Microbiología
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Item Evaluación antimicrobiana de colistina encapsulada con nanoliposomas recubiertos de quitosano de mediano peso molecular, frente a bacterias gramnegativas sensibles y multidrogoresistentes(Universidad Santiago de Cali, 2021) Betancourt Ayala, Yeiston; Oñate Garzón, Jose Fernando; Rivera Sánchez, Sandra PatriciaColistin is a last resort antibiotic which has been reimplemented in clinical practice in order to combat infections by gram-negative and multidrug-resistant bacteria, however, this antibiotic has lost affinity towards this type of bacteria, being caused by the increase and dissemination of strains resistant to this polypeptide. In this work, the antimicrobial activity of colistin encapsulated in nanoliposomes coated with chitosan of medium molecular weight was evaluated against the sensitive Escherichia coli strains, and Pseudomonas aeruginosa sensitive and multidrug resistant strains. Physicochemical properties such as particle size, polydispersity index and zeta potential were determined using Zetasizer nano ZSP. The results for the chitosan-coated systems showed changes in size (from 461.5 nm uncharged to 322.2 nm with colistin), polydispersity index (from 0.219 unloaded to 0.449 with colistin), and zeta potential (from -2.1 mV unloaded). at 15.0 mV with colistin). After encapsulating the colistin, the minimum inhibitory concentration (MIC) of the formulations was determined by the broth microdilution method for P.a ATCC (27853), sensitive population P.a and resistant P.a. For antimicrobial activity, resistance was obtained in strain No. 2, decrease in minimum inhibitory concentration in strain No. 1, sensitivity in strain No. 3 and population strain (W.t).Item Terapia fágica en la era de la multirresistencia bacteriana. Una revisión sistemática(Universidad Santiago de Cali, 2021) Pantoja Camacho, Lady Daniela; Martinez Martinez, Edgar Andrés; Aranaga, Carlos Andrés; Falco Restrepo, Aura DayanaAntibiotics have played an important role in the treatment of infections caused by bacteria. However, the high rates of resistance currently reported towards these drugs represent a public health problem. Bacteriophages constitute an alternative to mitigate the resistance to the use of antibiotics because they are capable of infecting and lysing bacteria in a specific way, without these processes being affected by the changes that led to the acquisition of antibiotic resistance. Therefore, bacteriophages are suitable candidates to exert biocontrol in bacteria of clinical interest. To determine whether phage therapy has been successful in the treatment of infections caused by multidrug-resistant bacteria, this systematic review of scientific literature was carried out. Using PRISMA methodology, three scientific databases were selected: Pubmed, Science Direct, and Google Scholar, from which 25 research articles and clinical cases from the last 10 years that met the inclusion criteria were included. A review of the information from each study was carried out and it was determined that most of the infections were caused by bacteria such as S. aureus, K. pneumoniae, and A. baumanii. The results indicate that the era of multi-resistance to antibiotics promoted the increase in therapy with bacteriophages in the last three years. Likewise, in 92% of the cases studied, its application was successful. Even though positive results have been obtained in the application of phage therapy, more studies related to pharmacokinetics are needed, as well as to demonstrate more safety concerning its administration, to standardize the treatment to be used according to the infection to be treated.Item Establecimiento de las condiciones de compostaje utilizando microorganismos eficientes y desechos orgánicos producidos en restaurantes de la Universidad Santiago de Cali(Universidad Santiago de Cali, 2021) Cosme Perlaza, Jefrid Leandro; Molina Rada, Ananda Esther; Quijano, Silvia Andrea; Falco, AuraThe Santiago de Cali University produces a wide variety of wastes that are mostly organic and, currently, are not used properly. Composting emerges as an alternative that transforms solid waste into organic fertilizer for the soil, however, this process usually takes several months. The use of efficient microorganisms is an option to optimize the time of the composting process. The objective of this work was to establish the conditions for composting organic waste produced in restaurants of the Universidad Santiago de Cali, using efficient microorganisms and the Autonomous Composting System SAC-2250. Initially, the standardization of the conventional composting process was carried out, evaluating four treatments with different amounts and combinations of substrate. The results indicate that treatment 1 (3 parts of organic matter per 1 of sawdust) had the best behavior compared to that reported in the literature (the duration of the process is 45 days). Subsequently, three efficient microorganisms identified as Klebsiella oxytoca, Sphingomonas paucimobilis and Pantoea spp were isolated and inoculated in treatment 1. The results indicate that the inoculum reduced the composting process in 20 days, when compared with the control cell. The proper management of the organic waste will significantly reduce the accumulation of them, decreasing the environmental impact and therefore the rate of cleanliness in the institution, in addition it faces an aesthetic and landscape component in the community Santiaguina.Item Detección molecular de Leptospira spp en roedores plaga del Zoológico de Cali(Universidad Santiago de Cali, 2020) Jaramillo Ruiz, Felipe Antonio; Nieto Ramírez, Luisa MaríaLeptospirosis is a zoonosis caused by bacteria of the genus Leptospira spp, with rodents being its best known reservoir. The Zoo of Cali controls rodent plagues which potentially keep the circulation and presence of this bacterium active. To prove the presence of Leptospira spp and its pathogenic species among the plague rodents of the Cali Zoo, a total of 32 rats were captured between May and August 2019. Using samples of renal tissue, it was carried out the amplification by PCR of rrs and lipL32 genes, detecting a positivity of 12.5% for both genes. lipL32 also constitutes a molecular marker of pathogenicity whose product was also analyzed by Sanger sequencing, identifying L. interrogans species with a similarity of 100%. The results achieved allow confirming the presence of pathogenic species Leptospira spp in the renal tissue of rodents that circulate in the area of Cali Zoo, generating an evidence of the potential risk of transmission to other animal species, including visitors or workers of the institution.Item Actividad enzimática de levaduras recolectadas de diferentes ambientes del Valle del Cauca(Universidad Santiago de Cali, 2020) Olaya Hurtado, Dora Stefany; Ossa Cabra, Liseth Tatiana; Martínez Garay, Carlos Andrés; Ramírez Castrillón, MauricioAgro-industrial waste affects the environment, which makes it a current problem. A sustainable strategy is the use of microorganisms, such as yeast, to metabolize and to degrade these compounds, which will allow the development of bioremediation strategies. In this research, we tested yeasts from the mycoteca of Universidad Santiago de Cali, collected from different environments of Valle del Cauca, to determine their enzymatic activity. For this, they were grown in media with different substrates, to evaluate their ability to degrade them through the determination of an enzymatic coefficient (PZ), which takes into account the degradation halos formed. A total of 95 yeast strains were evaluated, of which 37 strains presented some enzymatic activity. Several strains showed potential in this field; the LN6A, P4, LC071A, YAM1, and YAM3 strains had the highest enzymatic activity; while some had the ability to degrade or metabolize two different substrates (LN4A, MRC33, LC112, P4, LN7C) or up to three types of substrate (MRC39). In addition to this, the LN4A strain, from the Navarro lagoon and identified as Candida tropicalis, presented a higher enzymatic activity in two types of substrate.Item Bacterias potencialmente degradadoras de hidrocarburos aisladas en Santiago de Cali, Valle del Cauca(Universidad Santiago de Cali, 2020) Machacado Salas, Maryuris; Rache Arce, Diana Carolina; Rosero García, Doris AmandaOil hydrocarbon pollution is one of the main problems around the world since it generates negative ecological, economic, and social impacts. Colombia has been affected by hydrocarbon spills that contaminate different environments such as water and soil. Bacteria have been reported with the ability to degrade hydrocarbons, becoming an excellent strategy for designing studies that contribute solutions to this problem. In the present study, a methodology was standardized to isolate hydrocarbon degrading bacteria in six biological oxidation lagoons and a pure leachate from a treatment plant located in the Old Navarro Landfill at Santiago de Cali city. Three tests were conducted: leachate contamination, disk test and tube test, and 17 bacterial morphotypes with degrading potential of gasoline, diesel and ACPM were found. The bacteria identified were Serratia marcescens (morphotype 97), Bacillus sp. (morphotypes 90, 117 and 263), Bacillus cereus (morphotype 120) and Exiguobacterium sp. (morphotypes 123 and 137). This work carried out to standardize a methodology to isolate bacterial morphotypes in the Old Navarro Landfill and allowed future studies to study the degradation mechanisms in bacteria, and solutions that contribute to the reduction of hydrocarbon contamination.Item Revisión sistemática de degradación microbiana de Tereftalato de Polietileno (PET)(Universidad Santiago de Cali, 2021) Benavides Fernández, Cesar David; Guzmán Castillo, Michelly Paola Johana; Carvajal Rodríguez, Lida Vivian; Quijano Pérez, Silvia AndreaThe environmental problems caused by plastic waste, mainly Polyethylene Terephthalate (PET), have increased the levels of environmental pollution. This is due to its high production and inefficient methods of disposal and recycling, affecting the various aquatic and terrestrial ecosystems. Although chemical and physical degradation techniques have been carried out, these have brought negative effects to the environment; therefore, the use of microorganisms has become important in recent years. For this reason, it was carried out a systematic revision of literature that pretended to know the studies and findings made by diverse investigators about PET degradation by wild and genetically modified microorganisms. It was carried out a search of publications in different data bases. Besides, it was elaborated a table where the different wild microorganisms with metabolic potential for the degradation of this polymer and those microorganisms genetically modified for the same purpose are shown. Likewise, the enzymes, proteins and genes used for its elaboration were studied. The wild microorganisms that were most found as PET degraders were some genera of bacteria with 53.8% that correspond to 35 genera, followed by fungi with 44.6% that correspond to 29 genera and a genus of microalgae that corresponds to 1.5%. Among these microorganisms, the most reported genre in fungi was Aspergillus sp., in bacteria it was the genre Bacillus sp. and of microalgae the only genre reported was Spirulina sp. As for the microorganisms genetically modified, it was found that 30 strains of Escherichia coli have been used by means of genetic recombination using mainly the enzyme PETasa.Item Revisión sistemática de las metodologías implementadas en la industria cárnica con desinfectantes cuyo compuesto principal es el amonio cuaternario(Universidad Santiago de Cali, 2021) Seba Prasca, Danna Reyhan; Martínez Garay, Carlos AndrésItem Aislamiento, identificación y caracterización de bacterias ácido acéticas (BAA) para la producción de vinagre a partir de vino tinto(Universidad Santiago de Cali, 2021) Portilla Sinisterra, Andrés Fernando; Vera Lizcano, OmairaStudies of the microorganisms associated with the fermentation processes, their identification and the standardization of their biotechnological use, are of great interest for the economic and technological growth of a country. In this study, a winemaking protocol was obtained to later produce vinegar for human consumption through acetic fermentation, which is carried out mainly by acetic bacteria under aerobic conditions. 10 batches of wine were produced from Isabella grapes, obtained in the municipality of Ginebra-Valle del Cauca, an alcohol percentage between 9,8 – 11,2% was reached, to later obtain acetic acid. The Orleans method was used to make vinegar, which consists of stationary oxidation of ethanol in acetic acid, under the conditions required for the growth of acetic bacteria, from which a concentration of acetic acid between 47,4 - 60 g / L. Subsequently, the bacteria of the Acetobacteraceae family were isolated by means of cutives and identified by means of biochemical techniques. Later, with the Vitek 2 team, the Acetobacter acetti species was identified as the acetic bacteria found in vinegar, it was cryopreserved. This microorganism can be used to produce balsamic vinegar, which is of great commercial interest.Item Estructura de comunidades bacterianas con resistencia a los antibióticos en los sistemas de aguas (una revisión narrativa, aportes para la vigilancia epidemiológica)(Universidad Santiago de Cali, 2021) Sánchez Baena, Ana María; Caicedo Bejarano, Luz Dary; Chávez Vivas, MónicaItem Activación foto- catalítica de nano partículas de MnO2 obtenidas a partir de ablación laser, aplicada a superficies auto-limpiantes(Universidad Santiago de Cali, 2021) Villegas Díaz, Claudia Lorena; Ávila Torres, Yenny Patricia; Ríos Acevedo, John JairoThe nano-particles of metallic materials have many applications, a field of special interest is the hospital, since there are many infections associated with health care (HAI) these infections must be related to hospitalization or procedures performed in the hospital. Mainly originated by Staphylococcus aureus and Escherichia coli, for this reason materials are required that are capable of eliminating these bacteria attached to it, and thus prevent the high number of infections (self-cleaning surfaces). A new material with these characteristics is manganese oxide (MnO2), used in the manufacture of steel, with which hospital equipment is manufactured. In this study, different factors affecting bactericidal photocatalysis were tested, showing that the attack is discriminated for gram positive and gram negative bacteria, the action mechanism is governed via hydroxyl radicals and to a lesser degree via superficial voids. Finally, a material with little recombination is obtained, which represents a success in the synthesis of metal oxide.Item Caracterización de poblaciones bacterianas como potenciales optimizadores en el proceso de compostaje de la empresa Incauca S.A.S.(Universidad Santiago de Cali, 2021) Díaz Caicedo, Lizeth Natalia; Corrales Ducuara, Alba Rocío; Mercado Álvarez, Ana MaríaComposting is a totally aerobic bioremediation process, in which microorganisms that rapidly and effectively degrade organic matter act. One of the great challenges of the sugar sector is to optimize the degradation times of the organic waste produced by the processing of sugar cane and fuel alcohol. Currently, INCAUCA S.A.S has implemented a sustainable management for waste management, which requires efficient methodologies for the processing and degradation of sugar cane products. In this study, efficient bacteria were characterized in two composting plants of the company INCAUCA S.A.S, as a sustainable strategy to optimize the process of degradation of organic matter. Genera such as Pseudomonas, Bacillus and Aeromonas were identified with an identity greater than 97% indicating having an important role in the composting process, 13 isolates presented halos of cellulose degradation.Item Genes que codifican para proteínas transportadoras exhiben mutaciones no sinónimas en parásitos de Plasmodium vivax que circulan en área endémica para malaria en Amazonas, Brasil(Universidad Santiago de Cali, 2021) Tabares León, Dolly Isabella; Vera Lizcano, OmairaPlasmodium transmission continues to be a public health problem, in 2018 it caused 228 million cases, the highest parasite load is caused by Plasmodium falciparum and Plasmodium vivax. In America 75% of malaria cases are caused by Plasmodium vivax. Chloroquine is the first-line antimalarial, however, resistance is found in 90% of Plasmodium falciparum isolates and 10% in Plasmodium vivax. In this work, the non-synonymous point mutations in genes that code for transporter proteins of Plasmodium vivax parasites exposed to chloroquine, circulating in areas endemic for malaria in Brazil, will be analyzed. The prevalence of mutations will be evaluated using the surveyor mutation software, using the strain susceptible to Chloroquine, Sal I., as a reference strain. The finding of non-synonymous mutations in the genes studied can provide guidance for the study of resistance to Chloroquine.Item Estudio de la interacción de un péptido catiónico derivado de la Cecropina-D Gallería mellonella con sistemas de modelos de membranas multilaminares que muestran similitud con las membranas bacterianas(Universidad Santiago de Cali, 2021) Ante Vasquez, Cristian Geovany; Vergara Moreno, Esmeralda; Oñate Garzón, Jose Fernando; Polo Cerón, DorianAntimicrobial peptides are of great importance in many living organisms, since they are part of the innate immune system, performing the role of effectors in defense against infectious agents. These are found in a great diversity of living beings, from which a great variety of these molecules have been isolated, such as CECROPINA-D from Galleria mellonella; the synthetic peptide M1 of 39 amino acids that has been obtained from the sequence of Cecropina Galleria mellonella, is a cationic homologue derived from the originally extracted peptide. It is known that the antimicrobial action of these molecules is due to the attraction of opposite charges that occur between the microbial membrane with an anionic charge and the peptide with cationic charge, therefore, it causes alterations in the change of phase resulting in an increase of the permeability of the membrane. However, there is not enough information about the mechanisms of action that peptides must cause the phase change of the membrane; In this work, the effect of the peptide on the thermotropic behavior of membrane models that simulate those of bacteria, consisting of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) and DMPG (1,2 -Dimyristoyl-sn-glycero-3-phosphorylglycerol), respectively. Furthermore, an in-silico analysis allows us to recognize the peptide-membrane molecular interactions necessary to understand this effect. For both activities, the Differential Scanning Calorimetry (DCS) technique and Molecular Dynamics algorithms were implemented, respectively. The results confirmed the perturbation capacity of the M1 peptide. It is estimated that this capacity is given by the modulation of the physicochemical characteristics and parameters on the membrane models. A strong effect was observed in the multilamellar membranes (MLVs) formed by the mixture Phosphatidylcholine (DMPC) and Phosphatylglycerol (DMPG) in a ratio (3: 1), on the change from gel to crystalline phase with the presence of the peptide, reducing by 1, 7 ° C the temperature necessary for the transition. At 1:10 concentration of the peptide, a gel to crystalline phase change occurred without requiring energy supplied by an external system. In Molecular Dynamics, HB-type interactions were observed: hydrogen bonding; IE: electrostatic interaction; and HI: hydrophobic interaction present in the system for a time of 10 ns, distributed with data collection every 2 ns, finding a large presence of hydrogen bond-type interactions between peptide M1 and the rest of the system, with affinity for lipids of DMPG and absence of affinity with DMPC lipids, in addition the main amino acids that participated in these interactions were identified. Other data found and exposed in this work are the result of RMSD and the data of the results of the Radius of Gyration of peptide M1 in the system.Item Catálogo de levaduras en Colombia: Revisión sistemática(Universidad Santiago de Cali, 2021) Barona Colorado, Anabel; Bolaños Burbano, Dahyana; Ramírez Castrillón, MauricioThe diversity of fungi in Colombia is not well known, where there are at least 7,273 species, a low number when compared to other countries. Yeasts have been little explored and little is known about their sampling effort. Therefore, this work aimed to review all the publications studies of repositories, databases, and public collections reporting the isolation and identification of environmental yeasts in Colombia from the years 2000 to 2020. All clinical isolates (human or related to zoonotic diseases) were excluded. 112 species of environmental yeasts occurring in four regions and 11 departments of Colombia were found, with 73.4% of yeasts belonging to Ascomycota and 26.6% to Basidiomycota. The most common primary environments were associated with different parts of plants, soils, and animals. Secondary environments with the reported yeasts were fermented fruits and fermented beverages. The most representative species were Cryptococcus neoformans (544 strains), Cryptococcus vini (360), and Cryptococcus gattii (243).Item Revisión sistemática sobre el efecto antimicrobiano de la proteasa actinidina del kiwi (Actinidia deliciosa) en la industria alimentaria(Universidad Santiago de Cali, 2022) Arteaga Caceres, Geraldine; Cajiao Diaz, Carolay Andrea; Martínez Garay, Carlos Andrés; Gaviria Cantin, Tania CristinaItem Identificación de bacterias productoras de betalactamasas de espectro extendido en fertilizantes orgánicos(Universidad Santiago de Cali, 2023) Espinosa Santa, Gabriela; Montero Castrillón, Paola Andrea; Correa Bermúdez, Adriana María; Falco, Aura DayanaOrganic fertilizers have played a fundamental role nowadays due to their multiple benefits on soils and on the environment by not producing harmful chemicals for it, without leaving behind certain key factors such as their components to make them more natural, such as the waste produced by livestock. Thus, a search for enzymes encoded by third generation cephalosporin resistance genes was carried out by means of susceptibility tests, synergy tests and PCR from industrial and artisanal fertilizers, which are available for free sale to the public. The results indicated 100% presence of genes related to antibiotic resistance in the 19 isolates analyzed, 68.42% of which were identified as E. coli and 31.58% as K. pneumoniae, with the bla CTX-M gene standing out among them, being present in 84.21% of the isolates. In conclusion, it was confirmed that organic fertilizers can act as a possible source of dissemination of multiresistances.Item Caracterización genética de aislados de Vibrio metschnikovii resistentes a antibióticos provenientes de una planta de tratamiento de lixiviados ubicada en Cali(Universidad Santiago de Cali, 2022) Zúñiga Espitia, Carolina; Falco Restrepo, Aura DayanaVibrio metschnikovii is a Gram-negative bacillus that inhabits aquatic environments, including leachates, which are formed from the percolation of waste deposited in landfills. And that due to the high load of contaminants generate a selective pressure on bacteria, leading them to acquire extragenic elements such as plasmids that are disseminated from one bacterium to another through horizontal gene transfer, giving them characteristics that allow them to survive in adverse environments. Due to the high prevalence of V. metschnikovii isolates resistant to antibiotics in one of the lagoons without physicochemical treatment of a Leachate Treatment Plant, located in the municipality of Santiago de Cali, genetic characterization of these isolates was carried out in this work, with the objective of determining the genetic diversity of each one of the isolates. For this purpose, the isolates were genotyped by amplifying the extragenic palindromic repetitive sequences through the polymerase chain reaction (rep-PCR). Additionally, it was determined whether the isolates carried plasmids and whether they had the ability to transfer horizontally. The results indicate that, although rep sequences are found in a wide variety of bacteria, V. metschnikovii does not have them. For this reason, it is suggested that pulsed-field gel electrophoresis studies be carried out to determine the genetic relationship between bacterial isolates. Additionally, it was possible to purify plasmid DNA in an amikacin-resistant isolate, which cannot be transferred by conjugation.Item Dermatofitos en suelos del zoológico de la ciudad de Cali, Colombia(Universidad Santiago de Cali, 2022) Quintero Barragán, Daniel; Grisales Toro, Anyelly; Caicedo Bejarano, Luz Dary; Ramirez Castrillon, MauricioThe dermatophyte fungi present in the soils of the animal houses of the Zoological of the city of Cali, Colombia, were studied. The objective of the study was to determine the presence of dermatophyte fungi in these habitats and the variation of their presence according to some physicochemical parameters of the soil. The Vanbreuseghem hair-hook technique was used, and measurements of pH, conductivity, organic matter, ash, and moisture percentage were also taken. 37/60 (61.6%) of the samples were positive for the Nannizzia gypsea complex; no other dermatophyte was isolated. Soil pH values ranged from 4.63 to 9.36 and the isolation rate of the fungus was higher in soils with a pH range of 5.5 to 6.9 and this difference was statistically significant. The other physicochemical parameters were not significant for the presence of the fungus.Item Determinación de la capacidad de formación de biopelículas en aislados de Escherichia coli resistentes a betalactámicos(Universidad Santiago de Cali, 2024) Montehermoso Ramos, Kyara Stefania; Aranaga Arias, Carlos Andrés; Falco, Aura DayanaEscherichia coli is a bacterium capable of forming biofilms on invasive medical devices such as catheters, urinary catheters, artificial respirators, etc. When the infection is caused by isolates of E. coli resistant to beta-lactam antibiotics, therapeutic options are severely limited, increasing patient morbidity and mortality. The main mechanism of resistance to beta-lactams is the production of beta-lactamase enzymes that hydrolyze and inactivate them. In Colombia, the blaKPC gene, encoding for KPC carbapenemase (Klebsiella pneumoniae Carbapenemase), is endemic in the country and, along with other enzymes like VIM and NDM, is primarily responsible for beta- lactam resistance. The objective of this study was to determine the biofilm formation capacity in isolates of beta-lactam-resistant E. coli. To achieve this, the presence of the blaKPC gene was detected using polymerase chain reaction, while the ability to form biofilms was assessed using the crystal violet assay. The results indicate that the blaKPC gene was present in 88% of the isolates evaluated, and 100% could form biofilms. These findings underscore the complexity of infections caused by beta-lactam-resistant E. coli and contribute to the development of more effective public health policies by hospital infection committees, tailored to the evolving bacterial resistance landscape, with the aim of reducing the prevalence of resistant strains at the hospital level.