Occurrence of Listeria monocytogenes in fresh and processed foods in Navarra (Spain)

Relatedness of Listeria monocytogenes Isolates Recovered from Selected Ready-To-Eat Foods and Listeriosis Patients in the United States

“…For example, pulsotype 11 (serotype 1/2b) was confined to 18 isolates recovered from deli salads in California, and pulsotype 90 (serotype 1/2b) was confined to nine isolates recovered from smoked seafood in Maryland. However, previous studies and our work indicate that many pulsotypes are found in more than one food type, which indicates that there is no clear correlation between certain subtypes and specific food products (1,2,31).…”

“…A study that examined the prevalence of L. monocytogenes in frankfurter packages from seven plants demonstrated that 90% had the same ribotype profile and serotype (34). Other investigators have also reported that 75 to 90% of isolates from food and food processing environments tested belonged to serogroup 1/2 (1,9,11,27,31). About 50% of our food isolates displayed only 13 pulsotypes, and 88% of the isolates belonged to serogroup 1/2 (60% belonged to serotype 1/2a, 27% belonged to serotype 1/2b, and 1.6% belonged to serotype 1/2c).…”

Detection and enumeration of viable Listeria monocytogenes cells from ready-to-eat and processed vegetable foods by culture and DVC-FISH

“…Both are the most common serotypes isolated in human listeriosis cases (Liu, 2006) and have been previously detected in foods (Vitas, Aguado & García-Jalón, 2004;Kiss, Tirczka, Szita, Bernath & Csiko, 2006).…”

Presence of GadD1 Glutamate Decarboxylase in Selected Listeria monocytogenes Strains Is Associated with an Ability To Grow at Low pH

“…In E. coli gadA, a number of its regulators and other acid-induced genes are present on a "fitness island" that contributes significantly to acid adaptation (13,29). Given the apparent advantage of gadD1T1 ϩ strains in mildly acidic conditions, akin to those that Listeria encounters in low-pH foods, the absence of these genes in serogroup 4 strains may at least partly explain why they are less frequently identified in foods (21,30). The absence of gadD1T1 from serotype 4b L. monocytogenes, the causative agent of epidemic listeriosis, indicates that its presence is not required for the organism to bring about this disease.…”