RESUMO
BACKGROUND: In January 2015, a total of 11 new diagnoses of human immunodeficiency virus (HIV) infection were reported in a small community in Indiana. We investigated the extent and cause of the outbreak and implemented control measures. METHODS: We identified an outbreak-related case as laboratory-confirmed HIV infection newly diagnosed after October 1, 2014, in a person who either resided in Scott County, Indiana, or was named by another case patient as a syringe-sharing or sexual partner. HIV polymerase (pol) sequences from case patients were phylogenetically analyzed, and potential risk factors associated with HIV infection were ascertained. RESULTS: From November 18, 2014, to November 1, 2015, HIV infection was diagnosed in 181 case patients. Most of these patients (87.8%) reported having injected the extended-release formulation of the prescription opioid oxymorphone, and 92.3% were coinfected with hepatitis C virus. Among 159 case patients who had an HIV type 1 pol gene sequence, 157 (98.7%) had sequences that were highly related, as determined by phylogenetic analyses. Contact tracing investigations led to the identification of 536 persons who were named as contacts of case patients; 468 of these contacts (87.3%) were located, assessed for risk, tested for HIV, and, if infected, linked to care. The number of times a contact was named as a syringe-sharing partner by a case patient was significantly associated with the risk of HIV infection (adjusted risk ratio for each time named, 1.9; P<0.001). In response to this outbreak, a public health emergency was declared on March 26, 2015, and a syringe-service program in Indiana was established for the first time. CONCLUSIONS: Injection-drug use of extended-release oxymorphone within a network of persons who inject drugs in Indiana led to the introduction and rapid transmission of HIV. (Funded by the state government of Indiana and others.).
Assuntos
Surtos de Doenças , Infecções por HIV/epidemiologia , HIV-1/genética , Oximorfona/administração & dosagem , Abuso de Substâncias por Via Intravenosa/complicações , Adolescente , Adulto , Coinfecção , Busca de Comunicante , Infecções por HIV/transmissão , Hepatite C/epidemiologia , Humanos , Indiana/epidemiologia , Masculino , Pessoa de Meia-Idade , Uso Comum de Agulhas e Seringas/efeitos adversos , Filogenia , Apoio Social , Adulto JovemRESUMO
In January 2016, highly pathogenic avian influenza (HPAI) A(H7N8) virus and low pathogenicity avian influenza (LPAI) A(H7N8) virus were detected in commercial turkey flocks in Dubois County, Indiana. The Indiana State Department of Health (ISDH) and the Dubois County Health Department (DCHD) coordinated the public health response to this outbreak, which was the first detection of HPAI A(H7N8) in any species (1). This response was the first to fully implement unpublished public health monitoring procedures for HPAI responders that were developed by the U.S. Department of Agriculture (USDA) and CDC in 2015 (Sonja Olsen, CDC, personal communication, October 2017). No cases of zoonotic avian influenza infection in humans were detected during the outbreak.
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Surtos de Doenças/veterinária , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Prática de Saúde Pública , Perus/virologia , Animais , Surtos de Doenças/prevenção & controle , Indiana/epidemiologia , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologiaRESUMO
In January 2015, an outbreak of undiagnosed human immunodeficiency virus (HIV) infections among persons who inject drugs (PWID) was recognized in rural Indiana. By September 2016, 205 persons in this community of approximately 4400 had received a diagnosis of HIV infection. We report results of new approaches to analyzing epidemiologic and laboratory data to understand transmission during this outbreak. HIV genetic distances were calculated using the polymerase region. Networks were generated using data about reported high-risk contacts, viral genetic similarity, and their most parsimonious combinations. Sample collection dates and recency assay results were used to infer dates of infection. Epidemiologic and laboratory data each generated large and dense networks. Integration of these data revealed subgroups with epidemiologic and genetic commonalities, one of which appeared to contain the earliest infections. Predicted infection dates suggest that transmission began in 2011, underwent explosive growth in mid-2014, and slowed after the declaration of a public health emergency. Results from this phylodynamic analysis suggest that the majority of infections had likely already occurred when the investigation began and that early transmission may have been associated with sexual activity and injection drug use. Early and sustained efforts are needed to detect infections and prevent or interrupt rapid transmission within networks of uninfected PWID.
Assuntos
Surtos de Doenças , Infecções por HIV/genética , Infecções por HIV/transmissão , HIV-1/genética , Alcaloides Opiáceos/efeitos adversos , Abuso de Substâncias por Via Intravenosa/complicações , Adulto , Busca de Comunicante , Feminino , Infecções por HIV/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Comportamento Sexual , Estados Unidos/epidemiologiaRESUMO
This multicenter study analyzed Nocardia spp., including extraction, spectral acquisition, Bruker matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identification, and score interpretation, using three Nocardia libraries, the Bruker, National Institutes of Health (NIH), and The Ohio State University (OSU) libraries, and compared the results obtained by each center. A standardized study protocol, 150 Nocardia isolates, and NIH and OSU Nocardia MALDI-TOF MS libraries were distributed to three centers. Following standardized culture, extraction, and MALDI-TOF MS analysis, isolates were identified using score cutoffs of ≥2.0 for species/species complex-level identification and ≥1.8 for genus-level identification. Isolates yielding a score of <2.0 underwent a single repeat extraction and analysis. The overall score range for all centers was 1.3 to 2.7 (average, 2.2 ± 0.3), with common species generally producing higher average scores than less common ones. Score categorization and isolate identification demonstrated 86% agreement between centers; 118 of 150 isolates were correctly identified to the species/species complex level by all centers. Nine strains (6.0%) were not identified by any center, and six (4.0%) of these were uncommon species with limited library representation. A categorical score discrepancy among centers occurred for 21 isolates (14.0%). There was an overall benefit of 21.2% from repeat extraction of low-scoring isolates and a center-dependent benefit for duplicate spotting (range, 2 to 8.7%). Finally, supplementation of the Bruker Nocardia MALDI-TOF MS library with both the OSU and NIH libraries increased the genus-level and species-level identification by 18.2% and 36.9%, respectively. Overall, this study demonstrates the ability of diverse clinical microbiology laboratories to utilize MALDI-TOF MS for the rapid identification of clinically relevant Nocardia spp. and to implement MALDI-TOF MS libraries developed by single laboratories across institutions.
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Técnicas Bacteriológicas/métodos , Nocardiose/diagnóstico , Nocardiose/microbiologia , Nocardia/classificação , Nocardia/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Nocardia/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estados UnidosRESUMO
The Aspergillus fumigatus sterol regulatory element binding protein (SREBP) SrbA belongs to the basic Helix-Loop-Helix (bHLH) family of transcription factors and is crucial for antifungal drug resistance and virulence. The latter phenotype is especially striking, as loss of SrbA results in complete loss of virulence in murine models of invasive pulmonary aspergillosis (IPA). How fungal SREBPs mediate fungal virulence is unknown, though it has been suggested that lack of growth in hypoxic conditions accounts for the attenuated virulence. To further understand the role of SrbA in fungal infection site pathobiology, chromatin immunoprecipitation followed by massively parallel DNA sequencing (ChIP-seq) was used to identify genes under direct SrbA transcriptional regulation in hypoxia. These results confirmed the direct regulation of ergosterol biosynthesis and iron uptake by SrbA in hypoxia and revealed new roles for SrbA in nitrate assimilation and heme biosynthesis. Moreover, functional characterization of an SrbA target gene with sequence similarity to SrbA identified a new transcriptional regulator of the fungal hypoxia response and virulence, SrbB. SrbB co-regulates genes involved in heme biosynthesis and demethylation of C4-sterols with SrbA in hypoxic conditions. However, SrbB also has regulatory functions independent of SrbA including regulation of carbohydrate metabolism. Loss of SrbB markedly attenuates A. fumigatus virulence, and loss of both SREBPs further reduces in vivo fungal growth. These data suggest that both A. fumigatus SREBPs are critical for hypoxia adaptation and virulence and reveal new insights into SREBPs' complex role in infection site adaptation and fungal virulence.
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Aspergillus fumigatus , Proteínas Fúngicas , Proteínas de Ligação a Elemento Regulador de Esterol , Transcriptoma , Aspergillus fumigatus/genética , Aspergillus fumigatus/metabolismo , Aspergillus fumigatus/patogenicidade , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/genética , Sequenciamento de Nucleotídeos em Larga Escala , Proteínas de Ligação a Elemento Regulador de Esterol/biossíntese , Proteínas de Ligação a Elemento Regulador de Esterol/genéticaRESUMO
GPI-anchoring is a universal and critical post-translational protein modification in eukaryotes. In fungi, many cell wall proteins are GPI-anchored, and disruption of GPI-anchored proteins impairs cell wall integrity. After being synthesized and attached to target proteins, GPI anchors undergo modification on lipid moieties. In spite of its importance for GPI-anchored protein functions, our current knowledge of GPI lipid remodelling in pathogenic fungi is limited. In this study, we characterized the role of a putative GPI lipid remodelling protein, designated PerA, in the human pathogenic fungus Aspergillus fumigatus. PerA localizes to the endoplasmic reticulum and loss of PerA leads to striking defects in cell wall integrity. A perA null mutant has decreased conidia production, increased susceptibility to triazole antifungal drugs, and is avirulent in a murine model of invasive pulmonary aspergillosis. Interestingly, loss of PerA increases exposure of ß-glucan and chitin content on the hyphal cell surface, but diminished TNF production by bone marrow-derived macrophages relative to wild type. Given the structural specificity of fungal GPI-anchors, which is different from humans, understanding GPI lipid remodelling and PerA function in A. fumigatus is a promising research direction to uncover a new fungal specific antifungal drug target.
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Antifúngicos/metabolismo , Aspergillus fumigatus/fisiologia , Azóis/metabolismo , Parede Celular/fisiologia , Retículo Endoplasmático/metabolismo , Proteínas Fúngicas/metabolismo , Fatores de Virulência/metabolismo , Animais , Aspergillus fumigatus/genética , Aspergillus fumigatus/crescimento & desenvolvimento , Aspergillus fumigatus/metabolismo , Parede Celular/metabolismo , Modelos Animais de Doenças , Farmacorresistência Fúngica , Proteínas Fúngicas/genética , Deleção de Genes , Aspergilose Pulmonar Invasiva/microbiologia , Aspergilose Pulmonar Invasiva/patologia , Camundongos , Esporos Fúngicos/crescimento & desenvolvimento , Virulência , Fatores de Virulência/genéticaRESUMO
The human pathogen Aspergillus fumigatus adapts to stress encountered in the mammalian host as part of its ability to cause disease. The transcription factor SrbA plays a significant role in this process by regulating genes involved in hypoxia and low-iron adaptation, antifungal drug responses and virulence. SrbA is a direct transcriptional regulator of genes encoding key enzymes in the ergosterol biosynthesis pathway, including erg25A and erg25B, and ΔsrbA accumulates C4-methyl sterols, suggesting a loss of Erg25 activity [C4-sterol methyl oxidase (SMO)]. Characterization of the two genes encoding SMOs in Aspergillus fumigatus revealed that both serve as functional C4-demethylases, with Erg25A serving in a primary role, as Δerg25A accumulates more C4-methyl sterol intermediates than Δerg25B. Single deletion of these SMOs revealed alterations in canonical ergosterol biosynthesis, indicating that ergosterol may be produced in an alternative fashion in the absence of SMO activity. A Δerg25A strain displayed moderate susceptibility to hypoxia and the endoplasmic reticulum stress-inducing agent DTT, but was not required for virulence in murine or insect models of invasive aspergillosis. Inducing expression of erg25A partially restored the hypoxia growth defect of ΔsrbA. These findings implicated Aspergillus fumigatus SMOs in the maintenance of canonical ergosterol biosynthesis and indicated an overall involvement in the fungal stress response.
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Aspergillus fumigatus/enzimologia , Aspergillus fumigatus/fisiologia , Ergosterol/metabolismo , Proteínas Fúngicas/efeitos adversos , Oxigenases de Função Mista/metabolismo , Adaptação Fisiológica , Aspergilose/microbiologia , Aspergillus fumigatus/genética , Proteínas Fúngicas/genética , Humanos , Metilação , Oxigenases de Função Mista/genéticaRESUMO
Sterol regulatory element binding proteins (SREBPs) are a class of basic helix-loop-helix transcription factors that regulate diverse cellular responses in eukaryotes. Adding to the recognized importance of SREBPs in human health, SREBPs in the human fungal pathogens Cryptococcus neoformans and Aspergillus fumigatus are required for fungal virulence and susceptibility to triazole antifungal drugs. To date, the exact mechanism(s) behind the role of SREBP in these observed phenotypes is not clear. Here, we report that A. fumigatus SREBP, SrbA, mediates regulation of iron acquisition in response to hypoxia and low iron conditions. To further define SrbA's role in iron acquisition in relation to previously studied fungal regulators of iron metabolism, SreA and HapX, a series of mutants were generated in the ΔsrbA background. These data suggest that SrbA is activated independently of SreA and HapX in response to iron limitation, but that HapX mRNA induction is partially dependent on SrbA. Intriguingly, exogenous addition of high iron or genetic deletion of sreA in the ΔsrbA background was able to partially rescue the hypoxia growth, triazole drug susceptibility, and decrease in ergosterol content phenotypes of ΔsrbA. Thus, we conclude that the fungal SREBP, SrbA, is critical for coordinating genes involved in iron acquisition and ergosterol biosynthesis under hypoxia and low iron conditions found at sites of human fungal infections. These results support a role for SREBP-mediated iron regulation in fungal virulence, and they lay a foundation for further exploration of SREBP's role in iron homeostasis in other eukaryotes.
Assuntos
Antifúngicos/farmacologia , Aspergillus fumigatus/efeitos dos fármacos , Ergosterol/metabolismo , Ferro/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Animais , Aspergillus fumigatus/patogenicidade , Farmacorresistência Fúngica/genética , Regulação Fúngica da Expressão Gênica/genética , Homeostase , Humanos , Pneumopatias Fúngicas/tratamento farmacológico , Pneumopatias Fúngicas/genética , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Sideróforos/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/genética , Triazóis/farmacologiaRESUMO
OBJECTIVES: Despite clinical relevance, commercially available molecular tools for accurate ß-lactamase detection are limited. In this study, we evaluated the performance of the ARM-D® ß-lactamase Kit, a commercially available multiplex PCR assay designed to detect nine ß-lactamase genes, including the five major plasmid-mediated carbapenemases, ESBL, or AmpC genes circulating in the United States. METHODS: A diverse collection of 113 Gram-negative isolates, including 42 with multiple ß-lactamases was selected from the U.S. Centers for Disease Control and Prevention (CDC) & Food and Drug Administration (FDA) Antibiotic Resistance Isolate Bank, to represent the most frequently detected bacterial species carrying plasmid-mediated ß-lactam resistance genes. RESULTS: Results were compared with whole genome sequence data. Of 164 ß-lactamase gene targets with 49 unique variants, all were detected correctly without any cross-reactivity. The sensitivity and specificity were 100% (164/164) and 99.9% (852/853), respectively. CONCLUSION: The ARM-D® ß-lactamase Kit detected a wide range of ß-lactamase genotypes at a low upfront cost. The Streck assay represents a suitable, comprehensive tool for the detection of key ß-lactamase resistance genes of public health concern in the United States.
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The cobas® EBV and BKV assays are the first FDA-approved, quantitative assays for monitoring posttransplant reactivation of these viruses. In this study, we assessed performance of the fully-automated cobas® assays, compared with Diasorin Molecular ASR, our laboratory developed test, and demonstrated a strong interassay correlation for BK and EBV monitoring.
Assuntos
Vírus BK , Infecções por Vírus Epstein-Barr , Transplante de Células-Tronco Hematopoéticas , Transplante de Rim , Infecções por Polyomavirus , Humanos , Herpesvirus Humano 4/genética , Infecções por Vírus Epstein-Barr/diagnóstico , Vírus BK/genética , Infecções por Polyomavirus/diagnóstico , Carga Viral , DNA Viral , Transplante de Células-Tronco Hematopoéticas/efeitos adversosRESUMO
As triazole antifungal drug resistance during invasive Aspergillus fumigatus infection has become more prevalent, the need to understand mechanisms of resistance in A. fumigatus has increased. The presence of two erg11 (cyp51) genes in Aspergillus spp. is hypothesized to account for the inherent resistance of this mold to the triazole fluconazole (FLC). Recently, an A. fumigatus null mutant of a transcriptional regulator in the sterol regulatory element binding protein (SREBP) family, the ΔsrbA strain, was found to have increased susceptibility to FLC and voriconazole (VCZ). In this study, we examined the mechanism engendering the observed increase in A. fumigatus triazole susceptibility in the absence of SrbA. We observed a significant reduction in the erg11A transcript in the ΔsrbA strain in response to FLC and VCZ. Transcript levels of erg11B were also reduced but not to the extent of erg11A. Interestingly, erg11A transcript levels increased upon extended VCZ, but not FLC, exposure. Construction of an erg11A conditional expression strain in the ΔsrbA strain was able to restore erg11A transcript levels and, consequently, wild-type MICs to the triazole FLC. The VCZ MIC was also partially restored upon increased erg11A transcript levels; however, total ergosterol levels remained significantly reduced compared to those of the wild type. Induction of the erg11A conditional strain did not restore the hypoxia growth defect of the ΔsrbA strain. Taken together, our results demonstrate a critical role for SrbA-mediated regulation of ergosterol biosynthesis and triazole drug interactions in A. fumigatus that may have clinical importance.
Assuntos
Antifúngicos/farmacologia , Aspergilose/tratamento farmacológico , Aspergillus fumigatus , Sistema Enzimático do Citocromo P-450/genética , Farmacorresistência Fúngica/efeitos dos fármacos , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Organismos Geneticamente Modificados/genética , Proteínas de Ligação a Elemento Regulador de Esterol/genética , Animais , Aspergilose/microbiologia , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/enzimologia , Aspergillus fumigatus/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Ergosterol/biossíntese , Fluconazol/farmacologia , Proteínas Fúngicas/metabolismo , Teste de Complementação Genética , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Organismos Geneticamente Modificados/metabolismo , Pirimidinas/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Proteínas de Ligação a Elemento Regulador de Esterol/deficiência , Transcrição Gênica/efeitos dos fármacos , Triazóis/farmacologia , VoriconazolRESUMO
BACKGROUND: Historically, United States' carbapenem-resistant Enterobacterales (CRE) surveillance and mechanism testing focused on three genera: Escherichia, Klebsiella, and Enterobacter (EsKE); however, other genera can harbour mobile carbapenemases associated with CRE spread. OBJECTIVES: From January through May 2018, we conducted a 10 state evaluation to assess the contribution of less common genera (LCG) to carbapenemase-producing (CP) CRE. METHODS: State public health laboratories (SPHLs) requested participating clinical laboratories submit all Enterobacterales from all specimen sources during the surveillance period that were resistant to any carbapenem (Morganellaceae required resistance to doripenem, ertapenem, or meropenem) or were CP based on phenotypic or genotypic testing at the clinical laboratory. SPHLs performed species identification, phenotypic carbapenemase production testing, and molecular testing for carbapenemases to identify CP-CRE. Isolates were categorized as CP if they demonstrated phenotypic carbapenemase production and ≥1 carbapenemase gene (bla KPC, bla NDM, bla VIM, bla IMP, or bla OXA-48-like) was detected. RESULTS: SPHLs tested 868 CRE isolates, 127 (14.6%) were from eight LCG. Overall, 195 (26.3%) EsKE isolates were CP-CRE, compared with 24 (18.9%) LCG isolates. LCG accounted for 24 (11.0%) of 219 CP-CRE identified. Citrobacter spp. was the most common CP-LCG; the proportion of Citrobacter that were CP (11/42, 26.2%) was similar to the proportion of EsKE that were CP (195/741, 26.3%). Five of 24 (20.8%) CP-LCG had a carbapenemase gene other than bla KPC. CONCLUSIONS: Participating sites would have missed approximately 1 in 10 CP-CRE if isolate submission had been limited to EsKE genera. Expanding mechanism testing to additional genera could improve detection and prevention efforts.
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BACKGROUND: Laboratory assays for determining recent HIV-1 infection are an important public health tool for aiding in the estimation of HIV incidence. Some incidence assay analytes are remarkably predictive of time since seroconversion and may be useful for additional applications, such as predicting recent transmission events during HIV outbreaks and informing prevention strategies. METHODS: Plasma samples (n = 154) from a recent HIV-1 outbreak in a rural community in Indiana were tested with the customized HIV-1 Multiplex assay, based on the Bio-Rad Bio-Plex platform, which measures antibody response to HIV envelope antigens, gp120, gp160, and gp41. Assay cutoffs for each analyte were established to determine whether an individual seroconverted within 30, 60, or 90 days of the sample collection date. In addition, a novel bioinformatics method was implemented to infer infection dates of persons newly diagnosed with HIV during the outbreak. RESULTS: Sensitivity/specificity of the HIV-1 Multiplex assay for predicting seroconversion within 30, 60, and 90 days, based on a training data set, was 90.5%/95.4%, 94.1%/90%, and 89.4%/82.9%, respectively. Of 154 new diagnoses in Indiana between December 2014 and August 2016, the majority (71%) of recent infections (≤3 months since seroconversion) were identified between February and May 2016. The epidemiologic curve derived from the bioinformatics analysis indicated HIV transmission began as early as 2010, grew exponentially in 2014, and leveled off in April 2015. CONCLUSIONS: The HIV-1 Multiplex assay has the potential to identify and monitor trends in recent infection during an epidemic to assess the efficacy of programmatic or treatment interventions.
Assuntos
Anticorpos Anti-HIV/imunologia , Antígenos HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp160 do Envelope de HIV/imunologia , Infecções por HIV/epidemiologia , Algoritmos , Proteína gp41 do Envelope de HIV/imunologia , Infecções por HIV/diagnóstico , Infecções por HIV/transmissão , Soropositividade para HIV/epidemiologia , HIV-1/imunologia , Humanos , Indiana/epidemiologia , Sensibilidade e Especificidade , Soroconversão/fisiologiaRESUMO
BACKGROUND: A high prevalence (92.3%) of hepatitis C virus (HCV) co-infection among HIV patients identified during a large HIV outbreak associated with injection of oxymorphone in Indiana prompted genetic analysis of HCV strains. METHODS: Molecular epidemiological analysis of HCV-positive samples included genotyping, sampling intra-host HVR1 variants by next-generation sequencing (NGS) and constructing transmission networks using Global Hepatitis Outbreak and Surveillance Technology (GHOST). FINDINGS: Results from the 492 samples indicate predominance of HCV genotypes 1a (72.2%) and 3a (20.4%), and existence of 2 major endemic NS5B clusters involving 49.8% of the sequenced strains. Among 76 HIV co-infected patients, 60.5% segregated into 2 endemic clusters. NGS analyses of 281 cases identified 826,917 unique HVR1 sequences and 51 cases of mixed subtype/genotype infections. GHOST mapped 23 transmission clusters. One large cluster (nâ¯=â¯130) included 50 cases infected with ≥2 subtypes/genotypes and 43 cases co-infected with HIV. Rapid strain replacement and superinfection with different strains were found among 7 of 12 cases who were followed up. INTERPRETATION: GHOST enabled mapping of HCV transmission networks among persons who inject drugs (PWID). Findings of numerous transmission clusters, mixed-genotype infections and rapid succession of infections with different HCV strains indicate a high rate of HCV spread. Co-localization of HIV co-infected patients in the major HCV clusters suggests that HIV dissemination was enabled by existing HCV transmission networks that likely perpetuated HCV in the community for years. Identification of transmission networks is an important step to guiding efficient public health interventions for preventing and interrupting HCV and HIV transmission among PWID. FUND: US Centers for Disease Control and Prevention, and US state and local public health departments.
Assuntos
Coinfecção , Surtos de Doenças , Hepatite C , Oximorfona , População Rural , Abuso de Substâncias por Via Intravenosa/epidemiologia , Adulto , Coinfecção/epidemiologia , Coinfecção/transmissão , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/transmissão , Hepatite C/epidemiologia , Hepatite C/transmissão , Humanos , Indiana/epidemiologia , Masculino , Pessoa de Meia-IdadeRESUMO
Infection by the human fungal pathogen Aspergillus fumigatus induces hypoxic microenvironments within the lung that can alter the course of fungal pathogenesis. How hypoxic microenvironments shape the composition and immune activating potential of the fungal cell wall remains undefined. Herein we demonstrate that hypoxic conditions increase the hyphal cell wall thickness and alter its composition particularly by augmenting total and surface-exposed ß-glucan content. In addition, hypoxia-induced cell wall alterations increase macrophage and neutrophil responsiveness and antifungal activity as judged by inflammatory cytokine production and ability to induce hyphal damage. We observe that these effects are largely dependent on the mammalian ß-glucan receptor dectin-1. In a corticosteroid model of invasive pulmonary aspergillosis, A. fumigatus ß-glucan exposure correlates with the presence of hypoxia in situ. Our data suggest that hypoxia-induced fungal cell wall changes influence the activation of innate effector cells at sites of hyphal tissue invasion, which has potential implications for therapeutic outcomes of invasive pulmonary aspergillosis.