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Neonatal sepsis leads to severe morbidity and occasionally death among neonates within the first week following birth, particularly in low- and middle-income countries. Empirical therapy includes antibiotics recommended by WHO. However, these have been ineffective against antimicrobial multidrug-resistant bacterial strains such as Klebsiella spp, Escherichia coli, and Staphylococcus aureus species. To counter this problem, new molecules and alternative sources of compounds with antibacterial activity are sought as options. Actinobacteria, particularly pathogenic strains, have revealed a biotechnological potential still underexplored. This study aimed to determine the presence of biosynthetic gene clusters and the antimicrobial activity of actinobacterial strains isolated from clinical cases against multidrug-resistant bacteria implicated in neonatal sepsis. In total, 15 strains isolated from clinical cases of actinomycetoma were used. PCR screening for the PKS-I, PKS-II, NRPS-I, and NRPS-II biosynthetic systems determined their secondary metabolite-producing potential. The strains were subsequently assayed for antimicrobial activity by the perpendicular cross streak method against Escherichia fergusonii Sec 23, Klebsiella pneumoniae subsp. pneumoniae H1064, Klebsiella variicola H776, Klebsiella oxytoca H793, and Klebsiella pneumoniae subsp. ozaenae H7595, previously classified as multidrug-resistant. Finally, the strains were identified by 16S rRNA gene sequence analysis. It was found that 100% of the actinobacteria had biosynthetic systems. The most frequent biosynthetic system was NRPS-I (100%), and the most frequent combination was NRPS-I and PKS-II (27%). All 15 strains showed antimicrobial activity. The strain with the highest antimicrobial activity was Streptomyces albus 94.1572, as it inhibited the growth of the five multidrug-resistant bacteria evaluated.

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BACKGROUND: In Mexico and around the world, water in dental units, including triple syringes, comes from municipal chlorinated water mains. The microbial contamination of dental unit water systems constitutes a risk factor for opportunistic infections. OBJECTIVES: The present work aimed to identify the bacteria present in the triple-syringe water lines of dental units at a dental school of a public university in Mexico, with a hypothesis that opportunistic bacteria of importance to human health would be found. MATERIAL AND METHODS: A cross-sectional study was carried-out. A total of 100 samples of triple-syringe tubing from dental units operated by a dental school of a public university in Mexico were analyzed before and after their use in dental practice. Bacterial biofilm was cultured and isolated from the tubing, using standard microbiological methods, and then the species present were identified through 16S rRNA gene sequencing. The characterization of the biofilm was performed by means of scanning electron microscopy (SEM). RESULTS: Bacterial growth was observed in 20% of the non-disinfected and 10% of the disinfected samples, with 11 strains isolated. Six genera and 11 bacterial species were genetically identified. Coagulasenegative staphylococci (CoNS), considered opportunistic human pathogens, were among the most critical microorganisms. Scanning electron microscopy revealed a thick polymeric matrix with multiple bacterial aggregates. CONCLUSIONS: Opportunistic bacteria from human skin and mucous membranes were detected. Under normal conditions, these bacteria are incapable of causing disease, but are potentially harmful to immunosuppressed patients.

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ABSTRACT Neonatal sepsis leads to severe morbidity and occasionally death among neonates within the first week following birth, particularly in low- and middle-income countries. Empirical therapy includes antibiotics recommended by WHO. However, these have been ineffective against antimicrobial multidrug-resistant bacterial strains such as Klebsiella spp, Escherichia coli, and Staphylococcus aureus species. To counter this problem, new molecules and alternative sources of compounds with antibacterial activity are sought as options. Actinobacteria, particularly pathogenic strains, have revealed a biotechnological potential still underexplored. This study aimed to determine the presence of biosynthetic gene clusters and the antimicrobial activity of actinobacterial strains isolated from clinical cases against multidrug-resistant bacteria implicated in neonatal sepsis. In total, 15 strains isolated from clinical cases of actinomycetoma were used. PCR screening for the PKS-I, PKS-II, NRPS-I, and NRPS-II biosynthetic systems determined their secondary metabolite-producing potential. The strains were subsequently assayed for antimicrobial activity by the perpendicular cross streak method against Escherichia fergusonii Sec 23, Klebsiella pneumoniae subsp. pneumoniae H1064, Klebsiella variicola H776, Klebsiella oxytoca H793, and Klebsiella pneumoniae subsp. ozaenae H7595, previously classified as multidrug-resistant. Finally, the strains were identified by 16S rRNA gene sequence analysis. It was found that 100% of the actinobacteria had biosynthetic systems. The most frequent biosynthetic system was NRPS-I (100%), and the most frequent combination was NRPS-I and PKS-II (27%). All 15 strains showed antimicrobial activity. The strain with the highest antimicrobial activity was Streptomyces albus 94.1572, as it inhibited the growth of the five multidrug-resistant bacteria evaluated.

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Mycetoma is a neglected tropical disease (NTD) declared by the World Health Organization (WHO) in 2016. It is characterized by the progressive growth of nodules and granulomatous lesions on the legs, arms, and trunk. It is potentially disfiguring and causes disability or amputations in working-age people from marginalized areas. The causative agents can be fungi (eumycetoma) or actinobacteria (actinomycetoma), the latter being the most common in America and Asia. Nocardia brasiliensis is the most important causal agent of actinomycetoma in the Americas. Taxonomic problems have been reported when identifying this species, so this study aimed to detect the 16S rRNA gene variations in N. brasiliensis strains using an in silico enzymatic restriction technique. The study included strains from clinical cases of actinomycetoma in Mexico, isolated from humans and previously identified as N. brasiliensis by traditional methods. The strains were characterized microscopically and macroscopically, then subjected to DNA extraction and amplification of the 16S rRNA gene by PCR. The amplification products were sequenced, and consensus sequences were constructed and used for genetic identification and in silico restriction enzyme analysis with the New England BioLabs® NEBcutter program. All study strains were molecularly identified as N. brasiliensis; however, in silico restriction analysis detected a diversity in the restriction patterns that were finally grouped and subclassified into 7 ribotypes. This finding confirms the existence of subgroups within N. brasiliensis. The results support the need to consider N. brasiliensis as a complex species.

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Rheumatoid Arthritis (RA) is an autoimmune disease characterized by loss of immune tolerance and chronic inflammation. It is pathogenesis complex and includes interaction between genetic and environmental factors. Current evidence supports the hypothesis that gut dysbiosis may play the role of environmental triggers of arthritis in animals and humans. Progress in the understanding of the gut microbiome and RA. has been remarkable in the last decade. In vitro and in vivo experiments revealed that gut dysbiosis could shape the immune system and cause persistent immune inflammatory responses. Furthermore, gut dysbiosis could induce alterations in intestinal permeability, which have been found to predate arthritis onset. In contrast, metabolites derived from the intestinal microbiota have an immunomodulatory and anti-inflammatory effect. However, the precise underlying mechanisms by which gut dysbiosis induces the development of arthritis remain elusive. This review aimed to highlight the mechanisms by which gut dysbiosis could contribute to the pathogenesis of RA. The overall data showed that gut dysbiosis could contribute to RA pathogenesis by multiple pathways, including alterations in gut barrier function, molecular mimicry, gut dysbiosis influences the activation and the differentiation of innate and acquired immune cells, cross-talk between gut microbiota-derived metabolites and immune cells, and alterations in the microenvironment. The relative weight of each of these mechanisms in RA pathogenesis remains uncertain. Recent studies showed a substantial role for gut microbiota-derived metabolites pathway, especially butyrate, in the RA pathogenesis.

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ABSTRACT Mycetoma is a neglected tropical disease (NTD) declared by the World Health Organization (WHO) in 2016. It is characterized by the progressive growth of nodules and granulomatous lesions on the legs, arms, and trunk. It is potentially disfiguring and causes disability or amputations in working-age people from marginalized areas. The causative agents can be fungi (eumycetoma) or actinobacteria (actinomycetoma), the latter being the most common in America and Asia. Nocardia brasiliensis is the most important causal agent of actinomycetoma in the Americas. Taxonomic problems have been reported when identifying this species, so this study aimed to detect the 16S rRNA gene variations in N. brasiliensis strains using an in silico enzymatic restriction technique. The study included strains from clinical cases of actinomycetoma in Mexico, isolated from humans and previously identified as N. brasiliensis by traditional methods. The strains were characterized microscopically and macroscopically, then subjected to DNA extraction and amplification of the 16S rRNA gene by PCR. The amplification products were sequenced, and consensus sequences were constructed and used for genetic identification and in silico restriction enzyme analysis with the New England BioLabs® NEBcutter program. All study strains were molecularly identified as N. brasiliensis; however, in silico restriction analysis detected a diversity in the restriction patterns that were finally grouped and subclassified into 7 ribotypes. This finding confirms the existence of subgroups within N. brasiliensis. The results support the need to consider N. brasiliensis as a complex species.

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Cervical cancer (CC) is considered a public health problem. Recent studies have evaluated the possible relationship between the cervicovaginal microbiome and gynecologic cancer but have not studied the relationship between aerobic bacterial communities and neoplasia. The study aimed to identify the cultivable aerobic bacterial microbiota in women with cervical cancer as a preliminary approach to the metagenomic study of the cervicovaginal microbiome associated with cervical cancer in Mexican women. An observational cross-sectional study was conducted, including 120 women aged 21-71 years, divided into two study groups, women with locally advanced CC (n=60) and women without CC (n=60). Sociodemographic, gynecological-obstetric, sexual, and habit data were collected. Cervicovaginal samples were collected by swabbing, from which standard microbiological methods obtained culturable bacteria. The strains were genetically characterized by PCR-RFLP of the 16S rRNA gene and subsequently identified by sequencing the same gene. Variables regularly reported as risk factors for the disease were found in women with CC. Differences were found in the prevalence and number of species isolated in each study group. Bacteria commonly reported in women with aerobic vaginitis were identified. There were 12 species in women with CC, mainly Corynebacterium spp. and Staphylococcus spp.; we found 13 bacterial species in the group without cancer, mainly Enterococcus spp. and Escherichia spp. The advanced stages presented a more significant number of isolates and species. This study provided a preliminary test for cervicovaginal metagenomic analysis, demonstrating the presence of aerobic cervicovaginal dysbiosis in women with CC and the need for more in-depth studies.

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The aim of this work was to evaluate the effect of the concentration of gelatin (G) (3-6 g), whey protein (W) (2.5-7.5 g) and chitosan (C) (0.5-2.5 g) on the physical, optical and mechanical properties of composite edible films (CEFs) using the response surface methodology (RSM), as well as optimizing the formulation for the packaging of foods. The results of the study were evaluated via first- and second-order multiple regression analysis to obtain the determination coefficient values with a good fit (R ˃ 0.90) for each of the response variables, except for the values of solubility and b*. The individual linear effect of the independent variables (the concentrations of gelatin, whey protein and chitosan) significantly affected (p ≤ 0.05) the water vapor permeability (WVP), strength and solubility of the edible films. The WVP of the edible films varied from 0.90 to 1.62 × 10-11 g.m/Pa.s.m2, the resistance to traction varied from 0.47 MPa to 3.03 MPa and the solubility varied from 51.06% to 87%. The optimized values indicated that the CEF prepared with a quantity of 4 g, 5 g and 3 g of gelatin, whey protein and chitosan, respectively, provided the CEF with a smooth, continuous and transparent surface, with L values that resulted in a light-yellow hue, a lower WVP, a maximum strength (resistance to traction) and a lower solubility. The results revealed that the optimized formulation of the CEF of G-W-C allowed a good validation of the prediction model and could be applied, in an effective manner, to the food packaging industry, which could help in mitigating the environmental issues associated with synthetic packaging materials.

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INTRODUCTION: The effects of fatty acids on health vary and depend on the type, amount, and route of consumption. EPA and DHA have a defined role in health, unlike coconut oil. OBJECTIVE: The aim was to investigate the changes in metabolic regulation and the composition of the culture-dependent microbiota after supplementation with different fatty acids in db/db mice. Material and Methods. We were using 32 8-week-old db/db mice, supplemented for eight weeks with EPA/DHA derived from microalgae as well as coconut oil. The lipid, hormonal profiles, and composition of the culture-dependent microbiota and the phylogenetic analysis based on the 16S rRNA gene sequencing were determined for identification of the intestinal microbiota. RESULTS: Enriched diet with EPA/DHA reduced TNF-α, C-peptide, insulin resistance, resistin, and the plasma atherogenic index, but increased TC, LDL-c, VLDL-c, and TG without changes in HDL-c. Coconut oil raised the HDL-c, GIP, and TNF-α, with TG, insulin resistance, adiponectin, and C-peptide reduced. CONCLUSION: The most abundant microbial populations were Firmicutes and the least Proteobacteria. EPA/DHA derived from microalgae contributes to improving the systemic inflammatory status, but depressed the diversity of the small intestine microbiota. Coconut oil only decreased the C-peptide, raising TNF-α, with an unfavorable hormonal and lipid profile.

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Recently, it was demonstrated that doxorubicin (Dox.HCl), a chemotherapeutic agent, could be photoactivated by Cerenkov radiation (CR). The objective of the present work was to develop a multimodal chemotherapy-radiotherapy-photodynamic therapeutic system based on reconstituted high-density lipoprotein (rHDL) loaded with Dox.HCl and 177Lu-DOTA. 177Lu acts as a therapeutic radionuclide and CR source. The system can be visualized by nuclear imaging. Fluorescence microscopy showed that rHDL-Dox specifically recognized cancer cells (T47D) that are positive for SR-B1 receptors. Encapsulated Dox.HCl was released into the cells and produced reactive oxygen species when irradiated with a 450-nm laser (photodynamic effect). The same effect occurred when Dox.HCl was irradiated by 177Lu CR. Through in vitro experiments, it was confirmed that the addition of 177Lu-DOTA to the rHDL-Dox nanosystem did not affect the specific recognition of SR-B1 receptors expressed in cells, or the cellular internalization of 177Lu-DOTA. The toxicity induced by the rHDL-Dox/177Lu nanosystem in cell lines with high (T47D and PC3), poor (H9C2) and almost-zero (human fibroblasts (FB)) expression of SR-B1 was evaluated in vitro and confirmed the synergy of the combined chemotherapy-radiotherapy-photodynamic therapeutic effect; this induced toxicity was proportional to the expression of the SR-B1 receptor on the surface of the cells used. The HDL-Dox/177Lu nanosystem experienced uptake by tumor cells and the liver-both tissues with high expression of SR-B1 receptors-but not by the heart. 177Lu CR offered the possibility of imparting photodynamic therapy where laser light could not reach.

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