Updated

A hospital in Arkansas has isolated its entire intensive care unit and isn't admitting new patients due to the outbreak of a potentially deadly drug-resistant bacterial infection, FOXNews.com has confirmed.

All ICU patients at St. Joseph's Mercy Health Center in Hot Springs, Ark., have been isolated and forced to remain in the unit, said Dr. Vineet Chopra, director of the hospital's medicine program and the chair of the infection control committee.

The multi-drug-resistant bacteria known as acinetobacter has affected six critically ill patients so far, four of them in intensive care and the other two in the general medical population, Chopra said.

The six patients were infected by the organism and have been receiving intravenous antibiotics as treatment, according to Chopra. So far, he said, they're "responding well."

It is not known how the patients were exposed to the pathogen acinetobacter.

The strain bears similarities to so-called "staph" infections but is unrelated, according to Chopra. It tends to afflict very sick people, can be fatal and is the third most common bacterial infection in hospital ICUs.

"It's not a super bug," Chopra said. "It's got absolutely no relation to staph. But it is a dangerous bacteria."

Though the infection wasn't caused by the more common methicillin-resistant staphylococcus aureus bacteria that leads to staph outbreaks, this acinetobacter strain shows similar drug resistance and, like staph, is "present in the environment — and present everywhere," Chopra explained.

"The difference between this and staph is that this tends to attack individuals only when they are very sick," he said. "It can start from any pore opening and can cause skin wounds, soft tissue wounds and pneumonia. It can be very serious."

As with staph, acinetobacter can also lead to sepsis, a dramatic immunity response by the body causing fever as high as 101 degrees Fahrenheit, an elevated heart rate and low blood pressure, according to Chopra.

"It's associated with high mortality," he said.

Doctors at St. Joseph's noticing an "unusual clustering" of the infection Thursday night stopped new admissions to the intensive care unit and blocked the area to visitors, Chopra said. The ICU was quarantined beginning at about 9:30 p.m. Thursday.

Staff have not been affected, and have been allowed to come and go as long as they wear protective gear when treating the infected patients and ensure that no infectious materials leave the rooms, according to Chopra. The hospital's other ICU patients are all being tested, he said.

"There is complete surveillance going on right now on all ICU patients," said Chopra. "We're in surf and turf mode. We're keeping an eye on all our patients everywhere."

St. Joseph's is working with the Centers for Disease Control, the state health department and other officials offering guidance on how to handle the situation.

The CDC in Atlanta and Arkansas health department are planning to send representatives to ensure that proper steps are taken to end the outbreak. Chopra said the ICU will remain in isolation mode until the CDC tells the hospital it's safe to open it up again.

The hospital is putting off elective surgeries for a few days, and new ICU patients will be diverted to another nearby hospital, according to Chopra.

St. Joseph's has 300 beds total, 25 of them in the intensive care unit.