Bacterial diseases

At birth, the entire intestinal tract is

sterile

infant gut is colonized by

maternal and environmental bacteria during birth and through feeding and other contacts

by ____ years old the microbiota is similar to that of an adult

2.5

microbiota help protect the host from the colonization by

pathogenic species

Bacteria effect on humans

• most don’t cause disease in humans

• can be beneficial or pathogenic

beneficial bacteria

microbiome in the body can help prevent growth of other more dangerous bacteria

Pathogens

cause disease

aerobic bacteria

need oxygen

anaerobic bacteria

have trouble living/growing in the presences of oxygen

facultative bacteria

can live/grow with or without oxygen

gram staining

the differences in staining are due to differences in cell wall

gram positive

stain blue/purple

gram negative

stain red/pink

bacteria shapes

• sphere (cocci)

• rods (bacilli)

• spirals (spirochetes)

Pertussis (whopping cough)

• the bacteria attach to the cilia that line part of the upper respiratory system and release toxins that damage the cilia and cause airways to swell

• babies are highly susceptible

• vaccine preventable

what is pertussis caused by ?

bacterium Bordetella purtussis

how is pertussis transmitted?

highly contagious, airborne transmission by coughing or sneezing

Helicobacter pylori (H. pylori)

• found in feces, saliva, and plaque on the teeth

• common worldwide

• increases acid production population, interferes with the stomach’s normal protection from stomach acid, and produced toxins

how is H. pylory transmitted

through kissing or other close contact

H. pylori bacteria protect themselves by

• growing in the protective mucus layer of the stomach lining —> protect them from stomach acid

• producing ammonia —> protect from stomach acid, facilitates penetration of mucus layer

effects of H pylori

inflammation of stomach lining, peptic ulcer disease, some types of stomach cancer

symptoms of H. pylori

indigestion, pain and discomfort in upper abdomen

how is Staphylococcus aureus spread?

• skin to skin contact

• from contaminated surfaces or shared personal items

what does staph cause?

• skin infections

• bacteria in blood and sepsis

• pneumonia

• endocarditis

• osteomyelitis

who is at greater risk for staph infection?

people with diabetes or cancer

what is tuberculosis caused by?

by Mycobacterium tuberculosis (gram positive and gram negative)

how is TB spread?

occurs through the air when a person with active TB coughs, speaks, sneezes

latent TB

no symptoms, not contagious

active TB

causes illness, usually contagious, can occur weeks or years after infection

active TB symptoms

coughing, chest pain, unintentional weight loss, fatigue, fever, night sweats, chills, loss of apetite

pulmonary TB

• 85% of cases

• contagious

• persistent cough

extra pulmonary TB

kidney, spine, brain, symptoms can very according to symptoms invovled

people at higher risk for TB INFECTION

• people who have been around people with TB disease

• people from a country where TB is common

• people who spend time in high risk settings

people at higher risk for TB DISEASE

• people with HIV infection

• people who inject illegal drugs

• babies, young children, elderly

TB is not spread by

• shaking someone hand

• sharing food or drink

• touching bed linens or toilet seats

• sharing toothbrushes

• kissing

is TB curable/treatment ?

• antibiotics

• tough regimen

multidrug resistant TB (MDR TB)

resistant at least to isoniazid and rifampin (2 most potent TB drugs)

extensively drug resistant TB (XDR TB)

resistant isoniazid and rifampin, plus any fluoroquinolone and at least one of three injectable second line drugs