Actinomycetes

Fungi like bacteria

Gram +ve

Gram +ve,nonmotile, none sporing,noncapsulated,filaments that break up into bacillary and coccoid elements

Medically imp-

1. Actinomyces-anerobic,non acid fast-grows only in a narrow range of temp.

2. Nocardia-aerobic, acidfast –grows in a wide range of temp.

3. Streptomyces -antibiotics

Actinomyces ---ray fungus

Due to ray like appearance of the organisms in the granules

Human actinomycosis—A.israeliCattle—A.bovis

Actinomycosis

C/C granulomatous infectionIndurated swelling in connective

tissue,suppuration,discharge of sulphur granules

Leasion often points to skin,leading to multiple sinuses

Endogenous inf. In humans—normally present in mouth ,intestine,etc----

Trauma,FB,poor oral hygeine---

A.israeli-most common causative agent Usually cooperative d/s-associated with other

bacteria Four main clinical forms

1. Cervicofacial-indurated lesions on cheek and submaxillary regions

2. Thoracic-laesions in lungs,pleura,pericardium,chest wall

3. Abdominal—around caecum,abdominal wall,liver

4. Pelvic—associated with use of IUD

5. Gingivitis,peridontitis

Lab d/g-microscopySulphur granules—in pus—demo-shaking in tt

with saline-on standing granules sedimentGranules –also by applying gauze pad over

sinusesYellowish colour-stained by gramInfact—bacterial colonies—densenetwork of

thin gram +ve filaments,surronded by peripheral zone of swollen radiating club shaped structures-which r believed to be antigen-antibody complexes

In thioglycollate—A.israeli produces small spidary colonies

Epidemiology-in agricultural workers---young males

T/T-Penicillin in large doses/tetracycline

Nocardia

Infection exogenous Causes –

cutaneous,subcutaneous,systemic lesions

1. N.asteroides

2. N.brasiliensis

3. N.caviae

Cutaneous-local abcess,cellulitis,lymphocutaneous lesions

Sub cutaneous-Actinomycotic mycetomaSystemic –caused by N.asteroids—pulmonary

d/s ,pneumonia,lung abcess—lesion resembling TB

Colonies—pigment-yellow to redT/t- cotremoxazole-for several monthsMinocyclineAmikacinecefotaxime

Actinomycotic mycetoma

Presents as tumour with multiple dischargimg sinuses

Localised granulomatous d/s of subcutaneous,and deeper tissues

Esp, footAlso known as MaduramycosisCan be caused by fungi and bacteriaBotryomycosis-similar lesion if caused by

staph aureus and other pyogenic org.

Bacterial mycetomas-by actinomyces,nocardiaIn actinomycotic—granules-white to yellow-

filaments -thinIn eumycotic—granules –black---filaments-stout