DSpace Collection:

Epidemiologia baseada em esgoto como ferramenta de uma só saúde: vigilância do SARS-CoV-2 e da resistência antimicrobiana em Escherichia coli e Klebsiella pneumoniae.

Fri, 28 Aug 2026 00:00:00 GMT

Title: Epidemiologia baseada em esgoto como ferramenta de uma só saúde: vigilância do SARS-CoV-2 e da resistência antimicrobiana em Escherichia coli e Klebsiella pneumoniae. Abstract: Wastewater-Based Epidemiology (WBE) has established itself as a strategic tool for health surveillance, enabling non-invasive pathogen monitoring and community health assessment from a One Health perspective. This thesis aimed to investigate the circulation dynamics of SARS-CoV-2 and characterize the antimicrobial resistance profile of Escherichia coli and Klebsiella pneumoniae in raw sewage in the municipality of Uberlândia-MG, Brazil. The study was divided into two surveillance axes: virological and bacterial. In the first axis, SARS-CoV-2 viral load was quantified by RT-qPCR and variants were genomically identified by sequencing at the four wastewater treatment plants of Uberlândia-MG throughout the pandemic and post-pandemic periods, correlating environmental data with clinical indicators of reported cases and deaths. The results evidenced the effectiveness of WBE as an early warning system, demonstrating concordance between viral load in effluents and the epidemiological waves of COVID- 19. In the second axis, six E. coli and three K. pneumoniae isolates recovered from the Uberabinha wastewater treatment plant were characterized for antimicrobial susceptibility and whole-genome sequence data, including sequence types, resistance genes and mutations, virulence factors and plasmid replicons; the same sewage samples were subjected to targeted enrichment metagenomics, expanding the detection of ESKAPEE taxa (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., and Escherichia coli) and resistance determinants not recovered by culture. The analyses revealed a high prevalence of multidrug-resistant (MDR) strains, including the detection of critical resistance mechanisms (blaCTX-M, blaKPC-2, blaNDM, blaVIM), evidencing complementarity between culture, genomic sequencing and targeted metagenomics. It is concluded that integrated raw sewage surveillance is essential for public health, providing robust data for managing viral outbreaks and controlling the spread of bacterial resistance from a One Health perspective.

Integridade cromatínica e morfometria das cabeças espermáticas e suas relações com a concepção em éguas

Wed, 25 Feb 2026 00:00:00 GMT

Title: Integridade cromatínica e morfometria das cabeças espermáticas e suas relações com a concepção em éguas Abstract: The evaluation of sperm chromatin and morphometry has gained relevance for diagnosing subfertility in stallions, especially when conventional seminal parameters do not explain reproductive failures. This study investigated whether changes in chromatin compaction, detected by Toluidine Blue, Feulgen Reaction, and Acridine Orange, as well as computational sperm head morphometric variables, correlate with conception in mares inseminated with fresh or cooled semen. Additionally, sperm morphometry was compared between Quarter Horse and Mangalarga stallions in order to evaluated possible differences between breeds and whether there was a correlation with conception. Ninety-seven semen samples used for artificial insemination were analyzed, and at least 150 sperm heads per sample were examined for chromatin compaction and morphometric variables. Chromatin characteristics evaluated showed no significant correlation with conception, indicating low sensitivity of these smear methods to predict reproductive performance when ejaculates meet minimum quality standards. In contrast, morphometric variables showed a significant correlation, with the width/length ratio (r= -0,226; p= 0,0398) and ellipticity (r= 0,226; p= 0,0400) standing out, in addition to a moderate correlation for form factor (r= -0,211; p= 0,0556) and Fourier 0 (r= 0,172; p= 0,1210). Significant differences were also observed between breeds, although these did not impact conception rates. The results indicate that, while the evaluated chromatin methods are not effective predictors, computational sperm head morphometry shows potential as a complementary objective tool for estimating stallion fertility.

Avaliação otológica canina e sua relação com endocrinopatias: aspectos técnicos, micológicos e bacterianos

Tue, 24 Feb 2026 00:00:00 GMT

Title: Avaliação otológica canina e sua relação com endocrinopatias: aspectos técnicos, micológicos e bacterianos Abstract: Accurate assessment of canine otological microbiota is essential for proper diagnosis and management of otitis externa, one of the most common conditions in small animal practice. This thesis investigated technical, mycological, and bacterial aspects of canine otological microbiota, with emphasis on their relationship with endocrinopathies. Eighty dogs were evaluated, including 40 with hypothyroidism or hypercortisolism and 40 healthy controls, matched by age, sex, and breed. Animals underwent complete otological evaluation including otoscopy, auricular cytology, bacterial and fungal culture. For mycological analysis, hair samples were collected by manual traction or sterile vaginal cervical brush and inoculated in DTM medium for dermatophyte identification. Quantification of Malassezia spp. was performed by cytological evaluation, and bacterial samples were identified by MALDI-TOF, subjected to antimicrobial susceptibility testing using the VITEK system, biofilm formation capacity assessment by crystal violet method followed by microbiological counting of the sessile form, and ultrastructural analysis by scanning electron microscopy. Additionally, commercial and compounded propolis-based products were tested for antibiofilm efficacy. The prevalence of Malassezia spp. was significantly higher in endocrinopathic dogs (37.5%) compared to controls (10.0%; p<0.01), with dogs with otological malasseziosis presenting a 5.4-fold higher risk of being endocrinopathic (OR = 5.40; 95% CI: 1.60-18.20). Positive fungal culture for dermatophytes was identified exclusively in endocrinopathic dogs (5.0%). Different Staphylococcus strains were isolated, with all S. pseudintermedius strains demonstrating biofilm formation capacity (BFI>1.10) and variable antimicrobial resistance profiles. Results demonstrate strong association between endocrinopathies and opportunistic fungal infections, emphasizing the importance of endocrine investigation in recurrent otitis cases, and highlight the role of bacterial biofilms in persistence of otological infections.

Economic values for fertility, growth, carcass, and meat quality traits for seedstock and cow-calf operations in the Southeastern United States

Thu, 22 Jan 2026 00:00:00 GMT

Title: Economic values for fertility, growth, carcass, and meat quality traits for seedstock and cow-calf operations in the Southeastern United States Abstract: This study aimed to estimate trait-specific economic values for use as weights in economic selection indexes for Brahman and Angus–Brahman beef cattle operations. Economic values (EVs) were derived for fertility, growth, and carcass traits using the UF Purebred Brahman and the UF Multibreed Angus–Brahman (MAB) herds as a reference population. Bioeconomic models were developed using herd variable costs, revenues, and management data collected from February 2024 to May 2025. The BRA herd is a seedstock production operation focused on the breeding and marketing of registered, genetically superior purebred animals, providing genetic material to support the long-term sustainability of the beef cattle industry. In addition to the BRA herd, a simulated scenario was developed to represent a broader range of seedstock operations in the Southeastern United States. Offspring from the BRA herd and the seedstock scenario were either sold at weaning or yearling, retained as replacements, slaughtered for carcass evaluation, or sold for breeding purposes. The MAB herd is a cow-calf operation that focuses on breeding cows to produce one healthy, marketable calf per cow per year, supplying the beef industry with enough and high-quality meat. In addition to the MAB herd, three simulated scenarios were developed to represent a broader range of cow–calf operations in the Southeastern United States. Offspring from the MAB herd and from the simulated scenarios were either sold at weaning or yearling, retained as replacements, or marketed to a meat processor. EVs were estimated as the expected change in profitability resulting from a one-unit change in performance of a specific trait, while holding all other traits constant. EVs were estimated for calving success-to-sale (CSS), age at first pregnancy (AFP), weaning weight (WW), yearling weight (WY), weight at 15 months of age (W15), weight at 18 months of age (W18), dressing percentage (DP), USDA quality grade (QG), and USDA yield grade (YG). In the BRA herd and the simulated seedstock scenario, calving success-to-sale was the most economically important trait, followed by AFP, DP, QG, WY, YG, W15, and WW. In the MAB herd and the three simulated scenarios, calving success-to-sale was also the most highly valued trait, followed by AFP, DP, QG, YG, and growth traits. The relative importance of growth traits in the MAB herd and simulated scenarios varied by marketing endpoint, highlighting the need to align selection for growth traits with revenue-generating sale strategies. In conclusion, trait specific economic values enable selection strategies for improving the efficiency of genetic progress. Overall, the results support data-driven breeding decisions to optimize productivity, profitability, and genetic progress through multiple-trait selection.