Why Mycoplasma Is Antibiotic Resistant?

All mycoplasmas lack a cell wall and, therefore, all are inherently resistant to beta-lactam antibiotics (e.g., penicillin).

Why is mycoplasma pneumoniae resistant to antibiotics that interfere with cell wall synthesis?

Mycoplsma has an Intrinsic Resistance to B-lactams since they lack the target (cell wall, peptidoglycan) on which the antibiotic can acts. because of this pathogen lack the cell wall.

Why are mycoplasma not affected by penicillin?

Mycoplasmas are the smallest free-living microorganisms, being about 300 nm in diameter. They are bounded by a triple-layered membrane and, unlike conventional bacteria, do not have a rigid cell wall. Hence, they are not susceptible to penicillins and other antibiotics that act on this structure.