title: Phenotypic and genotypic characteristics of Vibrio cholerae O1 isolated from the Sierra Leone cholera outbreak in 2012.
abstract: BACKGROUND
  This study describes phenotypic, genotypic and antibiotic susceptibility patterns of the strains isolated from the 2012 Sierra Leone cholera outbreak. Rectal swabs were collected from patients and cultured for Vibrio cholerae O1.
  
  
  METHODS
  The isolates were subjected to multiplex PCR, mismatch amplification mutation assay (MAMA) PCR, pulsed field gel electrophoresis (PFGE), and antibiotic sensitivity tests using disk diffusion and minimum inhibitory concentration (MIC) E-test following standard procedures.
  
  
  RESULTS
  Out of 17 rectal swabs tested, 15 yielded V. cholerae O1 biotype El Tor, serotype Ogawa. All the strains belonged to 'altered' variants as MAMA PCR result showed the presence of classical cholera toxin B. PFGE result revealed four pulse types. Using antibiotic disk diffusion, all the isolates were resistant to erythromycin, chloramphenicol, furazolidone, and trimethoprim/sulfamethoxazole (SXT) except SL1 which was sensitive to chloramphenicol and SXT. All the isolates were sensitive to nalidixic acid, tetracycline, doxycycline, azithromycin, and ciprofloxacin except SL2 which was resistant to nalidixic acid. However, variable sensitivity patterns were observed for kanamycin. The ranges of MIC were 0.125-0.50 mg/l, 0.003-0.023 mg/l and 0.38-0.75 mg/l for azithromycin, ciprofloxacin and tetracycline, respectively.
  
  
  CONCLUSIONS
  This study demonstrates that altered variants of V. cholerae O1 of four clonal types were responsible for the 2012 outbreak of cholera in Sierra Leone.
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Zahid H
authors.initials: ZH
authors.lastname: Mahmud
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Shafiqul
authors.initials: S
authors.lastname: Islam
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Rokon U
authors.initials: RU
authors.lastname: Zaman
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Mahmuda
authors.initials: M
authors.lastname: Akter
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Kaisar A
authors.initials: KA
authors.lastname: Talukder
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Pradip K
authors.initials: PK
authors.lastname: Bardhan
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Azharul I
authors.initials: AI
authors.lastname: Khan
authors.affiliation: Central Public Health Reference Laboratory, Ministry of Health and Sanitation, Connaught Hospital, Free Town, Sierra Leone.
authors.forename: Faye C
authors.initials: FC
authors.lastname: Rhodes
authors.affiliation: Central Public Health Reference Laboratory, Ministry of Health and Sanitation, Connaught Hospital, Free Town, Sierra Leone.
authors.forename: Abdul
authors.initials: A
authors.lastname: Kamara
authors.affiliation: World Health Organization, 21A and B Riverside Drive, off King Harman Road, Freetown, Sierra Leone.
authors.forename: Isatta M
authors.initials: IM
authors.lastname: Wurie
authors.affiliation: World Health Organization, 21A and B Riverside Drive, off King Harman Road, Freetown, Sierra Leone.
authors.forename: Wondimagegnehu
authors.initials: W
authors.lastname: Alemu
authors.affiliation: Central Public Health Reference Laboratory, Ministry of Health and Sanitation, Connaught Hospital, Free Town, Sierra Leone.
authors.forename: Amara
authors.initials: A
authors.lastname: Jambai
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: Shah M
authors.initials: SM
authors.lastname: Faruque
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh.
authors.forename: John D
authors.initials: JD
authors.lastname: Clemens
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh sislam@icddrb.org.
authors.forename: Mohammad S
authors.initials: MS
authors.lastname: Islam
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002771:Cholera / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D002939:Ciprofloxacin / Q000494:pharmacology; D004269:DNA, Bacterial / Q000235:genetics*; D004196:Disease Outbreaks; D004305:Dose-Response Relationship, Drug; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D012807:Sierra Leone / Q000453:epidemiology; D013752:Tetracycline / Q000494:pharmacology; D041241:Vibrio cholerae O1 / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D002939:Ciprofloxacin; D017963:Azithromycin; D013752:Tetracycline
keywords: Cholera; Outbreak; Sierra Leone; Vibrio cholerae O1