scholarly journals Whole-Genome Sequencing for Investigation of Possible Hospital Transmission of Tuberculosis

2020 ◽  
Vol 41 (S1) ◽  
pp. s435-s435
Author(s):  
Jenna Rasmusson ◽  
Priya Sampathkumar ◽  
Nancy Wengenack

Background: Whole-genome sequencing (WGS) is increasingly used in epidemiological investigations of infectious diseases. We describe the use of WGS to identify drug-resistance variants of tuberculosis (TB) and to determine potential transmission between patients at an academic medical center. Methods: Chart review and interviews of patients and healthcare workers along with WGS of M. tuberculosis isolates from the patients. Clinical information: In June 2019, patient A, a 20-year-old college student born in the United States was admitted with massive hemoptysis. The patient was identified as having active, cavitary TB that was acid-fast smear positive, and the mycobacterial culture grew M. tuberculosis. Patient B, a 40-year-old foreign-born patient with advanced lung cancer was acid-fast smear negative, but mycobacterial cultures were positive for M. tuberculosis. The 2 patients had overlapping stays in the medical intensive care unit. There was concern that patient B had acquired TB during her stay in the hospital from patient A, who was highly infectious. WGS showed that the mycobacterial isolates from the 2 patients were unrelated. Patient A was a student at a college campus where the state health department had previously issued a health advisory concerning active pulmonary TB in a student; and 7 additional TB cases were subsequently identified through contact investigation. Patient A denied any contact with other persons who were part of the outbreak and had not been included in the contact investigations of any of the cases. Of the 8 outbreak cases, 6 had been seen at our institution and had isolates available for testing. WGS showed that these 6 isolates matched patient A, establishing that she was part of the college outbreak. Conclusions: WGS was useful in establishing the source of M. tuberculosis infection in a patient who did not have known exposure to TB and in demonstrating that transmission of TB did not occur in the hospital.Funding: NoneDisclosures: None

2020 ◽  
Vol 110 (7) ◽  
pp. 1255-1259
Author(s):  
Emily Giroux ◽  
Guillaume J. Bilodeau

The filamentous ascomycete fungus Lachnellula willkommii is the causal agent of European larch canker (ELC), one of the most destructive diseases of larch in Europe and a regulated plant pathogen of quarantine significance in Canada and the United States. L. willkommii was first detected in Massachusetts, North America in 1927 on a larch plantation cultivated with nursery stock imported from Great Britain. Despite the decades of practices aimed at eliminating the pathogen, it has reappeared in coastal areas of Canada and the United States. There is concern ELC could spread throughout the range of eastern larch, a transcontinental species typical of the Boreal forest that spans the North American landscape. There is geographic range overlap between several nonpathogenic indigenous Lachnellula species and the reported distribution of L. willkommii in North America. Morphological and biological methods to distinguish L. willkommii are often inadequate as the fungus does not always produce the phenotypic structures that distinguish it from these other saprophytic Lachnellula species. Whole genome sequencing technologies were used to obtain the draft genome sequences of L. willkommii and six other Lachnellula species. Molecular markers identified from the genomic data may be used to discriminate L. willkommii from its nonpathogenic relatives.


2019 ◽  
Vol 16 (7) ◽  
pp. 441-450 ◽  
Author(s):  
Eric Brown ◽  
Uday Dessai ◽  
Sherri McGarry ◽  
Peter Gerner-Smidt

2017 ◽  
Vol 30 (1) ◽  
pp. 42-55 ◽  
Author(s):  
Karen J. LeCount ◽  
Linda K. Schlater ◽  
Tod Stuber ◽  
Suelee Robbe Austerman ◽  
Timothy S. Frana ◽  
...  

The gel diffusion precipitin test (GDPT) and restriction endonuclease analysis (REA) have commonly been used in the serotyping and genotyping of Pasteurella multocida. Whole genome sequencing (WGS) and single nucleotide polymorphism (SNP) analysis has become the gold standard for other organisms, offering higher resolution than previously available methods. We compared WGS to REA and GDPT on 163 isolates of P. multocida to determine if WGS produced more precise results. The isolates used represented the 16 reference serovars, isolates with REA profiles matching an attenuated fowl cholera vaccine strain, and isolates from 10 different animal species. Isolates originated from across the United States and from Chile. Identical REA profiles clustered together in the phylogenetic tree. REA profiles that differed by only a few bands had fewer SNP differences than REA profiles with more differences, as expected. The GDPT results were diverse but it was common to see a single serovar show up repeatedly within clusters. Several errors were found when examining the REA profiles. WGS was able to confirm these errors and compensate for the subjectivity in analysis of REA. Also, results of WGS and SNP analysis correlated more closely with the epidemiologic data than GDPT. In silico results were also compared to a lipopolysaccharide rapid multiplex PCR test. From the data produced in our study, WGS and SNP analysis was superior to REA and GDPT and highlighted some of the issues with the older tests.


2016 ◽  
Vol 60 (9) ◽  
pp. 5515-5520 ◽  
Author(s):  
Patrick F. McDermott ◽  
Gregory H. Tyson ◽  
Claudine Kabera ◽  
Yuansha Chen ◽  
Cong Li ◽  
...  

ABSTRACTLaboratory-basedin vitroantimicrobial susceptibility testing is the foundation for guiding anti-infective therapy and monitoring antimicrobial resistance trends. We used whole-genome sequencing (WGS) technology to identify known antimicrobial resistance determinants among strains of nontyphoidalSalmonellaand correlated these with susceptibility phenotypes to evaluate the utility of WGS for antimicrobial resistance surveillance. Six hundred fortySalmonellaof 43 different serotypes were selected from among retail meat and human clinical isolates that were tested for susceptibility to 14 antimicrobials using broth microdilution. The MIC for each drug was used to categorize isolates as susceptible or resistant based on Clinical and Laboratory Standards Institute clinical breakpoints or National Antimicrobial Resistance Monitoring System (NARMS) consensus interpretive criteria. Each isolate was subjected to whole-genome shotgun sequencing, and resistance genes were identified from assembled sequences. A total of 65 unique resistance genes, plus mutations in two structural resistance loci, were identified. There were more unique resistance genes (n =59) in the 104 human isolates than in the 536 retail meat isolates (n =36). Overall, resistance genotypes and phenotypes correlated in 99.0% of cases. Correlations approached 100% for most classes of antibiotics but were lower for aminoglycosides and beta-lactams. We report the first finding of extended-spectrum β-lactamases (ESBLs) (blaCTX-M1andblaSHV2a) in retail meat isolates ofSalmonellain the United States. Whole-genome sequencing is an effective tool for predicting antibiotic resistance in nontyphoidalSalmonella, although the use of more appropriate surveillance breakpoints and increased knowledge of new resistance alleles will further improve correlations.


2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Bradley T Endres ◽  
Khurshida Begum ◽  
Hua Sun ◽  
Seth T Walk ◽  
Ali Memariani ◽  
...  

Abstract Background The epidemic Clostridioides difficile ribotype 027 strain resulted from the dissemination of 2 separate fluoroquinolone-resistant lineages: FQR1 and FQR2. Both lineages were reported to originate in North America; however, confirmatory large-scale investigations of C difficile ribotype 027 epidemiology using whole genome sequencing has not been undertaken in the United States. Methods Whole genome sequencing and single-nucleotide polymorphism (SNP) analysis was performed on 76 clinical ribotype 027 isolates obtained from hospitalized patients in Texas with C difficile infection and compared with 32 previously sequenced worldwide strains. Maximum-likelihood phylogeny based on a set of core genome SNPs was used to construct phylogenetic trees investigating strain macro- and microevolution. Bayesian phylogenetic and phylogeographic analyses were used to incorporate temporal and geographic variables with the SNP strain analysis. Results Whole genome sequence analysis identified 2841 SNPs including 900 nonsynonymous mutations, 1404 synonymous substitutions, and 537 intergenic changes. Phylogenetic analysis separated the strains into 2 prominent groups, which grossly differed by 28 SNPs: the FQR1 and FQR2 lineages. Five isolates were identified as pre-epidemic strains. Phylogeny demonstrated unique clustering and resistance genes in Texas strains indicating that spatiotemporal bias has defined the microevolution of ribotype 027 genetics. Conclusions Clostridioides difficile ribotype 027 lineages emerged earlier than previously reported, coinciding with increased use of fluoroquinolones. Both FQR1 and FQR2 ribotype 027 epidemic lineages are present in Texas, but they have evolved geographically to represent region-specific public health threats.


2019 ◽  
Vol 85 (23) ◽  
Author(s):  
Shaokang Zhang ◽  
Hendrik C. den Bakker ◽  
Shaoting Li ◽  
Jessica Chen ◽  
Blake A. Dinsmore ◽  
...  

ABSTRACT SeqSero, launched in 2015, is a software tool for Salmonella serotype determination from whole-genome sequencing (WGS) data. Despite its routine use in public health and food safety laboratories in the United States and other countries, the original SeqSero pipeline is relatively slow (minutes per genome using sequencing reads), is not optimized for draft genome assemblies, and may assign multiple serotypes for a strain. Here, we present SeqSero2 (github.com/denglab/SeqSero2; denglab.info/SeqSero2), an algorithmic transformation and functional update of the original SeqSero. Major improvements include (i) additional sequence markers for identification of Salmonella species and subspecies and certain serotypes, (ii) a k-mer based algorithm for rapid serotype prediction from raw reads (seconds per genome) and improved serotype prediction from assemblies, and (iii) a targeted assembly approach for specific retrieval of serotype determinants from WGS for serotype prediction, new allele discovery, and prediction troubleshooting. Evaluated using 5,794 genomes representing 364 common U.S. serotypes, including 2,280 human isolates of 117 serotypes from the National Antimicrobial Resistance Monitoring System, SeqSero2 is up to 50 times faster than the original SeqSero while maintaining equivalent accuracy for raw reads and substantially improving accuracy for assemblies. SeqSero2 further suggested that 3% of the tested genomes contained reads from multiple serotypes, indicating a use for contamination detection. In addition to short reads, SeqSero2 demonstrated potential for accurate and rapid serotype prediction directly from long nanopore reads despite base call errors. Testing of 40 nanopore-sequenced genomes of 17 serotypes yielded a single H antigen misidentification. IMPORTANCE Serotyping is the basis of public health surveillance of Salmonella. It remains a first-line subtyping method even as surveillance continues to be transformed by whole-genome sequencing. SeqSero allows the integration of Salmonella serotyping into a whole-genome-sequencing-based laboratory workflow while maintaining continuity with the classic serotyping scheme. SeqSero2, informed by extensive testing and application of SeqSero in the United States and other countries, incorporates important improvements and updates that further strengthen its application in routine and large-scale surveillance of Salmonella by whole-genome sequencing.


2020 ◽  
pp. 104063872093387
Author(s):  
Patrick K. Mitchell ◽  
Brittany D. Cronk ◽  
Ian E. H. Voorhees ◽  
Derek Rothenheber ◽  
Renee R. Anderson ◽  
...  

Epidemics of H3N8 and H3N2 influenza A viruses (IAVs) in dogs, along with recognition of spillover infections from IAV strains typically found in humans or other animals, have emphasized the importance of efficient laboratory testing. Given the lack of active IAV surveillance or immunization requirements for dogs, cats, or horses imported into the United States, serotype prediction and whole-genome sequencing of positive specimens detected at veterinary diagnostic laboratories are also needed. The conserved sequences at the ends of the viral genome segments facilitate universal amplification of all segments of viral genomes directly from respiratory specimens. Although several methods for genomic analysis have been reported, no optimization focusing on companion animal strains has been described, to our knowledge. We compared 2 sets of published universal amplification primers using 26 IAV-positive specimens from dogs, horses, and a cat. Libraries prepared from the resulting amplicons were sequenced using Illumina chemistry, and reference-based assemblies were generated from the data produced by both methods. Although both methods produced high-quality data, coverage profiles and base calling differed between the 2 methods. The sequence data were also used to identify the subtype of the IAV strains sequenced and then compared to standard PCR assays for neuraminidase types N2 and N8.


2015 ◽  
Vol 82 (2) ◽  
pp. 459-466 ◽  
Author(s):  
S. Zhao ◽  
G. H. Tyson ◽  
Y. Chen ◽  
C. Li ◽  
S. Mukherjee ◽  
...  

ABSTRACTThe objectives of this study were to identify antimicrobial resistance genotypes forCampylobacterand to evaluate the correlation between resistance phenotypes and genotypes usingin vitroantimicrobial susceptibility testing and whole-genome sequencing (WGS). A total of 114Campylobacterspecies isolates (82C. coliand 32C. jejuni) obtained from 2000 to 2013 from humans, retail meats, and cecal samples from food production animals in the United States as part of the National Antimicrobial Resistance Monitoring System were selected for study. Resistance phenotypes were determined using broth microdilution of nine antimicrobials. Genomic DNA was sequenced using the Illumina MiSeq platform, and resistance genotypes were identified using assembled WGS sequences through blastx analysis. Eighteen resistance genes, includingtet(O),blaOXA-61,catA,lnu(C),aph(2″)-Ib,aph(2″)-Ic,aph(2′)-If,aph(2″)-Ig,aph(2″)-Ih,aac(6′)-Ie-aph(2″)-Ia,aac(6′)-Ie-aph(2″)-If,aac(6′)-Im,aadE,sat4,ant(6′),aad9,aph(3′)-Ic, andaph(3′)-IIIa, and mutations in two housekeeping genes (gyrAand 23S rRNA) were identified. There was a high degree of correlation between phenotypic resistance to a given drug and the presence of one or more corresponding resistance genes. Phenotypic and genotypic correlation was 100% for tetracycline, ciprofloxacin/nalidixic acid, and erythromycin, and correlations ranged from 95.4% to 98.7% for gentamicin, azithromycin, clindamycin, and telithromycin. All isolates were susceptible to florfenicol, and no genes associated with florfenicol resistance were detected. There was a strong correlation (99.2%) between resistance genotypes and phenotypes, suggesting that WGS is a reliable indicator of resistance to the nine antimicrobial agents assayed in this study. WGS has the potential to be a powerful tool for antimicrobial resistance surveillance programs.


mBio ◽  
2015 ◽  
Vol 6 (6) ◽  
Author(s):  
Wieland Meyer

ABSTRACT Cryptococcus gattii, the sister species of Cryptococcus neoformans, is an emerging pathogen which gained importance in connection with the ongoing cryptococcosis outbreak on Vancouver Island. Many molecular studies have divided this species into for major lineages: VGI, VGII, VGIII, and VGIV. This commentary summarizes the whole-genome sequencing (WGS) studies that have been carried out with this species, re-emphasizing the phylogenetic relationships, showing chromosomal rearrangements between those four groups, and identifying VGII as ancestral population within C. gattii. In addition, WGS specific to VGII, containing the Vancouver Island outbreak genotypes and those from the Pacific Northwest region of the United States, has placed the origin of this lineage within South America and identified specific genes responsible for either brain or lung infection. It also showed, that many genotypes are spread across a number of different continents, as has been previously shown by multilocus sequence typing (MLST). In addition, it showed that recombination occurs more frequently between mitochondrial than nuclear genomes.


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