Collection And Transport Of Specimens

Cotton-, Dacron-, or calcium alginate-tipped swabs are suitable for collecting most upper respiratory tract microorganisms. If the swab remains moist, no further precautions need to be taken for specimens that are cultured within 4 hours of collection. After that period, some kind of transport medium to maintain viability and prevent overgrowth of contaminating organisms should be used. Swabs for detection of group A streptdr cocci (Streptococcus pyogenes) are the only exception. This organism is highly resistant to desiccation and remains viable on a dry swab for as long as 48 to 72 hou ..Throat swabs of this type can be placed in glassine paper envelopes for mailing or transport to a distant labora* tory. Throat swabs are also adequate for recovery of adenoviruses and herpesviruses, Corynebacterium diphthe-riae, Mycoplasma, Chlamydia, and Candida spp. Recovery ofj C. diphtheriae is enhanced by culturing both the throat and nasopharynx.

Nasopharyngeal swabs are better suited for recovery of respiratory syncytial virus, parainfluenza virus Bordetella pertussis, Neisseria spp., and the other viruses causing rhinitis. Optimum conditions for the collection and transport of specimens for viral detection or culture are described in Chapter 51. Although swabs made ' calcium alginate are commonly used to collect nasopharyngeal specimens (excluding those specimens foj chlamydia or viral culture), nasopharyngeal secretions collected by either aspiration and/or washing are the1 best specimens for Bordetella pertussis because a largei amount of material is obtained.313 The type of swab used for collection is very important. For example, cofci ton swabs should never be used for culture because fibers contain fatty acids on the surface that kill Bordetella. Calcium alginate or Dacron swabs are acceptably for obtaining nasopharyngeal swab specimens with, calcium alginate being the best for culture. Howe vet ii polymerase chain reaction (PCR) is to be performing Dacron or rayon swabs on plastic shafts are preferred, q

Specimens for B. pertussis ideally should be inoculated directly to fresh culture media at the patient's bedside. If this is not possible, transport for less than 2 hours in 1 % casamino acid medium at room temperature is acceptable. If specimens are plated on the day of collection, Amies transport medium with charcoal is acceptable. If specimens are plated more than 24 hours after collection, Regan-Lowe or Jones-Kendrick transport medium is optimal; both contain charcoal, starch, and nutrients as well as cephalexin. If lengthy delays in transport are expected, transport of specimens in Regan-Lowe medium at 4° C is recommended.5,13

Bacterial Vaginosis Facts

Bacterial Vaginosis Facts

This fact sheet is designed to provide you with information on Bacterial Vaginosis. Bacterial vaginosis is an abnormal vaginal condition that is characterized by vaginal discharge and results from an overgrowth of atypical bacteria in the vagina.

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