scholarly journals Development of Candida auris Short Tandem Repeat Typing and Its Application to a Global Collection of Isolates

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Theun de Groot ◽  
Ynze Puts ◽  
Indira Berrio ◽  
Anuradha Chowdhary ◽  
Jacques F. Meis
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
South Asian ◽  
Tandem Repeat ◽  
Cost Effective ◽  
Whole Genome ◽  
Candida Auris ◽  
Str Typing ◽  
Content Type ◽  
Short Tandem

ABSTRACT Candida auris is a pathogenic yeast that causes invasive infections with high mortality. Infections most often occur in intensive care units of health care facilities. It is crucial to trace the source and prevent further spread of C. auris during an outbreak setting; therefore, genotyping of C. auris is required. To enable fast and cost-effective genotyping, we developed a short tandem repeat (STR) typing assay for C. auris. STRs in C. auris were identified, and from an initial selection of 23 STRs, 12 were used to develop a STR typing assay. Having shown that the STR typing assay was reproducible and specific, a robust set of 444 C. auris isolates was investigated to identify genotypic diversity. In concordance with whole-genome sequencing (WGS) analysis, we identified five major different C. auris clusters of South American, South Asian, African, East Asian, and Iranian origin. Overall, a total of 40 distinct genotypes were identified, with the largest variety in the South Asian clade. Comparison with WGS demonstrated that isolates with <20 single nucleotide polymorphisms (SNPs) are mostly not differentiated by STR analysis, while isolates with 30 or more SNPs usually have differences in one or more STR markers. Altogether, a highly reproducible and specific STR typing assay for C. auris was developed; this assay distinguishes the five different C. auris clades in identical fashion to WGS, while most isolates differing by >30 SNPs, as determined via WGS, are also separated. This new C. auris-specific genotyping technique is a rapid, reliable, and cost-effective alternative to WGS analysis to investigate outbreaks. IMPORTANCE Candida auris is an emerging fungal pathogen now recognized as a threat to public health. The pathogen has spread worldwide and causes mainly hospital-associated outbreaks. To track and trace outbreaks and to relate them to new introductions from elsewhere, whole-genome sequencing and amplified fragment length polymorphism (AFLP) have been used for molecular typing. Whole-genome sequencing is costly and available only at a few centers, and AFLP is a complicated technique and hard to interpret. We describe a novel simple STR genotyping technique based on short tandem repeats in the C. auris genome. We also show that the performance of this STR-based genotyping technique has proven comparable to that of WGS. Overall, this work provides a novel, rapid, reliable, and cost-effective method of molecular outbreak investigations of C. auris.

scholarly journals Development of Candida auris microsatellite typing and its application on a global collection of isolates

2019 ◽  
Author(s):  
Theun de Groot ◽  
Ynze Puts ◽  
Indira Berrio ◽  
Anuradha Chowdhary ◽  
Jacques F. Meis
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Tandem Repeats ◽  
Cost Effective ◽  
Whole Genome ◽  
Candida Auris ◽  
Str Typing ◽  
Pathogenic Yeast ◽  
Str Analysis ◽  
Microsatellite Typing

AbstractCandida auris is a pathogenic yeast that causes invasive infections with high mortality. Infections most often occur in intensive care units of healthcare facilities. It is crucial to trace the source and prevent further spread of C. auris during an outbreak setting, therefore, genotyping of C. auris is required. To enable fast and cost-effective genotyping, we developed a microsatellite typing assay for C. auris.Short tandem repeats (STRs) in C. auris were identified, and a novel STR typing assay for C. auris was developed using 4 panels of three multiplex PCRs. Having shown that the microsatellite typing assay was highly reproducible and specific, a robust set of 444 C. auris isolates was investigated to identify genotypic diversity. In concordance with whole-genome sequencing (WGS) analysis we identified five major different C. auris clusters, namely, South-America, South-Asia, Africa, East-Asia and Iran. Overall, a total of 40 distinct genotypes were identified, with the largest variety in the East Asian clade. Comparison with WGS demonstrated that isolates with <20 SNPs are mostly not differentiated by STR analysis, while isolates with 30 or more SNPs usually have differences in one or more STR markers.Altogether, a highly reproducible and specific microsatellite typing assay for C. auris was developed, which distinguishes the five different C. auris clades in identical fashion to WGS, while most isolates differing >20 SNPs, as determined via WGS, are also separated. This new C. auris specific genotyping technique is a rapid, reliable, cost-effective alternative to WGS analysis to speedily investigate outbreaks.ImportanceCandida auris is an emerging fungal pathogen now recognized as a threat to public health. The pathogen has spread worldwide and mainly causes hospital associated outbreaks. To track and trace outbreaks and to relate them to new introductions from elsewhere, whole genome sequencing and amplified fragment length polymorphism (AFLP) have been used for molecular typing. While the former is costly and only available in few centers, AFLP is a complicated technique and standardization is not possible. We describe a novel simple microsatellite genotyping technique based on small tandem repeats in the C. auris genome. Further we show that this microsatellite based genotyping technique has been proven comparable to WGS. Overall, this work provides a novel, rapid, reliable and cost-effective method of molecular outbreaks investigations of C. auris.

scholarly journals Expanding U.S. Laboratory Capacity for Neisseria gonorrhoeae Antimicrobial Susceptibility Testing and Whole-Genome Sequencing through the CDC's Antibiotic Resistance Laboratory Network

2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Ellen N. Kersh ◽  
Cau D. Pham ◽  
John R. Papp ◽  
Robert Myers ◽  
Richard Steece ◽  
...  
Keyword(s):  
Public Health ◽  
Antibiotic Resistance ◽  
Neisseria Gonorrhoeae ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Whole Genome ◽  
Content Type ◽  
Laboratory Capacity

ABSTRACT U.S. gonorrhea rates are rising, and antibiotic-resistant Neisseria gonorrhoeae (AR-Ng) is an urgent public health threat. Since implementation of nucleic acid amplification tests for N. gonorrhoeae identification, the capacity for culturing N. gonorrhoeae in the United States has declined, along with the ability to perform culture-based antimicrobial susceptibility testing (AST). Yet AST is critical for detecting and monitoring AR-Ng. In 2016, the CDC established the Antibiotic Resistance Laboratory Network (AR Lab Network) to shore up the national capacity for detecting several resistance threats including N. gonorrhoeae. AR-Ng testing, a subactivity of the CDC’s AR Lab Network, is performed in a tiered network of approximately 35 local laboratories, four regional laboratories (state public health laboratories in Maryland, Tennessee, Texas, and Washington), and the CDC’s national reference laboratory. Local laboratories receive specimens from approximately 60 clinics associated with the Gonococcal Isolate Surveillance Project (GISP), enhanced GISP (eGISP), and the program Strengthening the U.S. Response to Resistant Gonorrhea (SURRG). They isolate and ship up to 20,000 isolates to regional laboratories for culture-based agar dilution AST with seven antibiotics and for whole-genome sequencing of up to 5,000 isolates. The CDC further examines concerning isolates and monitors genetic AR markers. During 2017 and 2018, the network tested 8,214 and 8,628 N. gonorrhoeae isolates, respectively, and the CDC received 531 and 646 concerning isolates and 605 and 3,159 sequences, respectively. In summary, the AR Lab Network supported the laboratory capacity for N. gonorrhoeae AST and associated genetic marker detection, expanding preexisting notification and analysis systems for resistance detection. Continued, robust AST and genomic capacity can help inform national public health monitoring and intervention.

scholarly journals Tracing Melioidosis Back to the Source: Using Whole-Genome Sequencing To Investigate an Outbreak Originating from a Contaminated Domestic Water Supply

2015 ◽  
Vol 53 (4) ◽  
pp. 1144-1148 ◽  
Author(s):  
Evan McRobb ◽  
Derek S. Sarovich ◽  
Erin P. Price ◽  
Mirjam Kaestli ◽  
Mark Mayo ◽  
...  
Keyword(s):  
Water Supply ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Clinical Isolates ◽  
Whole Genome ◽  
Northern Australia ◽  
Source Attribution ◽  
Environmental Strain ◽  
Content Type ◽  
Groundwater Supply

Melioidosis, a disease of public health importance in Southeast Asia and northern Australia, is caused by the Gram-negative soil bacillusBurkholderia pseudomallei. Melioidosis is typically acquired through environmental exposure, and case clusters are rare, even in regions where the disease is endemic.B. pseudomalleiis classed as a tier 1 select agent by the Centers for Disease Control and Prevention; from a biodefense perspective, source attribution is vital in an outbreak scenario to rule out a deliberate release. Two cases of melioidosis within a 3-month period at a residence in rural northern Australia prompted an investigation to determine the source of exposure.B. pseudomalleiisolates from the property's groundwater supply matched the multilocus sequence type of the clinical isolates. Whole-genome sequencing confirmed the water supply as the probable source of infection in both cases, with the clinical isolates differing from the likely infecting environmental strain by just one single nucleotide polymorphism (SNP) each. For the first time, we report a phylogenetic analysis of genomewide insertion/deletion (indel) data, an approach conventionally viewed as problematic due to high mutation rates and homoplasy. Our whole-genome indel analysis was concordant with the SNP phylogeny, and these two combined data sets provided greater resolution and a better fit with our epidemiological chronology of events. Collectively, this investigation represents a highly accurate account of source attribution in a melioidosis outbreak and gives further insight into a frequently overlooked reservoir ofB. pseudomallei. Our methods and findings have important implications for outbreak source tracing of this bacterium and other highly recombinogenic pathogens.

scholarly journals Putative Integrative Mobile Elements That Exploit the Xer Recombination Machinery Carrying blaIMI-Type Carbapenemase Genes in Enterobacter cloacae Complex Isolates in Singapore

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Tse H. Koh ◽  
Nurdyana Binte Abdul Rahman ◽  
Jeanette W. P. Teo ◽  
My-Van La ◽  
Balamurugan Periaswamy ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Multilocus Sequence Typing ◽  
Enterobacter Cloacae ◽  
Mobile Elements ◽  
Whole Genome ◽  
Content Type ◽  
Flanking Regions ◽  
Enterobacter Cloacae Complex

ABSTRACT Whole-genome sequencing was performed on 16 isolates of the carbapenemase-producing Enterobacter cloacae complex to determine the flanking regions of bla IMI-type genes. Phylogenetic analysis of multilocus sequence typing (MLST) targets separated the isolates into 4 clusters. The bla IMI-type genes were all found on Xer-dependent integrative mobile elements (IMEX). The IMEX elements of 5 isolates were similar to those described in Canada, while the remainder were novel. Five isolates had IMEX elements lacking a resolvase and recombinase.

scholarly journals Using molecular testing and whole-genome sequencing for tuberculosis diagnosis in a low-burden setting: a cost-effectiveness analysis using transmission-dynamic modelling

Thorax ◽  
2021 ◽  
Vol 76 (3) ◽  
pp. 281-291 ◽  
Author(s):  
Tendai Mugwagwa ◽  
Ibrahim Abubakar ◽  
Peter J White
Keyword(s):  
Cost Effectiveness ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Drug Sensitivity ◽  
Cost Effective ◽  
Molecular Testing ◽  
Whole Genome ◽  
Transmission Dynamic ◽  
Sensitivity Testing ◽  
Combined Use

BackgroundDespite progress in TB control in low-burden countries like England and Wales, there are still diagnostic delays. Molecular testing and/or whole-genome sequencing (WGS) provide more rapid diagnosis but their cost-effectiveness is relatively unexplored in low-burden settings.MethodsAn integrated transmission-dynamic health economic model is used to assess the cost-effectiveness of using WGS to replace culture-based drug-sensitivity testing, versus using molecular testing versus combined use of WGS and molecular testing, for routine TB diagnosis. The model accounts for the effects of faster appropriate treatment in reducing transmission, benefiting health and reducing future treatment costs. Cost-effectiveness is assessed using incremental net benefit (INB) over a 10-year horizon with a quality-adjusted life-year valued at £20 000, and discounting at 3.5% per year.ResultsWGS shortens the time to drug sensitivity testing and treatment modification where necessary, reducing treatment and hospitalisation costs, with an INB of £7.1 million. Molecular testing shortens the time to TB diagnosis and treatment. Initially, this causes an increase in annual costs of treatment, but averting transmissions and future active TB disease subsequently, resulting in cost savings and health benefits to achieve an INB of £8.6 million (GeneXpert MTB/RIF) or £11.1 million (Xpert-Ultra). Combined use of Xpert-Ultra and WGS is the optimal strategy we consider, with an INB of £16.5 million.ConclusionRoutine use of WGS or molecular testing is cost-effective in a low-burden setting, and combined use is the most cost-effective option. Adoption of these technologies can help low-burden countries meet the WHO End TB Strategy milestones, particularly the UK, which still has relatively high TB rates.

scholarly journals Whole-Genome Sequencing Confirms that Burkholderia pseudomallei Multilocus Sequence Types Common to Both Cambodia and Australia Are Due to Homoplasy

2014 ◽  
Vol 53 (1) ◽  
pp. 323-326 ◽  
Author(s):  
Birgit De Smet ◽  
Derek S. Sarovich ◽  
Erin P. Price ◽  
Mark Mayo ◽  
Vanessa Theobald ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Genome Analysis ◽  
Burkholderia Pseudomallei ◽  
Whole Genome ◽  
Whole Genome Analysis ◽  
Content Type ◽  
Sequence Types

Burkholderia pseudomalleiisolates with shared multilocus sequence types (STs) have not been isolated from different continents. We identified two STs shared between Australia and Cambodia. Whole-genome analysis revealed substantial diversity within STs, correctly identified the Asian or Australian origin, and confirmed that these shared STs were due to homoplasy.

scholarly journals Whole-Genome Sequencing Allows for Improved Identification of Persistent Listeria monocytogenes in Food-Associated Environments

2015 ◽  
Vol 81 (17) ◽  
pp. 6024-6037 ◽  
Author(s):  
Matthew J. Stasiewicz ◽  
Haley F. Oliver ◽  
Martin Wiedmann ◽  
Henk C. den Bakker
Keyword(s):  
Listeria Monocytogenes ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Genetic Determinants ◽  
Single Nucleotide ◽  
Content Type ◽  
Food Borne ◽  
Clonal Spread

ABSTRACTWhile the food-borne pathogenListeria monocytogenescan persist in food associated environments, there are no whole-genome sequence (WGS) based methods to differentiate persistent from sporadic strains. Whole-genome sequencing of 188 isolates from a longitudinal study ofL. monocytogenesin retail delis was used to (i) apply single-nucleotide polymorphism (SNP)-based phylogenetics for subtyping ofL. monocytogenes, (ii) use SNP counts to differentiate persistent from repeatedly reintroduced strains, and (iii) identify genetic determinants ofL. monocytogenespersistence. WGS analysis revealed three prophage regions that explained differences between three pairs of phylogenetically similar populations with pulsed-field gel electrophoresis types that differed by ≤3 bands. WGS-SNP-based phylogenetics found that putatively persistentL. monocytogenesrepresent SNP patterns (i) unique to a single retail deli, supporting persistence within the deli (11 clades), (ii) unique to a single state, supporting clonal spread within a state (7 clades), or (iii) spanning multiple states (5 clades). Isolates that formed one of 11 deli-specific clades differed by a median of 10 SNPs or fewer. Isolates from 12 putative persistence events had significantly fewer SNPs (median, 2 to 22 SNPs) than between isolates of the same subtype from other delis (median up to 77 SNPs), supporting persistence of the strain. In 13 events, nearly indistinguishable isolates (0 to 1 SNP) were found across multiple delis. No individual genes were enriched among persistent isolates compared to sporadic isolates. Our data show that WGS analysis improves food-borne pathogen subtyping and identification of persistent bacterial pathogens in food associated environments.

scholarly journals Evaluation of Whole-Genome Sequencing for Identification and Typing of Vibrio cholerae

2018 ◽  
Vol 56 (11) ◽  
Author(s):  
David R. Greig ◽  
Ulf Schaefer ◽  
Sophie Octavia ◽  
Ebony Hunter ◽  
Marie A. Chattaway ◽  
...  
Keyword(s):  
Public Health ◽  
Whole Genome Sequencing ◽  
Vibrio Cholerae ◽  
Species Identification ◽  
Genome Sequencing ◽  
National Level ◽  
Whole Genome ◽  
Content Type ◽  
El Tor ◽  
The Impact

ABSTRACT Epidemiological and microbiological data on Vibrio cholerae strains isolated between April 2004 and March 2018 (n = 836) and held at the Public Health England culture archive were reviewed. The traditional biochemical species identification and serological typing results were compared with the genome-derived species identification and serotype for a subset of isolates (n = 152). Of the 836 isolates, 750 (89.7%) were from a fecal specimen, 206 (24.6%) belonged to serogroup O1, and 7 (0.8%) were serogroup O139; 792 (94.7%) isolates were from patients reporting recent travel abroad, most commonly to India (n = 209) and Pakistan (n = 104). Of the 152 V. cholerae isolates identified by use of kmer, 149 (98.1%) were concordant with those identified using the traditional biochemical approach. Traditional serotyping results were 100% concordant with those of the whole-genome sequencing (WGS) analysis for the identification of serogroups O1 and O139 and classical and El Tor biotypes. ctxA was detected in all isolates of V. cholerae O1 El Tor and O139 belonging to sequence type 69 (ST69) and in V. cholerae O1 classical variants belonging to ST73. A phylogeny of isolates belonging to ST69 from U.K. travelers clustered geographically, with isolates from India and Pakistan located on separate branches. Moving forward, WGS data from U.K. travelers will contribute to global surveillance programs and the monitoring of emerging threats to public health and the global dissemination of pathogenic lineages. At the national level, these WGS data will inform the timely reinforcement of direct public health messaging to travelers and mitigate the impact of imported infections and the associated risks to public health.

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