Microbiology Section 3 asdfasdf

EA for cholera

Vibrio cholerae

Describe Vibrio cholerae

slightly curved, G- rod w single polar flagellum; associated with salty waters

What does Vibrio cholerae produce?

the cholera toxin--causes the host cells to secrete electrolytes and water, "rice water stools"

What happens when you have cholera?

can lose 12-20L of fluid per day--causes shock collapse, organ failure and eventually death

Transmission of cholera? treatment?

contaminated water (when sanitation and sewage disposal symptoms are compromised); IV fluid replacement

Example of an outbreak of cholera?

outbreak in haiti after an earthquake due to deficient septic shock

Strategies for disaster preparedness of cholera

oral rehydration solutions (sugar, salt, water) and stockpilling vaccines

Etiology

what causes the diease

Pathogenesis

how the disease progresses

Pathological change

how the disease effects the body

Infections

invasion or colonization of the body by pathogens

Disease

an abnormal state in which the body is not performing normal functions

Microbiota

microorganisms that live within the body

Goals of the human microbiome

establish resource repository, develop reference for microbial genome sequences, how changes in the human microbiome are associated w human health and disease, and study ethical, legal, and social implications

Metagenomics

broad genetic perspective on a single microbial community

Whole Genome sequencing

extensive genetic sequencing of a microbial community

Microbial antagonism

competitive exclusion, competition between microbes (2 in the same host)

Normal microbiota protect the host by

competing for nutrients, producing substances harmful to invading microbes, and affecting pH and available O2

Examples of microbial antagonism

Candida albicans and Clostridium difficile

What does Candida ablicans do?

Lactobacillus keeps the amount of Candida in check in the human vagina

What does the microbial antagonist Clostridium difficile do?

invasion of the large intestine

Symbiosis

relationship between normal microbiota and the host

Difference: commensalism, Mutualism, and parasitism

+, unaffected; +,+ ; +, -

Where is the world health organization?

geneva switzerland

Epidemiology

science that studies when and where diseases occur and how they are transmitted

what is a communication disease and ex?

transmitted from host to host; measles, influenza, and chickenpox

Infectious Disease

diseases caused by pathogen and have a vector or reservoir

Systemic Disease

Cancer, can't be transmitted from one to another

Incidence

new cases in a time period; new cases per 100,000 or 10,000 individuals

Prevalence

number of people who have a disease at a specific time; people w diseases per 10,000 individuals

Endemic Disease and example

disease constantly present in a population; malaria in NE India

Epidemic Disease

disease acquired by many people in a given area in a short time

Pandemic Disease

Difference between acute vs chronic

rapid, short; slow, long

Latent Period

period of inactivity before disease develops

Local Infection

pathogens are limited to a small area of the body

Systemic Infection

an infection throughout the body

Stages of infection

incubation period, prodromal period, period of illness, period of decline, relapse

What can be a reservoir host?

animal, human, or non-living

Vector

gets infected and then transmits host to another--living organism

father of epidemiology; british surgeon and anesthesiologist

John Snow

What did John Snow do?

conducted near perfect epidemiological investigations; contaminated water from public pump on broad street

public health achievements in the 20th century

vaccine, motor vehicle safety, workplace safety, safe food, decline in heart attacks

How many COVID cases were there WW? How many deaths?

676 mill, and 6.86 mill

what was the epidemiology of COVID-19 in the US: pop? total cases? total death? ratio of resident deaths? death per 100k? fully vaccinated?

pop- 332m; c-104,673,730; d-51,253; res-1/338; per 100k-356; 68%

What is the epidemiology of COVID-19 in Canada: pop? total cases? total death? ratio of resident deaths? death per 100k? fully vaccinated?

p-37.9m, c-4,595,042; d-51,253; res-1/733; per 100k-136; 84%

Epidemiology of COVID-19 in Germany: pop? total cases? total death? ratio of resident deaths? death per 100k? fully vaccinated?

p- 83m; c-38,068,912; d-167,604; res-1/496; 100k-202; 76%

Epidemiology of COVID-19 in Mexico: pop? total cases? total death? ratio of resident deaths? death per 100k? fully vaccinated?

p-127.58m; c-7,435,066; d-332,885; res-1/383; 100k-261; 65%

Epidemiology of COVID-19 in Brazil:pop? total cases? total death? ratio of resident deaths? death per 100k? fully vaccinated?

p-211m; c-36,997,328; d-698,382; res-1/302; 100k-310; 83%

Epidemiology of COVID-19 in Australia: pop? total cases? total death? ratio of resident deaths? death per 100k? fully vaccinated?

p-25.7m; c-11,347,698; d-19,265; res-1/1317; 100k-76; 85%

Epidemiology of COVID-19 in UK: pop? total cases? total death? ratio of resident deaths? death per 100k? fully vaccinated?

p-66.83m, c-24,341,611; d-206,246; res-1/324; 100k-325; 76%

Epidemiology of COVID-19 in Nebraska: pop? total cases? total death? ratio of resident deaths? death per 100k? fully vaccinated?

p-1.93m, c-575,134; d-5,998; res-1/389; 100k-310; 65%

pathogenicity

ability to cause disease

Virulence

the degree of pathogenicity

what are the two ways a microbe could enter a susceptible host

mucous membrane (nose, mouth, eyes, vagina) or parental membranes (skin)

Portal of entry

area of the body that the etiological agent invades

what 3 things determine the pathogenicity of disease

portal of entry, number of microbes, and adherence

2 amounts of microbes

ID50 and LD50

What does ID50 mean?

infectious dose for 50% of host population

What does LD50 mean?

lethal dose for 50% of a sample population

Bacillus anthracis: portal of entry and ID50?

skin: 10-50 endospores, inhalation: 10,000-20,000 endospores, ingestion: 250,000-1,000,000 endspores

ID 50 for toxin Botulinum

0.03ng/kg

ID50 for Shiga toxin?

250 ng/kg

Staphylococcal enterotoxin ID50

1350ng/kg

Adherence

how pathogen attaches to host

characteristics of bacteria cell capsules

glycocalyx around cell wall

How does the glycocalyx around the bacteria cell wall affect the cell?

impairs phagocytosis

examples of bacteria that have a glycocalyx that impairs phagocytosis (encapsulated)

Haemophilus influenzae (pneumonia and meningitis), Bacillus anthracis (anthrax), and Yersinia Pestis (plague)

Components of bacteria cell wall

M protein, Opa protein and waxy lipid

What do M proteins do? example of bact with this?

resists phagocytosis; Strepococcus pyogenes

What do Opa proteins do? Example of bact with this?

allows attachment to host cell; Neisseria gonorrheae

What do Waxy lipids do? Example of bacteria with this?

resists digestion; Mycobacterium tuberculosis--affects alveolar macrophages

Once inside a cell, bacteria can...

take nutrients, cause cellular damage, and release toxins

Toxins

poisonous substances produced by microorganisms

antitoxins are specific __

antibodies

Examples of symptoms caused by toxins

produce fever, cardiovascular problems, diarrhea, and shock

Interferon

[C] increases when needing to fight toxin and increase body temp

Toxemia

amount of toxin present in host's blood

2 types of toxins

exotoxins and endotoxin

Exotoxin and example

produced inside bacteria and then secreted out during the log phase, cause toxicity; ex: Clostridium botulinum

Endotoxin and example

when bacteria dies, it gets released from cell wall and causes toxicity; ex: Salmonella typhimurium

Shock

life threatening decrease in BP and often causes organ failure

Septic Shock

shock induced by bacteria (endotoxic shock--G - bact); cytokine storm--due to massive amount of cytokine released to neutralize the toxin

Factors of Viral Pathogenicity

invading host, evading host's defenses, and causing damage/death of host cell while reproducing

Pathogenic Properties of viruses

cytopathic effects

Cytopathic effects (CPE)

visible effects of viral infection, stopping cell synthesis or alter function

What pathogenic properties of viruses help stop cell synthesis or alter function

creating inclusion bodies in cell cytoplasm, fusing cells to create a syncytium (1 large cell w many nuclei), and producing interferons to protect neighboring cells from apoptosis

What part of protozoans cause symptoms?

their waste products

How do protozoans avoid host defenses?

digesting cells and tissue fluids, growing in phagocytes, and may attach to host cell surface

Helminths use __ for growth

host tissue

Helminths produce ___ and cause __

large masses and waste products; cellular damage

Hydatid cyst

caused by larva of dog tape worm

Dog tapeworm

Echinococcus granulosus

What issues can helminths cause?

symptomatic liver and lung cysts

What symptoms are caused by helminths?

hepatic enlargement, epigastric pain, nausea and vomiting, allergic reaction

What do cysts in the lung because of helminths cause?

bacterial, fungal growth and anaphylactic shock

Diagnosis for helminths

CAT scan, MRI, serological tests, and ELISA

Are all port of entry/exit for pathogens the same?

no but most are the same

Immunity

ability to ward off disease

Susceptibility

Lack of resistance to a disease