Aerobic Gram-Positive Bacilli Part II Division of Medical Technology Carol Larson MSEd, MT(ASCP) Please click audio icon to hear Carol’s narration

Gram stain –Morphology –Arrangement Formation of spores Catalase reaction Click icon for audio Differentiation of Major GPR Genera

Spore-forming GPR, catalase positive –Bacillus species –Bacillus anthracis –Bacillus cereus Nonspore-forming GPR, catalase positive –Listeria monocytogenes –Corynebacterium species (diphtheroids) –Corynebacterium diphtheriae –Corynebacterium jekeium Click icon for audio GPR Discussed in Student Lab

Nonspore-forming GPR, catalase negative –Gardnerella species –Erysipelothrix species –Lactobacillus species Branching Nocardioform GPR –Nocardia species –Streptomyces species Click icon for audio GPR Discussed in This Lecture

Two types –Short GPR –Long, filamentous GPR Non-sporulating Click icon for audio Erysipelothrix rhusiopathiae Gram Stain GPR, pleomorphic, Non-spore forming, Catalase negative

Erysipelothrix rhusiopathiae Colony Morphology Grows on BAP –Nonhemolytic or alpha hemolytic Microaerophilic Click icon for audio GPR, pleomorphic, Non-spore forming, Catalase negative

Catalase negative Motility –Nonmotile –Test-tube brush growth pattern in semisolid motility tube at 48 hours H 2 S positive in KIA/TSI (only GPR) Sucrose non“F” Click icon for audio Erysipelothrix rhusiopathiae Identification GPR, pleomorphic, Non-spore forming, Catalase negative

Zoonotic –Swine erysipelas (fatal to pigs) Man – skin disease –Erysipelas –Direct contact with infected animal –Rarely disseminates causing septicemia with arthritis or endocarditis Click icon for audio Erysipelothrix rhusiopathiae Clinical Significance GPR, pleomorphic, Non-spore forming, Catalase negative

What are the key biochemical reactions that identify Erysipelothrix rhusiopathiae? Two gram stain morphologies (GPR), two colony types on SBA, catalase negative, H2S positive, test-tube brush pattern in motility tube, sucrose non“F”

Two types –Long slender GPR in chains –Short GPCB Non-sporulating Click icon for audio Lactobacillus species Gram Stain GPR, pleomorphic, Non-spore forming, Catalase negative

Grows on BAP –Multiple colony morphologies –Nonhemolytic or alpha hemolytic Microaerophilic Click icon for audio Lactobacillus species Colony Morphology GPR, pleomorphic, Non-spore forming, Catalase negative

Catalase negative Sucrose “F” Vancomycin “R” Click icon for audio Lactobacillus species Identification GPR, pleomorphic, Non-spore forming, Catalase negative

Lactobacillus species Clinical Significance Normal flora –Mouth –GI tract –Female vaginal tract Rarely pathogenic –Endocarditis –Meningitis Click icon for audio GPR, pleomorphic, Non-spore forming, Catalase negative

What is the clinical significance of Lactobacillus species? It is considered normal flora of the mouth, gastrointestinal tract, and female genital tract

Nonspore-forming GPR, catalase negative –Gardnerella species –Erysipelothrix species –Lactobacillus species Click icon for audio Review

Actinomycetes –Nocardia species –Streptomyces species Click icon for audio Branching Nocardioform GPR

Nocardia species Gram Stain Pleomorphic, branching, fine, delicate filaments with fragmentation GPR Often appears beaded Click icon for audio Branching Nocardioform GPR

Grows on SBA, Mycology media and LJ media Aerobic growth appears at 3-30 days Waxy, bumpy or velvety rugose forms, yellow to orange colonies Click icon for audio Nocardia species Colony Morphology Branching Nocardioform GPR

Nocardia species Identification Partially acid-fast positive Presence of granules in specimen Catalase positive Click icon for audio Branching Nocardioform GPR

Nocardia species Clinical Significance Habitat: soil and water Mycetoma (actinomycetoma) –Tissue swelling –Draining sinus tracts –Presence of granules Immunocompromised patients –Pulmonary and disseminated infections Click icon for audio Branching Nocardioform GPR

What is the key characteristic in identifying Nocardia species? Branching GPR that is partially acid fast positive

What primary disease does Nocardia cause and what 3 symptoms are seen? Mycetoma (aka actinomycetoma). Triad of symptoms: tissue swelling, draining sinus tracts, and the presence of granules

GPR with extensive branching, chains and spores Does not fragment easily Click icon for audio Streptomyces species Gram Stain Branching Nocardioform GPR

Streptomyces species Colony Morphology Grows on SBA, Mycology media and LJ media Aerobic growth appears at 3-30 days Waxy, bumpy or velvety rugose forms, yellow to orange colonies Click icon for audio Branching Nocardioform GPR

Acid-fast negative Click icon for audio Streptomyces species Identification Branching Nocardioform GPR

Streptomyces species Clinical Significance Habitat: soil and decaying vegetation Mycetoma (actinomycetoma) Rarely: –Pericarditis –Bacteremia –Brain abscess Click icon for audio Branching Nocardioform GPR

How can you differentiate Streptomyces from Nocardia? Streptomyces is acid-fast negative and Nocardia is partially acid-fast positive

Nonspore-forming GPR, catalase negative –Gardnerella species –Erysipelothrix species –Lactobacillus species Branching Nocardioform GPR –Nocardia species –Streptomyces species Click icon for audio Aerobic GPR Summary

Who am I? BAP, growth at 2 daysGram Stain Erysipelothrix rhusiopathiae Motility Tube: “test-tube brush” pattern of growth TSI

Who am I? LJ agar at 1 weekGram Stain Nocardia species Causes Actinomycetoma Acid Fast Stain