Fungi-like Bacteria

Aerobic gram-positive bacteria Nocardia, Rhodococcus, Actinomadular, treptomyces, … Anaerobic gram-positive bacteria Actinomyces, Peptostreptococcus, Propionibacterium, Lactobacillus,… Actinobacteria (Actinomycetes)

Actinomycetes Filamentous, Branching Bacilli Nonmotile May produce mycelium

Gram + and may be acid-fast living normally in oral cavity, tonsils and intestines and also in soil. Some aerobic and some anaerobic Actinomyces and Nocardia primary genera involved in Actinomycosis

Actinomyces Actinomycosis (Lumpy jaw) Non-spore forming (mostly) anaerobic gram- positive bacteria Colonize the upper respiratory tract, oral cavity The most common cause is A. israelii, a normal flora Modified acid fast (1% instead of 20% H 2 SO 4 ) : Negative

An Endogenous infection & Painful bscesses inbscesses  Cervicofacial Common complication of tooth extraction, poor oral hygiene and rampant dental caries. Oral Actinomyces play significant role in development of plaque and dental caries.  Thoracic  Abdominal The outbreak is unrelated to age, sex, season, or occupation.Actinomycosis

Actinomycosis (cont.) Starts with a trauma moving bacteria inside the mucosa. Actinomycosis characterized by: - abscesses grow larger as the disease progresses, often over months. - A chronic granolomatous disease. - Purulent

Pathogenesis Abscess Abscess and lesions with fibrous walls and pus with sulfur granules develop. Granules Granules include: macrophages, other histologic cells, fibrin and bacteria. The edges of bacteria have come out of these granules.

Symptoms and signs of Actinomycosis

Laboratory Diagnosis Prompt transport of specimens to laboratory in anaerobic device Direct examination “Sulfur granule” (10x) Exudate from an abdominal wound infection

Lab diagnosis: by Exudates, Pus and drainage samples Microscopic Examined for granules (1 mm), yellow color Crushed between two slides. Culture Washed several time in sterile distilled water Crushed with sterile glass rod, and inoculated onto media.

Laboratory Diagnosis Direct examination The delicate filamentous bacilli (arrow) at the peripheral of crushed granule

Laboratory Diagnosis Culture BHI, BA, Thioglycolate broth Aerobic condition Anaerobic condition 37 0 C 37 0 C Molar tooth colony

NOCARDIA Aerobic Saprophytes in soil, water Branching filament Fragmentation rod, coccoid form Gram-positive beaded form

Nocardia asteroides Nocardia brasiliensis GPB, Catalase +, urease +, parafine hydrolysis Colonies: grow in about 1 week, irregular, outstanding, different pigments (white, orange, red).

NOCARDIA Cell wall; mycolic acid (wax-like cell wall) Modified acid fast (1% instead of 20% H 2 SO 4 ) Acid fast Nocardia causes mostly opportunistic infections (in AIDS, Tuberculosis….)

Transmission sporadic disease in humans animals Normally found in soil, these organisms cause occasional sporadic disease in humans and animals. oral microfloranormal gingiva and periodontal pockets Noccardia is an oral microflora. Also in the normal gingiva and periodontal pockets along with other species, such as Actinomyces.

Nocardia brasiliensis lobar pneumonia Nocardia brasiliensis causes lobar pneumonia (pulmonary disease similar to TB). Fever abscess chest pain different from TB by lack of granoluma.

Nocardiosis It is most common in men with a compromised immune system. In patients with brain infection, mortality exceeds 80%. In other forms, mortality is 50%, even with appropriate therapy.

Treatment Penicillin for 6-12 months

Nocardiosis

Laboratory Diagnosis Direct examination Sputum, pus, tissue biopsy Gram’stain Modified acid fast : positive GPB, branching

Laboratory Diagnosis Culture BHI, SDA, BA, Thayer-martin agar - Glabrous, folded, heaped - White to pink, orange Nocardia brasiliensis, SDA, 30 0 C, 9 days

Laboratory Diagnosis Biochemical test Top right ; casein + Bottom right ; starch + Bottom left ; tyrosine + Top left ; xanthine -

Laboratory Diagnosis Identification Biochemical test: 1. Resistant to Lysozyme 2. Paraffin hydrolysis Lysozyme test Right : resistant to lysozyme Left : not grow in the presence of lysozyme

Isolation Paraffin baiting technique Glass rod coat with paraffin McClung’s carbon free broth Incubate 37 0 C, 2 weeks Laboratory Diagnosis

Streptomyces Antibiotic production