RESUMO
BACKGROUND: Iatrogenic blood contamination during cerebrospinal fluid (CSF) centesis is common, which can limit the diagnostic usefulness of the sample. A novel ultrasound-guided CSF collection technique is described in horses, by which CSF is obtained from the atlantoaxial (AA) space. HYPOTHESIS/OBJECTIVES: To compare ultrasound-guided AA centesis with lumbosacral (LS) centesis in South American camelids (SAC). The hypotheses were that AA centesis would yield samples with less blood contamination although being technically more challenging than LS centesis. ANIMALS: Eight clinically healthy adult SAC from a university-owned teaching herd. METHODS: Single-blinded, randomized, 4-way, 4-period crossover study in which 2 veterinarians each performed both centesis techniques on each animal once. Cytological sample analysis was performed, and the technical difficulty of sample acquisition was assessed. RESULTS: The CSF was collected successfully and without complications by either technique during all collection attempts. Aspects of technical difficulty and concentrations of CSF analytes did not vary significantly between techniques. Median total nucleated cell and red blood cell counts were 1/µL and 0.5/µL and 167.5/µL and 155/µL for AA and LS techniques, respectively. The median total protein concentration was 32.9 mg/dL and 38 mg/dL for AA and LS centeses. A median of 1 attempt was necessary for both centesis techniques and the median number of needle repositioning events was 1 for AA and 0 for LS. CONCLUSION AND CLINICAL IMPORTANCE: Depending on clinical circumstances, ultrasound-guided AA centesis appears to be an acceptable alternative to other techniques for collection of CSF from SAC.
Assuntos
Líquido Cefalorraquidiano , Paracentese , Humanos , Cavalos , Animais , Paracentese/veterinária , Estudos Cross-Over , Ultrassonografia , Contagem de Eritrócitos/veterinária , América do SulRESUMO
Listeria monocytogenes is a bacterium that infect humans and animals and causes a zoonotic disease characterized by encephalitis, septicemia or abortion. In addition, listeriosis leads to significant economic losses due to animal death and sacrifice. This research compared the technique of immunofluorescence (IF) and immunohistochemistry (IHC) for the diagnosis of L. monocytogenes in formalin-fixed and paraffin-embedded (FFPE) tissues. A total of 30 tissue blocks from 15 animals with history and/or lesions compatible with listeriosis were selected. For both IHC and IF, the same diluted (1:200) polyclonal primary antibody was used against L. monocytogenes serotypes 1 and 4. For IHC, a polymer secondary antibody conjugated to peroxidase (HRP) was used. For IF, samples were incubated with a fluorescein-labeled anti-rabbit IgG secondary antibody. Each sample was classified according to the presence and percentage of immunolabeling area. From 30 samples, 10 were positive at least for one technique, whereas eight samples were positive for both IHC and IF with similar score. There was strong immunolabeling in tissue samples from bovines experimentally infected with L. monocytogenes ATCC 7644, as well as in nervous tissues from naturally infected ruminants. Additionally, IF did not show any difference in sensitivity when compared to IHC. Using processed biological materials for IF, instead of fresh tissues, is a quite unique technique, since there are few protocols described. Therefore, this study demonstrated that both techniques are efficient to detect L. monocytogenes in FFPE tissues.
Listeria monocytogenes é uma bactéria que infecta humanos e animais, podendo causar uma doença zoonótica caracterizada por encefalite, septicemia e abortos. Além disso, a listeriose resulta em perdas econômicas significativas pela morte e sacrifício de animais. O objetivo deste trabalho foi comparar a técnica de imunofluorescência (IF) e imuno-histoquímica (IHQ) para detecção de L. monocytogenes em tecidos fixados e parafinizados. Foram selecionados 30 blocos de tecidos de 15 animais com histórico e/ou lesões compatíveis com listeriose. Para ambas as técnicas, foi utilizado o mesmo anticorpo primário policlonal diluído (1:200) para detecção de L. monocytogenes sorotipos 1 e 4. Para a IHQ foi utilizado anticorpo secundário em polímero acoplado a peroxidase (HRP). Para a IF, as amostras foram incubadas com anticorpo secundário anti-IgG de coelho marcado com fluoresceína. Cada amostra foi classificada quanto à presença de imunomarcação e porcentagem de área positiva. Das 30 amostras, 10 foram positivas em pelo menos uma das técnicas, sendo oito amostras positivas em ambas IHQ e IF com o mesmo escore. Houve forte imunomarcação tanto em amostras de bovino experimentalmente infectado com L. monocytogenes ATCC 7644, como em amostras de tecido nervoso de ruminantes naturalmente infectados. Além disso, a IF não apresentou diferença na sensibilidade quando comparada com a IHQ. O uso de materiais biológicos processados para IF, ao invés de tecidos frescos, é algo inovador, uma vez que existem poucos protocolos descritos. Portanto, este estudo demonstrou que as duas técnicas foram eficientes para detectar L. monocytogenes em tecidos fixados em formol e parafinizados.