Calidad microbiológica del agua del lago volcánico Quilotoa. Cotopaxi-Ecuador / Microbiological quality of the water of the Quilotoa volcanic lake. Cotopaxi Ecuador

INTRODUCCIÓN: el agua de los lagos volcánicos no es estéril, en ella se ha adaptado a través de milenios una microbiota con diversas capacidades metabólicas. La diversidad microbiana de los lagos volcánicos en Ecuador ha sido poco estudiada y aún se desconoce su abundancia y riqueza. OBJETIVO: el objetivo del presente estudio fue conocer la calidad microbiológica del agua del lago Quilotoa, situado en la Provincia de Cotopaxi-Ecuador. MATERIALES Y METODOS: se realizaron dos muestreos durante el año 2019, recolectando un total 32 muestras. La calidad microbiológica se cuantifico utilizando la técnica de filtración por membrana en agar R2A para bacterias heterótrofas, agar eosina azul de metileno para coliformes, agar manitol salado para Staphylococcus, agar cetrimide para Pseudomonas y agar Sabouraud con cloranfenicol para hongos. RESULTADOS: los resultados promedios fueron para bacterias heterótrofas de 2,00 x 102 UFC/mL; Pseudomonas 7,00x 10 UFC/mL, Staphylococcus 3,80 x 10 UFC/mL y hongos 1,40 x 10 UFC/mL. No se detectó la presencia de bacterias coliformes. CONCLUSIONES: los grupos microbianos presentes en bajo número son indicativos de una microbiota característica adaptada a las condiciones fisicoquímicas de este lago. Se concluye que se trata de un lago con una población microbiana escasa lo que indicaría una buena calidad microbiológica.

INTRODUCTION: the water of volcanic lakes is not sterile, native microbiota shows different metabolic capabilities established over millennia. The microbial diversity of volcanic lakes in Ecuador have been little studied and their abundance and richness are still unknown. OBJECTIVE: the objective of this study was to know the microbiological quality of water of Lake Quilotoa, located in the Province of Cotopaxi-Ecuador. MATERIALS AND METHODS: two samplings were carried out during 2019, collecting a total of 32 samples. Microbiological quality was quantified using the membrane filtration technique on R2A agar for heterotrophic bacteria, eosin blue methylene agar for coliforms, salty mannitol agar for Staphylococcus, cetrimide agar for Pseudomonas and Sabouraud agar with chloramphenicol for fungi. RESULTS: the average results were for heterotrophic bacteria 2.00 x 102 CFU/mL, Pseudomonas 7.00 x 10 CFU/mL, Staphylococcus 3.80 x 10 CFU/mL and fungi 1.40 x 10 CFU/mL. The presence of coliform was not detected. CONCLUSIONS: the microbial groups present in low numbers are indicative of a characteristic microbiota adapted to the physicochemical conditions of this lake. It is concluded that it is a lake with a few microbial populations, which might indicate a good microbiological quality.

Tuning Crystal Structures of Iron-Based Metal-Organic Frameworks for Drug Delivery Applications.

Iron-based metal-organic frameworks (Fe-MOFs) have emerged as promising candidates for drug delivery applications due to their low toxicity, structural flexibility, and safe biodegradation in a physiological environment. Here, we studied two types of Fe-MOFs: MIL-53 and MIL-88B, for in vitro drug loading and releasing of ibuprofen as a model drug. Both Fe-MOFs are based on the same iron clusters and organic ligands but form different crystal structures as a result of two different nucleation pathways. The MIL-53 structure demonstrates one-dimensional channels, while MIL-88B exhibits a three-dimensional cage structure. Our studies show that MIL-53 adsorbs more ibuprofen (37.0 wt %) compared to MIL-88B (19.5 wt %). A controlled drug release was observed in both materials with a slower elution pattern in the case of the ibuprofen-encapsulated MIL-88B. This indicates that a complex cage structure of MIL-88 is beneficial to control the rate of drug release. A linear correlation was found between cumulative drug release and the degree of material degradation, suggesting the biodegradation of Fe-MILs as the main drug elution mechanism. The cytotoxicity of MIL-88B was evaluated in vitro with NIH-3T3 Swiss mouse fibroblasts, and it shows that MIL-88B has no adverse effects on cell viability up to 0.1 mg/mL. This low toxicity was attributed to the morphology of MIL-88B nanocrystals. The very low toxicity and controlled drug release behavior of Fe-MIL-88B suggest that better materials for drug-delivery applications can be created by controlling not only the composition but also the crystal structure and nanoparticle morphology of the material.

Conjugation of Paclitaxel to Hybrid Peptide Carrier and Biological Evaluation in Jurkat and A549 Cancer Cell Lines.

Paclitaxel (PTX) is one of the most potent cancer drugs; however, its low solubility and strong systemic side effects limit its clinical applications. To overcome these issues, new drug formulations and chemical modifications have been proposed. In this study, we present conjugation of PTX to hybrid collagen-cell penetrating peptide (COL-CPP) carriers. The peptide carrier is highly soluble and utilizes a unique stabilization strategy: folding into a triple helix. Here, we report the formation of PTX-COL-CPP prodrug that has similar drug potency as free PTX when tested in Jurkat (human T lymphocyte of acute T cell leukemia) cells but not in A549 (human epithelial of lung carcinoma) cells. Confocal images and flow cytometry show that this behavior originates from lower cellular uptake of COL-CPP and endosomal entrapment of the prodrug in A549, but not in Jurkat cells.

High-risk HPV types in lesions of the uterine cervix of female commercial sex workers in the Philippines.

In order to prevent cervical cancer, vaccines against human papilloma virus types 16 (HPV-16) and 18 (HPV-18) have been implemented worldwide. However, the HPV types that cause cancer can differ according to geographical area and ethnicity. In this new era of the HPV vaccine, it is important to elucidate the prevalent HPV types in each area. Therefore, the prevalence of HPV infection and cervical abnormalities among 369 female commercial sex workers in the Philippines were examined. HPV L1 gene was amplified by polymerase chain reaction (PCR) using modified GP5+/6+ primers, and genotyping was performed by sequencing cloned PCR products. HPV DNA was detected in 211 (57.2%) women, among whom 46 HPV types were identified. HPV-52 was most common and multiple-type infection was observed in 44.5%. Among 56 women with abnormal cervical cytology (low- and high-grade squamous intraepithelial lesions and adenocarcinoma in situ), HPV-52 was most common (23.2%), followed by HPV-16 (19.6%), -58 (10.7%), and -67 (10.7%). Only 27% of these women were positive for HPV-16 and -18. Multivariate analysis revealed that HPV-16, -39, -52, -67, and -82 were significantly associated with abnormal cytology. Repeated analysis of HPV-52 single-positive samples using the original GP5+/6+ PCR primers produced negative results in 57% of cases, suggesting that the prevalence of HPV-52 infection may have been underestimated in previous studies, and the current vaccines may not be sufficient for preventing infection and the development of premalignant lesions of the cervix in women in the Philippines.