Exam 1 Flashcards
Which statement does NOT correctly describe the current problems related to medical microbiology?
- Emerging or re-emergin diseases continue to pose new microbiological problems
- Globally, infectious diseases cause more than 20% of all deaths.
- Examples of re-emerging infectios diseases include TB, malaria, and hepatitis
- Modern lifestyles and technical developments facilitate transmission of disease
- All of the above correctly dscribe current status of infectius disease
_____, as a macroparasite, can grow in one host but cannot complete its full life cycle and thus must reproduce outside of the host
- Influenza virus
- Pathogenic E. coli
- Candida albicans
- Schistosoma haematobium (a fluke)
- All of the above are microparasites
Vibrio cholera is a(n) _____ because it causes disease by living on the surface of the intesting without invading
- Extracellular pathogen
- Obligate intracellular pathogen
- Facultative intracellular pathogen
- Macroparasite
- Facultative microparasite
Antibodies bind extraceulluar pathogens and facilitate their uptake and destruction by phagocytes. This action of the antibody is called _______.
- Neutralization
- Opsonization
- Complement activation
- Cell-mediated immunity
- Antibody-mediated immunity
Bacteria can be classified by the following EXCEPT
- Morphology
- Gram Reaction
- Serological properties
- Slime layer formation
- DNA sequence
One of the most important pathogens in Gram-negative cocci is
- Staphylococcus aureus
- Neisseria meningitidis
- Haemophilus influenzae
- Salmonella typhimurium
- Escherichia coli
Which pair is INCORRECT
- Flagella–H antigen
- LPS–Endotoxin
- Pili–Attachment
- Endospore–Survival under harsh conditions
- Slime layer–Strengthens the pathogen’s cell wall
Hepatitis B virus sometimes causes ____ where the host cell remains alive and continues to release virus particles by budding
- A lytic infection
- A persistent infection
- A latent infection
- A transformation
- A cell lysis
Which statement is NOT true about fungal pathogens?
- Many grow as a mass of hyphae
- They are multinucleate or multicellular organisms with a thick peptidoglycan cell wall
- Some fungi form part of our body’s normal flora
- Many fungal pathogens form hyphae at environmental temperatures, but occur as yeast cells in the host
- Hyphae form of Candida albicans is the pathogenic form found inside the human hose
Plasmodium falciparum is a(n) _______ pathogen
- Fungal
- Bacterial
- Protozoan
- Viral
- Helminthic
Which does NOT correctly describe prions?
- Prions are small proteins
- Prions are extremely resistant to heat, disinfectants, and irradiation
- Prions do not elicit immune response
- Prions are sensitive to Proteinase K digestion
- Disease caused by prions typically have a long incubation period
Influenza virus attaches by its ____ to sialic acid and portion of glycoproteins found on the mucous membranes
- Hemagglutinin
- Neuroaminidase
- CD4
- P antigen
- Reverse transcriptase
Which statement is NOT true about the normal flora on our body
- In terms of number, approximately ten times more normal flora cells are present than our own body cells
- Viruses, fungi, and protozoa are also regularly found as normal flora
- The normal flora is acquired shortly after birth and the members of the normal flora are usually kept constant throughout life
- Members of the normal flora can cause hospital-acquired infection when patients are exposed to invasive treatments
- ALl of the above are correct
_____ is an anti-microbial peptide secreted by human eccrine sweat glands onto the skin as a part of the innate host defense system
- Dermcidin
- Lysozyme
- Pepsin
- Bacteriocin
- Bile salt
Which is NOT found as a member of normal flora in the upper respiratory tract?
- Streptococcus pyogenes
- Staphylococcus aureus
- Corynebacterium diphtheriae
- Streptococcus pneumoniae
- E. coli
______ is present in the stomach and can cause gastric ulcers
- Streptococcus pyogenes
- Helicobacter pylori
- Enterococcus faecalis
- Streptococcus pneumoniae
- None of the above
The bacteria present in the large intestines carry out the following EXCEPT
- Gas production
- Odor production
- Production of some essential vitamins
- Production of some steroids
- All of the above are carried out by gut microorganisms
Which microbe is responsible for producing the acidic conditions int he vagina?
- Lactobacillus areophilus
- Candida alibicans
- E. coli
- Streptococcus acidophilus
- Gardnerella vaginalis
In general, the _____ ratio is regarded to be of significant relevance in human gut microbiota composition
- Firmicutes to Bacteroidetes
- Actinomyces to Bacteroidetes
- Bacteroidetes to Clostridia
- Actinobacteria to Firmicutes
- None of the above
In the lower respiratory tract, the bacterial cells settled onto the epithelia are beaten and pushed upward by ________
- Pili
- Flagellated cells
- Ciliated cells
- Mucus layer
- Macrophages
Briefly describe how our immune system defend against “intracellular pathogens”. For full credit, you have to include two types of intracellular pathogens
- Intracellular pathogen in the cytoplast: helped by TH1
- Intracellular pathogen inside the endosome: killed by cytotoxic T cells
Briefly explain why only capsulated Streptococcus pneumoniae can cause a fata infection, but unencapsulated mutations cause no disease
Capsules inhibit phagocytosis
Many transforming viruses carry ____ that cause transformation when their genome is incorporated into the host genome
Oncogenes
Fungal infections are broadly termed ______
Mycoses
Infectious disease transmitted from animals to humans are called __________
Zoonosis
________ is a prion disease that was identified with cannibalistic behavior in Papua New Guinea
Kuru
Briefly describe how prions may damage our body
Interaction of abnormal priorns changes normal prion into abnormal prion, which then causes damage such as aggregation
Saliva produces two enzymes ____ and ______, that are toxic to bacteria
Lysozyme and lactoperoxidase
Briefly describe the develpment of dental plaque and cavity. Also describe how dextran contributes to the formation of dental cavities
- Formation of plaques by *L. sabrinus, etc. *
- Deprivation of oxygen
- Secondary bacteria such as Fusobacterium grow
- Microbes produce lactic acid
- L. mutans and others produce dextran from sucrose by dextransucrase
- Dental caries develop
Briefly explain why the skin is not a good place for most microbes to grow
- Low pH
- High salt
- Chaning physical conditions
- Anti-microbial substances produced by skin cells
When an organism infects the body, the defense system alread in place called _____ may prpevent replication and spread of the infections agent
Innate immunity
Enhancement of phagocytosis by the binding of C3b or antibody on the bacterial surface is called ____
Opsonization
Phagocytes recognize _____ such as LPS on the bacterial surface via their cell surface via their cell surface pattern recognition receptors
Pathogen Associated Molecular Patterns (PAMPs)
Briefly explain anti-bodydependent cellular cytotoxicity
Parasites bigger than antibodies are killed by antibodies (IgG) mediated killing
