In contrast, WT animals exhibited minimal mortality with the standard S. aureus infectious inoculum used in these studies (i.e. 7×10 10 cfu).
Simple public health measures, like hand washing, will decrease the infectious inoculum, help prevent disease outbreaks, as well as promote the evolution of less virulent pathogens.
While the minimum infectious period ranged from 6 to 7 days, the average maximum infectious period ranged from approximately 20 to nearly 40 days.
In tricky situations, exploratory laparotomy could probably be performed, as it seems not to be associated with an increased mortality, and represents an effective way to treat NE, perform microbiological samples and remove infectious inoculum.
Estimates of the reproduction ratio (R) for the first generation of transmission ranged from 4.9 to 24.2 for the minimum infectious period and from 9.8 to 66.3 for the maximum infectious period, depending on the isolate.
In the virulence assay, isolates were injected at an infectious inoculum of 1×105 cells, using 12 to 19 larvae per strain per replicate at 37°C.
For bacterial replication experiments only, the infectious inoculum was harvested from αBCYE plates rather than from early stationary phase liquid cultures used for all other assays.
The infectious inoculum was injected directly into the hemolymph via the penultimate or ultimate pseudo-pods using a Hamilton syringe (Hamilton USA).
Firstly the size of the infectious inoculum, secondly the route, with intracerebral inoculation being more efficient than oral, intraperitoneal and intravenous injection, thirdly the polymorphisms in the Prnp gene of both donor and recipient.
A major problem with this theoretical protection mechanism is that it needs to eliminate all parasites present in the infectious inoculum, otherwise an exacerbated form of the disease can be anticipated once surviving parasites infect deactivated macrophages.
