RESUMO

E. coli is considered one of the most important zoonotic pathogens worldwide. Highly virulent and antimicrobial-resistant strains of E. coli have been reported in recent years, making it essential to understand their ecological origins. In this study, we analyzed the characteristics of E. coli strains present in the natural population of American bison (Bison bison) in Mexico. We sampled 123 individuals and determined the presence of E. coli using standard bacteriological methods. The isolated strains were characterized using molecular techniques based on PCR. To evaluate the diversity of E. coli strains in this population, we analyzed 108 suggestive colonies from each fecal sample. From a total of 13,284 suggestive colonies, we isolated 33 E. coli strains that contained at least one virulence gene. The virotypes of these strains were highly varied, including strains with atypical patterns or combinations compared to classical pathotypes, such as the presence of escV, eae, bfpB, and ial genes in E. coli strain LMA-26-6-6, or stx2, eae, and ial genes in E. coli strain LMA-16-1-32. Genotype analysis of these strains revealed a previously undescribed phylogenetic group. Serotyping of all strains showed that serogroups O26 and O22 were the most abundant. Interestingly, strains belonging to these groups exhibited different patterns of virulence genes. Finally, the isolated E. coli strains demonstrated broad resistance to antimicrobials, including various beta-lactam antibiotics.

RESUMO

Overuse of antimicrobials has greatly contributed to the increase in the emergence of multidrug-resistant bacteria, a situation that hinders the control and treatment of infectious diseases. This is the case with urinary tract infections (UTIs), which represent a substantial percentage of worldwide public health problems, thus the need to look for alternatives for their control and treatment. Previous studies have shown the usefulness of autologous bacterial lysates as an alternative for the treatment and control of UTIs. However, a limitation is the high cost of producing individual immunogens. At the same time, an important aspect of vaccines is their immunogenic amplitude, which is the reason why they must be constituted of diverse antigenic components. In the case of UTIs, the etiology of the disease is associated with different bacteria, and even Escherichia coli, the main causal agent of the disease, is made up of several antigenic variants. In this work, we present results on the study of a bacterial lysate composed of 10 serotypes of Escherichia coli and by Klebsiella pneumoniae, Klebsiella aerogenes, Enterococcus faecalis, Proteus mirabilis, Citrobacter freundii, and Staphylococcus haemolyticus. The safety of the compound was tested on cells in culture and in an animal model, and its immunogenic capacity by analysing in vitro human and murine macrophages (cell line J774 A1). The results show that the polyvalent lysate did not cause damage to the cells in culture or alterations in the animal model used. The immunostimulatory activity assay showed that it activates the secretion of TNF-α and IL-6 in human macrophages and TNF-α in murine cells. The obtained results suggest that the polyvalent lysate evaluated can be an alternative for the treatment and control of chronic urinary tract infections, which will reduce the use of antimicrobials.

Assuntos

RESUMO

Enterobacteriaceae are considered one the most important zoonotic pathogens. In this study, we analyzed the characteristics of E. coli and Salmonella spp. strains present in carnivores from Janos Biosphere Reserve, Mexico. These microorganisms had been isolated from a wide range of domestic and free-range animals, including wild carnivores. Fifty-five individuals were sampled, and the presence of Salmonella and E. coli was determined by bacteriological standard methods. Strains isolated were characterized by molecular methods and in vitro infection assays. Eight different species of carnivores were captured, including coyotes (Canis latrans), gray fox (Urocyon cinereoargenteus), desert foxes (Vulpes macrotis), striped skunks (Mephitis mephitis), hooded skunks (Mephitis macroura), lynxes (Lynx rufus), raccoons (Procyon lotor), and badgers (Taxidea taxus). Salmonella spp. and E. coli were isolated from four species of carnivores. Five Salmonella spp. strains were isolated, and their molecular characterization revealed in three of them the presence of fimbrial and virulence genes associated with cell invasion. In vitro evaluation of these strains showed their capability to invade human Hep2 cells. Sixty-one E. coli strains were isolated; different serotypes and phylogroups were observed from these strains. Additionally, the presence of virulence genes showed differently.

RESUMO

This study was conducted to evaluate the productive performance, intestinal health, and description of the cecum microbiota in broilers supplemented with ß-mannanases (MNs) and bacteriophages (BPs). Six hundred one-day-old broilers were divided into four groups and fed one of the following diets: CON-corn-soybean meal + 10 ppm enramycin (ENR); MN: CON + 500 ppm MN; BP: CON + 500 ppm BP; MN + BP: BP + 500 ppm MN. The BP and MN factors showed similar performances to ENR. MN improved the concentration of IgA in the jejunum at 35 days of age. The morphometric index (IM) of the thymus increased by adding MN, while BP increased the liver and thymus IM. The histological analysis showed that BP and MN improved the intestinal morphology. MN + BP showed a tendency to decrease the abundance of Proteobacteria and increase the abundance of Bacteroidetes, indicating better microbiota function. In conclusion, our results demonstrate that the combination of MN + BP has potential in poultry nutrition; however, we highly recommend further experiments to confirm this hypothesis.

RESUMO

A polyherbal feed mixture containing (Achyrantes aspera, Trachyspermum ammi, Citrullus colocynthis, Andrographis paniculata, and Azadirachta indica) was evaluated in growing calves through blood chemistry, blood biometry, and gene expression during the pre-ruminant to weaning period. Forty Holstein calves (initial BW 45.6 ± 3.2 kg; 22.8 ± 0.9 days post birth) from a dairy farm were randomly assigned to the following treatments: 0, 3, 4, and 5 g/d of a polyherbal mixture, dosed in colloid gels with gelatin. Calves were housed in individual outdoor boxes with ad libitum access to a 21.5% CP calf starter and water and fed individually with a mixture of milk and a non-medicated milk replacer (22% CP). Blood samples were collected on day 59 for blood chemistry, blood biometry, and gene expression analysis in leukocyte through microarray assays. Immunoglobulins were quantified by enzyme-linked immunosorbent assay. The animals treated with the polyherbal mixture showed a quadratic effect on final body weight, daily weight gain, final hip height, and final thoracic girth. The best performance results were obtained with a treatment dose of 4 g/d. The serum IgG increased linearly with the treatment doses. Gene set enrichment analysis of upregulated genes revealed that the three biological processes with higher fold change were tight junction, mucin type O-Glycan biosynthesis, and intestinal immune network for IgA production. Also, these upregulated genes influenced arachidonic acid metabolism, and pantothenate and CoA biosynthesis. Gene ontology enrichment analysis indicated that the pathways enriched were PELP1 estrogen receptor interacting protein pathways, nuclear receptors in lipid metabolism and toxicity, tight junction, ECM-receptor interaction, thyroid hormone signaling pathways, vascular smooth muscle contraction, ribosome function, glutamatergic synapse pathway, focal adhesion, Hippo, calcium, and MAPK signaling pathways.

RESUMO

Tilmicosin is an antimicrobial agent used to treat intramammary infections against Staphylococcus aureus and has clinical anti-inflammatory effects. However, the mechanism by which it modulates the inflammatory process in the mammary gland is unknown. We evaluated the effect of tilmicosin treatment on the modulation of the mammary innate immune response after S. aureus infection and its effect on casein production in mammary epithelial cells. To achieve this goal, we used immortalized mammary epithelial cells (MAC-T), pretreated for 12 h or treated with tilmicosin after infection with S. aureus (ATCC 27543). Our data showed that tilmicosin decreases intracellular infection (P < 0.01) and had a protective effect on MAC-T reducing apoptosis after infection by 80% (P < 0.01). Furthermore, tilmicosin reduced reactive oxygen species (ROS) (P < 0.01), IL-1ß (P < 0.01), IL-6 (P < 0.01), and TNF-α (P < 0.05) production. In an attempt to investigate the signaling pathways involved in the immunomodulatory effect of tilmicosin, mitogen-activated protein kinase (MAPK) phosphorylation was measured by fluorescent-activated cell sorting. Pretreatment with tilmicosin increased ERK1/2 (P < 0.05) but decreased P38 phosphorylation (P < 0.01). In addition, the anti-inflammatory effect of tilmicosin helped to preserve casein synthesis in mammary epithelial cells (P < 0.01). This result indicates that tilmicosin could be an effective modulator inflammation in the mammary gland. Through regulation of MAPK phosphorylation, ROS production and pro-inflammatory cytokine secretion tilmicosin can provide protection from cellular damage due to S. aureus infection and help to maintain normal physiological functions of the bovine mammary epithelial cell.

Assuntos

RESUMO

Antecedentes: La caries tiene etiología multifactorial, se presenta por desbalance entre factores patológicos y protectores, es un problema de salud pública que en México afecta a 95% de los niños. Objetivo: Determinar la prevalencia de caries, establecer el nivel de riesgo y evaluar su relación con la incidencia de caries a los tres y seis meses. Material y métodos: Estudio observacional, descriptivo y longitudinal en clínica estomatológica de una universidad ubicada al sur de la Ciudad de México. Previo consentimiento informado, se realizó revisión bucal por dos cirujanos dentistas calibrados para el diagnóstico de caries/ICDAS (kappa 95.37%), llevada a cabo en sillón dental con luz artificial bajo principios para el control de infecciones. Se estableció nivel de riesgo mediante el Sistema Internacional para la Gestión de Caries/ICCMS empleando como indicadores: consumo de alimentos cariogénicos (Lipari/Andrade), pH (tiras Hidryon), prueba de saliva estimulada, experiencia de caries (CPOD/ceod), higiene bucal (O'Leary) y cultivo de Streptococcus mutans. Se realizó análisis estadístico para determinar medidas de tendencia central, dispersión y asociación entre variables mediante exacta de Fisher, STATA.SE/10. Resultados: La población en estudio fue de 42 niños con rango de edad de tres a 15 años, mediana de 7.04 (RIC = 5-9). La prevalencia de caries fue 95.23%, con estadios severos en 83.3%, el nivel de riesgo fue alto en 73.7% y se asoció con severidad de caries (p = 0.000), consumo de carbohidratos (p = 0.000), experiencia de caries (ceod) (p = 0.000) y S. mutans (p = 0.000). La incidencia de caries a los tres meses fue de 71.0% y a los seis meses de 11.1%. Conclusiones: La prevalencia de caries fue alta (95.23%) así como el riesgo de caries (73.7%), con elevada incidencia a tres meses (71%), aun cuando los pacientes estaban en tratamiento odontológico. La atención restaurativa prevalece a pesar de hacer diagnóstico de lesiones reversibles y determinación del nivel de riesgo (AU)

Background: Caries has multifactorial etiology, presented by the imbalance between pathological/protective factors, is a public health problem, affecting 95% of children in México. Objective: To determine the prevalence of caries, to establish the level of risk and to evaluate its relation with incidence of caries at three and six months. Material and methods: Observational, descriptive and longitudinal study in the stomatologic clinic of the UAM-Xochimilco. Before informed consent, oral revision was performed by two dental surgeons calibrated for the diagnosis of caries/ICDAS (kappa 95.37%), carried out in dental chair with artificial light under principles for the control of infections. Risk level was established through the International System for Caries Management/ICCMS; using as indicators: consumption of cariogenic foods (Lipari/Andrade), pH (Hidryon strips), stimulated saliva test, caries experience (CPOD/ceod), oral hygiene (O'Leary) and culture of Streptococcus mutans. Statistical analysis was performed to determine measures of central tendency, dispersion and association between variables with Fisher's exact, STATA.SE/10. Results: The study population consisted of 42 children with ages ranging from 3 to 15 years, median of 7.04 (Q1 = 5-Q3 = 9). The prevalence of caries was 95.23%, with severe stages in 83.3%, the risk level was high in 73.7% and was associated with caries severity (p = 0.000), carbohydrate consumption (p = 0.000), caries experience (ceod) (p = 0.000) and S. mutans (p = 0.000). The incidence of caries at three months was 71.0% and at six months 11.1%. Conclusions: The prevalence of caries was high (95.23%), as well as the risk for caries (73.7%), and high incidence at three months (71%), despite the fact that the patients were in dental treatment. Restorative care prevails despite the diagnosis of reversible lesions and determination of the level of risk (AU)

Assuntos

RESUMO

Amphibians are globally threatened by habitat loss and fragmentation; species within the order Ambystoma are not the exception, as there are 18 species of mole salamanders in México, of which 16 are endemic and all species are under some national or international status of protection. The mole salamander, Ambystoma altamirani is a microendemic species, which is distributed in central México, within the trans-Mexican volcanic belt, and is one of the most threatened species due to habitat destruction and the introduction of exotic species. Nine microsatellite markers were used to determine the genetic structure, genetic variability, effective population size, presence of bottlenecks and inbreeding coefficient of one population of A. altamirani to generate information which might help to protect and conserve this threatened species. We found two genetic subpopulations with significant level of genetic structure (FST = 0.005) and high levels of genetic variability (Ho = 0.883; He = 0.621); we also found a small population size (Ne = 8.8), the presence of historical (M = 0.486) and recent bottlenecks under IAM and TPM models, with a low, but significant coefficient of inbreeding (FIS = -0.451). This information will help us to raise conservation strategies of this microendemic mole salamander species.

Assuntos

RESUMO

Human activities are affecting the distribution of species worldwide by causing fragmentation and isolation of populations. Isolation and fragmentation lead to populations with lower genetic variability and an increased chance of inbreeding and genetic drift, which results in a loss of biological fitness over time. Studies of the genetic structure of small and isolated populations are critically important for management and conservation decisions. Ambystoma rivulare is a micro-endemic Mexican mole salamander from central Mexico. It is found in the most ecologically disturbed region in Mexico, the Trans-Mexican Volcanic Belt. The goal of this study of the population genetics of the micro-endemic mole salamander was to provide information to be used as a basis for future research and conservation planning of this species and other species of the Ambystoma genus in Mexico. The structural analysis found two subpopulations, one for each river sampled, with no signs of admixture and very high levels of genetic differentiation. Medium to high levels of heterozygosity and few alleles and genotypes were observed. Evidence of an ancestral genetic bottleneck, low values of effective population size, small inbreeding coefficients, and low gene flow were also found.

Assuntos

RESUMO

Genealogical records of animals (studbook) are created to avoid reproduction between closely related individuals, which could cause inbreeding, particularly for such endangered species as the Panthera onca (Linnaeus, 1758). Jaguar is the largest felid in the Americas and is considered an important ecological key species. In Mexico, wild jaguar populations have been significantly reduced in recent decades, and population decline typically accompany decreases in genetic variation. There is no current census of captive jaguars in Mexico, and zoos do not follow a standardized protocol in breeding programs based on genetic studies. Here, we emphasise the importance of maintaining an adequate level of genetic variation and propose the implementation of standardised studbooks for jaguars in Mexico, mainly to avoid inbreeding. In addition, achieving the aims of studbook registration would provide a population genetic characterisation that could serve as a basis for ex situ conservation programmes.

Assuntos