Molecular Epidemiological Study of Aspergillus fumigatus in a Bone Marrow Transplantation Unit by PCR Amplification of Ribosomal Intergenic Spacer Sequences

Abstract

We have developed a PCR-based method for the subspecific discrimination of Aspergillus fumigatus types by using two primers designed to amplify the intergenic spacer regions between ribosomal DNA transcription units. The method permitted the reproducible discrimination of 11 distinct DNA types among a total of 119 isolates of A. fumigatus collected from patients and from the environment of a bone marrow transplantation (BMT) unit over a three-year period. Ten DNA types of A. fumigatus were isolated from patients in the BMT unit; eight of these types were also found in the hospital environment, and six of these were present in the unit itself. Thirteen BMT patients developed infection with one of three DNA types some months after these had first been found in the environment of the unit. In other instances, the same DNA types ofA. fumigatus were isolated from BMT patients that were later recovered from the environment of the unit. Several DNA types ofA. fumigatus were found in the hospital environment over an 18-month period. Molecular typing of multiple isolates of A. fumigatus, obtained from postmortem tissue samples, showed that one patient was infected with a single DNA type, but two others had up to three different DNA types. Our findings suggest that A. fumigatus infection in BMT recipients may be nosocomial in origin and underline the need for careful environmental monitoring of units in which high-risk patients are housed.

Molecular typing of Trichophyton rubrum clinical isolates from Poland

“…10 Interestingly, a similar approach, based on the detection of NTS polymorphisms, has been employed for subtyping other Trichophyton species, including T. mentagrophytes 23,24 and T. tonsurans, 25,26 as well as non-dermatophyte fungi, such as Candida krusei 27 or Aspergillus fumigatus. 28 Intraspecific diversity of T. rubrum clinical isolates…”

First report on autochthonous urease-positive Trichophyton rubrum (T. raubitschekii) from South-east Europe

“…Strains were delineated with a PCR‐ribotyping method amplifying repeat elements of the ribosomal intergenic spacer region (IGS) utilizing two primers (IGSL‐IGSR) 12 . The final concentration of template DNA was adjusted at 10 ng per 1 µL of 50 µL PCR reaction.…”

Clinical evaluation of a polymerase chain reaction assay to detect Aspergillus species in bronchoalveolar lavage samples of neutropenic patients

“…Such assays, in addition to being potentially more sensitive than current culture‐based methods, may be specifically designed to encompass the desired range of genera and specimen types. A number of previous studies evaluating PCR‐mediated detection of Aspergillus species showed significantly improved sensitivity but involved assays with different methods and objectives, partly to optimize culture assays, partly for typing in epidemiological studies (Aufauvre‐Brown et al , 1992; van Belkum et al , 1993; Girardin et al , 1994; Anderson et al , 1996; Rath et al , 1996; Brandt et al , 1998; Fletcher et al , 1998; Radford et al , 1998). Studies with clinical samples, such as blood or BAL, were mostly done retrospectively and, with few exceptions, with small numbers of patients (Spreadbury et al , 1993; Tang et al , 1993; Makimura et al , 1994; Melchers et al , 1994; Bretagne et al , 1995, 1998; Verweij et al , 1995a; Walsh et al , 1995; Kappe et al , 1996; Yamakami et al , 1996, 1998; Einsele et al , 1997, 1998; Jones et al , 1998; Van Burik et al , 1998; Kawamura et al , 1999; Skladny et al , 1999).…”