Amanda N. Wavrin Week 11: Difference between revisions
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*These results suggest that passage through the human gastointestinal tract increases infectivity of the cholera bacterium | *These results suggest that passage through the human gastointestinal tract increases infectivity of the cholera bacterium | ||
*They tested to see whether or not the human shed ''V. cholerae'' maintained its hyperinfectious state after being dispersed back into the environment | *They tested to see whether or not the human shed ''V. cholerae'' maintained its hyperinfectious state after being dispersed back into the environment | ||
*After being infected into mice, they found that the hyperinfectious state remained | |||
*They proposed that human passage enhances the infectivity of ''V. cholerae'' by lowering the infectious dose in secondary individuals | |||
*They then conducted transcriptional profiling of human shed ''V. cholerae'' by using DNA microarray | |||
* The DNA microarray contained around 87 percent of the ORFs of the Bangladeshi O1 El Tor reference strain | |||
*stool samples were collected from three patients in the ICDDR | |||
*The samples were filtered and frozen | |||
*The samples showed the 'rice water' appearance typically found with ''V. cholerae'' | |||
*The contained around 100 million ''V. cholerae'' per millilitre and showed few contaminating bacteria | |||
*The stools were analyzed using gel electrophoresis | |||
*One microgram of RNA from each sample was used for DNA synthesis, labelled with Cy5 and hybridized to the microarray with a Cy3 labelled reference strain- an expotentially growing O1 Inaba El Tor strain | |||
The relative flourescent intensities were determined using an Axon scanner and the data was quantified, normalized, and corrected | |||
*Using the Statistical Analysis for Microarrays program, they were able to identify significant differences in the intensity ratios | |||
* |
Revision as of 20:11, 11 April 2010
Vibrio cholerae Journal Club Article
Host-induced Epidemic Spread of the Choler Bacterium
Vocabulary
- Electrophoresis-separation of ionic molecules, (principally proteins) by the differential migration through a gel according to the size and ionic charge of the molecules in an electrical field. High resolution techniques normally use a gel support for the fluid phase
- Gavage-Forced feeding by stomach tube
- Enumerate-To count; to reckon; to ascertain the units of
- Chemotaxis-a response of motile cells or organisms in which the direction of movement is affected by the gradient of a diffusible substance. Differs from chemokinesis in that the gradient alters probability of motion in one direction only, rather than rate or frequency of random motion
- Inoculation-The process of introducing an antigenic substance or vaccine into the body to trigger immune response against a specific disease.
- Dissemination-The act of dispersing or diffusing something
- Homogenization-The process by which a material is made homogeneous
- Chromogenic-Producing colour, a chromogenic colony is a pigmented colony
- Murine-Of, relating to, a member of the rodent family muridae, including rats and mice
- Shine-Dalgarno sequence-A short stretch of nucleotides on a prokaryotic mRNA molecule upstream of the translational start site, that serves to bind to ribosomal RNA and thereby bring the ribosome to the initiation codon on the mRNA
Dictionary used: biology-online.org dictionary
Outline
- It is unclear as to what factors enhance the transission of pathogens during epidemic spread
- Vibrio Cholera is a water-borne diarrhoel disease
- Cholera was studied in its natural habitat in Dhaka, Bangladesh
- Stool samples were collected and tested for V. cholerae O1 Inaba El Tor from patients at the International Centre for Diarrhoeal Disease Research
- These strains were used in murine infection studies by mixing an in vitro strain with the stool V. cholerae and using the mixture to inoculate mice
- The mice were euthanized after around 24 hours and the bacteria was collected from the mice and plated.
- out put ratios of stool-sample V. cholerae to the in vitro strain were corrected and represent the competitive indices
- A CI above one indicates enhanced infectivity
- A CI below one indicates decreased infectivity
- Human shed V. cholerae consistently showed enhances infectivity
- However, when the V. cholerae strain was purified and cultured in vitro this competitive advantage was lost
- These results suggest that passage through the human gastointestinal tract increases infectivity of the cholera bacterium
- They tested to see whether or not the human shed V. cholerae maintained its hyperinfectious state after being dispersed back into the environment
- After being infected into mice, they found that the hyperinfectious state remained
- They proposed that human passage enhances the infectivity of V. cholerae by lowering the infectious dose in secondary individuals
- They then conducted transcriptional profiling of human shed V. cholerae by using DNA microarray
- The DNA microarray contained around 87 percent of the ORFs of the Bangladeshi O1 El Tor reference strain
- stool samples were collected from three patients in the ICDDR
- The samples were filtered and frozen
- The samples showed the 'rice water' appearance typically found with V. cholerae
- The contained around 100 million V. cholerae per millilitre and showed few contaminating bacteria
- The stools were analyzed using gel electrophoresis
- One microgram of RNA from each sample was used for DNA synthesis, labelled with Cy5 and hybridized to the microarray with a Cy3 labelled reference strain- an expotentially growing O1 Inaba El Tor strain
The relative flourescent intensities were determined using an Axon scanner and the data was quantified, normalized, and corrected
- Using the Statistical Analysis for Microarrays program, they were able to identify significant differences in the intensity ratios