Genome-wide study of the defective sucrose fermenter strain of Vibrio cholerae from the Latin American cholera epidemic.
The 7th cholera pandemic reached Latin America in 1991, spreading from Peru to virtually all Latin American countries. During the late epidemic period, a strain that failed to ferment sucrose dominated cholera outbreaks in the Northern Brazilian Amazon region. In order to understand the genomic characteristics and the determinants of this altered sucrose fermenting phenotype, the genome of the strain IEC224 was sequenced. This paper reports a broad genomic study of this strain, showing its correlation with the major epidemic lineage. The potentially mobile genomic regions are shown to possess GC content deviation, and harbor the main V. cholera virulence genes. A novel bioinformatic approach was applied in order to identify the putative functions of hypothetical proteins, and was compared with the automatic annotation by RAST. The genome of a large bacteriophage was found to be integrated to the IEC224's alanine aminopeptidase gene. The presence of this phage is shown to be a common characteristic of the El Tor strains from the Latin American epidemic, as well as its putative ancestor from Angola. The defective sucrose fermenting phenotype is shown to be due to a single nucleotide insertion in the V. cholerae sucrose-specific transportation gene. This frame-shift mutation truncated a membrane protein, altering its structural pore-like conformation. Further, the identification of a common bacteriophage reinforces both the monophyletic and African-Origin hypotheses for the main causative agent of the 1991 Latin America cholera epidemics.
Laboratory of Environmental Microbiology, Evandro Chagas Institute, Ananindeua, Pará, Brazil.
Daniel Rios
DR
Garza
Cristiane C
CC
Thompson
Edvaldo Carlos Brito
EC
Loureiro
Bas E
BE
Dutilh
Davi Toshio
DT
Inada
Edivaldo Costa Sousa
EC
Junior
Jedson Ferreira
JF
Cardoso
Márcio Roberto T
MR
Nunes
Clayton Pereira Silva
CP
de Lima
Rodrigo Vellasco Duarte
RV
Silvestre
Keley Nascimento Barbosa
KN
Nunes
Elisabeth C O
EC
Santos
Robert A
RA
Edwards
Ana Carolina P
AC
Vicente
Lena Lillian Canto
LL
de Sá Morais
D001435:Bacteriophages / Q000145:classification / Q000235:genetics; D001482:Base Composition; D002771:Cholera / Q000453:epidemiology*; D004279:DNA, Viral; D058872:Epidemics; D016680:Genome, Bacterial; D020071:Interspersed Repetitive Sequences; D007843:Latin America / Q000453:epidemiology; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D013395:Sucrose / Q000378:metabolism*; D014734:Vibrio cholerae / Q000235:genetics* / Q000378:metabolism* / Q000821:virology
D004279:DNA, Viral; D013395:Sucrose