Incubation of premise plumbing water samples on Buffered Charcoal Yeast Extract agar at elevated temperature and pH selects for Legionella pneumophila

2017 ◽  
Vol 123 ◽  
pp. 439-447 ◽  
Author(s):  
Harm R. Veenendaal ◽  
Anke J. Brouwer-Hanzens ◽  
Dick van der Kooij
Keyword(s):  
Elevated Temperature ◽  
Yeast Extract ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Extract Agar ◽  
Premise Plumbing ◽  
Yeast Extract Agar

Charcoal-yeast extract agar: primary isolation medium for Legionella pneumophila.

1979 ◽  
Vol 10 (4) ◽  
pp. 437-441 ◽  
Author(s):  
J C Feeley ◽  
R J Gibson ◽  
G W Gorman ◽  
N C Langford ◽  
J K Rasheed ◽  
...  
Keyword(s):  
Yeast Extract ◽  
Legionella Pneumophila ◽  
Isolation Medium ◽  
Primary Isolation ◽  
Extract Agar ◽  
Yeast Extract Agar

scholarly journals Legionella pneumophila feoAB Promotes Ferrous Iron Uptake and Intracellular Infection

2002 ◽  
Vol 70 (10) ◽  
pp. 5659-5669 ◽  
Author(s):  
Marianne Robey ◽  
Nicholas P. Cianciotto
Keyword(s):  
Yeast Extract ◽  
Legionella Pneumophila ◽  
Ferrous Iron ◽  
Iron Uptake ◽  
Iron Transport ◽  
Growth Defect ◽  
Wild Type ◽  
Extract Agar ◽  
Ferrous Iron Transport ◽  
Yeast Extract Agar

ABSTRACT In order to determine the role of ferrous iron transport in Legionella pathogenesis, we identified and mutated the feoB gene in virulent Legionella pneumophila strain 130b. As it is in Escherichia coli, the L. pneumophila feoB gene was contained within a putative feoAB operon. L. pneumophila feoB insertion mutants exhibited decreased ferrous but not ferric iron uptake compared to the wild type. Growth on standard buffered charcoal yeast extract agar or buffered yeast extract broth was unaffected by the loss of L. pneumophila FeoB. However, the L. pneumophila feoB mutant had a reduced ability to grow on buffered charcoal yeast extract agar with a reduced amount of its usual iron supplementation, a phenotype that could be complemented by the addition of feoB in trans. In unsupplemented buffered yeast extract broth, the feoB mutant also had a growth defect, which was further exacerbated by the addition of the ferrous iron chelator, 2,2′-dipyridyl. The feoB mutant was also 2.5 logs more resistant to streptonigrin than wild-type 130b, confirming its decreased ability to acquire iron during extracellular growth. Decreased replication of the feoB mutant was noted within iron-depleted Hartmannella vermiformis amoebae and human U937 cell macrophages. The reduced intracellular infectivity of the feoB mutant was complemented by the introduction of a plasmid containing feoAB. The L. pneumophila feoB gene conferred a modest growth advantage for the wild type over the mutant in a competition assay within the lungs of A/J mice. Taken together, these results indicate that L. pneumophila FeoB is a ferrous iron transporter that is important for extracellular and intracellular growth, especially in iron-limited environments. These data represent the first evidence for the importance of ferrous iron transport for intracellular replication by a human pathogen.

Comparison of agar-based methods for the isolation and enumeration of heterotrophic bacteria with the new Multidose IDEXX(tm) SimPlate method

2004 ◽  
Vol 50 (1) ◽  
pp. 277-280
Author(s):  
M. Vulindlu ◽  
A. Charlett ◽  
S. Surman ◽  
J.V. Lee
Keyword(s):  
Yeast Extract ◽  
Heterotrophic Bacteria ◽  
Treatment Plant ◽  
Plant Performance ◽  
Extract Agar ◽  
Quality Of Water ◽  
Heterotrophic Microorganisms ◽  
External Sources ◽  
Conventional Methods ◽  
Yeast Extract Agar

Pour and spread plates are the conventional methods of choice for the isolation and enumeration of heterotrophic microorganisms in treated water supplies. The tests are performed at 22°C and 37°C for 72 h and 48 h respectively. Counts at 22°C are associated with pollution of water systems from external sources, while counts at 37°C are used as an indication of treatment plant performance and the deterioration of the general quality of water. Conventional methods using Yeast Extract Agar for a pour plate and R2A agar for a spread plate were compared with the multidose IDEXXTM SimPlate method for the isolation and enumeration of heterotrophic bacteria in water. SimPlate gave a significantly higher count on average than the conventional methods. The R2A method showed the next highest count, being significantly higher than Yeast Extract Agar. In addition, unlike the pour and spread plate methods, SimPlate was easier to use, reduced labour, and the test results were far easier to read.

Nannocystis exedens: A Potential Biocompetitive Agent against Aspergillus flavus and Aspergillus parasiticus

2001 ◽  
Vol 64 (7) ◽  
pp. 1030-1034 ◽  
Author(s):  
WILLIE J. TAYLOR ◽  
FRANCES A. DRAUGHON
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Biocontrol Agent ◽  
Aspergillus Parasiticus ◽  
Extract Agar ◽  
Potential Biocontrol Agent ◽  
Aflatoxigenic Fungi ◽  
Close Proximity ◽  
Zones Of Inhibition ◽  
Yeast Extract Agar

This study examined the potential for controlling toxigenic Aspergillus flavus and Aspergillus parasiticus by biological means using a myxobacterium commonly found in soil. The ability of Nannocystis exedens to antagonize A. flavus ATCC 16875, A. flavus ATCC 26946, and A. parasiticus NRRL 3145 was discovered. Cultures of aflatoxigenic fungi were grown on 0.3% Trypticase peptone yeast extract agar for 14 days at 28°C. When N. exedens was grown in close proximity with an aflatoxigenic mold, zones of inhibition (10 to 20 mm) developed between the bacterium and mold colony. A flattening of the mold colony on the sides nearest N. exedens and general stunting of growth of the mold colony were also observed. When N. exedens was added to the center of the cross-streak of a mold colony, lysis of the colony by the bacterium was observed after 24 h. Microscopic observations revealed that N. exedens grew on spores, germinating spores, hyphae, and sclerotia of the molds. These results indicate that N. exedens may be a potential biocontrol agent against A. flavus and A. parasiticus.

scholarly journals Several Metarhizium Species Produce Ergot Alkaloids in a Condition-Specific Manner

2020 ◽  
Vol 86 (14) ◽  
Author(s):  
Caroline E. Leadmon ◽  
Jessi K. Sampson ◽  
Matthew D. Maust ◽  
Angie M. Macias ◽  
Stephen A. Rehner ◽  
...  
Keyword(s):  
Yeast Extract ◽  
Ergot Alkaloid ◽  
Genomic Sequence ◽  
Close Association ◽  
Acid Amide ◽  
Ergot Alkaloids ◽  
Lysergic Acid ◽  
Content Type ◽  
Extract Agar ◽  
Yeast Extract Agar

ABSTRACT Genomic sequence data indicate that certain fungi in the genus Metarhizium have the capacity to produce lysergic acid-derived ergot alkaloids, but accumulation of ergot alkaloids in these fungi has not been demonstrated previously. We assayed several Metarhizium species grown under different conditions for accumulation of ergot alkaloids. Isolates of M. brunneum and M. anisopliae accumulated the lysergic acid amides lysergic acid α-hydroxyethyl amide, ergine, and ergonovine on sucrose-yeast extract agar but not on two other tested media. Isolates of six other Metarhizium species did not accumulate ergot alkaloids on sucrose-yeast extract agar. Conidia of M. brunneum lacked detectable ergot alkaloids, and mycelia of this fungus secreted over 80% of their ergot alkaloid yield into the culture medium. Isolates of M. brunneum, M. flavoviride, M. robertsii, M. acridum, and M. anisopliae produced high concentrations of ergot alkaloids in infected larvae of the model insect Galleria mellonella, but larvae infected with M. pingshaense, M. album, M. majus, and M. guizhouense lacked detectable ergot alkaloids. Alkaloid concentrations were significantly higher when insects were alive (as opposed to killed by freezing or gas) at the time of inoculation with M. brunneum. Roots of corn and beans were inoculated with M. brunneum or M. flavoviride and global metabolomic analyses indicated that the inoculated roots were colonized, though no ergot alkaloids were detected. The data demonstrate that several Metarhizium species produce ergot alkaloids of the lysergic acid amide class and that production of ergot alkaloids is tightly regulated and associated with insect colonization. IMPORTANCE Our discovery of ergot alkaloids in fungi of the genus Metarhizium has agricultural and pharmaceutical implications. Ergot alkaloids produced by other fungi in the family Clavicipitaceae accumulate in forage grasses or grain crops; in this context they are considered toxins, though their presence also may deter or kill insect pests. Our data report ergot alkaloids in Metarhizium species and indicate a close association of ergot alkaloid accumulation with insect colonization. The lack of accumulation of alkaloids in spores of the fungi and in plants colonized by the fungi affirms the safety of using Metarhizium species as biocontrol agents. Ergot alkaloids produced by other fungi have been exploited to produce powerful pharmaceuticals. The class of ergot alkaloids discovered in Metarhizium species (lysergic acid amides) and their secretion into the growth medium make Metarhizium species a potential platform for future studies on ergot alkaloid synthesis and modification.

scholarly journals ISOLASI DAN IDENTIFIKASI KAPANG PADA PINDANG BANDENG (Chanos chanos) PRESTO

2019 ◽  
Vol 2 (1) ◽  
pp. 15
Author(s):  
Resmi Rumenta Siregar
Keyword(s):  
Yeast Extract ◽  
Rose Bengal ◽  
Fusarium Solani ◽  
Penicillium Citrinum ◽  
Malt Extract Agar ◽  
Malt Extract ◽  
Chanos Chanos ◽  
Extract Agar ◽  
Fusarium Sp ◽  
Yeast Extract Agar

Ikan pindang adalah salah satu olahan yang sangat disukai oleh masyarakat Indonesia. Hal ini dapat dilihat dari produksi ikan pindang yang setiap tahunnya mengalami peningkatan. Sebagai contoh di Kabupaten Bogor, produksi ikan pindang pada tahun 2013 sebesar 3.643,56 ton, meningkat menjadi 10.334,44ton pada tahun 2015. Ikan pindang disisi lain, sangat mudah mengalami kemunduran mutu disebabkan masih tingginya kadar air, pengemasan yang tidak memenuhi standar serta proses pengolahan yang pada umumnya kurang menerapkan prinsip sanitasi yang baik. Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi kapang yang tumbuh pada bandeng presto. Sampel Bandeng presto diambil dari CV. Cindy Group. Kapang diisolasi dengan metode pengenceran bertingkat menggunakan media DRBC (Dichloran Rose Bengal Chloramphenicol Agar), kemudian diidentifikasi secara morfologi menggunakan media Malt Extract Agar dan Czapek’s Yeast Extract Agar. Nilai Aktivitas air (aw) bandeng presto memiliki kisaran rata-rata 0,96 – 0,97. Secara makroskopis terlihat adanya pertubuhan kapang pada permukaan ikan bandeng presto setelah penyimpanan selama 3 hari pada suhu ruang (20-250C). Sebanyak 5 isolat kapang diisolasi dari ikan pindang sampel bandeng presto. Hasil identifikasi secara mikroskopis diketahui bahwa kapang yang tumbuh ada ikan pindang tersebut adalah spesies Penicillium citrinum, Eurotium chevalieri, Fusarium solani, Fusarium sp, dan Cladosporium sp. Kadar aw ikan pindang resto yang masih tinggi (0,96-0,97) menyebabkan ikan pindang mengalami pembusukan yang diakibatkan oleh bakteri.  

Evaluation of Recovery Media for Heated Clostridium sporogenes Spores1

1979 ◽  
Vol 42 (12) ◽  
pp. 946-947 ◽  
Author(s):  
I. J. PFLUG ◽  
M. SCHEYER ◽  
G. M. SMITH ◽  
M. KOPELMAN
Keyword(s):  
Yeast Extract ◽  
Culture Media ◽  
Clostridium Sporogenes ◽  
Extract Agar ◽  
Significant Difference ◽  
Yeast Extract Agar

The efficiency of four culture media for recovery of heat-activated and heated Clostridium sporogenes spores was studied. Yeast extract agar gave the highest spore recovery. The effect of the method of preparing the yeast extract agar on the recovery of heated spores was also evaluated. The results indicate that (a) a significantly lower spore recovery was obtained when the dextrose was omitted completely or when added to the medium before autoclaving, and (b) no significant difference in spore recovery was found between yeast extract agar freshly made or prepared and stored at 4 C up to 11 days before use.

scholarly journals Influence of culture media in viability test of conidia of entomopathogenic fungi

2006 ◽  
Vol 36 (4) ◽  
pp. 1309-1312 ◽  
Author(s):  
Edimara Aparecida Francisco ◽  
Dinalva Alves Mochi ◽  
Antônia do Carmo Barcelos Correia ◽  
Antonio Carlos Monteiro
Keyword(s):  
Yeast Extract ◽  
Culture Medium ◽  
Culture Media ◽  
Complete Medium ◽  
Paecilomyces Fumosoroseus ◽  
Lecanicillium Lecanii ◽  
Extract Agar ◽  
High Germination ◽  
Microscope Slides ◽  
Yeast Extract Agar

This work aimed at investigatimg whether the culture medium used in viability tests affects the conidial germination of Lecanicillium lecanii, Beauveria bassiana and Paecilomyces fumosoroseus isolates. The tests were performed on microscope slides containing one of the culture media: agar-water (AW), minimal medium (MM), potato-dextrose agar (PDA), potato-dextrose-1% yeast extract agar (PDAY), Sabouraud-dextrose-yeast extract agar (SDAY), and complete medium (CM). Three areas per slide were delimited and 0.05ml of a 5.5 x 105 conidia ml-1 suspension was applied to each area. One bioassay was performed for each isolate. Germination was determined after 15 hours of incubation at 26±0.5°C. The culture media influenced the germination of the species studied, verifying within and inter specific variations. CM and PDA provided the highest germination of L. lecanii isolates and the lowest was obtained on SDAY and AW. The germination of B. bassiana isolates was favoured by CM, PDA and PDAY media, a fact not observed in AW and MM. P. fumosoroseus isolates showed the highest germination on CM and PDA media and the lowest on SDAY. However, some isolates presented high germination on nutrient-poor media (AW and MM).

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