aerobic gram positive bacilli
Gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells making the cell wall more porous and incapable of retaining the crystal violet stain. The spore-forming bacteria can again be divided based on their respiration: Bacillus is a facultative anaerobe, while Clostridium is an obligate anaerobe. Also, Rathybacter, Leifsonia, and Clavibacter are three gram-positive genera that cause plant disease. Aerobic Non–Spore-Forming Gram-Positive Bacilli: Corynebacterium, Listeria, Erysipelothrix, Actinomycetes, and Related Pathogens. The non–spore-forming gram-positive bacilli are a diverse group of aerobic and anaerobic bacteria. This chapter focuses on the aerobic members of this group. The anaerobic, non–spore-forming gram-positive bacilli such as Propionibacterium species and Actinomyces species are discussed in Chapter 21 on anaerobic infections. 1 Invited audience members will follow you as you navigate and present. 2  People invited to a presentation do not need a Prezi account. 3  This link expires 10 minutes after you close the presentation. 4  A maximum of 30 users can follow your presentation.  Learn more about this feature in our knowledge base article. BLOOD CULTURE GROWING A GRAM-POSITIVE ROD. A report from the laboratory that a blood culture contains a gram-positive rod suggests that the organism is a diphtheroid or Corynebacterium species, Clostridium species, Propionibacterium acnes, Listeria monocytogenes, or Bacillus species. Lactobacillus, Listeria, Erysipelothrix, Kurthia, Caryophanon, Bronchothrix, Renibacterium. 1. Listeria monocytogenes - ubiquitous, motile, short to long filaments in palisades, beta-hemolytic, resists cold, heat, salt, pH extremes and bile. Most Bacillus species isolated in the laboratory, except for Bacillus anthracis, are contaminants. The organism is an aerobic, gram-positive rod that forms spores. Bacillus cereus and Bacillus subtilis have been associated with post-traumatic endophthalmitis. Bacteremia generally occurs in the compromised patient with a central venous line. Violet stained gram-positive cocci and pink stained gram-negative rod-shaped bacteria. Gram-positive bacteria are bacteria that give a positive result in the Gram stain test. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through a microscope. In gram-positive bacteria, the S-layer is attached to the peptidoglycan layer (in gram-negative bacteria, the S-layer is attached directly to the outer membrane). Specific to gram-positive bacteria is the presence of teichoic acids in the cell wall. Culture – Anaerobic blood agar, thioglycollate, Egg Yolk Agar (EYA), Cycloserine Cefoxitin Fructose Agar (CCFA), Peptone – Yeast Glucose broth (PYG), Brucella/ Blood Agar (BRU/BA), PRAS. - Primary plates should be freshly prepared or used within 2 weeks of preparation.
Corynebacterium, Listeria, Erysipelothrix, Actinomycetes, and Related Pathogens.