A ProMed Mail posting on December 24th reported that the FDA is investigating an outbreak of Salmonella Potsdam, an exceptionally rare serotype.  Seven cases have been identified but there is no indication of the vehicle or source as investigations are still in progress. 

The posting made reference to an outbreak of Salmonella Potsdam in 2002 in New South Wales, Australia, responsible for twelve diagnosed cases.  The vehicles were a Caesar dressing that yielded S. Potsdam and mayonnaise.  Time-temperature abuse and inadequate cleaning were noted in the implicated restaurant along with deficiencies in hygiene in the packing plant supplying eggs to the kitchen. Salmonella Potsdam was also investigated in 2011 with respect to an outbreak in ducklings attributed to the supply hatchery.