Genetic diversity of Brucella abortus strains from cattle and water buffalo in the Italian province of Caserta.

Brucella abortus is an important zoonotic pathogen that infects cattle and buffaloes. In Italy the application of eradication programs combined with vaccination has greatly contributed to reduce the incidence of brucellosis. However, despite the eradication programs brucellosis continue to persist with a high endemicity in some areas of Italy including the province of Caserta. In the present study the genomes of 44 B. abortus strains isolated from different outbreak cases that affected the province of Caserta were sequenced to characterize the genetic diversity of the Brucella strains circulating during the period from 2017 to 2022. The relatedness among these isolates was compared to 52 publicly available genomes of Italian B. abortus isolates. The results highlighted a low genetic diversity in the B. abortus population present in the Caserta area with the persistence of a low number of Brucella lineages and suggests a reduction in circulating lineages in recent years due to eradication programs.