What disease does Actinomyces israelii cause?

Actinomyces israelii is an uncommon cause of appendicitis. Rarely, A. israelii can lead to infections of the small intestine, appendix, or colon.

How is Actinomyces israelii transmitted?

MODE OF TRANSMISSION: The Actinomyces spp. commonly inhabits the oral cavity, the gastrointestinal tract, and the female genital tract, where they exist as commensals. Infection occurs when mechanical insult disrupts the mucosal barrier or organisms gain access to privileged sites.

What infection does Actinomyces cause?

Actinomycosis is a chronic localized or hematogenous anaerobic infection caused by Actinomyces israelii and other species of Actinomyces. Findings are a local abscess with multiple draining sinuses, a tuberculosis-like pneumonitis, and low-grade systemic symptoms.

Is Actinomyces israelii spore forming?

Actinomyces Species are filamentous, branching, gram-positive, pleomorphic, non–spore-forming, catalase-negative, anaerobic or microaerophilic/capnophilic bacilli.

Is Actinomyces israelii acid fast?

Abstract. Open-lung biopsy in a child with chronic pneumonia revealed branched gram-positive acid-fast organisms, later identified as Actinomyces israelii. Like Nocardia asteroides, A israelii can be acid fast by the commonly used Putt stain. The pneumonia was cured with 12 weeks of penicillin treatment.

What Actinomyces species is the most commonly human pathogens?

With the use of 16S (small subunit) ribosomal RNA (16S rRNA) sequencing, at least 21 species of Actinomyces have been identified in humans. A. israelii is the predominant disease-causing species (median, 73% of cases), although other Actinomyces spp., including A. naeslundii (the second most frequent Actinomyces sp.)

Which of the following would be a virulence factor of a pathogen?

Factors that are produced by a microorganism and evoke disease are called virulence factors. Examples are toxins, surface coats that inhibit phagocytosis, and surface receptors that bind to host cells.

What do actinomycetes do?

They play major roles in the cycling of organic matter; inhibit the growth of several plant pathogens in the rhizosphere and decompose complex mixtures of polymer in dead plant, animal and fungal material results in production of many extracellular enzymes which are conductive to crop production.

Why are actinomycetes clinically important?

Since then, several aerobic actinomycetes have been a major source of interest for the commercial drug industry and have proved to be extremely useful microorganisms for producing novel antimicrobial agents. They have also been well known as potential veterinary pathogens affecting many different animal species.

What is difference between actinomycetes and bacteria?

The main difference between actinomycetes and bacteria is that the actinomycetes are a type of bacteria considered as the transitional state of fungi from bacteria whereas the bacteria is a single-celled organism with a simple cellular structure.

What is a virulence factor in bacteria list 5 virulence factors?

Specific Virulence Factors

• Adherence and Colonization Factors. To cause infection, many bacteria must first adhere to a mucosal surface.
• Invasion Factors.
• Capsules and Other Surface Components.
• Endotoxins.
• Structure of Endotoxin.