Evaluation of the Impact of a Sequencing Assay for Detection of Drug Resistance on the Clinical Management of Tuberculosis.

BACKGROUND: In 2012, the California Department of Public Health began using pyrosequencing (PSQ) to detect mutations associated with resistance to isoniazid, rifampin, quinolones and injectable drugs in Mycobacterium tuberculosis complex. We evaluated the impact of the PSQ assay on the clinical management of tuberculosis (TB) in California. METHODS: TB surveillance and laboratory data for specimens submitted 1 August 2012 through 31 December 2016 were analyzed to determine time to effective treatment initiation. A survey of clinicians was used to assess how PSQ results influenced clinical decision making. RESULTS: Of 1957 specimens tested with PSQ, 52% were sediments and 46% were culture isolates, submitted a median of 8 and 35 days, respectively, after collection. Among 36 patients with multidrug-resistant (MDR) TB who had a sediment specimen submitted for PSQ, median time from specimen collection to MDR-TB treatment initiation was 12 days vs 51 days when PSQ was not used. Completed surveys were returned for 303 patients, 177 of whom reported a treatment change; 75 (42%) of clinicians reported PSQ as a reason for change. Twenty-one patients either had an MDR-TB risk factor and a smear-positive sputum specimen, but had PSQ performed on a culture isolate (9/36 [25%]); or did not have PSQ used for MDR-TB diagnosis (12/38 [32%]) and thus had an opportunity for earlier MDR-TB diagnosis with PSQ on sediment. CONCLUSIONS: Patients with MDR-TB initiated effective treatment 5 weeks earlier when PSQ was used compared to those without PSQ. Survey data suggest clinicians use PSQ to devise effective TB drug regimens. To maximize the benefit of PSQ, earlier submission of specimens should be prioritized.

Characterization of Clinical Isolates of Talaromyces marneffei and Related Species, California, USA.

Talaromyces marneffei and other Talaromyces species can cause opportunistic invasive fungal infections. We characterized clinical Talaromyces isolates from patients in California, USA, a non-Talaromyces-endemic area, by a multiphasic approach, including multigene phylogeny, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and phenotypic methods. We identified 10 potentially pathogenic Talaromyces isolates, 2 T. marneffei.

Genomic sequencing is required for identification of tuberculosis transmission in Hawaii.

BACKGROUND: Tuberculosis (TB) caused an estimated 1.4 million deaths and 10.4 million new cases globally in 2015. TB rates in the United States continue to steadily decline, yet rates in the State of Hawaii are perennially among the highest in the nation due to a continuous influx of immigrants from the Western Pacific and Asia. TB in Hawaii is composed of a unique distribution of genetic lineages, with the Beijing and Manila families of Mycobacterium tuberculosis (Mtb) comprising over two-thirds of TB cases. Standard fingerprinting methods (spoligotyping plus 24-loci Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeats [MIRU-VNTR] fingerprinting) perform poorly when used to identify actual transmission clusters composed of isolates from these two families. Those typing methods typically group isolates from these families into large clusters of non-linked isolates with identical fingerprints. Next-generation whole-genome sequencing (WGS) provides a new tool for molecular epidemiology that can resolve clusters of isolates with identical spoligotyping and MIRU-VNTR fingerprints. METHODS: We performed WGS and SNP analysis and evaluated epidemiological data to investigate 19 apparent TB transmission clusters in Hawaii from 2003 to 2017 in order to assess WGS' ability to resolve putative Mtb clusters from the Beijing and Manila families. This project additionally investigated MIRU-VNTR allele prevalence to determine why standard Mtb fingerprinting fails to usefully distinguish actual transmission clusters from these two Mtb families. RESULTS: WGS excluded transmission events in seven of these putative clusters, confirmed transmission in eight, and identified both transmission-linked and non-linked isolates in four. For epidemiologically identified clusters, while the sensitivity of MIRU-VNTR fingerprinting for identifying actual transmission clusters was found to be 100%, its specificity was only 28.6% relative to WGS. We identified that the Beijing and Manila families' significantly lower Shannon evenness of MIRU-VNTR allele distributions than lineage 4 was the cause of standard fingerprinting's poor performance when identifying transmission in Beijing and Manila family clusters. CONCLUSIONS: This study demonstrated that WGS is necessary for epidemiological investigation of TB in Hawaii and the Pacific.

Official American Thoracic Society/Infectious Diseases Society of America/Centers for Disease Control and Prevention Clinical Practice Guidelines: Diagnosis of Tuberculosis in Adults and Children.

BACKGROUND: Individuals infected with Mycobacterium tuberculosis (Mtb) may develop symptoms and signs of disease (tuberculosis disease) or may have no clinical evidence of disease (latent tuberculosis infection [LTBI]). Tuberculosis disease is a leading cause of infectious disease morbidity and mortality worldwide, yet many questions related to its diagnosis remain. METHODS: A task force supported by the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America searched, selected, and synthesized relevant evidence. The evidence was then used as the basis for recommendations about the diagnosis of tuberculosis disease and LTBI in adults and children. The recommendations were formulated, written, and graded using the Grading, Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: Twenty-three evidence-based recommendations about diagnostic testing for latent tuberculosis infection, pulmonary tuberculosis, and extrapulmonary tuberculosis are provided. Six of the recommendations are strong, whereas the remaining 17 are conditional. CONCLUSIONS: These guidelines are not intended to impose a standard of care. They provide the basis for rational decisions in the diagnosis of tuberculosis in the context of the existing evidence. No guidelines can take into account all of the often compelling unique individual clinical circumstances.

Official American Thoracic Society/Infectious Diseases Society of America/Centers for Disease Control and Prevention Clinical Practice Guidelines: Diagnosis of Tuberculosis in Adults and Children.

BACKGROUND: Individuals infected with Mycobacterium tuberculosis (Mtb) may develop symptoms and signs of disease (tuberculosis disease) or may have no clinical evidence of disease (latent tuberculosis infection [LTBI]). Tuberculosis disease is a leading cause of infectious disease morbidity and mortality worldwide, yet many questions related to its diagnosis remain. METHODS: A task force supported by the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America searched, selected, and synthesized relevant evidence. The evidence was then used as the basis for recommendations about the diagnosis of tuberculosis disease and LTBI in adults and children. The recommendations were formulated, written, and graded using the Grading, Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: Twenty-three evidence-based recommendations about diagnostic testing for latent tuberculosis infection, pulmonary tuberculosis, and extrapulmonary tuberculosis are provided. Six of the recommendations are strong, whereas the remaining 17 are conditional. CONCLUSIONS: These guidelines are not intended to impose a standard of care. They provide the basis for rational decisions in the diagnosis of tuberculosis in the context of the existing evidence. No guidelines can take into account all of the often compelling unique individual clinical circumstances.

Rapid deletion-based subtyping system for the Manila family of Mycobacterium tuberculosis.

The Manila family of Mycobacterium tuberculosis is a group of clonal isolates seen throughout the Pacific Basin. Commonly used rapid molecular typing methods often leave large groups of Manila family isolates clustered together. Here we describe a simple deletion-based PCR method that improves the discrimination for Manila family isolates, with or without the use of mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) classification, and that is both rapid and affordable. Twenty-eight Manila family isolates, classified by spoligotyping, were collected from around the Pacific Basin from 1995 to 2003 and were tested for known genomic deletions. Nine of 15 regions of difference tested were identified as potentially discriminatory, with 18 distinct patterns; of these 9, 5 were selected for optimal discrimination using 61 Manila family isolates collected from California in 2009. For this geographically limited sample, the single large cluster was reduced to 14 distinct patterns. When the isolates were tested by spoligotyping and MIRU-VNTR, the addition of deletion analysis increased the number of distinct patterns from 43 to 56. In summary, the two study groups, which together form a single group of 89 isolates by spoligotyping, were segregated into 17 subgroups by our deletion-based subtyping system.

Rapid drug susceptibility testing with a molecular beacon assay is associated with earlier diagnosis and treatment of multidrug-resistant tuberculosis in California.

To assess the clinical impact of a molecular beacon (MB) assay that detects multidrug-resistant tuberculosis (MDR TB), we retrospectively reviewed records of 127 MDR TB patients with and without MB testing between 2004 and 2007. Use of the MB assay reduced the time to detection and treatment of MDR TB.

Comparison of restriction fragment length polymorphism with the polymorphic guanine-cytosine-rich sequence and spoligotyping for differentiation of Mycobacterium tuberculosis isolates with five or fewer copies of IS6110.

The use of IS6110 as a marker for molecular epidemiological studies is limited when a Mycobacterium tuberculosis isolate has five or fewer copies of IS6110. Restriction fragment length polymorphism analysis with a highly polymorphic GC-rich repetitive sequence located in the plasmid pTBN12 (PGRS RFLP) and spoligotyping (based on the polymorphism of the DR region) are two frequently used secondary typing methods. The aim of this study was to compare the performance of these two methods in a population-based study in San Francisco. We included all patients with culture-positive tuberculosis from 1999 to 2007 with IS6110 RFLP results presenting five or fewer bands. PGRS RFLP and spoligotyping were performed using standardized methods. We determined the concordance between the two methods regarding cluster status and the risk factors for an isolate to be in a cluster with each of the methods. Our data indicate that both methods had similar discriminatory power and that the risk factors associated with clustering by either method were the same. Although the cluster/unique status was concordant in 84% of the isolates, patients were clustered differently depending on the method. Therefore, the methods are not interchangeable, and the same method should be used for longitudinal studies.

Extensively drug-resistant tuberculosis in california, 1993-2006.

BACKGROUND: Extensively drug-resistant (XDR) tuberculosis (TB) is a global public health emergency. We investigated the characteristics and extent of XDR TB in California to inform public health interventions. METHODS: XDR TB was defined as TB with resistance to at least isoniazid, rifampin, a fluoroquinolone, and 1 of 3 injectable second-line drugs (amikacin, kanamycin, or capreomycin). Pre-XDR TB was defined as TB with resistance to isoniazid and rifampin and either a fluoroquinolone or second-line injectable agent but not both. We analyzed TB case reports submitted to the state TB registry for the period 1993-2006. Local health departments and the state TB laboratory were queried to ensure complete drug susceptibility reporting. RESULTS: Among 424 multidrug-resistant (MDR) TB cases with complete drug susceptibility reporting, 18 (4.2%) were extensively drug resistant, and 77 (18%) were pre-extensively drug resistant. The proportion of pre-XDR TB cases increased over time, from 7% in 1993 to 32% in 2005 (P = .02)). Among XDR TB cases, 83% of cases involved foreign-born patients, and 43% were diagnosed in patients within 6 months after arrival in the United States. Mexico was the most common country of origin. Five cases (29%) of XDR TB were acquired during therapy in California. All patients with XDR TB had pulmonary disease, and most had prolonged infectious periods; the median time for conversion of sputum culture results was 195 days. Among 17 patients with known outcomes, 7 (41.2%) completed therapy, 5 (29.4%) moved, and 5 (29.4%) died. One patient continues to receive treatment. CONCLUSIONS: XDR TB and pre-XDR TB cases comprise a substantial fraction of MDR TB cases in California, indicating the need for interventions that improve surveillance, directly observed therapy, and rapid drug susceptibility testing and reporting.

Clinical Impact on Tuberculosis Treatment Outcomes of Discordance Between Molecular and Growth-Based Assays for Rifampin Resistance, California 2003-2013.

Background. Data from international settings suggest that isolates of Mycobacterium tuberculosis with rpoB mutations testing phenotypically susceptible to rifampin (RIF) may have clinical significance. We analyzed treatment outcomes of California patients with discordant molecular-phenotypic RIF results. Methods. We included tuberculosis (TB) patients, during 2003-2013, whose specimens tested RIF susceptible phenotypically but had a rpoB mutation determined by pyrosequencing. Demographic data were abstracted from the California TB registry. Phenotypic drug-susceptibility testing, medical history, treatment, and outcomes were abstracted from medical records. Results. Of 3330 isolates tested, 413 specimens had a rpoB mutation (12.4%). Of these, 16 (3.9%) had molecular-phenotypic discordant RIF results. Seven mutations were identified: 511Pro, 516Phe, 526Asn, 526Ser (AGC and TCC), 526Cys, and 533Pro. Fourteen (88%) had isoniazid (INH) resistance, 6 of whom were also phenotypically resistant to ethambutol (EMB) and/or pyrazinamide (PZA). Five patients (25%), 1 with 511Pro and 4 with 526Asn, relapsed or failed treatment. The initial regimen for 3 patients was RIF, PZA, and EMB; 1 patient received RIF, PZA, EMB, and a fluoroquinolone (FQN); and 1 patient received RIF, EMB, FQN, and some second-line medications. Upon retreatment with an expanded regimen, 3 (75%) patients completed treatment, 1 patient moved before treatment completion, and 1 patient continues on treatment. The remaining 11 patients had a successful outcome with 9 having received a FQN and/or a rifamycin. Conclusions. Rifampin molecular-phenotypic discordance was rare, and most isolates had INH resistance. Patients who did not receive an expanded regimen had poor outcomes. These mutations may have clinical importance, and expanded treatment regimens should be considered.

Transmission of mycobacterium tuberculosis via lung transplantation.

Organ donors are not routinely screened for tuberculosis (TB) in the United States. We investigated a case of pulmonary TB in a double-lung transplant recipient. We reviewed the donor's and recipient's records, and used molecular methods to compare the lung recipient's isolate with others from three sources: her hospital, the California state health department's genotyping database, and the donor's resident-nation of Guatemala. A respiratory specimen obtained from the lung recipient 1 day after transplantation grew Mycobacterium tuberculosis. Donor chest radiograph had a previously unnoticed pulmonary opacity that was present on post-transplant recipient chest radiographs and computed tomographs. The recipient's isolate was molecularly distinct from others at her hospital and in the state database, but was identical to two isolates from Guatemala. Tuberculosis was transmitted from lung donor to recipient. As organ transplantation becomes more common worldwide, similar cases could occur. Screening for TB in potential organ donors should be considered.