Study of the antibacterial capacity of extracts of Solanum incanum L., (Solanaceae) traditionally used for the management of avian cholera in rural areas of Burkina Faso

Nowadays, thanks to the rise of microbial resistance, the lack of health care personnel and especially the high cost of synthetic molecules, phytotherapy could be a panacea in many developing countries. For this reason, the present work which aims to evaluate the phenolic compounds and to study the antibacterial capacity of extracts of roots, stems, leaves and fruits of Solanum incanum L., (Solanaceae) traditionally used for the treatment of pasteurellosis or avian cholera in Burkina Faso, was undertaken. For this purpose, we collected plant material in the commune of Dedougou. After extraction with acetone and water, colorimetric tests were carried out on the different extracts and revealed mostly the presence of tannins and coumarins. The Hydroacetone macerated extract was found to be very interesting for biological activities compared to the macerated extracts and the aqueous decoctions. Inhibition of bacterial growth on different bacterial strains was also shown for all the extracts, especially with Hydroacetone extract. These results could be mainly explained by the inhibitory effect of phenolic compounds. The Hydroacetone extract was also found to be especially very relevant for the prevention and treatment of microbial diseases from poultry.

Herd immunity drives the epidemic fadeout of avian cholera in Arctic-nesting seabirds

Avian cholera, caused by the bacterium Pasteurella multocida, is a common and important infectious disease of wild birds in North America. Between 2005 and 2012, avian cholera caused annual mortality of widely varying magnitudes in Northern common eiders (Somateria mollissima borealis) breeding at the largest colony in the Canadian Arctic, Mitivik Island, Nunavut. Although herd immunity, in which a large proportion of the population acquires immunity to the disease, has been suggested to play a role in epidemic fadeout, immunological studies exploring this hypothesis have been missing. We investigated the role of three potential drivers of fadeout of avian cholera in eiders, including immunity, prevalence of infection, and colony size. Each potential driver was examined in relation to the annual real-time reproductive number (Rt) of P. multocida, previously calculated for eiders at Mitivik Island. Each year, colony size was estimated and eiders were closely monitored, and evaluated for infection and serological status. We demonstrate that acquired immunity approximated using antibody titers to P. multocida in both sexes was likely a key driver for the epidemic fadeout. This study exemplifies the importance of herd immunity in influencing the dynamics and fadeout of epidemics in a wildlife population.