Bacterial Infections Quiz

Infectious Disease: Bacterial Infections

• Bacterial infections are a significant health concern, with a wide range of causative agents causing varying degrees of illness.
• Different bacterial infections have varying presentations, symptoms, and treatment approaches.

Bacterial Infections: Specific Agents

• Actinomycosis: Gram-positive, anaerobic bacteria. Characterized by abscesses, draining sinuses, and fibrosis, often in the cervicofacial area. Associated with pain with chewing and weight loss.
• Bacillus anthracis: Gram-positive rod. Causes anthrax, with different presentations depending on the route of infection (cutaneous, inhalational, gastrointestinal). The least dangerous form is cutaneous anthrax; inhalation anthrax is the most deadly.
• Bartonella henselae: Causes cat scratch fever, typically through contact with fleas on animals. Characterized by memory loss, fever, fatigue, and headache. Diagnosis is clinical, or through tissue/blood cultures.
• Botulism: Caused by Clostridium botulinum, a gram-positive, anaerobic bacillus. Three routes of infection (food-borne, infantile, and wound botulism). Symptoms vary, but can include descending paralysis and difficulty swallowing.
• Bordetella pertussis: Gram-negative bacteria, causes pertussis or "whooping cough." Characterized by stages including catarrhal, paroxysmal, and convalescent.
• Campylobacter jejuni infection: Gram-negative bacteria. Presents with fever, headache, malaise, myalgias, cramping and watery stools (usually >10). Diagnosis is usually via stool culture (and sometimes serologic tests) to test for the presence of C. jejuni.
• Chlamydia: Chlamydia trachomatis is the causative agent for Chlamydia. An STI with possible complications including urethritis, proctitis, epididymitis, endocervicitis and perihepatitis. Diagnosis via nucleic acid test (PCR) is preferred.
• Cholera: Caused by Vibrio cholerae. A severe diarrheal illness with potentially life-threatening dehydration (and watery "rice water stools"). Diagnosis usually via stool culture and clinical diagnosis.
• Clostridium difficile infection: Caused by Clostridioides difficile. A severe infection caused by antibiotic use as it disrupts gut flora. Characterized by diarrhea often with abdominal pain, and nausea (especially in older adults). Diagnosis is usually via stool PCR or antigen tests.
• Clostridium perfringens: Gram-positive, anaerobic bacteria that cause food poisoning (characterized by symptoms that typically subside within 24 hours).
• Coagulase negative staphylococci (CoNS): Gram-positive bacteria. Part of normal skin flora but can cause serious bloodstream and wound infections.
• Corynebacterium diphtheriae: Gram-positive bacteria, causes diphtheria. Commonly presents with a sore throat, fever, and cervical lymphadenopathy, and potentially a gray pseudomembrane on the throat. Diagnosed through clinical exam and throat cultures. Treatment includes hospitalization.
• Escherichia coli: Gram-negative bacteria found as part of normal human flora, causes diarrhea. It varies by subtype; some types are pathogenic.
• Group A streptococci (GAS): Causes strep throat and can lead to serious complications if untreated. Characterized by sore throat, fever, and neck pain. Diagnosis with throat culture, or rapid antigen test.
• Haemophilus influenzae: Causes various infections, including epiglottitis and meningitis. Characterized by sore throat, progressing to difficulty breathing, drooling, and difficulty swallowing. Diagnosis through cultures and direct visualization of the epiglottis (if possible).
• Legionella species: Gram-negative bacteria, causes legionellosis. Typical symptoms include cough, fever, headache, diarrhea and neurologic dysfunction. Diagnosis with urine antigen tests, stool cultures, and/or CXR. Treatment with macrolides or fluoroquinolones.
• Listeria: Listeria Monocytogenes is a gram-positive intracellular bacterium that can cause severe illness in immunocompromised individuals, or pregnant women, or neonates with risk of being carried from mother to fetus, characterized by fever, headache, nausea, vomiting, diarrhea, and possibly neurological symptoms. Diagnosis through cultures. Treatment with supportive care and fluids, antimicrobial therapy; likely needing hospitalizations.
• Moraxella catarrhalis: Gram-negative bacteria, causes ear infections, and upper respiratory tract infections. Symptoms may include nasal discharge, ear pain, cough, and potential complications such as mastoiditis, and meningitis.
• Neisseria meningitidis: Gram-negative bacteria. Causes meningitis, but symptoms may include fever, stiffness in neck and back, rash, and neurological dysfunction.
• Neisseria gonorrhoeae: Gram-negative diplococcus; STI, causing gonorrhea, with symptoms including dysuria and purulent discharge.
• Rheumatic fever: A complication of untreated streptococcal infection. Characterized by fever, arthritis, and other symptoms.
• Rocky Mountain spotted fever: Caused by Rickettsia rickettsii. A zoonotic infection spread through tick bites, characterized by a rash, and fever. Diagnosis is clinical, initially, and possibly additional lab testing.
• Salmonella: Gram-negative bacteria; causes gastrointestinal illness. Presents with fever, cramping, nausea, bloody diarrhea, vomiting (potential dehydration)
• Shigella: Gram-negative bacteria; causes dysentery (bloody diarrhea, cramps, nausea, fever). Caused by ingesting contaminated food or water.
• Staphylococcus aureus: Gram-positive bacteria; can cause various infections (skin, bone, respiratory tract tissue) and may lead to bacteremia, or septic shock. Can present with various symptoms including abscess, cellulitis, and localized pain.
• Streptococcus pneumoniae: Gram-positive bacteria causes pneumonia (most common), otitis, and meningitis, causing possible fever, cough, pleuritic pain, tachypnea. Diagnosis through cultures, or urinary antigen tests.
• Tetanus: Caused by Clostridium tetani. Characterized by muscle spasms, trismus, and potentially respiratory failure ("lockjaw").
• Tularemia: Caused by Francisella tularensis. A zoonotic infection that presents with fever, headache, regional lymphadenopathy, which may progress to other symptoms. Diagnosis with culture or PCR of fluid.
• Vibrio species: Group of gram-negative bacteria. Some species like Vibrio cholerae cause acute diarrheal illness.
• Yersinia pestis: Gram-negative bacteria, causes plague (bubonic, septicemic, pneumonic). Characterized by fever, chills, lymphadenopathy, which may involve other symptoms. Diagnosis via lymph node biopsy, or blood cultures.

Test your knowledge on Actinomyces and C. diff infections. This quiz covers the pathogenic behavior, symptoms, and treatment options associated with these bacteria. Additionally, learn more about Anthrax and its related complications.