RESUMEN
Quorum sensing (QS) is a mechanism of synthesis and detection of signaling molecules to regulate gene expression and coordinate behaviors in bacterial populations. In Bacillus subtilis, multiple paralog Rap-Phr QS systems (receptor-signaling peptides) are highly redundant and multifunctional, interconnecting the regulation of differentiation processes such as sporulation and competence. However, their functions in the Bacillus cereus group are largely unknown. We evaluated the functions of Rap proteins in Bacillus thuringiensis Bt8741, which codes for eight Rap-Phr systems; these were individually overexpressed to study their participation in sporulation, biofilm formation, spreading, and extracellular proteolytic activity. Our results show that four Rap-Phr systems (RapC, RapK, RapF, and RapLike) inhibit sporulation, two of which (RapK and RapF) probably dephosphorylate Spo0F from the Spo0A phosphorelay; these two Rap proteins also inhibit biofilm formation. Four systems (RapC, RacF1, RacF2, and RapLike) participate in spreading inhibition; finally, six systems (RapC, -F, -F2, -I, and -I1 and RapLike) decrease extracellular proteolytic activity. We foresee that functions performed by Rap proteins of Bt8741 could also be carried out by Rap homologs in other strains within the B. cereus group. These results indicate that Rap-Phr systems constitute a highly multifunctional and redundant regulatory repertoire that enables B. thuringiensis and other species from the B. cereus group to efficiently regulate collective functions during their life cycle in the face of changing environments.IMPORTANCE The Bacillus cereus group of bacteria includes species of high economic, clinical, biological warfare, and biotechnological interest, e.g., B. anthracis in bioterrorism, B. cereus in food intoxications, and B. thuringiensis in biocontrol. Knowledge about the ecology of these bacteria is hindered by our limited understanding of the regulatory circuits that control differentiation and specialization processes. Here, we uncover the participation of eight Rap quorum-sensing receptors in collective functions of B. thuringiensis These proteins are highly multifunctional and redundant in their functions, linking ecologically relevant processes such as sporulation, biofilm formation, spreading, extracellular proteolytic activity, and probably other functions in species from the B. cereus group.
Asunto(s)
Bacillus thuringiensis/fisiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Biopelículas/crecimiento & desarrollo , Secuencia Conservada , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Percepción de Quorum , Esporas Bacterianas/genéticaRESUMEN
Bacteria of the Bacillus cereus group colonize several ecological niches and infect different hosts. Bacillus cereus, a ubiquitous species causing food poisoning, Bacillus thuringiensis, an entomopathogen, and Bacillus anthracis, which is highly pathogenic to mammals, are the most important species of this group. These species are closely related genetically, and their specific toxins are encoded by plasmids. The infectious cycle of B. thuringiensis in its insect host is regulated by quorum-sensing systems from the RNPP family. Among them, the Rap-Phr systems, which are well-described in Bacillus subtilis, regulate essential processes, such as sporulation. Given the importance of these systems, we performed a global in silico analysis to investigate their prevalence, distribution, diversity and their role in sporulation in B. cereus group species. The rap-phr genes were identified in all selected strains with 30% located on plasmids, predominantly in B. thuringiensis. Despite a high variability in their sequences, there is a remarkable association between closely related strains and their Rap-Phr profile. Based on the key residues involved in RapH phosphatase activity, we predicted that 32% of the Rap proteins could regulate sporulation by preventing the phosphorylation of Spo0F. These Rap are preferentially located on plasmids and mostly related to B. thuringiensis. The predictions were partially validated by in vivo sporulation experiments suggesting that the residues linked to the phosphatase function are necessary but not sufficient to predict this activity. The wide distribution and diversity of Rap-Phr systems could strictly control the commitment to sporulation and then improve the adaptation capacities of the bacteria to environmental changes.
Asunto(s)
Bacillus cereus/genética , Proteínas Bacterianas/genética , Fosfoproteínas Fosfatasas/genética , Percepción de Quorum/genética , Bacillus cereus/enzimología , Bacillus cereus/metabolismo , Bacillus subtilis/enzimología , Bacillus subtilis/genética , Bacillus thuringiensis/enzimología , Bacillus thuringiensis/genética , Proteínas Bacterianas/metabolismo , Análisis por Conglomerados , Esterasas/genética , Esterasas/metabolismo , Péptidos/química , Fosfoproteínas Fosfatasas/metabolismo , Filogenia , Plásmidos/genética , Plásmidos/metabolismo , Percepción de Quorum/fisiología , Esporas Bacterianas/genética , Esporas Bacterianas/metabolismoRESUMEN
BACKGROUND: The Personal Health Record (PHR) and Electronic Health Record (EHR) play a key role in more efficient access to health records by health professionals and patients. It is hard, however, to obtain a unified view of health data that is distributed across different health providers. In particular, health records are commonly scattered in multiple places and are not integrated. OBJECTIVE: This article presents the implementation and evaluation of a PHR model that integrates distributed health records using blockchain technology and the openEHR interoperability standard. We thus follow OmniPHR architecture model, which describes an infrastructure that supports the implementation of a distributed and interoperable PHR. METHODS: Our method involves implementing a prototype and then evaluating the integration and performance of medical records from different production databases. In addition to evaluating the unified view of records, our evaluation criteria also focused on non-functional performance requirements, such as response time, CPU usage, memory occupation, disk, and network usage. RESULTS: We evaluated our model implementation using the data set of more than 40 thousand adult patients anonymized from two hospital databases. We tested the distribution and reintegration of the data to compose a single view of health records. Moreover, we profiled the model by evaluating a scenario with 10 superpeers and thousands of competing sessions transacting operations on health records simultaneously, resulting in an average response time below 500â¯ms. The blockchain implemented in our prototype achieved 98% availability. CONCLUSION: Our performance results indicated that data distributed via a blockchain could be recovered with low average response time and high availability in the scenarios we tested. Our study also demonstrated how OmniPHR model implementation can integrate distributed data into a unified view of health records.
Asunto(s)
Cadena de Bloques , Registros Electrónicos de Salud/normas , Registros de Salud Personal , Programas Informáticos , Algoritmos , HumanosRESUMEN
The advances in the Information and Communications Technology (ICT) brought many benefits to the healthcare area, specially to digital storage of patients' health records. However, it is still a challenge to have a unified viewpoint of patients' health history, because typically health data is scattered among different health organizations. Furthermore, there are several standards for these records, some of them open and others proprietary. Usually health records are stored in databases within health organizations and rarely have external access. This situation applies mainly to cases where patients' data are maintained by healthcare providers, known as EHRs (Electronic Health Records). In case of PHRs (Personal Health Records), in which patients by definition can manage their health records, they usually have no control over their data stored in healthcare providers' databases. Thereby, we envision two main challenges regarding PHR context: first, how patients could have a unified view of their scattered health records, and second, how healthcare providers can access up-to-date data regarding their patients, even though changes occurred elsewhere. For addressing these issues, this work proposes a model named OmniPHR, a distributed model to integrate PHRs, for patients and healthcare providers use. The scientific contribution is to propose an architecture model to support a distributed PHR, where patients can maintain their health history in an unified viewpoint, from any device anywhere. Likewise, for healthcare providers, the possibility of having their patients data interconnected among health organizations. The evaluation demonstrates the feasibility of the model in maintaining health records distributed in an architecture model that promotes a unified view of PHR with elasticity and scalability of the solution.
Asunto(s)
Sistemas de Computación , Registros Electrónicos de Salud , Registros de Salud Personal , Comunicación , Personal de Salud , HumanosRESUMEN
OBJECTIVE: To determine the association of parental use of integrated personal health records (PHRs) with children's adherence to immunization and well-child care (WCC) visit recommendations. STUDY DESIGN: For the immunization and WCC visit measures, we retrospectively analyzed, respectively, 766 and 639 matched pairs at Kaiser Permanente (KP) Hawaii and 2795 and 2448 pairs at KP Northwest who were ≤ 31 days old at enrollment and continuously enrolled for 2 years between January 2007 and July 2011. The independent variable (≥ 1 PHR feature used vs none) was matched using propensity scores on parental and children characteristics. The dependent variables were 2 measures from the 2010 Healthcare Effectiveness Data and Information Set: combination 2 immunization (all immunizations vs
Asunto(s)
Registros de Salud Personal , Accesibilidad a los Servicios de Salud/normas , Inmunización/estadística & datos numéricos , Guías de Práctica Clínica como Asunto , Calidad de la Atención de Salud , Femenino , Hawaii , Humanos , Inmunización/normas , Recién Nacido , Masculino , Estudios RetrospectivosRESUMEN
The BLR-1 and BLR-2 proteins of Trichoderma atroviride are the Neurospora crassa homologs of white collar-1 and -2, two transcription factors involved in the regulation of genes by blue light. BLR-1 and BLR-2 are essential for photoinduction of phr-1, a photolyase-encoding gene whose promoter exhibits sequences similar to well-characterized light regulatory elements of Neurospora, including the albino proximal element and the light response element (LRE). However, despite the fact that this gene has been extensively used as a blue light induction marker in Trichoderma, the function of these putative regulatory elements has not been proved. The described LRE core in N. crassa comprises two close but variably spaced GATA boxes to which a WC-1/-2 complex binds transiently upon application of a light stimulus. Using 5' serial deletions of the phr-1 promoter, as well as point mutations of putative LREs, we were able to delimit an ~ 50 bp long region mediating the transcriptional response to blue light. The identified light-responsive region contained five CGATB motifs, three of them displaying opposite polarity to canonical WCC binding sites. Chromatin immunoprecipitation experiments showed that the BLR-2 protein binds along the phr-1 promoter in darkness, whereas the application of a blue light pulse results in decreased BLR-2 binding to the promoter. Our results suggest that BLR-2 and probably BLR-1 are located on the phr-1 promoter in darkness ready to perform their function as transcriptional complex in response to light.