Bacterial Diseases

AIPMT-NEET Biology Aspirants, read out the next AIPMT Biology Study material/ Notes on Bacterial Diseases about their causative agents, important for AIPMT-NEET Biology.Free online notes for AIPMT-NEET.

Bacteria cause a large number of diseases in human beings, but they are also useful for mankind in several other ways. Few microbes provide important products like cheese, alcohol, enzymes, etc. You can read about these in topic Microbes in human welfare. Disease causing bacteria can be gram-positive or gram-negative. Mode of infection can be through air, food & water, animals or by direct contact. Air-borne diseases are Diphtheria, Pertussis, Tuberculosis, Pneumonia etc. Animal-borne are Lyme disease, Plague. Anthrax, Leprosy and tetanus are direct contact diseases. Food and water-borne diseases include Botulism, Cholera, typhoid etc. Below is the list of few common diseases caused by bacteria, their mode of infection, symptoms,  and preventive measures to be taken for disease.

Disease Pathogenic Organism/ Causative agent Mode of Infection/ Symptoms Prevention and control measures
Diphtheria Corynebacterium diphtheria (gram-positive) Affects Nasopharynx by producing exotoxin DPT (DiphtheriaPertussis-Tetanus) vaccine; diphtheria toxoid
Pertussis “Whooping cough Bordetella pertussis  (gram-negative) Affects upper respiratory tract, produces pertussis toxin DPT vaccine, pertussis vaccine
Tetanus Clostridium tetani    (gram-positive) Produces endospores, enters body through wounds, produces 2 toxins- Tetanospasmin & tetanolysin ;severe cases lead to trismus “lockjaw” DPT vaccine , tetanus toxoid
Meningitis Neisseria meningitidis Inflammation of brain or spinal cord meninges (membranes) Antibiotics (penicillin, chloramphenicol)
Pneumonia Streptococcus pneumoniae (gram-positive) and Haemophilus influenzae Affects upper respiratory tract; produces capsular
polysaccharide of hyaluronic acid
Penicillin and Pneumovax 23 vaccine
Tuberculosis Mycobacterium tuberculosis Bacteria infects lungs and form nodules “tubercles bacille Calmette-Guérin (BCG) vaccine; Mantoux test
Lyme Disease Borrelia burgdorferi Host organism- ticks; so caused by tick bite; skin rashes LYMErix vaccine,  cleaning with soap; destroying ticks
Plague Yersinia pestis         (gram-negative) Transmitted from rodents to human by the bite of an infected flea Rodent control and USP-Plague vaccine
Anthrax Bacillus anthracis    (gram-positive) Direct contact with infected animals (cattle, goats, sheep) ; Produces anthrax toxins; bioterrorism threat Vaccination of cattle is
important control measure
Leprosy or Hansen’s disease Mycobacterium leprae Nasal secretions of infected person; bacterium invades peripheral nerve and skin cell; skin becomes sensation less Sulfone drug Dapsone and Rifampin
Syphilis (sexually transmitted disease) Treponema pallidum Infection through mucous membrane or skin; causes red ulcers or chancre Antibiotics; sexual hygiene, VDRL  test
Botulism Clostridium botulinum (gram-positive) Home-canned food with bacterial endospores; food poisoning; endospores produce botulinum toxin  which affect motor neurons Hemagglutination test ; safe food-processing;
Cholera Vibrio cholerae         (gram-negative) Ingesting food /water contaminated by fecal material of  infected person; Shellfish is natural reservoir of bacteria; produces cholera toxin choleragen; causes diahorrea Oral rehydration therapy with NaCl plus glucose to stimulate water uptake by the intestine;
Typhoid Salmonella typhi Ingestion of food or water contaminated by feces of infected person/animal; Typhoid mary– lady who acted as carrier of typhoid Widal test; Purification of
drinking water, milk pasteurization, prevention of food
Shigellosis or Bacillary dysentery Shigella (gram-negative) Transmitted by the fecal-oral route—primarily by food, fingers, feces, and flies (the four “F’s”); affects GIT tract ; watery stools often contain blood, mucus, and pus Fluid and electrolyte replacement ; good personal hygiene and maintenance of a clean water supply; trimethoprim –sulfamethoxazole antibiotic dose
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  • Thanks for this notes

    Ramesh kuwar 7 months ago Reply


    • Thanks a lot Ramesh for appreciation

      admin 7 months ago Reply


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