Invasive Mycosis Due to Species of Blastobotrys in Immunocompromised Patients with Reduced Susceptibility to Antifungals

Abstract

gCases of invasive mycosis due to Blastobotrys serpentis and B. proliferans identified by sequencing in a preterm patient and a rhabdomyosarcoma patient, respectively, are reported. Both species revealed elevated fluconazole and echinocandin MICs by the CLSI broth microdilution method. Additionally, B. serpentis exhibited high amphotericin B MICs, thus posing serious therapeutic challenges. CASE REPORTSC ase 1. A 29-week gestation preterm male infant at birth was admitted on 24 April 2013 because of respiratory distress. The infant was born by normal vaginal delivery to a 24-year-old primigravida mother. On admission at day 1, the child was not active and had tachypnoea with a respiratory rate of 68/min and his chest X-ray showed mild haziness. Examination of the cardiovascular system revealed no abnormal heart sounds and equal bilateral peripheral pulses. The abdomen was soft, with no organomegaly noted. On day 5, a loud murmur was detected and an echocardiography revealed a large patent ductus arteriosus of 2.2 mm in size which was surgically closed. His total leukocyte count was elevated (24,000 cells/l), and his C-reactive protein level was 0.1 mg/liter. Two days later, the infant developed abdominal distension and the X-ray revealed a pneumoperitoneum. This was managed with a peritoneal drainage followed by laparotomy. During surgery, a gangrenous gastric fundus with a sloughed greater curvature, leading to an approximately 40% to 45% loss of stomach volume, was seen. The necrotic tissues were removed; gastric anastomosis was done with placement of a gastrojejunal feeding tube via gastrotomy. The child underwent operation twice again, on days 14 and 29 of admission, because of anastomotic leakage and perforation due to a gangrenous bowel. Histopathological examination of tissue biopsy specimens of the distal ileum, terminal ileum, and stoma showed active inflammatory changes, but no granuloma and ganglion cells were present, ruling out Hirschsprung disease. The child was empirically treated with ampicillin and gentamicin starting from day 1 of admission along with prophylactic fluconazole (3 mg/kg of body weight twice weekly) due to a high risk for invasive candidiasis. Further during the course of treatment, meropenem therapy was included on day 3, cefoperazone-sulbactam therapy a week later, and ofloxacin therapy on day 17. The clinical course and the therapy instituted are depicted in Fig. 1. Cultures of the discharge from the laprotomy incision site on day 15 of admission grew yeasts identified as Stephanoascus ciferrii (identification, 86%) by the use of a Vitek2 yeast ID system (bioMérieux, Marcy l'Etoile, France) which exhibited a high fluconazole MIC (Ͼ64 g/ml) by AST-YS06 (bioMérieux). Blood cultures in Bactec Peds Plus/F vials taken on days 16, 18, 21, 23, and 26 of admission grew fluconazole-resistant S. ciferrii after 2 to 3 days of incubation at 37°C. The endotracheal aspirate collected on day 23 also grew S. ciferrii. The patient had already received fluconazole (6 mg/kg) for 17 days; the trea...

Bacterial but Not Fungal Gut Microbiota Alterations Are Associated With Common Variable Immunodeficiency (CVID) Phenotype

“…This genus was not previously reported in the context of the human gut, and therefore it may not be a true gut colonizer. On the other hand, Blastobotrys species are capable of growing in 37°C, and they were reported to cause invasive fungal infections, although extremely rare, in immunocompromised patients (73). Therefore, this possible association deserves deeper examination.…”

In Vitro Activities of Eight Antifungal Drugs against a Global Collection of Genotyped Exserohilum Isolates

“…S1 in the supplemental material), as described previously (17,18), and subjected to sequencing of the internal transcribed spacer (ITS) region (see Fig. S2 in the supplemental material).…”

Pulmonary infection secondary to Blastobotrys raffinosifermentans in a cystic fibrosis patient: Review of the literature

“…Candida species are frequently isolated from the airways of cystic fibrosis patients, as are Aspergillus , Scedosporium, Exophiala species and members of the Rasamsonia argillacea species complex, either as colonisers or as true causes of infection 17–19 . In addition, Blastobotrys species have been reported to be cultured from respiratory samples in CF patients and chronic bronchitis, and from peritoneal fluid in patients undergoing continuous ambulatory peritoneal dialysis 7–9,11 . However, many clinical microbiology laboratories do not routinely identify yeasts cultured from respiratory specimens.…”

“…However, many clinical microbiology laboratories do not routinely identify yeasts cultured from respiratory specimens. Biochemical and proteomic assays used in clinical laboratories may misidentify members of this genus 6,8,11 . Identification to the species level using DNA sequencing may be challenging due to low nucleotide variation.…”

“…These properties may also be predisposing factors for human infections, as members of this genus have also been reported as lung colonisers and potential aetiologic agents of invasive disease in cystic fibrosis patients 6,7 . Species that have been reported as capable of causing disease in immunocompromised hosts include B proliferans, B serpentis, B adeninivorans and B raffinosifermentans 6–9 . More than 20 species within the genus Blastobotrys have been described, and at least 12 are capable of growth at human body temperature (ie 37°C) 10 …”