Kolkata, Jan 8 : The condition CPM leader and former West Bengal Chief Minister Jyoti Basu, who is battling pneumonia, remained critical on Friday with doctors putting him back on full ventilation.

The ventilatory support of Basu had been reduced partially on Thursday evening.

The report of a bacterial test done on him would be available today.

Basu''s health condition deteriorated on Wednesday morning, following which he was put on a ventilator.

The 95-year-old former West Bengal Chief Minister was kept under observation for the last three days in the ICU.

Earlier in July 2009, Basu was admitted to the hospital when he complained of discomfort in the abdomen and a disturbed sleep. (ANI)