Bacterial diseases-actinomyces, Biology

Actinomyces


Members of the genus Actinomyces are facultative anerobic, gram-positive, non acid-fast, non-spore forming, nonhaemolytic rods. All Actinomyces require rich media containing blood or serum. No growth occurs on Sabouraud’s agar at room temperature. Actinomycosis is a chronic, granulomatous, suppurative and sporadic infection of human, cattle, horse, pig, sheep, buffalo, deer and other animals. A. bovis causes Actinomycosis or lumpy jaw in cattle. The organism has not been recovered from the environmental sources and is thought to be located endogenously in the gum, teeth, tonsillar crypts, throat and gastrointestinal tract of apparently healthy animals and human. However, laceration and ulceration of the mucous membranes of mouth by sharp pieces of feed or thorns may often provide an opportunity to the organism to become potentially pathogenic. The infection is more common in young calves during the eruption of teeth and is manifested by oesteomyelitis of the bones of head, particularly the mandible and maxilla. The disease usually affects young persons 20-29 years old and shows high incidence in male agricultural workers. About 65% of the cases are of cervico-facial region and 20% of abdominal. Rarely, actinomycosis of lung, liver, heart, brain, spleen, kidney, testis and skin may occur because of blood- borne metastatic lesions. Sometimes, pyogenic bacteria may produce secondary infection and thus complicate the case. The pathogens invade the tissue and grow in the form of colonies which are white and semi-transparent in the beginning and later turn to dark brown or yellow or to sulphur granule. The granules when examined under microscope reveal gram-positive central mass with surrounding gram-negative clubs. The clubs are more commonly observed in animal actinomycosis than human.


Symptoms:
Actinomyces bovis causes lumpy jaw of cattle. The affected animals show one or more painless, hard and immovable swellings on the maxilla and mandible. Later the swelling becomes painful and breaks through the skin discharging sticky honey-like fluid which shows hard, whitish yellow granules. Due to excessive swelling, animal feels difficulty in respiration as well as mastication. Sometimes the alimentary tract is involved with the interference in ruminal movement and ingestion as a result of which the animal exhibits chronic tympany and diarrhoea. Very occasionally the haematogenous spread may occur from the primary lesion involving lung, brain and  testis. Actinomycosis of skin and udder is sometimes observed in pigs. Mastitis in sows is sometimes associated with Actinomyces. Poll evil and fistulous withers in horses contain Actinomyces.


Diagnosis:
Clinically, the disease resembles abscesses on cheek and throat region, with foreign bodies in the mouth and feed jammed between teeth and cheek. Needle puncture reveals the presence and type of pus. The demonstration of typical “sulphur granules”-yellowish particles in tissues or pus is sufficient for diagnosis. Smears made from sulphur granules should be examined for the presence of Gram-positive thin filaments and Gram-negative club like structures (composed of mineral and the detritus of inflammatory and immune response) called rosettes. The granules after washing with sterile distilled water should be cultured on brain heart infusion (BHI) agar or thiogylocate broth to isolate the aetiological agent.


Treatment and prevention:
A. bovis is sensitive to penicillin, streptomycin, tetracyclines, cephalosporins, lincomycin and sulfonamides. Local lesions may be treated with the iodine ointment. Lugol‘s iodine or streptomycin (5 g dissolved in 1 ml of distilled water) may be infiltrated into the hard swelling. If the swelling still persists as hard, the same may be removed by surgery. The wound should be dressed daily with tincture of iodine. Potassium iodide 6-10 g orally/ day for 5-7 days, and sodium iodide 2.2 g/ 30 kg body weight as 10 % solution intravenously in 2 doses, with 15 days interval may be useful both in osteomyelitis and systemic actinomycosis. Treatment with sulphanilamide, sulphapyridine, sulphathiazole 2.2 g/ 15 kg body weight or penicillin 0.3-0.5 million IU/ animal intramuscularly for 4-7 days is effective in animals and human. Since the infection occurs by endogenous route, predisposing environmental factors which cause oral laceration should be eliminated.

Posted Date: 9/17/2012 5:40:14 AM | Location : United States







Related Discussions:- Bacterial diseases-actinomyces, Assignment Help, Ask Question on Bacterial diseases-actinomyces, Get Answer, Expert's Help, Bacterial diseases-actinomyces Discussions

Write discussion on Bacterial diseases-actinomyces
Your posts are moderated
Related Questions
Adverse effects of menactra The most common adverse reactions to Menactra include headache, fatigue and malaise, in addition to pain, redness and induration at the site of injec

How ecosyestem concept is useful to the study of environment?

Seed A seed is a mature ovule enclosing an embryonic plant, stored food material (in endosperm, persistent nucellus or embryo itself) and a seed coat formed by one or two inte

describe and compare reproduction in all the kingdoms except kingdom animalia

Describe Valvular PS Murmur and their characterstics? Characteristic: Harsh crescendo-decrescendo murmur along the left sternal border and loudest at pulmonary area, conducted

A rural town in an established agricultural area with no prospects for extensive development is located along a river that is used as the source of water supply for the community.

explain in detail various types of epithelial tissue

Egg - Synergids The three cells of the egg apparatus are arranged in triangular fashion with the egg sharing a common wall with the two synergids and the central cell. In the

Q. Besides the liver which is the other adnexal gland of the digestive system that releases substances in the duodenum participating in extracellular digestion? The other adnex

Q. What is extracellular digestion? Extracellular digestion is so that in which food breaking into utile molecules that can be internalized by the cell is done in the extracell