scholarly journals Plasmid Patterns of Bacillus thuringiensis Type Strains

2007 ◽  
Vol 74 (1) ◽  
pp. 125-129 ◽  
Author(s):  
Arturo Reyes-Ramírez ◽  
Jorge E. Ibarra
Keyword(s):  
Bacillus Thuringiensis ◽  
Gel Electrophoresis ◽  
Extrachromosomal Dna ◽  
Basic Pattern ◽  
Agarose Gels ◽  
Strain Characterization ◽  
Different Strains ◽  
Characterization Procedure ◽  
Unique Plasmid ◽  
Type Strains

ABSTRACT Practically all Bacillus thuringiensis strains contain a set of self-replicating, extrachromosomal DNA molecules or plasmids, which vary in number and size in the different strains. The plasmid patterns obtained from gel electrophoresis have previously been used as a tool to characterize strains, but comparison of the plasmid patterns has been limited in the number and diversity of strains analyzed. In this report, we were able to compare the plasmid patterns of 83 type strains (out of 84) and 47 additional strains from six serotypes. The information obtained from this comparison showed the importance of this tool as a strain characterization procedure and indicates the complexity and uniqueness of this feature. For example, with one exception, all type strains showed a unique plasmid pattern. All were unique in such a way that none showed even a single comigrating plasmid in the agarose gels, and therefore, cluster analysis was impossible, indicating that plasmid patterns are qualitative rather than quantitative features. Furthermore, comparison between strains belonging to the same serotype showed a great difference in variability. Some serotypes (e.g., israelensis) showed the same basic pattern among all its strains, while other serotypes (e.g., morrisoni) showed a great diversity of patterns. These results indicate that plasmid patterns are valuable tools to discriminate strains below the serotype level.

scholarly journals The Distribution of Several Genomic Virulence Determinants Does Not Corroborate the Established Serotyping Classification of Bacillus thuringiensis

2021 ◽  
Vol 22 (5) ◽  
pp. 2244
Author(s):  
Anton E. Shikov ◽  
Yury V. Malovichko ◽  
Arseniy A. Lobov ◽  
Maria E. Belousova ◽  
Anton A. Nizhnikov ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Protein Identification ◽  
Core Gene ◽  
Comparative Genomic ◽  
Virulence Determinants ◽  
Strain Characterization ◽  
Proteomic Approach ◽  
Liquid Chromatography Tandem Mass ◽  
Identity Threshold ◽  
Genome Assemblies

Bacillus thuringiensis, commonly referred to as Bt, is an object of the lasting interest of microbiologists due to its highly effective insecticidal properties, which make Bt a prominent source of biologicals. To categorize the exuberance of Bt strains discovered, serotyping assays are utilized in which flagellin serves as a primary seroreactive molecule. Despite its convenience, this approach is not indicative of Bt strains’ phenotypes, neither it reflects actual phylogenetic relationships within the species. In this respect, comparative genomic and proteomic techniques appear more informative, but their use in Bt strain classification remains limited. In the present work, we used a bottom-up proteomic approach based on fluorescent two-dimensional difference gel electrophoresis (2D-DIGE) coupled with liquid chromatography/tandem mass spectrometry(LC-MS/MS) protein identification to assess which stage of Bt culture, vegetative or spore, would be more informative for strain characterization. To this end, the proteomic differences for the israelensis-attributed strains were assessed to compare sporulating cultures of the virulent derivative to the avirulent one as well as to the vegetative stage virulent bacteria. Using the same approach, virulent spores of the israelensis strain were also compared to the spores of strains belonging to two other major Bt serovars, namely darmstadiensis and thuringiensis. The identified proteins were analyzed regarding the presence of the respective genes in the 104 Bt genome assemblies available at open access with serovar attributions specified. Of 21 proteins identified, 15 were found to be encoded in all the present assemblies at 67% identity threshold, including several virulence factors. Notable, individual phylogenies of these core genes conferred neither the serotyping nor the flagellin-based phylogeny but corroborated the reconstruction based on phylogenomics approaches in terms of tree topology similarity. In its turn, the distribution of accessory protein genes was not confined to the existing serovars. The obtained results indicate that neither gene presence nor the core gene sequence may serve as distinctive bases for the serovar attribution, undermining the notion that the serotyping system reflects strains’ phenotypic or genetic similarity. We also provide a set of loci, which fit in with the phylogenomics data plausibly and thus may serve for draft phylogeny estimation of the novel strains.

scholarly journals Stenotrophomonas terrae sp. nov. and Stenotrophomonas humi sp. nov., two nitrate-reducing bacteria isolated from soil

2007 ◽  
Vol 57 (9) ◽  
pp. 2056-2061 ◽  
Author(s):  
Kim Heylen ◽  
Bram Vanparys ◽  
Filip Peirsegaele ◽  
Liesbeth Lebbe ◽  
Paul De Vos
Keyword(s):  
Soil Analysis ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Gene Sequence Analysis ◽  
Species Analysis ◽  
Different Strains ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Type Strains ◽  
Physiological And Biochemical

Three Gram-negative, rod-shaped, non-spore-forming, nitrate-reducing isolates (R-32746, R-32768T and R-32729T) were obtained from soil. Analysis of repetitive sequence-based PCR showed that the three isolates represented two different strains. 16S rRNA gene sequence analysis and DNA–DNA hybridization placed them within the genus Stenotrophomonas and revealed that they were genotypically different from each other and from all recognized Stenotrophomonas species. Analysis of the fatty acid composition and physiological and biochemical tests allowed differentiation from their closest phylogenetic neighbours. They are therefore considered to represent two novel species, for which the names Stenotrophomonas terrae sp. nov. and Stenotrophomonas humi sp. nov. are proposed, with strains R-32768T (=LMG 23958T=DSM 18941T) and R-32729T (=LMG 23959T=DSM 18929T), respectively, as the type strains.

Glycerol incorporation in certain oral streptococci

1980 ◽  
Vol 30 (3) ◽  
pp. 759-765
Author(s):  
T A Kral ◽  
L Daneo-Moore
Keyword(s):  
Dry Weight ◽  
Defined Medium ◽  
Oral Streptococci ◽  
Chemically Defined Medium ◽  
Low Concentrations ◽  
Saturation Kinetics ◽  
Wild Rats ◽  
Different Strains ◽  
Streptococcus Rattus ◽  
Type Strains

Cells of 30 different strains of oral streptococci were grown in a chemically defined medium supplemented with [14C]glycerol to determine their ability to incorporate the labeled glycerol. Of the five species tested, only two, the rat-type strains (Streptococcus rattus) and strains isolated from wild rats (Streptococcus ferus), were able to incorporate the nonfermentable substrate, glycerol. For those strains capable of incorporating glycerol, the amount incorporated ranged from 0.15 to 0.43% of the cellular dry weight and followed simple saturation kinetics. The amount of glycerol incorporated depended solely on the concentration of glycerol in the growth medium. As a result, cultures exposed to low concentrations of glycerol ceased incorporation of the labeled glycerol before cessation of exponential growth.

STUDY OF IIA VON WILLEBRAND'S DISEASE (VWD) VARIANTS TO DETERMINE DEGREE AND TYPES OF HETEROGENEITY

1987 ◽  
Author(s):  
S M Enayat ◽  
F G H Hill ◽  
Y Sultan ◽  
C W Williams
Keyword(s):  
Monoclonal Antibodies ◽  
Factor Viii ◽  
Structure Function ◽  
Gel Electrophoresis ◽  
Agarose Gels ◽  
Factor Viii Related Antigen ◽  
The Third ◽  
Edta Plasma ◽  
Abnormal Pattern ◽  
The Common

Thirty four IIA vWD patients (16 from kindred I, 2 from kindred II and 17 unrelated patients) from 19 families were studied to compare multimer patterns using discontinuous SDS gel electrophoresis on a variety of agarose gels. Platelet multi-mers and effect of EDTA on plasma multimers were also studied in some.The large kindred and 9 other patients showed identical multimer and triplet abnormalities. The 11 other patients showed different multimer patterns either by having intermediate multimers or different triplet patterns. The second kindred had a similar triplet abnormality to kindred I but had intermediate multimers. Two other patients showed similar patterns except on 2% agarose gels when differences in the lowest multimer was seen. Of the 3 patients of YS, one showed the common IIA pattern but also had intermediate multimers, another had an unusually faint upper triplet band, while the third in addition to a faint upper triplet band with ESVWF 2+ had no identification of minor or major bands with ESVWF 10+ Another patient lacked high and some intermediate multimers but had a normal triplet pattern. The pattern we have seen in Kernoff's patient (1) still appears unique. In kindred II abnormal triplets persisted and high multimers appeared in EDTA plasma. In kindred I (and similar patients) intermediate multimers and a change in triplet pattern was observed in EDTA while lysed platelets showed an abnormal pattern different to the plasma one.This emphasizes the heterogeneity of IIA vWD and the need to consider multimer deletion, triplet pattern, platelet multimers, effect of EDTA in trying to subclassify in order to study structure function relationships of vWF.1. Kernoff PBA, Gruson R, Rizza CR. (1974) A variant of factor VIII related antigen. Br. J. Haematol. 26: 435.+ESVWF 2 and 10 are monoclonal antibodies to vWF epitopes.

scholarly journals Fecal Klebsiella pneumoniae Carriage Is Intermittent and of High Clonal Diversity

2020 ◽  
Vol 11 ◽  
Author(s):  
Sarah Lepuschitz ◽  
Kathrin Hauser ◽  
Agnes Schriebl ◽  
Claudia Schlagenhaufen ◽  
Anna Stöger ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Clonal Diversity ◽  
Positive Sample ◽  
Strain Characterization ◽  
Major Species ◽  
Stool Samples ◽  
Enriched Cultures ◽  
Different Strains ◽  
Healthcare Associated

The Klebsiella pneumoniae complex comprises several closely related entities, which are ubiquitous in the natural environment, including in plants, animals, and humans. K. pneumoniae is the major species within this complex. K. pneumoniae strains are opportunistic pathogens and a common cause of healthcare-associated infections. K. pneumoniae can colonize the human gastrointestinal tract, which may become a reservoir for infection. The aim of this study was to investigate the fecal K. pneumoniae carriage in six healthy individuals during a 1 year period. Stool samples were obtained once a week. Using direct and pre-enriched cultures streaked on ampicillin-supplemented agar plates, up to eight individual colonies per positive sample were selected for further characterization. Whole genome sequencing (WGS) was performed for strain characterization. Sequence type (ST), core genome complex type (CT), K and O serotypes, virulence traits, antibiotic resistance profiles, and plasmids were extracted from WGS data. In total, 80 K. pneumoniae isolates were obtained from 48 positive cultures of 278 stool samples from five of the six test subjects. The samples of the five colonized volunteers yielded at most two, three, four (two persons), and five different strains, respectively. These 80 K. pneumoniae isolates belonged to 60 STs, including nine new STs; they were of 70 CTs, yielded 48 K serotypes, 11 O serotypes, and 39 wzc and 51 wzi alleles. Four of the five subjects harbored serotypes K20 and K47, as well as STs ST37, ST101, ST1265, and ST20, which had previously been linked to high-risk K. pneumoniae clones. In total, 25 genes conferring antibiotic resistance and 42 virulence genes were detected among all 80 isolates. Plasmids of 15 different types were found among 65 of the isolates. Fecal carriage of individual strains was of short duration: 70 strains were found on a single sampling day only, and 5 strains were isolated in samples collected over two consecutive weeks. Two of the five colonized individuals—working colleagues having meals together—shared identical K. pneumoniae types four times during the study period. Our findings point toward the potential role of food as a reservoir for K. pneumoniae in humans.

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