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 GC ratio
• Some are pathogenic, but some are very useful

3
(No Transcript)
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-sy
mbiotic-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
9
(No Transcript)
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/Pr
ojects/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_innov
ations/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 bacterias 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

16
(No Transcript)
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 Contd

• 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 Hansens 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.

21
(No Transcript)
22
Cornyebacteria

• Corynebacteria (coryneclub-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

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
• 35-37C
• 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 ltwww.ispub.com/.../ijid/vol6n1/actino
  -fig1.jpggt.
• 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 ltwww.woundsresearch.com/article/4143gt.
• Rollins, David M. "BSCI 424 Pathogenic
  Microbiology -- Actinomyces." University of
  Maryland College Chemical Life Sciences. Aug.
  2000. University of Maryland. 23 Mar. 2009
  lthttp//www.life.umd.edu/classroom/bsci424/Pathoge
  nDescriptions/Actinomyces.htmgt.
• 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?topicKeyantibiot/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
  lthttp//www.genoscope.cns.fr/spip/Frankia-alni-a-
  symbiotic-nitrogen.htmlgt.
• "History's Greatest Innovations BusinessWeek."
  BusinessWeek Slide Shows and Multimedia. 24 Mar.
  2009 lthttp//images.businessweek.com/ss/07/
• 02/0216_innovations/source/12.htmgt.
• 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
  lthttp//www.sanger.ac.uk/Projects/S_coelicolor/mi
  cro_images 4.shtmlgt.
• 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