Medical Microbiology

Clostridium 247

proteinases,DNases,lecithinases,andhyaluronidase,allofwhichdestroytis-

suestructures,resultinginaccumulationsoftoxicmetabolites.

Pathogenesisandclinicalpicture.Duetotheubiquitouspresenceofclostri-

dia,theyfrequentlycontaminateopenwounds,oftentogetherwithothermi-

croorganisms.Detectionofclostridiainawoundisthereforenoindicationof

aclostridialinfection.Theseinfectionsdevelopwhenalowtissueredoxpo-

tentialmakesanaerobereproductionpossible,resultingintissuenecrosis.

Twosuchinfectionsofdifferingseverityaredescribedbelow:

&Anaerobiccellulitis.Infectionrestrictedtothefascialspacesthatdoesnot

affectmusculature.Gasformationintissuescausesacracking,poppingsen-

sationundertheskinknownascrepitus.Thereisnotoxemia.

Clostridiumperfringensandsporogenes

Fig.4. 7 a C. perfringens: gram

stainingofapreparationofwound

pus. Large, thick, gram-positive

rods.Clinicaldiagnosis:gasgan-

greneinagunshotwound.

bC.sporogenes:Sporestainingof

apreparationfromanagedbroth

culture.Thick-walledsporesstained

red.Occasionally“tennisracquet”

forms.

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Kayser, Medical Microbiology © 2005 Thieme