Pathogen Cards Set #2 Comparative Study Notes

Escherichia coli (E. coli)

• Common Name: Traveler’s Diarrhea
• Gram Stain and Morphology: Gram Negative ($-$), Rod-shaped.
• Symptoms:
  • May cause diarrhea.
  • Gastroenteritis.
  • May invade the bloodstream.
  • Causes kidney damage through the production of toxins.
• Infective Source:
  • Contaminated water.
  • Undercooked beef.
  • Indicative of fecal contamination.
• Diagnosis: Isolation of the organism.
• Treatment: Chloramphenicol.
• Prevention: Chlorinated water.

Salmonella typhosa

• Common Name: Typhoid Fever
• Gram Stain and Morphology: Gram Negative ($-$), Rod-shaped.
• Symptoms:
  • High fever ($104$).
  • Headache.
  • Diarrhea occurring in week $2-3$.
  • May spread to the kidney, liver, and spleen.
  • Characteristic signs include spleen enlargement and rose spots on the skin.
• Epidemiology: Large number of carriers; mortality rate is $1-2\%$ general, but $40\%$ if untreated.
• Infective Source: Contaminated food or water.
• Diagnosis: Isolation of the organism from blood, urine, or feces.
• Treatment: Chloramphenicol, cephalosporins (cephlasporins).
• Prevention: Sanitary control of sewage; vaccine is partially effective.

Borrelia vincenti and Fusobacterium fusiform

• Common Name: Trench Mouth
• Organism Profiles:
  • Borrelia vincenti: Gram Negative ($-$) spirochete.
  • Fusobacterium fusiform: Gram Negative ($-$) rod.
• Symptoms:
  • Ulcerative gingivitis.
  • Lesions in the mouth.
  • Produces foul breath.
• Infective Source:
  • Contaminated objects.
  • Kissing.
  • Poor oral hygiene.
  • Nutritional deficiencies.
• Diagnosis: Clinical Picture.
• Treatment: Penicillin drugs.
• Prevention: Good hygiene and avoidance of contact.

Vibrio cholerae

• Common Name: Asiatic cholera
• Gram Stain and Morphology: Gram Negative ($-$), Curved Rod.
• Symptoms:
  • Gastrointestinal (GI) tract infection.
  • Severe diarrhea with characteristic ‐rice water schools" (stools).
  • Dehydration: May lose up to $20$ liters of fluid per day.
  • Often associated with shellfish.
  • Mortality: $50\%$ fatal if untreated.
• Infective Source:
  • Improper sanitation.
  • Shellfish.
  • Contaminated water.
• Diagnosis: Isolation of human organism from stool.
• Treatment: Tetracycline administered along with fluid replacement.
• Prevention: Cooked shellfish and chlorinated water.

Brucella species

• Common Name: Brucellosis
• Gram Stain and Morphology: Gram Negative ($-$), Rod-shaped.
• Symptoms:
  • Prevalent in farmers and animal workers.
  • Infection progresses to the lymph nodes.
• Infective Source: Infected cattle.
• Diagnosis: Isolation of the organism or ELISA.
• Treatment: Tetracyclines.
• Prevention: Pasteurization of milk and elimination of infected cattle.

Salmonella typhimurium

• Common Name: Salmonellosis
• Gram Stain and Morphology: Gram Negative ($-$), Rod-shaped.
• Symptoms:
  • Onset usually starts about $12-36$ hours after exposure.
  • Inflammation of the GI tract.
  • Fever, nausea, diarrhea, abdominal pain, and vomiting.
• Infective Source: Milk, raw eggs, and meat (specifically chickens).
• Diagnosis: Isolation from stool or ELISA.
• Treatment: Ampicillin (noted as somewhat useful).
• Prevention: Sanitary protocol.

Polivirus (picornavirus)

• Symptoms: Headache, sore throat, fever, and nausea; the virus will damage the motor nerve.
• Infective Source: Intestinal tract of an infected person; fecal-oral contamination.
• Diagnosis: Isolation of the virus from the throat or feces.
• Treatment: Symptomatic.
• Prevention: Vaccine.

Balantidium coli

• Classification: Protist
• Symptoms: Typically a mild disease with abdominal pain; however, it may cause a fatal dysentery.
• Infective Source: Contaminated food or water.
• Diagnosis: Isolation of the organism from fecal matter.
• Treatment: Tetracyclines and Metronidazole.
• Prevention: Avoid contaminated food and water.

Actinomycess israelii / Actinomyces bovis

• Gram Stain and Morphology: Gram Positive ($+‐$), Rod-shaped.
• Symptoms:
  • Gingivitis or a disease called "lumpy jaw."
  • Lesions in the mouth that fill with pus.
  • Can destroy the tissue of the head, neck, and lungs.
• Infective Source: Cattle or Normal Flora.
• Diagnosis: Isolation of organism and clinical picture.
• Treatment: Sulfonamides, tetracycline.
• Prevention: None.

Hepatitis virus A

• Symptoms:
  • Infects the liver, kidney, and spleen.
  • Virus can survive on cutting boards for days.
  • Loss of appetite, malaise, nausea, diarrhea, abdominal pain, fever, and chills.
  • Jaundice and liver enlargement/tenderness.
  • Recovery takes approximately $8-12$ weeks.
• Infective Source: Contaminated food/water or carriers.
• Diagnosis: ELISA.
• Treatment: Symptomatic.
• Prevention: Good sanitation and Intravenous (IV) antibody.

Hepatitis Virus B

• Symptoms:
  • Often an asymptomatic infection.
  • Headache, loss of appetite, low-grade fever, joint pain, weakness, nausea, and jaundice.
  • Tender, enlarged liver.
• Infective Source: Blood, body fluid, saliva, breastmilk, and semen; common in same-sex partners.
• Diagnosis: Clinical symptoms.
• Treatment: None.
• Prevention: Vaccine, safe sex, and sterilization of needles.

Hepatitis C

• Symptoms: Mild symptoms such as loss of appetite, weakness, and liver damage; symptoms are slow and progressive.
• Infective Source: Blood transfusions, IV drug use, heterosexual sex, and kidney dialysis.
• Diagnosis: Clinical symptoms.
• Treatment: None.
• Prevention: None.

Giardia lamblia

• Classification: Protist
• Symptoms:
  • Prolonged diarrhea that may last for weeks.
  • Malaise, nausea, abdominal pain, weakness, and weight loss.
  • Approximately $7\%$ of the population are healthy carriers.
• Infective Source: Waterborne disease or unwashed vegetables.
• Diagnosis: String test or FA (Fluorescent) antibody.
• Treatment: Metronidazole.
• Prevention: Good hygiene.

Clostridium botulinum

• Gram Stain and Morphology: Gram Positive ($+‐$), Rod-shaped.
• Symptoms:
  • Nausea; notably no fever.
  • Double vision and difficulty swallowing.
  • Weakness transitioning to gradual paralysis for one to $10$ days.
  • Death results from respiratory and cardiac failure.
  • Mortality rate: $70\%$ for untreated cases.
• Infective Source: Improperly canned foods; also found in honey.
• Warning: Never give a child under the age of one honey.
• Diagnosis: Clinical picture and inoculation with mice.
• Treatment: Antitoxin is available but not very effective.
• Prevention: Proper canning and cooking of food.

Herpes Simplex Type I

• Classification: Virus
• Symptoms:
  • Lesions develop in response to stress, anxiety, diet, hormonal changes, or solar exposure.
  • Infection Rate: $90\%$ of the population has this virus, though only $15\%$ develop symptoms.
  • Incubation: $4-10$ days.
  • May infect the eye, oral cavity, or Central Nervous System (CNS).
• Infective Source: Transmitted by oral or respiratory routes.
• Diagnosis: Clinical picture.
• Treatment: Acyclovir (Zovirax/Zoovirax).
• Prevention: None.

Infectious Mononucleosis

• Virus: Epstein-Barr Virus
• Symptoms: Tiredness, swollen lymph nodes, low fever, difficulty performing routine tasks, and headaches.
• Infective Source: Close oral contact.
• Diagnosis: Symptomatic.
• Treatment: None.
• Prevention: None.

Rotavirus

• Classification: Virus
• Symptoms:
  • Most common cause of viral gastroenteritis.
  • More pronounced disease in children.
  • Fever, diarrhea, and vomiting lasting $5-8$ days.
• Transmission: Fecal-oral route.
• Diagnosis: ELISA.
• Treatment: Symptomatic.
• Prevention: Vaccine, good hygiene, and aseptic techniques.

Leptospira species

• Common Name: Leptospirosis / Fort Bragg Fever
• Gram Stain and Morphology: Gram Positive ($+‐$), Spirochete.
• Symptoms:
  • Incubation period of $1$ to $2$ weeks.
  • Headache, muscle pain, chills, and fever.
  • Infection may involve the liver and kidneys.
• Infective Source: Urine-polluted water.
• Diagnosis: Isolation of the organism from blood or spinal fluid.
• Treatment: Penicillin or chloramphenicol.
• Prevention: Avoid urine-polluted water.

Listeria monocytogenes

• Common Name: Listerosis (Listeriosis)
• Gram Stain and Morphology: Gram Positive ($+‐$), Rod-shaped.
• Symptoms:
  • In healthy adults, it is a mild, symptomless disease.
  • Caution: Highly dangerous for pregnant women, immune-suppressed individuals, and cancer patients.
  • Infant mortality rate: $60\%$
• Infective Source: Excreted from animal feces; outbreaks associated with food.
• Diagnosis: Isolating and culturing the organism.
• Treatment: Antibiotics.
• Prevention: Properly cooked food.

Ascaris

• Classification: Helminth (Ascariasis/Intestinal Roundworm)
• Symptoms:
  • Pneumonia-like symptoms in the lungs.
  • Intestinal irritation.
  • Worms may grow up to $1$ foot in length.
• Infective Source: Contaminated food or water.
• Diagnosis: Worm emerges from the anus.
• Treatment: Mebendazole (mebeddazole).
• Prevention: Aseptic technique.

Cryptosporidium species

• Classification: Protist
• Symptoms: Diarrhea (often in immune-suppressed individuals), respiratory infections, and gall bladder infections.
• Infective Source: Water systems, usually water in contact with cattle.
• Diagnosis: Fluorescent antibody test.
• Treatment: Drink plenty of fluids.
• Prevention: Aseptic technique.

Helicobacter pylori

• Gram Stain and Morphology: Gram Negative ($-$), Curved morphology.
• Symptoms:
  • Usually asymptomatic.
  • Major cause of peptic ulcer disease and gastritis.
  • Presents as gnawing or burning epigastric pain.
  • Less common symptoms: nausea, vomiting, loss of appetite, or bleeding.
• Infective Source: Fecal-oral route.
• Diagnosis: Fecal antigen assay, urea breath test, rapid urease test, or histology of a biopsy specimen.
• Treatment: Amoxicillin, metronidazole.
• Prevention: None.

Enterobius vermicularis

• Classification: Helminth (Pinworm)
• Symptoms: Mild symptoms often go undiagnosed; abdominal discomfort.
• Infective Source: Contaminated individuals spread worm eggs via fingers and hands.
• Diagnosis: Eggs found in a fecal sample.
• Treatment: Pyrantel pamoate, mebendazole.
• Prevention: Aseptic techniques.

Shigella species

• Common Name: Bacillary dysentery / Shigellosis
• Gram Stain and Morphology: Gram Negative ($-$), Rod-shaped.
• Symptoms: Abdominal cramps, diarrhea, and blood in mucus in the stool; may cause ulcers in the intestine.
• Infective Source: Contaminated food and water.
• Diagnosis: Isolation of organism from stool.
• Treatment: Fluoroquinolones (Flourquinolones).
• Prevention: Sanitary food and water.

Entamoeba histolytica

• Classification: Protist (Amoebic dysentery / Amoebiasis)
• Symptoms:
  • Mild or severe diarrhea with blood and mucus in stool.
  • Severe cases cause intestinal ulcers.
  • May result in up to $30$ bowel movements per day.
  • $5\%$ of patients are asymptomatic carriers.
• Infective Source: Contaminated food and water.
• Diagnosis: Isolation of organism from fecal sample.
• Treatment: Metronidazole.
• Prevention: Clean food and water.

Streptococcus mutans

• Gram Stain: Gram Positive ($+‐$)
• Symptoms: Plaque accumulations leading to tooth decay.
• Infective Source: Diet and hygiene.
• Diagnosis: Symptoms and clinical picture.
• Treatment: Good oral hygiene.
• Prevention: Fluoride toothpaste and avoidance of sweets.

Trichinella spiralis

• Classification: Helminth (Trichina worm/Trichinosis)
• Symptoms: Fever, swelling around the eyes, upset GI, small hemorrhages under the fingernails, and possibly some muscle pain.
• Infective Source: Improperly cooked pork.
• Diagnosis: ELISA.
• Treatment: Thiabendazole and corticosteroids.
• Prevention: Avoid raw pork.

Taenia saginata

• Classification: Helminth (Beef Tapeworm)
• Symptoms: Produces very few symptoms; possibly some abdominal pain. The worm may grow to a length greater than $18$ feet.
• Infective Source: Improperly cooked beef.
• Diagnosis: Eggs or proglottids in feces.
• Treatment: Niclosamide.
• Prevention: Properly cooked beef.

Campylobacter jejuni

• Common Name: Gastroenteritis / Campylobacteriosis
• Gram Stain: Gram Negative ($-$)
• Symptoms:
  • One of the leading causes of GI tract problems in humans.
  • Fever, cramping, abdominal pain, and diarrhea with blood and mucus in stools.
• Infective Source: Improperly cooked or sanitized food handling; common in children and daycares.
• Diagnosis: Symptoms and isolation of the organism.
• Treatment: Erythromycin.
• Prevention: Aseptic techniques and good hygiene.

Norwalk Virus

• Classification: Virus (Calcivirus / Calicivirus)
• Symptoms: Nausea, vomiting, diarrhea, and cramps; recovery typically in $2-3$ days.
• Infective Source: Fecal-oral route.
• Diagnosis: Symptoms and duration.
• Treatment: Plenty of fluids.
• Prevention: Wash hands, cook shellfish, and wash raw vegetables.

Clostridium difficile (C. dif)

• Gram Stain and Morphology: Gram Positive ($+‐$), Rod-shaped.
• Symptoms: Diarrhea due to antitoxins, abdominal cramps, fever, and leukocytosis; carry danger of perforation of the cecum and death.
• Infective Source: Endogenous; Normal flora.
• Diagnosis: Stool culture, PCR, or ELISA for toxins.
• Treatment: Withdrawal of antibiotics; in severe cases, metronidazole or vancomycin.
• Prevention: None.

Cyclospora cayetanensis

• Classification: Protist
• Symptoms: Watery diarrhea, stomach cramps, bloating, fever, and muscle aches.
• Infective Source: Fecal-oral route (fruits and vegetables).
• Diagnosis: Stool PCR.
• Treatment: TMP-SFX.
• Prevention: Washing and cooking fruits and vegetables; good hygiene.

Strongyloides stercoralis

• Classification: Helminth (Roundworm)
• Symptoms:
  • Itchy red rash at the site of entry.
  • Pneumonitis and eosinophila (eosinophilia).
  • Bloody diarrhea and malabsorption.
  • Liver enlargement.
  • Death may result in immunosuppressed patients.
• Infective Source: Soil contact.
• Diagnosis: Blood count, serology, egg or worm detection.
• Treatment: Thiabendazole.
• Prevention: Sanitation.

Diphyllobotruim latum

• Classification: Helminth (Fish Tapeworm)
• Symptoms: Anemia, abdominal discomfort, and nausea.
• Infective Source: Seafood, specifically raw fish (sushi).
• Diagnosis: Blood count, serology, egg, or worm detection.
• Treatment: Praziquantel or Niclosamide.
• Prevention: Cook fish.

Schistosoma mansoni

• Classification: Helminth (Liver Fluke)
• Symptoms:
  • Itching at the area of penetration.
  • Fever, chills, diarrhea, and cough.
  • Hepatomegaly and splenomegaly (spleenomegaly).
  • Bladder obstruction.
• Infective Source: Contact with infected water.
• Diagnosis: Eggs in urine or feces.
• Treatment: Praziquantel.
• Prevention: Sanitation.