Viability predictive factors of the daughter vesicles in hepatic cystic echinococcosis.

INTRODUCTION: Management of cystic echinococcosis (CE) requires knowledge of certain aspects related to the survival of Echinococcus granulosus. The viability of daughter vesicles (DV) is a determining factor in guiding therapeutic indications, particularly for transiently active Cysts type CE3b. PURPOSE: To determine the predictive factors of DV viability and its impact on the therapeutic management of CE3b type. MATERIALS AND METHODS: This is a prospective pilot study with an analytical aim on patients with cystic echinococcosis of the liver type CE2 and CE3b, operated in the General Surgery Department of Habib-Bourguiba Academic Hospital, Sfax-Tunisia for 22 months from March 2018 until December 2019. The unit of the study is the DV. A parasitological study of the DV was done in the parasitology laboratory. RESULTS: During the study period, 27 (40.9%) of 66 operated CE Disease from 21 patients containing 248 DV were explored. The median viability of DV protoscoleces was 16.7%. In bivariate analysis, factors for viability of DV protoscoleces were: fever, acute cholangitis, hyperbilirubinemia, left liver location, rock water and bilious echinococcal fluid (EF), cyst size ≥ 43 mm, Intracystic pressure ≥ 35 mmHg, DV size ≥ 6.5 mm, volume, number of DV/cyst ≥ 5, and opaque wall (p < 0.05). Predictive factors for the Non-viability of DV were: CE3b type, purulent EF, gelatinous EF. In multivariate analysis, only CE2 type, cyst size ≥ 43 mm, number of DV/cyst ≥ 5 and DV size ≥ 6.5 mm were factors significantly associated with the viability of DV protoscoleces. CONCLUSION: CE3b cysts without the criteria of viability of DV protoscoleces may become candidates for the 'Wait-and-Watch' procedure.

A case of pediatric primary osteolytic extradural and complicated hydatid cyst revealed by a skull vault swelling.

Hydatidosis is a parasitic infestation whose etiological agent is the larva of the cestode Echinococcus granulosus. It is a zoonosis, and the human being behaves as an accidental intermediate host in the parasitic cycle with pediatric predominance. The most frequent clinical presentation is hepatic, followed by pulmonary, with cerebral hydatidosis being extremely rare. Imaging is characteristic, generally dealing with single cystic lesion, usually unilocular and less frequently multilocular, located mainly intraaxially. Extradural hydatid cyst, whether primary or secondary, remains very rare or even exceptional. The primary disease remains extremely rare, and its clinical picture is related to the number, size, and location of the lesions. Infection within these cerebral hydatid cysts remains an extremely rare occurrence, and only few cases were reported previously in the literature. The authors report the nosological review of the clinical, imaging, surgical, and histopathological records of a pediatric primary osteolytic extradural and complicated hydatid cyst in a 5-year-old North African male patient coming from a rural area who presented for progressive onset of a painless left parieto-occipital soft swelling without any neurological disorder with good outcomes after surgery. The authors report this case due the fact that it had not been documented before in the pediatric population and to the success of the specialized treatment.

Early postoperative intra-axial dissemination of a pediatric extradural and complicated hydatid cyst.

Hydatid disease is very common around the Mediterranean basin and endemic in some parts of the world. Cerebral involvement remains rare, represents only about 2% of all hydatid localizations and mainly affects the pediatric population. Extradural hydatid cyst is very rare or even exceptional when it is associated with or followed by intracerebral disseminations. Here, the authors report a new exceptional case of an early multiple intra-axial hydatid dissemination in a 5-year-old North African male patient from a rural area who underwent surgery 3 months after a primary osteolytic extradural and complicated hydatid cyst with good clinical and radiological outcomes.

Molecular epidemiology of a Malassezia pachydermatis neonatal unit outbreak.

The non-lipid-dependent yeast Malassezia pachydermatis is predominantly zoophilic but occasionally colonizes the human skin. This yeast caused an outbreak in a neonatal iIntensive care unit (NICU). This study aimed to describe the molecular epidemiology of this M. pachydermatis outbreak. All the M. pachydermatis isolates collected at a French University Hospital from January 2012 to April 2013 were included in the study. M. pachydermatis isolates, sampled from various biological samples sites in 25 patients, were identified via MALDI-TOF mass spectrometry and typed using intergenic-spacer 1 (IGS1) nucleotide sequence polymorphisms analysis. By analyzing 90 IGS1 sequences (including 43 deposited in GenBank), we found that of the 186 M. pachydermatis isolates, 47 were viable for typing and all of them clustered within type 3; 78.7% clustered within the 3D subtype; the remaining clustered within three newly described subtypes: 3E (4.3%), 3F (8.5%) and 3 G (8.5%). No particular subtype was associated with a collection site or a particular time period. This first molecular investigation of a M. pachydermatis outbreak in neonates showed that multiple genotypes can colonize the same neonate patient by. The source of this polyclonal outbreak could not be identified. It stopped after infection control measures, including the prohibition of a lipid-rich moisturizing hand cream used by the health care staff, had been implemented.

Molecular Genotyping of Candida parapsilosis Species Complex.

BACKGROUND: The Candida parapsilosis complex species has emerged as an important cause of human disease. The molecular identification of C. parapsilosis isolates at the species level can be helpful for epidemiological studies and then for the establishment of appropriate therapies and prophylactic measures. METHODS: The present study was undertaken to analyze 13 short tandem repeat (STR) markers (7 minisatellites and 6 microsatellites) in a global set of 182 C. parapsilosis complex isolates from different origins including invasive and superficial clinical sites. RESULTS: Upon the analysis of 182 strains of C. parapsilosis complex species, 10-17 haplotypes were detected for each minisatellite marker. The combination of 7 minisatellite markers yielded 121 different genotypes with a 0.995 D value. Upon the analysis of 114 isolates (68 from invasive infections and 46 from superficial infections), 21-32 genotypes were detected for each microsatellite marker. The combination of all 13 markers yielded 96 different genotypes among 114 isolates with a high degree of discrimination (0.997 D value). The same multilocus genotype was shared by isolates recovered from some patients and from the hand of theirs correspondent healthcare worker. For another patient, the same multilocus genotype of C. metapsilosis was detected in blood and skin confirming that candidemia usually arises as an endogenous infection following prior colonization. CONCLUSIONS: These STR markers are a valuable tool for the differentiation of C. parapsilosis complex strains, to support epidemiological investigations especially studies of strain relatedness and pathways of transmission.

Virulence factors, antifungal susceptibility and molecular mechanisms of azole resistance among Candida parapsilosis complex isolates recovered from clinical specimens.

BACKGROUND: The aim of this study was to determine the biofilm formation, the extracellular enzymatic activities of 182 clinical isolates of the Candida parapsilosis complex. METHODS: Molecular identification of the C. parapsilosis species complex was performed using PCR RFLP of SADH gene and PCR sequencing of ITS region. The susceptibility of ours isolates to antifungal agents and molecular mechanisms underlying azole resistance were evaluated. RESULTS: 63.5% of C. parapsilosis were phospholipase positive with moderate activity for the majority of strains. None of the C. metapsilosis or C. orthopsilosis isolates was able to produce phospholipase. Higher caseinase activities were detected in C. parapsilosis (Pz = 0.5 ± 0.18) and C. orthopsilosis (Pz = 0.49 ± 0.07) than in C. metapsilosis isolates (Pz = 0.72 ± 0.1). 96.5% of C. parapsilosis strains and all isolates of C. metapsilosis and C. orthopsilosis produced gelatinase. All the strains possessed the ability to show haemolysis on blood agar. C. metapsilosis exhibited the low haemolysin production with statistical significant differences compared to C. parapsilosis and C. orthopsilosis. The biofilm forming ability of C. parapsilosis was highly strain dependent with important heterogeneity, which was less evident with both C. orthopsilosis and C. metapsilosis. Some C. parapsilosis isolates met the criterion for susceptible dose dependent to fluconazole (10.91%), itraconazole (16.36%) and voriconazole (7.27%). Moreover, 5.45% and 1.82% of C. parapsilosis isolates were respectively resistant to fluconazole and voriconazole. All strains of C. metapsilosis and C. orthopsilosis were susceptible to azoles; and isolates of all three species exhibited 100% of susceptibility to caspofungin, amphotericin B and 5-flucytosine. CONCLUSIONS: A combination of molecular mechanisms, including the overexpression of ERG11, and genes encoding efflux pumps (CDR1, MDR1, and MRR1) were involved in azole resistance in C. parapsilosis.

Molecular study of the Candida parapsilosis complex in Sfax, Tunisia.

Candida parapsilosis, which was previously considered to be a complex of three genetically distinct groups, has emerged as a significant agent of nosocomial infections. Recently, this complex was separated into three species: C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis In Tunisia, data pertaining to these fungi are limited. Thus, the purpose of our study was to determine by BanI PCR-RFLP and ITS sequencing, the occurrence of Candida parapsilosis complex among 182 isolates identified as C. parapsilosis by phenotypical methods. C. parapsilosis sensu stricto represented 94.5% of all isolates, while C. metapsilosis and. C. orthopsilosis were identified in 3.3% and 2.2%, respectively. Sequence analysis of internal transcribed spacer region confirmed and revealed only one genotype among the C. parapsilosis sensu stricto strains, three genotypes among six C. metapsilosis strains and two genotypes among four C. orthopsilosis strains.

Real-Time PCR Identification of Six Malassezia Species.

Lipophilic yeast Malassezia species is widely found on the skin surface of humans and other animals. This fungus can cause pityriasis versicolor, Malassezia folliculitis, and seborrheic dermatitis. Still now, there is a problem with species identification of Malassezia with conventional methods. We developed a real-time polymerase chain reaction (PCR) assay with multiple hybridization probes for detecting M. globosa, M. furfur, M. restricta, M. sympodialis, M. slooffiae, and M. pachydermatis. The amplification curves and specific melting peaks of the probes hybridized with real-time PCR product were used for species identifications. The assay was further evaluated on 120 samples which were performed by swabbing from 60 domestic animals (23 goats, 10 dogs, 15 cows, 3 cats, 8 rabbits, and 1 donkey) and in 70 human samples (28 patients with pityriasis versicolor, 17 breeders, and 25 control group). Fifteen M. pachydermatis were identified from animals. From human, 61 isolates were identified as M. globosa (28), M. furfur (15), M. restricta (6), M. sympodialis (8), M. slooffiae (2), and M. pachydermatis (2). Eight cases of co-detection from 6 patients and 2 breeders were revealed. Our findings show that the assay was highly effective in identifying Malassezia species. The application of multiplex real-time PCR provides a sensitive and rapid identification system for Malassezia species, which may be applied in further epidemiological surveys from clinical samples.

Molecular characterization of strains of the Trichophyton verrucosum complex from Tunisia.

Trichophyton verrucosum is the most frequent etiologic agent of cattle dermatophytosis. Throughout the world, it was the second most common agent of zoophilic dermatophytes in human. The aim of our study was to evaluate the efficacy of the PCR- RFLP and PCR-sequencing methods for the identification and differentiation of T. verrucosum strains.Thirty-six clinical strains identified by morphological characteristics as T. verrucosum were isolated from patients referred to parasitology-mycology laboratory of Sfax University Hospital. Identification of our strains by conventional methods was confirmed by molecular methods in 94.4% of cases. Two strains were reclassified as T. violaceum PCR products digested with HinfI produced three profiles and two patterns with MvaI. Sequence analysis revealed a polymorphism in the ITS1and 5.8S regions. Analysis and alignment of consensus sequences has distinguished two types of genotypes among our T. verrucosum strains. The ITS type I was the dominant genotype (93.7%). Phylogenetic study showed that one cluster comprised T. verrucosum strains with ITS type I and species of T. mentagrophytes complex. It was related to Arthroderma vanbreuseghemii complex. The other cluster contained the two T. verrucosum strains with ITS type II, and was related to Arthroderma benhamiae complex. In this study, most of T. verrucosum isolates were type I, dissimilar to others rare studies where type II has been the most common. Specie and strain differentiation is relevant because it helps in prescribing the correct treatment and determining the source of the infection.

Molluscicidal activity of Solanum elaeagnifolium seeds against Galba truncatula intermediate host of Fasciola hepatica: Identification of ß-solamarine.

CONTEXT: The persistence of fascioliasis in many developing countries urges the search for simple, cheap, and effective substances. In this view, plants provide interesting molluscicidal activities thanks to the secondary metabolites they produce. The genus Solanum is known for its potent effect on vector snails. OBJECTIVE: The molluscicidal activity of Solanum elaeagnifolium Cav. (Solanaceae) seeds against Galba truncatula Müll. (Lymnaeidae), intermediate host of Fasciola hepatica L. (Fasciolidae), was evaluated. MATERIALS AND METHODS: Solanum elaeagnifolium seeds were powdered and successively extracted using n-hexane, methylene chloride, acetone, and methanol, for 20 h each. After filtration, solvents were evaporated. An acid-base treatment was conducted on seed methanolic extract to isolate total alkaloids and ß-solamarine. Total saponins fraction was obtained after successive macerations and evaporations. The molluscicidal activity was evaluated by subjecting snails, in groups of 10, for 48 h to 500 mL of extracts, fractions, and pure product aqueous solutions, each containing amounts, ranging from 1 to 50 mg of plant material in 5 mg increments. RESULTS: The methanolic extract of seeds, ß-solamarine isolated for the first time from this plant and total saponins fraction showed very potent activities on snails, giving respective median lethal concentrations (LC50) of 1.18, 0.49, and 0.94 mg/L. Total alkaloids fraction obtained from the methanolic extract was less active giving an LC50 value of 14.67 mg/L. DISCUSSION AND CONCLUSION: This study emphasizes that glycoalkaloids and saponins of Solanum elaeagnifolium are potent molluscicidal agents. Seed methanolic extract, ß-solamarine, and total saponins fraction may be used as molluscicides.

Highly discriminatory variable-number tandem-repeat markers for genotyping of Trichophyton interdigitale strains.

Trichophyton interdigitale is the second most frequent cause of superficial fungal infections of various parts of the human body. Studying the population structure and genotype differentiation of T. interdigitale strains may lead to significant improvements in clinical practice. The present study aimed to develop and select suitable variable-number tandem-repeat (VNTR) markers for 92 clinical strains of T. interdigitale. On the basis of an analysis of four VNTR markers, four to eight distinct alleles were detected for each marker. The marker with the highest discriminatory power had eight alleles and a D value of 0.802. The combination of all four markers yielded a D value of 0.969 with 29 distinct multilocus genotypes. VNTR typing revealed the genetic diversity of the strains, identifying three populations according to their colonization sites. A correlation between phenotypic characteristics and multilocus genotypes was observed. Seven patients harbored T. interdigitale strains with different genotypes. Typing of clinical T. interdigitale samples by VNTR markers displayed excellent discriminatory power and 100% reproducibility.

Changes in genotype and fluconazole susceptibility of isolates from patients with Candida glabrata in Tunisia.

UNLABELLED: Candida glabrata has emerged as an opportunistic pathogen of considerable importance in invasive and superficial infections. AIMS: To analyze the development of fluconazole resistance in patients under treatment through epidemiological survey in our hospital. PATIENTS AND METHODS: Twenty two patients (89 clinical strains) were collected. Molecular typing of isolates was performed by polymorphic markers. Analysis of gene expression was realized by reverse transcriptase-real time polymerase chain reactions (RT-qPCR). RESULTS: Genetic analysis showed that 63% persists with apparently unchanged strains (n=14). Among them, four showed fluconazole resistance development. A strain replacement was observed in 6 patients and two patients selected more resistant isolates during the course of treatment. An analysis of Candida glabrata cerebellar degeneration-related protein 1 (CgCDR1), Candida glabrata cerebellar degeneration-related protein 2 (CgCDR2) and Candida glabrata sterol 14 alpha-demetylase Erg 11 (CgERG11) expression revealed an over-expression in 10 resistant isolates. CONCLUSION: This study demonstrated that C. glabrata strain undergo frequent changes in vivo. The increase in CgCDR1 and CgCDR2 expression was the most mechanism associated with fluconazole resistance.

Chronic blepharitis due to Demodex: A prospective study in Sfax (Tunisia).

INTRODUCTION: Chronic blepharitis is a common cause of eye irritation and dryness. They are often treated without regard to causal factors such as parasites which are rarely mentioned. AIM: To describe the role of Demodex in the pathogenesis of chronic blepharitis, to analyze the epidemiological, clinical, diagnostic and therapeutic particularities. METHODS: This is a prospective, case-control study conducted in the mycology parasitology department at the Habib Bourguiba university hospital in Sfax covering 100 cases with chronic blepharitis and 87 control cases. Clinical examination and eyelash removal were performed with direct examination for qualitative and quantitative analysis, before and after treatment. RESULTS: Demodex was significantly more found in patients than in controls (48% vs 13.8%). The quantitative analysis showed a significant difference between the two groups with 52.1% of Demodex (+++) for patients versus 8.3% for controls. Demodex blepharitis were treated with yellow oxid mercure ophthalmic ointment with a good outcome in 81,3%. CONCLUSION: Although it is admitted to be a saprophyte of the skin, a large number of arguments argues for the incrimination of Demodex in the etiopathogenesis of chronic blepharitis, hence the interest of eyelashes examination and a parasitic research in front of any chronic blepharitis resistant to usual treatments. In case of positive research, a specific treatment should be prescribed. Its effectiveness is another argument for the etiological diagnosis.

IMPatienT: An Integrated Web Application to Digitize, Process and Explore Multimodal PATIENt daTa.

Medical acts, such as imaging, lead to the production of various medical text reports that describe the relevant findings. This induces multimodality in patient data by combining image data with free-text and consequently, multimodal data have become central to drive research and improve diagnoses. However, the exploitation of patient data is problematic as the ecosystem of analysis tools is fragmented according to the type of data (images, text, genetics), the task (processing, exploration) and domain of interest (clinical phenotype, histology). To address the challenges, we developed IMPatienT (Integrated digital Multimodal PATIENt daTa), a simple, flexible and open-source web application to digitize, process and explore multimodal patient data. IMPatienT has a modular architecture allowing to: (i) create a standard vocabulary for a domain, (ii) digitize and process free-text data, (iii) annotate images and perform image segmentation, (iv) generate a visualization dashboard and provide diagnosis decision support. To demonstrate the advantages of IMPatienT, we present a use case on a corpus of 40 simulated muscle biopsy reports of congenital myopathy patients. As IMPatienT provides users with the ability to design their own vocabulary, it can be adapted to any research domain and can be used as a patient registry for exploratory data analysis. A demo instance of the application is available at https://impatient.lbgi.fr/.

Investigation of Azole Resistance Involving cyp51A and cyp51B Genes in Clinical Aspergillus flavus Isolates.

This study aimed to investigate azole resistance mechanisms in Aspergillus flavus, which involve cyp51A and cyp51B genes. Real-time Reverse Transcriptase qPCR method was applied to determine the overexpression of cyp51A and cyp51B genes for 34 A. flavus isolates. PCR sequencing of these two genes was used to detect the presence of gene mutations. Susceptibility test found sensitivity to voriconazole (VOR) in all strains. 14.7% and 8.8% of isolates were resistant to itraconazole (IT) and posaconazole (POS), respectively, with a cross-resistance in 5.8%. For the double resistant isolates (IT/POS), the expression of cyp51A was up to 17-fold higher. PCR sequencing showed the presence of 2 mutations in cyp51A: a synonymous point mutation (P61P) in eight isolates, which did not affect the structure of CYP51A protein, and another non synonymous mutation (G206L) for only the TN-33 strain (cross IT/POS resistance) causing an amino acid change in the protein sequence. However, we noted in cyp51B the presence of the only non-synonymous mutation (L177G) causing a change in amino acids in the protein sequence for the TN-31 strain, which exhibits IT/POS cross-resistance. A short single intron of 67 bp was identified in the cyp51A gene, whereas three short introns of 54, 53, and 160 bp were identified in the cyp51B gene. According to the models provided by PatchDock software, the presence of non-synonymous mutations did not affect the interaction of CYP51A and CYP51B proteins with antifungals. In our study, the overexpression of the cyp51A and cyp51B genes is the primary mechanism responsible for resistance in A. flavus collection. Nevertheless, other resistance mechanisms can be involved.

Microsatellite typing of Aspergillus flavus in patients with various clinical presentations of aspergillosis.

Aspergillus flavus is the second most important Aspergillus species associated with aspergillosis and the incidence of infections caused by it are increasing in the immunocompromised population. This species is of major epidemiological importance in regions with a dry and hot climate. Despite the growing clinical significance of A. flavus, data on its molecular epidemiology are scarce. This study was aimed at examining whether isolates from distinct genotypes were involved in distinct clinical forms of aspergillosis. Sixty-three clinical isolates of A. flavus recovered from 35 patients with various clinical presentations of aspergillosis were characterized by microsatellite typing. The highest discriminatory power for a single locus was obtained with the AFLA1 marker, which had 14 distinct alleles and a 0.903 D value. The combination of all six markers yielded 48 different genotypes with a 0.994 D value. There was a considerable genetic diversity in the isolates and patients with invasive aspergillosis were usually colonized by multiples genotypes. There was no evidence that a given genotype was associated with a particular clinical presentation of A. flavus aspergillosis. The occurrence of more than one genotype in clinical samples indicates that a patient may be infected by multiple genotypes and that any particular isolate from a clinical specimen may not necessarily be the one causing aspergillosis.

Genetic diversity of Pneumocystis jirovecii strains based on sequence variation of different DNA region.

Pneumocystis jirovecii is an important opportunistic pathogen that causes severe pneumonia in immunocompromised patients. The aim of the present study was to investigate the genetic diversity of P. jirovecii strains by direct sequencing and analysis of the Upstream Conserved Sequence (UCS) region, mitochondrial large-subunit (mtLSU) rRNA and dihydrofolate reductase (DHFR) genes. We identified the polymorphisms in P. jirovecii strains of 15 immunocompromised patients, as well as detecting a new tandem repeat of 5 nucleotides in UCS region. The following three different types of repeat unit were found: type a GCCCA; type b GCCCT; and type c GCCTT. In addition, we identified the repeat unit which consisted of 10 nucleotides and three different patterns of UCS repeats with 3 and 4 repeats, i.e., 1, 2, 3 (86.7%), 1, 2, 3, 3 (6.6%) and a new genotype 2, 2, 3, 3 (6.6%). The polymorphism in the mtLSUrRNA gene was seen primarily at position 85 where we detected three different genotypes. Genotype 3 and genotype 2 were the most abundant with frequencies of 53.3% and 40%, respectively. With regard to the DHFR gene, only two (20%) patients had nucleotide substitution in position 312. In conclusion, the multilocus analysis facilitated the typing of P. jirovecii strains and proved the important genetic biodiversity of this fungus.

Genotypic Analysis of the Population Structure in Malassezia globosa and Malassezia restricta.

The molecular characterization of Malassezia spp. isolates from animals and humans has not been thoroughly studied. Although a range of molecular methods has been developed for diagnosing Malassezia species, they have several drawbacks, such as inefficiency in differentiating all the species, high cost and questionable reproducibility. The present study aimed to develop VNTR markers for genotyping Malassezia isolated from clinical and animal samples. A total of 44 M. globosa and 24 M. restricta isolates were analyzed. Twelve VNTR markers were selected on seven different chromosomes (I, II, III, IV, V, VII and IX), six for each Malassezia species. The highest discriminatory power for a single locus was obtained with the STR-MG1 marker (0.829) and STR-MR2 marker (0.818) for M. globosa and M. restricta, respectively. After the analysis of multiple loci, 24 genotypes were noted among 44 isolates in M. globosa, with a discrimination index D of 0.943 and 15 genotypes were noted among 24 isolates in M. restricta, with a discrimination index D of 0.967. An endogenous infection was detected in two patients. Different genotypes of M. globosa strains colonized one patient. Interestingly, VNTR markers analysis revealed a carriage between a breeder and his dog in three cases for M. globosa and two for M. restricta. The FST (0.018 to 0.057) values indicate a low differentiation between the three populations of M. globosa. These results suggest a dominant clonal mode of reproduction in M. globosa. The typing of M. restricta showed a genotypic diversity of the strains, which can cause various skin pathologies. However, patient five was colonized with strains having the same genotype collected from different body parts (back, shoulder). VNTR analysis was capable of identifying species with high accuracy and reliability. More importantly, the method would facilitate monitoring Malassezia colonization in domestic animals and humans. It was shown that the patterns are stable and the method is discriminant, making it a powerful tool for epidemiological purposes.

Amphotericin B in vitro resistance is associated with fatal Aspergillus flavus infection.

Whether in vitro antifungal susceptibility findings correlate with the outcome of patients with invasive aspergillosis (IA) remains debated. This study aimed to test whether IA patients' outcomes were associated with in vitro susceptibility results. To do so, we determined the in vitro susceptibility to amphotericin B (AMB) of 37 Aspergillus flavus isolates from 14 patients with haematological malignancies diagnosed with proven or probable IA, of which 13 were treated with AMB deoxycholate. Minimal inhibitory concentrations (MICs) were determined by Etest with the isolates classified as in vitro sensitive (AMB-S) or resistant (AMB-R) if their MICs were < 2 or ≥ 2 mg/l, respectively. The association of the patients' death with primary disease, administered antifungal treatment, and infection with AMB-R A. flavus was tested using generalized estimating equations logistic regression. We assessed AMB-R in 31/37 (84%) isolates. In the patients treated with AMB, the survival rate was 2/3 (67%) and 2/9 (22%) for those infected with AMB-S or AMB-R A. flavus, respectively. Both infection with AMB-R A. flavus (P = 0.014) strain and acute myelocytic leukaemia as the underlying primary disease (P = 0.036) were independent predictors of death. Our findings indicate that in vitro resistance predicts a poor outcome in patients with A. flavus invasive disease treated with AMB. Recent advances in non-culture-based microbiological methods should not discourage efforts to obtain in vitro antifungal susceptibility results, which are critical for the choice of antifungal therapy in patients with IA.

Invasive aspergillosis: resistance to antifungal drugs.

Although the arsenal of agents with anti-Aspergillus activity has expanded over the last decade, mortality due to invasive aspergillosis remains unacceptably high. Resistance of the Aspergillus spp. species to antifungal drugs increased in the last 20 years with the increase in antifungal drugs use and might partially account for treatment failures. Recent advances in our understanding of mechanisms of antifungal drug action in Aspergillus, along with the standardization of in vitro susceptibility testing methods, have brought resistance testing to the forefront of clinical mycology. Recent modifications in taxonomy and understanding of the acquired resistance mechanisms of Aspergilli to drugs should support a better management of Aspergillus infections. In this paper, we review the current knowledge on epidemiology and underlying mechanisms involved in antifungal resistance in Aspergillus.