Table36.3 Comparisonof mainmicrobiologicalmethodsfor hygienemonitoring
Method Advantages Disadvantages
Swabbing Widelyusedand accepted. No universallyagreedprotocol.
Can be qualitative(typesof
organisms)and quantitative.Methods,media,etc. varywidely
betweencompaniesand conditions.
Anyshape,size or surfacearea
can be tested.
Relativelyinexpensive.Incubationand sterilisation
facilitiesneededor external
contractlaboratory.Staffwith
somemicrobiologicaltraining
needed.
Poorrecoveryespeciallydry
surfaces.Poorreproducibility.
Motileorganismscan cover
surfacesof agar.Contactplate Directcontactwithsurface. Flat smoothsurfacesonly.
Betterreproducibilitythan
swabbing.Motileorganismscan coversurface
of agar.
Fixedrelativelysmallarea. Possibleagarresidueon surface.
Can be boughtpre-prepared.
Availablein varietyof media.Lidscan becomedetachedin
transport,althoughone makewith
a lockablelid is available.
Relativelyinexpensive. Incubationand sterilisation
disposalfacilitiesneeded.Dipslide Directcontactwithsurface. Flat smoothsurfacesusually.
Betterreproducibilitythan
swabbing.Motileorganismscan coversurface
of agar.
Fixedarea/narrowshape,
relativelysmallsurfacearea.Incubationand sterilisation
disposalfacilitiesneeded.
Can be boughtpre-preparedin
a varietyof media.Possibleagarresidueon surface.Differentmediaon reverseside
of paddleif required.Semiquantitativedependingon
numbers.Minimalincubationfacilities
needed(portable).
Can be usedto test rinsewater.
Sealedunit withscrewcap.
Longershelf-life.
Paddlecan be hingedfor easier
use.Improvingsurfacesamplingand detection of contamination 597