BackgroundWe evaluated if flowcytometry, using Sysmex UF-5000, could improve diagnosis of urinary tract infections by rapid identification of culture negative and contaminated samples prior to culture plating, thus reducing culture plating workload and response time. We also evaluated if it is possible to reduce the response time for antibiotic susceptibility profiles using the bacteria information flag on Sysmex UF-5000 to differentiate between Gram positive and negative bacteria, followed by direct Antibiotic Susceptibility Testing (dAST) on the positive urine samples.MethodsOne thousand urine samples were analyzed for bacteria, white blood cells and squamous cells by flowcytometry before culture plating. Results from flowcytometric analysis at different cut-off values were compared to results of culture plating. We evaluated dAST on 100 urine samples that were analyzed as positive by flowcytometry, containing either Gram positive or Gram negative bacteria.ResultsUsing a cut-off value with bacterial count ≥100.000/mL and WBCs ≥10/μL, flowcytometry predicted 42,1% of samples with non-significant growth. We found that most contaminated samples contain few squamous cells. For 52/56 positive samples containing Gram negative bacteria dAST was identical to routine testing. Overall, there was concordance in 555/560 tested antibiotic combinations.ConclusionFlowcytometry offers advantages for diagnosis of urinary tract infections. Screening for negative urine samples on the day of arrival reduces culture plating and workload, and results in shorter response time for the negative samples. The bacteria information flag predicts positive samples containing Gram negative bacteria for dAST with high accuracy, thus Antibiotic Susceptibility Profile can be reported the day after arrival. For the positive samples containing Gram negative bacteria the concordance was very good between dAST and Antibiotic Susceptibility Testing in routine. For positive samples containing Gram positive bacteria the results were not convincing. We did not find any correlation between epithelial cells and contamination.

Bakgrunn. Bakgrunn. En variant av Chlamydia trachomatis (nvC trachomatis) har skapt problemer for chlamydiadiagnostikken i Sverige. Andelen nvC trachomatis i Sverige i 2006–07 var fylkesvis 25–80 % av dem som var smittet av C trachomatis. Vårt formål har vært å overvåke nvC trachomatis blant våre pasienter fra januar 2007 frem til juli 2008. Materiale og metode. Materiale og metode. 1.1. 2007–30.6. 2008 ble alle chlamydiaprøver ved Fürst Medisinsk Laboratorium dobbeltanalysert. Deteksjon av C trachomatis ble utført på isolert DNA med Cobas TaqMan 48 (Roche Diagnostics). Deteksjon og verifikasjon av nvC trachomatis ble utført med egenutviklede sanntid polymerasekjedereaksjonsmetoder. Resultater. Resultater. 61 av 23 726 pasienter ble identifisert som bærere av nvC trachomatis. Andelen C trachomatis-bærere som var nvC trachomatis-positive økte fra 1,0 % i første kvartal 2007 til 3,2 % i andre kvartal 2008. Fortolkning. Fortolkning. Våre resultater viser en langsom, men jevn økning i andelen nvC trachomatis-positive prøver. Sammenliknet med tidligere prevalenstall rapportert i Sverige (25–80 %), er forekomsten av nvC trachomatis lav i våre data. Epidemiologien til nvC trachomatis bidrar til kunnskapen om spredning av seksuelt overførbare infeksjoner og understreker at man finner bare det man leter etter.

BACKGROUND:A mutant Chlamydia trachomatis variant (nvC trachomatis) has made it more difficult to diagnose chlamydia in Sweden. The proportion of nvC trachomatis has varied between Swedish counties (25-80 %) in the period 2006-07. Our goal has been to monitor nvC trachomatis among our patients from January 2007 and up to July 2008.MATERIAL AND METHODS:In this time period, all C trachomatis samples at Fürst Medical Laboratory, Norway were analyzed twice. Cobas TaqMan 48 (Roche Diagnostics) was used to detect C trachomatis in isolated DNA and real-time PCR methods developed by us were used to both detect and verify nvC trachomatis.RESULTS:61 patients of 23 726 patients were identified as carriers of nvC trachomatis. The proportion of C trachomatis carriers who were positive for nvC trachomatis increased from 1.0 % in the first quarter of 2007 to 3.2 % in the second quarter of 2008.INTERPRETATION:Our results show a slow but steady increase in the proportion of nvC trachomatis positive tests. As compared to previous rates reported in Sweden (25-80 %), the occurrence of nvC trachomatis in our data is low. The epidemiology of this chlamydia mutant contributes to the understanding of mechanisms for spread of sexually transmitted infections and emphasize that you only find what you are looking for.