Synergism between molecules derived from Garcinia brasiliensis and antimicrobial drugs on field isolates of Mycoplasma hyopneumoniae.

Mycoplasma hyopneumoniae (M. hyopneumoniae) is one of the smallest free-living bacteria found in nature; it has an extremely small genome and lacks a cell wall. It is the main etiological agent of porcine enzootic pneumonia (EP), a chronic respiratory disease with worldwide distribution that causes significant losses in swine production. Due to the great economic impact caused by EP, new strategies for treating and controlling this agent are researched. The objective of this study was to verify the anti-M. hyopneumoniae activity of compounds derived from Garcinia brasiliensis and the synergism with the main antimicrobials used in the treatment of EP; this is the first study assessing the synergism between bioactive molecules and antimicrobial compounds in vitro against isolates of M. hyopneumoniae. The minimum inhibitory concentrations (MICs) of the antimicrobials tiamulin, valnemulin, and enrofloxacin, as well as the bioactive compounds guttiferone-A (Gut-A), 7-epiculsone (7-Epic), copper 7-epiculsone (7-Epic-Cu), and benzophenone, were determined. Subsequently, the interactions of antibiotics with the compounds were evaluated using the checkerboard method. Three field M. hyopneumoniae isolates were used, and the J strain was used as a control. The MIC values of the antimicrobials compared to the field isolates were equal to and lower than those of the reference strain J. Among the compounds used, 7-Epic-Cu showed the lowest MIC value. Synergistic association was observed for Gut-A with tiamulin and valnemulin, whereas 7-Epic and 7-Epic-Cu showed synergistic action with enrofloxacin. No synergistic effect was observed for benzophenone. Despite being an initial study, the results suggest that these combinations hold promise for the treatment of infections caused by M. hyopneumoniae.

Interaction of Mycobacterium avium subsp. paratuberculosis with bovine sperm.

Mycobacterium avium subsp. paratuberculosis (MAP) is responsible for Paratuberculosis mainly affecting domestic ruminants. The interaction between MAP and sperm and/or germ cells has not yet been established, however the adherence between MAP and the host cell surface is associated to the 85 complex proteins that bind to the host cell's fibronectin. Therefore, this study aimed to evaluate the binding of MAP to bovine sperm and to verify changes in these cells by the presence of MAP before and after sperm cryopreservation. Polyclonal antibodies to MAP 85 complex proteins were produced and utilized in the analyzes. Two Nelore bulls were used for semen collection and MAP dilutions (103-108 CFU/mL) were inoculated in the samples; sperm motility and vigor were evaluated using light microscopy at different times before and after cryopreservation and in the presence and absence of the antibodies 85A and 85B. Interaction of MAP and sperm, interaction of MAP and sperm in the presence of Ab 85A and in the presence of Ab 85B were analyzed by scanning electron microscopy. The viability of MAP after sperm cryopreservation were evaluated by plating the samples after thawing. It was observed that sperm in the presence of MAP shows a decrease in motility and vigor, and that the higher the MAP concentration, the lower the sperm performance. It was possible to determine the viability of MAP after cryopreservation in samples of higher concentrations, which demonstrates the potential of transmission of this pathogen through artificial insemination. The interaction of MAP with bovine sperm occurs mainly in the midpiece and may be linked to the proteins 85A and 85B present in the MAP membrane.