RESUMO
Interferon gamma release assays are used to screen various patient populations for latent tuberculosis infection. In this issue of the Journal of Clinical Microbiology, J. D. Ward, C. Cornaby, and J. L. Schmitz (J Clin Microbiol 59:e00811-21, 2021, https://doi.org/10.1128/JCM.00811-21) investigated an increased indeterminate rate in the QuantiFERON-TB Gold Plus assay among COVID-19 patients that was independent of immunosuppressive agents and lymphopenia. In their study, COVID-19 patients with indeterminate QuantiFERON-TB Gold Plus results trended toward decreased survival as well as increased serum interleukin-6 (IL-6) and IL-10 levels, although the differences were not statistically significant. They suggest that this pattern of cytokine expression supports an impairment of Th1, specifically interferon gamma production, in critically ill COVID-19 patients, as indicated by indeterminate QuantiFERON-TB Gold Plus results. Clinicians should be aware of the increased rate of indeterminate QuantiFERON-TB Gold Plus results in critically ill COVID-19 patients.
Assuntos
COVID-19 , Tuberculose Latente , Humanos , Testes de Liberação de Interferon-gama , Interleucina-10 , Tuberculose Latente/diagnóstico , SARS-CoV-2RESUMO
Traditionally, physicians have not used cefepime (a fourth-generation cephalosporin with greater stability against ß-lactamases) or ß-lactam/ß-lactamase inhibitors (BLBLIs) for infections caused by bacteria (generally Escherichia coli and Klebsiella species) that produce an extended-spectrum ß-lactamase (ESBL). Many microbiology laboratories have historically labelled these ESBL-producing organisms as resistant to all cephalosporins regardless of their MIC. The recommendation to eliminate ESBL identification started with EUCAST in 2009, followed by CLSI in 2010. As a consequence, many ESBL-producing organisms that were previously labelled as resistant to all cephalosporins may be reclassified as susceptible to some (particularly cefepime), depending on their MICs. Because there are limited treatment options against ESBL-producing organisms, there is growing interest in using cefepime and BLBLIs. In this review, we examine the clinical outcomes of therapy directed against ESBL-producing Enterobacteriaceae and the pharmacokinetics/pharmacodynamics of cefepime and BLBLIs to construct a clinical framework for how physicians can best employ these carbapenem-sparing alternatives for the treatment of infections caused by ESBL-producing Enterobacteriaceae. We conclude that standard-dose cefepime is a reasonable option for the definitive therapy of invasive infections resulting from ESBL-producing E. coli and Klebsiella species when the MIC for the organism is ≤ 2 mg/L (CLSI) or ≤ 1 mg/L (EUCAST), although higher doses may be considered for MICs in the 4-8 mg/L range. Piperacillin/tazobactam is also a reasonable option when the MIC is ≤ 16 mg/L.
Assuntos
Antibacterianos/uso terapêutico , Cefalosporinas/uso terapêutico , Infecções por Enterobacteriaceae/tratamento farmacológico , Enterobacteriaceae/efeitos dos fármacos , Inibidores Enzimáticos/uso terapêutico , Inibidores de beta-Lactamases , Cefepima , Enterobacteriaceae/enzimologia , Humanos , Resultado do Tratamento , beta-Lactamases/metabolismoRESUMO
IMPORTANCE: For the diagnosis and post-treatment monitoring of H. pylori infection, non-invasive testing methodologies improve patient comfort, particularly for children. Previously, only the BreathTek UBT had FDA approval for use in pediatric patients and required an adjustment calculation based on age, height, and weight of the patient. The purpose of this study was to evaluate the performance of the PyloPlus UBT assay in a pediatric population.
Assuntos
Infecções por Helicobacter , Helicobacter pylori , Humanos , Criança , Ureia , Sensibilidade e Especificidade , Infecções por Helicobacter/diagnóstico , Testes Respiratórios/métodosRESUMO
Cancer patients are at risk for severe coronavirus disease 2019 (COVID-19) outcomes due to impaired immune responses. However, the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is inadequately characterized in this population. We hypothesized that cancer vs non-cancer individuals would mount less robust humoral and/or cellular vaccine-induced immune SARS-CoV-2 responses. Receptor binding domain (RBD) and SARS-CoV-2 spike protein antibody levels and T-cell responses were assessed in immunocompetent individuals with no underlying disorders (n = 479) and immunocompromised individuals (n = 115). All 594 individuals were vaccinated and of varying COVID-19 statuses (i.e., not known to have been infected, previously infected, or "Long-COVID"). Among immunocompromised individuals, 59% (n = 68) had an underlying hematologic malignancy; of those, 46% (n = 31) of individuals received cancer treatment <30 days prior to study blood collection. Ninety-eight percentage (n = 469) of immunocompetent and 81% (n = 93) of immunocompromised individuals had elevated RBD antibody titers (>1,000 U/mL), and of these, 60% (n = 281) and 44% (n = 41), respectively, also had elevated T-cell responses. Composite T-cell responses were higher in individuals previously infected with SARS-CoV-2 or those diagnosed with Long-COVID compared to uninfected individuals. T-cell responses varied between immunocompetent vs carcinoma (n = 12) cohorts (P < 0.01) but not in immunocompetent vs hematologic malignancy cohorts. Most SARS-CoV-2 vaccinated individuals mounted robust cellular and/or humoral responses, though higher immunogenicity was observed among the immunocompetent compared to cancer populations. The study suggests B-cell targeted therapies suppress antibody responses, but not T-cell responses, to SARS-CoV-2 vaccination. Thus, vaccination continues to be an effective way to induce humoral and cellular immune responses as a likely key preventive measure against infection and/or subsequent more severe adverse outcomes. IMPORTANCE: The study was prompted by a desire to better assess the immune status of patients among our cancer host cohort, one of the largest in the New York metropolitan region. Hackensack Meridian Health is the largest healthcare system in New Jersey and cared for more than 75,000 coronavirus disease 2019 patients in its hospitals. The John Theurer Cancer Center sees more than 35,000 new cancer patients a year and performs more than 500 hematopoietic stem cell transplants. As a result, the work was undertaken to assess the effectiveness of vaccination in inducing humoral and cellular responses within this demographic.
Assuntos
COVID-19 , Neoplasias Hematológicas , Neoplasias , Glicoproteína da Espícula de Coronavírus , Humanos , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Vacinação , Imunidade Celular , Anticorpos Antivirais , Imunidade HumoralAssuntos
Candida/isolamento & purificação , Candidíase/diagnóstico , Bases de Dados de Ácidos Nucleicos , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candida/genética , Farmacorresistência Fúngica Múltipla , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Mycobacterium abscessus group (MAG) are rapidly growing acid-fast bacteria that consist of three closely related species: M. abscessus (Ma), M. bolletii (Mb), and M. massiliense (Mm). Differentiation of these species can be difficult but is increasingly requested owing to recent infectious outbreaks and their differential drug resistance. We developed a novel and rapid pyrosequencing method using short signature sequences (35 to 45 bp) at a hypervariable site in the rpoB gene to differentiate the three MAG species, along with M. chelonae (Mc), and M. immunogenum (Mi). This method was evaluated using 111 M. chelonae-abscessus complex (MCAC) isolates, including six reference strains. All isolates were successfully differentiated to the species level (69 Ma, four Mb, six Mm, 23 Mc, and nine Mi). The species identifications by this method had 100% agreement with Sanger sequencing as well as an in-silico rpoB typing method. This short signature sequencing (SSS) method is rapid (6 to 7 h), accurately differentiates MAG species, and is useful for informing antimicrobial therapy decision. IMPORTANCE Mycobacterium abscessus group (MAG) are rapidly growing acid-fast bacteria that include three species: M. abscessus, M. massiliense, and M. bolletii. These species are among the leading causes of nontuberculosis mycobacteria infections in humans but difficult to differentiate using commonly used methods. The differences of drug resistance among the species shape the treatment regimens and make it significant for them to be differentiated accurately and quickly. We developed and evaluated a novel short signature sequencing (SSS) method utilizing a gene called rpoB to differentiate the three MAG species, as well as other two species (M. chelonae and M. immunogenum). The identification results had 100% agreement with both the reference method of Sanger sequencing and rpoB typing method via a computer-simulated analysis. This SSS method was accurate and quick (6 to 7 h) for species differentiation, which will benefit patient care. The technology used for this method is affordable and easy to operate.
Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Mycobacterium , Proteínas de Bactérias/genética , DNA Bacteriano/genética , Humanos , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Mycobacterium abscessus/genética , Filogenia , Análise de Sequência de DNARESUMO
This report describes a chronically ill child who presented with high fever and was diagnosed with catheter-related sepsis. Aureobasidium pullulans variety melanigenum, a dematiaceous fungus that rarely causes opportunistic infections, was recovered from multiple blood cultures. Antifungal susceptibilities were performed and the minimum inhibitory concentration (MIC) for fluconazole was 64 mg/l, suggestive of fluconazole resistance. The patient made a full recovery after removal of the catheter line and treatment with liposomal amphotericin B. This is the first case report of an elevated in vitro fluconazole MIC of an A. pullulans isolate and only the third case of successful treatment of A. pullulans fungemia.
Assuntos
Ascomicetos/isolamento & purificação , Fungemia/diagnóstico , Fungemia/microbiologia , Micoses/diagnóstico , Micoses/microbiologia , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Ascomicetos/classificação , Ascomicetos/genética , Sangue/microbiologia , Infecções Relacionadas a Cateter/diagnóstico , Infecções Relacionadas a Cateter/tratamento farmacológico , Infecções Relacionadas a Cateter/microbiologia , Infecções Relacionadas a Cateter/patologia , Criança , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Farmacorresistência Fúngica , Fluconazol/farmacologia , Fungemia/tratamento farmacológico , Fungemia/patologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Micoses/tratamento farmacológico , Micoses/patologia , Análise de Sequência de DNARESUMO
The culture method remains vital in diagnosing fungal infections, but extensive data-based evaluation of the method, especially for filamentous fungi (molds), is minimal. The purpose of this study was to characterize mold recoveries from fungal cultures and the impact of media and incubation duration. Clinical specimens for fungal cultures were submitted primarily from the eastern and central United States, and mold isolation data were prospectively collected and analyzed. A total of 1,821 molds in 59 genera were isolated from 1,687 positive specimens, accounting for approximately 5.6% of our cohort of 30,000 fungal cultures. Within 2 weeks, nearly 90% of molds and 97.3% of Aspergillus fumigatus complex were recovered (>95% confidence interval [CI]). All Mucorales fungi were recovered within 11 days of incubation. The recovery peak time was day 3 for Mucorales fungi, day 4 for hyaline molds, day 5 for dematiaceous molds, and day 7 for Onygenales fungi. The recovery of Histoplasma capsulatum and Trichophyton species in the fourth week of incubation reveals that a 3-week incubation time is insufficient. Inhibitory mold agar was the best medium for recovering all mold types among all tested specimen types, yielding nearly 78% of mold growth overall, indicating the necessity of selective medium for fungal cultures. IMPORTANCE Fungal culture is the gold standard method of diagnosing fungal infections, but important information, such as the impact of media and incubation times on fungal recovery, is not well documented. This study addressed these gaps using extensive data-based evaluation focused on molds. We identified the best medium types and incubation times for better fungal culture practice. We analyzed 1,821 molds from 1,687 positive specimens in our cohort of approximately 30,000 fungal cultures. Mold recovery peaked between 3 and 7 days of incubation, dependent upon the type of mold. Some well-defined fungal pathogens, such as Histoplasma capsulatum and Trichophyton species, were isolated in the fourth week of incubation. Inhibitory mold agar was identified as the best medium for recovering all mold types among all tested specimen sources. As we are aware, this is the largest study of fungal culture methods and supports 4 weeks of incubation for optimal mold recovery.
Assuntos
Fungos/crescimento & desenvolvimento , Fungos/isolamento & purificação , Micoses/microbiologia , Meios de Cultura/química , Meios de Cultura/metabolismo , Fungos/genética , Fungos/metabolismo , Humanos , Micoses/diagnósticoRESUMO
Organisms of the Mycobacterium chelonae-abscessus group can be significant pathogens in humans. They produce a number of diseases including acute, invasive and chronic infections, which may be difficult to diagnose correctly. Identification among members of this group is complicated by differentiating at least eleven (11) known species and subspecies and complexity of identification methodologies. Treatment of their infections may be problematic due to their correct species identification, antibiotic resistance, their differential susceptibility to the limited number of drugs available, and scarcity of susceptibility testing.
Assuntos
Infecções por Mycobacterium não Tuberculosas/epidemiologia , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium abscessus/isolamento & purificação , Técnicas Bacteriológicas , Testes Diagnósticos de Rotina , Farmacorresistência Bacteriana , Humanos , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Mycobacterium abscessus/classificação , Mycobacterium abscessus/efeitos dos fármacosRESUMO
AIMS: Acid-fast bacterium (AFB) identification from formalin-fixed paraffin-embedded (FFPE) tissues is challenging and may not be readily available to the clinical laboratory. A method to detect and identify AFB from FFPE tissues using PCR and pyrosequencing (PCR-Seq) was developed and evaluated. METHODS: The method was validated using spiked cell-clotted paraffin blocks before use with patients' specimens. DNA was extracted from tissue sections, and a 16S rRNA gene fragment was amplified and a signature sequence was produced on a PyroMark ID system. Sequences were aligned to established databases for AFB identification. Additional tissue sections were stained and examined for AFB. RESULTS: Both sensitivity and specificity were 100% on spiked cell-clotted blocks without cross-reactivity with non-AFB. Of 302 FFPE tissues from patients, 116 (38%) were AFB-stain positive; 83 (72%) of these had AFB identified. The 21 AFB identified included Mycobacterium tuberculosis complex (14 cases), Mycobacterium leprae (3), Mycobacterium genavense (2), Mycobacterium marinum-ulcerans group (3) and 17 other AFB (61). Thirteen cases were AFB-stain indeterminate and 4 were positive by the PCR-Seq method. Of the AFB stain-negative cases, 167 were negative and 6 were positive by PCR-Seq. CONCLUSIONS: The PCR-Seq method provided specific identification of various AFB species or complexes from FFPE tissues.
Assuntos
DNA Bacteriano/análise , Mycobacterium/isolamento & purificação , Nocardia/isolamento & purificação , Inclusão em Parafina , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA/métodos , Fixação de Tecidos , Formaldeído , Marcadores Genéticos , Humanos , Mycobacterium/genética , Nocardia/genética , RNA Ribossômico 16S/genética , Sensibilidade e EspecificidadeRESUMO
Complement can be activated via three pathways: classical, alternative, and lectin. Cryptococcus gattii and Cryptococcus neoformans are closely related fungal pathogens possessing a polysaccharide capsule composed mainly of glucuronoxylomannan (GXM), which serves as a site for complement activation and deposition of complement components. We determined C3 deposition on Cryptococcus spp. by flow cytometry and confocal microscopy after incubation with serum from C57BL/6J mice as well as mice deficient in complement components C4, C3, factor B, and mannose binding lectin (MBL). C. gattii and C. neoformans activate complement in EGTA-treated serum indicating that they can activate the alternative pathway. However, complement activation was seen with factor B(-/-) serum suggesting activation could also take place in the absence of a functional alternative pathway. Furthermore, we uncovered a role for C4 in the alternative pathway activation by Cryptococcus spp. We also identified an unexpected and complex role for MBL in complement activation by Cryptococcus spp. No complement activation occurred in the absence of MBL-A and -C proteins although activation took place when the lectin binding activity of MBL was disrupted by calcium chelation. In addition, alternative pathway activation by C. neoformans required both MBL-A and -C, while either MBL-A or -C was sufficient for alternative pathway activation by C. gattii. Thus, complement activation by Cryptococcus spp. can take place through multiple pathways and complement activation via the alternative pathway requires the presence of C4 and MBL proteins.