A 6500-year-old Middle Neolithic child from Pollera Cave (Liguria, Italy) with probable multifocal osteoarticular tuberculosis.

Clear skeletal evidence of prehistoric tuberculosis (TB) is rare, especially in children. We describe and differentially diagnose the pathological changes displayed by a five-year-old child, Pollera 21 (PO21) dated to the Middle Neolithic of Liguria (Italy), or 5740±30 BP (Beta-409341; 6635-6453cal BP, 2σ, OxCal 4.2). PO21 shows a number of osteoarticular lesions, mainly of a lytic nature with very little bone proliferation: the vertebral column, the shoulder and pelvic girdles, and the ribcage are involved. Given the nature and pattern of the lesions, we propose a diagnosis of multifocal (or multiple) bone TB. Attempts to detect TB aDNA through molecular analysis gave negative results, but this alone is not sufficient to prove that PO21 was not infected with TB. The lesions observed in PO21 share similarities with other published evidence, such as spinal and joint involvement, and disseminated cyst-like lesions. Conversely, PO21 does not show diffuse bone deposition, such as hypertrophic osteoarthropathy (HOA) or endocranial modifications such as serpens endocrania symmetrica (SES). PO21 adds to our knowledge of patterns of TB manifestation in archaeological skeletal remains, which is especially important considering the variability in types and patterns of osteoarticular lesions seen today in people with TB.

Genetic Diversity of Tick-Borne Rickettsial Pathogens; Insights Gained from Distant Strains.

The ability to capture genetic variation with unprecedented resolution improves our understanding of bacterial populations and their ability to cause disease. The goal of the pathogenomics era is to define genetic diversity that results in disease. Despite the economic losses caused by vector-borne bacteria in the Order Rickettsiales, little is known about the genetic variants responsible for observed phenotypes. The tick-transmitted rickettsial pathogen Anaplasma marginale infects cattle in tropical and subtropical regions worldwide, including Australia. Genomic analysis of North American A. marginale strains reveals a closed core genome defined by high levels of Single Nucleotide Polymorphisms (SNPs). Here we report the first genome sequences and comparative analysis for Australian strains that differ in virulence and transmissibility. A list of genetic differences that segregate with phenotype was evaluated for the ability to distinguish the attenuated strain from virulent field strains. Phylogenetic analyses of the Australian strains revealed a marked evolutionary distance from all previously sequenced strains. SNP analysis showed a strikingly reduced genetic diversity between these strains, with the smallest number of SNPs detected between any two A. marginale strains. The low diversity between these phenotypically distinct bacteria presents a unique opportunity to identify the genetic determinants of virulence and transmission.