The relationship between performance on the Shipley Institute of Living Scale (SILS) and hepatitis C infection among active injection drug users in Baltimore, Maryland.

BACKGROUND: Hepatitis C represents a significant public health problem, particularly among injection drug users. Other than injection drug practices, little is understood about individual level characteristics that may place some injection drug users at particularly high risk. OBJECTIVES: The current study sought to examine two associations among active, regular heroin injection drug users. The first was to determine whether there was an association between two scales from the Shipley Institute of Living Scale (SILS: a neuropsychological measure used to estimate cognitive impairment/intellectual functioning) and self-reported preexisting conditions independent of years of drug use. The second was to examine whether performance on the scales was associated with hepatitis C infection. METHODS: Data from 260 HIV negative injection drug users from the Baltimore metropolitan region were used. Participants completed a risk behavior interview, brief neuropsychological battery, and were tested for Hepatitis C. RESULTS: Findings indicated that scale performances varied by self-reported learning disabilities and attention deficit disorder. Poorer performance on one scale was statistically significantly associated with greater hepatitis C prevalence on the vocabulary scale, the discrepancy scale showed a statistical trend. CONCLUSIONS: Cognitive impairment measured among this sample of injection drug use was related to pre-existing conditions and hepatitis C independent of years of drug use. Such impairment may exist prior to initiation of use and increase vulnerability to poor health outcomes among injection drug users. SCIENTIFIC SIGNIFICANCE: This study highlights the need for interventions targeting a possible high risk subpopulation of injection drug users.

Endosymbiotic adaptations in three new bacterial species associated with Dictyostelium discoideum: Paraburkholderia agricolaris sp. nov., Paraburkholderia hayleyella sp. nov., and Paraburkholderia bonniea sp. nov.

Here we give names to three new species of Paraburkholderia that can remain in symbiosis indefinitely in the spores of a soil dwelling eukaryote, Dictyostelium discoideum. The new species P. agricolaris sp. nov., P. hayleyella sp. nov., and P. bonniea sp. nov. are widespread across the eastern USA and were isolated as internal symbionts of wild-collected D. discoideum. We describe these sp. nov. using several approaches. Evidence that they are each a distinct new species comes from their phylogenetic position, average nucleotide identity, genome-genome distance, carbon usage, reduced length, cooler optimal growth temperature, metabolic tests, and their previously described ability to invade D. discoideum amoebae and form a symbiotic relationship. All three of these new species facilitate the prolonged carriage of food bacteria by D. discoideum, though they themselves are not food. Further studies of the interactions of these three new species with D. discoideum should be fruitful for understanding the ecology and evolution of symbioses.