Antifungal Susceptibility Data Research Articles

Susceptibility Testing of Environmental and Clinical Aspergillus sydowii Demonstrates Potent Activity of Various Antifungals

The genus Aspergillus consists of a vast number of medically and environmentally relevant species. Aspergillus species classified in series Versicolores are ubiquitous in the environment and include the opportunistic pathogen Aspergillus sydowii, which is associated with onychomycosis and superficial skin infections. Despite frequent clinical reports of A. sydowii and related series Versicolores species, antifungal susceptibility data are scarce, hampering optimal treatment choices and subsequent patient outcomes. Here, we employed antifungal susceptibility testing (AFST) based on microbroth dilution on a set of 155 series Versicolores strains using the common antifungals amphotericin B, itraconazole, voriconazole, posaconazole, isavuconazole and micafungin with the addition of luliconazole and olorofim. All strains were identified using partial calmodulin gene sequencing, with 145 being A. sydowii, seven A. creber and three A. versicolor, using the latest taxonomic insights. Overall, tested antifungals were potent against the entire strain collection. In comparison to A. fumigatus, azole and amphotericin B MICs were slightly elevated for some strains. AFST with luliconazole and olorofim, here reported for the first time, displayed the highest in vitro activity, making these antifungals interesting alternative drugs but clinical studies are warranted for future therapeutic use.

Genomic epidemiology and antifungal-resistant characterization of Candida auris, Colombia, 2016-2021.

Candida auris is an emerging fungus that presents a serious global health threat and has caused multiple outbreaks in Colombia. This work discusses the likelihood of introductions and local transmission of C. auris and provides an updated description of the molecular mechanisms associated with antifungal resistance in Colombia. Efforts like this provide information about the evolving C. auris burden that could help guide public health strategies to control C. auris spread.

Three Cases of Catheter-related Bloodstream Infection Caused by Phialemonium curvata : A Case Report and Literature Review.

With recent developments in the field of microbiology, an increasing number of yeasts and molds with the potential to cause infections in humans are identified every year. In addition to the challenges in identifying clinical isolates, there is limited antifungal susceptibility data available for Phialemonium species, leading to uncertainty in optimal treatment recommendations. In this article, catheter-related bloodstream infections caused by Phialemonium curvata (previously Phialemonium curvatum ) in 3 immunosuppressed patients are presented. Furthermore, the literature was reviewed to identify the clinical spectrum and treatment approaches for the reported infections. The cases presented here were analyzed along with 24 cases reported in the literature. Among all cases, 21 (77.7%) patients had an underlying condition. Nine (33.3%) patients had hematologic/oncologic malignancies and solid organ transplants. Twenty-two (81.4%) patients had a history of device or invasive interventions. Surgical procedures, removal of contaminated devices or tissue were found to reduce the risk of death by 86.7%. Correspondence analysis revealed a significant association between antifungal treatment and outcome ( P < 0.001). The correspondence analysis could explain 53.9% of this relationship. Monotherapy and combination therapy were associated with survival. While salvage treatment or no antifungal therapy was associated with mortality, intravitreal injection or topical application of voriconazole was associated with sequelae. Surgical intervention and removal of contaminated devices or tissue should be considered at an early stage.

Antifungal susceptibility of the clinical and environmental strains of Cryptococcus gattii sensu lato in Taiwan.

The rare occurrence of human cryptococcosis caused by Cryptococcus gattii sensu lato leads to difficulties in establishing the antifungal susceptibility profile between species of this potentially lethal pathogen, which may be crucial for treating cryptococcosis. To establish an antifungal susceptibility profile of C. gattii s.l. in Taiwan. A total of 104 environmental C. gattii s.l. strains (including multilocal sequence typing ST7, ST106, ST274, ST328, ST546, ST548 and ST630) and 21 previously collected clinical strains (including ST7, ST44, ST06, ST274, ST328 and ST329) were included in this study. We determined the minimum inhibitory concentrations (MICs) of six antifungal agents (itraconazole, fluconazole, voriconazole, posaconazole, flucytosine and amphotericin B) against environmental C. gattii s.l. strains and compared the antifungal susceptibility profiles of environmental strains with those of clinical strains. The antifungal susceptibility data demonstrated that the MICs of antifungal agents against environmental strains were comparable to those against clinical strains. Compared with strains of Cryptococcus deuterogattii, those of C. gattii sensu stricto were more susceptible to azoles and flucytosine. The differences in antifungal susceptibility between the strains of each sequence type (ST) were significant. Correlation analysis of MICs revealed cross-resistance between azoles in environmental strains of C. gattii s.l. Geographic differences in the antifungal susceptibility of C. gattii s.l. isolated from different cities in Taiwan were observed in this study. Clinical and environmental strains were indistinguishable in antifungal susceptibility. The antifungal susceptibility of C. gattii s.l. is associated with STs. Therefore, establishing an ST-oriented domestic antifungal susceptibility database may help treat C. gattii s.l.-induced cryptococcosis.

Single-dose pharmacokinetics of orally administered terbinafine in bearded dragons (Pogona vitticeps) and the antifungal susceptibility patterns of Nannizziopsis guarroi.

To identify the antifungal susceptibility of Nanniziopsis guarroi isolates and to evaluate the single-dose pharmacokinetics of orally administered terbinafine in bearded dragons. 8 healthy adult bearded dragons. 4 isolates of N guarroi were tested for antifungal susceptibility. A compounded oral solution of terbinafine (25 mg/mL [20 mg/kg]) was given before blood (0.2 mL) was drawn from the ventral tail vein at 0, 4, 8, 12, 24, 48, 72, and 96 hours after administration. Plasma terbinafine concentrations were measured with high-performance liquid chromatography. The antifungal minimum inhibitory concentrations against N guarroi isolates ranged from 4,000 to > 64,000 ng/mL for fluconazole, 125 to 2,000 ng/mL for itraconazole, 125 to 2,000 ng/mL for ketoconazole, 125 to 1,000 ng/mL for posaconazole, 60 to 250 ng/mL for voriconazole, and 15 to 30 ng/mL for terbinafine. The mean ± SD peak plasma terbinafine concentration in bearded dragons was 435 ± 338 ng/mL at 13 ± 4.66 hours after administration. Plasma concentrations remained > 30 ng/mL for > 24 hours in all bearded dragons and for > 48 hours in 6 of 8 bearded dragons. Mean ± SD terminal half-life following oral administration was 21.2 ± 12.40 hours. Antifungal susceptibility data are available for use in clinical decision making. Results indicated that administration of terbinafine (20 mg/kg, PO, q 24 to 48 h) in bearded dragons may be appropriate for the treatment of dermatomycoses caused by N guarroi. Clinical studies are needed to determine the efficacy of such treatment.

Antifungal susceptibility profile of invasive Candida glabrata isolates (2009-2020) from a tertiary care hospital laboratory in Pakistan.

Introduction. Invasive infections with Candida glabrata are a global concern due to poor clinical outcomes and propensity to acquire resistance to antifungal agents. Hypothesis/Gap Statement. Monitoring emerging resistance and trends in Candida glabrata, an important agent of candidemia in Pakistan, is critical for patient management; data that is missing from Pakistan. Aim. Thus, this study evaluated antifungal resistance and MICs) distribution in invasive C. glabrata isolates from Pakistan. Methods. This cross-sectional and retrospective study was conducted from January 2009 to March 2020 at a clinical laboratory in Pakistan that has a nation-wide network. Antifungal susceptibility data of 277 candidemia, deep organ and soft tissue (invasive) C. glabrata sensu lato isolates against fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, micafungin, caspofungin and amphotericin B was retrieved. Susceptibility testing was performed using colorimetric broth microdilution and interpreted using CLSI criteria. Demographics, clinical history and outcome were studied. Chi-square test was used to demonstrate association between antifungal resistance and clinical characteristics of the patients. Results. We identified 277 patients with invasive C. glabrata infection. Of which 48 (18.4%) isolates were resistant to fluconazole (MIC ≥64 mg l-1), one isolate each was resistant to amphotericin (MIC=2 mg l-1), anidulafungin (MIC=1 mg l-1) and micafungin (MIC=0.5 mg l-1). MIC90 for fluconazole was 64 mg l-1 and other triazoles 2 mg l-1, caspofungin 0.12 mg l-1, anidulafungin 0.06 mg l-1, micafungin 0.03 mg l-1 and amphotericin 0.5 mg l-1. Fluconazole MIC ≥64 mg l-1, caspofungin MIC >0.06 mg l-1 and amphotericin MIC >0.25 mg l-1 (above MIC50) were significantly associated with patient being alive at the time of reporting, no use of healthcare devices, nor infection with other fungi. Fluconazole resistance was significantly associated with prior antifungal use by the patient. Conclusion. Surveillance data of antifungal resistance among common Candida species should be monitored closely for identification of resistant strains.

Real-Life Considerations on Antifungal Treatment Combinations for the Management of Invasive Mold Infections after Allogeneic Cell Transplantation.

Background: Antifungal combination treatment is frequently administered for invasive mold infections (IMIs) after allogeneic hematopoietic cell transplantation (HCT). Here, we describe the indications, timing, and outcomes of combination antifungal therapy in post-HCT IMI. Methods: A single-center, 10-year, retrospective cohort study including all adult HCT recipients with proven/probable IMI between 1 January 2010 and 1 January 2020 was conducted. Results: During the study period, 515 patients underwent HCT, of whom 47 (9.1%) presented 48 IMI episodes (46 patients with one IMI episode and 1 patient with two separate IMI episodes): 33 invasive aspergillosis (IA) and 15 non-IA IMIs. Almost half (51%) of the patients received at least one course of an antifungal combination (median: 2/patient): 23 (49%), 20 (42%), and 4/47 (9%) patients received pure monotherapy, mixed monotherapy/combination, and pure combination treatment, respectively. Combination treatment was started at a median of 8 (IQR: 2, 19) days post-IMI diagnosis. Antifungal management was complex, with 163 treatment courses prescribed overall, 48/163 (29.4%) concerning antifungals in combination. The clinical reasons motivating the selection of initial combination antifungal therapy included severe IMI (18, 38%), lack of antifungal susceptibility data (14, 30%), lack of pathogen identification (5, 11%), and combination treatment until reaching a therapeutic azole serum level (6, 13%). The most common combination treatments were azole/liposomal amphotericin-B (28%) and liposomal amphotericin-B/echinocandin (21%). Combination treatment was administered cumulatively for a median duration of 28 days (IQR: 7, 47): 14 (IQR: 6, 50) days for IA and 28 (IQR: 21, 34) days for non-IA IMI (p = 0.18). Overall, 12-week mortality was 30%. Mortality was significantly higher among patients receiving ≥50% of treatment as combination (logrank = 0.04), especially those with non-IA IMI (logrank = 0.03). Conclusions: Combination antifungal treatment is frequently administered in allogeneic HCT recipients with IMI to improve clinical efficacy, albeit in an inconsistent and variable manner, suggesting a lack of relevant data and guidance, and an urgent need for new studies to improve therapeutic options.

In vitro activities of 8 antifungal drugs against 126 clinical and environmental Exophiala isolates.

Exophiala is the main genus of black fungi comprising numerous opportunistic species. Data on antifungal susceptibility of Exophiala isolates are limited, while infections are potentially fatal. In vitro activities of eight antifungal drugs (AMB, five azoles, two echinocandins) against 126 clinical (n=76) and environmental (n=47) isolates from around the world were investigated. E.oligosperma (n=58), E.spinifera (n=33), E.jeanselmei (n=14) and E.xenobiotica (n=21) were included in our dataset. The resulting MIC90 s of all strains were as follows, in increasing order: posaconazole 0.063μg/ml, itraconazole 0.125μg/ml, voriconazole and amphotericin B 1μg/ml, isavuconazole 2μg/ml, micafungin and caspofungin 4μg/ml, and fluconazole 64μg/ml. Posaconazole, itraconazole and micafungin were the drugs with the best overall activity against Exophiala species. Fluconazole could not be considered as a treatment choice. No significant difference could be found among antifungal drug activities between these four species, neither in clinical nor in environmental isolates. Antifungal susceptibility data for Exophiala spp. are crucial to improve the management of this occasionally fatal infection and the outcome of its treatment.

Cryptococcus neoformans and Cryptococcus gattii Species Complexes in Latin America: A Map of Molecular Types, Genotypic Diversity, and Antifungal Susceptibility as Reported by the Latin American Cryptococcal Study Group.

Cryptococcosis, a potentially fatal mycosis, is caused by members of the Cryptococcus neoformans and Cryptococcus gattii species complexes. In Latin America, cryptococcal meningitis is still an important health threat with a significant clinical burden. Analysis of publicly available molecular data from 5686 clinical, environmental, and veterinary cryptococcal isolates from member countries of the Latin American Cryptococcal Study Group showed that, as worldwide, C. neoformans molecular type VNI is the most common cause of cryptococcosis (76.01%) in HIV-infected people, followed by C. gattii molecular type VGII (12.37%), affecting mostly otherwise healthy hosts. These two molecular types also predominate in the environment (68.60% for VNI and 20.70% for VGII). Among the scarce number of veterinary cases, VGII is the predominant molecular type (73.68%). Multilocus sequence typing analysis showed that, in Latin America, the C. neoformans population is less diverse than the C. gattii population (D of 0.7104 vs. 0.9755). Analysis of antifungal susceptibility data showed the presence of non-wild-type VNI, VGI, VGII, and VGIII isolates in the region. Overall, the data presented herein summarize the progress that has been made towards the molecular epidemiology of cryptococcal isolates in Latin America, contributing to the characterization of the genetic diversity and antifungal susceptibility of these globally spreading pathogenic yeasts.

Canine sporotrichosis: polyphasic taxonomy and antifungal susceptibility profiles of Sporothrix species in an endemic area in Brazil.

Sporotrichosis, a mycosis caused by pathogenic species of the genus Sporothrix, affects diverse species of mammals. Until 2007, Sporothrix schenckii was considered the unique etiologic agent of sporotrichosis. Canine sporotrichosis is a poorly reported disease, and the majority of cases are from Rio de Janeiro, Brazil. There are scarce studies on the characterization of canine isolates of Sporothrix schenckii complex, as well as few antifungal susceptibility data available. The aim of this study was to characterize the clinical isolates of Sporothrix from dogs from Brazil at species level and evaluate their antifungal susceptibility profile. Polyphasic taxonomy was used to characterization at species level (morphological, phenotypical characteristics, and molecular identification). Antifungal susceptibility profiles (amphotericin B, itraconazole, ketoconazole, posaconazole, and terbinafine) were determined using the Clinical and Laboratory Standards Institute broth microdilution method (M38-A2). According to phenotypic identification and molecular analysis, 46 isolates included in this study were identified as S. brasiliensis and one as S. schenckii. Amphotericin B presented the highest minimum inhibitory concentration values, and the other drugs showed effective in vitro antifungal activity. This is the first report of S. schenckii in dogs from Brazil, since S. brasiliensis is the only species that has been described in canine isolates from Rio de Janeiro to date. Nevertheless, no differences were observed in the antifungal susceptibility profiles between the S. brasiliensis and S. schenckii isolates, and it is important to continuously study new canine clinical isolates from Rio de Janeiro, Brazil.

Nigrospora oryzae Pulmonary Infection in a Bronchogenic Cancer: an Opportunistic Invader?

The genus Nigrospora is a cosmopolitan dematiaceous ascomycetes fungus which inhabits the soil and includes both entomopathogenic and phytopathogenic properties. Among the evolving species of Nigrospora, the frequently isolated are Nigrospora sphaerica (N. sphaerica) and Nigrospora oryzae (N. oryzae). N. sphaerica has been implicated in human infections like corneal ulcer, onychomycosis, respiratory allergies, deep mycoses, and skin infections in both immunocompetent and immunocompromised individuals, whereas N. oryzae is an established plant pathogen and the only reported human association is its isolation from human superficial skin scrapings. Here, we report a case of pulmonary infection by N. oryzae in a 55-year-old male with a neoplasm of squamous cell origin and diffuse skeletal metastasis. Bronchoalveolar lavage and biopsies of lung tissue demonstrated branching septate hyphae and extensive tumor necrosis and malignant cells, respectively. Fungal culture and molecular sequencing established N. oryzae as the etiological agent. The patient was treated with itraconazole and palliative radiotherapy. Due to the poor compliance and unfavorable effects of treatments, the patient opted for alternative therapies and succumbed due to ongoing invasive pathogenesis. To the best of our knowledge, this is the first communication describing a dematiaceous mold N. oryzae causing opportunistic pulmonary infection in a lung neoplasm along with antifungal susceptibility data against seven antifungal drugs using the reference CLSI method.

Clinical Usefulness of Susceptibility Breakpoints for Yeasts in the Treatment of Candidemia: A Noninterventional Study.

This prospective noninterventional study evaluated whether antifungal susceptibility data (MIC) provided for Candida clinical isolates on the basis of recently established breakpoints are taken into account by clinicians to guide their treatment decision making process, and assessed the response in MIC- and non-MIC-based treatment groups. During a six month period, the usage of systemic antifungals was recorded in detail and compared with mycological data (Candida species and MICs) in candidemia patients. Patients were assigned to a susceptible or resistant infection group based on European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints; treatment decisions were under the professional discretion of the treating physicians. 123 patients were evaluated with Candida albicans accounting for 59%, Candida glabrata for 19%, Candida parapsilosis for 15%, Candida tropicalis for 4% and Candida krusei for 3%. Antifungal treatment correlated with species and MICs in 80% (n = 99 patients), high MICs and species-dependent guideline recommendations were ignored in 20% (n = 24 patients); the overall outcome of candidemia cases in our study population was excellent, as by day 14, all patients were cleared from fungal blood stream infection (mean 5.6 days, range 2–12). The current variability in antifungal usage and the delay in initiating appropriate therapy indicate a need for antifungal stewardship to improve the management of invasive fungal infections.

Molecular Identification and In Vitro Antifungal Susceptibility of Aspergillus Isolates Recovered from Otomycosis Patients in Western China.

Aspergillus species are the most common causative agents involved in otomycosis. In this study, 45 Aspergillus isolates were obtained from patients with otomycosis in western China during 2013-2016. The aim of this study is to identify the Aspergillus isolates to the species level by using β-tubulin gene sequencing and to evaluate their in vitro susceptibility to nine antifungal drugs: amphotericin B, itraconazole, voriconazole, posaconazole, ravuconazole, isavuconazole, caspofungin, micafungin and anidulafungin according to CLSI M38-A2. Our results indicate that A. tubingensis (18/45) is the predominant Aspergillus species causing ear infections in western China, which is three times more than its sibling species A. niger (6/45) and A. welwitschiae (2/45). Other detected species were A. fumigatus (n = 8), A. terreus (n = 7) and A. flavus (n = 4). Antifungal susceptibility data indicate that triazoles and echinocandins are active against the most Aspergillus isolates. There are no significant differences in the susceptibility among A. niger, A. tubingensis and A. welwitschiae to each of the antifungals tested. One azole-resistant A. fumigatus isolate with a TR34/L98H mutation in the CYP51A gene and one posaconazole-resistant A. terreus isolate presented among the studied isolates. In conclusion, A. tubingensis is the most prevalent Aspergillus species causing otomycosis in western China. Posaconazole and echinocandins are potential drugs for treatment of otomycosis due to Aspergillus; however, in vivo efficacy remains to be determined.

1698. Epidemiology and Antifungal Susceptibility of Candidemia Among Adult Patients at a Tertiary Care Hospital in South Korea During an 8-Year Period

BackgroundCandidemia continues to contribute to significant morbidity and mortality in the hospital. This study aimed to evaluate the epidemiology and antifungal susceptibility at a tertiary care hospital in South Korea during an 8-year period.MethodsAdult patients ≥19 years with candidemia at a tertiary care hospital in South Korea from 2006 to 2018 were reviewed, and cases of candidemia with antifungal susceptibility data were included for the analysis.ResultsThere were 270 cases of candidemia with fluconazole susceptibility data from 2011 to 2018. Overall, fluconazole resistance rate of candidemia was 8.5%. Between period 1 (2011–2015) and period 2 (2016–2018), fluconazole resistance rate was significantly higher in the period 2 (14.3%) than in the period 1 (0.9%), P < 0.001. Among candidemia caused by different Candida spp., a significant increase of fluconazole-resistant C. parapsilosis candidemia was noted in the period 2 (12 out of 34 cases; 35.3%) when compared with the period 1 (0 out of 17 cases; 0.0%), P = 0.004. Although there was a trend of higher fluconazole resistance rate for candidemia caused by C. albicans (9.1% vs. 1.8%), C. tropicalis (2.7% vs. 0.0%), and C. glabrata (11.1% vs. 0.0%) in the period 2 than in the period 1, no statistical significance was observed. Echinocandin (caspofungin and micafungin) susceptibility data were available for 211 cases of candidemia from 2013 to 2018. There were no cases of caspofungin-resistant candidemia except for 2 cases of C. utilis candidemia. However, there were 9 cases of micafungin-resistant candidemia (1 case of C. tropicalis candidemia out of 51 cases [2.0%], 6 cases of C. glabrata candidemia out of 18 cases [33.3%], and 2 cases of C. utilis candidemia out of 2 cases [100.0%]). Micafungin-resistant C. tropicalis and C. glabrata candidemia cases were susceptible to caspofungin.ConclusionA significant increase of fluconazole-resistant candidemia in recent years was noted, particularly among C. parapsilosis candidemia cases. Echinocandin resistance among candidemia cases is rare. However, close monitoring needs to be considered for the possible emergence of differential echinocandin resistance.Disclosures All authors: No reported disclosures.

Absence of Azole or Echinocandin Resistance in Candida glabrata Isolates in India despite Background Prevalence of Strains with Defects in the DNA Mismatch Repair Pathway.

Candida glabrata infections are increasing worldwide and exhibit greater rates of antifungal resistance than those with other species. DNA mismatch repair (MMR) gene deletions, such as msh2Δ, in C. glabrata resulting in a mutator phenotype have recently been reported to facilitate rapid acquisition of antifungal resistance. This study determined the antifungal susceptibility profiles of 210 C. glabrata isolates in 10 hospitals in India and investigated the impact of novel MSH2 polymorphisms on mutation potential. No echinocandin- or azole-resistant strains and no mutations in FKS hot spot regions were detected among the C. glabrata isolates, supporting our in vitro susceptibility testing results. CLSI antifungal susceptibility data showed that the MICs of anidulafungin (geometric mean [GM], 0.12 μg/ml) and micafungin (GM, 0.01 μg/ml) were lower and below the susceptibility breakpoint compared to that of caspofungin (CAS) (GM, 1.31 μg/ml). Interestingly, 69% of the C. glabrata strains sequenced contained six nonsynonymous mutations in MSH2, i.e., V239L and the novel mutations E459K, R847C, Q386K, T772S, and V239/D946E. Functional analysis of MSH2 mutations revealed that 49% of the tested strains (40/81) contained a partial loss-of-function MSH2 mutation. The novel MSH2 substitution Q386K produced higher frequencies of CAS-resistant colonies upon expression in the msh2Δ mutant. However, expression of two other novel MSH2 alleles, i.e., E459K or R847C, did not confer selection of resistant colonies, confirming that not all mutations in the MSH2 MMR pathway affect its function or generate a phenotype of resistance to antifungal drugs. The lack of drug resistance prevented any correlations from being drawn with respect to MSH2 genotype.

Genotypic analysis of clinical and environmental Cryptococcus neoformans isolates from Brazil reveals the presence of VNB isolates and a correlation with biological factors

Cryptococcal infections are mainly caused by members of the Cryptococcus neoformans species complex (molecular types VNI, VNII, VNB, VNIV and the AD hybrid VNIII). PCR of the mating type loci and MLST typing using the ISHAM-MLST consensus scheme were used to evaluate the genetic relationship of 102 (63 clinical and 39 environmental) C. neoformans isolates from Uberaba, Brazil and to correlate the obtained genotypes with clinical, antifungal susceptibility and virulence factor data. All isolates were mating type alpha. MLST identified 12 known and five new sequence types (ST). Fourteen STs were identified within the VNI isolates, with ST93 (57/102, 56%) and ST77 (19/102, 19%) being the most prevalent. From the nine VNII isolates previously identify by URA5-RFLP only four (ST40) were confirmed by MLST. The remaining five grouped within the VNB clade in the phylogenetic analysis corresponding to the sequence type ST504. Other two environmental isolates also grouped within VNB clade with the new sequence type ST527. The four VNII/ST40 isolates were isolated from CSF. The two VNIV sequence types (ST11 and ST160) were isolated from blood cultures. Two of six patients evaluated with more than one isolates had mixed infections. Amongst the VNI isolates 4 populations were identified, which showed differences in their susceptibility profiles, clinical outcome and virulence factors. These results reinforce that ST93 is the most prevalent ST in HIV-infected patients in the Southeastern region of Brazil. The finding of the VNB molecular type amongst environmental Brazilian isolates highlights that this genotype is not restricted to the African continent.

Refractory sporotrichosis due to Sporothrix brasiliensis in humans appears to be unrelated to in vivo resistance.

Sporotrichosis is a subacute to chronic infection caused by members of the Sporothrix schenckii complex. Itraconazole is the first choice antifungal drug for treating this infection, with terbinafine and potassium iodide as alternatives and amphotericin B used in cases of severe infections. Correlation of antifungal susceptibility data with the clinical outcome of the patients is scarce. The aim of this study was to correlate clinical and mycological data in patients with refractory sporotrichosis. In this work, antifungal susceptibilities, determined according to the reference M38-A2 CLSI protocol, of 25 Sporothrix strains, isolated from seven human cases of sporotrichosis with adversities in the treatment, are presented. Tested drugs included itraconazole, ketoconazole, posaconazole, voriconazole, terbinafine, and amphotericin B. Fungi were identified using the T3B PCR fingerprinting. This method identified all strains as Sporothrix brasiliensis and also demonstrated a high degree of similarity between the strains. In general, voriconazole was ineffective against all strains, and elevated minimal inhibitory concentrations (MICs) were observed for amphotericin B. High itraconazole and terbinafine MICs were not observed in S. brasiliensis isolates from patients of this study. Moreover, a significant increase in itraconazole and terbinafine MIC values from strains isolated from the same patient in different periods was not observed. The results suggest that the antifungal susceptibility to terbinafine and itraconazole determined by the reference method does not play an important role in therapeutic failure of sporotrichosis and that acquisition of resistance during prolonged antifungal treatment is not likely to occur in S. brasiliensis.

Antifungal susceptibility of clinical and environmental Cryptococcus neoformans and Cryptococcus gattii isolates in Jabalpur, a city of Madhya Pradesh in Central India.

In this study, we present antifungal susceptibility data of clinical and environmental isolates of Central Indian Cryptococcus neoformans (Serotype A, n = 8 and n = 50 respectively) and Cryptococcus gattii (Serotype B, n = 01 and n = 04 respectively). Susceptibilities to fluconazole, itraconazole and ketoconazole were determined by using NCCLS broth micro-dilution methodology. The total number of resistant strains for fluconazole in case of C. neoformans and C. gattii showed a significant difference by using chi-square test (p < 0.05*), while considering fisher's exact p value was nonsignificant (p > 0.05). However, the total number of resistant strains for itraconazole and ketoconazole was not found statistically significant. A comparison of geometric means of clinical and environmental strains of C. gattii and C. neoformans was not found statistically significant using student ‘t’ test (p value > 0.05 NS). Though less, the antifungal data obtained in this study suggests that primary resistance among environmental and clinical isolates of C. neoformans and C. gattii against tested antifungal was present and C. gattii comparatively was less susceptible than C. neoformans var. grubii isolates to fluconazole than to itraconazole and ketoconazole. A continuous surveillance of antifungal susceptibility of clinical and environmental isolates of C. neoformans and C. gattii is desirable to monitor the emergence of any resistant strains for better management of cryptococcosis patients.

In vitro susceptibility of antifungal drugs against Sporothrix brasiliensis recovered from cats with sporotrichosis in Brazil.

Sporotrichosis is an important subcutaneous mycosis of humans and animals. Classically, the disease is acquired upon traumatic inoculation of Sporothrix propagules from contaminated soil and plant debris. In addition, the direct horizontal transmission of Sporothrix among animals and the resulting zoonotic infection in humans highlight an alternative and efficient rout of transmission through biting and scratching. Sporothrix brasiliensis is the most virulent species of the Sporothrix schenckii complex and is responsible for the long-lasting outbreak of feline sporotrichosis in Brazil. However, antifungal susceptibility data of animal-borne isolates is scarce. Therefore, this study evaluated the in vitro activity of amphotericin B, caspofungin, itraconazole, voriconazole, fluconazole, and ketoconazole against animal-borne isolates of S. brasiliensis. The susceptibility tests were performed through broth microdilution (M38-A2). The results show the relevant activity of itraconazole, amphotericin B, and ketoconazole against S. brasiliensis, with the following MIC ranges: 0.125-2, 0.125-4 and 0.0312-2 μg/ml, respectively. Caspofungin was moderately effective, displaying higher variation in MIC values (0.25-64 μg/ml). Voriconazole (2-64 μg/ml) and fluconazole (62.5-500 μg/ml) showed low activity against S. brasiliensis strains. This study contributed to the characterization of the in vitro antifungal susceptibility of strains of S. brasiliensis recovered from cats with sporotrichosis, which have recently been considered the main source of human infections.

Molecular characterization and in vitro antifungal susceptibility of 80 clinical isolates of mucormycetes in Delhi, India.

Mucormycosis is a highly aggressive disease which is usually fatal in immunocompromised patients. The species of mucormycetes show significant differences in susceptibility to amphotericin B, azoles and terbinafine. The precise species level identification for this fungal group could be achieved by internal transcribed-spacer (ITS) region sequencing. Herein, we present the largest series of antifungal susceptibility data of molecularly characterised isolates of mucormycetes reported so far from India. Eighty isolates originating from 71 patients comprised 50 (62.5%) from pulmonary cases, 15 (19%) from rhino-orbital-cerebral, 13 (16.2%) from cutaneous and 2 (2.5%) from disseminated mucormycosis. ITS and D1/D2 regions sequencing of the isolates identified, Rhizopus arrhizus var. delemar (n = 25), R. arrhizus var. arrhizus (n = 15), R. microsporus (n = 17), R. stolonifer (n = 3), Syncephalastrum racemosum (n = 11), Apophysomyces elegans (n = 2), A. variabilis (n = 2), Lichtheimia ramosa (n = 3) and Mucor circinelloides f. lusitanicus (n = 2). Amplified fragment length polymorphism analysis was done to genotype Rhizopus isolates and revealed 5 clusters of R. arrhizus, which were well separated from R. microsporus. Amphotericin B was the most potent antifungal followed by posaconazole, itraconazole and isavuconazole. Etest and CLSI MICs of amphotericin B showed 87% agreement. Overall, the commonest underlying condition was uncontrolled diabetes mellitus. Records of 54 patients revealed fatalities in 28 cases.