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Question 605
Microbiology → General
Classification
Question
SSBAQuestion Header
Which sequence contains organisms that are all Gram negative?
Question Stem
Which combination consists entirely of Gram-negative organisms despite representing different bacterial forms?
Options
A
Neisseria gonorrhoeae, Listeria monocytogenes, Vibrio cholerae
B
Treponema pallidum, Bacillus anthracis, Gardnerella vaginalis
C
Neisseria meningitidis, Clostridium difficile, Leptospira interrogans
D
Escherichia coli, Actinomyces israelli, Vibrio cholerae
E
Neisseria gonorrhoeae, Treponema pallidum, Vibrio cholerae
Explanation
Neisseria gonorrhoeae, Treponema pallidum and Vibrio cholerae are all Gram negative, representing a coccus, a spirochete and a comma-shaped vibrio respectively. Every alternative contains a Gram-positive organism.
Option Validity
A) Listeria monocytogenes is Gram positive.
B) Bacillus anthracis is Gram positive.
C) Clostridium difficile is Gram positive.
D) Actinomyces israelli is Gram positive.
Further Reading
Saxena R. Textbook for MRCOG-1: Basic Sciences in Obstetrics and Gynaecology. Chapter 6 — Microbiology and Immunology: Table 6.1 — Common forms of bacteria. Printed pages 183–184.