Health director-general Dr Noor Hisham Abdullah said laboratory tests found the bacteria in the clinical samples of the patients and the laksa sample.
He said the bacteria is known as "salmonella enterica serovar weltevreden".
A total of 83 cases, including two deaths, were reported after customers consumed laksa bought at a food stall in Kupang, Kedah.
“The bacteria was detected in the laksa noodle which was bought last Oct 4 at a food stall. The laksa noodle was produced at a processing premises which is also owned by the food stall owner.
“The risk factors contributing to food poisoning are likely to arise from the process of preparing and storing unclean laksa noodles and the temperature during the process of preparing the laksa," Dr Noor Hisham said.
"Salmonella enterica serovar weltevreden" is bacteria that can cause fever, vomiting, stomach ache and diarrhoea.
According to Dr Noor Hisham, the Baling district health office has informed the owner of the food stall of the test results.
