missed questions, review Flashcards
if your E. coli culture looks blue after Gram staining, what did you most likely do wrong?
failure to decolorize with alcohol
(it’s not failure to counter-stain with safranin because the culture would be colorless in that case, assuming you did prior steps correctly)
for each of these technical errors of Gram staining, predict what would happen:
a. failure to use fresh culture
b. failure to heat fix
c. failure to stain with Gentian violet
d. failure to apply iodine
e. failure to decolorize with alcohol
f. failure to counter-stain with safranin
(assume all other steps were done correctly)
a. failure to use fresh culture = dead cells
b. failure to heat fix = no cells
c. failure to stain with Gentian violet = all pink cells
d. failure to apply iodine = all pink cells
e. failure to decolorize with alcohol = all blue cells
f. failure to counter-stain with safranin = colorless Gram(-)
what part of the envelope of Shigella (Gram-) contributes most to its toxicity?
Lipid A endotoxin of outer membrane (contained in LPS, lipopolysaccharide)
*remember Lipid A can cause toxicity whether bacteria is dead or alive
what is the structure of Lipid A, the part of LPS responsible for causing toxicity?
disaccharide substituted with saturated fatty acids
R-factor (resistance genes) are usually transferred via a ____
plasmid, via conjugation
what needs to happen for stable maintenance of a transferred antibiotic resistance gene?
plasma genes need to integrate into a chromosome (DNA which replicates)
requires homologous recombination
which of these processes is NOT involved in moving genes from one cell to another?
a. conjugation
b. homologous recombination
c. transduction
d. transformation
e. movement of a transposon
e. movement of a transposon - moving DNA from one plasmid to another or to the chromosome (within a cell)
which of these processes of genetic transfer in bacteria requires homologous recombination?
a. transformation
b. conjugation
c. transduction
a. transformation (uptake of genetic material from environment)
A culture of Salmonella is found to have a mixture of cells expressing different H (flagellar) antigens. What genetic process accounts for this?
inversion of DNA segment which contains the promoter for the flagellin gene
where in the body does Neisseria meningitidis establish asymptotic carrier state?
nasopharynx
which of the following is essential for the generation of antibodies against bacterial surface proteins?
a. B lymphocytes are stimulated in a “T-independent” fashion
b. CD8+ lymphocytes proliferate
c. DC cells phagocytose and digest bacterial proteins
d. peptides from bacterial proteins are presented by Class I MHC
c. DC cells phagocytose and digest bacterial proteins
on what kind of plate and what conditions can Neisseria meningitidis be cultured?
Thayer-Martin agar and elevated CO2: chocolate agar containing antibiotics to inhibit normal flora
what component of Neisseria meningitidis causes septic shock?
LOS (lipo-oligosaccharide) - contains Lipid A endotoxin
[remember that septic shock is due to endotoxins, while toxic shock is due to exotoxin superantigens]
what does it mean when a bacteria is catalase positive? (what does this enzyme do?)
catalase = hydrogen peroxidase
catalyzes H2O2 —> H2O + O2
protective against ROS
contrast the causes of septic shock and toxic shock syndrome
septic shock: due to endotoxins that cause inflammatory response
toxic shock syndrome: due to superantigen exotoxins that cause polyclonal T cell activation
match the pathogen with the more likely mode of infection:
staphylococcus or streptococcus
a. contamination of a needle or injection site with oral flora
b. entry of skin flora through a needle-stick site
staph.: skin flora
strep.: oral flora (alpha-hemolytic)
which Gram+ coccus is uniformly sensitive to penicillin G?
a. staph. aureus
b. staph. epidermidis
c. strep. pneumoniae
d. strep. pyogenes
d. strep. pyogenes
You are culturing a bacteria which you suspect to be Strep. pyogenes, Group A streptococcus that is beta-hemolytic. To confirm your suspicion, you do a bacitracin test. What do you expect the result to be?
Bacitracin sensitive
antibodies to which antigen of Streptococcus pneumoniae are most important for effective immunity?
a. teichoic acid
b. peptidoglycan
c. C-carbohydrate
d. Type III system
e. polysaccharide capsule
e. polysaccharide capsule - most important virulence factor of Strep. pneumoniae (no capsule = non-infectious)
which is more likely to be highly antibiotic resistant, Enterococcus or Group D Streptococcus?
Enterococcus
Which test result would best distinguish Strep. pneumoniae from other alpha-hemolytic Streptococci?
a. sensitivity to bacitracin
b. sensitivity to optochin
c. sensitivity to penicillin G
d. sensitivity to methicillin
e. sensitivity to rifampin
b. sensitivity to optochin
recall that other alpha-hemolytic Strep, Viridans group, is optochin resistant
What bacterial component defines the Lancefield Groups?
cell-associated or C-carbohydrate
what does it mean when colonies on MacConkey agar plates turn dark pink?
strain ferments lactose, which causes pH to drop and pH indicator dye turns pink
what does it means when a TSI (Triple Sugar Iron) agar slant turns yellow?
TSI slants contain pH indicator that turns yellow if pH drops because of fermentation of either/both lactose or sucrose
what is the clinical outcome of the heat stable toxin of E. coli stimulating guanyl cyclase?
stabile toxin: structural analogue of gut peptide hormone which stimulates guanyl cyclase coupled receptor
*increase in either cAMP (labile toxin, resembles cholera toxin) or cGMP causes salt/osmotic outflow into gut lumen and watery diarrhea
Verotoxin =
Shiga-like toxin
where would a young child most likely contract Shigella?
a. reptile such as snake or iguana
b. dog or cat
c. cow, horse, sheep
d. parakeet or other bird
e. another child
f. spores present in soil
e. another child - Shigella found only in humans, transmitted via fecal oral route
*note that Shigella is resistant to stomach acid and has a low infectious dose
Yersinia enterocolitica and Yersinia pseudotuberculosis both use a Type III secretion system to prevent:
a. phagocytosis by neutrophils
b. fusion of phagosomes with lysosomes
c. processing and presentation of antigens
a. phagocytosis by neutrophils
[remember that Yersinia enterocolitica and Yersinia pseudotuberculosis are acquired from animals or ingestion of contaminated meat or dairy]
what is the antigenic component of Haemophilus influenzae vaccine?
Hib conjugate vaccine: purified capsular polysaccharide covalently bound to diphtheria toxoid
severe projectile vomiting a few hours after eating contaminated food is a hallmark of food poisoning caused by
Staphylococcus aureus
primary mechanism for Enterococcal resistance to vancomycin is via expression of
VanHAX operon (D-Ala-D-Ala —> D-Ala-D-Lac)
when a person living in a closed community (military, college) presents with severe headache + neck stiffness + fever, your first thought should be
Neisseria meningitidis
increased production of endogenous metabolite PABA (p-aminobenzoic acid) causes resistance to
sulfamethoxazole - sulfonamides are anti-metabolite antibiotics that block the first enzyme in folate synthesis, which uses PABA as a reactant
therefore, resistance works by overwhelming drug with increased PABA
the most important virulence factor for the development of UTIs
pili (adhesins): necessary for adhesion to urethra
name the toxin which:
a. induces adenylate cyclase
b. inhibits protein synthesis on 60s ribosomal subunit
c. ribosylates EF-2 (elongation factor 2)
a. induces adenylate cyclase —> Cholera toxin and labile toxin of E. coli
b. inhibits protein synthesis on 60s ribosomal subunit —> Shiga toxin (and Shiga-like toxin)
c. ribosylates EF-2 (elongation factor 2) —> pseudomonas exotoxin A and diphtheria toxin
what bacterial infection will cause copious amounts of watery diarrhea but no fever
Vibrio cholerae
endotoxins are only found in Gram(+/-)
endotoxins only found in Gram (-), in LPS
exotoxins found in both Gram+/-
how do beta-lactamases inactivate penicillin?
transient covalent linkage
Hemolytic Uremic Syndrome (HUS) is typically caused by ____ toxin, produced by ______ bacteria
HUS: caused by Shiga toxin produced by Shigella or STEC E. coli
what would you expect to see after an acid-fast stain of tuberculosis sputum?
red-staining bacilli
what is the purpose of culturing Mycobacterium tuberculosis on Lowenstein-Jensen agar and in the BACTEC system?
culture allows testing for antibiotic sensitivity/resistance
what characteristic of M. tuberculosis is most essential for its transmission?
impermeable lipid-rich envelope
A first-year resident tests tuberculin-positive and requires prophylactic treatment - which drug should be given?
a. streptomycin (aminoglycoside)
b. ciprofloxacin (fluoroquinolone)
c. isoniazid
d. rifampin
e. ethambutol
c. isoniazid
what is the most important type of immune defense against M. tuberculosis?
killing by macrophages activated by TH1 cells via gamma interferon
in what kind of immunodeficient patient might a PPD test produce a false-negative?
patients with impaired cell-mediated immunity may produce false-negative PPD because immune response to tuberculosis is TH1 mediated (activate macrophages via IFNy)
if cells infected with Chlamydia trachomatis were examined by staining and light microscopy, what would be observed?
membrane-bounded inclusion body within the cytoplasm
what property of Rickettsia (causing RMSF) prevents its recovery by culture?
it can only be grown in living mammalian cells
if cells infected with Rickettsia were examined by electron microscopy, what would be observed?
small rod-shaped bacilli free in the cytosol (intracellular)
what structural feature is unique to bacteria such as Borrelia burgdorferi and Treponema pallidum?
a. outer membrane with porins
b. pili for tight adherence
c. flagella within the outer membrane
d. high-affinity iron-transport systems in the cell envelope
c. flagella within the outer membrane - endoflagella
A 25yo pregnant woman develops chorioamnionitis from Bacteroides fragilis - how did the organism reach the fetal membranes?
Bacteroids fragilis is normal intestinal flora - spread from endogenous source to her genitourinary tract
which bacteria is most likely to be acquired from home-canned foods?
Clostridium botulinum - produces spores not easily killed by boiling
Your patient presents with a lesion they said began as a small red swelling which enlarged and then ulcerated. A swab of the ulcer contains large Gram+ rods and aerobic culture on sheep blood agar produces non-hemolytic colonies. When the ulcer heals, it produces a thick black scab.
What is most likely going on?
Bacillus anthracis cutaneous infection
Bacteroides fragilis is isolated from your patient’s abscess - what condition most likely facilitated the infection?
a. treatment with sulfonamide
b. tissue ischemia
c. antibiotic treatment for another bacterial infection
d. colonization of the large intestine with spores of this organism
tissue ischemia - Bacteroides fragilis is anaerobic
to what do neutralizing antibodies for Polio virus bind?
a. matrix protein
b. nucleocapsid protein
c. membrane glycoproteins
d. non-structural proteins
nucleocapsid protein
which of these steps only occurs in “early” phase of viral replication?
a. production of virion structural proteins
b. synthesis of viral-encoded enzymes
c. transcription of viral genes
d. production of new viral genome
b. synthesis of virus-encoded enzymes
which of the following will detect only infectious virions?
a. ELISA
b. PCR
c. hemagglutination
d. plaque assay
e. western blot
plaque assay - non-infectious viruses will not be able to lyse cells
where does variation that differentiates serotypes occur?
a. structural variation of proteins at viral surface
b. variation in symmetry of nucleocapsid
c. presence or absence of particular proteins in virions
d. structural variations of viral internal proteins
structural variation of proteins at virus surface
some viruses spread through inducing fusion of uninfected cells with infected cells - what mode of immune defense does this escape?
neutralization of virions by antibody
what kind of immunity do viruses escape by inhibiting synthesis of MHC I?
CD8+ CTL
what is required for transfer of DNA from a bacteriophage from one bacterium to another?
a. direct contact between donor and recipient cells
b. excision of the bacteriophage from the bacterial chromosome, replication, and new virus formation
c. replication of a conjugative plasmid
b. excision of the bacteriophage from the bacterial chromosome, replication, and new virus formation
DNA from bacteriophages integrate into chromosome - need to pop out and replicate to spread
some isolated resistance genes are found to lie close to each other in DNA and are adjacent to a gene with transposase sequence motifs. This group of genes is flanked by inverted DNA repeats - what is this whole thing called?
transposon
what does N. meningitidis have that N. gonorrhoeae doesn’t have that helps it evade immunity?
N. meningitidis has capsule that confers resistance to killing by phagocytes
N. gonorrhoeae is unencapsulated
An 8mo boy has a history of Gram+ middle ear infection, as well as infections by non-encapsulated H. influenzae, S. pneumoniae, and a staph. skin infection which responded poorly to antibiotics. Turns out he has an immunodeficiency syndrome - what aspect of his immunity is defective?
antibodies, complement, and neutrophils - predominant immunity against extracellular bacteria
mechanism of cholera toxin
stimulates Gs protein that activates adenyl cyclase —> increase in cAMP, more fluids in lumen of GI —> water diarrhea
which bacterial toxin causes an increase in cGMP
heat stabile toxin (ST) of ETEC (traveller’s diarrhea) stimulates guanyl cyclase and increase cGMP
ETEC also has labile toxin (LT) which is cholera-like toxin, and increase cAMP
both cause fluid in lumen —> diarrhea
which describes the function of ETEC heat-labile exotoxin?
a. enters intestinal epithelial cells, catalyzes synthesis of cGMP in cytosol
b. ADP-ribosylates a large G protein which stimulates adenyl cyclase
c. cleaves ribosomal RNA and inhibits protein synthesis by 80S ribosomes
b. ADP-ribosylates a large G protein which stimulates adenyl cyclase
this is cholera-like toxin —> cAMP —> watery diarrhea
Yersinia enterocolitica and Yersinia pseudotuberculosis cuase intense inflammation in intestinal lymph nodes. A virulence factor aiding infection is their Type III secretion system, which blocks:
a. phagocytosis of Yersinia by neutrophils
b. fusion of phagosomes with lysosomes
c. cytokine synthesis by infected macrophages
a. phagocytosis of Yersinia by neutrophils
which phrase best describes the antigenic components of the recommended pertussis vaccine?
a. toxoid plus other purified antigens
b. purified capsular polysaccharides, linked to Diphtheria toxoid
c. live attenuated bacteria
a. toxoid plus other purified antigens
DTap: Diptheria Toxoid, acellular Pertussis
what produces the induration and erythema seen with tuberculin skin tests?
a. induction of primary antibody response
b. cytokine production by CD4+ T cells
c. killing of infected human cells by CD8+ CTL
b. cytokine production by CD4+ T cells
CD4+ T —> IFNy —> macrophage
in a person with intact immunity, which of the following is most likely to be followed by development of active TB?
a. re-activation of previously dormant bacteria in the lung
b. brief exposure to a person with active TB
a. re-activation of previously dormant bacteria in the lung
what is given as prophylactic treatment for TB?
isoniazid (INH)
how does Edema Factor of anthrax work? how does Lethal Factor work?
Edema Factor: calmodulin-activated adenyl cyclase —> causes increase in cAMP —> fluid leakage
Lethal Factor: protease that cleaves a MAPK (protein kinase) involved in signal transduction —> tissue necrosis
*recall Protective Antigen is required for these to enter host cell
HIV+ patient has pneumonia. Bronchoalveolar fluid is recovered which contains cyst forms of _____
Pneumocystis carinii (P. jirovecii) —> Pneumocystis pneumonia
*this fungus is acquired in childhood and does not affect healthy people
what does Coccioides immitis look like when cultured on Saboraud agar + glucose?
hyphal growth - conidia develop in rods looking like bamboo kinda
*in tissue, looks like large spheres with many endospores
*found in SW USA/ Central+South America desert soil
what virulence factor is essential for CNS infection by all of these: S. pneumoniae, H. influenzae, N. meningitidis, and Cryptococcus neoformans?
these all have polysaccharide capsule that is required for infection!
which 2 fungi are associated with bird droppings
- Histoplasma capsulatum
- Cryptococcus neoformans
contrast what HSV and EBV do in latently-infected cells
HSV: NO protein production in latency, produce anti-sense transcripts
EBV: produce only early proteins
what virus is associated with retinitis in AIDS patients
cytomegalovirus (CMV)
how are VZV and Rubella both transmitted
oropharyngeal secretions and respiratory route
what virus causes Roseola infection in infants (fever + rash on neck and trunk)
HHV-6 (also implicated in HIV progression)
via respiratory secretions, latent in peripheral lymphocytes
which of these is true of Herpesviridae?
a. formation of syncytia
b. large intra-nuclear inclusions
c. death of infected cells by lysis
b. large intra-nuclear inclusions
dsDNA, icosahedral nucleocapsid, enveloped
what family of viruses causes syncytia?
Paramyxoviridae: (-)RNA, enveloped, helical
includes Parainfluenza, measles, mumps, RSV
what features determines oncogenic potential of a particular HPV type?
affinity of binding between viral early proteins and host cell growth-regulatory proteins
most common cause of tonsilitis
Adenovirus
can also cause keratoconjunctivitis, pharyngitis with fever and cough, and infantile gastroenteritis
what virus has large “owl’s-eye” intra-nuclear inclusions, and causes extensive erythematous rash of newborns?
cytomegalovirus (CMV): beta herpesvirus (latent in monocytes)
dsDNA, enveloped, icosahedral
via body fluids, causes cytomegaly but does not kill cells
why is it unlikely that a non-toxic drug will be developed that will inhibit replication of Papilloma viruses?
Papilloma (like HPV) use host cell biochemistry for replication, transcription, translation
what virus is associated with causing Progressive Multifocal Leukoencephalopathy (PML) in AIDS patients?
Human Polyoma Virus JC
which describes the virions of Vaccinia virus?
a. envelope contains HA and NA
b. lateral bodies are located between the viral core and membrane
c. virions are smaller than the virions of Herpesvirus
b. lateral bodies are located between the viral core and membrane
which of these describes SARS virus?
a. long slender enveloped virions with helical nucleocapsids
b. large naked virions with elaborate double-walled protein shells
c. large enveloped virions with prominent club-shaped glycoprotein spikes
c. large enveloped virions with prominent club-shaped glycoprotein spikes
remember these give it the appearance of a corona, or crown
what is the most likely outcome following infection with St. Louis encephalitis virus?
a. mild encephalitis
b. asymptomatic or sub clinical infection
b. asymptomatic or sub clinical infection
however in elderly patients severe CNS disease develops (stiff neck, meningitis, coma, disability)
no vaccine
what disease is echovirus most significant for causing
echovirus: meningitis, Hand/foot/mouth, conjunctivitis, febrile rash
but most importantly meningitis
recall this is naked, icosahedral, +RNA enterovirus (of picornaviridae)
how does Polio get to CNS
gut —> viremia —> CNS
on Polio virion, where are the epitopes important for neutralization?
proteins on the virion which are protruding and coming to a point
recall Polio is naked, icosahedral, +RNA enterovirus (picornaviridae)
what family of viruses have fusion (F) proteins?
paramyxoviruses (-ssRNA): include parainfluenza, measles, mumps, RSV
these also cause syncytia
which calicivirus causes outbreaks of diarrhea
Norwalk: naked, icosahedral, +ssRNA
how does Amantadine work as a prophylactic drug for Influenza?
inhibits M2 protein, which forms ion channel that lowers pH to allow for uncoating
blocks fusion of viral and endosomal membranes in response to decreased pH
what does Hemagglutination Inhibition (HAI) assay detect in serological diagnosis of Influenza?
antibody to influenza virus
Hantavirus is found in southwest US and causes pulmonary infection - how is it transmitted?
inhalation of aerosolized rodent urine/feces, or of material contaminated with these
among viruses, what structural feature is unique to the virions of Arenaviruses?
they contain host cell ribosomes ! woah !
*note arenaviruses mostly produce systemic febrile illnesses
lactose-fermenting Gram- rod isolated from bloody stool
E. coli
young child with loose stools, fever, cramping, muscle aches, but no blood in stool
she has several pet turtles
what is it
Salmonella spp.
how does Rickettsia rickettsii rash spread
limbs to trunk
which organism would be most likely to be a contamination caused by poor antiseptic technique, rather than true infection?
a. Staph. epidermidis
b. Pseudomonas aeruginosa
c. Strep. pneumoniae
a. Staph. epidermidis
fever and bloody diarrhea, curved Gram- rod
Campylobacter jejuni
patient works as tree remover, has lump on left forearm
Gram+ bacteria is isolated that only grows in aerobic culture. It is most likely:
a. Nocardia asteroides
b. Actinomyces israelii
c. Bacillus cereus
d. Aspergillus fumigatus
a. Nocardia asteroides
which bacteria causes formation of a tough pseudomembrane that is difficult to remove without causing bleeding?
Corynebacterium diptheriae
what is the most common source of rabies infection in the US?
bats
note this is not the only thing bats are associated with
which viruses are segmented?
BOAR:
Bunyavirus
Orthomyxovirus (Influenza)
Arenavirus
Rotavirus
inspiratory stidor =
croup (like the cough in parainfluenza virus)
what does the fusion protein of parainfluenza, mumps, RSV, and measles do?
fusion protein causes syncytia (multi-nucleated giant cells)
which zoonotic bacteria has bipolar staining
Pasteurella
which Gram+ rod bacteria has a narrow zone of beta hemolysis
Listeria monocytogenes
when does adenovirus vs influenza and RSV cause infection?
adenovirus: year round
influenza and RSV: winter
what are the curved rod Gram- bacteria?
campylobacter, vibrio, helicobacter
in what cells does Salmonella typhi spread systemically?
monocytes/macrophages
what is the mechanism of vancomycin resistance?
expression of 1+ genes encoding enzymes that produce peptidoglycan with D-ala-D-lac termini
via VanHAX operon
this is seen in enterococci
are monobactams (aztreonam) cross-reactive with penicillin?
no!
_____ are lipopolysaccharides, ______ are proteins
ENDOTOXIN: LPS
EXOTOXIN: protein
only Gram- have LPS (endotoxin) but both Gram+/- have exotoxins
what disease is caused by spirochete bacteria and spread by human body louse?
relapsing fever via Borrelia reccurrentis
which bacteria, transmitted by a flea bite, causes maculopapular rash on trunk, arms, and thighs?
Rickettsia typhi: causes endemic/murine typhus, vector is rat and rat flea
what medium is used for culturing M. tuberculosis
Lowenstein-Jensen medium
vaginal itching and erythema with thick/white discharge and foul smell is most likely caused by…
candida albicans
pelvic inflammatory disease is most likely caused by…
Chlamydia trachomatis is most common bacterial STD and most often cause of PID
after that would be N. gonorrhoeae
chronic diarrhea in an AIDS patient and a fecal smear that shows acid-fast oocyts
what is the most likely causative organism?
Cryptosporidium
which is the only form of plasmodium that causes cerebral involvement?
Plasmodium falciparum (worst one)
1 choice for anthrax prophylaxis
Ciprofloxacin (FQ/fluoroquinolone)
what test distinguishes Group B (Strep. agalactiae) from other beta hemolytic strep?
CAMP test: positive result shows arrowhead-shaped area of hemolysis next to bacterial streak on blood agar (due to CAMP factor)
which of these is transmitted via an arthropod vector?
a. Bunyavirus
b. arenavirus
c. parvovirus
a. Bunyavirus - arthropod vectors
what is the main component of the EBV capsid?
VCA protein: viral capsid antigen !!!
all mAbs for Covid are given via what route of administration?
infusion or injection !
what type of organism does MacConkey agar select AGAINST
gram+
MAC agar only grows Gram- bacteria !!
what color do bacteria that ferment sugars on HE agar appear as?
yellow!!
how doe most transforming genes found in DNA viruses cause tumor formation?
inactivation of tumor suppressor gene products such as p53 and Rb
What kind of rash is associated with Hand Foot & Mouth Disease when caused by Coxsackievirus?
red vesicular rash
*note that VZV also causes vesicular rash
What bacterial species is associated with causing rice water stool?
Cholera - due to mucus in the stool
the most common source of rabies in the US is…
bats
which viral families have segmented DNA?
BOAR:
Bunyaviridae
Orthomyxoviridae
Arenaviridae
Rotavirus
what do the anti-influenza drugs Amantadine and Rimantadine target?
M2 protein, which lowers cell pH to facilitate viral uncoating
inspiratory stridor =
inspiratory stridor = croup
seen with parainfluenza infection
what protein causes the synctia seen with infection by parainfluenza, measles, mumps, and rsv?
fusion protein
what is the difference in the rash caused by Herpes Simplex Virus 2 (HSV 2) and Varicella Zoster Virus (VZV)?
both caused red vesicular rash
but HSV2 rash is painful
What Gram- bacteria has classic bipolar staining?
Pasteurella
Which Gram+ rod grows with a narrow zone of beta hemolysis on blood agar?
Listeria monocytogenes
Contrast when infections by Adenovirus vs Influenza vs RSV are most common
Adenovirus: infections year-round
Influenza/RSV: winter infections
What virus is the most common cause of tonsillitis?
Adenovirus
also causes hemorrhagic cervicitis
What kind of vaccine is available for Adenovirus, and who is it given to?
live vaccine, military only
What are the curved Gram- bacteria? (3)
- Campylobacter jejuni
- Vibrio cholerae
- Helicobacter pylori
