Mycoplasma is a genus of very small bacteria that lack a cell wall. Due to their very small size and their flexible shape, these pathogens are able to pass bacteria filters and, for this reason cannot be safely removed by means of such filters during the manufacture of medicinal products. Mycoplasma include species which cause diseases of the respiratory and urogenital tracts in humans.
Various test methods are applied to ascertain that neither the original cells used for the production of biological medicinal products – the so-called master cell banks – nor the production cells themselves are contaminated with mycoplasma bacteria. One of the most sensitive test methods is the nucleic acid amplification technique (NAT). It involves amplification of sections of the bacterial genome by a billion, enabling the detection of the pathogenic agent. As with other test methods, a prerequisite for test reliability is its verification using suitable reference materials – so-called WHO International Standards (IS).
Coworkers of PD Dr Micha Nübling, head of the Section Molecular Virology of the Division Virology at the Paul-Ehrlich-Institut, have developed the first IS for NAT testing for mycoplasma (“1st WHO IS for mycoplasma DNA for NAT assay designed for generic mycoplasma detection”). The Section at the PEI forms part of the WHO Collaborating Centre for Quality Assurance of Blood Products and in vitro Diagnostic Devices at the institute. Part of the development process of the IS involved an international feasibility study, in which four distantly related mycoplasma species were assayed in different concentrations by 21 laboratories using 26 NAT methods. Based on the results obtained from these studies, the WHO standard was designed and manufactured and finally established by the WHO “Expert Committee on Biological Standardization (ECBS)”. Professor Klaus Cichutek, president of the Paul-Ehrlich-Institut, is a member of the ECBS.
This WHO IS is now available for the determination of quality features of NAT tests (e.g. the detection limit), the calibration of quantitative assays and the definition of regulatory requirements for mycoplasma testing. “We are pleased that we have succeeded in developing this WHO standard, which will contribute to making worldwide test methods for the detection of mycoplasmas – more reliable and comparable with each other“, says PD Dr Micha Nübling.
Nübling CM, Baylis SA, Hanschmann KM, Montag-Lessing T†,
Chudy M, Kreß J, Ulrych U, Czurda S, Rosengarten R, and
the Mycoplasma Collaborative Study Group (2015): World Health Organization International Standard to Harmonize Assays for Detection of Mycoplasma DNA. Appl Environ Microbiol. 2015 Jun 12. pii: AEM.01150-15
The Paul-Ehrlich-Institut, Federal Institute for Vaccines and Biomedicines in Langen near Frankfurt/Main, is a senior federal authority reporting to the Federal Ministry of Health (Bundesministerium für Gesundheit, BMG). It is responsible for the research, assessment, and marketing authorisation of biomedicines for human use and veterinary vaccines. Its remit also includes the authorisation of clinical trials and pharmacovigilance, i.e. recording and evaluation of potential adverse effects. Other duties of the institute include official batch control, scientific advice and inspections. In-house experimental research in the field of biomedicines and life science form an indispensable basis for the varied and many tasks performed at the institute. The PEI, with its roughly 800 staff, also has advisory functions at a national level (federal government, federal states (Länder)), and at an international level (World Health Organization, European Medicines Agency, European Commission, Council of Europe etc.).