Achromobacter xylosoxidans is the predominant Achromobacter species isolated from diverse non-respiratory samples.

Achromobacter spp. are emerging opportunistic Gram-negative rods responsible for diverse nosocomial or community-acquired infections. We describe, for the first time, the distribution of Achromobacter spp., defined by nrdA gene sequencing, and their antimicrobial susceptibility in a variety of non-respiratory samples recovered from hospitalized patients from 2010 to 2015. Of the 63 isolates studied, A. xylosoxidans was the most prevalent (41 isolates), and with the exception of A. insuavis (four isolates), the remaining 10 species identified were represented by one or two isolates only. All isolates were uniformly susceptible to piperacillin and piperacillin-tazobactam and 97% to meropenem, but 76% showed resistance to ciprofloxacin. This study confirms the diversity of Achromobacter spp. in non-cystic fibrosis (CF) isolates and the predominance of A. xylosoxidans, as previously reported for CF sputum isolates. There was no apparent link between the clinical site of infection and the species of Achromobacter.

Regulation of the proapoptotic functions of prostate apoptosis response-4 (Par-4) by casein kinase 2 in prostate cancer cells.

The proapoptotic protein, prostate apoptosis response-4 (Par-4), acts as a tumor suppressor in prostate cancer cells. The serine/threonine kinase casein kinase 2 (CK2) has a well-reported role in prostate cancer resistance to apoptotic agents or anticancer drugs. However, the mechanistic understanding on how CK2 supports survival is far from complete. In this work, we demonstrate both in rat and humans that (i) Par-4 is a new substrate of the survival kinase CK2 and (ii) phosphorylation by CK2 impairs Par-4 proapoptotic functions. We also unravel different levels of CK2-dependent regulation of Par-4 between species. In rats, the phosphorylation by CK2 at the major site, S124, prevents caspase-mediated Par-4 cleavage (D123) and consequently impairs the proapoptotic function of Par-4. In humans, CK2 strongly impairs the apoptotic properties of Par-4, independently of the caspase-mediated cleavage of Par-4 (D131), by triggering the phosphorylation at residue S231. Furthermore, we show that human Par-4 residue S231 is highly phosphorylated in prostate cancer cells as compared with their normal counterparts. Finally, the sensitivity of prostate cancer cells to apoptosis by CK2 knockdown is significantly reversed by parallel knockdown of Par-4. Thus, Par-4 seems a critical target of CK2 that could be exploited for the development of new anticancer drugs.