Clinical Laboratory Biosafety Gaps: Lessons Learned from Past Outbreaks Reveal a Path to a Safer Future.

Patient care and public health require timely, reliable laboratory testing. However, clinical laboratory professionals rarely know whether patient specimens contain infectious agents, making ensuring biosafety while performing testing procedures challenging. The importance of biosafety in clinical laboratories was highlighted during the 2014 Ebola outbreak, where concerns about biosafety resulted in delayed diagnoses and contributed to patient deaths. This review is a collaboration between subject matter experts from large and small laboratories and the federal government to evaluate the capability of clinical laboratories to manage biosafety risks and safely test patient specimens. We discuss the complexity of clinical laboratories, including anatomic pathology, and describe how applying current biosafety guidance may be difficult as these guidelines, largely based on practices in research laboratories, do not always correspond to the unique clinical laboratory environments and their specialized equipment and processes. We retrospectively describe the biosafety gaps and opportunities for improvement in the areas of risk assessment and management; automated and manual laboratory disciplines; specimen collection, processing, and storage; test utilization; equipment and instrumentation safety; disinfection practices; personal protective equipment; waste management; laboratory personnel training and competency assessment; accreditation processes; and ethical guidance. Also addressed are the unique biosafety challenges successfully handled by a Texas community hospital clinical laboratory that performed testing for patients with Ebola without a formal biocontainment unit. The gaps in knowledge and practices identified in previous and ongoing outbreaks demonstrate the need for collaborative, comprehensive solutions to improve clinical laboratory biosafety and to better combat future emerging infectious disease outbreaks.

The Bordetella type III secretion system effector BteA contains a conserved N-terminal motif that guides bacterial virulence factors to lipid rafts.

The Bordetella type III secretion system (T3SS) effector protein BteA is necessary and sufficient for rapid cytotoxicity in a wide range of mammalian cells. We show that BteA is highly conserved and functionally interchangeable between Bordetella bronchiseptica, Bordetella pertussis and Bordetella parapertussis. The identification of BteA sequences required for cytotoxicity allowed the construction of non-cytotoxic mutants for localization studies. BteA derivatives were targeted to lipid rafts and showed clear colocalization with cortical actin, ezrin and the lipid raft marker GM1. We hypothesized that BteA associates with the cytoplasmic face of lipid rafts to locally modulate host cell responses to Bordetella attachment. B. bronchiseptica adhered to host cells almost exclusively to GM1-enriched lipid raft microdomains and BteA colocalized to these same sites following T3SS-mediated translocation. Disruption of lipid rafts with methyl-beta-cyclodextrin protected cells from T3SS-induced cytotoxicity. Localization to lipid rafts was mediated by a 130-amino-acid lipid raft targeting domain at the N-terminus of BteA, and homologous domains were identified in virulence factors from other bacterial species. Lipid raft targeting sequences from a T3SS effector (Plu4750) and an RTX-type toxin (Plu3217) from Photorhabdus luminescens directed fusion proteins to lipid rafts in a manner identical to the N-terminus of BteA.