Microbiology Flashcards
What is the most common cause of viral (aseptic) meningitis?
Enterovirus
What are the dematiaceous molds?
Fast growers: Bipolaris, Drechslera, Exserohilum, Helminthosporum, Curvularia, Alternaria, Ulocladium and Stemphilium
Slow growers: Exophialia, Wangiella, Hortaea, Pseudoallescheria boydii/Scedosporium boydii complex and Scedosporium prolificans
What is being shown here that is acquired from eating poorly cooked shellfish?
Paragonimus (lung fluke)
What rapid growing mycobacterium:
• Negative iron uptake
• Tolerant to 5% NaCl (heavy growth)
• Negative nitrate reductase
• Resistant to all standard anti-TB drugs
• Fewer drug options than M. fortuitum
– Susceptible to amikacin, cefoxitin, imipenem,
clarithromycin
– Resistant to fluoroquinolones
• Clarithromycin is the drug of choice for localized
infections, although resistant strains are emerging
M. abscessus
Explain how the different fermenters change the color of KIA/TSI slants initially and then at 24 hours (kind of a vague question but this is a paragraph in compendium and seems like good testable material).
Initially, a bacterium that ferments glucose but not lactose will produce an acidic (yellow) slant and acidic (yellow) butt. After the limited quantity of glucose is consumed, the organism will begin oxidative metabolism of proteins, which can only take place in the oxygen rich environment of the slant; this will turn the slant back to alkaline (red) by 24 hours, while the butt will remain yellow.
Therefore, when interpreting at 24 hours if the bottom is yellow and top is red, it means glucose fermenter only but if the top were yellow too it means lactose/sucrose fermenter in addition to glucose fermenter (both yellow, ferments both)
What diseases and responsible organisms are transmitted by body lice (Pediculus humanus)?
- Epidemic typhus (Rickettsia prowazekii)
- Liceborne relapsing fever (Borrelia recurrentis)
- Trench fever (Bartonella quintana)
What is the preferred lab test for Cryptococcus?
Latex antigen test
What organism is seen in the photo?
Toxoplasma gondii
The latent form is represented by slow-growing protozoa forms called bradyzoites encased in cysts with a cyst wall. Multiple basophilic dot-like parasites can be seen in cysts
What two mediums are mycobacterium spp grown in?
Lowenstein Jensen (solid medium egg based)
Middlebrook (agar based)
What is the only malaria spp to have quartan fevers (every 72 hours instead of 48 hours)?
P malariae
What parasitic organism is shown here and how can you be sure?
Entamoeba histolytica
Cannot distinguish E. histolytica/dispar unless RBCs seen in trophozoites
Erythrophagocytosis is diagnositc of histolytica cyst
Which bacterial spp produces chalky white colonies which become salmon orange pink when they mature, have a “musty basement” odor, is lysozyme resistant and has aerial hyphae?
Nocardia spp
What egg is this?
Taenia spp
What are the ampC organisms resistant to that the ESBLs are not?
The cephamycins (cefoxitin and cefotetan)
AmpC is also resistant to the beta lactamase inhibitors
Which virus causes this cytopathic effect?
HSV
RAPID (time to CPE 1-3 days), shrunken or enlarged cells starting at the edge of the cell sheet, sweeping CPE, occasional giant cells
Can be found in PMK and Hep2 (++) but grows best in HDF cells (+++)
*PMK=Primary Monkey Kidney, Hep2/HeLa=Human Epithelial Cells, HDF=Human Diploid Fibroblasts
The organism seen here on this cornmeal plate looks similar to Candida glabrata (which will not have spaces between colonies) and it is UREASE positive and produces MELANIN on bird seed agar?
Cryptococcus neoformans
Urease positive and also phenol oxidase positive
Which clostridium species is boxcar shaped and preliminary ID involves demonstrating lecithinase activity?
C. perfringens
*Double zone of beta hemolysis on blood agar
Where is the latency and what are the acute and reactivation diseases caused by:
1) HHV6
2) HHV7
3) HHV8
1) HHV 6 is dorment in T cells and causes roseola (exanthem subitum) and can be reactivated in immunocomprised
2) HHV7 is dorment in lymphocytes and causes roseola (occasionally) and can be reactivated in immunocomprised
3) HHV8 is dorment in B lymphocytes and endothelial cells and causes unknown disease acutely but reactivation causes Kaposi sarcoma and Primary Body Cavity lymphoma
Fulminant rocky mountain spotted fever can be seen in patients with what other disease?
Glucose-6-phosphatase deficiency
What antibiotics are the enterococci intrinsically resistant to?
The enterococci are intrinsically resistant to cephalosporin antibiotics, clindamycin, trimethoprim-sulfamethoxazole, and the aminoglycosides (with the exception of high-level aminoglycoside resistance screening). In vitro susceptibility testing should not be performed on enterococci for these antimicrobial agents as these agents may appear effective in vitro but are not clinically effective.
What two types of malaria DO recur from the liver?
– P. vivax – high incidence, most of the world except Western Africa
– P. ovale – lower incidence, occupies the niche in Western Africa
What are the major causes of pneumonia in the setting of animal exposure from:
1) Cattle or cats
2) Birds
3) Bat or bird droppings, especially pigeons
4) Mouse urine and feces
5) Rabbits
1) Coxiella burnetii
2) Chlamydophila psittaci and Cryptococcus neoformans
3) Histoplasma capsulatum
4) Hantavirus
5) Francisella tularensis
What organism is this?
Fusarium
Common in fungal keratitis (most commonly F. solani complex)
Macro and Microconidia
Where in the US can Mycobacterium leprae be found?
Causes leprosy (Hansen disease)
In the US, found in Hawaii, Texas and Louisiana where it is harbored by armadillos.
Cannot be cultured on artificial media. In tissue biopsy, be visualized with Fite stain
What is the 3 day test that rapid grower mycobacterium spp will be positive for?
Positive 3 day arylsulfatase test
–M. fortuitum complex (polymyxin B - S)
–M. chelonae (polymyxin B – R; citrate negative,
growth in 5% NaCl)
– M. abscessus (polymyxin B – R; citrate positive,
no growth in 5% NaCl)
What HPV types cause anogenital squamous cell carcinoma? What is the caveat with verrucous carcinoma?
HPV 16 and 18 account for most cases
Verrucous carcinoma (giant condyloma of Bushke and Lowenstein) is nearly always associated with HPV 6 or HPV 11
Which Enterobacteriaceae are strong lactose fermenters?
E coli, Klebsiella, Enterobacter
What two organisms are seen in intracellular vacuoles where they appear as mulberries or morulae and how you do tell them apart?
Ehrlichiosis and Anaplasma
Human MONOCYTIC ehrlichiosis (HME) is caused by Ehrlichia chaffeensis
Human GRANULOCYTIC anaplasmosis (HGA) is caused by Anaplasma phagocytophilum
Therefore, the intracellular inclusions will look the same with both organisms and are told apart by the KIND of cell they are inside (monocyte=Ehrlichia, granulocytes=Anaplasma)
Describe the mechanism and gene involved in MRSA
Based upon expression of altered penicillin binding proteins; these carry the mecA gene which allows them to express PBP2A, a penicillin target with little affinity for the drug. MRSA can be identified using routine disk diffusion testing with cefoxitin as the indicator drug, or with DNA hybridization probes to detect mecA or by detection of PBP2A using latex agglutination.
What diseases and responsible organisms are transmitted by the Culex spp of mosquito?
- Arboviral disease including west nile virus, St Louis encephalitis virus, Japanese encephalitis virus
- Lymphatic filariasis (Brugia malayi and Wuchereria bancrofti)
*Anopheles spp also transmits lymphatic filariasis
What is Dr. Huber’s mneumonic for remembering the AmpC Beta-lactamase producing organisms? *AmpC organisms are resistant to beta-lactamase inhibitors–generally causes resistance to all beta-lactams, except carbapenems and 4th generation cephalosporins (cefepime)
“My SPACE”
Morganella
Serratia
Proteus (not mirabilis), Providencia, Psuedomonas
Aeromonas, Acinetobacter
Citrobacter freundii (not kosari)
Enterobacter
What is the difference between a tube coagulase test and a slide coagulase test and which is the definitive one?
-Tube coagulase test detects FREE (secreted) coagulase and is the DEFINITIVE test–isolate is mixed with plasma in a tube and if coagulase is present will complex with coagulase reacting factor (CRF) in plasma which converts fibrinogen to fibrin forming a clot. Necessary to examine at 4 and 24 hours to avoid false negative. -Slide coagulase test detects cellbound coagulase (known as clumping factor). This test is faster but need tube test to confirm
Interpret this KIA/TSI slant:
K/A (red/yellow) means alkaline slant over acid butt. The bottom was fermented and the top was not! If the bottom is yellow, it means glucose fermenter and if the top were yellow it means lactose/sucrose fermenter. This result means the bacteria is a glucose fermenter only.
In addition, it is an H2S producer.
Possibilities include: Salmonella, Edwardsiella, Citrobacter (freundii), Proteus
“Black PECS”
What organism is shown here?
Trypanosoma cruzi
*Brucei looks similar except it will not be C shaped and it can be seen dividing wheras Cruzi will not usually be seen dividing
What HPV types (in order of frequency) cause oral focal epithelia hyperplasia (Heck disease)?
13, 32
What types of HPV (in order of frequency) cause HSIL?
16, 18, 31, 33, 35
This nematode is acquired from ingestion of raw or undercooked fish and biopsy may disclose an eosinophil rich granuloma containing the nematode.
Anasakiasis
What parasite is shown here on this acid fast stain which is characterized by these smudgy blobs but if you are lucky you will see the 4 sporozoites (left)? Antigen detection is test of choice
Cryptosporidium
- Resistant to chlorination, killed by ozonation, desiccation (2 h)
- Organisms excyst in small intestine, enter brush border epithelial cells but remain extracytoplasmic
VERY low infectious dose
What two gene loci have been identified in isoniazid resistance in TB?
What about rifampin, pyrazinamide and streptomycin resistance?
*alot of info on 1 card but this was in OSLER lecture, seems important but I don’t know how important so I just made a card
– katG: a catalase/peroxidase, probably responsible for transforming INH to an active drug
– inhA: involved in mycolic acid synthesis, probably a direct target of INH action
Alterations in these 2 genes responsible for at least 85% of INH resistance
Rifampin resistance
– rpoB, the beta subunit of RNA polymerase alterations in this locus responsible for >95% of RMP resistance
Pyrazinamide resistance
– pncA, pyrazinamidase, cleaves pyrazinamide to pyrazinoic acid
– PZA inhibits a fatty acid synthetase; resistance mutations in this locus as well
Streptomycin resistance
– rpsL, S12 ribosomal protein
– rrs, 16S ribosomal RNA
What is a modified acid fast stain and name 4 organisms it is useful in IDing.
Decolorization with dilute sulfuric acid rather than 1M HCl
Nocardia, Cryptosporidium, Cyclospora and Isospora
What is the one haemophilus that does not require X or V Factor to grow (the only one that will grow by itself on blood agar)?
Haemophilus aphrophilus
*not really haemophilus anymore, moved to aggregatibacter
Abscesses (liver, lung, brain) and endocarditis (the H in HACEK)
In what patient population has an unusual inhalational form of Sporothrix been identified?
chronic alcoholics
What organisms produce a green metallic sheen on EMB agar?
E coli and rarely Citrobacter freundii
The optimal culture temperature for initial incubation is 37C. What are the caveats regarding:
1) Yersinia enterocolitica and certain Pseudomonas spp (P fluorescens, P putida)
2) Campylobacter jejuni and Campylobacter coli
3) Listeria monocytogenes
1) Grow optimally at 25-30C
2) Grow optimally at 42C
3) Grows optimally at 37C but displays its characteristic motility only at 25C and is notoriously able to multiply at refrigeration temperature (4C)
What form of plasmodium spp is being shown here?
Band form of P. malariae
Think of this one as the “gigolo” of the spp because it likes older red cells so they wil be SMALLER
Band form is pathognomonic!
Mature form will have 8-12 merozoites rosetting with PIGMENT
Which antibiotics have almost universal coverage against the anaerobes?
Metronidazole, carbapenams and beta-lactam combos have almost universal coverage
What is the general mechanism of action for ESBL?
ESBLs are TEM and SHV class beta lactamases that hydrolyze penicillins, cephalosporins and the monobactam, aztreonam, conferring resistance to all of these drug classes. ESBLs do not hydrolyze the cephamycin antibiotics (ie; cefoxitin and cefotetan). ESBL’s are also inhibited by beta-lactamase inhibitors such as clavulanate, sulbactam and tazobactam.
*LOOK FOR–decreased susceptibility to 3rd generation cephalosporins or aztreonam with MICs>1mcg/mL and resistance to multiple cephalosporins but susceptibility to cephamycins (cefoxitin and cefotetan)
Which two selective medias are used for cultivation and isolation hardy enteric gram negative rods?
- MAC (has bile salts and crystal violet which inhibit growth of gram positive bacteria and delicate gram negative bacteria)
- EMB (eosin methylene blue which has aniline dyes that inhibit the growth of gram positive bacteria)
1) Which Nocardia complex can cause indolent soft tissue infections in normal immunocompetent hosts? 2) Which Nocardia complex can cause invasive pulmonary infection and disseminated infection involving CNS in immunocompromised hosts?
1) Nocardia brasiliensis complex
2) Nocardia asteroides complex (includes N. asteroides, N. nova, N. abscessus and N. farcinica–particularly drug resistant)
What is being shown here that is acquired by eating larvae with edible water plants?
Fasciola hepatica (liver fluke)/Fasciolopsis buski (intestinal fluke)
Cannot tell eggs apart
What disease and responsible organism is transmitted by the reduviid bug (Triatominae)?
American trypanosomiasis “Chagas disease” (Trypanosoma cruzi)
Which rapid growing mycobacterium:
- Positive iron uptake
- Tolerant to 5% NaCl (heavy growth)
- Positive nitrate reductase
- Resistant to all standard anti-TB drugs
M. fortuitum group
What yeast is presumptively ID’d using a rapid trehalose assimilation test?
Candida glabrata
Which species is responsible for the majority of cases of aspergilloma and allergic bronchopulmonary aspergillosis?
A fumigatus
1) What are the anaerobic spore forming gram positive bacilli?
2) What are the anaerobic non-spore forming gram positive bacilli?
3) What are the aerobic spore forming gram positive bacilli?
4) What are the aerobic non-spore forming gram positive bacilli?
1) Clostridium spp (perfringens, septicum, botulinum, tetani, difficile)
2) Actinomyces (same gram stain as Nocardia but Nocardia is aerobic and acid fast unlike Actinomyces), Propionibacterium
3) Bacillus spp (anthracis, cereus)
4) Listeria monocytogenes, Erysipelothrix rhusiopathiae, Nocardia, Rhodococcus equi, Corynebacterium diphtheria and Tropheryma whipplei
What is the carriage rate for Neisseria meningitides and what is the site?
10%, oropharynx
What is the significance of the lipopolysaccharide portion of the gram negative cell wall?
Endotoxin (Lipid A portion)
O polysaccharides are used for serotyping
Which dermatophyte produces a red pigment on the BACK of the plate and shows tear shaped microconidia arranged along the hyphae giving a “birds on a wire” appearance?
Trichophyton rubrum
What biochemical test can be used to differentiate between the MTB complex species?
M. tuberculosis complex contains VERY closely related organisms which include M. bovis, BCG and M. africanum
Niacin/Nitrate can help!
MTB is niacin/nitrate positive, M. bovis and africanum are negative
All produce a catalase that is labile at 68 degrees; most other mycobacteria produce heat-stable catalase!
Which Enterobacteriaceae are hydrogen sulfide positive?
Salmonella, Edwardsiella, Citrobacter freundii, Proteus
What is the carriage rate for strep pneumo in adults and in children and what is the site?
Adults-5%, Children-50%
Oropharynx
What does the Campy-BAP contain?
Antimicrobials to which Campylobacter spp are resistant (cephalothin, vancomycin, trimethoprim, amphotericin B and polymyxin B)
What egg is this?
Trichuris trichiura (whipworm)
Remember that the name is symmetrical and so is the egg with a lucent mucoid plus on each end
What are the viruses that are NOT cultivatable with routine viral culture?
HIV-1; hepatitis C virus; hepatitis B virus; parvovirus B-19; human herpesviruses 6, 7, and 8; Epstein-Barr virus; human papillomavirus; BK virus; and JC virus
What are the features of Legionnaires’ disease?
Atypical pneumonia with high fever, hyponatremia, renal dysfunction, diarrhea and neurologic abnormalities
Carbapenemases are grouped as molecular classes A, B and D. What organisms have:
1) Class A
2) Class B
3) Class D
4) What test illustrates KPC mediated resistance?
1) Predominately KPC which are found in Kleb pneumo, other Enterobacteriaceae and Serratia marcescens
2) Comprise the metallo-beta-lactamases such as IMP, VIM and SPM which are produced by Pseudomonas aeruginosa, Acinetobacter, Stenotrophomonas maltophilia and Enterbacteriaceae
3) OXA carbapenemase which are produced by Acinetobacter baumannii
4) Hodge test–Streak agar plate with carbapenam susceptible E. coli and put ertapenam disk in center and streak test organisms out from the disk. KPC organisms will distort zone of inhibition
What parasitic infection can cause rectal prolapse?
Trichuris trichiura (whipworm)
What are the metallo-beta-lactamases, what organisms have this and what antibiotic are these susceptible to that is different from the ESBLs and AmpC organisms?
VIM and IMP most common
Require zinc for activity
Pseudomonas and Acinetobacter (and a few enterics)
Usually susceptible to aztreonam (but may be hidden by other enzymes)
What is the most common helminthic infection in the world?
Ascaris lumbricoides
What are the important thermally dimorphic fungi?
Histoplasma capsulatum
Blastomyces dermatitidis
Coccidioides immits/posadasii
Paracoccidioides brasiliensis
Sporothrix schenkii
Penicillium marnefei
What two antibiotics are Proteus spp intrinsically resistant to?
Tetracycline and nitrofurantoin
What virus causes the inclusion shown?
Herpes Simplex Virus
This picture is showing a Cowdry type A inclusion (“owl eye”) bodies in multinucleated cells; nuclei are molded and chromatin in marginated
DEFINITE BQ!
Need to know how to recognize glucose fermentation in OF media (oxidation/fermentation) media.
Which of these pairs of tubes is showing glucose fermentation?
Pair 3
First tube in each pair is open and the second in each pair is overlayed (closed)
No yellow at all is negative reaction
Yellow in open tube but not closed = oxidation only
Yellow in both tubes = glucose fermentation
What are 3 causes of false positive results with Cryptococcus antigen test?
– Trichosporon beigelii infection (cross-reactive polysaccharide is produced)
– Contamination with agar and syneresis fluid on agar
– Platinum wire loops
What virus causes X linked lymphoproliferative disease (Duncan disease) and what is this disease?
EBV
Fulminant primary EBV infection, frequently fatal. Affects mainly males and patients with this disorder mount an overactive immune response to EBV resulting in fulminant infectious mononucleosis, B cell lymphoma, aplastic anemia and dysgammaglobulinemia.
Mechanism of death is usually hepatic necrosis; may be due to hemophagocytosis, agammaglobulinemia, B cell lymphoma
Defect is found in the SH2DIA (SAP) gene
Results in uncontrolled activation of T/NK cells following EBV infection
The CDC has defined a positive HIV1 Western blot as?
Any two of the following bands: p24, gp41, gp120/160
*p24 protein is the earliest detectable at 2-3 weeks
With malarial infections, how are the following inherited red cell anomalies protective?
a) Hgb S
b) Duffy negative blood type
c) G6PD Def
d) hereditary ovalocytosis
a) protective against P falciparum
b) protective againt P vivax
c) protestive against all spp
d) protective against cerebral malaria
What is the treatment for carbapenamase producing organisms (Klebsiella, E. coli)?
At this time, there are a limited selection of treatment options for CRE infections. Clinicians have been forced to re-evaluate the use of agents, which have been historically rarely used due to efficacy and/or toxicity concerns, such as polymyxins, fosfomycin, and aminoglycosides
BQ!
Organism Associated with Butyric Acid Production in the Chromatographic Test:
Fusobacterium
What serotypes of adenovirus are associated with:
1) respiratory illness
2) hemorhaggic cystitis
3) childhood gastroenteritis
1) serotypes 1-14 and 21
2) serotypes 11 and 21
3) serotypes 40 and 41
The mold form of Paracoccidioides is identical to that of which other fungus?
Blastomyces
Paracoccidioides has been called the “South American Blastomyces: because they look and behave very similarly
Of the plasmodium species, which one is shown here and can be idenfied if this finding is seen on smear?
Plasmodium OVALE
Most reliable diagnostic feature (albeit often difficult to find) to support the identification is a Schizont containing 6-14 merozoites clustered around the “dark pigment”. This was the only schizont seen on 5 thin smears and contains 7 very dark staining merozoites. Enumerating these merozoites is a very reliable method for determining P. vivax from P. ovale, as P. vivax Schizonts contain 12-24 merozoites.
Which spp of mycobacterium is characterized by:
Found in hot water systems—optimum growth temperature is 42°C.
May take 6 weeks or longer to grow because 37°C incubation is not optimal.
Causes chronic pulmonary disease in adults with underlying disease (e.g. COPD or bronchiectasis).
Extrapulmonary infection seen only in immunocompromised.
Slow growth, optimum growth at 42°C
Long, thin, branching, acid-fast rods on smear from liquid culture (“atypical morphology”)
Scotochromogenic and identified biochemically (arylsulfatase pos)
M. xenopi
Tuberculosis can be caused by any of the M. tuberculosis complex which includes which organisms?
M. tuberculosis
M. microti
M. bovis
M. africanum
M. canetti
What is the carriage rate for staph aureus and what site?
50%, nares
What organism is being shown in this Fite stain?
M. leprae
Acid fast organisms infiltrating a nerve
What is the most common cause of abdominal TB?
Mycobacterium bovis
What two types of malaria DON’T recur from the liver?
– P. falciparum – high incidence and severity
*so severe and you don’t see anything in blood other then ring forms because if it matures over the ring form, it sticks to vessel walls like crazy so you do not see it in peripheral blood
– P. malariae – lower incidence and severity
Both worldwide in the tropics
What two bacteria non glucose fermenting gram negative rods that are inherently resistant to carbapenams (treated with trimeth-sulfa)?
Stenotrophomonas maltophilia
Burkholderia cepacia
What should you avoid when performing a catalase test? What are the other important catalase positive pathogens other than Staph?
Avoid contaminating with blood agar since RBCs produce catalase
Other catalase positive pathogens: Campylobacter spp, Listeria spp and Bacillus spp
Which bacterial organism colony morphology is nonhemolytic with irregular borders (Medusa head colonies) that are tenacious and stand up when teased with a loop?
Bacillus anthracis
*This is one of the few NONMOTILE bacillus organisms
What organism causes encephalitis characterized by bilateral hemorrhagic necrosis within the anterior temporal lobes and is associated with RBCs in the CSF?
Herpes Simplex Type 1
CSF: RBCs, very high protein and low glucose
*HSV2 can cause meningitis but not encephalitis. HSV1 lies dormant in the trigeminal ganglia and HSV2 lies dormant in sacral ganglia.
What virus causes the effect shown?
Measles (Rubeola)
This is a Warthin-Finkeldey giant cell which can have up to 50 or more nuclei!
The inclusions are nuclear, cytoplasmic and syncytial
What virus causes the inclusion shown?
CMV
A nuclear AND cytoplasmic inclusion that produces “owl eye” appearance but they are not multinucleated like HSV
What disease does this organism cause?
Scabies
What is being shown in the picture and what infection is this characteristic of?
This is a fibrin ring granuloma commonly seen in the liver and bone marrow of patients with Q fever caused by Coxiella burnetii
Which anaerobe is ALWAYS resistant to metronidazole?
Propionibacterium acnes
Which bacteria traverse the bowel wall and entrench themselves within reticuloendothelial cells of the liver, spleen and gallbladder and what is this disease? The gallbladder then acts as a reservoir continually reinfecting the bowel leading to long term shedding.
Salmonella typhi and Salmonella paratyphi
Typhoid fever
What bacteria is gram invisible, requires L cysteine supplementation for in vitro culture, shows whitish colonies in 2-5 days on BCYE and ID can be confirmed by direct fluorescent antibody or latex aggluttination methods?
Legionella
What is this?
Schistosoma hematobium
What organism causes both granulomatous amebic encephalitis and amebic keratitis in contact lens wearers?
Acanthamoeba
*Balamuthia mandrillaris also causes GAE
What are some key characteristics and toxin produced by the following diarrheagenic strains of E coli:
1) EHEC (enterohemorrhagic)
2) ETEC (enterotoxigenic)
3) EIEC (enteroinvasive)
4) EPEC (enteropathogenic)
5) EAggEC (enteroaggregative)
1) EHEC (enterohemorrhagic)–capable of producing Shiga toxin associated with HUS, esp O157:H7
2) ETEC (enterotoxigenic)–watery diarrhea, main cause of “traveler’s diarrhea”, produces choleralike toxin
3) EIEC (enteroinvasive)–causes dysentery similar to Shigella, produces Shigalike toxin (T3SS), like Shigella it is nonmotile and lactose nonfermenting
4) EPEC (enteropathogenic)–causes dysentery similar to Shigella, DOES NOT produce Shigalike toxin
5) EAggEC (enteroaggregative)–infant diarrhea in underdeveloped countries and refractory diarrhea in HIV pts
VRE: What are the types of resistance and antibiotics affected by: 1) VanA gene 2) VanB gene 3) VanC gene
1) high level inducible resistance, vancomycin and televancin (Enterococcus faecium and faecalis)
2) high-to-moderate inducible resistance, vancomycin only (Enterococcus faecium and faecalis)
3) low level constitutive resistance, vancomycin only (Enterococcus casseliflavus and gallinarum–intrinsically resistant to vanc)
What is the lab test for Aspergillus (not the IgE test for allergic bronchopulmonary aspergillosis)?
ELISA assay for the serum marker galactomannan and/or 1-3-beta-D-glucan
What egg is this?
Ascaris lumbricoides
*this LUMBER as rough outer surface
What aspergillus spp is associated with oxalosis (calcium oxalate tissue deposition)?
A. niger
What two main diseases does HTLV virus cause?
HTLV1 infects CD4 T lymphocytes
1) Tropical spastic paraparesis (HTLV associated myelopathy)
affects women 3:1, causes demyelinating lesions within the upper thoracic and lower cervical cord
2) Adult T cell leukemia/lymphoma
Lifetime risk 5% in infected people before the age of 20yrs, incubation period of 20-30 years. Patients present with HSM, jaundice, wt loss and may feature hypercalcemia, skin rash, high serum concentrations of free IL-2 receptor and pronounced sense of thirst
Detection of β-D-galactoaminidase activity identifies what spp of Candida?
Albicans
Which drugs lack proven in vivo efficacy for infections with Enterococci?
Enterococci may appear susceptible to cephalosporins, clindamycin, trimethoprim-sulfamethoxazole, and aminoglycosides (except for high-level resistance screening) in vitro. However, these antimicrobials have no proven in vivo, clinical efficacy. Antimicrobial susceptibility reports should therefore not report these drugs as susceptible.
What are the two exceptions for treating asymptomatic bacteriuria? What is the criteria for diagnosis?
Exceptions: pregnant women and patients undergoing urologic instrumentation
Criteria: Asymptomatic women–two consecutive voided urines with isolation of the same species, >105 cfu/mL
Asymptomatic men–single voided urine with isolation of a single species >105 cfu/mL
Men or women–single catheterized specimen, single bacterial species >102 cfu/mL
What is a Jarisch-Herxheimer reaction?
A reaction to endotoxin-like products released by the death of harmful microorganisms within the body during antibiotic treatment. It is classically associated with penicillin treatment of syphilis. Duration in syphilis is normally only a few hours. The reaction is also seen in other diseases caused by spirochetes.
What is the rapid urease test and what organisms does it help identify?
Proteus and H pylori (urease positive)
Splitting (hydrolysis) of urea alkalinizes the medium leading to color change (pink or red)
Many bacteria have urease activity but only a few can degrade it quickly (within 4 hours) and are designated “rapid urease positive” organisms
Brucella is also rapid urease positive
What biochemical test is pretty much the only difference between Klebsiella oxytoca and Klebsiella pneumoniae?
K. oxytoca is indole positive and K. pneumoniae is indole negative
What are the viral cytopathic effects of Varicella Zoster Virus (VZV) and how does it differ from HSV?
VZV grows very poorly in culture and it takes about 14 days to grow whereas HSV is very rapid (1-3 days). The CPE is the same characterized by focal shrunken or enlarged cells, but advancing in a slow continuous manner.
VZV will NOT grow in Hep2/HeLa cells (HSV will) but will grow in PMK and HDF cells.
*PMK=Primary Monkey Kidney, Hep2/HeLa=Human Epithelial Cells, HDF=Human Diploid Fibroblasts
What are the IV Runyon groups and what are the organisms in them?
Classification for non-TB mycobacterium
I Photochromogens
Only produce pigment after exposure to light (M. kansasii–often isoniazid resistant and M. marinum)
Others: M. simiae, M. asiaticum, M. szulgai (22-24 degrees)
II Scotochromogens
Always pigmented (M. gordonae)–called tap water chromogen because it is so commonly isolated and almost never pathogenic, report as contaminant, M. xenopi, M. scrofulaceum M. flaviscens, M. szulgai (37 degrees)
III Nonchromogens
No pigment (M avium complex and TB complex)
IV Rapid growers
M. chelonae and fortuitum complexes
Name three methods for direct exam of fungal specimens.
Calcofluor white, KOH, Lactophenol cotton blue/KOH
What is the most common cause of aseptic meningitis in the winter and spring?
Lymphocytic Choriomeningitis Virus (LCM)
What is this?
Taenia saginata
Eggs of T. saginata are not infectious, unlike T solium; thus cysticercosis (larval form of disease in humans) due to T saginata does not occur
What supplementation does Francisella tularensis require to grow?
Sulfhydryl compounds (cysteine and cystine); can be isolated on routine media after extended incubation.
Oxidase and urease negative, beta lactamase positive
What is the purpose of using buffered charcoal yeast extract (BCYE) agar?
Recovery of Legionella spp
Contains cysteine and iron supplementation which is necessary to support growth of Legionella. The activated charcoal helps bind and sequester growth inhibitors that may be present in the specimen
What diseases and responsible organisms are transmitted by the Anopheles species of mosquito?
- Dog heartworm (Dirofilaria immitis)
- Malaria (Plasmodium spp)
- Lymphatic filariasis (Brugia malayi and Wuchereria bancrofti)
*Culex spp also transmits lymphatic filariasis
What are the molecular pathogen specific targets for staph aureus and MRSA in multiplex PCR assay?
Staphylococcal protein A (spa), SCCmec, and mecA gene
The spa gene is specific for staph aureus. SCCmec is the genetic element carrying mecA which is inserted by transposition into the orfX gene. The mecA gene encodes the protein conferring methicillin resistance which codes for the production of penicillin binding protein 2A (PBP2A) which acts as a beta lactam resistant transpeptide.
If you see organisms in a macrophage, how can you tell apart Leishmania vs Histoplasma and which one is being shown in this picture?
Leishmania
will show discrete organisms with nucleus and kinetoplast (PAS NEG)
The picture here is showing Histoplasma which will show budding yeast but parent and bud are not within a discrete membrane (PAS POS)
Which of the dimorphic fungi are associated with sclerosing mediastinitis?
Histoplasma
What spp of plasmodium is shown here?
P. ovale
Makes the red cells ovale
Schuffner dots ARE seen
What are the two primary diseases caused by EBV infection?
1) Infectious mononucleosis (mainly in adolescents and young adults)
2) X linked lymphoproliferative disease (Duncan disease) which mainly affects males. Patients with this disorder mount an overactive immune response to EBV resulting in fulminant infectious mononucleosis, B cell lymphoma, aplastic anemia and dysgammaglobulinemia
Which bacterial organism’s presumptive ID involves demonstration of the ability to reduce potassium tellurite to metallic tellurite? This organism’s presumptive ID is also demonstrated by brown-black colonies surrounded by black halos on Tinsdale agar.
Corynebacterium diphtheriae
*also must show toxigenicity! They have to be infected with a certain type of phage to produce a toxin so to test for the toxin there is a Elek test!
Name that microfilariae! (A-D)
A) Wucheria bancrofti
Sheathed, nuclei stop short of end of tail
B) Brugia malayi
Sheathed, two small nuclei in tail
C) Onchocerca volvulus
Unsheathed, from skin, not blood (if you seen unsheathed microfilariae in blood, it is probably Mansonella perstans!)
D) Loa Loa
Sheathed, nuclei to continue to end of tail
How many oil immersion fields but you examine on thick and thin smears when looking for malaria?
at least 100 oil immersion thick film fields or 300 thin film fields is required to acheive the reported sensitivity (5 parasites/uL)
What are the 3rd generation cephalosporins?
Cefotaxime
Ceftriaxone
Ceftizoxime
Ceftazidime
This fungus has a yellow-green to olive colony and LIGHT reverse of the plate.
Aspergillus flavus
What organism is this?
Trichinella spiralis
*if you see worms encysted in muscle, think about this organism
Why is it important to distinguish between Candida albicans and dubliniensis?
They are morphologically identical and are both germ tube positive but dubliniensis is more likely to develop fluconazole resistance
Distinguish by:
– C. albicans growth at 45C
– C. dubliniensis dark-green colonies on Chromagar
– C. dubliniensis reduction of 2,3,5-triphenyltetrazolium chloride
What is Ramsey Hunt syndrome and what causes it?
Reactivation of VZV in geniculate ganglion of the facial nerve
Causes: otalgia, unilateral facial paresis, vertigo, hearing loss and tinnitus
What is Bowenoid papulosis and what causes it?
Multiple small (2-3 mm) pearly papules in the genital region (penis, vulva, anus) that histologically resembles SCC in situ.
Rarely progresses to invasive cancer.
Caused by HPV 16 and/or 18
What diseases and responsible organisms are transmitted by the sandfly (Phlebotomus and Lutzomyia spp)?
- Leishmaniasis (Leishmania spp)
- Bartonellosis; Carrion disease (Bartonella bacilliformis)
- Arboviral disease (Vesicular stomatitis virus, Toscana and Sicilian virus)
What two parasitic infections are capable of person to person spread?
Enterobius vermicularis
Hymenolepis nana
By what mechanism does EBV cause primary infection?
Enteres body through pharyngeal or genital mucosa
Infects B lymphocytes via the C3d receptor (CD21)
CD8 T cells proliferate and are responsible for peripheral atypical lymphocytosis
The site of EBV latency is in the B cells; EBV genome persists in episomal form
In addition to Staphylococcus, what are the other catalase positive pathogens?
Campylobacter spp, Listeria spp, Bacillus spp
What is the novobiocin susceptibility test used for?
Distinguish Staphylococcus saprophyticus (resistant) from other coagulase negative Staph (susceptible)
What is the germ tube test?
Separate spp of Candida
– Grow yeast in serum 2h
– Separates C. albicans (+ germ tube) and other Candida species (no germ tube, instead budding hyphae)
C. albicans is generally fluconazole susceptible (>95%)whereas other Candida include species with a higher frequency of resistance.
When Candida is grown in human or sheep serum at 37°C for 3 hours, they forms a germ tubes, which can be detected with a wet KOH films as filamentous outgrowth extending from yeast cells. It is positive for Candida albicans and Candida dubliniensis. Approximately 95 – 97% of Candida albicans isolated develop germ tubes when incubated in a proteinaceous media.
What do you have to do in order to grow Malasessia furfur?
Put olive oil on the plate!
They need lipid to grow
Which Enterobacteriaceae are Voges-Proskauer (VP) positive?
Klebsiella, Enterobacter, Hafnia, Serratia, Pantoea
Which anaerobic gram negative bacilli show brick red fluorescence when exposed to UV light and after several days of growth, the colonies appear brown black in natural light?
Porphyromonas/Prevotella
What is Loffler syndrome?
When nematode (roundworm, hookworm) larvae penetrate mucosa, enter bloodstream and larvae is carried to lungs.
May produce transient infiltrates with eosinophilia
What organism is this (including species)?
Aspergillus fumigatus
The phialides only cover the TOP whereas flavus goes ALL the way around (see pic)
Which bacteria forms white cerebriform (molar tooth) colonies?
Actinomyces israelii
What organism is shown here?
- Asymptomatic to invasive intestinal / extraintestinal
- Fetid “pigpen” odor to breath reported
Balantidium coli
-Stool O&P – large ciliate
Cysts have macro and micro nucleus
The only medically significant ciliate organism is:
Balantidium coli
Cilia and characteristic kidney bean-shaped macronucleolus
What is this?
Schistosoma mansoni
What organism is being shown here (kind of trick question)?
Mycobacterium!
You can only tell because of the characteristic “ghost cells”–the organisms are not picking up stain but you see a space where they are
What diseases and responsible organisms are transmitted by rat fleas?
- Plague (Yersinia pestis)
- Murine typhus (Rickettsia typhus)
What organism is shown here?
It is unique in that high titers of serum antibodies is BAD (ie people that form Abs have disseminated disease) and the dissapearance of the antibodies is a sign of effective therapy?
Coccidioidomycosis
What egg is being shown?
Hookworm (can’t tell apart Necator from Ancylostoma)
Lucent shell with early embryo inside
Interpret this KIA/TSI slant:
K/A (red/yellow) means alkaline slant over acid butt. The bottom was fermented and the top was not! If the bottom is yellow, it means glucose fermenter and if the top were yellow it means lactose/sucrose fermenters. This result means the bacteria is a glucose fermenter only.
Possibilites include: Shigella, Serratia, Morganella, Providencia, Yersinia
“MY SPS”
This dimorphic fungi looks like this as yeast (cigar bodies) and produces a black colony in culture, what is it?
Sporothrix schenckii
The slide culture will look like this (daisy shaped with threads connecting to conidiophore)
What is the organism seen here?
Enterobius vermicularis
Cross section shows characteristic lateral alae
This fungus has a dark brown to black colony with a LIGHT reverse of the plate.
Aspergillus niger
What virus causes the inclusion shown?
Adenovirus
This is showing the smudge cells (a nuclear inclusion) produced by adenovirus in a case of adenovirus pneumonia.
*They could show this type of inclusion in multiple different organs
What bacteria requires nicotinic acid, cysteine, and methionine for growth but does NOT require X or V factor, grows in 2-4 days on Bordet-Gengou or Regan-Lowe media incubated 35C with supplemental CO2 and colonies are small smooth and shiny which has been likened to a drop of mercury?
Bordetella
Interpret this KIA/TSI slant:
A/A (yellow/yellow) means acid slant over acid butt. If the bottom is yellow, it means glucose fermenter and if the top were yellow it means lactose/sucrose fermenter. This organism is fermenting BOTH glucose and lactose.
Possibilites include: E coli, Klebsiella, Enterobacter and Citrobacter (not freundii which is H2S pos)
“CEEK”
What is the name of the structure shown and what is it associated with?
Sclerotic (muriform) bodies which are sclerotic bodes having internal septations in more than one plane
Seen in chromoblastomycosis which is a subcutaneous mycosis assoiated with promient pseudoepitheliomatosis hyperplasia
Principle agents: Fonsecaea pedrosoi, Phialophora verrucosa and Cladophialophora carrionii
What diseases and responsible organisms are transmitted by the Lone Star tick (Amblyomma americanum)?
- Erlichiosis (Ehrlichia spp)
- Tularemia (Francisella tularensis)
- Southern tick associated illness (unknown etiology)
What organism is shown here?
Banana form of P. falciparum (gametocyte)
If you see this, it is diagnostic but usually you will see the ring forms with either 1 or 2 dots or Applique forms where the organism is plastered against the side of the red cell
*Falciparum is the “slut” of the plasmodiums because it will infect any and every red cell
What disease and responsible organism is transmitted by the Tsetse fly (Glossina spp)?
African trypanosomiasis (Trypanosoma brucei)
What organism causes the characteristic feature shown in the picture which can permit preliminary ID?
Mycobacterium tuberculosis
*Picture is showing CORDING
What disease and responsible organism is transmitted by the dung fly (Musca sorbens)?
Trachoma (Chlamydia trachomatis)
What is this?
Taenia solium
(Pork tapeworm–solium is a shorter word than saginata and pigs are smaller than cows)
Also solium has less uterine branches than saginata
What fungi has pseudohyphal extensions that extend from one corner of the rectangular arthroconidia and resemble a hockey stick?
Geotrichum
Urease negative
What organism found in stool is shown here?
Isospora belli
-Eosinophilia often present (not for other coccidians, Cryptosporidum and Cyclospora)
Auto-fluorescence or modified acid fast stain
What is the organism shown in this picture?
- Questionable clinical significance – can find in almost every stool
- Report when in significant numbers
Blastocystis hominis
What plasmodium spp is shown here and how can you tell?
Schuffner dots of P. vivax
Vivax is the “dirty old man” of the plasmodium spp because it likes young red cells
Red cells are ENLARGED
When they mature, they shown 12-20 merozoites so that is very helpful in distinguishing it from P. malariae
This fungus has cinnamon brown colonies on the surface with a YELLOW or ORANGE reverse of the plate.
Aspergillus tereus
What dimorphic fungi seen here produces this characteristic colony with diffuseable orange pigment?
Penicillium marneffii
What virus causes the effect shown?
Rabies
This is showing a Negri body (cytoplasmic inclusion) within a neuron
Which virus causes this cytopathic effect?
Adenovirus
Grapelike clusters on Hep2!
Time to CPE: 2-7 days
*PMK=Primary Monkey Kidney, Hep2/HeLa=Human Epithelial Cells, HDF=Human Diploid Fibroblasts
What organism is shown?
Trypanosoma
Cruzi and Brucei (African sleeping sickness) look the same but if you see a dividing form (pic) it’s NOT cruzi
What diseases and responsible organisms are transmitted by the Dermacentor spp of tick?
*Most common in southern and western US is Dermacentor andersoni, and in southern and eastern US is Dermacentor variabilis
- Rocky Mountain Spotted Fever (Rickettsia rickettsia)
- Tularemia (Francisella tularensis)
- Colorado tick fever (Colorado tick fever virus)
If you see worms moving on agar plate with bacteria, what should you think about?
Strongyloides stercoralis
Autoinfection is unqiue to this worm! This is the only one of the infective nematodes that is capable of replicating and produces more worms (with other you only have as many worms as you ingested eggs)
Strongy is infected organs as they go and cause chronic eosinophilia which makes people with HTLV, on steroids and neutropenic susceptible to hyperinfection
What bacteria shows puffball or cottonball colonies in serum supplemented thioglycolate broth, gram stain shows tangles of gram variable filamentous rods with moniliform swellings and is the causative agent of rat bite fever?
Streptobacillus moniliformis
Interpret this KIA/TSI slant:
(K/K) Red over Red means Alkaline slant over Alkaline butt so nothing was fermented
This excludes all enterobacteriaceae as all are glucose fermenters. Possibilites include nonfermentative bacteria such as Pseudomonas, Eikenella, Moraxella, and Campylobacter.
Which virus causes this cytopathic effect?
CMV
Slow, focal clusters of CPE (plaques) on HDF ONLY!
Time to CPE: 14 days
*PMK=Primary Monkey Kidney, Hep2/HeLa=Human Epithelial Cells, HDF=Human Diploid Fibroblasts
DEFINITE BQ!
What organism is shown here which has been grown at 30C and shows fluffy mold with TUBERCULATED MACROCONIDIA (spiny large spores)?
HISTOPLASMA
Testing: serum antibodies (CF or ID to H or M antigens) or immunoassay for antigens** **in urine, serum, CSF
At 37C will show narrow based budding (picture)
What are the serology findings at different stages of EBV infection?
Early acute: heterophile pos, IgM anti VCA pos, IgG anti VCAagG pos
Acute: add IgG anti EA and anti EBNA
Convalescent: heterophile and IgM go away, left with IgG anti EA, IgG anti VCAAgG and anti EBNA
Remote: may loser IgG anti VCAAgG and left with anti EBNA and IgG anti EA
What disease and responsible organism is transmitted by the Ornithodoros spp of tick (soft ticks)?
Relapsing fever (Borrelia spp)
Definite board Q!
Be able to differentiate colonies of Staph from colonies of C. diphtheriae on tellurite agar.
Which is this?
Staph!
They will have a clear zone around them from lecithinase production
Here is what C. Diphtheriae looks like
What disease and responsible organism is transmitted by mites (Liponyssoides sanguineus)?
Rickettsial pox (Rickettsia akari)
This fast growing dematiaceous mold has oval transversely septated conidia that arise from bent conidiophores and they have germ tubes from both ends of the conidia in saline mounts incubated for 12-24 hours.
Bipolaris
What organism is shown here which shows broad, aseptate hyphae, branching at 90 degree in tissue?
Mucormycetes (Rizopus, Mucor, Absidia)
What diseases and responsible organisms are transmitted by the deer fly (Chrysops spp)?
- Tularemia “deerfly fever” (Francisella tularensis)
- Loiasis (Loa loa)
These 3 dematiaceous slow growing molds have early yeast like growth (seen here) and late grow is mold like.
Exophiala, Wangiella, Hortaea
(mold seen here)
Slow growing dematiaceous molds that are moldlike early and late: Pseudoallescheria boydii/Scedosporium boydii complex and Scedosporium prolificans
What parasitic organism is shown on this acid fast stain? If you stain 4 cysts, usually only a couple will pick up the stain so you will see some refractile, some staining. These also AUTOFLUORESCE blue in UV light
Cyclospora
Kind of looks like crinkled paper inside
Not picked up with Giardia/Cryptosporidium antigen test
What is the characteristic lesion of yellow fever in the liver?
Extensive midzonal necrosis, Councilman bodies (eosinophilic structure in pic), microvesicular fatty metatmorphosis and ABSENCE of an inflammatory component
This fungus has a blue-green colony with distinct white apron and a LIGHT reverse of the plate.
Aspergillus fumigatus
This slow growing dematicaceous mold has gray or black surface and reverse, its growth is inhibited by cyclohexamide, it has no sexual state and it’s resistant not only to ampho B but also to the azoles and echinocandins making antifungal therapy ineffective.
Scedosporium prolificans
What is the spirochete shown (tight coils with hooked ends) and what disease does it cases?
Leptospira interrogans
Causes Weil disease which has classic triad of meningitis, hepatitis and nephritis.
Humans are infected through contact with the urine of an infected animal, the usual portal of entry being the conjunctiva or abasions/cuts in skin.
In US, highest incidence in Hawaii and rats are usual hosts
What diseases and responsible organisms are transmitted by the Ixodes spp of tick?
*Most common Eastern US is Ixodes scapularis, in Western US is Ixodes pacificus and in Europe is Ixodes ricinus
- Lyme disease (Borrelia burgdorferi)
- Babesiosis (Babesia spp)
- Anaplasmosis (Anaplasma phagocytophilum)
- Tickborne encephalitis (Tickborne encephalitis virus)
What disease and responsible organism is transmitted by midges (Culicoides spp)?
Filariasis (Mansonella spp)
What organism is being shown in this intestinal biopsy?
Microsporidia (apical aspect of cells containing intraceullular organisms)
What organism is shown here?
Babesia!
Usually will see ring forms predominate which are similar to plasmodium but the Maltese cross is characteristic
DEFINITE BOARD Q!
Stem gives a kid with diarrhea. What virus is this?
Rotavirus
What disease and responsible organism is transmitted by chiggers (Trombiculid mite)?
Scrub typhus (Orientia tsutsugamushi)
What organism is being shown?
Aspergillus
this one is probably Niger based on the pigment but fumigatus and flavus will look just like this only no pigment
Neutropenia or phagocyte dysfunction (eg, CGD) is
the key risk factor for invasive aspergillosis because neutrophils are the primary defense.
Which virus causes this cytopathic effect?
RSV
Syncytia in Hep2 cells (syncytia can be produced in various cell types by measles, parainfluenza and mumps viruses)
Time to CPE: about 14 days
*PMK=Primary Monkey Kidney, Hep2/HeLa=Human Epithelial Cells, HDF=Human Diploid Fibroblasts
If you see this picture of a fragmenting nucleus in this flagellate, what is your diagnosis?
Dientamoeba fragilis
Usually asymptomatic but can cause diarrhea and anal pruritus and in fact is often co-infected with Enterobius vermicularis
Which virus causes this cytopathic effect?
Enteroviruses (including coxsackie A and B, echovirus, poliovirus)
Causes an angular, tear shaped cells that can be focally swollen or glassy.
Time to CPE: 1-7 days
Seen best in primary monkey kidney (PMK) or human diploid fibroblasts (HDF)
What disease and responsible organism is transmitted by dog and cat fleas?
Double pored dog tapeworm (Dipylidium caninum)
What aspergillus spp is resistant to amphotericin B and has this colony morphology?
A. terreus
What medium can be used to distinguish between Cryptococcus gattii and neoformans?
Canavanine glycine bromthymol blue agar (CGB agar) can be used to distinguish between C. gattii and C. neoformans.
C. gattii is blue on this medium.
Requires genotyping for confirmation.
What bacteria is seen growing in this Staph streak test as pinpoint colonies?
Haemophilus spp
A phenomenon called satellitism. This is due to the ability of S. aureus to synthesize V factor (NAD), and releases X factor (hemin) by lysing blood. A colony of possible Haemophilus species can be subcultured to an SBA plate and streaked as a lawn. A single streak of S. aureus is made through the inoculum . After overnight growth in a CO2 enriched environment, the haemophilus conlonies may be observed within the hemolytic area adjacent to the staphylococcal growth.
What diseases and responsible organisms are transmitted by the Aedes spp of mosquito (most commonly Aedes aegypti and Aedes albopictus)?
Arboviral disease including dengue virus, yellow fever virus, and Chikungunya virus
This organism is acquired through ingestion of undercooked freshwater fish, the egg is 30 um, found in parts of Asia, causes chronic biliary infection.
Clonorchis sinensis
What disease and responsible organism is transmitted by the black fly (Simulium spp)?
Onchocerciasis “river blindness” (Onchocerca volvulus)
