ABSTRACT
The second international meeting on endemic mycoses of the Americas (IMEMA) and the first international symposium on implantation mycoses (ISIM) took place in Santiago del Estero, Argentina, on September 25-27, 2023. The conference provided a platform for researchers, clinicians, and experts to discuss the latest developments in the field of endemic and implantation mycoses. Topics included epidemiology, diagnostic advances, treatment strategies, and the impact of environmental factors on the spread of these fungal diseases. IMEMA and ISIM contributed to the regional discourse on the mycoses, emphasizing the importance of international cooperation in addressing these public health challenges.
IMEMA/ISIM, held in Santiago del Estero, Argentina, convened experts to discuss endemic and implantation mycoses, covering topics such as epidemiology, diagnostics, treatment, and advocacy. The event highlighted ongoing efforts in combating these diseases.
Subject(s)
Endemic Diseases , Mycoses , Humans , Mycoses/epidemiology , Mycoses/microbiology , Americas/epidemiology , Argentina/epidemiology , Prosthesis-Related Infections/microbiology , Prosthesis-Related Infections/epidemiologyABSTRACT
The National Reference Laboratory in Clinical Mycology of Argentina conducted a retrospective review of human coccidioidomycosis cases diagnosed by the National Mycology Laboratory Network of Argentina between 2010 and 2022 to determine the burden of the disease in the country. A total of 100 human coccidioidomycosis cases were documented, with a higher prevalence in male patients (male-to-female ratio of 1.9:1), with a median age of 41 years. Comparing the number of cases between two 10-year periods (2000-2009 and 2010-2019), the increase was 36.51% (from 63 to 86 cases). Among the 100 recorded cases, 79 tested positive using the double immunodiffusion test. Spherules were observed in 19 cases through histopathology or direct microscopic examination and the fungus was isolated in 39 cases. Thirty-six isolates were identified as Coccidioides posadasii through partial sequencing of the Ag2/PRA gene. Catamarca province had the highest number of cases, comprising 64% of the total, with an incidence rate above 1.0-2.5/100,000 inhabitants until 2018. However, there has been a recent downward trend in the region from 2018 to 2022. It is concerning that more than half of diagnosed cases were chronic pulmonary or disseminated forms, indicating a lack of early disease detection. To rectify this issue, it is imperative to conduct targeted training programs for healthcare personnel and enhance public awareness within the endemic area. This will contribute to a better understanding of the true burden of coccidioidomycosis and enable the implementation of appropriate sanitary control measures.
Subject(s)
Coccidioides , Coccidioidomycosis , Humans , Coccidioidomycosis/epidemiology , Coccidioidomycosis/microbiology , Argentina/epidemiology , Male , Female , Adult , Retrospective Studies , Middle Aged , Coccidioides/genetics , Coccidioides/isolation & purification , Aged , Young Adult , Prevalence , Incidence , Adolescent , Child , Aged, 80 and over , Child, PreschoolABSTRACT
This study aimed to perform a seroepidemiological survey on the prevalence of sporotrichosis among cats living in the Northern area of Buenos Aires, where a four-fold increase of Sporothrix brasiliensis infections were diagnosed during the last decade. For this purpose, an in-house indirect ELISA test sensitized with S. brasiliensis crude antigens was used. The ELISA test showed 100.0% sensitivity and 95.0% specificity. Antibodies against S. brasiliensis antigens were detected in 3.7% (9/241) of healthy cats evaluated, suggesting likely exposure or infection to this fungus. This ELISA test would be a valuable screening tool for diagnosing sporotrichosis and for seroepidemiological surveys.
S. brasiliensis is the primary cause of feline sporotrichosis in Argentina. The seroprevalence of sporotrichosis infection in urban localities of Buenos Aires province is reported for the first time. An ELISA test using S. brasiliensis crude antigens is also described.
ABSTRACT
Rapid and accurate yeasts species identification in clinical laboratories is important for appropriate and timely antifungal treatment. We evaluate the performance of the new medium CHROMagar™ Candida Plus for presumptive identification of yeasts species and MALDI-TOF identification. We identify 303 strains belonging to 60 clinically relevant yeasts species by using the new medium. Presumptive identification was correct at the Candida albicans complex, Candida tropicalis and Pichia kudriavzevii (Candida krusei) species. However, although this medium was able to identify all Candida auris and Candida glabrata strains, other species were misidentified as C. auris or C. glabrata. A total of 215 strains were identified by using MALDI-TOF and evaluated two incubation temperatures (30°C and 37°C) and two incubation times (24 h and 72 h). Most strains (94%; 202/215) were correctly identified at the species (n:190) or complex level (n:12) at both temperatures and incubation times. However, we observed that the time of incubation (24 h vs. 72 h) affects the score values when yeasts are incubated at 37°C, but does not affect score values when yeasts are incubated at 30°C. In conclusion, the new medium has a good performance in the presumptive identification of the C. albicans complex, C. tropicalis and P. kudriavzevii (C. krusei). In addition, this medium is useful for the screening of C. auris and C. glabrata isolates, but identification should be confirmed by other more specific techniques, like MALDI-TOF.
Subject(s)
Candida , Yeasts , Humans , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Culture Media , Candida albicans , Candida glabrata , Candida tropicalisABSTRACT
The aim of this study was to determine the genotypic diversity of 22 Cryptococcus gattii species complex clinical isolates from Argentina and to place these genotypes within the diversity of clinical, veterinary and environmental isolates from Latin America. Mating type and antifungal susceptibility of the isolates were also determined. By URA5-RFLP, nine isolates were identified as molecular type VGI, 10 as VGII, one as VGIII and two as VGIV. Multilocus sequence typing (MSLT), following the International Society for Human and Animal Mycology (ISHAM) consensus MLST scheme, was used to determine the genotypic diversity. Our results suggest that, in Argentina, VGI isolates have low genetic diversity, while VGII isolates have high genetic diversity. Both isolates identified as VGIV by URA5-RFLP were genotyped by MLST as belonging to the currently named VGVI clade. From all isolates, eight sequence types (STs) were unique for Argentina, while five STs have been reported already in other countries, being of high interest the genotypes ST20 and ST7 since they belong to the subtypes VGIIa and VGIIb, respectively, which are associated with hypervirulent strains responsible for outbreaks in North America. To note, geographical analysis showed that some genotypes may be associated with some regions in Argentina. Most isolates were MATα, but we are reporting one isolate MATa for the first time in the country. Antifungal susceptibility tests showed that itraconazole, voriconazole and posaconazole had high activity against all isolates, while amphotericin B, fluconazole and 5-fluorocytosine were the least active drugs against all studied isolates.
Subject(s)
Cryptococcosis , Cryptococcus gattii , Animals , Humans , Antifungal Agents/pharmacology , Multilocus Sequence Typing , Argentina , Cryptococcosis/microbiology , GenotypeABSTRACT
BACKGROUND: The Americas are home to biologically and clinically diverse endemic fungi, including Blastomyces, Coccidioides, Emergomyces, Histoplasma, Paracoccidioides and Sporothrix. In endemic areas with high risk of infection, these fungal pathogens represent an important public health problem. OBJECTIVES: This report aims to summarise the main findings of the regional analysis carried out on the status of the endemic mycoses of the Americas, done at the first International Meeting on Endemic Mycoses of the Americas (IMEMA). METHODS: A regional analysis for the Americas was done, the 27 territories were grouped into nine regions. A SWOT analysis was done. RESULTS: All territories reported availability of microscopy. Seventy percent of territories reported antibody testing, 67% of territories reported availability of Histoplasma antigen testing. None of the territories reported the use of (1-3)-ß-d-glucan. Fifty two percent of territories reported the availability of PCR testing in reference centres (mostly for histoplasmosis). Most of the territories reported access to medications such as trimethoprim-sulfamethoxazole, itraconazole, voriconazole and amphotericin B (AMB) deoxycholate. Many countries had limited access to liposomal formulation of AMB and newer azoles, such as posaconazole and isavuconazole. Surveillance of these fungal diseases was minimal. CONCLUSIONS: A consensus emerged among meeting participants, this group concluded that endemic mycoses are neglected diseases, and due to their severity and lack of resources, the improvement of diagnosis, treatment and surveillance is needed.
Subject(s)
Histoplasmosis , Mycoses , Humans , Antifungal Agents/therapeutic use , Mycoses/diagnosis , Mycoses/drug therapy , Mycoses/epidemiology , Itraconazole/therapeutic use , Histoplasma , Histoplasmosis/diagnosis , Histoplasmosis/drug therapy , Histoplasmosis/epidemiology , Americas/epidemiologyABSTRACT
We report a case of disseminated histoplasmosis and COVID-19 infection in a renal transplant recipient in Argentina. The patient exhibited respiratory symptoms, and a chest computed tomography scan (CT) showed multiple bilateral centrilobular opacities with a tree-in-bud pattern in both lobes. The patient was initially treated as having bacterial community-acquired pneumonia, and then tuberculosis. A month later, histoplasmosis was diagnosed, and Histoplasma capsulatum LAmB clade was isolated from sputum, skin and oral lesions. The patient was hospitalized and treatment was started with intravenous liposomal amphotericin B. During the course of the antifungal therapy the respiratory symptoms worsened, a new chest CT showed a unilateral lesion with a ground glass appearance and SARS-CoV-2 was detected in a new nasopharyngeal sample. In addition, plasma therapy was administered, and the immunosuppressive regimen was adjusted (everolimus was interrupted, mycophenolate mofetil reduced, and meprednisone increased). Finally, the patient's progress was favorable and was discharged after five days on oral itraconazole treatment for histoplasmosis.
Subject(s)
COVID-19 , Histoplasmosis , Kidney Transplantation , Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , COVID-19/complications , Everolimus , Histoplasma , Histoplasmosis/complications , Histoplasmosis/drug therapy , Itraconazole/therapeutic use , Kidney Transplantation/adverse effects , Mycophenolic Acid , SARS-CoV-2ABSTRACT
The National Quality Control Program in Mycology (PNCCM) of Argentina was established in 1996 to improve the quality of the mycological diagnosis, to help establish and to set up standardized procedures and continuous training of laboratory staff. The aim of this study was to assess the effectiveness of the PNCCM in the 1996-2018 period. Data from the National Mycology Laboratory Network (NMLN) and PNCCM database was used to estimate the increase in the number of controlled laboratories and jurisdictions, the percentage of participation, the improvement in the quality of results and the adherence to the program. Satisfaction surveys were performed to assess user satisfaction. The number of controlled laboratories increased from 29 to 146; participation increased from 49% to 93% and general adherence was 72% in the evaluated period (1996-2018). Improvement in the quality of the results was 15% for low complexity samples; 7% for intermediate complexity samples and 14% for the identification of high complexity strains. Up to 84% of the users consider the PNCCM to be "very good" and 16% "satisfactory". These results show the importance of the PNCCM, which is widely accepted by mycological diagnostic laboratories from Argentina.
Subject(s)
Laboratories , Mycology , Argentina , Diagnostic Tests, Routine , Humans , Quality ControlABSTRACT
Histoplasmosis is a worldwide systemic endemic mycosis caused by several cryptic species included within the Histoplasma capsulatum complex. Domestic and wild mammals are susceptible to infection by this fungus and could be used as indicators of its presence in the environment. The aim of the study was to identify the natural reservoirs of H. capsulatum in the Argentinean Humid Pampas eco-region analyzing a wildlife frozen-tissue collection and trace its distribution patterns over time and space. Tissue samples from 34 small wild mammals caught in the Humid Pampas were analyzed using two molecular markers: 100 kDa protein coding gene (Hcp100) and ITS1 rDNA. Results showed that 32.4% of them were infected with H. capsulatum and its DNA was detected in 5/17 Calomys laucha; 3/6 Calomys musculinus; 1/5 Akodon azarae, 1/3 Monodelphis dimidiata; and 1/2 Didelphis albiventris. In the single specimen studied of Cavia aperea, no H. capsulatum DNA was detected. This is the first H. capsulatum infection report in C. laucha and C. musculinus rodents and M. dimidiate opossum which proves that tissue collections are an important source of material for epidemiological studies of endemic disease over time.
Subject(s)
Animals, Wild/microbiology , Disease Reservoirs/microbiology , Histoplasma/isolation & purification , Histoplasmosis/epidemiology , Animals , Argentina/epidemiology , DNA, Fungal/genetics , Endemic Diseases , Epidemiologic Studies , Histoplasma/genetics , Humans , Tissue Banks , Zoonoses/epidemiologyABSTRACT
The aim of this work was to know the frequency and geographical distribution of genotypes and mating types of Cryptococcus neoformans and Cryptococcus gattii species complexes isolated from human infections in Argentina during the period from April 2009 to April 2011. A multicenter study was conducted, in which 372 isolates were obtained from 61 laboratories throughout the country. Of those, 98.8% of the isolates belonged to the C. neoformans species complex and 1.1% to the C. gattii species complex. Genotype VNI (MATα) was the most frequently isolated (n=326, 87.6%), followed by VNII (MATα) (n=22, 5.9%), the recently described VNII-VNIV (aADα) hybrid (n=14, 3.8%), VNIV (MATα) (n=4, 1.1%), VNIII (αADa) hybrid (n=1, 0.3%), and VNIII (αADα) hybrid (n=1, 0.3%). The Argentine Central region showed the greatest number of cases and genotype diversity. Interestingly, a relative high frequency was observed in genotype VNII (MATα) in the Cuyo, Northeast and Northwest regions and, also in VNII-VNIV (aADα) hybrids in the Northwest region. C. gattii species complex was isolated at a low rate; 3 VGI (MATα) and 1 VGII (MATα) isolates were obtained from the Northwest and Central regions. In conclusion, this study shows that genotype frequencies seem to vary among regions in Argentina and reveals a relatively high frequency of rare hybrids in the Northwest region. Further regional clinical and environmental studies may help to elucidate if those variations in frequencies are associated with the existence of regional ecological niches or any other regional factors.
Subject(s)
Cryptococcosis , Cryptococcus gattii , Cryptococcus neoformans , Argentina/epidemiology , Cryptococcosis/epidemiology , Cryptococcus gattii/genetics , Cryptococcus neoformans/genetics , Genotype , Humans , Mycological Typing TechniquesABSTRACT
Coccidioidomycosis is a highly prevalent systemic mycosis in Latin America and has been reported (human and zoonotic cases) in México, Guatemala, Honduras, Colombia, Venezuela, Brazil, Paraguay, Bolivia, and Argentina. The incidence of coccidioidomycosis in Latin America is unknown due to lack of clinical awareness and limited access to laboratory diagnosis. Coccidioidomycosis is as prevalent in Mexico as in the endemic regions of the United States. The number of cases reported in Brazil and Argentina has progressively increased during the last decade, including areas that were not considered as endemic. Genetic studies have shown that the prevalent species in Latin America is Coccidioides posadasii. Coccidioides immitis has been reported sporadically in indigenous cases from Mexico and Colombia. Coccidioidomycosis and tuberculosis share some risk factors such as immunosuppression and residing in areas endemic for these conditions, so their coexistence in the same patient is not uncommon in Latin America. In most regions, clinical diagnosis of coccidioidomycosis is based on direct sputum examination and histopathology results from biopsies or autopsies. This would explain why primary coccidioidomycosis is rarely diagnosed, and most cases published are about chronic pulmonary or disseminated disease.
Subject(s)
Coccidioides/isolation & purification , Coccidioidomycosis/diagnosis , Coccidioidomycosis/epidemiology , Coccidioides/genetics , Endemic Diseases/prevention & control , Endemic Diseases/statistics & numerical data , Humans , Immunocompromised Host , Latin America/epidemiology , Sputum/microbiologyABSTRACT
Mycelial basidiomycetes rarely produce mycoses in animals including humans. We report a case of a 9-year-old female mongrel dog with lesions in the prescapular lymph nodes. The histopathology of a lymph node sample showed flexuous septate hyphae, and a sterile mold grew in culture from that specimen. DNA sequencing of the ITS region allowed us to identify the fungus as Tropicoporus tropicalis. The dog was treated with itraconazole, but it was euthanized six months later due to an unfavorable clinical outcome. Tropicoporus tropicalis is an infrequent pathogen of pets, and the use of molecular tools is needed for its identification. Animal infections due to T. tropicalis were not previously been reported in Argentina.
Subject(s)
Basidiomycota/isolation & purification , Dog Diseases/diagnosis , Dog Diseases/pathology , Mycoses/pathology , Mycoses/veterinary , Animals , Antifungal Agents/administration & dosage , Argentina , Basidiomycota/classification , Basidiomycota/genetics , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Dog Diseases/drug therapy , Dogs , Female , Histocytochemistry , Itraconazole/administration & dosage , Lymph Nodes/pathology , Microbiological Techniques , Mycoses/drug therapy , Sequence Analysis, DNA , Treatment FailureABSTRACT
We studied 23 clinical and environmental strains of Sporothrix schenckii sensu lato collected from 1984 to 2017 in Argentina. The molecular identification (partial sequencing of a fragment of the calmodulin gene) of the strains was performed. For the yeast and mycelial phases, the in vitro susceptibility testing by a microdilution reference method was determined against eight antifungal drugs. Strains studied were identified as S. schenckii sensu stricto 13 (56.5%), S. brasiliensis 8 (34.7%) and S. globosa 2 (8.7%). The most active antifungal drugs tested for the yeast and mycelial phases expressed as geometric mean (GM) value of the minimal inhibitory concentration (MIC) (µg mL-1 ) were terbinafine (0.07 and 0.24), posaconazole (0.13 and 0.58), itraconazole (0.38 and 1.10) and ketoconazole (0.22 and 0.89), while fluconazole (110.10 and 131.92) and flucytosine (2.96 and 79.03) were the less active. For voriconazole and amphotericin B the GM-MIC values were acceptably low for the yeast phase (0.39 and 0.72 µg mL-1 ), while the mycelial phase showed values ≥2-fold higher (8.76 and 1.88 µg mL-1 ), P < .05. Here, we described S. schenckii sensu stricto, S. brasiliensis and S. globosa, these species were isolated from humans, animals and soil and are circulating in Argentina since at least 1984.
Subject(s)
Antifungal Agents/pharmacology , Sporothrix/drug effects , Sporothrix/genetics , Sporotrichosis/microbiology , Animals , Argentina/epidemiology , Calmodulin/genetics , Flucytosine/pharmacology , Humans , Itraconazole/pharmacology , Microbial Sensitivity Tests , Phylogeny , Sequence Analysis, DNA , Soil Microbiology , Sporothrix/isolation & purification , Sporotrichosis/epidemiology , Triazoles/pharmacologyABSTRACT
Paracoccidioidomycosis (PCM) is among the systemic mycoses which are endemic only in Latin America. In Argentina, the vast majority of the cases are reported at north of latitude 34.5° S. The disease is produced by thermodimorphic fungi of the genus Paracoccidoides: P. brasiliensis (S1), P. americana (PS2), P. restrepiensis (PS3), P. venezuelensis (PS4) y P. lutzii. The natural habitat of members of this genus is the soil, where they produce infectious conidia. Little is known, however, about their specific ecologic niche(s), and this knowledge gap hampers the design of measures to control the infection. Rural male workers are the group most at risk of developing PCM. Infection occurs by inhalation of aerosolized conidia and may either be asymptomatic or cause mild respiratory symptoms. In turn, this primary infection may be self-limited or progress to severe pulmonary or disseminated disease. The disease has two clinical presentations: (i) acute or subacute (juvenile), frequent in children, adolescents and people with immunodeficiencies; and (ii) chronic progressive, in adults. Active lesions often resolve into fibrotic scars which can cause dysphagia, dysphonia, adrenal insufficiency, and intestinal obstruction. Although efficient tools are available for diagnosis and treatment, the nonspecific nature of PCM clinical manifestations frequently delay the diagnosis. In addition, the poor adherence to long antifungal treatments allows the advance of the disease and the development of extensive fibrosis compromising severely and permanently respiratory and adrenal functions, thus altering the patient"s quality of life and even causing his/her death.
Subject(s)
Neglected Diseases , Paracoccidioides/classification , Paracoccidioidomycosis , Humans , Paracoccidioidomycosis/diagnosis , Paracoccidioidomycosis/parasitology , Paracoccidioidomycosis/therapyABSTRACT
Coccidioides immitis and C. posadasii are the etiologic agents of coccidioidomycosis, an endemic fungal disease of the Americas. In Colombia, this mycosis is uncommon, and only five cases, two of them imported, have been documented.By means of DNA sequencing, C. immitis was identified in formalin-fixed, paraffin-embedded archival tissues samples from the 5th Colombian patient diagnosed in 1997. The patient was born in Pinto, Department of Magdalena, and had never visited other geographic regions, a reason to consider that the mycosis had been acquired locally.This species is primarily found in California although it has been occasionally reported in other geographic areas such as Mexico and Brazil. This is the first indigenous report of C. immitis-associated coccidioidomycosis in a Colombian patient.
Subject(s)
Coccidioides/isolation & purification , Coccidioidomycosis/diagnosis , Molecular Diagnostic Techniques , Pathology, Molecular , Biopsy , Coccidioides/genetics , Coccidioidomycosis/microbiology , Coccidioidomycosis/pathology , Colombia , Formaldehyde , Humans , Male , Middle Aged , Paraffin , Patients , Tissue FixationABSTRACT
Coccidiomycosis is a potentially life-threatening fungal infection endemic to certain regions of Argentina. The infection is caused by Coccidioides spp. and is primarily diagnosed by Coccidioides antibody (Ab) detection. Access to rapid, highly accurate diagnostic testing is critical to ensure prompt antifungal therapy. The sona Coccidioides Ab Lateral Flow Assay (LFA) performs faster and requires less laboratory infrastructure and equipment compared with other Ab detection assays, potentially providing a substantial improvement for rapid case screening in coccidioidomycosis-endemic regions; however, validation of this test is needed. Thus, we aimed to evaluate the analytical performance of the sona Coccidioides Ab (LFA) and compare agreement with anti-Coccidioides Ab detection assays. A total of 103 human sera specimens were tested, including 25 specimens from patients with coccidioidomycosis and 78 from patients without coccidioidomycosis. The sona Coccidioides Ab Lateral Flow Assay (LFA) was performed with a sensitivity of 88%, and specificity and accuracy of 87%. Furthermore, the Coccidioides Ab LFA had good agreement with other anti-Coccidioides Ab detection assays. Our findings suggest the sona Coccidioides Ab LFA has satisfactory performance and may be useful for diagnosing coccidioidomycosis in endemic regions.
ABSTRACT
BACKGROUND: Coccidioides immitis and C. posadasii cause coccidioidomycosis, a disease that is endemic to North and South America, but for Central America, the incidence of coccidioidomycosis has not been clearly established. Several studies suggest genetic variability in these fungi; however, little definitive information has been discovered about the variability of Coccidioides fungi in Mexico (MX) and Argentina (AR). Thus, the goals for this work were to study 32 Coccidioides spp. isolates from MX and AR, identify the species of these Coccidioides spp. isolates, analyse their phenotypic variability, examine their genetic variability and investigate the Coccidioides reproductive system and its level of genetic differentiation. METHODS: Coccidioides spp. isolates from MX and AR were taxonomically identified by phylogenetic inference analysis using partial sequences of the Ag2/PRA gene and their phenotypic characteristics analysed. The genetic variability, reproductive system and level of differentiation were estimated using AFLP markers. The level of genetic variability was assessed measuring the percentage of polymorphic loci, number of effective allele, expected heterocygosity and Index of Association (IA). The degree of genetic differentiation was determined by AMOVA. Genetic similarities among isolates were estimated using Jaccard index. The UPGMA was used to contsruct the corresponding dendrogram. Finally, a network of haplotypes was built to evaluate the genealogical relationships among AFLP haplotypes. RESULTS: All isolates of Coccidioides spp. from MX and AR were identified as C. posadasii. No phenotypic variability was observed among the C. posadasii isolates from MX and AR. Analyses of genetic diversity and population structure were conducted using AFLP markers. Different estimators of genetic variability indicated that the C. posadasii isolates from MX and AR had high genetic variability. Furthermore, AMOVA, dendrogram and haplotype network showed a small genetic differentiation among the C. posadasii populations analysed from MX and AR. Additionally, the IA calculated for the isolates suggested that the species has a recombinant reproductive system. CONCLUSIONS: No phenotypic variability was observed among the C. posadasii isolates from MX and AR. The high genetic variability observed in the isolates from MX and AR and the small genetic differentiation observed among the C. posadasii isolates analysed, suggest that this species could be distributed as a single genetic population in Latin America.
Subject(s)
Coccidioides/genetics , Coccidioides/isolation & purification , Coccidioidomycosis/microbiology , Genetic Variation , Amplified Fragment Length Polymorphism Analysis , Argentina , Coccidioides/classification , Coccidioides/growth & development , Humans , Mexico , Molecular Sequence Data , PhylogenyABSTRACT
As the distribution of Candida species and their susceptibility to antifungal agents have changed, a new means of accurately and rapidly identifying these species is necessary for the successful early resolution of infection and the subsequent reduction of morbidity and mortality. The current work aimed to evaluate ribosomal RNA gene sequencing for the identification of medically relevant Candida species in comparison with a standard phenotypic method. Eighteen reference strains (RSs), 69 phenotypically identified isolates and 20 inconclusively identified isolates were examined. Internal transcribed spaces (ITSs) and D1/D2 of the 26S ribosomal RNA gene regions were used as targets for sequencing. Additionally, the sequences of the ITS regions were used to establish evolutionary relationships. The sequencing of the ITS regions was successful for 88% (94/107) of the RS and isolates, whereas 100% of the remaining 12% (13/107) of the samples were successfully analysed by sequencing the D1/D2 region. Similarly, genotypic analysis identified all of the RS and isolates, including the 20 isolates that were not phenotypically identified. Phenotypic analysis, however, misidentified 10% (7/69) of the isolates. Phylogenetic analysis allowed the confirmation of the relationships between evolutionarily close species. Currently, the use of genotypic methods is necessary for the correct identification of Candida species.
Subject(s)
Candida/genetics , DNA, Fungal/analysis , DNA, Ribosomal Spacer/genetics , Genes, rRNA/genetics , Candida/classification , Genotype , Humans , Phenotype , Polymerase Chain Reaction , Sequence Analysis, RNAABSTRACT
Introduction: Paracoccidioidomycosis is a systemic mycosis endemic in Latin America. Climate change and host migration emphasize the need to optimize this infection diagnosis. Objective: To evaluate the implementation of Paracoccidioides spp. DNA detection in the mycological diagnosis of patients with suspected paracoccidioidomycosis. Materials and methods: It is a retrospective study with laboratory data from patients with clinical suspicion of paracoccidioidomycosis, who consulted a university hospital from a non-endemic area. Results: We analyzed the laboratory results of samples from 19 patients with suspected paracoccidioidomycosis. Seventeen out of 19 patients were born in or had visited an endemic area in Latin America. Fourteen adult male patients were confirmed to have paracoccidioidomycosis by conventional diagnosis: the direct examination was positive in 12 samples while fungal growth was found only in 4. Anti-Paracoccidioides spp. antibodies were detected in 10 patients, 8 of them with proven paracoccidioidomycosis. Nested PCR for Paracoccidioides spp. detection was performed on clinical samples from 14 patients, and positive results were obtained for 9 out of 10 patients with the conventional diagnosis of paracoccidioidomycosis. Conclusions: The incorporation of molecular techniques to detect Paracoccidioides spp. DNA complements the conventional diagnosis of paracoccidioidomycosis. This tool allows the prescription of antifungal treatment in those cases where the fungus is not observed in the clinical samples.
Introducción: La paracoccidioidomicosis es una micosis sistémica y endémica en Latinoamérica. El cambio climático y el movimiento migratorio del huésped enfatizan la necesidad de optimizar el diagnóstico de esta infección. Objetivo: Evaluar la implementación de la detección de ADN de Paracoccidioides spp. al diagnóstico micológico de pacientes con sospecha de paracoccidioidomicosis. Materiales y métodos. Estudio retrospectivo con datos de laboratorio de pacientes con sospecha de paracoccidioidomicosis en un hospital de área no endémica. Resultados: Se analizaron los resultados de las muestras de 19 pacientes con sospecha clínica de paracoccidioidomicosis. El 90 % de los pacientes había nacido o visitado un área endémica de esta micosis en Latinoamérica. En 14 pacientes varones adultos se confirmó paracoccidioidomicosis por diagnóstico convencional. El examen directo fue positivo en 12 pacientes con enfermedad comprobada y en 4 de ellos se obtuvo crecimiento del hongo. Se detectaron anticuerpos contra Paracoccidioides spp. en ocho pacientes con la enfermedad. Se realizó PCR anidada con muestras de 14 pacientes para detectar ADN de Paracoccidioides spp. En 9 de los 10 pacientes con diagnóstico convencional de paracoccidioidomicosis se obtuvo una prueba de PCR positiva. Conclusiones: La implementación de técnicas moleculares para detectar ADN de Paracoccidioides spp. complementa el diagnóstico convencional de paracoccidioidomicosis y permite instaurar el tratamiento antifúngico, sobre todo en los casos clínicos donde no se observa la presencia del hongo en las muestras clínicas. La migración actual de poblaciones humanas dificulta el diagnóstico de paracoccidioidiomicosis y otras infecciones endémicas, por lo que se requiere optimizar el diagnostico micológico en los laboratorios clínicos para tratar pacientes con este tipo micosis desatendida.
Subject(s)
Hospitals , Tolnaftate , Polymerase Chain ReactionABSTRACT
Information on paracoccidioidomycosis (PCM) in Argentina is fragmented and has historically been based on estimates, supported only by a series of a few reported cases. Considering the lack of global information, a national multicentric study in order to carry out a more comprehensive analysis was warranted. We present a data analysis including demographic and clinical aspects of a historical series of 466 cases recorded over 10 years (2012-2021). Patients were aged from 1 to 89 years. The general male: female (M:F) ratio was 9.5:1 with significant variation according to the age group. Interestingly, the age range 21-30 shows an M:F ratio of 2:1. Most of the cases (86%) were registered in northeast Argentina (NEA), showing hyperendemic areas in Chaco province with more than 2 cases per 10,000 inhabitants. The chronic clinical form occurred in 85.6% of cases and the acute/subacute form occurred in 14.4% of cases, but most of these juvenile type cases occurred in northwestern Argentina (NWA). In NEA, the incidence of the chronic form was 90.6%; in NWA, the acute/subacute form exceeded 37%. Diagnosis by microscopy showed 96% positivity but antibody detection displays 17% of false negatives. Tuberculosis was the most frequent comorbidity, but a diverse spectrum of bacterial, fungal, viral, parasitic, and other non-infectious comorbidities was recorded. This national multicenter registry was launched in order to better understand the current status of PCM in Argentina and shows the two endemic zones with a highly diverse epidemiology.