Daunorubicin is commonly used in the treatment of acute lymphoblastic leukaemia (ALL). The aim of this study was to explore the kinetics of double strand break (DSB) formation of three ALL cell lines following exposure to daunorubicin and to investigate the effects of daunorubicin on the cell cycle and the protein kinases involved in specific checkpoints following DNA damage and recovery periods. Three ALL cell lines CCRF-CEM and MOLT-4 derived from T lymphocytes and SUP-B15 derived from B lymphocytes were examined following 4 h treatment with daunorubicin chemotherapy and 4, 12 and 24 h recovery periods. Cell viability was measured via MTT (3-(4,5-dimethylthiazol-2-yl)-2–5 diphenyltetrazolium bromide) assay, reactive oxygen species (ROS) production by flow cytometry, double stranded DNA breaks by detecting γH2AX levels while stages of the cell cycle were detected following propidium iodide staining and flow cytometry. Western blotting was used to detect specific proteins while RNA was extracted from all cell lines and converted to cDNA to sequence Ataxia–telangiectasia mutated (ATM). Daunorubicin induced different degrees of toxicity in all cell lines and consistently generated reactive oxygen species. Daunorubicin was more potent at inducing DSB in MOLT-4 and CCRF-CEM cell lines while SUP-B15 cells showed delays in DSB repair and significantly more resistance to daunorubicin compared to the other cell lines as measured by γH2AX assay. Daunorubicin also causes cell cycle arrest in all three cell lines at different checkpoints at different times. These effects were not due to mutations in ATM as sequencing revealed none in any of the three cell lines. However, p53 was phosphorylated at serine 15 only in CCRF-CEM and MOLT-4 but not in SUP-B15 cells. The lack of active p53 may be correlated to the increase of SOD2 in SUP-B15 cells. The delay in DSB repair and lower sensitivity to daunorubicin seen in the B lymphocyte derived SUP-B15 cells could be due to loss of function of p53 that may be correlated to increased expression of SOD2 and lower ROS production.

Achromobacter spp. are becoming increasingly associated with lung infections in patients suffering from cystic fibrosis (CF). A. marplatensis, which is closely related to A. xylosoxidans, has been isolated from the lungs of CF patients and other human infections. This article describes the isolation, morphology and characterization of two lytic bacteriophages specific for an A. marplatensis strain isolated from a pneumonia patient. This host strain was the causal agent of hospital acquired pneumonia–the first clinical report of such an occurrence. Full genome sequencing revealed bacteriophage genomes ranging in size from 45901 to 46,328 bp. Transmission electron microscopy revealed that the two bacteriophages AMA1 and AMA2 belonged to the Siphoviridae family. Host range analysis showed that their host range did not extend to A. xylosoxidans. The possibility exists for future testing of such bacteriophages in the control of Achromobacter infections such as those seen in CF and other infections of the lungs. The incidence of antibiotic resistance in this genus highlights the importance of seeking adjuncts and alternatives in CF and other lung infections.