CcrZ is a pneumococcal spatiotemporal cell cycle regulator that interacts with FtsZ and controls DNA replication by modulating the activity of DnaA.

Most bacteria replicate and segregate their DNA concomitantly while growing, before cell division takes place. How bacteria synchronize these different cell cycle events to ensure faithful chromosome inheritance by daughter cells is poorly understood. Here, we identify Cell Cycle Regulator protein interacting with FtsZ (CcrZ) as a conserved and essential protein in pneumococci and related Firmicutes such as Bacillus subtilis and Staphylococcus aureus. CcrZ couples cell division with DNA replication by controlling the activity of the master initiator of DNA replication, DnaA. The absence of CcrZ causes mis-timed and reduced initiation of DNA replication, which subsequently results in aberrant cell division. We show that CcrZ from Streptococcus pneumoniae interacts directly with the cytoskeleton protein FtsZ, which places CcrZ in the middle of the newborn cell where the DnaA-bound origin is positioned. This work uncovers a mechanism for control of the bacterial cell cycle in which CcrZ controls DnaA activity to ensure that the chromosome is replicated at the right time during the cell cycle

Amoxicillin-resistant Streptococcus pneumoniae can be resensitized by targeting the mevalonate pathway as indicated by sCRilecs-seq.

Antibiotic resistance in the important opportunistic human pathogen Streptococcus pneumoniae is on the rise. This is particularly problematic in the case of the β-lactam antibiotic amoxicillin, which is the first-line therapy. It is therefore crucial to uncover targets that would kill or resensitize amoxicillin-resistant pneumococci. To do so, we developed a genome-wide, single-cell based, gene silencing screen using CRISPR interference called sCRilecs-seq (subsets of CRISPR interference libraries extracted by fluorescence activated cell sorting coupled to next generation sequencing). Since amoxicillin affects growth and division, sCRilecs-seq was used to identify targets that are responsible for maintaining proper cell size. Our screen revealed that downregulation of the mevalonate pathway leads to extensive cell elongation. Further investigation into this phenotype indicates that it is caused by a reduced availability of cell wall precursors at the site of cell wall synthesis due to a limitation in the production of undecaprenyl phosphate (Und-P), the lipid carrier that is responsible for transporting these precursors across the cell membrane. The data suggest that, whereas peptidoglycan synthesis continues even with reduced Und-P levels, cell constriction is specifically halted. We successfully exploited this knowledge to create a combination treatment strategy where the FDA-approved drug clomiphene, an inhibitor of Und-P synthesis, is paired up with amoxicillin. Our results show that clomiphene potentiates the antimicrobial activity of amoxicillin and that combination therapy resensitizes amoxicillin-resistant S. pneumoniae. These findings could provide a starting point to develop a solution for the increasing amount of hard-to-treat amoxicillin-resistant pneumococcal infections

Association between self-reported motivation to quit smoking with effectiveness of smoking cessation intervention among patients hospitalized for acute coronary syndromes in Switzerland.

Guidelines recommend brief smoking cessation interventions for hospitalized smokers reporting low motivation-to-quit. However, an intensive smoking cessation intervention may improve smoking cessation for these smokers. We conducted a secondary analysis of a pre-post interventional study that tested the efficacy of a proactive approach systematically offering intensive smoking cessation intervention to all hospitalized smokers with acute coronary syndrome (ACS) compared to a reactive approach offering it only to smokers willing to quit. We analyzed data from one study site in Switzerland, which recorded motivation-to-quit smoking at study inclusion between 08.2009 and 02.2012. The primary outcome was smoking cessation at 1- and 5-year. We tested for interaction by participant's motivation-to-quit score (low vs. high motivation), and calculated multivariable adjusted risk ratios (RR), stratified by motivation score. We obtained motivation scores for 230 smokers. Follow-up was 94% (217/230) at 1-year and 68% (156/230) at 5-year. Among participants with low motivation to quit, 19% of smokers in the reactive phase had quit at 1 year compared to 50% of smokers in the proactive phase (multivariable adjusted RR = 2.85, 95%CI:0.91-8.91). Among highly motivated smokers, rates did not differ between phases: 48% vs. 49% (multivariable adjusted RR = 1.02, 95%CI:0.75-1.39, p-value for interaction between motivation-to-quit categories = 0.10). At 5-year follow-up, the point estimates were similar. While our study has limitations inherent to the study design and sample size, we found that a proactive approach to offer systematic smoking cessation counseling for smokers with ACS reporting low motivation to quit was associated with higher smoking cessation rates at 1 year

Long-term effects of systematic smoking cessation counselling during acute coronary syndrome, a multicentre before-after study.

In the Special Program University Medicine-Acute Coronary Syndromes (SPUM-ACS) observational study (clinical trial registration: NCT01000701), a multicentre before-after clinical trial, we assessed 5-year outcome after acute coronary syndrome, comparing a systematic with an opportunistic smoking cessation counselling phase. We studied smokers who were hospitalised for acute coronary syndromes (ACS), and we assessed self-reported smoking cessation, incidence of cardiovascular events and mortality 5 years after hospital discharge. In the observational phase, from August 2009 to October 2010, only smokers who requested smoking cessation counselling received it during hospitalisation. In the interventional phase, from November 2010 to February 2012, hospitalised smokers with ACS were systematically offered intensive smoking cessation counselling including four telephone calls within 2 months of discharge. Because of the before-after design, the care givers were aware of study phase. The objective was to assess whether systematic counselling to every smoker with ACS has an impact on the long-term smoking cessation rate, incidence of cardiovascular events and mortality. Missing data on smoking cessation were analysed with multiple imputation. The study was not powered to assess differences in 5-year smoking cessation rates or cardiovascular outcomes. Overall, 458 smokers with ACS were included at baseline (225 during the intervention phase and 233 during the observation phase). At 5 years, 286 (62.4%) reported their smoking status (140 for the intervention phase and 146 for the observation phase) and 51 (11.1%) had died. There was no statistically significant difference in the abstinence rate between the interventional phase (75/140, 54%), and the observational phase (68/146, 47%), with a risk ratio with multiple imputation adjusted for age, sex, education and ACS type of 1.13 (95% confidence interval [CI] 0.84-1.51, p = 0.4). The 5-year risk of major acute cardiovascular event was similar in the intervention phase as compared with the observational phase. The multivariate adjusted hazard ratio for all-cause mortality was 0.84 (95% CI 0.45-1.60, p = 0.6). In this controlled long-term interventional study, systematic intensive smoking cessation counselling in all hospitalised smokers with ACS did not increase 5-year smoking cessation rates, nor decrease cardiovascular event recurrence, as compared with opportunistic smoking cessation counselling during hospitalization