Exam 2 Juice Flashcards
Of the following, which would be most resistant to sterilization?
A. Bacterial spores
B. Cryptosporidia
C. Mycobacteria
D. Enveloped viruses
E. Gram negative bacteria
A. Bacterial spores
What cells are responsible for delayed-type hypersensitivity?
Th1 cells, macrophages
Predominant effect of histamine released by basophils and mast cells in immediate hypersensitivity
Bronchoconstriction
Which lymphocytes are typically found in a tuberculous granuloma
Th1 (macrophages)
Which of the following antibacterial agents is an inhibitor of nucleic acid synthesis, is bactericidal, and has good activity against oral facultative and obligate anaerobes?
A. Metronidazole
B. Vancomycin
C. Sulfonamides and trimethaprim
D. Chloramphenicol
A. Metronidazole
Lumpy jaw is a dentoalveolar infection most often associated with which of the following teeth?
A. 1
B. 4
C. 19
D. 25
C. 19
Other than its toxin, the major virulence factor of Bacillus anthracis is the:
A. capsule
B. endotoxin
C. teichoic acid
D. fimbrial adhesion factors
A. capsule
Which class of beta-lactamases is the MOST COMMON and generally contains mainly penicillinases?
Class A
Congenital vaccinia is a potential complication of immunization during pregnancy for prevention of:
A. Smallpox
B. chicken pox
C. pertussis
D. tetanus
E. pneumococcus
A. smallpox
Which antimicrobial interacts with 30S bacterial ribosome?
A. Tetracycline
B. Erythromycin
C. Chloramphenicol
D. Clindamycin
E. Fusidic acid
A. Tetracycline
Which of the following NAM pentapeptide terminal residues confers intrinsic resistance to Vancomycin?
A. D-ala-D-ala
B. D-ala-D-serine
C. D-serine-D-serine
D. D-lysine-D-serine
B. D-ala-D-serine
Opisthotonos is a characteristic manifestation of the effects of which toxin?
A. Alpha toxin
B. Shigatoxin
C. Tetanospasmin
D. Botulinum toxin A
E. Endotoxin
C. Tetanospasmin
Mycobacterium tuberculosis is capable of surviving in:
Macrophages
Mechanism of action of vancomycin
Inhibition of cell wall synthesis
Certain strains of E. coli produce shigatoxin when lysogenized. This means that the toxin protein is coded for by a:
Bacteriophage
Drug of choice for cervicofacial actinomycosis
Penicillin
Which genus other than Clostridium includes medically important Gram positive, spore forming rods
Bacillus
Which of the following antibacterials would never be used systemically?
A. Vancomycin
B. Bacitracin
C. Cycloserine
D. Gentamycin
E. Chloramphenicol
B. Bacitracin (it is a topical only!)
A child presents with rash, fever, strawberry tongue. Toxin responsible is:
A. Pyrogenic exotoxin
B. Streptolysin S
C. Exfoliatin
D. Enterotoxin A
Pyrogenic exotoxin
Which class of immunoglobulin can be transferred transplacentally, leading to hemolytic disease of the newborn?
IgG
Which of the following organisms is associated with “sulfur granules”
A. Actinomyces israelii
B. Aspergillus fumigatus
C. Candida albicans
D. Rhizopus arrhizus
E. histoplasma capsulatum
A. Actinomyces israelii
other one is A. viscosus
An eschar is a cutaneous form of which disease?
A. nocardiasis
B. tetanus
C. anthrax
D. actinomycosis
E. Aspergillus
C. anthrax
Which of the following may contribute to evasion of the immune system by a tumor?
A. lack of MHC expression by the tumor cells
B. mononuclear infiltrate of the tumor
C. Expression of oncofetal antigens by the tumor cells
D. Expression of viral antigens by the tumor cells
A. lack of MHC expression by the tumor cells
In the spleen, T cells are found primarily in the:
Periarterial lymphatic sheath (PALS)
Which of the following anti-microbials is an RNA synthesis inhibitor?
A. rifampin
B. Chloramphenicol
C. Vancomycin
D. metronidazole
A. rifampin
A mutation in bacterial DNA gyrase is likely to result in resistance to which of the following antimicrobials?
A. amphotericin B
B. ciprofloxacin
C. penicillin
D. streptomycin
E. ceftriaxone
B
Which of the following is a common initial manifestation of botulism in an adult?
A. diplopia
B. watery diarrhea
C. spasm of the muscles of mastication
D. myonecrosis
E. epiglottis
Diplopia
Approximately 10% of patients who demonstrate allergy to penicillins are also allergic to a similar class of compounds known as:
Cephalosporins
A third year dental student is found to have a positive PPD skin test. Six months ago the test was negative. Chest x-ray reveals no abnormality. The student should be trated with 6-12 month course of
Isoniazid
The profound clinical effect of superantigens is due to their ability to activate huge numbers of:
T lymphocytes
Antibiotic-associated colitis is caused by an exotoxin elaborated by:
C. difficile
C. perfringens food poisoning is most often associated with:
Poultry
Which antibiotic can cause staining of developing teeth?
tetracycline
Which of the following antimicrobials inhibits folic acid synthesis?
A. Macrolides
B. Cephalosporins
C. Tetracyclines
D. Aminoglycosides
E. Sulfonamides
E. sulfonamides
What is the mechanism of action of the botulinum neurotoxin?
Prevents the release of acetylcholine from the alpha motor neuron
Current standard for water quality using in routine dental treatments is below ____ of heterotrophic water bacteria
500
Erythromycin, a macrolide, acts by inhibiting bacterial:
Protein synthesis
Which of the following lymphokines secreted by Th2 cells is required for class switching resulting in IgE synthesis?
IL-4
Among the carbapenem-resistant enterobacteriaceae, which most commonly causes disease?
Klebsiella pneumoniae
Which of the following Gram-negative organisms can cause disease characterized by gangrene and septic shock, and has a high fatality rate?
A. Yersinia enterocolitica
B. Vibrio vulnificus
C. Campylobacter jejuni
D. Enterotoxigenic E. coli
B
Erysipelas is a skin infection caused by:
S. pyogenes
Which of the following T lymphocyte product acts by forming pores in target cell membranes?
A. perforin
B. granzyme
C. complement
D. collagenase
E. interferon-beta
Perforin
All children older than one month with definite or probable bacterial meningitis should be initially treated with:
Vancomycin plus cephalosporin
The single greatest source of salmonellosis in the US is
Chickens
Recognition of antigen by CD8 t cells requires the presentation of antigen in association with
MHC I
The most reliable means of diagnosing typhoid fever is:
Bone marrow culture
Positive selection of T cells in the thymus involves selection of only those cells which:
A. are self-tolerant
B. react to self peptides
C. do not react to self peptides
D. recognize MHC
D. recognize MHC
The most common cause of bacillary dysentery is:
A. campylobacter jejuni
B. E. coli
C. Vibrio cholerae
D. Shigella sonnei
E. Salmonella enteritidis
Shigella sonnei
Streptococcal toxin shock syndrome is due to which bacterial product?
A. endotoxin
B. pyrogenic exotoxin
C. hyaluronidase
D. serine protease
E. streptokinase
B. pyrogenic exotoxin
Which serotype of Haemphilus influenzae causes the most serious disease?
b
Which organisms can be distinguised from similar organisms by the fact that they can produce H2S from thiosulfate?
Salmonella typhi
The family of enzymes responsible for TCR gene rearrangements would be:
VDJ recombinase
Which is the most common cause of bacterial meningitis in a newborn?
Streptococcus agalactiae
Subjects who lack MHC class II would be most likely to result in a deficiency of:
CD4+ T cells
In the designation of E. coli O157:H7, the H refers to antigens of the:
Flagella
Effective immunity to S. pneumoniae is conferred by antibodies directed against:
Capsular polysaccharide
An organism that forms smooth, pale yellow colonies on blood agar, is catalase positive and coagulase positive is most likely to be:
S. aureus
In the US, the most common cause overall of bacterial meningitis is:
S. pneumoniae
Which cytokine is produced by monocytes stimulated by endotoxin and is responsible for the fever production in septic shock?
A. GM-CSF
B. IFN-gamma
C. IL-12
D. TNF-alpha
D. TNF-alpha
The spinal fluid in bacterial meningitis is characterized by:
Increased numbers of neutrophils
Target cells present peptide fragments derived from the endogenous pathway using:
Class I MHC
Strains of E. coli that cause pyelonephritis are characterized by the possession of:
A. Unique P fimbrial antigens
B. Phase variation of flagellar antigens
C. Specific O antigens
D. Production of shigatoxin
A. Unique P fimbrial antigens
Which of the following cells express both class I and class II MHC?
A. Macrophages
B. Neutrophils
C. Buccal mucosal epithelium
D. erythrocytes
E. resting t lymphocytes
A. macrophages
In the process of negative selection, an auto-reactive thymocyte is eliminated as a consequence of its interaction with a thymic epithelial cell which:
Presents self antigen in association with an MHC molecule
The human MHC is located on chromosome:
6
Growth of which organism is inhibited by optochin?
S. pneumoniae
In MHC II molecules, antigen peptide fragments are accomodated in a groove between the:
alpha 1 and beta 1 domains
The organisms that cause plague belong to which genus?
Yersinia
Patients with cystic fibrosis are particularly susceptible to pulmonary infections caused by which organism?
Pseudomonas aeruginosa
The bacterium that is strongly associated with gastric ulcers and gastric cancer is characterized by the production of:
Urease
Currently, the drug of choice for treatment of systemic infections with MRSA is:
vancomycin
Growth of S. pneumoniae on blood agar is characterized by which type of hemolysis?
Alpha
Which S. pyogenes antigen is responsible for the induction of protective antibody?
A. hyaluronidase
B. streptolysin
C. Polysaccharise capsular antigen
D. M protein
E. G protein
D. M protein
Rheumatic fever is a sequela of S. pyogenes infection of the:
A. heart valves
B. bones or joints
C. central nervous system
D. skin
E. Pharynx
E. pharynx
Rest are areas where antibodies cross react with these tissues
In a patient with intestinal infection, the finding of neutrophils in the feces is indicative of:
Invasive bacteria
A 25 year old female presents with fever, flank pain, dysuria. Examination of the urine reveals many neutrophils, >200,000 CFU/mL, and many white cell casts. The presence of casts indicates which infection?
Pyelonephritis
Which interleukin triggers DNA remodeling (and more specifically TCR locus de-methylation)
IL-7
Currently, Staphylococcal Toxic Shock Syndrome is most commonly associated with:
A. Immune deficiency
B. tampon use
C. wound infection
D. Concurrent STD
C. Wound infection
The toxin responsible for the pathology of Scalded Skin Syndrome is:
Exfoliatin
The major function of the CD3 seta (z) chain is:
Signal transduction
The vast majority of cases of osteomyelitis are caused by:
S. aureus
Which cytokine is produced primarily by Th1 cells?
IL-2
Which of the following is a Class II MHC gene product?
A. HLA A2
B. HLA B
C. HLA CR
D. HLA DQ
E. HLA E
D
Which of the following organisms is most likely to be involved in subacute bacterial endocarditis?
A. Group A Strep
B. S. agalactiae
C. Group B Strep
D. Viridans Strep
D. Viridans
Which of the following has been implicated in the etiology of dental caries?
A. S. mutans
B. S. agalactiae
C. S. pyogenes
D. S. pneumoniae
E. S. fecalis
S. mutans
A six year old child presents with symptoms suggestive of rheumatic fever. His mother reports that he complained of a sore throat about three weeks ago, but he was not very ill with it and she did not take him to the pediatrician. Which test would determine if the sore throat has been due to S. pyogenes infection?
Anti-streptolysin O (ASO) titer
A child presents with lesions on her face and legs that are oozy and covered with a honey colored crust. Culture of the lesions reveals Gram positive cocci that are catalase negative. A zone of hemolysis is noted around the colonies on the blood agar plate. This is reported by the lab to be of which type of hemolysis?
A. alpha
B. beta
C. gamma
D. delta
Beta
The hemolytic uremic syndrome is caused by a strain of E. coli that produces a toxin similar to that produced by which genus?
Shigella
Immunogenicity, or the ability of a vaccine to stimulate an effective, specific, adaptive immune response, is inversely correlated with:
Attenuation
Which of the following is/are examples of natural passive immunity?
A. Placental IgG transfer
B. IgA in breast milk
C. Lactoferrin in breast milk
D. all of the above
D
In an immunocompetent adult, the most common manifestation of S. pneumoniae infection is:
Lobar pneumonia
Streptococcal species found as normal oral flora usually produce which sort of hemolysis in culture?
Alpha
A 31 year old bank teller presents with bloody diarrhea, abdominal cramps, and a fever. Microscopic examination of the stool shows the presence of many neutrophils and erythrocytes. The most likely causative organism is:
A. H. pylori
B. Salmonella Enteritidis
C. Campylobacter jejuni
D. Shigella sonnei
E. Vibrio cholerae
D
Streptococcal pyrogenic exotoxins (Spe) function as:
Superantigens
The CDC recommends that water used for routine dental treatment should:
A. Contain less than 500 CFU/mL
B. be dionized
C. Be distilled
D. exceed the regulatory standards for drinking water
A
S. pneumoniae can best be distinguished from S. pyogenes by which test?
Optochin test
The currently approved HPV vaccine for both boys and girls (Gardasil) is a quadrivalent vaccine against HPV types:
6, 11, 16, 18
The currently recommended poliomyelitis vaccine consists of:
Killed virus
Which would be the most likely non-suppurative sequela of streptococcal impetigo?
A. rheumatic fever
B. Endocarditis
C. Glomerulonephritis
D. Erythema nodosum
Glomerulonephritis
The hyaluronic acid capsule of S. pyogenes is a virulence factor because it inhibits:
Phagocytosis
Three days ago, a patient received her third immunization with tetanus toxoid. What class of antibodies specific for tetanus toxoid would one expect to find in her serum?
Low IgM; High IgG
Which bacterium is thought to be associated with gastric carcinoma?
H. pylori
Which part of the IgG molecule can bind to a specific membrane receptor on a phagocytic cell?
Fc fragment
Which of the following cells express both class I and class II MHC
B lymphocytes
also macrophages. depends what answer is available
The spinal fluid in bacterial meningitis is characterized by
Increased protein levels
also high neutrophils
low glucose
wbc 0-60,000
The antigenic component upon which Lancefield grouping of Streptococci is based is a:
Cell wall polysaccharide
T independent antigens include:
A. tetanus toxoid
B. human albumin
C. Streptococcal M protein
D. Pneumococcal polysaccharide
D. Pneumococcal polysaccharide
In general, live virus vaccines should not be administered to individuals who are:
A. immune deficient
B. pregnant
C. being treated with cytotoxic drugs
D. Receiving radiation therapy
E. all of the above
E
The cardiac inflammation that occurs in rheumatic fever is probably due to:
Antibody cross reactivity between streptococcal and cardiac tissue antigens
Which organism if gram negative, motile, and ferments lactose?
A. Shigella sonnei
B. Salmonella paratyphi
C. Vibrio vulnificus
D. E. coli
E. C. jejuni
D
The drug of choice for prevention of recurrent rheumatic fever is
Penicillin
Which of the following streptococcal products is responsible for beta hemolysis of blood agar?
A. Erythrogenic toxin
B. streptokinase
C. Streptolysin B
D. Hyaluronidase
C
The administration of Hep B immune globulin results in which type of immunity?
Artificial passive
The main advantage of passive immunization over active immunization is:
it provides immediate protection
Enterotoxins are bacterial products that induce vomiting and diarrhea when ingested in microgram amounts. Which organism below produces them?
A. E faecalis
B. S pyogenes
C. S. aureus
D. S. epidermidis
C
A patient develops explosive, watery, high volume diarrhea 24 hours after eating seafood imported from South America. No blood is visible in the stool. Which bacterium is most likely involved?
Vibrio cholerae
The major virulence factor of Group A, beta hemolytic Streptococcus is
M protein
A confirmatory test for the ID of E. coli is
Indole test
In humoral immunity, memory cells are formed as a result of differentiation of
Antigen activated B cells
In healthy carriers of S. Typhi, the organism is found in which site
Gallbladder
MMR vaccine consists of:
Live attenuated organisms
The drug of choice for Staphylococcal infections is
Methicillin
