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Antimicrobial Agents and Chemotherapy Aug 2020Analysis of the genome sequence of ATCC 43969 identified the gene, encoding YEM-1, a putative subclass B2 metallo-β-lactamase. The objectives of our work were to...
Analysis of the genome sequence of ATCC 43969 identified the gene, encoding YEM-1, a putative subclass B2 metallo-β-lactamase. The objectives of our work were to produce and purify YEM-1 and to complete its kinetic characterization. YEM-1 displayed the narrowest substrate range among known subclass B2 metallo-β-lactamases, since it can hydrolyze imipenem, but not other carbapenems, such as biapenem, meropenem, doripenem, and ertapenem, with high catalytic efficiency. A possible explanation of this activity profile is the presence of tyrosine at residue 67 (loop L1), threonine at residue 156 (loop L2), and serine at residue 236 (loop L3). We showed that replacement of Y67 broadened the activity profile of the enzyme for all carbapenems but still resulted in poor activity toward the other β-lactam classes.
Topics: Anti-Bacterial Agents; Carbapenems; Hydrolysis; Imipenem; Yersinia; beta-Lactamases
PubMed: 32540974
DOI: 10.1128/AAC.00105-20 -
Science Advances Mar 2020We identified a glucosyltransferase (YGT) and an ADP-ribosyltransferase (YART) in , highly related to glucosylating toxins from , the cause of antibiotics-associated...
We identified a glucosyltransferase (YGT) and an ADP-ribosyltransferase (YART) in , highly related to glucosylating toxins from , the cause of antibiotics-associated enterocolitis. Both toxins consist of an amino-terminal enzyme domain, an autoprotease domain activated by inositol hexakisphosphate, and a carboxyl-terminal translocation domain. YGT -acetylglucosaminylates Rab5 and Rab31 at Thr and Thr, respectively, thereby inactivating the Rab proteins. YART ADP-ribosylates Rab5 and Rab31 at Gln and Gln, respectively. This activates Rab proteins by inhibiting GTP hydrolysis. We determined the crystal structure of the glycosyltransferase domain of YGT (YGT) in the presence and absence of UDP at 1.9- and 3.4-Å resolution, respectively. Thereby, we identified a previously unknown potassium ion-binding site, which explains potassium ion-dependent enhanced glycosyltransferase activity in clostridial and related toxins. Our findings exhibit a novel type of inverse regulation of Rab proteins by toxins and provide new insights into the structure-function relationship of glycosyltransferase toxins.
Topics: ADP Ribose Transferases; Bacterial Proteins; Bacterial Toxins; Crystallography, X-Ray; Glucosyltransferases; Glycosylation; Glycosyltransferases; HeLa Cells; Humans; Protein Domains; Uridine Diphosphate; Yersinia; rab GTP-Binding Proteins; rab5 GTP-Binding Proteins
PubMed: 32195351
DOI: 10.1126/sciadv.aaz2094 -
Journal of Clinical Microbiology Dec 1989Allelic variation in the chromosomal genome of 81 isolates of Yersinia enterocolitica and single isolates of Yersinia intermedia, Yersinia frederiksenii, Yersinia...
Allelic variation in the chromosomal genome of 81 isolates of Yersinia enterocolitica and single isolates of Yersinia intermedia, Yersinia frederiksenii, Yersinia mollaretii, and Yersinia kristensenii was assessed by analysis of electrophoretically demonstrable polymorphism in 21 genes encoding metabolic enzymes. Eighteen distinctive multilocus genotypes (electrophoretic types [ETs]) were identified. Clustering of the ETs from a matrix of pairwise genetic distances, based on the 21 enzyme loci, confirmed the genetic distinctness of serogroup 3 isolates of Y. intermedia, Y. frederiksenii, Y. mollaretii, and Y. kristensenii and identified another serogroup 3 isolate that was also not a member of Y. enterocolitica. The 13 ETs of Y. enterocolitica clustered into two groups: cluster A, which included eight ETs represented by isolates of serogroups 1; 2; 3; 5,27; and 9, and cluster B, which included four ETs represented by isolates of serogroups 8, 13, and 21. Clones of cluster A were found to be distributed worldwide, but those of cluster B were largely restricted to North America. Isolates of genotypes belonging to cluster B were lethal to mice, whereas those of cluster A were not, suggesting an influence of the chromosomal background on the virulence of Y. enterocolitica.
Topics: Alleles; Animals; Bacterial Typing Techniques; Bacteriophage Typing; Cluster Analysis; Enzymes; Genetic Variation; Genotype; Humans; Phenotype; Phylogeny; Polymorphism, Genetic; Serotyping; Yersinia; Yersinia enterocolitica
PubMed: 2687316
DOI: 10.1128/jcm.27.12.2678-2683.1989 -
Journal of Clinical Microbiology Nov 1990A total of 1,835 Yersinia spp. were isolated from 925 (60.5%) of 1,530 wild mice and from 139 (79.9%) of 174 moles living in mountainous areas of eastern Shimane...
A total of 1,835 Yersinia spp. were isolated from 925 (60.5%) of 1,530 wild mice and from 139 (79.9%) of 174 moles living in mountainous areas of eastern Shimane Prefecture, Japan. The Yersinia spp. included 1,106 Yersinia enterocolitica, 26 Y. enterocolitica-like, 176 Yersinia mollaretii, 149 Yersinia frederiksenii, 70 Yersinia intermedia, 231 Yersinia kristensenii, 5 Yersinia aldovae, and 72 Yersinia pseudotuberculosis. Human pathogenic Y. enterocolitica was not isolated. Y. pseudotuberculosis was divided into 10 virulent 40- to 50-MDa plasmid-positive (P+) strains (serotypes 1b, 4b, and untypeable) and 62 plasmid-negative (P-) strains (serotypes 1b, 2b, 2c, 4a, 5a, 5b, 6, 7, and untypeable). P+ strains of serotypes 1b (two strains), 4b (seven strains), and untypeable (one strain) were isolated from nine Apodemus specious and one Apodemus argenteus. The isolates of Yersinia spp. were more frequently detected in newborn mice and during the breeding season. The P+ Y. pseudotuberculosis strains were recovered at less than 10(4) cells per g of the cecal contents. Thus, the prevalence of Yersinia spp. in small wild animals depends on the newborn animals born during the cold months, and wild mice in mountainous areas are important reservoirs of Y. pseudotuberculosis.
Topics: Animals; Female; Japan; Male; Moles; Muridae; Seasons; Virulence; Yersinia pseudotuberculosis; Yersinia pseudotuberculosis Infections
PubMed: 2254420
DOI: 10.1128/jcm.28.11.2448-2455.1990 -
Journal of Microorganism Control 2023Bacterial stresses can occur from the production to the distribution environments of produce, and these stresses can lead to nonlethal bacterial damage that is an...
Bacterial stresses can occur from the production to the distribution environments of produce, and these stresses can lead to nonlethal bacterial damage that is an injured state called sublethally injured bacteria. The damage is mainly due to the disruption of the surface structure and cytoplasmic membrane of the cells. Sublethally sanitizer-injured indicator coliform bacteria injured by chlorine, ethanol, and/or fungicide stress could exhibit on vegetables during production and harvest. Chlorine stress and cold stress could induce sublethally injured indicator and pathogenic coliform bacteria on fresh-cut vegetables during processing and subsequent storage. Enterobacter kobei and Pantoea ananatis injurd by chlorine stress, E. amnigenus, E. asburiae, and E. kobei injured by ethanol stress, and Rahnella aquatilis, Yersinia mollaretii, and Escherichia coli injured by fungicide stress could be amongst the injured cells in the coliforms detected in the produce environments. To ensure the microbiological quality and safety of fresh-cut vegetables, it is necessary to adjust the concentration of sanitizer to a level that kills bacteria and does not produce sanitizer- injured cells when sanitizer is applied to the produce, and also to consider the storage temperature to inhibit the recovery of injured bacteria due to cold injury during the chilling storage period.
Topics: Vegetables; Colony Count, Microbial; Chlorine; Food Microbiology; Fungicides, Industrial; Bacteria; Escherichia coli; Ethanol
PubMed: 38233167
DOI: 10.4265/jmc.28.4_153 -
Acta Veterinaria Scandinavica Jun 2012Pigs are regarded as the main reservoir for human pathogenic Yersinia enterocolitica, which is dominated by bioserotype 4/O:3. Other animals, including sheep, have...
BACKGROUND
Pigs are regarded as the main reservoir for human pathogenic Yersinia enterocolitica, which is dominated by bioserotype 4/O:3. Other animals, including sheep, have occasionally been reported as carriers of pathogenic strains of Y. enterocolitica. To our knowledge, this is the first study performed in the Nordic countries in which the presence of Y. enterocolitica in sheep is investigated.
METHODS
Tonsils and faecal samples collected from sheep slaughtered on the island Gotland (Sweden) from September 2010 through January 2011 were analysed for presence of Y. enterocolitica. In an attempt to maximize recovery, several cultural strategies were applied. Various non-selective media were used and different temperatures and durations of the enrichment were applied before subculturing on Cefsulodin Irgasan Novobiocin (CIN) agar. Presumptive Y. enterocolitica colonies were subjected to urease, API 20E and agglutination test. Yersinia enterocolitica isolates were biotyped, serotyped, and tested for pathogenicity using a TaqMan PCR directed towards the ail-gene that is associated with human pathogenic strains of Y. enterocolitica.
RESULTS
The samples collected from 99 sheep yielded 567 presumptive Y. enterocolitica colonies. Eighty urease positive isolates, from 35 sheep, were identified as Y. enterocolitica by API 20E. Thirty-four of 35 further subtyped Y. enterocolitica isolates, all from faecal samples, belonged to biotype 1A serotype O:5, O:6. O:13,7 and O:10. One strain was Yersinia mollaretii serotype O:62. No human pathogenic strains of Y. enterocolitica were found in the investigated sheep. Other species identified were Y. kristensenii (n = 4), Y. frederiksenii/intermedia (n = 3), Providencia rettgeri (n = 2), Serratia marcescens (n = 1) and Raoultella ornithinolytica (n = 1).
CONCLUSIONS
This study does not support the hypothesis that sheep play an important role in transmission of the known human pathogenic Y. enterocolitica in the studied geographical region. However, because there are studies indicating that some strains of Y. enterocolitica biotype 1A may cause disease in humans, the relative importance of sheep as carriers of human pathogenic strains of Y. enterocolitica remains unclear. Tonsils do not appear to be favourable sites for Y. enterocolitica biotype 1A in sheep.
Topics: Animals; Bacterial Typing Techniques; DNA, Bacterial; Feces; Palatine Tonsil; Polymerase Chain Reaction; Seasons; Serotyping; Sheep; Sheep Diseases; Sweden; Yersinia Infections; Yersinia enterocolitica
PubMed: 22748116
DOI: 10.1186/1751-0147-54-39 -
BioTechniques Dec 2016Protein consensus-based surface engineering (ProCoS) is a simple and efficient method for directed protein evolution combining computational analysis and molecular...
Protein consensus-based surface engineering (ProCoS) is a simple and efficient method for directed protein evolution combining computational analysis and molecular biology tools to engineer protein surfaces. ProCoS is based on the hypothesis that conserved residues originated from a common ancestor and that these residues are crucial for the function of a protein, whereas highly variable regions (situated on the surface of a protein) can be targeted for surface engineering to maximize performance. ProCoS comprises four main steps: () identification of conserved and highly variable regions; () protein sequence design by substituting residues in the highly variable regions, and gene synthesis; () in vitro DNA recombination of synthetic genes; and () screening for active variants. ProCoS is a simple method for surface mutagenesis in which multiple sequence alignment is used for selection of surface residues based on a structural model. To demonstrate the technique's utility for directed evolution, the surface of a phytase enzyme from (Ymphytase) was subjected to ProCoS. Screening just 1050 clones from ProCoS engineering-guided mutant libraries yielded an enzyme with 34 amino acid substitutions. The surface-engineered Ymphytase exhibited 3.8-fold higher pH stability (at pH 2.8 for 3 h) and retained 40% of the enzyme's specific activity (400 U/mg) compared with the wild-type Ymphytase. The pH stability might be attributed to a significantly increased (20 percentage points; from 9% to 29%) number of negatively charged amino acids on the surface of the engineered phytase.
Topics: 6-Phytase; Directed Molecular Evolution; Enzyme Stability; Fungal Proteins; Models, Molecular; Protein Engineering; Sequence Alignment; Yersinia
PubMed: 27938322
DOI: 10.2144/000114483 -
Journal of Food Protection Oct 2016Chemical sanitizers may induce no injury (bacteria survive), sublethal injury (bacteria are injured), or lethal injury (bacteria die). The proportion of coliform...
Chemical sanitizers may induce no injury (bacteria survive), sublethal injury (bacteria are injured), or lethal injury (bacteria die). The proportion of coliform bacteria that were injured sublethally by chlorine and fungicide mixed with agricultural water (pond water), which was used to dilute the pesticide solution, was evaluated using the thin agar layer (TAL) method. In pure cultures of Enterobacter cloacae , Escherichia coli , and E. coli O157:H7 (representing a human pathogen), the percentage of chlorine-injured cells was 69 to 77% for dilute electrolyzed water containing an available chlorine level of 2 ppm. When agricultural water was mixed with electrolyzed water, the percentage of injured coliforms in agricultural water was 75%. The isolation and identification of bacteria on TAL and selective media suggested that the chlorine stress caused injury to Enterobacter kobei . Of the four fungicide products tested, diluted to their recommended concentrations, Topsin-M, Sumilex, and Oxirane caused injury to coliform bacteria in pure cultures and in agricultural water following their mixture with each pesticide, whereas Streptomycin did not induce any injury to the bacteria. The percentage of injury was 45 to 97% for Topsin-M, 80 to 87% for Sumilex, and 50 to 97% for Oxirane. A comparison of the coliforms isolated from the pesticide solutions and then grown on either TAL or selective media indicated the possibility of fungicide-injured Rahnella aquatilis , Yersinia mollaretii , and E. coli . These results suggest the importance of selecting a suitable sanitizer and the necessity of adjusting the sanitizer concentration to a level that will kill the coliforms rather than cause sanitizer-induced cell injury that can result in the recovery of the coliforms.
Topics: Chlorine; Colony Count, Microbial; Disinfectants; Escherichia coli O157; Humans; Water
PubMed: 28221856
DOI: 10.4315/0362-028X.JFP-16-124 -
PloS One 2017Dental caries is the most prevalent disease in humans globally. Efforts to control it have been invigorated by an increasing knowledge of the oral microbiome...
Dental caries is the most prevalent disease in humans globally. Efforts to control it have been invigorated by an increasing knowledge of the oral microbiome composition. This study aimed to evaluate the bacterial diversity in occlusal biofilms and its relationship with clinical surface diagnosis and dietary habits. Anamneses were recorded from thirteen 12-year-old children. Biofilm samples collected from occlusal surfaces of 46 permanent second molars were analyzed by 16S rRNA amplicon sequencing combined with the BLASTN-based search algorithm for species identification. The overall mean decayed, missing and filled surfaces modified index [DMFSm Index, including active white spot lesions (AWSL)] value was 8.77±7.47. Biofilm communities were highly polymicrobial collectively, representing 10 bacterial phyla, 25 classes, 29 orders, 58 families, 107 genera, 723 species. Streptococcus sp_Oral_Taxon_065, Corynebacterium matruchotii, Actinomyces viscosus, Actinomyces sp_Oral_Taxon_175, Actinomyces sp_Oral_Taxon_178, Actinomyces sp_Oral_Taxon_877, Prevotella nigrescens, Dialister micraerophilus, Eubacterium_XI G 1 infirmum were more abundant among surfaces with AWSL, and Streptococcus gordonii, Streptococcus sp._Oral_Taxon_058, Enterobacter sp._str._638 Streptococcus australis, Yersinia mollaretii, Enterobacter cloacae, Streptococcus sp._Oral_Taxon_71, Streptococcus sp._Oral_Taxon_F11, Centipeda sp._Oral_Taxon_D18 were more abundant among sound surfaces. Streptococcus mutans was detected on all surfaces in all patients, while Streptococcus sobrinus was detected only in three patients (mean relative abundances 7.1% and 0.6%, respectively). Neither species differentiated healthy from diseased sites. Diets of nine of the subjects were scored as high in fermentable carbohydrates (≧2X/day between meals). A direct association between relative abundances of bacteria and carbohydrate consumption was observed among 18 species. High consumption of fermentable carbohydrates and sound surfaces were associated with a reduction in bacterial diversity. PCoA plots displayed differences in bacterial community profiles between sound and diseased surfaces. Our study showed that, in addition to mutans streptococci, other species may be associated with the initiation of dental caries on occlusal surfaces, and that biofilm diversity of tooth surfaces is influenced by carbohydrate consumption and a surface's health status.
Topics: Bacteria; Brazil; Child; Cross-Sectional Studies; Dental Caries; Diet; Female; Humans; Male; Microbiota; Mouth; Surface Properties
PubMed: 28678838
DOI: 10.1371/journal.pone.0180621 -
Applied and Environmental Microbiology Feb 1993Multilocus enzyme electrophoresis was used to analyze 244 strains of nine Yersinia species isolated from the environment, animals, and humans at 18 genes encoding...
Multilocus enzyme electrophoresis was used to analyze 244 strains of nine Yersinia species isolated from the environment, animals, and humans at 18 genes encoding metabolic enzymes. All 18 enzymes were polymorphic. Among the 137 electrophoretic types (ETs) distinguished, the mean allelic diversity per locus was 0.531. Yersinia frederiksenii ETs were divided into three major clusters that were separated by a large genetic distance, and one ET was more closely related to Yersinia enterocolitica. Thus, strains classically identified as Y. frederiksenii may represent more than one species. Furthermore, two strains identified as Yersinia kristensenii proved to be more closely related to Yersinia mollaretii. Environmental strains formed independent groups. A very interesting ET consisting of as many as 61 isolates of Yersinia enterocolitica was detected, and the epidemiologic relevance of this ET is discussed. Human strains of Y. enterocolitica biotype 4 and Yersinia pseudotuberculosis were recognized as being closely related to animal strains of the same species. Therefore, animal strains of these two species may be considered potential human pathogens.
Topics: Animals; Bacteriophage Typing; Electrophoresis; Environmental Microbiology; Genetic Variation; Genetics, Population; Humans; Lod Score; Yersinia
PubMed: 8434911
DOI: 10.1128/aem.59.2.442-450.1993