Chapter 21: Prokaryotes and Diseases

Exam 3 Review

Pathogen

a disease-causing organism

Pathology (field)

the study of disease

Pathology (clinical definition)

the damage caused by a pathogen

Virulence

the degree of pathogenicity exhibited by a pathogen

Virulence Factor

a gene which contributes to virulence

What layer is the RED

Epidermis

What layer is the ORANGE

Dermis

What layer is the YELLOW

Subcutaneous

Perspiration and ______ contain nutrients for microbial growth.

Sebum

Salt inhibits microbes via ________

osmotic stress

Lysozyme damages ________

peptidoglycan

Antimicrobial peptides inhibit _________

defensins

Microbiota of the Skin include:

Fungi and Bacteria

What Bacteria is on the skin

mainly Gram-positive, salt-tolerant bacteria

Name bacteria on the skin

Staphylococci

Micrococci

Diphtheroids

opportunistic pathogen

these species normally do not cause disease and will only do so under certain conditions

Staphylococcus aureus has many ________ in its genome

virulence factors

Types of Staphylococcal Skin Infections: Folliculitis

infection of a hair follicle. Often presents as pimples

Types of Staphylococcal Skin Infections: Abscess

a localized accumulation of pus (immune cells that have died) at the site of an infection

Types of Staphylococcal Skin Infections: Impetigo

highly contagious skin infection which usually affects young children

___________ is an opportunistic pathogen present in water that is very resistant to antimicrobial control agents; the cause of otitis externa (swimmer’s ear)

Pseudomonas aeruginosa

Nervous System Diseases: Meningitis

inflammation of meninges

Nervous System Diseases: Encephalitis

inflammation of the brain

Nervous System Diseases: Meningoencephalitis

inflammation of meninges and brain

Clostridium tetani is a Gram-_________, endospore-forming, obligate anaerobe

positive

Clostridium tetani causes _________ due to release of tetanospasmin (a neurotoxin) which blocks relaxation pathway in muscles

tetanus

Why does tetanus occur in deep wounds?

provide anaerobic conditions

Clostridium botulinum is Gram-positive, endospore-forming, obligate anaerobe that causes botulism due to intoxication of botulinal toxin which blocks release of neurotransmitter causing ___________

flaccid paralysis

Septicemia

Persistent pathogens or their toxins in blood

Sepsis

Systemic inflammatory response

Severe sepsis

Sepsis and decreased blood pressure

Septic shock

Sepsis and uncontrollable decreased blood pressure (leads to multi-organ system failure, and frequently death)

Anthrax is caused by what bacteria?

Bacillus anthracis

Describe Bacillus anthracis

Gram-positive, endospore-forming aerobic rod

Where are anthrax spores found?

In soil and can be carried by cattle and sheep

What are the 2 major forms of Anthrax?

Cutaneous Anthrax and Pulmonary Anthrax

What is the mode of action of Cutaneous Anthrax?

Endospores enter via a break in the skin

What is the mode of action of Pulmonary Anthrax?

Endospores are inhaled and enter the bloodstream to cause septicemia (PATIENT DIES OF SEPTIC SHOCK)

What is the mortality rate of cutaneous anthrax?

20% mortality rate without antibiotic therapy

What is the mortality rate of pulmonary anthrax?

Without antibiotic treatment the mortality rate is nearly 100%

What is the causative agent for the Plague?

Yersinia pestis

Is the bacteria that causes the plague gram-negative or gram-positive?

gram-negative rod

Which of the following is not a carrier of Yersinia pestis:

Donkey

What is the vector of the Plague? (hint: Xenopsylla cheopis)

Flea

Which of the following is not a form of the plague?

Exorthic

Which plague form is the most common?

Bubonic

What are “bubeos” ? (a common symptom of the bubonic plague)

severely enlarged lymph nodes

What is the mode of action in pneumonic plague?

Bacteria entered via the lungs and easily pass to the bloodstream to produce widespread septicemia & septic shock

The causative agent for Lyme disease:

Borrelia burgdorferi

Describe the shape of Borrelia burgdorferi (spirochete)

long, spiral‑shaped, Gram‑negative bacterium

What is the vector of Lyme Disease

Blacklegged Ticks

Which of the following is not a phase of Lyme Disease:

Hair loss, or thinning hair

What is the cause of Pharyngitis (Strep Throat)

Streptococcus pyogenes

Otitis Media

Middle Ear Infection

What cause of Otitis Media only makes up 35% of cases?

S. pneumoniae

What cause of Otitis Media only makes up 20-30% of cases?

H. influenzae

What cause of Otitis Media only makes up 10-15% of cases?

M. catarrhalis

What cause of Otitis Media only makes up 8-10% of cases?

S. pyogenes

What cause of Otitis Media only makes up 1-2% of cases?

S. aureus

Pertussis

Whooping cough

What causes Whooping Cough?

Bordetella pertussis

Describe Bordetella pertussis

Gram-negative coccobacillus

What vaccine prevents Whooping Cough?

DTaP

What causes Tuberculosis? (___________ tuberculosis)

Mycobacterium

Describe Mycobacterium tuberculosis

Acid-fast rod

What is wrong with the tuberculosis vaccine?

its efficacy is inconsistent

What are the two common causative microorganisms for Pneumonia?

Streptococcus pneumoniae and Haemophilus influenzae

What is the mode of action of Pneumonia?

The bronchial tubes or alveoli are infected which causes fluid accumulation in the lung. This decreases the efficacy of oxygen exchange in the lung (difficulty breathing)

Which of the following is not a defense of the GI system?

Archillae Peptimonis

Dental plaque is a _______

biofilm

Many of our oral bacteria are _____________, and the acidic waste products of fermentation can eat away at enamel

acid fermenters

Dental Caries

Cavities

what causes cavities?

Streptococcus mutans

Porphyromonas gingivitis

causes gingivitis

Periodontitis

a chronic condition in which periodontal pockets form, and bacterial toxins actually degrade the gingiva (gums) and bone supporting the teeth

Name the types of Ulcers:

Infectious and non-infectious

What is the cause of infectious ulcers?

Helicobacter pylori

Ulcers are treatable by antiobiotics

True

The formation of ulcers: the mucus layer protects stomach from activity of ____________. Inflammation caused by infection interrupts mucus formation & leaves the stomach sensitive to its own acid

gastric acids

What causes cholera?

Vibrio cholerae

Cholera Toxin induces intestinal cells to shed ______________ resulting in very severe diarrhea

electrolytes and water

What is the cause of death for people with cholera?

Dehydration

Urinary system infection is NOT prevented by:

Being pure of heart

Urinary bladder and upper urinary tract are _______

Sterile

The most common causative agent for UTIs is _____________ which has been transferred from the rectum

Escherichia coli

Urethritis

An inflammation of the urethra (least severe)

Cystitis

An inflammation of the urinary bladder

Pyelonephritis

An inflammation of one or both kidneys (most severe)

What causes Gonorrhea

Neisseria gonorrhoeae

What causes Syphilis?

Treponema pallidum

Describe Treponema Pallidum (spirochete)

long, spiral‑shaped, Gram‑negative bacterium, slow growth cycle

What is the mode of action for syphilis

Invades mucosa or through skin breaks Treponema Pallidum

What are the stages of Syphilis?

Primary, Secondary, Latent, and Tertiary

Describe the Primary stage of syphilis:

chancre at site of infection

Describe the Secondary stage of syphilis:

skin and mucosal rashes

Describe the Latent stage of syphilis:

no symptoms

Describe the Tertiary stage of syphilis:

gummas (deep lesions on many organs – rarely seen these days due to antibiotic therapy)

explain how syphilis can be congenital?

transmitted to the fetus in the womb during latent phase. Prevents normal neurological development. (If mother is in another stage the likely result is stillbirth)

Pelvic Inflammatory Disease is usually:

Neisseria gonorrhoeae and/or Chlamydia trachomatis

Salpingitis

(infection of uterine tubes) is the most serious form and can cause scarring which results in sterility (or life- threatening ectopic (tubal) pregnancy)