Publications by authors named "Laura K Najvar"

Article Synopsis
  • The study investigated nikkomycin Z's effectiveness in treating central nervous system coccidioidomycosis in mice, showing significant improvements in survival and reduction of brain fungal burden compared to control.
  • Mice were given nikkomycin Z at doses of 50, 100, and 300 mg/kg three times daily, or fluconazole, starting two days post-inoculation with the fungus.
  • Nikkomycin Z targets fungal cell walls, making it a potentially safer treatment option than traditional antifungals, which can have adverse effects due to interactions with human enzymes.
View Article and Find Full Text PDF

Ibrexafungerp (formerly SCY-078) is the first member of the triterpenoid class that prevents the synthesis of the fungal cell wall polymer β-(1,3)-D-glucan by inhibiting the enzyme glucan synthase. We evaluated the efficacy of ibrexafungerp against pulmonary mucormycosis using an established murine model. Neutropenic mice were intratracheally infected with either or .

View Article and Find Full Text PDF

Candidiasis is one of the most frequent nosocomial infections affecting an increasing number of at-risk patients. remains the most frequent causative agent of candidiasis, but, in the last decade, has emerged as a formidable multi-drug-resistant pathogen. Both species are fully capable of forming biofilms, which contribute to resistance, increasing the urgency for new effective antifungal therapies.

View Article and Find Full Text PDF

There is increased concern that the quality, generalizability and reproducibility of biomedical research can be influenced by the sex of animals used. We studied the differences between male and female mice in response to invasive pulmonary mucormycosis including susceptibility to infection, host immune reaction and responses to antifungal therapy. We used diabetic ketoacidotic (DKA) or neutropenic mice infected with either or .

View Article and Find Full Text PDF

is an emerging pathogen that has rapidly spread to many countries on multiple continents. Invasive infections caused by this species are associated with significant mortality, and treatment options are limited due to antifungal resistance. Ibrexafungerp is the first-in-class member of the triterpenoids, which inhibit the production of (1,3)-β-d-glucan and can be administered orally.

View Article and Find Full Text PDF

The and activity of the arylamidine T-2307 against was evaluated. T-2307 demonstrated activity (MIC ranges ≤ 0.008 to 0.

View Article and Find Full Text PDF

The emerging pathogenic yeast is associated with antifungal resistance and high mortality. The novel antifungal agent manogepix (APX001A) inhibits glycosylphosphatidylinositol-anchored protein maturation and has demonstrated activity against numerous pathogenic fungi, including Our objective was to evaluate the efficacy of fosmanogepix, the -phosphonooxymethyl prodrug (APX001), following delayed initiation of therapy in a murine model of invasive candidiasis. Neutropenic mice were intravenously infected with a fluconazole-resistant clinical isolate of Twenty-four hours postinoculation, treatment began with vehicle control, fosmanogepix (104 and 130 mg/kg of body weight by intraperitoneal injection three times daily, or intraperitoneal 260 mg/kg twice daily), fluconazole (20 mg/kg by oral gavage once daily), or caspofungin (intraperitoneal 10 mg/kg once daily) and continued for 7 days.

View Article and Find Full Text PDF

We evaluated extended-interval dosing of the investigational echinocandin rezafungin (1, 4, and 16 mg/kg on days 1, 4, and 7 postinoculation) for the treatment of disseminated invasive aspergillosis caused by azole-resistant Survival was significantly improved in mice treated with each dose of rezafungin and supratherapeutic posaconazole (20 mg/kg twice daily). Kidney fungal burden, as measured by quantitative real-time PCR, was also significantly reduced in mice treated with rezafungin although variability was observed.

View Article and Find Full Text PDF

is an emerging pathogen associated with significant mortality and often multidrug resistance. VT-1598, a tetrazole-based fungal CYP51-specific inhibitor, was evaluated and against Susceptibility testing was performed against 100 clinical isolates of by broth microdilution. Neutropenic mice were infected intravenously with , and treatment began 24 h postinoculation with a vehicle control, oral VT-1598 (5, 15, and 50 mg/kg of body weight once daily), oral fluconazole (20 mg/kg once daily), or intraperitoneal caspofungin (10 mg/kg once daily), which continued for 7 days.

View Article and Find Full Text PDF

VT-1129 is a novel fungal enzyme-specific Cyp51 inhibitor with potent cryptococcal activity. Because of its long half-life (>6 days in mice) and our desire to quickly reach potent efficacy, we evaluated a VT-1129 loading dose-maintenance dose strategy against cryptococcal meningitis. VT-1129 plasma and brain pharmacokinetics were first studied in healthy mice, and these data were used to model loading dose-maintenance dose regimens to generate different steady-state concentrations.

View Article and Find Full Text PDF

Cryptococcal meningitis is a significant cause of morbidity and mortality in immunocompromised patients. VT-1129 is a novel fungus-specific Cyp51 inhibitor with potent activity against species. Our objective was to evaluate the efficacy of VT-1129 against cryptococcal meningitis.

View Article and Find Full Text PDF

Olorofim (formerly F901318) is an advanced analog of the orotomide class that inhibits fungal pyrimidine biosynthesis. We evaluated the and activities of olorofim against species. activity was assessed against 59 clinical isolates.

View Article and Find Full Text PDF
Article Synopsis
  • Coccidioidal meningitis is a serious condition that often requires lifelong antifungal treatment; the new drug VT-1598 shows promise in combating this infection.
  • VT-1598, a specific inhibitor targeting fungi, was tested in mice infected with coccidioidomycosis, demonstrating significant improvements in survival rates and reductions in fungal presence in the brain.
  • Results indicate that VT-1598 maintains effective plasma levels and sustained fungal suppression, supporting the need for human clinical trials to assess its effectiveness for treating this disease.
View Article and Find Full Text PDF
Article Synopsis
  • Echinocandins are standard treatments for Candida glabrata infections, but rising resistance and their injectable-only form limit their use; SCY-078 is a new oral treatment being tested.
  • A study tested the effectiveness of SCY-078 in mice with infections from both standard and echinocandin-resistant C. glabrata strains, with varying dosages administered.
  • Results showed that SCY-078 significantly reduced fungal presence in the kidneys for both isolates, suggesting it could be a promising oral therapy against resistant infections.
View Article and Find Full Text PDF

Previously, modified release itraconazole in the form of a melt-extruded amorphous solid dispersion based on a pH dependent enteric polymer combined with hydrophilic additives (HME-ITZ), exhibited improved in vitro dissolution properties. These properties agreed with pharmacokinetic results in rats showing high and sustained itraconazole (ITZ) systemic levels. The objective of the present study was to better understand the best choice of rodent model for evaluating the pharmacokinetic and efficacy of this orally administered modified release ITZ dosage form against invasive Aspergillus fumigatus.

View Article and Find Full Text PDF

Candida albicans, normally found as a commensal in the gut, is a major human fungal pathogen responsible for both mucosal and systemic infections in a wide variety of immunocompromised individuals, including cancer patients and organ transplant recipients. The gastrointestinal tract represents a major portal of entry for the establishment of disseminated candidiasis in many of these individuals. Here we report the development of a diet-based mouse model for disseminated candidiasis acquired via the gastrointestinal tract.

View Article and Find Full Text PDF

We evaluated the efficacy of isavuconazole against cryptococcal meningitis. Treatment with either oral isavuconazole (120 mg/kg and 240 mg/kg twice a day [BID]) or fluconazole as the positive control significantly improved survival in mice infected intracranially with either Cryptococcus neoformans USC1597 or H99 and significantly reduced brain fungal burdens for both isolates. Concentrations of isavuconazole in plasma and brain tissue also demonstrated that the greatest improvements in survival and fungal burden were associated with elevated exposures.

View Article and Find Full Text PDF

The EuropeanAspergillusPCR Initiative (EAPCRI) has provided recommendations for the PCR testing of whole blood (WB) and serum/plasma. It is important to test these recommended protocols on nonsimulated "in vivo" specimens before full clinical evaluation. The testing of an animal model of invasive aspergillosis (IA) overcomes the low incidence of disease and provides experimental design and control that is not possible in the clinical setting.

View Article and Find Full Text PDF

Objectives: Candida species are major causes of invasive mycoses in immunocompetent and immunocompromised hosts. Treatment options are limited in the setting of antifungal resistance and increased rates of echinocandin-resistant Candida glabrata have been reported. The novel arylamidine T-2307 demonstrates potent in vitro antifungal activity against Candida species.

View Article and Find Full Text PDF

ASP9726 is an investigational echinocandin with in vitro activity against Aspergillus species. We evaluated the pharmacokinetics and efficacy of this agent in an established guinea pig model of invasive pulmonary aspergillosis. ASP9726 plasma concentrations were measured in guinea pigs administered either a single dose or multiple doses of this agent at 2.

View Article and Find Full Text PDF

We evaluated the in vitro and in vivo activities of the investigational arylamidine T-2307 against echinocandin-resistant Candida albicans. T-2307 demonstrated potent in vitro activity, and daily subcutaneous doses between 0.75 and 6 mg/kg of body weight significantly improved survival and reduced fungal burden compared to placebo control and caspofungin (10 mg/kg/day) in mice with invasive candidiasis caused by an echinocandin-resistant strain.

View Article and Find Full Text PDF

The in vitro and in vivo activity of the inositol acyltransferase inhibitor E1210 was evaluated against echinocandin-resistant Candida albicans. E1210 demonstrated potent in vitro activity, and in mice with invasive candidiasis caused by echinocandin-resistant C. albicans, oral doses of 10 and 40 mg E1210/kg of body weight twice daily significantly improved survival and reduced fungal burden compared to those of controls and mice treated with caspofungin (10 mg/kg/day).

View Article and Find Full Text PDF

Improved diagnostics are needed to detect invasive pulmonary aspergillosis, a life-threatening infection caused by the pathogenic fungus Aspergillus fumigatus. We are investigating secreted fungal proteases as novel biomarkers for the diagnosis of this disease. Although the A.

View Article and Find Full Text PDF

Interest in lateral-flow devices (LFDs) as potential point-of-care assays for the diagnosis of infectious diseases has increased. Our objective was to evaluate the interlaboratory and interstudy reproducibility and the effects of antifungal therapy on an LFD developed for invasive pulmonary aspergillosis (IPA) detection. An established neutropenic guinea pig model of IPA caused by Aspergillus fumigatus was used.

View Article and Find Full Text PDF

Miltefosine is an alkyl phosphocholine with good oral bioavailability and in vitro activity against Cryptococcus species that has gained interest as an additional agent for cryptococcal infections. Our objective was to further evaluate the in vivo efficacy of miltefosine in experimental in vivo models of cryptococcal meningoencephalitis and disseminated cryptococcosis. Mice were infected intracranially or intravenously with either C.

View Article and Find Full Text PDF