy cattle, food samples, and asymptomatic children, 12 possessed the eae gene included in the locus of enterocyte effacement (LEE) pathogenicity island. Based on gene typing, we observed 7 different eae espA espB tir pathotypes among the 12 STEC strains and described the new espAbetav variant. As previously observed, the O157 serogroup is associated with eaegamma, O26 is associated with eaebeta, and O103 is associated with eaeepsilon. However, the unexpected eaezeta allele was detected in 5 of the 12 isolates. PCR amplification and pulsed-field gel electrophoresis using the I-CeuI endonuclease followed by Southern hybridization indicated that the LEE was inserted in the vicinity of the selC (three isolates), pheU (two isolates), or pheV (six isolates) tRNA gene. Six isolates harbored two or three of these tRNA loci altered by the insertion of integrase genes (CP4-int and/or int-phe), suggesting the insertion of additional foreign DNA fragments at these sites. In spite of great genetic diversity of LEE pathotypes and LEE insertion sites, bovine strains harbor alleles of LEE genes that are frequently found in clinical STEC strains isolated from outbreaks and sporadic cases around the world, underscoring the potential risk of the bovine strains on human health.
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PMID:Localization of the insertion site and pathotype determination of the locus of enterocyte effacement of shiga toxin-producing Escherichia coli strains. 1471 26

Caecum samples collected from 653 slaughtered sheep from two Swiss abattoirs were examined. The aim of this study was: (i) to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC), Salmonella spp. and Campylobacter spp.; (ii) to further characterize isolated strains; and (iii) to discuss the results obtained with their relevance to food safety. The percentage of samples testing positive for STEC by a polymerase chain reaction was 29.9%. The prevalence of positive Salmonella spp. samples was 11.0% and of Campylobacter spp. 17.5%. In 55.3% of the 76 isolated non-O157 STEC strains, stx2 variants (mostly stx2d) were detected. Additional virulence factors were harbored by 55.3% of the STEC strains, 10.5% of them being eae positive, 55.3% ehxA positive and 2.6% astA positive. All isolated salmonella were identified as Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7). Pulsed-field gel electrophoresis (PFGE) was performed for genotyping and 22 different restriction endonuclease digestion profiles were found among these strains for the different farms of origin. Of the 114 isolated Campylobacter spp. strains, 64.9% were shown to be Campylobacter jejuni and 35.1% Campylobacter coli, nine strains showed resistance against tetracycline, ciprofloxacin/nalidixic acid or streptomycin. In conclusion, sheep are a reservoir for the pathogens of latent zoonoses as non-O157 STEC, S. enterica subsp. diarizonae and Campylobacter spp. The maintenance of slaughter hygiene is consequently of crucial importance. It can be measured in daily practice by "slaughter-process-controls" and regular microbiological monitoring of carcasses. These are valuable tools for verifying slaughter hygiene according to hazard analysis critical control point principles.
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PMID:Prevalence and characteristics of Shiga toxin-producing Escherichia coli, Salmonella spp. and Campylobacter spp. isolated from slaughtered sheep in Switzerland. 1503 67

Phenotypic and genetic markers of Shiga toxin-producing Escherichia coli (STEC) O26 from North America were used to develop serotype-specific protocols for detection of this pathogen. Carbohydrate fermentation profiles and prevalence of gene sequences associated with STEC O26 (n = 20) were examined. Non-STEC O26 (n = 17), E. coli O157 (n = 20), E. coli O111 (n = 22), and generic E. coli (n = 21) were used as comparison strains. Effects of supplements: cefixime-tellurite, 4-methylumbelliferyl-beta-D-glucuronide (MUG) and chromogenic additives (5-bromo4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal), 5-bromo-4-chloro-3-indolyl-beta-D-glucuronide (X-GlcA) and o-nitrophenyl-beta-D-galactopyranoside (ONPG), added to isolation agar media were examined. Tests for presence of gene sequences encoding beta intimin (eae beta), Shiga toxin 1 and 2 (stx1 and stx2), H7 flagella (flicCh7), enterohemolysin (ehlyA), O26 somatic antigen (wzx), and high pathogenicity island genes (irp2 and fyuA) were conducted using multiplex polymerase chain reaction. Pulsed-field gel electrophoresis (PFGE) of XbaI restriction endonuclease genomic DNA digests was used to establish clonality among E. coli O26 strains. Of the 26 carbohydrates tested, only rhamnose had diagnostic value. Rhamnose non-fermenters included STEC O26 (100%), non-STEC O26 (40%), generic E. coli (29%), E. coli O111 (23%), and E. coli O157 (0%). Rhamnose non-fermenting colonies growing on Rhamnose-McConkey agar supplemented with X-GlcA, X-Gal, or ONPG, respectively, were blue, white, or faint yellow, whereas rhamnose-fermenters were red. Blue colonies from X-GlcA-containing media were the most well-defined and easiest to pick for further tests. All STEC O26 were MUG-fluorescent, while STEC O157 (n = 18) were non-fluorescent. E. coli O111 and generic E. coli strains were either MUG-positive or-negative. Serotype-specific detection of STEC O26 was achieved by selecting cefixime-tellurite-resistant, MUG-fluorescent, rhamnose-nonfermenting colonies, which carried stx1, eae beta, irp2, and wzx gene sequences. STEC O26 prevalence in dairy farm environmental samples determined using the developed isolation and genetic detection protocols was 4%. PFGE indicated the presence of one major cluster of E. coli O26 with 72-100% DNA fragment-length digest similarity among test strains. The serotype-specific detection methods described herein have potential for routine application in STEC O26 diagnosis.
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PMID:Phenotypic and genetic markers for serotype-specific detection of Shiga toxin-producing Escherichia coli O26 strains from North America. 1599 72

Restriction endonuclease fragment length polymorphism (RFLP) is useful for the epidemiological study of herpes simplex virus type 1 (HSV-1). We report here the identification of a major BglII RFLP variant of HSV-1, designated BgKL, found in 27.0% of 636 HSV-1 clinical isolates. We have also established its geographic distribution in Japan. BgKL has an unusually large BglII K fragment. SalI cleavage analyses showed that 97% of BgKL variant isolates lack both the SalI C-J and the F-J cleavage sites and have an unusually large SalI D or E fragment, and 91% of the BgKL variants lack both SalI G and H fragments. Furthermore, 96% of BgKL isolates have an unusually small KpnI M fragment. Therefore, BgKL is a marker for these five mutations in most HSV-1 isolates and is a useful HSV-1 RFLP marker. The BgKL variant was found in 59% of HSV-1 isolates from Shikoku Island, 44% of HSV-1 isolates from the Chugoku region of Honshu Island, 31% of HSV-1 isolates from Kyushu Island, 0% of HSV-1 isolates from Okinawa Island, 49% of HSV-1 isolates from Osaka, 27% of HSV-1 isolates from Shiga, 13% of HSV-1 isolates from the Chubu Region, and 9% of HSV-1 isolates from the Tohoku Region of Honshu Island. Differences in the frequency of BgKL between the Shikoku-Chugoku-Osaka area (49%) and Kyushu, between Kyushu and Okinawa, between the Shikoku-Chugoku-Osaka area and Shiga, and between Shiga and Tohoku are all statistically significant. The BgKL frequency decreases in a geographical gradient suggest that this HSV-1 variant was dispersed from Shikoku to the surrounding regions and then to more distant regions. The BgKL frequency in Tokyo was similar to the nationwide average. These are the first data to suggest a geographic and demographic dispersion pattern of HSV-1. Implications for the epidemiology and diversification of HSV-1 are discussed.
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PMID:Geographical distribution of the herpes simplex virus type 1 BgKL variant in Japan suggests gradual dispersion of the virus from Shikoku Island to the other Islands. 1675 6

This chapter describes the procedure of generating pulsed-field gel electrophoresis (PFGE) profiles (DNA fingerprints) of Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) and non-O157 STEC strains within 48 h, based on the standardized laboratory protocol developed by the Centers for Disease Control and Prevention, USA. The protocol describes the preparation of agarose plugs containing STEC O157 and non-O157 STEC cells, the digestion of bacterial DNA in the plugs using restriction endonuclease enzymes, and the electrophoresis conditions to generate the characteristic PFGE profiles of STEC O157 and non-O157 STEC isolates.
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PMID:PFGE for Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) and non-O157 STEC. 2586 57


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