title: Ruminant rhombencephalitis-associated Listeria monocytogenes strains constitute a genetically homogeneous group related to human outbreak strains.
abstract: Listeriosis is a disease that causes significant economic losses at the farm level because of high morbidity and mortality in ruminants. This study was performed to investigate the role of ruminants in the epidemiology of listeriosis in northern Italy and the possible association of animal-adapted strains of Listeria monocytogenes with strains associated with human disease. Twenty ruminant rhombencephalitis isolates previously confirmed as L. monocytogenes by bacteriology and PCR were characterized by serotyping, pulsed-field gel electrophoresis, multi-virulence-locus sequence typing (MVLST), and multiplex single nucleotide polymorphism (mSNP) typing for the detection of epidemic clones. Subtyping results were subsequently compared with those obtained from human, food, and environmental isolates of L. monocytogenes, including 311 isolates from the University of Turin, Grugliasco, Italy, and 165 isolates representing major human listeriosis outbreaks worldwide, in addition to other unrelated isolates. Both mSNP typing and MVLST showed that 60% of the isolates analyzed belonged to epidemic clone I (ECI), which has been epidemiologically linked to several human outbreaks of listeriosis. In particular, the 1981 Canada outbreak was linked to the use of sheep manure and the 1985 California outbreak was linked to the use of raw cow's milk. In our study, ECI isolates were collected from different ruminant species on geographically and temporally distinct occasions for the last 13 years. Our results support the hypothesis that ruminants represent possible natural reservoirs of L. monocytogenes strains capable of causing epidemics of listeriosis in humans.
authors: Department of Veterinary Sciences, University of Turin, Grugliasco, Italy.
authors: Paulo Ricardo Dell'Armelina
authors: PR
authors: Rocha
authors: Sara
authors: S
authors: Lomonaco
authors: Maria Teresa
authors: MT
authors: Bottero
authors: Alessandra
authors: A
authors: Dalmasso
authors: Alessandro
authors: A
authors: Dondo
authors: Carla
authors: C
authors: Grattarola
authors: Fabio
authors: F
authors: Zuccon
authors: Barbara
authors: B
authors: Iulini
authors: Stephen John
authors: SJ
authors: Knabel
authors: Maria Teresa
authors: MT
authors: Capucchio
authors: Cristina
authors: C
authors: Casalone
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques / Q000379:methods; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004196:Disease Outbreaks; D005260:Female; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000382:microbiology; D015511:Goat Diseases / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology; D006041:Goats; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008089:Listeria monocytogenes / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008088:Listeriosis / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology; D014774:Virulence
chemical_list: D004269:DNA, Bacterial