Just for Fun: ASM Website Washup'org

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Just for Fun ASM Website Washup.org

• American Society for Microbiology, slogans
• Americas Dirty little secret
• Dont get Caught Dirty Handed
• See WashUp.org
• Try typing in Wash Up America
• Do you wash your hands after using a public rest
  room?
• 91 of adults say always
• 83 were observed to do so
• What about public restrooms in major airports?
• 78 New York of adults actually wash their hands
• What was the impact of SARS?
• Toronto, Canada
• Travelers washed almost every time.

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Less than half of adults state that they always
wash their hands after petting a dog or cat,
coughing or sneezing or handling money
Among U.S. Adults
Q I am going to read you a list of activities
and Id like you to tell me how often you make it
a practice of washing your hands. How often do
you wash your hands after
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Review

• What are the three most common routine primary
  plating media?
• If an isolate is a Gram positive, upon which
  media do you expect to see growth?
• If an isolate is a Gram negative, upon which
  media do you expect to see growth?
• What determines the likelihood that a primary
  Gram Stain will be required?

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Gram positive cocciStreptococcaceae

• B009 Stafford Hall
• Brenda.Tessmann _at_ .uvm.edu
• 656-8254

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Gram Positive Cocci

• General Characteristics
• Most frequently isolated microbes after family,
  Enterobacteriaceae
• Wide spread in nature
• Common inhabitants of skin, mucous membranes, GI
  tract
• Two clinically significant families
• Streptococcaceae
• Micrococcaceae

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Streptococcaceae

• Includes
• Streptococcus / Enterococcus / many others
• cells form chains as cells divide in only one
  plane
• catalase negative
• form small colonies
• lt 1mm in diameter
• transparent / translucent

Streptococcaceae Right
Cell division
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Micrococcaceae

• Includes
• Staphylococcus / Micrococcus / Rothia
  (Stomatococcus)
• cells form clusters/tetrads as cells divide in gt
  one plane
• catalase positive
• form larger colonies than Streptococcaceae
• 1-4 mm in diameter
• more opaque

Micrococcaceae Left
Cell division
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Classification of Streptococcaceae

• Methods
• Genus/species
• Hemolytic patterns (alpha, beta, gamma)
• Lancefield groupings (cell wall antigens)
• polysaccharide group A, B, C, F and G or...
• lipoteichoic acid group D

• Example of Classification for one microbe
• Streptococcus pyogenes
• Beta streptococcus
• Group A streptococcus
• GABHS (hospital term Group A beta hemolytic
  strep)

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Streptococcus pyogenes
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Streptococcus pyogenes

• Humans are the natural reservoir
• Spread person to person
• Virulence Factors
• Hyaluronic acid capsule
• M proteins
• Pyrogenic Toxins
• Exotoxins A, B, C
• Hemolysins
• Streptolysin O
• Streptolysin S
• Streptokinase
• DN-ases

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Lysogenic Bacteriophages
Microbes in diagram on the right, infected with
bacteriophage ie. Coccus-Streptococcus pyogenes
producing pyrogenic toxins
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Diseases caused by Grp A Streptococcus
Pyoderma or Impetigo
Pharyngitis
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Diseases caused by Grp A Streptococcus
Erysipelas
Cellulitis
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Diseases caused by Grp A Streptococcus
Scarlet Fever
Necrotizing fasciitis
Note See Donnas and Jackies stories Web site
is listed in handout
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Diseases caused by Grp A Streptococcus

• Streptococcal Toxic Shock
• Endocarditis acute form
• non-suppurative sequelae of Grp A
• Rheumatic fever
• Glomerulonephritis

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Streptococcus agalactiae

• Beta streptococcus or Group B Streptococcus
• Many serotypes - based on capsular antigens and
  protein C
• Most common beta-hemolytic streptococci isolated
  from blood

• Virulence factors of Group B Streptococcus
• Polysaccharide capsule
• Produce a variety of enzymes

• Diseases of Group B Streptococcus
• Neonatal Disease - neonatal sepsis
• mother is colonized infant infected during
  birth
• small become ill, extremely serious
• risk factors premature delivery, hard labor,
  early membrane rupture
• Early-onset Disease occurs lt7 days of life
• Late-onset Disease occurs 1 wk to 3 mos of life

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• Other Beta Streptococci
• Include
• Group C, G and F
• Conditions include
• Mild pharyngitis and other diseases usually
  without sequelae
• Not very common
• Unlike Group A and Group B Streptococci gt one
  species

• Alpha Streptococci
• Viridans Streptococci Group
• group of species NOT Genus and species
• named for alpha hemolytic on BAP
• Normal flora
• Diseases of viridans streptococci
• Dental caries
• Bacterial Endocarditis (sub-acute)

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• Streptococcus pneumoniae (pneumococcus)
• Gram positive, Lancet-shaped, diplococcus
• Very Serious Pathogen
• Huge Polysaccharide capsule
• gt90 capsular types known to date
• 23 types cause 88 of pneumococcal
  bacteremia/meningitis
• vaccine for immunocompromised and elderly
• Virulence Factors
• Capsule
• Protein adhesins
• Pneumolysin

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Streptococcus pneumoniae

• Predisposing factors
• prior viral infection
• Diseases associated with Streptococcus pneumoniae
• Otitis media and sinusitis
• Pneumonia
• most common community acquired
• abrupt, severe shaking chills
• sustained high fever
• productive cough
• sputum...rust colored
• Bacteremia / Septicemia
• 25 - 30 of patients with pneumonia
• Meningitis
• Neonatal Sepsis
• recognized recently

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Enterococcus sp.

• Enterococcus faecalis
• most frequent enterococcal species isolated
• Enterococcus faecium
• also isolated
• Normal flora in GI tracts of humans and other
  animals
• Used in water testing as indicators of animal
  contamination
• Involved in Nosocomial infections
• Resistant to a wide variety of antimicrobials
  including Vancomycin
• Vancomycin Resistant Enterococci VRE
• VRE may pass Vancomycin resistance to
  Staphylococcus aureus
• Diseases caused by Enterococcus sp.
• Urinary tract infections (Ascending)
• Intra abdominal or pelvic infections - post
  surgery

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Identification of Streptococcus sp.

• Primary Gram Stain of specimen may or may be
  useful
• Throat culture No....why?
• Pneumonia Yes - can be diagnostic
• Gram Positive lancet shaped diplococci with
  chains
• good Sputum which is rust-colored

• Quickie Strep Test often performed in
  physicians office
• Take two swabs
• Place one in an extraction broth, incubate
• Extraction broth removes the Lancefield antigens
• Mix unknown antigen with known anti-A linked to
  latex particle
• Agglutination indicates presence of Group A strep
• Very specific, but not very sensitive
• Results
• Positive treat with antibiotics
• Negative use the second swab to inoculate a BAP

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Identification of Streptococcus sp.
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Identification of Streptococcus sp.

• Gram Stain of culture
• Classic description
• GPC and GPDC
• long chains in broth
• shorter chains from plates
• Realistic description
• also see...coccobacillary forms
• little or inconsistent chain formation

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More Realistic Pictures
Classic Appearance
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Identification of StreptococciBased on Hemolysis
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CAMP Testfor grp B beta strep
Quellung Test Apparent capsular swelling
Strain specific
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Reality Check

• We discussed 6 microbes
• Group A beta Streptococci, Streptococcus pyogenes
• Group B beta Streptococci, Streptococcus
  agalactiae
• Group C beta Streptococci
• Viridans Group Streptococci
• Streptococcus pneumoniae
• Enterococcus sp.
• Murex lists 13 different microbes in their
  abbreviated scheme
• Lists only Catalase Negative GPC having the
  Lancefield Antigen

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Murex GPC schemeCatalase Negative GPC
FYI Do NOT memorize this chart
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Case Study 1 Gram Positive Microbe

• Symptoms
• Severe shaking chills and High fever
• Tight, heavy chest
• Coughing up flem
• History
• Prior viral upper respiratory tract (urt)
• ER admission
• Acutely ill, but responsive patient
• Fever, intermittent shaking chills
• Productive cough showing rust coloring
• What specimen will you obtain?
• Would a primary Gram stain be useful?
• If so, how?
• If not, why?

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Case Study Gram Positive Microbe

• Assuming a good quality specimen, what would be
  seen on a primary Gram stain?
• What would you choose for plating media?
• What atmosphere would be used for growth?
• What do you anticipate for a predominant microbe
  on non-selective media?
• Are there any unusual characteristics expected?
• Do you expect usual throat flora?

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Case Study 2 Gram Positive Microbe

• Background
• Five year old male
• Seen in pediatricians office
• High fever
• Sore throat
• Swollen lymph nodes
• Prior viral upper respiratory tract (urt)
• What is the condition?
• What specimen will you obtain?
• Would a primary Gram stain be useful?
• If so, how?
• If not, why?

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Case Study Gram Positive Microbe

• What would you use for plating media?
• What atmosphere would be used for growth?
• What do you anticipate for a predominant microbe
  on non-selective media?