Diagnosis of Vibrio cholerae O1 Infection in Africa

Abstract

Isolation of Vibrio cholerae O1 is necessary for cholera outbreak confirmation. Rapid diagnostic testing of fecal specimens, based on lipopolysaccharide detection of V. cholerae O1 or O139, may assist in early outbreak detection and surveillance. Cary-Blair transport medium is recommended for specimen transport. Filter paper, although used in epidemics, needs evaluation against rectal swab specimens. Fecal specimens are subcultured onto selective and nonselective media, including 5% blood agar and TCBS agar, for detection of V. cholerae O1 or O139. Suspicious, oxidase-positive isolates are serotyped in monovalent antisera. Antimicrobial-susceptibility testing is performed to detect resistance. Molecular characterization supports phenotypic identification and outbreak investigations. The presence of genes encoding cholera toxin, lipopolysaccharide, and El Tor biotype traits can be confirmed. Standardized pulsed-field gel electrophoresis analysis facilitates strain comparison. Quality management ensures reliability of results through validation and verification of functional laboratory equipment; quality control of testing procedures, laboratory reagents, and consumables; and participation in proficiency-testing schemes.

Vibrio cholerae and Cholera biotypes

“…Rapid diagnostic tests such as reverse passive latex agglutination test (RP LA) have also been proved effective for the detection of CT (Yamasaki et al, 2013). Recently, various tests have been developed and they mostly focus on the detection of the lipopolysaccharide of V. cholerae O1 and O139 by monoclonal antibodies, using the vertical-flow immunochromatography principle (Keddy et al, 2013). These are commercial membrane-based rapid diagnostic tests that have been used to detect the presence of cholera infection under laboratory and field conditions with variable sensitivity and specificity.…”

Laboratory evaluation of immunochromatographic rapid diagnostic tests for cholera in Haiti

“…[ 4 ] Culture to isolate and identify the causative bacterium, Vibrio cholerae , may take up to 3 days to complete and requires laboratory capacity that is often absent in underserved settings. [ 5 ] Furthermore, the accuracy of culture methods and their reliability as gold standards are increasingly being called into question due to their suboptimal sensitivity. [ 3 , 5 , 6 ] PCR-based technologies, although more accurate than stool culture, are rarely available in settings most afflicted by cholera.…”

“…[ 5 ] Furthermore, the accuracy of culture methods and their reliability as gold standards are increasingly being called into question due to their suboptimal sensitivity. [ 3 , 5 , 6 ] PCR-based technologies, although more accurate than stool culture, are rarely available in settings most afflicted by cholera. [ 5 ]…”

“…[ 3 , 5 , 6 ] PCR-based technologies, although more accurate than stool culture, are rarely available in settings most afflicted by cholera. [ 5 ]…”

Production and Characterization of Monoclonal and Polyclonal Antibody Against Recombinant Outer Membrane Protein

“…Traditional identification of V. cholerae is often achieved through the isolation of the bacteria and time-consuming, laborious routine microbiological and biochemical analysis that require three working days before obtaining the results (Suzita et al, 2009;Ferdous, 2009). Among several molecular-based techniques, only PCR assay has been useful in detecting V. cholerae based on their gene (Vidal et al, 2007;Keddy et al, 2013). Recently, Srisuk et al (2010) has reported a new Loop-mediated isothermal Amplification (LAMP) assay which target the same gene with higher sensitivity than simple PCR.…”