Microbiology

This genus contains 100's of species

These species are sub-divided into three groups based on thier action on red blood cells.

Beta-hemolytic destroy RBC's
Alpha-hemolytic draw potassium out of RBC's changes color to green
Non-hemolytic no effect

This group subdivided into 17 groups
Group A
Group B

Group A

Group A
Strept throat
Scarlet fever
Impetigo
Erysipelas
Puerpera; sepsis (childbed fever)
Post complications - kidney inflammation
Rheumatic fever - rheumatic heart disease (only after throat infection)

Causes
Puerpera sepsis (child bed fever)
Impetigo

Usually happens after wound infection

Usually happens after wound infection
strains of S. pyenes capable of flesh eating do so because they produce two toxins that make them more virulent

Pyogenic exotoxin A

Exotoxin B

Group B

Group B- S.agalactiae

Common flora in the vaginal tract of about 1/3 of pregnant women.Commonly tested for during pregnancy

can cause a serious infection if newborn becomes infectedearly onset-within 7 days-pneumonia 55% death ratelate onset 1to 8 weeks -meningitis-23%

Causes of dental carries (the most common infectious diseases of human beings)
Plauqe forms and adheres to tooth
When sucrose is present, S mutans attaches to plaque. It produces Lactic acid which dissolves tooth enamel
The longer the acidic state the greater the chance of tooth decay

The only infection in the top 10 list of causes of death in the U.S

Transmission is usually endogenous- meaning self transmission

30% of healthy adults carry as transient flora in there upper respiratory tract

When their immune system is weakend - it is allowed to grow in the lungs
as the bacteria grow fluid flows into the lungs around the infection
but the fluid actually nourishes the bacteria and the bacteria grow
as the bacteria grow more fluid flows into the lungs
the more fluid in the lungs the harder to treat the infection

Treated-5%
Untreated-30%
Over the age of 70-60%

Vaccine for S.pneumonia

Caused by Mycoplasma pneumonia

Commonly called walking pneumonia

Leading cause of pneumonia is school aged children and young adults
transmission- droplets
incubation 1-4 weeks
it is mild pneumonia with symptoms of fever cough malaise and headache can be detected with X-ray 5-10%
Estimated 2 million cases annually
Rarely fatal

This bacteria mainly attack persons with weakend immune systems including eldery, alcoholics, nursing home patients

This bacteria mainly attack persons with weakend immune systems including eldery, alcoholics, nursing home patients
Transmission droplets-first grows in mouth and throat and then carried to lungs
incubation period 1 to 3 days
symptoms start as normal pneumonia symptoms cough fever chest pain
How ever they have more chills and sputum is red and gelatinous
they have a capsule thus resisting phagocytosis
Death rate without treatment is 50 to 80% death occurring quicker than other pneumonia patients

symptoms have more chills and sputum is red and gelatinous

Common name is Whooping cough
Caused by bordetella pertussis

Common name is Whooping cough
Caused by bordetella pertussis
Transmission-highly communicable, direct contact with dischages from mucus membranes
incubation 7-21 days
the bacteria attaches to ciliated cells growing very dense
They decrease cillia activity and paches of cilliated cells slough off.
Some bronchioles become completly ovstructed resulting in small area of collapes lung
Toxins releases kill epithelial cells

Caused by Legionella pneumophila

This bacteria can survive in the phagocytes then mulitply in the phagocyte and are released after death of the phagocyte
This results in tissue death of alveoli which cause multiple small abscesses in the lungs. Bacteremia is also common
The same bacteria causes a milder form called Pontiac fever

Reservior naturally found in enviornment usually in water. Especially like warm water enviroments hot tubes cooling towers A/C system in lg. buildings
incubation period 2 to 10 days
symptoms muscle aches, headaches fever cough chest pain.
Healthy people resistant to infection smokers and those with chronic diseases such as cancer heart lung and kidney diseases are most susceptible