Evaluation of Gradient Concentration Strips for Detection of Terbinafine Resistance in Trichophyton spp.

The number of dermatophytosis cases resistant to terbinafine is increasing all over the world. Therefore, there is a need for antifungal susceptibility testing of dermatophytes for better management of the patients. In the present study, we have evaluated a gradient test (GT) method for testing the susceptibility of dermatophytes to terbinafine. MIC values to terbinafine determined by the EUCAST reference technique and by gradient test were compared for 79 Trichophyton spp. isolates. Overall, MICs were lower with gradient test (MIC50 of 0.002 µg/mL) than with EUCAST (MIC50 of 0.016 µg/mL). Good categorical agreement (>90%) between the 2 techniques was obtained but the essential agreement was variable depending on the batch of gradient test.

Reliability of a terbinafine agar containing method for the screening of dermatophyte resistance.

The increase in terbinafine resistance worldwide due to Trichophyton indotineae underlies the need for surveillance networks, deploying easy to perform methods to correctly identify resistant isolates and thereby reduce their spread. In the present study, we evaluated the performances of the terbinafine containing agar method (TCAM). Different technical parameters, such as culture medium (RPMI agar [RPMIA] or Sabouraud dextrose agar [SDA]) and inoculum size, were evaluated. Our study showed that terbinafine susceptibility determined using the TCAM was reliable and independent of the inoculum or medium used. We then performed a multicenter, blinded study. 5 isolates of T. indotineae and 15 of genotype I or II of T. interdigitale, including 5 terbinafine-resistant isolates (4 T. indotineae and 1 T. interdigitale), were sent to eight clinical microbiology laboratories. Each laboratory analyzed the 20 isolates' terbinafine susceptibility by the TCAM using both culture media. TCAM allowed all participants to correctly determine the terbinafine susceptibility of analyzed isolates without prior training. All participants agreed that the dermatophyte tested, regardless of species or genotype, grew better on SDA than on RPMIA medium but accumulated fungal growth after 14 days eventually minimized the effect of this difference. In conclusion, TCAM is a reliable, easy to perform screening method for assessing terbinafine resistance. However, despite good performances, TCAM is a qualitative method and minimal inhibitory concentrations must be determined by the European Committee for Antimicrobial Susceptibility Testing standardized method to follow the evolution of terbinafine resistance levels.

The increase in terbinafine resistance worldwide due to Trichophyton indotineae underlies the need for surveillance networks. The terbinafine containing agar method is a reliable and easy-to-use tool in clinical microbiology laboratories. It can be used to rapidly screening resistant isolates, thereby reducing their spread.

Severe Scabies: A French Multi-centre Study Involving 95 Patients with Crusted and Profuse Disease and Review of the Literature.

The aim of this multi-centre French retrospective study was to identify severe, i.e. crusted and profuse, scabies patients. Records were retrieved from 22 Dermatology or Infectious Diseases departments in the Ile-de-France from January 2009 to January 2015 to characterize epidemiology, demography, diagnosis, contributing factors, treatment features, and outcomes in severe scabies. A total of 95 inpatients (57 crusted and 38 profuse) were included. A higher number of cases was observed among elderly patients (>75 years), mostly living in institutions. Thirteen patients (13.6%) reported a history of previously treated scabies. Sixty-three patients (66.3%) had been seen by a previous practitioner for the current episode (up to 8 previous visits). Initial misdiagnosis (e.g. eczema, prurigo, drug-related eruptions, psoriasis) was documented in 41 patients (43.1%). Fifty-eight patients (61%) had already received 1 or more previous treatments for their current episode. Forty percent received corticosteroids or acitretin for an initial diagnosis of eczema or psoriasis. Median time from the onset of symptoms to the diagnosis of severe scabies was 3 months (range 0.3-22). Itch was present in all patients at diagnosis. Most patients (n=84, 88.4%) had comorbidities. Diagnostic and therapeutic approaches varied. Complications occurred in 11.5% of cases. To date, there is no consensus for diagnosis and treatment, and future standardization of is required for optimal management.

Toxoplasmosis as an Early Complication of Allogeneic Hematopoietic Cell Transplantation.

Among 419 consecutive allogeneic hematopoietic cell transplant recipients, we observed 17 (4.0%) cases of toxoplasmosis at a median time of day 45 (range, 6 to 322) after transplant. Seven of these 17 cases occurred before day 30 after transplant. Because of the lack of PCR screening and trimethoprim-sulfamethoxazole prophylaxis before engraftment, the diagnosis of toxoplasmosis was late, and 5 of these 7 patients died. Analyzing these cases, early Toxoplasma blood PCR screening, starting from transplant, is crucial.

Aspergillus pseudodeflectus: a new human pathogen in liver transplant patients.

BACKGROUND: Liver transplant recipients are at high risk of developing invasive aspergillosis and in particular by Aspergillus fumigatus which is the most commonly encountered species in this population. Other non-fumigatus Aspergillus species with reduced susceptibility to antifungal drugs can also be involved. Accurate identification associated to antifungal susceptibility testing is essential for therapy adjustment. We report a case of invasive pulmonary aspergillosis due to Aspergillus pseudodeflectus in a liver transplant recipient. To our knowledge, this is the first reported case of invasive aspergillosis due to this species with a reduced susceptibility to azoles. CASE PRESENTATION: A 64 year-old woman with drug-induced fulminant hepatitis underwent liver transplantation. Prophylactic treatment with caspofungin was introduced due to aspergillosis risk factors consisting in hemodialysis and fulminant hepatitis. Six weeks after transplantation, CT scan showed a right pulmonary opacity associated with an increase of galactomannan (index 5.4). Culture of BAL grew with several colonies of Aspergillus sp. The diagnosis of invasive aspergillosis was probable according to the EORTC criteria. The antifungal susceptibility tests (Etest®) revealed low MICs to echinocandins and amphotericin B) but high MICs to azoles. After these results, voriconazole was switched to liposomal amphotericin B. The patient died one month after diagnosis from a refractory septic shock with multiple organ failure. A molecular identification of isolate, based on partial ß-tubulin and calmodulin genes, was performed and identified A. pseudodeflectus. CONCLUSIONS: Our case raises the question of pathogenicity of this species, which belongs to Aspergillus section Usti and is genetically and morphologically very close to Aspergillus calidoustus that was previously reported in human transplant recipients.

Echinocandin Resistance in Candida Species Isolates from Liver Transplant Recipients.

Liver transplant recipients are at risk of invasive fungal infections, especially candidiasis. Echinocandin is recommended as prophylactic treatment but is increasingly associated with resistance. Our aim was to assess echinocandin drug resistance in Candida spp. isolated from liver transplant recipients treated with this antifungal class. For this, all liver-transplanted patients in a University Hospital (Créteil, France) between January and June of 2013 and 2015 were included. Susceptibilities of Candida isolates to echinocandins were tested by Etest and the EUCAST reference method. Isolates were analyzed by FKS sequencing and genotyped based on microsatellites or multilocus sequence typing (MLST) profiles. Ninety-four patients were included, and 39 patients were colonized or infected and treated with echinocandin. Echinocandin resistance appeared in 3 (8%) of the treated patients within 1 month of treatment. One patient was colonized by resistant Candida glabrata, one by resistant Candida dubliniensis, and one by resistant Candida albicans Molecular analysis found three mutations in FKS2 HS1 (F659S, S663A, and D666E) for C. glabrata and one mutation in FKS1 HS1 (S645P) for C. dubliniensis and C. albicans Susceptible and resistant isolates belonged to the same genotype. To our knowledge, this is the first study on echinocandin resistance in Candida spp. in a liver transplant population. Most resistant isolates were found around/in digestive sites, perhaps due to lower diffusion of echinocandin in these sites. This work documents the risk of emergence of resistance to echinocandin, even after short-term treatment.

Correlation Between Pneumocystis jirovecii Mitochondrial Genotypes and High and Low Fungal Loads Assessed by Single Nucleotide Primer Extension Assay and Quantitative Real-Time PCR.

We designed a single nucleotide primer extension (SNaPshot) assay for Pneumocystis jirovecii genotyping, targeting mt85 SNP of the mitochondrial large subunit ribosomal RNA locus, to improve minority allele detection. We then analyzed 133 consecutive bronchoalveolar lavage (BAL) fluids tested positive for P. jirovecii DNA by quantitative real-time PCR, obtained from two hospitals in different locations (Hospital 1 [n = 95] and Hospital 2 [n = 38]). We detected three different alleles, either singly (mt85C: 39.1%; mt85T: 24.1%; mt85A: 9.8%) or together (27%), and an association between P. jirovecii mt85 genotype and the patient's place of hospitalization (p = 0.011). The lowest fungal loads (median = 0.82 × 10(3) copies/µl; range: 15-11 × 10(3) ) were associated with mt85A and the highest (median = 1.4 × 10(6) copies/µl; range: 17 × 10(3) -1.3 × 10(7) ) with mt85CTA (p = 0.010). The ratios of the various alleles differed between the 36 mixed-genotype samples. In tests of serial BALs (median: 20 d; range 4-525) from six patients with mixed genotypes, allele ratio changes were observed five times and genotype replacement once. Therefore, allele ratio changes seem more frequent than genotype replacement when using a SNaPshot assay more sensitive for detecting minority alleles than Sanger sequencing. Moreover, because microscopy detects only high fungal loads, the selection of microscopy-positive samples may miss genotypes associated with low loads.

High diversity of non-sporulating moulds in respiratory specimens of immunocompromised patients: should all the species be reported when diagnosing invasive aspergillosis?

Non-sporulating moulds (NSMs) isolated from respiratory specimens are usually discarded without further testing although they may have pathogenic effects in immunocompromised patients. The objective of this study was to determine the identity and frequency of NSMs in patients with haematological malignancies. We analysed the mycological results of 251 consecutive respiratory samples from 104 haematology patients. Yeast and sporulating moulds were identified at the genus/species level according to their phenotypic features. NSMs were identified by internal transcribed spacer (ITS) sequencing. We detected 179 positive samples, of which 10.1% (18/179) were mixtures of moulds and 26.3% (47/179) were mixtures of moulds and yeast. We identified 142 moulds belonging to 11 different genera/species or groups, with Aspergillus fumigatus (n = 50), Penicillium spp. (n = 31) and NSM (n = 24) being the most frequently isolated species. Twenty-two NSMs were successfully sequenced: 18 were basidiomycetes and six were ascomycetes, corresponding to 16 different genera/species. NSMs were isolated with A. fumigatus in the same sample or in a subsequent sample in five patients with probable invasive aspergillosis. The conclusion is that the respiratory specimens of immunocompromised patients frequently contain very diverse mould species that may increase the virulence of pathogenic species. Reporting all mould species isolated when diagnosing invasive fungal infection could test this hypothesis.

An axillary skin lesion revealing disseminated paracoccidioidomycosis.

Paracoccidioidomycosis, uncommon in Europe, primarily affects South America travellers. We report a 58-year-old Colombian man, who has lived in France for 20 years, presented with an axillary skin lesion seven years after his last trip to Colombia. The diagnosis of paracoccidioidomycosis was established using histopathological, mycological, and molecular analyses.

Association between circulating DNA, serum (1->3)-ß-D-glucan, and pulmonary fungal burden in Pneumocystis pneumonia.

Circulating Pneumocystis jirovecii DNA and (1→3)-ß-d-glucan determined in 70 serum samples from immunocompromised patients were compared to fungal load in bronchoalveolar lavage fluids assessed using quantitative polymerase chain reaction. Both serum biomarkers are influenced by pulmonary fungal load, which should be taken into account when diagnosing Pneumocystis infection.

Clinical significance of quantifying Pneumocystis jirovecii DNA by using real-time PCR in bronchoalveolar lavage fluid from immunocompromised patients.

Quantitative PCR (qPCR) is more sensitive than microscopy for detecting Pneumocystis jirovecii in bronchoalveolar lavage (BAL) fluid. We therefore developed a qPCR assay and compared the results with those of a routine immunofluorescence assay (IFA) and clinical data. The assay included automated DNA extraction, amplification of the mitochondrial large-subunit rRNA gene and an internal control, and quantification of copy numbers with the help of a plasmid clone. We studied 353 consecutive BAL fluids obtained for investigation of unexplained fever and/or pneumonia in 287 immunocompromised patients. No qPCR inhibition was observed. Seventeen (5%) samples were both IFA and qPCR positive, 63 (18%) were IFA negative and qPCR positive, and 273 (77%) were both IFA and qPCR negative. The copy number was significantly higher for IFA-positive/qPCR-positive samples than for IFA-negative/qPCR-positive samples (4.2 ± 1.2 versus 1.1 ± 1.1 log(10) copies/µl; P < 10(-4)). With IFA as the standard, the qPCR assay sensitivity was 100% for ≥2.6 log(10) copies/µl and the specificity was 100% for ≥4 log(10) copies/µl. Since qPCR results were not available at the time of decision-making, these findings did not trigger cotrimoxazole therapy. Patients with systemic inflammatory diseases and IFA-negative/qPCR-positive BAL fluid had a worse 1-year survival rate than those with IFA-negative/qPCR-negative results (P < 10(-3)), in contrast with solid-organ transplant recipients (P = 0.88) and patients with hematological malignancy (P = 0.26). Quantifying P. jirovecii DNA in BAL fluids independently of IFA positivity should be incorporated into the investigation of pneumonia in immunocompromised patients. The relevant threshold remains to be determined and may vary according to the underlying disease.

Trichophyton bullosum: a new zoonotic dermatophyte species.

We report the first human case of dermatophytosis caused by Trichophyton bullosum in a 21-year-old male who had a skin lesion located on his forearm. The dermatophyte was isolated in culture and further identified by sequence analysis of internal transcripted spacer regions. The species T. bullosum is a zoophilic dermatophyte rarely isolated from the coat of horses in Africa and Asia. In the present case, it was probably transmitted by contact with an infected donkey in a rural area in France. Antifungal therapy led to remission of the lesion in the patient after 2 months of treatment. T. bullosum ITS region sequences were closely related to those of the African species of Arthroderma benhamiae and grouped in a zoophilic cluster with Trichophyton verrucosum, T. erinacei and the Trichophyton anamorph of A. benhamiae (zoophilic species of the T. mentagrophytes complex). Systematic molecular identification could contribute to an accurate identification of this unusual species.

Terbinafine Resistance in Dermatophytes: A French Multicenter Prospective Study.

In recent years, we have moved from the sporadic description of terbinafine-resistant (TerR) Trichophyton spp. isolates to the Indian outbreak due to T. indotineae. Population flows have spread TerR worldwide, altering local epidemiology. We conducted a prospective multicentric study to determine the relative frequency of TerR isolates in France (Paris area) and of the newly introduced T. indotineae species. TerR isolates were screened by the terbinafine-containing-agar-medium (TCAM) method and confirmed by EUCAST. Sequencing methods were used to identify isolates to the species/genotype level and to analyze substitutions in the squalene epoxidase gene (SQLE). In total, 3 isolates out of 580 (T. rubrumn = 1; T. interdigitalen = 1; T. indotineaen = 1) grew on TCAM, showed terbinafine resistance by EUCAST and harbored the Phe397Leu (n = 2) or Leu393Ser (n = 1) substitution in the SQLE. ITS-sequencing of isolates of the T. mentagrophytes/interdigitale complex (n = 125) revealed a relative frequency of 4.8% for T. indotineae and the presence of T. mentagrophytes genotype VII. Despite the detection of terbinafine resistance, isolates from this complex remained susceptible to itraconazole, voriconazole and amorolfine. Terbinafine resistance is present in France and the dermatophyte epidemiology is changing. Efficient systems must be implemented to survey the evolution of newly introduced species and to identify TerR isolates.

MALDI-TOF Mass Spectrometry Online Identification of Trichophyton indotineae Using the MSI-2 Application.

Trichophyton indotineae is an emerging pathogen which recently spread from India to Europe and that is more prone than other species of the Trichophyton mentagrophytes complex to show resistance to terbinafine, resulting in the necessity of rapid identification. Here, we improved the online MSI-2 MALDI-TOF identification tool in order to identify T. indotineae. By multiplying the culture conditions (2 culture media and 6 stages of growth) prior to protein extractions for both test isolates and reference strains, we added 142 references corresponding to 12 strains inside the T. mentagrophytes complex in the online MSI-2 database, of which 3 are T. indotineae strains. The resulting database was tested with 1566 spectra of 67 isolates from the T. mentagrophytes complex, including 16 T. indotineae isolates. Using the newly improved MSI-2 database, we increased the identification rate of T. indotineae from 5% to 96%, with a sensitivity of 99.6%. We also identified specific peaks (6834/6845 daltons and 10,634/10,680 daltons) allowing for the distinction of T. indotineae from the other species of the complex. Our improved version of the MSI-2 application allows for the identification of T. indotineae. This will improve the epidemiological knowledge of the spread of this species throughout the world and will help to improve patient care.

Cytochrome b gene quantitative PCR for diagnosing Plasmodium falciparum infection in travelers.

A cytochrome b (cytb) gene quantitative PCR (qPCR) assay was developed to diagnose malaria in travelers. First, manual and automated DNA extractions were compared and automated DNA extraction of 400 µl of blood was found to be more efficient. Sensitivity was estimated using the WHO international standard for Plasmodium falciparum DNA and compared to that of a previously published qPCR targeting the 18S rRNA coding gene (18S qPCR). The limit of detection of the cytb qPCR assay was 20 DNA copies (i.e., 1 parasite equivalent) per 400 µl of extracted whole blood and was comparable for the two qPCR assays. Both qPCR assays were used on blood samples from 265 consecutive patients seen for suspicion of malaria. There were no microscopy-positive and qPCR-negative samples. Positive cytb qPCR results were observed for 51 samples, and all but 1 were also 18S qPCR positive. Eight (16%) of these 51 samples were negative by microscopic examination. The 8 cytb qPCR-positive and microscopy-negative samples were from African patients, 3 of whom had received antimalarial drugs. Three non-P. falciparum infections were correctly identified using an additional qPCR assay. The absence of PCR inhibitors was tested for by the use of an internal control of mouse DNA to allow reliable quantification of circulating DNA. The high analytical sensitivity of both qPCR assays combined with automated DNA extraction supports its use as a laboratory tool for diagnosis and parasitemia determination in emergencies. Whether to treat qPCR-positive and microscopy-negative patients remains to be determined.

Low prevalence of resistance to azoles in Aspergillus fumigatus in a French cohort of patients treated for haematological malignancies.

OBJECTIVES: An increase in invasive aspergillosis (IA) due to azole-resistant Aspergillus fumigatus isolates has been reported for 10 years. Our study aimed to estimate the prevalence of azole resistance in isolates prospectively collected in patients with haematological diseases. METHODS: One hundred and eighteen isolates were collected from 89 consecutive patients over 4 years. Fifty-one patients had proven or probable IA. Species identification was ascertained based on ß-tubulin gene sequencing. The MICs of azole drugs were determined using Etest(®), and the cyp51A gene and its promoter were sequenced to detect mutations. RESULTS: All isolates were identified as A. fumigatus and all of them but one had itraconazole and voriconazole MICs of ≤ 2 mg/L and posaconazole MICs of ≤ 0.25 mg/L. An isolate for which the itraconazole MIC was high (itraconazole MIC = 16 mg/L; voriconazole MIC = 0.38 mg/L; and posaconazole MIC = 0.25 mg/L) was recovered from a patient naive to azole treatment and had a new G432S substitution. To establish whether this mutation existed in other isolates, the 1426-2025 bp cyp51A locus was sequenced for all. G432S was not found. CONCLUSIONS: In A. fumigatus, the prevalence of azole resistance is currently low in the haematological population in the Paris area. Surveillance programmes for azole resistance to adapt antifungal treatments are warranted for clinical isolates of A. fumigatus.

Microsporum praecox: molecular identification of a new case and review of the literature.

We report a rare case of dermatophytosis due to Microsporum praecox in a 28-year-old female horse rider. The skin lesion was located on the right external malleolus. Microscopic examination of skin scrapings revealed a dermatophyte which was also isolated in culture. The identification of M. praecox was confirmed by molecular biology (sequence analysis of PCR products amplified from internal transcribed spacer regions with universal primers). Combined antifungal therapy with oral terbinafine and topical cyclopiroxolamide resulted in complete remission of the fungal lesion within 1 month. Since 1944, only 29 cases of human M. praecox infection have been reported in the literature. The clinical features and treatment of these cases are reviewed. The prevalence of M. praecox infection is probably underestimated, and systematic molecular identification could improve our understanding of the epidemiology of this fungal dermatosis.

Empirical versus preemptive antifungal therapy for high-risk, febrile, neutropenic patients: a randomized, controlled trial.

BACKGROUND: Empirical antifungal therapy is the standard of care for neutropenic patients with hematological malignancies who remain febrile despite broad-spectrum antibacterial treatment. Recent diagnostic improvements may ensure the early diagnosis of potentially invasive fungal disease. Reserving antifungals for this stage may achieve similar survival rates and reduce treatment toxicity and costs. METHODS: In this multicenter, open-label, randomized noninferiority trial, we compared an empirical antifungal strategy with a preemptive one. Empirical treatment was defined as antibacterial treatment of patients who have persistent or recurrent fever. Preemptive treatment was defined as treatment of patients who have clinical, imaging, or galactomannan-antigen-assay evidence suggesting fungal disease. First-line antifungal treatment was amphotericin B deoxycholate (1 mg/kg/day) or liposomal amphotericin (3 mg/kg/day), depending on daily renal function. The primary efficacy outcome was the proportion of patients alive at 14 days after recovery from neutropenia. RESULTS: The median duration of neutropenia (neutrophil count, <500 cells/mm3) for the 293 patients enrolled was 18 days (range, 5-69 days). By intention-to-treat analysis, survival was 97.3% with empirical treatment and 95.1% with preemptive treatment. The lower 95% confidence limit for the difference in mortality was -5.9%, which was within the noninferiority margin of -8%. Probable or proven invasive fungal infections were more common among patients who received preemptive treatment than among patients who received empirical treatment (13 of 143 vs. 4 of 150; P < .05), and most infections occurred during induction therapy (12 of 73 patients in the preemptive treatment group vs. 3 of 78 patients in the empirical treatment group were infected during induction therapy; P < .01). Preemptive treatment did not decrease nephrotoxicity but decreased costs of antifungal therapy by 35%. CONCLUSIONS: Preemptive treatment increased the incidence of invasive fungal disease, without increasing mortality, and decreased the costs of antifungal drugs. Empirical treatment may provide better survival rates for patients receiving induction chemotherapy.

Concomitant Presence of Aspergillus Species and Mycobacterium Species in the Respiratory Tract of Patients: Underestimated Co-occurrence?

OBJECTIVES: Aspergillus and Mycobacterium are opportunistic pathogens that can cause severe pulmonary diseases. To date, the clinical significance of their concomitant isolation and potential interactions in the lung remains poorly understood. The aim of this study was to assess the prevalence of their concomitant isolation from respiratory samples, and to depict the related clinical and microbiological characteristics. METHODS: A retrospective monocentric study was conducted from January 2011 to December 2017, including all in-patients from whom positive cultures of Aspergillus and Mycobacterium were obtained on respiratory samples within a 3-month period. Clinical, radiological and laboratory data were analyzed. Patients were categorized by a clinical and microbiological committee as "infected" or "colonized" by both pathogens according to current guidelines. RESULTS: Overall, 140 patients had ≥1 respiratory samples positive for Mycobacterium and concomitantly sent for fungal culture, and 708 were positive for Aspergillus, concomitantly sent for mycobacterial culture. Only 50 had at least one positive culture for both Mycobacterium sp. and Aspergillus sp. Men represented 63% of patients, mean age was 61 years. A third of patients were immunocompromised and 92% had underlying lung diseases. Aspergillus was primarily found as a colonizing agent. Proportion of Mycobacterium Avium Complex (p = 0.02) was higher in patients co-carrying Aspergillus spp. CONCLUSION: In this first study focusing on co-isolation of Mycobacteria and Aspergillus in patient's respiratory samples, co-infection remains rare. Further studies are warranted in order to precise the exact relationship between these opportunistic pathogens and the clinical impact of co-isolations.