Deoxyribonucleic acid (DNA) was extracted and purified from three isolates of , representing serotypes A and D, and from two isolates of , representing serotypes B and C. Portions of each DNA pool were labeled in vitro by nick translation. Thermal elution profiles were determined and were used to calculate the thermal elution midpoint temperature and moles percent guanine-plus-cytosine content for each DNA. The thermal elution midpoint temperatures of the five DNAs ranged from 91.3 to 92.9°C, and the corresponding estimated contents ranged from 53.4 to 57.2 mol%. Hybridizations were performed with all possible pairs of homologous and heterologous DNAs. The DNAs of serotypes A and D of demonstrated relatedness values of 87.7 to 93.5%. DNAs of serotypes B and C of showed 88.5% relatedness. Hybridizations of DNAs of with those of , however, yielded relatedness values of only 55.2 to 63%, indicating that these DNAs are significantly different. Moreover, thermal elution studies revealed substantial base mismatching in heteroduplexes formed between DNAs of and . These data support previous conclusions suggesting that and are closely related but different species.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error