blood agar hemolysis by gram negative bacteria?

[spirochete]

I've looked all over and I can only find information on blood agar hemolyis for gram positive bacteria. Can I take this to mean that gram negative bacteria are generally gamma hemolytic? If so, are there any notable exceptions to this?

[biohazard]

Firstly, I presume you are talking about beta hemolytic bacteria here - although my reply will cover a bit of the alpha type too. Secondly, no, you cannot assume there aren't hemolytic gram negative bacteria, even though the references are scarce

If memory serves me right, Pseudomonas aeruginosa is a good example of gram negative bacteria that is often beta hemolytic. However, in clinical diagnostics this is rarely used, because P. aeruginosa can be easily detected with other means more reliably.

Furthermore (again, if I recall correctly), even E. coli has hemolytic strains - the type of hemolysis varying between alpha and beta.

Hope this helps!

[hisunny4u]

hi ....
even i dont exactly.... actually even i am working on hemolysins of leptospira ...u can also conform hemolysis not only by blood agar assay ..u can also conform by taking sheep blood cells and then adding ur toxin and finally checking ur % of hemolysis...but blood agar assay gives u details abt alpha r beta r gamma....

[hisunny4u]

And one more thing is that each gram psoitive and gram negative organisms relaease different type of toxins(alpha ,beta,gamma)..need not b same