Catheter-related fungemia by Hansenula anomala

Fungemia With Wickerhamomyces anomalus: A Case Report and Literature Review

We report the case of an 84-year-old man with a history of IgG4-related sclerosing cholangitis who was diagnosed with advanced esophageal cancer and underwent radiation and chemotherapy. An implantable central venous access port was placed for chemotherapy and total parenteral nutrition. The patient presented with a fever and received antimicrobial therapy for acute cholangitis but remained febrile, and subsequently, yeast was detected in the aerobic bottle of blood culture obtained from the central venous line. The yeast was identified as Wickerhamomyces anomalus. Liposomal amphotericin B was administered, and the central line access port was removed. After confirmation of negative blood cultures and 14 days post treatment, he underwent reinsertion of the central line access port. Due to persistent pain at the insertion site, fluconazole was added for an additional 14 days, and the patient was discharged and transferred to another hospital. Wickerhamomyces anomalus is a rare fungal infection with other synonyms including Pichia anomala, Hansenula anomala, and Candida pelliculosa. A literature review of 53 case reports of Wickerhamomyces anomalus, Pichia anomala, Hansenula anomala, and Candida pelliculosa was conducted, with a total of 211 cases reviewed. Fungemia was reported in 94% of cases, with central venous catheterization, parental feeding, low birth weight, and immunocompromised status identified as major risk factors. The majority of cases were pediatric, particularly neonatal, and there were reports of nosocomial infections causing outbreaks, with some cases involving the eye such as endophthalmitis or keratitis.

Investigation of the Emerging Nosocomial Wickerhamomyces anomalus Infections at a Chinese Tertiary Teaching Hospital and a Systemic Review: Clinical Manifestations, Risk Factors, Treatment, Outcomes, and Anti-fungal Susceptibility

Wickerhamomyces anomalus is an emerging pathogen, which has been associated with clonal outbreaks and poor clinical outcomes. Despite being an important emerging yeasts species, our understanding concerning the microbiological and clinical characteristics of infections due to this species is limited. Herein, we are reporting a retrospective analysis of fungemia patients with W. anomalus from a 2,100-bed hospital in Shanghai during 2014–2016. Moreover, we conducted an extensive literature review to gain a deeper clinical and microbiological insights. Detailed clinical data were recorded. Antifungal susceptibility testing (AFST) followed CLSI M27-A3, and isolates were identified using MALDI-TOF MS. In total, 13 patients were identified with a mortality rate of 38.5% (5/13). Central venous catheter (CVC), broad-spectrum antibiotic therapy, total parenteral nutrition (TPN), surgery, and mechanical ventilation were the most frequently observed risk factors. Eight patients (61.5%) experienced mixed bacterial/Candida bloodstream infections, and four patients developed mixed candidemia (MC). W. anomalus isolates showed high minimum inhibitory concentrations (MICs) against all azoles tested and flucytosine, while AMB showed the highest in vitro activity. Azoles were used for 84.6% (11/13) of the cases, while 36.4% (4/11) of them died. When combining with the AFST data and the literature review, our study highlights the poor efficacy of azoles and optimal efficacy of AMB and LAMB against infections caused by W. anomalus. In conclusion, our study highlights the emerging threat of W. anomalus affecting both neonates and adults. Furthermore, our results advocate the use of AMB formulations rather than azoles among patients infected with W. anomalus. Future studies are warranted to reach a definitive consensus regarding the utility of echinocandins among such patients.

Genotypic variation and antifungal susceptibilities of Candida pelliculosa clinical isolates

At the Istituto Ricovero Cura Carattere Scientifico, Ospedale Maggiore di Milano, Italy, Candida pelliculosa accounted for 3.3 and 4.4 % of all Candida species other than Candida albicans collected during 1996 and 1998, respectively. Genetic variability was investigated by electrophoretic karyotyping and inter-repeat PCR, and the susceptibility to five antifungal agents of 46 strains isolated from 37 patients during these 2 years was determined. Combination of the two typing methods yielded 14 different DNA types. Although the majority of DNA types were randomly distributed among different units, one DNA type was significantly more common in patients hospitalized in a given unit compared with those from other wards (P = 0.034), whereas another DNA type was more frequently isolated in patients hospitalized during 1996 than in those hospitalized during 1998 (P = 0.002). Fluconazole, itraconazole and posaconazole MIC90 values were 16, 1 and 4 μg ml−1, respectively. All isolates but three were susceptible in vitro to flucytosine. All isolates were susceptible in vitro to amphotericin B. These data suggest that there are possible relationships among strains of C. pelliculosa, wards and time of isolation. Amphotericin B seems to be the optimal drug therapy in infections due to this yeast species.

Hansenula anomala outbreak at a surgical intensive care unit: a search for risk factors

During a 5-month period, Hansenula anomala (H. anomala), an opportunistic fungus, caused an outbreak of infections in eight adult patients treated at a surgical intensive care unit (ICU). The source of the infections and route of transmission could not be identified. A case-control study included 32 patients treated simultaneously at the surgical ICU. Univariate analysis pointed to the following significant risk factors: blood alkalosis, reduced urea, duration of hospitalization, bacteremia and colonization with Pseudomonas aeruginosa, and an APACHE II score >17 (during bacteremia or fungemia). The stepwise logistic regression multivariate analysis showed only the duration of blood alkalosis to be significant in case patients.

Uncommon opportunistic fungi: new nosocomial threats

During the past two decades opportunistic fungal infections have emerged as important causes of morbidity and mortality in patients with severe underlying illnesses and compromised host defenses. While Aspergillus and Candida spp. collectively account for the majority of these infections, recent epidemiological trends indicate a shift towards infections by Aspergillus spp., nonalbicans Candida spp., as well as previously uncommon opportunistic fungi. Apart from an expanding number of different Zygomycetes, previously uncommon hyaline filamentous fungi (such as Fusarium species, Acremonium species, Paecilomyces species, Pseudallescheria boydii, and Scedosporium prolificans), dematiaceous filamentous fungi (such as Bipolaris species, Cladophialophora bantiana, Dactylaria gallopava, Exophiala species, and Alternaria species) and yeast-like pathogens (such as Trichosporon species, Blastoschizomyces capitatus, Malassezia species, Rhodotorula rubra and others) are increasingly encountered as causing life threatening invasive infections that are often refractory to conventional therapies. On the basis of past and current trends, the spectrum of fungal pathogens will continue to evolve in the settings of an expanding population of immunocompromised hosts, selective antifungal pressures, and shifting conditions in hospitals and the environment. An expanded and refined drug arsenal, further elucidation of pathogenesis and resistance mechanisms, establishment of in vitro/in vivo correlations, incorporation of pharmacodynamics, combination- and immunotherapies offer hope for substantial progress in prevention and treatment.

Environmental surveillance and other control measures in the prevention of nosocomial fungal infections

The steady world-wide increase in the number of severely immunocompromised patients in most hospitals has made the control and prevention of nosocomial systemic fungal infections a critical quality-of-care standard. Early diagnosis and antifungal prophylaxis of these infections are complicated, so avoiding the acquisition of the pathogen in the case of Aspergillus and minimizing the predisposing risk factors in the case of Candida are more effective approaches. The maintenance of good air quality in critical areas in hospitals is mandatory to reduce the incidence of invasive aspergillosis. We review the currently available Center for Disease Control recommendations and report our own experiences in the field. The indications and problems of fungal environmental and patient surveillance are also discussed.

Amphotericin B lipid complex for Hansenula anomala pneumonia

OBJECTIVE

To document the first successful treatment of a patient with Hansenula anomala pneumonia.

CASE SUMMARY

A healthy 32-year-old white man who underwent splenectomy and aortic repair following a motor vehicle accident developed a life-threatening infection 2 days after admission into the intensive care unit (ICU). A rare fungus, H. anomala, was isolated from his lungs, blood, and urine. Lipid complex amphotericin B (ABLC) was initiated following worsening signs of infection complicated by renal failure. The patient received ABLC for 17 days, eventually making a full recovery, allowing ICU discharge 1 month after admission.

DISCUSSION

This case represents the first successful treatment of H. anomala pneumonia reported in the literature. H. anomala infections typically occur in immunocompromised, neonatal, or pediatric populations in extrapulmonary sites. All 6 cases of H. anomala pneumonia reported in the literature were fatal, and all preceded the availability of ABLC. This case of H. anomala pneumonia is unique because our adult patient survived possibly due to the availability of aggressive treatment.

CONCLUSIONS

ABLC may be the agent of choice for treatment of H. anomala infections, particularly in patients with acute renal failure.

Pathogenicity of Hansenula anomala in model of immunocompromised mice

Systemic infections caused by opportunistic fungi have shown an increased frequency in the past 10 years, particularly in immunocompromised patients. Hansenula anomala is an ascosporogenous yeast of the Ascomycetes class found in the skin, throat, and digestive tract transient normal flora. This study was conducted to compare the pathogenicity of H. anomala and Candida albicans in a model of immunocompromised mice. Thirty-eight Swiss mice were divided into two groups as follows: 30 animals received an intraperitoneal (i.p.) injection of cyclophosphamide (200 mg/kg) four days before the induction of infection with H. anomala (1 x 10(6) yeasts/mL), and 8 animals received 100 mg/kg of cyclophosphamide at 3-day intervals during 3 weeks before inoculation of 1 x 10(7) yeasts/mL. All animals were treated with amoxicillin/clavulanic acid (40 mg/kg) four days before induction of infection. A group of mice inoculated with C. albicans (ATCC 64548) served as control. Tissue samples from the lung, spleen, liver, and kidney for histological and mycologic studies were obtained at necropsy. In each animal, the number of viable yeasts per gram of kidney was determined. The organs most frequently infected by H. anomala were the kidneys and the liver (20%), and the lung (10%). However, in conditions of sustained immunosuppression, H. anomala was found in 65.5% of the organs examined. It is concluded that in an experimental model of immunocompromised mice, the pathogenicity of H. anomala was low.

Fungaemia caused by Hansenula anomala--an outbreak in a cancer hospital

Yeasts belonging to the genus Hansenula are rarely encountered as the cause of infection in clinical practice. A wide spectrum of infections caused by these fungi can be seen, ranging from asymptomatic fungaemia to severe disease. We describe an outbreak of 24 cases of infection due to H. anomala in an oncological hospital in Rio de Janeiro, Brazil. The median age of the patients was 11 years, of whom 54.2% were female; 91.7% of the Hansenula fungaemia occurred in the haematology unit. The most frequent primary disease diagnosis was leukaemia (62.5%), and all of those infected had had a central venous catheter or peripheral venous catheter and had been treated previously with broad-spectrum antibiotics. Numerous other risk factors were observed in our cases: previous use of steroids, chemotherapy, radiation therapy and neutropenia (data not shown). No deaths could be attributed to Hansenula.

Sexual forms of yeasts in clinical samples

The sexual or teleomorphic state of yeasts has only been described in a few clinically involved species, mainly those of the Saccharomycetaceae family. With the aim of gathering information on their incidence in human pathology, a study has been made of a total of 2,135 strains isolated from clinical samples and cultivated in McClary agar. From these, 8 strains in teleomorphic state were identified: Kluyveromyces marxianus [1], Pichia anomala [2], Pichia farinosa [1], Pichia membranaefaciens [1] and Saccharomyces cerevisiae [3]. The two strains of P. anomala were responsible for fungemia; K, marxianus and the two strains of S. cerevisiae produced vaginitis; the other strains were oral cavity colonizers.

New and emerging yeast pathogens

The most common yeast species that act as agents of human disease are Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Cryptococcus neoformans. The incidence of infections by other yeasts has increased during the past decade. The most evident emerging pathogens are Malassezia furfur, Trichosporon beigelii, Rhodotorula species, Hansenula anomala, Candida lusitaniae, and Candida krusei. Organisms once considered environmental contaminants or only industrially important, such as Candida utilis and Candida lipolytica, have now been implicated as agents of fungemia, onychomycosis, and systemic disease. The unusual yeasts primarily infect immunocompromised patients, newborns, and the elderly. The role of central venous catheter removal and antifungal therapy in patient management is controversial. The antibiograms of the unusual yeasts range from resistant to the most recent azoles and amphotericin B to highly susceptible to all antifungal agents. Current routine methods for yeast identification may be insufficient to identify the unusual yeasts within 2 days after isolation. The recognition of unusual yeasts as agents of sometimes life-threatening infection and their unpredictable antifungal susceptibilities increase the burden on the clinical mycology laboratory to pursue complete species identification and MIC determinations. Given the current and evolving medical practices for management of seriously ill patients, further evaluations of the clinically important data about these yeasts are needed.

Catheter-related infections by Hansenula anomala in children

During August and September, 1992, we experienced 4 cases of Hansenula anomala (H. anomala, synonym Pichia anomala) fungemia in immunocompromised patients. Two patients had been suffering from a malignant disease, 3 of them had received broad-spectrum antibiotics and a central venous catheter (CVC) had been inserted in all of them. H. anomala was isolated as the sole pathogen from all 4 patients. Three of them responded favorably to fluconazole after withdrawal of the catheter, but one failed. H. anomala should be considered as a possible cause of catheter-related infections.

Fungaemia due to Candida pelliculosa in a case of acute pancreatitis

We describe a case of fungaemia due to Candida pelliculosa (teleomorph: Hansenula anomala) in an otherwise non-immunocompromised patient with acute necrotizing pancreatitis of unknown origin. This species of Candida should be added to the list of pathogenic fungi which are increasingly important not only in patients with underlying immunosuppressive disease but also in patients with, for instance, severe surgical illness.

Hansenula anomala fungemia in an infant with gastric and cardiac complications with a review of the literature

A 6-month-old female infant, with a birth weight of 2.74 kilograms, was born with multiple congenital abnormalities, including gastric and gastrointestinal defects. She was admitted to the hospital with hematemesis. The patient could not be fed orally, and parenteral nutrition was initiated through a central venous catheter. Following pyloroplasty, she developed superior vena cava syndrome, renal disfunction and episodes of sepsis. Stool and respiratory specimens were negative for fungi, but four blood cultures yielded Hansenula anomala var. anomala. Cultures for fungi from intravenous catheter tips were negative. The baby was treated with amphotericin B (am B) and 5-fluorocytosine (5-FC), (amB; 0.1 mg/kg body weight and 5-FC, 100 mg, q.i.d.). The minimal inhibitory concentrations of am B, 5-FC, am B + 5-FC (1:1, w:w) and fluconazole to H. anomala were 1.56, less than 0.195, 1.56, and 1.56 micrograms, respectively. Following antifungal therapy and removal of the catheter, the patient tolerated oral feeding and, at the time of discharge, her weight had increased to 4.91 kg. This report records H. anomala as an opportunistic yeast pathogen for the first time in Alberta, Canada. Previously published cases of H. anomala infections are reviewed.

Transient fungaemia due to Candida pelliculosa in a patient with AIDS

Candida pelliculosa Redaelli (syn. Hansenula anomala) was isolated from blood cultures of a patient with acquired immunodeficiency syndrome. The transient candidaemia was apparently associated with intravenous drug addiction. The isolate was identified by standard methods such as API 20 C Aux and 16 discs carbon auxanogram. The isolate was sensitive to amphotericin B, 5-fluorocytosine and ketoconazole. This organism adds to the growing list of Candida species associated with acquired immunodeficiency syndrome.