Thioredoxin fused CHH1 protein as antigen for polyclonal antisera: Application to regulate glycemia in Penaeus monodon

Crustacean hyperglycemic hormone (CHH) family neuropeptides have been in research limelight for the past two decades due to their importance in the regulation of glycemia, moulting and gonad development in crustaceans. Under natural conditions, low levels of CHH neuropeptide and the structural similarity of the three CHH family neuropeptides limit their purification directly from the animal. In this study, we isolated the mature region of the CHH1 gene, constructed the recombinant translation expression vector (pET32a+ - PmCHH1) and produced thioredoxin fused protein in E scherichia coli (BL21 (DE3) pLysS). The translation expression vector construct (pET32a+ - PmCHH1) was successfully built for production of thioredoxin fused mature CHH1 protein (mf-PmCHH1-29.47 kDa). Mf-PmCHH1 produced a hyperglycemic effect similar to that of the eyestalk extract when experimentally injected into adult eyestalk ablated Penaeus monodon. The polyclonal antiserum (anti-mf-PmCHH1) was developed in mice against the purified thioredoxin fused mf-PmCHH1 protein. A hypoglycemic effect was induced in adult P. monodon by the polyclonal antiserum which was raised against thioredoxin fused CHH1 protein. Immunolocalization of CHH1 producing neurosecretory cells in the eyestalk of P. monodon was a practical result obtained with the polyclonal antiserum anti-mf-PmCHH1. Therefore, mf-PmCHH1 and its antiserum (anti-mf-PmCHH1) are added to the list of tools to better understand the endocrine mechanisms regulating glycemia and reproduction in P. Monodon

Virulence potential and antibiotic susceptibility pattern of motile aeromonads associated with freshwater ornamental fish culture systems: a possible threat to public health

Aeromonas spp. are ubiquitous aquatic organisms, associated with multitude of diseases in several species of animals, including fishes and humans. In the present study, water samples from two ornamental fish culture systems were analyzed for the presence of Aeromonas. Nutrient agar was used for Aeromonas isolation, and colonies (60 No) were identified through biochemical characterization. Seven clusters could be generated based on phenotypic characters, analyzed by the programme NTSYSpc, Version 2.02i, and identified as: Aeromonas caviae (33.3%), A. jandaei (38.3%) and A. veronii biovar sobria (28.3%). The strains isolated produced highly active hydrolytic enzymes, haemolytic activity and slime formation in varying proportions. The isolates were also tested for the enterotoxin genes (act, alt and ast), haemolytic toxins (hlyA and aerA), involved in type 3 secretion system (TTSS: ascV, aexT, aopP, aopO, ascF-ascG, and aopH), and glycerophospholipid-cholesterol acyltransferase (gcat). All isolates were found to be associated with at least one virulent gene. Moreover, they were resistant to frequently used antibiotics for human infections. The study demonstrates the pathogenic potential of Aeromonas, associated with ornamental fish culture systems suggesting the emerging threat to public health.

Leuconostoc garlicum: An unusual pathogen in the era of vancomycin therapy.

Leuconostoc garlicum, belonging to the family of Leuconostocaceae, is a catalase-negative, Gram-positive ovoid cocci, intrinsically resistant to vancomycin. Clinical infection by Leuconostoc garlicum is rare. We report a case of respiratory tract infection subsequent to vancomycin therapy.