Microbiology Part 1 (TJ-HYN)

medmaestro's version from 2015-09-28 08:38

Clinical condition-Organism responsible

Name of microbial/Clinical conditionOrganisms responsible
Shanghai fever / Whirlpool fever / Jacuzzi feverPseudomonas
Pontiac feverLegionella
Malta fever / Undulant fever/ Mediterranean feverBrucella
Glanders(In Horses)Burkholderia mallei
Meliodosis / Whitmore bacillusburkholderia pseudomallei
3 day feverSandfly fever
5 day fever / Trench feverBartonella Quintana
Rat bite feverSpirillum minus,Streptobacillus moniliformis
8th day diseaseTetanus neonatorum
Fitz Hugh Curtis SyndromeGonococci,Chlamydia
Brazilian purpuric fever (It is an acute septicemic fulminant illness affecting children)Haemophilus aegypticus (Haemophilus influenzae biogroup aegyptius (Hae) is a causative agent of acute and often purulent conjunctivitis, more commonly known as pink eye. It was discovered independently by Koch and Weeks in the 1880s .Also causes Brazilian purpuric fever)
Circling diseaseListeria meningitidis
Oroya feverBartonella
Carrison’s diseaseBartonella bacilliformis
Cat scratch diseaseBartonella henselae
Red leg diseaseAeromonas
Chigger typhus / Scrub typhusOrientia tsutsugamushi
YawsTreponema pertunae
PintaTreponema carateum
Eaton agentMycoplasma
Friedlander bacillusKlebsiella
Axenfeld bacillusMoraxella lacunata
Kanagawa phenomenonVibrio parahaemolyticus
Medusa head appearanceBacillus anthracis
Nagler’s reactionClostridium perfringens
Chinese letter pattern / Cuneiform bacillusCorynebacterium diphtheria
Citron bodyChlamydia psittaci

Few questions in Microbiology on Bacterial Culture media

Question Answer
1. Name some simple mediaPeptone water, Nutrient broth and agar.
2. Name some enriched mediaBlood agar, Chocolate agar, Dorset egg medium and Loeffler’s serum medium.
3. Name some transport mediaAmies medium, Pikes medium, Stuart’s medium, Buffered glycerol saline and VR medium.
4. Name some enrichment brothSelenite F broth, Tetrathionate broth and Alkaline peptone water.
5. How are the media sterilized?Most media are sterilized by autoclaving.
6. Which media are not autoclavable?(1)Blood, serum, antibiotic and sugar containing media.(2)Highly selective media such as Wilson & Blair’s, TCBS etc.
7. How are media solidified?By adding 2 3% agar.
8. What is the percentage of blood used in Blood agar?5% defibrinated sheep blood.
9. What is the melting and solidifying point of agar?95°C and 45°C respectively.
10. How is chocolate agar prepared?By adding 5% blood to hot, melted nutrient agar. It is also known as lysed blood agar.
11. Name the serum containing media.Loeffler’s serum slope and Hiss serum water.
12. Name the egg containing media.Dorset egg medium and LJ medium.
13. Name the media, which enhances Staphylococcal pigment productionMilk agar and glycerol monoacetate agar.
14. What is the melting point of gelatin?24°C. It remains as liquid when incubated at 37°C.
15. Which medium is used to selectively grow gram positive bacteria?Colistin Nalidixic acid Agar (CNA).
16. Name some lactose fermenters and nonlactose fermenters.(1)Lactose fermenters are Klebsiella pneumoniae and Escherichia coli (2)Nonlactose fermenters are Salmonella typhi, Proteus spp, Shigella spp, Pseudomonas aeruginosa, Vibrio cholerae
17. Name the media used for cultivating anaerobesRobertson’s Cooked Meat medium (R.C.M), Chopped meat glucose broth and Thioglycollate broth are the LIQUID MEDIA. Blood agar with suitable blood agar base, reducing agents and nutrition supplements can be used to grow anaerobes.
18. What are the media used for blood culture?Glucose broth, Bile broth and Brain heart infusion broth.
19. Why is agar preferred to gelatin?Agar is required in smaller quantity (2-3%, in contrast to 10-15%of gelatin), is solid at the incubating temperature (while gelatin is liquid at this temperature) and does not contribute to the nutritional property of the medium (gelatin is liquefied by some bacteria).
20. What are indicator media?Indicator media indicates the presence of certain bacteria by the change in colour. MacConkey's medium indicates the growth of lactose fermenters by pink coloured colonies.
21. What are differential media?Media that aid in differentiation among bacteria based on some phenotypic property (such as sugar fermentation) are differential media.MacConkey differentiates LF from NLF.
22. What do you mean by enriched media?Media that are supplemented with extra nutrition in the form of blood, serum, egg yolk etc are enriched media. They are suitable for fastidious bacteria.
23. What is biphasic medium?Biphasic medium contains both solid and liquid medium in the same bottle. Blood is inoculated into the liquid medium and subcultures are performed by tilting the bottle. Used in Castaneda method of Blood culture

How are media made selective?

Material added to make media selectiveExamples of selective media
a)AntibioticThayer Martin agar for Neisseria gonorrhoeae, CIN agar for Yersinia enterocolitica
b)DyeBrilliant green in LJ media for Mycobacterium tuberculosis, Crystal violet blood agar for Group A Streptococcus,
c) pHTCBS and alkaline peptone water (pH >8) for Vibrio cholerae.
d) SaltMannitol salt agar, with 7.5% NaCl for Staphylococcus aureus.
e) ChemicalsBile salts in Mac Conkey’s agar, Potassium tellurite in Hoyle’s medium and Mc Leod’s medium for Corynebacterium diphtheriae, Sodium azide agar for Enterococcus sp., Bismuth sulphite in Wilson and Blair agar for Salmonella typhi.
f) DisinfectantCetrimide agar for Pseudomonas aeruginosa