scholarly journals Dodonaea viscosavar.angustifoliaInhibits Germ Tube and Biofilm Formation byC. albicans

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Serisha Devi Naicker ◽  
Mrudula Patel
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Plant Extract ◽  
Biofilm Formation ◽  
Germ Tube ◽  
Therapeutic Potential ◽  
Hydrolytic Enzymes ◽  
Pairwise Comparison ◽  
Tube Formation ◽  
Crude Plant Extract

The virulence factors ofCandida albicansare germ tube and biofilm formation, adherence to host tissues, and production of hydrolytic enzymes. This study investigated the effect ofDodonaea viscosavar.angustifoliaextract on the germ tube and biofilm formation ofC. albicans. Serum containing the three subinhibitory concentrations of leaf extract was inoculated withC. albicans, incubated, and viewed under a light microscope. Number of cells with germ tube was recorded and the results were analysed using Scheffe test for pairwise comparison. Biofilms were grown on coverslips in the presence of plant extracts and processed for scanning electron microscopy (SEM). Planktonic cells were grown in the presence of plant extract for 6 h and processed for electron microscopy (TEM). The crude plant extract significantly (P<0.01) reduced the germ tube formation ofC. albicansat 3.125 (85.36%), 1.56 (61.91%), and 0.78 mg/mL (26.27%) showing a concentration dependent effect. SEM results showed concentration dependent reduction in biofilm and hyphae formation. TEM results showed that the plant extract caused damage to the cell wall and cell membrane. DVA extract has ability to reduce virulence ofC. albicansby inhibiting germ tube and biofilm formation through damage to the cell wall. Therefore, it has therapeutic potential.

scholarly journals The Effect of Zuccagnia punctata, an Argentine Medicinal Plant, on Virulence Factors from Candida Species

2014 ◽  
Vol 9 (7) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Nuño Gabriela ◽  
Alberto María Rosa ◽  
Zampini Iris Catiana ◽  
Cuello Soledad ◽  
Ordoñez Roxana Mabel ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Candida Species ◽  
Biofilm Formation ◽  
Germ Tube ◽  
Fungal Infections ◽  
Tube Formation ◽  
Planktonic Cells ◽  
Invasive Potential ◽  
Invasion Mechanisms ◽  
Candida Biofilm

Zuccagnia punctata Cav. has been used as a traditional medicine in Argentina for the treatment of bacterial and fungal infections. In this study, we evaluated the ability of Z. punctata extract (ZpE) and compounds isolated from it to inhibit the growth and virulence factors of Candida species. ZpE showed inhibitory activity against planktonic cells of all assayed Candida species with MIC values of 400 μg/mL and with MFC values between 400 and 1,200 μg/mL. The principal identified compounds by HPLC-MS/MS and UV-VIS were chalcones (2′,4′-dihydroxy-3′-methoxychalcone, 2′,4′- dihydroxychalcone), flavones (galangin, 3,7-dihydroxyflavone and chrysin) and flavanones (naringenin, 7-hydroxyflavanone and pinocembrine). These compounds were more effective as inhibitors than the extracts upon biofilm formation as well as on preformed Candida biofilm and yeast germ tube formation. Furthermore, ZpE and chalcones are able to inhibit exoenzymes, which are responsible for the invasion mechanisms of the pathogens. All these effects could moderate colonization, thereby suppressing the pathogen invasive potential. Our results indicate that ZpE and chalcones could be used in antifungal therapy.

Investigations of Entomophthora muscae (Cohn) (Entomophthorales: Entomophthoraceae) conidial infection on housefly Musca domestica (Linn.) by scanning electron microscopy

1993 ◽  
Vol 39 (4) ◽  
pp. 363-366
Author(s):  
C. M. Tu ◽  
B. L. Singh
Keyword(s):  
Electron Microscopy ◽  
Germ Tube ◽  
Tube Formation ◽  
Insect Cuticle ◽  
Entomophthora Muscae ◽  
Entomogenous Fungus ◽  
Insect Pathology ◽  
Germ Tubes ◽  
Infection Cushion ◽  
Scanning Electron

An entomogenous fungus, Entomophthora muscae, was studied morphologically with respect to the formation of primary and secondary conidia and germ tubes. The fungus penetrated the insect cuticle by germ tubes that were produced at the base of each conidium that penetrated directly through the cuticle. Fungal germ-tube formation and penetration of host integument were observed. The tough germ-tube penetration point seemed to provide abundant energy for the penetration of the host integument. Conidia not directly on the integument formed secondary conidia but were never observed to form germ tubes. Neither appressorium nor infection cushion was observed on the germ tubes.Key words: Entomophthora muscae, entomogenous fungus, insect mycosis, insect pathology, conidia.

Physiological and ultrastructural changes occurring during germination of sclerotia of Sclerotium rolfsii

1977 ◽  
Vol 55 (9) ◽  
pp. 1137-1142 ◽  
Author(s):  
I. Chet ◽  
D. Timar ◽  
Y. Henis
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Germ Tube ◽  
Surrounding Medium ◽  
Sclerotium Rolfsii ◽  
Tube Formation ◽  
Ultrastructural Changes ◽  
Nutrient Source ◽  
External Nutrient

Sclerotia of Sclerotium rolfsii germinated without the addition of an exogenous nutrient source. The germinating sclerotia excreted sugars and amino acids to the surrounding medium. Continuous washing of sclerotia prevented germination. In germinating sclerotia, the rate of uptake and incorporation into macromolecules of [3H]uridine and[3H]leucine was very low in the first 6 h but increased rapidly during the next 6 h. Electron microscopy of germinating sclerotial slices revealed that only the granulated medullar cells were involved in germ-tube formation. The germination tubes were very electron-dense and had a large number of mitochondria near their tips. The huge vesicles of the cortex cells appeared almost empty in the germinating sclerotium. It is suggested that these cells serve as an external nutrient reservoir for the germination tubes.

scholarly journals Differential Physiological Prerequisites and Gene Expression Profiles of Conidial Anastomosis Tube and Germ Tube Formation in Colletotrichum gloeosporioides

2021 ◽  
Vol 7 (7) ◽  
pp. 509
Author(s):  
Nikita Mehta ◽  
Ravindra Patil ◽  
Abhishek Baghela
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Germ Tube ◽  
Colletotrichum Gloeosporioides ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Hyphal Growth ◽  
Tube Formation ◽  
Cell Wall Degrading Enzymes ◽  
Exclusive Processes

The conidia of a hemibiotrophic fungus, Colletotrichum gloeosporioides, can conventionally form a germ tube (GT) and develop into a fungal colony. Under certain conditions, they tend to get connected through a conidial anastomosis tube (CAT) to share the nutrients. CAT fusion is believed to be responsible for the generation of genetic variations in few asexual fungi, which appears problematic for effective fungal disease management. The physiological and molecular requirements underlying the GT formation versus CAT fusion remained underexplored. In the present study, we have deciphered the physiological prerequisites for GT formation versus CAT fusion in C. gloeosporioides. GT formation occurred at a high frequency in the presence of nutrients, while CAT fusion was found to be higher in the absence of nutrients. Younger conidia were found to form GT efficiently, while older conidia preferentially formed CAT. Whole transcriptome analysis of GT and CAT revealed highly differential gene expression profiles, wherein 11,050 and 9786 genes were differentially expressed during GT formation and CAT fusion, respectively. A total of 1567 effector candidates were identified; out of them, 102 and 100 were uniquely expressed during GT formation and CAT fusion, respectively. Genes coding for cell wall degrading enzymes, germination, hyphal growth, host-fungus interaction, and virulence were highly upregulated during GT formation. Meanwhile, genes involved in stress response, cell wall remodeling, membrane transport, cytoskeleton, cell cycle, and cell rescue were highly upregulated during CAT fusion. To conclude, the GT formation and CAT fusion were found to be mutually exclusive processes, requiring differential physiological conditions and sets of DEGs in C. gloeosporioides. This study will help in understanding the basic CAT biology in emerging fungal model species of the genus Colletotrichum.

An analysis of the metabolism and cell wall composition of Candida albicans during germ-tube formation

1983 ◽  
Vol 29 (11) ◽  
pp. 1514-1525 ◽  
Author(s):  
Patrick A. Sullivan ◽  
Chiew Yoke Yin ◽  
Christopher Molloy ◽  
Matthew D. Templeton ◽  
Maxwell G. Shepherd
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Germ Tube ◽  
Dry Weight ◽  
Tube Formation ◽  
Cell Wall Composition ◽  
Yeast Cells ◽  
Tube Forming ◽  
Insoluble Glucan ◽  
Germ Tubes

The uptake of nutrients (glucose, glutamine, and N-acetylglucosamine), the intracellular concentrations of metabolites (glucose-6-phosphate, cyclic AMP, amino acids, trehalose, and glycogen) and cell wall composition were studied in Candida albicans. These analyses were carried out with exponential-phase, stationary-phase, and starved yeast cells, and during germ-tube formation. Germ tubes formed during a 3-h incubation of starved yeast cells (0.8 × 108 cells/mL) at 37 °C during which time the nutrients glucose plus glutamine or N-acetylglucosamine (2.5 mM of each) were completely utilized. Control incubations with these nutrients at 28 °C did not form germ tubes. Uptake of N-acetylglucosamine and glutamine was inhibited by cycloheximide which suggests that de novo protein synthesis was required for the induction of these uptake systems. The glucose-6-phosphate content varied from 0.4 nmol/mg dry weight for starved cells to 2–3 nmol/mg dry weight for growing yeast cells and germ tube forming cells. Trehalose content varied from 85 nmol/mg dry weight (growing yeast cells and germ tube forming cells) to 165 nmol/mg weight (stationary-phase cells). The glycogen content decreased during germ-tube formation (from 800 to 600 nmol glucose equivalent/mg dry weight) but increased (to 1000 nmol glucose equivalent/mg dry weight) in the control incubation of yeast cells. Cyclic AMP remained constant throughout germ-tube formation at 4–6 pmol/mg dry weight. The total amino acid pool was similar in exponential, starved, and germ tube forming cells but there were changes in the amounts of individual amino acids. The overall cell wall composition of yeast cells and germ tube forming cells were similar: lipid (2%, w/w); protein (3–6%), and carbohydrate (77–85%). The total carbohydrates were accounted for as the following fractions: alkali-soluble glucan (3–8%), mannan (20–23%), acid-soluble glucan (24–27%), and acid-insoluble glucan (18–26%). The relative amounts of the alkali-soluble and insoluble glucan changed during starvation of yeast cells, reinitiation of yeast-phase growth, and germ-tube formation. Analysis of the insoluble glucan fraction from cells labelled with [14C]glucose during germ-tube formation showed that the chitin content of the cell wall increased from 0.6% to 2.7% (w/w).

scholarly journals Deciphering the differential physiological and molecular requirements for conidial anastomosis tube fusion and germ tube formation in Colletotrichum gloeosporioides

2021 ◽  
Author(s):  
Nikita Mehta ◽  
Ravindra Patil ◽  
Abhishek Baghela
Keyword(s):  
Cell Wall ◽  
Germ Tube ◽  
Colletotrichum Gloeosporioides ◽  
Hyphal Growth ◽  
Tube Formation ◽  
Cell Wall Degrading Enzymes ◽  
Asexual Fungi ◽  
Host Fungus ◽  
Whole Transcriptome Analysis ◽  
Exclusive Processes

AbstractThe conidia of a hemibiotrophic fungus Colletotrichum gloeosporioides can conventionally form germ tube (GT) and develop in to a fungal colony, while under certain conditions, they tend to get connected with each other through conidial anastomosis tube (CAT) so as to share the nutrients. CAT fusion is believed to be responsible for generation of genetic variations in few asexual fungi, which appears problematic for effective fungal disease management. The physiological and molecular mechanism underlying the GT versus CAT formation remained unexplored. In the present study, we have deciphered the decision switch responsible for GT formation versus CAT fusion in C. gloeosporioides. GT formation occurred at high frequency in the presence of nutrients, while CAT fusion was found to be higher in absence of nutrients. Younger conidia were found to form GT efficiently, whilst older conidia preferentially formed CAT. Whole transcriptome analysis of GT and CAT fusion revealed differential molecular requirements for these two processes. We identified 11050 and 9786 differentially expressed genes (DEGs) in GT and CAT, respectively. A total 1567 effector candidates were identified, of them 103 and 101 were uniquely secreted during GT and CAT formation respectively. Genes coding for cell wall degrading enzymes, germination, hyphal growth, host-fungus interaction and virulence were up-regulated during GT formation. Whilst, genes involved in stress response, cell wall remodelling, membrane transport, cytoskeleton, cell cycle, and cell rescue were highly up-regulated during CAT fusion. To conclude, the GT and CAT fusion were found to be mutually exclusive processes, requiring differential physiological conditions and sets of DEGs in C. gloeosporioides. This will help to understand the basic CAT biology in the genus Colletotrichum.

scholarly journals Effect of static magnetic fields against some virulence factor of C.albicans: germ tube formation, adhesion ability and biofilm formation

2013 ◽  
Vol 7 (1) ◽  
pp. 54-60
Author(s):  
Nada S. Rezooqe
Keyword(s):  
Magnetic Fields ◽  
Biofilm Formation ◽  
Germ Tube ◽  
Dry Weight ◽  
Tube Formation ◽  
Inhibitory Effects ◽  
Static Magnetic Fields ◽  
Adhesion Ability ◽  
Negative Pole ◽  
Germination Ability

In vitro, inhibitory effects of static magnetic fields in the type of two poles and negative and positive pole on some virulence factors belong to C.albicans as pathogenic microorganism was investigated in this study. According to the findings of this study static magnetic fields in the type of two poles and negative pole displayed a variable degree of inhibitory effects against this microorganism via its virulence factors such as: germ tube formation, adhesion ability and biofilm formation in which negative pole showed more strongly effect than two poles as inhibitory values ranged from 35% as germination ability, 30% adhesion ability after 3hrs of treatment and 2.2mg/disk dry weight as biofilm formation after 72hrs of treatment compared with the inhibitory values for two poles ranged from 30% as germination ability, 25% adhesion ability after 3hrs of treatment and 2.7mg/ disk dry weight as biofilm formation after 72hrs of treatment . Following our earlier demonstration, the effects of positive pole also investigated in this study as 10 % for germination ability, 10% adhesion ability after 3hrs of treatment and 3mg/ disk dry weight as biofilm formation after 72hrs of treatment. These results revealed that static magnetic fields in the type of negative pole may be useful as antifungal agent against Candida albicans.

scholarly journals Regulation of Growth, Cell Shape, Cell Division, and Gene Expression by Second Messengers (p)ppGpp and Cyclic Di-GMP in Mycobacterium smegmatis

2016 ◽  
Vol 198 (9) ◽  
pp. 1414-1422 ◽  
Author(s):  
Kuldeepkumar Ramnaresh Gupta ◽  
Priyanka Baloni ◽  
Shantinath S. Indi ◽  
Dipankar Chatterji
Keyword(s):  
Gene Expression ◽  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Division ◽  
Mycobacterium Smegmatis ◽  
Biofilm Formation ◽  
Second Messengers ◽  
Antibiotic Sensitivity ◽  
Cell Length ◽  
Content Type

ABSTRACTThe alarmone (p)ppGpp regulates transcription, translation, replication, virulence, lipid synthesis, antibiotic sensitivity, biofilm formation, and other functions in bacteria. Signaling nucleotide cyclic di-GMP (c-di-GMP) regulates biofilm formation, motility, virulence, the cell cycle, and other functions. InMycobacterium smegmatis, both (p)ppGpp and c-di-GMP are synthesized and degraded by bifunctional proteins RelMsmand DcpA, encoded byrelMsmanddcpAgenes, respectively. We have previously shown that the ΔrelMsmand ΔdcpAknockout strains are antibiotic resistant and defective in biofilm formation, show altered cell surface properties, and have reduced levels of glycopeptidolipids and polar lipids in their cell wall (K. R. Gupta, S. Kasetty, and D. Chatterji, Appl Environ Microbiol 81:2571–2578, 2015,http://dx.doi.org/10.1128/AEM.03999-14). In this work, we have explored the phenotypes that are affected by both (p)ppGpp and c-di-GMP in mycobacteria. We have shown that both (p)ppGpp and c-di-GMP are needed to maintain the proper growth rate under stress conditions such as carbon deprivation and cold shock. Scanning electron microscopy showed that low levels of these second messengers result in elongated cells, while high levels reduce the cell length and embed the cells in a biofilm-like matrix. Fluorescence microscopy revealed that the elongated ΔrelMsmand ΔdcpAcells are multinucleate, while transmission electron microscopy showed that the elongated cells are multiseptate. Gene expression analysis also showed that genes belonging to functional categories such as virulence, detoxification, lipid metabolism, and cell-wall-related processes were differentially expressed. Our results suggests that both (p)ppGpp and c-di-GMP affect some common phenotypes inM. smegmatis, thus raising a possibility of cross talk between these two second messengers in mycobacteria.IMPORTANCEOur work has expanded the horizon of (p)ppGpp and c-di-GMP signaling in Gram-positive bacteria. We have come across a novel observation thatM. smegmatisneeds (p)ppGpp and c-di-GMP for cold tolerance. We had previously shown that the ΔrelMsmand ΔdcpAstrains are defective in biofilm formation. In this work, the overproduction of (p)ppGpp and c-di-GMP encasedM. smegmatisin a biofilm-like matrix, which shows that both (p)ppGpp and c-di-GMP are needed for biofilm formation. The regulation of cell length and cell division by (p)ppGpp was known in mycobacteria, but our work shows that c-di-GMP also affects the cell size and cell division in mycobacteria. This is perhaps the first report of c-di-GMP regulating cell division in mycobacteria.

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