Programa de Pós-Graduação em Medicina Veterinária
http://repositorio.ufsm.br/handle/1/2321
2024-03-28T17:47:02ZDinâmica de anticorpos em cães submetidos a diferentes protocolos de tratamento para leishmaniose visceral canina
http://repositorio.ufsm.br/handle/1/31648
Dinâmica de anticorpos em cães submetidos a diferentes protocolos de tratamento para leishmaniose visceral canina
Costa, Eliesse Pereira
Sangioni, Luis Antonio
Visceral leishmaniasis is a zoonotic disease that has a significant impact on public
health. Dogs are the main urban reservoirs of Leishmania spp. infection. In this study,
we evaluated the dynamics of antibodies in dogs that were treated with different
therapeutic protocols for canine visceral leishmaniasis (CVL). Therefore, serum antiLeishmania spp. antibody (IgG) titers were considered and clinical scores were
performed according to Brasileish (2018) guidelines, in order to verify the correlations
of these variables. This research included 23 dogs naturally infected by Leishmania
spp. which were grouped based on the treatment protocol defined by clinical
veterinarians: G1 were treated with allopurinol (n = 6); G2 were treated with allopurinol
in combination with Milteforan® (n = 10); and G3 were treated with allopurinol
associated with Milteforan® and the LeishTec® vaccine (n = 7). The dogs were
monitored monthly for a period of one year. To verify serum antibody titers, an indirect
immunofluorescence reaction was performed. We found that dogs from G1 and G2
had lower clinical scores and antibody titers, when compared to the parameters
evaluated in pre-treatment; however, clinical relapses were observed in three animals.
In G3, clinical scores were lower than pre-treatment; however, they presented
relatively stable antibody titers and no clinical relapse was observed. It should be noted
that, due to the challenges of parasitic loads in infections, the immune response of
animals must be considered in controlling the infection. Furthermore, it is highlighted
that the evaluation of antibodies in isolation does not constitute a good parameter for
therapeutic evaluation. Therefore, it is necessary to include other criteria that make it
possible to determine the parasite load, verify the most appropriate therapeutic
protocol for CVL and establish the reservoir status of infected and treated dogs.
Universidade Federal de Santa Maria
Dissertação
2024-02-01T00:00:00ZAtividade antimicrobiana de porfirina catiônica 4-H2TMeP frente a bactérias multirresistentes cultivadas em biofilmes e sobre fragmentos de pele de cães
http://repositorio.ufsm.br/handle/1/31563
Atividade antimicrobiana de porfirina catiônica 4-H2TMeP frente a bactérias multirresistentes cultivadas em biofilmes e sobre fragmentos de pele de cães
Bernicker, Mayara Rosa
Cargnelutti, Juliana Felipetto
Canine integumentary infections caused by antimicrobial-resistant microorganisms constitute a One
Health threat. This is attributed to the potential transmission from animals to their owners, becoming
particularly alarming when these microorganisms demonstrate resistance to more than three classes of
antimicrobials, characterizing them as multidrug-resistant (MDR). These infections may arise from
multiple microorganisms that frequently organize into biofilms. Biofilm formation not only contributes
to infection persistence but also poses an additional challenge to treatment, as bacteria within these
communities exhibit increased resistance to conventional antimicrobial. Therefore, considering the
multidrug resistance and the bacteria's ability to colonize skin surfaces in biofilm, an urgent search for
alternative methods of microbial inactivation is imperative. Antimicrobial Photodynamic Therapy
(aPDT) using porphyrins has shown promise in inactivating viruses, yeasts, and bacteria. Numerous in
vitro studies demonstrate that the tetra-cationic porphyrin 4-H2TMeP can effectively inactivate
bacteria, possessing the advantage of easy commercial availability, water solubility, and multi-target
action through singlet oxygen production. Thus, this dissertation aimed to evaluate the antibacterial
activity of the porphyrin 4-H2TMeP against mono-and polymicrobial biofilms cultivated by MDR
bacteria and on canine skin fragments. The porphyrin 4-H2TMeP was tested against three clinical
MDR isolates of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius. In
all experiments, a non-cytotoxic concentration of 40 µM 4-H2TMeP was used. Biofilms in
monoculture and mixed cultures (S. pseudintermedius + E. coli) were treated with 4-H2TMeP and
exposed to white LED light irradiation for 30, 60, and 90 minutes. In canine skin fragments,
monocultures were treated with 4-H2TMeP and irradiated for 30 (S. pseudintermedius), 60 (E. coli), or
60 and 90 minutes (P. aeruginosa); polymicrobial cultures containing S. pseudintermedius and E. coli
were subjected to irradiation for 60 and 90 minutes. The effectiveness of aPDT was evaluated by
counting colony-forming units (CFUs) from biofilm and swabs collected from skin fragments
containing bacterial cultures, which were then cultured in media post-treatment. The seeded plates
were incubated for 24 hours at 37 °C in aerobic conditions, and statistically compared CFUs were
assessed between treated and control groups. Results demonstrated that 4-H2TMeP reduced
concentrations of S. pseudintermedius and E. coli in individual and mixed biofilms, significantly
decreasing bacterial concentrations (p < 0.05) in mono- and polymicrobial cultures grown on canine
skin samples, with emphasis on S. pseudintermedius inactivation. However, no significant reduction in
P. aeruginosa was observed in consolidated biofilms and monocultures on dog skin, even with
extended irradiation time. The results obtained in this study are promising and encourage further in
vivo experiments using the 4-H2TMeP porphyrin in aPDT to inactivate MDR bacteria in animal skin
lesions, potentially validating its clinical use in cases unresponsive to conventional therapy
Universidade Federal de Santa Maria
Dissertação
2024-02-08T00:00:00ZNeurocriptococose em cães e gatos: aspectos anatomopatológicos e morfologia fúngica
http://repositorio.ufsm.br/handle/1/31025
Neurocriptococose em cães e gatos: aspectos anatomopatológicos e morfologia fúngica
Oliveira, Miguel Dewes
Kommers, Glaucia Denise
Cryptococcosis is a fungal infection that commonly affects dogs and cats, often manifesting
with neurological signals. This study aimed to access the neuropathological characteristics of
cryptococcosis in nine cats and two dogs that were necropsied at the Laboratório de Patologia
Veterinária (LPV) of Universidade Federal de Santa Maria (UFSM), and using these data, it
was compiled the scientific article that composes this dissertation. The methodology used included the review of the necropsy reports of cases diagnosed with cryptococcosis involving the
nervous system, collecting data such as sex, breed, age, clinical signs, location of the lesions,
macroscopy and histology. Histological reevaluation was performed (using hematoxylin and
eosin [HE] and Alcian Blue) to characterize and locate the lesions, morphology of the agent,
fungal load, type and intensity of the inflammatory infiltrate, lesions in the nervous parenchyma
and morphological characteristics of the yeasts. Fungal morphological criteria, such as capsule
and yeast wall thickness and budding frequency, were analyzed in each case. Only six cases
presented neurological signs, with blindness and head tilt being the most common, in addition
to other varied signs, such as syncope, drowsiness and ataxia. Debilitating and immunosuppressive conditions were detected in five cases. Macroscopic lesions in the central nervous system
(CNS) were found in five cases, presenting as irregular, friable, soft, gelatinous and grayish
masses, with distinct borders. In the sections analyzed, within the availability of paraffin blocks
for reevaluation, the histological findings revealed that the telencephalic cortex was the most
affected site in the CNS, observed in the 11 cases. This region exhibited a higher fungal load
and lower inflammatory response, compared to other neurolocations. Among the cortical regions, the frontal cortex was involved in four cases, the parietal cortex in six and the occipital
cortex in five. The cerebellum was also affected in all cases, but showed a milder inflammatory
response and lower fungal burden than the telencephalic cortices. Furthermore, pulmonary involvement was also observed in all cases. The inflammatory intensity associated with yeasts in
the CNS was predominantly mild to moderate, being accentuated in only two cases, and the
fungal load was more frequently moderate or severe, being mild in only two cases. The heterogeneity observed in the inflammatory response and fungal burden reveals the complex nature
of this infection. Other affected nervous tissues were the optic nerve and the nerve roots and
ganglia of the spinal cord, mainly in cats. In conclusion, this study shows the neuropathological
features of cryptococcosis in a series of cases in dogs and cats, emphasizing the importance of
considering specific neurolocations in this fungal infection. In addition to contributing to a better understanding of the simultaneous involvement of the respiratory and nervous systems.
Universidade Federal de Santa Maria
Dissertação
2023-12-15T00:00:00ZAspectos anatomopatológicos da tireoide de gatos domésticos necropsiados na região central do Rio Grande do Sul (2022-2023)
http://repositorio.ufsm.br/handle/1/30907
Aspectos anatomopatológicos da tireoide de gatos domésticos necropsiados na região central do Rio Grande do Sul (2022-2023)
Herbichi, Alana Pivoto
Flores, Mariana Martins
The thyroid is of great importance in feline medicine due to the high prevalence of
hyperthyroidism in this species. This is considered the main endocrinopathy in elderly cats,
being associated with primary follicular proliferative changes. Meanwhile, hypothyroidism is
a rare endocrinopathy in felines. To date, there are few studies evaluating thyroid lesions in cats.
The objective of this work is to characterize proliferative and non-proliferative thyroid changes
in a population of 61 cats submitted to necropsy without prior clinical suspicion of thyroid
changes. Our objective was also to investigate possible associations between the presence of
proliferative thyroid lesions, affected age group and concomitant cardiac and renal lesions. To
this end, collection and anatomopathological evaluation of the thyroids of cats submitted to
necropsy (2022-2023) were carried out in a veterinary pathology laboratory in the central region
of Rio Grande do Sul, Brazil. During necropsy, both thyroids were macroscopically analyzed,
collected, fixed in 10% buffered formalin, routinely processed and stained using the
hematoxylin and eosin (HE) technique. Of the 61 thyroids analyzed, 15 (24.6%) had some
macroscopic change and 48 (78.7%) had some histological change, of which 33 had
proliferative changes and 48 had some non-proliferative change. In the first manuscript,
proliferative changes were analyzed. The proliferative lesions observed were hyperplasia
(18/33 [54.5%]) and cystic adenoma (6/33 [18.2%]) and microfollicular carcinoma (1/33
[3.03%]). A positive correlation was observed between higher proliferative scores and older
age. Approximately half (48.4%) of cats with a proliferative lesion had a proliferation score
equal to or above A4, a score most frequently associated with hyperthyroidism. Of the 33 cats
with proliferative thyroid lesions, 10 (30.3%) had hypertrophic cardiomyopathy and 11 (33.3%)
had concomitant renal lesions. The results observed in this first study suggest that feline
hyperthyroidism may be clinically underdiagnosed in this region. In the second manuscript,
non-proliferative thyroid changes were investigated. Follicular cysts (28/61 [45,9%]),
lipofuscin accumulation (28/61 [45,9%]) and ectopic thymic tissue (7/61 [11,5%]) were the
most common findings, being the latter observed in young cats. Some of the non-proliferative
lesions observed in this second study have the potential to cause hypo- or hyperthyroidism in
felines. The high prevalence of histological changes in the thyroid of cats without prior clinical
suspicion of thyroid disease in the central region of Rio Grande do Sul is the main finding of
these two studies and highlights the importance of investigating thyroid changes in domestic
cats, even in those individuals who do not present a palpable increase in thyroid volume. It is
hoped that this study will contribute to increased research and improved diagnosis of hyper and
hypothyroidism in cats.
Universidade Federal de Santa Maria
Dissertação
2023-11-13T00:00:00Z