Q.23 Match the diseases in Group I with their causative organisms in Group II
Group I                                                                          Group II
(P) Syphilis                                                                  (1) Shigella dysenteriae
(Q) Bacillary dysentery                                             (2) Bordetella pertusis
(R) Gas gangrene                                                       (3) Treponema pallidum
(S) Whooping cough                                                  (4) Clostridium perfringens

(A) P-2, Q-1, R-4, S-3
(B) P-3, Q-4, R-2, S-1
(C) P-2, Q-3, R-4, S-1
(D) P-3, Q-1, R-4, S-2

The correct answer is (D) P-3, Q-1, R-4, S-2.​

Disease-Causative Agent Matches

Syphilis (P) results from infection by the spirochete Treponema pallidum (3), a Gram-negative bacterium transmitted primarily through sexual contact. Bacillary dysentery (Q) stems from Shigella dysenteriae (1), which invades intestinal mucosa causing severe diarrhea and bloody stools. Gas gangrene (R) arises from Clostridium perfringens (4), an anaerobic spore-former producing gas and toxins in wounded tissues. Whooping cough (S) is induced by Bordetella pertussis (2), leading to paroxysmal coughing via pertussis toxin.​

Option Analysis

• (A) P-2, Q-1, R-4, S-3: Incorrect; mismatches syphilis with Bordetella pertussis and whooping cough with Treponema pallidum.​

• (B) P-3, Q-4, R-2, S-1: Incorrect; wrongly pairs bacillary dysentery with Clostridium perfringens.​

• (C) P-2, Q-3, R-4, S-1: Incorrect; assigns Bordetella pertussis to syphilis and Treponema pallidum to bacillary dysentery.​

• (D) P-3, Q-1, R-4, S-2: Correct; accurately links each disease to its pathogen based on established microbiology.​

Discover the precise syphilis bacillary dysentery gas gangrene whooping cough causative organisms pairings essential for CSIR NET Life Sciences. This guide breaks down Group I diseases with Group II pathogens, verifies matches via microbiology facts, and analyzes all options for competitive exam prep.​

Pathogen Profiles

• Treponema pallidum (3): Spiral-shaped spirochete causing syphilis stages from chancre to neurosyphilis; cannot be cultured on artificial media.​

• Shigella dysenteriae (1): Gram-negative rod producing Shiga toxin; low infectious dose triggers bacillary dysentery epidemics.​

• Clostridium perfringens (4): Anaerobic spore-former; alpha-toxin lyses cells in gas gangrene post-trauma.​

• Bordetella pertussis (2): Gram-negative coccobacillus; pertussis toxin disrupts respiratory cilia in whooping cough.​

Exam Strategy Tips

Perfect matching questions by recalling:

• Spirochetes for STDs like syphilis.

• Enterobacteriaceae (Shigella) for dysentery.

• Clostridia for anaerobic infections.

• Bordetella for respiratory whoops.​