title: Molecular Epidemiology and Antibiotic Susceptibility of Vibrio cholerae Associated with a Large Cholera Outbreak in Ghana in 2014.
abstract: Ghana is affected by regular cholera epidemics and an annual average of 3,066 cases since 2000. In 2014, Ghana experienced one of its largest cholera outbreaks within a decade with more than 20,000 notified infections. In order to attribute this rise in cases to a newly emerging strain or to multiple simultaneous outbreaks involving multi-clonal strains, outbreak isolates were characterized, subtyped and compared to previous epidemics in 2011 and 2012.
  
  
  
  Serotypes, biotypes, antibiotic susceptibilities were determined for 92 Vibrio cholerae isolates collected in 2011, 2012 and 2014 from Southern Ghana. For a subgroup of 45 isolates pulsed-field gel electrophoresis, multilocus sequence typing and multilocus-variable tandem repeat analysis (MLVA) were performed. Eighty-nine isolates (97%) were identified as ctxB (classical type) positive V. cholerae O1 biotype El Tor and three (3%) isolates were cholera toxin negative non-O1/non-O139 V. cholerae. Among the selected isolates only sulfamethoxazole/trimethoprim resistance was detectable in 2011, while 95% of all 2014 isolates showed resistance towards sulfamethoxazole/trimethoprim, ampicillin and reduced susceptibility to ciprofloxacin. MLVA achieved the highest subtype discrimination, revealing 22 genotypes with one major outbreak cluster in each of the three outbreak years. Apart from those clusters genetically distant genotypes circulate during each annual epidemic.
  
  
  
  This analysis suggests different endemic reservoirs of V. cholerae in Ghana with distinct annual outbreak clusters accompanied by the occurrence of genetically distant genotypes. Preventive measures for cholera transmission should focus on aquatic reservoirs. Rapidly emerging multidrug resistance must be monitored closely.
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Eibach
authors.affiliation: National Center of Microbiology, Institute of Health Carlos III, Madrid, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Herrera-León
authors.affiliation: National Center of Microbiology, Institute of Health Carlos III, Madrid, Spain.|European Public Health Microbiology Training Programme (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
authors.forename: Horacio
authors.initials: H
authors.lastname: Gil
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany.|German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Hogan
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany.|German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Ehlkes
authors.affiliation: Ghana Health Service, Disease Surveillance Service, Accra, Ghana.
authors.forename: Michael
authors.initials: M
authors.lastname: Adjabeng
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany.|German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany.|University Medical Centre Hamburg-Eppendorf (UKE), Hamburg, Germany.
authors.forename: Benno
authors.initials: B
authors.lastname: Kreuels
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR), Kumasi, Ghana.
authors.forename: Michael
authors.initials: M
authors.lastname: Nagel
authors.affiliation: Ghana Health Service, National Public Health and Reference Laboratory (NPHRL), Accra, Ghana.
authors.forename: David
authors.initials: D
authors.lastname: Opare
authors.affiliation: Department of Biological, Environmental and Occupational Health Sciences, School of Public Health, University of Ghana, Accra, Ghana.
authors.forename: Julius N
authors.initials: JN
authors.lastname: Fobil
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany.|German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: May
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D002771:Cholera / Q000453:epidemiology* / Q000382:microbiology*; D002772:Cholera Toxin / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005838:Genotype; D005869:Ghana / Q000453:epidemiology; D006801:Humans; D008297:Male; D018598:Minisatellite Repeats / Q000235:genetics; D058885:Multilocus Sequence Typing; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D065288:Serogroup; D013420:Sulfamethoxazole / Q000494:pharmacology; D014295:Trimethoprim / Q000494:pharmacology; D014734:Vibrio cholerae / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D041241:Vibrio cholerae O1 / Q000302:isolation & purification; D037521:Virulence Factors / Q000235:genetics; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D037521:Virulence Factors; D002772:Cholera Toxin; D014295:Trimethoprim; D013420:Sulfamethoxazole