Medical Microbiology: Infectious Diseases Flashcards (Vocabulary Style)

A comprehensive set of vocabulary-style flashcards covering UTIs, STIs, gastrointestinal infections, hepatology, respiratory infections, CNS infections, vector-borne diseases, vaccines, and common pathogenic organisms.

Urinary Tract Infection (UTI)

Infection of the urinary tract most often caused by E. coli; symptoms include dysuria, urinary frequency, urgency, and suprapubic pain; may progress to pyelonephritis; treated with nitrofurantoin, TMP-SMX, or fosfomycin; prevention includes hydration and urinating after intercourse.

Escherichia coli (E. coli)

Most common causative organism of UTIs.

Staphylococcus saprophyticus

Common cause of UTIs in young women.

Klebsiella

Gram-negative bacterium that can cause UTIs.

Proteus

Bacterial genus associated with UTIs; may contribute to urinary stone formation.

Dysuria

Painful or burning sensation during urination.

Frequency

Increased urge to urinate.

Urgency

Sudden, strong need to urinate.

Pyelonephritis

Upper UTI with fever, flank pain, and nausea/vomiting.

Transmission & Epidemiology (UTIs)

UTIs are not sexually transmitted, but sexual activity increases risk; women are more affected due to shorter urethra.

Prevention & Treatment (UTIs)

Hydration, urinating after intercourse, proper hygiene; antibiotics as listed (nitrofurantoin, TMP-SMX, fosfomycin).

Nitrofurantoin

Antibiotic commonly used for uncomplicated UTIs.

Trimethoprim-sulfamethoxazole (TMP-SMX)

Antibiotic used for UTIs (often first-line in non-pregnant patients).

Fosfomycin

One-dose antibiotic option for UTIs.

Gonorrhea

Sexually transmitted infection caused by Neisseria gonorrhoeae; can affect urethra, cervix, pharynx, and conjunctiva; may disseminate.

Neisseria gonorrhoeae

Gram-negative diplococcus; etiologic agent of gonorrhea.

Urethritis (men)

Gonorrhea in men commonly presents as urethritis with dysuria and discharge.

Cervicitis, PID (women)

Gonorrhea in women can cause cervicitis and pelvic inflammatory disease.

Disseminated gonococcal infection (arthritis-dermatitis syndrome)

Dissemination of N. gonorrhoeae causing arthritis and dermatitis.

Vertical Transmission → Neonatal conjunctivitis

Gonorrhea transmitted from mother to newborn can cause neonatal conjunctivitis.

Condoms, safe sex practices

Prevention measure to reduce gonorrhea transmission.

Chlamydia trachomatis

Obligate intracellular bacterium; often asymptomatic; causes cervicitis, urethritis, PID; can cause conjunctivitis or pneumonia in neonates; most common bacterial STI in the U.S.

Urethritis (men) – Chlamydia

Chlamydia in men can cause urethritis.

Cervicitis, PID – Chlamydia

Chlamydia in women can cause cervicitis and pelvic inflammatory disease.

Vertical transmission (birth) – Chlamydia

Chlamydia can be transmitted to newborns during delivery.

No vaccine for gonorrhea or chlamydia

No available vaccine for these STIs.

Ceftriaxone + doxycycline (if chlamydia not excluded)

Common treatment approach when gonorrhea is suspected and chlamydia co-infection has not been ruled out.

Trichomonas vaginalis

Protozoan parasite causing trichomoniasis; women: frothy greenish-yellow discharge, foul odor, vaginal itching; “strawberry cervix”; men often asymptomatic.

Metronidazole or tinidazole

Antiprotozoal treatment for trichomoniasis; partners must be treated.

Syphilis

Infection with Treponema pallidum; stages include primary chancre, secondary rash on palms/soles, latent, tertiary gummas/neurosyphilis; congenital syphilis possible.

Treponema pallidum

Spirochete bacterium causing syphilis.

Primary chancre

Painless ulcer at the infection site in early syphilis.

Secondary syphilis rash (palms/soles)

Rash characteristic of secondary syphilis.

Congenital syphilis

Syphilis transmitted from mother to fetus; can cause stillbirth, bone deformities, neurologic deficits.

Penicillin

Antibiotic treatment of choice for all stages of syphilis.

Hepatitis A

RNA virus (picornavirus); fecal–oral transmission; typically self-limited; vaccine available; prevention via good hygiene.

Hepatitis B

DNA virus (hepadnavirus); blood/sexual transmission; risk of chronic infection; vaccine available; antivirals for chronic disease.

Hepatitis C

RNA virus (flavivirus); bloodborne transmission; no vaccine; treated with direct-acting antivirals (DAAs) with high cure rates.

Hepatitis D

Defective RNA virus requiring HBV to replicate; more severe disease with HBV coinfection; limited treatment (interferon).

Hepatitis E

RNA virus (hepevirus); fecal–oral transmission; usually self-limiting; more dangerous in pregnancy; sanitation-focused prevention.

HBV vaccine prevents HDV

HBV vaccination provides protection against HDV coinfection.

Gastritis – Helicobacter pylori

H. pylori is the most common cause of gastritis; spread via oral–oral or fecal–oral routes; eradication therapy includes PPI + clarithromycin + amoxicillin or metronidazole.

Helicobacter pylori

Spiral gram-negative bacterium; causes gastritis and peptic ulcers.

Gastritis signs & symptoms

Epigastric discomfort, nausea, bloating; may be caused by H. pylori or NSAID use.

Gastric ulcers vs duodenal ulcers

Gastric ulcers: pain worsens with eating; duodenal ulcers: pain relieved by eating; may cause GI bleeding.

NSAID-induced ulcers

Ulcer risk due to chronic NSAID use; can co-occur with H. pylori infection.

Peptic Ulcer Disease (PUD) therapy

Eradication of H. pylori and/or PPI therapy; reduce NSAID use when possible.

Hepatitis & liver cancer risk (HCV/HBV)

HCV is the leading worldwide risk for hepatocellular carcinoma; HBV is a leading global cause of liver cancer; vaccination and antiviral therapies modify risk.

Pharyngitis (viral etiology)

Most pharyngitis is viral; common viruses include adenovirus, rhinovirus, influenza, EBV.

Streptococcus pyogenes (Group A strep) – pharyngitis

Bacterial cause of sore throat; treat with penicillin or amoxicillin.

Acute Otitis Media (AOM)

Infection of the middle ear; signs include ear pain, fever, and bulging/red tympanic membrane; common pathogens: S. pneumoniae, H. influenzae, Moraxella catarrhalis.

Otitis media pathogens

Typical bacteria causing AOM: Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis.

Community-Acquired Pneumonia (CAP)

Pneumonia acquired outside healthcare settings; pathogens include S. pneumoniae, Mycoplasma pneumoniae, H. influenzae, Legionella; viruses like influenza/RSV.

CAP pathogens

Bacterial: S. pneumoniae, M. pneumoniae, H. influenzae, Legionella; Viral: influenza, RSV, SARS-CoV-2.

Pneumococcal and influenza vaccines

Vaccines reduce CAP risk.

Outpatient CAP treatment

Macrolides (e.g., azithromycin) or doxycycline; alternatively amoxicillin or doxycycline depending on guidelines.

Hospital-Acquired Pneumonia (HAP)

Pneumonia >48 hours after admission; often in hospitalized or immunocompromised patients; pathogens include Pseudomonas, Klebsiella, E. coli, S. aureus (MRSA).

Ventilator-Associated Pneumonia (VAP)

Pneumonia occurring in patients on mechanical ventilation.

MRSA

Methicillin-resistant Staphylococcus aureus; causes skin infections and other invasive infections; treated with agents like vancomycin or linezolid; infection control essential.

RSV (Respiratory Syncytial Virus)

Virus causing winter outbreaks; severe disease in infants (bronchiolitis) and elderly; prevention via hygiene and monoclonal antibodies/vaccines being developed.

Nirsevimab

Monoclonal antibody for RSV prevention in high-risk infants.

Palivizumab

Monoclonal antibody for RSV prevention in high-risk infants.

Tuberculosis (TB)

Mycobacterium tuberculosis; chronic cough, night sweats, weight loss; airborne transmission; RIPE therapy; BCG vaccine; MDR-TB requires second-line drugs.

RIPE therapy

First-line TB treatment: rifampin, isoniazid, pyrazinamide, ethambutol.

BCG vaccine

Live attenuated vaccine used in TB prevention in certain settings; variable effectiveness.

MDR-TB

Multidrug-resistant TB requiring second-line drugs.

Malaria

Plasmodium spp. (P. falciparum, vivax, ovale, malariae); cyclical fever; transmitted by Anopheles mosquitoes; prevent with nets, repellents, prophylaxis; treated with ACT; chloroquine in sensitive strains.

Plasmodium species

Protozoan parasites causing malaria.

ACT (artemisinin-based combination therapy)

First-line treatment for uncomplicated malaria in many regions.

Atovaquone-proguanil, doxycycline, mefloquine

Common malaria chemoprophylaxis options.

Lyme disease

Infection with Borrelia burgdorferi from Ixodes ticks; early localized phase with erythema migrans; early disseminated neurologic or cardiac symptoms; late persistent arthritis.

Borrelia burgdorferi

Spirochete bacterium causing Lyme disease.

Erythema migrans

Bull’s-eye rash at site of tick bite in early Lyme disease.

Meningitis (bacterial vs viral)

Inflammation of meninges; bacterial etiologies include N. meningitidis, S. pneumoniae, H. influenzae, Listeria; viral etiologies include enteroviruses and HSV; bacterial meningitis requires urgent IV antibiotics.

Neisseria meningitidis

Gram-negative diplococcus; a common cause of bacterial meningitis.

Listeria monocytogenes

Gram-positive rod; neonatal meningitis common; risk from contaminated foods; pregnant women at risk.

Neonatal meningitis (E. coli K1 and Group B Strep)

Common causes of meningitis in newborns.

Subacute encephalitis (Toxoplasma gondii, SSPE)

T. gondii: encephalitis in immunocompromised; SSPE: rare measles complication occurring years after infection.

Prions (CJD)

Infectious protein causing spongiform encephalopathies; progressive dementia and neurological decline; no cure; prevention via safety practices.

Rabies

Rabies virus; fatal once symptoms appear; PEP includes wound cleaning, rabies immunoglobulin, and vaccine series.

Tetanus

Clostridium tetani toxin (tetanospasmin) causing muscle stiffness and spasms; wound entry; prevent with DTaP/Tdap vaccination and TIG.

Botulism

Clostridium botulinum toxin causing flaccid paralysis; foodborne, infant, and wound forms; prevention includes proper canning and avoiding honey in infants.

Foodborne botulism

Toxin-mediated botulism from improperly canned foods.

Infant botulism

Spores germinate in an infant’s gut (e.g., honey); causing weakness and floppiness.

Wound botulism

Botulinum toxin produced in contaminated wounds.

Measles (Rubeola)

Measles virus infection; fever, cough, coryza, Koplik spots, and a characteristic rash; highly contagious; prevent with MMR vaccination.

Varicella-Zoster Virus (VZV)

Virus causing chickenpox (primary) and shingles (reactivation); vaccination with Varicella and Shingrix; antivirals like acyclovir used for treatment.

Chickenpox (Varicella)

VZV infection with itchy vesicular rash; highly contagious in children.

Shingles (Herpes Zoster)

Reactive VZV causing dermatomal vesicular rash and neuropathic pain.

Impetigo

Bacterial skin infection (S. aureus or S. pyogenes) with honey-colored crusts; highly contagious; treated with topical or oral antibiotics.

Ringworm (Tinea)

Fungal skin infection caused by Trichophyton, Microsporum, or Epidermophyton; circular scaly rash; treated with topical or oral antifungals.

Conjunctivitis (Pink Eye)

Inflammation of the conjunctiva caused by viral, bacterial, or allergic etiologies; contagious forms common; treated based on cause (eye drops/ointments or supportive care).

Bacterial conjunctivitis treatment

Antibiotic eye drops or ointment.

Viral conjunctivitis treatment

Typically self-limited; supportive care.

Allergic conjunctivitis treatment

Antihistamines and avoidance of allergens.