Bacteria causing pyometra in bitch and queen induce neutrophil extracellular traps.
Neutrophils are capable of releasing their DNA in response to infectious agents to form neutrophil extracellular traps (NETs) to destroy pathogens. Even though pyometra in queens and bitches is a common disease, its pathogenesis is not fully understood. The aim of this study was to assess the presence of NETs in the endometrium of queens and bitches suffering from pyometra. Pyometra and normal uteri were obtained after ovariohysterectomy from adult queens and bitches in diestrus. Uterine contents were evaluated for bacterial isolation and identification and for NETs presence. Escherichia coli were isolated in 5/5 queens and 4/5 bitches, and Streptococcus spp in one bitch. Sterile glass coverslips were placed on the endometrium surface to obtain material for NETs that were evaluated by immunocytochemistry (histone, neutrophil elastase or myeloperoxidase), fluorescence microscopy or scanning electron microscopy. NETs in endometrium content were positively stained by DNA histone DAPI, myeloperoxidase and by neutrophil elastase. NETs were spread in all observed queen and bitch endometria of pyometra cases. Ultrastructure images of NETs depicted clusters of globular material with fine filaments deposited on or around thick filaments and trapped bacteria. To the best of our knowledge these are the first findings confirming NETs endometrial presence in queen and bitch pyometra. Nevertheless, the precise role of NETs in pyometra in the bitch and queen, either to contribute to the defeat of infection or to its persistence remains to be unraveled.
['Rebordão|M R|MR|', 'Alexandre-Pires|G|G|', 'Carreira|M|M|', 'Adriano|L|L|', 'Carneiro|C|C|', 'Nunes|T|T|', 'Mateus|L|L|', 'Ferreira-Dias|G|G|']
D000818:Animals D004283:Dog Diseases D004285:Dogs D004717:Endometrium D004926:Escherichia coli D065206:Extracellular Traps D005260:Female D008855:Microscopy, Electron, Scanning D008856:Microscopy, Fluorescence D055112:Pyometra D013291:Streptococcus
Pyometra Bitch Queen Neutrophil extracellular traps (NETs) Escherichia coli Streptococcus spp