Changes in respiratory tract microbiota have been associated with diseases such as tuberculosis, a global public health problem that affects millions of people each year. This pilot study was carried out using sputum, oropharynx, and nasal respiratory tract samples collected from patients with pulmonary tuberculosis and healthy control individuals, in order to compare sample types and their usefulness in assessing changes in bacterial and fungal communities.

Background: The presence of skin problems in patients using external lower limb prosthesis is recurrent. This has generated the need to develop interfaces for prosthesis with the ability to control microbial growth. Silver nanoparticles (AgNPs) have been implemented in the development of biomaterials because of their high antimicrobial activity. This article discusses the development of an AgNP-containing polymer composite with antimicrobial activity for developing prosthetic liners. Methods: AgNPs were synthesized using a photochemical method and certain physicochemical properties were characterized. Furthermore, the antimicrobial activity of AgNPs against Staphylococcus aureus ATCC 25923 and methicillin-resistant Staphylococcus aureus (MRSA), was assessed on the basis of their minimum inhibitory concentrations (MICs). AgNPs were incorporated into a silicon elastomer to assess certain physicomechanical properties, antimicrobial activity and cytotoxic effect of the material. Results: The maximum antimicrobial activity of the material against Staphylococcus aureus ATCC 25923 and MRSA was 41.58% ±2.97% at AgNP concentration of 32.98 μ g/mL and 14.85% ±5.94% at AgNP concentration of 16.49 μ g/mL, respectively. Additionally, the material exhibited tensile yield strength, rupture tensile strength, and tensile modulus of elasticity of 0.70 - 1.10 MPa, 0.71–1.06 MPa, and 0.20 - 0.30 MPa, respectively. The mechanical characteristics of the material were within the acceptable range for use in external lower limb prosthetic and orthotic interfaces. Conclusions: It was possible to incorporate the AgNPs in a silicone elastomer, finding that the composite developed presented antimicrobial activity against Staphylococcus aureus ATCC 25923 and MRSA when compared to non-AgNP material samples.

Determining the prevalence of intestinal parasitism and identifying the associated risk factors in the village of Loma Arena, Bolivar department, Colombia. The community's sanitary and educational conditions were evaluated by using a questionnaire which was applied to each family group. Two stool samples obtained by spontaneous evacuation, on two different days, were gathered from each participating person for the coproparasitological study. The coprological test involved direct examination in saline physiological solution and temporary staining with Lugol's solution and the formol-ether concentration method. It was found that 92 % of the population was parasitised, 92 % of them with at least one pathogenic parasite. Polyparasitism was very important (89,2 %); a maximum of 7 species per host was found. Helminth and protozoa coinfection was frequent (64 %). There was only 0,9 % teniosis prevalence. There was a significant association between symptomatology and parasite presence (p< 0.05), though such relationship was not seen with potentially pathogenic parasites (with the exception of Trichuris trichura and abdominal pain). The statistical analysis did not reveal any relationship between parasitism and educational level or sanitary habits. The uniform distribution of most intestinal parasites amongst the five age-groups evaluated showed that people in Loma Arena were evenly exposed to sources of infection in all age-groups.

Background: The detection of coinfections is important to initiate appropriate antimicrobial therapy. Molecular diagnostic testing identifies pathogens at a greater rate than conventional microbiology. We assessed both bacterial coinfections identified via culture or the BioFire® FilmArray® Pneumonia Panel (FA-PNEU) in patients infected with SARS-CoV-2 in the ICU and the concordance between these techniques. Methods: This was a prospective study of patients with SARS-CoV-2 who were hospitalized for no more than 48 h and on mechanical ventilation for no longer than 24 h in 8 ICUs in Medellín, Colombia. We studied mini-bronchoalveolar lavage or endotracheal aspirate samples processed via conventional culture and the FA-PNEU. Coinfection was defined as the identification of a respiratory pathogen using the FA-PNEU or cultures. Serum samples of leukocytes, C-reactive protein, and procalcitonin were taken on the first day of intubation. We analyzed the empirical antibiotics and the changes in antibiotic management according to the results of the FA-PNEUM and cultures. Results: Of 110 patients whose samples underwent both methods, FA-PNEU- and culture-positive samples comprised 24.54% versus 17.27%, respectively. Eighteen samples were positive in both techniques, 82 were negative, 1 was culture-positive with a negative FA-PNEU result, and 9 were FA-PNEU-positive with negative culture. The two bacteria most frequently detected by the FA-PNEU were Staphylococcus aureus (37.5%) and Streptococcus agalactiae (20%), and those detected by culture were Staphylococcus aureus (34.78%) and Klebsiella pneumoniae (26.08%). The overall concordance was 90.1%, and when stratified by microorganism, it was between 92.7 and 100%. The positive predictive value (PPV) was between 50 and 100% and were lower for Enterobacter cloacae and Staphylococcus aureus. The negative predictive value (NPV) was high (between 99.1 and 100%); MecA/C/MREJ had a specificity of 94.55% and an NPV of 100%. The inflammatory response tests showed no significant differences between patients whose samples were positive and negative for both techniques. Sixty-one patients (55.45%) received at least one dose of empirical antibiotics. Conclusions: The overall concordance was 90.1%, and it was between 92.7% and 100% when stratified by microorganisms. The positive predictive value was between 50 and 100%, with a very high NPV.

ABSTRACT During the last decade, there has been increasing awareness of the massive number of microorganisms, collectively known as the human microbiota, that are associated with humans. This microbiota outnumbers the host cells by approximately a factor of ten and contains a large repertoire of microbial genome-encoded metabolic processes. The diverse human microbiota and its associated metabolic potential can provide the host with novel functions that can influence host health and disease status in ways that still need to be analyzed. The microbiota varies with age, with features that depend on the body site, host lifestyle and health status. The challenge is therefore to identify and characterize these microbial communities and use this information to learn how they function and how they can influence the host in terms of health and well-being. Here we provide an overview of some of the recent studies involving the human microbiota and about how these communities might affect host health and disease. A special emphasis is given to studies related to tuberculosis, a disease that claims over one million lives each year worldwide and still represents a challenge for control in many countries, including Colombia. RESUMEN En las últimas décadas ha incrementado nuestro conocimiento sobre la gran cantidad de microorganismos que conviven con nosotros, comunidades que colectivamente se conocen como la microbiota humana. El número de microorganismos que conforman la microbiota supera el número de células del cuerpo humano por un factor de diez aproximadamente y aporta un gran repertorio de genes y procesos metabólicos. La diversidad de la microbiota humana y su potencial metabólico brindan al hospedero una serie de funciones que complementan sus procesos y a su vez pueden influir sobre la salud del ser humano en formas que apenas se empiezan a conocer. La microbiota varía desde el nacimiento hasta la vejez del individuo, con características que dependen del sitio corporal, del estilo de vida y del estado de salud del hospedero. El reto actual es aprovechar el conocimiento derivado de la identificación y caracterización de estas comunidades microbianas para entender cómo funcionan estos microorganismos y cómo pueden influir de forma positiva o negativa sobre la salud del humano. En este documento ofrecemos una revisión general de algunos estudios recientes sobre la microbiota humana y su posible efecto en el hospedero en términos de salud y bienestar. Igualmente, se mencionan estudios sobre microbiota y su posible asociación con la tuberculosis, una enfermedad que todavía cobra más de un millón de vidas anualmente a nivel mundial y cuyo control todavía representa un gran reto en varios países del mundo, incluido Colombia. Palabras clave: 16S ARNr, diversidad microbiana, microbioma, Mycobacterium tuberculosis.

Keywords: Strongyloides stercoralis; Intestinal diseases; Helminthology; Molecular diagnostic techniques