Several resistant clones previously described in Spain were identified [9, 10]. The emm4T4 Sfi1 (79) clone resembles to clone B described in 1999 . It was the most common in the present study, indicating it to still be circulating in Spain. This clone has a wide distribution, and it has recently been identified in Finland, Greece, Italy, England and
Sweden . Clone C, previously identified in Spain, the United Kingdom and the United States  was not detected among the present isolates, although Selleckchem NVP-BEZ235 it might be related to the present clones emm4T4 Sfi4 and emm4T4 Sfi5. The major macrolide-resistant clone emm75T25 Sfi12(41) was similar (additional band between 48.5 and 97 kb) to clone D described by Perez-Trallero et al. . The emm6T6 Sfi17 and emm84T25 Sfi22 clones might be associated with resistance since they were only observed in isolates resistant to erythromycin. SIS3 purchase Regarding tetracycline resistance, we detected values of 6.8% between 1994 and 2006, indicating there to be no trend towards increased tetracycline in Spain. However, higher rates have been found in other countries such as Israel (23.6%), Denmark (33.7%), Portugal (38.7%) or Iran (42%) [10–12]. In this study, a predominance of genotype with both genes tet(M) and tet(O) (42.6%) was observed. But
no Spanish reports citing the predominance of both genes appears to exist, tet(M) alone is usually the most common resistance determinant followed by tet(O) . In the present tetracycline-population, emm77T28 was the main emm/T type. emm77 has been previously associated with resistance to tetracycline in Israel and Europe . In Italy and Norway, an emm77 clone has been reported that is characterised by its carrying tet(O) linked to erm(A)and being associated with the iMLSB phenotype . In the present study, the two co-resistant emm77T28 isolates showed genotypes different to those described by Palmieri et al. . With regard to co-resistance, we found that all isolates
(19) except one had the cMLSB macrolide resistance phenotype such 5-Fluoracil as Greece (Athens) and PR-171 cost Norway [5, 15]. In contrast, in Finland, iMLSB isolates showing co-resistance have reached rates of 93% . A correlation between the M phenotype and co-resistance has been also reported , but this was not detected in the present study. Of the 19 co-resistant isolates, five carried tet(M)/erm(B) as their only resistance genes, suggesting they may carry conjugative transposons of the Tn916 family in which erm(B) and tet(M) are linked ,whereas 13 harboured tet(M)/erm(B) associated with other resistance genes. In the remaining isolate, the erm(B), mef(A), tet(M) and tet(O) genes were all detected. mef(A) and tet(O) linkage has been previously reported in co-resistant isolates [22, 25]. In the present work, mef(A) appeared associated with other macrolide resistance genes and linked to tet(M) (1 isolate) or to tet(M)/tet(O) (5). The main emm/T type detected in coresistant isolates was emm11T11 (57.8%).