Mycoplasma Clearance and Risk Analysis in a Model Bioprocess

Abstract

Mycoplasmas are a type of bacteria that lack cell walls and are occasional cell culture contaminants. In a biotechnology setting, because they can pass through 0.2 μm filters, mycoplasmas could pose a potential patient safety hazard if undetected contaminants from the production culture were not completely removed by downstream biotechnology manufacturing. In this study we investigated the ability of typical commercial monoclonal antibody purification operations to clear and kill mycoplasmas, using Acholeplasma laidlawii as a model organism. Our spike/removal studies have shown that protein A column chromatography clears about 4–5 log₁₀. Column regeneration effectively prevents A. laidlawii column carryover between chromatography runs. Moreover, low-pH hold steps, typically implemented after protein A purification, effectively kill A. laidlawii using either pH 3.8 glycine or acetate solutions (LRV ≥5.30 and ≥4.57, respectively). Solvent/detergent treatment, used in some processes instead of low-pH hold, also completely kills highly concentrated A. laidlawii (LRV ≥5.95).

LAY ABSTRACT: Biotechnology medicines need to be free from contaminating microorganisms such as mycoplasmas, a type of bacteria that can cause disease in humans (e.g., walking pneumonia). Here we show that some monoclonal antibody manufacturing steps can effectively clear and/or kill Acholeplasma laidlawii, a model mycoplasma species used in our study. This provides an additional level of safety assurance of biotechnology medicines for patients.