Safety in the Microbiology Lab

Safety in the Microbiology Lab

An Introduction to Principles and Practices at Biosafety Levels 1, 2 & 3

Pre-Test

Some Category A agents pose limited to moderate risk to the laboratory worker (BSL-2) while others (BSL-3) pose a greater risk.

o What does this tell you about the:
1. ease or difficulty for bioterrorists to produce BSL-2 and BSL-3 agents?
2. ease or difficulty to control BSL-2 and BSL-3 agents if used for bioterrorism?
* Why is Anthrax (a BSL-2) agent considered a very likely biothreat agent?
* What microbiology clues would implicate tularemia as a bioterror event?
* How do microbiologists protect themselves form accidental exposure to pathogenic microorganisms?

Learning Objectives

* By the end of the lesson the student will understand:
o The need for and use of biosafety designations
o Standard (or Good) Laboratory Practices
o The basic principles and practices for working in Labs designated BSL 1, BSL 2 or BSL 3
o CDC Priority Categories and the Select Agents Act
o Examples of microorganisms designated by their Biosafety Level

Microorganism Categories

* How are microorganisms categorized?
o By genetics to show how they are related
o By tissues they infect to show how they cause disease
o By pathogenicity and communicability (also known as their BioSafety Level)

Guidelines for Microorganism Use

* Besides federal law and regulations other guidelines exist for the use and control of microorganisms:
o CDC/NIH Biosafety in Microbiological and Biomedical Laboratories (BMBL)
o WHO (World Health Organization) Biosafety Manual
o USDA (United States Department of Agriculture) protocols

Guidelines for Microorganism Use

* All the afore mentioned agencies use the same system to categorize microorganisms based on the organisms danger to the laboratory worker and other research personnel.

* The microbes are placed into 4 categories called : Biosafety Levels (BSL 1-4)

BSL Labs

* Microbiology Laboratories are set up and maintained to meet a specific containment level. The designated level conveys information about infection potential and engineering controls implemented to protect workers.

Dangerous/exotic agents which pose high risk of life-threatening disease, aerosol-transmitted lab infections; or related agents with unknown risk of transmission Indigenous or exotic agents with potential for aerosol transmission; disease may have serious or lethal consequences

Associated with human disease, hazard = percutaneous injury, ingestion, mucous membrane exposure
Not known to consistently cause disease in healthy adults
Biosafety Levels for Infectious Agents
BSL = Containment
BSL-3 practices plus: Clothing change before entering, Shower on exit, All material decontaminated on exit from facility
BSL-2 practice plus: Controlled access, Decontamination of all waste, Decontamination of lab clothing before laundering,
Baseline serum antibody analysis
BSL-1 practice plus: Limited access, Biohazard warning signs, "Sharps" precautions, Biosafety manual defining any needed waste decontamination or medical surveillance policies
Standard Microbiological Practices
Engineering Controls by Biosafety Level
CDC Categories of Diseases/Agents
Select Agents Act
Biological Agent
Toxin
What are the Select Agents?

* Abrin
* Bacillus anthracis
* Cercopithecine herpesvirus 1 (Herpes B virus)
* Coccidioides posadasii
* Conotoxins
* Crimean-Congo haemorrhagic fever virus
* Diacetoxyscirpenol
* Ebola viruses
* Lassa fever virus
* Marburg virus
* Monkeypox virus
* Ricin
* Rickettsia prowazekii
* Rickettsia rickettsii
* Saxitoxin
* Shiga-like ribosome inactivating proteins
* South American Haemorrhagic Fever viruses
* Tetrodotoxin
* Tick-borne encephalitis complex viruses
* Variola major virus (Smallpox virus)
* Variola minor virus
* Yersinia pestis

Bioterrorism Agents: Laboratory Risk
High-priority agents include organisms that pose a risk to national security because they:

o can be easily disseminated or transmitted from person to person;
o result in high mortality rates and have the potential for major public health impact;
o might cause public panic and social disruption; and
o require special action for public health preparedness.



Category A Definition
Category A Disease/Agents

* Anthrax (Bacillus anthracis)
* Botulism (Clostridium botulinum toxin)
* Plague (Yersinia pestis)
* Smallpox (Variola major)
* Tularemia (Francisella tularensis)
* Viral hemorrhagic fevers (filoviruses [e.g., Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo])
Category B Definition
Category B Disease/Agents

* Brucellosis (Brucella species)
* Epsilon toxin of Clostridium perfringens
* Food safety threats (e.g., Salmonella species, Escherichia coli O157:H7, Shigella)
* Glanders (Burkholderia mallei)
* Melioidosis (Burkholderia pseudomallei)
* Psittacosis (Chlamydia psittaci)
* Q fever (Coxiella burnetii)
* Ricin toxin from Ricinus communis (castor beans)
* Staphylococcal enterotoxin B
* Typhus fever (Rickettsia prowazekii)
* Viral encephalitis (alphaviruses [e.g., Venezuelan equine encephalitis, eastern equine encephalitis, western equine encephalitis])
* Water safety threats (e.g., Vibrio cholerae, Cryptosporidium parvum)

Category C Definition
Category C Disease/Agents


Safety in the Microbiology Lab.ppt