scholarly journals Whole-Genome Single-Nucleotide-Polymorphism Analysis for Discrimination of Clostridium botulinum Group I Strains

2014 ◽  
Vol 80 (7) ◽  
pp. 2125-2132 ◽  
Author(s):  
Narjol Gonzalez-Escalona ◽  
Ruth Timme ◽  
Brian H. Raphael ◽  
Donald Zink ◽  
Shashi K. Sharma

ABSTRACTClostridium botulinumis a genetically diverse Gram-positive bacterium producing extremely potent neurotoxins (botulinum neurotoxins A through G [BoNT/A-G]). The complete genome sequences of three strains harboring only the BoNT/A1 nucleotide sequence are publicly available. Although these strains contain a toxin cluster (HA+OrfX−) associated with hemagglutinin genes, little is known about the genomes of subtype A1 strains (termed HA−OrfX+) that lack hemagglutinin genes in the toxin gene cluster. We sequenced the genomes of three BoNT/A1-producingC. botulinumstrains: two strains with the HA+OrfX−cluster (69A and 32A) and one strain with the HA−OrfX+cluster (CDC297). Whole-genome phylogenic single-nucleotide-polymorphism (SNP) analysis of these strains along with other publicly availableC. botulinumgroup I strains revealed five distinct lineages. Strains 69A and 32A clustered with theC. botulinumtype A1 Hall group, and strain CDC297 clustered with theC. botulinumtype Ba4 strain 657. This study reports the use of whole-genome SNP sequence analysis for discrimination ofC. botulinumgroup I strains and demonstrates the utility of this analysis in quickly differentiatingC. botulinumstrains harboring identical toxin gene subtypes. This analysis further supports previous work showing that strains CDC297 and 657 likely evolved from a common ancestor and independently acquired separate BoNT/A1 toxin gene clusters at distinct genomic locations.

2008 ◽  
Vol 83 (5) ◽  
pp. 2285-2297 ◽  
Author(s):  
Chunqing Luo ◽  
Marta Bueno ◽  
Jeffrey Kant ◽  
Jeremy Martinson ◽  
Parmjeet Randhawa

ABSTRACT BK virus (BKV) genotyping has been historically based on nucleotides 1744 to 1812 in the VP1 gene. We reevaluated this practice by making BKV whole-genome and gene-specific phylogenetic trees as well as performing single nucleotide polymorphism (SNP) analysis of 162 sequences available in the public domain. It was found that currently known BKV subtypes and subgroups can no longer be reliably determined by sequencing certain partial gene sequences. Phylogenetic trees based on large T-antigen (LTA) allow separation of subtype I into subgroups Ia, Ib1, Ib2, and Ic, with bootstrap values of 100%, which are better than bootstraps obtained using VP1 sequences (bootstrap values of 71 to 97%). Subtype IV can be subdivided into subgroups, but LTA bootstrap values (33 to 80%) are lower than those obtained by whole-genome analysis (68 to 87%). Subtypes V and VI provisionally identified earlier on the basis of more limited sequence data are better classified as subgroups Ib2 and Ib1, respectively. LTA positions 3634, 3772, 3934, and 4339 can serve as a minimal SNP set to distinguish between the four major BKV subtypes. No subtype II-, IVa-, or IVb-defining SNPs are available in the VP1 gene. However, the overall congruence of viral strain classification based on either VP1 or LTA phylogenetic analysis indicates that these two areas of the viral genome are genetically linked. Interstrain genetic recombination between distant loci in the VP1 and LTA areas is not a common event.


2011 ◽  
Vol 55 (10) ◽  
pp. 4718-4727 ◽  
Author(s):  
Susu Duan ◽  
David A. Boltz ◽  
Jiang Li ◽  
Christine M. Oshansky ◽  
Henju Marjuki ◽  
...  

ABSTRACTNeuraminidase (NA) inhibitors are among the first line of defense against influenza virus infection. With the increased worldwide use of the drugs, antiviral susceptibility surveillance is increasingly important for effective clinical management and for public health epidemiology. Effective monitoring requires effective resistance detection methods. We have developed and validated a novel genotyping method for rapid detection of established NA inhibitor resistance markers in influenza viruses by single nucleotide polymorphism (SNP) analysis. The multi- or monoplex SNP analysis based on single nucleotide extension assays was developed to detect NA mutations H275Y and I223R/V in pandemic H1N1 viruses, H275Y in seasonal H1N1 viruses, E119V and R292K in seasonal H3N2 viruses, and H275Y and N295S in H5N1 viruses. The SNP analysis demonstrated high sensitivity for low-content NA amplicons (0.1 to 1 ng/μl) and showed 100% accordant results against a panel of defined clinical isolates. The monoplex assays for the H275Y NA mutation allowed precise and accurate quantification of the proportions of wild-type and mutant genotypes in virus mixtures (5% to 10% discrimination), with results comparable to those of pyrosequencing. The SNP analysis revealed the lower growth fitness of an H275Y mutant compared to the wild-type pandemic H1N1 virus by quantitatively genotyping progeny viruses grown in normal human bronchial epithelial cells. This novel method offers high-throughput screening capacity, relatively low costs, and the wide availability of the necessary equipment, and thus it could provide a much-needed approach for genotypic screening of NA inhibitor resistance in influenza viruses.


2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Anna Janowicz ◽  
Fabrizio De Massis ◽  
Massimo Ancora ◽  
Cesare Cammà ◽  
Claudio Patavino ◽  
...  

ABSTRACT The use of whole-genome sequencing (WGS) using next-generation sequencing (NGS) technology has become a widely accepted method for microbiology laboratories in the application of molecular typing for outbreak tracing and genomic epidemiology. Several studies demonstrated the usefulness of WGS data analysis through single-nucleotide polymorphism (SNP) calling from a reference sequence analysis for Brucella melitensis, whereas gene-by-gene comparison through core-genome multilocus sequence typing (cgMLST) has not been explored so far. The current study developed an allele-based cgMLST method and compared its performance to that of the genome-wide SNP approach and the traditional multilocus variable-number tandem repeat analysis (MLVA) on a defined sample collection. The data set was comprised of 37 epidemiologically linked animal cases of brucellosis as well as 71 isolates with unknown epidemiological status, composed of human and animal samples collected in Italy. The cgMLST scheme generated in this study contained 2,704 targets of the B. melitensis 16M reference genome. We established the potential criteria necessary for inclusion of an isolate into a brucellosis outbreak cluster to be ≤6 loci in the cgMLST and ≤7 in WGS SNP analysis. Higher phylogenetic distance resolution was achieved with cgMLST and SNP analysis than with MLVA, particularly for strains belonging to the same lineage, thereby allowing diverse and unrelated genotypes to be identified with greater confidence. The application of a cgMLST scheme to the characterization of B. melitensis strains provided insights into the epidemiology of this pathogen, and it is a candidate to be a benchmark tool for outbreak investigations in human and animal brucellosis.


2011 ◽  
Vol 77 (24) ◽  
pp. 8648-8655 ◽  
Author(s):  
Henk C. den Bakker ◽  
Andrea I. Moreno Switt ◽  
Craig A. Cummings ◽  
Karin Hoelzer ◽  
Lovorka Degoricija ◽  
...  

ABSTRACTIn this study, we report a whole-genome single nucleotide polymorphism (SNP)-based evolutionary approach to study the epidemiology of a multistate outbreak ofSalmonella entericasubsp.entericaserovar Montevideo. This outbreak included 272 cases that occurred in 44 states between July 2009 and April 2010. A case-control study linked the consumption of salami made with contaminated black and red pepper to the outbreak. We sequenced, on the SOLiD System, 47 isolates with XbaI PFGE pattern JIXX01.0011, a common pulsed-field gel electrophoresis (PFGE) pattern associated with isolates from the outbreak. These isolates represented 20 isolates collected from human sources during the period of the outbreak and 27 control isolates collected from human, food, animal, and environmental sources before the outbreak. Based on 253 high-confidence SNPs, we were able to reconstruct a tip-dated molecular clock phylogeny of the isolates and to assign four human isolates to the actual outbreak. We developed an SNP typing assay to rapidly discriminate between outbreak-related cases and non-outbreak-related cases and tested this assay on an extended panel of 112 isolates. These results suggest that only a very small percentage of the human isolates with the outbreak PFGE pattern and obtained during the outbreak period could be attributed to the actual pepper-related outbreak (20%), while the majority (80%) of the putative cases represented background cases. This study demonstrates that next-generation-based SNP typing provides the resolution and accuracy needed for outbreak investigations of food-borne pathogens that cannot be distinguished by currently used subtyping methods.


2018 ◽  
Vol 6 (25) ◽  
Author(s):  
Alisha A. Mullen ◽  
Ciara D. Lynch ◽  
Shannon M. Hill ◽  
Cian P. Holohan ◽  
Tadhg Ó Cróinín ◽  
...  

ABSTRACT No genome sequence of a species from Barnettozyma, a yeast genus in the family Phaffomycetaceae, is currently available. We isolated two B. californica strains from soils in Ireland and generated draft sequences of their 11.7-Mb genomes. Single nucleotide polymorphism (SNP) analysis showed 20,490 differences between the strains and suggests that B. californica is haploid.


2020 ◽  
Vol 18 (3) ◽  
pp. 154-164 ◽  
Author(s):  
Ismail Koyuncu ◽  
Ataman Gönel ◽  
Emrah Ozcan ◽  
Ebru Temiz ◽  
Şahin Toprak ◽  
...  

Background: Emergence of Kaposi's Sarcoma in the cases other than HIV, following the use of immunosuppressant drugs, demonstrates that it is related to weak immunity. The fact that this malignancy does not occur in every HIV-positive patient suggests that genetic predisposition may also be effective. Replacement of one of the base pairs of adenine, guanine, cytosine, and thymine that constitute the DNA sequence in the human genome with another base pair can affect susceptibility to disease, response to treatment, and immunity. Objective: The purpose of this study is to analyze the Single Nucleotide Polymorphism that could predispose to Kaposi's sarcoma of an HIV-infected patient and to identify which nucleotides such SNPs correspond to, using the microarray technology. Material and Method: The blood samples of individuals, one of whom was diagnosed with Kaposi's Sarcoma HIV (+) visiting the outpatient clinic of infectious diseases polyclinic of Harran University Research and Practice Hospital and of a healthy individual with no Kaposi's Sarcoma, were used in the study. Following the DNA isolation of the blood samples taken from the respective individuals, a SNP analysis was conducted on the microarray device. 204,000 SNPs obtained were scanned later on in the databases in an attempt to identify the SNPs related to Kaposi's Sarcoma. Results: In the 204,000 SNP screenings, we scrutinized the SNPs that differ in the case of Kaposi's Sarcoma [KS (+) and HIV (+)] on the basis of Control [KS(-) and HIV(-)] and HIV+ [KS(-)], and two SNPs of the ENDRA gene, three SNPs of the ADRA1A gene, six SNPs of the STIM1 gene, four SNPs of the EFNB2 gene, and one SNP of the CD209 gene were found to be different. However, when it comes to all SNPs (all the 204.000 SNPs) screened in terms of allele, it was observed that the AA and BB alleles were lower in the patient with Kaposi's Sarcoma [KS (+) and HIV (+)] compared to other groups and AB alleles were found to be higher than others in the patient with Kaposi's sarcoma [KS] (+) and HIV (+)]. Conclusion: In the microarray study we have conducted, 204,000 SNPs were screened for Control (HIV-) HIV (+) and HIV (+) patient with Kaposi's Sarcoma. It was found that 32,362 of those SNPs had different alleles in the Kaposi's Sarcoma [KS + HIV (+)] patient, while they had the same ones in the control [KS (-) and HIV (-)] and HIV + [KS (-)] group. 16 of the 32,362 SNPs took place among the genes related to Kaposi's Sarcoma. In the cases of Kaposi's Sarcoma with suspected diagnosis, it can be used as a beneficial laboratory test.


2015 ◽  
Vol 54 (3) ◽  
pp. 556-564 ◽  
Author(s):  
Célia Leão ◽  
Robert J. Goldstone ◽  
Josephine Bryant ◽  
Joyce McLuckie ◽  
João Inácio ◽  
...  

Typing ofMycobacterium aviumsubspeciesparatuberculosisstrains presents a challenge, since they are genetically monomorphic and traditional molecular techniques have limited discriminatory power. The recent advances and availability of whole-genome sequencing have extended possibilities for the characterization ofMycobacterium aviumsubspeciesparatuberculosis, and whole-genome sequencing can provide a phylogenetic context to facilitate global epidemiology studies. In this study, we developed a single nucleotide polymorphism (SNP) assay based on PCR and restriction enzyme digestion or sequencing of the amplified product. The SNP analysis was performed using genome sequence data from 133Mycobacterium aviumsubspeciesparatuberculosisisolates with different genotypes from 8 different host species and 17 distinct geographic regions around the world. A total of 28,402 SNPs were identified among all of the isolates. The minimum number of SNPs required to distinguish between all of the 133 genomes was 93 and between only the type C isolates was 41. To reduce the number of SNPs and PCRs required, we adopted an approach based on sequential detection of SNPs and a decision tree. By the analysis of 14 SNPsMycobacterium aviumsubspeciesparatuberculosisisolates can be characterized within 14 phylogenetic groups with a higher discriminatory power than mycobacterial interspersed repetitive unit–variable number tandem repeat assay and other typing methods. Continuous updating of genome sequences is needed in order to better characterize new phylogenetic groups and SNP profiles. The novel SNP assay is a discriminative, simple, reproducible method and requires only basic laboratory equipment for the large-scale global typing ofMycobacterium aviumsubspeciesparatuberculosisisolates.


2015 ◽  
Vol 53 (4) ◽  
pp. 1227-1238 ◽  
Author(s):  
Erika Scaltriti ◽  
Davide Sassera ◽  
Francesco Comandatore ◽  
Marina Morganti ◽  
Carmen Mandalari ◽  
...  

We retrospectively analyzed a rareSalmonella entericaserovar Manhattan outbreak that occurred in Italy in 2009 to evaluate the potential of new genomic tools based on differential single nucleotide polymorphism (SNP) analysis in comparison with the gold standard genotyping method, pulsed-field gel electrophoresis. A total of 39 isolates were analyzed from patients (n= 15) and food, feed, animal, and environmental sources (n= 24), resulting in five different pulsed-field gel electrophoresis (PFGE) profiles. Isolates epidemiologically related to the outbreak clustered within the same pulsotype, SXB_BS.0003, without any further differentiation. Thirty-three isolates were considered for genomic analysis based on different sets of SNPs, core, synonymous, nonsynonymous, as well as SNPs in different codon positions, by Bayesian and maximum likelihood algorithms. Trees generated from core and nonsynonymous SNPs, as well as SNPs at the second and first plus second codon positions detailed four distinct groups of isolates within the outbreak pulsotype, discriminating outbreak-related isolates of human and food origins. Conversely, the trees derived from synonymous and third-codon-position SNPs clustered food and human isolates together, indicating that all outbreak-related isolates constituted a single clone, which was in line with the epidemiological evidence. Further experiments are in place to extend this approach within our regional enteropathogen surveillance system.


Sign in / Sign up

Export Citation Format

Share Document