This variant is significantly different from those isolated during previous cholera outbreaks in the 1990s in the same geographic area. Indeed, it holds a peculiar CTXΦ array and the SXT-like element ICEVchAng3. Ribotype analysis suggests that this strain might have spread to West Africa from the Indian Subcontinent. Methods Bacterial strains, susceptibility tests and transfer of drug resistances selleckchem We
analyzed V. cholerae strains isolated in Angola or India between 1992 and 2006 (Table 1). All strains were isolated from stool samples and/or rectal swabs from patients, and after isolation on thiosulfate citrate bile sucrose agar and biochemical identification, bacterial strains were routinely grown in Luria-Bertani (LB) or agar plates at 37°C and maintained at -80°in LB broth containing 30% (vol/vol) glycerol. Table 1 V. cholerae O1 strains analyzed in this study Isolation Strain Place Year Antibiotic resistance profile Antibiotic resistance genes ICE content CTXΦ array Ribotype Reference VC175 Angola (Luanda) 2006 Ap, Pn, Sm, Su, Tp floR, strA, strB, dfrA1, sulII b ICEVchAng3 B R1 This study VC189 Angola (Luanda) 2006 Ap, Pn, Sm, Su, Tp floR, strA, strB, dfrA1, sulII b ICEVchAng3 B R1 This study VC582 Angola (Luanda) 1992 Ap, Cm, Kn, Pn, Sm, Sp, Su, Tc, Tpa aph, tetG, cat1, blaP1, dfrA15, aadA8, sul2 c – A R2  VC1383 Angola (Benguela) 1994 Ap, Cm, Kn, Pn, Sm, Sp, Su, Tc, Tpa aph, tetG, cat1, blaP1, dfrA15, aadA8, sul2 c
– A R3  VC547 Angola (Bengo river) 1994 Ap, Cm, Kn, Pn, Sm, Sp, Su, Tc, Tpa aph, tetG, cat1, blaP1, dfrA15, aadA8, sul2 c – A R4  VC7452 India (Sevagram) 1995 Ap, Nx, Pn, Sm, Sp, Su, Tp floR, strA, strB, dfrA1, https://www.selleckchem.com/products/3-methyladenine.html sulII b ICEVchInd5d B R1  VC15699 India (Sevagram) 1999 Ap, Nx, Pn, Sm, Sp, Su, Tp floR, strA, strB, dfrA1, sulII b ICEVchInd5
B R1  VC9258 India (Sevagram) 1999 Ap, Nx, Pn, Sm, Sp, Su, Tp floR, strA, strB, dfrA1, sulII b ICEVchInd5 B R1  aResistance profile conferred by conjugative plasmid p3iANG ; blocated on the ICE; clocated on p3iANG; dICE fully sequenced. Abbreviations: Ap, ampicillin; Cm, chloramphenicol; Kn, kanamycin; Nx, nalidixic acid; Pn, penicillin; Sm, streptomycin; Sp, spectinomycin; Su, sulfamethoxazole; Tc, tetracycline; Amino acid Tp, trimethoprim. Antimicrobial susceptibility was tested at the following concentrations: ampicillin (Ap), 100 μg/ml; chloramphenicol (Cm), 20 μg/ml; kanamycin (Km), 50 μg/ml; nalidixic acid (Nx), 40 μg/ml; penicillin (Pn), 20 μg/ml; rifampin (Rf), 100 μg/ml; spectinomycin (Sp), 50 μg/ml; streptomycin (Sm), 50 μg/ml; sulfamethoxazole (Su), 160 μg/ml; tetracycline (Tc), 12 μg/ml; and Entinostat manufacturer trimethoprim (Tm), 32 μg/ml. Antibiotic concentrations were defined according to their MIC breakpoints as previously described [18, 20] and were included in ISO sensitest (Oxoid) agar plates. Bacterial strains were spotted onto the plates as previously described . Conjugation assays were used to transfer ICEVchAng3 from V.