Examinando por Autor "Thomson, Pamela"
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Ítem Antimicrobial Resistance and Extended-Spectrum Beta-Lactamase Genes in Enterobacterales, Pseudomonas and Acinetobacter Isolates from the Uterus of Healthy Mares(MDPI, 2023-09) Thomson, Pamela; García, Patricia; Río, Camila del; Castro, Rodrigo; Núñez, Andrea; Miranda, CarolinaAntibiotic-resistant bacteria are a growing concern for human and animal health. The objective of this study was to determine the antimicrobial resistance and extended-spectrum beta-lactamase genes in Enterobacterales, Pseudomonas spp. and Acinetobacter spp. isolates from the uterus of healthy mares. For this purpose, 21 mares were swabbed for samples, which were later seeded on blood agar and MacConkey agar. The isolates were identified using MALDI-TOF and the antimicrobial susceptibility test was performed using the Kirby–Bauer technique. To characterize the resistance genes, a polymerase chain reaction (PCR) scheme was performed. Of the isolates identified as Gram-negative, 68.8% were Enterobacterales, represented by E. coli, Enterobacter cloacae, Citrobacter spp., and Klebsiella pneumoniae; 28.1% belonged to the genus Acinetobacter spp.; and 3.1% to Pseudomonas aeruginosa. A 9.3% of the isolates were multidrug-resistant (MDR), presenting resistance to antibiotics from three different classes, while 18.8% presented resistance to two or more classes of different antibiotics. The diversity of three genes that code for ESBL (blaTEM, blaCTX-M and blaSHV) was detected in 12.5% of the strains. The most frequent was blaSHV, while blaTEM and blaCTX-M were present in Citrobacter spp. and Klebsiella pneumoniae. These results are an alarm call for veterinarians and their environment and suggest taking measures to prevent the spread of these microorganisms.Ítem Assessment of changes in the oral microbiome that occur in dogs with periodontal disease(MDPI, 2021-12) Santibáñez, Rodrigo; Rodríguez-Salas, Camila; Flores-Yáñez, Carla; Garrido, Daniel; Thomson, PamelaThe oral microbiome in dogs is a complex community. Under some circumstances, it contributes to periodontal disease, a prevalent inflammatory disease characterized by a complex interaction between oral microbes and the immune system. Porphyromonas and Tannerella spp. are usually dominant in this disease. How the oral microbiome community is altered in periodontal disease, especially sub-dominant microbial populations is unclear. Moreover, how microbiome functions are altered in this disease has not been studied. In this study, we compared the composition and the predicted functions of the microbiome of the cavity of healthy dogs to those with from periodontal disease. The microbiome of both groups clustered separately, indicating important differences. Periodontal disease resulted in a significant increase in Bacteroidetes and reductions in Actinobacteria and Proteobacteria. Porphyromonas abundance increased 2.7 times in periodontal disease, accompanied by increases in Bacteroides and Fusobacterium. It was predicted that aerobic respiratory processes are decreased in periodontal disease. Enrichment in fermentative processes and anaerobic glycolysis were suggestive of an anaerobic environment, also characterized by higher lipopolysaccharide biosynthesis. This study contributes to a better understanding of how periodontal disease modifies the oral microbiome and makes a prediction of the metabolic pathways that contribute to the inflammatory process observed in periodontal disease. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Ítem Changes in the gut microbiome and colic in horses: Are they causes or consequences?(Faculty of Veterinary Medicine, University of Tripoli, 2022) Lara, Felipe; Castro, Rodrigo; Thomson, PamelaThe gut microbiome is a compound for millions of microorganisms that coexist in an organized way and contribute to the fermentation of different types of indigestible fibers by the small intestine. Some techniques, such as the massive sequencing of the 16S ribosomal RNA gene, have made it possible to obtain information about the abundance and functionality of the microorganisms that compose the equine gut microbiome and the interaction with their environment. Recent studies have identified the change in the composition of the intestinal microbiome during and after a colic episode, although is not clear if it is a cause or a consequence. The objective of this review was to elucidate whether there is a direct relationship between the changes that occur in the gut microbiome and colic in the equine. A systematized search in Embase, Web of Science, and PubMed was realized. Although there is good evidence that horses with colic have a change in their gut microbiome, it is not fully understood whether these changes are causes or effects. It is necessary to delve into this topic, considering studying larger population sizes. In addition, it would be of great value to previously know the normal intestinal microbiome of a group of healthy horses, which in the future could develop an episode of colic, to compare the before and after in the same individual. © 2022, Faculty of Veterinary Medicine, University of Tripoli. All rights reserved.Ítem Characterization of microbial communities and predicted metabolic pathways in the uterus of healthy mares(Faculty of Veterinary Medicine, University of Tripoli, 2022) Thomson, Pamela; Pareja, Josefina; Núñez, Andrea; Santibáñez, Rodrigo; Castro, RodrigoBackground: Culture-independent techniques have made it possible to expand the knowledge about the composition of bacterial communities present in the healthy uterus and their role in health and disease, mainly in humans. However, in animals like mares, there is a dearth of information regarding this area. Aim: To narrow this knowledge gap, the objective of this study was to identify and characterize the composition and function of the uterine microbiome of a group of Chilean purebred mares (CPM), an equine breed with the oldest genealogical record in South America and an economical important reproductive industry. Methods: From uterine biopsy samples obtained during estrus, DNA extraction and targeted sequencing were performed to investigate the bacterial diversity and its probable metabolic function. Results: CPM biopsy samples were characterized by having a varied microbial composition, where the four most relatively abundant phyla were Proteobacteria (69.6%), Firmicutes (21.1%), Bacteroidetes (7.8%), and Actinobacteria (1.06%); which made up 99.6% of the total identified phyla. In contrast, Actinobacteria and Fusobacteria were the phyla not identified in all samples. Of a total of 59 genera identified across all samples, Staphylococcus was the most abundant genus with an average relative abundance of 18.88%, followed by Pseudomonas (17.9%), Escherichia/ Shigella (10.42%), and Klebsiella (9.92%). Conclusion: These findings contribute to the knowledge of microbes' presence in the uterus, while future studies are required to demonstrate the role of these microorganisms in health and disease. © 2022, Faculty of Veterinary Medicine, University of Tripoli. All rights reserved.Ítem Dermatophytosis caused by Trichophyton benhamiae in a sea lion. First report(Elsevier B.V., 2024-12) López, Ronar; Silva, Víctor; Bown, Viviana; Godoy-Martínez, Patricio; Thomson, PamelaFungal infections in marine animals, particularly pinnipeds, have seen a notable increase, often linked to compromised immune systems in captive environments. Trichophyton species, while common in terrestrial mammals, have sporadically caused dermatophytosis in pinnipeds. A South American sea lion (Otaria byronia) presented with Trichophyton benhamiae infection, marking the first such case in this species. Effective treatment combined oral terbinafine with topical ozonized oil, supported by silymarin for liver protection. Accurate fungal identification and sensitivity testing were key to the successful management and recovery of the patient. © 2024Ítem Differences in the composition and predicted functions of the intestinal microbiome of obese and normal weight adult dogs(PeerJ Inc., 2022-02) Thomson, Pamela; Santibáñez, Rodrigo; Rodríguez-Salas, Camila; Flores-Yañez, Carla; Garrido, DanielObesity is a multifactorial nutritional disorder highly prevalent in dogs, observed in developed and developing countries. It is estimated that over 40% of the canine population suffers from obesity, which manifests in an increased risk of chronic osteoarticular, metabolic, and cardiovascular diseases. The intestinal microbiome of obese animals shows increases in the abundance of certain members capable of extracting energy from complex polysaccharides. The objective of this study was to compare the composition and predicted function of the intestinal microbiome of Chilean obese and normal weight adult dogs. Twenty clinically healthy dogs were classified according to their body condition score (BCS) as obese (n = 10) or normal weight (n = 10). DNA was extracted from stool samples, followed by next-generation sequencing of the 16S rRNA V3–V4 region and bioinformatics analysis targeting microbiome composition and function. Significant differences were observed between these groups at the phylum level, with anincrease in Firmicutes and a decrease in Bacteroidetes in obese dogs. Microbiome compositions of these animals correlated with their BCS, and obese dogs showed enrichment in pathways related to transport, chemotaxis, and flagellar assembly. These results highlight the differences in the gut microbiome between normal weight and obese dogs and prompt further research to improve animal health by modulating the gut microbiome. Copyright 2022 Thomson et al.Ítem Preliminary Functional Analysis of the Gut Microbiome in Colic Horses(Multidisciplinary Digital Publishing Institute (MDPI), 2024-11) Thomson, Pamela; Garrido, Daniel; Santibáñez, Rodrigo; Lara, FelipeColic in horses is a common condition that can affect different organs of the abdominal cavity. In recent years, attempts have been made to associate this pathology with changes that occur in the intestinal microbiome. Through a case–control study, we analyzed the intestinal microbiome of a group of healthy horses and another with colic by massive sequencing of 16S rRNA to observe the differences in the bacterial composition and functionality of these groups. The intestinal microbiomes of both groups are dominated by the phyla Firmicuteota, Bacteroidota, and Pseudomonadota. The abundance of Firmicuteota was negatively correlated with Pseudomonadota and Actinobacteriota in horses with colic. The microbiome of equine colic was predicted to be enriched with aerobic respiration pathways and fatty acid and amino acid degradation, observations that indicate discrete but important differences in the intestinal microbiome of horses with colic, which correlate with a more pro-inflammatory microbial community.Ítem Sporotrichosis Outbreak Due to Sporothrix brasiliensis in Domestic Cats in Magallanes, Chile: A One-Health-Approach Study(MDPI, 2023-02) Thomson, Pamela; González, Carlos; Blank, Olivia; Ramírez, Valentina; Río, Camila del; Santibáñez, Sebastián; Pena, PamelaSporotrichosis is an implantation mycosis with subcutaneo-lymphatic or, more rarely, a viscerally disseminated affection; it can be acquired through traumatic percutaneous inoculation of the fungus present in soil or plant matter, or by feline scratching. Among the causative agents, Sporothrix brasiliensis is considered the most virulent species with a high prevalence in Brazil and recently in Argentina. Objective: To describe a S. brasiliensis outbreak in domestic and feral cats detected in the Magallanes region of southern Chile. Materials and Methods: Between the months of July and September 2022, three cats presented with suppurative subcutaneous lesions located mainly on the head and thoracic limbs. The cytology revealed the presence of yeasts with morphological characteristics suggestive of Sporothrix spp. The histopathology confirmed pyogranulomatous subcutaneous lesions associated with the presence of the same yeasts. The fungal culture followed by the partial gene sequence and analysis of the ITS region confirmed the diagnosis of the S. brasiliensis as the causative agent. The cats were treated with itraconazole associated in one case with potassium iodide. The evolution of the patients was favorable in all cases. Conclusions: An outbreak caused by S. brasiliensis was detected in domestic and feral cats in austral Chile. The correct identification of this fungus and antifungigram is essential for treatment decisions and for designing dissemination control and prevention programs under a one health approach that consider the health of people, animals, and the environment. © 2023 by the authors.