Proteomic Analysis of Growth Phase-Dependent Expression of Legionella pneumophila Proteins Which Involves Regulation of Bacterial Virulence Traits

Legionella pneumophila, which is a causative pathogen of Legionnaires' disease, expresses its virulent traits in response to growth conditions. In particular, it is known to become virulent at a post-exponential phase in vitro culture. In this study, we performed a proteomic analysis of differences in expression between the exponential phase and post-exponential phase to identify candidates associated with L. pneumophila virulence using 2-Dimentional Fluorescence Difference Gel Electrophoresis (2D-DIGE) combined with Matrix-Assisted Laser Desorption/Ionization–Mass Spectrometry (MALDI-TOF-MS). Of 68 identified proteins that significantly differed in expression between the two growth phases, 64 were up-regulated at a post-exponential phase. The up-regulated proteins included enzymes related to glycolysis, ketone body biogenesis and poly-3-hydroxybutyrate (PHB) biogenesis, suggesting that L. pneumophila may utilize sugars and lipids as energy sources, when amino acids become scarce. Proteins related to motility (flagella components and twitching motility-associated proteins) were also up-regulated, predicting that they enhance infectivity of the bacteria in host cells under certain conditions. Furthermore, 9 up-regulated proteins of unknown function were found. Two of them were identified as novel bacterial factors associated with hemolysis of sheep red blood cells (SRBCs). Another 2 were found to be translocated into macrophages via the Icm/Dot type IV secretion apparatus as effector candidates in a reporter assay with Bordetella pertussis adenylate cyclase. The study will be helpful for virulent analysis of L. pneumophila from the viewpoint of physiological or metabolic modulation dependent on growth phase

Legionella DotM structure reveals a role in effector recruiting to the Type 4B secretion system

Legionella pneumophila, a causative agent of pneumonia, utilizes the Type 4B secretion (T4BS) system to translocate over 300 effectors into the host cell during infection. T4BS systems are encoded by a large gene cluster termed dot/icm, three components of which, DotL, DotM, and DotN, form the “coupling complex”, which serves as a platform for recruitment of effector proteins. One class of effectors includes proteins containing Glu-rich/E-block sequences at their C terminus. However, the protein or region of the coupling complex mediating recruitment of such effectors is unknown. Here we present the crystal structure of DotM. This all alpha-helical structure exhibits patches of positively charged residues. We show that these regions form binding sites for acidic Glu-rich peptides and that mutants targeting these patches are defective in vivo in the translocation of acidic Glu-rich motif-containing effectors. We conclude that DotM forms the interacting surface for recruitment of acidic Glu-rich motif-containing Legionella effectors

Clinical characteristics and patterns of healthcare utilization in patients with painful neuropathic disorders in UK general practice: a retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>Clinical characteristics and patterns of healthcare utilization in patients with painful neuropathic disorders (PNDs) who are under the care of general practitioners (GPs) in the UK are not well understood.</p> <p>Methods</p> <p>Using a large electronic UK database, we identified all adults (age ≥ 18 years) with any GP encounters between 1 January 2006 - 31 December 2006 at which a diagnosis of PND was noted ("PND patients"). An age-and gender-matched comparison group also was constituted consisting of randomly selected patients with one or more GP encounters-but no mention of PNDs-during this period. Characteristics and patterns of healthcare utilization of patients in the two groups were then examined over the one-year study period.</p> <p>Results</p> <p>The study sample consisted of 31,688 patients with mention of PNDs and an equal number of matched comparators; mean age was 56 years, and 62% were women. The prevalence of various comorbidities was higher among patients in the PND group, including digestive disorders (31% vs. 17% for comparison group), circulatory disorders (29% vs. 22%), and depression (4% vs. 3%) (all <it>p </it>< 0.01). Receipt of prescriptions for pain-related pharmacotherapy also was higher among PND patients, including nonsteroidal anti-inflammatory drugs (56% of PND patients had one or more such prescriptions vs. only 22% in the comparison group), opioids (49% vs. 12%), tricyclic antidepressants (20% vs. 1%), and antiepileptics (12% vs. 1%) (all <it>p </it>< 0.01). PND patients also averaged significantly more GP visits (22.8 vs. 14.2) and referrals to specialists (2.8 vs. 1.4) over one year (both comparisons <it>p </it>< 0.01).</p> <p>Conclusions</p> <p>Patients with PNDs under the care of GPs in the UK have relatively high levels of use of healthcare services and pain-related pharmacotherapy.</p

Activity of Bdellovibrio Hit Locus Proteins, Bd0108 and Bd0109, Links Type IVa Pilus Extrusion/Retraction Status to Prey-Independent Growth Signalling

Bdellovibrio bacteriovorus are facultatively predatory bacteria that grow within gram-negative prey, using pili to invade their periplasmic niche. They also grow prey-independently on organic nutrients after undergoing a reversible switch. The nature of the growth switching mechanism has been elusive, but several independent reports suggested mutations in the hit (host-interaction) locus on the Bdellovibrio genome were associated with the transition to preyindependent growth. Pili are essential for prey entry by Bdellovibrio and sequence analysis of the hit locus predicted that it was part of a cluster of Type IVb pilus-associated genes, containing bd0108 and bd0109. In this study we have deleted the whole bd0108 gene, which is unique to Bdellovibrio, and compared its phenotype to strains containing spontaneous mutations in bd0108 and the common natural 42 bp deletion variant of bd0108. We find that deletion of the whole bd0108 gene greatly reduced the extrusion of pili, whereas the 42 bp deletion caused greater pilus extrusion than wild-type. The pili isolated from these strains were comprised of the Type IVa pilin protein; PilA. Attempts to similarly delete gene bd0109, which like bd0108 encodes a periplasmic/secreted protein, were not successful, suggesting that it is likely to be essential for Bdellovibrio viability in any growth mode. Bd0109 has a sugar binding YD- repeat motif and an N-terminus with a putative pilin-like fold and was found to interact directly with Bd0108. These results lead us to propose that the Bd0109/Bd0108 interaction regulates pilus production in Bdellovibrio (possibly by interaction with the pilus fibre at the cell wall), and that the presence (and possibly retraction state) of the pilus feeds back to alter the growth state of the Bdellovibrio cell. We further identify a novel small RNA encoded by the hit locus, the transcription of which is altered in different bd0108 mutation background

Chemical Genetics Reveals Bacterial and Host Cell Functions Critical for Type IV Effector Translocation by Legionella pneumophila

Delivery of effector proteins is a process widely used by bacterial pathogens to subvert host cell functions and cause disease. Effector delivery is achieved by elaborate injection devices and can often be triggered by environmental stimuli. However, effector export by the L. pneumophila Icm/Dot Type IVB secretion system cannot be detected until the bacterium encounters a target host cell. We used chemical genetics, a perturbation strategy that utilizes small molecule inhibitors, to determine the mechanisms critical for L. pneumophila Icm/Dot activity. From a collection of more than 2,500 annotated molecules we identified specific inhibitors of effector translocation. We found that L. pneumophila effector translocation in macrophages requires host cell factors known to be involved in phagocytosis such as phosphoinositide 3-kinases, actin and tubulin. Moreover, we found that L. pneumophila phagocytosis and effector translocation also specifically require the receptor protein tyrosine phosphate phosphatases CD45 and CD148. We further show that phagocytosis is required to trigger effector delivery unless intimate contact between the bacteria and the host is artificially generated. In addition, real-time analysis of effector translocation suggests that effector export is rate-limited by phagocytosis. We propose a model in which L. pneumophila utilizes phagocytosis to initiate an intimate contact event required for the translocation of pre-synthesized effector molecules. We discuss the need for host cell participation in the initial step of the infection and its implications in the L. pneumophila lifestyle. Chemical genetic screening provides a novel approach to probe the host cell functions and factors involved in host–pathogen interactions

The association between lower back pain and health status, work productivity, and health care resource use in Japan

Alesia B Sadosky,1 Marco DiBonaventura,2 Joseph C Cappelleri,3 Nozomi Ebata,4 Koichi Fujii4 1Pfizer Inc, New York, NY, USA; 2Kantar Health, New York, NY, USA; 3Pfizer Inc, Groton, CT, USA; 4Pfizer Japan Inc, Tokyo, Japan Introduction: This study investigated the effect of pain severity on health status, work productivity, health care resource use, and costs among respondents with lower back pain (LBP), in Japan. Materials and methods: Data from the 2013 Japan National Health and Wellness Survey, a survey of Japanese adults, were analyzed (N=30,000). All respondents provided informed consent, and the protocol was institutional review board-approved. Respondents who reported experiencing LBP were propensity score&ndash;matched to those without LBP, based on demographics and health history. Using regression modeling, patients with mild, moderate, and severe pain were compared against matched controls, with respect to health status (Mental and Physical Component Summary scores, and health utilities from the Short Form&reg;-36 Health Survey version 2), work productivity (Work Productivity and Activity Impairment &ndash; General Health version), health care resource use, and annual per-patient costs (estimated using published annual wages and resource use event costs). Results: A total 1,897 patients reported experiencing LBP in the past month (6.32%); 52.45% reported their pain as mild, 32.79% as moderate, and 14.76% as severe. Increasing pain severity was associated with significantly lower levels of mental component scores (46.99 [mild], 42.93 [moderate], and 40.58 [severe] vs 48.10 [matched controls]), physical component scores (50.29 [mild], 46.74 [moderate], and 43.94 [severe] vs 52.93 [matched controls]), and health utilities (0.72 [mild], 0.66 [moderate], and 0.62 [severe] vs 0.76 [matched controls]) (all P&lt;0.05). Indirect costs were significantly higher (P&lt;0.05) among those with moderate (&yen;1.69 million [MM] [equivalent to 17,000, based on United States dollar exchange rates on September 1, 2014]) and severe (¥1.88 MM [19,000]) pain, relative to matched controls (&yen;0.95 MM [9,500]). Direct costs were only marginally different (P=0.05) between those with severe pain and matched controls (¥1.33 MM [13,000] vs &yen;0.54 MM [$5,000]). Conclusion: Increasing pain severity among respondents with LBP was associated with significantly worse health status, to a clinically-relevant degree, along with greater indirect and direct costs, in Japan. Keywords: low back pain, pain severity, quality of life, cos

A cost-consequence analysis of parecoxib and opioids vs opioids alone for postoperative pain: Chinese perspective

Magdolna Barra,1 Edit Rem&aacute;k,1 Dong Dong Liu,2 Li Xie,2 Lucy Abraham,3 Alesia B Sadosky4 1Evidera, Budapest, Hungary; 2Health Economics &amp; Outcomes Research, Pfizer Investment Co., Ltd., Beijing, China; 3Health Economics &amp; Outcomes Research, Pfizer Ltd, Tadworth, UK; 4Health Economics &amp; Outcomes Research, Pfizer Inc, New York, NY, USA Purpose: The use of parecoxib plus opioids for postoperative analgesia in noncardiac surgical patients seems to be cost-saving in Europe due to a reduction in opioid use and opioid-related adverse events. Given the lack of information on postoperative analgesic use in Asia, this study assessed the economic consequences of the addition of parecoxib to opioids vs opioids alone to treat postsurgical pain in China.Methods: A cost-consequence economic evaluation assessed direct medical costs related to opioid-related clinically meaningful events (CMEs) utilizing dosing information and reported frequency of events from a Phase III, randomized, double-blind, global clinical trial (PARA-0505-069) of parecoxib plus opioids vs opioids alone for 3 days following major orthopedic, abdominal, gynecologic, or noncardiac thoracic surgery requiring general or regional anesthesia. The cost of CMEs was calculated using information on resource utilization and unit costs provided by a panel of clinical experts in China. Sensitivity analyses were performed to test the robustness of the results.Results: Patients treated with parecoxib plus opioids reported fewer CMEs (mean 0.62 vs 1.04 events per patient [P&lt;0.0001]) compared with opioids alone for the 3-day postoperative period. This suggested a potential savings of 356 Chinese yuan (&yen;) per patient over the 3 days (total cost of &yen;1,418 for parecoxib plus opioids vs &yen;1,774 with opioid use alone).Conclusion: Fewer CMEs with parecoxib plus opioids suggest a reduction in medical resource utilization and reduced costs compared to opioids alone when modeling analgesic use in noncardiac surgery patients in China. Keywords: multimodal analgesia, parecoxib, opioids, treatment cost