Emergence of fusarioses in a university hospital in Turkey during a 20-year period

Fusarium species have started appearing increasingly as the main cause of infections, particularly in immunocompromised patients. In this study, we aimed to present the first epidemiological data from Turkey, analyze fusariosis cases that have been monitored in a university hospital during the past 20 years, identify the responsible Fusarium species, and determine antifungal susceptibilities. A total of 47 cases of fusariosis was included in the study. Fusarium isolates were identified by multilocus sequence typing (MLST). Antifungal susceptibility was tested by the broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI) methodology. Of the Fusarium infections, 23.4 % were superficial, 44.7 % were locally invasive, and 31.9 % were disseminated. A significant increase was observed over the years. The Fusarium fujikuroi species complex (FFSC) proved to be the most frequent agent group (17 cases; 51.5 %), followed by the Fusarium solani species complex (FSSC) (14 cases; 42.4 %), the Fusarium dimerum species complex (FDSC), and the Fusarium oxysporum species complexes (FOSC) (one case each). Amphotericin B had the highest in vitro activity against all species. Voriconazole and posaconazole showed interspecies variability across and within Fusarium species complexes. In conclusion, our data support the fact that regional differences exist in the distribution of the Fusarium species and that species-specific differences are observed in antifungal susceptibility patterns. The monitoring of local epidemiological data by determining fungal identity and susceptibility are of importance in guiding the clinical follow-up of patients.Türk Mikrobiyoloji DerneğiMinistry of Health, Muscat, Oma

Airborne transmission of invasive fusariosis in patients with hematologic malignancies

<div><p>From 2006 to 2013, an increasing incidence of fusariosis was observed in the hematologic patients of our University Hospital. We suspected of an environmental source, and the indoor hospital air was investigated as a potential source of the fungemia. Air samplings were performed in the hematology and bone marrow transplant (BMT) wards using an air sampler with pre-defined air volumes. To study the molecular relationship among environmental and clinical isolates, 18 <i>Fusarium</i> spp. recovered from blood cultures were included in the study. DNA sequencing of a partial portion of <i>TEF1α</i> gene was performed for molecular identification. Molecular typing was carried out by multi-locus sequence typing (MLST) using a four-gene scheme: <i>TEF1α</i>, rDNA, <i>RPB1</i> and <i>RPB2</i>. One hundred four isolates were recovered from the air of the hematology (n = 76) and the BMT (n = 28) wards. <i>Fusarium</i> isolates from the air were from five species complexes: <i>Fusarium fujikuroi</i> (FFSC, n = 56), <i>Fusarium incarnatum-equiseti</i> (FIESC, n = 24), <i>Fusarium solani</i> (FSSC, n = 13), <i>Fusarium chlamydosporum</i> (FCSC, n = 10), and <i>Fusarium oxysporum</i> (FOSC, n = 1). Fifteen <i>Fusarium</i> isolates recovered from blood belonged to FSSC, and three to FFSC. MLST identified the same sequence type (ST) in clinical and environmental isolates. ST1 was found in 5 isolates from blood and in 7 from the air, both identified as FSSC (<i>Fusarium petroliphilum</i>). STn1 was found in one isolate from blood and in one from the air, both identified as FFSC (<i>Fusarium napiforme</i>). <i>F</i>. <i>napiforme</i> was isolated from the air of the hospital room of the patient with fungemia due to <i>F</i>. <i>napiforme</i>. These findings suggested a possible clonal origin of the <i>Fusarium</i> spp. recovered from air and bloodcultures. In conclusion, our study found a diversity of <i>Fusarium</i> species in the air of our hospital, and a possible role of the air as source of systemic fusariosis in our immunocompromised patients.</p></div

Primers used for sequencing of clinical and environmental <i>Fusarium</i> isolates.

<p>Primers used for sequencing of clinical and environmental <i>Fusarium</i> isolates.</p

Distribution of <i>Fusarium</i> species isolated from hospital air.

<p>The frequency of each species complex in the hematology (A, n = 76) and BMT (B, n = 28) wards is shown. The species identified for each complex is presented outside the graphs. The species found exclusively in hematology unit are marked with (*). FCSC: <i>F</i>. <i>chlamydosporum</i> species complex; FFSC: <i>F</i>. <i>fujikuroi</i> species complex; FIESC: <i>F</i>. <i>incarnatum-equiseti</i> species complex; FOSC: <i>F</i>. <i>oxysporum</i> species complex; FSSC: <i>F</i>. <i>solani</i> species complex.</p

Detailed information about ST1 (<i>F</i>. <i>petroliphilum—</i>FSSC) and STn1 (<i>F</i>. <i>napiforme—</i>FFSC) isolates.

<p>Detailed information about ST1 (<i>F</i>. <i>petroliphilum—</i>FSSC) and STn1 (<i>F</i>. <i>napiforme—</i>FFSC) isolates.</p

Sequence types (ST) determined by sequencing of portions of the genes <i>TEF1α</i>, rDNA, <i>RPB1</i> and <i>RPB2</i> for <i>Fusarium</i> species isolated from air and blood.

<p>The number of samples with each ST is shown above the bar. FSSC: <i>F</i>. <i>solani</i> species complex. FFSC: <i>F</i>. <i>fujikuroi</i> species complex. ST: sequence type.</p

Molecular identification of <i>Fusarium</i> species isolated from hospital air samplings.

<p>(A) and (B) shows <i>TEF1α</i> DNA sequencing classification in species complex and species, respectively. The number of isolates is shown above each bar. FCSC: <i>F</i>. <i>chlamydosporum</i> species complex; FFSC: <i>F</i>. <i>fujikuroi</i> species complex; FIESC: <i>F</i>. <i>incarnatum-equiseti</i> species complex; FOSC: <i>F</i>. <i>oxysporum</i> species complex; FSSC: <i>F</i>. <i>solani</i> species complex.</p