Download - Questions from slideshows Page 1 What are clinicaly important G+ cocci? Staphylococci, streptococci, enterococci How can we differenciate staphylococci.

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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

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.

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.

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

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

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

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.

What are obligatory pathogenous

enterobacteria?

Yersinia (pestis!), Shigella, Salmonella (AP!) And some opportune pathogenous?

Escherichia, Klebsiella, Enterobacter, Serracia, Proteus, Providentia, Morganella, Citrobacter…

Is there a difference enterococci / enterobacteriaA 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.)

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

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

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“

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

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

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

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)

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

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)

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)

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

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

– 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