The condition of Marxist patriarch Jyoti Basu, who is battling pneumonia, remained critical on Friday with doctors putting him back on full ventilation.

The ventilatory support of 95-year-old Basu had been reduced partially last evening. The report of a bacterial test done on him would be available today, Susruth Banerjee, who is a member of the medical board at the private AMRI hospital, where Basu was admitted on Friday, told reporters.