Abx Screening of P. larvae

Made a batch of MYPGP agar + several antibiotics in order to determine the sensitivities of P. larvae to them. This experiment is a preliminary to an upcoming allelic exchange.

Antibiotics

Kanamycin 50 ug/ml

Ampicillin 100 ug/ml

Erythromycin 5 ug/ml

Polymyxin 60 units

(A stock of each antibiotic is stored at 4C)

250 mL of each MYPG-Abx agar was created. A four day old broth culture of P. larvae in MYPGP+thiamine broth (grown at 37C 5%CO2) was diluted ten fold down to 10^-3. Drop plates were preformed on each antibiotic agar for each P. larvae dilution. 

Plates were incubated at 37C in the static incubator (not inverted) overnight and then transferred to the 37C 5%CO2 incubator for three days. The growth on each of the plates are shown below:

 

 

It would appear that P. larvae is

Polymyxin resistant, but sensitive to erythromycin, ampicillin, and kanamycin. A few of the colonies that grew on the No Abx control and from the Polymyxin plates were converted to genomic lysates and will be amplified via PCR using the 16SrRNA P. larvae identification primers, AFB-F/R.

//EWW