Non Sporing Anaerobes

Non – sporing anaerobes –

• Have been recognized as an important cause of human & animal.

• Commensal flora of man & animal in mouth oropharynx, gastrointestinal tract & genital tract.

Anaerobes have been estimated to be 104 – 105/ml in small intestine, 108/ml in saliva, 1011/qm in colon.

• When body resistance is lowered – opportunistic infection.]

• Classification –

• I] Cocci –

• A] Gram Positive

• a. peptostreptococcus.

• b. Peptococcus.

• B] Gram Negative

• Villanelle.

• II] Bacilli –

• 1] Endospore forming

• Clostridia.

 2] Non – sporing

• A] Gram positive –

• a. Eubacterium.

• b. Propinibacterium.

• c. Lactobacillus.

• d. Mobiluncus.

• e. Bifidobacterium.

• f. Actinomyces.

• B] Gram negative –

• a. Bacteroides.

• b. Prevotellia.

• c. Porphyromonas.

• d. Fusobacterium.

• e. Leptotrichia.

• III] Spirochetes –

• a. Treponema.

• b. Borrelia.

• Several anaerobes that occurs in soil & water which may be industrial & agricultural importance.

• Ex – Methanobacteria.

• Butyrivibrios.

Anaerobic cocci –

• Normal flora – skin, mouth, intestine & vagina. They can be divided into Gram positive, Gram

negative group’s.

• Gram positive cocci –

• A] Peptococcus –

Gram +ve, non – sporing, anaerobic cocci that do not form chains, 0.5-1 um, single pairs.

B] peptostreptococcus –

• 0.3-1 um, chain, commonest anaerobic occur’s isolated from human infectious such as pleuropulmonary disease, brain abscess etc.

Gram negative cocci –

• Veilloneua –

• 0.3 – 2.5 um, gram negative cocci, short chain pairs, usually non – pathogenic. But occasionally invade blood stream.

Anaerobic Gram Positive Bacilli –

A] Eubacterium –

• Strictly anaerobic. Grow slow.

• Normally – mouth, intestinal flora.

• E. branchy, E. nodatum – periodontitis.

B] Lactobacillus –

• Gram positive, frequently show bipolar staining.

• Normally mouth, gut & vagina.

• Ferment material such as milk, cheese.

• Lactobacillus – dental caries – dentine & enamel dissolved by acid.

C] Bifidobacterium –

• Pleomorphic rods. Show’s true & false branching.

• Present in large intestine, mouth. Occasionary pathogenic.

D] Prepionibacterium –

• Gm +ve

• Pleomorphic

• Non motile

• On skin

E] Actinomyces –

F] Mobiluncus –

• Motile

• Gm variable rod

• Isolated from vagina

• Anaerobic Gram Negative Bacillus –

• Belong the family bacteriodaceae. & classified into genera bactericides, fusobacterium & leptotrichia.

• Bactericides –

• Commonsal – Mouth, R.T, gastrointestinal & female genital tract.

• Morphology – Gm –ve, anaerobic, non – sporing, non – motile, pleomorphic.

• Media – Brain heart infusion agar (BHI).

• Disease – Peritonitis – bowel injury.

• Pelvic inflammatory disease.

• Abdominal & brain abscess.

• Pus – Foul smelling.

• B. fragilis – Frequently isolated.

• P. Melaninogenica – Black colony / brown – hemin derivative not by melanin.

• isolated from lung / liver abscess, lesion of intestine, mouth gum.

• P. gingivalis – Periodontal disease.

• P. endodontalis – Dental root canal infection.

B] Fusobacterium –

• Gm –ve, strict anaerobes, thin long.

• F. nucleatum – found in oral infection & pleuropulanonary sepsis.

C] Leptotrichia –

• Long, straigh, curved Gm –ve, non sporing non motile.

• Previously – F. fusiforme.

• Normally – L. buccalis – mouth G.I.T.

• Cause – acute ulcerative gingivitis.

 Anaerobic infection’s –

• Usually endogenous.

• By normal flora.

• Normally skin, mouth, nasopharynx, intestine & vagina.

• When host resistance lowered.

• Usually localised, dissemination may occur by bacteremia.

Lab diagnosis –

• Infection from normal flora so their isolation from clinical specimen has to be interpreted cautiously.

• Mere presence – does not prove it as a causative agent.

• Specimen –

• Such a manner to avoid normal flora.

• Ex – sputum – lung abscess aspiration – lung abscess

• To minimize contact with air during collection, transport & handling.

• Satisfactory method – to aspirate sample.

• Into airtight syringe, plug it.

• Pus & fluid in airtight bottle fill completely.

• Swab’s are unsatisfactory.

• Sputum, urine, faces, secretion from nasotracheal suction – unsatisfactory.

• Indications of anaerobic infection –Faull odor.

• Sulphur granulate – Actinomycetes.

• Failure to isolate organism from pus deep abscesse presentation.

• Pus show’s red fluorescence under UV light – ex. P.melaninogenica.

• Failure to response to conventional antimicrobial treatment.

• Direct microscopy –

• Gram stain:-

• Pus – variety of org’s numerous pus cell’s.

• Culture –

• Freshly prepared blood agar

• 37oc anaerobically.

• 24-48 hr’s in presence of 10% co2

• Other media – Rcm, thioglycolate broth.

• Anaerobiosis – by Gas – pack system.

• Aerobically culture – control for anaerobic plate. & some aerobic bacteria are involved. In

• anaerobic infection.

• Fusobacterium – longer growth period.

• Identify – colony morphology & biochemical test’s.