RESUMO
BACKGROUND AIMS: Therapeutic disruption of immune checkpoints has significantly advanced the armamentarium of approaches for treating cancer. The prominent role of the programmed death-1 (PD-1)/programmed death ligand-1 axis for downregulating T cell function offers a tractable strategy for enhancing the disease-modifying impact of CAR-T cell therapy. METHODS: To address checkpoint interference, primary human T cells were genome edited with a next-generation CRISPR-based platform (Cas9 chRDNA) by knockout of the PDCD1 gene encoding the PD-1 receptor. Site-specific insertion of a chimeric antigen receptor specific for CD19 into the T cell receptor alpha constant locus was implemented to drive cytotoxic activity. RESULTS: These allogeneic CAR-T cells (CB-010) promoted longer survival of mice in a well-established orthotopic tumor xenograft model of a B cell malignancy compared with identically engineered CAR-T cells without a PDCD1 knockout. The persistence kinetics of CB-010 cells in hematologic tissues versus CAR-T cells without PDCD1 disruption were similar, suggesting the robust initial debulking of established tumor xenografts was due to enhanced functional fitness. By single-cell RNA-Seq analyses, CB-010 cells, when compared with identically engineered CAR-T cells without a PDCD1 knockout, exhibited fewer Treg cells, lower exhaustion phenotypes and reduced dysfunction signatures and had higher activation, glycolytic and oxidative phosphorylation signatures. Further, an enhancement of mitochondrial metabolic fitness was observed, including increased respiratory capacity, a hallmark of less differentiated T cells. CONCLUSIONS: Genomic PD-1 checkpoint disruption in the context of allogeneic CAR-T cell therapy may provide a compelling option for treating B lymphoid malignancies.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Receptores de Antígenos Quiméricos , Humanos , Animais , Camundongos , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Receptores de Antígenos de Linfócitos T , Receptor de Morte Celular Programada 1/metabolismo , Linhagem Celular Tumoral , Linfócitos T , Imunoterapia AdotivaRESUMO
During September 2019, public health authorities in El Paso County, Colorado, were notified of four patients who had presented to nearby hospitals with clinical features consistent with botulism, a paralytic illness caused by botulinum neurotoxin. One patient died soon after presentation; the other three patients required intensive care but recovered after receiving botulism antitoxin. Botulinum toxin type A was detected in serum from all patients. On further investigation, all four patients had shared a meal that included commercially prepared roasted potatoes from an individual package without refrigeration instructions that had been left unrefrigerated for 15 d. Storage of the product at ambient temperature likely allowed botulism spores to produce botulinum toxin, resulting in severe illness and death. The manufacturer improved labeling in response to this outbreak. Public health officials should consider unrefrigerated potato products as a potential source of botulism; clinicians should consider botulism as a possible cause of paralytic illness.
Assuntos
Toxinas Botulínicas Tipo A , Botulismo , Clostridium botulinum , Solanum tuberosum , Humanos , Botulismo/diagnóstico , Botulismo/epidemiologia , Botulismo/etiologia , Antitoxina Botulínica , Colorado/epidemiologia , Surtos de DoençasRESUMO
RNA-guided CRISPR-Cas9 endonucleases are widely used for genome engineering, but our understanding of Cas9 specificity remains incomplete. Here, we developed a biochemical method (SITE-Seq), using Cas9 programmed with single-guide RNAs (sgRNAs), to identify the sequence of cut sites within genomic DNA. Cells edited with the same Cas9-sgRNA complexes are then assayed for mutations at each cut site using amplicon sequencing. We used SITE-Seq to examine Cas9 specificity with sgRNAs targeting the human genome. The number of sites identified depended on sgRNA sequence and nuclease concentration. Sites identified at lower concentrations showed a higher propensity for off-target mutations in cells. The list of off-target sites showing activity in cells was influenced by sgRNP delivery, cell type and duration of exposure to the nuclease. Collectively, our results underscore the utility of combining comprehensive biochemical identification of off-target sites with independent cell-based measurements of activity at those sites when assessing nuclease activity and specificity.
Assuntos
Sistemas CRISPR-Cas/genética , Mapeamento Cromossômico/métodos , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Genoma/genética , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNARESUMO
Compounds based on the 2,3-distyrylindole scaffold were found to exhibit bactericidal properties upon irradiation with white light. At the concentration of 1⯵M, the lead compound 1 completely (ca. 109â¯CFU/mL) eradicated such Gram-positive organisms as S. aureus (MRSA, MSSA), E. faecalis (VRE), S. pyogenes and S. mutans when irradiated with white light for 2â¯min. At the concentration of 5⯵M and in the presence of polymyxin E at non-bactericidal 1.25⯵g/mL concentration, 1 also showed a 7-log to 9-log reductions in bacterial counts of such Gram-negative organisms as multi-drug resistant (MDR) A. baumannii, MDR P. aeruginosa, E. coli and Klebsiella pneumoniae (CRE: KPC and NDM-1), also when irradiated with white light for 2â¯min. The structure-activity relationship studies revealed that unsubstituted at benzene rings 2,3-distyrylindole 2 was most potent and gave a 5-order of magnitude eradication of a MRSA strain at the concentration of 30â¯nM upon irradiation with white light. Initial mechanistic experiments revealed the disruption of bacterial cell membrane, but indicated that singlet oxygen production, which is commonly associated with photodynamic therapy, may not play a role in the bactericidal effects of the 2,3-distyrylindoles.
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Antibacterianos/química , Indóis/química , Antibacterianos/farmacologia , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Indóis/farmacologia , Luz , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Oxigênio Singlete/metabolismo , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Increasing evidence suggests that influenza reassortment not only contributes to the emergence of new human pandemics but also plays an important role in seasonal influenza epidemics, disease severity, evolution, and vaccine efficacy. We studied this process within 2091 H3N2 full genomes utilizing a combination of the latest reassortment detection tools and more conventional phylogenetic analyses. RESULTS: We found that the amount of H3N2 intra-subtype reassortment depended on the number of sampled genomes, occurred with a steady frequency of 3.35%, and was not affected by the geographical origins, evolutionary patterns, or previous reassortment history of the virus. We identified both single reassortant genomes and reassortant clades, each clade representing one reassortment event followed by successful spread of the reassorted variant in the human population. It was this spread that was mainly responsible for the observed high presence of H3N2 intra-subtype reassortant genomes. The successfully spread variants were generally sampled within one year of their formation, highlighting the risk of their rapid spread but also presenting an opportunity for their rapid detection. Simultaneous spread of several different reassortant lineages was observed, and despite their limited average lifetime, second and third generation reassortment was detected, as well as reassortment between viruses belonging to different vaccine-associated clades, likely displaying differing antigenic properties. Some of the spreading reassortants remained confined to certain geographical regions, while others, sharing common properties in amino acid positions of the HA, NA, and PB2 segments, were found throughout the world. CONCLUSIONS: Detailed surveillance of seasonal influenza reassortment patterns and variant properties may provide unique information needed for prediction of spread and construction of future influenza vaccines.
Assuntos
Vírus da Influenza A Subtipo H3N2/genética , Evolução Molecular , Genoma Viral/genética , Humanos , Vírus da Influenza A Subtipo H3N2/classificação , Influenza Humana/transmissão , Influenza Humana/virologia , FilogeniaRESUMO
Allogeneic chimeric antigen receptor (CAR) T cell therapies hold the potential to overcome many of the challenges associated with patient-derived (autologous) CAR T cells. Key considerations in the development of allogeneic CAR T cell therapies include prevention of graft-vs-host disease (GvHD) and suppression of allograft rejection. Here, we describe preclinical data supporting the ongoing first-in-human clinical study, the CaMMouflage trial (NCT05722418), evaluating CB-011 in patients with relapsed/refractory multiple myeloma. CB-011 is a hypoimmunogenic, allogeneic anti-B-cell maturation antigen (BCMA) CAR T cell therapy candidate. CB-011 cells feature 4 genomic alterations and were engineered from healthy donor-derived T cells using a Cas12a CRISPR hybrid RNA-DNA (chRDNA) genome-editing technology platform. To address allograft rejection, CAR T cells were engineered to prevent endogenous HLA class I complex expression and overexpress a single-chain polyprotein complex composed of beta-2 microglobulin (B2M) tethered to HLA-E. In addition, T-cell receptor (TCR) expression was disrupted at the TCR alpha constant locus in combination with the site-specific insertion of a humanized BCMA-specific CAR. CB-011 cells exhibited robust plasmablast cytotoxicity in vitro in a mixed lymphocyte reaction in cell cocultures derived from patients with multiple myeloma. In addition, CB-011 cells demonstrated suppressed recognition by and cytotoxicity from HLA-mismatched T cells. CB-011 cells were protected from natural killer cell-mediated cytotoxicity in vitro and in vivo due to endogenous promoter-driven expression of B2M-HLA-E. Potent antitumor efficacy, when combined with an immune-cloaking armoring strategy to dampen allograft rejection, offers optimized therapeutic potential in multiple myeloma. See related Spotlight by Caimi and Melenhorst, p. 385.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Mieloma Múltiplo , Humanos , Mieloma Múltiplo/genética , Mieloma Múltiplo/terapia , Antígeno de Maturação de Linfócitos B/metabolismo , Antígenos HLA-E , Linfócitos T , Receptores de Antígenos de Linfócitos T , Imunoterapia Adotiva , Antígenos de Histocompatibilidade Classe I/metabolismo , Aloenxertos/patologiaRESUMO
In plants, the ERF/EREBP family of transcriptional regulators plays a key role in adaptation to various biotic and abiotic stresses. These proteins contain a conserved AP2 DNA-binding domain and several uncharacterized motifs. Here, we describe a short motif, termed 'EDLL', that is present in AtERF98/TDR1 and other clade members from the same AP2 sub-family. We show that the EDLL motif, which has a unique arrangement of acidic amino acids and hydrophobic leucines, functions as a strong activation domain. The motif is transferable to other proteins, and is active at both proximal and distal positions of target promoters. As such, the EDLL motif is able to partly overcome the repression conferred by the AtHB2 transcription factor, which contains an ERF-associated amphiphilic repression (EAR) motif. We further examined the activation potential of EDLL by analysis of the regulation of flowering time by NF-Y (nuclear factor Y) proteins. Genetic evidence indicates that NF-Y protein complexes potentiate the action of CONSTANS in regulation of flowering in Arabidopsis; we show that the transcriptional activation function of CONSTANS can be substituted by direct fusion of the EDLL activation motif to NF-YB subunits. The EDLL motif represents a potent plant activation domain that can be used as a tool to confer transcriptional activation potential to heterologous DNA-binding proteins.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Ativação Transcricional , Motivos de Aminoácidos , Sequência de Aminoácidos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Clonagem Molecular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Flores/metabolismo , Flores/fisiologia , Genes de Plantas , Genes Reporter , Dados de Sequência Molecular , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/fisiologia , Regiões Promotoras Genéticas , Estrutura Terciária de Proteína , Protoplastos/citologia , Protoplastos/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Tempo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , TransfecçãoRESUMO
People who relocate to a new environment may experience health effects from a change in ambient air pollution. We undertook a literature review of studies of such relocations and health effects and report the results as a narrative analysis. Fifteen articles of heterogeneous designs met the inclusion criteria. Four short-term (relocation duration less than six months) and three long-term (relocation duration six months or greater) studies reported evidence of the effect of relocation on physiological outcome, biomarkers or symptoms. All had potential weaknesses of design or analysis but, as a whole, their results are broadly consistent in suggesting short-term adverse effects of air pollutants or their reversibility. One long-term study provided evidence that changes in air pollution exposure during adolescence have a measurable effect on lung function growth. Four cohort studies were also identified that used relocation to strengthen evidence of air-pollution-exposure relationships by using a design that incorporates effective randomization of exposure or the use of relocation to improve exposure classification. However, three studies of relocation during pregnancy provided limited evidence to conclude an effect of relocation-related change in exposure on pregnancy outcome. Overall, most relocation studies are consistent with short- or long-term adverse effects of air pollution on biological function or mortality, but many studies of change in exposure have design weaknesses that limit the robustness of interpretation. We outline principles for improved design and analysis to help strengthen future studies for the insights they can provide from their quasi-experimental designs, including on the nature and timing of functional changes of relocation-related changes in exposure to ambient air pollution.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Adolescente , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Exposição Ambiental/análise , Feminino , Humanos , Material Particulado/análise , Gravidez , Resultado da GravidezRESUMO
OBJECTIVES: Cardiorespiratory instability may be undetected in monitored step-down unit patients. We explored whether using an integrated monitoring system that continuously amalgamates single noninvasive monitoring parameters (heart rate, respiratory rate, blood pressure, and peripheral oxygen saturation) into AN instability index value (INDEX) correlated with our single-parameter cardiorespiratory instability concern criteria, and whether nurse response to INDEX alert for patient attention was associated with instability reduction. DESIGN: Prospective, longitudinal evaluation in sequential 8-, 16-, and 8-wk phases (phase I, phase II, and phase III, respectively). SETTING: A 24-bed trauma step-down unit in single urban tertiary care center. PATIENTS: All monitored patients. INTERVENTIONS: Phase I: Patients received continuous single-channel monitoring (heart rate, respiratory rate, blood pressure, and peripheral oxygen saturation) and standard care; INDEX background was recorded but not displayed. Phase II: INDEX was background-recorded; staff was educated on use. Phase III: Staff used a clinical response algorithm for INDEX alerts. MEASUREMENT AND MAIN RESULTS: Any monitored parameters even transiently beyond local cardiorespiratory instability concern triggers (heart rate of <40 or >140 beats/min, respiratory rate of <8 or >36 breaths/min, systolic blood pressure of <80 or >200 mm Hg, diastolic blood pressure of >110 mm Hg, and peripheral oxygen saturation of <85%) defined INSTABILITYmin. INSTABILITYmin further judged as both persistent and serious defined INSTABILITYfull. The INDEX alert states were defined as INDEXmin and INDEXfull by using same classification. Phase I and phase III admissions (323 vs. 308) and monitoring (18,258 vs. 18,314 hrs) were similar. INDEXmin and INDEXfull correlated significantly with INSTABILITYmin and INSTABILITYfull (r = .713 and r = .815, respectively, p < .0001). INDEXmin occurred before INSTABILITYmin in 80% of cases (mean advance time 9.4 ± 9.2 mins). Phase I and phase III admissions were similarly likely to develop INSTABILITYmin (35% vs. 33%), but INSTABILITYmin duration/admission decreased from phase I to phase III (p = .018). Both INSTABILITYfull episodes/admission (p = .03) and INSTABILITYfull duration/admission (p = .05) decreased in phase III. CONCLUSION: The integrated monitoring system INDEX correlated significantly with cardiorespiratory instability concern criteria, usually occurred before overt instability, and when coupled with a nursing alert was associated with decreased cardiorespiratory instability concern criteria in step-down unit patients.
Assuntos
Arritmias Cardíacas/diagnóstico , Monitorização Fisiológica/instrumentação , Insuficiência Respiratória/diagnóstico , Processamento de Sinais Assistido por Computador , Determinação da Pressão Arterial/métodos , Cuidados Críticos/métodos , Prestação Integrada de Cuidados de Saúde/métodos , Eletrocardiografia/métodos , Feminino , Seguimentos , Indicadores Básicos de Saúde , Frequência Cardíaca/fisiologia , Humanos , Estudos Longitudinais , Masculino , Monitorização Fisiológica/métodos , Oximetria/métodos , Consumo de Oxigênio/fisiologia , Estudos Prospectivos , Respiração , Medição de Risco , Centros de TraumatologiaRESUMO
Foodborne botulism is an intoxication caused by ingestion of food containing botulinum neurotoxin. Cases of foodborne botulism are usually sporadic (single, unrelated) but outbreaks of two or more cases occur. In this mini-review we will examine the following for the period 2001-2017, in the United States: botulism surveillance data, outbreaks of botulism affecting 10 or more people, and the public health preparedness and response approach.
RESUMO
Outbreaks of wound botulism are rare, but clinicians and health departments should maintain suspicion for signs, symptoms, and risk factors of wound botulism among persons who inject drugs in order to initiate treatment quickly. This report describes an outbreak of three wound botulism cases among persons in two adjacent counties who injected drugs. Provisional information about these cases was previously published in the CDC National Botulism Surveillance Summary. All three cases in this outbreak were laboratory-confirmed, including one case with detection of botulinum toxin type A in a wound culture sample taken 43 days after last possible heroin exposure. Findings highlight the delay in diagnosis which led to prolonged hospitalization and the persistence of botulinum toxin in one patient.
Assuntos
Botulismo , Usuários de Drogas , Abuso de Substâncias por Via Intravenosa , Infecção dos Ferimentos , Botulismo/diagnóstico , Botulismo/epidemiologia , Botulismo/etiologia , Heroína/efeitos adversos , Humanos , New Mexico , Abuso de Substâncias por Via Intravenosa/complicações , Infecção dos Ferimentos/induzido quimicamente , Infecção dos Ferimentos/epidemiologiaRESUMO
The 2019 Novel Coronavirus SARS-CoV 2 (COVID-191) pandemic has severely impacted global health, safety, economic development and diplomacy. The government of Nepal issued a lockdown order in the Kathmandu Valley for 80 days from 24 March to 11 June 2020. This paper reports associated changes in ambient PM2.5 measured at fixed-site monitors and changes in personal exposure to PM2.5 monitored by APT Minima by four American diplomats who completed monitoring before and during lockdown (24 h for each period per person, 192 person-hours in total). Time activities and use of home air pollution mitigation measures (use of room air cleaners (RACs), sealing of homes) were recorded by standardized diary. We compared PM2.5 exposure level by microenvironment (home (cooking), home (other activities), at work, commuting, other outdoor environment) in terms of averaged PM2.5 concentration and the contribution to cumulative personal exposure (the product of PM2.5 concentration and time spent in each microenvironment). Ambient PM2.5 measured at fixed-sites in the US Embassy and in Phora Durbar were 38.2% and 46.7% lower than during the corresponding period in 2017-2019. The mean concentration of PM2.5 to which US diplomats were exposed was very much lower than the concentrations of ambient levels measured at fixed site monitors in the city both before and during lockdown. Within-person comparisons suggest personal PM2.5 exposure was 50.0% to 76.7% lower during lockdown than before it. Time spent outdoors and cooking at home were large contributors to cumulative personal exposure. Low indoor levels of PM2.5 were achieved at work and home through use of RACs and measures to seal homes against the ingress of polluted air from outside. Our observations indicate the potential reduction in exposure to PM2.5 with large-scale changes to mainly fossil-fuel related emissions sources and through control of indoor environments and activity patterns.
Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Poluição do Ar , COVID-19 , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Controle de Doenças Transmissíveis , Exposição Ambiental/análise , Monitoramento Ambiental , Empregados do Governo , Humanos , Nepal , Material Particulado/análise , SARS-CoV-2RESUMO
Botulism is typically described as a rapidly progressing, severe neuroparalytic disease. Foodborne botulism is transmitted through consuming food or drink that has been contaminated with botulinum toxin. During a botulism outbreak linked to illicitly brewed alcohol (also known as "hooch" or "pruno") in a prison, 11 (35%) of 31 inmates that consumed contaminated hooch had mild illnesses. This includes 2 inmates with laboratory confirmed botulism. The most frequently reported signs and symptoms among the 11 patients with mild illness included dry mouth (91%), hoarse voice (91%), difficulty swallowing (82%), fatigue (82%), and abdominal pain (82%). Foodborne botulism is likely underdiagnosed and underreported in patients with mild illness. Botulism should be considered on the differential diagnosis for patients with cranial nerve palsies.
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Botulismo , Bebidas Alcoólicas , Botulismo/diagnóstico , Surtos de Doenças , Humanos , Mississippi , PrisõesRESUMO
Aim: The current report describes the discovery of indole derivatives that synergize with standard antibiotics. Materials & methods: The antibacterial activities were determined using an optimized time-kill method, while viability of mammalian cells was assessed using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Results: The synergy is observed with methicillin- and vancomycin-resistant Staphylococcus aureus bacterial strains, against which the standard antibiotics show no activities of their own. Our indole derivatives in combination with antibiotics lack toxicity toward mammalian cells, do not promote the evolution of resistance of S. aureus in comparison to clinically established antibiotics, and likely work by permeabilizing bacterial cell membranes. Conclusion: The above-mentioned findings demonstrate the potential clinical applications of our indole derivatives.
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Antibacterianos/química , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Indóis/química , Indóis/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Sinergismo Farmacológico , Quimioterapia Combinada , Humanos , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/fisiologia , Estrutura Molecular , Infecções Estafilocócicas/microbiologiaRESUMO
Type I CRISPR-Cas systems are the most abundant adaptive immune systems in bacteria and archaea1,2. Target interference relies on a multi-subunit, RNA-guided complex called Cascade3,4, which recruits a trans-acting helicase-nuclease, Cas3, for target degradation5-7. Type I systems have rarely been used for eukaryotic genome engineering applications owing to the relative difficulty of heterologous expression of the multicomponent Cascade complex. Here, we fuse Cascade to the dimerization-dependent, non-specific FokI nuclease domain8-11 and achieve RNA-guided gene editing in multiple human cell lines with high specificity and efficiencies of up to ~50%. FokI-Cascade can be reconstituted via an optimized two-component expression system encoding the CRISPR-associated (Cas) proteins on a single polycistronic vector and the guide RNA (gRNA) on a separate plasmid. Expression of the full Cascade-Cas3 complex in human cells resulted in targeted deletions of up to ~200 kb in length. Our work demonstrates that highly abundant, previously untapped type I CRISPR-Cas systems can be harnessed for genome engineering applications in eukaryotic cells.
Assuntos
Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Escherichia coli , Genoma/genética , Células HEK293 , Humanos , Modelos GenéticosRESUMO
BACKGROUND: Listeriosis, a life-threatening foodborne illness caused by Listeria monocytogenes, affects approximately 2500 Americans annually. Between July and October 2002, an uncommon strain of L. monocytogenes caused an outbreak of listeriosis in 9 states. METHODS: We conducted case finding, a case-control study, and traceback and microbiological investigations to determine the extent and source of the outbreak and to propose control measures. Case patients were infected with the outbreak strain of L. monocytogenes between July and November 2002 in 9 states, and control patients were infected with different L. monocytogenes strains. Outcome measures included food exposure associated with outbreak strain infection and source of the implicated food. RESULTS: Fifty-four case patients were identified; 8 died, and 3 pregnant women had fetal deaths. The case-control study included 38 case patients and 53 control patients. Case patients consumed turkey deli meat much more frequently than did control patients (P = .008, by Wilcoxon rank-sum test). In the 4 weeks before illness, 55% of case patients had eaten deli turkey breast more than 1-2 times, compared with 28% of control patients (odds ratio, 4.5; 95% confidence interval, 1.3-17.1). Investigation of turkey deli meat eaten by case patients led to several turkey processing plants. The outbreak strain was found in the environment of 1 processing plant and in turkey products from a second. Together, the processing plants recalled > 30 million pounds of products. Following the outbreak, the US Department of Agriculture's Food Safety and Inspection Service issued new regulations outlining a L. monocytogenes control and testing program for ready-to-eat meat and poultry processing plants. CONCLUSIONS: Turkey deli meat was the source of a large multistate outbreak of listeriosis. Investigation of this outbreak helped guide policy changes designed to prevent future L. monocytogenes contamination of ready-to-eat meat and poultry products.
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Surtos de Doenças , Microbiologia de Alimentos/legislação & jurisprudência , Listeria monocytogenes/isolamento & purificação , Listeriose/epidemiologia , Listeriose/microbiologia , Carne/microbiologia , Adolescente , Adulto , Animais , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Perus , Estados Unidos/epidemiologiaRESUMO
CONTEXT: Nuclear pharmacies prepare radiopharmaceutical products for use in common diagnostic procedures, including myocardial perfusion studies. Hepatitis C virus (HCV) transmission has not been reported previously in the setting of nuclear imaging studies. OBJECTIVE: To investigate an outbreak of acute HCV infection identified among patients who underwent myocardial perfusion studies on October 15, 2004, using an injected radiopharmaceutical. DESIGN, SETTING, AND PATIENTS: Outbreak investigation including molecular epidemiology and pharmacy site investigation at outpatient cardiology clinics and a nuclear pharmacy in Maryland. Ninety patients who received injections drawn from select radiopharmaceutical vials prepared on October 14-15, 2004, at a single nuclear pharmacy were offered testing for bloodborne pathogens. Pharmacy procedures were reviewed and HCV quasi species analysis was performed. MAIN OUTCOME MEASURES: Hepatitis C virus infection and quasispecies sequence similarity. RESULTS: Sixteen patients with acute HCV infection were identified from 3 separate clinics. All patients received radiopharmaceutical injections drawn from a single pharmacy vial (vial 1). None of the 59 tested patients who received doses from 6 other vials had acute HCV infection. Blood from a potential source patient with HCV and human immunodeficiency virus (HIV) infection was processed for a radiolabeled white blood cell study in the pharmacy 12 hours before vial 1 was prepared. The HCV quasispecies sequences from this potential source patient were nearly identical to those from cases (97.8%-98.5% similarity). No acute HIV infections were identified. Pharmacy practices that could have led to blood cross-contamination included reuse of needles and syringes during dilutions and use of common flow hoods for some steps in the preparation of sterile and blood-derived products. CONCLUSIONS: Sixteen persons acquired HCV infection from a blood-contaminated radiopharmaceutical. The source and practices that could have facilitated breaks in aseptic technique were identified at the pharmacy. Nuclear pharmacies that handle biological products should follow appropriate aseptic technique to prevent contamination of sterile radiopharmaceuticals.