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1.
MMWR Morb Mortal Wkly Rep ; 72(23): 627-632, 2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37289660

RESUMO

More than 30,000 monkeypox (mpox) cases were reported in the United States during the 2022 multinational outbreak; cases disproportionately affected gay, bisexual, and other men who have sex with men (MSM). Substantial racial and ethnic disparities in incidence were also reported (1). The national mpox vaccination strategy* emphasizes that efforts to administer the JYNNEOS mpox vaccine should be focused among the populations at elevated risk for exposure to mpox (2). During May 2022-April 2023, a total of 748,329 first JYNNEOS vaccine doses (of the two recommended) were administered in the United States.† During the initial months of the outbreak, lower vaccination coverage rates among racial and ethnic minority groups were reported (1,3); however, after implementation of initiatives developed to expand access to mpox vaccination,§ coverage among racial and ethnic minority groups increased (1,4). A shortfall analysis was conducted to examine whether the increase in mpox vaccination coverage was equitable across all racial and ethnic groups (5). Shortfall was defined as the percentage of the vaccine-eligible population that did not receive the vaccine (i.e., 100% minus the percentage of the eligible population that did receive a first dose). Monthly mpox vaccination shortfalls were calculated and were stratified by race and ethnicity; monthly percent reductions in shortfall were also calculated compared with the preceding month's shortfall (6). The mpox vaccination shortfall decreased among all racial and ethnic groups during May 2022-April 2023; however, based on analysis of vaccine administration data with race and ethnicity reported, 66.0% of vaccine-eligible persons remained unvaccinated at the end of this period. The shortfall was largest among non-Hispanic Black or African American (Black) (77.9%) and non-Hispanic American Indian or Alaska Native (AI/AN) (74.5%) persons, followed by non-Hispanic White (White) (66.6%) and Hispanic or Latino (Hispanic) (63.0%) persons, and was lowest among non-Hispanic Asian (Asian) (38.5%) and non-Hispanic Native Hawaiian and other Pacific Islander (NH/OPI) (43.7%) persons. The largest percentage decreases in the shortfall were achieved during August (17.7%) and September (8.5%). However, during these months, smaller percentage decreases were achieved among Black persons (12.2% and 4.9%, respectively), highlighting the need for a focus on equity for the entirety of a public health response. Achieving equitable progress in JYNNEOS vaccination coverage will require substantial decreases in shortfalls among Black and AI/AN persons.


Assuntos
Mpox , Minorias Sexuais e de Gênero , Vacina Antivariólica , Masculino , Humanos , Estados Unidos/epidemiologia , Etnicidade , Homossexualidade Masculina , Cobertura Vacinal , Grupos Minoritários , Vacinação
2.
MMWR Morb Mortal Wkly Rep ; 72(15): 398-403, 2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37053122

RESUMO

As of December 31, 2022, a total of 29,939 monkeypox (mpox) cases* had been reported in the United States, 93.3% of which occurred in adult males. During May 10-December 31, 2022, 723,112 persons in the United States received the first dose in a 2-dose mpox (JYNNEOS)† vaccination series; 89.7% of these doses were administered to males (1). The current mpox outbreak has disproportionately affected gay, bisexual, and other men who have sex with men (MSM) and racial and ethnic minority groups (1,2). To examine racial and ethnic disparities in mpox incidence and vaccination rates, rate ratios (RRs) for incidence and vaccination rates and vaccination-to-case ratios were calculated, and trends in these measures were assessed among males aged ≥18 years (males) (3). Incidence in males in all racial and ethnic minority groups except non-Hispanic Asian (Asian) males was higher than that among non-Hispanic White (White) males. At the peak of the outbreak in August 2022, incidences among non-Hispanic Black or African American (Black) and Hispanic or Latino (Hispanic) males were higher than incidence among White males (RR = 6.9 and 4.1, respectively). Overall, vaccination rates were higher among males in racial and ethnic minority groups than among White males. However, the vaccination-to-case ratio was lower among Black (8.8) and Hispanic (16.2) males than among White males (42.5) during the full analytic period, indicating that vaccination rates among Black and Hispanic males were not proportionate to the elevated incidence rates (i.e., these groups had a higher unmet vaccination need). Efforts to increase vaccination among Black and Hispanic males might have resulted in the observed relative increased rates of vaccination; however, these increases were only partially successful in reducing overall incidence disparities. Continued implementation of equity-based vaccination strategies is needed to further increase vaccination rates and reduce the incidence of mpox among all racial and ethnic groups. Recent modeling data (4) showing that, based on current vaccination coverage levels, many U.S. jurisdictions are vulnerable to resurgent mpox outbreaks, underscore the need for continued vaccination efforts, particularly among racial and ethnic minority groups.


Assuntos
Mpox , Minorias Sexuais e de Gênero , Masculino , Adulto , Humanos , Estados Unidos/epidemiologia , Adolescente , Etnicidade , Homossexualidade Masculina , Grupos Minoritários , Vacinação , Brancos
3.
J Cell Sci ; 133(9)2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32079654

RESUMO

Mitochondrial DNA of Trypanosoma brucei and related parasites is a catenated network containing thousands of minicircles and tens of maxicircles, called kinetoplast DNA (kDNA). Replication of a single nucleoid requires at least three DNA polymerase I-like proteins (i.e. POLIB, POLIC and POLID), each showing discrete localizations near the kDNA during S phase. POLIB and POLID have roles in minicircle replication but the specific role of POLIC in kDNA maintenance is less clear. Here, we use an RNA interference (RNAi)-complementation system to dissect the functions of two distinct POLIC regions, i.e. the conserved family A DNA polymerase (POLA) domain and the uncharacterized N-terminal region (UCR). While RNAi complementation with wild-type POLIC restored kDNA content and cell cycle localization of kDNA, active site point mutations in the POLA domain impaired minicircle replication similar to that of POLIB and POLID depletions. Complementation with POLA domain alone abolished the formation of POLIC foci and partially rescued the RNAi phenotype. Furthermore, we provide evidence that the UCR is crucial in cell cycle-dependent protein localization and facilitates proper distribution of progeny networks. This is the first report of a DNA polymerase that impacts on mitochondrial nucleoid distribution.This article has an associated First Person interview with the first author of the paper.


Assuntos
DNA Polimerase I , Trypanosoma brucei brucei , DNA Polimerase gama , Replicação do DNA/genética , DNA de Cinetoplasto/genética , DNA Mitocondrial , Polimerização , Proteína C , Proteínas de Protozoários/genética , Trypanosoma brucei brucei/genética
5.
Zoonoses Public Health ; 66(8): 974-977, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31512375

RESUMO

Reptile contact can result in zoonotic non-typhoidal salmonellosis. In April 2018, Oregon Public Health Division contacted CDC about a cluster of four Salmonella serovar Fluntern (SF) illnesses in four states (OR, CA, IA, NY); patients reported contact with geckos, a popular reptile pet. PulseNet, the national molecular subtyping network of food-borne disease surveillance, subsequently identified additional SF clinical isolates. Twelve cases in 11 states were identified; median age was 5 years (range: <1-58 years). Three patients were hospitalized; no deaths were reported. Of those with exposure information (n = 10), all reported reptile exposure; 9 (90%) specified contact with leopard geckos. No common source of geckos was identified from reported purchase locations. Los Angeles County (LAC) health officials isolated SF from one patient's leopard gecko. Five reptile/gecko isolates were identified from the USDA National Veterinary Services Laboratories (NVSL) from 2015 to 2018. Five countries responded to an Epidemic Intelligence Information System post by PulseNet; reptile isolate sequence data were received from Czech Republic. A clinical case from England was identified through the National Center for Biotechnology Information pathogen detection pipeline; the patient did not report contact with leopard geckos. Whole genome sequencing analysis revealed substantial genetic diversity between clinical and animal isolates; however, gecko and clinical isolates from LAC were highly related (1 allele difference). This investigation linking SF illnesses to leopard geckos highlights an important public health risk from pets. A better understanding of how geckos are distributed by the pet industry in the United States could improve traceability to points of origin and mitigate Salmonella transmission at gecko breeders. Earlier NVSL reports of SF isolates from geckos suggest the risk of human SF infection from geckos is not new. This investigation demonstrates a need to educate gecko breeders, retailers and gecko owners about the continued Salmonella infection risk from pet geckos.


Assuntos
Lagartos/microbiologia , Animais de Estimação/microbiologia , Salmonelose Animal/transmissão , Salmonella/genética , Zoonoses/transmissão , Adolescente , Adulto , Alelos , Animais , Criança , Pré-Escolar , Surtos de Doenças , Feminino , Variação Genética , Hospitalização , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Salmonella/isolamento & purificação , Estados Unidos , Adulto Jovem , Zoonoses/microbiologia
6.
Front Public Health ; 7: 172, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31316960

RESUMO

Infections caused by pathogens commonly acquired from consumption of food are not always transmitted by that route. They may also be transmitted through contact to animals, other humans or the environment. Additionally, many outbreaks are associated with food contaminated from these non-food sources. For this reason, such presumed foodborne outbreaks are best investigated through a One Health approach working across human, animal and environmental sectors and disciplines. Outbreak strains or clones that have propagated and continue to evolve in non-human sources and environments often show more sequence variation than observed in typical monoclonal point-source outbreaks. This represents a challenge when using whole genome sequencing (WGS), the new gold standard for molecular surveillance of foodborne pathogens, for outbreak detection and investigation. In this review, using recent examples from outbreaks investigated in the United States (US) some aspects of One Health approaches that have been used successfully to solve such outbreaks are presented. These include using different combinations of flexible WGS based case definition, efficient epidemiological follow-up, traceback, surveillance, and testing of potential food and environmental sources and animal hosts.

7.
Nat Commun ; 10(1): 2720, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221973

RESUMO

Public Health Laboratories (PHLs) in Puerto Rico did not escape the devastation caused by Hurricane Maria. We implemented a quality management system (QMS) approach to systematically reestablish laboratory testing, after evaluating structural and functional damage. PHLs were inoperable immediately after the storm. Our QMS-based approach began in October 2017, ended in May 2018, and resulted in the reestablishment of 92% of baseline laboratory testing capacity. Here, we share lessons learned from the historic recovery of the largest United States' jurisdiction to lose its PHL capacity, and provide broadly applicable tools for other jurisdictions to enhance preparedness for public health emergencies.

8.
Mol Biol Cell ; 29(21): 2540-2552, 2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30133333

RESUMO

Trypanosoma brucei has a unique catenated mitochondrial DNA (mtDNA) network called kinetoplast DNA (kDNA). Replication of kDNA occurs once per cell cycle in near synchrony with nuclear S phase and requires the coordination of many proteins. Among these are three essential DNA polymerases (TbPOLIB, IC, and ID). Localization dynamics of these proteins with respect to kDNA replication stages and how they coordinate their functions during replication are not well understood. We previously demonstrated that TbPOLID undergoes dynamic localization changes that are coupled to kDNA replication events. Here, we report the localization of TbPOLIC, a second essential DNA polymerase, and demonstrate the accumulation of TbPOLIC foci at active kDNA replication sites (antipodal sites) during stage II of the kDNA duplication cycle. While TbPOLIC was undetectable by immunofluorescence during other cell cycle stages, steady-state protein levels measured by Western blot remained constant. TbPOLIC foci colocalized with the fraction of TbPOLID that localized to the antipodal sites. However, the partial colocalization of the two essential DNA polymerases suggests a highly dynamic environment at the antipodal sites to coordinate the trafficking of replication proteins during kDNA synthesis. These data indicate that cell cycle-dependent localization is a major regulatory mechanism for essential mtDNA polymerases during kDNA replication.


Assuntos
Ciclo Celular , DNA Polimerase Dirigida por DNA/metabolismo , Mitocôndrias/enzimologia , Trypanosoma brucei brucei/citologia , Trypanosoma brucei brucei/enzimologia , Replicação do DNA , DNA de Cinetoplasto/biossíntese , DNA de Cinetoplasto/metabolismo , Técnicas de Silenciamento de Genes , Inativação Gênica , Proteínas de Protozoários/metabolismo , Fase S
9.
MMWR Morb Mortal Wkly Rep ; 67(11): 333-336, 2018 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-29565842

RESUMO

Hurricane Maria made landfall in Puerto Rico on September 20, 2017, causing major damage to infrastructure and severely limiting access to potable water, electric power, transportation, and communications. Public services that were affected included operations of the Puerto Rico Department of Health (PRDOH), which provides critical laboratory testing and surveillance for diseases and other health hazards. PRDOH requested assistance from CDC for the restoration of laboratory infrastructure, surveillance capacity, and diagnostic testing for selected priority diseases, including influenza, rabies, leptospirosis, salmonellosis, and tuberculosis. PRDOH, CDC, and the Association of Public Health Laboratories (APHL) collaborated to conduct rapid needs assessments and, with assistance from the CDC Foundation, implement a temporary transport system for shipping samples from Puerto Rico to the continental United States for surveillance and diagnostic and confirmatory testing. This report describes the initial laboratory emergency response and engagement efforts among federal, state, and nongovernmental partners to reestablish public health laboratory services severely affected by Hurricane Maria. The implementation of a sample transport system allowed Puerto Rico to reinitiate priority infectious disease surveillance and laboratory testing for patient and public health interventions, while awaiting the rebuilding and reinstatement of PRDOH laboratory services.


Assuntos
Tempestades Ciclônicas , Desastres , Laboratórios/organização & administração , Prática de Saúde Pública , Centers for Disease Control and Prevention, U.S. , Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/epidemiologia , Testes Diagnósticos de Rotina , Humanos , Vigilância da População , Porto Rico/epidemiologia , Estados Unidos
10.
Euro Surveill ; 22(23)2017 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-28662764

RESUMO

PulseNet International is a global network dedicated to laboratory-based surveillance for food-borne diseases. The network comprises the national and regional laboratory networks of Africa, Asia Pacific, Canada, Europe, Latin America and the Caribbean, the Middle East, and the United States. The PulseNet International vision is the standardised use of whole genome sequencing (WGS) to identify and subtype food-borne bacterial pathogens worldwide, replacing traditional methods to strengthen preparedness and response, reduce global social and economic disease burden, and save lives. To meet the needs of real-time surveillance, the PulseNet International network will standardise subtyping via WGS using whole genome multilocus sequence typing (wgMLST), which delivers sufficiently high resolution and epidemiological concordance, plus unambiguous nomenclature for the purposes of surveillance. Standardised protocols, validation studies, quality control programmes, database and nomenclature development, and training should support the implementation and decentralisation of WGS. Ideally, WGS data collected for surveillance purposes should be publicly available, in real time where possible, respecting data protection policies. WGS data are suitable for surveillance and outbreak purposes and for answering scientific questions pertaining to source attribution, antimicrobial resistance, transmission patterns, and virulence, which will further enable the protection and improvement of public health with respect to food-borne disease.


Assuntos
Bases de Dados Factuais , Surtos de Doenças , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Genoma Bacteriano , Saúde Pública , Sequenciamento Completo do Genoma/normas , Bases de Dados Factuais/normas , Doenças Transmitidas por Alimentos/epidemiologia , Humanos , Laboratórios , Tipagem de Sequências Multilocus
11.
MMWR Morb Mortal Wkly Rep ; 66(25): 663-667, 2017 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-28662015

RESUMO

Foodborne salmonellosis causes an estimated 1 million illnesses and 400 deaths annually in the United States (1). Salmonella Anatum is one of the top 20 Salmonella serotypes in the United States. During 2013-2015 there were approximately 300-350 annual illnesses reported to PulseNet, the national molecular subtyping network for foodborne disease surveillance. In June 2016, PulseNet identified a cluster of 16 Salmonella Anatum infections with an indistinguishable pulsed-field gel electrophoresis (PFGE) pattern from four states.* In April 2016, the same PFGE pattern had been uploaded to PulseNet from an isolate obtained from an Anaheim pepper, a mild to medium hot pepper. Hot peppers include many pepper varieties, such as Anaheim, jalapeño, poblano, and serrano, which can vary in heat level from mild to very hot depending on the variety and preparation. This rare PFGE pattern had been seen only 24 times previously in the PulseNet database, compared with common PFGE patterns for this serotype which have been seen in the database hundreds of times. Local and state health departments, CDC, and the Food and Drug Administration (FDA) investigated to determine the cause of the outbreak. Thirty-two patients in nine states were identified with illness onsets from May 6-July 9, 2016. Whole-genome sequencing (WGS) was performed to characterize clinical isolates and the Anaheim pepper isolate further. The combined evidence indicated that fresh hot peppers were the likely source of infection; however, a single pepper type or source farm was not identified. This outbreak highlights challenges in reconciling epidemiologic and WGS data, and the difficulties of identifying ingredient-level exposures through epidemiologic investigations alone.


Assuntos
Capsicum/microbiologia , Comércio , Surtos de Doenças , Intoxicação Alimentar por Salmonella/epidemiologia , Salmonella/isolamento & purificação , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Microbiologia de Alimentos , Humanos , Masculino , Pessoa de Meia-Idade , Salmonella/genética , Estados Unidos/epidemiologia , Adulto Jovem
12.
PLoS One ; 12(1): e0168615, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28076361

RESUMO

In contrast to planktonic cells, bacteria imbedded biofilms are notoriously refractory to treatment by antibiotics or bacteriophage (phage) used alone. Given that the mechanisms of killing differ profoundly between drugs and phages, an obvious question is whether killing is improved by combining antibiotic and phage therapy. However, this question has only recently begun to be explored. Here, in vitro biofilm populations of Pseudomonas aeruginosa PA14 were treated singly and with combinations of two phages and bactericidal antibiotics of five classes. By themselves, phages and drugs commonly had only modest effects in killing the bacteria. However some phage-drug combinations reduced bacterial densities to well below that of the best single treatment; in some cases, bacterial densities were reduced even below the level expected if both agents killed independently of each other (synergy). Furthermore, there was a profound order effect in some cases: treatment with phages before drugs achieved maximum killing. Combined treatment was particularly effective in killing in Pseudomonas biofilms grown on layers of cultured epithelial cells. Phages were also capable of limiting the extent to which minority populations of bacteria resistant to the treating antibiotic ascend. The potential of combined antibiotic and phage treatment of biofilm infections is discussed as a realistic way to evaluate and establish the use of bacteriophage for the treatment of humans.


Assuntos
Antibacterianos/farmacologia , Biofilmes , Modelos Biológicos , Fagos de Pseudomonas/metabolismo , Pseudomonas aeruginosa , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Linhagem Celular , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Humanos , Pseudomonas aeruginosa/fisiologia , Pseudomonas aeruginosa/virologia
13.
PLoS Curr ; 82016 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-28018748

RESUMO

INTRODUCTION: Recently, Salmonella enterica serovar Poona caused a multistate outbreak, with 245 out of 907 cases occurring in California. We report a comparison of pulsed-field gel electrophoresis (PFGE) results with whole genome sequencing (WGS) for genotyping of Salmonella Poona isolates. METHODS: CA Salmonella Poona isolates, collected from July to August 2015, were genotyped by PFGE using XbaI restriction enzyme. WGS was done using Nextera XT library kit with 2x300 bp or 2x250 bp sequencing chemistry on the Illumina MiSeq Sequencer.  Reads were mapped to the de novo assembled serovar Poona draft genome (48 contigs, N50= 223,917) from the outbreak using CLCbio GW 8.0.2. The phylogenetic tree was generated based on hqSNPs calling. Genomes were annotated with CGE and PHAST online tools. In silico MLST was performed using the CGE online tool. RESULTS: Human (14) and cucumber (2) Salmonella Poona isolates exhibited 3 possibly related PFGE patterns (JL6X01.0018 [predominant], JL6X01.0375, JL6X01.0778).  All isolates that were related by PFGE also clustered together according to the WGS. One isolate with a divergent PFGE pattern (JL6X01.0776) served as an outlier in the phylogenetic analysis and substantially differed from the outbreak clade by WGS. All outbreak isolates were assigned to MLST sequence type 447. The majority of the outbreak-related isolates possessed the same set of Salmonella Pathogenicity Islands with few variations. One outbreak isolate was sequenced and analyzed independently by CDC and CDPH laboratories; there was 0 SNP difference in results. Additional two isolates were sequenced by CDC and the raw data was processed through CDPH and CDC analysis pipelines. Both data analysis pipelines also generated concordant results.  Discussion: PFGE and WGS results for the recent CA Salmonella enterica serovar Poona outbreak provided concordant assignment of the isolates to the outbreak cluster. WGS allowed more robust determination of genetic relatedness, provided information regarding MLST-type, pathogenicity genes, and bacteriophage content. WGS data obtained independently at two laboratories showed complete agreement.

14.
PLoS One ; 10(6): e0126915, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26114477

RESUMO

The maximum exponential growth rate, the Malthusian parameter (MP), is commonly used as a measure of fitness in experimental studies of adaptive evolution and of the effects of antibiotic resistance and other genes on the fitness of planktonic microbes. Thanks to automated, multi-well optical density plate readers and computers, with little hands-on effort investigators can readily obtain hundreds of estimates of MPs in less than a day. Here we compare estimates of the relative fitness of antibiotic susceptible and resistant strains of E. coli, Pseudomonas aeruginosa and Staphylococcus aureus based on MP data obtained with automated multi-well plate readers with the results from pairwise competition experiments. This leads us to question the reliability of estimates of MP obtained with these high throughput devices and the utility of these estimates of the maximum growth rates to detect fitness differences.


Assuntos
Bactérias/crescimento & desenvolvimento , Fenômenos Fisiológicos Bacterianos , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Conjugação Genética , Farmacorresistência Bacteriana , Glucose/metabolismo , Mutação
15.
Curr Opin Microbiol ; 21: 18-21, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25090240

RESUMO

We postulate that phenotypic resistance to antibiotics, persistence, is not an evolved (selected-for) character but rather like mutation, an inadvertent product of different kinds of errors and glitches. The rate of generation of these errors is augmented by exposure to these drugs. The genes that have been identified as contributing to the production of persisters are analogous to the so-called mutator genes; they modulate the rate at which these errors occur and/or are corrected. In theory, these phenotypically resistant bacteria can retard the rate of microbiological cure by antibiotic treatment.


Assuntos
Antibacterianos/farmacologia , Bactérias/genética , Farmacorresistência Bacteriana/genética , Mutação/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Evolução Molecular , Testes de Sensibilidade Microbiana
16.
Mol Microbiol ; 87(1): 196-210, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23216794

RESUMO

Binding of the Origin Recognition Complex (ORC) to replication origins is essential for initiation of DNA replication, but ORC has non-essential functions outside of DNA replication, including in heterochromatic gene silencing and telomere maintenance. Trypanosoma brucei, a protozoan parasite that causes human African trypanosomiasis, uses antigenic variation as a major virulence mechanism to evade the host's immune attack by expressing its major surface antigen, the Variant Surface Glycoprotein (VSG), in a monoallelic manner. An Orc1/Cdc6 homologue has been identified in T. brucei, but its role in DNA replication has not been directly confirmed and its potential involvement in VSG repression or switching has not been thoroughly investigated. In this study, we show that TbOrc1 is essential for nuclear DNA replication in mammalian-infectious bloodstream and tsetse procyclic forms (BF and PF). Depletion of TbOrc1 resulted in derepression of telomere-linked silent VSGs in both BF and PF, and increased VSG switching particularly through the in situ transcriptional switching mechanism. TbOrc1 associates with telomere repeats but appears to do so independently of two known T. brucei telomere proteins, TbRAP1 and TbTRF. We conclude that TbOrc1 has conserved functions in DNA replication and is also required to control telomere-linked VSG expression and VSG switching.


Assuntos
Inativação Gênica , Complexo de Reconhecimento de Origem/genética , Trypanosoma brucei brucei/genética , Glicoproteínas Variantes de Superfície de Trypanosoma/genética , Variação Antigênica , Replicação do DNA , DNA de Protozoário/biossíntese , DNA de Protozoário/genética , Genes de Protozoários , Glicoproteínas de Membrana/genética , Complexo de Reconhecimento de Origem/metabolismo , Regiões Promotoras Genéticas , Trypanosoma brucei brucei/metabolismo
17.
Eukaryot Cell ; 11(7): 844-55, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22286095

RESUMO

Trypanosomes contain a unique form of mitochondrial DNA called kinetoplast DNA (kDNA) that is a catenated network composed of minicircles and maxicircles. Several proteins are essential for network replication, and most of these localize to the antipodal sites or the kinetoflagellar zone. Essential components for kDNA synthesis include three mitochondrial DNA polymerases TbPOLIB, TbPOLIC, and TbPOLID). In contrast to other kDNA replication proteins, TbPOLID was previously reported to localize throughout the mitochondrial matrix. This spatial distribution suggests that TbPOLID requires redistribution to engage in kDNA replication. Here, we characterize the subcellular distribution of TbPOLID with respect to the Trypanosoma brucei cell cycle using immunofluorescence microscopy. Our analyses demonstrate that in addition to the previously reported matrix localization, TbPOLID was detected as discrete foci near the kDNA. TbPOLID foci colocalized with replicating minicircles at antipodal sites in a specific subset of the cells during stages II and III of kDNA replication. Additionally, the TbPOLID foci were stable following the inhibition of protein synthesis, detergent extraction, and DNase treatment. Taken together, these data demonstrate that TbPOLID has a dynamic localization that allows it to be spatially and temporally available to perform its role in kDNA replication.


Assuntos
DNA Polimerase Dirigida por DNA/metabolismo , Mitocôndrias/enzimologia , Proteínas de Protozoários/metabolismo , Trypanosoma brucei brucei/enzimologia , Ciclo Celular , Replicação do DNA , DNA de Cinetoplasto/genética , DNA de Cinetoplasto/metabolismo , DNA Polimerase Dirigida por DNA/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Transporte Proteico , Proteínas de Protozoários/genética , Trypanosoma brucei brucei/citologia , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/metabolismo
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