Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Immunity ; 50(1): 241-252.e6, 2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30552025

RESUMEN

Passive administration of HIV neutralizing antibodies (nAbs) can protect macaques from hard-to-neutralize (tier 2) chimeric simian-human immunodeficiency virus (SHIV) challenge. However, conditions for nAb-mediated protection after vaccination have not been established. Here, we selected groups of 6 rhesus macaques with either high or low serum nAb titers from a total of 78 animals immunized with recombinant native-like (SOSIP) Env trimers. Repeat intrarectal challenge with homologous tier 2 SHIVBG505 led to rapid infection in unimmunized and low-titer animals. High-titer animals, however, demonstrated protection that was gradually lost as nAb titers waned over time. An autologous serum ID50 nAb titer of ∼1:500 afforded more than 90% protection from medium-dose SHIV infection. In contrast, antibody-dependent cellular cytotoxicity and T cell activity did not correlate with protection. Therefore, Env protein-based vaccination strategies can protect against hard-to-neutralize SHIV challenge in rhesus macaques by inducing tier 2 nAbs, provided appropriate neutralizing titers can be reached and maintained.


Asunto(s)
Vacunas contra el SIDA/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH/fisiología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/fisiología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Humanos , Macaca mulatta , Vacunación
2.
Emerg Infect Dis ; 29(1): 217-219, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36573647

RESUMEN

We describe a case of catheter-related bacteremia caused by Mycolicibacterium iranicum in the United States. The case highlights the value of using next-generation sequencing to identify infrequent and emerging pathogens and the challenges associated with choosing appropriate treatments because of limited knowledge of drug resistance mechanisms in those emerging pathogens.


Asunto(s)
Bacteriemia , Mycobacteriaceae , Infecciones por Mycobacterium no Tuberculosas , Humanos , Catéteres/efectos adversos , California , Bacteriemia/diagnóstico , Bacteriemia/tratamiento farmacológico , Bacteriemia/complicaciones , Infecciones por Mycobacterium no Tuberculosas/microbiología , Micobacterias no Tuberculosas
3.
J Clin Microbiol ; 61(11): e0035723, 2023 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-37877730

RESUMEN

The bioMérieux BIOFIRE Joint Infection (JI) Panel is a multiplex in vitro diagnostic test for the simultaneous and rapid (~1 h) detection of 39 potential pathogens and antimicrobial resistance (AMR) genes directly from synovial fluid (SF) samples. Thirty-one species or groups of microorganisms are included in the kit, as well as several AMR genes. This study, performed to evaluate the BIOFIRE JI Panel for regulatory clearance, provides data from a multicenter evaluation of 1,544 prospectively collected residual SF samples with performance compared to standard-of-care (SOC) culture for organisms or polymerase chain reaction (PCR) and sequencing for AMR genes. The BIOFIRE JI Panel demonstrated a sensitivity of 90.9% or greater for all but six organisms and a positive percent agreement (PPA) of 100% for all AMR genes. The BIOFIRE JI Panel demonstrated a specificity of 98.5% or greater for detection of all organisms and a negative percent agreement (NPA) of 95.7% or greater for all AMR genes. The BIOFIRE JI Panel provides an improvement over SOC culture, with a substantially shorter time to result for both organisms and AMR genes with excellent sensitivity/PPA and specificity/NPA, and is anticipated to provide timely and actionable diagnostic information for joint infections in a variety of clinical scenarios.


Asunto(s)
Antiinfecciosos , Artritis Infecciosa , Humanos , Saccharomyces cerevisiae/genética , Líquido Sinovial/microbiología , Reacción en Cadena de la Polimerasa Multiplex , Bacterias/genética , Artritis Infecciosa/diagnóstico
4.
Immunity ; 40(5): 657-68, 2014 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-24768347

RESUMEN

Broadly neutralizing HIV antibodies are much sought after (a) to guide vaccine design, both as templates and as indicators of the authenticity of vaccine candidates, (b) to assist in structural studies, and (c) to serve as potential therapeutics. However, the number of targets on the viral envelope spike for such antibodies has been limited. Here, we describe a set of human monoclonal antibodies that define what is, to the best of our knowledge, a previously undefined target on HIV Env. The antibodies recognize a glycan-dependent epitope on the prefusion conformation of gp41 and unambiguously distinguish cleaved from uncleaved Env trimers, an important property given increasing evidence that cleavage is required for vaccine candidates that seek to mimic the functional HIV envelope spike. The availability of this set of antibodies expands the number of vaccine targets on HIV and provides reagents to characterize the native envelope spike.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , Proteína gp41 de Envoltorio del VIH/inmunología , Línea Celular , Epítopos/inmunología , Células HEK293 , Proteína gp120 de Envoltorio del VIH/inmunología , Proteína gp41 de Envoltorio del VIH/metabolismo , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , VIH-1/inmunología , Humanos , Datos de Secuencia Molecular , Polisacáridos/inmunología
5.
J Virol ; 92(16)2018 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-29875239

RESUMEN

Certain major histocompatibility complex class I (MHC-I) alleles are associated with spontaneous control of viral replication in human immunodeficiency virus (HIV)-infected people and simian immunodeficiency virus (SIV)-infected rhesus macaques (RMs). These cases of "elite" control of HIV/SIV replication are often immune-mediated, thereby providing a framework for studying anti-lentiviral immunity. In this study, we examined how vaccination impacts SIV replication in RMs expressing the MHC-I allele Mamu-B*17 Approximately 21% of Mamu-B*17+ and 50% of Mamu-B*08+ RMs control chronic-phase viremia after SIVmac239 infection. Because CD8+ T cells targeting Mamu-B*08-restricted SIV epitopes have been implicated in virologic suppression in Mamu-B*08+ RMs, we investigated whether this might also be true for Mamu-B*17+ RMs. Two groups of Mamu-B*17+ RMs were vaccinated with genes encoding Mamu-B*17-restricted epitopes in Vif and Nef. These genes were delivered by themselves (group 1) or together with env (group 2). Group 3 included MHC-I-matched RMs and served as the control group. Surprisingly, the group 1 vaccine regimen had little effect on viral replication compared to group 3, suggesting that unlike Mamu-B*08+ RMs, preexisting SIV-specific CD8+ T cells alone do not facilitate long-term virologic suppression in Mamu-B*17+ RMs. Remarkably, however, 5/8 group 2 vaccinees controlled viremia to <15 viral RNA copies/ml soon after infection. No serological neutralizing activity against SIVmac239 was detected in group 2, although vaccine-elicited gp140-binding antibodies correlated inversely with nadir viral loads. Collectively, these data shed new light on the unique mechanism of elite control in Mamu-B*17+ RMs and implicate vaccine-induced, nonneutralizing anti-Env antibodies in the containment of immunodeficiency virus infection.IMPORTANCE A better understanding of the immune correlates of protection against HIV might facilitate the development of a prophylactic vaccine. Therefore, we investigated simian immunodeficiency virus (SIV) infection outcomes in rhesus macaques expressing the major histocompatibility complex class I allele Mamu-B*17 Approximately 21% of Mamu-B*17+ macaques spontaneously controlled chronic phase viremia after SIV infection, an effect that may involve CD8+ T cells targeting Mamu-B*17-restricted SIV epitopes. We vaccinated Mamu-B*17+ macaques with genes encoding immunodominant epitopes in Vif and Nef alone (group 1) or together with env (group 2). Although neither vaccine regimen prevented SIV infection, 5/8 group 2 vaccinees controlled viremia to below detection limits shortly after infection. This outcome, which was not observed in group 1, was associated with vaccine-induced, nonneutralizing Env-binding antibodies. Together, these findings suggest a limited contribution of Vif- and Nef-specific CD8+ T cells for virologic control in Mamu-B*17+ macaques and implicate anti-Env antibodies in containment of SIV infection.


Asunto(s)
Productos del Gen env/inmunología , Productos del Gen nef/inmunología , Productos del Gen vif/inmunología , Antígenos de Histocompatibilidad Clase I/genética , Vacunas contra el SIDAS/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/prevención & control , Virus de la Inmunodeficiencia de los Simios/inmunología , Alelos , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Macaca mulatta , Vacunas contra el SIDAS/administración & dosificación , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/fisiología , Carga Viral , Viremia/prevención & control , Replicación Viral
6.
PLoS Pathog ; 13(7): e1006529, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28732035

RESUMEN

The ability to control lentivirus replication may be determined, in part, by the extent to which individual viral proteins are targeted by the immune system. Consequently, defining the antigens that elicit the most protective immune responses may facilitate the design of effective HIV-1 vaccines. Here we vaccinated four groups of rhesus macaques with a heterologous vector prime/boost/boost/boost (PBBB) regimen expressing the following simian immunodeficiency virus (SIV) genes: env, gag, vif, rev, tat, and nef (Group 1); env, vif, rev, tat, and nef (Group 2); gag, vif, rev, tat, and nef (Group 3); or vif, rev, tat, and nef (Group 4). Following repeated intrarectal challenges with a marginal dose of the neutralization-resistant SIVmac239 clone, vaccinees in Groups 1-3 became infected at similar rates compared to control animals. Unexpectedly, vaccinees in Group 4 became infected at a slower pace than the other animals, although this difference was not statistically significant. Group 1 exhibited the best post-acquisition virologic control of SIV infection, with significant reductions in both peak and chronic phase viremia. Indeed, 5/8 Group 1 vaccinees had viral loads of less than 2,000 vRNA copies/mL of plasma in the chronic phase. Vaccine regimens that did not contain gag (Group 2), env (Group 3), or both of these inserts (Group 4) were largely ineffective at decreasing viremia. Thus, vaccine-induced immune responses against both Gag and Env appeared to maximize control of immunodeficiency virus replication. Collectively, these findings are relevant for HIV-1 vaccine design as they provide additional insights into which of the lentiviral proteins might serve as the best vaccine immunogens.


Asunto(s)
Infecciones por VIH/inmunología , VIH-1/inmunología , Recto/virología , Vacunas contra el SIDAS/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología , Animales , Anticuerpos Antivirales/inmunología , Modelos Animales de Enfermedad , Infecciones por VIH/virología , VIH-1/genética , VIH-1/fisiología , Humanos , Macaca mulatta , Recto/inmunología , Vacunas contra el SIDAS/administración & dosificación , Vacunas contra el SIDAS/genética , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/genética , Replicación Viral , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/genética
7.
J Virol ; 91(11)2017 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-28331088

RESUMEN

Antibodies recognizing conserved CD4-induced (CD4i) epitopes on human immunodeficiency virus type 1 (HIV-1) Env and able to mediate antibody-dependent cellular cytotoxicity (ADCC) have been shown to be present in sera from most HIV-1-infected individuals. These antibodies preferentially recognize Env in its CD4-bound conformation. CD4 downregulation by Nef and Vpu dramatically reduces exposure of CD4i HIV-1 Env epitopes and therefore reduce the susceptibility of HIV-1-infected cells to ADCC mediated by HIV-positive (HIV+) sera. Importantly, this mechanism of immune evasion can be circumvented with small-molecule CD4 mimetics (CD4mc) that are able to transition Env into the CD4-bound conformation and sensitize HIV-1-infected cells to ADCC mediated by HIV+ sera. However, HIV-1 developed additional mechanisms to avoid ADCC, including Vpu-mediated BST-2 antagonism, which decreases the overall amount of Env present at the cell surface. Accordingly, BST-2 upregulation in response to alpha interferon (IFN-α) was shown to increase the susceptibility of HIV-1-infected cells to ADCC despite the activity of Vpu. Here we show that BST-2 upregulation by IFN-ß and interleukin-27 (IL-27) also increases the surface expression of Env and thus boosts the ability of CD4mc to sensitize HIV-1-infected cells to ADCC by sera from HIV-1-infected individuals.IMPORTANCE HIV-1 evolved sophisticated strategies to conceal Env epitopes from ADCC-mediating antibodies present in HIV+ sera. Vpu-mediated BST-2 downregulation was shown to decrease ADCC responses by limiting the amount of Env present at the cell surface. This effect of Vpu was shown to be attenuated by IFN-α treatment. Here we show that in addition to IFN-α, IFN-ß and IL-27 also affect Vpu-mediated BST-2 downregulation and greatly enhance ADCC responses against HIV-1-infected cells in the presence of CD4mc. These findings may inform strategies aimed at HIV prevention and eradication.


Asunto(s)
Citotoxicidad Celular Dependiente de Anticuerpos , Antígenos CD/genética , Antígenos CD4/inmunología , Epítopos/inmunología , VIH-1/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Antígenos CD/metabolismo , Antígenos CD4/metabolismo , Proteínas Ligadas a GPI/deficiencia , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/metabolismo , VIH-1/genética , Proteínas del Virus de la Inmunodeficiencia Humana/genética , Proteínas del Virus de la Inmunodeficiencia Humana/metabolismo , Humanos , Evasión Inmune , Interferón beta/farmacología , Interleucinas/farmacología , Células Jurkat , Imitación Molecular , Regulación hacia Arriba , Proteínas Reguladoras y Accesorias Virales/genética , Proteínas Reguladoras y Accesorias Virales/metabolismo , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
8.
J Virol ; 90(13): 6127-6139, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-27122574

RESUMEN

UNLABELLED: Although antibodies to the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein have been studied extensively for their ability to block viral infectivity, little data are currently available on nonneutralizing functions of these antibodies, such as their ability to eliminate virus-infected cells by antibody-dependent cell-mediated cytotoxicity (ADCC). HIV-1 Env-specific antibodies of diverse specificities, including potent broadly neutralizing and nonneutralizing antibodies, were therefore tested for ADCC against cells infected with a lab-adapted HIV-1 isolate (HIV-1NL4-3), a primary HIV-1 isolate (HIV-1JR-FL), and a simian-human immunodeficiency virus (SHIV) adapted for pathogenic infection of rhesus macaques (SHIVAD8-EO). In accordance with the sensitivity of these viruses to neutralization, HIV-1NL4-3-infected cells were considerably more sensitive to ADCC, both in terms of the number of antibodies and magnitude of responses, than cells infected with HIV-1JR-FL or SHIVAD8-EO ADCC activity generally correlated with antibody binding to Env on the surfaces of virus-infected cells and with viral neutralization; however, neutralization was not always predictive of ADCC, as instances of ADCC in the absence of detectable neutralization, and vice versa, were observed. These results reveal incomplete overlap in the specificities of antibodies that mediate these antiviral activities and provide insights into the relationship between ADCC and neutralization important for the development of antibody-based vaccines and therapies for combating HIV-1 infection. IMPORTANCE: This study provides fundamental insights into the relationship between antibody-dependent cell-mediated cytotoxicity (ADCC) and virus neutralization that may help to guide the development of antibody-based vaccines and immunotherapies for the prevention and treatment of HIV-1 infection.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Citotoxicidad Celular Dependiente de Anticuerpos , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Vacunas contra el SIDA/inmunología , Animales , Anticuerpos Monoclonales/metabolismo , Anticuerpos Neutralizantes/metabolismo , Especificidad de Anticuerpos , Sitios de Unión de Anticuerpos , Células HEK293 , Infecciones por VIH/prevención & control , Infecciones por VIH/terapia , Infecciones por VIH/virología , VIH-1/aislamiento & purificación , Humanos , Macaca mulatta , Pruebas de Neutralización , Virus de la Inmunodeficiencia de los Simios/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/metabolismo
9.
J Virol ; 90(23): 10701-10714, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-27654287

RESUMEN

Although Nef is the viral gene product used by most simian immunodeficiency viruses to overcome restriction by tetherin, this activity was acquired by the Vpu protein of HIV-1 group M due to the absence of sequences in human tetherin that confer susceptibility to Nef. Thus, it is widely accepted that HIV-1 group M uses Vpu instead of Nef to counteract tetherin. Challenging this paradigm, we identified Nef alleles of HIV-1 group M isolates with significant activity against human tetherin. These Nef proteins promoted virus release and tetherin downmodulation from the cell surface and, in the context of vpu-deleted HIV-1 recombinants, enhanced virus replication and resistance to antibody-dependent cell-mediated cytotoxicity (ADCC). Further analysis revealed that the Vpu proteins from several of these viruses lack antitetherin activity, suggesting that under certain circumstances, HIV-1 group M Nef may acquire the ability to counteract tetherin to compensate for the loss of this function by Vpu. These observations illustrate the remarkable plasticity of HIV-1 in overcoming restriction by tetherin and challenge the prevailing view that all HIV-1 group M isolates use Vpu to counteract tetherin. IMPORTANCE Most viruses of HIV-1 group M, the main group of HIV-1 responsible for the global AIDS pandemic, use their Vpu proteins to overcome restriction by tetherin (BST-2 or CD317), which is a transmembrane protein that inhibits virus release from infected cells. Here we show that the Nef proteins of certain HIV-1 group M isolates can acquire the ability to counteract tetherin. These results challenge the current paradigm that HIV-1 group M exclusively uses Vpu to counteract tetherin and underscore the importance of tetherin antagonism for efficient viral replication.

10.
Proc Natl Acad Sci U S A ; 111(17): 6425-30, 2014 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-24733916

RESUMEN

Tetherin is an IFN-inducible transmembrane protein that inhibits the detachment of enveloped viruses from infected cells. HIV-1 overcomes this restriction factor by expressing HIV-1 viral protein U (Vpu), which down-regulates and degrades tetherin. We report that mutations in Vpu that impair tetherin antagonism increase the susceptibility of HIV-infected cells to antibody-dependent cell-mediated cytotoxicity (ADCC), and conversely that RNAi knockdown of tetherin, but not other cellular proteins down-modulated by Vpu, decreases the susceptibility of HIV-infected cells to ADCC. These results reveal that Vpu protects HIV-infected cells from ADCC as a function of its ability to counteract tetherin. By serving as link between innate and adaptive immunity, the antiviral activity of tetherin may be augmented by virus-specific antibodies, and hence much greater than previously appreciated.


Asunto(s)
Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Citoprotección , Infecciones por VIH/inmunología , Infecciones por VIH/patología , Proteínas del Virus de la Inmunodeficiencia Humana/metabolismo , Proteínas Reguladoras y Accesorias Virales/metabolismo , Sustitución de Aminoácidos , Citotoxicidad Celular Dependiente de Anticuerpos/efectos de los fármacos , Antígenos CD/metabolismo , Antígenos CD4/metabolismo , Citoprotección/efectos de los fármacos , Proteínas Ligadas a GPI/antagonistas & inhibidores , Proteínas Ligadas a GPI/metabolismo , Eliminación de Gen , Humanos , Interferón-alfa/farmacología , Interferencia de ARN/efectos de los fármacos , Receptores de Superficie Celular/metabolismo , Miembro 1 de la Familia de Moléculas Señalizadoras de la Activación Linfocitaria
11.
J Virol ; 89(20): 10648-55, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26269175

RESUMEN

UNLABELLED: The cytoplasmic tails of human and simian immunodeficiency virus (HIV and SIV, respectively) envelope glycoproteins contain a highly conserved, membrane-proximal endocytosis motif that prevents the accumulation of Env on the surface of infected cells prior to virus assembly. Using an assay designed to measure the killing of virus-infected cells by antibody-dependent cell-mediated cytotoxicity (ADCC), we show that substitutions in this motif increase the susceptibility of HIV-1- and SIV-infected cells to ADCC in a manner that directly correlates with elevated Env levels on the surface of virus-infected cells. In the case of HIV-1, this effect is additive with a deletion in vpu recently shown to enhance the susceptibility of HIV-1-infected cells to ADCC as a result of tetherin-mediated retention of budding virions on the cell surface. These results reveal a previously unappreciated role for the membrane-proximal endocytosis motif of gp41 in protecting HIV-1- and SIV-infected cells from antibody responses by regulating the amount of Env present on the cell surface. IMPORTANCE: This study reveals an unappreciated role for the membrane-proximal endocytosis motif of gp41 in protecting HIV-1- and SIV-infected cells from elimination by Env-specific antibodies. Thus, strategies designed to interfere with this mechanism of Env internalization may improve the efficacy of antibody-based vaccines and antiretroviral therapies designed to enhance the immunological control of HIV-1 replication in chronically infected individuals.


Asunto(s)
Anticuerpos Antivirales/biosíntesis , Citotoxicidad Celular Dependiente de Anticuerpos/genética , Endocitosis/inmunología , VIH-1/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Antivirales/genética , Antígenos CD/genética , Antígenos CD/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/virología , Línea Celular , Membrana Celular/química , Membrana Celular/inmunología , Membrana Celular/virología , Secuencia Conservada , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/inmunología , Expresión Génica , Proteína gp41 de Envoltorio del VIH/genética , Proteína gp41 de Envoltorio del VIH/inmunología , VIH-1/genética , Interacciones Huésped-Patógeno , Proteínas del Virus de la Inmunodeficiencia Humana/genética , Proteínas del Virus de la Inmunodeficiencia Humana/inmunología , Humanos , Inmunidad Celular , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/virología , Datos de Secuencia Molecular , Estructura Terciaria de Proteína , Alineación de Secuencia , Virus de la Inmunodeficiencia de los Simios/genética , Proteínas Reguladoras y Accesorias Virales/genética , Proteínas Reguladoras y Accesorias Virales/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética
12.
Am J Clin Pathol ; 159(2): 111-115, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36495133

RESUMEN

OBJECTIVES: The aim of this study is to evaluate the effectiveness of a CRISPR-based human and bacterial ribosomal RNA (rRNA) depletion kit (JUMPCODE Genomics) on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) shotgun metagenomic sequencing in weakly positive respiratory samples. METHODS: Shotgun metagenomics was performed on 40 respiratory specimens collected from solid organ transplant patients and deceased intensive care unit patients at UCLA Medical Center in late 2020 to early 2021. Human and bacterial rRNA depletion was performed on remnant library pools prior to sequencing by Illumina MiSeq. Data quality was analyzed using Geneious Prime, whereas the identification of SARS-CoV-2 variants and lineages was determined by Pangolin. RESULTS: The average genome coverage of the rRNA-depleted respiratory specimens increased from 72.55% to 93.71% in overall samples and from 29.3% to 83.3% in 15 samples that failed to achieve sufficient genome coverage using the standard method. Moreover, rRNA depletion enhanced genome coverage to over 85% in 11 (73.3%) of 15 low viral load samples with cycle threshold values up to 35, resulting in the identification of genotypes. CONCLUSION: The CRISPR-based human and bacterial rRNA depletion enhanced the sensitivity of SARS-CoV-2 shotgun metagenomic sequencing, especially in low viral load samples.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , ARN Ribosómico , Metagenómica/métodos
13.
Microorganisms ; 11(10)2023 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-37894195

RESUMEN

The global rise of drug resistant tuberculosis has highlighted the need for improved diagnostic technologies that provide rapid and reliable drug resistance results. Here, we develop and validate a whole genome sequencing (WGS)-based test for identification of mycobacterium tuberculosis complex (MTB) drug resistance to rifampin, isoniazid, pyrazinamide, ethambutol, and streptomycin. Through comparative analysis of drug resistance results from WGS-based testing and phenotypic drug susceptibility testing (DST) of 38 clinical MTB isolates from patients receiving care in Los Angeles, CA, we found an overall concordance between methods of 97.4% with equivalent performance across culture media. Critically, prospective analysis of 11 isolates showed that WGS-based testing provides results an average of 36 days faster than phenotypic culture-based methods. We showcase the additional benefits of WGS data by investigating a suspected laboratory contamination event and using phylogenetic analysis to search for cryptic local transmission, finding no evidence of community spread amongst our patient population in the past six years. WGS-based testing for MTB drug resistance has the potential to greatly improve diagnosis of drug resistant MTB by accelerating turnaround time while maintaining accuracy and providing additional benefits for infection control, lab safety, and public health applications.

14.
J Clin Virol ; 165: 105520, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37336174

RESUMEN

Cytomegalovirus (CMV) causes severe systemic and tissue-invasive disease in immunocompromised patients, particularly solid organ and hematopoietic stem cell transplant recipients. While antiviral drugs offer promising efficacy, clinical management is complicated by the high frequency of drug resistance-associated mutations. The most commonly encountered mutations occur in the genes encoding for the drug targets: UL54 (DNA polymerase), UL56 (terminase complex), and UL97 (phosphotransferase), conferring resistance to ganciclovir/cidofovir/foscarnet, letermovir, and ganciclovir/maribavir, respectively. Currently, standard practice for detecting drug resistance is sequencing-based genotypic analysis by commercial reference laboratories with strictly prescribed sample requirements and reporting parameters that can often restrict testing in a highly vulnerable population. In order to circumvent these limitations, we developed a dual-step next-generation sequencing (NGS)-based clinical assay that utilizes full-length gene amplification by long-range PCR followed by shotgun sequencing for mutation analysis. This laboratory-developed test (LDT) achieved satisfactory performance with 96.4% accuracy, 100% precision, and an analytical sensitivity of 300IU/mL with 20% allele frequency. Highlighted by two clinical cases, our NGS LDT was able to provide critical results from patient specimens with viral loads <500IU/mL and volumes <0.5 mL - conditions otherwise unacceptable by reference laboratories. Here, we describe the development and implementation of a robust NGS LDT that offers greater testing flexibility and sensitivity to accommodate a more diverse patient population.


Asunto(s)
Infecciones por Citomegalovirus , Citomegalovirus , Humanos , Citomegalovirus/genética , Infecciones por Citomegalovirus/diagnóstico , Infecciones por Citomegalovirus/tratamiento farmacológico , Amplificación de Genes , Antivirales/farmacología , Antivirales/uso terapéutico , Ganciclovir/uso terapéutico , Mutación , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Farmacorresistencia Viral/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/uso terapéutico
15.
J Microbiol Methods ; 208: 106726, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37120137

RESUMEN

Whole genome sequencing (WGS) of Mycobacterium avium complex (MAC) isolates in the clinical laboratory setting allows for rapid and reliable subspecies identification of a closely related complex of human pathogens. We developed a bioinformatics pipeline for accurate subspecies identification and tested 74 clinical MAC isolates from various anatomical sites. We demonstrate that reliable subspecies level identification of these common and clinically significant MAC isolates, including M. avium subsp. hominissuis (most dominant in causing lower respiratory tract infections in our cohort), M. avium subsp. avium, M. intracellulare subsp. intracellulare, and M. intracellulare subsp. chimaera, can be achieved by analysis of only two marker genes (rpoB and groEL/hsp65). We then explored the relationship between these subspecies and anatomical site of infection. Further, we conducted an in silico analysis and showed our algorithm also performed well for M. avium subsp. paratuberculosis but failed to consistently identify M. avium subsp. silvaticum and M. intracellulare subsp. yongonense, likely due to a lack of available reference genome sequences; all the 3 subspecies were not found in our clinical isolates and rarely reported to cause human infections. Accurate MAC subspecies identification may provide the tool and opportunity for better understanding of the disease-subspecies dynamics in MAC infections.


Asunto(s)
Infección por Mycobacterium avium-intracellulare , Paratuberculosis , Animales , Humanos , Complejo Mycobacterium avium/genética , Mycobacterium avium/genética , Infección por Mycobacterium avium-intracellulare/diagnóstico , Infección por Mycobacterium avium-intracellulare/microbiología , Secuenciación Completa del Genoma
16.
IDCases ; 28: e01491, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35369567

RESUMEN

A 7-year-old cystic fibrosis patient with increased cough, new pulmonary infiltrate, and declining pulmonary function was diagnosed with clarithromycin resistant Mycobacterium abscessus infection. Treatment was initiated with clofazimine, linezolid and cefoxitin; she responded well to therapy and achieved microbiological clearance after completion of 12-month treatment. One year later, she had re-emergence of worsening symptoms and her sputum culture again grew clarithromycin resistant M. abscessus. Using a laboratory developed whole genome sequencing (WGS) test, the bacterium was determined to be the same strain with the same resistance mechanisms, indicating a relapse. This was deemed a critical element of clinical information, as the isolation of a genetically distinct organism would have indicated a new infection and would have served as evidence that a 12-month regimen was likely sufficient to achieve eradication. The confirmation of a relapse prompted the prolongation of the therapy plan to a goal of 24 months. Reinfection and relapse are great challenges in patients with cystic fibrosis who may acquire new strain of M. abscessus from the environment, may harbor multiple subpopulations of bacteria, or may have persistent infections but intermittent bacteria shedding that could not be eradicated. WGS has emerged as a powerful molecular tool to accurately differentiate re-infection from relapse thus solving this conundrum.

17.
Open Forum Infect Dis ; 8(11): ofab526, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35005055

RESUMEN

Among 880 healthcare workers with a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test, 264 (30.0%) infections were identified following receipt of at least 1 vaccine dose. Median SARS-CoV-2 cycle threshold values were highest among individuals receiving 2 vaccine doses, corresponding to lower viral shedding. Vaccination might lead to lower transmissibility of SARS-CoV-2.

18.
Expert Rev Mol Diagn ; 21(3): 333-342, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33849372

RESUMEN

Background: Here we compare the performance of the high-throughput BD COR System (COR) to the Viper LT System (Viper) using the BD Onclarity HPV assay.Research Design and Methods: Remnant clinical specimens, contrived specimens in SurePath (BD) and PreservCyt (Hologic) media, and prospective clinical specimens in BD Cervical Brush Diluent (CBD) were tested. Outcomes included intra-laboratory agreement of Onclarity results on COR and inter-system agreement between COR and Viper.Results: Onclarity reproducibility on COR resulted in standard deviation and correlation of variation of Ct values ranging from 0.14 to 1.98 and 0.49% to 2.15%, respectively, for contrived specimens, and 0.9-3.08 and 2.89-9.21%, respectively, for clinical specimens. In the COR and Viper clinical agreement study, OPA for Onclarity ranged from 97.1%-98.9%, depending on the collection media type. PPA values for pooled, HPV(+) specimens at low positive (C95), and moderate positive (3XC95) target concentrations were ≥95.0% and 100%, respectively; PPA values associated with HPV 16, 18, 31, 45, 33/58, 52, 35/39/68, 51, and 56/59/66, individually, ranged from 93.8%-100%.Conclusions: Onclarity performance on COR is equivalent to Viper, and is accurate and reproducible for detection of all high-risk HPV genotypes, with a throughput of 330 results from a single 8-hour shift.


Asunto(s)
Infecciones por Papillomavirus , Neoplasias del Cuello Uterino , Femenino , Humanos , Papillomaviridae/genética , Infecciones por Papillomavirus/diagnóstico , Estudios Prospectivos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Neoplasias del Cuello Uterino/diagnóstico
19.
Microbiol Resour Announc ; 9(15)2020 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-32273361

RESUMEN

We have isolated a likely bacterial pathogen from cerebrospinal fluid from a Ugandan infant suffering from hydrocephalus. Whole-genome sequencing and assembly of the genome of the clinical isolate, as well as that of a previously deposited reference strain, identified the isolate as Paenibacillus thiaminolyticus, which has not been associated with widespread human infections.

20.
Sci Transl Med ; 12(563)2020 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-32998967

RESUMEN

Postinfectious hydrocephalus (PIH), which often follows neonatal sepsis, is the most common cause of pediatric hydrocephalus worldwide, yet the microbial pathogens underlying this disease remain to be elucidated. Characterization of the microbial agents causing PIH would enable a shift from surgical palliation of cerebrospinal fluid (CSF) accumulation to prevention of the disease. Here, we examined blood and CSF samples collected from 100 consecutive infant cases of PIH and control cases comprising infants with non-postinfectious hydrocephalus in Uganda. Genomic sequencing of samples was undertaken to test for bacterial, fungal, and parasitic DNA; DNA and RNA sequencing was used to identify viruses; and bacterial culture recovery was used to identify potential causative organisms. We found that infection with the bacterium Paenibacillus, together with frequent cytomegalovirus (CMV) coinfection, was associated with PIH in our infant cohort. Assembly of the genome of a facultative anaerobic bacterial isolate recovered from cultures of CSF samples from PIH cases identified a strain of Paenibacillus thiaminolyticus This strain, designated Mbale, was lethal when injected into mice in contrast to the benign reference Paenibacillus strain. These findings show that an unbiased pan-microbial approach enabled characterization of Paenibacillus in CSF samples from PIH cases, and point toward a pathway of more optimal treatment and prevention for PIH and other proximate neonatal infections.


Asunto(s)
Coinfección , Hidrocefalia , Paenibacillus , Animales , Niño , Humanos , Lactante , Ratones , Uganda
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA