Bacterial Diseases

A. Salmonella and Human Diseases: (bacterial diseases)

Salmonella are pathogenic bacilli which cause three kinds of
infection to humans viz., enteric fever (Typhoid or Paratyphoid),
Gastroenteritis and Septicemia.

Typhoid fever is caused by S.typhi. It is transmitted via Pathogen
contained food and water. The disease is characterized by a continued fever, inflammation of the intestine, formation of intestinal ulcers and
enlargement of the spleen.

Gastroenteritis is caused by Salmonella, but most commonly by
S.choleraesuis. The bacteria reach the blood stream from the intestinal tract,
where it multiplies. It causes recurring high fever, chills, loss of appetite and
weight loss. When the bacteria infect the organs from blood they can cause
meningitis, pneumonia, abscesses, nephritis, osteomyelitis, or endocarditis,
etc.

B. Cholera : (bacterial diseases)

Cholera is caused by Vibrio cholere. It is a disease of antiquity and
has been the cause of untold sufferings and death. Cholera is transmitted in
water and food contaminated with this bacteria. In the small intestine, the
bacteria adhere to epithelium, multiply and produce the enterotoxin. The
symptoms of cholera are vomiting, profuse diarrhoeal stool (rice water stool)
Which results in severe dehydration, loss of minerals, increased blood
acidity and haemoconcentration.

C. Plague : (bacterial diseases)

Plague is caused by the bacterial species Yersinia pestis, a non motile
gram negative bacilli. There are two types of plagues. They are bubonic
plague and pneumonic plague. Bubonic plague is characterized by enlarged
and inflamed lymph glands (Bubos). The symptoms are shivering, fever,
nausea, vomiting and general weakness. In untreated cases the bubonic plague
can cause 58% mortality. Pneumonic plague is a pneumonia characterized
by a thin watery sputum with bright red streaks of blood. The mortality is
100% in untreated cases.

D. Syphilis : (bacterial diseases)

The disease syphilis is a well known and dreadful sexually
transmitted disease (STD). It is caused by Treponema pallidium. Syphilis
occurs only in humans and is transmitted by direct sexual contact (Venereal
syphilis) or through placenta from an infected mother to the foetus
(Congenital syphilis). Venereal syphilis progresses in three stages viz.,
primary, secondary and tertiary stage. The symptoms are very prominent in the tertiary stage. It will lead to blindness, loss of hearing, brain damage,
insomnia, headache and delusions and spinal cord damage.

E. Gonorrhoea : (bacterial diseases)

Gonorrhoea is another sexually transmitted disease caused by
Neisseria gonorrhoea. In the males the primary site of infection is the
urethra. In the female it is the cervix. It causes pain during urination and a
yellowish discharge from the urethra of males. In females also it causes
painful urination and vaginal discharge. Other symptoms are fever,
abdominal pain, arthritis, meningitis etc.