RALEIGH, N.C. — Health investigators have converged on a Charlotte-area restaurant suspected of being a source of multiple salmonella illnesses, and they're analyzing the facility's suppliers for any possible link to a national outbreak that has sickened more than 1,000 people, officials said Friday.

State food protection experts took 42 samples from the restaurant, including a variety of vegetables, fruits and spices. By analyzing the samples and those who ate at the restaurant in the second week of June, investigators hope to identify specific connections between the food and any bacteria.

"This is one of the most recent outbreaks," said Joe Reardon, director of North Carolina's Food and Drug Protection Division. "These samples are significantly important and we hope to identify what the probable source might be."

None of the items taken this week from the unidentified restaurant came from North Carolina, but officials declined to further discuss their origins until tests are completed next week. The sicknesses reported from the restaurant were relatively recent compared to others during the outbreak, providing investigators with a newer caseload and a small scene to investigate.

As for trying to find links to other illnesses nationwide or in the state, Reardon added, "This is something that we're working night and day and we'll work throughout this weekend."

Ongoing studies by the Centers for Disease Control and Prevention, which just finished comparing 144 people who got sick in June with 287 people who live near them but didn't fall ill, have so far proved inconclusive.

Having a specific site in Charlotte has allowed investigators to consider a wide variety of foods that could be tainted. Looking beyond the CDCs' top suspects - tomatoes and peppers - North Carolina labs are testing everything from onions to avocados to paprika.

Reardon said they've tracked some of the items to two suppliers who were able to provide extensive documentation about the origins and destinations of their products, helping investigators catalog details.

Six people in Charlotte's Mecklenburg County have confirmed cases of the salmonella subtype, Saintpaul, that has spread across the country. In total, health officials have identified 14 people in North Carolina with that strain.

Dr. Jeffrey Engel, the state epidemiologist, said the Mecklenburg cases have not all come from one restaurant but that the eatery used in the investigation was able to provide detailed documentation about ingredients. He urged the public not to be concerned, saying there's no widespread problem and that no state restaurants have been closed because of the findings. Engel said many clusters of cases are being investigated associated with different restaurants.

“The concern is we haven’t found a source yet. In North Carolina, it appears the cases associated with this particular strain appear to be trickling and not pouring out,” Engel said.

However, North Carolina experts believe the number of cases will continue to rise as the investigation continues into the Mecklenburg cases.

"We're concerned," Engel said. "This is a national outbreak. We're seeing an uptick of these cases in North Carolina, so we're concerned."

Two cases have also been identified in Wake County, and one each in Brunswick, Guilford, Forsyth, Sampson, Rutherford and Bladen counties.

Salmonella illnesses are common; North Carolina has some 2,000 cases each year. But those usually come from raw eggs, undercooked chicken or simple errors such as a child drinking out of a dog bowl - not a single-source contamination that has spread nationwide in recent months.

The national number of cases has topped 1,000, with the first sickness beginning on April 10 and the latest starting on June 26, according to the Centers for Disease Control and Prevention. The CDC first reported a case in North Carolina on June 16 - about two months after the outbreak began. Engel said the numbers have started to climb as more people and doctors have learned about outbreaks elsewhere.

Federal health investigators have yet to pinpoint the source of the strain. They initially blamed raw tomatoes but this week expanded their list of suspects to include jalapenos and cilantro. The government advises people to continue avoiding certain raw tomatoes - red round, plum and Roma - unless they were grown in areas cleared of suspicion, and they're asking people prone to illness to avoid raw jalapeno and serrano peppers.

Cases have spread to most states from coast to coast. While most of the reports have centered in the Southwest, from Texas to Arizona, there are also other pockets: Illinois and Maryland, for example, have high rates.

State officials said none of the produce under scrutiny right now is grown in North Carolina.

North Carolina has far more cases than South Carolina, which has two, but far less than Virginia, which has 29.

"We're working with other states to get to the bottom of this," Engel said.

But there's no guarantee North Carolina experts will pinpoint the source of the outbreak. Engel said the CDC has conducted three similar restaurant cluster studies around the country to no avail.

Engel said the food borne illness eventually runs its course.

“A few people have been hospitalized, none in North Carolina, but virtually everybody recovers,” Engel said.

Local farmers said the salmonella scare has left them fielding many questions from concerned shoppers.

“You have to do a lot of explaining throughout the day when you’re putting out tomatoes and the first thing they always ask is where they come from,” farmer Sheila Tart said.

Shoppers at the State Farmers Market said these days they prefer home grown produce.

“It’s fresher, better priced,” shopper Bob Moore said Friday.