Bioprospecting of extremophilic perchlorate-reducing bacteria: report of promising Bacillus spp. isolated from sediments of the bay of Cartagena, Colombia.

Three extremophile bacterial strains (BBCOL-009, BBCOL-014 and BBCOL-015), capable of degrading high concentrations of perchlorate at a range of pH (6.5 to 10.0), were isolated from Colombian Caribbean Coast sediments. Morphological features included Gram negative strain bacilli with sizes averaged of 1.75 × 0.95, 2.32 × 0.65 and 3.08 × 0.70 µm, respectively. The reported strains tolerate a wide range of pH (6.5 to 10.0); concentrations of NaCl (3.5 to 7.5% w/v) and KClO4- (250 to 10000 mg/L), reduction of KClO4- from 10 to 25%. LB broth with NaCl (3.5-30% w/v) and KClO4- (250-10000 mg/L) were used in independent trials to evaluate susceptibility to salinity and perchlorate, respectively. Isolates increased their biomass at 7.5 % (w/v) NaCl with optimal development at 3.5 % NaCl. Subsequently, ClO4- reduction was assessed using LB medium with 3.5% NaCl and 10000 mg/L ClO4-. BBCOL-009, BBCOL-014 and BBCOL-015 achieved 10%, 17%, and 25% reduction of ClO4-, respectively. The 16 S rRNA gene sequence grouped them as Bacillus flexus T6186-2, Bacillus marisflavi TF-11 (T), and Bacillus vietnamensis 15 - 1 (T) respectively, with < 97.5% homology. In addition, antimicrobial resistance to ertapenem, vancomycine, amoxicillin clavulanate, penicillin, and erythromycin was present in all the isolates, indicating their high adaptability to stressful environments. The isolated strains from marine sediments in Cartagena Bay, Colombia are suitable candidates to reduce perchlorate contamination in different environments. Although the primary focus of the study of perchlorate-reducing and resistant bacteria is in the ecological and agricultural realms, from an astrobiological perspective, perchlorate-resistant bacteria serve as models for astrobiological investigations.

Antileishmanial Activity and In Silico Molecular Docking Studies of Malachra alceifolia Jacq. Fractions against Leishmania mexicana Amastigotes.

Malachra alceifolia Jacq. (family Malvaceae), known as "malva," is a medicinal plant used as a traditional therapy in many regions of America, Africa and Asia. Traditionally, this plant is used in the form of extracts, powder and paste by populations for treating fever, stomachache, inflammation, and parasites. However, the ethnopharmacological validation of M. alceifolia has been scarcely researched. This study showed that the chloroform fraction (MA-IC) and subfraction (MA-24F) of the leaves of M. alceifolia exhibited a potential antileishmanial activity against axenic amastigotes of Leishmania mexicana pifanoi (MHOM/VE/60/Ltrod) and had high and moderate cytotoxic effects on the viability and morphology of macrophages RAW 264.7. This study reports, for the first time, possible terpenoid metabolites and derivatives present in M. alceifolia with activity against some biosynthetic pathways in L. mexicana amastigotes. The compounds from the subfractions MA-24F were highly active and were analyzed by gas chromatography-mass spectrometry (GC-MS) and by a molecular docking study in L. mexicana target protein. This study demonstrates the potential modes of interaction and the theoretical affinity energy of the metabolites episwertenol, α-amyrin and methyl commate A, which are present in the active fraction MA-24F, at allosteric sites of the pyruvate kinase, glyceraldehyde-3-phosphate dehydrogenase, triose phosphate isomerase, aldolase, phosphoglucose isomerase, transketolase, arginase and cysteine peptidases A, target proteins in some vital biosynthetic pathways were responsible for the survival of L. mexicana. Some phytoconstituents of M. alceifolia can be used for the search for potential new drugs and molecular targets for treating leishmaniases and infectious diseases. Furthermore, contributions to research and the validation and conservation of traditional knowledge of medicinal plants are needed globally.

An Overview of Genus Malachra L.-Ethnobotany, Phytochemistry, and Pharmacological Activity.

The genus Malachra L. belongs to the family Malvaceae. It includes herbs or subshrubs of nine accepted species with approximately thirty synonyms, and it has been widely used in community folk medicine to treat health problems including inflammation, nasal obstruction, leishmaniasis, malaria, childbirth, kidney disorders, fever, respiratory tract diseases, among others. From the genus Malachra L., flavonoids, steroids, triterpenes, anthocyanins, leucoanthocyanins, saponins, carbohydrates, phenols, glycosides, and alkaloids have been isolated and identified. Some pharmacological reports have indicated that the genus has antidiarrheal, antiepileptic, antiulcerogenic, antioxidant, anticonvulsant, antiviral, anticancer, antibacterial, anthelmintic, and hepatoprotective properties. However, there have been limited studies of bioactive molecules with pharmacological and biological activities associated with Malachra alceifolia Jacq., Malachra capitata (L.) L., Malachra fasciata Jacq., Malachra radiata (L.) L., Malachra ruderalis Gürke., Malachra rudis Benth., Malachra helodes Mart., Malachra urens Poit. ex Ledeb. & Alderstam., and Malachra officinalis Klotzsch. In this review, we consider the conservation of these species to save the ancestral knowledge of their traditional use in populations, and their pharmacological potential for future studies in search of alternatives for solutions to diseases in humans and animals and tools for the design and search of potential bioactive compounds against infectious and non-infectious agents.

Vaccines platforms and COVID-19: what you need to know.

BACKGROUND: The novel SARS-CoV-2, responsible for the COVID-19 pandemic, is the third zoonotic coronavirus since the beginning of the 21 first century, and it has taken more than 6 million human lives because of the lack of immunity causing global economic losses. Consequently, developing a vaccine against the virus represents the fastest way to finish the threat and regain some "normality." OBJECTIVE: Here, we provide information about the main features of the most important vaccine platforms, some of them already approved, to clear common doubts fostered by widespread misinformation and to reassure the public of the safety of the vaccination process and the different alternatives presented. METHODS: Articles published in open access databases until January 2022 were identified using the search terms "SARS-CoV-2," "COVID-19," "Coronavirus," "COVID-19 Vaccines," "Pandemic," COVID-19, and LMICs or their combinations. DISCUSSION: Traditional first-generation vaccine platforms, such as whole virus vaccines (live attenuated and inactivated virus vaccines), as well as second-generation vaccines, like protein-based vaccines (subunit and viral vector vaccines), and third-generation vaccines, such as nanoparticle and genetic vaccines (mRNA vaccines), are described. CONCLUSIONS: SARS-CoV-2 sequence information obtained in a record time provided the basis for the fast development of a COVID-19 vaccine. The adaptability characteristic of the new generation of vaccines is changing our capability to react to emerging threats to future pandemics. Nevertheless, the slow and unfair distribution of vaccines to low- and middle-income countries and the spread of misinformation are a menace to global health since the unvaccinated will increase the chances for resurgences and the surge of new variants that can escape the current vaccines.

Homology Modeling of Leishmanolysin (gp63) from Leishmania panamensis and Molecular Docking of Flavonoids.

Leishmaniasis is a chronic disease caused by protozoa of the distinct Leishmania genus transmitted by sandflies of the genus Phlebotomus (old world) and Lutzomyia (new world). Among the molecular factors that contribute to the virulence and pathogenesis of Leishmania are metalloproteases, e.g., glycoprotein 63 (gp63), also known as leishmanolysin or major surface protease (MSP). This protease is a zinc-dependent metalloprotease that is found on the surface of the parasite, abundant in Leishmania promastigote and amastigote. This study describes the prediction of three-dimensional (3D) structures of leishmanolysin (UniProt ID A0A088RJX7) of Leishmania panamensis employing a homology modeling approach. The 3D structure prediction was performed using the SWISS-MODEL web server. The tools PROCHECK, Molprobyty, and Verify3D were used to check the quality of the model, indicating that they are reliable. Best docking configurations were identified applying AutoDock Vina in PyRx 0.8 to obtain a potential antileishmanial activity. Biflavonoids such as lanaroflavone, podocarpusflavone A, amentoflavone, and podocarpusflavone B showed good scores among these molecules. Lanaroflavone appears to be the most suitable compound from binding affinity calculations.

Biodegradation of biodiesel-oil by Cellulosimicrobium sp. Isolated from Colombian Caribbean soils.

Biodiesel is considered to be a natural substitute for fossil fuel. The comparatively low toxicity of biodiesel and its susceptibility to microbial biodegradation could reduce its environmental impact. Currently, biodiesel is sold previously mixed with petroleum-based hydrocarbons. The aim of this work was to measure the biodegradation potential of commercially available biodiesel, using bacterial strains (BBCOL-001, BBCOL-002, and BBCOL-003) isolated from a tropical forest soils in the Colombian Caribbean. According to nucleotide sequencing of the gene encoding for 16S rRNA, the strains belong to members of the genus Cellulosimicrobium. GC-MS analysis showed that biodiesel-oil alkanes were degraded by an average of 81.5% with optical density reaching 0.2-0.3 in minimal salt media at 37°C for 5 days. Individual diesel-oil alkanes were degraded by the strains at rates between 64.9% to 100%. The increase in bacterial biomass confirmed the use of the substrates by the microorganisms, suggesting these hydrocarbons are a carbon source. Changes in the biochemical behaviour of the strains suggested their capacity to adapt to environmental conditions might be an important resource for bioremediation.

Multicompartment Mercury Contamination in Major Gold Mining Districts at the Department of Bolivar, Colombia.

Artisanal and small-scale gold mining is the main source of human exposure to mercury (Hg) in many countries. This study was designed to evaluate total Hg (T-Hg) concentrations in human hair, fish, soil, and air from two major gold-mining districts (GMDs) at the department of Bolivar, Colombia. Total Hg was analyzed using a direct Hg analyzer. The mean T-Hg concentration in hair samples was 3.07 ± 0.14 µg/g (range 0.15-25.1 µg/g; median 2.02 µg/g). The highest Hg level was observed in Mojana GMD, specifically at Achi-La Raya (9.2 ± 0.6 µg/g) and the lowest in Morales, at the Middle Magdalena GMD (1.50 ± 0.16 µg/g). Hair T-Hg values exceeded the U.S. Environmental Protection Agency reference level of 1.0 µg/g. Correlation between T-Hg in hair and stature was negative for the Mojana, but the opposite for Middle Magdalena, although for both GMDs hair T-Hg correlated positively with fish intake. The highest average T-Hg fish concentrations were observed in Caquetaia kraussii (0.37 ± 0.10 µg/g), Sorubim cuspicaudus (0.32 ± 0.16 µg/g), Plagioscion surinamensis (0.22 ± 0.02 µg/g), Trachelyopterus insignis (0.20 ± 0.02 µg/g), and Pseudoplatystoma magdaleniatum (0.20 ± 0.02 µg/g). Human health risk assessment of Hg based on fish consumption suggested that, with the exception of P. magdalenae, all economically important fish species are potentially harmful for the communities. Soil Hg levels in amalgam burning facilities were extremely high, and Hg in the air around mines and gold-processing shops exceeded international guidelines. In short, Hg pollution in GMDs of Bolivar is extensive, and this situation requires special attention to reduce environmental and human health problems.

Antibacterial activity of Cordia dentata Poir, Heliotropium indicum Linn and Momordica charantia Linn from the Northern Colombian Coast / Actividad antibacterial de Cordia dentata Poir, Heliotropium indicum Linn y Momordica charantia Linn de la costa norte de Colombia

SUMMARY Cordia dendata Poir, Heliotropium indicum Linn and Momordica charantia Linn are used for treatment of the most common human diseases and health disorders in folk medicine of the population from the northern Colombian coast. In this study, chemical composition and antibacterial activity of the ethanol extract and fractions from C. dentata, H. indicum and M. charantia were investigated. The chemical constituents of qualitative detection were examined by Thin Layer Chromatography (TLC). The antibacterial activity was determined by agar gel diffusion and broth microdilution method. The main identified compounds were flavonoids, cardiac glycosides, alkaloids, saponins, terpenoids, tannins and coumarins. The minimal inhibitory concentration (MIC) was 31.25 to 1000 µg /mL for Gram-positive and Gram-negative bacteria, respectively. These results indicated that ethanol extract and fractions from C. dentata, H. indicum and M. charantia significantly inhibited the growth of standard strains. Potent antibacterial activities of C. dentata, H. indicum and M. charantia may be considered in future study, particularly against antibiotic-resistant cases.

RESUMEN Cordia dendata Poir, Heliotropium indicum Linn y Momordica charantia Linn son usadas para el tratamiento de las enfermedades más comunes y trastornos de salud en la medicina popular de la población de la costa norte de Colombia. En este estudio se investigó la composición química y la actividad antibacterial de los extractos etanólicos y fracciones de C. dentata, H. indicum y M. charantia. Los constituyentes químicos se examinaron por detección cualitativa cromatografía de capa fina (TLC, por sus siglas en inglés). La actividad antibacterial se determinó por difusión en agar y microdilución en caldo. Los mayores compuestos identificados fueron flavonoides, glucósidos cardiotónicos, alcaloides, saponinas, terpenoides, taninos y cumarinas. La concentración inhibitoria mínima (MIC, por sus siglas en inglés) fue de 31,25 a 1000 /µg/mL para bacterias Gram-positivas y Gram-negativas, respectivamente. Estos resultados indican que el extracto etanólico y las fracciones de C. dentata, H. indicum y M. charantia inhibieron de manera significa el crecimiento de las cepas estándar. La potente actividad antibacterial de C. dentata, H. indicum y M. charantia puede considerarse en posteriores estudios, en particular frente a casos de antibióticos resistentes.

Repellent and Anti-quorum Sensing Activity of Six Aromatic Plants Occurring in Colombia.

Essential oils (EOs) are widely used as biopesticides and to control bacterial infections. This study describes the ability of six EOs isolated from plants cultivated in Colombia to perform as repellents against Ulomoides dermestoides and as quorum sensing (QS) inhibitors. EOs from Aloysia triphylla, Cymbopogon nardus, Lippia origanoides, Hyptis suaveolens, Swinglea glutinosa and Eucalyptus globulus were repellents classified as Class IV, IV, IV, III, II, and II, respectively, whereas the commercial repellent IR3535 only reached Class II after 2 h exposure. All EOs presented small, but significant inhibitory properties against the QS system in Escherichia coli (pJBA132) at 25 µg/mL after 4 h exposure. These data suggest evaluated EOs from Colombia are sustainable, promising new sources of natural repellents and could be important as anti-quorum sensing molecules.