Whole Genome Sequencing and Comparative Genomic Analysis of Field Strains Isolated from Poultry in Poland.

is an intracellular bacterium belonging to the family. Poultry is considered to be the major reservoir of this agent, which has worldwide distribution and a particularly consistent worldwide occurrence in chicken flocks. The bacterium has been linked to respiratory disease in humans but without definitive confirmation; nevertheless, while it has not been proved to be the cause of human respiratory disease, a recent report from Italy verified its bird-to-human transmission. This aspect being significant for public health, more research is needed to gain insight into the infection biology of . In this study, the genomes of eleven novel field strains from different regions of Poland were analyzed comparatively. It was confirmed that strains are closely related, with at least 99.46% sequence identity. They possess a conservative genome structure involving the plasticity zone with a complete cytotoxin, the type three secretion system, inclusion membrane proteins, polymorphic membrane proteins, A and B histone-like proteins, and the chlamydial protease-like activating factor exoenzyme, as well as plasmids. Genetic diversity seems to be restricted. However, some genetic loci, such as A and multi-locus sequence typing target genes, are diverse enough to enable high-resolution genotyping and epidemiological tracing.