Clinical and Demographic Features of Paracoccidioidomycosis in Argentina: A Multicenter Study Analysis of 466 Cases.

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.

Usefulness of Sona Aspergillus Galactomannan LFA with digital readout as diagnostic and as screening tool of COVID-19 associated pulmonary aspergillosis in critically ill patients. Data from a multicenter prospective study performed in Argentina.

COVID-19-associated pulmonary aspergillosis (CAPA) incidence varies depending on the country. Serum galactomannan quantification is a promising diagnostic tool since samples are easy to obtain with low biosafety issues. A multicenter prospective study was performed to evaluate the CAPA incidence in Argentina and to assess the performance of the lateral flow assay with digital readout (Sona Aspergillus LFA) as a CAPA diagnostic and screening tool. The correlation between the values obtained with Sona Aspergillus LFA and Platelia® EIA was evaluated. In total, 578 serum samples were obtained from 185 critically ill COVID patients. CAPA screening was done weekly starting from the first week of ICU stay. Probable CAPA incidence in critically ill patients was 10.27% (19/185 patients when LFA was used as mycological criteria) and 9% (9/100 patients when EIA was used as mycological criteria). We found a very good correlation between the two evaluated galactomannan quantification methods (overall agreement of 92.16% with a Kappa statistic value of 0.721). CAPA diagnosis (>0.5 readouts in LFA) were done during the first week of ICU stay in 94.7% of the probable CAPA patients. The overall mortality was 36.21%. CAPA patients' mortality and length of ICU stay were not statistically different from for COVID (non-CAPA) patients (42.11 vs 33.13% and 29 vs 24 days, respectively). These indicators were lower than in other reports. LFA-IMMY with digital readout is a reliable tool for early diagnosis of CAPA using serum samples in critically ill COVID patients. It has a good agreement with Platelia® EIA. LAY SUMMARY: The incidence of COVID-associated pulmonary aspergillosis (CAPA) in critically-ill Argentinian patients was established (10.27%). Serum galactomannan quantification was useful as a screening tool for this mycosis. A good agreement between Platelia® EIA and Sona Aspergillus LFA is reported.

Differential distribution patterns of Fonsecaea agents of chromoblastomycosis, exemplified by the first case due to F. monophora from Argentina.

Chromoblastomycosis is a mutilating infection of the skin and subcutaneous tissues caused by melanized fungi belonging to the order Chaetothyriales. Proven cases of the main agent, Fonsecaea pedrosoi are mainly limited to (sub)tropical, humid climates of Latin and Central America and the Caribbean. Fonsecaea monophora has a global distribution along the equator. Cases outside the (sub)tropics have thus far mostly been considered to have been imported, but here we report the first endemic case by F. monophora from Argentina. Patient was a 82-year-old rural female worker from Corrientes, a province with a dry continental climate.

Acute pulmonary involvement by paracoccidiodomycosis disease immediately after kidney transplantation: Case report and literature review.

Paracoccidioides brasiliensis is the cause of paracoccidioidomycosis, one of the most important systemic mycoses in Latin America. Human disease has been observed in a limited geographic and ecological niche, and it is attributed to exposure to the fungus in soil. Most primary infections are subclinical, as the infection is contained by the host mainly through cell-mediated immune response. However, as the fungus has the ability to survive in a dormant state for long periods, an impairment of the immune response may lead to reactivation and clinical disease. Surprisingly, paracoccidioidomycosis has rarely been reported in transplanted patients. The aim of this communication is to report a case occurring in a kidney recipient in an acute clinical form immediately after transplantation, and to review the available information on previously reported cases.

Set of classical PCRs for detection of mutations in Candida glabrata FKS genes linked with echinocandin resistance.

Clinical echinocandin resistance among Candida glabrata strains is increasing, especially in the United States. Antifungal susceptibility testing is considered mandatory to guide therapeutic decisions. However, these methodologies are not routinely performed in the hospital setting due to their complexity and the time needed to obtain reliable results. Echinocandin failure in C. glabrata is linked exclusively to Fks1p and Fks2p amino acid substitutions, and detection of such substitutions would serve as a surrogate marker to identify resistant isolates. In this work, we report an inexpensive, simple, and quick classical PCR set able to objectively detect the most common mechanisms of echinocandin resistance in C. glabrata within 4 h. The usefulness of this assay was assessed using a blind collection of 50 C. glabrata strains, including 16 FKS1 and/or FKS2 mutants.

Influence of capsule size on the in vitro activity of antifungal agents against clinical Cryptococcus neoformans var. grubii strains.

Cryptococcosis causes disseminated disease in AIDS patients. In contrast to what occurs in laboratory conditions, a large capsule is produced by Cryptococcus neoformans in vivo during infection. The aim of this study was to compare the in vitro activity of different antifungal agents against 34 clinical isolates of C. neoformans var. grubii without or with capsule induction (CLSI, CLSI-C, respectively), following the CLSI M27A3 document. Capsule induction was obtained by addition of NaHCO(3) and incubation with CO(2). The geometric means of the MICs, in µg ml(-1), for CLSI and CLSI-C cultures, respectively, were 1.9 and 9.8 for fluconazole; 0.04 and 0.08 for itraconazole; 0.04 and 0.05 for voriconazole; 0.16 and 0.38 for amphotericin B; and 1.6 and 5.6 for 5-flucytosine. Thus fluconazole showed the highest MICs after capsule induction. Determination of antifungal activity after capsule induction may be clinically relevant and could be used to evaluate the correlation between in vitro results and clinical outcome.

Evaluation of the in vitro activity of amphotericin B by time-kill curve methodology against large and small capsulate C. neoformans isolates.

We have evaluated and compared the activity of amphotericin B (AMB) by time-kill curve methodology against 20 clinical Cryptococcus neoformans isolates in which capsule induction in vitro was performed. Overall, large capsulated isolates were more resistant to killing by AMB over time when compared with those small capsulate ones.

Synthesis and antifungal activity of some substituted phenothiazines and related compounds.

Several phenothiazines and related compounds were synthesized and their antifungal activity was evaluated in vitro. The results observed for α-chloro-N-acetyl phenothiazine led us to choose this compound as a lead in the search of antifungal agents.

Activity and post antifungal effect of chlorpromazine and trifluopherazine against Aspergillus, Scedosporium and zygomycetes.

The phenothiazine compounds chlorpromazine and trifluopherazine are antipsychotic agents that exhibit antimicrobial activity against bacteria, some protozoa and yeasts. Data of activity against filamentous fungi are lacking. The in vitro activity and postantifungal effect (PAFE) of chlorpromazine and trifluopherazine was determined against Aspergillus species, zygomycetes and Scedosporium species. In vitro susceptibility testing was performed with CLSI M38A and the PAFE was determined with previously established methods. Both drugs inhibited the growth of all fungi tested at concentrations of 16 to 64 microg ml(-1). For Aspergillus species the mean PAFE was 3.7 and 4.7 h; for zygomycetes, 3.1 and 3.4 h; for Scedosporium, 4.3 and 5.3 h for chlorpromazine and trifluoroperazine respectively. These are the first drugs shown to induce PAFE against Scedosporium. We show that phenothiazine compounds have in vitro antifungal activity and exhibit PAFE against a broad range of filamentous fungal pathogens. Although the exact mechanism of action is unknown, further studies are needed to explore the clinical usefulness of phenothiazine compounds.

Antifungal combinations.

The increase in fungal infections and the change in fungal epidemiology is caused by the extensive use of antifungal agents to treat fungal infections that are being diagnosed in severly immunocompromised hosts. In addition, opportunistic fungal infections resistant to antifungal drugs have become increasingly common, and the armamentarium for treatment remains limited. A possible approach to overcoming these problems is to combine antifungal drugs, especially if the mechanisms of action are different. The in vitro test is the first step to evaluate possible antifungal combinations. In this chapter, the three most frequently used metholodologies are described: checkerboard, E-test, and time-kill curves. The description of each technique and intrepretaion of the results are addressed in detail.

Potent synergistic in vitro interaction between nonantimicrobial membrane-active compounds and itraconazole against clinical isolates of Aspergillus fumigatus resistant to itraconazole.

To develop new approaches for the treatment of invasive infections caused by Aspergillus fumigatus, the in vitro interactions between itraconazole (ITZ) and seven different nonantimicrobial membrane-active compounds--amiodarone (AMD), amiloride, lidocaine, lansoprazole (LAN), nifedipine (NIF), verapamil, and fluphenazine--against seven ITZ-susceptible and seven ITZ-resistant (ITZ-R) strains were evaluated by the checkerboard microdilution method based on National Committee for Clinical Laboratory Standards M-38A guidelines. The nature and the intensity of the interactions were assessed by a nonparametric approach (fractional inhibitory concentration [FIC] index model), a fully parametric response surface approach (Greco model) of the Loewe additivity no-interaction theory, and the nonparametric (Prichard model) and semiparametric response surface approaches of the Bliss independence (BI) no-interaction theory. Statistically significant synergy was found for the combination of ITZ and AMD and the combination of LAN and NIF, although with different intensities against ITZ-R strains. The FIC index values ranged from 1 to 0.02 for ITZ-AMD, 0.53 to 0.04 for ITZ-LAN, and 0.28 to 0.06 for ITZ-NIF. By use of the BI-based model, the strongest synergy was found for the combination of ITZ with AMD, followed by the combination of ITZ and NIF. The parametric models could not be fit adequately because most of the drugs alone did not show any effect and, thus, no sigmoid dose-response. In general, the combination of ITZ with calcium pump blockers displayed in vitro synergistic activity, primarily against ITZ-R strains, and warrants further investigation.

In vitro synergistic interaction between amphotericin B and pentamidine against Scedosporium prolificans.

To develop new approaches for the treatment of invasive infections caused by Scedosporium prolificans, the in vitro interaction between amphotericin B and pentamidine against 30 clinical isolates was evaluated using a checkerboard microdilution method based on the National Committee for Clinical Laboratory Standards M38-P guidelines. The interaction between the drugs was analyzed using fractional inhibitory concentration index (FICI) analysis and response surface modeling. Amphotericin B alone was inactive against all the isolates. The geometric mean MIC for pentamidine was 57 micro g/ml (range, 8 to 256 micro g/ml; MIC at which 50% of the isolates tested were inhibited [MIC(50)], 64 micro g/ml; MIC(90), 128 micro g/ml). The combination was synergistic against 28 of 30 isolates (93.3%) by FICI analysis and 30 of 30 (100%) by response surface modeling analysis. Antagonism was not observed.

In vitro susceptibilities of zygomycetes to combinations of antimicrobial agents.

Combinations of antimicrobial agents were tested against 35 strains of zygomycetes. The interaction between amphotericin B and rifampin was synergistic or additive. Flucytosine alone was inactive and, upon combination with amphotericin B, synergy was not achieved. The combination of amphotericin B with terbinafine was synergistic for 20% of strains, and the interaction between terbinafine and voriconazole was synergistic for 44% of strains. Antagonism was not observed.

Method for measuring postantifungal effect in Aspergillus species.

An in vitro method for determination of postantifungal effect (PAFE) in molds was developed by using three isolates each of Aspergillus fumigatus, A. flavus, A. terreus, A. nidulans, and A. ustus. MICs of amphotericin B and itraconazole were determined by using National Committee for Clinical Laboratory Standards guidelines (M38-P). The inoculum was prepared in RPMI 1640 broth buffered with MOPS (morpholinepropanesulfonic acid) at pH 7.0, and conidia were exposed to amphotericin B and itraconazole at concentrations of 4, 1, and 0.25 times the MIC, each for 4, 2, and 1 h at 37 degrees C. The same procedure was followed for controls with drug-free medium. Following exposure, the conidia were washed three times in saline and the numbers of CFU per milliliter were determined. Exposed and control conidia were then inoculated into microtitration plates and incubated at 37 degrees C for 48 h in a spectrophotometer reader. The optical density (OD) was measured automatically at 10-min intervals, resulting in growth curves. PAFE was quantified by comparing three arbitrary points in the control growth curve, the first increase of OD and the points when 20 and 50% of the maximal growth were reached, with the growth curve of drug-exposed conidia. Amphotericin B induced PAFE in A. fumigatus at four times the MIC after 2 and 4 h of exposure ranging from 1.83 to 6.00 h and 9.33 to 10.80 h, respectively. Significantly shorter PAFEs or lack of PAFE was observed for A. terreus, A. ustus, and A. nidulans. Itraconazole did not induce measurable PAFE in the Aspergillus isolates at any concentration or exposure time tested. Further studies are warranted to investigate the implications of PAFE in relation to clinical efficacy and dosing frequency.

In vitro activities of pentamidine, pyrimethamine, trimethoprim, and sulfonamides against Aspergillus species.

The susceptibilities of 70 strains of Aspergillus species were tested against seven different sulfa drugs and pentamidine by a microdilution method with RPMI 1640 and yeast nitrogen base media. Sulfamethoxazole, sulfadiazine, and pentamidine were active in vitro. The MICs obtained with RPMI 1640 were significantly higher than those with yeast nitrogen base. More studies are needed to further elucidate the action of these drugs.

Interferon gamma increases survival in murine experimental cryptococcosis

Se evaluo la efectividad del interferon-µ (IFN-µ) recombinante de rata en un modelo experimental de criptococosis desarollado en ratones Balb/C inoculados por via intraperitoneal con la cepa Rivas de Cryptococcus neoformas (C. neoformans). Se tuvieron en cuenta el tiempo de sobrevida de los animales, el aspecto macroscopico de los organos en la autopsia, la presencia de levaduras capsuladas en los tejidos y la siembra masiva de un homogenato de cerebro. El tratamiento con IFN-µ, en dosis diarias de 10.000 UI, no modifico estos parametros cuando la dosis infectante fue de 10 indice 7 levaduras y el tratamiento se retardo 5 dias post-infeccion (media de sobrevida de 21 vs. 23 dias en los grupos de control y tratados con IFN-µ, respectivamente)...