Pasteurella haemolytica is highly sensitive to ultraviolet irradiation.

The response of Pasteurella haemolytica to ultraviolet irradiation was determined. The results for survival show that P. haemolytica is very sensitive to UV-irradiation. This UV-sensitivity is similar to E. coli strains defective in UV repair mechanism(s). Analysis of the distribution of TCA insoluble versus TCA soluble [3H]thymine dimers in UV-irradiated DNA of P. haemolytica during a 2-h post-irradiation period indicates that the bacterium is deficient in an excision-repair system. These data suggest that P. haemolytica lacks some of the important mechanisms to repair UV-induced damage.