scholarly journals Pseudomonas aeruginosa-Candida albicans Interactions: Localization and Fungal Toxicity of a Phenazine Derivative

2008 ◽  
Vol 75 (2) ◽  
pp. 504-513 ◽  
Author(s):  
Jane Gibson ◽  
Arpana Sood ◽  
Deborah A. Hogan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Small Molecules ◽  
Solid Medium ◽  
Genetic Screen ◽  
Red Pigment ◽  
Pigment Formation ◽  
Intracellular Targeting ◽  
Phenazine Derivative ◽  
Redox Active

ABSTRACT Phenazines are redox-active small molecules that play significant roles in the interactions between pseudomonads and diverse eukaryotes, including fungi. When Pseudomonas aeruginosa and Candida albicans were cocultured on solid medium, a red pigmentation developed that was dependent on P. aeruginosa phenazine biosynthetic genes. Through a genetic screen in combination with biochemical experiments, it was found that a P. aeruginosa-produced precursor to pyocyanin, proposed to be 5-methyl-phenazinium-1-carboxylate (5MPCA), was necessary for the formation of the red pigmentation. The 5MPCA-derived pigment was found to accumulate exclusively within fungal cells, where it retained the ability to be reversibly oxidized and reduced, and its detection correlated with decreased fungal viability. Pyocyanin was not required for pigment formation or fungal killing. Spectral analyses showed that the partially purified pigment from within the fungus differed from aeruginosins A and B, two red phenazine derivatives formed late in P. aeruginosa cultures. The red pigment isolated from C. albicans that had been cocultured with P. aeruginosa was heterogeneous and difficult to release from fungal cells, suggesting its modification within the fungus. These findings suggest that intracellular targeting of some phenazines may contribute to their toxicity and that this strategy could be useful in developing new antifungals.

Complexes of Cu (II) with a-Ketoglutaric Acid and 1- (o-tolyl) Biguanide Synthesis, characterization and biological Activity

2019 ◽  
Vol 70 (10) ◽  
pp. 3603-3610
Author(s):  
Madalina Mihalache ◽  
Cornelia Guran ◽  
Aurelia Meghea ◽  
Vasile Bercu ◽  
Ludmila Motelica ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Biological Activity ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Copper Complexes ◽  
Substrate Adhesion ◽  
Inert Substrate

The three copper complexes having a-ketoglutaric acid (H2A) and 1- (o-tolyl) biguanide (TB) ligands have been synthesized and characterized. The proposed formulas for these complexes are: [Cu(TB)(HA)]Cl (C1), [Cu(TB)(HA)CH3COO]�H2O (C2) and [Cu(TB)(HA)](NO3) (C3) where HA represents deprotonated H2A. The complexes obtained were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, antifungal activity on Candida albicans ATCC 10231 and antitumor activity on HeLa tumor cells. Due to the antitumor, antifungal, antimicrobial activity and inhibition of inert substrate adhesion, complexes synthesized could be used for potential therapeutic applications.

Potent Chitin Synthase Inhibitors from Plants

2020 ◽  
Vol 16 (1) ◽  
pp. 58-63
Author(s):  
Amrutha Vijayakumar ◽  
Ajith Madhavan ◽  
Chinchu Bose ◽  
Pandurangan Nanjan ◽  
Sindhu S. Kokkal ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Caenorhabditis Elegans ◽  
Aspergillus Niger ◽  
Small Molecules ◽  
Tip Growth ◽  
Chitin Synthase ◽  
Chitin Synthesis ◽  
Hyphal Tip Growth ◽  
Hyphal Tip

Background: Chitin is the main component of fungal, protozoan and helminth cell wall. They help to maintain the structural and functional characteristics of these organisms. The chitin wall is dynamic and is repaired, rearranged and synthesized as the cells develop. Active synthesis can be noticed during cytokinesis, laying of primary septum, maintenance of lateral cell wall integrity and hyphal tip growth. Chitin synthesis involves coordinated action of two enzymes namely, chitin synthase (that lays new cell wall) and chitinase (that removes the older ones). Since chitin synthase is conserved in different eukaryotic microorganisms that can be a ‘soft target’ for inhibition with small molecules. When chitin synthase is inhibited, it leads to the loss of viability of cells owing to the self- disruption of the cell wall by existing chitinase. Methods: In the described study, small molecules from plant sources were screened for their ability to interfere with hyphal tip growth, by employing Hyphal Tip Burst assay (HTB). Aspergillus niger was used as the model organism. The specific role of these small molecules in interfering with chitin synthesis was established with an in-vitro method. The enzyme required was isolated from Aspergillus niger and its activity was deduced through a novel method involving non-radioactively labelled substrate. The activity of the potential lead molecules were also checked against Candida albicans and Caenorhabditis elegans. The latter was adopted as a surrogate for the pathogenic helminths as it shares similarity with regard to cell wall structure and biochemistry. Moreover, it is widely studied and the methodologies are well established. Results: Out of the 11 compounds and extracts screened, 8 were found to be prospective. They were also found to be effective against Candida albicans and Caenorhabditis elegans. Conclusion: Purified Methyl Ethyl Ketone (MEK) Fraction1 (F1) of Coconut (Cocos nucifera) Shell Extract (COSE) was found to be more effective against Candida albicans with an IC50 value of 3.04 μg/mL and on L4 stage of Caenorhabditis elegans with an IC50 of 77.8 μg/mL.

Successful Control of a Co-Infection Caused by Candida albicans and Pseudomonas aeruginosa in Keratitis

2020 ◽  
Vol 20 ◽  
Author(s):  
Debarati Paul ◽  
Suman Saha ◽  
Neelam Singh ◽  
Jayansgu Sengupta ◽  
Santi M. Mandal
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Histopathological Examination ◽  
Specific Interaction ◽  
Major Threat ◽  
Effective Combination ◽  
Male Farmer ◽  
Successful Control ◽  
The Right ◽  
Corneal Button

Introduction: Nowadays, co-infection by interspecific organisms is major threat in infection control. To identify the effective combination of drugs to control the keratitis caused by Candida albicans with Pseudomonas aeruginosa are attributed in this study. Materilas and Methods: The patient of a 47 years old male farmer with infection in the right eye which showed redness and watering was treated with fortified cefazolin and fortified tobramycin before referral. No pigmentation or vascularisation was noted. The excised corneal button was also subjected to microbiological and histopathological examination. Results: A rare case of keratitis caused by co-infection of Candida albicans with Pseudomonas aeruginosa was identified. Results confirmed the inter-specific interaction of the two microorganisms. Conclusion: Cases of co-infection by Candida and Pseudomonas are not abundantly reported and difficult to treat. In this case, treatment involved Amphotercin-B and ciprofloxacin, effectively eradicated the infection. This therapy may be successfully implied for such cases of co-infection in future.

Confocal and SEM imaging to demonstrate food pathogen- biofilm biocontrol by pyocyanin from Pseudomonas aeruginosa BTRY1

2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Opportunistic Pathogens ◽  
Redox Active ◽  
Sem Imaging ◽  
The Impact

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

Thực trạng ô nhiễm vi sinh vật trong khăn ướt dùng một lần ở các nhà hàng, quán ăn tại thành phố Nha Trang năm 2019

2021 ◽  
Vol 31 (9) ◽  
pp. 83-89
Author(s):  
Dương Thị Hồng Thắm ◽  
Hồ Văn Quốc ◽  
Lý Thế Vinh ◽  
Nguyễn Tất Hòa ◽  
Đỗ Thái Hùng
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Candida Albicans

Nghiên cứu mô tả cắt ngang năm 2019 trên 150 mẫu khăn ướt dùng 1 lần làm từ vải không dệt, được lấy từ 150 nhà hàng, quán ăn trên địa bàn thành phố Nha Trang nhằm  mô tả thực trạng mức độ ô nhiễm vi sinh vật đếm được, các vi khuẩn gây bệnh Pseudomonas aeruginosa, Staphylococcus aureus và nấm Candida albicans. Kết quả nghiên cứu cho thấy 68% (102/150) nhà hàng quán ăn có mẫu khăn ướt dùng 1 lần đạt tiêu chuẩn khăn ướt dùng cho các đối tượng khác theo TCVN 11528:2016. Tổng số vi sinh vật đếm được trung bình là 5,6 × 106 ± 3,7 × 107 CFU/g (XTB ± SD), thấp nhất là < 10 CFU/g, cao nhất là 3,5 × 108 CFU/g. Có 20,3% (12/59) nhà hàng, quán ăn có mẫu khăn ướt bị nhiễm vi sinh vật phân lập được P. aeruginosa, với số lượng trung bình là: 3,6 × 106 ± 2,0×107 CFU/g, cao nhất là 1,4 × 108 CFU/g và thấp nhất là < 10 CFU/g. Không phát hiện thấy S. aureus và C. albicans trong các mẫu khăn ướt thu thập được. Nghiên cứu này cho thấy có gần 40% nhà hàng, quán ăn có mẫu khăn ướt bị ô nhiễm ít nhất 1 tác nhân vi sinh vật, do vậy các nhà hàng, quán ăn cần lựa chọn các cơ sở cung cấp khăn ướt có chất lượng tốt.

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