scholarly journals Candida albicans Airway Colonization Facilitates Subsequent Acinetobacter baumannii Pneumonia in a Rat Model

2016 ◽  
Vol 60 (6) ◽  
pp. 3348-3354 ◽  
Author(s):  
Xiaojiang Tan ◽  
Ruilan Chen ◽  
Song Zhu ◽  
Huijun Wang ◽  
Dongxing Yan ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Acinetobacter Baumannii ◽  
Amphotericin B ◽  
Rat Model ◽  
Virulence Genes ◽  
Control Group ◽  
Interleukin 17 ◽  
Content Type ◽  
Ifn Γ

The objective of the study was to determine the effects ofCandida albicansrespiratory tract colonization onAcinetobacter baumanniipneumonia in a rat model. Rats were colonized withC. albicansby instillation of 3 × 106CFU into their airways, while sterile saline was instilled in the control group. The colonized rats were further divided into two groups: treated with amphotericin B or not. The rats were subsequently infected withA. baumannii(108CFU by tracheobronchial instillation).A. baumanniilung CFU counts, cytokine lung levels, and rates ofA. baumanniipneumonia were compared between groups.In vitroexpression ofA. baumanniivirulence genes was measured by reverse transcription (RT)-PCR after 24-hour incubation withC. albicansor with Mueller-Hinton (MH) broth alone. Rats withCandidacolonization developedA. baumanniipneumonia more frequently and had higherA. baumanniiCFU burdens and heavier lungs than controls. AfterA. baumanniiinfection, lung interleukin 17 (IL-17) concentrations were lower and gamma interferon (IFN-γ) concentrations were higher inCandida-colonized rats than in controls.Candida-colonized rats treated with amphotericin B had a decreased rate ofA. baumanniipneumonia and lower IFN-γ levels but higher IL-17 levels than untreated rats. Expression ofbasC,barB,bauA,ptk,plc2, andpld2was induced while expression ofompAandabaIwas suppressed inA. baumanniicultured in the presence ofC. albicans.C. albicanscolonization facilitated the development ofA. baumanniipneumonia in a rat model. AmongCandida-colonized rats, antifungal treatment lowered the incidence ofA. baumanniipneumonia. These findings could be due to modification of the host immune response and/or expression ofA. baumanniivirulence genes byCandidaspp.

scholarly journals Evaluation of Immunostimulatory Activities of Synthetic Mannose-Containing Structures Mimicking the β-(1→2)-Linked Cell Wall Mannans of Candida albicans

2012 ◽  
Vol 19 (11) ◽  
pp. 1889-1893 ◽  
Author(s):  
Kaarina Ranta ◽  
Kaisa Nieminen ◽  
Filip S. Ekholm ◽  
Moniká Poláková ◽  
Mattias U. Roslund ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Mouse Macrophages ◽  
Ifn Γ ◽  
Low Levels ◽  
Necrosis Factor

ABSTRACTImmunostimulatory properties of synthetic structures mimicking the β-(1→2)-linked mannans ofCandida albicanswere evaluatedin vitro. Contrary to earlier observations, tumor necrosis factor (TNF) production was not detected after stimulation with mannotetraose in mouse macrophages. Divalent disaccharide 1,4-bis(α-d-mannopyranosyloxy)butane induced TNF and some molecules induced low levels of gamma interferon (IFN-γ) in human peripheral blood mononuclear cells (PBMC).

scholarly journals New Triazole NT-a9 Has Potent Antifungal Efficacy against Cryptococcus neoformans In Vitro and In Vivo

2019 ◽  
Vol 64 (2) ◽  
Author(s):  
Ren-Yi Lu ◽  
Ting-Jun-Hong Ni ◽  
Jing Wu ◽  
Lan Yan ◽  
Quan-Zhen Lv ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Pathogenic Fungi ◽  
Control Group ◽  
Survival Times ◽  
Content Type ◽  
Fungal Burden ◽  
Wide Range

ABSTRACT In the past decades, the incidence of cryptococcosis has increased dramatically, which poses a new threat to human health. However, only a few drugs are available for the treatment of cryptococcosis. Here, we described a leading compound, NT-a9, an analogue of isavuconazole, that showed strong antifungal activities in vitro and in vivo. NT-a9 showed a wide range of activities against several pathogenic fungi in vitro, including Cryptococcus neoformans, Cryptococcus gattii, Candida albicans, Candida krusei, Candida tropicalis, Candida glabrata, and Candida parapsilosis, with MICs ranging from 0.002 to 1 μg/ml. In particular, NT-a9 exhibited excellent efficacy against C. neoformans, with a MIC as low as 0.002 μg/ml. NT-a9 treatment resulted in changes in the sterol contents in C. neoformans, similarly to fluconazole. In addition, NT-a9 possessed relatively low cytotoxicity and a high selectivity index. The in vivo efficacy of NT-a9 was assessed using a murine disseminated-cryptococcosis model. Mice were infected intravenously with 1.8 × 106 CFU of C. neoformans strain H99. In the survival study, NT-a9 significantly prolonged the survival times of mice compared with the survival times of the control group or the isavuconazole-, fluconazole-, or amphotericin B-treated groups. Of note, 4 and 8 mg/kg of body weight of NT-a9 rescued all the mice, with a survival rate of 100%. In the fungal-burden study, NT-a9 also significantly reduced the fungal burdens in brains and lungs, while fluconazole and amphotericin B only reduced the fungal burden in lungs. Taken together, these data suggested that NT-a9 is a promising antifungal candidate for the treatment of cryptococcosis infection.

Comparison of antifungal efficacies of moxifloxacin, liposomal amphotericin B, and combination treatment in experimental Candida albicans endophthalmitis in rabbits

2010 ◽  
Vol 56 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Yudum Tiftikcioğlu Deren ◽  
Şengül Özdek ◽  
Ayşe Kalkanci ◽  
Nalan Akyürek ◽  
Berati Hasanreisoğlu
Keyword(s):  
Candida Albicans ◽  
Minimum Inhibitory Concentration ◽  
Amphotericin B ◽  
Combination Treatment ◽  
Liposomal Amphotericin ◽  
Inhibitory Concentration ◽  
Liposomal Amphotericin B ◽  
Control Group

The goal of this study was to compare in vitro and in vivo efficacy of moxifloxacin and liposomal amphotericin B (Amp-B) monotherapies and combination treatment against Candida albicans in an exogenous endophthalmitis model in rabbit eyes. Microplate dilution tests and checkerboard analysis were performed to detect in vitro efficacies. Endophthalmitis was induced by intravitreal injection of C. albicans in 40 rabbit eyes with simultaneous intravitreal drug injection according to prophylactic treatment groups. Group 1 (control group) received 0.1 mL of balanced salt solution, group 2 (moxi group) 100 µg moxifloxacin/0.1 mL, group 3 (Amp-B group) 10 µg liposomal Amp-B/0.1 mL, and group 4 (combi group) both 100 µg moxifloxacin/0.05 mL and 10 µg liposomal Amp-B/0.05 mL intravitreally. Clinical examination, quantitative analysis of microorganisms, and histopathologic examination were performed as in vivo studies. The minimum inhibitory concentration of liposomal Amp-B against C. albicans was found to be 1 µg/mL. Moxifloxacin showed no inhibition of in vitro C. albicans growth. The minimum inhibitory concentration values of liposomal Amp-B for C. albicans were reduced two- to eightfold with increasing concentrations of moxifloxacin in vitro. In vivo, there was no C. albicans growth in the combi group (zero of eight eyes), whereas three eyes (37.5%) showed growth in the Amp-B group. Vitreous inflammation, retinal detachment, focal retinal necrosis, and outer nuclear layer loss were found to be lower in the moxi group compared with the control group. Ganglion cell and inner nuclear layer loss was observed in all eyes (100%) in both the moxi and combi groups, whereas only in 25% (two of eight eyes) in the Amp-B group. Moxifloxacin strongly augments the efficacy of liposomal Amp-B against C. albicans in vitro, although it has no in vitro antifungal activity when used alone. It is interesting that we found a synergistic effect for in vitro tests but failed to demonstrate it in vivo. When 100 µg moxifloxacin/0.1 mL is given intravitreally, it has some toxic effects that are limited to the inner retinal layers.

scholarly journals In VitroInteractions between Aspirin and Amphotericin B against Planktonic Cells and Biofilm Cells of Candida albicans and C. parapsilosis

2012 ◽  
Vol 56 (6) ◽  
pp. 3250-3260 ◽  
Author(s):  
Yabin Zhou ◽  
Ganggang Wang ◽  
Yutang Li ◽  
Yang Liu ◽  
Yu Song ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Antimicrobial Agents ◽  
Positive Interactions ◽  
Antibiofilm Activity ◽  
Data Generation ◽  
Planktonic Cells ◽  
Content Type ◽  
Time Kill

ABSTRACTThe increase in drug resistance and invasion caused by biofilm formation brings enormous challenges to the management ofCandidainfection. Aspirin's antibiofilm activityin vitrowas discovered recently. The spectrophotometric method and the XTT {2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide} reduction assay used for data generation make it possible to evaluate fungal biofilm growth accurately. The combined use of the most commonly used methods, the fractional inhibitory concentration index (FICI) and a newly developed method, the ΔEmodel, which uses the concentration-effect relationship over the whole concentration range instead of using the MIC index alone, makes the interpretation of results more reliable. As an attractive tool for studying the pharmacodynamics of antimicrobial agents, time-kill curves can provide detailed information about antimicrobial efficacy as a function of both time and concentration. In the present study,in vitrointeractions between aspirin (acetylsalicylic acid [ASA]) and amphotericin B (AMB) against planktonic cells and biofilm cells ofCandida albicansandC. parapsilosiswere evaluated by the checkerboard microdilution method and the time-kill test. Synergistic and indifferent effects were found for the combination of ASA and AMB against planktonic cells, while strong synergy was found against biofilm cells analyzed by FICI. The ΔEmodel gave more consistent results with FICI. The positive interactions in concentration were also confirmed by the time-kill test. Moreover, this approach also revealed the pharmacodynamics changes of ASA and synergistic action on time. Our findings suggest a potential clinical use for combination therapy with ASA and AMB to augment activity against biofilm-associated infections.

scholarly journals Impaired Virulence and Fitness of a Colistin-Resistant Clinical Isolate of Acinetobacter baumannii in a Rat Model of Pneumonia

2013 ◽  
Vol 57 (10) ◽  
pp. 5120-5121 ◽  
Author(s):  
Sami Hraiech ◽  
Antoine Roch ◽  
Hubert Lepidi ◽  
Thérèse Atieh ◽  
Gilles Audoly ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Growth Kinetics ◽  
Rat Model ◽  
Bacterial Count ◽  
Mortality Rates ◽  
The Other ◽  
Lung Damage ◽  
Content Type ◽  
Systemic Dissemination

ABSTRACTWe compared the fitness and lung pathogenicity of two isogenic clinical isolates ofAcinetobacter baumannii, one resistant (ABCR) and the other susceptible (ABCS) to colistin.In vitro, ABCR exhibited slower growth kinetics than ABCS. In a rat model of pneumonia, ABCR was associated with less pronounced signs of infection (lung bacterial count, systemic dissemination, and lung damage) and a better outcome (ABCR and ABCS mortality rates, 20 and 50%, respectively [P= 0.03]).

scholarly journals Gallic and Ellagic Acids Are Promising Adjuvants to Conventional Amphotericin B for the Treatment of Cutaneous Leishmaniasis

2020 ◽  
Vol 64 (12) ◽  
Author(s):  
Michel Muálem de Moraes Alves ◽  
Daniel Dias Rufino Arcanjo ◽  
Kayo Alves Figueiredo ◽  
Jéssica Sara de Sousa Macêdo Oliveira ◽  
Felipe José Costa Viana ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Amphotericin B ◽  
Leishmania Major ◽  
Negative Control ◽  
Control Group ◽  
Histopathological Analysis ◽  
Activated Macrophages ◽  
Content Type

ABSTRACT In this study, we demonstrated the potential associative effect of combining conventional amphotericin B (Amph B) with gallic acid (GA) and with ellagic acid (EA) in topical formulations for the treatment of cutaneous leishmaniasis in BALB/c mice. Preliminary stability tests of the formulations and in vitro drug release studies with Amph B, GA, Amph B plus GA, EA, and Amph B plus EA were carried out, as well as assessment of the in vivo treatment of BALB/c mice infected with Leishmania major. After 40 days of infection, the animals were divided into 6 groups and treated twice a day for 21 days with a gel containing Amph B, GA, Amph B plus GA, EA, or Amph B plus EA, and the negative-control group was treated with the vehicle. In the animals that received treatment, there was reduction of the lesion size and reduction of the parasitic load. Histopathological analysis of the treatments with GA, EA, and combinations with Amph B showed circumscribed lesions with the presence of fibroblasts, granulation tissue, and collagen deposition, as well as the presence of activated macrophages. The formulations containing GA and EA activated macrophages in all evaluated parameters, resulting in the activation of cells of the innate immune response, which can generate healing and protection. GA and EA produced an associative effect with Amph B, which makes them promising for use with conventional Amph B in the treatment of cutaneous leishmaniasis.

scholarly journals Synergistic Activity of the Tyrocidines, Antimicrobial Cyclodecapeptides from Bacillus aneurinolyticus, with Amphotericin B and Caspofungin against Candida albicans Biofilms

2014 ◽  
Vol 58 (7) ◽  
pp. 3697-3707 ◽  
Author(s):  
Anscha Mari Troskie ◽  
Marina Rautenbach ◽  
Nicolas Delattin ◽  
Johan Arnold Vosloo ◽  
Margitta Dathe ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Membrane Integrity ◽  
Antifungal Drugs ◽  
Infection Model ◽  
Synergistic Activity ◽  
Significant Activity ◽  
Content Type ◽  
Micromolar Range

ABSTRACTTyrocidines are cationic cyclodecapeptides fromBacillus aneurinolyticusthat are characterized by potent antibacterial and antimalarial activities. In this study, we show that various tyrocidines have significant activity against planktonicCandida albicansin the low-micromolar range. These tyrocidines also preventedC. albicansbiofilm formationin vitro. Studies with the membrane-impermeable dye propidium iodide showed that the tyrocidines disrupt the membrane integrity of matureC. albicansbiofilm cells. This membrane activity correlated with the permeabilization and rapid lysis of model fungal membranes containing phosphatidylcholine and ergosterol (70:30 ratio) induced by the tyrocidines. The tyrocidines exhibited pronounced synergistic biofilm-eradicating activity in combination with two key antifungal drugs, amphotericin B and caspofungin. Using aCaenorhabditis elegansinfection model, we found that tyrocidine A potentiated the activity of caspofungin. Therefore, tyrocidines are promising candidates for further research as antifungal drugs and as agents for combinatorial treatment.

Levels interleukine-4 and interleukin-17 (IL-4, IL-17) of blood in patients with habitual recurrent pregnancy loss, which occurred in a loop in vitro fertilization

2016 ◽  
pp. 137-139
Author(s):  
K.P. Golovatyuk ◽  
Keyword(s):  
In Vitro Fertilization ◽  
Conditioned Medium ◽  
Mononuclear Cells ◽  
Recurrent Miscarriage ◽  
Interleukin 4 ◽  
Control Group ◽  
Interleukin 17 ◽  
Vitro Fertilization ◽  
Blood Mononuclear Cells

The objective: was to investigate the levels of cytokines IL-4 and IL-17 in serum and conditioned medium cultures of blood mononuclear cells (MNC) and evaluation association between their products and miscarriage, which occurred in IVF cycles. Patients and methods. We observed 240 patients with recurrent miscarriage, came in IVF cycles, and 100 apparently healthy fertile women in the control group. The concentrations of IL-4 and IL-17 in serum and conditioned medium of MNC cultures were determined. Results. The levels of IL-4 in the serum and conditioned medium in spontaneous and stimulated mitogen secretion was not significantly different from those in the control group, whereas IL-17 levels were higher than those in the control group serum, in conditioned media of stimulated and non-stimulated MNCs. Conclusion. Disregulation of activity of circulating blood mononuclear cells in women with recurrent miscarriage that followed IVF, is accompanied by increased secretion of IL-17 and almost constant production of IL-4 on the back of high stimulation index of production of these cytokines. Key words: in vitro fertilization, miscarriage, interleukin-4, interleukin-17, serum stimulated and non-stimulated mononuclear blood.

scholarly journals In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

2011 ◽  
Vol 56 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marisa H. Miceli ◽  
Stella M. Bernardo ◽  
T. S. Neil Ku ◽  
Carla Walraven ◽  
Samuel A. Lee
Keyword(s):  
Candida Albicans ◽  
Metabolic Activity ◽  
Biofilm Formation ◽  
High Dose ◽  
Dependent Manner ◽  
Planktonic Cells ◽  
Content Type ◽  
Heparin Sodium ◽  
The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

scholarly journals Dectin-2-Targeted Antifungal Liposomes Exhibit Enhanced Efficacy

mSphere ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Suresh Ambati ◽  
Emma C. Ellis ◽  
Jianfeng Lin ◽  
Xiaorong Lin ◽  
Zachary A. Lewis ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Aspergillus Fumigatus ◽  
Effective Dose ◽  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Antifungal Drugs ◽  
Extracellular Matrices ◽  
Content Type ◽  
Order Of Magnitude ◽  
Life Threatening

ABSTRACT Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus cause life-threatening candidiasis, cryptococcosis, and aspergillosis, resulting in several hundred thousand deaths annually. The patients at the greatest risk of developing these life-threatening invasive fungal infections have weakened immune systems. The vulnerable population is increasing due to rising numbers of immunocompromised individuals as a result of HIV infection or immunosuppressed individuals receiving anticancer therapies and/or stem cell or organ transplants. While patients are treated with antifungals such as amphotericin B, all antifungals have serious limitations due to lack of sufficient fungicidal effect and/or host toxicity. Even with treatment, 1-year survival rates are low. We explored methods of increasing drug effectiveness by designing fungicide-loaded liposomes specifically targeted to fungal cells. Most pathogenic fungi are encased in cell walls and exopolysaccharide matrices rich in mannans. Dectin-2 is a mammalian innate immune membrane receptor that binds as a dimer to mannans and signals fungal infection. We coated amphotericin-loaded liposomes with monomers of Dectin-2’s mannan-binding domain, sDectin-2. sDectin monomers were free to float in the lipid membrane and form dimers that bind mannan substrates. sDectin-2-coated liposomes bound orders of magnitude more efficiently to the extracellular matrices of several developmental stages of C. albicans, C. neoformans, and A. fumigatus than untargeted control liposomes. Dectin-2-coated amphotericin B-loaded liposomes reduced the growth and viability of all three species more than an order of magnitude more efficiently than untargeted control liposomes and dramatically decreased the effective dose. Future efforts focus on examining pan-antifungal targeted liposomal drugs in animal models of fungal diseases. IMPORTANCE Invasive fungal diseases caused by Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus have mortality rates ranging from 10 to 95%. Individual patient costs may exceed $100,000 in the United States. All antifungals in current use have serious limitations due to host toxicity and/or insufficient fungal cell killing that results in recurrent infections. Few new antifungal drugs have been introduced in the last 2 decades. Hence, there is a critical need for improved antifungal therapeutics. By targeting antifungal-loaded liposomes to α-mannans in the extracellular matrices secreted by these fungi, we dramatically reduced the effective dose of drug. Dectin-2-coated liposomes loaded with amphotericin B bound 50- to 150-fold more strongly to C. albicans, C. neoformans, and A. fumigatus than untargeted liposomes and killed these fungi more than an order of magnitude more efficiently. Targeting drug-loaded liposomes specifically to fungal cells has the potential to greatly enhance the efficacy of most antifungal drugs.

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