Penicillin for Syphilis?

[MudPhud20XX]

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FA says penicillin and vancomycin are mainly for gram positive, since these two drugs cannot penetrate the thick outer membrane of gram negative bugs. But don't they say we use penicillin G for syphilis treatment and isn't syphilis considered as gram negative? Can anyone help me out? Many thanks in advance.

 

[mcloaf]

Treponema isn't really considered a gram negative organism AFAIK. It's too small to visualize using gram staining and light microscopy, and its cell wall structure is different than that of classical gram negatives.

 

[igcgnerd]

Treponema isn't really considered a gram negative organism AFAIK. It's too small to visualize using gram staining and light microscopy, and its cell wall structure is different than that of classical gram negatives.

Exactly. It isn't as much of a gram neg- bus as a non gram staining bug.

 

[notbobtrustme]

Syphilis is closely related to gram negatives, it's just shaped weird so that it doesn't gram stain properly. Penicillin wouldn't work if syphilis didn't have some sort of peptidoglycan cell wall.

 

[MudPhud20XX]

Thank you guys. Could you help me with this question below too? I had a question about the mechanism of polycystic ovarian dz (PCOD).

So I was looking at Pathoma and it says estrone that is being converted from androgen in adipose tissue does a negative feedback decreasing FSH and thus result in cystic degeneration of follicles. I get this idea, but won't this prevent the multiple ovarian follicular cysts formation to begin with? Many thanks in advance.

 

[Phloston]

Spirochetes are considered neither gram(+) nor (-). They're in their own unique category.

And beta-lactams still work on gram(-) organisms. Gram(-)s still have cell walls.

Think about it. Aminoglycosides specifically target aerobic gram(-) rods, yet we know aminoglycosides + beta-lactams are synergistic (e.g., gentamycin + ampicillin for pyelonephritis). The beta-lactam won't kill the gram(-) organism, but it allows the aminoglycoside to better penetrate into the cell.

 

[notbobtrustme]

Spirochetes are considered neither gram(+) nor (-). They're in their own unique category.

They are gram negatives by DNA analysis.

 

[thehundredthone]

So I was looking at Pathoma and it says estrone that is being converted from androgen in adipose tissue does a negative feedback decreasing FSH and thus result in cystic degeneration of follicles. I get this idea, but won't this prevent the multiple ovarian follicular cysts formation to begin with? Many thanks in advance.

It's the androgen excess/LH imbalance that causes the stromal hypertrophy and follicular cyst formation.