Medical Microbiology

Mycobacterium 267

eratingaccompanyingflora,followedbycentrifugationtoenrichtheconcen-

tration.

&Microscopy.Ziehl-Neelsenand/orauraminefluorescentstaining(p. 21 2).

Thismethodproducesrapid resultsbuthasa lowlevelofsensitivity

(> 104 –1 05 /ml)andspecificity(acid-fastrodsonly).

&Cultureonspecialsolidandinspecialliquidmediums.Timerequirement:

fourtoeightweeks.

&Identification.Biochemicaltestswithpurecultureifnecessary.Timere-

quirement:onetothreeweeks.

&Resistancetestwithpureculture.Timerequirement:threeweeks.

Rapidmethods.AnumberofdifferentrapidTBdiagnosticmethodshave

beenintroducedinrecentyearsthatrequirelesstimethanthetraditional

methods.

&Culture.Early-stagegrowthdetectioninliquidmediumsinvolvingiden-

tificationofTBmetabolicproductswithhighlysensitive,semi-automated

equipment.Timerequirement:onetothreeweeks.Tentativediagnosis.

&Identification.Analysisofcellularfattyacidsbymeansofgaschromato-

graphyandofmycolicacidsbymeansofHPLC.Timerequirement: 12 days

withapureculture.

&DNAprobes.UsedtoidentifyM.tuberculosiscomplexandothermycobac-

teria.Timerequirement:severalhourswithapureculture.

&Resistancetest.Useofsemi-automatedequipment(seeabove).Prolifera-

tion/nonproliferationdeterminationinliquidmediumscontainingstandard

antituberculoticagents(Table4. 4 ).Timerequirement:7–1 0 days.

Table4. 4 SchemeforChemotherapyofTuberculosis

Standardscheme Months Shortscheme* Months

Initialphase isoniazid(INH)

rifampicin(RMP)

ethambutol(EMB)

2 isoniazid

rifampicin

ethambutol

pyrazinamide(PZA)

2

Continuation

phase

isoniazid

rifampicin

7 isoniazid

rifampicin

4

* AlternativeincasesofconfirmedINHsensitivityormildclinicalpicture:initial

treatmentwithacombinationoffixedINH+RMP+PZAfortwomonths

4

Kayser, Medical Microbiology © 2005 Thieme