An Approach to Suspected Invasive Fungal Infection in Patients with Hematologic Malignancy and HCT Recipients with Persistent Neutropenic Fever Despite Mold-Active Prophylaxis

D-index as a Risk Factor for Invasive Fungal Infections in Patients With Acute Lymphoblastic Leukemia From a Reference Hematology Center in Bogota

Introduction Patients with hematologic malignancies are susceptible hosts for the development of invasive fungal infection (IFI), one of the main life-threatening infectious complications faced by these patients. Currently, we have antifungal prophylaxis strategies and antifungal treatment schemes and we recognize that the main risk factor involved is profound and prolonged neutropenia. D-index and cumulative D-index are quantitative parameters, which determine the magnitude of neutropenia, as a function of duration and depth and their value correlates with the occurrence of IFI. Material and methods A case-control study in patients older than 18 years with acute lymphoblastic leukemia (ALL) was admitted between 2009 and 2019 at the National Cancer Institute for induction, consolidation and salvage chemotherapy. Results A total of 167 patients were included, who received 288 cycles of chemotherapy, the latter were considered the unit of analysis. A generalized estimating equations (GEE) model was designed to analyze correlated data; three quantitative and continuous variables of interest were included in this model: age (years), D-index and deep neutropenia (days). For the population D-index, an odds ratio (OR) = 1.000227 (95% CI 1.0002-1.0004); p < 0.001 was obtained. Conclusion D-index is associated with the development of IFI in patients with ALL, with an exponential increase in OR as the absolute value of the D-index increases.

Optimized Production of the Allylamine Antifungal "Terbinafine" by Lysinibacillus Isolate MK212927 Using Response Surface Methodology

Purpose

We aimed to optimize the factors affecting the production of the allylamine antifungal, terbinafine, by Lysinibacillus isolate MK212927, a natural producer of this broad-spectrum fungicidal compound.

Methods

We employed a central composite design to optimize the five most important variables influencing the production of terbinafine which were carbon source, nitrogen source, temperature, pH and agitation.

Results

The optimum conditions were found to be starch 5 g/L, ammonium chloride 5 g/L, temperature 32°C, agitation 150 rpm and pH 7. The actual response (inhibition zone diameter) was highly comparable to the value predicted by the model, indicating a valid model. Using the standard calibration curve of terbinafine, the optimized conditions resulted in an increase in the antifungal metabolite production (terbinafine) by about 1.6-fold (1814.662 µg/mL compared to 1165.550 µg/mL under standardized conditions).

Conclusion

This is the first report, to the best of our knowledge, on optimized production of terbinafine by Lysinibacillus species. Hence, these findings may be useful as baseline data for scaling up the production of terbinafine from a natural microbial source.

Utility of nested polymerase chain reaction for fungus in detecting clinically suspected patients of invasive fungal infections and its clinical correlation and comparison with fungal culture

Aims and Objectives:

The aim and objective of this study is to detect invasive fungal infections (IFIs) early and with more sensitivity by the nested polymerase chain reaction (PCR) for fungus as compared to fungal culture in clinically suspected patients and also explore its correlation in reference to age, duration of symptoms, immunocompromised status, and other risk factors predisposing to IFIs.

Materials and Methods:

In this cross-sectional study, 50 suspected patients admitted in medical acute care unit/intensive care unit (ACU/ICU) of Sir Sunderlal Hospital, Banaras Hindu University, Varanasi, India, comprised the study. All cases were selected based on the predefined inclusion and exclusion criteria. A detailed history, clinical examination, and all required investigations were done in all suspected patients. Blood samples were taken for nested-PCR for fungus and culture. Nested PCR was performed on extracted DNA form samples collected from all participants under the study.

Results:

Our study comprised of 50 suspected immunocompromised patients of IFIs. Among the participants under the study, the most common risk factor was diabetes mellitus (28% cases). Nearly two-thirds (60%) of the cases were 50 years or more. Around 70% of the cases had a history of illness more than 2 weeks. Nested PCR for fungus came out to be positive in 21/50 patients (42%); however, fungal culture was positive in none. Among the admitted patient in ACU/ICU, 75% were neutropenic.

Conclusions:

IFIs are more common in immunocompromised individuals, patients with comorbidities, long history of symptoms, and elderly population. Nested PCR for fungus has a high sensitivity (as compared to the fungal culture), and also they are rapid in giving the results. Thus, nested PCR for fungus can be used in a cost-effective manner for the early and reliable diagnosis of clinically suspected IFIs.