Development of a genetic tool for functional screening of anti-malarial bioactive extracts in metagenomic libraries.

BACKGROUND: The chemical treatment of Plasmodium falciparum for human infections is losing efficacy each year due to the rise of resistance. One possible strategy to find novel anti-malarial drugs is to access the largest reservoir of genomic biodiversity source on earth present in metagenomes of environmental microbial communities. METHODS: A bioluminescent P. falciparum parasite was used to quickly detect shifts in viability of microcultures grown in 96-well plates. A synthetic gene encoding the Dermaseptin 4 peptide was designed and cloned under tight transcriptional control in a large metagenomic insert context (30 kb) to serve as proof-of-principle for the screening platform. RESULTS: Decrease in parasite viability consistently correlated with bioluminescence emitted from parasite microcultures, after their exposure to bacterial extracts containing a plasmid or fosmid engineered to encode the Dermaseptin 4 anti-malarial peptide. CONCLUSIONS: Here, a new technical platform to access the anti-malarial potential in microbial environmental metagenomes has been developed.

Klebsiella pneumoniae yfiRNB operon affects biofilm formation, polysaccharide production and drug susceptibility.

Klebsiella pneumoniae is an opportunistic pathogen important in hospital-acquired infections, which are complicated by the rise of drug-resistant strains and the capacity of cells to adhere to surfaces and form biofilms. In this work, we carried out an analysis of the genes in the K. pneumoniae yfiRNB operon, previously implicated in biofilm formation. The results indicated that in addition to the previously reported effect on type 3 fimbriae expression, this operon also affected biofilm formation due to changes in cellulose as part of the extracellular matrix. Deletion of yfiR resulted in enhanced biofilm formation and an altered colony phenotype indicative of cellulose overproduction when grown on solid indicator media. Extraction of polysaccharides and treatment with cellulase were consistent with the presence of cellulose in biofilms. The enhanced cellulose production did not, however, correlate with virulence as assessed using a Caenorhabditis elegans assay. In addition, cells bearing mutations in genes of the yfiRNB operon varied with respect to the WT control in terms of susceptibility to the antibiotics amikacin, ciprofloxacin, imipenem and meropenem. These results indicated that the yfiRNB operon is implicated in the production of exopolysaccharides that alter cell surface characteristics and the capacity to form biofilms--a phenotype that does not necessarily correlate with properties related with survival, such as resistance to antibiotics.

Comparative analysis of diguanylate cyclase and phosphodiesterase genes in Klebsiella pneumoniae.

BACKGROUND: Klebsiella pneumoniae can be found in environmental habitats as well as in hospital settings where it is commonly associated with nosocomial infections. One of the factors that contribute to virulence is its capacity to form biofilms on diverse biotic and abiotic surfaces. The second messenger Bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) is a ubiquitous signal in bacteria that controls biofilm formation as well as several other cellular processes. The cellular levels of this messenger are controlled by c-di-GMP synthesis and degradation catalyzed by diguanylate cyclase (DGC) and phophodiesterase (PDE) enzymes, respectively. Many bacteria contain multiple copies of these proteins with diverse organizational structure that highlight the complex regulatory mechanisms of this signaling network. This work was undertaken to identify DGCs and PDEs and analyze the domain structure of these proteins in K. pneumoniae. RESULTS: A search for conserved GGDEF and EAL domains in three sequenced K. pneumoniae genomes showed that there were multiple copies of GGDEF and EAL containing proteins. Both single domain and hybrid GGDEF proteins were identified: 21 in K. pneumoniae Kp342, 18 in K. pneumoniae MGH 78578 and 17 in K. pneumoniae NTUH-K2044. The majority had only the GGDEF domain, most with the GGEEF motif, and hybrid proteins containing both GGDEF and EAL domains were also found. The I site for allosteric control was identified only in single GGDEF domain proteins and not in hybrid proteins. EAL-only proteins, containing either intact or degenerate domains, were also identified: 15 in Kp342, 15 in MGH 78578 and 10 in NTUH-K2044. Several input sensory domains and transmembrane segments were identified, which together indicate complex regulatory circuits that in many cases can be membrane associated. CONCLUSIONS: The comparative analysis of proteins containing GGDEF/EAL domains in K. pneumoniae showed that most copies were shared among the three strains and that some were unique to a particular strain. The multiplicity of these proteins and the diversity of structural characteristics suggest that the c-di-GMP network in this enteric bacterium is highly complex and reflects the importance of having diverse mechanisms to control cellular processes in environments as diverse as soils or plants and clinical settings.

Post-COVID syndrome. A case series and comprehensive review.

The existence of a variety of symptoms with a duration beyond the acute phase of COVID-19, is referred to as post-COVID syndrome (PCS). We aimed to report a series of patients with PCS attending a Post-COVID Unit and offer a comprehensive review on the topic. Adult patients with previously confirmed SARS-CoV-2 infection and PCS were systematically assessed through a semi-structured and validated survey. Total IgG, IgA and IgM serum antibodies to SARS-CoV-2 were evaluated by an electrochemiluminescence immunoassay. A systematic review of the literature and meta-analysis were conducted, following PRISMA guidelines. Univariate and multivariate methods were used to analyze data. Out of a total of 100 consecutive patients, 53 were women, the median of age was 49 years (IQR: 37.8-55.3), the median of post-COVID time after the first symptoms was 219 days (IQR: 143-258), and 65 patients were hospitalized during acute COVID-19. Musculoskeletal, digestive (i.e., diarrhea) and neurological symptoms including depression (by Zung scale) were the most frequent observed in PCS patients. A previous hospitalization was not associated with PCS manifestation. Arthralgia and diarrhea persisted in more than 40% of PCS patients. The median of anti-SARS-CoV-2 antibodies was 866.2 U/mL (IQR: 238.2-1681). Despite this variability, 98 patients were seropositive. Based on autonomic symptoms (by COMPASS 31) two clusters were obtained with different clinical characteristics. Levels of anti-SARS-CoV-2 antibodies were not different between clusters. A total of 40 articles (11,196 patients) were included in the meta-analysis. Fatigue/muscle weakness, dyspnea, pain and discomfort, anxiety/depression and impaired concentration were presented in more than 20% of patients reported. In conclusion, PCS is mainly characterized by musculoskeletal, pulmonary, digestive and neurological involvement including depression. PCS is independent of severity of acute illness and humoral response. Long-term antibody responses to SARS-CoV-2 infection and a high inter-individual variability were confirmed. Future studies should evaluate the mechanisms by which SARS-CoV-2 may cause PCS and the best therapeutic options.

Multiple Dictyostelid Species Destroy Biofilms of Klebsiella oxytoca and Other Gram Negative Species.

Dictyostelids are free-living phagocytes that feed on bacteria in diverse habitats. When bacterial prey is in short supply or depleted, they undergo multicellular development culminating in the formation of dormant spores. In this work, we tested isolates representing four dictyostelid species from two genera (Dictyostelium and Polysphondylium) for the potential to feed on biofilms preformed on glass and polycarbonate surfaces. The abilities of dictyostelids were monitored for three hallmarks of activity: 1) spore germination on biofilms, 2) predation on biofilm enmeshed bacteria by phagocytic cells and 3) characteristic stages of multicellular development (streaming and fructification). We found that all dictyostelid isolates tested could feed on biofilm enmeshed bacteria produced by human and plant pathogens: Klebsiella oxytoca, Pseudomonas aeruginosa, Pseudomonas syringae, Erwinia amylovora 1189 (biofilm former) and E. amylovora 1189 Δams (biofilm deficient mutant). However, when dictyostelids were fed planktonic E. amylovora Δams the bacterial cells exhibited an increased susceptibility to predation by one of the two dictyostelid strains they were tested against. Taken together, the qualitative and quantitative data presented here suggest that dictyostelids have preferences in bacterial prey which affects their efficiency of feeding on bacterial biofilms.

Probable case of spotted fever group rickettsial infection in a new suspected endemic area, Colombia.

Spoted fever group (SFG) rickettsioses are actually considered as emerging and re-emerging zoonotic diseases, caused by pathogenic bacteria of the spotted fever group rickettsiae (SFGR). Recently, serologic studies in human and animals conducted in Colombian Orinoquia, showed a high seroprevalence against SFGR. In June 2015, a 50-year-old male was admitted to a hospital in Bogotá, Colombia, with two days of malaise and temperature of 39°C, associated to generalized rash 24h after the onset of fever. He referred a work visit and outdoor activities in rural area of the Department of Meta 15days prior the onset of symptoms. The patient was transferred to the intensive care unit with supplementary oxygen, inotropic support and was assessed by the infectious diseases department, indicating the addition of Doxycycline. After seven days of antibiotic treatment the patient was discharged with no evidence of new symptoms or sequels. Retrospectively, two serum samples collected during the acute and convalescent phase were evaluated; there was four fold rise in titer against SFGR. With the foregoing, associated with the recent serological evidence that suggests the circulation of SFGR species in the Colombian Orinoquia, we consider to recognize this region as a new endemic area for SFG Rickettsioses.

Representaciones sociales de las relaciones sexuales y sífilis en población transgénero / The social representations over the sexual relations and syphilis in trangender people / Representações sociais sobre as relações sexuais e sífilis em pessoas trans

En Colombia hay muy pocos estudios que reflejen la situación actual de la sífilis en la población transgénero, pero queda en evidencia que existe una alta relación de esta enfermedad con las prácticas sexuales que ejercen. (Palacios M, 2017) Por tal razón es necesario reconocer cuales son las representaciones sociales que tiene la población transgénero sobre relaciones sexuales y la sífilis con el fin de implementar las intervenciones correspondientes a partir de la identificación de los factores de riesgo. El objetivo fue identificar las representaciones sociales sobre relaciones sexuales y sífilis, en personas Transgénero de la localidad de los Mártires en Bogotá. El diseño fue cualitativo, se apoyó en métodos asociativos para la recolección del contenido y la organización de las representaciones sociales, como son listados libres y cuestionarios de comparación de pares. Se integró una muestra por bola de nieve, participaron 32 mujeres transgénero. El análisis fue a través del enfoque estructural de las representaciones sociales con el apoyo de la teoría de grafos. Los resultados obtenidos mostraron una visión social y emocional de las representaciones sociales de los conceptos de relaciones sexuales y sífilis, información que se convierte en una en base para poder abordar la salud sexual de esta población

There are very few studies in Colombia that reflects the actual impact of the syphilis in the trangender population, but it is very clear that there is a high correlation of this illness with the sexual practices that They carry out (Palacios M, 2017)in such situation, it is necessary to recognize which ones are the social representations that the transgender population have over the sexual relations and the syphilis in order to implement the correspondent measurements, starting with the identification of the risk factors. The object was to identify the social representations over the sexual relations and syphilis in trangender pepole in the locality of los Martires in Bogota. The design was qualitative and it was based in assiciative methods for the recollection of the contents and the organization of the social representation, due to the fact that They are free listings and comparison questionnaires of pairs, a sample of a snow ballot was integrated. There were 32 trangender women, the analysis was made through structural focus of the social representations with the support of the Grafos theory. The final results showed a social and emotional vision of the social representations of the sexual relations and syphilis concepts, such information creates a base to be able to confront the sexual health of the population

Na Colômbia, há poucos estudos que pensam a situação atual da sífilis na população transgênero, mas fica em evidência que existe uma alta relação desta doença com suas práticas sexuais (Tradução nossa - (Palacios M, 2017). Por essa razão, é preciso reconhecer quais são as representações sociais que tem a população transgênero sobre relações sexuais e a sífilis com o fim de implementar as intervenções correspondentes a partir da identificação dos fatores de risco. O intuito foi identificar as representações sociais sobre as relações sexuais e sífilis em pessoas trans da localidade dos Mártires em Bogotá. O desenho foi qualitativo, apoiou-se em métodos associativos para a recolecção do conteúdo e a organização das representações sociais, como são as listas livres e os questionários de comparação de pares. Integrou-se uma amostra por bola de neve. Participaram 32 mulheres trans. A análise foi através do enfoque estrutural das representações socias com o apoio da teoria de grafos. Os resultados obtidos mostraram uma visão social e emocional das representações sociais dos conceitos de relações sexuais e sífilis, informação que se converte em uma base para abordar a saúde sexual desta população

Cuidados genéricos para restablecer el equilibrio durante el puerperio / Generic care to restore balance in the postpartum period

El puerperio es un período que no debe considerarse exclusivamente biológico y desde la visión del no profesional o «emica¼ implica una travesía llena de riesgos para la mujer y su recién nacido. Por la pérdida de un mayor contacto con el sistema y profesionales de la salud durante esta etapa, toma gran relevancia el cuidado que se brinda al interior del hogar y como una cuestión femenina en medio de un mundo mágico de prácticas, creencias y tabúes definiendo unas acciones que se desarrollan desde los saberes de autocuidado, del hogar y otras tradicionales. Todas estas configuran el cuidado genérico de la salud durante la etapa del puerperio que se puede considerar universal en algunos aspectos, y a la vez, diverso teniendo en cuenta el contexto sociocultural donde se origina y desarrolla. Acercarse a este mundo mágico es una ocasión para el diálogo, aún pendiente, entre lo «emic¼ y lo «ethic¼ para el mejoramiento de la calidad de vida de la puérpera y el recién nacido de las poblaciones rurales, en condiciones de marginalidad y vulnerabilidad donde cobra un notable número de víctimas la mortalidad materna perinatal. Este artículo de revisión tiene como objetivo analizar los cuidados no profesionales o genéricos que se realizan en el entorno del domicilio durante el puerperio en diferentes contextos socioculturales; desde la exploración de la producción científica en el tema(AU)

The puerperium is a period that must not be considered exclusively biological and from the vision of unprofessional or «Emica¼ involve a journey full of risks for women and their newborn. The loss of contact of the health system and professionals during this stage, it takes an outstanding the care provided in home and as a matter of women in a magical world of practices, beliefs and taboos about defining actions that are developed from the knowledge of self, home and other traditions. All these actions make up the generic health care during the postpartum period may be considered universal in some aspects, and so far, taking into account different socio-cultural context where it originates and develops. Getting closer to this magical world is an occasion for dialogue, still pending, between «emic¼ and «ethic¼ to improve the quality of life of the postpartum and newborn rural populations in poverty and vulnerability conditions where a significant number of victims of perinatal maternal mortality. This review article aims to analyze the professional or generic care performed in the home environment during the postpartum period in different cultural contexts, from the exploration of scientific production in the field(AU)

Identificación de genes de Mycobacterium tuberculosis que se expresan bajo condiciones de estrés anaeróbico / Identification of Mycobacterium tuberculosis gen differentially expresed during anaerobic stress conditions

Objetivo: identificar genes de M. tuberculosis que se inducen bajo condiciones de limitación de oxigeno para estudiar su posterior efecto sobre la viabilidad del patógeno. Materiales y métodos: se crecieron cultivos de la cepa no patógena M. smegmatis mc²155 en cajas de microcultivo bajo condiciones de estrés anaeróbico. Se construyó una biblioteca genómica de M. tuberculosis H37Rv en el plasmado pGFP, la cual fue introducida dentro de M. smegmatis. A partir de observación de las células de M. smegmatis recombinantes bajo luz UV se identificaron clones que indujeran la expresión del gen reportero bajo condiciones de limitación de oxígeno. Los plásmidos recombinantes de estos clones fueron aislados y los insertos secuenciados. Las secuencias obtenidas fueron analizadas comparándolas con el genoma completo de M. tuberculosis. Resultados: Se estandarizaron las condiciones in vitro para realizar estudios por estrés anaeróbico usando la micobacteria M. smegmatis. El tamizaje de la genoteca de M. tuberculosis dentro de M. smegmatis llevó a la identificación de 3 posibles fragmentos genómicos que inducen la expresión de gfp en condiciones de estrés anaeróbico. La secuencia de estos insertos reveló que contenían posibles secuencias reguladoras, dos de ellas corriente arriba de los genes para las proteínas hipotéticas Rv2603 y Rv3267 de M. tuberculosis y la otra para un marco abierto de lectura no identificado. Conclusiones: Utilizando librerías genómicas y una micobacteria no patógena como M. smegmatis es posible identificar genes de M. tuberculosis posiblemente involucrados en resistencia a condiciones de estrés