A protective role for type I interferon signaling following infection with Mycobacterium tuberculosis carrying the rifampicin drug resistance-conferring RpoB mutation H445Y.

Interleukin-1 (IL-1) signaling is essential for controlling virulent Mycobacterium tuberculosis (Mtb) infection since antagonism of this pathway leads to exacerbated pathology and increased susceptibility. In contrast, the triggering of type I interferon (IFN) signaling is associated with the progression of tuberculosis (TB) disease and linked with negative regulation of IL-1 signaling. However, mice lacking IL-1 signaling can control Mtb infection if infected with an Mtb strain carrying the rifampin-resistance conferring mutation H445Y in its RNA polymerase ß subunit (rpoB-H445Y Mtb). The mechanisms that govern protection in the absence of IL-1 signaling during rpoB-H445Y Mtb infection are unknown. In this study, we show that in the absence of IL-1 signaling, type I IFN signaling controls rpoB-H445Y Mtb replication, lung pathology, and excessive myeloid cell infiltration. Additionally, type I IFN is produced predominantly by monocytes and recruited macrophages and acts on LysM-expressing cells to drive protection through nitric oxide (NO) production to restrict intracellular rpoB-H445Y Mtb. These findings reveal an unexpected protective role for type I IFN signaling in compensating for deficiencies in IL-1 pathways during rpoB-H445Y Mtb infection.

Drug resistant Mycobacterium tuberculosis strains have altered cell envelope hydrophobicity that influences infection outcomes in human macrophages.

Mycobacterium tuberculosis (M.tb), the causative agent of tuberculosis (TB), is considered one of the top infectious killers in the world. In recent decades, drug resistant (DR) strains of M.tb have emerged that make TB even more difficult to treat and pose a threat to public health. M.tb has a complex cell envelope that provides protection to the bacterium from chemotherapeutic agents. Although M.tb cell envelope lipids have been studied for decades, very little is known about how their levels change in relation to drug resistance. In this study, we examined changes in the cell envelope lipids [namely, phthiocerol dimycocerosates (PDIMs)], glycolipids [phosphatidyl-myo-inositol mannosides (PIMs)], and the PIM associated lipoglycans [lipomannan (LM); mannose-capped lipoarabinomannan (ManLAM)] of 11 M.tb strains that range from drug susceptible (DS) to multi-drug resistant (MDR) to pre-extensively drug resistant (pre-XDR). We show that there was an increase in the PDIMs:PIMs ratio as drug resistance increases, and provide evidence of PDIM species only present in the DR-M.tb strains studied. Overall, the LM and ManLAM cell envelope levels did not differ between DS- and DR-M.tb strains, but ManLAM surface exposure proportionally increased with drug resistance. Evaluation of host-pathogen interactions revealed that DR-M.tb strains have decreased association with human macrophages compared to DS strains. The pre-XDR M.tb strain with the largest PDIMs:PIMs ratio had decreased uptake, but increased intracellular growth rate at early time points post-infection when compared to the DS-M.tb strain H37Rv. These findings suggest that PDIMs may play an important role in drug resistance and that this observed increase in hydrophobic cell envelope lipids on the DR-M.tb strains studied may influence M.tb-host interactions.

The epidemiology, transmission, diagnosis, and management of drug-resistant tuberculosis-lessons from the South African experience.

Drug-resistant tuberculosis (DR-TB) threatens to derail tuberculosis control efforts, particularly in Africa where the disease remains out of control. The dogma that DR-TB epidemics are fueled by unchecked rates of acquired resistance in inadequately treated or non-adherent individuals is no longer valid in most high DR-TB burden settings, where community transmission is now widespread. A large burden of DR-TB in Africa remains undiagnosed due to inadequate access to diagnostic tools that simultaneously detect tuberculosis and screen for resistance. Furthermore, acquisition of drug resistance to new and repurposed drugs, for which diagnostic solutions are not yet available, presents a major challenge for the implementation of novel, all-oral, shortened (6-9 months) treatment. Structural challenges including poverty, stigma, and social distress disrupt engagement in care, promote poor treatment outcomes, and reduce the quality of life for people with DR-TB. We reflect on the lessons learnt from the South African experience in implementing state-of-the-art advances in diagnostic solutions, deploying recent innovations in pharmacotherapeutic approaches for rapid cure, understanding local transmission dynamics and implementing interventions to curtail DR-TB transmission, and in mitigating the catastrophic socioeconomic costs of DR-TB. We also highlight globally relevant and locally responsive research priorities for achieving DR-TB control in South Africa.

Impact of active surveillance and decolonization strategies for methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit.

OBJECTIVE: To assess the impact of active surveillance and decolonization strategies on methicillin-resistant Staphylococcus aureus (MRSA) infection rates in a NICU. STUDY DESIGN: MRSA infection rates were compared before (2014-2016) and during (2017-2022) an active surveillance program. Eligible infants were decolonized with chlorohexidine gluconate (CHG) bathing and/or topical mupirocin. Successful decolonization and rates of recolonization were assessed. RESULTS: Fifty-two (0.57%) of 9 100 hospitalized infants had invasive MRSA infections from 2014 to 2022; infection rates declined non-significantly. During the 6-year surveillance program, the risk of infection was 16.9-times [CI95 8.4, 34.1] higher in colonized infants than uncolonized infants. Those colonized with mupirocin-susceptible MRSA were more likely successfully decolonized (aOR 9.7 [CI95 4.2, 22.5]). Of 57 infants successfully decolonized who remained hospitalized, 34 (60%) became recolonized. CONCLUSIONS: MRSA infection rates did not significantly decline in association with an active surveillance and decolonization program. Alternatives to mupirocin and CHG are needed to facilitate decolonization.

Opportunities and limitations of genomics for diagnosing bedaquiline-resistant tuberculosis: a systematic review and individual isolate meta-analysis.

BACKGROUND: Clinical bedaquiline resistance predominantly involves mutations in mmpR5 (Rv0678). However, mmpR5 resistance-associated variants (RAVs) have a variable relationship with phenotypic Mycobacterium tuberculosis resistance. We did a systematic review to assess the maximal sensitivity of sequencing bedaquiline resistance-associated genes and evaluate the association between RAVs and phenotypic resistance, using traditional and machine-based learning techniques. METHODS: We screened public databases for articles published from database inception until Oct 31, 2022. Eligible studies performed sequencing of at least mmpR5 and atpE on clinically sourced M tuberculosis isolates and measured bedaquiline minimum inhibitory concentrations (MICs). A bias risk scoring tool was used to identify bias. Individual genetic mutations and corresponding MICs were aggregated, and odds ratios calculated to determine association of mutations with resistance. Machine-based learning methods were used to define test characteristics of parsimonious sets of diagnostic RAVs, and mmpR5 mutations were mapped to the protein structure to highlight mechanisms of resistance. This study was registered in the PROSPERO database (CRD42022346547). FINDINGS: 18 eligible studies were identified, comprising 975 M tuberculosis isolates containing at least one potential RAV (mutation in mmpR5, atpE, atpB, or pepQ), with 201 (20·6%) showing phenotypic bedaquiline resistance. 84 (29·5%) of 285 resistant isolates had no candidate gene mutation. Sensitivity and positive predictive value of taking an any mutation approach was 69% and 14%, respectively. 13 mutations, all in mmpR5, had a significant association with a resistant MIC (adjusted p<0·05). Gradient-boosted machine classifier models for predicting intermediate or resistant and resistant phenotypes both had receiver operator characteristic c statistic of 0·73 (95% CI 0·70-0·76). Frameshift mutations clustered in the α1 helix DNA-binding domain, and substitutions in the α2 and α3 helix hinge region and in the α4 helix-binding domain. INTERPRETATION: Sequencing candidate genes is insufficiently sensitive to diagnose clinical bedaquiline resistance, but where identified, some mutations should be assumed to be associated with resistance. Genomic tools are most likely to be effective in combination with rapid phenotypic diagnostics. This study was limited by selective sampling in contributing studies and only considering single genetic loci as causative of resistance. FUNDING: Francis Crick Institute and National Institute of Allergy and Infectious Diseases at the National Institutes of Health.

Genotype-Phenotype Characterization of Serial Mycobacterium tuberculosis Isolates in Bedaquiline-Resistant Tuberculosis.

BACKGROUND: Emerging resistance to bedaquiline (BDQ) threatens to undermine advances in the treatment of drug-resistant tuberculosis (DRTB). Characterizing serial Mycobacterium tuberculosis (Mtb) isolates collected during BDQ-based treatment can provide insights into the etiologies of BDQ resistance in this important group of DRTB patients. METHODS: We measured mycobacteria growth indicator tube (MGIT)-based BDQ minimum inhibitory concentrations (MICs) of Mtb isolates collected from 195 individuals with no prior BDQ exposure who were receiving BDQ-based treatment for DRTB. We conducted whole-genome sequencing on serial Mtb isolates from all participants who had any isolate with a BDQ MIC >1 collected before or after starting treatment (95 total Mtb isolates from 24 participants). RESULTS: Sixteen of 24 participants had BDQ-resistant TB (MGIT MIC ≥4 µg/mL) and 8 had BDQ-intermediate infections (MGIT MIC = 2 µg/mL). Participants with pre-existing resistance outnumbered those with resistance acquired during treatment, and 8 of 24 participants had polyclonal infections. BDQ resistance was observed across multiple Mtb strain types and involved a diverse catalog of mmpR5 (Rv0678) mutations, but no mutations in atpE or pepQ. Nine pairs of participants shared genetically similar isolates separated by <5 single nucleotide polymorphisms, concerning for potential transmitted BDQ resistance. CONCLUSIONS: BDQ-resistant TB can arise via multiple, overlapping processes, including transmission of strains with pre-existing resistance. Capturing the within-host diversity of these infections could potentially improve clinical diagnosis, population-level surveillance, and molecular diagnostic test development.

Mycobacterium tuberculosis carrying the rifampicin drug-resistance-conferring rpoB mutation H445Y is associated with suppressed immunity through type I interferons.

IMPORTANCE: This study highlights the impact of specific rifampicin-resistance-conferring mutations on the host immune response to Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). Clinical reports have previously suggested that multi-drug-resistant) TB patients exhibit altered peripheral immune responses as compared with their drug-sensitive TB counterparts. The murine model of infection with Mtb strains carrying drug-resistance-conferring mutations recapitulated these findings and allowed us to mechanistically interrogate the pathways responsible for driving the divergent immune responses. Our findings underscore the need for greater investigation into bacterial heterogeneity to better appreciate the diversity in host-pathogen interactions during TB disease.

Emergence and evolution of drug-resistant Mycobacterium tuberculosis in eastern China: A six-year prospective study.

Understanding the emergence and evolution of drug resistance can inform public health intervention to combat tuberculosis (TB). In this prospective molecular epidemiological surveillance study from 2015 to 2021 in eastern China, we prospectively collected whole-genome sequencing and epidemiological data on TB patients. We dissect the ordering of drug resistance mutation acquisition for nine commonly used anti-TB drugs, and we found that the katG S315T mutation first appeared around 1959, followed by rpoB S450L (1969), rpsL L43A (1972), embB M306V (1978), rrs 1401 (1981), fabG1 (1982), pncA (1985) and folC (1988) mutations. GyrA gene mutations appeared after the year of 2000. We observed that the first expansion of Mycobacterium tuberculosis (M.tb) resistance population among eastern China appeared after the introduction of isoniazid, streptomycin and para-amino salicylic acid, and the second expansion after the ethambutol, rifampicin, pyrazinamide, ethionamide and aminoglycosides. We speculate these two expansions are linked with population shift historically. By geospatial analysis, we found drug-resistant isolates migrated within eastern China. With epidemiological data of clonal strains, we observed some strains can evolve continuously in individuals and transmit readily in a population. In conclusion, this study mirrored the emergence and evolution of drug-resistant M.tb in eastern China were linked to the sequence and timing of introduction of anti-TB drugs, and multiple factors may contribute to the resistant population enlarged. To resolve the epidemic of drug-resistant TB, it requires applying anti-TB drugs carefully and/or identifying resistant patients timely to prevent them from developing high-level resistance and transmitting to others.

Opportunities and limitations of genomics for diagnosing bedaquiline-resistant tuberculosis: an individual isolate metaanalysis.

Background: Clinical bedaquiline resistance predominantly involves mutations in mmpR5 (Rv0678). However, mmpR5 resistance-associated variants (RAVs) have a variable relationship with phenotypic M. tuberculosis resistance. We performed a systematic review to (1) assess the maximal sensitivity of sequencing bedaquiline resistance-associated genes and (2) evaluate the association between RAVs and phenotypic resistance, using traditional and machine-based learning techniques. Methods: We screened public databases for articles published until October 2022. Eligible studies performed sequencing of at least mmpR5 and atpE on clinically-sourced M. tuberculosis isolates and measured bedaquiline minimum inhibitory concentrations (MICs). We performed genetic analysis for identification of phenotypic resistance and determined the association of RAVs with resistance. Machine-based learning methods were employed to define test characteristics of optimised sets of RAVs, and mmpR5 mutations were mapped to the protein structure to highlight mechanisms of resistance. Results: Eighteen eligible studies were identified, comprising 975 M. tuberculosis isolates containing ≥1 potential RAV (mutation in mmpR5, atpE, atpB or pepQ), with 201 (20.6%) demonstrating phenotypic bedaquiline resistance. 84/285 (29.5%) resistant isolates had no candidate gene mutation. Sensitivity and positive predictive value of taking an 'any mutation' approach was 69% and 14% respectively. Thirteen mutations, all in mmpR5, had a significant association with a resistant MIC (adjusted p<0.05). Gradient-boosted machine classifier models for predicting intermediate/resistant and resistant phenotypes both had receiver operator characteristic c-statistics of 0.73. Frameshift mutations clustered in the alpha 1 helix DNA binding domain, and substitutions in the alpha 2 and 3 helix hinge region and in the alpha 4 helix binding domain. Discussion: Sequencing candidate genes is insufficiently sensitive to diagnose clinical bedaquiline resistance, but where identified a limited number of mutations should be assumed to be associated with resistance. Genomic tools are most likely to be effective in combination with rapid phenotypic diagnostics.

Signatures of transmission in within-host M. tuberculosis variation.

Background: Because M. tuberculosis evolves slowly, transmission clusters often contain multiple individuals with identical consensus genomes, making it difficult to reconstruct transmission chains. Finding additional sources of shared M. tuberculosis variation could help overcome this problem. Previous studies have reported M. tuberculosis diversity within infected individuals; however, whether within-host variation improves transmission inferences remains unclear. Methods: To evaluate the transmission information present in within-host M. tuberculosis variation, we re-analyzed publicly available sequence data from three household transmission studies, using household membership as a proxy for transmission linkage between donor-recipient pairs. Findings: We found moderate levels of minority variation present in M. tuberculosis sequence data from cultured isolates that varied significantly across studies (mean: 6, 7, and 170 minority variants above a 1% minor allele frequency threshold, outside of PE/PPE genes). Isolates from household members shared more minority variants than did isolates from unlinked individuals in the three studies (mean 98 shared minority variants vs. 10; 0.8 vs. 0.2, and 0.7 vs. 0.2, respectively). Shared within-host variation was significantly associated with household membership (OR: 1.51 [1.30,1.71], for one standard deviation increase in shared minority variants). Models that included shared within-host variation improved the accuracy of predicting household membership in all three studies as compared to models without within-host variation (AUC: 0.95 versus 0.92, 0.99 versus 0.95, and 0.93 versus 0.91). Interpretation: Within-host M. tuberculosis variation persists through culture and could enhance the resolution of transmission inferences. The substantial differences in minority variation recovered across studies highlights the need to optimize approaches to recover and incorporate within-host variation into automated phylogenetic and transmission inference. Funding: NIAID: 5K01AI173385.

Genomic Epidemiology and Serology Associated with a SARS-CoV-2 R.1 Variant Outbreak in New Jersey.

Examining the neutralizing capacity of monoclonal antibodies (MAbs) used to treat COVID-19, as well as antibodies recovered from unvaccinated, previously vaccinated, and infected individuals, against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) remains critical to study. Here, we report on a SARS-CoV-2 nosocomial outbreak caused by the SARS-CoV-2 R.1 variant harboring the E484K mutation in a 281-bed psychiatric facility in New Jersey among unvaccinated inpatients and health care professionals (HCPs). A total of 81 inpatients and HCPs tested positive for SARS-Cov-2 by reverse transcription (RT)-PCR from 29 October 9 to 30 November 2020. The R.1 variant exhibits partial or complete resistance to two MAbs in clinical use, as well as 2 receptor binding domain MAbs and 4 N-terminal domain (NTD) MAbs. NTD MAbs against pseudovirus harboring single characteristic R.1 mutations highlight the role of S255F in loss of activity. Additionally, we note dampened neutralization capacity by plasma from individuals with previous SARS-CoV-2 infection or sera from vaccinated individuals. The relative resistance of the R.1 variant is likely lower than that of B.1.351 and closer to that of P.1 and B.1.526. The R.1 lineage has been reported in 47 states in the United States and 40 countries. Although high proportions exhibited symptoms (26% and 61% among patients and HCPs, respectively) and relative antibody resistance, we detected only 10 R.1 variants from over 2,900 samples (~0.34%) collected from January to October 2021. Among 3 vaccinated individuals previously infected with R.1, we observed robust neutralizing antibody responses against SARS-CoV-2 wild type and VOCs. IMPORTANCE The neutralizing capacities of monoclonal antibodies used to treat COVID-19 and of those recovered from previously infected and vaccinated individuals against SARS-CoV-2 variants of concern (VOCs) remain important questions. We report on a nosocomial outbreak caused by a SARS-CoV-2 R.1 variant harboring an E484K mutation among 81 unvaccinated inpatients and health care professionals. We note high attack rates with symptoms in nearly 50% of infected individuals, in sharp contrast to an unrelated institutional outbreak caused by the R.1 variant among a vaccinated population. We found little evidence of significant community spillover. This variant exhibits partial or complete resistance to two monoclonal antibodies in clinical use and dampened the neutralization capacity of convalescent-phase plasma from individuals with previous infection or sera from vaccinated individuals. Among three vaccinated individuals previously infected with R.1, we observed robust neutralizing antibody responses against SARS-CoV-2 wild type and VOCs. These findings underscore the importance of vaccination for prevention of symptomatic COVID-19 disease.

The role of prisons in disseminating tuberculosis in Brazil: A genomic epidemiology study.

Background: Globally, prisons are high-incidence settings for tuberculosis. Yet the role of prisons as reservoirs of M. tuberculosis, propagating epidemics through spillover to surrounding communities, has been difficult to measure directly. Methods: To quantify the role of prisons in driving wider community M. tuberculosis transmission, we conducted prospective genomic surveillance in Central West Brazil from 2014 to 2019. We whole genome sequenced 1152 M. tuberculosis isolates collected during active and passive surveillance inside and outside prisons and linked genomes to detailed incarceration histories. We applied multiple phylogenetic and genomic clustering approaches and inferred timed transmission trees. Findings: M. tuberculosis sequences from incarcerated and non-incarcerated people were closely related in a maximum likelihood phylogeny. The majority (70.8%; 46/65) of genomic clusters including people with no incarceration history also included individuals with a recent history of incarceration. Among cases in individuals with no incarceration history, 50.6% (162/320) were in clusters that included individuals with recent incarceration history, suggesting that transmission chains often span prisons and communities. We identified a minimum of 18 highly probable spillover events, M. tuberculosis transmission from people with a recent incarceration history to people with no prior history of incarceration, occurring in the state's four largest cities and across sampling years. We additionally found that frequent transfers of people between the state's prisons creates a highly connected prison network that likely disseminates M. tuberculosis across the state. Interpretation: We developed a framework for measuring spillover from high-incidence environments to surrounding communities by integrating genomic and spatial information. Our findings indicate that, in this setting, prisons serve not only as disease reservoirs, but also disseminate M. tuberculosis across highly connected prison networks, both amplifying and propagating M. tuberculosis risk in surrounding communities. Funding: Brazil's National Council for Scientific and Technological Development and US National Institutes of Health.

Connecting the dots: understanding how human mobility shapes TB epidemics.

Tuberculosis (TB) remains a leading infectious cause of death worldwide. Reducing TB infections and TB-related deaths rests ultimately on stopping forward transmission from infectious to susceptible individuals. Critical to this effort is understanding how human host mobility shapes the transmission and dispersal of new or existing strains of Mycobacterium tuberculosis (Mtb). Important questions remain unanswered. What kinds of mobility, over what temporal and spatial scales, facilitate TB transmission? How do human mobility patterns influence the dispersal of novel Mtb strains, including emergent drug-resistant strains? This review summarizes the current state of knowledge on mobility and TB epidemic dynamics, using examples from three topic areas, including inference of genetic and spatial clustering of infections, delineating source-sink dynamics, and mapping the dispersal of novel TB strains, to examine scientific questions and methodological issues within this topic. We also review new data sources for measuring human mobility, including mobile phone-associated movement data, and discuss important limitations on their use in TB epidemiology.

Recurrent Subclinical Tuberculosis Among Antiretroviral Therapy-Accessing Participants: Incidence, Clinical Course, and Outcomes.

BACKGROUND: Undiagnosed asymptomatic subclinical tuberculosis (TB) remains a significant threat to global TB control, accounting for a substantial proportion of cases among people living with human immunodeficiency virus (HIV)/AIDS (PLWHA). We determined incidence, progression, and outcomes of subclinical TB in antiretroviral therapy (ART)-accessing PLWHA with known previous TB in South Africa. METHODS: A total of 402 adult PLWHA previously treated for TB were enrolled in the prospective Centre for the AIDS Programme of Research in South Africa TRuTH (TB Recurrence Upon TB and HIV treatment) Study. Participants were screened for TB with quarterly clinical and bacteriologic evaluation and biannual chest radiographs over 36 months. Those with suspected or confirmed TB were referred to the National TB Programme. Participants received HIV services, including ART. Incidence rate of TB was estimated using Poisson regression and descriptive statistical analyses summarized data. RESULTS: A total of 48 of 402 (11.9%) bacteriologically confirmed incident recurrent TB cases were identified, comprising 17 of 48 (35.4%) subclinical TB cases and 31 of 48 (64.5%) clinical TB cases. Age, sex, and body mass index were similar among subclinical, clinical, and no TB groups. Incidence rates (95% Confidence Interval [CI]) of recurrent TB overall, in clinical and subclinical TB groups were 2.3 (1.7-3.0), 1.5 (1.1-2.2), and 0.9 (0.5-1.4) per 100 person-years, respectively. In the subclinical TB group, 14 of 17 (82.4%) were diagnosed by TB culture only, 11 of 17 (64.7%) received TB treatment, and 6 of 17 (35.3%) resolved TB spontaneously. CONCLUSIONS: High incidence rates of recurrent subclinical TB in PLWHA highlight inadequacies of symptom-based TB screening in high TB-HIV burden settings.

Rifampin resistance mutations in the rpoB gene of Enterococcus faecalis impact host macrophage cytokine production.

Antibiotic-resistant bacteria in the genus Enterococcus are a major cause of nosocomial infections and are an emergent public health concern. Similar to a number of bacterial species, resistance to the antibiotic rifampicin (RifR) in enterococci is associated with mutations in the gene encoding the ß subunit of RNA polymerase (rpoB). In Mycobacterium tuberculosis, RifRrpoB mutations alter mycobacterial surface lipid expression and are associated with an altered IL-1 cytokine response in macrophages upon infection. However, it is not clear if RifR mutations modulate host cytokine responses by other bacteria. To address this question, we utilized Enterococcus faecalis (E. faecalis). Here, we treated human monocyte-derived macrophages with heat-inactivated wild type or RifRrpoB mutants of E. faecalis and found that RifR mutations reduced IL-1ß cytokine production. However, RifR mutations elicited other potent pro- and anti-inflammatory responses, indicating that they can impact other immune pathways beyond IL-1R1 signaling. Our findings suggest that immunomodulation by mutations in rpoB may be conserved across diverse bacterial species and that subversion of IL-1R1 pathway is shared by RifR bacteria.

Whole Genome Sequencing Assessing Impact of Diabetes Mellitus on Tuberculosis Mutations and Type of Recurrence in India.

BACKGROUND: Evidence describing the impact of diabetes mellitus (DM) on the recurrence and mutation rate of Mycobacterium tuberculosis (Mtb) is limited. METHODS: This study was nested in 3 cohort studies of tuberculosis (TB) patients with and without DM in India. Paired Mtb isolates recovered at baseline and treatment failure/recurrence underwent whole genome sequencing. We compared acquisition of single-nucleotide polymorphisms (SNPs), TB drug resistance mutations, and type of recurrence (endogenous reactivation [<8 SNPs] or exogenous reinfection [≥8 SNPs]) by DM status. RESULTS: Of 1633 enrolled in the 3 parent cohorts, 236 (14.5%) had microbiologically confirmed TB treatment failure/recurrence; 76 Mtb isolate pairs were available for sequencing (22 in TB-DM and 54 in TB-only). The SNP acquisition rate was overall was 0.43 (95% confidence interval [CI], .25-.64) per 1 person-year (PY); 0.77 (95% CI, .40-1.35) per 1 PY, and 0.44 (95% CI, .19-.86) per 1 PY at treatment failure and recurrence, respectively. Significant difference in SNP rates by DM status was seen at recurrence (0.21 [95% CI, .04-.61]) per 1 PY for TB-only vs 1.28 (95% CI, .41-2.98) per 1 PY for TB-DM; P = .02). No significant difference in SNP rates by DM status was observed at treatment failure. Acquired TB drug resistance was seen in 4 of 18 (22%) in TB-DM vs 4 of 45 (9%) in TB-only (P = .21). Thirteen (17%) participants had exogenous reinfection; the reinfection rate at recurrence was 25% (3/12) for TB-DM vs 17% (4/24) in TB-only (P = .66). CONCLUSIONS: Considerable intrahost Mtb mutation rates were present at recurrence among patients with DM in India. One-fourth of patients with DM had exogenous reinfection at recurrence.

Readmission Rates in Stroke Patients with and without Infections: Incidence and Risk Factors.

BACKGROUND: Stroke patients are at increased risk for acquiring infections in the hospital and risk of readmission. We aimed to examine whether an infection acquired during the initial stroke admission contributes to increased risk of readmission and infection during readmission. METHODS: We performed a retrospective cohort study incorporating all adult ischemic stroke patients from three New York City hospitals from 2006 to 2016. A validated computer algorithm defined infections based on electronically-available laboratory culture data. Multivariable logistic regression was used to evaluate the crude and adjusted association of infections present on admission (IPOA) and healthcare-associated infections (HAI) with 60-day readmissions, and infection during readmission. RESULTS: Among the 10,436 stroke patients, 17% had infections during initial admission of which 52% were IPOA and 48% were HAI. The risk of readmission was significantly higher for those with HAIs (OR = 1.40; 95% CI: 1.20-1.64) and IPOA (OR = 1.26; 95% CI: 1.09-1.47). The presence of infection during the 60-day readmission was also independently predicted by HAI (OR = 3.27; 95% CI: 2.60-4.12) and IPOA (OR = 2.54; 95% CI: 2.01-3.22). Patients with a Gram-negative infection were not at higher odds for readmission compared to patients with a Gram-positive infection (OR 1.07, 95%CI 0.81-1.42). CONCLUSION: Among stroke patients, HAI and IPOA were predictors of readmission within 60 days and infection during readmission.