The influence of in vitro fitness defects on pneumococcal ability to colonize and to cause invasive disease
2008

How Growth Defects Affect Pneumococcal Disease

Sample size: 11 publication 10 minutes Evidence: moderate

Author Information

Author(s): Fernebro Jenny, Blomberg Christel, Morfeldt Eva, Wolf-Watz Hans, Normark Staffan, Normark Birgitta Henriques

Primary Institution: Swedish Institute for Infectious Disease Control

Hypothesis

Does the in vitro growth rate of Streptococcus pneumoniae affect its ability to cause disease in vivo?

Conclusion

Severe growth defects in pneumococci can prevent them from causing invasive disease, but they can still colonize the upper airways.

Supporting Evidence

  • One serotype 14 carrier isolate showed a significantly longer generation time compared to other isolates.
  • Three mutants showed reduced invasiveness that correlated with their in vitro growth rate.
  • Even severe growth defects allowed pneumococci to colonize the upper airways.

Takeaway

Some bacteria can grow slowly and still live in your nose without making you sick, but if they grow too slowly, they can't make you sick at all.

Methodology

The study involved analyzing clinical isolates of pneumococci and creating mutants to assess their growth rates and virulence in mice.

Limitations

The study did not pinpoint specific genes responsible for the observed defects in growth and virulence.

Statistical Information

P-Value

p<0.0001

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1471-2180-8-65

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