Side-by-side comparison

of SmaI and Cfr9I PFGE profiles yielded identical banding patterns consistent with unequivocal comparability of both restriction patterns. Reproducibility of the method was confirmed with 5 NT SmaI -MRSA isolates which were re-analyzed 3 times and yielded identical banding patterns. Genetic diversity of NTSmaI -MRSA All PFGE patterns of Trichostatin A solubility dmso the NT SmaI -MRSA were compared with a database consisting of more than 4000 isolates containing over 700 Alvocidib supplier different PFGE types obtained with SmaI digestion. Surprisingly, newly-obtained banding patterns of NT SmaI -MRSA isolates did not match with any known PFGE cluster in the national database of MRSA isolates collected since 2002. Thirty t011 isolates revealed 16 different PFGE patterns (figure 1). The largest PFGE cluster consisted of 5 isolates, and 5 patterns were found more than once (n = 19). No correlation was found between PFGE cluster

and geographic location. The minimal similarity (Dice coefficient, represented by UPGMA, 0.5% optimization and 1.0% tolerance) between the different patterns was 64% (data not shown). Thirty t108 isolates revealed 14 different PFGE selleck inhibitor patterns (figure 1). The largest cluster contained 12 isolates and 4 patterns were found more than once (n = 20). The clusters showed no geographical correlation. The minimal similarity of the t108 isolates was 50% (data not shown). One t108 isolate yielded a very distinct PFGE pattern (figure 1, pattern H). Without this isolate the minimal similarity of the t108 isolates would be 80%. The minimal similarity of the 60 NT SmaI -MRSA isolates was 35%, but most isolates share 80% or more similarity (figure 1). SCCmec typing of the 60 NT SmaI -MRSA isolates

showed SCCmec type IV (n = 14) and SCCmec type V (n= 43). Three isolates yielded a variant Palmatine of SCCmec type V (indicated in figure 1 with V*) and no SCCmec types I, II or III were found (figure 1). Figure 1 Dendrogram of the Cfr 9I PFGE results of NT Sma -MRSA isolates with the 2 most prevalent spa -types in the Netherlands. Transmission of ST398 isolates The results of Cfr9I PFGE of 8 pairs of veterinarians and one of their close family members showed that 5 pairs gave indistinguishable banding patterns suggesting possible transmission of ST398 (figure 2 shows 2 pairs of indistinguishable banding patterns). Two pairs that did not match also had different spa-types (figure 2). One pair which had the same spa-type differed in a single PFGE band (data not shown). Six isolates belonging to an outbreak in a residential care facility with spa-types t2383 and t011 all shared the same banding pattern (figure 2). Furthermore, the transmission between pigs, pig farmers and their family on 9 different pig farms (table 1, figure 2) was studied. Farms 1 to 5 shared the same spa-type whereas on farms 6 to 9, two or more different spa-types were present.