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Rotavirus is the main cause of acute diarrhea in children up to five years of age. In this regard, probiotics are commonly used to treat or prevent gastroenteritis including viral infections. The anti-rotavirus effect of Bifidobacterium longum and Chlorella sorokiniana, by reducing viral infectivity and improving IFN-type I response, has been previously reported. The present study aimed to study the effect of B. longum and/or C. sorokiniana on modulating the antiviral cellular immune response mediated by IFN-γ, IL-10, SOCS3, STAT1, and STAT2 genes in rotavirus-infected cells. To determine the mRNA relative expression of these genes, HT-29 cells were treated with B. longum and C. sorokiniana alone or in combination, followed by rotavirus infection. In addition, infected cells were treated with B. longum and/or C. sorokiniana. Cellular RNA was purified, used for cDNA synthesis, and amplified by qPCR. Our results demonstrated that the combination of B. longum and C. sorokiniana stimulates the antiviral cellular immune response by upregulating IFN-γ and may block pro-inflammatory cytokines by upregulating IL-10 and SOCS3. The results of our study indicated that B. longum, C. sorokiniana, or their combination improve antiviral cellular immune response and might modulate pro-inflammatory responses.

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Probiotics are effective to treat or prevent gastrointestinal infections, and microalgae have demonstrated important health-promoting effects and in some cases function as prebiotics. In this regard, the anti-rotavirus effect of Bifidobacterium longum and Chlorella sorokiniana by reducing viral infectivity is well known. However, their effect on immune response against rotavirus has not yet been investigated. Therefore, the aim of this study was to determine the role of Bifidobacterium longum and/or Chlorella sorokiniana in influencing an IFN type I-mediated antiviral response in rotavirus-infected cells. In pre-infection experiments, HT-29 cells were treated with B. longum and C. sorokiniana alone or in combination, followed by rotavirus infection, whereas in post-infection assays, HT-29 cells were treated after infection. The cells' mRNA was then purified to determine the relative expression level of IFN-α, IFN-ß, and precursors of interferons such as RIG-I, IRF-3, and IRF-5 by qPCR. We showed that combination of B. longum and C. sorokiniana significantly increased IFN-α levels in pre-infection and IFN-ß in post-infection assays, as compared with individual effects. Results indicate that B. longum, C. sorokiniana, or their combination improve cellular antiviral immune response.

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Plant-associated microorganisms represent a potential source of new antitumor compounds. The aim of the present study was to isolate endophytic and rhizosphere Gram-positive bacteria from Ibervillea sonorae and produce extracts with antitumor activity. Methanol and ethyl acetate extracts were obtained from 28 d bacterial fermentation, after which murine L5178Y-R lymphoma cells growth inhibition was evaluated at concentrations ranging from 15.62 µg/mL to 500 µg/mL by the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide reduction colorimetric assay. IC50 and the selectivity index (SI) were calculated and compared with healthy control human peripheral blood mononuclear cells (PBMC). Identification of the isolated strains was performed using the 16S ribosomal gene and by MALDI-TOF MS mass spectrometry. The endophytic and rhizosphere bacterial extracts from strains ISE-B22, ISE-B26, ISE-B27, ISS-A01, ISS-A06, and ISS-A16 showed significant (p < 0.05) L5178Y-R cell growth inhibition, compared with an untreated control. The rhizosphere Micromonospora echinospora isolate ISS-A16 showed the highest (90.48%) percentage of lymphoma cells growth inhibition and SI (19.1) for PBMC, whereas the Bacillus subtilis ISE-B26 isolate caused significant (p < 0.01) growth inhibition (84.32%) and a SI of 5.2. Taken together, results of the present study evidenced antitumor effects by I. sonorae endophytic and rhizosphere bacteria culture extracts. Further research will involve the elucidation of the compounds that exert the antitumor activity and their evaluation in pre-clinical studies.

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Endophytic fungi have become potential sources of antitumor agents, particularly against antineoplastic-resistant cancer cells, with marginal or nil adverse effects for the oncological patient. Endophytic fungi were isolated from stems of the Lophocereus marginatus cactus, commonly found in Mexico. Methanol extracts were then obtained from fungus liquid cultures and their effects on tumor cell growth against murine lymphoma (L5178Y-R), human colorectal adenocarcinoma (HT-29), and human breast cancer (MCF-7) cells were evaluated at concentrations ranging from 31 µg/mL to 250 µg/mL via the colorimetric 3- [4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide reduction assay, using monkey kidney epithelial (MA-104) and human peripheral mononuclear (PBMC) cells as controls. Furthermore, we obtained the IC50 and the selectivity index (SI) was calculated from the IC50 ratio of normal and tumor cells. In addition, molecular identification of fungi showing cytotoxic activity was determined, using internal transcribed spacer molecular markers. PME-H001, PME-H002, PME-H005, PME-H007, and PME-H008 filamentous fungus strain extracts showed significant (p < 0.05) tumor cell growth inhibition. In particular, they significantly (p < 0.05) inhibited L5178Y-R cell growth, whereas the least susceptible cell line was HT-29. The endophytic strain PME-H008 of Cladosporium sp. caused the highest growth inhibition percentage against L5178Y-R and HT-29 cells with 96.6% (p < 0.01) and 42.5% (p < 0.05) respectively, and the highest SIs against L5178Y-R cells with 2.4 and 2.9 for MA-104 and PBMCs, respectively, whereas the PME-H005 extract showed SIs of 2.77 and 1.5 against MCF-7 and L5178Y-R cells, respectively, as compared with PBMCs. In addition, the endophytic strain PME-H007 of Metarhizium anisopliae caused the highest percentage of growth inhibition (p < 0.01) against MCF-7 cells with 55.8% at 250 µg/mL. We demonstrated in vitro antitumor effects of L. marginatus endophytic fungi. Further research will involve the isolation and in vivo testing of bioactive compounds.

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BACKGROUND AND OBJECTIVES: Enteric viral infections are among the leading causes of gastroenteritis in children up to five years of age worldwide. This study was aimed to determine the disease severity, incidence, and molecular genotyping of rotaviruses, noroviruses, astroviruses, and enteric adenoviruses as gastroenteritis agents among children up to five years old. MATERIALS AND METHODS: Gastroenteritis severity was determined by using the Ruuska and Vesikari score, whereas the incidence of enteric infections and their genotyping were determined by reverse transcription-polymerase chain reaction (RT-PCR) and sequence analysis. RESULTS: Rotaviruses were observed to possess the highest incidence with 10% (18/179) of the cases positives; nevertheless, noroviruses had the highest severe gastroenteritis score (13 ±â€¯3 points). Results indicated that 56% (10/18) of the detected rotavirus strains were genotype G12P[8], 50% (4/8) of noroviruses were GII.4 and 25% (2/8) were genotype GI.8. Out of the sapovirus positive samples, 30% (2/6) were genotyped as GI·I and GII·I. Sixty percent of the astrovirus strains (3/5) were genotype HAstV-2, and 20% (1/5) were genotype HAstV-6. Additionally, one of the adenovirus strains was identified as human mastadenovirus C type 6 specie. CONCLUSIONS: The diarrhea severity reduction in children provides evidence that the rotavirus vaccination program in the northwest of Mexico has been successful, even among children infected by the rotavirus emergent strain G12, however, norovirus resulted as the leading severe gastroenteritis-causing agent in children with rotavirus vaccine.

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