Microbiology-Parasitology Flashcards by Jehan Salapuddin

Jaundice, bleeding, uremia

Weil syndrome

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Test for monitoring treatment of syphilis and test of cure

RPR, VDRL

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What part is usually affected in aortitis caused by syphilis?

Vasa vasorum

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Seen in secondary syphilis

Condylomata lata

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Test for CNS syphilis

VDRL

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Causative agent for Pinta

Treponema carateum

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Gram-neg, causes skin and bone infections in human bites

Eikenella corrodens

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Cat scratch fever

Bartonella henselae

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Cellulitis after bitten by a cat. What is the most likely dominant organism

Pasteurella multocida

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Vector of Y. Pestis

Oriental rat flea (yeye the rat flea)
Xenopsylla cheopsis

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Safety pin appearance, gram-neg rod; sudden fever, chills, multiple painful lymph nodes

Yersinia pestis

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Reservoir of F. Tularensis

Rabbits (francis the rabbit!)

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Aerobic, Gram-neg bacillus, MDR and commonly associated with hospital environment and hospitalized patients

Acinetobacter baumanii

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Mechanism of action of exotoxin A of P. Aeruginosa

Tissue necrosis and inactivation of elongation factor 2

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Etiologic agent of soft tissue infection on burn patients

Pseudomonas aeruginosa

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29 yo female, recurrent UTI, nephrolithiasis; gram negative rods urease positive with swarming motility. What is the etiology?

Proteus mirabilis

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Struvite stones formed by Proteus mirabilis composition

Magnesium-ammonium-phosphate

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59 yo, alcoholic male, productive cough with mucoid bloody sputum. Large capsules in gram stain

Klebsiella pneumoniae

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Cancers associated with H.pylori

Gastric carcinoma
MALT lymphomas

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Urease positive bacteria

Proteus mirabilis
Klebsiella pneumoniae
H.pylori
Ureaplasma urealyticum

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Triple therapy for H.pylori

Amoxicillin
Clarithromycin
PPI

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Small, motile, non-spore forming with microarrophilic bacilli associated with GBS

Campylobacter jejuni
(GB jejuni)

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female, grayish vaginal discharge, stippled epithelial cells on wet mount

Bacterial vaginosis

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Gram-neg rod associated with painful genital ulcers

Haemophilus ducreyi

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DOC for rikettsial infections

Doxycycline

Drug contraindicated in Rikettsia because they stimulate Rikettsial growth

Sulfonamides

A type of rikketsial disease that does not present with fever or rash, has chronic onset and highest mortality

Q fever (Coxiella burnetii)

Types of Chlamydia trachomatis associated with lymphogranuloma venereum

Types L1-L3

Types of C.trachomatis that causes genital tract infections and associated with Reiter syndrome

Types D-K

Types of C.trachomatis associated with trachoma

Types A-C

Treatment for Chlamydia

Doxycycline 100mg BID x 7 days

22 yo, sexually active female with unilateral painful inguinal lymphadenopathy. Extensive enlargement of chains of nodes above and below the inguinal ligament.

Chlamydia trachomatis L1-L3 (Lymphograneuloma venereum)

Round to oval cytoplasmic inclusion bodies near nuclei of conjunctival epithelial cells in trachoma

Halberstadter-Prowazek inclusion

MCC of atypical pneumonia, this bacteria has sterol in membrane and can cause to form cold agglutinins

Mycoplasma pneumoniae

DOC for erythema nodosum leprosum

Thalidomide

M.leprae can be cultured using

Mouse foot pad or in armadillo

Dx tool for latent TB not affected by prior BCG vax or infection with nontb mycobacteria

Interferon gamma release assays (IGRAs)

Pathognomonic finding of miliary tb

Choroidal tubercles

MC site of extraPTB

Lymph node (scrofula)

DNA viruses

Hepadnaviridae Herpes Adeno Pox Parvo Polyoma Papillomaviridae

All DNA viruses have double-stranded except

parvovirus

All DNA viruses have linear DNA except

Papilloma Polyoma Hepadna

All DNA viruses are icosahedral and replicates in the nucleus except

Poxvirus

DNA virus that causes aplastic anemia in sickle cell anemic patients

Parvovirus

Bright red macules on cheeks with lacy reticulated erythema over extremities

Erythema infectiosum (5th disease)

Histopath finding in adenovirus

Cowdry type B intranuclear inclusions

DNA virus that can cause hemorrhagic cystitis

Adenovirus

Most common viral STD worldwide

Human papilloma virus

HPV gene virus that Inhibits p53 gene

Inhibits Rb gene in HPV

Types of HPV strain associated with cervical cancer

HOC 16,18, 31, 33

HPV strain causing condyloma acuminata

6, 11

HPV strains in Gardasil vaccine (quadrivalent)

6,11,16,18

Virus causing hemorrhagic cystitis in kidney transplant patients

Bk polyoma virus (Bad Kidney)

Site of latency of HSV-1

Trigeminal ganglia

Site of latency of HSV 2

Lumbosacral ganglia

Most common cause of sporadic encephalitis

HSV 1

Complication of VZV involving geniculate region causing facial paralysis

Ramsay-Hunt syndrome

28 year old pregnant with painful vesicles on genitalia. What positive diagnostic test would result to congenital anomalies risk?

Tzanck smear (varicella, herpes simplex)

What is the expected positive result in tzanck smear?

Giant multinucleated cells

Vesicular centrifugal rash, dewdrop on a rose petal

Varicella

Most common viral cause of congenital abnormalities

Cytomegalovirus

Owl's eye nuclear inclusionz

Cytomegalovirus

Treatment of choice for cytomegalovirus

Ganciclovir

Atypical cells in infectious mononucleosis

Downey cells

Malignancies associated with EBV

Burkitt lymphoma B-cell lymphoma Nasopharyngeal Hairy leukoplakia CNS lymphoma

Erythematous papules on soft palate and base of uvula on HHV 6 patients

Nagayama spots

HHV8 malignancy

Kaposi sarcoma

Papular skin lesion with umbilicated center with intracytoplasmic eosinophilic inclusions, 6 yo

Molluscum contagiosum (henderson-paterson bodies)

Only DNA virus that produces DNA by reverse transcription with mRNA

hepa b virus

Most specific marker for acute HBV infection

IgM anti HBcAg

Marker for hepa b cure

Anti-HBsAg

Very infective hepa b marker

HBeAg

1st vaccine to prevent cancer

Hepatitis B virus vaccine

40 yo, grayish vaginal discharge, wet mount showed stippled epithelial cells

Bacterial vaginosis

Gram-neg rod, painful genital ulcers

Haemophilus ducreyi

All viruses are haploid except

Retrovirus

All RNA viruses have SSRNA except

Reovirus

All RNA viruses replicate in cytoplasm except

Influenza and retrovirus

Virus replicating in motor neurons in anterior horn of spinal cord causing paralysis

Poliovirus

Route of polio sabin vaccine

Oral

Most common viral cause of myocarditis and pericarditis

Coxsackie virus

8yo, tender vesicles on oropharynx, high fever, sore throat, odynophagia.

Coxsackie A virus

Rhinoviruses do not cause gastroenteritis. Why?

Acid-labile

Most common cause of common colds

Rhinovirus

Hepa virus with high mortality in pregnant

Hepatitis E

Hepa virus transmitted fecal-orally

Hepa A and E

Most common cause of viral diarrhea in adults

Norwalk virus

Gold standard for diagnosing HIV

Western blot analysis

MCC of childhood diarrhea

rotavirus

rotavirus vaccine can be given until what age

32 weeks

part of influenza virus that is responsible for binding to cell surface receptor

hemagglutinin

part of influenza virus that cleaves neuraminic acid to release progeny virus from the infected cell

neuraminidase

reassortments in the genome RNA may lead to new pandemics

antigenic shift

DOC for influenza

oseltamivir

multinucleated giant cells in measles

warthin-finkeldey bodies

MC complication of mumps

aseptic meningitiis

most important cause of pneumonia and bronchiolitis in infants, has fusion protein forming multinucleated giant cells

RSV

3yo with cough associated with inspiratory stridor. Xray showed steeple sign. Dx?

Laryngotracheobronchitis (croup)

inclusion body in rabies virus

negri bodies

bullet shaped SS RNA virus transmitted by animal bite and moves by retrograde axonal transport to CNS

Rabies virus

what structure of Coronavirus is important for host attachment and penetration

S protein

coronavirus binds to which receptor of the lungs?

ACE-2 receptor

characteristic lab findings in dengue patient

increased hct leukopenia thrombocytopenia

MC etiologic agent of post-transfusion hepatitis

Hepatitis C

congenital rubella syndrome includes

cataracts sensorineural deafness mental retardation PDA Blueberry muffin baby *bulag, bingi, bobo, butas ang puso, pangit ang color

lab method used to detect specific DNA molecules

southern blot analysis

HIV gene that codes for reverse transcriptase which transcribes RNA genome into DNA

pol gene

protein in HIV that fuses viral envelope with cell membrane

gp41

protein present in HIV that interacts with CD4 receptor

p24

AIDS is diagnosed when CD4 is less than

200

MCC of epidemic viral encephalitis

Japanese B virus

unicellular form of fungi seen in 35-37C

yeast

multicellular form of fungi seen in room temperature

mold

kind of hyphae seen as a feature of most medically important fungi

septate hyphae

negative stain to detect cryptococcus neoformans

india ink

stain added to KOH which stains fungal cell wll and makes it fluorescent

calcoflour white

stain for the detection of pneumocystis carinii

gomori-methenamine silver stain

standard culture for isolation of fungal agents

saboraud's dextrose agaar

MOA of amphotericin B

binds to ergosterol in fungal cell membranes forming leaky pores

most prevalent mycosis in the world, only fungal disease infective to other organisms

cutaneous mycoses

hypo/hyperpigmented macules/patches with characteristic of spaghetti and meatballs appearance in KOH prep

Malassezia furfur

M. furfur shows what kind of fluorescence on Wood's lamp

coppery-orange

organism that can cause fungemia in premature infants on IV lipid supplements

M. furfur

microsporum shows what kind of fluorescence on wood's lamp

yellow

causative agent of tinea nigra

hortae werneckii

causative agent of black piedra

piedraia hortae

causative agent of white piedra

trichosporon

main reason why cutaneous mycoses cant cause deep infections

unable to grow in 37C or in serum

most prevalent of all dermatophytosis

tinea pedia (athlete's foot)

44 yo, gardener, persistent lesion on 2nd digit of left hand for several weeks. Biopsy showed asteroid bodies and elongated budding yeast which looked like cigar. Dx?

sporotricosis (sporothrix schenkii)

DOC for sporotricosis

itraconazole

sulfur granules from interconnecting draining sinuses is pathognomonic of what mycosis

mycetoma

detection of sclerotic bodies is diagnostic of which

chromoblastomycosis

Systemic mycoses that have presence of spherules filled with endospores

coccidioides immitis

systemic mycoses with broad based budding yeast

blastomyces dermatitidis

systemic mycoses with multiple budding yeast arranged like a WHEEL

paracoccidioides brasiliensis

systemic mycoses associated with bird or bat droppings with presence of macrophage filled yeast

histoplasma capsulatum

systemic mycoses that is a mimicker of squamous cell carcinoma

blastomyces dermatitidis

patient with DKA have a necrotic eschar on nasal cavity. Biopsy showed nonseptate broad based hyphae that branch at right angles. What causative agent?

Rhizopus

chemoprophylaxis for HIV against cryptococcus

fluconazole

MCC of meningoencephalitis in HIV, associated with pigeon droppings

cryptococcus neoformans

33 year old HIV positive female came to ER due to headache and altered LOC. Lumbar puncture showed oval narrow based budding on India ink. What causative agent?

cryptococcus neoformans

DOC for c. neoformans

amphotericin B + flucytosine

DOC for chemoprophylaxis for AIDS against to prevent c.neoformans infection

fluconazole

15 year old female with curd-like discharge. Diagnostics showed pseudo hyphae at room temperature. What causative agent?

candida

unique feature of candida albicans seen when it grows at 25C

pseudohyphae

chronic mucocutaneous candidiasis associated with lack of immune function

T-cell function

unique feature of candida albicans seen when it grows at 37C

germ tube

fungi with septate hyphae forms V shaped branches at acute angles

aspergiLLus

radio sign of gas surrounding aspergilloma

monod sign

ideal specimen for pneumocystis jirovecii

bronchioalveolar lavage

AIDS patient with sudden onset DOB. Bronchial washing showed PCP pneumonia. DOC

TMP-SMX

Prophylaxis for P.jirovecii

TMP-SMX

Host that harbors the asexual or larval stage

Intermediate Host

Host where the parasite attains sexual maturity

Definitive Host

Gold standard in diagnosing intestinal protozoans

Direct Fecal smear

Amebic liver abscess, which is the most common extraintestinal form of E. histolytica is located most commonly at the ___________.

Anterior-superior aspect of the liver

What is the drug of choice for asymptomatic intestinal E. histolytica infection

Luminal agents (Iodoquinol or Paromomycin)

Microscopic finding in trophozoite that diagnostic of E. histolytica

Ingested RBC

Characteristic ulcer seen in amoebic colitis caused by E. histolytica?

Flask-shaped ulcers

Commensal amoeba that is morphologically similar to E. histolytica but genetically different

Entamoeba dispar

Primary amebic meningoencephalitis is caused by ________

Naegleria fowleri

Secondary amebic meningoencephalitis is caused by _________

Entamoeba histolytica

Microscopic finding diagnostic of Iodamoeba butschlii

Large glycogen body

Causative agent of Gay Bowel Syndrome

Giardia lamblia

A 30-year-old male who went hiking recently came to the ER due to persistent abdominal pain, bloatedness and frequent loose stools which smells like rotten egg. Microscopy showed a parasite that looks like an old man with eyeglasses and present with falling leaf motility. What is the causative agent?

Giardia lamblia

Acid fast parasite that is capable of autoinfection and associated with severe form of diarrhea in immunocompromised patients

Cryptosporidium parvum

Drug of choice for C. parvum in immunocompetent patients

Nitazoxanide

1st line of treatment in HIV patients infected with Cryptosporidium parvum

HAART

A butcher who handles pigs presents with acute diarrhea. Fecal smear revealed a ciliated protozoan. What is the causative agent?

Balantidium coli

Characteristic ulcer seen in patient infected with Balantidium coli

Wide neck ulcers

A 30-year-old female came in due greenish foul-smelling vaginal discharge. Wet mount was done which showed motile pear shaped trophozoites. What is the treatment of choice in this case?

Metronidazole or Tinidazole 2grams single dose

Causative agent of Granulomatous amebic encephalitis

Acanthameoba

Drug of choice for free-living amoebas

miltefisone

A plain cranial CT scan of a 28-year-old sexually active male showed multiple ring enhancing lesions on the cerebral cortex. What stage of the parasite is most likely inside the lesions

bradyzoites

Prophylaxis for Toxoplasma gondii

Pyrimethamine + Sulfadiazine + Folinic acid

Definitive host of Toxoplasma gondii

domestic cats

Test used to determine presence or absence of antibodies against Toxoplasma

Sabin-Feldman methylene blue dye test

Vector for Leishmaniasis

Sandfly (Phlebotomus/Lutzomyia)

Diagnostic stage of Leishmania

amastigote

Infective stage of Leishmania

promastigote

Test done to determine presence of exposure to Leishmania spp

Montenegro skin test

Unilateral palpebral swelling in Chaga’s disease is called _____.

Romaña sign

A 20 year old male who had a vacation from Zimbabwe was noted to have fever, periorbital edema, dilated cardiomyopathy, achalasia and hepato-splenomegaly. Upon history, he was bitten by a reduviid bug while strolling around. What is the drug of choice for this patient?

Nifurtimox

Vector of African trypanosomiasis

Tsetse fly (Glossina)

Infective stage of T. cruzi

Metacyclic Trypomastigote

Diagnostic stage of T. cruzi

Trypomastigote

Common features seen in Chronic Chagas Disease

Arrhythmias Megaesophagus Megacolon

What is the characteristic histopathologic feature seen in the CSF of patients infected with African Trypanosomiasis

Morula cells of Mott

East African sleeping sickness is caused by

Trypanosoma brucei rhodiense

Which type of African Trypanosomiasis is more acute and fatal

East African Sleeping sickness

Babesia microti is a parasite that is transmitted by Ixodes tick. What is the pathognomonic feature of this parasite?

Maltese cross formation

Intermediate host of Plasmodium species

Humans

Malaria is the most important parasitic disease in man. It is caused by Plasmodium sp. through the bite of an infected female Anopheles minimus. On what stage of its life cycle does it infect the human RBC?

Schizonts

Gold standard for detection of malaria

Thin and thick blood smear

Which population are immune to malaria

Those with RBC defects (G6PD, sickle cell)

Coarse granulation seen in Plasmodium falciparum

Maurer Dots

Punctate granulations seen in Plasmodium vivax

Schuffner Dots

Fine dots seen in Plasmodium malariae

Ziemann stippling/dots

Presence of bands seen in the trophozoites is pathognomonic of which plasmodium species

Plasmodium malariae

Term used when there is return of a malarial disease after its apparent cessation (1-6months)

Relapse

Mechanism of why relapse occurs on malaria

Reactivation of hypnozoites

Which drug is given in addition to Oral Chloroquine to patients infected with P. vivax or P. ovale to prevent relapse

Primaquine

Finding of sausage-shaped or banana-shaped gametocytes in peripheral smear is characteristic of __________

Plasmodium falciparum

Nematodes that can cause superinfection

Strongyloides Capillaria Ascaris

Nematodes that have adults that stay in the large intestine

Enterobius Trichuris

Nematodes that have adults that stay in the small intestine

Capillaria Ascaris Strongyloides Hookworm

Nematodes that are capable of lung migration?

Ascaris Strongyloides Hookworm

Treatment of choice for majority of Nematodes

Albendazole or Mebendazole

A 30-year-old male was brought to the ER due to rectal prolapse. Fecalysis was done which revealed ova with bipolar plugs. What is the causative agent?

Trichuris trichiura (Whipworm)

A 10-year-old boy had extreme pruritus ani especially in the nighttime. You suspect that this boy has been infected by a pinworm. What diagnostic test are you going to request to confirm your diagnosis

Scotch tape test

Characteristic feature of E. vermicularis eggs

D shaped eggs

Type of anemia present in hookworm infection

Iron Deficiency anemia

Which hookworm causes more bleeding because of its two pairs of cutting teeth

Ancylostoma duodenale

Characteristic presentation of patients infected with animal hookworms such as Ancylostoma braziliense and Ancylostoma caninum

Cutaneous larva migrans

What is the method of incubating fecal material on filter paper strip test to recover hookworm and S. stercoralis

Harada Mori culture

Cochin-China diarrhea is caused by ______

Strongyloides stercoralis (Threadworm)

Treatment of choice for S. stercoralis infection

Ivermectin

A 45-year-old male came in due to intractable diarrhea. Laboratory exam showed hypoalbuminemia. Fecalysis showed eggs with flattened bipolar plugs that looks like a peanut. What is the causative agent

Capillaria philippinensis (Pudoc worm)

Treatment of choice for filariasis

Diethycarbamazine

Best time to collect blood specimen for the diagnosis of Brugia malayi and Wuchereria bancrofti

8pm to 4am

Technique used to increase the concentration and detection rate of microfilariae

Knott’s concentration technique

A filarial worm that has a kinky appearance with a terminal nucleus and prefers to stay in the limb lymphatics

Brugia malayi

A filarial worm that is noted to have diurnal periodicity and is usually seen crawling across the conjunctiva

Loa loa (African eye worm)

Vector of Loa loa

Deer Fly/ Mango Fly/ Chrysops

Causative agent of hanging groin deformity and river blindness

Onchocerca volvulus

The previous organism is transmitted thru which vector

Female blackfly (Simulium)

A tissue nematode that can cause myocarditis and present with periorbital edema

Trichinella spiralis

Definitive diagnosis for T. spiralis

Muscle biopsy

Another name for Dracunculus medinensis

Guinea fire worm

Most common cause of visceral larva migrans

Toxocara canis

Most common cause of parasitic meningitis

Angiostrongylus cantonensis

All eggs of Trematodes are operculated except

Schistosoma spp.

All human parasitic trematodes are hermaphrodites except

Schistosoma spp.

All human parasitic trematodes have metacercariae as their infective stage except

Schistosoma spp. (cercariae)

All human parasitic trematodes have 2 intermediate hosts except

Schistosoma spp. (1 intermediate host)

2ND intermediate host of Paragonimus westermani

Sundathelphusa philippina (Crabs)

Drug of choice for Fasciola sp.

Triclabendazole

Trematode that has been implicated to cause squamous cell carcinoma of the bladder

Schistosoma haematobium

The ova of this schistosome have a terminal spine

Schistosoma haematobium

The ova of this schistosome have a prominent lateral spine

Schistosoma mansoni

The ova of this schistosome have a small lateral spine or lateral knob

Schistosoma japonicum

The intermediate host of Schistosoma japonicum in the Philippines is

Oncomelania hupensis quadrasi

Main pathology for Schistosoma spp.

Host granulomatous reaction to eggs

A 36year old female from Leyte presents with an enlarged abdomen, ascites, esophageal varices and jaundice. You suspect that this is caused by a certain trematode. What laboratory test should you request for?

Circumoval Precipitin Test

A 30year old male is fond of eating undercooked crabs. He had a 3-week history of chronic cough with bloody sputum. What is the most likely diagnosis?

Paragonimiasis

Trematode that mimics peptic ulcer disease

Heterophyes heterophyes

A 50-year-old male came in due to jaundice and cholangiography was done which showed an arrowhead sign. He was diagnosed with Cholangiocarcinoma. You suspect this was caused by a trematode infection. How is this parasite transmitted to humans

Eating of undercooked fish (Cyprinidae)

2nd IH of Echinococcus granulosus

Pila luzonica

What do you call the hemorrhagic nasopharyngitis and dysphagia due to ingestion of raw Fasciola adult infected liver

Halzoun/marrara

All eggs of Cestodes are non- operculated except

Diphyllobothrium latum

Treatment of choice of majority of cestodes infection

Praziquantel

All Cestodes have 1 intermediate host except for

Diphyllobothrium latum (2 intermediate hosts)

The longest medically important Cestode of man

Diphyllobothrium latum

Neurocysticercosis is possible for Taenia solium because

Humans can serve as intermediate host

Type of anemia present in D. latum infection

Megaloblastic anemia

Criteria for cure of Cestode infections

Recovery of scolex

A 30 year old male came in to the clinic due to epigastric pain and pruritus ani. Fecalysis was done which revealed the presence of proglottids. Upon further interview, you noted he ate beef and pork on a street food near tondo last 2 months. Recalling your class in parasitology, if you noted the uterine branches to be around 5-10 after administration of India ink and there was presence of rostellum. What is most likely causative agent?

Taenia solium

Which tapeworm is composed of a scolex and only three proglottids thus it is known as one of the smallest tapeworms?

Echinococcus granulosus

Treatment of choice for Echinococcus species infection

Albendazole

Most common location of hydatid cysts in the liver

Inferior right lobe

Life threatening complication that can occur if hydatid cyst ruptures

Anaphylaxis

Presence of barrel shaped proglottids in stools is characteristic of which tapeworm

Dipylidium caninum

A 40-year-old male came in due to persistent abdominal pain and diarrhea. CBC was done and revealed normal MCH and MCHC but with increased MCV. Fecalysis was done which showed operculated eggs. What is the infective stage of this parasite?

Plerocercoid larvae or sparganum

Most frequently found tapeworm in developed countries and is capable of autoinfection

Hyemenolepis nana

Most infectious STD that has a crab like morphology

Pthirus pubis

What is the etiologic agent of the seven-year itch which also has a pathognomonic feature of burrows on interdigitations

Sarcoptes scabei var hominis (Itch mite)

Organisms known to cause autoinfection

Capillaria philippinensis Cryptosporidium parvum Hyemenolepis nana Enterobius vermicularis Strongyloides stercoralis Taenia solium

In cases of chronic carriers of Salmonella, the microorganism can usually be isolated at ______.

Gallbladder

A 30yr old male was brought to the ER due to bloody-diarrhea, abdominal pain and confusion. Culture of the stool showed non-lactose fermenting gram negative rods which are non- motile and does not produce H2S. What is the causative agent?

Shigella dysenteriae

Mode of action of Subunit A of Cholera toxin

ADP ribosylation leading to stimulated Gs protein which increases cAMP

Agar of choice for the isolation of Vibrio cholerae

Thiosulfate Citrate Bile Salt Sucrose agar

Treatment of choice for Cholera

Fluid and electrolyte replacement

The strain of Vibrio that led to a pandemic of Cholera in the past is _________

Vibrio cholerae 01 biotype El Tor

A 30-year-old male came to the ER due to watery diarrhea associated with abdominal cramps, vomiting, and low grade fever. Upon taking detailed history, it was noted that symptoms develop after eating raw seafood. What is the causative agent?

Vibrio vulnificus

Agar of choice for C. jejuni

Skirrow agar

Obligate intracellular agents that consist of RNA only with no protein coat

Viroids

DNA pieces that move readily from one site to another either within or between the DNA of bacteria, plasmids, and bacteriophages

Transposons

Pathology that results to prion production

Dysfunction due to protein misfolding

Fatal neurodegenerative prion protein disease in man which is transmitted thru cannibalism

Kuru

Treatment for Creutzfeldt- Jakob disease

No treatment available

Process of disinfection of tools in cases of prion disease

5% hypochlorite solution or 1.0 M sodium hydroxide or autoclaved at 15 psi for 1 hour

Only bacteria with no cell wall

Mycoplasma

Teichoic acid is present in the cell wall of _________?

Gram positive organisms

Active component of lipopolysaccharide

Lipid A

All gram-positive bacteria have no endotoxin except for which organism?

Listeria monocytogenes

What is the mordant used in Gram staining?

Gram’s Iodine

What is the decolorizer used in Gram staining?

Acetone Alcohol

What is the decolorizer used in Acid Fast staining?

Acid Alcohol

Bacteria’s that are cocci in shape and are gram negative

Neisseria Veillonella Moraxella

Capsule of Bacillus anthracis is composed of ________

Polypeptide of D-glutamate

Gram positive bacilli that are considered as spore formers

Bacillus spp. Clostridium spp.

The content of Mycobacteria that makes the dye difficult to penetrate the cell wall is _________

Mycolic Acid

Which of the process of genetic exchange requires bacteriophage?

Transduction

Stain used for Legionella spp.

Silver stain

Stain used to diagnose Whipple disease caused by Tropheryma whipplei

Periodic Acid-Schiff stain

Agar used for the isolation of Vibrio cholerae

Thiosulfate Citrate Bile Salts Sucrose

Agar used for the isolation of Mycoplasma pneumoniae

Eaton

Agar used for the isolation of Mycobacterium tuberculosis

Lowenstein- Jensen

Agar used for the isolation of Leptospira interrogans

Ellinghausen-McCullough- Johnson-Harris (EMJH)/Fletcher

What is the phase of bacterial growth cycle where antibiotics are most effective?

Log or Exponential Phase

What is the phase of bacterial growth cycle where spores are formed?

Stationary Phase

Antimicrobials that work by inhibiting DNA gyrase

Fluoroquinolones

Antibiotic that inhibits RNA polymerase

Rifampin

Mechanism of resistance to Vancomycin

Reprogramming of D-ala-D- ala

Mechanism of resistance to Methicillin

Mutation of Penicillin- Binding Protein

Gram positive cocci in clusters, catalase positive, coagulase positive

Staphylococcus aureus

Most common infection in open fractures?

Staphylococcus aureus

Gram positive cocci in clusters, catalase positive, coagulase negative, Novobiocin resistant

Staphylococcus saprophyticus

Gram positive cocci in clusters, catalase positive, coagulase negative, Novobiocin sensitive

Staphylococcus epidermidis

An IV drug user who develops endocarditis. What is the causative agent

Staphylococcus aureus (Affects the tricuspid valve)

A patient with a prosthetic heart valve develops endocarditis. What is the causative agent?

Staphylococcus epidermidis

A patient who underwent dental surgery develops endocarditis. What is the causative agent?

Viridans Streptococci

A patient with marantic endocarditis. Culture done showing growth of S. bovis. What is the next best step?

Colonoscopy to determine presence of Colon cancer

What is the causative agent of endocarditis in a patient who underwent GI/GU surgery?

Enterococcus faecalis

What is the diagnosis for a case of fever, migrating joint pains, and raised erythematous lesions with a history of pharyngitis?

Acute Rheumatic Fever (due to cross-reacting antibodies to M-protein)

What are the Jones criteria for acute rheumatic fever?

Polyarthritis, Carditis, Subcutaneous nodules, Erythema marginatum, Sydenham chorea

What is the causative agent of pneumonia that is Gram positive, cocci in chains, catalase negative, alpha hemolytic, optochin sensitive and bile soluble?

Streptococcus pneumoniae ## Footnote Positive Quellung reaction

What is the Gram classification and characteristics of Streptococcus bovis?

Gram positive cocci in chains, catalase negative, gamma hemolytic, no growth in 6.5% NaCl

What gene mediates methicillin resistance in Staphylococcus aureus?

mecA gene

What is the sequestered focus of osteomyelitis caused by Staphylococcus aureus?

Brodie abscess

What is the diagnosis for a case of fever, hypotension, strawberry tongue, desquamating rash, and multi-organ involvement in a patient with a history of using a tampon?

Toxic Shock Syndrome

What is the difference in Toxic Shock Syndrome caused by Staphylococcus aureus and Streptococcus pyogenes?

S. aureus has no site of pyogenic inflammation and blood CS negative

What toxin causes Scarlet fever?

Erythrogenic toxin

What elevated titers suggest antecedent Streptococcal pharyngitis?

Anti-Streptolysin O

What elevated titers suggest antecedent Streptococcal skin infection?

Anti-DNAse B

What is the most likely causative agent in a case of cardiac arrest with a history of arthritis and serpiginous rashes?

Streptococcus pyogenes

What is the superficial infection extending into dermal lymphatics?

Erysipelas ## Footnote Different from Erysipeloid caused by Erysipelothrix

What toxin of Staphylococcus causes necrosis of the skin and hemolysis?

Alpha toxin

What toxin of Streptococcus rapidly destroys tissue and causes Necrotizing Fasciitis?

Exotoxin B

What is the most common cause of neonatal pneumonia, sepsis, and meningitis?

Streptococcus agalactiae

At what age of gestation should pregnant women be screened for Group B Streptococci colonization?

35-37 weeks

What is the most common cause of CAP across all ages?

Streptococcus pneumoniae

What is the characteristic sputum of patients infected with Streptococcus pneumoniae?

Rusty colored sputum

What is the difference between Bacillus and Clostridium species?

Both are spore-forming, but Bacillus species are aerobic while Clostridium species are anaerobic

What is the most common form of anthrax?

Cutaneous anthrax

What is the most severe form of anthrax?

Gastrointestinal Anthrax

What is the drug of choice for cutaneous anthrax?

Ciprofloxacin

What are the characteristics of the organism in a case of food poisoning after eating reheated fried rice?

Gram (+) spore-forming bacilli, aerobic, motile

What is the preferred antibiotic for a carpenter with a punctured wound and muscle rigidity?

Metronidazole

What is the mechanism leading to muscle rigidity in the previous case?

Inhibiting the release of GABA by cleaving of synaptobrevin 2

What is the mode of action of botulinum toxin?

Blocking the release of acetylcholine

What is the most common source of infection in Floppy Baby Syndrome?

Ingestion of spores in household dust or honey

What is the most likely causative agent in a case of high-grade fever and dark serous fluid draining from a wound?

Clostridium perfringens

What is the toxin responsible for gas gangrene?

Lecithinase

What agar is used for Clostridium perfringens?

Egg yolk agar

What antibiotics can cause pseudomembranous colitis?

Clindamycin, 2nd and 3rd Cephalosporins and Ampicillin

What is the first step in treating C. difficile infection?

Stop the antibiotic responsible for the infection

Antibiotic of choice for treatment of C. difficile

Vancomycin

What’s the mechanism of the exotoxin of C. diphtheria?

Inhibits protein synthesis by adding ADP-ribose to elongation factor 2

Culture media of C. diphtheria

Loeffler’s medium or Potassium tellurite

Most common cause of urethritis and PID. Also the most common cause of septic arthritis in sexually active adults.

Neisseria gonorrhea

Treatment of choice for infections with N. gonorrhea

Ceftriaxone + Doxycycline

Antibiotic choice for C. diphtheria

Erythromycin

A newborn who was diagnosed with neonatal sepsis was admitted in the hospital. Culture shows a facultative intracellular rod that exhibits cold enhancement and a narrow zone of beta hemolysis. This organism can be transmitted by:

- Ingestion of unpasteurized milk products - Across placenta or contact during delivery

The organism discussed in the previous case escapes from the phagosome via which toxin?

Listeriolysin

A 30yr old man got into a fight and broke his jaw a few days ago which now has developed an abscess with draining pus. Anaerobic culture showed molar tooth colonies. What is the causative agent?

Actinomyces israelii

Treatment of choice for the causative agent discussed in the previous case?

Penicillin

A 40yr old HIV patient came due to chronic cough. PPD showed a negative result. Fite faraco stain demonstrated that organism is weakly acid fast. Culture showed orange colonies. What is the causative agent?

Nocardia asteroides

Drug of choice for Nocardia infection

Co-trimoxazole

GRAM NEGATIVE BACTERIA

Gram negative diplococci that can ferment glucose and maltose

Most severe form of meningococcemia which leads to bilateral hemorrhagic destruction of the adrenal glands

Waterhouse-Friedrichsen syndrome

Function of the capsule of Neisseria gonorrhea

Deficiency of what component of the immune system predisposes a patient to Neisseria infection

Complement 5-9 deficiency

None that’s why it is not significant

A 12-year-old male presents with flexion of legs and thighs with passive flexion of neck. What sign of meningeal irritation is this?

Brudzinski’s sign

Treatment of choice for Meningococcemia

Penicillin

Prevention is better than cure that’s why vaccine against N. meningitidis is available. This vaccine contains capsular polysaccharide of what strains of N. meningitidis?

A, C, Y and W-135

A 19-year-old male came in due to septic arthritis. Gram stain of the synovial fluid showed gram negative diplococci. Toxicity of this organism is mostly due to what toxin?

Lipooligosaccharide

Gold standard for the diagnosis of gonorrheal infection

Nucleic acid amplification test (NAAT)

A gram-negative rod with polyribitol phosphate capsule that can be cultured using chocolate agar. It causes epiglottitis.

Haemophilus influenzae type b

H. influenzae requires what factors to be able to grow?

X (Hemin) and V (NAD)

Satellite phenomenon of H. influenzae can be observed around colonies of what bacteria?

Staphylococcus aureus

What phase of pertussis infection are antibiotics most effective?

Catarrhal phase

Mechanism of action of pertussis toxin

- Causes ADP ribosylation - Activates G protein leading to increase cAMP

Legionella pneumophila

A 36yr old male was admitted due to pneumonia associated with non-bloody diarrhea and hyponatremia. What is the most likely causative agent?

Causative agent of Pontiac fever

Legionella pneumophila

Agar used for the isolation of Legionella pneumophilla

Charcoal yeast extract agar

Most common cause of urinary tract infection

Escherichia coli

Enterotoxigenic E. coli

A 28 year old male who went to travel to a local region in the Philippines went to the ER due to persistent watery diarrhea. Culture on EMB agar showed greenish metallic sheen. What strain of this bacteria is most likely the culprit?

A 40yr old male was brought to the ER due to persistent bloody diarrhea after eating hamburger which he bought from the street. He was noted to have hemolytic anemia, thrombocytopenia and uremia. What is the most likely causative agent?

E. coli 0157:H7

What is the facultative organism that is predominant in the large intestine and can be used as an index of fecal contamination of a water sample?

E. coli

What is the most predominant organism of the large intestine?

Bacteroides fragilis

This organism is considered as anaerobic.

Bacteroides fragilis

Tests used to detect antibodies against Salmonella in patient’s serum

Widal test

Capsular antigens for bacteria are labeled as K antigen except for Salmonella which is labeled as ________.

Vi antigen

Who are at greater risk of developing osteomyelitis due to S. cholerasuis?

Patients with sickle cell anemia

The most sensitive diagnostic modality for Salmonella infections

Bone marrow culture

Microbiology-Parasitology Flashcards

(388 cards)