scholarly journals Selective and differential medium for isolation of Clostridium difficile

1979 ◽  
Vol 9 (2) ◽  
pp. 214-219 ◽  
Author(s):  
W L George ◽  
V L Sutter ◽  
D Citron ◽  
S M Finegold
Keyword(s):  
Clostridium Difficile ◽  
Antimicrobial Agent ◽  
Rapid Method ◽  
Agar Medium ◽  
Egg Yolk ◽  
Blood Agar ◽  
Fluorescent Properties ◽  
Presumptive Identification ◽  
Differential Medium

Clostridium difficile is a recognized cause of pseudomembranous (antimicrobial agent-associated) colitis and may be one of the causes of antimicrobial agent-induced diarrhea. A selective and differential agar medium that contains cycloserine, cefoxitin, fructose, and egg yolk (CCFA) was developed to facilitate the isolation of C. difficile from fecal specimens. Quantitative cultures of 16 stock strains of C. difficile on this medium (and on a medium containing cycloserine, fructose, and egg yolk) yielded counts equivalent to those obtained on blood agar; other media selective for clostridia, including Clostrisel agar, reinforced clostridial agar plus 0.2% para-cresol, and egg yolk-neomycin agar (the latter was inoculated with cultures subjected to prior heat shocking), were also tested and found to be inhibitory to the growth of C. difficile. Of 28 fecal or colostomy effluent specimens cultured on the above media, 14 yielded C. difficile. CCFA was found to be the most sensitive and selective of these media for the recovery of C. difficile. Colonies of C. difficile growing on CCFA had distinctive morphological and fluorescent properties which were sufficient for presumptive identification. CCFA should provide a rapid method for the screening of fecal specimens from patients with antimicrobial agent-associated diarrhea or colitis for C. difficile.

Malonate Dulcitol Lysine Iron Agar—A New Differential Medium for the Identification of Salmonella Subgenera I—III

1972 ◽  
Vol 55 (1) ◽  
pp. 214-218
Author(s):  
John R Stroup
Keyword(s):  
Minimal Medium ◽  
Agar Medium ◽  
Decarboxylase Activity ◽  
Lysine Decarboxylase ◽  
Biochemical Tests ◽  
Presumptive Identification ◽  
Differential Medium

Abstract A new differential medium, malonate dulcitol lysine iron agar, containing malonate, dulcitol, L-lysine, and an H2S indicating system has been developed for use at the triple sugar iron agar stage for the identification of Salmonella subgenera I–III. This medium differentiates the subgenera on the basis of the malonate and dulcitol reactions. L-Lysine is incorporated to confirm lysine decarboxylase activity for dulcitol-positive subgenus I cultures. Since it is a near minimal medium, it i? advantageous to inoculate triple sugar iron agar or lysine iron agar slants in parallel with the new medium to act as a source of cells for “O” group serology and to avoid missing aberrant biochemical types. Although a few atypical reactions were noted, all of the 35 typical Salmonella of subgenera I–III tested were typical on malonate dulcitol lysine iron agar medium. Triple sugar iron agar can be considered as giving a presumptive test for Salmonella. However, as it does not differentiate the subgenera, this distinction must be made when the results of in-depth biochemical tests are known. As the subgenera can be differentiated on the basis of malonate and dulcitol reactions, the new medium should allow for the presumptive identification of Salmonella subgenera at least 24 hr earlier than is now possible with conventional procedures.

scholarly journals Comparative Study of Hicrome Agar Medium with Conventional Culture System for the Isolation of Uropathogens

2018 ◽  
Vol 24 (2) ◽  
pp. 128-135
Author(s):  
S Gul Nahar ◽  
M Bulbul Hasan ◽  
Mst Rokeya Khatun ◽  
M Nawshad Ali
Keyword(s):  
Urine Culture ◽  
Culture Media ◽  
Agar Medium ◽  
Blood Agar ◽  
Macconkey Agar ◽  
Biochemical Tests ◽  
College Hospital ◽  
Conventional Culture ◽  
Presumptive Identification ◽  
Chromogenic Agar

Objective: The present study was done to compare the performance of chromogenic agar medium and conventional culture media for the isolation and presumptive identification of uropathogen.Methodology: A total 300 sample were collected from Rajshahi Medical College Hospital, Bangladesh during January to June, 2008. Urine samples of the suspected UTI cases, showing pus cells >5/HPF on microscopic examination were included for urine culture simultaneously onto 2 conventional media (Blood agar and MacConkey agar) and chromogenic agar medium (HiCrome UTI agar medium). Results: Culture yielded 139 (46.33%) bacterial growth among them, 133 (44.33%) showed single organism and remaining 06 (2.00%) showed mixed growth of two organisms in different combinations. It is evident from the present study that both HiCrome UTI agar and Blood agar (BA) media supported growth of all 145 bacteria, while MacConkey (MAC) agar yielded 133(91.72%) bacterial growths. The rate of presumptive identification of the isolates was found significantly higher (97.24%) on HiCrome UTI agar when compared with the MacConkey agar (80.68%) and Blood agar (27.58%) media. Out of 91 E. coli isolated, 88(96.70%) could be identified differentially on HiCrome UTI agar medium in contrast to 85(93.40%) on MacConkey agar and only 06(06.59%) on Blood agar. Again, all 06 (100%) of the isolate-pairs of mixed growth were identified distinctly on HiCrome UTI agar, whereas both Blood agar and MacConkey agar media could revealed only 01(16.66%) of the polymicrobial growth.Conclusion: HiCrome UTI agar medium has been documented for its very high yielding rate, rapid presumptive identification of both single and polymicrobial growths with greater precision and avoidance of biochemical tests for further identification of uropathogens. Thus it can be recommended as primary urine culture medium to be used by the clinical microbiology laboratories.TAJ 2011; 24(2): 128-135

scholarly journals Antimicrobial Susceptibility of Helicobacter pylori Determined by the E Test Using Tetrazolium Egg Yolk Agar

1998 ◽  
Vol 36 (9) ◽  
pp. 2784-2785 ◽  
Author(s):  
Yanet Valdez ◽  
Billie Velapatiño ◽  
Robert H. Gilman ◽  
Vilma Gutierrez ◽  
Carlos León
Keyword(s):  
Helicobacter Pylori ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Agar Medium ◽  
Egg Yolk ◽  
Blood Agar ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Agar Dilution ◽  
H Pylori

Metronidazole and tetracycline E tests were compared to an agar dilution method for the antimicrobial susceptibility testing ofHelicobacter pylori. Sixteen strains were tested by using tetrazolium egg yolk (TEY) agar. The characteristic E test inhibition ellipse was clearer on TEY agar than on standard blood agar and gave results comparable to those of the agar dilution test. The use of TEY medium is preferable to that of blood agar medium in E test MIC determinations for H. pylori.

Trypanosoma ontarioensis n.sp. and T. paddae from Corvus brachyrhynchos brachyrhynchos in Ontario, Canada, with notes on the biology of T. ontarioensis n.sp.

1982 ◽  
Vol 60 (9) ◽  
pp. 2107-2115 ◽  
Author(s):  
Patrick T. K. Woo ◽  
Cheryl M. Bartlett
Keyword(s):  
Agar Medium ◽  
Gallus Domesticus ◽  
Blood Agar ◽  
Melopsittacus Undulatus ◽  
Ruffed Grouse ◽  
Bonasa Umbellus ◽  
Southern Ontario ◽  
Corvus Brachyrhynchos ◽  
Domestic Chicks ◽  
Serinus Canarius

Two morphologically distinct trypanosomes (Trypanosoma ontarioensis n.sp. and Trypanosoma paddae) were found by the haematocrit centrifuge technique in the blood of 53% (64 of 121) of Corvus brachyrhynchos brachyrhynchos wintering in southern Ontario. Trypanosoma ontarioensis n.sp. is a small trypanosome with subterminal kinetoplast. It is monomorphic and not host specific. It was readily cultured in diphasic blood-agar medium. Two-week cultures were infective and contained dividing sphaeromastigotes, epimastigotes, and trypomastigotes. Blood trypomastigotes were detected in low numbers in the blood of inoculated birds (Corvus brachyrhynchos brachyrhynchos, Bonasa umbellus, Gallus domesticus, Melopsittacus undulatus, and Serinus canarius) at 28 and 48 days postinfection. The crows, ruffed grouse, and domestic chicks were laboratory raised while the budgerigars and canaries were from pet stores. One canary that was further examined at 180, 360, 540, 730, and 910 days postinfection still had detectable numbers of trypanosomes in its blood.

scholarly journals Case Study: Misdiagnosis of Nonhemolytic Staphylococcus aureus Isolates from Cases of Bovine Mastitis as Coagulase-Negative Staphylococci

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 252
Author(s):  
Valerie E. Ryman ◽  
Felicia M. Kautz ◽  
Steve C. Nickerson
Keyword(s):  
Staphylococcus Aureus ◽  
Bovine Mastitis ◽  
Dairy Farm ◽  
Blood Agar ◽  
Coagulase Negative Staphylococci ◽  
Mannitol Salt Agar ◽  
Lactating Cows ◽  
Presumptive Identification ◽  
Microbiological Techniques

Staphylococcus aureus is one of the most concerning mastitis-causing pathogens in dairy cattle. Using basic microbiological techniques, S. aureus is typically identified by colony characteristics and hemolysis on blood agar where isolates without hemolysis are typically considered to be coagulase-negative staphylococci (CNS) isolates. Herein, we present a decade-long case study where suspected S. aureus isolates from one Georgia dairy farm were further tested to confirm presumptive identification. Presumptive identification of bacterial growth from 222 mammary secretions from bred Holstein heifers and lactating cows was conducted at the time of collection. Presumptive identification of S. aureus on blood agar was based on observation of colony morphology, color, and presence or absence of a broad zone of incomplete hemolysis and a smaller zone of complete hemolysis at 48 h. Those without hemolysis were presumptively characterized as CNS. All isolates were further plated on mannitol salt agar and a coagulase test was performed. A positive for both of these tests together was deemed to be S. aureus. A selection of isolates was tested using API® Staph to biochemically confirm S. aureus identification. Data showed that 63.96% of isolates presumed to be CNS isolates were identified as S. aureus, 9.46% of isolates presumed to be CNS isolates were identified as coagulase-positive staphylococci (CPS) species (but not S. aureus), and 26.58% of samples that were presumed to be CNS isolates were identified correctly.

Rapid method for presumptive identification of Corynebacterium jeikeium.

1993 ◽  
Vol 31 (12) ◽  
pp. 3320-3322 ◽  
Author(s):  
C P Cartwright ◽  
F Stock ◽  
P M Kruczak-Filipov ◽  
V J Gill
Keyword(s):  
Rapid Method ◽  
Presumptive Identification

Selective and Differential Medium for Isolation of Listeria monocytogenes from Foods

1993 ◽  
Vol 56 (4) ◽  
pp. 326-329 ◽  
Author(s):  
FRANK T. POYSKY ◽  
ROHINEE N. PARANJPYE ◽  
LAURA C. LASHBROOK ◽  
MARK E. PETERSON ◽  
GRETCHEN A. PELROY ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Lithium Chloride ◽  
Listeria Innocua ◽  
Department Of Agriculture ◽  
Methane Sulfonate ◽  
Presumptive Identification ◽  
Large Populations ◽  
Horse Blood ◽  
Fishery Products ◽  
Differential Medium

Hemolytic ceftazidime lithium chloride agar (HCLA) has been developed as a selective and differential plating medium for the isolation of Listeria monocytogenes from fishery products. Selectivity is based upon lithium chloride, colistin methane sulfonate, and ceftazidime. When horse blood was incorporated in the agar overlay, L. monocytogenes colonies were easily distinguished by their characteristic blue-gray color surrounded by narrow zones of ß-hemolysis. Listeria innocua, a species commonly present in foods, does not produce hemolysis on the medium. Therefore, one or more colonies of L. monocytogenes were easily distinguished from large populations of L. innocua. When used in combination with Food and Drug Administration and U.S. Department of Agriculture enrichment methodology, HCLA was effective in inhibiting competitive organisms, differentiating colonies of L. monocytogenes by their ß-hemolysis, and shortening the incubation time at 35°C for presumptive identification to 17–24 h.

A rapid method for the preparation of microvesicles of egg yolk lecithin

1982 ◽  
Vol 689 (2) ◽  
pp. 415-418 ◽  
Author(s):  
Stephen J. Dearden ◽  
Thomas F. Hunter ◽  
John Philp
Keyword(s):  
Rapid Method ◽  
Egg Yolk
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