Severe feline sporotrichosis associated with an increased population of CD8low cells and a decrease in CD4⁺ cells.

Sporotrichosis is a subcutaneous mycosis with worldwide distribution, especially in tropical and subtropical areas. Zoonotic transmission is described with cats being the main animal species involved. The occurrence of severe feline sporotrichosis with high fungal levels demonstrates the susceptibility of cats to this disease and the importance of studying its pathogenesis. This study describes the leukocytes profile in blood of cats with sporotrichosis by flow cytometry and its correlation with histopathology and fungal load. The cats with sporotrichosis were separated into groups L1, L2, and L3 (lesions at one, two, and three or more noncontiguous skin locations, respectively) and were classified as good, fair, or poor general conditions. The highest percentage of CD4+ cells was associated to L1 (P = .04) and to good general condition (P = .03). The percentage of CD8+ cells was greater in L2 and L3 (P = .01). CD8(low) expression occurred in 20 animals with sporotrichosis, mainly in L3 (P = .01) and was not observed in healthy controls. This expression was related to macrophage granulomas (P = .01) and predominated in cases with high fungal load. Altogether, the results indicated that control over feline sporotrichosis, with maintenance of a good general condition, fixed lesions, well-organized response and lower fungal load, is associated with increased CD4+ cells percentages. In contrast, a poor general condition, disseminated lesions and high fungal load were related to increased CD8+ cell percentages and increased expression of CD8(low). As conclusion these results point to an important role of the CD4:CD8 balance in determining the clinical outcome in feline sporotrichosis.

Generation and Characterization of Murine Monoclonal Antibodies anti-PBP2a of Methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug-resistant bacterium that causes serious infections worldwide. This pathogen is resistant to all beta lactam antibiotics due the presence of PBP2a, a transpeptidase enzyme that presents very low beta-lactam affinity. Here we report the generation and characterization of mouse monoclonal antibodies to PBP2a of MRSA strains. Two clones were obtained and characterized by immunoassays (ELISA, avidity index determination, and immunoblotting), isotyping, association/dissociation rate constants by surface plasmon resonance (SPR), and flow cytometry. Clone 38, which showed the best avidity and affinity, bound to PBP2a located on the bacterial surface by flow cytometry. Further studies are warranted in order to evaluate if these antibodies may help inhibit bacterial growth and be used to treat infections by MRSA.