chapter 12.1 case study, Distinct patterns of host adherence by Neisseria gonorrhoeae isolated from experimental gonorrhea.

aim

hypothesis

variants in pili genes will impact N. gonorrhoeae adherence and impact severity of infection

background

Neisseria gonorrhoeae: pathogen that has an adherence mechanism mediated by pilli

The poli genes undergo changes during infection

• Mutations: so whey look different physiologically to the immune system (DNA level)

• Phase changes: expressed at different levels, in different places throughout infection (RNA level)

• Help gonorrhoeae avoid the immune system, help adhere to cervical epithelial cells, promotes infection

Mutations and phase changes help N. gonorrhoeae avoid the immune system, increases adherence and promotes infection

Pili genes change during infection

• It will alter adherence

• And the changed adherence will change infection severity

Step 1: monitor changes in adherence and internalization

How well bacteria do the first step of pathogenesis lifestyle Like charges repel Few adhere, fewer CFU Count CFT too determine bar graph Strain y adhered better to human cells Measure how many pilo they express

Determine how many cells got into the epithelial cells  Get rid of the outer cells that are not invaded. Adhered but not invade Certain types of pilli (mutations) result in increased internalization

step 1:

	Improved	Reduced
Adherence	7uB, 6uF At all timepoints they are higher than the rest	4R1, SA, V3 At all timepointes they are lower
internalization	4R1, V3 Higher G29 is within the error bar of the parent, therefore does not count Inverse relationship with adherence	SA, 7B, 6uF All lower

Is there a correlation between better adherence and better internalization?

• No. SA both impacts negatively therefore there is no better
  

• recall// positive and negative correlation

• +ve: both variables incr or dcr together 

• -ve: one variable increases and the other decreases

conclusion

• Some strains showed improved or reduced ability to adhere and internalize

• There was NO CLEAR CORRELATION between improved adherence to internalization

  • Pattern was mostly followed

• Hypothesis was that variants will either increase or decrease N. gonorrhoeae adherence abilities and turn increase or decrease severity of infection

• There is no clear correlation for all strains, hypothesis is NOT supported