Microbiology - culture

medmaestro's version from 2015-11-03 04:54


OrganismCulture medium
Enteric pathogens-for Salmonella , Shigella-Hektoen enteric agar [DIFFERENTIAL] –Xylose-lysis-deoxycholate agar –Deoxycholate citrate agar –Eosin Methylene blue agar[DIFFERENTIAL] –MacConkey’s agar [DIFFERENTIAL] –SS agar[SELECTIVE] –Wilson Blair for Salmonella [SELECTIVE]
Vibrio cholera (likes ALKALINE growth medium)-TCBS(Thiosulphate Citrate Bile salts Sucrose AGAR) [SELECTIVE] –Mansour’s GTTTA [SELECTIVE] –Alkaline Bile Salt agar [SELECTIVE] –APW(Alkaline Peptone Water){ENRICHMENT}
Staphylococcus aureusMannitol Salt agar [SELECTIVE]
StreptococcusCrystal Violet blood agar [SELECTIVE]
Neisseria-Chocolate agar [ENRICHED],-Thayer-Martin mediium[SELECTIVE],-Modified NewYork medium [SELECTIVE]
Corynebacterium-Loeffler’s coagulated serum medium [ENRICHED], -Potassium Tellurite agar [DIFFERENTIAL]
Bacillus anthracisPLET ( (polymyxin-lysozyme-EDTA-thallous acetate) is a selective media used for the isolation of Bacillus anthracis from contaminated specimens)[SELECTIVE]
Bacillus cereusMYPA(Mannitol-yolk-polymyxin B agar (MYPA))[SELECTIVE] {Modified MYPA is (mMYPA) MYPA modified by supplementation with trimethoprim}
ANEROBES-Thioglycollate {Enrichment}, -RCM(Robertson’s Cooked Meat media){ENRICHMENT}
Listeria(1)PALCAM agar -Listeria Identification Agar also known as Polymyxin-Acriflavin-Lithium chloride-Ceftazidime-Aesculin-Mannitol (PALCAM) Agar was formulated by Van Netten et al and is recommended for the isolation of L. Monocytogenes from foods. PALCAM medium is highly selective due to the presence of Lithium Chloride, Ceftazidime, Polymyxin B And Acriflavin Hydrochloride. PALCAM medium is a differential diagnostic medium utilizing two indicator systems, as esculin and ferric citrate and mannitol and phenol red.[SELECTIVE]
Listeria (2)Oxford Agar [SELECTIVE MEDIUM] -used for the differentiation, the isolation and the enumeration of Listeria monocytogenes from milk and cheese, as well as in other food samples, even highly contaminated. PRINCIPLES - Polypeptone favors the excellent growth of Listeria. - Yeast extract is a source of vitamin B complex. - Starch is the energy source for microbial development. - Sodium chloride maintains osmotic balance. - Listeria hydrolyze esculin to glucose and esculetin, the latter compound forming a black complex with ferric ions supplied by ferric citrate. - Contaminating microflora is inhibited by Lithium Chloride, Cycloheximide, Colistin, Cefotetan, Fosfomycin And Acriflavine
Pseudomonas-Cetrimide agar [SELECTIVE] , -King’s media(for PIGMENT)
Hemophilus-Blood agar with staphylococcus streak [ENRICHED] ,-Chocolate agar [ENRICHED] ,LEVINTHAL’S Medium, -Fildes agar[ENRICHED]
Bordetella-Regan LowEe agar(Charcoal Blood agar) (The basal medium of Regan-Lowe Agar consists of charcoal agar supplemented with defibrinated horse blood. Charcoal, along with starch, neutralizes fatty acids and peroxides, which are toxic to Bordetella . Horse blood is an added enrichment which supports the growth of Bordetella spp. Cephalexin inhibits the growth of normal flora of the nasopharynx. Yeasts and fungi are inhibited by the inclusion of amphotericin B (Cat. no. Q32). Beef extract and enzymatic digest are incorporated in the medium to supply amino acids and other nitrogenous substances that are necessary for bacterial growth. Osmotic equilibrium is maintained by the addition of sodium chloride. Niacin (nicotinic acid) is a vitamin which is added for growth promotion {ENRICHMENT},
-Bordet Gengou Glycerin potato blood agar (Bordet-Gengou agar is a type of agar plate optimized to isolate Bordetella, containing blood, potato extract, and glycerol, with an antibiotic such as cephalexin or penicillin and sometimes nicotinamide.The potato extract provided nitrogen and vitamins, and potato starch absorbed fatty acids present in nasal secretions or collection-swab cotton that inhibited growth; glycerol was a carbon source.Medical Microbiology, 4th edition states that Regan-Lowe medium(containing charcoal, blood, and antibiotic) has replaced Bordet-Gengou medium as the medium of choice for routine Bordetella pertussis incubation.,
-Larcey’s DFP media SELECTIVE
Question Answer
MycobacteriumLöwenstein–Jensen medium (When grown on LJ medium, M. tuberculosis appears as brown, granular colonies (sometimes called "buff, rough and tough"). The media must be incubated for a significant length of time, usually four weeks, due to the slow doubling time of M. tuberculosis (15–20 hours) compared with other bacteria.
The usual composition as applicable to Mycobacterium tuberculosis is:
• Malachite green
• Glycerol
• Asparagine
• Potato starch
• Coagulated eggs
• Mineral salt solution
• Potassium dihydrogen phosphate
• Magnesium sulfate
• Sodium citrate
The original formulation included starch, which was later found to be unnecessary and hence omitted.
Low levels of penicillin and nalidixic acid are also present in LJ medium to inhibit growth of gram positive and gram negative bacteria, in order to limit growth to Mycobacteria species only. Presence of malachite green in the medium inhibits most other bacteria. It is disinfected and solidified by a process of inspissation. Presence of glycerol enhances the growth of Mycobacterium tuberculosis.
If the slopes are made on test tubes they must be stored in cold and used within a month.
For cultivation of M.bovis, glycerol is omitted and sodium pyruvate is added.
The medium appears green, opaque and opalescent.),
-Dorset egg medium SELECTIVE
Question Answer
LeptospiraEMJH(Ellinghausen-McCullough-Johnson-Harris (EMJH) medium-Leptospirosis is usually a biphasic illness and may present as *febrile illness, with or without meningitis, or as *Weil's syndrome, resulting in hemorrhagic renal failure and jaundice. (6) Acute onset consists of flu-like symptoms persisting for 4 to 7 days, with the second immune phase occurring within a few days. Clinical recognition of leptospirosis is complicated due to multi-organ infection and nonspecific clinical presentation. (6) Two major consistent microbiological sequelae of leptospiral infection are localization and persistence of leptospires in renal tissue and in the human genital tract.During the first week of illness, direct culture of the organism in blood, milk or spinal fluid is suggestive of acute leptospirosis. After the first week, fresh urine or, if testing is delayed, urine diluted 1:10 in 1% bovine serum albumin is recommended. However, due to the length of culture, more rapid methods of detection, such as serologic, immunochemical, histological or PCR, are more helpful for timely treatment of serious infections. The microscopic agglutination test (MAT) is considered the gold standard for identification, but this technique is not well suited for guiding clinical management due to decreased sensitivity with fluctuating titers. (6,13)In the early 1920s, Fletcher developed an enriched medium for the cultivation of Leptospira from clinical specimens, including urine, blood, kidney and liver tissues. (2,13) Hardy Diagnostics Fletcher's Media is based on this formulation and contains peptone, beef extract and rabbit serum which provide essential amino acids, carbon and nitrogenous compounds to support bacterial growth. Sodium chloride provides ions necessary for maintaining osmotic equilibrium. Fletcher's Media contains minimal agar and is a semi-solid medium, making it useful for detecting motile organisms) [ENRICHED]
CampylobacterSkirrow’s , Butzler , Campy BAP (Campylobacter Agar with 5 Antimicrobics and 10% Sheep Blood is a selective medium for the primary isolation of Campylobacter jejuni from stool specimens. ) (Campy-BAP) [SELECTIVE]
LegionellaBCYE(Buffered Charcoal Yeast Extract) [SELECTIVE]