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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.
Assuntos
Infecção Hospitalar/epidemiologia , Dermatomicoses/epidemiologia , Surtos de Doenças , Unidades de Terapia Intensiva Neonatal , Malassezia/classificação , Epidemiologia Molecular , Adulto , Análise por Conglomerados , Infecção Hospitalar/microbiologia , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Dermatomicoses/microbiologia , Feminino , França , Hospitais Universitários , Humanos , Lactente , Recém-Nascido , Controle de Infecções/métodos , Malassezia/química , Malassezia/genética , Malassezia/isolamento & purificação , Masculino , Filogenia , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
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.
Assuntos
Candida parapsilosis/classificação , Candida parapsilosis/genética , Genótipo , Técnicas de Genotipagem/métodos , Tipagem Molecular/métodos , Técnicas de Tipagem Micológica/métodos , Candida parapsilosis/isolamento & purificação , Candidíase/microbiologia , Variação Genética , Humanos , Repetições de Microssatélites , Epidemiologia Molecular/métodos , Sequências de Repetição em TandemRESUMO
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.
Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Candida parapsilosis/efeitos dos fármacos , Farmacorresistência Fúngica/genética , Fatores de Virulência/genética , Candida parapsilosis/genética , Humanos , Testes de Sensibilidade Microbiana , TunísiaRESUMO
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.
Assuntos
Candida/classificação , Candida/genética , Candidíase/epidemiologia , Candidíase/microbiologia , Variação Genética , Adolescente , Adulto , Idoso , Candida/isolamento & purificação , Criança , Pré-Escolar , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Técnicas de Tipagem Micológica , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Tunísia/epidemiologia , Adulto JovemRESUMO
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.
Assuntos
Malassezia/classificação , Malassezia/genética , Tipagem Molecular/métodos , Técnicas de Tipagem Micológica/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Gatos , Bovinos/microbiologia , Cães , Equidae/microbiologia , Cabras/microbiologia , Humanos , Malassezia/isolamento & purificação , Desnaturação de Ácido Nucleico/genética , RNA Ribossômico/genética , Coelhos , Pele/microbiologia , Tinha Versicolor/microbiologiaRESUMO
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.
Assuntos
Técnicas de Diagnóstico Molecular/métodos , Tipagem Molecular/métodos , Tinha/diagnóstico , Tinha/microbiologia , Trichophyton/classificação , Trichophyton/isolamento & purificação , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Genótipo , Hospitais Universitários , Humanos , Técnicas Microbiológicas/métodos , Reação em Cadeia da Polimerase/métodos , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA/métodos , Homologia de Sequência , Trichophyton/genética , TunísiaRESUMO
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.
Assuntos
Repetições Minissatélites , Tipagem Molecular/métodos , Técnicas de Tipagem Micológica/métodos , Tinha/microbiologia , Trichophyton/classificação , Trichophyton/genética , Adulto , Idoso , Feminino , Variação Genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Tinha/diagnóstico , Adulto JovemRESUMO
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.
Assuntos
Antifúngicos , Aspergillus flavus , Azóis , Sistema Enzimático do Citocromo P-450 , Farmacorresistência Fúngica , Proteínas Fúngicas , Testes de Sensibilidade Microbiana , Aspergillus flavus/genética , Aspergillus flavus/efeitos dos fármacos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Farmacorresistência Fúngica/genética , Antifúngicos/farmacologia , Azóis/farmacologia , Humanos , Aspergilose/microbiologia , Mutação , Voriconazol/farmacologia , Triazóis/farmacologiaRESUMO
The interplay between human microbiota and various physiological systems has garnered significant attention in recent years. The gut microbiota plays a critical role in maintaining physiological homeostasis and influences various aspects of human health, particularly via the gut brain axis. Since 2017, the challenging concept of the gut-retina axis has emerged thanks to a network analysis emphasizing the potential role of the gut microbiota disruption in the development of the age-related macular degeneration and further retinal damages. Many other ocular disorders have been linked to the dysbiosis of the gut microbiota, including uveitis and glaucoma. It has been shown that age related macular degeneration can be prevented or reversed using a diet that induces changes in the gut microbiota. The potential link between the gut microbiota as well as others types of microbiota such as the ocular surface microbiota and the development/progression of age related as well as inherited retinal degenerations and other degenerative eye diseases, has recently been broadened. Therefore, the pathogenesis of several eye diseases has recently been associated with a larger perception called the gut eye axis. This mini-review examines the potential mechanisms underlying the gut eye axis and suggests implications for the management of eye diseases. By understanding the modulation of the gut microbiota and its impact on eye disease, this mini-review provides insight into potential therapeutic interventions and avenues for future research.
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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.
Assuntos
Aspergilose/microbiologia , Aspergillus flavus/classificação , Aspergillus flavus/genética , Repetições de Microssatélites , Tipagem Molecular , Técnicas de Tipagem Micológica , Aspergilose/epidemiologia , Aspergillus flavus/isolamento & purificação , DNA Fúngico/química , DNA Fúngico/genética , Genótipo , Humanos , Epidemiologia Molecular , Dados de Sequência Molecular , Análise de Sequência de DNARESUMO
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.
RESUMO
BACKGROUND: The ubiquitous environmental fungus Aspergillus flavus is also a life-threatening avian pathogen. OBJECTIVES: This study aimed to assess the genetic diversity and population structure of A. flavus isolated from turkey lung biopsy or environmental samples collected in a poultry farm. METHODS: A. flavus isolates were identified using both morphological and ITS sequence features. Multilocus microsatellite genotyping was performed by using a panel of six microsatellite markers. Population genetic indices were computed using FSTAT and STRUCTURE. A minimum-spanning tree (MST) and UPGMA dendrogram were drawn using BioNumerics and NTSYS-PC, respectively. RESULTS: The 63 environmental (air, surfaces, eggshells and food) A. flavus isolates clustered in 36 genotypes (genotypic diversity = 0.57), and the 19 turkey lung biopsies isolates clustered in 17 genotypes (genotypic diversity = 0.89). The genetic structure of environmental and avian A. flavus populations were clearly differentiated, according to both F-statistics and Bayesian model-based analysis' results. The Bayesian approach indicated gene flow between both A. flavus populations. The MST illustrated the genetic structure of this A. flavus population split in nine clusters, including six singletons. CONCLUSIONS: Our results highlight the distinct genetic structure of environmental and avian A. flavus populations, indicative of a genome-based adaptation of isolates involved in avian aspergillosis.
Assuntos
Aspergilose , Aspergillus flavus , Animais , Aspergillus flavus/genética , Teorema de Bayes , Fazendas , Aspergilose/epidemiologia , Aspergilose/microbiologia , Aspergilose/veterinária , Aves , Perus , Estruturas GenéticasRESUMO
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.
Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Aspergillus flavus/efeitos dos fármacos , Farmacorresistência Fúngica , Aspergilose Pulmonar Invasiva/microbiologia , Aspergilose Pulmonar Invasiva/mortalidade , Adolescente , Adulto , Anfotericina B/uso terapêutico , Antifúngicos/uso terapêutico , Aspergillus flavus/isolamento & purificação , Estudos de Coortes , Feminino , Neoplasias Hematológicas/complicações , Humanos , Aspergilose Pulmonar Invasiva/tratamento farmacológico , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Análise de Sobrevida , Resultado do Tratamento , Adulto JovemRESUMO
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.
Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Aspergillus/isolamento & purificação , Farmacorresistência Fúngica , Aspergilose Pulmonar Invasiva/epidemiologia , Aspergilose Pulmonar Invasiva/microbiologia , HumanosRESUMO
Seventy-seven strains of Malassezia were included in this study. Biofilm and hydrolytic enzyme production were studied by using specific solid media. The Real-Time reverse transcriptase qPCR method was applied to determine the overexpression of genes encoding the extracellular enzymes. All included Malassezia species produced biofilms. No statistically significant difference was observed between Malassezia species in biofilm formation (p = 0.567). All Malassezia species produced lipase, and 95% of Malassezia globosa showed a strong enzymatic activity (Pz = 0.55 ± 0.02). A statistically significant difference was observed between the mean keratinase indices of Malassezia slooffiae and the other Malassezia species (p = 0.005). The overexpression of one or more genes was observed in 100% of strains isolated from patients with folliculitis, 87.5% - with pityriasis versicolor, and 57.14% of the control group isolates. A statistically significant difference in the lipase gene expression (p = 0.042) was between the strains from patients with folliculitis and the control group. This investigation provides more information about the frequency of the production of the major enzymes considered virulence factors of Malassezia species. Interestingly, the overexpression of one or more genes was observed in strains isolated from patients with Malassezia disorders.
Assuntos
Foliculite , Malassezia , Tinha Versicolor , Humanos , Malassezia/genética , Fatores de Virulência , Lipase/metabolismoRESUMO
This study aimed at comparing a real-time PCR assay and a PCR-ELISA assay of both serum and bronchoalveolar lavage (BAL) samples for the diagnosis of invasive aspergillosis (IA) in patients with hematological malignancies. Using a nested case-control design, 163 patients at risk were prospectively monitored and PCR assays were performed on frozen aliquots of 459 sera which were prospectively sampled twice weekly and 42 BAL specimens sampled from 43 probable and one proven IA cases and 47 matched controls. The data from three patients classified as possible IA were excluded from the nested case-control study. The sensitivity of real-time PCR and PCR-ELISA assays in serum was 73% and 86%, respectively and specificity was 100% for both. In BAL, sensitivity was 64% for real-time PCR, 71% for PCR-ELISA and 86% for Galactomannan antigen (GMA) assays with specificities of 96%, 96%, and 93%, respectively. While slightly less sensitive, the real time-PCR assay was highly specific and considerably faster and more workable than PCR-ELISA. Combining real-time PCR and GMA detection for both serum and BAL samples enhances routine laboratory IA diagnosis.
Assuntos
Aspergillus/isolamento & purificação , Neoplasias Hematológicas/complicações , Aspergilose Pulmonar Invasiva/diagnóstico , Mananas/análise , Reação em Cadeia da Polimerase/métodos , Adolescente , Adulto , Idoso , Antígenos de Fungos/análise , Líquido da Lavagem Broncoalveolar/microbiologia , Criança , Pré-Escolar , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Galactose/análogos & derivados , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Soro/microbiologia , Adulto JovemRESUMO
Aspergillus flavus is the second most important Aspergillus species causing human infections. The importance of this fungus increases in regions with a dry and hot climate. Small phylogenetic studies in Aspergillus flavus indicate that the morphological species contains several genetically isolated species. Different genotyping methods have been developed and employed in order to better understand the genetic and epidemiological relationships between environmental and clinical isolates. Understanding pathogen distribution and relatedness is essential for determining the epidemiology of nosocomial infections and aiding in the design of rational pathogen control methods. Typing techniques can also give us a deeper understanding of the colonization pattern in patients. Most of these studies focused on Aspergillus fumigatus because it is medically the most isolated species. To date, there has not been any publication exclusively reviewing the molecular typing techniques for Aspergillus flavus in the literature. This article reviews all these different available methods for this organism.
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Aspergillus flavus/classificação , Aspergillus flavus/genética , Tipagem Molecular/métodos , Técnicas de Tipagem Micológica/métodos , Aspergillus fumigatus/classificação , Aspergillus fumigatus/genética , Humanos , Repetições de Microssatélites , Epidemiologia Molecular/métodos , Polimorfismo de Fragmento de RestriçãoRESUMO
Assessing the relatedness of strains isolated from patients and their environment is instrumental in documenting the source of preventable health care-associated life-threatening Aspergillus flavus human infection clusters. The present study aimed at identifying and selecting suitable microsatellite markers for A. flavus typing. This typing scheme was then applied to investigate the A. flavus epidemiology within a hematology unit in Sfax, Tunisia. Use of a combination of five markers made it possible to discern clusters of isolates and to substantiate the genetic diversity of A. flavus within clusters. Isolates from Tunisia and Marseille, France, displayed distinct haplotypes, indicating a highly significant geographical structuring of A. flavus. The typing of clinical and environmental A. flavus isolates in a hematology unit provided insights into its hospital epidemiology. From a heterogeneous genetic background, a cluster indicative of a clonal propagation episode within the unit could be identified. In two patients with invasive aspergillosis, the same genotype was found in clinical and environmental isolates, indicating hospital-acquired colonization and infection. In further studies, this novel microsatellite typing scheme might be instrumental in illuminating important epidemiological issues about A. flavus population genetics or epidemiology, including tracing the sources and routes of transmission.
Assuntos
Aspergilose/microbiologia , Aspergillus flavus/genética , Repetições de Microssatélites/genética , Aspergilose/epidemiologia , Análise por Conglomerados , Microbiologia Ambiental , Variação Genética , Unidades Hospitalares , Humanos , Análise de Sequência de DNA , Tunísia/epidemiologiaRESUMO
There are limited data on in vitro susceptibility testing of echinocandins against Aspergillus species. The objective of this study was to describe the phenotypes of Aspergillus flavus observed on exposure to caspofungin in vitro and to test whether these phenotypes were associated with A. flavus genotypes. The caspofungin MICs of 37 A. flavus clinical isolates collected from 14 patients with invasive aspergillosis were determined using Etest assays. Caspofungin MICs ranged from 0.012 to 0.064 mg l(-1); the modal MIC was 0.023 mg l(-1) and the MIC50 and MIC90 were 0.032 and 0.064 mg l(-1), respectively. A clear end point was noted in 24 (65â%) isolates, whereas seven (19â%) displayed a trailing effect and six (16â%) showed paradoxical growth when exposed to caspofungin. In these A. flavus isolates, the absence of a significant population structure or genetic differentiation indicated that trailing or paradoxical growth phenotypes were independent of microsatellite genotype.
Assuntos
Antifúngicos/farmacologia , Aspergilose/microbiologia , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/crescimento & desenvolvimento , Equinocandinas/farmacologia , Adolescente , Adulto , Aspergillus flavus/genética , Aspergillus flavus/isolamento & purificação , Caspofungina , Feminino , Genótipo , Humanos , Lipopeptídeos , Masculino , Testes de Sensibilidade Microbiana , Repetições de Microssatélites , Pessoa de Meia-Idade , Tipagem Molecular , Técnicas de Tipagem Micológica , Fenótipo , Adulto JovemRESUMO
Recurrent vulvo-vaginal candidiasis (RVVC) is a significant problem facing women of child bearing age. It is now accepted that RVVC is the consequence of local immunodeficiency. The aim of this study was to assess differential secretion of IgAs and IgG anti-C. albicans in vaginal secretions of patients with RVVC, VVC and asymptomatic women. Vaginal secretions collected from 3 groups of women: 14 patients with RVVC, 8 patients with VVC and 17 asymptomatic women. Overall analysis of vaginal secretions revealed that the prevalence of IgAs (73%) and IgG (33%) antibodies anti-C. albicans were significantly different. The prevalence of IgAs antibodies was 86% in patients with RVVC, 75% in women with VVC and 61% in asymptomatic women. IgG antibodies were detected in 43% of women with RVVC, in 37% of women with VVC and in 18% of asymptomatic women. Sensibility and specificity of detection of IgA in vaginal secretion were 54% and 83%, respectively. The prevalence of detection of IgAs and IgG were more important in patients than asymptomatic women. However, RVVC cannot be attributed only to the impairment of local humoral immunity and further proteomic investigations are needed.