MICB Final Exam: Lecture 24 & 25 Bacterial Disease and Uses

Diptheria (Bacterial Disease Category, Bacteria Name, Gram-stain, Spread, Symptoms)

Category: Airborne

Bacteria: Corynebacterium diphtheriae

Structure: Gram-Positive

Spread: Nasal snot (doesn't dry out)

Symptoms: respiratory mucosa, thick mucus, fever, cough

Infection process of Diptheria

1. AB Diphtheria Exotoxin connects to binding site on host

2. Comes into cell in a Coated Vesicle via Endocytosis

3. The pH drops uncoating the vesicle

4. A - B subunits separate

5. B subunit goes to surface cell A subunit leaves vesicle and adds ADP ribose from NAD to elongation factor (EF)-2

-Inhibit translation, no protein syn.

Diptheria Vaccine

DTaP (toxoid vaccine, inactivated toxin)

Tuberculosis (Bacterial Catagory, Bacteria Name)

Category: Airborne

Bacteria: Mycobacterium tuberculosis

What important structure of the bacteria that causes TB provides protection?

Mycolic acids in cell wall

Process of TB infection

-Inhaled (infectious dose under 10 cells)

-Lung Phagocyosed by macrophages

-Services Intracellularly, can become latent in tubercles

What is the host response to TB?

Form tubercles

-Bacteria, macrophages, T Cells and Proteins (host and bacterial)

-Bacteria become latent

TB Skin Test

Mantoux Tuberculin Skin Test (TST)

-Bacterial proteins injected into forearm

-Immune response (induration) measured in mm (48-72 hrs)

-Reaction is delayed hypersensitivity, antigen presenting macrophages attract and activate sensitized memory T cells

TB vaccine

BCG: bacillus calmette-Guerin

-Live avirulent M.bovis

-not standard in US

TB Diagnosis

bloody sputum, chest x-ray, acid-fast staining, culture

TB Therapy

Antimicrobial Therapy

-Rifampin + Isoniazid: inhibits mycolic acid syn

-Daily, 6-9 months

-Antibiotic resistance emerging (MDR, Multidrug-resistant & XDR, extreme drug resistance)

What bacteria causes Streptococcal Diseases?

Category: Airborne

Bacteria: Streptococcus pyogenes (group A Beta Hemolytic) or S. pneumoniae (Gram Postive)

What does Streptococcal Diseases affect? Diagnosis?

Affect: Impetigo, throat, lung, pneumonia, ear (otitis media)

Diagnosis: Culture & Strep Test

How does a strep test work?

Uses labeled antibodies to detect cell wall carbohydrates

Streptococcal Diseases Treatments and Preventions

Treatment: Penicillins (cell wall inhibitor) & Erythromycin (inhibit protein syn.)

Prevention: Prevnar, Pneumococcal Vaccine

-Polysaccarhirde based

Streptococcal virulence factors

- Capsule and M protein -> promote adherence

- Antibody to M protein can x-react with heart tissue

- Causing Rheumatic Fever, an autoimmune disease

What kind of bacteria is the major "Flesh eating bacteria"? What does it cause?

Group A Streptococci

-Makes tissue destroying protease

-Lead to Necrotizing fasciitis

What bacteria is associated with too decay? Why?

Streptococcus mutans

-Part of dental plaque biofilm

-Fermentation --> acid --> enamel decay

Pertussis

Category: Airborne

Bacteria: Bordetella pertussis (Gram Negative)

What is the process of infection of whooping cough? What does it cause?

Colonize ciliated cells if the respiratory tract

Stage 1: Cold-like symptoms

Stage 2: Prolonged Cough (with inspiratory gasp or whoop)

What are the virulence factors of Pertussis?

-Pili: adherence

-Siderophores: acquire iron

-Pertussis toxin: AB exotoxin

Pertussis vaccine

Previous Vaccine DTP

DT-toxoids

P-killed bacteria

Current Vaccine DTaP

DT-toxoids

aP-acellular, toxoid, and other protein antigens

Tdap booster

Pertussis treatment

tetracycline

erythromycin

What is meningitis? What causes it?

-Inflammation brain, spinal cord meninges (membranes)

-Bacteria, Viruses Fungi

Bacteria:

-Haemophilus influenzae

-Streptococcus pneumoniae

-Neisseria meningitides (Gram-negative)

Neisseria meningitides bacterial virulence catagory and infection process

Category: Air Borne

Cause: Meningococcal Disease

Spread: Person-to-person, respiratory or throat secretion

Infection: Cross mucosal barrier into blood

Neisseria meningitides virulence factors and structure

Factors: Pili, capsules, lipopolysaccardide (LPS)

Structure: Gram Negative, Diplococcus

Serogroups

groups of strains with common surface antigens (A, B, C, Y, W)

-Based on capsular polysaccarides

Meningitis Symptoms and Diagnosis

Symptoms: Flu like, Initial sore throat, vomiting, confusion, stiffness in neck, rash

Diagnosis: Gram stain spinal fluid, culture

Meningitis Treatment and Prevention

Treatment: Antibiotics (cell wall, protein syn. etc)

Prevention:

MCV4 Vaccine: Based on capsular polysaccharide (doesn't protect against B strain)

Bexsero: Based on group B outer membrane protein (not capsular material)

What bacteria causes the Plague?

Yersinia pestis (gram -)

What are the forms of the plague?

Arthropod-Borne

Bubonic: Flea vector

Pneumonic: Person to Person

What form of the plague has flu like symptoms and is more dangerous?

Pneumonic plague is almost 100% fatal if not treated early

-Category A bioweapons agent

Buboe

enlarged lymph node

How does Yersina inject toxic proteins into human cells?

Type 3 secretion system - injectosome

What is the structure of the Type 3 secretion system?

-Hallow basal body

-Hallow Needle

-Form Pore in Membrane of human cells

What does Yersina inject into human cells? What do they do?

Injects effector proteins, Yops

Target:

-Block actin polymerization of cytoskeleton (inhibit phagocytosis of macrophage to engolf pathogen)

-Signaling, disrupting transcription factor NFkB

Lyme Disease

Arthropod-Borne

Bacteria: spirochete Borrelia burgdorferi

Vector: Blacklegged (deer) tick

Stages (and symptoms) of Lyme disease

1. Localized Stage: 7-10 Days

-Bulls eye rash (erythema migrans)

-Flu like Symptoms

2. Disseminated: Weeks or Months

-Muscle pain, arthritis

3. Late: Years

-Affect nervous system

What stage is the most treatable for lymes disease? Treatments?

Localized stage

-Doxycycline: Target Protein Syn. (from tetracycline)

-Penicillin: Target Cell Wall

In the Disseminated stage of lyme disease, what happens to the antibody?

Antibody to Borrelia proteins may cross react with human MHC

Anthrax (Bacterial Disease Category, Bacteria Name)

Direct Contact

Bacillus anthracis

Anthrax Virulence Factors

Capsule

Toxin: 3 part AB toxin targeting macrophages and cell death

-Toxin and Capsule encoded on seperate plasmids

Forms of Anthrax

Cutaneous--cut, abrasion

Pulmonary--spores inhaled

Process of infection in pulmonary anthrax

-Spores enter macrophages in lungs

-Spores undergo germination and produce toxins

-toxin kills macrophages and other cells

-bacteria spread and fatal if reach bloodstream

Treatment for pulmonary anthrax

Early Ciprofloxacin

Staphylococcal Disease (Bacterial Disease Category, Bacteria Name)

Direct Contact

S. aureus: invasive, virulent

S. epidermidis: less invasive, less virulent

Diagnosis and Symptoms of Staphylococcal Disease

Diagnosis: Coagulase test can be used to differentiate strains

Symptoms: Boils, carbuncles, toxic shock syndrome, food poisoning

Virulence factors of the more invasive bacteria causing Staphylococcal Disease

S. aureus

-Superantigens (TSST-1)

-Capsules

-IgA protease

-Coagnulase

-DNases

-Biofilm

How are virulence genes of Staphylococcal Disease controlled?

Quorum sensing

Two componet system

How are food and water borne bacterial diseases prevented?

Sanitation measures, antitoxins, and antibiotic therapy

Botulism (Bacterial Disease Category, Bacteria Name, Found In, Infection Process)

Category: Food and Water Borne

Bacteria: Clostridium botulinum

Found: Honey, canned foods

Process: AB toxin blocks acetylcholine release at neuromuscular junction

Listeriosis (Bacterial Disease Category, Bacteria Name)

Category: Food and Water Borne

Bacteria: Listeria monocytogenes

Cholera (Bacterial Disease Category, Bacteria Name, Infection Process, Treatment)

Category: Food and Water Borne

Bacteria: Vibrio cholerae

Process: Toxin causes hypersecretion

Treatment: Rehydration therapy, doxycycline

Salmonella (Bacterial Disease Category, Bacteria Name)

Category: Food and Water Borne

Bacteria: Salmonella typhimurium

What is the infectious strain (and name) of E.coli? What is its infectious dose?

E. coli 0157:H7

Enterohemorrhagic E. coli (EHEC)

Dose under 100 (other strains 1,000s to millions)

Carriers of E. coli

Cattle, Swine

What is the E. coli toxin, and what does it do?

Shiga Toxin - AB Toxin

-Binds to glycoprotein receptors on kidney & intestinal cells

-Cleaves human rRNA, stop translation to make proteins

Where are the toxin genes for the E. coli

Prophage (integrated form of viral genome)

What is the name for kidney failure caused by E. coli?

Hemolytic Uremic Syndrome (HUS)

What microbe is used to make Kimchi and Sauerkraut?

Leuconostoc

What is Natto?

soybeans fermented with Bacillus natto

Why is Natto stringy?

From bacterial capsular polysaccaride

What are the major fermentation products used in the food industry?

Lactic, propionic, ethanolic

Process of Fermentation

Glycolysis

1. Glucose

2. ADP to ATP via substrate-level phosphorylation;

NAD+ oxidized to NADH

3. 2 Pyruvate

4. NADH reduced to NAD+

When O2 low, pyruvate accepts e- that otherwise would have been on NADH

5. Waste products: Latic acid, ethanol, propionic acid

Starter Culture Bacteria used in Yogurt Production

Lactobacillus and Streptococcus

What fermentation product is used to make yogurt?

Lactose (in milk) hydrolyzed to glucose, fermented to lactic acid

Contamination with what microbe is a major concern in yogurt production?

One phage could disrupt whole process

Process of Cheese Production

Milk -1-> Coagulation, Curd -2-> Cheese

1. Add Lactococcus starter and renin enzyme

2. Ripening - more microbes added for specific cheeses

Microbe added for Swiss Cheese? Blue and Brie?

Swiss: Propionibacterium

Blue/Brie: Penicillium (fungus)

Probiotics (what are they? Benefits? Examples of foods that have them)

Lactobacillus, Bifidobacterium, etc.

Microbes added to diet to improve health

Benefits: Vitamin prod., Improved digestion, Pathogen inhibition

Foods: Kombucha, Activia

Prebiotics

compounds (fiber) that promote growth of beneficial microbes

Microbes in Komuncha Tea

Fermented tea using Bacteria (Bacillus) and Yeast (Saccharomyces)

SCOBY

symbiotic culture of bacteria and yeast

The starter culture

Beer-spoilage bacteria

Gram-Positive of the Bacteria Domain

What are the ingredients to beer?

barley: Breakdown of complex starches and proteins

hops: Antibacterial for flavor

water

yeast: Saccharomyces

How is beer made?

-Malting & mashing

-plant enzymes breakdown complex starches & proteins

What microbes are used in Ginger Beer? Fermentation products?

Fermentation of Ginger Spice and Sugar with

Saccharomyces and Lactobacillus