Reduced Susceptibility To Fluconazole Research Articles

CWHM-974 is a fluphenazine derivative with improved antifungal activity against Candida albicans due to reduced susceptibility to multidrug transporter-mediated resistance mechanisms.

Multidrug resistance (MDR) transporters such as ATP-Binding Cassette (ABC) and Major Facilitator Superfamily proteins are important mediators of antifungal drug resistance, particularly with respect to azole class drugs. Consequently, identifying molecules that are not susceptible to this mechanism of resistance is an important goal for new antifungal drug discovery. As part of a project to optimize the antifungal activity of clinically used phenothiazines, we synthesized a fluphenazine derivative (CWHM-974) with 8-fold higher activity against Candida spp. compared to the fluphenazine and with activity against Candida spp. with reduced fluconazole susceptibility due to increased MDR transporters. Here, we show that the improved C. albicans activity is because fluphenazine induces its own resistance by triggering expression of Candida drug resistance (CDR) transporters while CWHM-974 induces expression but does not appear to be a substrate for the transporters or is insensitive to their effects through other mechanisms. We also found that fluphenazine and CWHM-974 are antagonistic with fluconazole in C. albicans but not in C. glabrata, despite inducing CDR1 expression to high levels. Overall, CWHM-974 is one of the few examples of a molecule in which relatively small structural modifications significantly reduced susceptibility to multidrug transporter-mediated resistance.

Assessment of the accuracy of identification of clinical Candida species with reduced fluconazole susceptibility by rapid methods and their relative expression of major efflux pump genes

Assessment of the accuracy of identification of clinical Candida species with reduced fluconazole susceptibility by rapid methods and their relative expression of major efflux pump genes

Species characterization and antifungal susceptibility profile of yeast isolates from blood cultures of fungemic patients in Thammasat University Hospital, Thailand

Background: Candida albicans is the most isolated fungal agent in a worldwide health system. Species distribution of Candida infection is different according to geographical regions. However, a shift in favor of non-albicans Candida species with antifungals resistance have increased as an important cause of candidemia. Objectives: This study aimed to identify the species of yeasts isolated from the blood samples of patients at the university hospital and to determine in vitro susceptibilities of three most common isolates against nine antifungal agents. Materials and methods:In total, 130 yeast isolates from 130 patients were defined the species using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Antifungal susceptibility testing was carried out using broth dilution Sensititre YeastOne panels included amphotericin B, 5-fucytosine, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, micafungin, and caspofungin. Results: The most common species in all age groups was C. tropicalis (n=48, 36.9%), followed by C. albicans (n=38, 29.2%). C. glabrata (n=23, 17.7%) was more common among elderly patients, while C. parapsilosis (n=9, 6.9%) was more frequently isolated from younger patients. Antifungal susceptibility testing in Candida species expressed MIC in the low level of almost antifungal drug except for reduced fluconazole susceptibility against C. glabrata and C. tropicalis isolates. Conclusion: C. tropicalis is the most common infection in candidemic patients. Fluconazole resistance strains were found in C. glabrata and C. tropicalis, respectively. In addition, voriconazole resistance strains were found in C. tropicalis.

Epidemiology and Antifungal Susceptibility in Patients with Candidemia in a University Hospital, Thailand

Background: Candidemia is the most common nosocomial invasive fungal infection that causes high mortality. Emergence of drug-resistant Candida is reported worldwide but there are few studies in Thailand. Objective: To determine the epidemiology, antifungal susceptibility of Candida, and outcomes among adult patients with candidemia. Materials and Methods: A prospective, observational study in adult patients with candidemia was conducted in 2015 at a university hospital. Demographic, microbiological, and outcome data were recorded. Results: Fifty-two patients with candidemia were identified, of whom 76.9% had an underlying disease and 69.2% had risks for candidemia. Sixty-four percent of candidemia patients contracted non-albicans Candida and 36% had Candida albicans. C. tropicalis was the most common non-albicans Candida species isolated (35%), followed by C. parapsilosis (19%), and C. glabrata (10%). Fluconazole resistance was found in 12.5% of C. albicans and in 11.1% of C. parapsilosis isolates. Reduced fluconazole susceptibility or high-level fluconazole resistance was found in 68.7% of C. tropicalis isolates. All except C. parapsilosis had excellent susceptibility to echinocandins. Seventy-three percent (38/52) of patients received antifungal treatment, of whom, 78.9% received empiric fluconazole therapy, and 89.7% were started on antifungal treatment 24 hours after the isolation of Candida. The overall mortality rate was 51.9%. Conclusion: Fluconazole-resistant Candida became more prevalent particularly in C. tropicalis, which was the predominant species among non-albicans Candida causing candidemia. Empiric treatment with either amphotericin B or echinocandins would be appropriate in high-risk patients with suspected candidemia. Trial registration: Thai Clinical Trials Registry, TCTR20150605001 Keywords: Candida, Fluconazole, Resistant, Thailand

A targeted fungal prophylaxis protocol with static dosed fluconazole significantly reduces invasive fungal infection after liver transplantation.

Invasive fungal infection (IFI) after liver transplant (LTx) is associated with extensive morbidity and mortality. Targeted prophylaxis reduces risk, but qualifying criteria, drug of choice and regimen are unclear and compliance is inconsistent. Assess the impact of a risk factor-based fungal prophylaxis protocol (FPP) after LTx on fungal infection rates, fungal epidemiology, and transplant outcomes. Observational cohort study of adult LTx recipients between July 1, 2009, and June 30, 2017. Patients in the FPP group were given a set dose of 400mg fluconazole without renal adjustment on POD 1-14 via pharmacist delegation protocol. One hundred and eighty-nine patients met inclusion criteria; 50 in the FPP and 139 in the pre-implementation comparator group. Of those who would be considered high-risk, 22.3% received antifungal prophylaxis prior to FPP implementation vs 92% after implementation (P<.0001). There were significantly fewer fungal infections in the FPP group at 1year (12.5% vs 26.6%, P=.03). IFI in the pre-implementation control group was due to Candida species in 95% of cases; 30% were species with reduced fluconazole susceptibility. IFI in the FPP group was due to Candida species in all cases, and no isolates had reduced fluconazole susceptibility. Aspergillus did not account for any IFI between the groups. One-year patient and graft survival were similar between groups. In a multivariable model accounting for patient and donor age, donor type, MELD, and cold ischemic time, FPP was protective against fungal infection (HR 0.3, P=.015). FPP did not significantly impact graft survival (HR 0.4, P=.14), but trended toward improved patient survival. (HR 0.18, P=.06). Implementation of a targeted FPP utilizing static dosing of fluconazole 400mg×14days to those that meet high-risk criteria significantly reduces invasive fungal infection after liver transplant. Use of this protocol did not adversely affect fungal epidemiology and may have a positive impact on allograft and patient survival. Future large prospective studies are needed to better evaluate survival impact.

The small GTPase Rhb1 is involved in the cell response to fluconazole in Candida albicans.

Candida albicans is an important fungal pathogen in humans. Rhb1 is a small GTPase of the Ras superfamily and is conserved from yeasts to humans. In C. albicans, Rhb1 regulates the expression of secreted protease 2, low nitrogen-mediated morphogenesis, and biofilm formation. Moreover, our previous studies have indicated that Rhb1 is associated with the target of rapamycin (TOR) signaling pathway. In this study, we further explored the relationship between Rhb1 and drug susceptibility. The RHB1 deletion mutant exhibited reduced fluconazole susceptibility, and this phenotype occurred mainly through the increased gene expression and activity of efflux pumps. In addition, Mrr1 and Tac1 are transcription factors that can activate efflux pump gene expression. However, the RHB1 deletion, RHB1/MRR1 and RHB1/TAC1 double deletion mutants had no significant differences in efflux pump gene expression and fluconazole susceptibility, suggesting that Rhb1-regulated efflux pump genes do not act through Mrr1 and Tac1. We also showed that membrane localization is crucial for Rhb1 activity in response to fluconazole. Finally, Rhb1 was linked not only to the TOR but also to the Mkc1 mitogen-activated protein kinase signaling pathway in response to fluconazole. In sum, this study unveiled a new role of Rhb1 in the regulation of C. albicans drug susceptibility.

Oral candidal speciation, virulence and antifungal susceptibility in type 2 diabetes mellitus.

To determine the oral candidal carriage (OCC), activity of virulent factors and fluconazole susceptibility in subjects with type 2 diabetes mellitus (T2DM) and investigate their association with HbA1c measurements. A cross sectional study was conducted on 100 diabetics and 100 healthy volunteers. The virulence was assessed by measuring the phospholipase activity and proteolysis index. Fluconazole susceptibility was performed using the gradient diffusion method. The OCC, virulence factors and antifungal susceptibility were correlated with patients' HbA1c measurements. The OCC and candidal density carriage was significantly higher in diabetics. Candida albicans (C. albicans) was the most frequently isolated species followed by Candida tropicalis (C. tropicalis). Relatively uncommon species, Candida lusitaniae (C. lusitaniae) and Candida lipolytica (C. lipolytica) were isolated from the diabetics. Prevalence of virulence factor, proteinase, was greater in diabetic group (p<0.05). Reduced fluconazole susceptibility was noted among the isolates from diabetics; however it was not statistically significant (p=0.593). Except one, all the susceptible-dose dependent and resistant isolates were Candida no-albicans (C. non-albicans). C. albicans remains the predominant pathogen in diabetics, although other species are on the rise. Compared to control group, the isolated species from T2DM group had higher proteinase activity. Resistance to fluconazole was considerably greater among the C. non-albicans isolates from T2DM group. These findings warrant effective treatment modalities to reduce the occurrence of oropharyngeal candidiasis.

The Investigational Fungal Cyp51 Inhibitor VT-1129 Demonstrates Potent In Vitro Activity against Cryptococcus neoformans and Cryptococcus gattii.

Thein vitroactivities of the novel fungal Cyp51 inhibitor VT-1129 were evaluated against a large panel ofCryptococcus neoformansandCryptococcus gattiiisolates. VT-1129 demonstrated potent activities against bothCryptococcusspecies as demonstrated by low MIC50and MIC90values. ForC. gattii, thein vitropotency was maintained against all genotypes. In addition, significantly lower geometric mean MICs were observed for VT-1129 than for fluconazole againstC. neoformans, including isolates with reduced fluconazole susceptibility.

Fluconazole Resistance Patterns in Candida Species that Colonize Women with HIV Infection

BackgroundThe Women’s Interagency HIV Study was established in 1993 to study the natural history of HIV disease among women in the United States. It currently has enrolled 2,895 women testing positive for HIV infection and 972 women without HIV infection recruited from 6 national metropolitan locations. The clinical database information collected for each HIV-positive individual included CD4 cell counts, viral load, and antiviral treatment to evaluate HIV prognosis and related conditions in women. ObjectiveTo provide a baseline for fluconazole treatment prospects in women who test positive for HIV infection. As part of the ongoing Women’s Interagency HIV Study project, we investigated the fluconazole susceptibility of Candida spp. isolated from women with HIV in comparison to volunteer women without HIV. The implication of antifungal treatment on fluconazole susceptibility was evaluated by reviewing antifungal medication use for the past 2 years in each participant. In addition, genotyping of Candida spp. at oral and vaginal sites was monitored for 4 months in 9 patients. MethodsIn a cohort of 59 women with HIV and 24 women without HIV, colonization by Candida albicans and non-albicans species of the oral and vaginal sites was first determined. Fluconazole susceptibility was surveyed in vitro according to Clinical and Laboratory Standards Institute protocol. Antifungal drug treatment history was investigated for each patient to correspond with fluconazole susceptibility. Finally, series of isolates from several patients were followed for resistance and susceptibility. Their lineage was verified by genotyping multilocus sequence typing (MLST). ResultsA total of 280 Candida strains were recovered from oral and vaginal swabs of women with and without HIV infection. We found that patients with HIV were colonized with Candida spp. more frequently than women without HIV. The percent of isolates that were susceptibility dose dependent or resistant to fluconazole was higher in Candida glabrata compared with C. albicans isolates, but higher for C. albicans than other published data. Resistance was noted to be more common in vaginal sites. Fluconazole resistance in either species was not associated with relative CD4 cell counts or viral load. However an association with systemic application of fluconazole and resistance was noted. ConclusionsSystemic antifungal therapy, including a vaginal topical regimen in women with HIV infection correlated with reduced fluconazole susceptibility of oral and vaginal isolates. Genotype profiling has disclosed that a majority of isolates from the same individual are clustered together, suggesting the likelihood of an original strain with some microevolution. We observed a change from a susceptibility dose dependent to a resistant phenotype of isolates in 2 women with HIV infection, even though no treatments were received during the 4-month study and the prior 2 years.

Effect of pH on In Vitro Susceptibility of Candida glabrata and Candida albicans to 11 Antifungal Agents and Implications for Clinical Use

The treatment of vulvovaginal candidiasis (VVC) due to Candida glabrata is challenging, with limited therapeutic options. Unexplained disappointing clinical efficacy has been reported with systemic and topical azole antifungal agents in spite of in vitro susceptibility. Given that the vaginal pH of patients with VVC is unchanged at 4 to 4.5, we studied the effect of pH on the in vitro activity of 11 antifungal agents against 40 C. glabrata isolates and compared activity against 15 fluconazole-sensitive and 10 reduced-fluconazole-susceptibility C. albicans strains. In vitro susceptibility to flucytosine, fluconazole, voriconazole, posaconazole, itraconazole, ketoconazole, clotrimazole, miconazole, ciclopirox olamine, amphotericin B, and caspofungin was determined using the CLSI method for yeast susceptibility testing. Test media were buffered to pHs of 7, 6, 5, and 4. Under conditions of reduced pH, C. glabrata isolates remained susceptible to caspofungin and flucytosine; however, there was a dramatic increase in the MIC(90) for amphotericin B and every azole drug tested. Although susceptible to other azole drugs tested at pH 7, C. albicans strains with reduced fluconazole susceptibility also demonstrated reduced susceptibility to amphotericin B and all azoles at pH 4. In contrast, fluconazole-sensitive C. albicans isolates remained susceptible at low pH to azoles, in keeping with clinical observations. In selecting agents for treatment of recurrent C. glabrata vaginitis, clinicians should recognize the limitations of in vitro susceptibility testing utilizing pH 7.0.

Pharmacokinetic evaluation of fluconazole in critically ill patients

Introduction: Invasive candidiasis has emerged over the last few decades as an increasingly important nosocomial problem for the critically ill, affecting around 2% of intensive care unit patients. Although poor outcomes associated with invasive candidiasis among critically ill patients may relate to severe underlying disease processes and delayed institution of antifungal therapy, inadequate dosing of antifungal agents may also contribute.Areas covered: This drug evaluation provides a critical appraisal of the published literature pertaining to the pharmacokinetics of fluconazole in critically ill, obese or severely burned patients, including those receiving acute renal replacement therapy. The pharmacodynamics of fluconazole is also covered, as well as the likely clinical implications for optimal dosing and the toxicity of fluconazole. Last, variations in fluconazole susceptibility patterns of Candida spp. are also discussed.Expert opinion: Recently, there has been an increased but geographically variable prevalence of non-albicans Candida spp., causing invasive candidiasis and an overall trend towards reduced fluconazole susceptibility. The pathophysiological changes of critical illness, coupled with a lack of dose finding studies, support the use of local susceptibility patterns to guide fluconazole dosing until such time as pharmacokinetic–pharmacodynamic information to guide optimal fluconazole dosing strategies and pharmacodynamic targets becomes available.

Trends in Antifungal Drug Susceptibility of Cryptococcus neoformans Isolates Obtained through Population-Based Surveillance in South Africa in 2002-2003 and 2007-2008

Cryptococcus neoformans is the most common cause of meningitis among adult South Africans with HIV infection/AIDS. Widespread use of fluconazole for treatment of cryptococcal meningitis and other HIV-associated opportunistic fungal infections in South Africa may lead to the emergence of isolates with reduced fluconazole susceptibility. MIC testing using a reference broth microdilution method was used to determine if isolates with reduced susceptibility to fluconazole or amphotericin B had emerged among cases of incident disease. Incident isolates were tested from two surveillance periods (2002-2003 and 2007-2008) when population-based surveillance was conducted in Gauteng Province, South Africa. These isolates were also tested for susceptibility to flucytosine, itraconazole, voriconazole, and posaconazole. Serially collected isolate pairs from cases at several large South African hospitals were also tested for susceptibility to fluconazole. Of the 487 incident isolates tested, only 3 (0.6%) demonstrated a fluconazole MIC of ≥ 16 μg/ml; all of these isolates were from 2002-2003. All incident isolates were inhibited by very low concentrations of amphotericin B and exhibited very low MICs to voriconazole and posaconazole. Of 67 cases with serially collected isolate pairs, only 1 case was detected where the isolate collected more than 30 days later had a fluconazole MIC value significantly higher than the MIC of the corresponding incident isolate. Although routine antifungal susceptibility testing of incident isolates is not currently recommended in clinical settings, it is still clearly important for public health to periodically monitor for the emergence of resistance.

Clinical and economic outcomes of decreased fluconazole susceptibility in patients with Candida glabrata bloodstream infections

The impact of reduced fluconazole susceptibility on clinical and economic outcomes in patients with Candida glabrata bloodstream infections (BSI) is unknown. A retrospective cohort study was conducted to evaluate 30-day inpatient mortality and postculture hospital charges in patients with C glabrata BSI with decreased fluconazole susceptibility (minimum inhibitory concentration [MIC] ≥ 16 μg/mL) versus fluconazole-susceptible C glabrata BSI (MIC ≤ 8 μg/mL). These analyses were adjusted for demographics, comorbidities, and time at risk. Secondary analyses limited the C glabrata group with decreased fluconazole susceptibility to MIC ≥ 64 μg/mL. There were 45 (31%) deaths among 144 enrolled patients: 19 deaths (25%) among 76 patients with C glabrata BSI with decreased fluconazole susceptibility and 26 deaths (38%) among 68 patients with fluconazole-susceptible C glabrata BSI. Decreased fluconazole susceptibility was not independently associated with increased 30-day inpatient mortality (adjusted odds ratio, .60; 95% confidence interval (CI): .26-1.35; P = 0.22) or hospital charges (multiplicative change in hospital charges, .93; 95% CI: .60-1.43; P = 0.73). Older age was associated with increased mortality and increased time at risk was associated with increased hospital charges. Crude mortality rates remain high in patients with C glabrata BSI. However, decreased fluconazole susceptibility was not associated with increased mortality or hospital charges.

Evaluation of the V404I and V509M amino acid substitutions of ERG11 gene in Candida albicans isolates by pyrosequencing

The molecular mechanisms underlying fluconazole resistance in C. albicans involve mutations and the overexpression of the ERG11 gene and membrane transport proteins. We examined the relationship between the reduced fluconazole susceptibility of C. albicans and mutations of V404I and V509M in the ERG11 gene in 182 C. albicans clinical isolates using the Pyrosequencing method. DNAs from these clinical isolates with different levels of in-vitro fluconazole susceptibility--one resistant, five susceptible dose-dependent (SDD), four trailer, and 172 susceptible--were analyzed. None of the fluconazole-susceptible, SDD, trailer or resistant isolates had mutations of V404I or V509M. Our results showed that no correlation can be found between the V404I or V509M mutation and fluconazole susceptibility in C. albicans.

Candidaemia associated with decreased in vitro fluconazole susceptibility: is Candida speciation predictive of the susceptibility pattern?

Candidaemia is often treated with fluconazole in the absence of susceptibility testing. We examined factors associated with candidaemia caused by Candida isolates with reduced susceptibility to fluconazole. We identified consecutive episodes of candidaemia at two hospitals from 2001 to 2007. Species identification followed CLSI methodology and fluconazole susceptibility was determined by Etest or broth microdilution. Susceptibility to fluconazole was defined as: full susceptibility (MIC < or = 8 mg/L); and reduced susceptibility (MIC > or = 32 mg/L). Complete resistance was defined as an MIC > 32 mg/L. Of 243 episodes of candidaemia, 190 (78%) were fully susceptible to fluconazole and 45 (19%) had reduced susceptibility (of which 27 were fully resistant). Of Candida krusei and Candida glabrata isolates, 100% and 51%, respectively, had reduced susceptibility. Despite the small proportion of Candida albicans (8%), Candida tropicalis (4%) and Candida parapsilosis (4%) with reduced fluconazole susceptibility, these species composed 36% of the reduced-susceptibility group and 48% of the fully resistant group. In multivariate analysis, independent factors associated with reduced fluconazole susceptibility included male sex [odds ratio (OR) 3.2, P < 0.01], chronic lung disease (OR 2.7, P = 0.01), the presence of a central vascular catheter (OR 4.0, P < 0.01) and prior exposure to antifungal agents (OR 2.2, P = 0.04). A significant proportion of candidaemia with reduced fluconazole susceptibility may be caused by C. albicans, C. tropicalis and C. parapsilosis, species usually considered fully susceptible to fluconazole. Thus, identification of these species may not be predictive of fluconazole susceptibility. Other factors that are associated with reduced fluconazole susceptibility may help clinicians choose adequate empirical anti-Candida therapy.

Rapid detection of ERG11 gene mutations in clinical Candida albicans isolates with reduced susceptibility to fluconazole by rolling circle amplification and DNA sequencing

BackgroundAmino acid substitutions in the target enzyme Erg11p of azole antifungals contribute to clinically-relevant azole resistance in Candida albicans. A simple molecular method for rapid detection of ERG11 gene mutations would be an advantage as a screening tool to identify potentially-resistant strains and to track their movement. To complement DNA sequencing, we developed a padlock probe and rolling circle amplification (RCA)-based method to detect a series of mutations in the C. albicans ERG11 gene using "reference" azole-resistant isolates with known mutations. The method was then used to estimate the frequency of ERG11 mutations and their type in 25 Australian clinical C. albicans isolates with reduced susceptibility to fluconazole and in 23 fluconazole-susceptible isolates. RCA results were compared DNA sequencing.ResultsThe RCA assay correctly identified all ERG11 mutations in eight "reference" C. albicans isolates. When applied to 48 test strains, the RCA method showed 100% agreement with DNA sequencing where an ERG11 mutation-specific probe was used. Of 20 different missense mutations detected by sequencing in 24 of 25 (96%) isolates with reduced fluconazole susceptibility, 16 were detected by RCA. Five missense mutations were detected by both methods in 18 of 23 (78%) fluconazole-susceptible strains. DNA sequencing revealed that mutations in non-susceptible isolates were all due to homozygous nucleotide changes. With the exception of the mutations leading to amino acid substitution E266D, those in fluconazole-susceptible strains were heterozygous. Amino acid substitutions common to both sets of isolates were D116E, E266D, K128T, V437I and V488I. Substitutions unique to isolates with reduced fluconazole susceptibility were G464 S (n = 4 isolates), G448E (n = 3), G307S (n = 3), K143R (n = 3) and Y123H, S405F and R467K (each n = 1). DNA sequencing revealed a novel substitution, G450V, in one isolate.ConclusionThe sensitive RCA assay described here is a simple, robust and rapid (2 h) method for the detection of ERG11 polymorphisms. It showed excellent concordance with ERG11 sequencing and is a potentially valuable tool to track the emergence and spread of azole-resistant C. albicans and to study the epidemiology of ERG11 mutations. The RCA method is applicable to the study of azole resistance in other fungi.

The alternative oxidase of Candida albicans causes reduced fluconazole susceptibility

To evaluate the effect of Candida albicans mitochondrial respiratory status on antifungal azole susceptibility. The inhibitors cyanide and salicylhydroxamic acid (SHAM) were each combined with azoles to examine the effect of the combinations on C. albicans. C. albicans strains deleted for the alternative oxidase (Aox) were also examined for susceptibility to azoles and for the generation of intracellular reactive oxygen species (ROS). A chequerboard microdilution assay was performed on several C. albicans clinical strains including azole-resistant isolates to explore the combined effect of fluconazole and inhibitors of Aox. The induction of the alternative respiratory pathway by cyanide decreased susceptibility to azoles, while the inhibition of alternative respiration by SHAM increased azole susceptibility. It was found that ROS production was increased in the absence of Aox in C. albicans upon treatment by antifungals such as miconazole and benomyl. The combination of fluconazole with SHAM resulted in a synergistic effect on the killing of C. albicans clinical isolates. These results demonstrate that the induction of the alternative respiratory pathway confers reduced susceptibility to antifungal azoles, potentially through a mechanism that involves decreased intracellular ROS production during exposure to antifungal agents.

Reduced fluconazole susceptibility of Candida albicans isolates in women with recurrent vulvovaginal candidiasis: effects of long-term fluconazole therapy

Fluconazole resistance and resultant failure to control Candida vaginitis (vulvovaginal candidiasis) remains extremely uncommon; however, long-term clinically relevant decrease in fluconazole susceptibility undoubtedly occurs and accompanies prolonged fluconazole chemoprophylaxis. Accordingly, in patients with refractory vaginitis or breakthrough infections due to Candida albicans, in vitro susceptibility testing is essential to optimally manage vaginitis.

One year prospective survey of Candida bloodstream infections in Scotland.

A 12 month survey of candidaemia in Scotland, UK, in which every Scottish hospital laboratory submitted all blood isolates of yeasts for identification, strain typing and susceptibility testing, provided 300 isolates from 242 patients, generating incidence data of 4.8 cases per 100 000 population per year and 5.9 cases per 100 000 acute occupied bed days; 27.9 % of cases occurred in intensive care units. More than half the patients with candidaemia had an underlying disease involving the abdomen, 78 % had an indwelling intravenous catheter, 62 % had suffered a bacterial infection within the 2 weeks prior to candidaemia and 37 % had undergone a laparotomy. Candida albicans was the infecting species in 50 % of cases, followed by Candida glabrata (21 %) and Candida parapsilosis (12 %). Seven cases of candidaemia were caused by Candida dubliniensis, which was more prevalent even than Candida lusitaniae and Candida tropicalis (six cases each). Among C. glabrata isolates, 55 % showed reduced susceptibility to fluconazole, but azole resistance among other species was extremely low. Multilocus sequence typing showed isolates with high similarity came from different hospitals across the country, and many different types came from the hospitals that submitted the most isolates, indicating no tendency towards hospital-specific endemic strains. Multiple isolates of C. albicans and C. glabrata from individual patients were of the same strain type with single exceptions for each species. The high prevalence of candidaemia in Scotland, relative to other population-based European studies, and the high level of reduced fluconazole susceptibility of Scottish C. glabrata isolates warrant continued future surveillance of invasive Candida infections.

In vitro Activity of Sertaconazole against Dermatophyte Isolates with Reduced Fluconazole Susceptibility

We have studied the in vitro antifungal activity of sertaconazole against 114 dermatophytes with low susceptibility to fluconazole following the National Committee for Clinical Laboratory Standards for filamentous fungi (M38-P). However, several important factors such as the temperature (28 vs. 35°C) and time of incubation (4–10 days vs. 21–74 h), have been found to affect dermatophytes. Isolates were recently recovered from human samples. Sertaconazole was active against 114 isolates of 12 fungal dermatophyte species, showing an overall geometric mean of 0.41 µg/ml with a minimum inhibitory concentration (MIC) range of 0.01–2 µg/ml against these isolates with reduced fluconazole susceptibility. Differences between both antifungals were significant (p < 0.05). MIC₅₀ and MIC₉₀ of sertaconazole were of 0.5 and 1 µg/ml, respectively, while the MIC of fluconazole was ≧16 µg/ml. None of the isolates was resistant to sertaconazole during the study while for four isolates the MIC of fluconazole was ≧64 µg/ml. No evidence of cross-resistance between both antifungals was found.