1. Anaerobic, Non-Spore-Forming, Gram-Positive Bacteria

2. Table 41-1. New Classification of Selected Anaerobic Cocci Formerly in the Genus Peptostreptococcus
Organism
Historical Derivation
Anaerobic Cocci
Anaerococcus
an, without; aer, air; coccus, berry or coccus (anaerobic coccus)
Finegoldia
Named after the American microbiologist S. Finegold
Micromonas Peptostreptococcus
micro, tiny; monas, cell (tiny cell) pepto, cook or digest (the digesting streptococcus)
Schleiferella
Named after the German microbiologist K.H. Schleifer
Anaerobic Rods
Actinomyces
aktinos, ray; mykes, fungus (ray fungus referring to the radial arrangement of filaments in granules)
Bifidobacterium
bifidus, cleft; bakterion, small rod (a small clefted or bifurcated rod)
Eubacterium
eu, good or beneficial (a beneficial rod; that is, a rod normally present)
Lactobacillus
lacto, milk (milk bacillus; organism originally recovered in milk; also, lactic acid     is the primary metabolic product of fermentation)
Mobiluncus
mobilis, capable of movement or being active; uncus, hook (motile, curved rod)
Propionibacterium propionicum
propionic acid (propionic acid is the primary metabolic product of fermentation)

3. Table 41-1. New Classification of Selected Anaerobic Cocci Formerly in the Genus Peptostreptococcus
Former Classification
New Classification
P. anaerobius
Unchanged
P. asaccharolyticus
Schleiferella asaccharolytica
P. magnus
Finegoldia magna
P. micros
Micromonas micros
P. prevotii
Anaerococcus prevotii

4. Anaerobic, Non-Spore-Forming, Gram-Positive Rods
facultatively anaerobic or strictly anaerobic bacteria
colonize the skin and mucosal surfaces.
Actinomyces, Mobiluncus, Lactobacillus, and Propionibacterium
Bifidobacterium and Eubacterium
Table Anaerobic, Non-Spore-Forming, Gram-Positive Rods
Anaerobic Rods
Human Disease
Actinomyces spp.
Actinomycosis (cervicofacial, thoracic, abdominal, pelvic, central nervous system)
Propionibacterium spp.
Acne, lacrimal canaliculitis, opportunistic infections
Mobiluncus spp.
Bacterial vaginosis, opportunistic infections
Lactobacillus spp.
Endocarditis, opportunistic infections
Eubacterium spp.
Opportunistic infections
Bifidobacterium spp.

5. Actinomyces PHYSIOLOGY AND STRUCTURE
facultatively anaerobic or strictly anaerobic,
gram-positive rods.
no acid-fast
grow slowly in culture
filamentous forms or hyphae (균사)
(resembling fungi)
true bacteria : lack mitochondria,
nuclear membrane,
reproduce by fission,
inhibited by penicillin but not antifungal antibiotics.
- Human infection : Actinomyces israelii, Actinomyces meyeri, Actinomyces naeslundii, Actinomyces odontolyticus, and Actinomyces viscosus
Microscopic colony, Gram stain

6. PATHOGENESIS AND IMMUNITY
upper respiratory, gastrointestinal, and female genital tracts. not normally present on the skin surface.
low virulence potential, cause disease only when the normal mucosal barriers are disrupted by trauma, surgery, or infection
actinomycosis (방선균증)
- in keeping with the original idea that these organisms were fungi or "mycoses"
development of chronic granulomatous lesions  suppurative, form abscesses connected by sinus tracts.
sulfur granules in the abscesses and sinus tracts : yellow or orange, are masses of filamentous organisms bound together by calcium phosphate
The areas of suppuration are surrounded by fibrosing granulation tissue
Figure 41-3 Sulfur granule collected from the sinus tract in a patient with actinomycosis. Delicate filamentous rods (arrow) are seen at the periphery of the crushed granule

7. EPIDEMIOLOGY
- Actinomycosis - endogenous infection
- Disease is classified according to the organ systems involved.
: Cervicofacial infections : have poor oral hygiene or have undergone an invasive dental procedure or oral trauma. In the mouth, invade into the diseased tissue and initiate the infectious process.
: Thoracic infections generally have a history of aspiration, in the lungs and then spreading to adjoining tissues.
: Abdominal infections : gastrointestinal surgery or have suffered trauma to the bowel
: Pelvic infection : secondary manifestation of abdominal actinomycosis
or primary infection in a woman with an intrauterine device
: Central nervous system infections : represent hematogenous spread from another infected tissue, such as the lungs.

8. CLINICAL DISEASES - cervicofacial type :most cases of actinomycosis
: acute, pyogenic infection, slowly evolving, relatively painless process
: tissue swelling with fibrosis and scarring, as well as draining sinus tracts along the angle of the jaw and neck
- thoracic actinomycosis : nonspecific. Abscesses form in the lung tissue early in the disease and then spread into adjoining tissues as the disease progresses.
- Abdominal actinomycosis : abdomen, potentially involving virtually every organ system.
- Pelvic actinomycosis : benign form of vaginitis or, more commonly, there can be extensive tissue destruction, including the development of tuboovarian abscesses or ureteral obstruction.
- central nervous system actinomycosis : solitary brain abscess, but meningitis, subdural empyema, and epidural abscess are also seen.

9. LABORATORY DIAGNOSIS
- Laboratory confirmation of actinomycosis is often difficult
- the organisms are concentrated in sulfur granules and are sparse in involved tissues, a large amount of tissue or pus should be collected.
- If sulfur granules are detected in a sinus tract or in tissue, the granule should be crushed between two glass slides, stained, and examined microscopically.
fastidious and grow slowly under anaerobic conditions
Figure 41-6 Molar tooth appearance of Actinomyces israelii after incubation for 1 week. This colonial morphology serves as a reminder that the bacteria are normally found in the mouth.

10. TREATMENT, PREVENTION, AND CONTROL
Treatment for actinomycosis : combination of surgical débridement of the involved tissues and the prolonged administration of antibiotics.
susceptible to penicillin, erythromycin, clindamycin
Most species are resistant to metronidazole
tetracyclines have variable activity.

11. Propionibacterium
small gram-positive rods often arranged in short chains or clumps.
found on the skin (in contrast with the actinomyces), conjunctiva, external ear, and in the oropharynx and female genital tract.
anaerobic or aerotolerant, nonmotile, catalase positive, and capable of fermenting carbohydrates, producing propionic acid as their major by-product. - Propionibacterium acnes and Propionibacterium propionicus
stimulate an inflammatory response
Production of a low-molecular-weight peptide  attracts leukocytes  bacteria are phagocytized  release of bacterial hydrolytic enzymes (lipases, proteases, neuraminidase, and hyaluronidase  )  stimulate a localized inflammatory response.
- When injected into experimental animals, P. propionicus causes lacrimal canaliculitis (inflammation of the tear duct) and abscesses.
- Acne(duemfma) : Benzoyl peroxide, antibiotics- erythromycin, clindamycin

12. Mobiluncus
obligate anaerobic, gram-variable or gram-negative, curved rods with tapered ends.
gram-positive rods (1) have a gram-positive cell wall, (2) lack endotoxin, (3) are susceptible to vancomycin, clindamycin, erythromycin, ampicillin  but resistant to colistin.
- Two species, Mobiluncus curtisii and Mobiluncus mulieris,
- genital tract in low numbers but are abundant in women with bacterial vaginosis (vaginitis).

13. Bifidobacterium and Eubacterium
Lactobacillus
facultatively anaerobic or strictly anaerobic rods.
the normal flora of the mouth, stomach, intestines, and genitourinary tract
isolated in urine specimens and blood cultures.
Invasion into blood
(1) transient bacteremia from a genitourinary source (e.g., after childbirth or a gynecologic procedure), (2) endocarditis, and (3) opportunistic septicemia in an immunocompromised patient.
lactobacilli are resistant to vancomycin (an antibiotic commonly active against gram-positive bacteria)
A combination of penicillin with an aminoglycoside is required for bactericidal activity.
Bifidobacterium and Eubacterium
commonly found in the oropharynx, large intestine, and vagina
clinically insignificant contaminants.