HQ599507 see more (V. cholerae 1383), HQ599508 (V. cholerae 7452), HQ599509 (V. cholerae 547), HQ599510 (V. cholerae 582), and HQ599511 (V. cholerae 175). Results V. cholerae strains from 2006 show reduced resistance profile compared to previous epidemic strains We analyzed

two V. cholerae O1 El Tor clinical strains, VC175 and VC189 (Table 1), isolated at the Luanda Central Hospital (Angola). These strains were collected during the peak (May) of the cholera outbreak reported in Angola in 2006. The two strains were sensitive to tetracycline, chloramphenicol, and kanamycin but showed a multiresistant profile to ampicillin, penicillin, streptomycin, trimethoprim, and sulfamethoxazole (see Table 1 for complete phenotype and genotype). Despite this significant multidrug resistance, these strains showed a narrower resistance profile compared to those isolated in the previous 1987-1993 cholera epidemic, which were also resistant to tetracycline, chloramphenicol, spectinomycin and kanamycin [11]. We found no evidence

for the presence of conjugative plasmids or class 1 integrons in the 2006 strains Selonsertib in vivo analyzed (data not shown), which might explain their reduced drug resistance profile. Indeed, strains from 1987-1993 were associated with the conjugative plasmid p3iANG that holds genes encoding the resistance to tetracycline, chloramphenicol, kanamycin, and spectinomycin Vactosertib [11]. ICEVchAng3 is a sibling of ICEVchInd5 We assessed the presence of SXT/R391 family ICEs since they are a major cause of antibiotic

resistance spread among V. cholerae strains. Both strains were int SXT +, were shown to contain an ICE integrated into the prfC gene, and contained the conserved genes traI, traC and setR, respectively encoding a putative relaxase, a putative conjugation coupling protein, and a transcriptional repressor found in all SXT/R391 family members [31]. Based on these results we included this ICE in the SXT/R391 family and named it ICEVchAng3 according to the accepted nomenclature [32]. SXT/R391 ICEs exhibit significant genetic polymorphisms in hotspot content [12]. We used a first set of primers (primer set A), designed to HAS1 discriminate between SXTMO10 and R391 specific sequences [25], in order to prove the identity of the ICE circulating in the 2006 Angolan strains. Genes floR, strA, strB, sul2, dfrA18, dfrA1, the rumAB operon, and Hotspots or Variable Regions s026/traI, s043/traL, traA/s054, s073/traF and traG/eex were screened. The 2006 strains exhibited the same SXTMO10/R391 hybrid ICE pattern. Intergenic regions traG/eex (Variable Region 4) and traA/s054 (Hotspot 2) showed the molecular arrangement described in SXTMO10, whereas region s043/traL (Hotspot 1) was organized as in R391. Variable Region 3, inserted into the rumB locus, contained genes that mediate resistance to chloramphenicol, streptomycin and sulfamethoxazole: floR, strA, strB, sul2.