The Beta-Lactam Resistome Expressed by Aerobic and Anaerobic Bacteria Isolated from Human Feces of Healthy Donors.

Antibiotic resistance is a major health problem worldwide, causing more deaths than diabetes and cancer. The dissemination of vertical and horizontal antibiotic resistance genes has been conducted for a selection of pan-resistant bacteria. Here, we test if the aerobic and anaerobic bacteria from human feces samples in health conditions are carriers of beta-lactamases genes. The samples were cultured in a brain-heart infusion medium and subcultured in blood agar in aerobic and anaerobic conditions for 24 h at 37 °C. The grown colonies were identified by their biochemical profiles. The DNA was extracted and purified by bacterial lysis using thermal shock and were used in the endpoint PCR and next generation sequencing to identify beta-lactamase genes expression (OXA, VIM, SHV, TEM, IMP, ROB, KPC, CMY, DHA, P, CFX, LAP, and BIL). The aerobic bacterias Aeromonas hydrophila, Citrobacter freundii, Proteus mirabilis, Providencia rettgeri, Serratia fonticola, Serratia liquefaciens, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Pantoea agglomerans, Enterococcus faecalis, and Enterobacter cloacae, the anaerobic bacteria: Capnocytophaga species, Bacteroides distasonis, Bifidobacterium adolescentis, Bacteroides ovatus, Bacteroides fragilis, Eubacterium species, Eubacterium aerofaciens, Peptostreptococcus anaerobius, Fusobacterium species, Bacteroides species, and Bacteroides vulgatus were isolated and identified. The results showed 49 strains resistant to beta-lactam with the expression of blaSHV (10.2%), blaTEM (100%), blaKPC (10.2%), blaCYM (14.3%), blaP (2%), blaCFX (8.2%), and blaBIL (6.1%). These data support the idea that the human enteric microbiota constitutes an important reservoir of genes for resistance to beta-lactamases and that such genes could be transferred to pathogenic bacteria.

Leishmania: manipulation of signaling pathways to inhibit host cell apoptosis.

The maintenance of homeostasis in living systems requires the elimination of unwanted cells which is performed, among other mechanisms, by type I cell death or apoptosis. This type of programmed cell death involves several morphological changes such as cytoplasm shrinkage, chromatin condensation (pyknosis), nuclear fragmentation (karyorrhexis), and plasma membrane blebbing that culminate with the formation of apoptotic bodies. In addition to the maintenance of homeostasis, apoptosis also represents an important defense mechanism for cells against intracellular microorganisms. In counterpart, diverse intracellular pathogens have developed a wide array of strategies to evade apoptosis and persist inside cells. These strategies include the manipulation of signaling pathways involved in the inhibition of apoptosis where mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) play a key role. Leishmania is an intracellular protozoan parasite that causes a wide spectrum of diseases known as leishmaniasis. This parasite displays different strategies, including apoptosis inhibition, to down-regulate host cell defense mechanisms in order to perpetuate infection.

Acinetobacter baumannii Resistance: A Real Challenge for Clinicians.

Acinetobacter baumannii (named in honor of the American bacteriologists Paul and Linda Baumann) is a Gram-negative, multidrug-resistant (MDR) pathogen that causes nosocomial infections, especially in intensive care units (ICUs) and immunocompromised patients with central venous catheters. A. baumannii has developed a broad spectrum of antimicrobial resistance, associated with a higher mortality rate among infected patients compared with other non-baumannii species. In terms of clinical impact, resistant strains are associated with increases in both in-hospital length of stay and mortality. A. baumannii can cause a variety of infections; most involve the respiratory tract, especially ventilator-associated pneumonia, but bacteremia and skin wound infections have also been reported, the latter of which has been prominently observed in the context of war-related trauma. Cases of meningitis associated with A. baumannii have been documented. The most common risk factor for the acquisition of MDR A baumannii is previous antibiotic use, following by mechanical ventilation, length of ICU/hospital stay, severity of illness, and use of medical devices. Current efforts focus on addressing all the antimicrobial resistance mechanisms described in A. baumannii, with the objective of identifying the most promising therapeutic scheme. Bacteriophage- and artilysin-based therapeutic approaches have been described as effective, but further research into their clinical use is required.

Antibiotic-Resistant Septicemia in Pediatric Oncology Patients Associated with Post-Therapeutic Neutropenic Fever.

Death in cancer patients can be caused by the progression of tumors, their malignity, or other associated conditions such as sepsis, which is a multiphasic host response to a pathogen that can be significantly amplified by endogenous factors. Its incidence is continuously rising, which reflects the increasing number of sick patients at a higher risk of infection, especially those that are elderly, pediatric, or immunosuppressed. Sepsis appears to be directly associated with oncological treatment and fatal septic shock. Patients with a cancer diagnosis face a much higher risk of infections after being immunosuppressed by chemotherapy, radiotherapy, or anti-inflammatory therapy, especially caused by non-pathogenic, Gram-negative, and multidrug-resistant pathogens. There is a notorious difference between the incidence and mortality rates related to sepsis in pediatric oncologic patients between developed and developing countries: they are much higher in developing countries, where investment for diagnosis and treatment resources, infrastructure, medical specialists, cancer-related control programs, and post-therapeutic care is insufficient. This situation not only limits but also reduces the life expectancy of treated pediatric oncologic patients, and demands higher costs from the healthcare systems. Therefore, efforts must aim to limit the progression of sepsis conditions, applying the most recommended therapeutic regimens as soon as the initial risk factors are clinically evident-or even before they are, as when taking advantage of machine learning prediction systems to analyze data.

[Pseudomonas aeruginosa: Pathogenicity and antimicrobial resistance in urinary tract infection]. / Pseudomonas aeruginosa: patogenicidad y resistencia antimicrobiana en la infección urinaria.

Among the most frequent nosocomial infections associated with polyresistant bacteria and with a worse prognosis, are those produced by Pseudomonas aeruginosa. This bacterium has a high capacity to adapt to adverse conditions such as pH and osmolarity of urine. Pseudomonas aeruginosa is one of the main pathogens involved in nosocomial infections and immunosuppressed patients. This bacterium is considered an opportunistic infectious agent that has diverse mechanisms of pathogenicity, as well as resistance to antimicrobials, which contributes to the difficulty in the treatment of these infections. In the present bibliographic review, the taxonomy, pathogenicity mechanisms and resistance genes of P. aeruginosa are analyzed. Likewise, the micro-environmental factors of the urinary infection produced by this bacterium are approached, making an approach to the understanding of the pathophysiological bases of this infection.

Pseudomonas aeruginosa: patogenicidad y resistencia antimicrobiana en la infección urinaria / Pseudomonas aeruginosa: pathogenicity and antimicrobial resistance in urinary tract infection

Resumen Dentro de las infecciones nosocomiales más frecuentes asociadas a bacterias multi-resistentes y de peor pronóstico, se encuentran las producidas por Pseudomonas aeruginosa. Esta bacteria posee una alta capacidad de adaptación a condiciones adversas como por ejemplo el pH y la osmolaridad de la orina. Pseudomonas aeruginosa es uno de los principales patógenos implicados en infecciones nosocomiales y de pacientes inmunosuprimidos. Esta bacteria se considera un agente infeccioso oportunista que posee diversos mecanismos de patogenicidad, así como de resistencia a antimicrobianos, lo que contribuye a la dificultad en el tratamiento de estas infecciones. En la presente revisión bibliográfica se analizan la taxonomía, los mecanismos de patogenicidad y genes de resistencia de P. aeruginosa. Así también, se abordan los factores microambientales de la infección urinaria producida por esta bacteria, haciendo un acercamiento al entendimiento de las bases fisiopatológicas de esta infección.

Among the most frequent nosocomial infections associated with polyresistant bacteria and with a worse prognosis, are those produced by Pseudomonas aeruginosa. This bacterium has a high capacity to adapt to adverse conditions such as pH and osmolarity of urine. Pseudomonas aeruginosa is one of the main pathogens involved in nosocomial infections and immunosuppressed patients. This bacterium is considered an opportunistic infectious agent that has diverse mechanisms of pathogenicity, as well as resistance to antimicrobials, which contributes to the difficulty in the treatment of these infections. In the present bibliographic review, the taxonomy, pathogenicity mechanisms and resistance genes of P. aeruginosa are analyzed. Likewise, the micro-environmental factors of the urinary infection produced by this bacterium are approached, making an approach to the understanding of the pathophysiological bases of this infection.

The Use of Probiotic Therapy to Modulate the Gut Microbiota and Dendritic Cell Responses in Inflammatory Bowel Diseases.

: Recent investigations have shown that different conditions such as diet, the overuse of antibiotics or the colonization of pathogenic microorganisms can alter the population status of the intestinal microbiota. This modification can produce a change from homeostasis to a condition known as imbalance or dysbiosis; however, the role-played by dysbiosis and the development of inflammatory bowel diseases (IBD) has been poorly understood. It was actually not until a few years ago that studies started to develop regarding the role that dendritic cells (DC) of intestinal mucosa play in the sensing of the gut microbiota population. The latest studies have focused on describing the DC modulation, specifically on tolerance response involving T regulatory cells or on the inflammatory response involving reactive oxygen species and tissue damage. Furthermore, the latest studies have also focused on the protective and restorative effect of the population of the gut microbiota given by probiotic therapy, targeting IBD and other intestinal pathologies. In the present work, the authors propose and summarize a recently studied complex axis of interaction between the population of the gut microbiota, the sensing of the DC and its modulation towards tolerance and inflammation, the development of IBD and the protective and restorative effect of probiotics on other intestinal pathologies.

Characterization of Gene Families Encoding Beta-Lactamases of Gram-Negative Rods Isolated from Ready-to-Eat Vegetables in Mexico City.

Beta-lactam resistant bacteria, which are commonly resident in tertiary hospitals, have emerged as a worldwide health problem because of ready-to-eat vegetable intake. We aimed to characterize the genes that provide resistance to beta-lactam antibiotics in Enterobacteriaceae, isolated from five commercial salad brands for human consumption in Mexico City. In total, twenty-five samples were collected, grown in blood agar plates, and the bacteria were biochemistry identified and antimicrobial susceptibility testing was done. The carried family genes were identified by endpoint PCR and the specific genes were confirmed with whole genome sequencing (WGS) by Next Generation Sequencing (NGS). Twelve positive cultures were identified and their microbiological distribution was as follows: 8.3% for Enterobacter aerogene (n = 1), 8.3% for Serratia fonticola (n = 1), 16.7% for Serratia marcesens (n = 2), 16.7% for Klebsiella pneumoniae (n = 2), and 50% (n = 6) for Enterobacter cloacae. The endpoint PCR results showed 11 colonies positive for blaBIL (91.7%), 11 for blaSHV (91.7%), 11 for blaCTX (97.7%), 12 for blaDHA (100%), four for blaVIM (33.3%), two for blaOXA (16.7%), two for blaIMP (16.7%), one for blaKPC (8.3%), and one for blaTEM (8.3%) gen; all samples were negative for blaROB, blaCMY, blaP, blaCFX and blaLAP gene. The sequencing analysis revealed a specific genotype for Enterobacter cloacae (blaSHV-12, blaCTX-M-15, blaDHA-1, blaKPC-2); Serratia marcescens (blaSHV-1, blaCTX-M-3, blaDHA-1, blaVIM-2); Klebsiella pneumoniae (blaSHV-12, blaCTX-M-15, blaDHA-1); Serratia fonticola (blaSHV-12, blaVIM-1, blaDHA-1); and, Enterobacter aerogene (blaSHV-1, blaCTX-M-1, blaDHA-1, blaVIM-2, blaOXA-9). Our results indicate that beta-lactam-resistant bacteria have acquired integrons with a different number of genes that provide pan-resistance to beta-lactam antibiotics, including penicillins, oxacillins, cefalosporins, monobactams, carbapenems, and imipenems.

Human Dendritic Cells: Ontogeny and Their Subsets in Health and Disease.

Dendritic cells (DCs) are a type of cells derived from bone marrow that represent 1% or less of the total hematopoietic cells of any lymphoid organ or of the total cell count of the blood or epithelia. Dendritic cells comprise a heterogeneous population of cells localized in different tissues where they act as sentinels continuously capturing antigens to present them to T cells. Dendritic cells are uniquely capable of attracting and activating naïve CD4⁺ and CD8⁺ T cells to initiate and modulate primary immune responses. They have the ability to coordinate tolerance or immunity depending on their activation status, which is why they are also considered as the orchestrating cells of the immune response. The purpose of this review is to provide a general overview of the current knowledge on ontogeny and subsets of human dendritic cells as well as their function and different biological roles.

Apoptosis: Activation and Inhibition in Health and Disease.

There are many types of cell death, each involving multiple and complex molecular events. Cell death can occur accidentally when exposed to extreme physical, chemical, or mechanical conditions, or it can also be regulated, which involves a genetically coded complex machinery to carry out the process. Apoptosis is an example of the latter. Apoptotic cell death can be triggered through different intracellular signalling pathways that lead to morphological changes and eventually cell death. This is a normal and biological process carried out during maturation, remodelling, growth, and development in tissues. To maintain tissue homeostasis, regulatory, and inhibitory mechanisms must control apoptosis. Paradoxically, these same pathways are utilized during infection by distinct intracellular microorganisms to evade recognition by the immune system and therefore survive, reproduce and develop. In cancer, neoplastic cells inhibit apoptosis, thus allowing their survival and increasing their capability to invade different tissues and organs. The purpose of this work is to review the generalities of the molecular mechanisms and signalling pathways involved in apoptosis induction and inhibition. Additionally, we compile the current evidence of apoptosis modulation during cancer and Leishmania infection as a model of apoptosis regulation by an intracellular microorganism.

Health risks from exposure to untreated wastewater used for irrigation in the Mezquital Valley, Mexico: A 25-year update.

Wastewater reuse for agriculture is common worldwide; wastewater treatment, however, is rare in many countries, leading to high potential for exposure to harmful pathogens. Mexico City, one of the largest producers of untreated wastewater for agricultural use worldwide, was the site of key epidemiologic studies conducted in the 1990s. We both reviewed the literature on and conducted a cross-sectional study of diarrheal risk and wastewater contamination to provide an updated assessment of health risks and to inform an upcoming update of the 2006 WHO guidelines on wastewater reuse. We surveyed communities in the Mezquital Valley that use wastewater for irrigation and communities that use well water to compare the prevalence of self-reported diarrheal disease in children under five years old. Wastewater, well water, household environmental samples, and stool samples were collected and analyzed. Communities exposed to wastewater had a higher one-week prevalence of diarrhea (10%) compared to unexposed communities (5%). This association remained in an adjusted modified Poisson regression model (PR = 2.31, 95% CI 1.00, 5.31), but not when limited to households engaged in agriculture. Water quality indicators document differences between irrigation water from the two community groups. These results are in agreement with 25 population studies identified by our review that were conducted since or not included in the 2006 WHO guidelines and show consistent negative impacts of wastewater exposure on health. While overall diarrheal prevalence has declined when compared to studies conducted over 25 years ago in the same region, the association of diarrheal disease and wastewater exposure has remained and possibly increased. With rising urbanization worldwide, attention to these risks and wastewater treatment is becoming increasingly important.

Revisión de la literatura: relación e importancia de los canales de potasio en esclerosis múltiple / Literature review: value and importance of potassium channels in multiple sclerosis / Revisão de literatura: valor ea importância dos canais de potássio em esclerose múltipla

[{"text": "La esclerosis múltiple (EM) es una enfermedad inflamatoria del sistema nervioso central (SNC), caracterizada por la \r\ndesmielinización, con una preservación relativa de los axones. En pacientes con EM se han atribuido muchos signos \r\ny síntomas neurológicos a la conducción subyacente de déficits neurológicos de terminaciones neuronales. La idea de \r\nque la función neurológica podría mejorar si la conducción pudiera ser restaurada en axones desmielinizados lleva a \r\npensar en una prueba de mejoría bajo bloqueo de canales de potasio (K(+)) que pueda ser usada como un tratamiento \r\nsintomático de la patología. Hasta la fecha solo se han identificado dos posibles terapéuticas de amplio espectro del \r\ncanal de K(+) de tipo bloqueadores: 4-aminopiridina (4-AP) y 3,4-diaminopiridina (3,4-DAP), probados con éxito \r\nen pacientes con EM. Aunque ambos producen claros beneficios a nivel neurológico, su uso ha sido limitado por la \r\ntoxicidad. En este artículo se revisa el estado actual de las investigaciones sobre el uso de los bloqueadores de canales \r\nde potasio y su importancia a futuro en la terapéutica de la esclerosis múltiple y la ciencia básica aplicada a la inves\r\n-\r\ntigación clínica relacionada con la orientación terapéutica de canales de voltaje- K(+) canales (K(v)). Con base en las \r\núltimas publicaciones y en la experiencia de manejo en rehabilitación, su objetivo es ofrecer una perspectiva sobre \r\nel conocimiento del manejo clínico de este subtipo de canal de K en patologías desmielinizantes, que ha demostrado \r\nuna mejoría notable en la velocidad de marcha de pacientes que padecen esclerosis múltiple por medio de la molécula \r\nbloqueadora de canales de potasio (K).", "_i": "es"}, {"text": "Multiple sclerosis (MS) is an inflammatory disease \r\nof the central nervous system (CNS) characterized by \r\ndemyelination, with relative preservation of axons. In \r\nMS patients, many neurological signs and symptoms \r\nhave been attributed to the underlying neuronal endings \r\nconduction deficits. The idea that neurological function \r\ncould be improved if conduction could be restored in \r\ndemyelinated axons leads to an improvement in test block \r\npotassium channels (K+) and be used as a symptomatic \r\ntreatment of the disease. To date, there are only two \r\npotential therapeutic spectrum K+ channel type blockers, \r\n4-aminopyridine (4-AP) and 3,4-diaminopyridine (3,4-\r\nDAP), that have been successfully tested in patients with \r\nMS. Although both 4-AP and 3,4-DAP level produce \r\nclear neurological benefits, their use has been limited as \r\na result of toxicity. This article reviews the current state \r\nof research on the use of potassium channel blockers and \r\ntheir importance to the future of multiple sclerosis thera\r\n-\r\npeutics and the basic science and clinical research related \r\nto therapeutic targeting of voltage K+ in MS. By bringing \r\ntogether the most recent articles and publications based \r\non experiences in rehabilitation management of this \r\ndisease, the aim of this article is to provide a perspective \r\non knowledge about K+ channels in clinical treatments \r\nfor patients with multiple sclerosis and other demyelina\r\n-\r\nting diseases, which has shown that blocking K+ channels \r\nresulted in a significant improvement in walking speed of \r\npatients suffering from multiple sclerosis.", "_i": "en"}, {"text": "A esclerose múltipla (EM) é uma doença inflamatória do \r\nsistema nervoso central (SNC) caracterizada pela desmie\r\n-\r\nlinização, com uma preservação relativa dos axônios. \r\nMuitos síntomas neurológicos presentes em pacientes \r\ncom EM são atribuídos à condução subjacente de déficits \r\nneurológicos das terminações nervosas. A idéia de que a \r\nfunção neurológica poderia ser melhorada se a condução \r\nem axônios desmielinizados fosse restaurada indica uma \r\nmelhoria através de um bloqueio de canais de potássio \r\n(K(+)) para ser usado como um tratamento sintomático da \r\npatología. Até esta data foram identificados dois possíveis \r\nbloqueadores: 4-aminopiridina (4-AP) e 3,4-diaminopi\r\n-\r\nridina (3,4-DAP), testados com êxito em pacientes com \r\nEM. Apesar de ambos 4-AP e DAP produzirem claros \r\nbenefícios ao nível neurológico, seu uso foi limitado pela \r\nsua toxicidade. Neste artigo, é revisado o estado atual \r\ndas investigações sobre o uso de bloqueadores de canais \r\nde potássio e sua importância no futuro terapêutico \r\nda esclerose múltipla e na ciência voltada à canais de \r\nvoltagem K(+)( canais (K(v)). Com base nas últimas publi\r\n-\r\ncações de artigos e na gestão terapêutica, o objetivo deste \r\nartigo é oferecer uma perspectiva sobre o conhecimento \r\nda gestão clínica deste subtipo de canal K em patológicas \r\ndesmielinizantes, o qual tem demonstrado um progresso \r\nnotável na velocidade de melhoria dos pacientes que \r\npossuem esclerose múltipla ­ uma das principais patolo\r\n-\r\ngías do tipo desmielinizaste.", "_i": "pt"}]

Study on the microflora and biochemistry of cocoa fermentation in the Dominican Republic.

Cocoa fermentation was monitored at the IDIAF (Instituto Dominicano de Investigaciones Agropecuarias y Forestales) "Mata Larga" experimental station, in San Francisco de Macoris, Dominican Republic. The maximum average fermentation temperature reached 51 degrees C after 48 h and the pH reached 4.5 after 144 h of fermentation. A significant decrease in glucose, fructose and citric acid was seen in the pulp over the first 48 h. There was a delay of 24 h between maximum microbial growth and maximum concentrations of the respective metabolites, which occurred after 48 h for ethanol and after 72 h for acetic acid. A maximum concentration in lactic acid was found after around 120 h of fermentation. The aerobic mesophilic flora increased from 6.1x10(6) to a maximum of 4.2x10(7) CFU g(-1) of dry matter after 48 h of fermentation. Yeasts displayed maximum development after 24 h (6.1x10(7) CFU g(-1) of dry matter), whilst for lactic and acetic acid bacteria it occurred after 48 h (7.3x10(7) and 1.5x10(8) CFU g(-1) of dry matter respectively). The yeasts isolated belonged to the genera Hanseniaspora and Candida, the lactic acid bacteria to the genus Lactobacillus, and the acetic acid bacteria to the genus Acetobacter. The differences compared to other fermentation trials concerned the micropopulation from a qualitative point of view.

Estudio de la respuesta inmune humoral en cerdos infectados con huevos y posoncósferas de taenia solium / Study on immune humoral response in pigs infected with eggs and posoncospheres of taenia solium

Due to the importance of cysticercosis in Mexico and Latin America and to the fact that in the last years another mechanism of infection for this disease has been proposed, i.e. through postoncospheres and immunosuppression of the host, we have considered relevant to perform the present work, which consisted in assessing the immune response induced by dexamethasone as well as that produced by parasites in pigs infected with T. solium eggs, or postoncosphere-infected, and in postoncosphere-infected and dexamethasone treated animals. We used 10 recently weaned pigs, three were used as controls, two of them without the drug and one with it; two were infected with T. solium eggs; five with postoncospheres receiving also dexamethasone three of them. We evaluated the humoral response against parasite antigen using indirect haemagglutination (IH) and ELISA methods. Results of the immune humoral response revealed titres of up to 1:128 in T. solium eggs infected animals, of 1:16 in postoncosphere infected animals. Absorbance titres with of 1:32 towards the end of the experiment in postoncosphere plus dexamethasone animals. Absorbance titres with Elisa confirmed these findings. Data obtained by IH show that the antibody titres of the pigs challenged with postoncospheres and postoncospheres plus dexamethasone are positive as compared to the titres obtained in the pigs infected with T. solium eggs. Results from the Elisa confirmed this finding, since, from weeks 14 to 17, the pigs became positive, behaving as those pigs that developed cysticercosis. This is revelant as it indicates that the antiposcosphere antibodies recognized antigens of T. solium larvae