Publications by authors named "Joao V B Souza"

Background: The rising prevalence of fungal infections and challenges such as adverse effects and resistance against existing antifungal agents have driven the exploration of new antifungal substances.

Methods: We specifically investigated naphthoquinones, known for their broad biological activities and promising antifungal capabilities. It specifically examined the effects of a particular naphthoquinone on the cellular components of Candida albicans ATCC 60193.

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Cryptococcus neoformans is primarily responsible for cases of cryptococcal meningitis in individuals with HIV/AIDS. This study evaluated the susceptibility of C. neoformans obtained from individuals with cryptococcal meningitis associated with HIV/AIDS in Manaus, Amazonas, Brazil, against the action of the antifungals amphotericin B, flucytosine, fluconazole, itraconazole and posaconazole and analyzed it using Multilocus Sequence Typing (MLST) in order to identify the Sequence Types (STs).

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Amazon River dolphins are an important flagship species in the Anavilhanas National Park, Brazil, where they interact with visitors. This study aimed to quantify and identify fungi isolated from dolphin skin and oral samples and their surrounding environment in this unique ecosystem. Samples were collected from three dolphins and water samples from Flutuante dos Botos and the Novo Airão city harbor.

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Histoplasmosis is commonly observed in AIDS patients as a neglected opportunistic disease that has an important relationship with environmental factors. The present study described the clinical characteristics of HIV/AIDS patients diagnosed with disseminated histoplasmosis in a tertiary healthcare facility in Manaus, Amazonas, Brazil, and evaluated the patients' homes and urban environmental samples as a source of exposure to Histoplasma capsulatum. A review of medical records from 2017 to 2019 of patients with HIV/AIDS associated with histoplasmosis was carried out, as well as the collection of environmental samples in the homes of these patients.

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The aim of this study was to investigate the production, stability and applicability of colorants produced by filamentous fungi isolated from soil samples from the Amazon. Initially, the isolates were evaluated in a screening for the production of colorants. The influences of cultivation and nutritional conditions on the production of colorants by fungal isolates were investigated.

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Background: This study aimed at improving a real-time polymerase-chain-reaction (qPCR) assay for the detection of Histoplasma capsulatum, a fungal pathogen that can cause severe respiratory infections in humans, in clinical and soil samples.

Methods: Primer and probes were in-silico designed, in-silico and in-vitro evaluated including clinical biopsy materials and finally subjected to a real-world application with collected soil samples.

Results: Applying the qPCR assay with liver and lung biopsies from 71 patients each, including 59 patients infected with human immunodeficiency virus (HIV), as well as with Sabouraud (SAB) agar culture as the diagnostic reference standard, diagnostic accuracy of the qPCR assay of 100% (5/5) sensitivity and 96% (63/66) specificity for liver samples and 100% (4/4) sensitivity and 94% (63/67) specificity for the lung samples was recorded.

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There is a consensus that the antifungal repertoire for the treatment of cryptococcal infections is limited. Standard treatment involves the administration of an antifungal drug derived from natural sources (i.e.

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The emergence of multidrug resistance in bacterial pathogens is a growing public health concern requiring solutions including the discovery of new antimicrobial drugs. Fungi have been used for decades as a source of antimicrobials. Ongoing screenings for newly characterized fungal strains producing antimicrobials include environments that are difficult to access like the deep sea, glaciers, wastewaters and environments polluted due to human activity.

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An increase in global energy demand has caused oil prices to reach record levels in recent times. High oil prices together with concerns over CO emissions have resulted in renewed interest in renewable energy. Nowadays, ethanol is the principal renewable biofuel.

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In the last few decades, there has been a great demand for natural colorants. Synthetic colorants are known to be easy to produce, are less expensive, and remain stable when subjected to chemical and physical factors. In addition, only small amounts are required to color any material, and unwanted flavors and aromas are not incorporated into the product.

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Objectives: In the state of Amazonas, northern Brazil, cryptococcosis is endemic, with a predominance of Cryptococcus neoformans in individuals with HIV/AIDS, and Cryptococcus gattii VGII in non-HIV individuals. This study analysed the clinical isolates and clinical-epidemiological characteristics of HIV/AIDS patients diagnosed with cryptococcosis in a tertiary healthcare facility in Manaus, Amazonas and investigated the presence of agents of cryptococcosis in environmental samples.

Methods: A survey was made of data from HIV/AIDS patients diagnosed with cryptococcosis between January 2017 and December 2019, and environmental samples were collected at the patients' and their neighbours' homes.

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Article Synopsis
  • - The study investigates heteroresistance in the C. neoformans/C. gattii complex, specifically looking at resistance to fluconazole in isolates from Amazonas, Brazil, revealing varying susceptibility levels in clinical and environmental samples.
  • - A total of 45 isolates were analyzed, showing that clinical C. gattii isolates had significantly higher minimal inhibitory concentrations (MICs) compared to environmental strains, with all isolates exhibiting some degree of heteroresistance.
  • - The results indicated that many isolates can adapt to higher fluconazole concentrations over time, suggesting that current antifungal susceptibility tests may need reevaluation to better understand their implications for treatment and patient outcomes in cryptococcosis cases.
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In resource-limited settings, where pneumocystosis in immunocompromised patients is infrequently observed, cost-efficient, reliable, and sensitive approaches for the diagnostic identification of in human tissue samples are desirable. Here, an in-house fluorescence in situ hybridization assay was comparatively evaluated against Grocott's staining as a reference standard with 30 paraffin-embedded tissue samples as well as against in-house real-time PCR with 30 respiratory secretions from immunocompromised patients with clinical suspicion of pneumocystosis. All pneumocystosis patients included in the study suffered from HIV/AIDS.

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A common strategy in antifungal susceptibility testing is the utilization of the standardized protocol based on the microbroth dilution assay approach as described by the Clinical Laboratory Standards Institute (CLSI) (M27-A4). One major problem for laboratories in resource-limited countries with this protocol arises from the use of expensive culture media like RPMI-1640 and 3-N-morpholinopropanesulfonic acid (MOPS) buffer. One approach of circumventing this problem in cases of economic need is the evaluation of alternative culture media and buffers.

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Article Synopsis
  • - The study focuses on the prevalence and characteristics of pulmonary mycoses in patients who have smear-negative tuberculosis in the Brazilian Amazon.
  • - Conducted at two tuberculosis reference institutions, the study analyzed 213 patients using various diagnostic methods and found that 7% were diagnosed with pulmonary mycoses, particularly aspergillosis and paracoccidioidomycosis.
  • - A significant number of patients with pulmonary mycoses were former tuberculosis sufferers, with common symptoms including chronic cough and lung cavitation injuries.
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Cryptococcosis is a life-threatening fungal infection caused by the Cryptococcus neoformans/Cryptococcus gattii species complex. Most cases are recorded in patients suffering from HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome). However, this infection also occurs in non-HIV patients with a proportion of 10-30% of all cases.

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Due to the increasing numbers of fungal infections and the emergence of drug-resistant fungi, optimization and standardization of diagnostic methods for the measurement of antifungal susceptibility are ongoing. The M27-A4 document by the US Clinical and Laboratory Standards Institute (CLSI) is presently used for the interpretation of minimum inhibitory concentrations of major opportunistic yeast species as measured by broth microdilution testing in many countries. Although microdilution is considered a benchmark for reproducible and accurate results, increased testing capacity, and limited human bias, the method is often inaccessible to routine clinical laboratories and researchers, especially in low-income countries.

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We present postmortem evidence of invasive pulmonary aspergillosis (IPA) in a patient with severe COVID-19. Autopsies of COVID-19 confirmed cases were performed. The patient died despite antimicrobials, mechanical ventilation, and vasopressor support.

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Background: Cryptococcosis is a global invasive mycosis associated with significant morbidity and mortality. In the northern region of Brazil, this disease is caused by Cryptococcus neoformans genotype VNI and Cryptococcus gattii genotype VGII. However, few environmental studies have been conducted in this large tropical area.

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Background: Cryptococcosis is a fungal disease of bad prognosis due to its pathogenicity and the toxicity of the drugs used for its treatment. The aim of this study was to investigate the medicinal potential of carbazole and -carboline alkaloids and derivatives against and .

Methods: MICs were established in accordance with the recommendations of the Clinical and Laboratory Standards Institute for alkaloids and derivatives against and genotypes VNI and VGI, respectively.

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Biosurfactants are surface-active compounds that have sparked interest in recent years because of their environmental advantages over conventional surfactants. The aim of this study was to investigate the production of biosurfactants by soil fungi isolated from the Amazon forest. Fungi colonies were isolated from soil samples and screened for biosurfactant production in submerged fermentation.

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Cryptococcus neoformans and Cryptococcus gattii are the main causative agents of cryptococcosis, a systemic fungal disease that affects internal organs and skin, and which is acquired by inhalation of spores or encapsulated yeasts. It is currently known that the C. neoformans/C.

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