scholarly journals Impeding Bacillus spore germination in vitro and in milk by soy glycinin during long cold storage

2016 ◽  
Vol 62 (2) ◽  
pp. 52-59 ◽  
Author(s):  
Samir A. Mahgoub ◽  
Ali O. Osman ◽  
Mahmoud Z. Sitohy
Author(s):  
Henry H. Eichelberger ◽  
John G. Baust ◽  
Robert G. Van Buskirk

For research in cell differentiation and in vitro toxicology it is essential to provide a natural state of cell structure as a benchmark for interpreting results. Hypothermosol (Cryomedical Sciences, Rockville, MD) has proven useful in insuring the viability of synthetic human epidermis during cold-storage and in maintaining the epidermis’ ability to continue to differentiate following warming.Human epidermal equivalent, EpiDerm (MatTek Corporation, Ashland, MA) consisting of fully differentiated stratified human epidermal cells were grown on a microporous membrane. EpiDerm samples were fixed before and after cold-storage (4°C) for 5 days in Hypothermosol or skin culture media (MatTek Corporation) and allowed to recover for 7 days at 37°C. EpiDerm samples were fixed 1 hour in 2.5% glutaraldehyde in sodium cacodylate buffer (pH 7.2). A secondary fixation with 0.2% ruthenium tetroxide (Polysciences, Inc., Warrington, PA) in sodium cacodylate was carried out for 3 hours at 4°C. Other samples were similarly fixed, but with 1% Osmium tetroxide in place of ruthenium tetroxide. Samples were dehydrated through a graded acetone series, infiltrated with Spurrs resin (Polysciences Inc.) and polymerized at 70°C.


2018 ◽  
Vol 30 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Ramadan A. Hassanein ◽  
Ehab A. Salem ◽  
Ahmed A. Zahran

AbstractThis study was performed to explore the efficacy of combining more than one postharvest treatment in maintaining some quality attributes and reducing fungal pathogenicity in cold-stored guava fruits. The investigated postharvest treatments included the control, CaCl2(4%), lemongrass oil (2 dm3kg−1), gamma (γ) irradiation (0.2, 0.4 and 0.6 kGy), 0.4 kGy γ irradiation + CaCl2(4%), and 0.4 kGy γ irradiation + lemongrass oil (2 dm3kg−1). The studied physiochemical attributes included weight loss, decay percentage, fruit firmness, total soluble solids (TSS), titratable acidity (TA), and vitamin C content. Different fungal species were also isolated from decayed fruits and were identified asAlternaria alternata,Alternaria solani,Aspergillus niger,Botrytis cinerea,Fusarium solaniandRhizopus stolonifer. The severity of infection for the different fungi was determined, and anin vitroantifungal assay was conducted for lemongrass oil. All the investigated treatments generally reduced decay and water loss percentages, and controlled TSS, TA and vitamin C decrements that occurred during cold storage. On the other hand, higher irradiation doses generally increased fruit softness, and the 0.4 kGy γ dose did not contribute to the overall fruit quality when coupled with CaCl2and lemongrass oil, compared to CaCl2and lemongrass oil treatments alone.


1985 ◽  
Vol 63 (2) ◽  
pp. 337-339 ◽  
Author(s):  
Elmer L. Schmidt

Influences of eight saturated aliphatic acids (C5–C10, C12, and C16) on basidiospores of four isolates of wood-decay fungi (Poria tenuis and Trametes hispida, white rot fungi, and two isolates of the brown rot fungus Gloeophyllum trabeum) were observed in vitro. Spore responses after 24 h on malt extract agar containing 10, 102 or 103 ppm of each acid included normal germination, delay of germ tube emergence, vacuolation and degeneration of spore cytoplasm, and prevention of germ tube development without spore destruction. Acids of chain length C5–C10 prevented spore germination and killed spores of all fungi at concentrations of 20–50 ppm in media, whereas other acids tested were less active. Spore germination assay of decay fungi may prove useful as a screening tool to compare potency of wood preservatives.


Author(s):  
Jacqueline R. Phan ◽  
Dung M. Do ◽  
Minh Chau Truong ◽  
Connie Ngo ◽  
Julian H. Phan ◽  
...  

Clostridioides difficile infection (CDI) is the major identifiable cause of antibiotic-associated diarrhea. The emergence of hypervirulent C. difficile strains has led to increases in both hospital- and community-acquired CDI. Furthermore, CDI relapse from hypervirulent strains can reach up to 25%. Thus, standard treatments are rendered less effective, making new methods of prevention and treatment more critical. Previously, the bile salt analog CamSA was shown to inhibit spore germination in vitro and protect mice and hamsters from C. difficile strain 630. Here, we show that CamSA was less active at preventing spore germination of other C. difficile ribotypes, including the hypervirulent strain R20291. Strain-specific in vitro germination activity of CamSA correlated with its ability to prevent CDI in mice. Additional bile salt analogs were screened for in vitro germination inhibition activity against strain R20291, and the most active compounds were tested against other strains. An aniline-substituted bile salt analog, (CaPA), was found to be a better anti-germinant than CamSA against eight different C. difficile strains. In addition, CaPA was capable of reducing, delaying, or preventing murine CDI signs in all strains tested. CaPA-treated mice showed no obvious toxicity and showed minor effects on their gut microbiome. CaPA’s efficacy was further confirmed by its ability to prevent CDI in hamsters infected with strain 630. These data suggest that C. difficile spores respond to germination inhibitors in a strain-dependent manner. However, careful screening can identify anti-germinants with broad CDI prophylaxis activity.


2020 ◽  
Vol 13 (2) ◽  
pp. 235-246
Author(s):  
W.Q. Shi ◽  
L.B. Xiang ◽  
D.Z. Yu ◽  
S.J. Gong ◽  
L.J. Yang

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.


2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Robin M. Brusen ◽  
Christopher D. Rolfes ◽  
Stephen A. Howard ◽  
Michael G. Bateman ◽  
Paul A. Iaizzo

The current methodologies of clinical heart transplantation limit the ischemic window to 4–6 h. Periods longer than this can induce dysfunction in the organ and can lead to increased patient morbidity and mortality. An alternative to the current methods of static cold storage (CS) is continuous hypothermic perfusion (CHP), where a hypothermic oxygenated crystalloid solution is mechanically perfused through the coronary arteries. This has been shown to preserve the function for up to 72 h, but the techniques have yet to be optimized. We have developed an apparatus and methodology for performing CHP on large mammalian hearts, followed by reanimation in our in vitro Langendorff apparatus (The Visible HeartTM). We are also investigating the utility of the cardioprotective agents docosahexaenoic acid and [D-Ala2, D-Leu5] enkephalin, both of which have shown cardioprotective effects in our laboratory, and we believe that their addition to the preservation solution can further extend the transplant window. A series of pilot studies has been performed to date, with modestly successful results. Hearts preserved with CHP seem to show better functionality than CS hearts but far worse functionality than hearts reanimated immediately after explant. We hope to use this system to optimize CHP methodology and eventually develop a system for prolonging the window for heart transplantation.


mSphere ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Travis J. Kochan ◽  
Michelle S. Shoshiev ◽  
Jessica L. Hastie ◽  
Madeline J. Somers ◽  
Yael M. Plotnick ◽  
...  

ABSTRACTClostridium difficileis a Gram-positive obligate anaerobe that forms spores in order to survive for long periods in the unfavorable environment outside a host.C. difficileis the leading cause of nosocomial infectious diarrhea worldwide.C. difficileinfection (CDI) arises after a patient treated with broad-spectrum antibiotics ingests infectious spores. The first step inC. difficilepathogenesis is the metabolic reactivation of dormant spores within the gastrointestinal (GI) tract through a process known as germination. In this work, we aim to elucidate the specific conditions and the location within the GI tract that facilitate this process. Our data suggest thatC. difficilegermination occurs through a two-step biochemical process that is regulated by pH and bile salts, amino acids, and calcium present within the GI tract. Maximal germination occurs at a pH ranging from 6.5 to 8.5 in the terminal small intestine prior to bile salt and calcium reabsorption by the host. Germination can be initiated by lower concentrations of germinants when spores are incubated with a combination of bile salts, calcium, and amino acids, and this synergy is dependent on the availability of calcium. The synergy described here allows germination to proceed in the presence of inhibitory bile salts and at physiological concentrations of germinants, effectively decreasing the concentrations of nutrients required to initiate an essential step of pathogenesis.IMPORTANCEClostridium difficileis an anaerobic spore-forming human pathogen that is the leading cause of nosocomial infectious diarrhea worldwide. Germination of infectious spores is the first step in the development of aC. difficileinfection (CDI) after ingestion and passage through the stomach. This study investigates the specific conditions that facilitateC. difficilespore germination, including the following: location within the gastrointestinal (GI) tract, pH, temperature, and germinant concentration. The germinants that have been identified in culture include combinations of bile salts and amino acids or bile salts and calcium, butin vitro, these function at concentrations that far exceed normal physiological ranges normally found in the mammalian GI tract. In this work, we describe and quantify a previously unreported synergy observed when bile salts, calcium, and amino acids are added together. These germinant cocktails improve germination efficiency by decreasing the required concentrations of germinants to physiologically relevant levels. Combinations of multiple germinant types are also able to overcome the effects of inhibitory bile salts. In addition, we propose that the acidic conditions within the GI tract regulateC. difficilespore germination and could provide a biological explanation for why patients taking proton pump inhibitors are associated with increased risk of developing a CDI.


2020 ◽  
Vol 21 (11) ◽  
Author(s):  
Yupi ISNAINI ◽  
Titien Ngatinem Praptosuwiryo

Abstract. Isnaini Y, Praptosuwiryo TNg. 2020. In vitro spore germination and early gametophyte development of Cibotium barometz (L.) J. Sm. in different media. Biodiversitas 21: 5373-5381. Cibotium barometz (L.) J. Sm. is known as the golden chicken fern and included in Appendix II of CITES. It is an important export commodity for traditional and modern medicine. Globally, populations of this species are under significant pressure due to overexploitation in the wild. In vitro culture is one of the technologies used for ex-situ propagation and conservation of rare and endangered ferns and lycophytes. This study’s objectives were: (i) to observe in vitro spore germination and early gametophyte development of C. barometz, and (ii) to determine the best culture medium for rapid spore germination and early development of the gametophytes. The sterilized spores were sown in half-strength Murashige & Skoog (½MS) basal medium supplemented with combinations of 6-Benzylaminopurine (BAP) and α-Naphthalene acetic acid (NAA). A factorial combination of four BAP concentrations (0, 2, 4, and 6 mg L-1) with four concentrations of NAA (0; 0.01; 0.03 and 0.05 mg L-1) created 16 treatments replicated in a Completely Randomized Design. Spore germination of C. barometz was observed to be Vittaria-type, and its prothallial development was Drynaria-type. Spore germination started 7-14 days after sowing. Young heart-shape gametophytes consisting of 110-240 cells were formed in 45-61 days after sowing. The two best spore culture media for rapid spore germination and development of C. barometz gametophytes were ½ MS with or without 2 mg L-1 BAP.


1983 ◽  
Vol 3 (11) ◽  
pp. 1943-1948
Author(s):  
L J Kelly ◽  
R Kelly ◽  
H L Ennis

Spore germination in the slime mold Dictyostelium discoideum was used as a model to study the developmental regulation of protein and mRNA synthesis. Changes in the synthesis of these macromolecules occur during the transition from dormant spore to amoebae. The study of the mechanisms which regulate the quantity and quality of protein synthesis can best be accomplished with cloned genes. cDNA clones which hybridized primarily with mRNAs from only spores or germinating spores and not with growing amoebae were collected. Three such clones, denoted pLK109, pLK229, and pRK270, were isolated and had inserts of approximately 500, 1,200, and 690 base pairs, respectively. Southern blot hybridization experiments suggested that each of the genes is present in multiple copies in the D. discoideum genome. RNA blot hybridizations were performed to determine the sizes of the respective mRNAs and their developmental regulation. The mRNA that hybridized to pLK109 DNA was present predominantly in spores and at 1 h after germination but was absent in growing amoebae. Its concentration dramatically dropped at 3 h. The mRNA present in spores is apparently larger (approximately 0.5 kilobase) than in the later stages of germination (0.4 kilobase), indicating processing of the RNA during germination. The mRNA that hybridized to pLK229 DNA was approximately 1.0 kilobase and was present in very low amounts during growth. Its concentration rose until 1 h after spore germination and decreased thereafter. pRK270-specific RNA was approximately 2.7 kilobases and was found predominantly at 1 h after germination. It was present in lower concentrations at 2 and 3 h after germination and was absent in spores and amoebae. In vitro translation of mRNA selected from 1-h polyadenylated RNA which was hybridized to pLK109 or pLK229 DNA gave proteins of molecular weights consistent with the sizes of the mRNAs as determined by the RNA blot analysis.


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