Miscellaneous diseases - Microbiology

Neisseria meningitidis

Gram negative diplococci, serotypes A, B, and C are the most common cause of infection

Meningitis

Inflammation of meninges: Causes headache, painful/stiff neck, nausea, vomiting, and photophobia

Petechiae

Small purple dots that appear on the skin during a meningitis infection

Nasopharynx

The reservoir that holds the bacterium that causes meningitis

15%

Meningitis mortality rate, even with treatment

Streptococcus pneumonia

Most frequent cause of community acquired meningitis

Neonatal meningitis

A type of meningitis that is transmitted by the mother, often in utero and the birth canal

E. coli

Second most common cause of neonatal meningitis, 20% mortality

Poliomyelitis (infantile paralysis)

An acute enteroviral infection of the spinal cord, can cause paralysis

Bulbar poliomyelitis

A type of poliomyelitis that infects the brain stem, medulla, and cranial nerves, and causes permanent paralysis with loss of respiratory function

Acute Otitis Media (Ear infection)

Commonly caused by Streptococcus pneumonia

Diptheria

Caused by Corynebacterium diptheriae, has a high mortality rate within children, has a greenish pseudomembrane on the tonsils or pharynx

Influenza

Causes headaches, chills, dry cough, body aches, fever, stuffy nose, sore throat, and very tired / 1-4 day incubation period

H1N1 Swine flu

Same symptoms as the flu, but didn’t have fever and had some GI distress

Cytokine storm

Severe inflammation and irritation caused by an overabundance of cytokiens.

Whooping Cough Pertussis

Caused by Bordetella pertussis.

Catarrhal phase

Whooping cough phase where it incubates for 3-21 days

Paroxysmal phase

Whooping cough phase that has a bad coughing spell (whoops)

Convalescent phase

Whooping cough phase where the bacteria numbers decrease

Community acquired pneumonia

Streptococcus pneumoniae, also called pneumococcus

Walking pneumonia

A type of pneumonia caused by Mycoplasma pneumonia and Chlamydophila pneumoniae, called atypical pneumonia

Legionnaires disease

Caused by Legionella pneumophila

Symptoms of Legionnaires disease

High fever, coughing, diarrhea, and confusion

Diarrheal diseases - Infection

When a pathogen enters and multiplies, penetrates intestinal mucosa, and move to organs

Diarrheal diseases - Intoxication

Ingestion of a toxin, such as a Staphylococcus toxin that can develop in a few hours

Gastroenteritis

Inflammation of stomach and intestinal mucosa

Five Fs

Food, fingers, feces, fomites, and flies

Salmonella

Causes salmonellosis or typhoid fever

Typhoid Fever

Caused by the typhi variant of salmonella

Gastroenteritis Pathogens

Caused by paratyphi, hirschfeldii, and typhimurium

Salmonellosis symptoms

Vomiting, diarrhea, mucosal irritation, and bloody stool

Salmonellosis Treatment

Fluid and electrolyte replacement, or trimethoprim-sulfamethoxazole

Shigella Symptoms

Water stools, fever, intense abdominal pain, nausea and vomiting, bloody stool, mucus, and Dysentery

Dysentery

Diarrhea containing blood

Shigella Pathogenesis

Invades the villus cells of the large intestine, does not invade the blood, enters intestinal mucosa via Peyer’s patches.

Enterotoxin

Toxin that affects the GI tract and damages the mucosa and villi

Shiga toxin

Produced by Shigella dysenteriae

Shigella Transmission

Oral route, direct person-to-person, small infectious dose, spreads epidemically in day cares, prisons, mental institutions, nursing homes, and military camps

E. Coli

Most virulent enterohemorrhagic E. coli, or EHEC

E. coli symptoms

Mild gastroenteritis, fever, bloody diarrhea, hemolytic uremic syndrome (HUS), severe hemolytic anemia, causes kidney damage and failure, blindness, seizure, and stroke

E. coli Transmission

Ingestion of contaminated or undercooked beef, and fecal-oral route

Campylobacter

Most common bacterial cause of diarrhea in the US, 2 million cases per year; caused by Campylobacter jejuni

Campylobacter Symptoms

Watery stools, fever, vomiting, headaches, severe abdominal pain, may last longer than 2 weeks

Campylobacter Pathogenesis

Transmission via ingestion of contaminated water, milk, meat, and chicken

Gullain-Barre Syndrome (GBS)

Leading cause of acute paralysis, seemingly caused by an autoimmune reaction

Food Poisoning

Suspected when a patient presents severe nausea and frequent vomiting accompanied by diarrhea

Staphylococcus aureus exotoxin

Associated with eating foods that has been contaminated by handling and left unrefrigerated for a few hours. Heating does not prevent disease, recovery begins within 24 hours

Bacillus cereus exotoxin

Naturally present in soil, commonly on vegetables. Causes a diarrheal-like disease 8-16 hours after ingestion.

Bacillus cereus exotoxin - emetic

Vomiting disease (associated with fried rice), occurs after 2-5 hours after ingestion

Clostridium perfringens Exotoxin

Caused by food without good enough reheating, has live C. perfringens cells

Chronic Diarrhea

Diarrhea that lasts longer than 14 days

STD

Sexually transmitted disease

STI

Sexually transmitted infections

Gonorrhea

One of the most reportable diseases in the U.S., 350,000 cases reported per year in the U.S.

Gonorrhea symptoms

In males, single exposure results in infection 30% of the time, while in females its 90% of the time. Painful urination and yellow pus in males, while only bloody vaginal discharge in females

PRNG

Penicilllin Resistant Neisseria gonorrhoeae

Salpingitis

Inflammation of fallopian tube which can lead to scaring and infertility

Chlamydia

Most common reportable infectious disease in the U.S. with over 1 million cases, 75% are asymptomatic

Chlamydia symptoms

In males, symptoms are similar to gonorrhea, while in females, they have discharge, painful periods, and bleeding between periods.

Syphilis

Caused by Treponema pallidum, transmitted by sexual contact, treated with penicillin

Syphilis - Primary

Appearance of painless chancre sore which has an exudate of serum which is highly contagious

Syphilis - Secondary

Several weeks after primary, characterized by rash, malaise, mild fever, and patchy hair loss

Syphilis - Tertiary

Occurs after 2-4 years of latency, Gumma’s appear in organ and skin

Neurosyphilis

Personality changes, dementia, and seizures