Federal regulators in the United States said yesterday that they’ve found contamination in more drugs made by a pharmacy tied to a deadly meningitis outbreak.

The US Food and Drug Administration said it didn’t yet know the significance of the bacterial contamination discovered in recalled New England Compounding Centre products. Some of the bacteria found are rarely cited as a cause of disease in humans. And no NECC products have been tied to reports of infection from the bacteria, the FDA said.

But the agency said the findings bolster concerns about a lack of sterility at the now-closed company. Investigators there have already found standing water from a leaking boiler, filthy floor mats and records indicating drugs were shipped before sterility tests were returned.

The FDA test results were released hours after an announcement yesterday by US Representative Ed Markey that he’ll introduce legislation to strengthen the federal oversight over compounding pharmacies, which custom-mix solutions that generally aren’t commercially available. They aren’t regulated by the FDA.

Also yesterday, Massachusetts enacted emergency regulations that, like Markey’s bill, aim to prevent compounding pharmacies from being regulated like mom-and-pop drug stores if they’re actually large drug-making operations.

Markey announced his legislation outside the NECC building in Framingham. A tainted steroid made there, and used to treat back pain, has caused a fungal meningitis outbreak that’s spread to 19 states, making 377 people sick, 28 of whom have died.

The FDA test results released yesterday found bacteria in three separate batches of betamethasone, a steroid used to treat joint pain arthritis that’s different from the steroid implicated in the outbreak.

The agency also noted finding bacteria in cardioplegia solution, a drug used in open heart surgeries.