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1.
Open Forum Infect Dis ; 11(7): ofae346, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38989533

ABSTRACT

Amphotericin B (AmB) has broad fungicidal activity against many fungi, but the high incidence of adverse events, particularly nephrotoxicity, and the need for intravenous administration restrict its use for many patients. MAT2203, an investigational oral AmB formulation available under a compassionate use program, uses a lipid nanocrystal bilayer structure to deliver AmB with lower toxicity. We present a synopsis of clinical characteristics, treatment course, and outcomes for 5 patients who were treated with MAT2203. Outcomes were positive, with cure of infection noted in 4 patients and improvement in 1 patient who remains on therapy. MAT2203 was well tolerated with only modest gastrointestinal adverse effects. This new oral formulation might provide a safer treatment option for patients requiring extended courses of AmB.

2.
Antimicrob Agents Chemother ; : e0022524, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38958455

ABSTRACT

As comparative pharmacokinetic/pharmacodynamic (PK/PD) studies of liposomal amphotericin B (L-AMB) against Candida spp. are lacking, we explored L-AMB pharmacodynamics against different Candida species in an in vitro PK/PD dilution model. Eight Candida glabrata, Candida parapsilosis, and Candida krusei isolates (EUCAST/CLSI AMB MIC 0.125-1 mg/L) were studied in the in vitro PK/PD model simulating L-AMB Cmax = 0.25-64 mg/L and t1/2 = 9 h. The model was validated with one susceptible and one resistant Candida albicans isolate. The Cmax/MIC-log10CFU/mL reduction from the initial inoculum was analyzed with the Emax model, and Monte Carlo analysis was performed for the standard (3 mg/kg with Cmax = 21.87 ± 12.47 mg/L) and higher (5 mg/kg with Cmax = 83 ± 35.2 mg/L) L-AMB dose. A ≥1.5 log10CFU/mL reduction was found at L-AMB Cmax = 8 mg/L against C. albicans, C. parapsilosis, and C. krusei isolates (MIC 0.25-0.5 mg/L) whereas L-AMB Cmax ≥ 32 mg/L was required for C. glabrata isolates. The in vitro PK/PD relationship followed a sigmoidal pattern (R2 ≥ 0.85) with a mean Cmax/MIC required for stasis of 2.1 for C. albicans (close to the in vivo stasis), 24/17 (EUCAST/CLSI) for C. glabrata, 8 for C. parapsilosis, and 10 for C. krusei. The probability of target attainment was ≥99% for C. albicans wild-type (WT) isolates with 3 mg/kg and for wild-type isolates of the other species with 5 mg/kg. L-AMB was four- to eightfold less active against the included non-C. albicans species than C. albicans. A standard 3-mg/kg dose is pharmacodynamically sufficient for C. albicans whereas our data suggest that 5 mg/kg may be recommendable for the included non-C. albicans species.

3.
Mycobiology ; 52(3): 191-200, 2024.
Article in English | MEDLINE | ID: mdl-38948451

ABSTRACT

Candida ranks as among the most frequently encountered fungal infections that associated with high morbidity and mortality. Quinoxaline derivatives are a group of small molecules that showed a promising antimicrobial activity. This study aimed to investigate the fungicidal effects of 3-hydrazinoquinoxaline-2-thiol against Candida in comparison with Amphotericin B in vitro as a reference. Also, we aim to assess the efficacy of 3-hydrazinoquinoxaline-2-thiol in vivo using mice oral candidiasis model. Fifty-six Candida isolates were subjected to susceptibility testing by broth microdilution method for 3-hydrazinoquinoxaline-2-thiol and Amphotericin B. Therefore, Minimal inhibitory concentrations (MIC) were assessed and compared. The oral candidiasis mice model was used to evaluate the activity of 3-hydrazinoquinoxaline-2-thiol in vivo. Microbiological evaluation of progression and ELISA were used in this study. 3-hydrazinoquinoxaline-2-thiol was more effective than Amphotericin B against most clinical isolates of Candida albicans. Higher effectiveness was seen against Candida glabrata and Candida parapsilosis isolates. However, the efficiency against Candida tropicalis isolates varies. 3-hydrazinoquinoxaline-2-thiol was also effective against Pichia kudriavzevii and Clavispora lusitaniae. 3-hydrazinoquinoxaline-2-thiol showed a good efficacy in mice model against C. albicans cells ATCC 10231. 3-hydrazinoquinoxaline-2-thiol has shown promising antifungal and anti-inflammatory activity against different Candida species. More tests and experiments are needed.

4.
Hemodial Int ; 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38945692

ABSTRACT

A 61-year-old female with diabetes and stage 5 chronic kidney disease on hemodialysis since 3 years via left brachiocephalic arteriovenous fistula presented with uncontrolled sugars, weight loss, and dysphagia. On evaluation, she was found to have an oral thrush with leucocytosis. Initial blood and urine cultures were sterile, and ultrasonography revealed hypoechoic lesions in the left lobe of the liver. She had high-grade fever followed by seizures on postadmission Day 10. Brain imaging and serum electrolytes were normal. Cerebrospinal fluid analysis was noncontributory, and urine culture revealed Candida non-albicans with elevated white blood cell counts. She was started on fluconazole; however, her clinical condition deteriorated, with hemodynamic instability. Repeat abdominal computerized tomography revealed increasing hypodense lesions in the left lobe of the liver with elevated beta D glucan levels. Percutaneous drainage of the abscess revealed no fungal elements. In view of clinical deterioration, amphotericin B was started, which resulted in clinical improvement. Clinician should have high index of suspicion for fungal etiology in hemodialysis patients presenting with liver abscess.

5.
Clin Infect Dis ; 2024 Jun 29.
Article in English | MEDLINE | ID: mdl-38943665

ABSTRACT

BACKGROUND: Limited data exist on the antifungal activity of daily liposomal amphotericin B with flucytosine induction regimens for cryptococcal meningitis, which are recommended in high-income countries. Liposomal amphotericin B monotherapy at 3 mg/kg previously failed to meet non-inferiority criteria compared to amphotericin B deoxycholate in its registrational clinical trial. We aimed to compare the quantitative antifungal activity and mortality between daily amphotericin B deoxycholate and daily liposomal amphotericin among persons with HIV-related cryptococcal meningitis receiving adjunctive flucytosine 100 mg/kg/day. METHODS: We analyzed data from three clinical studies involving participants with HIV-associated cryptococcal meningitis receiving either daily liposomal amphotericin B at 3 mg/kg/day with flucytosine (N = 94) or amphotericin B deoxycholate at 0.7-1.0 mg/kg/day with flucytosine (N = 404) as induction therapy. We compared participant baseline characteristics, CSF early fungicidal activity (EFA), and 10-week mortality. RESULTS: We included 498 participants in this analysis, of whom 201 had available EFA data (N = 46 liposomal amphotericin; N = 155 amphotericin deoxycholate). Overall, there is no statistical evidence that the antifungal activity of liposomal amphotericin B (mean EFA = 0.495 log10 CFU/mL/day; 95%CI, 0.355-0.634) differ from amphotericin B deoxycholate (mean EFA = 0.402 log10 CFU/mL; 95%CI, 0.360-0.445) (P = 0.13). Mortality at 10 weeks trended lower for liposomal amphotericin (28.2%) vs amphotericin B deoxycholate (34.6%) but was not statistically different when adjusting for baseline characteristics (adjusted Hazard Ratio = 0.74; 95%CI, 0.44-1.25; P = 0.26). CONCLUSIONS: Daily liposomal amphotericin B induction demonstrated a similar rate of CSF fungal clearance and 10-week mortality as amphotericin B deoxycholate when combined with flucytosine for the treatment of HIV-associated cryptococcal meningitis.

6.
Microorganisms ; 12(6)2024 May 24.
Article in English | MEDLINE | ID: mdl-38930447

ABSTRACT

Chagas Disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, affecting 6-8 million people, mainly in Latin America. The medical treatment is based on two compounds, benznidazole and nifurtimox, with limited effectiveness and that produce severe side effects; consequently, there is an urgent need to develop new, safe, and effective drugs. Amphotericin B is the most potent antimycotic known to date. A21 is a derivative of this compound with the property of binding to ergosterol present in cell membranes of some organisms. In the search for a new therapeutic drug against T. cruzi, the objective of this work was to study the in vitro and in vivo effects of A21 derivative on T. cruzi. Our results show that the A21 increased the reactive oxygen species and reduced the mitochondrial membrane potential, affecting the morphology, metabolism, and cell membrane permeability of T. cruzi in vitro. Even more important was finding that in an in vivo murine model of infection, A21 in combination with benznidazole was able to reduce blood parasitemia, diminish the immune inflammatory infiltrate in skeletal muscle and rescue all the mice from death due to a virulent T. cruzi strain.

7.
Front Vet Sci ; 11: 1402691, 2024.
Article in English | MEDLINE | ID: mdl-38938913

ABSTRACT

Dermatophytic pseudomycetoma (DPM), which is a deeper dermal and/or subcutaneous infection of dermatophytes, has been rarely reported in Domestic Korean Short Hair Cats. A 3-year-old, spayed female, domestic Korean Short Hair Cat presented with a history of crusts, nodules, and pruritus for 1 year. At the initial presentation, multifocal ulcerative nodules covered with yellowish grains were noted on her ventral thorax, abdomen, flank, and left hindlimb. Cytology of ulcerative nodules revealed degenerative neutrophils, macrophages, multinucleated giant cells, and hyphae. Histological examination of nodules revealed pyogranulomatous dermatitis with fungal plaques, and Microsporum canis and Staphylococcus aureus were identified in the culture. Therefore, the cat was diagnosed with DPM with secondary pyoderma. Oral itraconazole (10 mg/kg, once a day) was administered, but no significant improvement was observed. Therefore, intralesional (IL) injection of amphotericin B (0.6 mg/nodule) and oral administration of terbinafine (30 mg/kg, twice a day) were administered to the cat. With these medications, ulceration and the number and size of nodules decreased significantly, although large dome-shaped nodules remained. Skin lesions were treated with oral terbinafine and itraconazole administration for 5 months. However, after 6 months, recurrence of multifocal ulcerative nodules was observed, and the cat died 10 months after initial presentation. In this case, IL amphotericin B and oral terbinafine administration were partially effective in DPM treatment, suggesting that this may be an option for DPM treatment. Further studies to determine dose and frequency of IL amphotericin B in the management of DPM are warranted.

8.
J Fungi (Basel) ; 10(6)2024 May 29.
Article in English | MEDLINE | ID: mdl-38921374

ABSTRACT

Pulmonary mucormycosis (PM) is an invasive and potentially fatal fungal infection, with Rhizopus microsporus (R. microsporus) being the most common pathogen. The routine therapy for this infection includes surgery and antifungal agents. However, the therapeutic effects of single agents are unsatisfactory due to the rapid progression of mucormycosis, while not all patients can tolerate surgery. Innovative treatment methods like combination therapy await validations of their clinical efficacy. We report a case of PM that was diagnosed via metagenomics next-generation sequencing (mNGS) of black drainage fluid from the patient's lung. The patient eventually recovered and was discharged after a combination therapy of oral isavuconazole, inhaled amphotericin B, and local perfusion of amphotericin B through bronchoscopy, which may be a promising strategy for the treatment of PM, especially for cases where surgery is not possible. A retrospective study of 297 cases in a literature review highlights the different treatment methods used in clinical practice.

9.
Future Microbiol ; : 1-10, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38904282

ABSTRACT

Aim: Currently, we have limited armamentarium of antifungal agents against Mucorales. There is an urgent need to discover novel antifungal agents that are effective, safe and affordable. Materials & methods: In this study, the anti-Mucorale action of native lactoferrin (LF) and its functional fragments CLF, RR6 and LFcin against three common Mucorale species are reported. The synergistic action of LF with antifungal agents like amphotericin B, isavuconazole and posaconazole was analyzed using checkerboard technique. Results: All the three mucor species showed inhibition when treated with fragments. The checkerboard assay confirmed that native LF showed the best synergistic action against Mucorales in combination with Amphotericin B. Conclusion: These results highlight the potential therapeutic value of native LF against Mucorales.


Black fungus, or 'mucormycosis', is a dangerous fungal infection. Normally, it affects people with a weakened immune system. It is only treatable when diagnosed early. It spreads by breathing the fungus in, eating contaminated food or direct contact with an infected wound. There are not many medicines that can treat this type of fungus, so it is important to find new ones. In this study, we tested a natural protein called lactoferrin and some of its building blocks, called peptides, to see if they could stop the fungus from growing. Lactoferrin and its peptides could stop the fungus from growing, especially when used with a medicine called amphotericin B. This means that lactoferrin could potentially be a helpful treatment for this fungal infection.

10.
Future Microbiol ; : 1-14, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38904325

ABSTRACT

The emergence of fungal pathogens and changes in the epidemiological landscape are prevalent issues in clinical mycology. Reports of resistance to antifungals have been reported. This review aims to evaluate molecular and nonmolecular mechanisms related to antifungal resistance. Mutations in the ERG genes and overexpression of the efflux pump (MDR1, CDR1 and CDR2 genes) were the most reported molecular mechanisms of resistance in clinical isolates, mainly related to Azoles. For echinocandins, a molecular mechanism described was mutation in the FSK genes. Furthermore, nonmolecular virulence factors contributed to therapeutic failure, such as biofilm formation and selective pressure due to previous exposure to antifungals. Thus, there are many public health challenges in treating fungal infections.


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11.
Iran J Microbiol ; 16(2): 280-284, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38854988

ABSTRACT

Background and Objectives: Amphotericin B is a broad-spectrum antifungal agent commonly used to treat Candida haemulonii infection. C. haemulonii was isolated from patients reported to be intrinsically resistant to amphotericin B, encoded by the ERG2 and ERG11 genes. However, there have been limited studies concerning amphotericin B-resistant C. haemulonii in Indonesia. The objective of this study is to explore the phenotypic and genotypic characteristics (ERG2 and ERG11) of C. haemulonii isolated from the ICU of a referral hospital in Indonesia. Materials and Methods: Identification and susceptibility tests were conducted using VITEK2. Thereafter, DNA was extracted and amplified using conventional PCR followed by DNA sequencing (Sanger method). Results: The results of the phenotypic susceptibility test showed that all C. haemulonii were resistant to amphotericin B. ERG2 and ERG11 sequences showed the same amino acid sequence and corresponded to references that are resistant to amphotericin B. Conclusion: The resistant properties of C. haemulonii against amphotericin B found in this study require further exploration, including comparing resistant and sensitive C. haemulonii to amphotericin B. In addition, it is necessary to analyze other genes besides ERG2 and ERG11.

12.
Iran J Microbiol ; 16(2): 273-279, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38854989

ABSTRACT

Background and Objectives: The presence of fungi in the respiratory tract as mycobiome, particularly Candida species (spp.), remains a serious problem due to increasing numbers of immunocompromised patients. The confirmed reliable existence of these pathogens due to frequent colonization is essential. This investigation aimed to recognize Candida spp. among isolates from bronchoalveolar lavage of immunocompromised and critically ill patients and to evaluate their susceptibility to antimycotic drugs. Materials and Methods: Bronchoalveolar lavage fluid was collected from 161 hospitalized patients presenting with suspected respiratory fungal infection /colonization. The specimens were examined by standard molecular and mycological assays. Candida spp. were recognized with sequence assessment of the D1-D2 section of the large subunit ribosomal DNA. The susceptibility of Candida isolates to common antimycotic drugs was distinguished by standard broth microdilution. Results: Seventy-one clinical isolates of Candida spp. were recognized. Candida albicans was the most frequent, followed by C. glabrata, C. krusei (Pichia kudriavzevii), C. dubliniensis, C. parapsilosis, and C. tropicalis. We found 5.1% of C. albicans isolates and 8% of C. glabrata isolates to show resistance to fluconazole. The whole of the Candida spp. were sensitive to amphotericin B and caspofungin. Conclusion: This study demonstrated that C. albicans and C. glabrata are the most common isolates of bronchoalveolar lavage fluid in patients, and the drug susceptibility screening confirmed that amphotericin B and caspofungin are effective against Candida spp. but some C. glabrata and C. albicans isolates showed resistance to fluconazole.

13.
mBio ; : e0047724, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38864609

ABSTRACT

Parasites of the genus Leishmania pose a global health threat with limited treatment options. New drugs are urgently needed, and genomic screens have the potential to accelerate target discovery, mode of action, and resistance mechanisms against these new drugs. We describe here our effort in developing a genome-wide CRISPR-Cas9 screen in Leishmania, an organism lacking a functional nonhomologous end joining system that must rely on microhomology-mediated end joining, single-strand annealing, or homologous recombination for repairing Cas9-induced double-stranded DNA breaks. A new vector for cloning and expressing single guide RNAs (sgRNAs) was designed and proven to be effective in a small pilot project while enriching specific sgRNAs during drug selection. We then developed a whole-genome library of 49,754 sgRNAs, targeting all the genes of Leishmania infantum. This library was transfected in L. infantum expressing Cas9, and these cells were selected for resistance to two antileishmanials, miltefosine and amphotericin B. The sgRNAs the most enriched in the miltefosine screen targeted the miltefosine transporter gene, but sgRNAs targeting genes coding for a RING-variant protein and a transmembrane protein were also enriched. The sgRNAs the most enriched by amphotericin B targeted the sterol 24 C methyltransferase genes and a hypothetical gene. Through gene disruption experiments, we proved that loss of function of these genes was associated with resistance. This study describes the feasibility of carrying out whole-genome CRISPR-Cas9 screens in Leishmania provided that a strong selective pressure is applied. Such a screen can be used for accelerating the development of urgently needed antileishmanial drugs.IMPORTANCELeishmaniasis, a global health threat, lacks adequate treatment options and drug resistance exacerbates the challenge. This study introduces a CRISPR-Cas9 screening approach in Leishmania infantum, unraveling mechanisms of drug resistance at a genome-wide scale. Our screen was applied against two main antileishmanial drugs, and guides were enriched upon drug selection. These guides targeted known and new targets, hence validating the use of this screen against Leishmania. This strategy provides a powerful tool to expedite drug discovery as well as potential therapeutic targets against this neglected tropical disease.

16.
Toxicon ; 246: 107795, 2024 Aug 02.
Article in English | MEDLINE | ID: mdl-38849008

ABSTRACT

Amphotericin B (AmB) induced liver and kidney injury is often responsible for hepatic and renal dysfunction. Therefore, the protection strategy on liver and renal functions in patients treated with AmB should be emphasized. In this paper, diammonium glycyrrhizinate (DG) and piperazine ferulate (PF) were taken as the research object to study its hepatoprotective and neuroprotective effect on AmB-induced liver and kidney damage in vitro and in vivo. The microplate method and ELISA kits were employed for the biochemical detection in the serum and urine of mice. Flow cytometric analysis and western blotting analysis were conducted to study the mechanism of DG and PF. Our results confirmed the prevention capacity of DG and PF on AmB-induced liver and kidney injury through the alleviation of pathological changes and enzyme reducing action. Furthermore, DG and PF suppressed ROS-mediated mitochondrial apoptosis in AmB-treated mice and cells through Caspase pathway and Caspase-independent AIF pathway. In summary, DG and PF could protect AmB-induced hepatotoxicity and nephrotoxicity by disrupting oxidative stress and apoptosis.


Subject(s)
Amphotericin B , Apoptosis , Chemical and Drug Induced Liver Injury , Glycyrrhizic Acid , Neuroprotective Agents , Animals , Apoptosis/drug effects , Mice , Glycyrrhizic Acid/pharmacology , Chemical and Drug Induced Liver Injury/prevention & control , Chemical and Drug Induced Liver Injury/drug therapy , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use , Amphotericin B/toxicity , Male , Liver/drug effects , Liver/pathology , Kidney/drug effects , Kidney/pathology , Oxidative Stress/drug effects , Piperazines/pharmacology , Piperazine/pharmacology , Protective Agents/pharmacology
17.
J Cutan Pathol ; 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38863080

ABSTRACT

BACKGROUND: Human protothecosis is an uncommon infection caused by Prototheca spp that rarely infects humans. AIM: Description of a rare disease and a review of its articles. MATERIALS AND METHODS: We reported a 24-year-old man who presented with red-brown papules and plaques on the trunk's lateral side. We reviewed the literature about disseminated protothecosis and reported our experience with a patient with protothecosis between 2021 and 2023. RESULTS: Overall, 54 cases of disseminated protothecosis were evaluated, 39 were due to P. wickerhamii, 12 were due to P. zopfii (22.2%), and three were due to Prototheca spp. We found that males were more affected (37 cases, 68.5%) than females (16 cases, 29.6%). The mean age of patients was 39.53 ± 22.48 years. However, disseminated protothecosis can affect people of any age (1-80 years). In contrast to P. wickerhamii, which causes blood, skin, brain, and gastrointestinal tract infections, P. zopfii was mainly found in the blood (7/22) and did not have a significant difference in the mortality rate (P = 0.11). DISCUSSION: Disseminated protothecosis is a rare disease in immunocompromised patients but is generally rarer in immunocompetent hosts. Several underlying disorders include immunocompromised patients, prolonged application of steroids, diabetes mellitus, malignancies, organ transplantation, AIDS, and surgeries. Amphotericin B has been the most effective agent for protothecosis and is reserved for visceral and disseminated infections. Regarding localized cutaneous types, excision or surgical debridement is used. CONCLUSION: Mulberry's appearance and appropriate cultural environments are helpful in diagnosing it.

18.
Mycopathologia ; 189(4): 54, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38865003

ABSTRACT

BACKGROUND: During the COVID-19 pandemic-associated mucor epidemic, acute antifungal drug shortage necessitated the exploration of other antifungals based on culture sensitivity. Itraconazole is a cheap, safe, and effective antifungal in sensitive cases. METHODOLOGY: We enrolled itraconazole-sensitive COVID-19-associated mucormycosis during the mucormycosis pandemic. After the intensive phase course of liposomal amphotericin B, Itraconazole was offered in susceptible cases during the maintenance phase along with standard of care. These patients were clinically and radiologically followed for 6 months. RESULTS: We enrolled 14 patients (Male: Female-11:3) of Rhino-orbito-cerebral mucormycosis (ROCM) which included 12 diabetics. All patients had facial swelling, orbital swelling, visual impairment, and headache. MRI showed involvement of bilateral sinus (10/14), orbital extension (13/14), cavernous sinus (5/14), cerebral part of the internal carotid artery (3/14), and brain infarcts (4/14). All 14 patients showed sensitivity to Itraconazole with 12 having minimum inhibitory concentration (MIC) ≤ 1 µg/ml and 2 having MIC ≤ 2 µg/ml. Follow-up at 6 months showed clinical improvement in the majority (11/14) and radiological improvement in six out of seven scanned patients. CONCLUSION: Our study shows the potential therapeutic role of oral Itraconazole in ROCM.


Subject(s)
Amphotericin B , Antifungal Agents , Itraconazole , Mucormycosis , Rhizopus oryzae , Humans , Male , Itraconazole/therapeutic use , Itraconazole/administration & dosage , Female , Mucormycosis/drug therapy , Amphotericin B/therapeutic use , Amphotericin B/administration & dosage , Antifungal Agents/therapeutic use , Antifungal Agents/administration & dosage , Middle Aged , Adult , Rhizopus oryzae/drug effects , Microbial Sensitivity Tests , COVID-19/complications , Aged , Drug Therapy, Combination , Treatment Outcome
19.
J Mass Spectrom ; 59(6): e5031, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38726684

ABSTRACT

Managing ocular microbial infections typically requires pharmacotherapy using antibiotic eye drops, such as moxifloxacin hydrochloride (MFX), combined with an antifungal agent like amphotericin B (AB). We carried out and validated an LC-MS/MS assay to quantify these compounds in rabbit tear fluid in order to look into the pharmacokinetics of these two drugs. We employed a protein precipitation technique for the extraction of drugs under examination. A Waters Symmetry C18 column was used to separate the analytes and internal standard. The composition of the mobile phase was like (A) 0.1% v/v formic acid in water and (B) methanol. The detection of MFX and AB was accomplished through the utilization of positive ion electrospray ionization under multiple reaction monitoring mode. The linearity curves for both analytes exhibited an acceptable trendline across a concentration range of 2.34-300 ng/mL for MFX and 7.81-1000 ng/mL for AB in surrogate rabbit tear fluid. The lower limit of quantitation for MFX was 2.34 ng/mL, while for AB, it was 7.81 ng/mL. The approach was strictly validated, encompassing tests of selectivity, linearity (with r2 > 0.99), precision, accuracy, matrix effects, and stability. Consequently, we employed this method to evaluate the pharmacokinetics profiles of MFX and AB in rabbit tear fluid following single topical doses.


Subject(s)
Moxifloxacin , Tandem Mass Spectrometry , Tears , Rabbits , Animals , Tandem Mass Spectrometry/methods , Tears/chemistry , Moxifloxacin/pharmacokinetics , Moxifloxacin/analysis , Reproducibility of Results , Amphotericin B/pharmacokinetics , Amphotericin B/analysis , Limit of Detection , Anti-Infective Agents/pharmacokinetics , Anti-Infective Agents/analysis , Chromatography, Liquid/methods , Ophthalmic Solutions/pharmacokinetics , Linear Models , Liquid Chromatography-Mass Spectrometry
20.
Microb Drug Resist ; 2024 May 10.
Article in English | MEDLINE | ID: mdl-38727600

ABSTRACT

Invasive fungal infections in humans with compromised immune systems are the primary cause of morbidity and mortality, which is becoming more widely acknowledged. Amphotericin B (AmB) is one of the antifungal drugs used to treat such infections. AmB binds with plasma membrane ergosterol, inducing cellular ions to leak and causing cell death. Reduction in ergosterol content and modification of cell walls have been described as AmB resistance mechanisms. In addition, when the sphingolipid level is decreased, the cell becomes more susceptible to AmB. Previously, PDR16, a gene that encodes phosphatidylinositol transfer protein in Saccharomyces cerevisiae, was shown to enhance AmB resistance upon overexpression. However, the mechanism of PDR16-mediated AmB resistance is not clear. Here, in this study, it was discovered that a plasma membrane proteolipid 3 protein encoded by PMP3 is essential for PDR16-mediated AmB resistance. PDR16-mediated AmB resistance does not depend on ergosterol, but a functional sphingolipid biosynthetic pathway is required. Additionally, PMP3-mediated alteration in membrane integrity abolishes PDR16 mediated AmB resistance, confirming the importance of PMP3 in the PDR16 mediated AmB resistance.

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