Characterization of resistance to tetracyclines and aminoglycosides of sheep mastitis pathogens: study of the effect of gene content on resistance.

Aims: Mastitis causes economic losses and antimicrobials are frequently used for mastitis treatment. Antimicrobial resistance surveys are still rare in the ovine field and characterization of strains is important in order to acquire information about resistance and for optimization of therapy.

Methods And Results: Bacterial pathogens recovered in milk samples from mastitis-affected ewes were characterized for resistance to tetracyclines and aminoglycosides, members of which are frequently used antimicrobials in small ruminants.

Characterization of an HIV type 1 strain with preferential replication in adherent cells.

HIV-E, emerging from persistently infected HeLa-T4 cells, replicates better in fibroblasts and epithelial cells with respect to the parental, T cell-derived HIV-T. The two viruses share the same env V3 loop, but differ in cellular molecules incorporated on the envelope. Even when similar amounts of virus attachment occurred, HIV-E replicated better than HIV-T in cells from solid tissues, and the response to exogenous Tat was more efficient.

Polyomavirus persistence in lymphocytes: prevalence in lymphocytes from blood donors and healthy personnel of a blood transfusion centre.

BK and JC polyomaviruses (BKV and JCV) are widespread in humans and are thought to persist and reactivate under immune alterations. In addition to the kidney, lymphoid cells have been proposed as a site of latency. However, while this was shown to occur in immunocompromised patients, discordant data were published for healthy humans.