Biology · Science General

Disease Causative Agents

2,258 Questions

Disease causative agents questions test your understanding of viral, bacterial, and fungal infections, along with their transmission methods. These are common topics in general science sections of SSC and railways exams. Practice these questions to accurately identify disease pathogens and symptoms.

Viral diseasesFoodborne illnessesDisease transmission methodsExtrinsic disease factorsCommon pathogens

Disease Causative Agents Questions

Multiple choice

Which of the following species of E. coli is responsible for outbreaks of bloody diarrhea and hemolytic uremic syndrome (HUS) worldwide?

  1. Enteropathogenic E. coli (EPEC)

  2. Enterotoxigenic E. coli (ETEC)

  3. Enteroinvasive Escherichia coli (EIEC)

  4. Enterohemorrhagic E. coli (EHEC)

  5. Enteroaggregative E. coli (EAggEC)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is a human pathogen responsible for outbreaks of bloody diarrhea and hemolytic uremic syndrome (HUS) worldwide.

Multiple choice

Which of the following statements regarding the pathogenesis of rickettsiae is INCORRECT?

  1. Rickettsiae grow free in the cytoplasm of cultured cells.

  2. Rickettsiae gets propelled by the host cell cytoplasm.

  3. Propulsion by F-actin helps in the spread of rickettsiae to adjacent endothelial cells.

  4. Growth of rickettsiae in the endothelium leads the damage of vascular integrity of an individual.

  5. Fusion of lysosomes with thrombocytes results in the digestion of dying rickettsia.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Gamma interferon and tumor necrosis factor alpha secreted by host immune cells activates the infected endothelial cell to destroy intracellular rickettsiae by the creation of autophagosomes. Later, fusion of lysosomes with autophagosomes results in the digestion of dying rickettsia  .

Multiple choice

Which of the following is the causative agent for gastric and duodenal ulcers?

  1. Yersinia entercolitica

  2. Shigella flexneri

  3. Helicobacter pylori

  4. Campylobacter jejuni

  5. Vibrio parahemolyticus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It is a gram-negative, spiral to pleomorphic, prokaryote. H. pylori infection is the main cause of chronic superficial gastritis and it is associated with both gastric and duodenal ulcers.

Multiple choice

Bacteremia is the presence of viable bacteria in the circulating blood. Which of the following is a common cause of bacteremia in human beings?

  1. C. botulinum

  2. C. difficile

  3. C. tetani

  4. B. fragilis

  5. P. aeruginosa
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Infections by P. aeruginosa are a common cause of bacteremia that is bacterial blood infections. Heart valves, particularly of intravenous drug users can also become infected. Symptoms include general malaise with fever, joint and muscle pain.

Multiple choice

Many factors play direct and indirect roles in Y. pestis pathogenesis. Which of the following factors are essential for rodent pathogenesis?

  1. Coagulase and Plasminogen activator

  2. Envelope (F-1) antigen

  3. Yops

  4. V and W proteins

  5. Low calcium response
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A group of 11 proteins, which are coded by plasmids, are essential for rodent pathogenesis and are responsible for cytotoxicity, inhibition of phagocyte migration and engulfment and platelet aggregation.

Multiple choice

Upon diagnosis, it was confirmed that Mr. Verma is suffering from oropharyngeal cancer. Which of the following is a causative agent of oropharyngeal cancer?

  1. Hepatitis B virus

  2. Human papillomavirus

  3. Epstein-Barr virus

  4. Human herpes virus 8

  5. Human T-lymphotrophic virus-1
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Human papillomavirus (HPV) is a major cause of cervical, anal, penile, and oropharyngeal cancer. The most common clinically significant manifestation of persistent genital HPV infection is cervical intraepithelial neoplasia (CIN).  

Multiple choice

The pyrogenic streptococcal exotoxins SPE, A, B, and C ____________.

  1. are M proteins

  2. cause post-streptococcal autoimmune disease

  3. produce high titers of anti-streptolysin O

  4. have hyaluronidase activity

  5. are superantigens
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The superantigens combine with the framework regions of certain TCR V beta families irrespective of their complementarity determining regions.

Multiple choice

Which one of the following diseases has been completely eradicated world-wide?

  1. Measles

  2. Smallpox

  3. Tuberculosis

  4. Cowpox

  5. Psittacosis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The eradication of smallpox was due to an enormous World Health Organization (WHO)-sponsored effort combining extensive vaccination and selective epidemiologic control methods. The WHO also hopes to eradicate poliomyelitis in the near future.

Multiple choice

Which of the following diseases are caused by Gram-negative bacteria? P. Typhoid Q. Cholera R. Plague S. Gonorrhoea

  1. Only P and Q

  2. Only P and S

  3. Only Q and R

  4. Only Q, R and S

  5. All of these
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Yes, it is the correct answer as all of the given diseases are caused by gram-negative bacteria. The causative agent of typhoid is Salmonella typhi (Gram-negative bacteria). Cholera is caused by Vibrio cholerae (Gram-negative bacteria). Plague is caused by Yersinia pestis (Gram-negative bacteria). Gonorrhoea is caused by Neisseria gonorrhoeae (Gram-negative bacteria).

Multiple choice

Which of the following is a pair of bacterial diseases?

  1. Malaria and Pneumonia

  2. Meningitis and Pneumonia

  3. Malaria and Meningitis

  4. Clonorchiasis and Tetanus

  5. Malaria and Clonorchiasis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Causative agent of meningitis is Neisseria meningitidus (Bacteria). Causative agent of pneumonia is Diplococcus pneumoniae (Bacteria).

Multiple choice

Which of the following viral diseases are caused by members of family Paramyxoviridae? P. Mumps Q. Measles R. Rubella S. Smallpox

  1. Only P and Q

  2. Only P and R

  3. Only P and S

  4. Only Q and R

  5. Only R and S
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mumps is caused by mumps virus, a member of the genus Rubulavirus in the family Paramyxoviridae. Measles (rubeola) is a skin disease with respiratory spread caused by Morbillivirus, a member of family Paramyxoviridae.