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 years ago
Thanks a lot Ramesh for appreciation
admin 7 years ago
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