Bacteria, fungi and parasites

Bacillus anthracis

Disease: Anthrax (cutaneous, inhalational, gastrointestinal). Affected Populations: Farmers, veterinarians, people handling animal products. Transmission: Spores from soil, contaminated animal products, bioterrorism. Virulence Factors: Anthrax toxin (protective antigen, lethal factor, edema factor), capsule. Symptoms: Black eschar (cutaneous), respiratory distress (inhalational), severe GI symptoms. Diagnosis: Culture, PCR, serology. Treatment: Ciprofloxacin, doxycycline; Anthrax vaccine available for high-risk groups.

Bordetella pertussis

Disease: Whooping cough. Affected Populations: Infants, unvaccinated individuals. Transmission: Respiratory droplets. Virulence Factors: Pertussis toxin, filamentous hemagglutinin. Symptoms: Severe cough, inspiratory whoop, vomiting. Diagnosis: PCR, culture, serology. Treatment: Azithromycin, supportive care. Vaccination recommended.

Borrelia burgdorferi

Disease: Lyme disease. Affected Populations: People exposed to endemic areas. Transmission: Ixodes tick bite. Virulence Factors: Antigenic variation, immune evasion. Symptoms: Erythema migrans, flu-like symptoms, arthritis. Diagnosis: Serology, PCR. Treatment: Doxycycline, amoxicillin.

Campylobacter jejuni

Disease: Gastroenteritis. Affected Populations: Those consuming undercooked poultry. Transmission: Fecal-oral route, contaminated food. Virulence Factors: Invasive factor, enterotoxin. Symptoms: Bloody diarrhea, abdominal pain, fever. Diagnosis: Stool culture. Treatment: Supportive care, antibiotics in severe cases.

Chlamydia trachomatis

Disease: STI, trachoma. Affected Populations: Sexually active individuals, infants. Transmission: Sexual contact, vertical transmission. Virulence Factors: Intracellular survival, immune evasion. Symptoms: Urethritis, cervicitis, conjunctivitis. Diagnosis: Nucleic acid amplification tests (NAAT). Treatment: Azithromycin, doxycycline.

Clostridium botulinum

Disease: Botulism. Affected Populations: Infants, canned food consumers. Transmission: Ingesting botulinum toxin in contaminated food. Virulence Factors: Botulinum toxin. Symptoms: Flaccid paralysis, respiratory failure. Diagnosis: Clinical diagnosis, detection of toxin. Treatment: Antitoxin, supportive care.

Clostridium difficile

Disease: Pseudomembranous colitis. Affected Populations: Hospitalized patients, antibiotic users. Transmission: Fecal-oral route. Virulence Factors: Toxin A and B. Symptoms: Watery diarrhea, abdominal pain, fever. Diagnosis: Stool assay for toxins. Treatment: Vancomycin, fidaxomicin.

Clostridium perfringens

Disease: Gas gangrene, food poisoning. Affected Populations: Individuals exposed to contaminated soil, improperly stored food. Transmission: Soil and fecal contamination. Virulence Factors: Alpha toxin. Symptoms: Crepitant tissue, fever, diarrhea. Diagnosis: Detection in tissue, culture. Treatment: Surgical debridement, penicillin.

Clostridium tetani

Disease: Tetanus. Affected Populations: Unvaccinated individuals, those with puncture wounds. Transmission: Soil contamination through wounds. Virulence Factors: Tetanospasmin toxin. Symptoms: Muscle spasms, lockjaw. Diagnosis: Clinical diagnosis. Treatment: Tetanus immunoglobulin, supportive care, vaccination.

Corynebacterium diphtheriae

Disease: Diphtheria. Affected Populations: Unvaccinated individuals. Transmission: Respiratory droplets. Virulence Factors: Diphtheria toxin. Symptoms: Sore throat, pseudomembrane formation, systemic effects. Diagnosis: Culture, PCR. Treatment: Antitoxin, antibiotics.

Escherichia coli

Disease: UTIs, gastroenteritis. Affected Populations: General population, especially young children and elderly. Transmission: Fecal-oral route. Virulence Factors: Adhesins, toxins. Symptoms: Dysuria, diarrhea, abdominal cramps. Diagnosis: Urine culture, stool culture. Treatment: Antibiotics, hydration.

Haemophilus influenzae

Disease: Epiglottitis, meningitis. Affected Populations: Unvaccinated children. Transmission: Respiratory droplets. Virulence Factors: Polysaccharide capsule. Symptoms: Fever, stridor, altered mental status. Diagnosis: Culture, PCR. Treatment: Ceftriaxone, supportive care.

Helicobacter pylori

Disease: Gastritis, peptic ulcers. Affected Populations: General population. Transmission: Fecal-oral, oral-oral. Virulence Factors: Urease production, cytotoxin. Symptoms: Abdominal pain, nausea, vomiting. Diagnosis: Endoscopy, urease breath test. Treatment: Triple therapy with antibiotics and proton pump inhibitors.

Listeria monocytogenes

Disease: Listeriosis. Affected Populations: Pregnant women, neonates, the immunocompromised. Transmission: Contaminated food (dairy, deli meats). Virulence Factors: Listeriolysin O. Symptoms: Fever, muscle aches, gastrointestinal symptoms. Diagnosis: Culture from blood or CSF. Treatment: Ampicillin, supportive care.

Mycobacterium tuberculosis

Disease: Tuberculosis. Affected Populations: Immunocompromised individuals, those in close contact with infected persons. Transmission: Respiratory droplets. Virulence Factors: Mycolic acids in the cell wall, immune evasion. Symptoms: Chronic cough, weight loss, hemoptysis. Diagnosis: Chest X-ray, sputum culture. Treatment: Isoniazid, rifampin, ethambutol.

Neisseria gonorrhoeae

Disease: Gonorrhea. Affected Populations: Sexually active individuals. Transmission: Sexual contact. Virulence Factors: Antigenic variation, pili. Symptoms: Purulent discharge, dysuria. Diagnosis: Nucleic acid amplification tests (NAAT). Treatment: Ceftriaxone, azithromycin.

Neisseria meningitidis

Disease: Meningitis. Affected Populations: Close living quarters (college dorms, military). Transmission: Respiratory droplets. Virulence Factors: Polysaccharide capsule, endotoxin. Symptoms: Fever, stiff neck, headache. Diagnosis: Culture, PCR, CSF analysis. Treatment: Ceftriaxone, prophylactic antibiotics for close contacts.

Plasmodium falciparum

Disease: Malaria. Affected Populations: Individuals in endemic areas. Transmission: Anopheles mosquito bite. Virulence Factors: Erythrocyte invasion, antigenic variation. Symptoms: Cyclic fevers, chills, sweats. Diagnosis: Blood smear, rapid diagnostic tests. Treatment: Artemisinin-based combination therapies.

Propionibacterium acnes

Disease: Acne vulgaris. Affected Populations: Adolescents, individuals with oily skin. Transmission: Skin flora. Virulence Factors: Lipases, inflammatory mediators. Symptoms: Comedones, pustules, nodules. Diagnosis: Clinical examination. Treatment: Topical retinoids, benzoyl peroxide.

Pseudomonas aeruginosa

Disease: Pneumonia, wound infections. Affected Populations: Hospitalized patients, immunocompromised individuals. Transmission: Direct contact, environmental reservoirs. Virulence Factors: Biofilm formation, exotoxin A. Symptoms: Green-blue pus, fever, cough. Diagnosis: Culture, sensitivity testing. Treatment: Piperacillin-tazobactam, meropenem.

Staphylococcus aureus

Disease: Skin infections, pneumonia. Affected Populations: General population, especially those with open wounds. Transmission: Direct contact. Virulence Factors: Coagulase, exotoxins. Symptoms: Red, swollen lesions, fever, cough. Diagnosis: Culture, sensitivity testing. Treatment: Methicillin, supportive care.

Staphylococcus epidermidis

Disease: Prosthetic device infections. Affected Populations: Individuals with implanted medical devices. Transmission: Skin flora. Virulence Factors: Biofilm formation. Symptoms: Fever, purulent discharge from site. Diagnosis: Culture from device or surrounding tissue. Treatment: Vancomycin.

Streptococcus agalactiae

Disease: Neonatal infections. Affected Populations: Pregnant women, newborns. Transmission: Vertical during childbirth. Virulence Factors: Polysaccharide capsule. Symptoms: Sepsis, meningitis, pneumonia. Diagnosis: Culture from blood or CSF. Treatment: Penicillin.

Streptococcus mutans

Disease: Dental caries. Affected Populations: General population, especially children. Transmission: Oral flora. Virulence Factors: Biofilm formation, acid production. Symptoms: Tooth pain, cavities. Diagnosis: Clinical examination. Treatment: Restorative dental care.

Viridans streptococci

Disease: Endocarditis. Affected Populations: Individuals with pre-existing heart conditions. Transmission: Oral flora during dental procedures. Virulence Factors: Biofilm formation. Symptoms: Fever, heart murmur, signs of embolism. Diagnosis: Blood culture. Treatment: Penicillin.

Streptococcus pneumoniae

Disease: Pneumonia, meningitis. Affected Populations: Elderly, those with chronic conditions. Transmission: Respiratory droplets. Virulence Factors: Polysaccharide capsule, pneumolysin. Symptoms: Cough, fever, respiratory distress. Diagnosis: Culture from sputum or CSF. Treatment: Ceftriaxone, penicillin.

Streptococcus pyogenes

Disease: Strep throat, necrotizing fasciitis. Affected Populations: General population, especially children. Transmission: Respiratory droplets. Virulence Factors: M protein, streptolysins. Symptoms: Sore throat, fever, severe pain. Diagnosis: Rapid antigen test, culture. Treatment: Penicillin.

Treponema pallidum

Disease: Syphilis. Affected Populations: Sexually active individuals. Transmission: Sexual contact. Virulence Factors: Immune evasion. Symptoms: Painless chancre (primary stage), rash (secondary stage). Diagnosis: Serology. Treatment: Benzathine penicillin.

Trichomonas vaginalis

Disease: Trichomoniasis. Affected Populations: Sexually active individuals. Transmission: Sexual contact. Virulence Factors: Flagella for motility. Symptoms: Foul-smelling discharge, itching. Diagnosis: Wet mount microscopy, NAAT. Treatment: Metronidazole.