Streptococcus agalactiae alters cerebral enzymes of phosphoryl transfer network in experimentally infected silver catfish: Impairment on brain energy homeostasis

It is recognized that phosphoryl transfer network, through the activities of creatine kinase (cytosolic and mitochondrial CK), adenylate kinase (AK) and pyruvate kinase (PK), provides new perspectives to understand the disturbances of energetic metabolism between sites of generation and utilization of adenosine triphosphate (ATP). Thus, the aim of this study was to evaluate the involvement of phosphoryl transfer network in the pathophysiology of Streptococcus agalactiae linked with central nervous system (CNS). Cerebral cytosolic and mitochondrial CK activities decreased in infected animals compared to uninfected animals, similarly to observed by cerebral AK and PK activities. Moreover, the cerebral ATP levels decreased in infected animals compared to uninfected animals. Based on these evidences, the inhibition and absence of efficient nucleocytoplasmic communication between CK isoenzymes caused an impairment on cerebral energetics. Moreover, the inhibition on hepatic AK and PK caused an impairment of communication between sites of ATP generation and ATP utilization, which is corroborated by cerebral ATP depletion. In summary, these alterations contribute to disease pathogenesis linked to CNS during fish streptococcosis.