In Vitro Activity of Isavuconazole and Amphotericin B in Association against Mucorales

Mucormycoses can be treated with the combination of Amphotericin B and Isavuconazole. This study evaluates the effects of these drugs in vitro against 59 strains representing 12 Mucorales. In vitro testing of the two drugs together and alone was performed using the MIC Test strip "Epsilon test synergy-method" (ETSM), which is more standard in clinical practice than microbroth dilution testing. Amphotericin B and Isavuconazole have synergistic/additive effects against L. corymbifera, R. arrhizus and M. circinelloides. Different effects have been shown for other Mucorales. ETSM can help the clinical management of mucormycosis from a practical point of view, due to its feasibility in the laboratory.

Deoxycholate amphotericin for management of mucormycosis: a retrospective cohort study from South India

INTRODUCTION

Liposomal amphotericin use is limited in developing countries due to its extremely high cost and availability. Therefore, the study aimed to evaluate deoxycholate amphotericin B's utility and adverse effect profile in patients with mucormycosis.

METHODOLOGY

This retrospective cohort study from 2019 to 2021 included patients with proven mucormycosis who received deoxycholate amphotericin B for more than or equal to five days and had at least three creatinine values on treatment. Baseline demographic details, risk factors and treatment details of all the patients were recorded. In addition, the details of treatment-related adverse effects and outcomes were ascertained.

RESULTS

Of the 57 included patients, a history of diabetes, COVID-19 and steroid use was present in 49 (86%), 43 (75.4%) and 33 (57.9%) patients, respectively. Isolated rhino-orbital mucormycosis was the most common presentation (n=49, 86%). The median time of follow-up was 48 (30.5-90) days. A total of 8 (14%) patients died during the hospital stay. The median duration of amphotericin treatment was 21 (14-40) days. Thirty-nine patients (68.4%) developed hypokalaemia on treatment, while 27 (47.4%) patients developed hypomagnesaemia. A total of 34 (59.6%) patients developed AKI on treatment. The median day of development of AKI was 6 (4-10) days. The median baseline, highest and final creatinine values were 0.78 (0.59-0.94) mg/dl, 1.27 (0.89-2.16) mg/dl and 0.93 (0.74-1.59) mg/ dl respectively. The median percentage change from baseline to highest value and last follow-up value was 45% (0.43%-161%) and 25% (-4.8%-90.1%) respectively. The final creatinine was less than 150% of the baseline in 36 (63.2%) patients.

CONCLUSION

Deoxycholate amphotericin is an acceptable alternative for treating mucormycosis in resource-constrained settings.

Mucormycosis in COVID-19 pandemic: Risk factors and linkages

Mucormycosis is a serious and potentially fatal fungal infection caused by a type of rare but opportunistic fungal pathogen called mucormycetes. Recently, mucormycosis, also known as black fungus, made severe chaos in India during the second wave (between April and June 2021) of the tragical COVID-19 epidemic by its sudden and devastating surge with up to 50% mortality rate. While the exact cause of its sharp rise suddenly and specifically during the second wave still remains debatable, it has been noted that the people who are diabetic and have recovered from COVID-19 infection are more predisposed to mucormycosis. Nevertheless, the precise reason and mechanism(s) underlying the surge of this deadly infection needs to be investigated to comprehend its pathogenesis and pathological elements and discover rationale preventative/ therapeutic solutions. It is speculated that the indiscriminate use of steroids, antibiotics and zinc as a self-medication practice that increased during the COVID-19 epidemic may have promoted the dysbiosis of gut microbiota thereby inducing immune-suppression and making the risk group highly susceptible to this mycotic disease. In these contexts, this timely article attempts to contemplate and discuss some of the possible factors and potential mechanisms that can help to understand and explain the conundrum of sudden, steep and deadly upsurge of mucormycosis infections during the second wave of COVID-19 epidemic.

COVID-19-associated mucormycosis: Preliminary report from a tertiary eye care centre

Purpose:

Mucormycosis is a life-threatening infection that has made sudden comeback in COVID-19 era. We conducted this study to determine demography, site of involvement, management, and outcome in these patients.

Methods:

All cases presenting with signs and symptoms of mucormycosis were thoroughly evaluated and confirmed diagnosis was made on demonstration of fungi in the tissue (or body fluids) either by direct microscopy and/or culture. Patients underwent computerized tomography scan for paranasal sinuses and magnetic resonance imaging scan with contrast orbit and brain to know extent of disease.

Results:

540 proven cases of mucormycosis were included. Most common age group affected was 41–50 years with male preponderance (69%). Sinonasal was the most common site of involvement in mucormycosis (100%), followed by orbital (51.85%), cerebral (9.44%), cutaneous (1.85%), and pulmonary (0.18%). Most common presentation was periocular and facial swelling (28%). 97.96% patients had associated diabetes and 89.44% patients had history of COVID-19 with concurrent steroids use (84.85%), higher antibiotics (82.59%), oxygen therapy (52.40%), remdesivir (28.89%), and biological agents (2.56%). Duration from COVID-19 positivity to presentation of mucormycosis was 22.56 days, while 4.44% patients had coexisting COVID-19 with mucormycosis. The mortality rate was 9.25% (50/540).

Conclusion:

Timely diagnosis and appropriate management can ameliorate the consequences of mucormycosis. With the third wave of COVID-19 coming, epidemiological study to identify risk factors and possible management options can help physicians to develop the treatment strategy.

Invasive Fungal Infections Among Immunocompromised Patients in Critical Care Settings: Infection Prevention Risk Mitigation

Most fungal infections are common in humans. Pathogenic fungi are opportunistic but can cause fungal infection disease in patients with immunocompromised conditions, such as malignancy, chemotherapy, transplantation, acquired immunodeficiency syndrome, and usage of immunosuppressant drugs. Most invasive infections are caused by Aspergillus species, mucormycetes, Cryptococcus species, and Candida species. This article focuses on environmental fungi such as Aspergillus species and mucormycetes because the mode of transmission is different. The purpose of this article is to discuss invasive fungal infections (IFIs) caused by environmental fungi and to educate critical care nurses about infection control and risk mitigation to prevent IFIs.

Fungal pneumonia in kidney transplant recipients

Fungal pneumonia is a dreaded complication encountered after kidney transplantation, complicated by increased mortality and often associated with graft failure. Diagnosis can be challenging because the clinical presentation is non-specific and diagnostic tools have limited sensitivity and specificity in kidney transplant recipients and must be interpreted in the context of the clinical setting. Management is difficult due to the increased risk of dissemination and severity, multiple comorbidities, drug interactions and reduced immunosuppression which should be applied as an important adjunct to therapy. This review will focus on the main causes of fungal pneumonia in kidney transplant recipients including Pneumocystis, Aspergillus, Cryptococcus, mucormycetes and Histoplasma. Epidemiology, clinical presentation, laboratory and radiographic features, specific characteristics will be discussed with an update on diagnostic procedures and treatment.

Saksenaea vasiformis infections: A case of an immunocompetent adult after mild injury and a literature review

Saksenaea vasiformis is an emerging human pathogen, belonging to the order Mucorales of the subphylum Mucormycotina, most often associated with rhino-cerebral, cutaneous and subcutaneous infections following trauma. A review of the published literature was attempted on the occasion of a cutaneous leg infection with favorable outcome in a young immunocompetent man after mild injury. The overall aim was the facilitation of the study and the integrated understanding of this kind of fungal infections.

Host Sensing by Pathogenic Fungi

The ability to cause disease extends from the ability to grow within the host environment. The human host provides a dynamic environment to which fungal pathogens must adapt to in order to survive. The ability to grow under a particular condition (i.e., the ability to grow at mammalian body temperature) is considered a fitness attribute and is essential for growth within the human host. On the other hand, some environmental conditions activate signaling mechanisms resulting in the expression of virulence factors, which aid pathogenicity. Therefore, pathogenic fungi have evolved fitness and virulence attributes to enable them to colonize and infect humans. This review highlights how some of the major pathogenic fungi respond and adapt to key environmental signals within the human host.

Role of isavuconazole in the treatment of invasive fungal infections

Despite recent advances in both diagnosis and prevention, the incidence of invasive fungal infections continues to rise. Available antifungal agents to treat invasive fungal infections include polyenes, triazoles, and echinocandins. Unfortunately, individual agents within each class may be limited by spectrum of activity, resistance, lack of oral formulations, significant adverse event profiles, substantial drug–drug interactions, and/or variable pharmacokinetic profiles. Isavuconazole, a second-generation triazole, was approved by the US Food and Drug Administration in March 2015 and the European Medicines Agency in July 2015 for the treatment of adults with invasive aspergillosis (IA) or mucormycosis. Similar to amphotericin B and posaconazole, isavuconazole exhibits a broad spectrum of in vitro activity against yeasts, dimorphic fungi, and molds. Isavuconazole is available in both oral and intravenous formulations, exhibits a favorable safety profile (notably the absence of QTc prolongation), and reduced drug–drug interactions (relative to voriconazole). Phase 3 studies have evaluated the efficacy of isavuconazole in the management of IA, mucormycosis, and invasive candidiasis. Based on the results of these studies, isavuconazole appears to be a viable treatment option for patients with IA as well as those patients with mucormycosis who are not able to tolerate or fail amphotericin B or posaconazole therapy. In contrast, evidence of isavuconazole for invasive candidiasis (relative to comparator agents such as echinocandins) is not as robust. Therefore, isavuconazole use for invasive candidiasis may initially be reserved as a step-down oral option in those patients who cannot receive other azoles due to tolerability or spectrum of activity limitations. Post-marketing surveillance of isavuconazole will be important to better understand the safety and efficacy of this agent, as well as to better define the need for isavuconazole serum concentration monitoring.

Posaconazole: an emerging therapeutic option for invasive rhino-orbito-cerebral mucormycosis

Posaconazole has significant activity against the Mucormycetes. However, data are limited on the clinical efficacy of posaconazole for treating rhino-orbito-cerebral mucormycosis (ROCM). The aim of this study is to assess the efficacy and safety of posaconazole in patients with ROCM. We included 12 consecutive adult patients admitted with ROCM and treated with posaconazole between January 2010 and February 2015. The main outcome of the study was the overall success rate (i.e. either complete or partial response) at the end of treatment. We also assessed serum posaconazole concentrations in a subgroup of patients. Of the 12 patients who received posaconazole, eight patients (66.6%) had complete resolution with median follow-up of 6.5 months (range 2-24 months). Two patients (16.6%) had significant reduction of disease and two (16.6%) had marked residual disease on follow-up. Uncontrolled diabetes was the predisposing factor in all except one patient. One patient developed diarrhoea on posaconazole, which settled without discontinuation of the drug. Posaconazole appears to be a safe and effective antifungal agent in diabetic patients with ROCM, especially in those who have toxicity with polyene therapy.