You can use selective media for bacteria Isolation, please see in attach file.

I used selective media but the isolation rate was very low

"wanna" is a vulgar version of "want to"

Try the enrichment step.

Growth in selective enrichment broths. H. pylori Special

Peptone broth (HPSPB), which contained the same ingredients as

HPSPA except the agar, was supplemented with various concen-

trations and combinations of antibiotics to create a selective en-

richment broth for isolating H. pylori. In each trial, six Erlenmeyer

flasks containing 96 ml of HPSPB without antibiotics and six

flasks containing HPSPB with various levels of antibiotics were

inoculated with H. pylori (ATCC strains 43504, 43629, or 43579).

For the first trial, the antibiotic combination tested was vanco-

mycin (10 mg/liter), amphotericin B (10 mg/liter), cefsulodin (10

mg/liter), and trimethoprim (10 mg/liter). Samples were collected

from the broths after 24 and 48 h of incubation, and 0.1 ml of

appropriate decimal dilutions was surface-plated on HPSPA, pro-

viding a total of 12 replications for each HPSPB antibiotic for-

mulation. After inoculation, all plates were incubated in a micro-

aerophilic atmosphere for 4 days at 378C, and the colonies were

counted. Colonies from each replicate were confirmed as H. pylori

as described above. The same methodology was used for three

subsequent trials, in which additional antibiotic combinations

were compared.