Transcript Streptococcus pneumoniae

Microbiology
Bacteria, Protozoa, Fungi, &
Viruses
Important Bacteria
Gram Positive Bacteria
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Staphylococcus aureus
Streptococcus pyogenes
Streptococcus pneumoniae
Bacillus anthracis
Clostridium botulinum
Clostridium perfringens
Clostridium tetani
Staph Aureus
Staph aureus
Is found on most people’s skin
Can cause toxic-shock syndrome
Can cause cellulitis, osteomyelitis, and
rarely, pneumonia.
Impetigo – staph aureus
Staph Forehead Abscess
Staph Infection of the Skin
Penicillin Killing Staph
Streptococcus pyogenes
 Also known as Group A strep (GAS)
 Famous for its role in pharyngitis (strep throat)
 Complications can include abscess, mastoiditis,
septicemia, osteomyelitis, scarlet fever,
rheumatic fever).
 Rheumatic fever – caused by autoimmune
reaction after infection by strep pyogenes,
causes heart valve damage, usually the mitral
valve.
Scarlet fever
Streptococcus pneumoniae
Very important cause of pneumonia (thus
it’s name)
Can also cause meningitis
Infants, elderly, immunosuppressed, and
alcoholics are more susceptible.
Can potentially be identified through
sputum sample
Streptococcus pneumoniae
Streptococcus pneumoniae
Bacillus anthracis
Forms spores, which are very hearty, and
can survive in poor conditions for years.
These spores are usually the cause of
infection.
Causes pulmonary and cutaneous
infection. Pulmonary infection is very
dangerous, and more than 50% of cases
are fatal.
Cutaneous anthrax
Bacillus Anthracis
Clostridium botulinum
Causes food poisoning
Toxin produced by the organism can lead
to nausea, vomiting, dizziness, cranial
palsy, double vision, speech and
swallowing difficulty, paralysis, and even
death (about 20% of cases)
Infants are particularly susceptible
Clostridium botulinum
Infant botulism
Clostridium perfringens
Often a cause of soft tissue infection, or
food poisoning (similar to botulism, but
less severe).
Soft tissue infections can be very severe,
even life threatening.
Often occurs after trauma
Clostridium perfringens
Clostridium perfringens
Clostridium perfringens
Clostridium tetani
Infection usually after a minor skin trauma
Symptoms include muscle stiffness,
spasms, and lockjaw.
May be fatal from respiratory failure
Clostridium tetani
Important Bacteria
 Gram Negative Bacteria
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Bordetella pertussis
Chlamydia trachomatis
Escherichia coli
Haemophilus influenzae
Klebsiella pneumoniae
Mycoplasma pneumoniae
Neisseria gonorrhoeae
Pseudomonas aeruginosa
Rickettsia rickettsii
Salmonella species
Bordetella pertussis
Causes whooping cough
We vaccinate against this disease
Highly contagious
Cause long illness that gets worse over 12 weeks, than severe cough can last up to
6 weeks. Eventually, cough decreases,
but may persist for several months.
Bordetella pertussis
Chlamydia trachomatis
Very important STD
Causes urethritis, cervicitis, salpingitis,
pelvic inflammatory disease
May be very subtle, which is why people
can so easily contract it
May also cause serious conjunctivitis in
infants (which is why we often put
antibacterial ointment in newborns’ eyes.
Chlamydia trachomatis
Normal cervix
Chlamydia trachomatis
Haemophilus influenzae
Very common cause of otitis media in
children (ear infections).
Usually cured easily by antibiotics,
however, often recurs due to structural
abnormalities of the infants’ head.
We vaccinate against h. flu type B, which
is a common cause of meningitis and
epiglottitis, which can both be fatal.
Haemophilus influenzae
Klebsiella pneumoniae
Causes pneumonia, urinary tract
infections, and is implicated in many
hospital acquired infections (nosocomial).
Textbooks like to point out that people with
this type of pneumonia have a very
strange sputum. It is often described as
currant jelly sputum.
Klebsiella pneumoniae
Mycoplasma pneumoniae
Is a very common cause of slowly
evolving, low-grade pneumonia. Usually
occurs in otherwise healthy people.
Very rarely fatal
Common cause of “walking pneumonia”
Mycoplasma pneumoniae
Neisseria gonorrhea
Causes mucous membrane infections,
usually the urogenital tract.
Causes urethritis, cervicitis, often with
much more obvious symptoms than
chlamydia (but they often travel together).
Can also cause throat infections and
conjunctivitis.
Neisseria gonorrhea
Pseudomonas aeruginosa
Causes soft tissue infections, and often
attacks burn patients, diabetics, and
trauma victims.
Causes an unusual blue-green pus, and
sweet odor.
Pseudomonas aeruginosa
Salmonella
Food poisoning
Usually is a self-limiting disease
May progress to a severe intestinal
infection causing diarrhea. This usually
can be supported with fluid replacement in
the patient.
Salmonella
Bacteria
Normal Flora in the Respiratory Tract
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Staphylococci
Streptococci
Diplococci
Klebsiella
Haemophilus
Niesseria
Mycoplasma
Candida albicans (Is candida a bacteria?)
Eukaryotic Organisms
Algae
Protozoa
Fungi
Algae
Algae are found in:
Fresh water
Salt water
Soil
Trees
Plants
Rocks
Petri dish
Types of Fungi
Mushrooms
Mold
Yeast
Fungi
Live in organic and inorganic matter
Main source of nutrients is decaying
matter
Reproduce with spores
Both harmful and beneficial
Can cause allergic reactions
Cheese, yogurt, beer, wine & penicillin
Fungus
Molds
Found in water,
soil, and food
Caused the
great potato
famine
Attack the
immune
supressed
Yeast
Yeast
Types of Yeast
Brewer's yeast Saccharomyces cerevisiae
Candida albicans or Candidiasis
Infections:
Oral Thrush
Vulva-vaginal candidiasis
Systemic yeast infections may occur in
persons with immune suppressed and
diabetic patients
Common Fungal Infections
Black mold causes respiratory disease
Aspergillus causes pneumonia
Pneumocystis carinii causes pneumonia
Tinea (ringworm)
Black mold
Aspergillus pneumonia
Pneumocystis carinii
Tinea
tinea
Protozoa
Single celled
Animal-like organisms
Ingest algae, yeast, bacteria, & other
protozoa
Most are pathogenic
Diseases caused by Protozoa
Amoebic dysentery
Giardia
Malaria
Diarrhea – many causes
Pneumonia
Meningoencephalitis
African sleeping sickness
Amoebic dysentery
Amoebic dysentery
Amoebic dysentery
Giardia
Causes giardiasis
This is a moderate diarrhea with
malabsorption
Transmitted by fecal/oral route
May diagnose by looking at stool sample
and seeing the organism
Giardia
Malaria (plasmodia)
Have a vertebrate host (humans) and an
insect host (mosquito)
Transmitted to people through mosquito
bites
Causes many symptoms, some general,
such as chills, fever, anemia.
Also may lead to liver damage because
this is where they multiply.
Malaria
Malaria in the blood (signet ring stage)
African sleeping sickness (trypanosoma
species)
Transmitted by the tsetse fly
Causes headache, fever, joint pains,
adenopathy, sever lethargy.
May lead to death if treatment is delayed
Trypanosoma
Viruses
Acellular
Smaller than bacteria
Infect an already existing cell
If they infect bacteria they are called
bacteriophages
Five specific properties of Viruses
Possess DNA or RNA
Replication is directed by viral nucleic acid
Do not divide by mitosis or binary fission
Lack genes & enzymes for energy
Viral life depends on:
 Ribosomes
 Enzymes
 Nutrients
Example of viral shape
Computerized model of HIV
Viral cycle
Virus injects RNA or DNA into host
The virus can remain latent or active
RNA/DNA transfers into each daughter
cell when the host cells divide
Active state can be induced by heat
Called the lysogenic cycle
Viral diseases
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RSV
SARS
AIDS
Small pox
Mumps
Measles
Hepatitis
Influenza
Rabies
Cold sores / fever blisters
Hantavirus
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Chicken pox
Warts
Colds
Genital herpes
Respiratory infx.
Poliomyelitis
Encephalitis
Leukemia
Intestinal infections
West Nile
Treatment for Viruses
Antibiotics are not effective!!
Antiviral agents tend to be narrow in
spectrum and have limited efficacy
Common Antiviral Medications:
 Ribavirin (Virazole)
 Acyclovir (Zovirax)
 Oseltamivir (Tamiflu)
Treatment for Viruses
Antivirals are not curative
Mechanism of action
 Inactivate enzymes needed for viral replication
Antiviral therapy should be initiated within
48 hours of the onset of an infection to
provide any benefit