Antibiotic testing in Roach after inoculation with F.t. LVS

I have just concluded my recent experiment that is a follow up from 12-12-14. I followed the same protocol, but narrowed the antibiotics to be tested and changed the administration of antibiotics. Instead of feeding the roaches antibiotics, I delivered antibiotics through a systemic injections with a sterile PBS solution.

We found that when streptomycin was delivered directly into the hymolymph, with was effective at rescuing roaches from death by F. tularensis. This gives us evidence that B. dubia roaches have an intact gastrointestinal track that streptomycin cannot cross when given through an oral administration.

Here are the antibiotics that I delivered through needle injections:
Streptomycin (32μg/roach)
Resazurin (11μg/roach)
Doxycycline (32μg/roach)

Azithromycin (100μg/roach)
Ciprofloxacin (1μg/roach)

We saw the following data:
ABX,    Day     0     1      2     3     4     5     6     7
Streptomycin  10    10     9     9     8     8     8     8
Doxycicline    10    10    10   10    9    9      9     9
Ciprofloxacin 10    10     7     7     6     6     6     6
Azithromycin 10    10     9     2     0     0     0     0
Resazurin       10    10     6     2     1     0     0     0
No ABX         10    10    5     2     0     0     0     0
No LVS          10    10   10   10  10   10   10   10

//BEE