Agreement of SLD results between laboratories in the “Workpackage 3 of the FP7 TB PAN-NET”.

*<p>All strains were tested in three rounds of testing: round 1 (n = 13), in the intermediate round (n = 11), and in round 2 of the “Workpackage 3 of the FP7 TB PAN-NET”.</p>**<p>All laboratories applied line probe assays, some additionally DNA sequencing methods.</p>***<p>The majority of laboratories applied MGIT 960 DST, some the proportion method on solid media, but the data are incomplete; intermediate level strains were excluded from this analysis.</p

Compilation of strains in round 1 of the WP3 of the TB PAN-NET” project.

<p>Compilation of strains in round 1 of the WP3 of the TB PAN-NET” project.</p

Methods applied in the different laboratories in both phases of SLD proficiency testing (“Baltic-Nordic TB-Laboratory Network” study).

*<p>some laboratories used more than one method.</p><p>PAS, p-amino salicylic acid.</p><p>LJ, Löwenstein Jensen; MIC, minimal inhibitory concentration.</p

Agreement of SLD testing in different laboratories in phase I and phase II of the “Baltic-Nordic TB-Laboratory Network” study.

<p>PAS, p-amino salicylic acid.</p

Certificates issued for a succesful EQA round.

<p>Certificates issued for a succesful EQA round.</p

Agreement of SLD results between laboratories in the four rounds of quality control.

*<p>The majority of laboratories applied MGIT 960 DST, only one laboratory performed the proportion method on solid media, but the data are incomplete.</p>**<p>susc. = susceptible, res. = resistant; intermediate level strains were excluded from this analysis.</p>***<p>n.d. = not done.</p

Comparison between RFLP and MIRU-VNTR Genotyping of <i>Mycobacterium tuberculosis</i> Strains Isolated in Stockholm 2009 to 2011

<div><p>Our aim was to analyze the difference between methods for genotyping of <i>Mycobacterium tuberculosis</i> complex isolates. We collected genotyping results from Restriction Fragment Length Polymorphism (RFLP) and Mycobacterial Interspersed Repetitive Units - Variable Numbers of Tandem Repeat (MIRU-VNTR) in a geographically limited area (Stockholm) during a period of three years. The number and proportion of isolates belonging to clusters was reduced by 45 and 35% respectively when combining the two methods compared with using RFLP or MIRU-VNTR only. The mean size of the clusters was smaller when combining methods and smaller with RFLP compared to MIRU-VNTR. In clusters with confirmed epidemiological links RFLP coincided slightly better than MIRU-VNTR but where there was a difference, the variation in MIRU-VNTR pattern was only in a single locus. In isolates with few IS<i>6110</i> bands in RFLP, MIRU-VNTR differentiated the isolates more, dividing the RFLP clusters. Since MIRU-VNTR is faster and less labour-intensive it is the method of choice for routine genotyping. In most cases it will be sufficient for epidemiological purposes but true clustering might still be considered if there are epidemiological links and the MIRU-VNTR results differ in only one of its 24 loci.</p></div

Clustering by different algorithms and epidemiological links.

<p>Clustering by different algorithms and epidemiological links.</p

Tuberculosis cases confirmed by culture, Stockholm 2009–2011 by region of origin (n = 406).

<p>Tuberculosis cases confirmed by culture, Stockholm 2009–2011 by region of origin (n = 406).</p

Number of <i>Mycobacterium tuberculosis</i> isolates clustering by different algorithms.

<p>Number of <i>Mycobacterium tuberculosis</i> isolates clustering by different algorithms.</p