Fungal Cultures
Specimens for fungal culture are best sent to RRDA in sterile containers without transport medium. If specimen transportation and processing is delayed, storage at 4°C is appropriate; hair, skin, and nail specimens are best stored at room temperature. Do not refrigerate samples suspected of Histoplasma, Blastomyces or Cryptococcus. Swabs should not be used, as the cotton fibers may be confused with hyphae on direct microscopic examination.
Dermatophytes:
Dermatophyte Test Medium (DTM) is employed. Any growth is evaluated both macroscopically and microscopically.
Systemic mycoses:
All suspected systemic fungal samples are referred to our reference laboratory.
WATER CULTURES
At RRDA, total bacterial counts are performed by filtering water through a 0.2 micron filter, placing filters on commercial media and counting colonies after 24 hours. Samples should be held on ice prior to submission. If samples will not be evaluated within 4 hours, special collection bags for chlorine neutralization (whirl-pak with sodium thiosulfate) and sample preservation are recommended. Minimum sample size is 100 mL.
CULTURES OF FEED
A representative 30 gram sample should be placed in saran wrap or a container and sent to RRDA. Food samples are checked for total bacteria, coliforms, molds and yeasts using standard procedures.
ENVIRONMENTAL MONITORING
It is best to use sterile culturettes, which provide a transport medium for the collection of samples. Prior to collecting a sample, moisten the swab with the transport medium. This may entail breaking a capsule in the transport tube. With the moistened swab, roll or rub the swab over the area to be tested. Then place the swab carefully back in the transport tube, seal well, label with the site tested and the date. Forward the samples to RRDA as soon as possible. Transport medium only maintains bacteria but does not promote growth.