Anaerobic Infection: Importance, Indications, List of Anaerobic Bacteria
Anaerobic infection
As you know, isolating the causative agent of anaerobic infection is really cumbersome. It means that leave the practice which is not a solution. This is not my personal opinion but according to researchers’ data; “many reports associate 50-60% of important infections with anaerobic bacteria.” This is the reason, we concern with anaerobic infections. The possibility of anaerobic infection indicated by the following clues and they are-
- The foul odor of the specimen
- site of infection in proximity to a mucosal surface
- Gas in specimen
- Black discoloration of blood containing exudates and these exudates may fluoresce under UV light.
- Secondary infections due to human or animal bite
- Earlier therapy with aminoglycosides drugs for e.g. gentamycin. amikacin and neomycin
- No growth of organisms aerobically seen on Gram stain of original exudates
- Presence of sulfur’ granules’ in discharge (actinomycosis). Unique morphology on Gram stain.
- Growth in the anaerobic zone of the medium and color change (meat medium)
- Growth anaerobically on media containing 75-100µg/ml kanamycin, neomycin
- Characteristic colonies on agar plates incubated anaerobically e.g. F. nucleatum and Clostridium perfringens
- The following bacterial young colonies of blood agar plate may fluoresce brick red under ultraviolet (UV) light- Prevotella melaninogenica, Prevotella asaccarolyticus, and Porphyromonas species.
List of anaerobic bacteria
Anaerobic bacilli
Gram-positive bacilli-
- Bifidobacterium
- Propionobacterium
- Eubacterium
- Lactobacillus
- Actinomyces
- Mobilincus
- Clostridium
Gram-negative bacilli
- Bacteroides
- Fusobacterium
- Prevotella
- Porphyromonas
- Leptotrichia
Anaerobic cocci
Gram-positive cocci
- Peptostreptococcus
- Coprococcus
- Ruminococcus
Gram-negative cocci
- Veillonella
- Acidaminococcus
- Megasphaera
Examples of anaerobic bacteria and the disease they cause –
Clostridium perfringens : Gas gangrene
Clostridium tetani : Tetanus
Clostridium botulinum : Botulism (complete paralysis of respiratory and other muscles )
Clostridium difficille : Colitis
Actinomyces spp. : Oral , cervicofacial , thoracic , pelvis and abdominal infection , dental caries
Propionibacterium spp. : Inflammatory process in acne
Bifidobacterium spp. : Bacteremia, diarrhea
Eubacterium spp. : Infection of abdomen, pelvis, or genitourinary tract
Bibliography
- Manual of Clinical Microbiology 8th Edition Patrick R. Murray
- Clinical Microbiology Procedure Handbook Second Edition update (2007) Lynne S. Garcia