• Actinomycosis  is a long-lasting disease caused by a microorganism (Actinomyces israelii) that is normally present in the mouth and throat.
• Infection occurs most commonly in the jaw or neck, usually following dental trauma, and sometimes in the abdominal membrane or lungs.
• Hard, very slow-growing swellings form and eventually turn into abscesses. 
• When the abscesses break down, pus is discharged through several openings in the skin (Sulfur granules). 
• Treatment with penicillin is usually effective.
• Disease is relatively uncommon. 
• Actinomycosis occurs worldwide with no racial predilection. 
• It is more common in patients with poor oral hygiene. 
• There is a male predominance of 4:1. 
• May present with pulmonary and skin manifestations. 

6. Describe the offending organism, its morphological, cultural characteristics and their normal habitat.

• Actinomycosis looks similar on gram stain to Nocardia, but generally is not acid fast.
• Anaerobic
• Filamentous bacteria which are beaded and non branching
• Actino is a Gram-positive bacteria.
• Actino exhibits some features typical of fungus branching mycelia formation However they are Gram-positive bacteria.
  • Lack of nuclear membrane, the cell wall characteristics and absence of mitochondria are all bacterial characteristics.
  • It reproduces by bacterial fission than sporogenic or filamentous budding.
• Not found in soil. They do not thrive at temperature below 30 degree C. 
• They are extremely host specific and A israelli causing infection in humans is never found in animals.
• These are filamentous bacteria which can be recognized on tissue sections 

7. How do these organisms gain access to humans?

• Actinomyces are normal inhabitants of the oral cavity and can become a pathogen. .
• They are commensal organisms and frequently found in dental caries and at gingival margins with poor oral hygiene. 

Patients with actinomycosis are generally normal hosts 

NOT immunocompromised. It is an uncommon infection in transplanted patients. 

It is not an opportunistic infection. It is due to aspiration of organisms from oral cavity. Patients with a predisposition to aspiration e.g. seizure disorder, mental retardation, episodes of unconsciousness, alcoholism etc are more prone to develop infection. This statement refers to pulmonary infection.

9. How do they invade and spread in humans?

• Actinomyces are normal inhabitants of the oral cavity.
• Gingivitis and caries of teeth contain aerobic and anaerobic bacteria. They provide a milieu suitable for growth of Actinomyces.
• If there is an injury to jaw they are able to invade the soft tissue of Jaw and progress.

10. What defenses humans have against these organisms?

• WBC

It is not an opportunistic infection. 

12. What is the end result of this battle between organisms and humans?

Necrotizing inflammation with abscess formation.

13. How do you diagnose this infection?

• They must be cultured strictly in anaerobic environment for at least one week.
•  In only 50% of cases organisms are successfully cultured. 
• The other concomitant organisms perhaps work in synergy to produce the necessary anaerobic environment for Actinomyces. 
• In actinomycosis there are sulphur granules which are ball-shaped bacterial colonies, gram-positive, with club-shaped ends of radially oriented filaments. 

14. What will be your therapeutic strategy?

• Actonomycosis needs to be treated with Penicillin 
• For protracted period of time. 

15. How can you prevent it from spreading to others? Prevent its occurrence?

• It is not a contagious infection. These organisms are normal inhabitants of the oral cavity.
• Proper care of Teeth and Gingiva should prevent a situation favoring growth of these organisms 

16. What are other clinical infections with these organisms?

Oral cervical disease, thoracic disease, mass lesions, pneumonia with or without pleural involvement, abdominal disease-abscess or mass secondary to disruption of the bowel mucosa, pelvic disease, CNS disease - rare, bone and soft tissue.

• Cervicofacial area 55%
• Abdominopelvic region 20%
• Thorax 15% :The indolent infection progresses to necrotizing pneumonia. If untreated abscesses develop with extensive parenchymal destruction. Predilection to bases and peripheral portion of lungs is due to aspiration as the initiating process. Disease spreads through pleura to chest wall as in our patient. In untreated cases sinus tracts can form with characteristic sulfur granules. Think Actino whenever a lesion crosses fissure or pleura, extends to contiguous mediastinum or chest wall.
• Rare pelvic form has been associated with Intrauterine contraceptive devices.