In vitro activity of a liposomal nystatin formulation (Nyotran) against Cryptococcus neoformans

The in vitro antifungal activity of a new liposomal nystatin formulation (NISTL, Nyotran, Aronex Ltd., EE.UU.) was evaluated by a microdilution method with RPMI based on the M27A document of the National Committee for Clinical Laboratory Standards (NCCLS) against 22 isolates of Cryptococcus neoformans. This antifungal activity was compared with those of other seven antifungal agents, such as nystatin (NIST), amphotericin B deoxycholate, liposomal amphotericin B, amphotericin B lipid complex, amphotericin B colloidal dispersion, fluconazole, and itraconazole. NISTL was more active in vitrothan NIST, showing MIC values 2-3 fold smaller in 90% of the isolates. The results obtained suggest that this new formulation would be very helpful for the treatment of cryptococcosis.     

Nebulized Liposomal Amphotericin B for Treatment of Pulmonary Infection Caused by <Emphasis Type="Italic">Hormographiella aspergillata</Emphasis>: Case Report and Literature Review

Invasive fungal infection is a serious complication following allogeneic hematopoietic stem cell transplantation. Pulmonary infection due to Hormographiella aspergillata is an uncommon condition associated with a high mortality rate. The susceptibility of H. aspergillata to available antifungal agents is not well established. We report for the first time a case of H. aspergillata lung infection that responded poorly to conventional treatment with liposomal amphotericin B (LAmB; 3 mg kg^?1 of body weight per day) with renal damage at higher posology (5 mg kg^?1 of body weight per day), but improved rapidly after addition of nebulized LAmB to intravenous LAmB (3 mg kg^?1 of body weight per day). Successful treatment of our patient using nebulized LAmB would be worth evaluating in cases refractory to standard treatment or when the reference treatment may not be extended due to interaction or side effects.     

Comparison of Different In Vitro Tests to Detect <Emphasis Type="Italic">Cryptococcus neoformans</Emphasis> Not Susceptible to Amphotericin B

Infections due to Cryptococcus neoformans cause severe disease, mostly in AIDS patients. The antifungal drug recommended for the initial treatment of these infections is amphotericin B with or without flucytosine, but treatment failure occurs, associated with high mortality. Thus, antifungal susceptibility testing is needed. However, the in vitro susceptibility tests available for C. neoformans are not useful to detect isolates that are not susceptible to antifungal agents such as amphotericin B. The aims of the present study were: (1) to determine and compare the in vitro activity of amphotericin B against C. neoformans clinical isolates by using different dilution and diffusion methods; (2) to evaluate the concordance among the methods used and the reference method; (3) to evaluate which method could be the best to correlate with the clinical outcome. The reference method EDef 7.2 from the European Committee on Antimicrobial Susceptibility Testing and commercial Etest strips were used to determine the minimal inhibitory concentration against amphotericin B. curves, minimal fungicidal concentration, and a disk diffusion method were also developed to evaluate the cidal activity of amphotericin B. The time–kill curve assay showed correlation (p < 0.05) with clinical outcome, whereas EDef 7.2, minimal fungicidal concentration, Etest, and disk diffusion showed no correlation (p > 0.05). Thus, the time–kill curve assay could be a potential tool to guide a more efficient treatment when amphotericin B is used.     

A Mucormycosis Case in a Cirrhotic Patient Successfully Treated with Posaconazole and Review of Published Literature

Mucormycosis is an invasive fungal infection associated with a high mortality rate, especially in immunocompromised hosts. Mucormycosis rarely occurs in cirrhotic patients. Here, we report a case of mucormycosis with underlying liver cirrhosis and diabetes mellitus. The patient suffered from maxillary sinusitis and osteomyelitis, and the infection was successfully treated with antifungal agents, surgical debridement, and hyperbaric oxygen therapy. The antifungal treatments used were liposomal amphotericin B, itraconazole, and posaconazole. Although our patient had liver cirrhosis (Child-Pugh classification B), no hepatic decompensation was developed during the treatment course of posaconazole. This is the first report of the safe and effective use of posaconazole for the treatment of mucormycosis in a cirrhotic patient.     

急性淋巴细胞白血病患者侵袭性头状地霉感染1例及文献回顾

目的:通过报道1例急性淋巴细胞白血病患者侵袭性头状地霉感染的临床资料,并结合文献探讨头状地霉感染的临床特点、有效的诊断及治疗方法。方法:报道国内首例急性淋巴细胞白血病患者化疗后骨髓抑制期感染头状地霉病例,并对该病的诊断及治疗等进行系统文献回顾。结果:该白血病患者经血培养证实为头状地霉感染,并累及肺脏、肝脏和皮肤,治疗过程中先后采用卡泊芬净、脂质体两性霉素B和脂质体两性霉素B联合伏立康唑等治疗,虽然脂质体两性霉素B联合伏立康唑治疗患者体温正常,临床症状稍有改善,但是患者在化疗后40天放弃治疗并死于心肺功能衰竭。结论:头状地霉感染的发病率低,临床症状不够典型,诊断困难,预后差。根据患者的临床表现,结合血培养、GM实验、G实验和CT扫描等检查,可有助于诊断。头状地霉感染尚无非常有效的治疗方式,采用脂质体两性霉素B或两性霉素B联合伏立康唑或其他新的抗真菌药物可能获得一定的疗效,早期诊断、早期联合治疗和患者早期脱离粒缺状态是治疗成功的关键。     

Lipid-based antifungal agents: a concise overview

The development of lipid formulations of antifungal drugs has been a remarkable progress in the systemic antifungal arena. The lipid-based amphotericin B formulations; amphotericin B lipid complex (ABLC), amphotericin B colloidal dispersion (ABCD), and liposomal amphotericin B (L-AMB) have been in clinical use since the 1990s. They are significantly less nephrotoxic than the parent compound and can be safely used at higher doses. The primary cost of these formulations is significantly high and the extent of data related to their head-to-head comparison remains limited. The lipid formulation of nystatin, liposomal nystatin, is another lipid-based polyene under development. Available data concerning the in vitro activity, pharmacokinetic profile, in vivo efficacy, and safety of these formulations are summarized in this overview.     

Biofilm Formation and its Impact on Antifungal Therapy

Fungi can protect themselves from host defences and antifungal drugs by the production of an extracellular hydrophobic matrix. Candida biofilms exhibit resistance to antifungal agents from all classes including the azoles, echinocandins, amphotericin B complex, and flucytosine. Although demonstrated on polystyrene and bronchial epithelia cells, until today, only indirect evidence for A. fumigatus biofilms in patients is available. The antifungals with the most activity against biofilms are the liposomal formulation of amphotericin B and agents in the echinocandin drug class. Importantly, echinocandins show excellent anti-biofilm activity against C. albicans at therapeutic concentrations. However, other biofilms formed by moulds, including A. fumigatus, are relatively resistant to echinocandins. Multiple mechanisms contribute to the intrinsic and acquired antifungal resistance during the different stages of fungal biofilm development. During the growth phase of the early biofilm various factors account for biofilm resistance. Combinational and sequential antifungal therapy as well as combination with enhancers can improve the effect of a single drug. Further studies are warranted to develop new therapeutic strategies targeting fungal biofilm-specific resistance mechanisms.     

Chromoblastomycosis due to Fonsecaea pedrosoi and F. monophora in Cuba

We report two cases of chromoblastomycosis due to Fonsecaea pedrosoi and F. monophora in otherwise healthy Cuban males. Direct microscopic examination of biopsies revealed muriform cells, the hallmark of chromoblastomycosis. The suspected agents were recovered in culture, identified on the basis of morphological criteria and confirmed by sequencing of the internal transcribed spacer regions of rDNA. Final treatment consisted of surgical excision. The patients were successfully cured since there was no relapse after a follow-up of more than a year. In vitro antifungal susceptibility testing of both isolates showed that itraconazole and posaconazole had potent activity. High MICs of amphotericin B (2 μg/ml), fluconazole (>64 μg/ml), anidulafungin (8 μg/ml) and caspofungin (8 μg/ml) were found.     

A Case Report of Penile Infection Caused by Fluconazole- and Terbinafine-Resistant <Emphasis Type="Italic">Candida albicans</Emphasis>

Candida albicans is the most common pathogen that causes balanoposthitis. It often causes recurrence of symptoms probably due to its antifungal resistance. A significant number of balanitis Candida albicans isolates are resistant to azole and terbinafine antifungal agents in vitro. However, balanoposthitis caused by fluconazole- and terbinafine-resistant Candida albicans has rarely been reported. Here, we describe a case of a recurrent penile infection caused by fluconazole- and terbinafine-resistant Candida albicans, as well as the treatments administered to this patient. The isolate from the patient was tested for drug susceptibility in vitro. It was sensitive to itraconazole, voriconazole, clotrimazole and amphotericin B, but not to terbinafine and fluconazole. Thus, oral itraconazole was administrated to this patient with resistant Candida albicans penile infection. The symptoms were improved, and mycological examination result was negative. Follow-up treatment of this patient for 3 months showed no recurrence.     

Biosynthesis of amphotericin derivatives lacking exocyclic carboxyl groups

Amphotericin B is a medically important antifungal antibiotic that is also active against human immunodeficiency virus, Leishmania parasites, and prion diseases. The therapeutic use of amphotericin B is restricted by severe side effects that can be moderated by liposomal formulation or structural alteration. Chemical modification has shown that suppression of charge on the exocyclic carboxyl group of amphotericin B substantially reduces toxicity. We report targeted deletions of the amphN cytochrome P450 gene from the chromosome of the amphotericin-producing bacterium Streptomyces nodosus. The mutant strains produced amphotericin analogues in which methyl groups replace the exocyclic carboxyl groups. These compounds retained antifungal activity and had reduced hemolytic activity.     

Evaluation of Systemic Antifungal Agents in X-Irradiated Mice

The effect of X irradiation on the survival time of animals experimentally infected with pathogenic fungi was studied, and the activity of antifungal agents in pre-irradiated hosts was evaluated. A 24-hr preinfection dose of X irradiation decreased the survival time of mice infected with Cryptococcus neoformans and Histoplasma capsulatum to a greater extent than Candida albicans or Blastomyces dermatitidis infections. Exposure to 400 r caused a significant reduction in the variation (S(2)) survival time of C. albicans or H. capsulatum mouse infections. A single 100-mg/kg dose of 5-fluorocytosine or amphotericin B administered within 24 hr postinfection significantly extended the survival time of mice infected with C. albicans. Delayed treatment with amphotericin B was effective against C. neoformans infections. Four 50-mg/kg doses of 5-fluorocytosine were more effective than a single 200-mg/kg dose against C. neoformans infections. A single dose of amphotericin B provided significant protection when administered 48 hr postinfection against B. dermatitidis in preirradiated mice. A single dose of saramycetin 48 hr postinfection was highly effective against H. capsulatum mouse infections. A 100-mg/kg dose of amphotericin B was only effective against this fungal pathogen when administered within 8 hr postinfection. In vivo activity of the antifungal agents studied was detected within 8 to 14 days. The relative in vivo activity of several antifungal agents indicated the importance of considering their individual pharmacological properties for optimum effectiveness. The experimental model used in this study should be useful for the detection and for the preclinical evaluation of new antifungal agents.     

Treatment of systemic candidiasis in a neutropenic murine model using immunoglobulin G bearing liposomal amphotericin B

Efficacy of immunoglobulin G (IgG) bearing liposomal amphotericin B (LAMB-IgG), liposomal amphotericin B without IgG (LAMB) or free amphotericin B (fAMB/Fungizone) was investigated in the treatment of systemic candidiasis in a neutropenic mouse model. Treatment with a single dose (0.6 or 0.9 mg amphotericin B per kg body weight) of LAMB-IgG resulted in a significant increase in the survival rate of neutropenic mice infected with 3×10⁵ cfu ofCandida albicans compared to untreated controls, mice injected with IgG, or liposome alone. Survival was also better in neutropenic mice treated with LAMB-IgG than in neutropenic mice treated with the same dose of LAMB or fAMB. Moreover, 65% of all mice survived the infection after treatment with a single dose of 0.6 mg AMB of the LAMB-IgG formulation. Quantitative culture counts of organs showed that both fAMB and LABM-IgG formulations even at a dose of 0.3 mg AMB/kg, clearedC. albicans from the spleens, livers, and lungs but not from the kidneys. However, a decreasd number ofC. albicans cells was recovered from the kidneys of mice that survived the infection. Results of the study suggest that LAMB-IgG is more effective than LAMB or fAMB in the therapy of disseminated candidiasis in neutropenic mice.     

Endogenous Fusarium Endophthalmitis During Treatment for Acute Myeloid Leukemia,Successfully Treated with 25-Gauge Vitrectomy and Antifungal Medications

Endogenous fungal endophthalmitis (EFE) caused by disseminated fusariosis is a rare condition that generally has a poor outcome, even with intensive therapy. Here, we describe a case in which this type of EFE was diagnosed with vitreous sampling and was successfully treated with 25-gauge vitrectomy and antifungals, including liposomal amphotericin B and voriconazole. A 16-year-old male patient undergoing treatment for acute myeloid leukemia complained of eye pain and blurred vision in his right eye. Treatment was initiated for a vitreous opacity, possibly associated with herpetic retinitis, but the patient worsened and he was referred to us. Right-eye visual acuity was limited to light perception. We suspected endogenous endophthalmitis and performed 25-gauge vitrectomy with antibiotic perfusion of ceftazidime, vancomycin, and voriconazole. Vitreous culturing revealed the presence of Fusarium solani species complex, and enhanced computed tomography revealed disseminated fusariosis lesions in the lung, spleen, and the soft tissue of the left upper arm. The patient received antifungal treatment with liposomal amphotericin B and voriconazole, and these conditions were eliminated. Visual acuity recovered to 20/400 after additional vitrectomy for tractional retinal detachment and was maintained at this level during the 6-month follow-up period. The success of our treatment allowed the capture of optical coherence tomography images of the retina during fusarium-associated endogenous endophthalmitis and the follow-up period. Furthermore, this case showed that immediate vitrectomy for suspected EFE and intensive treatment can lead to a good clinical outcome.     

In vitro and in vivo antifungal activities of liposomal amphotericin B,and amphotericin B lipid complex

The in vitro and in vivo antifungal activities of liposomal amphotericin B (L-AMPH) and amphotericin B lipid complex (ABLC), which is composed of amphotericin B and the phospholipids dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylglycerol, were compared with those of conventional amphotericin B (Fungizone®, AMPH). The acute intravenous toxicity was markedly lower in BALB/c mice; 50% lethal doses (LD_50s) were 2.75 mg/kg in AMPH, 32.9 mg/kg in L-AMPH and >75 mg/kg in ABLC. In vitro antifungal activities againstCandida albicans, C. parapsilosis, C. tropicalis, C. glabrata, andC. krusei were evaluated by the agar plate dilution method. The activities were unchanged againstC. albicans, but MICs increased more than four fold in 18 of the 20 strains other thanC. albicans in L-AMPH and in 9 of the 20 in ABLC. L-AMPH and ABLC were as efficacious as AMPH in the treatment of mice infected withC. albicans, and at a dose of 0.5 and 1.0 mg/kg of body weight, ABLC was more efficacious on survival. A ten-times larger dose (10 mg/kg) of L-AMPH and ABLC was administered to mice with 100% survival, suggesting improved tolerability as compared to amphotericin B.     

Characterization of Edenia gomezpompae Isolated from a Patient with Keratitis

Edenia gomezpompae, isolated from a patient suffering from keratitis, who was an agricultural worker with a 4-year history of diabetes mellitus, is described. Fungal hyphae were detected in corneal scrapings after microscopic examination and repeated culture. Isolates were identified by morphology and by sequencing the internal transcribed spacer region of ribosomal DNA. Chlamydospore characteristics of E. gomezpompae are described for the first time. The in vitro antifungal susceptibilities of the isolate were tested using five antifungal agents. With the exception of fluconazole, the other drugs (natamycin, amphotericin B, itraconazole, and voriconazole) assayed were highly effective against this fungus. The keratitis was cured after debridement of the corneal ulcer and treatment with 5 % natamycin. After 3 months, when the patient was reexamined, the corneal ulcer showed signs of healing, with no recurrence. To our knowledge, this is the first reported case of keratitis caused by E. gomezpompae, as well as being the first known case of disease in humans caused by this species.     

Amphotericin B deoxycholate for relapse visceral leishmaniasis in Bangladesh: a cross-sectional study

Objective

Based on studies in India (as there was no studies from outside India) amphotericin B deoxycholate has been considered as a backup drug for treatment of visceral leishmaniasis. However, treatment response and adverse effect to anti-leishmanial drugs may vary across different populations and in Bangladesh the effect to amphotericin B deoxycholate for treatment of visceral leishmaniasis is still unknown. Therefore, there is a need to explore cure rate and adverse effects to amphotericin B deoxycholate to justify its use on visceral leishmaniasis patients in Bangladesh.

Result

Here we report 34 visceral leishmaniasis patients who received treatment with amphotericin B deoxycholate in the Surya Kanta Kala-azar Research Centre from December 2011 to June 2015. The dose of the treatment was 1 mg/kg body weight for 15 days followed up until 12 months after treatment. Response to amphotericin B deoxycholate treatment was excellent as all 34 patients achieved a final cure. Hypokalaemia (47%), shivering (47%), vomiting (35%) and acidity (15%) were most common adverse events. However, we did not observe any serious adverse events. Amphotericin B deoxycholate for relapse visceral leishmaniasis was found to be highly effective and safe. Our study justified to include amphotericin B deoxycholate as a second line drug for visceral leishmaniasis in Bangladesh.

     

In?vitro and in?vivo study on the effect of antifungal agents on hematopoietic cells in mice

Liposomal amphotericin B, voriconazole, and caspofungin are currently used for systemic and severe fungal infections. Patients with malignant diseases are treated with granulocyte-colony stimulating factor (G-CSF) for the recovery of granulocytes after chemotherapy or hematopoietic cell (HC) transplantation. Since they have a high incidence of fungal infections, they inevitably receive antifungal drugs for treatment and prophylaxis. Despite their proven less toxicity for various cell types comparatively with amphotericin B and the decrease in the number of leukocytes that has been reported as a possible complication in clinical studies, the effect of liposomal amphotericin B, voriconazole, and caspofungin on HCs has not been clarified. The present study aimed to examine the in vitro and in vivo effect of these three modern antifungals on HCs. Colony-forming unit (CFU) assays of murine bone marrow cells were performed in methylcellulose medium with or without cytokines and in the presence or absence of various concentrations of liposomal amphotericin B, voriconazole, and caspofungin. In the in vivo experiments, the absolute number of granulocytes was determined during leukocyte recovery in sublethally irradiated mice receiving each antifungal agent separately, with or without G-CSF. In vitro, all three antifungal drugs were nontoxic and, interestingly, they significantly increased the number of CFU-granulocyte-macrophage colonies in the presence of cytokines, at all concentrations tested. This was contrary to the concentration-dependent toxicity and the significant decrease caused by conventional amphotericin B. In vivo, the number of granulocytes was significantly higher with caspofungin plus G-CSF treatment, higher and to a lesser extent higher, but not statistically significantly, with voriconazole plus G-CSF and liposomal amphotericin B plus G-CSF treatments, respectively, as compared with G-CSF alone. These data indicate a potential synergistic effect of these antifungals with the cytokines, in vitro and in vivo, with subsequent positive effect on hematopoiesis.     

AmBisome,tres retos: infección por Candida auris,infección del sistema nervioso central e infección asociada a biopelículas

The treatment of invasive fungal infections remains a challenge, both for the diagnosis and for the need of providing the appropriate antifungal therapy. Candida auris is a pathogenic yeast that is responsible for hospital outbreaks, especially in intensive care units; it is characterized by a high resistance to the antifungal agents and can become multidrug-resistant. At present, the recommended antifungal agents for the invasive infections with this pathogen are echinocandins, always after carrying out an antifungal susceptibility testing. In case of no clinical response or persistent candidemia, the addition of liposomal amphotericin B or isavuconazole may be considered. Both fungal infection of the central nervous system and that associated with biomedical devices remain rare entities affecting mainly immunocompromised patients. However, an increase in their incidence in recent years, along with high morbidity and mortality, has been shown. The treatment of these infections is conditioned by the limited knowledge of the pharmacokinetic properties of antifungals. A better understanding of the pharmacokinetic and pharmacodynamic parameters of the different antifungals is essential to determine the efficacy of the antifungal agents in the treatment of these infections.     

马尔尼菲蓝状菌病致溶骨性损害合并Sweet样皮疹1例

本文报道广西医科大学第一附属医院皮肤性病科收治的马尔尼菲蓝状菌病致溶骨性损害合并Sweet样皮疹1例。免疫力正常人群较少患马尔尼菲蓝状菌病。本例患者既往体健,起初合并融骨性损害,在两性霉素B、伊曲康唑治疗过程中逐渐出现Sweet样皮疹。患者经两性霉素B、伊曲康唑、激素等治疗后,病情逐渐好转。     

以反复多发脓肿为表现的播散型隐球菌病1例

报道以反复多发脓肿为表现的播散型隐球菌病患者1例。患者男,68岁,因＂全身反复多发性脓肿1a,伴低热2个月余＂入院,该患者以背部脓肿起病,反复发作累及肺部、骨骼、皮肤等多部位,多次组织及血标本病原学检查、隐球菌乳胶凝集试验均阴性,给予多种抗菌药物治疗无效,后在右髂部脓肿切开组织物中培养到新生隐球菌。经脓肿切开引流及静脉滴注两性霉素B脂质体联合伊曲康唑治疗后,脓肿消退,症状消失,改用氟康唑联合氟胞嘧啶治疗4个月后停药,并已随访至今7个月,患者未有发热及新的脓肿出现。