Institute for Microbiology, Medical Faculty of Masaryk University     and St. Anna Faculty Hospital
in Brno
Agents of wound infections

Types of wound
•common superficial injuries
•severe  contused wounds
•sustained in water
•sustained in the tropics
•surgical wounds
•burns
•bites inflicted by man/animal

Common superficial injuries
•Staphylococcus aureus
•Streptococcus pyogenes
•beta-hemolytic streptococci of other groups (above all G, F, C)
! Attention in the case of the foreign body in the wound (splinter, thorn) and in deeper stab
wounds (fork soiled by horse manure): Clostridium tetani

STAPHYLOCOCCI



Below: http://upload.wikimedia.org
 Left: microbewiki.kenyon.edu.
STREPTOCOCCI

microbiologybytes.wordpress.com/
CLOSTRIDIUM TETANI


Sir Charles Bell's portrait of a soldier dying of tetanus.
The characteristic rigidity of the body is referred to as opisthotonus and risus sardonicus.
(Original in the Royal College of Surgeons of Edinburgh, Scotland)
http://bioinfo.bact.wisc.edu

Severe  contused wounds
•Agents of clostridial myonecrosis
  (Clostridium perfringens, C. septicum,   C. novyi, C. histolyticum)
clostridial myonecrosis = anaerobic traumatosis =  gas gangrene ~  malignant edema
•Clostridium tetani

http://www.thewoundcarecenter.com



Wounds sustained in water
•In fresh water:
Pseudomonas aeruginosa
Aeromonas hydrophila
other pseudomonads and aeromonads
•In salt water:
Vibrio parahaemolyticus, V. vulnificus
Mycobacterium marinum (also in fresh-water swimming pools, fish tanks etc.)

Injuries sustained in the tropics
Mainly on feet
•soil nocardiae                              (Dermatophilus congolensis, Rhodococcus equi)
•atypical mycobacteria                      (Mycobacterium ulcerans, Mycobacterium haemophilum)
•micromycetes                                                        (Sporothrix schenckii,
Paracoccidioides brasiliensis)

Sporothrix schenckii (a dimorphic fungus that is a yeast in the body) - usually acquired by
implantation of spores at the site of minor trauma in an extremity.
Note the erythematous papule on the index finger just proximal to the nail (site of inoculation)
and the linear pattern of erythematous nodules (dermal and subcutaneous) extending proximally along
lymphatic vessels.
http://missinglink.ucsf.edu/lm/IDS_105_skinILM/Sporotrichosis.htm

Surgical wounds
- Staphylococcus aureus
- coagulase-negative staphylococci                             (mainly Staph. epidermidis)
- Enterobacteriaceae (E. coli, P. mirabilis)
- Streptococcus pyogenes
- anaerobes                                                (Peptostreptococcus micros,
Peptostreptococcus anaerobius,  Bacteroides fragilis)

Burns
Mostly:
- Pseudomonas aeruginosa
- Staphylococcus aureus
- Streptococcus pyogenes
- other streptococci
- enterococci
- candidae and aspergilli

P. AERUGINOSA



Bites inflicted by man
members of oral microflora:
- „oral streptococci“ (Streptococcus sanguinis, S. oralis, S. anginosus)
- anaerobes (Fusobacterium nucleatum ssp. nucleatum, Porphyromonas gingivalis)
Staphylococcus aureus

Animal bites
- Pasteurella multocida (cats, dogs)
- Staphylococcus aureus (any animal)
- Capnocytophaga canimorsus (dogs)
- Streptobacillus moniliformis (rats)
- Spirillum minus                                            (mice, rats, cats, dogs)

Other injuries by animals
Francisella tularensis (rodents, hares – tularemia)
Bartonella henselae (cat scratch disease)

FRANCISELLA TULARENSIS



Egon Schiele (1890-1918): Dead mother (1910)