Download P99_Questions_from_slideshow_beginning

Questions from slideshows Page 1
What are clinicaly important G+ cocci?
Staphylococci, streptococci, enterococci
 How can we differenciate staphylococci from other
G+ cocci?
Positive catalase and growth on BA + 10 % NaCl
 Which tests can clearly differenciate S. aureus?
Coagulase, clumping factor, hyaluronidase.
 What can help at primary oritentation?
Hemolysis, color of colonies, size of clusters

Page 2
How can we differenciate stepto/enterococci?
Streprococci do not grow neither on Slanetz
Bartley, nor on Bile-Aesculin medium. And
with exception of S. pyogenes, their PYR test
is negative.

Page 3
We know already: strain X is a Streptococcus.
What is the next step in diagnostics?
Evaluation of haemolytical effects on BA
 What is the worst pathogen among virid. str.?
Streptococcus pneumoniae
 What is its differenciation from oral streptoc.?
Optochin tests (besides microscopy, cultivation)
 When and how differenciation inside the
group of oral streptococci is performed?
Biochemically, in strains from blood culture etc.

Page 4
What are the worst haemolytical streptococci?
S. pyogenes, S. agalactiae
 How can we differenciate the first one?
Positive PYR test (and bacitracin test)
 And the second one?
CAMP test – test of haemolyt. synergism

Page 5
What are clinically important G+ rods?
E. g. Listeria, coryneforms, bacilli
 How can we differenciate stafylococci/other
cocci?
Positive catalase, growth on BA + 10 % NaCl
 How can we differenciate
streptococci/enterococci?
Streptococci do not grow neither on SB nor BE
medium; PYR test helps, too

Page 6
How can we differenciate enterococci mutually?
Arabinose test, EnCOCCUS test
 What is the primary atb resist. of enterococci?
Cephalosporins, macrolids, lincosamids; E. faecium
also ampicilin
 What are MRSA and VRE?
Multiresistant, epidemiologically important strains
 What is typical for Listeria?
They grow at low temperature, high NaCl
concentrations, chromogenous media used

Page 7
What is a palisade? And how are coryneforms
related to it?
Medieval fortifications. Coryneforms have
arrangement of „palisades“
 Could coryneforms be a part of normal flora?
Yes, on skin, together with staphylococci.
 What species of Bacillus are dangerous?
B. anthracis (Osama), B. cereus (spaghetti).
 How can bacilli help us?
We use them in sterilizer control.

Page 8
What are obligatory pathogenous
enterobacteria?
Yersinia (pestis!), Shigella, Salmonella (AP!)
 And some opportune pathogenous?
Escherichia, Klebsiella, Enterobacter, Serracia,
Proteus, Providentia, Morganella,
Citrobacter…

Page 9
Is there a difference enterococci / enterobacteria
A big one! Enterococcus is G + coccus, Enterobacteria,
incl. genus Enterobacter, are Gram– rods.
EnteroCOCCI are COCCI. (On the other hand, all
these bacteria have some relation to the intestine)
 Which bacteria do grow on Endo agar?
Enterobacteria, Vibrionaceae, G- non-fermenters
 How can we differenciate them?
Non-feremters do not ferment glucose, Vibrio is OX +
 How can we detect glucose fermentation?
E. g., Hajna medium remains red for non-fermenters.
(Many more tests exist.)

Page 10
What is the characteristics of Endo agar?
Firstly, only some G- rods grow on it. Secondly, red/pale
colour detects lactose positivity/negativity, what is an
advantage for Enterobacteria diagnostics
 What more media are used for enterobacteria?
CIN (Yersinia), XLD, MAL etc. (Salmonella)
 What more are used besides cultivation tests?
Biochemical determination (e. g. Enterotest 16)
 How can we differenciate EPEC? And S. Enteritidis?
For both, antigen analysis – slide agglutination

Page 11
Name several bacteria, what do not grow on
MH
E. g. streptococci and haemophili
 What is the typical morphology of Neisseria and
Moraxella in clinical material?
Gram-negative diplococci, mostly inside WBCs
 What is the result of oxidase and INAC test for
them?
OXI positive for all of then, INAC for Moraxella

Page 12
What is characteristic pro pseudomonads?
Typical odour, pigmentation (green, rarely other
colours), positive oxidase reaction
 When haemophili can grow on blood agar?
They may grow around a Staphylococcus as a
„satelite“
 What growth factors needs H. influenzae?
It requires both factor X and factor V.
 Why haemophilus invasive inf. are rare now?
That is because children are now vaccinated
against „Hib“

Page 13
Pathogenous neisseriae: what sugars do they
split?
Gonococcus splits glucose only, meningococcus
glucose and maltose
 What is cultured on BCYE and BG media?
BCYE is for Legionella, BG for Bordetella
 Why has Brucella melitensis its name?
From Malta island, with sheep and goats.
 What is the most common test for Francisella?
Indirect – e. g. agglutination in wells of a panel

Page 14
What is the G+ cell wall composition?
Peptidoglykan (murein), teichoic acid chains
 What is the G- cell wall composition?
Thin murein layer and outer membrane
 What bacteria do not Gram stain?
The bacteria without cell wall, or bacteria with a
cell wall different from other cell walls
 What bacteria did we see in sputum samples?
G+ cocci in clusters and chains, G- bacilli

Page 15
How can we get anaerobiose?
Mechanic in VL broth, physical in anaerobic boxes,
chemical in anaerobic jars
 What anaerobic bacteria are easily transmitted from
person or environment to person?
Clostridia, because they are spore forming
 Where in diagnostics of anaerobes mice are used?
In Clostridium tetani and Clostridium botulinum
 What toxin is tested on yolk agar?
Lecitinase of Clostridium perfringens

Page 16
What is special in mycobacterial cell wall?
Mycolic acids, making the cell wall hydrophobic
 What shapes may be seen in bacteria?
Cocci, coccobacilli, bacilli, filamentous
bacilli/fibers, spirochets, amorph (mycoplasms)

Page 17
What are the media for mycobacteria?
Šula, Ogawa, Banić, Löwenstein-Jenssen etc.
 What procedure should be done before start of
mycobacterial culture?
To treat them with a hydroxide (to kill contaminants)
 What are steps of Ziehl-Neelsen staining?
1. Hot carbolfuchsin, 2. acid alcohol, 3.
background

Page 18
How G+ cell wall does stain an why?
Violet, because of peptidoglykan (murein)
 How G- cell wall does stain?
Red (only thin murein  decoloration)
 How do we stain mycobacteria?
For hydrophobicity, Ziehl-Nielsen (not Gram)
 What shapes may be seen in bacteria?
Cocci, coccobacilli, bacilli, filamentous
bacilli/fibers, spirochets, amorph (mycoplasms)

Page 19
What are clinically important spirochets?
Borrelia, Treponema and Leptospira
 What tests are used for syfilis screening?
Non-treponema – RRR (RPR, VDRL),
treponema – MHA-TP
 What tests are used for syphilis confirmation?
FTA-ABS, ELISA, Western blotting, ev. PCR
 What tests are used for dg. of Borrelia?
ELISA as basic, Western blot for confirmation,
eventually PCR (from a specimen of full
blood)

Page 20
Do you know any bacteria that are usually
encapsulated?
For example, Str. pneumoniae, Klebsiella etc.
 Do you know the staining used for capsulla
observation?
It is Burri staining for capsulla (see J02 topic)
 What is the composition of capsulla?
Mostly polysaccharides
 What antibiotic susceptibility testing methods
do you know?
Diffusion disc test, microdillution test, E-test

Page 21
What are targets of microbiological diagnostics?
1. to find a pathogen (+ 2. antimicrobial susceptibility)
 For what we search in direct methods?
A microbe, its part or its product
 What is the difference between a sample and a
strain?
Sample/specimen = what is sent for examination.
Strain/isolate = pure culture of identical cells
 What method is needed to get a microbial strain?
Only culture on a solid medium

Page 22 – THE END
What types of parasites do you know?
Protozoa, Nematoda, Trematoda, Cestoda,
ectoparasites – arthropodes
 What method is used for pinworm diagnostic?
Graham method. Or Kato + Faust (stool)
 What are two ways of Trichomonas dg.?
1. sending C. A. T. swab, 2. smear  Giemsa
 What parasites are usually detected
indirectly?
Tissue parasites, mostly Toxoplasma
