Safety Precautions and Operating Procedures in an (A)BSL-4 Laboratory: 3. Aerobiology

Summary

As high-consequence pathogens can potentially infect subjects through airborne particles, aerobiology has been increasingly applied in pathogenesis research and medical countermeasure development. We present a detailed visual demonstration of aerobiology procedures during an aerosol challenge in nonhuman primates in an animal biosafety level 4 maximum containment environment.

Abstract

Aerosol or inhalational studies of high-consequence pathogens have recently been increasing in number due to the perceived threat of intentional aerosol releases or unexpected natural aerosol transmission. Specific laboratories designed to perform these experiments require tremendous engineering controls to provide a safe and secure working environment and constant systems maintenance to sustain functionality. Class III biosafety cabinets, also referred to as gloveboxes, are gas-tight enclosures with non-opening windows. These cabinets are maintained under negative pressure by double high-efficiency-particulate-air (HEPA)-filtered exhaust systems and are the ideal primary containment for housing aerosolization equipment. A well planned workflow between staff members within high containment from, for instance, an animal biosafety level-4 (ABSL-4) suit laboratory to the ABSL-4 cabinet laboratory is a crucial component for successful experimentation. For smooth study execution, establishing a communication network, moving equipment and subjects, and setting up and placing equipment, requires staff members to meticulously plan procedures prior to study initiation. Here, we provide an overview and a visual representation of how aerobiology research is conducted at the National Institutes of Health, National Institute of Allergy and Infectious Diseases Integrated Research Facility at Fort Detrick, Maryland, USA, within an ABSL-4 environment.

Introduction

Transmission of viruses generally occurs by direct or physical contact, but many important viral diseases (e.g., measles, chickenpox, influenza) are caused by pathogens that are transmitted by aerosol or respiratory droplets. Such pathogens have the potential to cause a pandemic with consequences ranging from widespread mild disease associated with loss of work (e.g., common cold) to rarer serious disease with high lethality (e.g., smallpox). High-consequence pathogens that spread naturally by aerosol or by intentional aerosol release (biological weapons) are of particular interest to aerobiology¹. Humans may become rapidly infect....

Protocol

This protocol adheres to the following animal care guidelines. Animals were housed in a facility accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International. All experimental procedures were approved by the National Institute of Allergy and Infectious Diseases, Division of Clinical Research, Animal Care and Use Committee and were in compliance with the Animal Welfare Act regulations, Public Health Service policy, and the Guide for the Care and Use of Laboratory Animals recommendations.

1. Aerobiology: Animal Biosafety Level 4 (ABSL-4) Suit Laboratory

1. Laboratory Preparat....

Results

The Class III biosafety cabinet (BSC) is a hermetically sealed stainless steel cabinet containing an ABSL-4 environment under negative pressure within an ABSL-4 cabinet laboratory (Figure 1). Materials can be introduced into the BSC by staff working in the ABSL-4 cabinet laboratory through an under-cabinet-mounted stainless steel tank (commonly referred to as a "dunk tank" in ABSL-4 or BSL-4 settings) containing a 5% dual quaternary ammonium (n-alkyl dimethyl benzyl ammon.......

Discussion

We outline the aerobiology procedures used at the IRF-Frederick for working with highly hazardous (Risk Group 4) pathogens. One purpose of visualizing the bioaerosol procedures is to emphasize the safety of staff when using a Class III BSC during experimentation with such pathogens to avoid laboratory-acquired infections. Class III BSCs maintain an inward directional airflow that exhausts into double HEPA filters to ensure that pathogens are contained within the laboratory (Figure 1).

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Micro-Chem Plus	National Chemical Laboratories	255
Ethanol	Fisher	BP2818500
Paraformaldehyde	Sigma-Aldrich	441244
Class III BSC	Germfree	DGB-10
Integrated BSC gloves	Piercan	10UY2032-9
Aerosol Management Platform (AeroMP)	Biaera Technologies	NA
Head-out plethysmography	Buxco/Data Sciences International	NA
Respriatory inductive plethysmography	Data Sciences International	NA
Centered flow tangential aerosol generator (CenTAG)	CH Technologies	NA
Collison nebulizer	BGI Inc.	CN25
Autoclave	Getinge	GEB 2404 AMB-2
Sperian positive-pressure suit	Honeywell Safety Products	BSL 4-2
Outer suit gloves (latex, Ansell Canners and Handlers)	Fisher	19-019-601
Outer suit gloves (nitrile/rubber, MAPA)	Fisher	2MYU1
Scrubs	Cintas	60975/60976
Socks	Cintas	944
Duct tape	Pack-N-Tape	51131069695
Towels	Cintas	2720
O-rings	O-ring warehouse	AS568-343
Overshoes	Amazon	B0034KZE22
Zip lube	Amazon	B000GKBEJA