Fungal peritonitis caused byBipolaris spicifera

Fungal Peritonitis in Peritoneal Dialysis Patients

Peritonitis is one of the most frequent complications of peritoneal dialysis (PD) and 1% – 15% of episodes are caused by fungal infections. The mortality rate of fungal peritonitis (FP) varies from 5% to 53%; failure to resume PD occurs in up to 40% of patients. The majority of these FP episodes are caused by Candida species. Candida albicans has historically been reported to be a more common cause than non-albicans Candida species, but in recent reports a shift has been observed and non-albicans Candida may now be more common. Unusual, often “nonpathogenic,” fungi are being increasingly reported as etiologic agents in FP. Clinical features of FP are not different from those of bacterial peritonitis. Phenotypic identification of fungi in clinical microbiology laboratories is often difficult and delayed. New molecular diagnostic techniques ( e.g., polymerase chain reaction) are being developed and evaluated, and may improve diagnosis and so facilitate early treatment of infected patients. Abdominal pain, abdominal pain with fever, and catheter left in situ are risk factors for mortality and technique failure in FP. In programs with high baseline rates of FP, nystatin prophylaxis may be beneficial. Each program must examine its own history of FP to decide whether prophylaxis would be beneficial. Catheter removal is indicated immediately after fungi are identified by Gram stain or culture in all patients with FP. Prolonged treatment with antifungal agents to determine response and attempt clearance is not encouraged. Antifungals should be continued for 10 days to 2 weeks after catheter removal. Attempts at reinsertion should be made only after waiting for 4 – 6 weeks.

Calcium Alginate Bead-mediated Enhancement of the Selective Recovery of a Lead Novel Antifungal Bacillomycin Variant

In the pursuit of new antifungal compounds, five coproduced lipopeptide variants (AF₁ to AF₅) from wild-type Bacillus subtilis RLID 12.1 were identified in our previous study. Out of five, AF₄ was identified as a novel lead molecule belonging to the bacillomycin family showing less cytotoxicity at its respective minimum inhibitory concentrations (MIC) evaluated against 81 strains of Candida and Cryptococcus species (including clinical isolates); besides this, AF₄ purified in the present study exhibited encouraging MIC values against 10 clinical mycelial fungi. Aiming for a selective production augmentation of AF₄ lipopeptide variant, a new fermentation media comprising malt extract (1.01%), dextrose (0.55%), peptone (1.79%), MnSO₄ (2 mM), and NaCl (0.5%) was formulated. Maximum production of 954.8 ± 10.8 mg/L was achieved with 44% selectivity at 30 °C compared to unoptimized conditions (186.4 ± 6.1 mg/L). Use of calcium alginate beads in the formulated media during the onset of lipopeptide production resulted in an augmentation in the selectivity of the most efficacious AF₄ variant to about 72% presumably due to attenuation of other coproduced lipopeptide variants AF₁ and AF₂. Difference in yield of lipopeptides varied with bead size, bead preparation ratios, and sodium alginate concentrations. Use of Ca-alginate beads in the upstream production process of the lead AF₄ variant may be considered as a novel strategy to address the potential challenge that may arise during the scale-up and downstream processing steps. Another significant finding derived from the study is that the proportion of bacillomycin variants of B. subtilis RLID 12.1 could be controlled by temperature and metal ions under static and shaking conditions.

The first case of cutaneous phaeohyphomycosis caused by Bipolaris spicifera in Northern China: A case report

Phaeohyphomycosis (PHM) is a term used to describe any fungus presenting in tissues with pseudohyphae, hyphae, brown yeast-like cells or a combination of these forms. Sinusitis and skin infections are the most common presentation of subcutaneous PHM caused by the fungus Bipolaris spicifera. However, the majority of cases have so far been encountered in tropical climatic zones. The present study documents a case of subcutaneous PHM caused by infection with Bipolaris spicifera in a 56-year-old Chinese man, who presented with plaque papillomatosis on the left foot. The organism isolated from the lesion scar and tissue was identified as Bipolaris spicifera by its morphology, histopathology and DNA sequencing. The patient was successfully treated with itraconazole and terbinafine.

Molecular identification and antifungal susceptibility of Curvularia australiensis, C. hawaiiensis and C. spicifera isolated from human eye infections

A reliable identification method was developed for three closely related Curvularia species, which are frequently isolated from human keratomycoses. Since the traditionally used morphological method and the increasingly used internal transcribed spacer (ITS)-based molecular method proved to be insufficient to discern C. australiensis, C. hawaiiensis and C. spicifera, other molecular targets, such as β-tubulin, translation elongation factor 1-α and the nuclear ribosomal intergenic spacer (IGS), were tested. Among them, the use of the highly divergent IGS sequence is suggested and the species-specific discriminating characters were determined in appropriate reference strains. It was also concluded that C. hawaiiensis and C. spicifera can be predominantly isolated from eye infections among the three species. The in vitro antifungal susceptibility of 10 currently used antifungal agents against 32 Curvularia isolates was also investigated. MICs were determined in each case. Isolates of C. spicifera proved to be less susceptible to the tested antifungals than those of C. hawaiiensis, which underline the importance of the correct identification of these species.

Unilateral renal phaeohyphomycosis due to Bipolaris spicifera in an immunocompetent child - rare case presentation and review of literature

Phaeohyphomycosis refers to infections caused by phaeoid fungi that can have an aggressive course in normal hosts. We report a case of left-sided renal phaeohyphomycosis due to Bipolaris spicifera in a 7-year-old immunocompetent male child. He presented with fever, dysuria, nausea, vomiting and flank pain. Examination revealed tenderness at the left costovertebral angle. Histological examination and culture of biopsy from left kidney and blood yielded the fungal pathogen Bipolaris spicifera. His past history revealed that he was diagnosed perinatally with bilateral hydronephrosis due to bilateral pelvic ureteric junction obstruction. He underwent an open dismembered pyeloplasty on the left side followed by the right side pyeloplasty at the age of 6 months and 1.5 years respectively. He was on a regular follow-up for 5 years and had been doing well. Now he was diagnosed as a case of unilateral renal phaeohyphomycosis. The patient was managed successfully with antifungal drugs amphotericin B and itraconazole. A review of previously reported bipolaris cases with their clinical manifestations, treatment and outcome is presented. Renal phaeohyphomycosis remains an unusual disease. Aggressive diagnostic approaches and careful management helped in survival of the patient.

Black Molds and Melanized Yeasts Pathogenic to Humans

A review is given of melanized fungi involved in human infection, including species forming budding cells and strictly filamentous representatives. Classically, they are known as "phaeoid" or "dematiaceous" fungi, and, today, agents are recognized to belong to seven orders of fungi, of which the Chaetothyriales and Pleosporales are the most important. Infections range from cutaneous or pulmonary colonization to systemic or disseminated invasion. Subcutaneous involvement, either primary or after dissemination, may lead to host tissue proliferation of dermis or epidermis. Particularly in the Chaetothyriales, subcutaneous and systemic infections may occur in otherwise apparently healthy individuals. Infections are mostly chronic and require extended antifungal therapy and/or surgery.

Virulence of Curvularia in a murine model

We have evaluated the virulence of two clinically relevant species of Curvularia; Curvularia spicifera and C. hawaiiensis, using an experimental model of disseminated infection in immunocompromised mice. Several inocula were tested over a range 1 × 10(3) -1 × 10(6) colony-forming units/animal. Both species had a similar behaviour, producing a high mortality. Tissue burden and histopathology studies demonstrated that lung was the organ most affected.

In vitro antifungal and demelanizing activity of Nepeta rtanjensis essential oil against the human pathogen Bipolaris spicifera

The antifungal activity of Nepeta rtanjensis Diklic & Milojevic essential oil was tested against the human pathogenic fungus Bipolaris spicifera (Bainier) Subramanian via mycelial growth assay and conidia germination assay. The minimally inhibitory concentration (MIC) of the oil was determined at 1.0 ?g ml-1, while the MIC for the antifungal drug Bifonazole in a positive control was determined at 10.0 ?g ml-1. The maximum of conidia germination inhibition was accomplished at 0.6 ?g ml-1. In addition, at 0.6 ?g ml-1 and 0.8 ?g ml-1 the oil was able to cause morphophysiological changes in B. spicifera. The most significant result is the bleaching effect of the melanized conidial apparatus of the test fungi, since the melanin is the virulence factor in human pathogenic fungi. These results showed the strong antifungal properties of N. rtanjensis essential oil, supporting its possible rational use as an alternative source of new antifungal compounds.

Melanized fungi in human disease

Melanized or dematiaceous fungi are associated with a wide variety of infectious syndromes, including chromoblastomycosis, mycetoma, and phaeohyphomycosis. [corrected]. Many are soil organisms and are generally distributed worldwide, though certain species appear to have restricted geographic ranges. Though they are uncommon causes of disease, melanized fungi have been increasingly recognized as important pathogens, with most reports occurring in the past 20 years. The spectrum of diseases with which they are associated has also broadened and includes allergic disease, superficial and deep local infections, pneumonia, brain abscess, and disseminated infection. For some infections in immunocompetent individuals, such as allergic fungal sinusitis and brain abscess, they are among the most common etiologic fungi. Melanin is a likely virulence factor for these fungi. Diagnosis relies on careful microscopic and pathological examination, as well as clinical assessment of the patient, as these fungi are often considered contaminants. Therapy varies depending upon the clinical syndrome. Local infection may be cured with excision alone, while systemic disease is often refractory to therapy. Triazoles such as voriconazole, posaconazole, and itraconazole have the most consistent in vitro activity. Further studies are needed to better understand the pathogenesis and optimal treatment of these uncommon infections.