Article Text

Download PDFPDF

Survival of upper respiratory tract bacteria on cotton-wool swabs.
  1. P W Ross,
  2. H Lough


    Plain, buffered cotton-wool swabs and albumen-coated cotton-wool swabs were prepared with known numbers of the following: Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, corynebacteria and Escherichia coli. Swabs were plated immediately (0 hours) after loading with a 0.1 ml standardised inoculum; each swab was plated out four times by streaking on both halves of two plates. At 0 hours recovery rates from first platings on solid media ranged from 3.3%-8.9%; from platings 1-4 ranges were 2.5%-5.7%. Both types of swabs gave similar results. The greater the delay in plating swabs at room temperature and 4 degrees C the lower was the recovery rate of H. influenzae and Strep. pneumoniae, though both species survived better on either kind of swab when these were held at 4 degrees C. There was a very small reduction in numbers of Staph. aureus from 24 to 48 hours but the recovery rate of corynebacteria was similar over the 48-hour period, at both room temperature and 4 degrees C. Twenty-four-hour counts of E. coli at room temperature were approximately five times greater than at 0 hours, and at 48 hours colonies were too numerous to count. At 4 degrees C, however, counts of E. coli fell during the 48-hour period.

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.