Gram Negative Organisms PM2 Pathophysiology

Gram Negative Cocci Neisseria gonorrheae Neisseria meningitidis Gram negative bacilli Escherichia coli Salmonella typhi Vibrio cholera Helicobacter pylori Yersinia pestis Bordetella pertussis

Neisseria gonorrheae MOT: Sexual contact Men: acute urethritis painful urination yellowish penile discharge “the drip” Women: mostly asymptomatic more complications:PID, infertility Babies: ophthalmia neonatorum

NEISSERIA: DIPLOCOCCI

OPHTHALMIA NEONATORUM

Neisseria meningitidis MOT: respiratory droplets Causes meningococcemia disseminated intravascular coagulopathy skin rashes  purpura meningitis

MENINGOCOCCEMIA

Escherichia coli MOT: fecal-oral route Most common cause of UTI Most common cause of traveller’s diarrhea Sources: contaminated food and water Diarrhea: watery bloody HUS – hemolytic uremic syndrome

Salmonella typhi MOT: fecal-oral route Causes typhoid fever fever rose spots diarrhea Carrier state: gallbladder Vaccine available

Salmonella typhi

Rose spots

Vibrio cholerae MOT: fecal-oral route Causes Cholera profuse, rice-water like diarrhea hypotension high mortality of not treated

Cholera bed

Yersinia pestis MOT: bite of rat flea Causes “the plague” Common still in Southwest USA Stages 1. bubonic plague enlarged, draining lymph nodes; painful, full of the bacteria 2. pneumonic plague cough, hemoptysis, highly contagious 3. septicemic plague

CERVICAL BUBOES

INGUINAL BUBOES

SEPTICEMIC PLAGUE

Helicobacter pylori MOT: person-to-person fecal-oral route Causes chronic gastritis May lead to gastric carcinoma

HELICOBACTER PYLORI

Bordetella pertussis MOT: respiratory route Causes: whooping cough or pertussis fever, cough and colds “whoop” Vaccine: DPT vaccine 2, 4 and 6 months of age booaster at 4 years old

Acid fast bacilli Mycobacterium tuberculosis Mycobacterium leprae Mycobacterium avium-intracellulare

Mycobacterium tuberculosis MOT: respiratory droplets Causes: pulmonary tuberculosis miliary tuberculosis cough, hemoptysis Bones, joints, meninges, kidneys, peritoneum, lymph nodes, skin, spine

TB Abnormal chest x-ray PPD test (purified protein derivative test) Long treatment: 6 to 9 months rifampicin isoniazid pyrazinamide ethambutol Vaccine: BCG at birth

TUBERCULIN SKIN TEST/MANTOUX TEST/ PPD TEST

Mycobacterium leprae MOT: contact with nasal secretions or skin exudates of patients Causes: leprosy Affects the Schwann cells in the skin; nerve damage Cooler areas affected: eyelids, nose, ears, scrotum

LEPROSY

Mycobacterium avium-intracellulare MOT: respiratory route Causes: pulmonary diseases disseminated disease Common in AIDS patients