Microbiology Midterm 2

Entry, Establishment, Defeat host defenses, Damage the host, Exit the host to be transmitted to another host

What are the requirements for a successful infection?

mucous membranes, skin, parenteral route

What are the portals of entry?

Respiratory tract

What is the most common portal of entry for infection?

Gastrointestinal tract

What is the second most common portal of entry for infection?

Sexually transmitted diseases

Microbes that infect the genitourinary tract are sometimes called?

Parenteral

What route of infection refers to breaks in the skin a that allows the passage of microbes?

Shorter urethra and proximity to anus

What factors are reasons why females obtain more urinary tract infections than males?

Capsules, fimbraie

During establishment, pathogens use virulence structures such as ______ or ________ to attach to the surface or tissues

Adhesins

Pathogens may also use _______ to attach to tissue

binary fission (1 —>2 —>4->8 etc)

Bacteria reproduce by

Passive defense

What is the inherent ability of a pathogen to protect themselves via intrinsic or extrinsic factors against the host's defenses?

Peptidoglycans

Bacterial cell walls contain _______ that help with passive defense

Very thick, M proteins, very thin, lipid A

Gram + cell walls are ________ and contain _______, while Gram - cell walls are _______ and contain ________

Increase adhesion to host tissue and inhibit phagocytosis

M proteins of Gram + thick cell walls increase what and inhibit what?

M proteins

Some streptococcus spp contain

Active defense

What kind of defense attacks the host defense?

M proteins

What substance is found only in the walls of all gram + bacteria and inhibits phagocytosis?

Lipid A

What feature of a Gram- cell wall produces an endotoxin that elicits a powerful immune response?

An outer lipopolysaccharide membrane (endotoxin)

To compensate for thin cell walls, gram - bacteria contain

Mycolic acid

What cell wall feature is exhibited in Mycobacterium species that inhibits phagocytosis and antibiotics?

Leukocidins

What type of bacterial enzyme destroys WBCs?

Hemolysins

What type of bacterial enzyme destroys both RBCs and WBCs?

Coagulase

What type of bacterial enzyme forms fibrin clots?

Kinase

What type of bacterial enzyme breaks down fibrin and destroys clots?

Hyaluronidase

What type of bacterial enzyme breaks down connective tissue?

Collagenase

What type of bacterial enzyme breaks down collagen?

2 categories

How many categories of bacteria toxins are there?

Cytotoxins

What type of exotoxin kills cells?

Neurotoxins

What type of exotoxin interferes with neurological signaling?

Enterotoxins

What type of exotoxin affects the lining of the digestive tract?

Disseminated intravascular clotting

What is the most dangerous effect of endotoxin poisoning?

Bacillus anthracis and Corynebacterium diphtheraie

What are some examples of bacteria that produces cytotoxins?

Clostridium tetani and Clostridium botulinum

What are some examples of bacteria that produce neurotoxins?

-Toxin enters presynaptic terminals of lower motor neurons

-Patient presents with "Lockjaw" and Opisthotonus (feet touch the back of the head)

What is the pathogenesis of a Clostridium tetani (Tetanus) infection?

Tetanus

Lockjaw is the common name for what disease?

-Inhibits release of acetylcholine

-Flaccid paralysis of skeletal muscle

-Begins as cranial nerve palsy (blurred or double vision)

What is the pathogenesis of a Clostridium botulinum (Botulism) infection?

Reservoir

A placer where pathogens grow and accumulate is called?

Zoonotic

What diseases are transmitted from animals to humans called?

Direct contact transmission

When an uninfected person is exposed to a pathogen via touching an infected reservoir, what type of contact transmission has occurred?

Indirect contact transmission

When an uninfected person is exposed to a pathogen via touching an infected fomite, what type of contact transmission has occurred?

Droplet transmission

When an uninfected individual inhales infected particulate matter expelled from an infected person, what type of contact transmission has occurred?

Vehicle transmission

What type of transmission occurs when a pathogen "rides"?

Found inside insect (bites)

A biological vector transmission includes what?

Found on insect body parts touching objects

A mechanical vector transmission includes what?

Arthropods (mosquitoes, ticks, fleas0

What is the most common vector of transmission?

Immunocompetence

The hosts ability to mount an immune defense is called?

Disease transmission and communicability

What idea is Koch's Postulates associated with?

Incubation period

In an illness, the earliest period free of signs and symptoms is called?

Prodromal period

In an illness, the first sign and symptoms of a disease appear in what period?

Period of illness

In an illness, the period of major signs and symptoms that produces an immune response is called?

Period of decline

In an illness, the period that has the highest chance of secondary infection is called?

Epidemiology

What is the study of the factors and mechanisms involved in the frequency and spread of a disease?

Prevalence

The total number of people infected within a population at any given time is called?

Incidence

The number of new cases contracted within a set population in a specific period is called?

Morbidity

The number of individuals affected by a disease during a set period divided by the total population is called?

Mortality

The number of deaths due to a specific disease during a specific period divided by the total population is called?

Endemic disease

What type of disease is found constantly within a population?

Epidemic disease

What type of disease is found suddenly higher than expected in a specific region?

-Arises from contacts with contaminated substances

-Affects large number of people but once source is identified quickly subsides

What are some of the characteristics of a Common Source Epidemic?

-Amplification for the number of infected individuals as person-to-person contact occurs

-Stays in the population for longer periods

-More difficult to control ("Patient Zero")

What are some of the characteristics of a Propagated Epidemic?

Propagated epidemic disease

Patient zero is most commonly associated with what disease?

Pandemic disease

What type of disease occurs in epidemic proportions throughout the world?

Post-peak

What phase of a pandemic is COVID-19 in right now?

Descriptive Study

What type of study is concerned with the physical aspects of patients and the spread of disease?

Analytical Study

What type of study focuses predominantly on cause and effect?

Analytical Study

What type of study always uses a control group?

Smallpox

What nationally notifiable disease should never be seen again?

Nosocomial Infections

What type of infection is acquired in a hospital/medical facility within 48 hours of visit?

Staphylococcus aureus

What is the most common organism in Nosocomial Infections?

Viruses

What type of microbe are known as obligate intracellular parasites?

Emerging infectious diseases

Infections that have never been seen before are considered?

Zika, Dengue hemorrhagic, Chikungunya, MERS, and COVID-19

What kinds of diseases are considered Emergent diseases?

Re-emerging infectious diseases

Diseases that were once thought of as being under control primarily due to antibiotics, vaccinations and insect control are considered?

Whooping cough, diphtheria, measles, mumps, polio

What kind diseases are considered re-emerging infectious diseases?

Nipah virus

What type of disease is condensed to India, Southeast Asia, and Micronesia that causes encephalitis or respiratory illness?

Fruit bats

What is the vector of transmission for Nipah virus?

Avian influenza

What is the most deadly form of influenza?

Chikungunya Virus

What emerging illness presents with fever and joint pain and is transmitted via infected mosquitoes?

Coronavirus

What type of virus causes Middle East Respiratory Syndrome (MERS)?

West Nile Virus

What type of virus entered the US in 1999 and is found in most states?

Mosquito

What is the vector of transmission for West Nile Virus?

Ebola

What is the deadliest type of viral hemorrhagic fevers?

Arboviruses

What type of virus is transmitted to a human host by an insect bite?

Viruses

Most of the emerging disease are considered what etiologic agent?

Aquatic birds

The stable reservoir of influenza is found where?

HIV/AIDS epidemic

What is the cause for the high TB rates in Africa?

Mexico

What country has the highest TB rates that immigrate to the US?

Cannot be destroyed (Resistatnt to cooking, autoclaving, disinfectants, and strong alkali treatment)

What possible ways can a prion be treated with?

Prions

Transmissible spongiform encephalopathies (TSEs) are considered what type of infection?

ELISA

What test is done to determine if a prion infections is present?

Scrapies (1762)

What was the first seen TSE found in sheep?

Creutzfeldt-Jakob Disease (can be new variant)

What is the human version of TSE called?

Kuru

What type of prion disease is spread in humans via cannibalism?

Above the trachea (larynx, pharynx, mouth)

In microbiology, what is considered an upper respiratory tract infection?

Trachea, bronchi, bronchioles, and alveoli

In microbiology, what is considered a lower respiratory infection?

Mucociliary escalator

What is the most important part of the respiratory tract systems defensives?

Pharyngitis

What is the technical name for a strep throat?

Otitis media

What is the name for an inner ear infection?

Otitis media

Mastoiditis is a potential complication of what condition?

Mastoiditis, Petrositis, or Labyrinthitis

What are possible complications if otitis media is left untreated?