بسم الله الرحمن الرحيم

NON-SPORING ANAEROBES

Prof. Khalifa Sifaw Ghenghesh

Part of the Normal Microbial Flora• In the mouth and oropharynx,

gastrointestinal tract and female genital tract of healthy individuals.

• Gram+ve and Gram – ve cocci, rods and filaments, as well as spiral forms.

Wide Variety of Infections• Wound infections• Periodontal disease

Most infections are of endogenous origin and polymicrobial (exception > clostridia)Infections in damaged and necrotic tissues, or in the immunocompromised.

Some clinical signs and indicators of non-clostridialanaerobic infections-------------------------------------------------------------------

Foul-smelling pus, discharge or lesionProduction of a large amount of pus (abscess formation) Proximal of lesion to mucosal surface or portal of entryFailure to isolate organism from pus (sterile pus)Infection associated with necrotic tissueDeep abscessGas formation in tissuesFailure to respond to conventional antimicrobial therapyPus which shows red fluorescence under UV lightDetection of “sulphur granules” in pus (actinomycosis)Infection of human or animal wound biteGram-negative bacteraemiaSeptic thrombophlebitis

Polymicrobial Flora

Mixed infections varies according the site affected.2-12 species or more are involved.May include strict and facultative anaerobes and microaerophilic organisms.Frequently comprise mixtures of Gram —ve rods (e.g. Bacteroides, Prevotella and Fusobacterium species) and Gram+ve cocci (peptostreptococci or streptococci or both)

Non-Sporing Gram-Negative Rods

Fusobacterium species• Oral origin (mainly)• Colonize the mucous membranes of

humans and animals• Commensals of upper respiratory and

gastrointestinal tracts.• Fusobacterium nucleatum

Leptotrichia species• Leptotrichia buccalis

• “Vincent’s gingivitis”

Bacteroides species and Related Gram —ve rods. 3 Groups:Saccharolytic group >> Most important:• Bacteroides fragilis (group)

• Intrabdominal and soft tissue infections below the waist

Moderately Saccharolytic group• Prevotella melaninogenica

Asaccharolytic group• Porphyromonas asaccharolytica• Porphyromonas gingivalis

•Periodontitis

Bacteroides fragilis ssp. fragilis cultured in blood agar medium for 48 hours.

Bacteroides fragilis

Fusobacterium sp.

Gram-Positive Anaerobic Cocci

Genus: Peptostreptococcus• P. asaccharolyticus• P. vaginalis

Infections in various parts of the body• Abscesses

Types of Infection and Clinical Specimens fromwhich Anaerobic Gram+ve Cocci are Isolated-------------------------------------------------------------------

Blood culturesCentral nervous system (including brain abscesses)Head and neck infections (including ear)Dental abscesses and infected root canalPeriodontal diseasesHuman and animal bitesPleural infectionsAbdominal infectionsGenito-urinary tract infectionsDecubitus ulcersFoot ulcersOsteomyelitis

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Gram-Negative Anaerobic Cocci

Genus: Veillonella• Normal flora of GIT• A regular component of

supragingival plaque and the tongue microflora

• A minor component of mixed anaerobic infection

Non-Sporing Gram-Positive Rods

Present in significant numbers in normal flora of the mouth, skin, GI and female genito-urinary tractsPropionibacteriumBifidobacteriumLactobacillusActinomycesEubacterium

Infection of the lachrymal canal (lachrymal canaliculitis)Some species are found in acne Occasionally isolated in infective endocarditis and infection associated with implaned prostheses

Spiral-Shaped, Motile organisms

Several Treponema species found in the mouthMixed anaerobic infections• Acute necrotizing ulcerative

gingivitis

Laboratory Diagnosis

Adequate clinical specimens are collected (preferably under reducing conditions) and rapidly transported to bacteriology laboratory.Microscopical examinationCultured on proper media and under anaerobic conditionsGas-liquid chromatography• Direct on pus and other clinical materials

Treatment

Surgical• Drainage of pus from abscess,

debridement, curettage and removal of necrotic tissue

Antibiotics• Penicillin, Metronidazole