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Introduction: USA300 has remained the dominant community and healthcare associated methicillin-resistant Staphylococcus aureus (MRSA) clone in the United States and in northern South America for at least the past 20 years. In this time, it has experienced epidemic spread in both of these locations. However, its pre-epidemic evolutionary history and origins are incompletely understood. Large sequencing databases, such as NCBI, PATRIC, and Staphopia, contain clues to the early evolution of USA300 in the form of sequenced genomes of USA300 isolates that are representative of lineages that diverged prior to the establishment of the South American epidemic (SAE) clade and North American epidemic (NAE) clade. In addition, historical isolates collected prior to the emergence of epidemics can help reconstruct early events in the history of this lineage. Methods: Here, we take advantage of the accrued, publicly available data, as well as two newly sequenced pre-epidemic historical isolates from 1996, and a very early diverging ACME-negative NAE genome, to understand the pre-epidemic evolution of USA300. We use database mining techniques to emphasize genomes similar to pre-epidemic isolates, with the goal of reconstructing the early molecular evolution of the USA300 lineage. Results: Phylogenetic analysis with these genomes confirms that the NAE and SAE USA300 lineages diverged from a most recent common ancestor around 1970 with high confidence, and it also pinpoints the independent acquisition events of the of the ACME and COMER loci with greater precision than in previous studies. We provide evidence for a North American origin of the USA300 lineage and identify multiple introductions of USA300 into South and North America. Notably, we describe a third major USA300 clade (the pre-epidemic branching clade; PEB1) consisting of both MSSA and MRSA isolates circulating around the world that diverged from the USA300 lineage prior to the establishment of the South and North American epidemics. We present a detailed analysis of specific sequence characteristics of each of the major clades, and present diagnostic positions that can be used to classify new genomes.
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Epidemias , Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Estados Unidos , Humanos , Filogenia , Infecciones Estafilocócicas/epidemiología , Genoma Bacteriano , Evolución MolecularRESUMEN
We typed 600 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected in 51 hospitals in the Rio de Janeiro, Brazil, metropolitan area during 2014-2017. We found that multiple new clonal complex (CC) 5 sequence types had replaced previously dominant MRSA lineages in hospitals. Whole-genome analysis of 208 isolates revealed an emerging sublineage of multidrug-resistant MRSA, sequence type 105, staphylococcal cassette chromosome mec II, spa t002, which we designated the Rio de Janeiro (RdJ) clone. Using molecular clock analysis, we hypothesized that this lineage began to expand in the Rio de Janeiro metropolitan area in 2009. Multivariate analysis supported an association between bloodstream infections and the CC5 lineage that includes the RdJ clone. Compared with other closely related isolates, representative isolates of the RdJ clone more effectively evaded immune function related to monocytic cells, as evidenced by decreased phagocytosis rate and increased numbers of viable unphagocytosed (free) bacteria after in vitro exposure to monocytes.
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Bacteriemia , Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Bacteriemia/epidemiología , Brasil/epidemiología , Humanos , Staphylococcus aureus Resistente a Meticilina/genética , Monocitos , Infecciones Estafilocócicas/epidemiologíaRESUMEN
Despite high efficacy rates, significant costs and logistical challenges associated with procuring stool from healthy donors for fecal microbiota transplantation (FMT) have presented barriers to broader institutional adoption and limited the availability of this life-saving treatment. Published outcomes for donor screening programs report donor deferral rates between 90% and 96%. Due to the paucity of FMT donor screening data, a secondary analysis on a cohort of previously screened donors (n = 7,968) was conducted to provide a synopsis of the observed trends and rationales for prospective stool donor deferrals. Upon completion of the evaluation, 1.7% of prospective donors (n = 134) qualified for stool donation. Over 50% of donors who completed the online pre-screen were deferred, primarily for a body mass index of 30 kg/m2 or greater (n = 1,516, 37.0%), logistics (n = 841, 20.5%), and travel history (n = 638, 15.5%). Despite pre-screening, 569 donors (72.8%) who completed the in-person clinical assessment were ultimately deferred due primarily to potentially microbiome-mediated diseases (n = 187, 32.9%). A notably small portion of donors (n = 46, 25.6%) were deferred during the laboratory assessment process suggesting the clinical assessment was effective at deferring donors at higher risk for transmissible diseases. Donors lost to follow-up throughout the screening process presented a significant challenge and contributed to a notable (n = 3,117; 39.1%) portion of donor attrition. Findings were used to support recommendations for improving prospective stool donor screening programs and to provide suggestions for future research.
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Selección de Donante/estadística & datos numéricos , Trasplante de Microbiota Fecal , Heces/microbiología , Donantes de Tejidos/estadística & datos numéricos , Adulto , Selección de Donante/organización & administración , Humanos , Perdida de Seguimiento , Microbiota , Estudios ProspectivosAsunto(s)
Infecciones por Clostridium/terapia , Trasplante de Microbiota Fecal , Heces/química , Preservación Biológica/métodos , Bacterias/química , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Bancos de Muestras Biológicas , Clostridioides difficile/fisiología , Infecciones por Clostridium/microbiología , Heces/microbiología , Congelación , Humanos , Preservación Biológica/instrumentaciónRESUMEN
Staphylococcus aureus is the most common cause of skin and soft tissue infections, yet the bacterial genetic changes associated with adaptation to human skin are not well characterized. S. aureus strains isolated from patients with chronic skin colonization and intermittent infection were used to determine the staphylococcal genotypes or phenotypes associated with adaptation to human skin. We demonstrate that polymorphisms in metabolic genes, particularly those involved in the tricarboxylic acid cycle, the fumarate-succinate axis, and the generation of terminal electron transporters, are unexpectedly common. These skin-adapted strains activated glycolysis and hypoxia-inducible factor-1α, interleukin (IL)-1ß, and IL-18 release from keratinocytes and promoted dermatopathology equivalent to a methicillin-resistant Staphylococcus aureus USA300 control in a murine model of infection. However, in contrast to USA300, a skin-adapted isolate failed to generate protection from a secondary infectious challenge. Within the context of human skin, there appears to be selection for S. aureus metabolic adaptive changes that promote glycolysis and maintain pathogenicity.
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INTRODUCTION: Prior research has found that psychopathology constructs such as depression and anxiety are associated with problematic use of Facebook (PFU). In the present study, we examined a structural equation model whereby depression, social anxiety and lower life satisfaction predicted PFU severity, while analyzing mediating variables including rumination, fear of missing out (FoMO), and frequency of Facebook use, as well as age and gender as covariates. METHOD: Participants were 296 college students administered a web survey of instruments measuring these constructs. RESULTS: Modeling results demonstrate that FoMO and rumination were significantly related to PFU severity. Facebook use frequency was related to PFU severity. FoMO and rumination each mediated relations between social anxiety and PFU severity. CONCLUSIONS: Results are discussed in the context of prior work on FoMO and excessive technology use, as well as several relevant theoretical frameworks.
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The global spread of specific clones of methicillin-resistant Staphylococcus aureus (MRSA) has become a major public health problem, and understanding the dynamics of geographical spread requires worldwide surveillance. Over the past 20 years, the ST239 lineage of MRSA has been recognized as an emerging clone across the globe, with detailed studies focusing on isolates from Europe and Asia. Less is known about this lineage in South America, and, particularly, Brazil where it was the predominant lineage of MRSA in the early 1990s to 2000s. To gain a better understanding about the introduction and spread of ST239 MRSA in Brazil we undertook a comparative phylogenomic analysis of ST239 genomes, adding seven completed, closed Brazilian genomes. Brazilian ST239 isolates grouped in a subtree with those from South American, and Western, romance-language-speaking, European countries, here designated the South American clade. After an initial worldwide radiation in the 1960s and 1970s, we estimate that ST239 began to spread in South America and Brazil in approximately 1988. This clone demonstrates specific genomic changes that are suggestive of local divergence and adaptational change including agrC single-nucleotide polymorphisms variants, and a distinct pattern of virulence-associated genes (mainly the presence of the chp and the absence of sea and sasX). A survey of a geographically and chronologically diverse set of 100 Brazilian ST239 isolates identified this virulence genotype as the predominant pattern in Brazil, and uncovered an unexpectedly high prevalence of agr-dysfunction (30%). ST239 isolates from Brazil also appear to have undergone transposon (IS256) insertions in or near global regulatory genes (agr and mgr) that likely led to rapid reprogramming of bacterial traits. In general, the overall pattern observed in phylogenomic analyses of ST239 is of a rapid initial global radiation, with subsequent local spread and adaptation in multiple different geographic locations. Most ST239 isolates harbor the ardA gene, which we show here to have in vivo anti-restriction activity. We hypothesize that this gene may have improved the ability of this lineage to acquire multiple resistance genes and distinct virulence-associated genes in each local context. The allopatric divergence pattern of ST239 also may suggest strong selective pressures for specific traits in different geographical locations.
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The immunocompetence handicap hypothesis (ICHH) proposes that testosterone has both beneficial effects on male reproductive potential and negative effects by suppressing the immune system. However, support for the ICHH has been variable and an alternative hypothesis suggests that testosterone may be acting indirectly via cortisol to suppress immunity (the stress-linked ICHH). A third hypothesis is that increased energetic investment in immunity results in the suppression of testosterone. We tested these hypotheses in male Cape ground squirrels (Xerus inauris) through two separate manipulations: first, by triggering a strong immune response using a lipopolysaccharide (LPS) injection and, secondly, by increasing circulating testosterone using silastic testosterone implants. Responding to an immune challenge significantly reduced testosterone, supporting the immune suppression hypothesis, while increasing circulating testosterone had no effect on immunocompetence, body mass, ectoparasite abundances or cortisol levels, failing to support either the ICHH or stress-linked ICHH. Our results add to the increasing body of literature that challenges the ICHH, and we conclude that the trade-off between testosterone and immunity is mediated through immune activation and not through testosterone in male Cape ground squirrels. Being able to test the ICHH, stress-linked ICHH and immune suppression hypotheses in a free-ranging mammal gives us a unique opportunity to examine the mechanisms mediating this trade-off.
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Sciuridae/inmunología , Testosterona/administración & dosificación , Animales , Peso Corporal , Implantes de Medicamentos/administración & dosificación , Hidrocortisona/sangre , Inmunocompetencia/efectos de los fármacos , Inmunocompetencia/fisiología , Lipopolisacáridos/farmacología , Masculino , Phthiraptera , Sciuridae/sangre , Sciuridae/parasitología , Siphonaptera , Testosterona/sangreRESUMEN
Investigation of the Hudson Valley watershed reveals many violacein-producing bacteria. These are of interest for their biotherapeutic potential in treating chytrid infections of amphibians. The draft whole-genome sequences for seven Janthinobacterium isolates with a variety of phenotypes are provided in this study.
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Water samples from the Hudson Valley watershed indicate that the area is host to many violacein-producing bacterial isolates. Here, we report the draft whole-genome sequence of Janthinobacterium sp. strain BJB412, an isolate lacking violacein production yet containing genes responsible for prodigiosin, biofilm production, and quorum sensing, like its purple-pigmented counterparts.
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In this citizen science-aided, college laboratory-based microbiology research project, secondary school students collaborate with college research students on an investigation centered around bacterial species in the local watershed. This study specifically investigated the prevalence of violacein-producing bacterial isolates, as violacein has been demonstrated as a potential bioremediation treatment for outbreaks of the worldwide invasive chytrid, Batrachochytrium dendrobatidis (Bd). The impact of this invasion has been linked to widespread amphibian decline, and tracking of the spread of Bd is currently ongoing. Secondary school students participated in this research project by sterilely collecting water samples from a local watershed, documenting the samples, and completing the initial sample plating in a BSL1 environment. In the second phase of this project, trained college students working in courses and as research assistants in the academic year and summer term in a BSL2 laboratory facility were able to use physiological, biochemical, and molecular techniques to further identify individual isolates as well as characterize their properties. Collaboration between these learning spaces provides an increased interest in the community for environmentally relevant research projects and allows for an expansion of the research team to increase study robustness. Journal of Microbiology & Biology Education.
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OBJECTIVE: To examine whether diabetes genetic risk testing and counseling can improve diabetes prevention behaviors. RESEARCH DESIGN AND METHODS: We conducted a randomized trial of diabetes genetic risk counseling among overweight patients at increased phenotypic risk for type 2 diabetes. Participants were randomly allocated to genetic testing versus no testing. Genetic risk was calculated by summing 36 single nucleotide polymorphisms associated with type 2 diabetes. Participants in the top and bottom score quartiles received individual genetic counseling before being enrolled with untested control participants in a 12-week, validated, diabetes prevention program. Middle-risk quartile participants were not studied further. We examined the effect of this genetic counseling intervention on patient self-reported attitudes, program attendance, and weight loss, separately comparing higher-risk and lower-risk result recipients with control participants. RESULTS: The 108 participants enrolled in the diabetes prevention program included 42 participants at higher diabetes genetic risk, 32 at lower diabetes genetic risk, and 34 untested control subjects. Mean age was 57.9 ± 10.6 years, 61% were men, and average BMI was 34.8 kg/m(2), with no differences among randomization groups. Participants attended 6.8 ± 4.3 group sessions and lost 8.5 ± 10.1 pounds, with 33 of 108 (30.6%) losing ≥5% body weight. There were few statistically significant differences in self-reported motivation, program attendance, or mean weight loss when higher-risk recipients and lower-risk recipients were compared with control subjects (P > 0.05 for all but one comparison). CONCLUSIONS: Diabetes genetic risk counseling with currently available variants does not significantly alter self-reported motivation or prevention program adherence for overweight individuals at risk for diabetes.
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Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/prevención & control , Asesoramiento Genético , Anciano , Femenino , Pruebas Genéticas , Humanos , Masculino , Persona de Mediana Edad , Motivación , SobrepesoRESUMEN
Advances in genetic epidemiology have increased understanding of common, polygenic preventable diseases such as type 2 diabetes. As genetic risk testing based on this knowledge moves into clinical practice, we propose that genetic counselors will need to expand their roles and adapt traditional counseling techniques for this new patient set. In this paper, we present a genetic counseling intervention developed for a clinical trial [Genetic Counseling/Lifestyle Change for Diabetes Prevention, ClinicalTrials.gov identifier: NCT01034319] designed to motivate behavioral changes for diabetes prevention. Seventy-two phenotypically high-risk participants received counseling that included their diabetes genetic risk score, general education about diabetes risk factors, and encouragement to participate in a diabetes prevention program. Using two validated genetic counseling scales, participants reported favorable perceived control and satisfaction with the counseling session. Our intervention represents one model for applying traditional genetic counseling principles to risk testing for polygenetic, preventable diseases, such as type 2 diabetes.
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Diabetes Mellitus Tipo 2/prevención & control , Asesoramiento Genético , Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad , HumanosRESUMEN
BACKGROUND: Type 2 diabetes genetic risk testing might motivate at-risk patients to adopt diabetes prevention behaviors. However, the influence of literacy and numeracy on patient response to diabetes genetic risk is unknown. OBJECTIVE: The authors investigated the association of health literacy, genetic literacy, and health numeracy with patient responses to diabetes genetic risk. DESIGN: and Measurements Overweight patients at high phenotypic risk for type 2 diabetes were recruited for a clinical trial of diabetes genetic risk testing. At baseline, participants predicted how their motivation for lifestyle modification to prevent diabetes might change in response to hypothetical scenarios of receiving "high" and "low" genetic risk results. Responses were analyzed according to participants' health literacy, genetic literacy, and health numeracy. RESULTS: Two-thirds (67%) of participants (n = 175) reported very high motivation to prevent diabetes. Despite high health literacy (92% at high school level), many participants had limited health numeracy (30%) and genetic literacy (38%). Almost all (98%) reported that high-risk genetic results would increase their motivation for lifestyle modification. In contrast, response to low-risk genetic results varied. Higher levels of health literacy (P = 0.04), genetic literacy (P = 0.02), and health numeracy (P = 0.02) were associated with an anticipated decrease in motivation for lifestyle modification in response to low-risk results. CONCLUSIONS: While patients reported that high-risk genetic results would motivate them to adopt healthy lifestyle changes, response to low-risk results varied by patient numeracy and literacy. However, anticipated responses may not correlate with true behavior change. If future research justifies the clinical use of genetic testing to motivate behavior change, it may be important to assess how patient characteristics modify that motivational effect.
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Toma de Decisiones , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/psicología , Conductas Relacionadas con la Salud , Alfabetización en Salud , Anciano , Técnicas de Apoyo para la Decisión , Diabetes Mellitus Tipo 2/epidemiología , Femenino , Pruebas Genéticas , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , Motivación , Sobrepeso/epidemiología , Sobrepeso/psicología , Medición de Riesgo , Factores SocioeconómicosRESUMEN
BACKGROUND: The efficacy of diabetes genetic risk testing to motivate behavior change for diabetes prevention is currently unknown. PURPOSE: This paper presents key issues in the design and implementation of one of the first randomized trials (The Genetic Counseling/Lifestyle Change (GC/LC) Study for Diabetes Prevention) to test whether knowledge of diabetes genetic risk can motivate patients to adopt healthier behaviors. METHODS: Because individuals may react differently to receiving 'higher' vs 'lower' genetic risk results, we designed a 3-arm parallel group study to separately test the hypotheses that: (1) patients receiving 'higher' diabetes genetic risk results will increase healthy behaviors compared to untested controls, and (2) patients receiving 'lower' diabetes genetic risk results will decrease healthy behaviors compared to untested controls. In this paper we describe several challenges to implementing this study, including: (1) the application of a novel diabetes risk score derived from genetic epidemiology studies to a clinical population, (2) the use of the principle of Mendelian randomization to efficiently exclude 'average' diabetes genetic risk patients from the intervention, and (3) the development of a diabetes genetic risk counseling intervention that maintained the ethical need to motivate behavior change in both 'higher' and 'lower' diabetes genetic risk result recipients. RESULTS: Diabetes genetic risk scores were developed by aggregating the results of 36 diabetes-associated single nucleotide polymorphisms. Relative risk for type 2 diabetes was calculated using Framingham Offspring Study outcomes, grouped by quartiles into 'higher', 'average' (middle two quartiles) and 'lower' genetic risk. From these relative risks, revised absolute risks were estimated using the overall absolute risk for the study group. For study efficiency, we excluded all patients receiving 'average' diabetes risk results from the subsequent intervention. This post-randomization allocation strategy was justified because genotype represents a random allocation of parental alleles ('Mendelian randomization'). Finally, because it would be unethical to discourage participants to participate in diabetes prevention behaviors, we designed our two diabetes genetic risk counseling interventions (for 'higher' and 'lower' result recipients) so that both groups would be motivated despite receiving opposing results. LIMITATIONS: For this initial assessment of the clinical implementation of genetic risk testing we assessed intermediate outcomes of attendance at a 12-week diabetes prevention course and changes in self-reported motivation. If effective, longer term studies with larger sample sizes will be needed to assess whether knowledge of diabetes genetic risk can help patients prevent diabetes. CONCLUSIONS: We designed a randomized clinical trial designed to explore the motivational impact of disclosing both higher than average and lower than average genetic risk for type 2 diabetes. This design allowed exploration of both increased risk and false reassurance, and has implications for future studies in translational genomics.
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Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/prevención & control , Conductas Relacionadas con la Salud , Motivación , Proyectos de Investigación , Consejo Dirigido , Femenino , Asesoramiento Genético , Pruebas Genéticas , Encuestas de Atención de la Salud , Conocimientos, Actitudes y Práctica en Salud , Promoción de la Salud/métodos , Humanos , Entrevista Psicológica/métodos , Estilo de Vida , Masculino , Polimorfismo de Nucleótido Simple , Medición de Riesgo/métodos , Tamaño de la Muestra , Mercadeo SocialRESUMEN
OBJECTIVE: Rapid advances in diabetes genetic epidemiology may lead to a new era of "personalized medicine" based on individual genetic risk assessment. There is minimal experience to guide how best to clinically implement such testing so that results (e.g., "higher" or "lower" relative genetic risk) improve rather than reduce patient motivation for behavior change. RESEARCH DESIGN AND METHODS: Between November 2009 and May 2010, we conducted in-depth interviews with 22 overweight participants at high phenotypic risk for type 2 diabetes to explore perceptions of diabetes genetic risk testing compared with currently available prediction using nongenetic risk factors (e.g., family history, abnormal fasting glucose, obesity). We used hypothetical scenarios to specifically investigate the impact of both "higher" and "lower" relative genetic risk results on participants' views about diabetes prevention. RESULTS: Many participants conferred a unique value on personal genetic risk information relative to nongenetic risk based on the perceived scientific certainty and durability of genetic results. In contrast, other participants considered their genetic risk within the overall context of their other measured risk factors. Reactions to diabetes genetic test results differed by current motivation levels. Whereas most subjects reported that "higher" risk results would motivate behavior change, subjects with lower current motivation often reported that "lower" genetic risk results would further reduce their motivation to engage in diabetes prevention behaviors. CONCLUSIONS: To be effective, future clinical implementation of type 2 diabetes genetic risk testing should be individualized based on each patient's risk perception and current level of motivation to prevent diabetes.