MICRO RECALLS PART 3
1.
Zinc sulfate concentration may NOT allow detection of ___.
a. Trichuris trichuria eggs
b. Giarda lamblia cysts
c. Strongyloides stercoralis rhabditiform larvae
d. Infertile ova of Ascaris lumbricoides
RATIO: Zinc sulfate flotation may not detect operculated or heavy eggs (Clonorchis eggs, unfertilized Ascaris eggs). –Bailey’s 14th
edition, page 615
2.
A trematode with male and female adult forms is ___.
a. Fasciolopsis buski
b. Schistosoma spp.
c. Clonorchis sinensis
d. Heterophyes heterophyes
RATIO: One of the main differences between the schistosomes and other trematodes is that instead of being hermaphroditic, there
are separate male and female adult worms
- Bailey’s 14th edition, page 753
3.
Which protozoa should be reported to the clinicians?
a. Endolimax nana
b. Entamoeba coli
c. Entamoeba dispar
d. Dientamoeba fragilis
RATIO: Trophozoite of Entamoeba histolytica/Entamoeba dispar (morphology does not allow differentiation between the two species)
4.
Nontuberculous colonies that develop pigment in the dark or light, and take longer than 7 days to appear on solid media are
known as ___.
a. Photochromogens
b. Nonphotochromogens
c. Schotochromogens
d. Dientamoeba fragilis
RATIO: The scotochromogens are slow-growing NTM that produce pigmented colonies whether grown in the dark or the light.
- Bailey’s 14th edition, page 529
5.
An organism that is (+) in niacin, nitrate reduction, appears to have a serpentine cording on culture and grows in Tween 80
Hydrolysis after 5 days is suggestive of:
a. M. bovis
b. M. tuberculosis
c. M. avium
d. M. kansasii
6. Which of the following can be used as positive control in Gram staining?
a. Escherichia coli
b. Streprococcus pyogenes
c. Pseudomonas aeruginosa
d. Staphylococcus aureus
RATIO:
Quality Control for gram stain
positive well : staphylococcus aureus = reaction should be blue/purple
negative well: Escherichia coli = reaction should be red/pink
7.
Which organism is used for the quality control of positive results in Kovac Method for indole Production?
a. H. influenza
b. K. oneumoniae
c. B. fragilis
d. E. coli
RATIO:
QUALITY CONTROL FOR INDOLE TEST
A. Kovac’s Method
Positive: Escherichia coli (ATCC25922)
Negative: Klebsiella pneumoniae (ATCC13883)
B. Ehrlich’s Method
Positive: Haemophilus influenzae (ATCC49766)
Negative: Haemophilus parainfluenza (ATCC76901)
C. Ehrlich’s Method (Anaerobic)
Positive: Porphyromonas asaccharolytica (ATCC25260)
Negative: Bacteroides fragilis (ATCC25285)
- Bailey’s 14th edition, page 225
8.
Which test is used to diagnose Giardia lamblia infection from duodenal specimens?
a. Guaiac’s
b. Entero
c. Biopsy
d. Knott’s
RATIO: Duodenal Capsule Technique (Entero-Test)
The duodenal capsule technique is a simple, convenient method for collecting duodenal contents, eliminating the need for intestinal
intubation. The technique involves the use of a length of nylon cord coiled inside a gelatin capsule. The cord protrudes through one
end of the capsule and is taped to the side of the patient’s face. The capsule is then swallowed. The gelatin dissolves in the stomach,
and the weighted cord is carried by peristalsis into the duodenum. The cord is attached to the weight by a slipping mechanism; the
weight is released and passes out in the stool when the cord is retrieved after 4 hours. The mucus collected on the cord is then
examined for parasites, including S. stercoralis, G. duodenalis/lamblia, Cryptosporidium spp., microsporidia, and the eggs of Clonorchis
sinensis.
- Bailey’s 14th edition, page 620
9.
What is NOT considered a Critical/panic value in a Microbiology laboratory?
a. Positive acid fast stain
b. S. pyogenes in a surgical wound
c. Positive blood cultures
d. Negative blood smear for malaria
RATIO:
Clinicians should be notified about “panic values” immediately. Panic values are potentially lifethreatening results, for example, positive
Gram stain for cerebrospinal fluid (CSF) or a positive blood culture. Reference ranges must be included on the report where
appropriate. All patient records should be maintained for at least 2 years
Common panic valuesinclude the following:
• Positive blood cultures
• Positive spinal fluid Gram stain or culture
• Streptococcus pyogenes (group A streptococcus) in a surgical wound
• Gram stain suggestive of gas gangrene (large boxcarshaped gram-positive rods)
• Blood smear positive for malaria
• Positive cryptococcal antigen test
• Positive acid-fast stain
• Detection of a select agent (e.g., Brucella) or other significant pathogen (e.g., Legionella, vancomycin-resistant S. aureus, or other
antibiotic-resistant organisms as outlined by the facility and infection control policies).
- Bailey’s 14th edition, page 70
10. A lesion
a.
b.
c.
d.
from the buccal mucosa of a patient with C. albicans in exudate shows ___.
Blastoconidia, occasional mycelium
Macroconidia, chlamydospores
Macroconidia, blastoconidia
Blastoconidia, chlamydospores
11. Which substance interferes with stool sample testing?
a. Cooking oil
b. Mineral oil
c. Calcium
d. Hair dye
RATIO:
Stool specimens containing barium are unacceptable; intestinal protozoa may be undetectable for 5-10 days after barium use. Certain
substances and medications also impede detection of intestinal protozoa: mineral oil, bismuth, antibiotics, antimalarial agents, and
nonabsorbable antidiarrheal preparations. After administration of any of these compounds, parasitic organisms may not be recovered
for a week to several weeks. Specimen collection should be delayed after barium or antibiotics are administered for 5-10 days or at
least 2 weeks, respectively.
- Bailey’s 14th edition, page 594
12. Which nematode egg requires a warm humid environment in order for the embryonated ovum to mature and become infective and
is transmitted through oral fecal route?
a. N. americanus
b. E. vermicularis
c. A. lumbricoides
d. A. stercoralis
RATIO:
Geographic distribution is associated with climate and poor sanitation. The eggs of A. lumbricoides require a warm humid environment
for the embryonated ovum to mature and become infective. Infection rates are elevated in povertystricken areas that have poor
sanitation. Transmission is through the fecal-oral route, usually through the ingestion of eggs on contaminated material
- Bailey’s 14th edition, page 703
13. Nucleic acid amplification test for detection of suspicious Bordetella, Chlamydia or Neisseria infections require a sample of ___.
a. DNA
b. Stool
c. Urine
d. RNA
e.
14. An emulsifying agent that stains nuclei of parasites and other structures to make them easily visible is ___.
a. Formal ether
b. Grams’ iodine
c. Saline solution
d. Lugol’s iodine
RATIO:
Lugol’s or D’antoni’s Iodine
Iodine Solution is often used in wet mounts of concentrated fecal material. It is useful for staining glycogen and making nuclei
visible in protozoan cysts. Protozoan cysts correctly stained with iodine contain yellow-gold cytoplasm, brown glycogen material,
and paler refractile nuclei. Dobell and O'Connor's Iodine is similar in formula and function to D'Antoni's Iodine
15. Anaerobic bacteria that has no definitive virulence factors known and is associated with inflammatory process in acne is ___.
a. Eubacterium
b. Propionibacterium
c. Bifidobacterium
d. Actinomyces
RATIO: -- Bailey’s 14th edition, page 516
16. The gold standard serologic test for rickettsioses/rickettsial disease is _____.
a. Nuclei acid hybridization test
b. Indirect immunofluorescent antibody assay
c. Microimmunofluorescence
d. Nucleic acid amplification
RATIO:
Typically, serologic assays are the only laboratory tests performed for the diagnosis of rickettsial diseases. Unfortunately, these
methods can only confirm a diagnosis in convalescent specimens and offer little help in diagnosing acute infections that could guide
antimicrobial therapy. The immunofluorescent antibody (IFA) test is considered the gold standard method for antibody
detection. Because of cross-reactivity among members of the same groups (spotted fever and typhus), generally only groupspecific
antibody is available. Antibodies to certain rickettsial species are known to cross-react with bacteria in the genus Proteus. This gave rise
to the Weil-Felix agglutination test.
-Mahon 5th edition, page 549
17. Which of the following is NOT true of virions?
a. Contains RNA
b. Reproduce independently
c. Contains DNA
d. Extracellular
Viruses are obligate intracellular parasites, meaning that they must be inside a living cell and use the host cell machinery to
replicate. For infection of a cell to occur, virions must absorb or attach to the cell surface.
-Mahon 5th edition, page 690
18. Which order of events should be followed at the conclusions of the shift of a laboratory worker to prevent the spread of blood
borne pathogens?
a. Disinfect area, remove gloves, wash hands remove lab coat
b. Remove gloves, disinfect area, wash hands, remove lab coat
c. Remove gloves, wash hands remove lab coat, disinfect area
d. Disinfect area, remove gloves, remove lab coat, wash hands
19. Contact with feline feces in cat litter is a primary source of ___.
a. Rabies
b. Cat-scratched fever
c. Giardia
d. Toxoplasma
RATIO: humans can acquire infection with T. gondii in several ways, such as ingestion or inhalation of the oocyst from soil or water,
ingestion of undercooked meat containing the cystlike structure containing bradyzoites, and congenital transmission. Primary risk
factors for acquiring the infection include cleaning a cat litter box, gardening without gloves, and eating raw or
undercooked meat or unwashed vegetables and fruit. The household cat and other members of the family Felidae serve as
definitive hosts for the organism.
-Mahon 5th edition, page 658
20. The mode of transmission of this organism is direct skin penetration. Which organism is referred to?
a. Strongyloides stercoralis
b. Entamoeba coli
c. Entamoeba hartmanii
d. Giardia lamblia
RATIO: - Bailey’s 14th edition, page 592
21. Which organism can cause granulomatous disease in animals?
a. Cardiobacterium
b. Capnocytophaga
c. Actinobacillus
d. Kingella
RATIO:Actinobacillus spp. cause granulomatous disease in animals and have been associated with soft tissue infection in
humans after animal bites. In addition, Actinobacillus equuli and Actinobacillus suis have been isolated from the human respiratory
tract in addition to animal bite wounds. Additional species (Actinobacillus ureae and Actinobacillus hominis) have been isolated from
patients that have developed meningitis after trauma or surgery
- Bailey’s 14th edition, page 431
22. In the life cycle of paragonimus, migration of ____ (also the infective stage) through muscle and tissue causes local pain and
immune response to tissue damage.
a. Proglottids
b. Miracidium
c. Metacercariae
d. Cercariae
RATIO: Light infections may be asymptomatic. The migration of the metacercariae(infective stage) through muscle and
tissue may cause local pain and an immune response to the tissue damage. In the lungs, the immune response causes
infiltration of eosinophils and neutrophils.
- Bailey’s 14th edition, page 751
23. How can anaerobic indigenous flora become pathogenic?
a. Failure to use PPE
b. Impairment of blood supply
c. Inadequate nutrition
d. Unhygienic practices
RATIO: Anaerobic bacteria are widely distributed in nature in oxygen-free habitats. Many members of the indigenous human flora are
anaerobic bacteria, including spirochetes and Gram-positive and Gram-negative cocci and rods. For example, the human colon, where
oxygen tension is low, contains large populations of anaerobic bacteria. Anaerobic indigenous flora components are potentially
pathogenic if displaced from their normal habitat. Most anaerobic infections are endogenously acquired from members of the
microflora, although Clostridium, found principally in the soil, also produces infections in humans. Proliferation of anaerobic
bacteria in tissue depends on the absence of oxygen. Oxygen is excluded from the tissue when the local blood supply is
impaired by trauma, obstruction, or surgical manipulation. Anaerobes multiply well in dead tissue.
-ncbi.nih.gov
Infections related to poor blood supply often involve S. aureus and group A streptococci. Those with open ulcers may become
colonized with Enterobacteriaceae and P. aeruginosa. Anaerobes are also frequently involved in these infections, as a result of the
blood supply creating anaerobic conditions.
- Bailey’s 14th edition, page 1041
24. A single-stranded RNA genome having a helical capsid with envelope is a characteristic of _____.
a. Coronavirus
b. Adenovirus
c. Filovirus
d. Flavivirus
RATIO:The coronaviruses, in the family Coronaviridae, and the genus Coronavirus, are enveloped helical viruses with ssRNA. They
were first identified by electron microscopy and were named for the distinctive club-shaped projections on their surfaces
-Mahon 5th edition, page 706
25. Which method of susceptibility testing involves subjecting the isolate to a series of concentrations of antimicrobial agents in a
broth environment?
a. B-test
b. Disk diffusion
c. Genotypic
d. Broth Dilution
RATIO: Broth dilution testing involves challenging the organism of interest with antimicrobial agents in a liquid environment. Each
antimicrobial agent is tested using a range of concentrations, commonly expressed as micrograms (mg) of active drug per milliliter
(mL) of broth (i.e., mg/mL).
- Bailey’s 14th edition, page 180
26. Select the type of bacteria that can use oxygen as terminal electron acceptor in respiration.
a. Aerobic
b. Acid-fast
c. Facultative
d. Anaerobic
-Aerobic bacteria use oxygen as a terminal electron acceptor and grow well in room air.
-Most clinically significant aerobic organisms are actually facultatively anaerobic, being able to grow in the presence (i.e., aerobically) or
absence (i.e., anaerobically) of oxygen.
-Other aerobic bacteria require only low levels of oxygen (approximately 20% or less) and are referred to as being microaerophilic or
microaerobic.
-Anaerobic bacteria are unable to use oxygen as an electron acceptor, but some aerotolerant strains will still grow slowly and poorly
in the presence of oxygen
Reference : Bailey’s 14th edition , page 95
27. An organism that causes chancroid and which appears as small gram negative coccobacilli is ____.
a. H. ducreyi
b. Gardnerella vaginalis
c. Bruella
d. N. gonorrhaea
Chancroid; genital lesions progress from tender papules (i.e., small bumps) to painful ulcers with several satellite
lesions
28. How will you know if an N95 mask works properly?
a. Covers the mouth
b. Covers the nose
c. Snug fit
d. Wet outside but dry inside
Always read and follow the manufacturer's directions when using an N95 mask. It must cover both the nose and mouth to
keep you from breathing in mold and dust. If it does not have a snug fit, it will not work properly. Correct fit of the mask
requires contact with smooth skin. It will not work properly for people with beards or facial hair. Even one-day beard growth has been
shown to let air leak in. Always use both straps on the mask to hold it in place to keep air from leaking around it. –
29. What type of organism demand special and enriched nutritional environment?
a. Nonpathogenic
b. Fastidious
c. Nonfastidious
d. Pathogenic
Fastidious bacteria - Hard to grow; requires additional growth factors.
Enriched media contain growth enhancers that are added to nonselective agar to allow fastidious organisms to flourish. Chocolate
agar is an enriched medium. – MAHON 5th edition
30. What does a desiccator do?
a. Preserve moisture-sensitive items
b. Precipitate
c. Dilute concentrated acids
d. Agglutinate
31. The required preventive maintenance of centrifuges is ___.
a. Check temperature everyday
b. Check and adjust every 3 hours
c. Check rpm every year
d. Check rpm every 6 months
-
Quick review cards for medical laboratory science by Dietz Polansky
32. In thioglycollate broth medium, where do you find obligate anaerobe?
a. Middle of the tube
b. At the bottom of the tube
c. At the top of the tube
d. Evenly spread in the tube
Thioglycollate broth
Components : Pancreatic digest of casein, soy broth, and glucose to enrich growth of most bacteria. Thioglycollate and agar reduce
Eh. May be supplemented with hemin and vitamin K.
Purpose : Supports growth of anaerobes, aerobes, microaerophilic, and fastidious microorganisms
-Baileys 14th edition page 94
33. Elongated embryonated, unoperculated ova with terminal spine seen in a urine specimen is indicative of ___.
a. Schistomosa haematobium
b. S. intercalatum
c. Schistosoma japonicum
d. S. mansoni
To optimize recovery of S. haematobium in urine, the specimen should be collected between noon and 2 pm.
-Bailey’s 14th edition
34. Which of the medically important streptococci is characterized by beta-hemolysis, bacitracin sensitive and PYR test positive?
a. Streprococcus pneumonia
b. Streptococcus pyogenes
c. Viridans group
d. Streptococcus agalactiae
35. What is an appropriate action if the diameters of the zones of inhibition are too large or too small with all the antimicrobials being
tested?
a. Decrease amount of agar dispensed
b. Ensure that discs are applied to inoculated plates within 15 minutes
c. Ensure that plates are incubated immediately after application of discs
d. Standardize inoculum
36. What is blood agar made of?
a. Beef extract and casein hydrosylate
b. Bile salts and sheep blood
c. Nutrients and 5% sheep blood
d. Sodium thioglycolate and sheep blood
37. A device used to incubate, agitate and monitor blood culture bottles for microbial growth is a ___ system.
a. Micobiological
b. Blood monitoring
c. Blood culture
d. Incubator
38. An organism appearing as small gram negative coccobacilli that causes chancroid is ___.
a. H. ducreyl
b. Gardnerella vaginalis
c. N. gonorrhaea
d. Brucella
39. Which is transmitted by a black fly by laying its eggs in running water and where the larvae attach to the rocks?
a. Onchocerca volvulus
b. Mansonella ozzardi
c. Brugia malayi
d. Wuchereria bancrofti
O. volvulus is found throughout Africa, Central America, and South America. The parasite is transmitted by the black fly, Simulium spp.
The black fly lays its eggs in running water where the larvae attach to rocks. The larvae feed on algae and bacteria. The
adults emerge as a flying insect. The females require a blood meal, whereas the males are nectar feeders. The flies feed predominantly
during the day.
– Bailey’s 14th edition , page 725
40. What is NOT considered Personal Protective Equipment?
a. Hand sanitizer
b. HEPA filter
c. Gloves
d. Laboratory coat
Remember ! Hepa filters are installed in Respirators such as in N95 respirators
Filtration of air is accomplished using highefficiency particulate air (HEPA) filters designed to remove organisms larger than 0.3 mm
from isolation rooms, operating rooms, and biologic safety cabinets (BSCs).
-Bailey’s 14th edition, page 44
41. Sputum sample from a female teenager with cystic fibrosis and diagnosed with pneumonia shows gram negative bacilli with
yellow, smooth columbium. Further testing gave the following results

oxidase (+)

TSI alkaline/alkaline

Glucose oxidized

Fluorescence (-)

Lysine decarboxylase (+)
What is the most likely organism involved?
a. Shewanella putrefaciens
b. Burkholderia cepacia
c. Klebsiella pneumonia
d. Stenotrophomonas maltophilia
B. cepacia complex contains plant pathogens that have arisen as opportunistic organisms, usually associated with pneumonia in
patients with CF or chronic granulomatous disease (CGD).
B. cepacia complex often produces a weak, slow, positive oxidase reaction. Almost all strains oxidize glucose, and many will oxidize
maltose, lactose, and mannitol. Most strains are lysine decarboxylase (LDC) and o nitrophenyl-β-Dgalactopyranoside (ONPG) positive,
whereas most strains are ornithine decarboxylase (ODC) negative and fail to reduce nitrate to nitrite. Isolates are motile by means of
polar tufts of flagella
-Bailey’s 14th edition
42. Which type of tapeworm is characterized by pollen grain like appearance of the proglottids?
a. Diphyllobothrium
b. Dipylidium
c. Hymenolepis
d. Taenia
T.saginata
I.H : Cattle
Mode of infection: Ingestion of Cysticercus in infected beef
Scolex: Quadrate, 1-2 mm in diameter; no rostellum or hooklets; 4 suckers
Usual means of diagnosis: Gravid proglottids in feces; they are longer than wide (19 3 17 mm) and have
15-20 lateral branches on each side of central uterine stem; they usually appear singly; spheroidal yellow-brown, thickshelled eggs (3143 mm in diameter) containing an oncosphere may be found in feces.
Diagnostic problems or notes: Eggs are identical to those of Taenia solium; ordinarily can distinguish between species only by
examination of gravid proglottids; eggs can be confused with pollen grains (handle all proglottids with extreme care).
-Bailey’s 14th edition, page 731
43. Which is NOT a strategy in Parasitology Quality Assurance?
a. Set up positive and negative controls
b. Ensure adequate training of all laboratory staff
c. Dispatch test results for ER immediately
d. Standardized reporting of concentration of parasites
Quality assurance procedures in the parasitology laboratory are similar to those in other laboratory sections. An updated procedure
manual; controls for staining procedures; and records of centrifuge calibration, ocular micrometer calibration, and refrigerator and
incubator temperatures should be available. Reagents and solutions must be properly labeled. In addition, the parasitology laboratory
should have the following:
• A reference book collection, including texts and atlases
• A set of digital images of common parasites
• A set of clinical reference specimens, including permanently stained smears and formalin-preserved feces
The department should also be enrolled in an external proficiency testing program. An ongoing internal proficiency testing program
should be used to enhance the identification skills of the laboratory scientists, especially if a full-time parasitologist is not employed.
-MAHON, 5th edition, page 631
44. Positive cultures of yeast and filamentous fungi are reported with the _____.
a. Gram staining result
b. Organism identification
c. Number of colonies
d. Culture characteristics
45. Identify the cause of Loeffler’s syndrome?
a. Acute inflammation
b. Hypersensitivity reaction
c. Granulomatous inflammation
d. Mechanical obstruction
p.s : DI KO TALAGA ALAM ANO ANG TAMANG SAGOT HAHAHAHAH
Organisms found in sputum that may cause pneumonia, pneumonitis, or Loeffler’s syndrome include the migrating larval stages of A.
lumbricoides (most common cause), S. stercoralis, and hookworm; the eggs of Paragonimus spp.; Echinococcus granulosus hooklets
and the protozoa Entamoeba histolytica, Entamoeba gingivalis, Trichomonas tenax, Cryptosporidium spp., and possibly the
microsporidia - Mahon
Loeffler’s syndrome, characterized by bilateral diffuse, mottled pulmonary infiltrates and mild bronchitis associated with peripheral
eosinophilia. – Henry’s 22nd edition
In rare cases, cutaneous larva migrans may be complicated by Löffler syndrome. This syndrome is thought to result from a type I
hypersensitivity reaction related to the pulmonary larval migration phase of various parasites. It is characterized by migratory
pulmonary eosinophilic infiltrates and peripheral eosinophilia, with malaise, fever, and cough – ncbi.nih.gov
46. What type of growth can an agar slant produce?
a. Turbid
b. Clear
c. Pellicle
d. Diffuse
Not sure 
47. Animals
a.
b.
c.
d.
that harbor parasites and serve as an important source of infection are known as ___ host.
Reservoir
Accidental
Natural
Intermediate
48. On BA plate, a non lactose fermenter that shows round, smooth, convex, colonies, appearing as black or very dark purple and has
ammonium cyanide odor is suggestive of _____.
a. Shigella dysenteriae
b. Chromobactereium violaceum
c. Vibrio cholera
d. Salmonella typhi
-Bailey’s 14th edition, page 403
49. What is the role of the reducing agent in the Stuart transport medium?
a. Maintain ciability of organisms
b. Neutralize the reaction
c. Prevent oxidation
d. Inhibit bacterial growth
50. Tapeworms anchor themselves to the inside of the intestine of their host using their ___.
a. Scolex
b. Legs
c. Mouth
d. Strobili
The anterior headlike segment of a tapeworm, or scolex, has suckers and, in some species, hooklets as a means of attachment to the
intestinal mucosa – MAHON 5th edition, page 667
51. Which specimen can be transported by itself for virus isolation?
a. Skin scrapping’s
b. NO swab
c. Wound discharge
d. CSF
52. What are the forms of Leishmaniasis?
a. Cutaneous, visceral, mucocutaneous
b. Gastrointestinal, mucocutaneous
c. Mucocutaneous, visceral
d. Visceral, mucocutaneous, respiratory
53. Refrigeration of stool specimen is not recommended when amoebic ___ are suspected.
a. Eggs
b. Larvae
c. Trophozoites
d. Cysts
Examination of fresh specimens permits the observation of motile trophozoites, but this must be carried out without delay. Liquid
(diarrheic) specimens (which are more likely to contain trophozoites) should be examined within 30 minutes of passage (not within 30
minutes of arrival in the laboratory!), and soft specimens (which may contain both trophozoites and cysts) should be examined within
one hour of passage. If delays cannot be avoided, the specimen should be preserved to avoid disintegration of the trophozoites.
Formed specimens (less likely to contain trophozoites) can be kept for up to one day, with overnight refrigeration if needed, prior to
examination.- CDC
54. Rickettsioses and other related diseases have a/an __ vector, except Coxiella burnetti.
a. Human
b. Arthropod
c. Mammalian
d. Aquatic
55. Which trematode egg resembles S. haematobium and acid fast positive using the Ziehl-Neelsen test?
a. S. japonicum
b. S. haematobium
c. S. intercalatum
d. S. mansoni
56. Automation in a public health laboratory where numerous specimens are submitted is advantageous because ___.
a. Laboratory reports are computer-generated
b. Increase productivity
c. Manpower hiring is decreased
d. Market is competitive
57. What is the relationship of the zone of inhibition to the MIC of the test bacterium?
a. Equally proportional
b. Directly proportional
c. Non related
d. Inversely proportional
Minimum Inhibitory Concentration (MIC) is defined as the lowest concentration (expressed as mg/L or μg/μL) of an antimicrobial
agent that inhibits the visible in-vitro growth of microorganisms. The MIC test determines the antimicrobial activity of a test agent
against a specific bacteria.
The MIC and the zone diameter of inhibition are inversely correlated. The more susceptible the microorganism is to the antimicrobial
agent, the lower the MIC and the larger the zone of inhibition. Conversely, the more resistant the microorganism, the higher the MIC
and the smaller the zone of inhibition. – Bailey’s
58. The following are general guidelines in specimen collection for viral studies, EXCEPT ____.
a. Collect specimen at night
b. Adequate volume
c. Sterile, chemically clean containers
d. Correct site
59. When a laboratory can document a satisfactory performance of daily disk diffusion susceptibility QC, the frequency of performing
this activity can be reduced to ___.
a. Every other week
b. Twice a week
c. Every week
d. Every month
60. What is the stage of Lyme Disease infection that produces a characteristic red, ring-shaped skin lesion with a central clearing that
first appears at the site of tick bite?
a. Venereal syphilis
b. Acute necrotizing ulcerative gingivitis
c. Erythema migrans
d. Lymphogranuloma venereum
Lyme disease is characterized by three stages, not all of which occur in any given patient. The first stage, erythema migrans (EM),
is the characteristic red, ring-shaped skin lesion with a central clearing that first appears at the site of the tick bite but may develop at
distant sites as well . Patients may experience headache, fever, muscle and joint pain, and malaise during this stage. The second
stage, beginning weeks to months after infection, may include arthritis, but the most important features are neurologic disorders (i.e.,
meningitis, neurologic deficits) and carditis. This is a and tissues. In addition, neurologic symptoms and infection may occur in the
meninges, spinal cord, peripheral nerves, and brain. The third stage is usually characterized by chronic arthritis or acrodermatitis
chronica atrophicans (ACA), a diffuse skin rash, and may continue for years. There is an association between Borrelia species and
distinct clinical manifestations. For example, B. garinii has been associated with up to 72% of European cases of neuroborreliosis.
–Bailey’s 14th edition, page 584
61. Which agar plate is utilized for N. gonorrhoeae and N. meningitides cultures?
a. Bile esculin
b. Thayer Martin
c. Campy blood
d. Bordet Gengou
Specimens received in the laboratory for isolation of N. meningitidis (for detection of carriers) or N. gonorrhoeaeshould be plated to a
selective medium, either modified Thayer-Martin or Martin-Lewis agar
-Bailey’s 14th edition, page 963
62. A 10 y/o female was admitted to the emergency room with 2 days of severe diarrhea after eating cheeseburger sandwich from a
local restaurant. Cultures from three consecutive stool samples contain blood and mucus. Growth on XLD agar has yellow colonies,
HE agar grew yellow colonies, Mac agar has light pink to dark pink colonies, and MAC with sorbitol agar grew dark pink and many
colorless colonies. Which is the most likely organism identified?
a. Yersinia enterocolitica
b. Salmonella typhi
c. Escherichia coli
d. Shigella sonnei
63. A pseudophyllidean cestode is characterized by _____.
a. A scolex bearing 2 slit-like grooves
b. Operculated eggs
c. Convoluted uterine tubes
d. Presence of a uterine pore
e.
64. The normal stool is brown due to ___.
a. Intake of iced tea
b. Type of food
c. Bile pigments
d. Dehydration
65. Modified trichome stains are used primarily to demonstrate_____.
a. Microsporidian spores
b. Coccidian oocysts
c. Helmith eggs
d. Protozoan cysts and trophozoites
Specially modified acid-fast stains are necessary for identification of intestinal coccidia and modified trichrome stains are recommended
for identification of intestinal microsporidia. These stains are specifically designed to allow identification of coccidian oocysts and
microsporidian spores, respectively
-Bailey’s page 615
Principle
This technique is designed to allow examination and recognition of organism morphology under oil immersion examination (x100
objective, for a total magnification of x1000), primarily allowing recovery and identification of intestinal microsporidial spores. The
internal morphology (horizontal or diagonal “stripes”) may be seen in some spores under oil immersion.
Specimen
Any stool specimen that is fresh or preserved in formalin, sodium acetate–acetic acid–formalin (SAF), or the newer single vial– system
fixatives (universal fixatives).
Reagents
Modified trichrome stain (using high dye–content chromotrope 2R) and associated solutions; dehydrating solutions (alcohols, xylenes,
or xylene substitutes); mounting fluid (optional).
Examination
Oil immersion examination (31000) of at least 300 fields; additional fields may be required if suspect organisms have been seen but are
not clearly identified.
Results
Identification of microsporidial spores may be possible; however, their small size makes recognition difficult. Final laboratory results
depend heavily on the appearance of the quality control (QC) slides and comparison with positive patient specimens.
Notes and Limitations
Because of the difficulty in getting dye to penetrate the microsporidial spore wall, this staining approach can be helpful. Procedure
limitations are related to specimen handling (proper centrifugation speeds and time, use of no more than two layers of wet gauze for
filtration, and complete understanding of the difficulties in recognizing microsporidial spores because of their small size [1-3 mm]).
-Bailey’s 14th edition, pages 617-618
66. Which type of Beta hemolytic streptococci show medium-sized colony on BAP, hydrolyzes hippurate giving an arrow head streak
intersecting with S. aureus.
a. S. typhi
b. S. agalactiae
c. S. pyogenes
d. S. marcescens
67. Identify the organism given the following biochemical reactions:

H2S (+)

Urea (-)

LDC (-)
a. Proteus
b. Citrobacter
c. Escherichia
d. Enterobacter
SPACEd = H2S +
68. The most commonly used digestion-decontamination reagent for Myebacterium suspected organism is ___.
a. NALC(N-Acetyl L-Cysteine)
b. 2% NaOH
c. KOH
d. HCl
-Mahon 5th edition, page 1023
69. Which of the following is considered a step during the pre-analytic phase?
a. Specimen handling in the biosafety cabinet
b. Preliminary identification of bacterial isolates
c. Specimen transport
d. Initial observation of culture characteristics
70. What organism can produce an antiphagocytic capsule and has the ability to adapt for intracellular survival?
a. Escherichia coli
b. Edwardsiella tarda
c. Citrobacter
d. Yersinia pestis
71. Scabies is a/an ___.
a. Invasion
b. Parasitism
c. Infection
d. Infestation
Scabies is a skin infestation caused by a mite known as the Sarcoptes scabiei.
Remember pag mga ectoparasite = infestation
pag Endoparasite= infection
72. How do you proceed with specimen handling when there is delay in the transport of specimen?
a. Add fixative solution
b. Store at 4 degree Celsius for no longer than 24 hours
c. Store in freezer ASAP
d. Add normal saline solution
73. Bacteria that thrive in extreme heat are called ____.
a. Thermophiles
b. Psychrotrophs
c. Mesophiles
d. Psychrophiles
Bacteria that grow best at high temperatures are called thermophiles (optimal growth at 50° to 60° C).-Mahon
74. Most bacteria causing food spoilage grow at __ pH.
a. Alkaline
b. Any
c. Acidic
d. Neutral
75. Which of the following is NOT a characteristic of Enterobacteriaceae?
a. Catalase (-)
b. Oxidase (-)
c. Able to reduce nitrate to nitrate
d. All ferments glucose
-Mahon 5th edition, page 421
76. Which of the following will fall within an analytical variable?
a. Specimen transport
b. Preservative to be used
c. Test processing
d. Test results
77. Testing
a.
b.
c.
d.
for antibiotic sensitivity is often done by the ___ method.
Kirby-Bauer
Stokes
Broth dilution
Etest
78. What is the intermediate host of Echinococcus multilocularis where the parasite is occasionally transmitted to humans through
ingestion of contaminated food or water?
a. Rodents
b. Coyotes
c. Dogs
d. Fly
Although rarely found in the brain of humans, Echinococcus multilocularis causes alveolar hydatid disease, which is a fatal form of
echinococcosis. It is the most lethal of all helmintic diseases. The cyst is extremely dangerous because it lacks a laminated
membrane and develops a series of connected chambers. The chambers contain little or no fluid and rarely contain a scolex. The
morphology of the cyst is very similar to that of E. granulosus, but the adult organisms are much smaller (1.2-3.7 mm). The cysts are
very resistant to cold temperatures.
E. multilocularis is found in Asia, Europe, and northern North America, including areas such as Alaska, Montana, and Minnesota. Foxes,
coyotes, and dogs are the definitive host for E. multilocularis, whereas rodents are the intermediate host
-Bailey’s 14th edition, page742
79. Which serologic profile concurs with an individual with chronic infection?
HBsAg Anti-HBc
Anti-HBs IGM anti-HBc
A
(+)
(+)
(-)
(+)
B
(-)
(-)
(-)
C
(-)
(-)
(+)
D
(+)
(+)
(-)
(-)
a.
b.
c.
d.
C
A
D
B
Note! 
A. Acute/early infection
B. Susceptible individual / No previous exposure
C.VACINNATED / IMMUNIZED
80. Which organism will BEST be identified using the following laboratory tests?
Gram stain examination
Reverse CAMP test
Lecithinase
Hemolysis
a. Clostridium perfringens
b. Streptococcusagalactiae
c. Bacillus anthracis
d. Propionibacterium acnes
81. To isolate Salmonella and Shigella species from other gram negative enteric bacilli, what medium is used?
a. macConkey’s agar
b. trypticase Soy broth
c. Nutrient Agar
d. Xylose Lysine Desoxycholate (XLD) agar
As with HE agar, xylose-lysine-deoxycholate (XLD) agar is selective and differential for Shigella spp. and Salmonella spp. The salt,
sodium deoxycholate, inhibits many gram-negative bacilli that are not enteric pathogens and inhibits grampositive organisms. A phenol
red indicator in the medium detects increased acidity from carbohydrate (i.e., lactose, xylose, and sucrose) fermentation. Enteric
pathogens, such as Shigella spp., do not ferment these carbohydrates, so their colonies remain colorless (i.e., the same approximate
pink to
red color of the uninoculated medium). Even though they often ferment xylose, colonies of Salmonella spp. Are also colorless on XLD
because of the decarboxylation of lysine, which results in a pH increase that causes the pH indicator to turn red. These colonies often
exhibit a black center that results from Salmonella spp. producing H2S. Several of the nonpathogenic organisms ferment one or more
of the sugars and produce yellow colonies
-Bailey’s 14th edition, page 94
82. Wandering larvae in the skin is caused by a ____.
a. Pinworm
b. Filarial
c. Hookworm
d. Whipworm
Ancylostoma braziliense and Ancylostoma caninum are common hookworms of dogs and cats. The parasites penetrate the skin and
cause cutaneous larva migrans (CLM), also referred to as creeping eruption.
-Bailey’s 14th edition, page 716
83. Why is there a need to allow sterilized material to stand for about 10 minutes in the autoclave chamber before unloading?
a. To allow trapped air to escape from hot liquids
b. To allow the room to cool
c. To cool down the autoclave door
d. To prevent inhalation of steam
84. Which organism can be visualized with silver impregnation method?
a. Vibrios
b. Salmonella
c. Shigella
d. Spirochetes
85. What is considered Nutritive Media?
a. CAN
b. Thioglycollate broth
c. BAP/CAP
d. MAC
Nutritive media contain nutrients that support growth of most nonfastidious organisms without giving any particular organism a
growth advantage. Nutrient media include tryptic soy agar and nutrient agar plates for bacteria, or Sabouraud’s dextrose agar for fungi
Nutritive media support the growth of a wide range of microorganisms and are considered nonselective because, theoretically, the
growth of most organisms is supported. Nutritive media can also be differential, in that microorganisms can be distinguished on the
basis of certain growth characteristics evident on the medium. Blood agar is considered both a nutritive and differential medium
because it differentiates organisms based on whether they are alpha (a)-, beta (b)-, or gamma (g)-hemolytic
86. Which is a liver fluke?
a. Paragonimus westermani
b. Chlonorchis sinensis
c. Schistosoma mansoni
d. Fasciolopsis buski
87. Infection of this parasite occurs via ingestion of poorly cooked freshwater fish containing the plerocercoid larval form. The
unembryonated operculated eggs with terminal; knob is similar to trematode eggs. Which is the cestode described?
a. H. diminuta
b. D. latum
c. D. canicum
d. H. nana
Diphyllobothrium latum, the freshwater broad fish tapeworm, is the largest human tapeworm. Adults have been known to reach up to
15 m in length, with more than 3000 to 4000 proglottids, and reside within a host for 30 years or more. The proglottids are
characteristically wider than long with a central rosette-shaped uterine structure (Figure 53-1). The scolex is spatulate and contains two
shallow sucking grooves referred to as bothria (Figure 53-2, A and B). D. latum has unembryonated eggs. The eggs are
operculated (appears as a lid) with a terminal knob, similar to trematode eggs .The intermediate hosts include
crustaceans and freshwater fish.
-Bailey’s 14th edtion, page 728
88. Which of the following beta-hemolytic Streptococci gives a positive hippurate test?
a. Strepyococcus agalactiae
b. Strepyococcus pyegenes
c. Strepyococcus anginosus
d. Strepyococcus pneumonia
89. The adult female has a distinctive morphology with spiral, winding, “barber pole” appearing uterus is a characterized of _____.
a. Toxocara cati
b. Trichinella spiralis
c. Parastrongylus cantonensis
d. Ancylostoma craziliense
Parastrongylus cantonensis, previously known as Angiostrongylus sp., is a filarial worm commonly referred to as the rat lung worm.
Definitive diagnosis relies on histologic identification of the adult female worm. The adult female worm has a distinctive morphologic
appearance with a spiral, winding, “barber pole” appearing uterus
-Bailey’s 14th edition, page 719
90. The gold standard for laboratory confirmation of malaria is ____.
a. Serological test
b. Examination of a Giemsa-stained blood smear
c. Immunochromatographic test
d. Molecular test (PCR)
Thick and thin smear using geimsa stain is still considered as the gold standard test for malarial detection
91. All of the following organisms share the Same morphologic similarities. All are small,curved, and motile, gram-negative bacilli:
EXCEPT:
a. Enterobacter
b. Arcobacter
c. Helicobacter
d. Campylobacter
Campylobacter, Arcobater, and Helocibacter. All organisms belonging to these genera are small, curved, motile, gram-negative bacilli.
With few exceptions, most of these bacteria also have a requirement for a microaerobic (5%-10% O2) atmosphere. – Bailey’s 14th
edition, page 452
92. A test that indicates the pseudoperoxidase activity of hemoglobin where oxygen is released from hydrogen peroxide to oxidize the
Guaiac reagent is ____.
a. Occult blood
b. Fecal fat
c. Knots
d. Cellulose tape
ARAL MABUTI MGA RMTS <3
-I.K Aytona