A massive lesion caused by spread of Staphylococcus aureus infection (often on the neck and upper back) is called a
1.Carbuncle
2.Furuncle
3.Abscess
4.Boil
A mutation in DNA gyrase is likely to result in resistance to which one of the following antibiotics?
1.Amphotericin B
2.Ciprofloxacin
3.Penicillin
4.Streptomycin
Bacterial conjunctivitis (inflammation of the eye conjunctiva) can be caused by:
1.Neisseria gonorrhoeae
2.Streptococcus pneumoniae
3.Pseudomonas aeruginosa
4.All of the above
Burn patients often develop nosocomial infection caused by:
1.Streptococcus epidermis
2.Corynebacterium spp.
3.Staphylococcus aureus
4.Pseudomonas aeruginosa
Cold agglutinin test is useful for the diagnosis of
1.N. menigitidis
2.Mycoplasma pneumoniae
3.H. influenzae
4.Cryptococcus neoformans
Colony-forming units per ml is the unit of
1.Microscopic count
2.Electronic enumeration
3.Plate count
4.Turbidimetric measurement
Disease-producing species occurring in a mixed culture can be selected by taking advantage of
1.special carbon source
2.special nitrogen source
3.its pathogenic properties
4.None
During exponential phase, growth rate is
1.rate of doubling population
2.time required for population to double
3.reciprocal of generation time
4.same as generation time
Gas gangrene is most likely associated with infection with
1.Staphylococcus aureus
2.Clostridium perfringenes
3.Streptococcus pneumoniae
4.Neisseria gonorrhoeae
How many cells present per millilitre in a bacterial culture can make the culture turbid?
1.1 cell
2.1000 cells
3.1 lakh cells
4.107-108 cells
In physical method of selection, endospore-forming bacteria can be obtained by heating the mixed culture to
1.60 degree C for 10 minutes
2.75 degree C for 10 minutes
3.80 degree C for 10 minutes
4.90 degree C for 10 minutes
In the growth equation: n= 3.3 (log10 N log10 No ), n stands for
1.initial population
2.growth constant
3.number of generations
4.total population
In which of the following phase secondary metabolites are produced during growth
1.Lag phase
2.Death phase
3.Stationary phase
4.Log/Exponential phase
Isolation of pure culture refers to
1.separation of a single colony
2.introduction of inoculum
3.purification of culture
4.to grow microorganisms on a surface
Lag phase is also known as
1.generation time
2.transitional period
3.period of initial adjustment
4.period of rapid growth
Resistance of Staphylococcus aureus to methicillin is most often caused by
1.Alternation of the major target for the drug
2.cell membrane impermeability
3.decreased uptake of the antibiotic
4.None
Scalded skin syndrome is caused by exotoxin (exfoliatins) produced by
1.Streptococcus pyogens
2.Pseudomonas aeruginosa
3.Propionibacterium acne
4.Staphylococcus aureus
Stool culture is primarily recommended when the complaint is
1.watery diarrhea
2.bloody diarrhea
3.for both bloody and watery diarrhea
4.an indication of anaerobic infection
The average size of the cells in the exponential phase is
1.larger than the initial size
2.smaller than the initial size
3.equal to the initial size
4.maybe smaller or larger than the initial size
The bacteria that multiply in blocked skin pores, metabolize sebum, and can lead to the development of acne are:
1.Pseudomonas aeruginosa
2.Propionibacterium spp.
3.Serratia marcescens
4.Streptococcus pyogenes
The generation time for E.coli is
1.30 minutes
2.26 minutes
3.20 minutes
4.10 minutes
The growth of bacterial population follows a geometric progression
1.True
2.False
3.None
4.More than one option is correct
The leading cause of preventable blindness in the world is caused by
1.Chlamydia trachomatis
2.Haemophilus influenzae
3.Streptococcus pneumoniae
4.Neisseria gonorrhoeae
The molecular basis for the effect of cholera toxin on duodenal mucosal cells is
1.Activation of adenylate Cyclase
2.Ribosylation of a guanosine triphosphate (GTP) binding protein.
3.Inactivation of a G1 protein
4.increased generation of cyclic adenosine monophosphate (cAMP)
The portion of the growth curve where a rapid growth of bacteria is observed is known as
1.Lag phase
2.Logarithmic phase
3.Stationary phase
4.Decline phase
The pus producing skin infections (pyoderma) can be caused by
1.Staphylococci
2.Streptococci
3.Corynebacteria
4.All of these
The role of bacterial capsules as virulence factors is usually related to their ability to interfere with
1.Antibody binding
2.Phagocytosis
3.B lymphocyte activation
4.Antibacterial penetration of bacterial cells
The synthesis of erythrogenic toxin by specific strains of group A Streptococcus is determined by a
1.Bacterial chromosomal gene
2.Specific virulence plasmid
3.gene carried by a lysogenic phage
4.Transposon
Throat culture is not useful to diagnose
1.Streptococcal sore throat
2.Pneumonia
3.Thrush
4.Diphtheria
Vibrio cholerae can grow in a medium with a pH of
1.8 5
2.5.9
3.3.6
4.3.1
Which of the following bacteria causing sexually transmitted disease can not be grown on artificial media?
1.Neisseria gonorrhoeae
2.Chlamydia trachomatis
3.Treponema pallidum
4.Treponema pallidum and Chlamydia trachomatis
Which of the following bacteria is not a most common bacterial pathogen causing diarrhea
1.Enterococcus faecalis
2.Shigella spp
3.Salmonella spp
4.Campylobacter spp
Which of the following bacteria is not most important causes of acute bacterial meningitis?
1.Neisseria menigitidis
2.Haemophilus influenzae
3.Streptococcus pneumoniae
4.Streptococcus pyogens
Which of the following bacteria is rarely associated with urinary tract infections?
1.Enterobacter spp
2.E.coli
3.Shigella spp
4.Proteus spp
Which of the following Gram negative rod is not a blood borne bacterial pathogen?
1.Shigella spp
2.Escherichia coli
3.Klebsiella pneumoniae
4.Pseudomonas aeruginosa
Which of the following instrument is used for bacterial count?
1.Petroff-Hausser counting chamber
2.Microscope
3.Chemostat
4.Turbidostat
Which of the following is not the characteristics of impetigo?
1.Common in children
2.Can be caused by Staphylococcus aureus
3.Can be caused by Streptococcus pyogenes
4.Can be caused by pseudomonads
Which of the following is a direct measurement of growth?
1.Determination of nitrogen content
2.Turbidimetric methods
3.Measurement of a specific chemical change produced on a constituent of the medium
4.Determination of Dry weight of cells
Which of the following is an indirect method for measuring bacterial growth?
1.Both Cell mass and Cell activity
2.Cell activity
3.Cell mass
4.Cell count
Which of the following is not a physical method for selection of pure culture?
1.Heat treatment
2.Use of dilute media
3.pH of the media
4.Cell size and motility
Which of the following is the relationship between optical density and cell mass?
1.linearly proportional
2.inversely proportional
3.exponentially proportional
4.not related
Which of the following is used to grow bacterial culture continuously?
1.Chemostat
2.Hemostat
3.Coulter-Counter
4.Turbidostat
Which of the following method is used for enumeration of bacteria in vaccines and cultures?
1.Microscopic Count
2.Membrane filter
3.Dry weight determination
4.Plate count
Which of the following method is used for viable count of a culture?
1.Plate-count method and membrane-filter count
2.Membrane-filter count
3.Plate-count method
4.Direct microscopic count
Which of the following microorganisms causes scarlet fever?
1.Streptococcus pyogens
2.Pseudomonas aeruginosa
3.Staphylococcus aureus
4.Propionibacterium acne
Which of the following statement regarding Campylobacter jejuni is not correct?
1.Incubation temperature is 42•C
2.It is commonly cultured in antibiotic containing media
3.It is a normal flora of intestine
4.None of the above
Which of the following test is not recommended for the diagnosis of Syphilis?
1.FTA-ABS test
2.MHA-TP test
3.Culture
4.VDRL test
Which one of the following factors, released by heating a suspension of sheep erythrocytes, is required for the growth of Haemophilus Influenzae in chocolate agar ?
1.Coagulase
2.Hemolysin
3.Nicotinamide adenine dinucleotide
4.Hemoglobin
Which one of the following factors, released by heating a suspension of sheep erythrocytes, is required for the growth of Haemophilus Influenzae in chocolate agar ?
1.Coagulase
2.Hemolysin
3.Nicotinamide adenine dinucleotide
4.Hemoglobin
Which phase shows reproduction rate equal to the equivalent death rate?
1.Stationary phase
2.Log phase
3.Death phase
4.Lag phase