Genital-oral transmission of Candida lusitaniae.

Candida lusitaniae is a vaginal commensal. Cases of vaginitis, vulvovaginitis and recurrent vulvovaginitis caused by this yeast are very rare. In the oral cavity, C. lusitaniae causes stomatitis in immunocompromised patients. We describe a case of stomatitis and angular cheilitis caused by C. lusitaniae in a female patient with type 2 diabetes. The infection was most likely transmitted following genital-oral intercourse with the patient's girlfriend, who was affected by C. lusitaniae vulvovaginitis.

Candida lusitaniae Fungemia in Children: A multicenter case series of emerging pathogen.

Candida lusitaniae fungemia is a serious infection that is rarely reported in children. The aim of this study is to describe a case series of C. lusitaniae fungemia and review previous publications regarding this rare pathogen. This is a multicenter case series of children diagnosed with C. lusitaniae fungemia. A total of 18 cases that occurred over a 15-year period in five tertiary hospitals were included. Additionally, a review of the literature regarding C. lusitaniae fungemia in children was performed. A total of 18 cases were enrolled; 11/18 (61%) were males, with a mean age of 2.3 years. All patients had severe underlying diseases and risk factors for opportunistic infection, most commonly prematurity and malignancies. More than one-third of cases occurred during the last 2 years of the study period. All isolates were susceptible to all tested antifungals. The survival rate following the acute infection was 94%, whereas the survival rate of 14 previously published cases was 71%, with the most common underlying diseases being CGD and malignancies. Candida lusitaniae fungemia is not a common event in the pediatric population, occurring exclusively in children with severe underlying diseases and significant risk factors. This cohort revealed better clinical outcomes than previously reported. All tested isolates were susceptible to all antifungal agents; variability in susceptibility as previously reported was not found in this study. The allegedly higher rate of infection in recent years is in need of further investigation in larger prospective studies in order to conclude if a real trend is at play.

Candida lusitaniae fungemia is a serious infection rarely reported in children. This cohort revealed better clinical outcomes than previously reported. All tested isolates were susceptible to all antifungal agents. The higher rate of infection in recent years is in need of further investigation.

Candida lusitaniae, an Emerging Opportunistic Pathogen in Immunocompetent Populations: A Case Report.

Candida lusitaniae is an emerging opportunistic pathogen in immunocompromised hosts and hospitalized patients. However, the incidence is low in immunocompetent hosts. Because of their characteristic similarities, C. lusitaniae may be confused with other fungal species, such as Candida tropicalis, Candida parapsilosis, and even Saccharomyces cerevisiae. Recently reported cases of serious infections caused by C. lusitaniae have proven detrimental, and some cases reported amphotericin resistance. Here, we present a case report of empyema caused by C. lusitaniae in an immunocompetent patient who was admitted to the intensive care unit and intubated for acute hypoxic respiratory failure. This case demonstrates the importance of recognizing this organism and initiating early treatment for the prevention of fatal complications.

Rapid Evolution of Multidrug Resistance in a Candida lusitaniae Infection during Micafungin Monotherapy.

Candida (Clavispora) lusitaniae is a rare, emerging non-albicans Candida species that can cause life-threatening invasive infections, spread within hospital settings, and rapidly acquire antifungal drug resistance, including multidrug resistance. The frequency and spectrum of mutations causing antifungal drug resistance in C. lusitaniae are poorly understood. Analyses of serial clinical isolates of any Candida species are uncommon and often analyze a limited number of samples collected over months of antifungal therapy with multiple drug classes, limiting the ability to understand relationships between drug classes and specific mutations. Here, we performed comparative genomic and phenotypic analysis of 20 serial C. lusitaniae bloodstream isolates collected daily from an individual patient treated with micafungin monotherapy during a single 11-day hospital admission. We identified isolates with decreased micafungin susceptibility 4 days after initiation of antifungal therapy and a single isolate with increased cross-resistance to micafungin and fluconazole, despite no history of azole therapy in this patient. Only 14 unique single nucleotide polymorphisms (SNPs) were identified between all 20 samples, including three different FKS1 alleles among isolates with decreased micafungin susceptibility and an ERG3 missense mutation found only in the isolate with increased cross-resistance to both micafungin and fluconazole. This is the first clinical evidence of an ERG3 mutation in C. lusitaniae that occurred during echinocandin monotherapy and is associated with cross-resistance to multiple drug classes. Overall, the evolution of multidrug resistance in C. lusitaniae is rapid and can emerge during treatment with only first-line antifungal therapy.

Mediator Subunit Med15 Regulates Cell Morphology and Mating in Candida lusitaniae.

Candida lusitaniae is an emerging opportunistic pathogenic yeast capable of shifting from yeast to pseudohyphae form, and it is one of the few Candida species with the ability to reproduce sexually. In this study, we showed that a dpp3Δ mutant, inactivated for a putative pyrophosphatase, is impaired in cell separation, pseudohyphal growth and mating. The defective phenotypes were not restored after the reconstruction of a wild-type DPP3 locus, reinforcing the hypothesis of the presence of an additional mutation that we suspected in our previous study. Genetic crosses and genome sequencing identified an additional mutation in MED15, encoding a subunit of the mediator complex that functions as a general transcriptional co-activator in Eukaryotes. We confirmed that inactivation of MED15 was responsible for the defective phenotypes by rescuing the dpp3Δ mutant with a wild-type copy of MED15 and constructing a med15Δ knockout mutant that mimics the phenotypes of dpp3Δ in vitro. Proteomic analyses revealed the biological processes under the control of Med15 and involved in hyphal growth, cell separation and mating. This is the first description of the functions of MED15 in the regulation of hyphal growth, cell separation and mating, and the pathways involved in C. lusitaniae.

Failure of liposomal amphotericin B therapy in patients with severe pancreatitis complicated by Candida lusitaniae infection.

Candida lusitaniae is an uncommon pathogen that accounts for approximately 1% of patients with candidiasis. In this report, we present the case of a 24-year-old woman with severe pancreatitis who was emergently admitted to Northern Yokohama Hospital. We started treating the pancreatitis and infections according to her culture results. However, her symptoms, accompanied by a necrotic pancreas, did not improve. Finally, C. lusitaniae was detected in the blood and catheter samples. We started antifungal treatment according to the culture results, but the patient died. Generally, the mortality rate for acute pancreatitis ranges from 3% for patients with interstitial edematous pancreatitis to 17% for those who develop pancreatic necrosis. Although we chose appropriate antibiotics and antifungal agents based on the culture results, the treatments failed. Early detection, sufficient doses of antimicrobials and frequent monitoring using sample culture are crucial because infection control may be inadequate, especially in tissues with low blood flow, such as necrotic tissues.

Overview on the Infections Related to Rare Candida Species.

Atypical Candida spp. infections are rising, mostly due to the increasing numbers of immunocompromised patients. The most common Candida spp. is still Candida albicans; however, in the last decades, there has been an increase in non-Candida albicans Candida species infections (e.g., Candida glabrata, Candida parapsilosis, and Candida tropicalis). Furthermore, in the last 10 years, the reports on uncommon yeasts, such as Candida lusitaniae, Candida intermedia, or Candida norvegensis, have also worryingly increased. This review summarizes the information, mostly related to the last decade, regarding the infections, diagnosis, treatment, and resistance of these uncommon Candida species. In general, there has been an increase in the number of articles associated with the incidence of these species. Additionally, in several cases, there was a suggestive antifungal resistance, particularly with azoles, which is troublesome for therapeutic success.

Balancing Positive and Negative Selection: In Vivo Evolution of Candida lusitaniae MRR1.

The evolution of pathogens in response to selective pressures present during chronic infections can influence their persistence and virulence and the outcomes of antimicrobial therapy. Because subpopulations within an infection can be spatially separated and the host environment can fluctuate, an appreciation of the pathways under selection may be most easily revealed through the analysis of numerous isolates from single infections. Here, we continued our analysis of a set of clonally derived Clavispora (Candida) lusitaniae isolates from a single chronic lung infection with a striking enrichment in the number of alleles of MRR1 Genetic and genomic analyses found evidence for repeated acquisition of gain-of-function mutations that conferred constitutive Mrr1 activity. In the same population, there were multiple alleles with both gain-of-function mutations and secondary suppressor mutations that either attenuated or abolished the constitutive activity, suggesting the presence of counteracting selective pressures. Our studies demonstrated trade-offs between high Mrr1 activity, which confers resistance to the antifungal fluconazole, host factors, and bacterial products through its regulation of MDR1, and resistance to hydrogen peroxide, a reactive oxygen species produced in the neutrophilic environment associated with this infection. This inverse correlation between high Mrr1 activity and hydrogen peroxide resistance was observed in multiple Candida species and in serially collected populations from this individual over 3 years. These data lead us to propose that dynamic or variable selective pressures can be reflected in population genomics and that these dynamics can complicate the drug resistance profile of the population.IMPORTANCE Understanding microbial evolution within patients is critical for managing chronic infections and understanding host-pathogen interactions. Here, our analysis of multiple MRR1 alleles in isolates from a single Clavispora (Candida) lusitaniae infection revealed the selection for both high and low Mrr1 activity. Our studies reveal trade-offs between high Mrr1 activity, which confers resistance to the commonly used antifungal fluconazole, host antimicrobial peptides, and bacterial products, and resistance to hydrogen peroxide. This work suggests that spatial or temporal differences within chronic infections can support a large amount of dynamic and parallel evolution and that Mrr1 activity is under both positive and negative selective pressure to balance different traits that are important for microbial survival.

Bioethanol Production from Azolla filiculoides by Saccharomyces cerevisiae, Pichia stipitis, Candida lusitaniae, and Kluyveromyces marxianus.

Ethanol was produced by separate hydrolysis and fermentation using Azolla filiculoides as a biomass. Thermal acid hydrolysis and enzymatic saccharification were used as pretreatment methods to produce monosaccharides from Azolla. The optimal content for thermal acid hydrolysis of 14% (w/v) Azolla weed slurry produced 16.7-g/L monosaccharides by using 200 mM H2SO4 at 121 °C for 60 min. Enzymatic saccharification using 16 U/mL Viscozyme produced 61.6 g/L monosaccharide at 48 h. Ethanol productions with ethanol yield coefficients from Azolla weed hydrolysate using Kluyveromyces marxianus, Candida lusitaniae Saccharomyces cerevisiae, and Pichia stipitis were 26.8 g/L (YEtOH = 0.43), 23.2 g/L (YEtOH = 0.37), 18.2 g/L (YEtOH = 0.29), and 13.7 g/L (YEtOH = 0.22), respectively. Saccharomyces cerevisiae produces the lowest yield as it utilized only glucose. Bioethanol from Azolla weed hydrolysate can be successfully produced by using Kluyveromyces marxianus because it consumed the mixture of glucose and xylose completely within 60 h.

Mrr1 regulation of methylglyoxal catabolism and methylglyoxal-induced fluconazole resistance in Candida lusitaniae.

Transcription factor Mrr1, best known for its regulation of Candida azole resistance genes such as MDR1, regulates other genes that are poorly characterized. Among the other Mrr1-regulated genes are putative methylglyoxal reductases. Methylglyoxal (MG) is a toxic metabolite that is elevated in diabetes, uremia, and sepsis, which are diseases that increase the risk for candidiasis, and MG serves as a regulatory signal in diverse organisms. Our studies in Clavispora lusitaniae, also known as Candida lusitaniae, showed that Mrr1 regulates expression of two paralogous MG reductases, MGD1 and MGD2, and that both participate in MG resistance and MG catabolism. Exogenous MG increased Mrr1-dependent expression of MGD1 and MGD2 as well as expression of MDR1, which encodes an efflux pump that exports fluconazole. MG improved growth in the presence of fluconazole and this was largely Mrr1-dependent with contributions from a secondary transcription factor, Cap1. Increased fluconazole resistance was also observed in mutants lacking Glo1, a Mrr1-independent MG catabolic enzyme. Isolates from other Candida species displayed heterogeneity in MG resistance and MG stimulation of azole resistance. We propose endogenous and host-derived MG can induce MDR1 and other Mrr1-regulated genes causing increased drug resistance, which may contribute to some instances of fungal treatment failure.

Candida lusitaniae Breakthrough Fungemia in an Immuno-Compromised Adolescent: Case Report and Review of the Literature.

Candida lusitaniae is a rare cause of candidemia that is known for its unique capability to rapidly acquire resistance to amphotericin B. We report the case of an adolescent with grade IV graft-vs.-host disease after hematopoietic cell transplantation who developed catheter-associated C. lusitaniae candidemia while on therapeutic doses of liposomal amphotericin B. We review the epidemiology of C. lusitaniae bloodstream infections in adult and pediatric patients, the development of resistance, and its role in breakthrough candidemia. Appropriate species identification, in vitro susceptibility testing, and source control are pivotal to optimal management of C. lusitaniae candidemia. Initial antifungal therapy may consist of an echinocandin and be guided by in vitro susceptibility and clinical response.

Endocarditis infecciosa debida a candida lusitaniae en un lactante menor: Reporte de caso / Infectious endocarditis due to Candida lusitaniae in an infant: A case report

Resumen Introducción: La endocarditis fúngica es una enfermedad infecciosa agresiva e infrecuente, considerada una emergencia en los servicios hospitalarios. Se ha evidenciado una incidencia de 0-12% del total de las admisiones pediátricas por endocarditis infecciosa. La mortalidad por Candida spp se encuentra alrededor del 50-80% en todos los casos. La Candida lusitaniae afecta principalmente a pacientes inmunocomprometidos, con uso de dispositivos intravasculares y el empleo de antibióticos de amplio espectro. Reporte de caso: Se presenta el caso de un lactante menor quien es diagnosticado con fungemia y endocarditis infecciosa por Candida lusitaniae en válvula nativa posterior a cirugía de corrección por transposición de grandes vasos. Discusión y Conclusiones: La endocarditis infecciosa por Candida lusitaniae es una entidad poco frecuente, con una prevalencia menor al 2% constituyéndose un escenario desafiante en la práctica clínica. Se describen las características de un lactante menor quien presentó endocarditis fúngica ya definidas en la literatura mundial. Es imprescindible la detección temprana y una intervención terapéutica vertiginosa; puesto que, la persistencia del inoculo, la resistencia antimicótica y el retraso en el diagnóstico conllevan a una condición amenazante para la vida del paciente.

Abstract Introduction: Fungal infective endocarditis is an aggressive and infrequent disease, considered an emergency in hospital services. Candida mortality is around 50-80% in all cases. The Candida lusitaniae mainly affects immunocompromised patients with chronic venous access and the use of broad-spectrum antibiotics. Case report: A minor infant is presented who is diagnosed with fungemia and infective endocarditis due to Candida lusitaniae in a native valve secondary to surgery by transposition of large vessels. Discussion and Conclusions: Candida lusitaniae infectious endocarditis is very rare, with a prevalence of less than 2% constituting a challenging scenario in clinical practice. The characteristics of fungemia and endocarditis already defined in the world literature are described. Early detection and a vertiginous therapeutic intervention are essential, since; latent infection, antifungal resistance and delay in diagnosis lead to a threatening condition for the patient's life.

A budding case of infectious endocarditis: Candida lusitaniae.

This is a case of recurrent Candida lusitaniae prosthetic valve endocarditis with budding yeast and pseudohyphae on the histopathology. This case illustrates the importance of keeping vigilant in recognizing some of the emerging drug resistant Candida species in our practice.

Susceptibility of uncommon Candida species to systemic antifungals by the EUCAST methodology.

The incidence of infections by uncommon Candida species has increased in recent years, however, in vitro susceptibility data are scarce. Here we assess the susceptibility of C. krusei, C. dubliniensis, C. lusitaniae, and C. guilliermondii complex isolates (n = 120) to antifungal agents by the EUCAST methodology. C. dubliniensis proved to be the most susceptible species, similar to that of C. albicans (P < .05), whereas C. guilliermondii was the least susceptible. Two C. krusei isolates were echinocandin-resistant and harbored a point mutation (L701M) in the FKS1. Some isolates were either fluconazole-resistant (C. lusitaniae, n = 2) or fluconazole non-wild type (C. guilliermondii, n = 3).

Candida lusitaniae - a case report of an intraperitoneal infection.

Candida lusitaniae is a rare opportunistic yeast which is known for its resistance to amphotericin B (AmB). It is responsible for about 19.3% of all infections caused by non-Candida albicans species, and for about 1.7% of all cases of genitourinary candidiasis brought about by the entire spectrum of Candida species. Most commonly it occurs in patients with hematologic malignancies, especially when a patient is receiving chemotherapy. Candida lusitaniae infection usually presents with fungemia; however, only 7.3% of all patients will develop peritonitis. This case study describes an immunocompetent female patient with an intraperitoneal infection caused by C. lusitaniae after laparoscopic hydrosalpinx surgery. The patient was treated with fluconazole according to susceptibility testing. Fluconazole was implemented both orally and by transvaginal injection into the space after the evacuated pseudocyst. Conservative treatment resulted in a temporary improvement of the patient's condition and a reduction of the pseudocyst. Candida lusitaniae is very similar to other Candida species in generating systemic and local infections - mainly in compromised patients. It is also unique in its ability to develop resistance to AmB. Proper identification and quick implementation of selective therapy with the right anti-fungal drug are crucial for successfully treating infected patients. Surgery should always be considered as a final treatment option.

A CTG Clade Candida Yeast Genetically Engineered for the Genotype-Phenotype Characterization of Azole Antifungal Resistance in Human-Pathogenic Yeasts.

A strain of the opportunistic pathogenic yeast Candida lusitaniae was genetically modified for use as a cellular model for assessing by allele replacement the impact of lanosterol C14α-demethylase ERG11 mutations on azole resistance. Candida lusitaniae was chosen because it is susceptible to azole antifungals, it belongs to the CTG clade of yeast, which includes most of the Candida species pathogenic for humans, and it is haploid and easily amenable to genetic transformation and molecular modeling. In this work, allelic replacement is targeted at the ERG11 locus by the reconstitution of a functional auxotrophic marker in the 3' intergenic region of ERG11 Homologous and heterologous ERG11 alleles are expressed from the resident ERG11 promoter of C. lusitaniae, allowing accurate comparison of the phenotypic change in azole susceptibility. As a proof of concept, we successfully expressed in C. lusitaniae different ERG11 alleles, either bearing or not bearing mutations retrieved from a clinical context, from two phylogenetically distant yeasts, C. albicans and Kluyveromyces marxianusCandida lusitaniae constitutes a high-fidelity expression system, giving specific Erg11p-dependent fluconazole MICs very close to those observed with the ERG11 donor strain. This work led us to characterize the phenotypic effect of two kinds of mutation: mutation conferring decreased fluconazole susceptibility in a species-specific manner and mutation conferring fluconazole resistance in several yeast species. In particular, a missense mutation affecting amino acid K143 of Erg11p in Candida species, and the equivalent position K151 in K. marxianus, plays a critical role in fluconazole resistance.

Bilateral Candida endophthalmitis accompanying Candida lusitaniae bloodstream infection: A case report.

Candida lusitaniae is an uncommon cause of candidiasis in humans. Ocular manifestations of C. lusitaniae infection have not been reported. C. lusitaniae is either intrinsically resistant to amphotericin B or can acquire such resistance. We describe a case of bilateral endophthalmitis due to C. lusitaniae bloodstream infection in a liver transplant patient with rectal cancer. The patient suffered fungemia and endophthalmitis and was treated with liposomal amphotericin B. The isolate was identified as C. lusitaniae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, the system based on biochemical tests, and sequencing of the internal transcribed spacer region. The minimal inhibitory concentrations were 0.06 µg/mL for amphotericin B and 2.0 µg/mL for fluconazole. Repeat blood cultures were negative and the endophthalmitis improved following treatment with liposomal amphotericin B. However, the treatment was changed to fluconazole due to nephrotoxicity. No recurrence occurred after completion of treatment.

Rapid and Accurate Molecular Identification of the Emerging Multidrug-Resistant Pathogen Candida auris.

Candida auris is an emerging multidrug-resistant fungal pathogen causing nosocomial and invasive infections associated with high mortality. C. auris is commonly misidentified as several different yeast species by commercially available phenotypic identification platforms. Thus, there is an urgent need for a reliable diagnostic method. In this paper, we present fast, robust, easy-to-perform and interpret PCR and real-time PCR assays to identify C. auris and related species: Candida duobushaemulonii, Candida haemulonii, and Candida lusitaniae Targeting rDNA region nucleotide sequences, primers specific for C. auris only or C. auris and related species were designed. A panel of 140 clinical fungal isolates was used in both PCR and real-time PCR assays followed by electrophoresis or melting temperature analysis, respectively. The identification results from the assays were 100% concordant with DNA sequencing results. These molecular assays overcome the deficiencies of existing phenotypic tests to identify C. auris and related species.

Voriconazole and posaconazole therapy for experimental Candida lusitaniae infection.

The in vitro activity of posaconazole (PSC) and voriconazole (VRC) was tested by using time-kill studies against 3 strains of Candida lusitaniae. Both drugs showed fungistatic activity against all strains. The efficacy of those compounds was evaluated by reducing kidney fungal burden and by determining (1→3)-ß-d-glucan serum levels in a murine model of invasive infection of C. lusitaniae. The therapies tested were VRC at 10, 25, or 40 mg/kg/day and PSC at 5, 12.5, or 20 mg/kg/twice a day. All the dosages showed efficacy in a dose-dependant manner being high doses of both antifungals able to sterilize some kidneys after 10 days. With the exception of the strain FMR 9474, against which PSC was more effective than VRC, no differences in reducing tissue burden were found between the treatments. All doses of both antifungals were able to significantly reduce (1→3)-ß-d-glucan serum levels with no significant differences between treatments and between the same doses of both drugs.

Functional dissection of HAMP domains in NIK1 ortholog from pathogenic yeast Candida lusitaniae.

Nik1 orthologs or group III hybrid histidine kinases (HHK) are ubiquitous signaling molecules in fungal pathogens. Besides osmosensing, they are also involved in hyphal morphogenesis, virulence, and conidiation. They are important molecular targets for antifungal agents. Nik1 orthologs contain a varying number of HAMP domain repeats (poly-HAMP) in the N-terminal region. Poly-HAMP plays a crucial role in their function. So far, the role of HAMP domains in their function has been studied only in a few Nik1 orthologs. In this paper, we describe the functional characterization of a Nik1 ortholog (ClNik1p) from Candida lusitaniae, an emerging and important fungal pathogen. We show that ClNik1p acts as a bona fide osmosensor and negatively regulates the downstream HOG pathway in Saccharomyces cerevisiae. Our data suggests a differential role of the HAMP domains in the functionality of ClNik1p. The HAMP domains H1, H2, H3 and H5 are essential for kinase activity, and H4 domain has a regulatory role. Among the HAMP like linker domains, only H4b was crucial for the activity of ClNik1p.