High G + C Gram Positive Bacteria

1. High G + C Gram Positive Bacteria Derek Frantz, Kara Sporik, Jessica Teague, Katie Stevenson, Kent Worthington

2. Phylum: Actinobacteria • Typically rod shaped • Most are pleomorphic • Gram positive • High G+C ratio • Some are pathogenic, but some are very useful

4. Nocardia • Gram-positive, rod shaped • Aerobic • Often acid-fast • Common in soil • Cells and cell walls have high lipid content • Nocardia asteroides, Nocardia brasiliensis

5. Cutaneous Nocardiosis • Nocardia brasiliensis is the most common cause • Usually presents as pyodermatous lesions, which then form abscesses. • Eventually, the disease can disseminate and spread to virtually any organ

6. Cutaneous Nocardiosis • The same patient in the previous figure after one year of treatment.

7. Frankia • Microaerobes • Symbionts of plants • Non pathogenic in humans • Similar to Mushrooms • Form nitrogen-fixing nodules in actihorhizal plants http://www.genoscope.cns.fr/spip/Frankia-alni-a-symbiotic-nitrogen.html

8. Infection of Plants • Causes root hair deformation • Vegetative hyphae penetrate nodules on a root • Differentiate into diazovesicles • 3 Cell types • Vegetative hyphae • Vesicles • Spores • All 3 types can be found when infecting a plant Frankia on Ceanothus roots. http://www.laspilitas.com/classes/Frankia.html

10. Streptomyces • Over 500 species • Strict Aerobe • Produce extracellular enzymes depending on their environment • Reproduces with asexual spores • Produces geosmin Streptomyces coelicolor http://www.sanger.ac.uk/Projects/S_coelicolor/micro_images4.shtml

11. Uses for Streptomyces • Produces antifungals and antibacterials • Produce most of our commercial antibiotics • Different species produce different antibiotics • Certain species may produce more than one http://images.businessweek.com/ss/07/02/0216_innovations/source/12.htm

12. Mycetoma • Caused by S. somaliensis and S. sudanensis and some fungii • Mainly infects the foot • Endemic in Africa, India and South America • Disease is acquired by contacting grains of bacterial spores from the soil • Normally in wounds • Diagnosed using radiology or ultrasound • Treatments: Surgery, Amputation, and some antifungal drugs

13. Actinomyces • Gram positive • Facultative anaerobes • Form filaments that can fragment • Actinomyces israelii

14. Actinomycosis • Tissue destroying disease usually affecting the head, neck or lungs due to the bacteria’s normal location in the nose or throat. • “lumpy jaw” or pulmonary actinomycosis

15. Actinomycosis Can be identified through fluid or tissue cultures. Treatment requires antibiotics for several months to a year. Patients should fully recover after proper treatment

17. Mycobacterium • Aerobic, nonendospore-forming rods • Myco,meaning fungus-like, was derived from their occasional exhibition of filamentous growth and are pleomorphic • Distinctive cell wall structurally similar to gram-negative bacteria • Outermost lipopolysaccharide layer in mycobacteria is replaced by mycolic acids, which form waxy, water-resistant layer. This makes the bacteria resistant to stresses such as drying, and few antimicrobial drugs are able to enter the cell and also gives it the distinctive staining property of acid-fastness • Nutrients enter the cell through this layer very slowly, which is a factor in the slow growth rate; it sometimes takes weeks for visible colonies to appear • Mycobacteria are widespread organisms, typical living in soil, water (including tap water treated with chlorine) and food sources. Some, however, including the tuberculosis and the leprosy organisms, appear to be obligate parasites (cannot live independently of its host) and are not found as free-living members of the genus.

18. M. tuberculosis • M. tuberculosis, which causes tuberculosis and is an obligate aerobe • Transmission of TB occurs primarily by the aerosol route but can also occur through the gastrointestinal tract. Coughing by people with active TB produces droplet nuclei containing infectious organisms which can remain suspended in the air for several hours. Infection occurs if inhalation of these droplets results in the organism reaching the alveoli of the lungs. • Only 10% of immunocompetent people infected with M. tuberculosis develop active disease in their lifetime - the other 90% do not become ill and cannot transmit the organism. However, in some groups such as infants or the immunodeficient, the proportion who develop clinical TB is much higher.

19. M. tuberculosis Cont’d • The classic symptons of tuberculosis are a chronic cough with blood tinged sputum, fever, night sweats, and weight loss. Infection of other organs causes a wide range of symptoms. The diagnosis relies on radiology (commonly chest X-rays, a tuberculin skin test, blood tests, as well as microscopic examination and microbiological culture of bodily fluids • Treatment for TB uses antibiotics to kill the bacteria. The two antibiotics most commonly used are rifampicin and isoniazid. However, instead of the short course of antibiotics typically used to cure other bacterial infections, TB requires much longer periods of treatment (around 6 to 12 months) to entirely eliminate mycobacteria from the body. Latent TB treatment usually uses a single antibiotic, while active TB disease is best treated with combinations of several antibiotics, to reduce the risk of the bacteria developing antibiotic resistance

20. M. leprae • M. leprae, also known as Hansen’s bacillus, causes leprosy • Although there remains some uncertainty about the mode of transmission of leprosy, most researchers agree that it is spread from person to person in respiratory droplets or nasal discharge. M. leprae may survive outside a human host for a period of hours or even days. • While human-to-human respiratory tramsmission is thought to be the likely cause of most infections, exposure to insect vectors, infected soil, and animals may also be possible modes of transmission. • M. leprae was sensitive to dapsone (diaminodiphenylsulfone), but resistance against this antibiotic has developed over time. Therapy with dapsone alone is now strongly contraindicated. Currently, a multidrug treatment (MDT) is recommended by the World Health Organization, including dapsone, rifampicin and clofazimine. In patients receiving the MDT, a high proportion of the bacilli die within a short amount of time without immediate relief of symptoms. This suggests that many symptoms of leprosy must be due in part to the presence of dead cells.

22. Cornyebacteria • Corynebacteria (coryne=club-shaped) are gram positive, aerobic, nonmotile, rod-shaped organisms with the characteristic of forming club shaped arrangements during normal growth • Consists of an extremely diverse group of bacteria, including animal and plant pathogens. Most do not cause disease, but are part of normal human skin flora. Corynebacteria are a diverse group found that can be found in soil, vegetables, sewage, skin, and cheese • Some are pleomorphic and form coccoid elements during growth

23. C. diphtheriae • C. diphtheriae is an aerobic, Gram positive organism, characterized by non-encapsulated, non-sporulated, immobile, straight or curved rods • It is pathogenic only in humans • C. diphtheriae produce diphtheria toxin, a proteic exotoxin, resulting in the inhibition of protein synthesis and thus is responsible for the signs of diphtheria. The inactivation of this toxin with an antitoxic is the basis of the antidiphtheric therapeutic vaccination. However, not all strains are toxigenic;. A non-toxigenic strain can become toxigenic by the infection of a bacteriophage • Diphtheria is an upper respiratory tract illness characterized by sore throat, low fever, and an adherent membrane (called a pseudomembrane) on the tonsils, pharynx, and/or nasal cavity • Diphtheria is a contagious disease spread by direct physical contact or breathing aerosolized secretions of infected individuals • The bacterium is sensitive to the majority of antibiotics, such as the penicillins, ampicillin, and tetracyclines

24. Propionibacterium • Slow growing • Nonspore forming • Gram-positive • Anaerobic bacteria • Rod-shaped or branched • Primarily commensal relationships • Produce lactic acid, propionic acid, and acetic acid • Unique metabolism

25. P. freudenreichii • Gram positive • Non motile • Rapid growth at 30° C under anaerobic conditions • Ferment lactic acid, CO2, and polyhydroxyl alcohols producing mainly propionic acid, acetic acid, and CO2. • Act as ripening starters in Swiss cheese • Flavors made from propionic acid • Holes produced by CO2

26. P. acnes • Bacteria found on human skin because lipid-rich microenvironment of hair follicle • Produces inflammatory mediators that result in papules, pustules, and later, nodulocystic lesions that are typical of inflammatory acne. • Cause Acne Vulgaris

27. Acne Vulgaris • Description/Symptoms • Lesions found on face, chest, and upper back. • 3 lesion catergories: • non-inflammatory papules • inflammatory papules • scars • 4 major pathophysiologic features: • Hyperkeritinization • Sebum production • Bacterial proliferation • Inflammation • Mechanism • Over activity of pilosebaceous apparatus during hormonal fluctuations. • Transmission: • Touching skin with hands • Heavy sweating without cleansing • Not cleansing skin • Tight fabrics • Oils and harsh chemicals-petroleum • Hair and hair products with a lot of oil

28. Acne Vulgaris • Diagnosis: • Whiteheads and blackheads present on skin • Persists after OTC med used • Physical exam with medical history considered • Women asked about menstruation • May need tests if thought to be caused by other medical problem • Treatment: • Manual extraction • Medicine: • Benzoyl peroxide • Alpha-hydroxy acid • Salicylic acid • Tea Tree Oil • Antibiotics • Topical (Clindamycin) • Oral (Erythromycin) • Oral Retinoids (Accutane)

29. Gardnerella • Gram-variable • Facultative anaerobe • Pleomorphic rod shape • Non-motile • Optimum growth temperature: 35-37°C • Gardnerella vaginalis: only species in the genus • Cause of Bacterial vaginosis (BV)- infection of female genital tract • Occurs mainly in women

30. Bacterial vaginosis (BV) • Mechanisms of infection: • Overgrowth of bacteria in the vagina • Reduction of Lactobacilli- maintain healthy acidic pH • Increase in Gardnerella vaginalis • Since vaginal flora are altered, pH of vagina increases • Risk Factors: • Sexual activity (not a STD) • Douching • Recent antibiotic use • Symptoms: • Fishy vaginal odor • Increased vaginal discharge (gray and thin)

31. Bacterial vaginosis (BV) • Diagnosis: • Wet mount slide prepared of saline solution/vaginal secretions and reviewed under low/high power objectives • Treatments: • Oral metronidazole (500 mg twice daily for 6 days ) • Sexual partners should also be treated • Mechanism of Metronidazole: • Toxic to cells • Metronidazole diffuses across membrane • Toxic particles interact with host cell DNA resulting in breakage

32. Bibliography • Smith M.D., David T. Chapter I: Actinomycosis. Preventive Medicine in World War II: Communicable Diseases. Vol. V. Washington D.C: AMMED, 1949. 1-3. • Enoz M.D., Murat. "Actinomycosis of the Tongue." The Internet Journal of Infectious Disease 7 (2007): 1-5. Internet Science Publications, LLC. 23 Mar. 2009 <www.ispub.com/.../ijid/vol6n1/actino-fig1.jpg>. • Wheeler, Chad K., Gary D. DeCesare, Rudolph J. Maneri, Wyatt G. Payne, and Martin C. Robson. "Cutaneous Nocardosis." Wounds (2005). Wound Research. 1 May 2005. HMP Communications. 23 Mar. 2009 <www.woundsresearch.com/article/4143>. • Rollins, David M. "BSCI 424 Pathogenic Microbiology -- Actinomyces." University of Maryland College Chemical & Life Sciences. Aug. 2000. University of Maryland. 23 Mar. 2009 <http://www.life.umd.edu/classroom/bsci424/PathogenDescriptions/Actinomyces.htm>. • Bergey, D. H.. Bergey's Manual of Determinative Bacteriology. Hagerstown: Lippincott Williams & Wilkins, 1994. • Curran, Diana. Bacterial Vaginosis. E.Medicine 2008. • Johnson, Melissa. Metronidazole: An overview. UpToDate Inc. 23 Mar. 2009 http://www.uptodate.com/patients/content/topic.do?topicKey=antibiot/10108. • Gardnerella Vaginalis - Symptoms, Treatment and Prevention. Consumer Health News, Information and Resources Updated Daily. 23 Mar. 2009 http://www.healthscout.com

33. Bibliography (cont.) • "A symbiotic nitrogen-fixing actinobacterium -." Site du Genoscope. 23 Mar. 2009 <http://www.genoscope.cns.fr/spip/Frankia-alni-a-symbiotic-nitrogen.html>. • "History's Greatest Innovations | BusinessWeek." BusinessWeek Slide Shows and Multimedia. 24 Mar. 2009 <http://images.businessweek.com/ss/07/ • 02/0216_innovations/source/12.htm>. • Madigan, Michael T., John Martinko, and Jack Parker. Brock Biology of Microorganisms (10th Edition). Upper Saddle River: Prentice Hall, 2002. • "S. coelicolor Genome Project." The Wellcome Trust Sanger Institute. 23 Mar. 2009 <http://www.sanger.ac.uk/Projects/S_coelicolor/micro_images 4.shtml>. • Tortora, Gerard J., Berdell R. Funke, and Christine L. Case. Microbiology An Introduction, Brief Edition. Boston: Benjamin-Cummings Company, 2004. • WebMD. 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. • Emedicine. Proprionibacterium. 1994. Medscape