Microbiology: Microbiology Systems Flashcards
How is Toxoplasma gondii characteristically transmitted?
Through cat feces or ingestion of undercooked meat
What organism causes both watery diarrhea and gas gangrene?
Clostridium perfringens
What are the sensitivity and specificity, respectively, of the ESR and CRP laboratory assays in the work-up for osteomyelitis?
Elevated values are sensitive for osteomyelitis, but not specific
What pathogen is associated with infection related to water aerosols?
Legionella
What virus is associated with genital herpes?
Herpes simplex virus-2, less commonly herpes simplex virus-1
What pathogens are likely responsible for infection related to intravascular catheters?
Staphylococcus aureus (including MRSA), Staphylococcus epidermidis (from long-term intravascular catheter use), Enterobacter
What pathogen is higher risk in unvaccinated individuals and presents with postauricular lymphadenopathy and a descending rash?
Rubella virus
What causes of pneumonia are associated with alcoholism?
Klebsiella and anaerobes secondary to aspiration (eg, Fusobacterium, Peptostreptococcus, Prevotella, Bacteroides)
What cause of pneumonia is associated with “currant jelly” sputum?
Klebsiella
When does chemical conjunctivitis present?
1-2 days after birth
Name the organisms that cause condylomata acuminata.
Human papillomavirus 6 and 11
Name the 6 organisms/agents that cause the ToRCHeS infections.
ToRCHeS: Toxoplasma gondii, Rubella, Cytomegalovirus, HIV, Herpes simplex virus type 2, Syphilis
What virus is responsible for chickenpox?
Varicella-zoster
How does conjunctivitis caused by chlamydia present?
Mild to severe hyperemia and thick, possibly bloody, mucopurulent discharge
What microorganism is associated with a food-borne illness from poultry, meat, and eggs?
Salmonella
When does neonatal conjunctivitis from gonorrhea present?
2-5+ days after birth
What UTI-causing organism is associated with a fruity odor and blue-green tint?
Pseudomonas aeruginosa, often acquired nosocomially
What pathogens are likely responsible for a nosocomial infection caused by decubitus ulcers, surgical wounds, or drains?
Staphylococcus aureus (including MRSA) or gram ⊖ anaerobes (eg, Bacteroides, Prevotella, Fusobacterium)
What STI presents with a painless, beefy red ulcerative genital lesion that bleeds on examination?
Donovanosis (or granuloma inguinale) caused by Klebsiella [Calymmatobacterium] granulomatis
Why is MRI better than radiographs for the diagnosis of osteomyelitis?
MRIs detect acute infection and detail anatomic involvement; radiographs are insensitive in early detection of osteomyelitis, although may be useful for chronic cases
What is the pathophysiology of lymphogranuloma venereum?
Infection of the lymphatics caused by Chlamydia trachomatis
What physical exam findings may be seen in Legionella infections?
Signs of pneumonia, neurologic abnormalities, and gastrointestinal symptoms (eg, diarrhea, nausea, vomiting)
Patients with chronic granulomatous disease are prone to infection by which organisms?
Catalase ⊕ microbes, especially Staphylococcus aureus
What virus is responsible for rubeola?
Measles
Watery diarrhea caused by which organism presents with rice-water stools in which you see comma-shaped organisms?
Vibrio cholerae infection
What microorganism is associated with a food-borne illness from reheated meat?
Clostridium perfringens
What microorganism is associated with a food-borne illness from deli meats or soft cheeses?
Listeria monocytogenes
What aspects of Enterococcus infections make them particularly difficult to treat?
They are often drug-resistant and nosocomial
What bacteria is typically found in dental plaques?
Streptococcus mutans
What bacteria are considered normal flora in the vagina?
Lactobacillus, Escherichia coli, and group B streptococcus
How might the mother of an infant diagnosed with Toxoplasma gondii infection present?
The mother is usually asymptomatic, with lymphadenopathy only in rare circumstances
In the absence of any further information, which organism is most likely involved in a traumatic open wound infection?
Clostridium perfringens
What are the 2 most common causes of nosocomial infections?
Escherichia coli (UTIs) and Staphylococcus aureus (wound infections)
What physical exam findings are seen in infections associated with wound infections, decubitus ulcers, or drains?
Erythema, tenderness, drainage, and induration
Which 2 organisms most frequently cause osteomyelitis of the vertebrae?
Staphylococcus aureus and Mycobacterium tuberculosis
What organism is associated with pediatric epiglottitis?
Haemophilus influenzae
A patient with meningitis has an ↑ opening pressure on lumbar puncture. CSF analysis shows ↑ protein, ↓ glucose, and a neutrophilic pleocytosis. Diagnosis?
Bacterial meningitis
When does neonatal conjunctivitis caused by chlamydia present?
5-14 days after birth
Name the most common causes of pneumonia in patients who are 4 weeks to 18 years of age.
Viruses (RSV), Mycoplasma, Chlamydia trachomatis, Chalmydia pneumoniae, Streptococcus pneumoniae (Runts May Cough Chunky Sputum)
What 2 microorganisms are associated with a quick onset and a quick resolution of food poisoning?
Staphylococcus aureus and Bacillus cereus cause food poisoning that is quick to start and brief in duration
What is the likely source of multiple brain abscesses?
Bacteremia
What vaginal infection presents with inflammation termed “strawberry cervix” and frothy, foul-smelling, green-yellow discharge?
Trichomonas vaginitis
What organism is associated with puncture wounds and lockjaw?
Clostridium tetani
Name 7 organisms that can cause bloody diarrhea.
Campylobacter, Entamoeba histolytica, enterohemorrhagic and enteroinvasive Escherichia coli, nontyphoidal Salmonella, Shigella, Yersinia enterocolitica
Why are UTIs 10 times more likely to occur in women than in men?
Women have a shorter urethra colonized by fecal flora
What allows for the motility of Salmonella?
Salmonella has flagella that allow it to move (Salmon swim)
What bacterial species is the leading cause of UTIs?
Escherichia coli
How does chemical conjunctivitis present?
Watery, nonpurulent discharge
What microscopy findings do you expect to see in a patient with Candida vulvovaginitis?
Pseudohyphae; infection characterized by thick, white vaginal discharge that resembles cottage cheese
What is the pH in Candida vulvovaginitis?
Normal (4–4.5)
In sexually active individuals, which pathogen rarely causes osteomyelitis but more commonly causes septic arthritis?
Neisseria gonorrhoeae
What organism is associated with pseudomembranous colitis and watery diarrhea?
Clostridium difficile
What is the most likely cause of meningitis in teenagers?
Neisseria meningitidis
A patient with meningitis has a normal opening pressure on lumbar puncture. CSF analysis shows normal protein and glucose with a lymphocytic pleocytosis. Diagnosis?
Viral meningitis
What is the mode of transmission of a ToRCHeS infection?
Caused by transmission of a microbe from mother to fetus, usually transplacental, but can also occur during delivery (eg, HSV-2)
What is the likely source of a single brain abscess?
Spread of infection from contiguous sites
What is another name for neonatal conjunctivitis?
Ophthalmia neonatorum
What is the most common source of Vibrio cholerae diarrhea?
Infected seafood
What exposures are associated with a Clostridium difficile infection?
Antibiotics and proton pump inhibitors
What are 3 congenital infections that present with dermal erythropoeisis and extravascular bleeding?
Toxoplasmosis, CMV, Rubella
How does cytomegalovirus infection present in the mother?
It is usually asymptomatic; rare cases may have mononucleosis-like symptoms
What is the mechanism of cytomegalovirus transmission?
Sexual contacts or organ transplantation
How does herpes simplex virus conjunctivitis present?
Conjunctival injection, nonpurulent discharge, vesicular skin lesions, keratitis, and disseminated infection
What pathogen is higher risk in unvaccinated individuals and presents with fever, drooling, dysphagia, difficulty breathing, and a swollen cherry-red throat?
Haemophilus influenzae type b causing epiglottitis (can affect immunized and unimmunized children)
How does gonorrheal conjunctivitis present?
Marked conjunctival injection, profuse purulent discharge, and lid swelling; corneal involvement can lead to blindness
What STI may present with urethritis, cervicitis, pelvic inflammatory disease, creamy purulent discharge, prostatitis, epididymitis, or arthritis?
Gonorrhea from Neisseria gonorrhoeae
What STI may result in jaundice?
Hepatitis caused by hepatitis B virus
What gastrointestinal complication may be seen in untreated PID?
Perihepatitis, or Fitz-Hugh–Curtis syndrome, characterized by “violin string” adhesions of the peritoneum to the liver capsule due to inflammation of the liver capsule
What does a urine sample testing positive for leukocyte esterase indicate?
WBC Activity
What STI presents with painless genital ulcers and painful inguinal lymphadenopathy resembling buboes?
Lymphogranuloma venereum
Which of the ToRCHeS infections often results in stillbirth or hydrops fetalis?
Syphilis
Which organism causing oral infections is associated with sulfur granules and branching rods?
Actinomyces israelii
Which 3 viruses cause watery diarrhea?
Rotavirus, enteric adenovirus, and norovirus
Which species of Chlamydia causes pneumonia in children younger than 3 years of age, and which causes it in school-aged children?
Chlamydia trachomatis in children younger than 3 years of age; Chlamydia pneumoniae in school-aged children
What are feared complications of gonorrhea conjunctivitis?
Blindness due to rapid corneal involvement, systemic dissemination
What are the dermatological manifestations of a congenital cytomegalovirus infection?
Petechial rash, “blueberry muffin” rash
What part of the body does Staphylococcus aureus normally colonize?
The Nose
What is the name of the condition when there is tuberculosis osteomyelitis involving the vertebrae?
Pott disease
Why does Staphylococcus aureus cause food poisoning quickly?
The toxins that cause the food poisoning are preformed
What organism causes chlamydia?
Chlamydia trachomatis (D-K)
What constellation of findings may be seen in a congenital Rubella infection?
Classic triad: eye abnormalities (eg, cataracts), ear issues (eg, deafness), congenital heart disease (eg, PDA) ± a “blueberry muffin” rash (“I [eye] ♥ ruby [rubella] earrings”)
What are the CSF protein levels in bacterial, fungal, and viral meningitis, respectively?
↑, ↑, normal to ↑
What pathological cells might be seen on a biopsy of a HPV-induced genital warts lesion?
Koilocytes
What risk factors predispose a patient to Clostridium difficile infection?
Recent antibiotic use
Pelvic inflammatory disease is most often caused by which 2 organisms?
Chlamydia trachomatis and Neisseria gonorrhoeae
What UTI-causing organism is associated with the formation of struvite stones?
Proteus mirabilis
What are the CSF opening pressure levels in bacterial, fungal, and viral meningitis, respectively?
↑, ↑, normal to ↑
What STI presents with exudative, painful genital ulcers and inguinal lymphadenopathy?
Chancroid
What organisms commonly cause osteomyelitis in IV drug users?
Staphylococcus aureus (most common), Pseudomonas, Candida
Name some of the common predisposing factors for UTIs.
Female sex, obstruction (eg, kidney stones, enlarged prostate), catheterization, kidney surgery, congenital genitourinary malformation (eg, vesicoureteral reflux), pregnancy, diabetes
What 2 protozoa are most likely to cause watery diarrhea?
Giardia and Cryptosporidium
What childhood rash presents with cough, conjunctivitis, coryza, and bluish spots on the buccal mucosa followed by a descending confluent rash?
Measles (rubeola); the blue-white spots on the buccal mucosa are known as Koplik spots
What is the most common route of transmission for microbes that cause UTIs?
Bacteria from the urethra ascends to the bladder
What pathogens are associated with infection related to urinary catheterization?
Proteus spp, Escherichia coli, or Klebsiella (infections in your PEcKer)
Which childhood rash can present with febrile seizures, especially in affected infants?
Human herpesvirus 6, which causes roseola (exanthem subitum)
What is the most common cause of neonatal conjunctivitis?
Chlamydia
What physical exam findings may be seen in infections caused by urinary catheterization?
Dysuria, leukocytosis, costovertebral tenderness, or flank pain
What stage of syphilis presents with a painless chancre?
Primary syphilis
What is the pH in bacterial vaginosis?
> 4.5
What organism is likely responsible for a brain abscess in a patient with AIDS and a CD4+ count <100 cells/mm3?
Toxoplasma
What STI presents with vaginitis and a strawberry-colored cervix?
Trichomoniasis caused by Trichomonas vaginalis
What pathogen is higher risk in unvaccinated individuals and presents with cough, runny nose, conjunctivitis, a diffuse rash, and blue-white spots in the mouth?
Measles virus (the mouth lesions are called Koplik spots)
Which settings are associated with hepatitis B and hepatitis C nosocomial infections?
Renal dialysis units, needlesticks
What finding on urinalysis can help to distinguish a UTI from pyelonephritis?
Detection of WBC casts (absent in a UTI, present with pyleonephritis)
What class of virus is responsible for German measles?
Togavirus (causative agent: Rubella virus)
Sinus and CNS infections in patients with diabetes are associated with which fungal organisms?
Mucor or Rhizopus spp
What characteristic radiographic exam findings may be seen after aspiration?
Infiltrates in the right lower lobe (or right upper or middle lobe if the patient is recumbent)
Which infectious agents are the most common causes of pneumonia in the immunocompromised?
Staphylococcus aureus, Pneumocystis jirovecii (with HIV), enteric gram ⊖ rods, fungi, and viruses
What organism is responsible for granuloma inguinale?
Klebsiella granulomatis
What organism leads to chancroid?
Haemophilus ducreyi
When does neonatal conjunctivitis from herpes simplex virus present?
Days-6 weeks after birth
Which organism is the most likely cause of infection in individuals with burn injuries?
Pseudomonas aeruginosa
What physical exam findings may be seen with aspiration pneumonia?
Purulent malodorous sputum
What organism presents with bloody diarrhea and pseudoappendicitis?
Yersinia enterocolitica
What cause of bloody diarrhea presents with liver abscesses?
Entamoeba histolytica, a protozoa that causes amebic dysentery
Name the 3 organisms that cause rashes on the hands and feet.
Coxsackie A virus, Treponema pallidum, and Rickettsia rickettsii
Which white blood cell type predominates in the CSF in bacterial, fungal, and viral meningitis, respectively?
PMN, lymphocyte, lymphocyte
In general, what organism is the most common cause of osteomyelitis?
Staphylococcus aureus (assume this cause if information is limited)
Which organism is commonly involved in surgical wound infections in postoperative patients?
Staphylococcus aureus
What 2 toxins are produced by enterotoxigenic Escherichia coli?
LT (heat-labile) and ST (heat-stable) toxins
What is the mechanism of syphilis maternal transmission?
Sexual contact
What pathogen is higher risk in unvaccinated individuals, resides in the nasopharynx, and causes meningitis in unvaccinated children?
Haemophilus influenzae type b
What characteristic sign may be seen on x-ray in Haemophilus influenzae epiglottitis?
Thumbprint sign
What infectious organism is associated with bilateral facial nerve palsy?
Borrelia burgdorferi (causes Lyme disease)
What organism is associated with bloody diarrhea caused by a lactose-negative bacterium with a low median infective dose (ID50)?
Shigella
What pathogens are associated with atypical causes of pneumonia?
Mycoplasma, Legionella, Chlamydophila, and viruses (RSV, CMV, influenza, adenovirus)
Which 2 organisms are likely causes of osteomyelitis in patients with prosthetic joint replacements?
Staphylococcus aureus and Staphylococcus epidermidis
Name the most common causes of pneumonia in adults 18-40 years of age.
Mycoplasma, Chlamydia pneumoniae, Streptococcus pneumoniae, viruses (eg, influenza)
Name 5 viral causes of meningitis.
Enteroviruses (particularly coxsackievirus), herpes simplex virus-2 (HSV-2), HIV, West Nile virus (which can result in encephalitis), varicella-zoster virus (VZV)
What cause of bloody diarrhea presents with a comma- or S-shaped bug that grows at 42°C?
Campylobacter
What are the most likely causes of meningitis in children 6 months to 6 years of age?
Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type B, or enteroviruses
Osteomyelitis from cat or dog bites is most frequently caused by which organism
Pasteurella multocida
What physical exam findings are seen in infections associated with intravascular catheters?
Erythema, tenderness, induration, drainage from access sites
How does a rubella infection typically present in a mother?
Rash, polyarthritis, polyarthralgia, and lymphadenopathy
Which organisms are higher risk of causing infections in patients with asplenia?
Any of the encapsulated bacteria; think SHiN: Streptococcus pneumoniae > > Haemophilus influenzae type b > Neisseria meningitidis
What pathogen is higher risk in unvaccinated individuals and presents with meningitis, myalgia, and paralysis?
Poliovirus
What is the cause of chemical conjunctivitis?
Irritation from antibiotic ointments
What are the common signs and symptoms of pyelonephritis?
Fevers, chills, costovertebral angle tenderness, flank pain, hematuria, WBC casts
What microscopy finding is seen in bacterial vaginosis?
Clue cells; infection characterized by thin, white discharge and fishy odor
A neonate delivered via cesarean section is colonized with bacteria at the time of birth?
No bacteria; neonates delivered by cesarean section are born without any flora but are colonized quickly after birth
What is the treatment of choice for bacterial vaginosis?
Metronidazole or clindamycin
Which 2 bacteria are considered part of the normal flora in the colon?
Bacteroides fragilis and, to a lesser extent, Escherichia coli
What UTI-causing organism is associated with “swarming” on agar due to motility?
Proteus mirabilis
What microorganism is associated with a food-borne illness from raw honey?
Clostridium botulinum (spores)
Staphylococcus epidermidis is part of the normal flora of what 2 parts of the body?
The skin and the nose
What stage of syphilis presents with gummas, tabes dorsalis, aortitis, general paresis, and an Argyll Robertson pupil?
Tertiary syphilis
How does congenital syphilis infection present if the baby survives?
Facial abnormalities (notched teeth, saddle nose, short maxilla), CN VIII deafness, saber shins
What organism is associated with neonatal meningitis or sepsis?
Group B streptococcus
How has the incidence of meningitis caused by Haemophilus influenzae changed over time?
↓ as a result of vaccination
What organism causes pneumonia in patients with HIV?
Pneumocystis jirovecii
What organism is the second most common cause of UTIs in sexually active females?
Staphylococcus saprophyticus
What causes of brain abscesses are associated with preceding dental infection or extraction?
Oral anaerobes
What microorganism is associated with a food-borne illness from reheated rice?
Bacillus cereus; “Food poisoning from reheated rice? Be serious!”
What causes of pneumonia are associated with IV drug use?
Streptococcus pneumoniae, Staphylococcus aureus
Which UTI-causing organisms are urease positive?
Proteus mirabilis, Klebsiella pneumoniae, and Staphylococcus saprophyticus
What are the most likely causes of meningitis in patients greater than 60 years of age?
Streptococcus pneumoniae, Listeria, and gram ⊖ rods
What microorganism is associated with a food-borne illness from contaminated seafood?
Vibrio parahaemolyticus and Vibrio vulnificus
What organism is associated with infection in transplant patients?
Cytomegalovirus
What causes of pneumonia are associated with aspiration?
Anaerobes
What is the maternal presentation of HIV infection?
Mother’s presentation varies depending on the CD4+ count
What pathogen is higher risk in unvaccinated individuals and presents with low-grade fever and coryza progressing to cough with post-tussive emesis?
Bordetella pertussis
What complications may be seen with a congenital herpes simplex virus-2 infection?
Meningoencephalitis and herpetic vesicular lesions
What UTI-causing bacterial species grows with strong, pink lactose fermentation on MacConkey agar?
Escherichia coli
What virus is responsible for roseola?
Human herpesvirus 6
What microorganism is associated with a food-borne illness from consumption of improperly canned foods?
Clostridium botulinum (toxins)
What pathogen is higher risk in unvaccinated individuals and presents with a sore throat and gray oral exudates that may cause airway obstruction?
Corynebacterium diphtheriae
Name the 4 types of infectious process that make up pelvic inflammatory disease.
Salpingitis, endometritis, hydrosalpinx, and tubo-ovarian abscess
What is the mechanism of transmission of herpes simplex virus-2?
Contact with skin or mucous membranes
How does maternal herpes simplex virus-2 infection present?
Either asymptomatic or herpetic (vesicular) lesions
What is seen on wet prep in a patient with trichomoniasis?
Motile trichomonads
Name the 4 bacterial organisms that can cause watery diarrhea.
Clostridium difficile, Clostridium perfringens, enterotoxigenic Escherichia coli, and Vibrio cholerae
What complication during pregnancy can result from exposure to parvovirus B19?
Hydrops fetalis
What causes of pneumonia are associated with hospitalization?
Staphylococcus aureus, Pseudomonas, and enteric gram ⊖ rods
A patient with meningitis has an ↑ opening pressure on lumbar puncture. CSF analysis shows ↑ protein, ↓ glucose, and a lymphocytic pleocytosis. Diagnosis?
Fungal or TB-induced meningitis
What childhood rash presents with a high fever for several days followed by diffuse rose-colored macules?
Roseola (exanthem subitum) caused by human herpesvirus-6 infection; can present with febrile seizures
What microorganism is associated with a food-borne illness from meats, mayonnaise, and custards?
Stapylococcus aureus, which produces preformed toxins
What STI leads to high risk for opportunistic infections, Kaposi sarcoma, and lymphoma?
AIDS from HIV
What are the 3 congenitally acquired infections in which the mother is usually asymptomatic?
Toxoplasma gondii, cytomegalovirus, and herpes simplex virus type 2
What pathogen is higher risk in unvaccinated individuals and presents with muscle spasms and spastic paralysis?
Clostridium tetani
What food poisoning microorganism may also cause wound infections from interactions with contaminated shellfish or water?
Vibrio vulnificus
What are some of the ways that the spastic paralysis of Clostridium tetani infection may present?
Lockjaw, opisthotonus
What reservoir is associated with Shigella?
Humans are its only reservoir
What organisms are associated with postviral causes of pneumonia?
Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae
What organism causes syphilis?
Treponema pallidum
What is the pH in Trichomonas vaginitis?
> 4.5
In addition to painful genital lesions, herpes simplex virus type 2 commonly causes what systemic symptoms?
Headaches, fevers, myalgias (herpes simplex virus-1 may also cause these symptoms, but not as commonly)
How is rubella typically acquired?
Respiratory droplets
A patient in the intensive care unit who has been intubated for a week shows ↑ sputum production on suctioning. A chest x-ray shows new infiltrates. Likely diagnosis?
Ventilator- associated pneumonia from Pseudomonas aeruginosa, Klebsiella, Acinetobacter, or Staphylococcus aureus (late onset)
What virus is responsible for hand-foot-mouth disease?
Coxsackievirus type A
What constellation of findings are seen in congenital cytomegalovirus infection?
Hearing loss, seizures, chorioretinitis, “blueberry muffin” rash, petechial rash, and periventricular calcifications
What food sources are commonly associated with a Salmonella infection?
Most likely poultry or eggs
What pathogens are associated with infections related to mechanical ventilation or endotracheal intubation?
Pseudomonas aeruginosa, Klebsiella, Acinetobacter, or Staphylococcus aureus
In a child with aToxoplasma gondii infection, what might be the other findings besides the classic triad of manifestations?
A “blueberry muffin” rash (the rash may accompany the triad of hydrocephalus, chorioretinitis, and intracranial calcifications)
What is the most likely cause of meningitis in patients aged 6-60 years?
Streptococcus pneumoniae, Neisseria meningitidis, enteroviruses, and herpes simplex virus
What behaviors might precede HIV infection?
Unsafe sexual practice, use of needles/needlesticks
What unique signs are seen with Clostridium difficile infection?
Watery diarrhea and leukocytosis
Which UTI-causing organism is characterized by producing a red pigment?
Serratia marcescens
What are the common signs and symptoms of cystitis from a UTI?
Dysuria, suprapubic pain, urinary frequency and urgency, urinalysis positive for WBCs
What organism is associated with cat or dog bites?
Pasteurella multocida
What UTI-causing organism is associated with a large mucoid capsule and viscous colonies?
Klebsiella pneumoniae
In which patient population would you suspect Haemophilus influenzae meningitis?
In unimmunized children
What microorganism is associated with a food-borne illness from undercooked meat?
Escherichia coli O157:H7
What 2 organisms commonly cause osteomyelitis in patients with sickle cell disease?
Salmonella and Staphylococcus aureus
What is the treatment of choice for Candida vulvovaginitis?
Azoles
What organism is responsible for causing lymphogranuloma venereum
Chlamydia trachomatis serotypes L1–L3
What organism causes meningitis and is associated with HIV
Cryptococcus spp
What reservoir is associated with Salmonella infections?
Animal reservoirs
What stages of syphilis may result in congenital infection?
The 1st (chancre) or 2nd (disseminated rash) stages
What STI is characterized by genital warts and koilocytes?
Condyloma acuminata
What pathogens are associated with nosocomial infection caused by aspiration?
Polymicrobial, gram ⊖ bacteria (often anaerobes)
How does genital herpes present?
Painful penile, vulvar, or cervical vesicles and ulcers
In which part of the body are viridans streptococci considered normal flora?
The oropharynx
What are some of the complications of salpingitis?
Adhesions, ectopic pregnancy, infertility, chronic pelvic pain
Which 2 organisms are common causes of pneumonia in neonates?
Group B streptococci and Escherichia coli are the most likely causes in newborns younger than 4 weeks of age
When will a urease test be positive in a patient with a UTI?
When the infection is due to a urease-producing organism (eg, Staphylococcus saprophyticus, Proteus, Klebsiella)
What organism is associated with PAS positivity?
Tropheryma whipplei (Whipple disease)
What microscopy findings do you expect to see in a patient with Trichomonas vaginitis?
Motile trichomonads (pear-shaped); infection characterized by frothy, foul-smelling vaginal discharge with a yellow-green hue
What is the test of choice for the diagnosis of acute osteomyelitis?
MRI (details sites that are involved)
What STI may present with conjunctivitis, urethritis, cervicitis, epididymitis, pelvic inflammatory disease, and reactive arthritis?
Chlamydia
Patients with neutropenia are highly susceptible to which 2 opportunistic fungal infections?
Candida albicans (often causes a systemic infection) or Aspergillus
Which organism is the most likely cause of pneumonia in individuals with cystic fibrosis?
Pseudomonas aeruginosa
Infection by which 2 organisms is most commonly linked to brain abscesses?
Viridans streptococcus and Staphylococcus aureus
What are the most likely causes of pneumonia in the elderly (>65 years of age) population?
Streptococcus pneumoniae, influenza virus, anaerobes, Haemophilus influenzae, and gram ⊖ rods
Name the most common causes of pneumonia in adults 40-65 years of age.
Strpetococcus pneumoniae, Haemophilus influenzae, Mycoplasma, anaerobes, viruses
What physical exam findings are seen in infection caused by mechanical ventilation or endotracheal intubation?
Increased sputum production (with a sweet odor if due to Pseudomonas)
What are the most common agents causing meningitis in newborns and infants up to 6 months of age?
Group B streptococci, Escherichia coli, and Listeria
Where in the CNS does abscess from sinusitis and dental infections typically present?
Frontal lobe
What virus is responsible for erythema infectiosum?
Parvovirus B19 (causes fifth disease)
What feature of enterohemorrhagic Escherichia coli causes bloody diarrhea and hemolytic-uremic syndrome?
Shiga-like toxin, produced by enterohemorrhagic E coli O157:H7
How does enteroinvasive Escherichia coli cause diarrhea?
By invasion of the colonic mucosa
A baby is born with hydrocephalus, chorioretinitis, and intracranial calcifications. What infection is the likely culprit?
Toxoplasma gondii
Where in the CNS does abscess from otitis media and mastoiditis typically present?
Temporal lobe and cerebellum
What is the cutaneous manifestation of erythema infectiosum (fifth disease)?
The classic “slapped cheek” rash that appears on the face (this is parvovirus B19 infection)
Which organism is most commonly associated with pus, empyema, and abscess formation?
Staphylococcus aureus
What are the initial steps in management in a patient with suspected meningitis?
Administer ceftriaxone and vancomycin empirically; if Listeria is suspected, add ampicillin
What is the most common sexually transmitted bacterial infection in the United States?
Chlamydia trachomatis
What are the CSF glucose levels in bacterial, fungal, and viral meningitis, respectively?
↓, ↓, normal
Which organisms cause pneumonia in patients with cystic fibrosis?
Pseudomonas, Burkholderia cepacia, Staphylococcus aureus, Steptococcus pneumoniae
What does a positive urine nitrite test indicate?
Nitrate reduction in urine by gram ⊖ bacteria such as Escherichia coli
How does congenital HIV infection present?
Recurrent infections or chronic diarrhea
What is the pathophysiology behind pyelonephritis?
Ascension of bacteria to the kidneys from the bladder
What childhood rash presents with fever, sore throat, and a red sandpaper-like rash in the neck, trunk, and extremities along with flushed cheeks and circumoral pallor?
Scarlet fever (Streptococcus pyogenes)
What stage of syphilis presents with fever, skin rashes, lymphadenopathy, and condyloma lata?
Secondary syphilis
What common vaginal infection presents without inflammation?
Bacterial vaginosis (inflammation is found with Trichomonas vaginitis [“strawberry cervix”] and Candida vulvovaginitis)
What childhood rash presents with pink macules and papules that start on the head and spread to the body and postauricular lymph nodes?
Rubella (caused by the rubella virus); the rash eventually desquamates
