Challenging fungal infections in cystic fibrosis: a case of mixed Aspergillus species infection and antifungal combination testing.

Aspergillus stands as the predominant fungal genus in the airways of cystic fibrosis (CF) patients, significantly contributing to their morbidity and mortality. Aspergillus fumigatus represents the primary causative species for infections, though the emergence of rare species within the Aspergillus section Fumigati has become noteworthy. Among these, Aspergillus lentulus is particularly significant due to its frequent misidentification and intrinsic resistance to azole antifungal agents. In the management of invasive aspergillosis and resistant infections, combination antifungal therapy has proven to be an effective approach. This report documents a case involving the death of a CF patient due to a pulmonary exacerbation linked to the colonization of multiple Aspergillus species, including A. lentulus, A. fumigatus, and A. terreus, and treated with Itraconazole (ITC) monotherapy. We delineated the procedures used to characterize the Aspergillus isolates in clinical settings and simulated in vitro the impact of the combination antifungal therapy on the isolates obtained from the patient. We evaluated three different combinations: Amphotericin B (AMB)+Voriconazole (VRC), AMB+Anidulafungin (AND), and VRC+AND. Notably, all strains isolated from the patient exhibited a significant decrease in their minimum inhibitory concentration (MIC) or minimum effective concentration (MEC) values when treated with all antifungal combinations. The VRC+AMB combination demonstrated the most synergistic effects. This case report emphasizes the critical importance of susceptibility testing and precise identification of Aspergillus species to enhance patient prognosis. It also underscores the potential benefits of combined antifungal treatment, which, in this case, could have led to a more favourable patient outcome.

Milteforan, a promising veterinary commercial product against feline sporotrichosis.

Sporotrichosis, the cutaneous mycosis most commonly reported in Latin America, is caused by the Sporothrix clinical clade species, including Sporothrix brasiliensis and Sporothrix schenckii sensu stricto. In Brazil, S. brasiliensis represents a vital health threat to humans and domestic animals due to its zoonotic transmission. Itraconazole, terbinafine, and amphotericin B are the most used antifungals for treating sporotrichosis. However, many strains of S. brasiliensis and S. schenckii have shown resistance to these agents, highlighting the importance of finding new therapeutic options. Here, we demonstrate that milteforan, a commercial veterinary product against dog leishmaniasis whose active principle is miltefosine, is a possible therapeutic alternative for the treatment of sporotrichosis, as observed by its fungicidal activity in vitro against different strains of S. brasiliensis and S. schenckii, and by its antifungal activity when used to treat infected epithelial cells and macrophages. Our results suggest milteforan as a possible alternative to treat feline sporotrichosis.

Uncovering a Novel cyp51A Mutation and Antifungal Resistance in Aspergillus fumigatus through Culture Collection Screening.

BACKGROUND: Aspergillus fumigatus is an important concern for immunocompromised individuals, often resulting in severe infections. With the emergence of resistance to azoles, which has been the therapeutic choice for Aspergillus infections, monitoring the resistance of these microorganisms becomes important, including the search for mutations in the cyp51A gene, which is the gene responsible for the mechanism of action of azoles. We conducted a retrospective analysis covering 478 A. fumigatus isolates. METHODS: This comprehensive dataset comprised 415 clinical isolates and 63 isolates from hospital environmental sources. For clinical isolates, they were evaluated in two different periods, from 1998 to 2004 and 2014 to 2021; for environmental strains, one strain was isolated in 1998, and 62 isolates were evaluated in 2015. Our primary objectives were to assess the epidemiological antifungal susceptibility profile; trace the evolution of resistance to azoles, Amphotericin B (AMB), and echinocandins; and monitor cyp51A mutations in resistant strains. We utilized the broth microdilution assay for susceptibility testing, coupled with cyp51A gene sequencing and microsatellite genotyping to evaluate genetic variability among resistant strains. RESULTS: Our findings reveal a progressive increase in Minimum Inhibitory Concentrations (MICs) for azoles and AMB over time. Notably, a discernible trend in cyp51A gene mutations emerged in clinical isolates starting in 2014. Moreover, our study marks a significant discovery as we detected, for the first time, an A. fumigatus isolate carrying the recently identified TR46/F495I mutation within a sample obtained from a hospital environment. The observed cyp51A mutations underscore the ongoing necessity for surveillance, particularly as MICs for various antifungal classes continue to rise. CONCLUSIONS: By conducting resistance surveillance within our institution's culture collection, we successfully identified a novel TR46/F495I mutation in an isolate retrieved from the hospital environment which had been preserved since 1998. Moreover, clinical isolates were found to exhibit TR34/L98H/S297T/F495I mutations. In addition, we observed an increase in MIC patterns for Amphotericin B and azoles, signaling a change in the resistance pattern, emphasizing the urgent need for the development of new antifungal drugs. Our study highlights the importance of continued monitoring and research in understanding the evolving challenges in managing A. fumigatus infections.

Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry azole susceptibility assessment in Candida and Aspergillus species.

BACKGROUND: Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) allows rapid pathogen identification and potentially can be used for antifungal susceptibility testing (AFST). OBJECTIVES: We evaluated the performance of the MALDI-TOF MS in assessing azole susceptibility, with reduced incubation time, by comparing the results with the reference method Broth Microdilution. METHODS: Resistant and susceptible strains of Candida (n = 15) were evaluated against fluconazole and Aspergillus (n = 15) against itraconazole and voriconazole. Strains were exposed to serial dilutions of the antifungals for 15 h. Microorganisms' protein spectra against all drug concentrations were acquired and used to generate a composite correlation index (CCI) matrix. The comparison of autocorrelations and cross-correlations between spectra facilitated by CCI was used as a similarity parameter between them, enabling the inference of a minimum profile change concentration breakpoint. Results obtained with the different AFST methods were then compared. FINDINGS: The overall agreement between methods was 91.11%. Full agreement (100%) was reached for Aspergillus against voriconazole and Candida against fluconazole, and 73.33% of agreement was obtained for Aspergillus against itraconazole. MAIN CONCLUSIONS: This study demonstrates MALDI-TOF MS' potential as a reliable and faster alternative for AFST. More studies are necessary for method optimisation and standardisation for clinical routine application.

Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry azole susceptibility assessment in Candida and Aspergillus species

BACKGROUND Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) allows rapid pathogen identification and potentially can be used for antifungal susceptibility testing (AFST). OBJECTIVES We evaluated the performance of the MALDI-TOF MS in assessing azole susceptibility, with reduced incubation time, by comparing the results with the reference method Broth Microdilution. METHODS Resistant and susceptible strains of Candida (n = 15) were evaluated against fluconazole and Aspergillus (n = 15) against itraconazole and voriconazole. Strains were exposed to serial dilutions of the antifungals for 15 h. Microorganisms' protein spectra against all drug concentrations were acquired and used to generate a composite correlation index (CCI) matrix. The comparison of autocorrelations and cross-correlations between spectra facilitated by CCI was used as a similarity parameter between them, enabling the inference of a minimum profile change concentration breakpoint. Results obtained with the different AFST methods were then compared. FINDINGS The overall agreement between methods was 91.11%. Full agreement (100%) was reached for Aspergillus against voriconazole and Candida against fluconazole, and 73.33% of agreement was obtained for Aspergillus against itraconazole. MAIN CONCLUSIONS This study demonstrates MALDI-TOF MS' potential as a reliable and faster alternative for AFST. More studies are necessary for method optimisation and standardisation for clinical routine application.

Selection of Aspergillus fumigatus isolates carrying the G448S substitution in CYP51A gene after long-term treatment with voriconazole in an immunocompromised patient.

We present a case of a 55-year-old man with a heart transplant who acquired Invasive Aspergillosis by Aspergillus fumigatus with the focus in the kidney. During about two years of antifungal treatment, most of the time with voriconazole, it was possible to obtain nine isolates of A. fumigatus, with the same genotypic characteristics, but with an increase in MIC for several azoles. The two last isolates presented high MICs for Voriconazole (>8 µg/mL>). Sequencing of the CYP51A gene showed G448S amino acid substitution in the same two isolates. In long-term treatments with antifungals, it would be important to regularly evaluate the susceptibility of isolated strains, as resistance to azoles has been increasingly described around the world.

Aspergillus fumigatus Clinical Isolates Carrying CYP51A with TR34/L98H/S297T/F495I Substitutions Detected after Four-Year Retrospective Azole Resistance Screening in Brazil.

Azole antifungal resistance in Aspergillus fumigatus is a worldwide concern. As in most public hospitals in Brazil, antifungal susceptibility tests are not routinely performed for filamentous fungi at our institution. A 4-year retrospective azole antifungal resistance screening revealed two azole-resistant A. fumigatus clinical isolates carrying the CYP51A TR34 (34-bp tandem repeat)/L98H (change of L to H at position 98)/S297T/F495I resistance mechanism mutations, obtained from two unrelated patients. Broth microdilution antifungal susceptibility testing showed high MICs for itraconazole, posaconazole, and miconazole. Short tandem repeat (STR) typing analysis presented high levels of similarity between these two isolates and clinical isolates with the same mutations reported from the Netherlands, Denmark, and China, as well as environmental isolates from Taiwan. Our findings might indicate that active searching for resistant A. fumigatus is necessary. They also represent a concern considering that our hospital provides tertiary care assistance to immunocompromised patients who may be exposed to resistant environmental isolates. We also serve patients who receive prophylactic antifungal therapy or treatment for invasive fungal infections for years. In these two situations, isolates resistant to the antifungal in use may be selected within the patients themselves. We do not know the potential of this azole-resistant A. fumigatus strain to spread throughout our country. In this scenario, the impact on the epidemiology and use of antifungal drugs will significantly alter patient care, as in other parts of the world. In summary, this finding is an important contribution to alert hospital laboratories conducting routine microbiological testing to perform azole resistance surveillance and antifungal susceptibility tests of A. fumigatus isolates causing infection or colonization in patients at high risk for systemic aspergillosis.

Surveillance for azoles resistance in Aspergillus spp. highlights a high number of amphotericin B-resistant isolates.

Aspergillus spp. are the most common invasive mould infection and are responsible for high mortality. Aspergillus fumigatus is currently of interest because resistance to azole antifungals has emerged. The Campinas University Hospital (HC-UNICAMP) receives high-risk patients susceptible to opportunistic infections but there have been no reports of resistant A. fumigatus. This study aimed to assess the susceptibility profile of Aspergillus isolates, specifically looking for azole resistance. ITS and ß-tubulin DNA sequencing was performed on 228 sequential clinical isolates. Broth microdilution susceptibility testing was performed for all isolates. A. fumigatus represented 74% of the isolates followed by Aspergillus flavus (12%). Nine A. fumigatus isolates from 9 different patients showed high MIC values to at least 1 azole, but cyp51A polymorphisms were detected in only 6 isolates and none correlated with known resistance mutations. The most troubling observation was that the minimum inhibitory concentration for amphotericin B was elevated (≥2 mg L-1 ) in 87% of patients with A. flavus isolates and 43% with Aspergillus fumigatus isolates. Given that amphotericin B is used to treat azole-resistant infections, these data highlight the need for continuous surveillance in Aspergillus for all antifungal resistance to implement correct treatment strategies for the management of these pathogens.