The condition of Marxist patriarch Jyoti Basu, who is battling pneumonia, remained critical today 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.

“The report will show the effectiveness of the current drugs being administered to him,” Mr. Banerjee said.

Basu’s conditional had deteriorated two days ago following which he was put on a ventilator.

Prime Minister Manmohan Singh had visited him in hospital yesterday.