Actinomyces/Actinomycosis

Classification

General Characteristics

Actinomyces

• General characteristics:
  • Structure: branching, filamentous rods Filamentous rods Nocardia/Nocardiosis/ bacilli Bacilli Shigella
  • Gram stain Gram stain Klebsiella: gram-positive Gram-Positive Penicillins
  • Other stain(s): not acid-fast
  • Spore Spore The reproductive elements of lower organisms, such as bacteria; fungi; and cryptogamic plants. Microsporidia/Microsporidiosis formation: non-spore–forming (differentiates Actinomyces from fungi Fungi A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including mushrooms; yeasts; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies. Mycology)
  • Oxygen requirement: anaerobe
• Culture medium: same as for other anaerobes Anaerobes Lincosamides
• Actinomycosis Actinomycosis Infections with bacteria of the genus actinomyces. Tetracyclines (disease-caused): 
  • Chronic suppurative and granulomatous infection
  • Associated with abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease formation with interconnecting sinus tracts
  • Sulfur granules:
    • Characteristic finding 
    • Microcolonies of the bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology with yellow color (no sulfur) and peripheral clubs
    • Found embedded in tissue elements

Clinically relevant species

• A. israelii (most common)
• A. gerencseriae
• A. naeslundii
• A. viscosus
• A. odontolyticus
• A. meyeri

Epidemiology

• Men > women
• Higher prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency in low socioeconomic areas and in those with poor dental hygiene
• Use of intrauterine device (IUD) has increased incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency in women.

Pathogenesis

Reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli and transmission

Reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli:

• Normal flora of:
  • Oral cavity
  • Reproductive tract
  • Gastrointestinal (GI) tract

Transmission:

• Trauma displaces the organism.
• Breaching the mucosal barrier and moving to areas with low oxygen (anaerobic environment) facilitate its multiplication.

Risk factors

• Poor oral hygiene 
• Gingivitis Gingivitis Inflammation of gum tissue (gingiva) without loss of connective tissue. Chédiak-Higashi Syndrome
• Dental surgery
• Dental trauma
• IUD use
• Alcoholism Alcoholism A primary, chronic disease with genetic, psychosocial, and environmental factors influencing its development and manifestations. The disease is often progressive and fatal. It is characterized by impaired control over drinking, preoccupation with the drug alcohol, use of alcohol despite adverse consequences, and distortions in thinking, most notably denial. Each of these symptoms may be continuous or periodic. Wernicke Encephalopathy and Korsakoff Syndrome
• Malnutrition Malnutrition Malnutrition is a clinical state caused by an imbalance or deficiency of calories and/or micronutrients and macronutrients. The 2 main manifestations of acute severe malnutrition are marasmus (total caloric insufficiency) and kwashiorkor (protein malnutrition with characteristic edema). Malnutrition in children in resource-limited countries
• Malignancy Malignancy Hemothorax and related local tissue damage (from the disease or from radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma treatment)
• Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus
• Osteonecrosis of the jaw Jaw The jaw is made up of the mandible, which comprises the lower jaw, and the maxilla, which comprises the upper jaw. The mandible articulates with the temporal bone via the temporomandibular joint (TMJ). The 4 muscles of mastication produce the movements of the TMJ to ensure the efficient chewing of food. Jaw and Temporomandibular Joint: Anatomy due to bisphosphonates Bisphosphonates Bisphosphonates are pyrophosphate analogs most well-known for treating osteoporosis by preventing bone loss. Bisphosphonates end in the suffix “-dronate” or “-dronic acid” (e.g., alendronate, risedronate, pamidronate) and bind to hydroxyapatite crystals in bone, inhibiting osteoclast-induced bone resorption. Bisphosphonates

Pathophysiology

• The bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology take advantage of the mucosal break, invading neighboring tissues.
• Once Actinomyces infection is established, inflammatory response follows (suppurative and granulomatous). 
• Infection spreads by creating sinuses that contain sulfur granules; these may drain into the surface. 
• Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease occur near the usual reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli.
• Pulmonary infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease occur, from direct extension Extension Examination of the Upper Limbs of the oropharyngeal source or by aspiration of oral and GI secretions.

Clinical Presentation

Cervicofacial disease

• Most common presentation
• Oral/facial abscesses in the jaw Jaw The jaw is made up of the mandible, which comprises the lower jaw, and the maxilla, which comprises the upper jaw. The mandible articulates with the temporal bone via the temporomandibular joint (TMJ). The 4 muscles of mastication produce the movements of the TMJ to ensure the efficient chewing of food. Jaw and Temporomandibular Joint: Anatomy (“lumpy jaw Jaw The jaw is made up of the mandible, which comprises the lower jaw, and the maxilla, which comprises the upper jaw. The mandible articulates with the temporal bone via the temporomandibular joint (TMJ). The 4 muscles of mastication produce the movements of the TMJ to ensure the efficient chewing of food. Jaw and Temporomandibular Joint: Anatomy”), draining through sinus tracts 
• Commonly affects the maxilla Maxilla One of a pair of irregularly shaped bones that form the upper jaw. A maxillary bone provides tooth sockets for the superior teeth, forms part of the orbit, and contains the maxillary sinus. Skull: Anatomy, cheek, and lower jaw Jaw The jaw is made up of the mandible, which comprises the lower jaw, and the maxilla, which comprises the upper jaw. The mandible articulates with the temporal bone via the temporomandibular joint (TMJ). The 4 muscles of mastication produce the movements of the TMJ to ensure the efficient chewing of food. Jaw and Temporomandibular Joint: Anatomy
• Forms characteristic yellow sulfur granules in pus or tissues:
  • Resemble grains of sand
  • Bacterial microcolonies
• May extend to other tissues, bones, and lymph Lymph The interstitial fluid that is in the lymphatic system. Secondary Lymphatic Organs nodes
• Manifestations:
  • Trismus Trismus Spasmodic contraction of the masseter muscle resulting in forceful jaw closure. This may be seen with a variety of diseases, including tetanus, as a complication of radiation therapy, trauma, or in association with neoplastic conditions. Tetanus and difficulty chewing
  • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways occurs with compression Compression Blunt Chest Trauma of neighboring structures.
• Often associated with dental caries, extractions, or jaw Jaw The jaw is made up of the mandible, which comprises the lower jaw, and the maxilla, which comprises the upper jaw. The mandible articulates with the temporal bone via the temporomandibular joint (TMJ). The 4 muscles of mastication produce the movements of the TMJ to ensure the efficient chewing of food. Jaw and Temporomandibular Joint: Anatomy trauma

Thoracic actinomycosis Actinomycosis Infections with bacteria of the genus actinomyces. Tetracyclines

• Transmission: 
  • Aspiration of oropharyngeal secretions
  • Introduction of bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology via esophageal injury Esophageal Injury Thoracic Trauma in Children
  • Direct extension Extension Examination of the Upper Limbs from neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess or abdomen
  • Hematogenous Hematogenous Hepatocellular Carcinoma (HCC) and Liver Metastases spread
• Presents as subacute pulmonary infection: fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, cough with sputum
• Lung parenchyma: may have cavitations, which can form sinus tracts
• These tracts can go through the chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall: Anatomy or invade the ribs Ribs A set of twelve curved bones which connect to the vertebral column posteriorly, and terminate anteriorly as costal cartilage. Together, they form a protective cage around the internal thoracic organs. Chest Wall: Anatomy.

Abdominal actinomycosis Actinomycosis Infections with bacteria of the genus actinomyces. Tetracyclines

• From a ruptured appendix Appendix A worm-like blind tube extension from the cecum. Colon, Cecum, and Appendix: Anatomy/bowel or an ulcer
• Patient may have had prior abdominal surgery.
• Presents with fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, change in bowel habits, abdominal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, weight loss Weight loss Decrease in existing body weight. Bariatric Surgery
• Extension Extension Examination of the Upper Limbs can affect any intraabdominal organ.

Pelvic actinomycosis Actinomycosis Infections with bacteria of the genus actinomyces. Tetracyclines

• In patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with an IUD
• May present as lower abdominal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and vaginal discharge
• May cause pelvic abscesses

Diagnosis and Management

Diagnosis

• Culture: 
  • Culture media and techniques: same as for other anaerobes Anaerobes Lincosamides 
  • Prolonged incubation Incubation The amount time between exposure to an infectious agent and becoming symptomatic. Rabies Virus (sometimes takes 7–21 days to appear)
  • Specimen(s): 
    • Pus (from draining sinuses)
    • Sputum
    • Specimens of tissue (with yellow-orange, microscopic sulfur granules)
  • In some cases, Actinomyces is seen on Pap smear Pap smear Cytological preparation of cells collected from a mucosal surface and stained with Papanicolaou stain. Cervical Cancer Screening.
    • If symptomatic of infection: IUD is removed and sent for culture.
    • If without symptoms: Patient is educated on symptoms to watch for and IUD is left in place.
• Microscopic examination of sulfur granule: composed of tissue elements and branching actinomycotic filaments (club-shaped at the periphery)
• Imaging studies:
  • Computed tomography (CT) scan of the abdomen: shows site and extent of the disease in abdominal infection
  • CT of the chest:
    • Evaluates thoracic infection
    • Shows mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast with central areas of low attenuation and ring-like rim enhancement 
    • Cavities also may be seen.
  • Pelvic ultrasound: 
    • Obtained when patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with symptoms of pelvic inflammatory disease Pelvic inflammatory disease Pelvic inflammatory disease (PID) is defined as a polymicrobial infection of the upper female reproductive system. The disease can affect the uterus, fallopian tubes, ovaries, and adjacent structures. Pelvic inflammatory disease is closely linked with sexually transmitted diseases, most commonly caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and Gardnerella vaginalis. Pelvic Inflammatory Disease
    • Look for abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease

Management

• Prolonged penicillin Penicillin Rheumatic Fever treatment 
  • Mild disease: 2–6 months
  • Severe disease: 6–12 months
• Alternatives for penicillin-allergic patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship: clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides or erythromycin Erythromycin A bacteriostatic antibiotic macrolide produced by streptomyces erythreus. Erythromycin a is considered its major active component. In sensitive organisms, it inhibits protein synthesis by binding to 50s ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins. Macrolides and Ketolides
• Surgical incision and drainage Incision And Drainage Chalazion may be required.
• Removal of IUD 

Comparison

Two clinically relevant gram-positive Gram-Positive Penicillins, branching, filamentous rods Filamentous rods Nocardia/Nocardiosis that must be distinguished:

Mnemonic:

 SNAP (Sulfonamides-Nocardia, Actinomyces–Penicillin)

Differential Diagnosis

• Appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis: presents with abdominal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and tenderness, mostly in the right lower quadrant Right lower quadrant Anterior Abdominal Wall: Anatomy. Computed tomography scan can help diagnose appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis. Abdominal actinomycosis Actinomycosis Infections with bacteria of the genus actinomyces. Tetracyclines can occur if appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis is complicated with rupture.
• Odontogenic abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease/infection: arises after dental extraction or from an infected tooth. Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease are often polymicrobial; most common bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology are Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus viridians, Peptostreptococcus Peptostreptococcus A genus of gram-positive, anaerobic, coccoid bacteria that is part of the normal flora of humans. Its organisms are opportunistic pathogens causing bacteremias and soft tissue infections. Perianal and Perirectal Abscess, and Staphylococcus Staphylococcus Staphylococcus is a medically important genera of Gram-positive, aerobic cocci. These bacteria form clusters resembling grapes on culture plates. Staphylococci are ubiquitous for humans, and many strains compose the normal skin flora. Staphylococcus. Culture will differentiate the organisms.
• Pelvic inflammatory disease Pelvic inflammatory disease Pelvic inflammatory disease (PID) is defined as a polymicrobial infection of the upper female reproductive system. The disease can affect the uterus, fallopian tubes, ovaries, and adjacent structures. Pelvic inflammatory disease is closely linked with sexually transmitted diseases, most commonly caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and Gardnerella vaginalis. Pelvic Inflammatory Disease: the more common bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology involved in this disease are Chlamydia trachomatis Chlamydia trachomatis Type species of Chlamydia causing a variety of ocular and urogenital diseases. Chlamydia and Neisseria gonorrhoeae Neisseria gonorrhoeae A species of gram-negative, aerobic bacteria primarily found in purulent venereal discharges. It is the causative agent of gonorrhea. Neisseria. Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease from both organisms are sexually transmitted. Actinomycosis Actinomycosis Infections with bacteria of the genus actinomyces. Tetracyclines is often associated with IUD use.