A high-throughput DNA sequencing study of fecal bacteria of seven Mexican horse breeds.

Horses are non-ruminant, herbivorous mammals, been used through history for various purposes, with a gut microbiota from cecum to the colon, possessing remarkable fermentative capacity. We studied the fecal microbiota of Azteca, Criollo, Frisian, Iberian, Pinto, Quarter and Spanish horse breeds living in Mexico by next-generation DNA sequencing of 16S rRNA gene libraries. Dominant phyla Firmicutes, Bacteroidetes, Proteobacteria, Spirochaetes, Fibrobacteres, Actinobacteria and Verrucomicrobia have different relative abundances among breeds, with contrasted alpha and beta diversities as well. Heatmap analysis revealed that Ruminococcaceae, Lachnospiraceae, Mogibacteriaceae families, and order Clostridiales are more abundant in Spanish, Azteca, Quarter and Criollo breeds. The LEfSe analysis displayed higher abundance of order Bacteroidales, family BS11, and genera Faecalibacterium, Comamonas, Collinsella, Acetobacter, and Treponema in Criollo, Azteca, Iberian, Spanish, Frisian, Pinto, and Quarter horse breeds. The conclusion is that dominant bacterial taxa, found in fecal samples of horse breeds living in Mexico, have different relative abundances.

The Bacterial and Fungal Microbiota of the Mexican Rubiaceae Family Medicinal Plant Bouvardia ternifolia.

Bouvardia ternifolia is a medicinal plant considered a source of therapeutic compounds, like the antitumoral cyclohexapeptide bouvardin. It is known that large number of secondary metabolites produced by plants results from the interaction of the host and adjacent or embedded microorganisms. Using high-throughput DNA sequencing of V3-16S and V5-18S ribosomal gene libraries, we characterized the endophytic, endophytic + epiphyte bacterial, and fungal communities associated to flowers, leaves, stems, and roots, as well as the rhizosphere. The Proteobacteria (average 80.7%) and Actinobacteria (average 14.7%) were the most abundant bacterial phyla, while Leotiomycetes (average 54.8%) and Dothideomycetes (average 27.4%) were the most abundant fungal classes. Differential abundance for the bacterial endophyte group showed a predominance of Erwinia, Propionibacterium, and Microbacterium genera, while Sclerotinia, Coccomyces, and Calycina genera predominated for fungi. The predictive metagenome analysis for bacteria showed significative abundance of pathways for secondary metabolite production, while a FUNguild analysis revealed the presence of pathotroph, symbiotroph, and saprotrophs in the fungal community. Intra and inter copresence and mutual exclusion interactions were identified for bacterial and fungal kingdoms in the endophyte communities. This work provides a description of the diversity and composition of bacterial and fungal microorganisms living in flowers, leaves, stems, roots, and the rhizosphere of this medicinal plant; thus, it paves the way towards an integral understanding in the production of therapeutic metabolites.

Are the children alright? A systematic review of psychological adjustment of children conceived by assisted reproductive technologies.

The present systematic review aims to assess the psychological adjustment of children born through assisted reproductive technologies (ARTs) and to screen for clinical problems when compared with normative data from the standardized indexes of mental health. Following PRISMA guidelines, the search was conducted from inception through September 2021 using APA PsycInfo, APA PsycArticles, Psychology and Behavioural Sciences Collection, Academic Search Complete, Pubmed, Scopus, Web of Science, Scielo, and RCAAP. Search terms related to ART and children's psychological adjustment were combined to Boolean operators to identify relevant published studies in English, French, Italian, Portuguese and Spanish. Peer-reviewed studies focused on the psychological adjustment of ART children aged between the 3 and 11 years were included. From a total of 337 results, 45 papers were eligible to be included in this review. Data extraction was performed independently by two authors and revised and confirmed by other two authors. All children scored below the clinical range for psychiatric symptoms when compared with normative data for the Strengths and Difficulties Questionnaire (SDQ) or the Achenbach System of Empirically Based Assessment (ASEBA), regardless of type of ART and different family configurations. Further, some evidence suggests that surrogacy children with gay fathers present the lowest levels of psychological problems when compared to normative data. These findings enable practitioners to develop an informed view of ART children mental health outcomes to help parents find more adaptive strategies to navigate their chosen pathways in healthier ways.

Attachment research and anti-racism: learning from Black and Brown scholars.

Preliminary evidence suggests that people and scholars of African and/or Latin American and Caribbean origin are often under-represented in mainstream attachment scholarship. In this commentary, we highlight the difficulty of conducting attachment theory research outside of the United States, particularly in Latin American countries. We reflect on the contributions by the authors of this special issue . We also identify (a) ways in which to center the experiences of Black and Brown people and scholars to push the field toward antiracism, and (b) the challenges of attachment theory and research in becoming anti-racist by considering the structural nature of racism.

The vaginal and fecal microbiota of a murine cervical carcinoma model under synergistic effect of 17ß-Estradiol and E7 oncogene expression.

Cervical cancer is an important health issue worldwide. Many factors are related to this condition as the persistence of human papillomavirus (HPV) infection (e.g. type 16 and 18), the use of hormonal contraceptives for long periods of time, pH changes and bacterial vaginosis. The association between the microbiota and cervical human cancer is an interesting issue to be explored; given that environmental and hormonal factors may change the vaginal microbiota contributing to this condition. Our hypothesis was that changes in the microbiota diversity is associated with the development of cervical cancer. We evaluated the microbiota diversity in vaginal lavages and fecal samples at different stages of cervical cancer development in a mice model (K14HPV16E7) with type 16 E7 oncogene expression (E7), under continuous or not continuous stimulus of 17ß-estradiol (E2) and compared it with a non-transgenic isogenic control (FVB) under same conditions. Our results indicate that continuous E2 administration during 6 months in the model with type 16 E7 expression causing development of cancer, is associated with significant changes in the microbiota diversity of the cervicovaginal lavages. Similar results were not observed in the same model when no E2 was administered to the mice. The FVB mice with no E7 expression which do not develop cervical cancer, did not show comparable changes in the microbiota diversity when E2 was administered during the same period. Normal evolution of the cervical epithelium and microbiota diversity were observed for the FVB mice with no E2 administration. Large changes in the microbiota diversity in fecal samples were not observed suggesting a specific organ effect of E7 expression associated to E2 on the vaginal microbiota.

Secure base scripted knowledge and preschoolers' social competence in samples from Mexico and Peru.

A central hypothesis in attachment theory poses that child-mother relationships have implications for children's social competence. A key task for researchers is that of investigating the pathways responsible for the association found between child attachment security and social competence. We studied whether children's secure base representations, defined as scripts, are associated with assessments of social competence in a preschool setting. We tested this association in samples from Mexico and Peru. Preschoolers' attachment representations were assessed via narratives gathered with the Attachment Story Completion Task. Teachers (in Mexico) and mothers (in Peru) provided questionnaire information about social competence. Attachment scripts predicted children's social competence in both samples. Results are discussed in terms of their implications for theory and research.

Gut Microbiota and Predicted Metabolic Pathways in a Sample of Mexican Women Affected by Obesity and Obesity Plus Metabolic Syndrome.

Obesity is an excessive fat accumulation that could lead to complications like metabolic syndrome. There are reports on gut microbiota and metabolic syndrome in relation to dietary, host genetics, and other environmental factors; however, it is necessary to explore the role of the gut microbiota metabolic pathways in populations like Mexicans, where the prevalence of obesity and metabolic syndrome is high. This study identify alterations of the gut microbiota in a sample of healthy Mexican women (CO), women with obesity (OB), and women with obesity plus metabolic syndrome (OMS). We studied 67 women, characterizing their anthropometric and biochemical parameters along with their gut bacterial diversity by high-throughput DNA sequencing. Our results indicate that in OB or OMS women, Firmicutes was the most abundant bacterial phylum. We observed significant changes in abundances of bacteria belonging to the Ruminococcaceae, Lachnospiraceae, and Erysipelotrichaceae families and significant enrichment of gut bacteria from 16 different taxa that might explain the observed metabolic alterations between the groups. Finally, the predicted functional metagenome of the gut microbiota found in each category shows differences in metabolic pathways related to lipid metabolism. We demonstrate that Mexican women have a particular bacterial gut microbiota characteristic of each phenotype. There are bacteria that potentially explain the observed metabolic differences between the groups, and gut bacteria in OMS and OB conditions carry more genes of metabolic pathways implicated in lipid metabolism.

Plasma and tissue disposition of florfenicol in Escherichia coli lipopolysaccharide-induced endotoxaemic sheep.

1. The purpose of this study was to understand the effects of the acute inflammatory response (AIR) induced by Escherichia coli lipopolysaccharide (LPS) on florfenicol (FFC) and FFC-amine (FFC-a) plasma and tissue concentrations. 2. Ten Suffolk Down sheep, 60.5 ± 4.7 kg, were distributed into two experimental groups: group 1 (LPS) treated with three intravenous doses of 1 µg/kg bw of LPS at 24, 16, and 0.75 h (45 min) before FFC treatment; group 2 (Control) was treated with saline solution (SS) in parallel to group 1. An IM dose of 20 mg FFC/kg was administered at 0.75 h after the last injection of LPS or SS. Blood and tissue samples were taken after FFC administration. 3. The plasma AUC0-4 h values of FFC were higher (p = 0.0313) in sheep treated with LPS (21.8 ± 2.0 µg·min/mL) compared with the control group (12.8 ± 2.3 µg·min/mL). Lipopolysaccharide injections increased FFC concentrations in kidneys, spleen, and brain. Low levels of plasma FFC-a were observed in control sheep (Cmax = 0.14 ± 0.01 µg/mL) with a metabolite ratio (MR) of 4.0 ± 0.87%. While in the LPS group, Cmax increased slightly (0.25 ± 0.01 µg/mL), and MR decreased to 2.8 ± 0.17%. 4. The changes observed in the plasma and tissue concentrations of FFC were attributed to the pathophysiological effects of LPS on renal hemodynamics that modified tissue distribution and reduced elimination of the drug.

Comfort with LGB people and attitudes toward same-sex parenting in Continental American Hispanic Nations.

Negative attitudes toward Lesbian, Gay, and Bisexual (LGB) individuals leads to a perceived inability of LGB individuals to foster 'appropriate' family relationships, inciting negative attitudes specifically toward same-sex parenting. Intergroup and interpersonal relationships play a critical role in fostering attitudes toward others wherein type of contact, frequency, degree of closeness in the relationship, and the positivity/negativity of interactions are potential mediator of these relations, Moreover, the mechanism behind co-constructing positive relationships with sexual and gender minorities is comfort with contact with LGB individuals. The present study explored the effects of interpersonal contact and the mediator role of comfort with LGB people in explaining attitudes toward same-sex parenting in Spanish-speaking countries in North, Central, and South America. These countries are of particular interest given the dearth of research in the region on attitudes toward same-sex parenting as well as the varying degrees of acceptance of and protections for same-sex parented families. A non-probabilistic sample of 1955 heterosexual cisgender participants from 14 countries was asked to complete a series of sociodemographic questions, a questionnaire about their interpersonal contact/comfort experiences with LGB people, and the Attitudes Toward Gay and Lesbian Parenting Scale. Results showed that comfort was vital in fostering accepting attitudes toward Same-Sex Parenting across countries. Findings also suggested that comfort with LGB people has a particularly powerful influence in regions with less legal and cultural acceptance of LGB individuals. Policies are not enough to instill widespread change: we must encourage, facilitate, and supervise the formation of relationships with LGB people.

Authentic gender development in non-binary children.

At present, the conceptualization of gender as a spectrum as well as non-binary identities have become increasingly visible and embraced. We are using non-binary as an umbrella term that refers to individuals who self-identify as a gender outside the gender binary, and/or who do not identify as always and completely being just a man or a woman. Our goal is to begin to create a framework for understanding gender development in non-binary children ages 0 to 8, since previous models have operated on cissupremacist assumptions, not applicable to non-binary people. As there is virtually no empirical data on the subject, we conducted a thorough literature review of current gender development theories and used our positionality as non-binary researchers to postulate two minimum criteria for non-binary gender identification: that a child learns about the existence of non-binary identities, and that they do not identify with the definitions they have been taught of what a boy or girl is. Children can learn about non-binary identities through media and knowledgeable community members and can develop "gender traits" authentically and come to identify as non-binary through biological predispositions, parental support, modeling, and being in peer groups that are supportive of identity exploration. Yet, children are not simply a product of their nature and nurture, as evidence has shown that humans are active agents in their gender development from a young age.

Attitudes Toward Lesbians, Gay Men, and Their Rights in a Sample of Ecuadorian Cisgender Men and Women.

Since 1997, Ecuador has undergone a series of changes to ensure family rights to sexual minorities. However, there is still limited research regarding attitudes toward them. This study focused on the attitudes toward lesbians (L), gay men (G), and their rights. A sample of 318 cisgender Ecuadorians who responded to an online survey was recruited. Analyses indicated that men, heterosexuals, who practice their religion, attend more frequently to religious services, and identify as conservative showed higher levels of prejudice against LG as well as less support toward their rights. Further, participants who did not have LG acquaintances, friends, family members, and those who did not know any LG parented family showed less support toward these populations. Multiple regression analyses indicated that believing that a person's sexual orientation is learned significantly predicted the attitudes measured in our study. Implications of these findings to help reduce prejudice against LG individuals are discussed.

Physical and Dietary Intervention with Opuntia ficus-indica (Nopal) in Women with Obesity Improves Health Condition through Gut Microbiota Adjustment.

Obesity is a multifactorial disease resulting in excessive accumulation of fat. Worldwide, obesity is an important public health problem, affecting a large proportion of the world population. The tender cactus Opuntia ficus-indica, commonly known in Mexico as "nopal", is widely distributed in this country, Latin America, South Africa, and the Mediterranean area. Nopal cladodes are commonly marketed in different forms as fresh, frozen, or pre-cooked, and used as fresh green vegetable. The aim of this study was to evaluate the capability of nopal to improve the health condition of participants affected by obesity, in a physical and dietary intervention, through gut microbiota modification. These results were contrasted with the effect of nopal in the gut microbiota of normal weight participants. We describe the association among biochemical, anthropometric markers, and the gut microbiota diversity found in fecal samples of the obese and normal weight groups. The results presented in this work suggest that caloric restriction, addition of nopal to the diet and physical activity, promote changes in the gut microbiota in obese women, improving the host metabolism, as suggested by the correlation between some bacterial species with biochemical and anthropometrical parameters.

The Influence of Holder Pasteurization on the Diversity of the Human Milk Bacterial Microbiota Using High-Throughput DNA Sequencing.

BACKGROUND: Human milk is the best food for infants; however, when breastfeeding is not possible, pasteurized milk from human milk banks is the best alternative. Little has been reported about variations in the bacterial microbiota composition of human milk after pasteurization. RESEARCH AIM: To characterize and compare the bacterial microbiota composition and diversity within human milk among Mexican mothers before and after the Holder pasteurization process. METHODS: A cross-sectional, observational, and comparative design was used. The effect of the pasteurization process on the bacterial composition and diversity of human milk samples of donors (N = 42) from a public milk bank was assessed before and after pasteurization by high throughput deoxyribonucleic acid sequencing of V3-16S rRNA gene libraries. Sequencing data were examined using the Quantitative Insights into Microbial Ecology software and Phyloseq in R environment. RESULTS: A varied community of bacteria was found in both raw and pasteurized human milk. The bacterial diversity of the milk samples was increased by the pasteurization, where some thermoduric bacteria of the phyla Proteobacteria, Firmicutes, and Actinobacteria were more abundant. The source tracker analysis indicated that at most 1.0% of bacteria may have come from another source, showing the safety of the process used to treat milk samples. CONCLUSION: The pasteurization process increased the bacterial diversity. We selected taxa capable of surviving the process, which could proliferate after the treatment without being a risk for infants.

Parental Burnout Assessment (PBA) in Different Hispanic Countries: An Exploratory Structural Equation Modeling Approach.

Parental burnout is a unique and context-specific syndrome resulting from a chronic imbalance of risks over resources in the parenting domain. The current research aims to evaluate the psychometric properties of the Spanish version of the Parental Burnout Assessment (PBA) across Spanish-speaking countries with two consecutive studies. In Study 1, we analyzed the data through a bifactor model within an Exploratory Structural Equation Modeling (ESEM) on the pooled sample of participants (N = 1,979) obtaining good fit indices. We then attained measurement invariance across both gender and countries in a set of nested models with gradually increasing parameter constraints. Latent means comparisons across countries showed that among the participants' countries, Chile had the highest parental burnout score, likewise, comparisons across gender evidenced that mothers displayed higher scores than fathers, as shown in previous studies. Reliability coefficients were high. In Study 2 (N = 1,171), we tested the relations between parental burnout and three specific consequences, i.e., escape and suicidal ideations, parental neglect, and parental violence toward one's children. The medium to large associations found provided support for the PBA's predictive validity. Overall, we concluded that the Spanish version of the PBA has good psychometric properties. The results support its relevance for the assessment of parental burnout among Spanish-speaking parents, offering new opportunities for cross-cultural research in the parenting domain.

Spatial Memory and Gut Microbiota Alterations Are Already Present in Early Adulthood in a Pre-clinical Transgenic Model of Alzheimer's Disease.

The irreversible and progressive neurodegenerative Alzheimer's disease (AD) is characterized by cognitive decline, extracellular ß-amyloid peptide accumulation, and tau neurofibrillary tangles in the cortex and hippocampus. The triple-transgenic (3xTg) mouse model of AD presents memory impairment in several behavioral paradigms and histopathological alterations from 6 to 16 months old. Additionally, it seems that dysbiotic gut microbiota is present in both mouse models and patients of AD at the cognitive symptomatic stage. The present study aimed to assess spatial learning, memory retention, and gut microbiota alterations in an early adult stage of the 3xTg-AD mice as well as to explore its sexual dimorphism. We evaluated motor activity, novel-object localization training, and retention test as well as collected fecal samples to characterize relative abundance, alpha- and beta-diversity, and linear discriminant analysis (LDA) effect size (LEfSe) analysis in gut microbiota in both female and male 3xTg-AD mice, and controls [non-transgenic mice (NoTg)], at 3 and 5 months old. We found spatial memory deficits in female and male 3xTg-AD but no alteration neither during training nor in motor activity. Importantly, already at 3 months old, we observed decreased relative abundances of Actinobacteria and TM7 in 3xTg-AD compared to NoTg mice, while the beta diversity of gut microbiota was different in female and male 3xTg-AD mice in comparison to NoTg. Our results suggest that gut microbiota modifications in 3xTg-AD mice anticipate and thus could be causally related to cognitive decline already at the early adult age of AD. We propose that microbiota alterations may be used as an early and non-invasive diagnostic biomarker of AD.

Gut microbiota in a population highly affected by obesity and type 2 diabetes and susceptibility to COVID-19.

Coronavirus disease 2019 (COVID-19) is a disease produced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and it is currently causing a catastrophic pandemic affecting humans worldwide. This disease has been lethal for approximately 3.12 million people around the world since January 2020. Globally, among the most affected countries, Mexico ranks third in deaths after the United States of America and Brazil. Although the high number of deceased people might also be explained by social aspects and lifestyle customs in Mexico, there is a relationship between this high proportion of deaths and comorbidities such as high blood pressure (HBP), type 2 diabetes, obesity, and metabolic syndrome. The official epidemiological figures reported by the Mexican government have indicated that 18.4% of the population suffers from HBP, close to 10.3% of adults suffer from type 2 diabetes, and approximately 36.1% of the population suffers from obesity. Disbalances in the gut microbiota (GM) have been associated with these diseases and with COVID-19 severity, presumably due to inflammatory dysfunction. Recent data about the association between GM dysbiosis and metabolic diseases could suggest that the high levels of susceptibility to SARS-CoV-2 infection and COVID-19 morbidity in the Mexican population are primarily due to the prevalence of type 2 diabetes, obesity, and metabolic syndrome.

Human milk microbiota associated with early colonization of the neonatal gut in Mexican newborns.

BACKGROUND: Human milk microbiota plays a role in the bacterial colonization of the neonatal gut, which has important consequences in the health and development of the newborn. However, there are few studies about the vertical transfer of bacteria from mother to infant in Latin American populations. METHODS: We performed a cross-sectional study characterizing the bacterial diversity of 67 human milk-neonatal stool pairs by high-throughput sequencing of V3-16S rDNA libraries, to assess the effect of the human milk microbiota on the bacterial composition of the neonate's gut at early days. RESULTS: Human milk showed higher microbial diversity as compared to the neonatal stool. Members of the Staphylococcaceae and Sphingomonadaceae families were more prevalent in human milk, whereas the Pseudomonadaceae family, Clostridium and Bifidobacterium genera were in the neonatal stool. The delivery mode showed association with the neonatal gut microbiota diversity, but not with the human milk microbiota diversity; for instance, neonates born by C-section showed greater richness and diversity in stool microbiota than those born vaginally. We found 25 bacterial taxa shared by both ecosystems and 67.7% of bacteria found in neonate stool were predicted to originate from human milk. This study contributes to the knowledge of human milk and neonatal stool microbiota in healthy Mexican population and supports the idea of vertical mother-neonate transmission through exclusive breastfeeding.

Influence of moderate beer consumption on human gut microbiota and its impact on fasting glucose and ß-cell function.

Beer is a beverage that has been consumed worldwide for thousands of years due to social, religious, and cultural reasons; it contains polyphenolic compounds as well as phenolic acids with a potential positive effect on human health. This study aimed to explore the impact of moderate beer consumption on human health and gut microbiota diversity. Three hundred fifty-five mL of non-alcoholic beer (NAB) or alcoholic beer (AB) were consumed daily by the participants for 30 days in each study. Anthropometric measures, blood samples for biochemistry, and fecal samples for microbiota analysis were collected on Day 1 and Day 30. Microbial diversity was characterized by high-throughput sequencing of 16S rDNA libraries, and data were analyzed using the QIIME pipeline. We found that NAB and AB have effects on the composition of the gut microbiota, favoring the proliferation of Bacteroidetes with respect to Firmicutes. No increase in weight, waist, and hip parameters was observed, and the liver and lipid profile values were not modified for NAB. In addition, the consumption of NAB induced a decrease in fasting blood serum glucose and an increase in functional ß cells, while, on the other hand, there was an increase in blood serum glucose and a decrease in functional ß cells with the consumption of AB. In general, beer consumption neither changed anthropometric values, nor affected liver function. Although the glucose values decreased with NAB or increased with AB, they remained within the normal range. Our conclusion is that moderate consumption of NAB has a positive effect on human health via supplementation of biological active polyphenol and phenolic acids, and by enrichment of the gut microbiota diversity with beneficial bacteria, while the presence of alcohol in AB interferes with this effect. More work should be done on this topic before general conclusions are drawn.

Characterization of the Gut Microbiota of Individuals at Different T2D Stages Reveals a Complex Relationship with the Host.

In this work, we studied 217 Mexican subjects divided into six groups with different stages of glucose intolerance: 76 Controls (CO), 54 prediabetes (PRE), 14 T2D no medication (T2D-No-M), 14 T2D with Metformin (T2D-M), 22 T2D with polypharmacy (T2D-P), and 37 T2D with polypharmacy and insulin (T2D-P+I). We aimed to determine differences in the gut microbiota diversity for each condition. At the phylum level, we found that Firmicutes and Bacteroidetes outline major changes in the gut microbiota. The gut bacterial richness and diversity of individuals in the T2D-No-M group were lesser than other groups. Interestingly, we found a significant difference in the beta diversity of the gut microbiota among all groups. Higher abundance was found for Comamonadaceae in PRE, and Sutterella spp. in T2D-No-M. In addition, we found associations of specific microbial taxa with clinical parameters. Finally, we report predicted metabolic pathways of gut microbiota linked to T2D-M and PRE conditions. Collectively, these results indicate that each group has specific predicted metabolic characteristics and gut bacteria populations for each phenotype. The results of this study could be used to define strategies to modulate gut microbiota through noninvasive treatments, such as dietary intervention, probiotics or prebiotics, and to improve glucose tolerance of individuals with prediabetes or T2D.

Flukicide efficacy against Fasciola hepatica of Triclabendazole and Nitroxynil in cattle of the central valley of Chile.

On a farm with permanent history of fasciolasis a study was performed aimed to know the efficacy of triclabendazole (TCBZ) and then to contrast with that of nitroxynil. Thirty-nine cattle naturally infected with Fasciola hepatica were randomly allocated into 4 experimental groups: Group 1 (control) was left untreated. Group 2 was treated with of 12 mg/kg body weight (bw) of TCBZ by oral route. Group 3 treated with 24 mg/kg bw TCBZ orally. Group 4 was treated with 10 mg/kg bw of nitroxynil subcutaneously. The anthelmintic efficacy was calculated as the percentage of reduction in faecal egg count (FEC) at 14 and 28 d post-treatment. Results indicated that there were no significant differences in the percentage of FEC reduction between control group and the groups treated with 12 or 24 mg/kg of TCBZ. On the contrary, the treatment with nitroxinyl significantly reduced the FEC and decreased the percentage of positive animals. In conclusion, Fasciola hepatica is reported for first time as resistant to TCBZ in Chile, which highlights the need of rotating drugs and assessing the efficacy of the administered drug in order to avoid the selection of resistant worms.