1. Lactobacilli grow best under
A. strict anaerobic conditions
B. microaerophilic conditions in presence of 5% CO2 and PH6
C. microaerophilic conditions in presence of 3% CO2 and PH5
D. microaerophilic conditions in presence of 2% CO2 and PH4
ANSWER: B
2. Which of the following genera is included in the family Bacteroi-daceae?
A. Bacteroides
B. Fusobacterium
C. Leptotrichia
D. All of these
ANSWER: D
3. The bacteria which is predominant flora of the human gut is
A. Escherichia coli
B. Clostridium perfringens
C. Bacteroides
D. Actinomyces
ANSWER: B
4. The current genus name of a saccharolytic group of Bacteroides is
A. Porphyromonas
B. Bacteroides
C. Prevotella
D. None of these
ANSWER: A
5. Colonies resembling molar teeth are produced by
A. Nocardia brasiliensis
B. N. asteroids
C. Actinomyces israelii
D. Actinomadura madurae
ANSWER: C
6. Which of the following bacterial colonies fluoresce brick-red in UV light?
A. B gingivalis
B. B melaninogenicus
C. Bacteroides fragilis
D. B levii
ANSWER: B
7. Which of the following bacteria is acid-fast?
A. Actinomyces
B. Nocardia
C. Streptomyces
D. Corynebacterium
ANSWER: B
8. Lactobacilli constitute the normal flora of
A. prepubertal vagina
B. adult vagina
C. post-menopausal vagina
D. none of these
ANSWER: B
9. Which of the following bacteria is gram-negative cocci?
A. Veillonella
B. Peptococcus
C. Peptostreptococcus
D. Sporosarcina
ANSWER: A
10. The commonest species of Bacteroides in fragilis group, which causes human infection, is
A. B vulgatus
B. B fragilis
C. B ovatus
D. B merdae
ANSWER: B
11. The commonest bacterial cause of cervicofacial actinomycosis is
A. A. naeslundii
B. A. viscosus
C. A. israelii
D. A. meyeri
ANSWER: C
12. Which of the following bacteria is moderately saccharolytic?
A. Bacteriodes fragilis
B. B gingivalis
C. B melaninogenicus
D. B levii
ANSWER: C
