Course # DL-974: Anaerobic Microbiology for the Clinical Laboratory
by James I. Mangels, MA, CLS, MT (ASCP), F(AAM) - Microbiology Consulting Services - Santa Rosa, CA
Approved for 3.0 CE
Level of Difficulty: Intermediate
Anaerobic bacteria cause a variety of infections in humans, including appendicitis, cholecystitis, otitis media, dental and oral infections, endocarditis, endometritis, brain abscess, myonecrosis, osteomyelitis, peritonitis, empyema, salpingitis, septic arthritis, liver abscess, sinusitis, wound infections following bowel surgery and trauma, perirectal and tuboovarian abscesses, and bacteremia (1). Many reports associate an incidence of at least 50% to 60% of important infections due to anaerobic bacteria.
Anaerobic bacteria are often overlooked or missed unless the specimen is properly collected and transported to the laboratory. Next, the specimen must be subjected to appropriate procedures for isolation, including the use of specialized media supplemented with growth factors and the use of proper incubation methods. Anaerobes vary in their nutritional requirements, but most isolates require vitamin K and hemin for growth. Anaerobes also vary in their sensitivity to oxygen: a brief exposure (10 min.) to atmospheric oxygen is enough to kill some organisms.
This course will discuss procedures for proper collection and transport of anaerobes; appropriate specimen types for culture, processing, incubation, and isolation; and methods of characterization of anaerobes from properly collected specimens. Practical schemes for isolating the majority of clinically important anaerobes will be described, including their salient features and cost-effective procedures for their work-up and identification.
Many laboratorians believe that the isolation and identification of anaerobes is difficult, expensive, and time consuming. This course will present methods that will permit rapid, yet cost-effective procedures for the recovery and identification of clinically significant anaerobes for any clinical laboratory.
On completion of this course the participant will be able to:
- Recognize the most important genera and species of clinically important anaerobes and the infections they may cause
- Describe the normal anaerobic indigenous flora
- List appropriate techniques for specimen selection, collection and transport
- Describe initial processing techniques and the media employed
- Identify laboratory methods used for initial grouping, presumptive identification, and definitive identification, and determine when each level is appropriate
- Identify techniques used for cost-effective clinical anaerobic bacteriology