Micro Flashcards
What are the two microoganisms that are:
Gram positive
Catalase negative
alpha hemolytic
how do you tell the apart?
Optochin Sensitive, Bile soluble
positive: Strep Pneumonia (Encapsulated)
negative: Strep Viridans (mutans)
What are three organism you become susceptible with sickle cell or after a splenectomy?
which is the most common involved in pneumonia?
Encapsulated Organisms
- Streptococcus Pneumonia
- Haemophilus influenza
- Neisseria Meningitidis
How does Parvovirus B19 present in children?
- “Slapped Cheeks” rash in children
- Aplastic crisis in sickle cell disease
- fetus - Hydrops fetalis (RBC dectruction)
in adults - pure RBC aplasia and RA-like Sx
What is the most important protective immunologic mechanism against encapsulated organisms?
IgG-mediated opsonization
What are three tests that can confirm Cryptococcus neoformans as the cause of meningitis in AIDS patients?
Latex particle agglutination - most specific, detects polysaccharide capsular antigen
India Ink - clear halo
Mucicarmine - red inner capsule
24 year old woman shows up to office with copious green vaginal discharge. What is the dx? what is the best dx test?
Trichomoniasis
Saline microscopy - motile protozoan
best dx test = Nucleic Acid Amplification test (NAAT)
What is the most common cause of osteomyelitis?
If an african american pt presents w anemia and osteomyelitis which combo should you treat with?
Staphylococcus aureus
Ciprofloxacin and Vancomycin
- -cipro - for salmonella
- -vanco - s. aureus
Cephalosporins bind to what type of bacterial structure?
cephalosporins irreversibly bind to penicillin binding proteins
Transpeptidases = PBP thatcross links peptidoglycans in bacterial cell wall
What viruses cause B cells to enter a immortal stage and maintain the capacity to secrete immunoglobulins?
What type of Abs?
Epstein-Barr virus
Heterophile IgM antibodies
What are two bacteria that can cause impetigo?
S. aureus
S. pyogenes (GAS)
What systemic symptoms usually follow a Group A Strep infection (impetigo)
what is the first line treatment?
facial puffiness
Dark urine
–Poststreptococcal glomerular nephritis (PSGN)
first line Tx: Penicillin
What technique is described:
bacteria fail to decolorize with hydrochloric acid and alcohol after staining carbofuschin?
Acid fast staining
What is the bacteria:
gram positive, lancet shaped diplococci?
Streptococcus Pneumoniae
What is the main source of rabies in the US?
bats
what bacteria is a/w ecthyma gangrenosum (skin patches with necrotic centers and occasional ulceration)
Pseudomonas aeruginosa
KOH stain shows large, round yeast with doubly refractory wall, and single broad-based bud
-Ohio and mississippi, river valleys, great lakes
Blastomyces dermatitidis
immunosuppressed pt
fungal rhinositis
light microscopy: v-shaped, narrow septate hyphae invading the tissue
Aspergillosis fumigatus
How does Isoniazid work?
inhibition of mycolic acid synthesis
group of kids get sick at summer camp
present with fever, cough, congestion, sore throat, red eyes, erythematous oropharynx
Crackles present in lower left field upon auscultation
Adenovirus
Pyrrolidonyl arylamidase postivity (PYR-positive)
S. pyogenes (GAS)
Oxidase-positive
gram negative bacilli
grows well on highly alkaline selective media (thiosulfate-citrate-bile salts-sucrose TCBS agar)
- identify bacteria and shape
- what is the mechanism of action of toxin
- what is tx?
- vibrio cholera - comma shaped (curved rod, mobile)
- stimulates G protein to activate adenylate cyclase
- if no altered mental status, no lethargy, strong pulse = ORAL fluid and electrolyte replacement
if serious sx = IV fluid, electrolytes
non-lactose fermenting, gram-negative rods on MacConkey agar.
bacteria ferments glucose without gas production
do not generate hydrogen sulfide when grown on triple sugar iron agar, cannot replicate at refrigeration temps
identify and its route of pathogenesis
shigella - mucosal invasion through Mcells over peyers patches
How are are E. coli and Enterobacter cloacae
- similar
- different
- both are gram negative, lactose fermenting
2. only ecoli is indole positive
What are the two most common causes of PID leading to infertility?
Neisseria Gonorrhea
Chlamydia trachomatis
What is the abx category of cefuroxime and what is its mechanism of action?
second gen cephalosporin, beta-lactam abx
acts against cell wall synthesis
What virus is strongly associated with cervical and anal squamous cell carcinoma? prevalence is increased with HIV infection
HPV types 16, 18
What is a common route of Hep A transmission in the US?
contaminated water/food
raw or steamed shellfish
Gram negative coccobacilli, associated with dog bite, mouse-like odor
Pasteurella multocida
what should you suspect in a patient from south america with achalasia
trypanosome cruzi infection
How does C.difficile damage the intestinal mucosa?
what would the colonoscopy biopsy most likely reveal?
Toxin A and B both damage cytoskeletal integrity
Colonic bx: inflammatory exudate composed of mucinous debris, fibrin, necrotic epithelial cells, polymorphonuclear cells
What abxs should be used with toxoplasmosis?
Pyrimethamine
Sulfadiazine
What should be suspected with a MRI showing ring-enhancing lesions
- negative toxoplasmosis
- positive EBV
primary central nervous system lymphoma (PCNSL)
–abnormal population of B-lymphocytes
How do Shiga-like toxins work?
inhibit protein synthesis in human cells (60s subunit)
–leads to intestinal mucosal cell death
=renal epithelial cell toxicity
What is Metronidazole used for?
treat anaeroes and parasites:
Giardia lamblia
Entamoeba histolytica, Trichomonas vaginalis.
Bacterial vaginosis (Gardnerella vaginalis)
How can neonatal tetanus be avoided?
Maternal Vaccination
What bacteria is a/w axillary lymphadenopathy and scratches from pets
-what is an additional Symptom that can appear
Cat-scratch disease: Bartonella henselae
Bacillary angiomatosis - in immunocompromised pts - red, purple papular skin lesions
How do you distinguish EHEC from other Ecoli?
Colorless colonies on sorbitol MacConkey (does not ferment sorbitol)
-shiga-like toxin = HUS (anemia, thrombocytopenia, acute renal failure)
identify the disease:
agitation, disorientation, pharyngospasm, photophobia leading to coma and death
what is the receptor that this disease binds to?
Rabies encephalitis
acetylcholine receptors
-widened mediastinum on chest xray
-microscopy: shows long chains described as “serpentine” or “medusa head”
what is special about the capsule formed by this agent?
bacillus anthracis
-forms capsule with D-glutamate instead of polysaccharide
recent history of viral esophagitis and pneumocystis pneumonia is virtually diagnostic of what infection?
HIV
What is this disease and how is it usually contracted?
fever lasting >10 days
severe, retroorbital pain a/w photophobia
pneumonia
increased liver enzymes
thrombocytopenia
q fever - coxiella burnetii
through animal waste
What disease and congenital defects are a/w the following symptoms in the mother:
immigrant, low-grade fever, macupapular rash w cephalocaudal progression, posterior auricular and suboccipital lymphadenopathy, eventual polyarthralgia
Rubella
sensorineural deafness
cataracts
cardiac malformations (PDA)
What type of virus is Herpes simplex I
double stranded, DNA, enveloped
What type of virus is rubella?
togavirus
what type of outer covering is a/w gram negative bean-shaped diplococci?
Neisseria meningitidis
–Outer membrane Lipooligosaccharide
what two infections are commonly the cause of ectopid pregnancy?
Neisseria gonorrhoeae
Chlamydia trachomatis
How does CMV infections present in:
- immunocompetent
- immunocompromised
- Mononucleosis-like illness
2. Odynophagia (linear esophageal ulcers), Retinitis
What activity is giardia lamblia infection a/w?
drinking contaminated water:
hx of camping, hiking in the mountains, white-water rafting
What secondary infection can form the in the cavitary lesion caused by a prior TB infection of the lung?
Aspergilloma colonization
what are the 3D’s of clostridium botulinum infection sx?
diplopia
dysphagia
dysphonia
Nikolsky’s sign, epidermal necrolysis, fever, pain a/w skin rash are symptomatic of what?
Staphylococcal Scaled Skin Syndrome
exotoxin
What is the use of fidaxomicin and what is the mechanism of action?
Clostridium difficile infection
inhibits the sigma subunit of RNA polymerase
A young woman with asymmetric polyarthritis (knee, elbow, wrist)
synovial fluid analysis = neutrophilic predominance and intracellular organisms
what is the cause?
Neisseria Gonorrhea
disseminated gonococcal infection (DGI)
What are serum electrolyte findings of a Legionella pneumonia infection?
What is the treatment of Legionnaire’s dz?
Hyponatremia
Tx: Fluroquinolones or Macrolides (Azithromycin)
What type of virus is parvovirus?
Nonenveloped single stranded DNA virus
What type of presentation can Listeria cause? what abx is used? why?
Meningitis in young infants or immunocompromised
-use Ampicillin (because Cephalosporin resistant)
What type of fungi is able to survive intracellularly inside a macrophage and cause systemic symptoms (cough, low-grade fever, hepatosplenomegaly)
Histoplasma capsulatum
What is the main toxin produced by Clostridium perfringens? what is its mechanism of action?
Lecithinase (alpha toxin) - degrades lecithin, destroys cellular phospholipid membranes
What diarrhea causing bacteria is a/w ascending muscle weakness and paralysis
what is another dz a/w with the weakness?
Campylobacter jejuni is a/w Guillain-Barre Syndrome
also:
Mycoplasma respiratory infections
What is the route of infection from outside to meninges of Neisseria Meningitis?
Pharynx - blood - choroid plexus - meninges
Abdominal pain
bloating, large, bulky stools
Small bowel bx: acid-Schiff-positive macrophages in lamina propria
Whipple’s disease (Tropheryma whipplei - gram positive rod)
Most common cause of septic arthritis in young person?
Gonococcal arthritis - Neisseria Gonorrhea
What is the most common Zink compensatory pattern in 80% of patients?
OA - rotated left
Thoracic inlet - rotated right
Thoracolumbar - rotated left
Pelvic - rotated right
14 year old boy
headache
fever
rash that begins on palms and soles and spreads to trunk
macules and petechiae covering most of body
Rocky Mountain Spotted Fever
5 year old
rash on hands, cognitively delayed since birth
Biltateral notched incisors, widely spaced
hepatosplenomegaly
ulcerative rash on feet
Congenital Syphillis
How is an eosin methylene blue (EMB) agar plate interpreted?
organisms that ferment lactose (like E coli) produced colonies that have a distinct green metallic sheen
What is a classic finding in mononucleosis (EBV) pts?
erythematous maculopapular rash that appears after a pat has been given antibiotics (amoxicillin) for presumed bacterial pharyngitis
Identify:
parasite - o
triad: periorbital edema, myositis, eosinophilia
preferentially involves muscles of the upper extremities, neck and face
Trichinellosis - mostly from ingestion of infected wild game - pigs
What are the top two causes of septicemia in sickle cell patients? Why?
- Strep Pneumo
- Haemophilus influenza
-because sickle cell patients eventually become asplenic
Motile gram positive rods
produces a narrow zone of B-hemolysis on blood agar
grows well at refrigeration temperature
identify organism and important aspect of immunity for removal
Listeria monocytogenes
Cell-mediated immunity
Which disease shows an intracellular maltese cross?
What disease is also transmitted by the same organism?
Babesiosis
Lyme disease is also transmitted by the Ixodes tick
25 year old has a stillbirth at 18 weeks gestations
she reports having pain in knees and feet while being on her feet all day teaching at elementary school
Fetal autopsy - pleural effusion, pulmonary hypoplasia, ascites
what was she infected by?
Parvovirus B19
- school outbreaks
- symmetric arthralgias
- fetal hydrops
HIV patient
watery diarrhea without fever, weakness
acid-fast pathogen
Cryptosporidosis
4 year old complaining of severe anal itching which is worse at night other children in class has the same
what is dx, what is the diagnostic test? what is the classification of the pathogen? What is tx?
Pinworms (Enterobius vermicularis) - cellophane/scotch tape test - reveal eggs
Nematode, dioecious (distinct male and female organisms)
Tx: Albendazole
Why does Hepatits D virus need Hepatitis B virus to infect?
HDV uses the HBV surface antigen (HBsAg) to replicate its own genetic material
15 year old male present with sore throat (2 weeks) + fatigue
oropharynx: erythema, tonsillar exudates, palatal petechiae, splenomegaly, posterior cervical adenopathy
Labs show lymphocytosis
identify pathogen and test?
Infection mononucleosis from EBV
–triad: fever, pharyngitis, lymphadenopaty
Heterophile antibody test
5 year old present with 3 days of diarrhea, initially water but then became blood-tinged
pt attends kindergarten
mild tachycardia, no fever
Stool: mucous, blood, non-motile bacterium, increase polymorphonuclear cells that grow white colonies on MacConkey agar
Identify pathogen
Shigella spp.
white on MacConkeys = lactose NONfermenter
–differs from salmonella because SHIGELLA IS IMMOTILE
What part of HIV
- helps with fusion and entry into attacked cells
- outermost part of protein that attaches to CD4 on T-cells
- gp41
2. gp120
high fever, muffled voice, inspiratory stridor, respiratory distress
identify dz and most common cause
Epiglottitis
Haemophilus influenza
What is the most common cause of pneumonia in adults and older children with cystic fibrosis?
Psuedomonas aeruginosa
burn patient with hemorrhagic bullae and sepsis
identify most probably pathogen?
What is the most appropriate pharm therapy?
ecthyma gangrenosum = hemorrhagic bullae
pseudomonas aeruginosa
Tx: Piperacillin or Ticarcillin/Tazobactam
Pt presents with painful ulcer in lower leg. She was recently in Sudan. upon inspection there is a worm protruding from the center of the ulcer
what is this and what could have prevented this?
Dracunculus medinensis - “protruding worm”
Drinking filtered water - dz is acquired through infection by drinking water containing infested fleas, and releases larvae when wound is placed in water
Gram negative, question mark shaped spirochete
causes flu-like symptoms, HA, fever, abdominal pain
Jaundice, photophobia
What is the pathogen and how it acquired?
Leptospira interrogans - animal urine
Which type of hernias occur:
1. Lateral
2. Medial
to the inferior epigastric arteries
- Indirect - through the deep inguinal ring, external superficial inguinal ring
- Direct
Which abx should be used to treat Trematode: Clonorchis sinensis?
Praziquantel - increases cell membrane permeability
28 yr old present with sudden onset of vomiting, diarrhea 6 hours ago. Pt just returned from Carribean cruise vacation last night. denies in blood in vomit or stool. Febrile
Identify pathogen and classification
Norovirus
Non-enveloped single stranded RNA virus
8 year old present after a seizure. has been severe headaches and high fevers the past two days. Exam shows somnolent child with temp of 104.1. lumbar puncture shows free living ameba.
Identify dz and predisposing factor?
Naegleria fowleri = rapidly fatal amebic meningoencephalitis
swimming in freshwater lakes
pt returns from trip to Uganda. reports five weeks of fever, headache, itchy hives, and cough that began after swimming in a river. Itching was the “worst itch I’ve ever had”.
Phys exam: inguinal lymphadenopathy, mild hepatosplenomegaly, small eggs in stool
identify pathogen, what is treatment? what is the mechanism of this treatment?
what can this pathogen cause if untreated (in third world countries)
Schistosomiasis - treat with Praziquantel
- -trematode (fluke)
- -praziquantal increase calcium permeability of the tegument of the worm = paralysis and death
Can lead to Squamous Cell Carcinoma of the Bladder
What is the most common cause of prosthetic valve acute endocarditis?
Staphylococcus aureus
- Coagulase-positive
- B-hemolytic
hunter went on a trip with his hunting dogs. after living with his dogs for a week he gets HA and generalized malaise. develops RUQ pain after 3 weeks. Febrile, HTN, Tachycardia, elevated liver fxn tests, lymphopenia
CT of head shows single large locular cyst
identify pathogen and tx?
Echinococcus granulosus
-tapeworm transmitted from eggs in dog feces - large, locular cysts found in liver, lungs, brain
Tx = albendazole
what dz does the tick Dermacentor andersoni transmit?
Colorado tick fever (ds RNA virus)
“saddleback fever”
pt (immigrant from Mexico) is brought to ED after a seizure. pt has been more irritable and aggressive than usual for the past week. Pt complains of abdominal pain and constipation. Head CT shows three 1 cm, calcified, spherical hypodensities
identify dz?
Cysticercosis = extra-intestinal cyst formation in Taenia solium or Taenia saginata tapeworm infection.
-infection from ingest1ion of cysts that contain larva in undercooked pork or beef.
What is the most common cause of nosocomial pneumonia due to use of a respirator
Pseudomonas aeruginosa
What is the most common pathogen causing croup? what type of pathogen is it?
Parainfluenza virus type 1
–enveloped helical Negative-sense ssRNA
18 year old present to ED with severe shortness of breath. started yesterday gotten worse over 24 hrs. just returned from a trip to the grand canyon.
Phys exam: interstitial infiltrates, ausculatation = ralles, wheezing.
Pt rapidly worsens.
ARDS secondary to HANTAVIRUS infection.
- -virus found in SW US.
- -inhalation of contaminated rodent feces in dry air.
- -typically present with moderate-severe resp symptoms that quickly worsen into ARDS
(severe pulmonary syndrome following flu like symptoms)
13 year old boy presents with sore throat, headache, and fatigue. Sx began one week ago. 102 fever, anterior and post cervical lymph nodes are symmetrically enlarged. Enlarged tonsils, erythematous, covered with exudate. elevated WBC, elevated lymphocytes with atypical lymphocytes (large lymphoctes with nucleoli)
what is dz and what is a likely complication?
Infectious Mononucleosis (EBV) - dx’d by heterophile Ab test “monospot”
–triad:
1. fever
2 pharyngitis
3. lymphadenopathy
ATYPICAL LYMPHOCYTOSIS (increased large lymphocytes with nucleoli)
Complication: Splenoegaly -> Splenic Rupture (refrain from athletic activity)
58 yr old pt presents with severe HA, facial pain, decreased mental status. face as 10/15 cm unilateral cellulitis w black, necrotic centers. hemorrhagic nasal discharge. Serum glucose: 380, bicarb: 5, pH: 7.1.
What is most likely etiology?
Rhizopus spp.
- -rhinocerebral infection w vascular involvement leading to necrotic facial cellulitis, pain, hemorrhagic nasal discharge, ALTERATION in mental status
- -more common in pts with uncontrolled diabetes mellitus
18 year old Hispanic pt presents with fever, joint pain of three week’s duration. He states that his fever seems to rise and fall throughout the day. sweats at night. Generalized joint pain, most pronounced at SI joints. recent hx of returning from mexico where he was working on his uncle’s dairy farm producing goat cheese and unpasteurized milk.
what is dx?
Brucellosis - contact w infected goats, sheep, unpasteurized milk
gram-negative aerobic coccobacilli - can invade both phagocytic and nonphagocytic cells - suppress bactericidal responses of the immune system
present: UNDULATING FEVER, joint pain (SI joint), large joints of the lower extremity, profuse sweating
What is the deficient enzyme:
15 year old pt with exercise intolerance, myalgias, muscle cramps, myoglobinuria after exercise
McArdle’s dz - Muscle phosphorylase
What is the deficient enzyme:
newborn Ashkenazi infant with severe hepatomegaly hypoglycemia, hyperlipidemia, lactic acidosis
von Gierke’s dz (glycogen storage dz type I)
–Glucose-6-phosphatase
–inability of liver to generate glucose during fasting - glycogen accumuates in the liver = symptoms
What is the deficient enzyme:
4 month old w generalized hypotonia, muscle weakness, respiratory distress, failure to thrive. CXR shows cardiomegalyl
Pompe’s dz (glycogen storage dz type II)
- -Alpha 1,4 glucosidase
- -accumulation of glycogen in tissues such as the skeletal muscle and myocardium = diffuse myopathy - leading to respiratory and cardiac failure
Pt presents with rapidly fluctuating fever. night sweats, general malaise. Single erythematous, nontender plaque on his arm and palpable liver 4cm under ribcage.
Elevated ALT, AST. decreased leukocytes, platelets
Bone marrow sample reveals Macrophages with amastigotes
what is dz and what was vector?
Leishmania donovani - infection of bone marrow, liver, spleen = pancytopenia
–Spiking fever, hepatomegaly, skin papules or ulcers
transmitted by Sandfly
pt w progressive muscle weakness in left leg. fevers/HA began 10 days ago, lasted for 3 days. Lumbar puncture shows elevated pressure, lymphocytosis, elevated protein, normal glucose. She acquired condtion from contaminated water. what is pathogen?
Poliomyelitis - picornavirus
–present with febrile illness that leads to focal neurologic deficits
What is the location of pathology in a primary tuberculosis infection?
Infiltrate in lower lob and adjacent lymphadenopathy
= “Ghon’s complex” in lower lobs
Pt presents with rash (ascending lymphangitis) that has been moving up arm. First noticed days after extensive yard work. Culture shows cigar-shaped budding yeast.
What is pathogen? what is treatment?
Sporothrix Schenckii - THERMAL DIMORPHIC fungus with cigar shaped yeast
“Rose-gardener’s disease” - begins as small papul at site of invocation (usually hand) then ulcerates
Tx: Itraconazole
4 month old presents with watery diarrhea. started loose stools and low fevers 2 days ago. Phys exam shows fever, and tachycardia. bowel sounds are hyperactive and stool guaiac test is negative What is the most likely etiology?
Rotavirus - the most common cause of gastroenteritis and diarrhea in young children
pt presents w fevers and severe, crushing pain in her face, back, and arms. Pt traveled to S America two weeks ago. macular rash on her chest and abdomen.
What is pathogen?
Dengue fever - icosahedral flavivirus (mosquito)
linear single stranded RNA
Bioterror associated organism. Pt sustained puncture wound on finger - febrile, chills, new erythematous swelling of right epitrochlear and axillary lymph nodes. Sharply demarcated ulceration of third finger of right hand with yellow exudate. Cultures show Gram negative coccobacillus gorwin in cysteine-glucose-blood agar
what is pathogen?
Francisella tularensis
- -ulceration w fevers, chills, lymphadenopathy
- –aerobic, gram neg bacillus, grows on cystein-glucose-blood agar
–only 5 bacteria needed to cause infection
–ulceration w yellow exudate
5 year old presents with fever, painful skin rash on arms and trunk. skin is erythematous w large blisters and serous fluid that contains organims. There is splitting of the epidermis at the stratum granulosum
what is most likely agent?
Staph aureus. - Bullous impetigo caused by exfoliative toxin
–if blisters had NO organisms - could possibly be Scalded-skin syndrome - from toxin
66 yr old pt present with abdominal pain, foul-smelling diarrhea, joint pain, weight loss for the past few months. Recently shown confusion. Exam shows adenopathy with abdominal distention. Sent home with abx that cover gram positive bacteria
what is pathogen and etiology?
Tropheryma Whippleii - Macrophages that phagocytose the organism compress the lacteals preventing absorption of chylomicrons
-SYSTEMIC dz - abd pain, diarrhea, arthralgias, neuro, cardiac problems, lymphadenopathy
Tx: doxycycline, macrolides
24 yr old woman presents with seizure. complained of fever, HA earlier in the morning. exhibited tonic-clonic symptoms shortly after. No longer convulsing, but emetic and confused. MRI shows left temporal lobe hemorrhage. CSF shows viral cause
what is pathogen?
Herpes simplex virus 1
19 year old presents w diarrrhea, abdominal cramping, progressive diarrhea with subjective fevers. Bloody diarrhea develops. Stool eval shows trophozoites w ingested erythrocytes
what is pathogen and tx?
Entamoeba histolytica
–amoebic dysentery (bloody diarrhea, fever, abdominal pain)
Tx: Metronidazole
Identify dz:
14 yr old male w lower abdominal pain, fever 5 days ago. painful swellings on posterior cheecks
Testicular swelling and tenderness.
Mumps
Identify pathogen:
8 year old w temp of 103.9. Complains of chills and irritable
Sustained a bite from pet cat on wrist 3 days ago. Notable erythema, edema, decreased range of motion in wrist
Pasteurella multocita - gram negative facultative anaerobic bacterium
—–causes Cellulitis, Osteomyelitis following bites from domesticated animals
(distinguish from Bartonella henselae “cat scratch” = regional lymphadenopathy, scratch, papule, fever, backache)
What are 3 factors that make pseudomonas lethal?
- Pyocyanin - blue-green pigment
- endotoxin
- EXOTOXIN A - inactivates elongation factor 2 (EF-2)
- –EF-2 in liver = inhibits protein synthesis and kills cells
identify pathogen:
19 yr old pt has rash. his sexual partner has similar rash on genitals and inner thich. 2-3 dome-shaped papules with a central umbilication on the penis and inner thigh
Poxvirus - Molluscum contagiosum
What is the therapy for duodenal ulcers from an H. pylori infection?
Triple Therapy:
Amoxicillin, Clarithromycin, + a proton pump inhibitor
18 year old w fever, headache, nausea, chills, vomiting. Petechial purpuric rash on legs. Nuchal rigidity. CSF: high protein, low glucose
what is pathogen?
Neisseria meningitidis
–meningitis with petechial/purpuric rash
(strep pneumo is most common cause of meningitis in children from 3mo-9years, and adults 19 years and older)
Older pts infected with influenza are at higher risk for a superinfection from what? what is the classic sign for this?
Streptococcus pneumoniae
-look for “double sickening” = pts started to get better then bein to experience fevers and worsening symptoms
AIDS pt presents with mental status changes, weakness, blurry vision. CSF is diagnostic for infection causing progressive multifocal leukoencephalopathy.
what is pathogen? how prevalent is it?
JC virus - causes progressive multifocal leukoencephalopathy (PML)
–widespread in the population, disease only seen in immunocompromised
Identify pathogen and shape/classification:
fevers, chills, cellulitis wit bullae on hands of saltwater fisherman who recently handled shellfish
Vibrio vulnificus
-Gram negative, Motile
Curved Rod
HA, fever, myalgia, macular erythematous rash on chest
no cough, nausea, vomiting, diarrhea
positive WEIL-FELIX
transmitted by Body Louse
what is pathogen?
Rickettsia prowazekii
- -Endemic Typhus
- —-flu like Sx w truncal rash
HIV pt w productive cough, fevers, chills, night sweats, myalgias. inspirator crackles in right lower lob. Sputum analysis reveals a filamentous, partially acid-fast, gram positive
what is pathogen?
Nocardia asteroides
- -gram positive
- -aerobic
- -weakly acid-fast
- -filamentous bacterium (branching filaments)
–known for causing pulmonary infection in immunocompromised individuals
What is the virulence factor of Mycoplasma pneumonia that allows it to evade immune response?
what is the dx stain?
how is it cultured?
P1 protein - serves as adhesin and allows the bacteria to adhere to the respiratory mucosa
doesnt have cell wall - so cannot be stained
grows on EATON’s AGAR
What are three most common causes of Otitis media?
what is the management?
- S. pneumoniae
- H. influenzae
- M. catarrhalis
Tx: Oral Amoxicillin
What is the initial drug of choice for malaria?
Chloroquine
What is the use of Primaquine (specific)
added to regiment if pt is infected w
P. vivax or P. ovale
-for Latent hepatic schizonts
PREVENTS FUTURE RELAPSES
Which type of malaria is considered a medical emergency?
Plasmodium falciparum
2 year old w fever, stiff neck after an upper respirator infection. Lumbar puncture shows gram-positive cocci
what is the most appropriate pharm management
Vancomycin
bacterial meningitis children: S. pneumo, N. menin, H. influ
gram + CSF = S. pneumo = use vancomycin
Identify dz:
Mexican immigrant w fatigue, weight loss, night sweats, chronic back pain. Febrile, MRI shows Vertebral lesion
Pott disease - vertebral osteomyelitis caused by Mycobacterium tuberculosis
Aids pt w fatigue and fever. Bone marrow bx reveals granulomas and a culture that grows budding yeast at 37C (98.6F) and a mold with hyphae at 25C (77F).
identify pathogen
Histoplasma capsulatum
- –dimorphic as:
1. mold in colder temps
2. intracellular yeast at body temp
inhaled from environment from bird/bat droppings
–infects alveolar macrophages
What is the treatment for Lyme disease (borrelia bugdorferi, spirochete)?
- for children under 8
- for adults
- Amoxicillin
2. doxycycline - contraindicated in children under 8 because of severe side fx of the bones and teeth
pt w abrupt onset of fever, chills, malaise, sever HA, two days sever nausea, vomiting, diarrhea. Recently returned from W Africa. Febrile, hypotensive, tachycardic. Diffuse erythematous, nonpruritis maculopapular rash on her face and neck. Fecal occult blood test is positive
what is the pathogen? what is the classification
Filoviridae (Ebola and Marburg Viruses)
–Non segmented negative sense RNA genome
48 year old recently returned from trip to SE Asia w exquisitely tender and enlarged palpable lymph node w associated fever, chills, general weakness. Painful area of swelling surrounded by dark hemorrhagic purpura on the left leg where pt was bitten by a flea
what is dz?
Yersinia pestis - bubonic plague
What are the treatments/mechanisms for cryptococcus neoformans meningitis/encephalitis?
Amphotericin
—increases membrane permeability by binding to erosterol in the plasma membrane
or Flucytosine - converted to 5-FU - intereferes w DNA synthesis
How can Strongyloides stercoralis infection be prevented?
Wearing appropriate footwear
What is the first line treatment for:
- gonorrhea
- chlamydia
- Ceftriaxone
2. Azithromycin or doxycycline
what is the most important virulence factor of gram positive cocci, catalase negative, clear hemolysis, bacitracin sensitivity that causes
- skin infection
- fever with rash
S. pyogenes - M protein
- cellulitis - M PROTEIN
- Scarlet fever - ERYTHROGENIC EXOTOXIN
What is the capsid structure and genomic content of Coxsackie A virus?
naked icosahedral capsid, single-stranded RNA
pt w watery, blood tinged diarrhea and fever of 3 days. recently returned from camping trip in mexico. Stool has RBC, WBC, cultures show organism ferments sorbitol. 10 days later Sx resolve w/o abx
identify pathogen
Enteroinvase Escherichia coli
Pt w fever, cough, chest pain, nausea, myalgias that works in textile factory
what is pathogen
what are 3 abx to use?
Bacillus Antracis
Penicillin
Doxycycline
Ciprofloxacin
5 yr of w severe watery diarrhea for 3 days. dehydrated, no signs of blood in stool. other children at school have the same problem
what id the pathogen? what is the shape/classification of the pathogen?
Rotavirus
-Double stranded segmented RNA virus
most common cause of severe non-bloody diarrhea in children under 5
