Breakthrough candidemia with hematological disease: Results from a single-center retrospective study in Japan, 2009-2020.

Breakthrough candidemia (BrC) is a significant problem in immunocompromised patients, particularly those with hematological disorders. To assess the characteristics of BrC in patients with hematologic disease treated with novel antifungal agents, we collected clinical and microbiological information on said patients from 2009 to 2020 in our institution. Forty cases were identified, of which 29 (72.5%) received hematopoietic stem cell transplant (HSCT)-related therapy. At BrC onset, the most administered class of antifungal agents were echinocandins, administered to 70% of patients. Candida guilliermondii complex was the most frequently isolated species (32.5%), followed by C. parapsilosis (30%). These two isolates were echinocandin-susceptible in vitro but had naturally occurring FKS gene polymorphisms that reduced echinocandin susceptibility. Frequent isolation of these echinocandin-reduced-susceptible strains in BrC may be associated with the widespread use of echinocandins. In this study, the 30-day crude mortality rate in the group receiving HSCT-related therapy was significantly higher than in the group not receiving it (55.2% versus 18.2%, P = .0297). Most patients affected by C. guilliermondii complex BrC (92.3%) received HSCT-related therapy and had a 30-day mortality rate of 53.8%; despite treatment administration, 3 of 13 patients had persistent candidemia. Based on our results, C. guilliermondii complex BrC is a potentially fatal condition in patients receiving HSCT-related therapy with echinocandin administration.

This retrospective study was conducted at a Japanese center specializing in hematopoietic stem cell transplants and found that the rare pathogen Candida guilliermondii complex was the most common cause of breakthrough candidemia, with high mortality rate, which is a concern for transplant patients.

A case of mediastinal abscess and infected aortic aneurysm caused by dissemination of Mycobacterium abscessus subsp. massiliense pulmonary disease.

An 81-year-old man was admitted to our hospital because of fever and malaise that had persisted for 3 months. The patient had undergone two aortic valve replacements, 10 and 5 years previously, because of aortic valve regurgitation and infectious endocarditis. He also had had asymptomatic Mycobacterium abscessus complex (MABC) pulmonary disease for the two previous years. Contrast-enhanced computed tomography showed a mediastinal abscess and an ascending aortic aneurysm. Mycobacterium abscessus subsp. massiliense was cultured from his blood, suggesting the aortic aneurysm was secondary to infection of an implanted device. After enlargement over only a few days, a leakage of contrast medium to the mediastinal abscess was found on computed tomography. The patient was diagnosed with rupture of an infectious aortic aneurysm, and emergency aortic replacement and drainage of the mediastinal abscess were successful. The patient was treated with several antibiotics, including meropenem, amikacin, and clarithromycin, and his general condition improved. Cultures from both the mediastinal abscess and a pericardial patch that was placed at the time of surgery 5 years previously revealed MABC. In our case, the infected aortic aneurysm most likely resulted from MABC pulmonary disease rather than from previous intraoperative contamination. This route of infection is rare. Physicians should be aware of the possibility of dissemination and subsequent infection of implants related to MABC pulmonary disease.

Simplified daptomycin dosing regimen for adult patients with methicillin-resistant Staphylococcus aureus infections based on population pharmacokinetic analysis.

Daptomycin is used to treat methicillin-resistant Staphylococcus aureus (MRSA) infections. Current guidelines recommend higher daptomycin doses (8-10 mg/kg) for severe infections; however, pharmacokinetic (PK) and pharmacodynamic-based dosing strategies are still limited. Therefore, we designed a new optimal daptomycin dosing regimen for patients with MRSA infections using a population PK modeling approach. A total of 110 plasma concentrations from 47 adult patients who received daptomycin in general wards were enrolled for population PK modeling. The target area under the concentration-time curve/minimum inhibitory concentration (MIC) ratio, target peak/MIC ratio, and threshold of the trough concentration for safety were set to >666, >60, and 24.3 mg/L, respectively. Renal function was indicated as a significant covariate for daptomycin clearance. The simulated probability of target attainment was more than 90% at MIC values of 0.25 and 0.5 mg/L in all patients at the standard dose (6 mg/kg). In contrast, comprehensive simulation assessments recommended 10 mg/kg every 24 h in patients with creatinine clearance >60 mL/min for MIC values of 1.0 mg/L. We propose a new simplified daptomycin dosing regimen stratified by renal function and MIC values based on PK model-based simulation analyses. The proposed regimen is expected to maximize clinical efficacy and minimize adverse events.

Successful allogeneic stem cell transplantation in a case with acute myeloid leukemia and invasive Schizophyllum commune rhinosinusitis.

Schizophyllum commune, a basidiomycete fungus, is a quite rare cause of invasive sinusitis for which no standard treatment has yet been established. We report herein a 59-year-old woman who developed S. commune rhinosinusitis after remission induction chemotherapy for her acute myeloid leukemia. No causative microorganisms were identified in the sinus lavage fluid culture, whereas nucleotide sequencing of the internal transcribed spacer region using endoscopic sinus biopsy specimen could confirm the pathogen as S. commune. Liposomal amphotericin B and voriconazole (VRCZ) treatment ameliorated both her clinical symptoms and laboratory findings. The patient was successfully treated with allogeneic stem cell transplantation, under continuous VRCZ administration, without aggravation of S. commune sinusitis. Molecular diagnosis and prompt intervention with suitable antifungal drugs may be crucial to manage this rare infectious complication.

Schizophyllum commune sinusitis after allogeneic bone marrow transplantation for myelodysplastic syndrome: A case report and literature review.

Sinusitis is a serious infectious complication of allogeneic hematopoietic stem cell transplantation. Schizophyllum commune (S commune) is a common basidiomycete fungus that is rarely involved in human disease. We report herein a case of S commune sinusitis after allogeneic bone marrow transplantation. A 66-year-old man with myelodysplastic syndrome underwent allogeneic bone marrow transplantation and developed maxillary and ethmoid sinusitis. The sinusitis did not improve with liposomal amphotericin B after neutrophil engraftment, so we considered that surgical intervention was needed for the recovery of sinusitis. Endoscopic sinus surgery was performed. In the debridement tissue of paranasal mucosa, filamentous fungal elements were observed. Moreover, genetic analysis of the tissue revealed the presence of S commune. Schizophyllum commune should be recognized as a fungal pathogen that causes sinusitis after allogeneic hematopoietic stem cell transplantation. This case suggests the effectiveness of prompt surgical intervention with liposomal amphotericin B treatment for S commune sinusitis and the usefulness of genetic diagnosis for cases under antifungal treatment. (160 words).

Gastrointestinal Graft-versus-Host Disease Is a Risk Factor for Postengraftment Bloodstream Infection in Allogeneic Hematopoietic Stem Cell Transplant Recipients.

Bloodstream infection (BSI) is a well-known cause of morbidity and mortality in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. Here, we conducted a retrospective study to assess the morbidity, etiology, risk factors, and outcomes of BSI in the postengraftment period (PE-BSI) after allo-HSCT. Forty-three of 316 patients (13.6%) developed 57 PE-BSI episodes, in which 62 pathogens were isolated: Gram-positive bacteria, gram-negative bacteria, and fungi, respectively, accounted for 54.8%, 35.5%, and 9.7% of the isolates. Multivariate analysis revealed methylprednisolone use for graft-versus-host disease (GVHD) prophylaxis (odds ratio [OR], 6.49; 95% confidence interval [CI], 1.49 to 28.2; P = .013) and acute gastrointestinal GVHD (GI-GVHD) (OR, 8.82; 95% CI, 3.99 to 19.5; P < .0001) as risk factors for developing PE-BSI. This finding suggested that GI-GVHD increases the risk of bacterial translocation and subsequent septicemia. Moreover, among patients with GI-GVHD, insufficient response to corticosteroids, presumably related to an intestinal dysbiosis, significantly correlated with this complication. Patients with PE-BSI presented worse outcome compared with those without (3-year overall survival, 47.0% versus 18.6%; P < .001). Close microbiologic monitoring for BSIs and minimizing intestinal dysbiosis may be crucial to break the vicious cycle between GI-GVHD and bacteremia and to improve transplant outcomes especially in patients who require additional immunosuppressants.

Mycobacterium abscessus and massiliense lung infection during macrolide treatment for bronchiolitis obliterans after allogeneic hematopoietic stem cell transplantation.

In patients undergoing allogeneic hematopoietic stem cell transplantation (allo-SCT), post-transplant lung infection is critical for their prognosis. Mycobacterium abscessus complex is not fully recognized as a nontuberculous mycobacteria (NTM) pathogen of post-SCT lung infection. Here, we present three post-allogeneic SCT patients who developed pulmonary infection caused by M. abscessus complex including M. abscessus and M. massiliense. In all three cases, macrolide antibiotics had been administered for bronchiolitis obliterans syndrome (BOS) before the confirmation of their infection, and macrolide resistance was noted in the M. abscessus isolates, one of which resulted in an unfavorable treatment outcome. It is important to consider M. abscessus lung infection as well as other NTM in patients receiving allo-SCT, particularly those receiving macrolide therapy for BOS.

[Disseminated Cryptococcosis with Eosinophilia and Elevated IgE in a Non-HIV-infected Patient].

In general, disseminated cryptococcosis usually occurs among immunocompromised patients, especially those with cell-mediated immunodeficiency, such as HIV-infected patients. We present herein a rare case of an apparently immunocompetent 33-year-old woman who developed disseminated cryptococcal diseases, which included meningitis and pneumonia with eosinophilia, and pulmonary tuberculosis during her disease course. Pneumonia with a diffuse micronodular pattern, immediately followed by meningitis, was diagnosed as disseminated cryptococcosis, because of the presence of yeast-like-fungi demonstrated by transbronchial lung biopsy and a positive cerebrospinal fluid (CSF) culture. In addition, the pneumonia exhibited eosinophilia in the peripheral blood and bronchoalveolar lavage fluid. Re-exacerbation of the pneumonia occurred approximately 3 weeks after onset, along with a sputum culture positive for Mycobacterium tuberculosis. Administration of anti-tuberculosis drugs resulted in recovery from the pulmonary tuberculosis. The treatment of cryptococcal meningitis was initiated using a standard induction regimen;however, an unrecovered status, highlighted by elevated CSF pressure, persisted. Finally, full recovery was induced by the addition of flucytosine treatment (100 mg/kg/day) and repeated daily via lumbar puncture. The allergic condition of this patient may have contributed to the onset of disseminated cryptococcosis.

[Bilateral Granulomatous Renal Masses after Intravesical BCG Therapy for Non-muscle-invasive Bladder Cancer and Carcinoma in Situ of the Upper Urinary Tract: A Case Study].

Bacillus Calmette-Guèrin (BCG) is commonly used not only as an infant vaccination, but also as a treatment of and prophylaxis to prevent recurrence in the management of non-muscle-invasive bladder cancer. However, the use of "live" BCG is sometimes complicated by associated infection. We present a case study of a 77-year-old man who developed bilateral renal masses after intravesical BCG therapy was initiated in November 2013, following transurethral resection of non-muscle-invasive bladder cancer. After four courses of BCG (Japan strain, 80 mg per treatment) instillations, a computed tomography examination for febrile episodes showed multiple bilateral renal masses, accompanied by a histological finding of a granulomatous reaction. An acid fast bacterium was cultured from only urine among blood, urine, and microscopic samples. Using the cultured strain, BCG infection was confirmed by the specific gene deletion pattern based on allele-specific polymerase chain reaction analysis. Anti-tuberculosis treatment, including isoniazid (300 mg/day), rifampicin (600 mg/day), and ethambutol (1,000 mg/day), was started for the BCG-related renal granuloma in February 2014. After 3 months, antibiotic therapy was discontinued owing to severe appetite loss, though the masses remained solid. No rapid growth has been detected after anti-BCG therapy. Intravesical BCG therapy is recommended worldwide as one of standard treatments for non-muscle-invasive bladder cancer. We should closely observe patients undergoing this approach for emerging BCG complications.

Pulmonary nocardiosis developed in a hematopoietic stem cell transplant recipient with bronchiolitis obliterans.

The chronic graft-versus-host disease often requires unceasing immunosuppressive therapy (IST), which increases a risk of infectious complications in hematopoietic stem cell transplantation (HSCT) recipients. We report an adult T-cell leukemia/lymphoma case who developed pulmonary nocardiosis, a rare pulmonary complication, after allogeneic HSCT despite administration of the prophylactic trimethoprim-sulfamethoxazole (TMP/STX). The inhaled corticosteroid in addition to systemic IST had been started for bronchiolitis obliterance 4 months prior to nocardiosis development. The patient was successfully treated with an increased dose of TMP/STX combined with meropenem. Transplantation physicians should keep this rare pulmonary complication in mind during sustained IST.