BIO 205 Chapters 9 and 10 Powerpoint

8/14/2019 BIO 205 Chapters 9 and 10 Powerpoint

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BIO 205

Chapters 9 and 10



Diseases of the Upper Respiratory Tract



•It is spread through person-to-person transfer of large dropletrespiratory secretions

•Bacterial meningitis can becaused by several bacterialspecies

•The meninges are threemembranous coverings of thebrain and spinal cord

Bacterial Meningitis Can Be LifeThreatening

•Neisseria meningitidis causes

meningococcal meningitis





Streptococcus

Haemophilus

•Haemophilus influenzae type bwas once thought to causeinfluenza, but actually causesHaemophilus meningitis

•Streptococcus pneumoniae causespneumococcal meningitis, as wellas pneumonia

•This results in hormoneimbalances

•In young children, meningococcalmeningitis can cause Waterhouse-

Friderichsen syndrome



– This causes pressure on the brain and spinal

cord

– All 3 species can cross the blood-brain barrier,inflaming the meninges



– Antibiotics are used to treat bacterialmeningitis and vaccines are available

• if untreated it can leadto coma and death

• paralysis

• blindness

• deafness

– The disease can cause:



Diseases of the Lower Respiratory Tract



– Mycobacterium tuberculosis enters the respiratorytract in small aerosolized droplets

– 2 million people die of TB every year, globally

• Tuberculosis Is a Major Cause of Death Worldwide



–Sputum coughed from the lower respiratorytract may contain blood

– Clinical TB develops within 3 months, and canbe transmitted to others

• They may never even know they areinfected

– About 90% of people who carry latent

tuberculosis will never develop an activeinfection



– If a tubercle breaks apart,bacteria spread throughout

the body

• They form a tuberclethat harbors M.tuberculosis

– Macrophages accumulatein the lung



– TB is a particularly big problem for AIDSpatients

– Multidrug-resistance Mycobacteriumtuberculosis is affecting which antibiotics areused to treat TB

– The tuberculin reaction in the Mantoux test canbe used for early detection of TB exposure

– Miliary tuberculosis is the development of active tubercles throughout the body



Introduction to Foodborne and WaterborneBacterial Diseases



• For example, age or sanitary conditions

– Demographics can make individuals more or less prone tofood/waterborne illness

• the infectious dose

• the toxin or microbe

– Clinical symptoms and duration of illness depend on:

• appearance of symptoms

• consumption of contaminated material

– The incubation period is the time between

Intoxications are illnesses in which bacterial toxins are ingestedwith food and water

Many Foodborne and Waterborne Diseases Have a Bacterial Cause

Infections are illnesses in which live bacterial pathogens in foodand water are ingested



– Improperly stored foods can contain large numbers of pathogens because of rapid multiplication

– Water contamination can occur by defecation of infectedindividuals in public water sources

• via knife, cutting board, etc.

• between foods

– Cross-contamination can occur:

– Infected humans can contaminate food they handle through thefecal-oral route

– Fruits and vegetables can be washed with contaminated water

– Meat can be infected during improper slaughter procedure

• There Are Several Ways Foods or Water BecomeContaminated





The cells are susceptible to stomach acid

V. cholerae are often consumed with raw oysters

and water

Cholera is caused by Vibrio cholerae

Cholera Can Involve Enormous Fluid Loss

A large infectious dose is needed to colonize the

intestines



V. cholerae

•Vaccines using dead V. cholerae are available

•Antibiotics and restoration of water and electrolytebalance are effective in treatment

•In untreated, fluid loss thickens the blood, leading toshock and coma

•Cholera toxin causes unrelenting loss of fluid andelectrolytes through diarrhea (up to 1 L/hour)



E. coli

Transmission occurs through the fecal-oral route

Escherichia coli is normally found in the human intestine,but certain serotypes are pathogenic

E. coli Diarrheas Cause Various Forms of Gastroenteritis

E t t i i E li (ETEC) t t th i t ti l



Enterophatogenic E. coli (EPEC) cause diarrhea ininfants, particularly where sanitation is lacking

a.k.a. traveler’s diarrhea

Enterotoxigenic E. coli (ETEC) penetrate the intestinalepithelium and produce a toxin that causesgastroenteritis



•Complications can occur in young children or the elderly, but most cases resolvein 5-10 days

•A small infectious does causes hemorrhagic colitis 1-8 days after infection

•Infection can occur from contact with cattle or swimming in/consumingcontaminated water

•Contamination also occurs in unpasteurized milk and juice, sprouts, lettuce, and

salami

•The most common form is O157:H7

•Enterohermorrhagic E. coli (EHEC) is often transmitted by undercooked groundbeef (or bagged spinach!)



End of Chapters 9 and 10

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BIO 205 Chapters 9 and 10 Powerpoint