Pneumonia in the elderly:

Interpretations of the Role of Plasma Albumin in Prognostic Indices: A Literature Review

This review assesses how publications interpret factors that influence the serum or plasma albumin (PA) level in prognostic indices, focusing on inflammation and nutrition. On PubMed, a search for "albumin AND prognosis" yielded 23,919 results. From these records, prognostic indices were retrieved, and their names were used as search strings on PubMed. Indices found in 10 or more original research articles were included. The same search strings, restricted to "Review" or "Systematic review", retrieved yielded on the indices. The data comprised the 10 latest original research articles and up to 10 of the latest reviews. Thirty indices had 294 original research articles (6 covering two indices) and 131 reviews, most of which were from recent years. A total of 106 articles related the PA level to inflammation, and 136 related the PA level to nutrition. For the reviews, the equivalent numbers were 54 and 65. In conclusion, more publications mention the PA level as a marker of nutrition rather than inflammation. This is in contrast to several general reviews on albumin and nutritional guidelines, which state that the PA level is a marker of inflammation but not nutrition. Hypoalbuminemia should prompt clinicians to focus on the inflammatory aspects in their patients.

Herd immunity in older adults from a middle-income country: A time-series trend analysis of community-acquired pneumonia mortality 2003-2017

Background and Aims

Community-acquired pneumonia is responsible for substantial mortality, and pneumococcus is commonly accepted as a major cause of pneumonia, regardless of laboratory confirmation. Child immunization programs have reported success in decreasing pneumonia mortality: directly in young children and indirectly (herd immunity) in unvaccinated adult populations in some countries. We assess changes in mortality trends for all-cause pneumonia in older adults associated with the introduction of pneumococcal vaccination for children in Peru.

Methods

This is a secondary analysis on administrative data collected periodically by the Peruvian Ministry of Health. An observational retrospective time series analysis was conducted using longitudinal population-based data from death certificates in Peru between 2003 and 2017. The time series includes 6 years before and 9 years after the introduction of the pneumococcal-conjugated vaccines in the national child immunization program in 2009. Monthly frequencies and annual rates for all-cause pneumonia deaths in children under 5 years of age and adults over 65 years of age are presented. Linear and quadratic trends are analyzed.

Results

Deaths among older adults accounted for 75.6% of all-cause pneumonia mortality in Peru, with 94.4% of these reporting "pneumonia due to unspecified organism" as the underlying cause of death. Comparing pre- and post-child immunization program periods, annual average mortality rates from unspecified pneumonia decreased by 22.7% in young children but increased by 19.6% in older adults. A linear trend model supports this overall tendency, but a quadratic curve explains the data better.

Conclusion

Pneumococcal-conjugated vaccines are developed using serotypes prevalent in selected countries from less common (invasive) pneumococcal disease and expected to prevent mortality worldwide from widespread (noninvasive) pneumonia. Our results do not support the presence of herd immunity from pneumococcal vaccination of children for community-acquired pneumonia in the increasingly ageing population of Peru. This should direct future research and could influence public health policy.

Elderly patients with concurrent hip fracture and lower respiratory tract infection: the pathogens and prognosis over different bedridden periods

BACKGROUND

Elderly patients who experience hip fractures often become bedridden and are at risk of developing lower respiratory tract infections. The current study was to investigate the etiology and bacterial drug resistance patterns of elderly patients with hip fractures and lower respiratory tract infections on prolonged bedridden time and to determine their prognosis.

METHODS

Patients diagnosed with hip fractures admitted from May 2015 to April 2017 were included. The basic characteristics including the patients' gender, age, fracture type, operation mode, bedridden duration, length of hospital stay, prognosis, past medical history, routine bloodwork, C-reactive protein (CRP), procalcitonin (PCT), blood biochemistry, blood gas analysis, glycosylated hemoglobin (HbA1C%), sputum smear, sputum culture, and anti-infection and related therapy were recorded. All patients were classified into three groups based on bed rest duration, including short-term (<1 month), mid-term (1-12 months), and long-term (> 12 months). The correlation between the bedridden time and the patients' basic characteristics, disease history, laboratory examination results, pathogen, anti-infection, and related therapy were evaluated. The risk factors related to the prognosis of the disease were investigated.

RESULTS

Prolonged bed rest in patients led to an increase in hospitalization time, mortality rates, and decreased serum albumin levels (P < 0.05). Sputum bacteriological culture results showed that, with bed rest prolongation, the proportion of Pseudomonas aeruginosa and fungal infections increased. Binomial logistic regression of pulmonary infection prognosis, glucocorticoid use during the anti-infective period, prolonged bedridden time, and serum albumin level showed that intravenous use of glucocorticoid during anti-infective treatment, bed rest > 1 year, and low serum albumin level were related to poor prognosis.

CONCLUSION

Elderly hip fracture patients with prolonged bedridden time had an increased chance of opportunistic pulmonary infection and decreased nutritional status. Glucocorticoids should be used cautiously.

Is There Any Difference in the Outcome of Geriatric and Non-Geriatric Severely Injured Patients?-A Seven-Year, Retrospective, Observational Cohort Study with Matched-Pair Analysis

Geriatric trauma is expected to increase due to the lifestyle and activity of the aging population and will be among the major future challenges in health care. Therefore, the aim of this study was to investigate differences between polytraumatized geriatric and non-geriatric patients regarding mortality, length-of-stay and complications with a matched pair analysis. We included patients older than 17 years with an Injury Severity Score (ISS) of 16 or more admitted to our level 1 trauma center between January 2008 and December 2015. The cohort was stratified into two groups (age < 70 and ≥ 70 years). One-to-one matching was performed based on gender, ISS, mechanism of injury (penetrating/blunt), Glasgow coma scale (GCS), base excess, and the presence of coagulopathy (international normalized ratio (INR) ≥ 1.4). Outcome was compared using the paired t-test and McNemar-test. A total of 1457 patients were identified. There were 1022 male (70%) and 435 female patients. Three hundred and sixty-four patients (24%) were older than 70 years. Matching resulted in 57 pairs. Mortality as well as length-of-stay were comparable between geriatric and non-geriatric polytraumatized patients. Complication rate (34% vs. 56%, p = 0.031) was significantly higher in geriatric patients. This indicates the possibility of similar outcomes in geriatric polytraumatized patients receiving optimal care.

Therapeutic effects of an orally administered edible seaweed-derived polysaccharide preparation, ascophyllan HS, on a Streptococcus pneumoniae infection mouse model

Ascophyllan HS is a commercially available preparation of the edible brown alga Ascophyllum nodosum containing ascophyllan, a sulfated polysaccharide with diverse beneficial biological activities. In this study, the effects of ascophyllan HS were evaluated in a severe intranasal Streptococcus pneumoniae infection mouse model. The control untreated mice started to die on day 7 and 80% had died by day 14 post-infection. Continuous oral administration of ascophyllan HS before and after bacterial infection resulted in a remarkable increase in survival rate, with 90% of the low (167 mg/kg body weight/day) and 100% of the high (500 mg/kg body weight/day) dose ascophyllan HS-treated mice surviving at day 14 post-infection. Histopathological observation of the lungs of the infected mice revealed the induction of typical pneumonia features in the alveolar spaces of the untreated control mice, such as extensive infiltration of inflammatory cells, edema, and fibrin deposition. In contrast, notable levels of lung injuries or alterations were not observed in the ascophyllan HS-treated mice, and only a minor lesion was observed in one mouse. Furthermore, bacterial burdens in the lungs were significantly reduced in the ascophyllan HS-treated mice as compared to the control mice at day 4 post-infection. Significantly higher levels of IL-12 were detected in the serum of ascophyllan HS-treated mice than that of control mice measured at the end of the infection experiment (day 14). These results suggest that orally administered ascophyllan HS exerts a therapeutic effect on S. pneumoniae infection by activating the host defense systems. This is the first report of the therapeutic effect of an orally administered seaweed polysaccharide preparation on S. pneumoniae infection. Our findings suggest that ascophyllan HS has the potential to be developed as nutraceuticals and pharmaceuticals applicable for humans as well as a safe and promising therapeutic agent against S. pneumoniae infection.

Mitochondrial Dysfunction in Aged Macrophages and Lung during Primary Streptococcus pneumoniae Infection is Improved with Pirfenidone

Pneumococcal infections remain a leading cause of death in older adults, with the most serious cases occurring in persons ≥65 years of age. There is an urgent need to investigate molecular pathways underlying these impairments and devise new therapeutics to modulate innate immunity. The goal of our current study is to understand the impact of chronological aging on mitochondrial function in response to Streptococcus pneumoniae, a causative agent of bacterial pneumonia. Using chronologically aged murine models, our findings demonstrate that decreased ATP production is associated with dysregulated mitochondrial complex expression, enhanced oxidative stress, diminished antioxidant responses, and decreased numbers of healthy mitochondria in aged adult macrophages and lung in response to S. pneumoniae. Pre-treatment of aged macrophages with pirfenidone, an anti-fibrotic drug with antioxidant and anti-inflammatory properties, improved mitochondrial function and decreased cellular oxidative stress responses. In vivo administration of pirfenidone decreased superoxide formation, increased healthy mitochondria number, improved ATP production, and decreased inflammatory cell recruitment and pulmonary oedema in aged mouse lung during infection. Taken together, our data shed light on the susceptibility of older persons to S. pneumoniae and provide a possible therapeutic to improve mitochondrial responses in this population.

Nutritional Aspects of Dysphagia Management

This chapter describes the nutritional aspects of dysphagia management by starting with the definition of these two conditions (dysphagia and malnutrition) that share three main clinical characteristics: (a) their prevalence is very high, (b) they can lead to severe complications, and (c) they are frequently underrecognized and neglected conditions. From an anatomical standpoint, dysphagia can result from oropharyngeal and/or esophageal causes; from a pathophysiological perspective, dysphagia can be caused by organic or structural diseases (either benign or malignant) or diseases causing impaired physiology (mainly motility and/or perception disorders). This chapter gathers up-to-date information on the screening and diagnosis of oropharyngeal dysphagia, the consequences of dysphagia (aspiration pneumonia, malnutrition, and dehydration), and on the nutritional management of dysphagic patients. Concerning this last topic, this chapter reviews the rheological aspects of swallowing and dysphagia (including shear and elongational flows) and its influence on the characteristics of the enteral nutrition for dysphagia management (solid/semisolid foods and thickened liquids; ready-to-use oral nutritional supplements and thickening powders), with special focus on the real characteristics of the bolus after mixing with human saliva.

Comparison of clinical characteristics and outcomes between aspiration pneumonia and community-acquired pneumonia in patients with chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) patients often have dysphagia through age and several co-morbidities, leading to aspiration pneumonia (AsP). COPD patients also have increased risk of developing community-acquired pneumonia (CAP). Using a national inpatient database in Japan, we aimed to compare clinical characteristics and outcomes between AsP and CAP in COPD patients and to verify the factors that affect in-hospital morality.

Methods

We retrospectively collected data on COPD patients (age ≥40 years) who were admitted for AsP or CAP in 1,165 hospitals across Japan between July 2010 and May 2013. We performed multivariable logistic regression analyses to examine the association of various factors with all-cause in-hospital mortality for AsP and CAP.

Results

Of 87,330 eligible patients, AsP patients were more likely to be older, male and have poorer general condition and more severe pneumonia than those with CAP. In-hospital mortality in the AsP group was 22.7 % and 12.2 % in the CAP group. After adjustment for patient background, AsP patients had significantly higher mortality than CAP patients (adjusted odds ratio, 1.19; 95 % confidence interval, 1.08–1.32). Subgroup analyses showed higher mortality to be associated with male gender, underweight, dyspnea, physical disability, pneumonia severity, and several co-morbidities. Further, older age and worse level of consciousness were associated with higher mortality in the CAP group, whereas those were not associated in the AsP group.

Conclusions

Clinical characteristics differed significantly between AsP and CAP in COPD patients. AsP patients had significantly higher mortality than those with CAP.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0064-5) contains supplementary material, which is available to authorized users.

Enhanced inflammation in aged mice following infection with Streptococcus pneumoniae is associated with decreased IL-10 and augmented chemokine production

Streptococcus pneumoniae is the most common cause of severe pneumonia in the elderly. However, the impact of aging on the innate inflammatory response to pneumococci is poorly defined. We compared the innate immune response in old vs. young adult mice following infection with S. pneumoniae. The accumulation of neutrophils recovered from bronchoalveolar lavage fluid and lung homogenates was increased in aged compared with young adult mice, although bacterial outgrowth was similar in both age groups, as were markers of microvascular leak. Aged mice had similar levels of IL-1β, TNF, IFN-γ, IL-17, and granulocyte colony-stimulating factor following S. pneumoniae infection, compared with young mice, but increased levels of the chemokines CXCL9, CXCL12, CCL3, CCL4, CCL5, CCL11, and CCL17. Moreover, levels of IL-10 were significantly lower in aged animals. Neutralization of IL-10 in infected young mice was associated with increased neutrophil recruitment but no decrease in bacterial outgrowth. Furthermore, IL-10 neutralization resulted in increased levels of CCL3, CCL5, and CXCL10. We conclude that aging is associated with enhanced inflammatory responses following S. pneumoniae infection as a result of a compromised immunomodulatory cytokine response.

Reduced levels of interleukin‑1 receptor antagonist act as a marker for pneumonia in the elderly

Pneumonia is a disease causing serious inflammation and infection of the lungs and accounts for >50,000 mortalities annually. The elderly are at an increased risk of developing pneumonia. Pneumonia is more serious in the elderly than in any other age group due to the increased inflammation and risk of community‑acquired pneumonia associated with aging. Interleukin‑1 receptor antagonist (IL‑1RA) is an anti‑inflammatory protein that counteracts the destructive effects of inflammatory proteins. Therefore, the possible association between pneumonia in elderly individuals and reduced levels of IL‑1RA was investigated in the present study. The number of lymphocytes was counted in all subjects and the relative protein expression levels of IL‑1RA were determined using western blot analysis. In addition, the immunological activities of IL‑1RA were measured using ELISA. The results demonstrated that the numbers of lymphocytes in the serum and bronchoalveolar lavage fluid (BALF) were significantly higher in elderly patients than those in young patients. Furthermore, the serum and BALF levels of IL‑1RA in elderly patients were significantly lower than those in young patients (P<0.05 and P<0.01, respectively). Therefore, reduced levels of IL‑1RA in BALF may act as a marker for pneumonia in the elderly and may be a potential adjuvant for the diagnosis of pneumonia in elderly individuals. The results also showed that smoking was associated with significant reductions in the levels of IL‑1RA in the BALF of elderly patients. The association between smokers and non‑smokers found in this study provides support for the hypothesis that smoking may contribute to the pathogenesis of pneumonia by further reducing IL‑IRA levels in certain elderly patients.

Macrophages from elders are more permissive to intracellular multiplication of Mycobacterium tuberculosis

The elderly account for a disproportionate share of all tuberculosis cases, and the population ageing may not fully explain this phenomenon. We have performed in vitro infection experiments to investigate whether there is an immunological basis for the apparent susceptibility of elders to tuberculosis. In our infection model, Mycobacterium tuberculosis induces a higher production of interleukin (IL)-6 and reactive oxygen species in macrophages from elders than from younger adults. This response did not prevent, however, an increased multiplication of M. tuberculosis in macrophages from elders as compared with the growth observed within cells from adults. By performing a factorial experiment, we have found that IFN-γ, but not IL-1β, IL-6 or TNF-α, stimulate the macrophages to restrict the multiplication of the bacterium in macrophages from elders. Although monocytes from elders seem to be in a higher level of activation, we present evidences that protein tyrosine phosphorylation response induced by M. tuberculosis is stronger in monocytes from adults than from elders. Using a protein array that detects 71 tyrosine phosphorylated kinases, we identified Pyk2 as the only kinase that displayed a difference of intensity larger than 50 % in adults than in elders. Furthermore, monocytes from elders that were incubated in the presence of tyrosine kinase inhibitors (genistein and PP2) allowed a higher level of bacterial multiplication. These observations may help to explain the susceptibility of elders to tuberculosis. An unexpected result was that both genistein and its negative control, daidzein, abundant soy isoflavones, promoted intracellular mycobacterial growth.

Aging of the CD4 T Cell Compartment

Higher morbidity and mortality following infections, particularly influenza, is observed in the elderly population. Because of this, people over 65 years old are often targeted for preventive immunization. Many vaccines, however, are not as effective in generating protective antibodies in older individuals. CD4⁺ T cells, through their B cell helper functions, play a central role in the humoral response. Aging has deleterious effects on the immune system, and understanding how aging impairs CD4⁺ T cell functions is of critical importance to design new immunization and treatment strategies targeted to the elderly population. In this paper, we review some of the qualitative and quantitative changes in the CD4⁺ T cell compartment that arise with aging. We also summarize the age-related intrinsic defects that impact naïve, memory and regulatory CD4⁺ T cell functions.

Modulation of bacterial pathogenesis by oppressive aging factors: insights into host-pneumococcal interaction strategies

Streptococcus pneumonia, (Spn, the pneumococcus), is the leading cause of community-acquired pneumonia (CAP) and is responsible for 15–40% deaths in the elderly worldwide. A primed inflammatory status is a significant risk factor for the increased severity of infectious diseases among the elderly (≥65 years of age). Studies have shown that expression of host receptors that the pneumococci bind to invade the tissues are increased thereby increasing the susceptibility to pneumococcal challenge in aged mice. Cellular senescence, an age-related phenomenon that leads to cell cycle arrest may also contribute to increased inflammation in aged mice. Evidence of cellular senescence in aged lungs of humans and mice adds credits to the concept of inflammaging and enhanced bacterial ligands expression during aging. Furthermore, cell senescence has been shown to occur in age-associated lung pathologies such as idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) that may predispose the elderly to pathogenic assaults, including S. pneumoniae. This review highlights the aspects of: chronic inflammation in the aged population; contribution of cellular senescence to age-associated inflammation and their impact on host receptor expression; and, increased susceptibility of fibrosis and emphysematous lesions-bearing lungs to microbial infections.

Evaluation of volitional and reflexive swallowing in elderly patients with a history of pneumonia

OBJECTIVES

Precise assessment of the risk of aspiration is critical in older patients with a history of pneumonia. However, the currently popular videofluoroscopic and videoendoscopic examinations of swallowing only evaluate volitional swallowing. A method for quantitative analysis of reflexive swallowing is not yet available.

METHODS

We evaluated volitional swallowing in the sitting position by videoendoscopic examination and then measured the volume of injected water that triggered reflexive swallowing in the supine position in 54 patients with a history of pneumonia and 24 control patients of a similar age who had no history of pneumonia.

RESULTS

The volume of injected water that triggered reflexive swallowing was larger in the pneumonia group than in the control group (mean, 1.64 +/- 0.61 mL versus 0.71 +/- 0.28 mL; p < 0.001). Both impaired volitional swallowing and impaired reflexive swallowing independently correlated with a history of pneumonia.

CONCLUSIONS

The endoscopic supine swallow-evoking test ("ESSET") may detect previously omitted risk factors for aspiration in patients who can volitionally swallow.

Aerosol vaccination induces robust protective immunity to homologous and heterologous influenza infection in mice

Live-attenuated influenza vaccine (LAIV) delivered by large droplet intranasal spray is efficacious against infection. However, many of the large droplets are trapped in the external nares and do not reach the target nasal airway tissues. Smaller droplets might provide better distribution yielding similar protection with lower doses. We evaluated 20 and 30 μm aerosol delivery of influenza virus in mice. A 15s aerosol exposure optimally protected against homologous and heterologous influenza infection and induced a robust immune response. These results demonstrate the feasibility of nasal vaccination using aerosolized particles, providing a strategy to improve vaccine efficacy and delivery.

Risk factors for aspiration pneumonia in frail older people: a systematic literature review

OBJECTIVE

To systematically review the risks for aspiration pneumonia in frail older people and the contribution of bad oral health among the risk factors.

DESIGN

Systematic literature review.

SETTING

PubMed (Medline), Web of Science, Cochrane Library, EMBASE, and CINAHL were searched for eligible studies, published in English in the period January 2000 to April 2009.

PARTICIPANTS

Frail older people.

MEASUREMENTS

Only publications with regard to hospitalized, institutionalized, or frail home-dwelling people of 60 years and older were eligible. Two authors independently assessed the publications for their methodological quality. Unadjusted and adjusted odds ratios and their corresponding 95% confidence intervals for respective risk factors related to aspiration pneumonia were extracted. The results were evaluated according to the levels of evidence of the Oxford Centre for Evidence-based Medicine.

RESULTS

A total of 21 publications fulfilled the quality criteria. Evidence level 2a (systematic review with homogeneity of cohort studies) was found for a positive relationship between aspiration pneumonia and age, male gender, lung diseases, dysphagia, and diabetes mellitus; 2b (individual cohort study) for severe dementia, angiotensin I-converting enzyme deletion/deletion genotype, and bad oral health; 3a (systematic review with homogeneity of case-control studies) for malnutrition; 3b (individual case-control study) for Parkinson's disease and the use of antipsychotic drugs, proton pump inhibitors, and angiotensin-converting enzyme inhibitors. The contribution of bad oral health among the risk factors seems limited.

CONCLUSION

Thirteen significant risk factors were identified: age, male gender, lung diseases, dysphagia, diabetes mellitus, severe dementia, angiotensin I-converting enzyme deletion/deletion genotype, bad oral health, malnutrition, Parkinson's disease, and the use of antipsychotic drugs, proton pump inhibitors, and angiotensin-converting enzyme inhibitors. The contribution of bad oral health seems limited.

Characterization of mutants deficient in the L,D-carboxypeptidase (DacB) and WalRK (VicRK) regulon, involved in peptidoglycan maturation of Streptococcus pneumoniae serotype 2 strain D39

Peptidoglycan (PG) hydrolases play critical roles in the remodeling of bacterial cell walls during division. PG hydrolases have been studied extensively in several bacillus species, such as Escherichia coli and Bacillus subtilis, but remain relatively uncharacterized in ovococcus species, such as Streptococcus pneumoniae (pneumococcus). In this work, we identified genes that encode proteins with putative PG hydrolytic domains in the genome of S. pneumoniae strain D39. Knockout mutations in these genes were constructed, and the resulting mutants were characterized in comparison with the parent strain for growth, cell morphology, PG peptide incorporation, and in some cases, PG peptide composition. In addition, we characterized deletion mutations in nonessential genes of unknown function in the WalRK(Spn) two-component system regulon, which also contains the essential pcsB cell division gene. Several mutants did not show overt phenotypes, which is perhaps indicative of redundancy. In contrast, two new mutants showed distinct defects in PG biosynthesis. One mutation was in a gene designated dacB (spd_0549), which we showed encodes an L,D-carboxypeptidase involved in PG maturation. Notably, dacB mutants, similar to dacA (D,D-carboxypeptidase) mutants, exhibited defects in cell shape and septation, consistent with the idea that the availability of PG peptide precursors is important for proper PG biosynthesis. Epistasis analysis indicated that DacA functions before DacB in D-Ala removal, and immunofluorescence microscopy showed that DacA and DacB are located over the entire surface of pneumococcal cells. The other mutation was in WalRK(Spn) regulon gene spd_0703, which encodes a putative membrane protein that may function as a type of conserved streptococcal shape, elongation, division, and sporulation (SEDS) protein.

Instability of ackA (acetate kinase) mutations and their effects on acetyl phosphate and ATP amounts in Streptococcus pneumoniae D39

Acetyl phosphate (AcP) is a small-molecule metabolite that can act as a phosphoryl group donor for response regulators of two-component systems (TCSs). The serious human respiratory pathogen Streptococcus pneumoniae (pneumococcus) synthesizes AcP by the conventional pathway involving phosphotransacetylase and acetate kinase, encoded by pta and ackA, respectively. In addition, pneumococcus synthesizes copious amounts of AcP and hydrogen peroxide (H(2)O(2)) by pyruvate oxidase, which is encoded by spxB. To assess possible roles of AcP in pneumococcal TCS regulation and metabolism, we constructed strains with combinations of spxB, pta, and ackA mutations and determined their effects on ATP, AcP, and H(2)O(2) production. Unexpectedly, ΔackA mutants were unstable and readily accumulated primary suppressor mutations in spxB or its positive regulator, spxR, thereby reducing H(2)O(2) and AcP levels, and secondary capsule mutations in cps2E or cps2C. ΔackA ΔspxB mutants contained half the cellular amount of ATP as a ΔspxB or spxB(+) strain. Acetate addition and anaerobic growth experiments suggested decreased ATP, rather than increased AcP, as a reason that ΔackA mutants accumulated spxB or spxR suppressors, although experimental manipulation of the AcP amount was limited. This finding and other considerations suggest that coping with endogenously produced H(2)O(2) may require energy. Starting with a ΔspxB mutant, we constructed Δpta, ΔackA, and Δpta ΔackA mutants. Epistasis and microarray experiment results were consistent with a role for the SpxB-Pta-AckA pathway in expression of the regulons controlled by the WalRK(Spn), CiaRH(Spn), and LiaSR(Spn) TCSs involved in sensing cell wall status. However, AcP likely does not play a physiological role in TCS sensing in S. pneumoniae.

TLR-2 independent recognition of Mycobacterium tuberculosis by CD11c+ pulmonary cells from old mice

The elderly are particularly susceptible to infectious diseases such as influenza, bacterial pneumonia, and tuberculosis. Current vaccines are only partially protective in old age, which makes the elderly a critical target group for the development of new vaccine strategies. The recognition of pathogens via toll like receptors (TLR) and the subsequent generation of pro-inflammatory cytokines has generated interest in incorporating TLR agonists into new vaccines to enhance immunogenicity. However, TLR function is reportedly decreased in old age, leading to questions regarding the benefit of including TLR agonists into vaccines for the elderly. It is critical that we understand the function and role of TLRs in aged hosts prior to approving new TLR based adjuvants for vaccines that will be delivered to the elderly. In this study we determine the ability of TLRs on pulmonary macrophages from old mice to recognize and respond to infection with the virulent pathogen Mycobacterium tuberculosis (M. tb). Although pulmonary (CD11c(+)) cells from old mice were fully capable of producing cytokines in response to M. tb infection, we demonstrate that in contrast to young mice, M. tb induced cytokine production occurred independently of TLR-2. Our data indicate that the inclusion of TLR-2 agonists into new vaccines may not be fully effective in the elderly population. Investigation into such age-related differences in TLR function is of critical importance for the design of effective vaccines that will protect the elderly against infectious diseases.

Evidence for moxifloxacin in community-acquired pneumonia: the impact of pharmaco-economic considerations on guidelines

OBJECTIVE

In an era of limited resources, policy makers and health care payers are concerned about the costs of treatment in addition to its effectiveness. However, guidelines do not tend to consider the cost-effectiveness of treatment options. This paper aims to conduct an international literature review with a view to assessing the impact of pharmaco-economic considerations of CAP treatment with moxifloxacin on recent guidelines.

METHODS

The pharmaco-economic state of the art of treating CAP with moxifloxacin is assessed and compared with guidelines issued by the European Respiratory Society and by the Infectious Diseases Society of America/American Thoracic Society. Also, evidence on moxifloxacin consumption and antimicrobial resistance, and the impact of resistance on the cost-effectiveness of moxifloxacin is reviewed. Studies were identified by searching PubMed, Centre for Reviews and Dissemination databases, Cochrane Database of Systematic Reviews, and EconLit up to January 2009.

RESULTS

The existing pharmaco-economic evidence indicates that moxifloxacin is a cost-effective treatment for CAP. However, data limitations and uncertainty surrounding the evolution of resistance emphasize the need for caution. As recommended by guidelines, the choice of antimicrobial should consider the local frequency of causative pathogens, the local pattern of antimicrobial resistance, and risk factors for resistant bacteria. The pharmaco-economic evidence corroborates the importance of these factors as they have an impact on the cost-effectiveness of treating CAP patients with moxifloxacin.

CONCLUSIONS

CAP guidelines need to take into account pharmaco-economic considerations by balancing the effectiveness of antimicrobial regimens against their costs. The pharmaco-economic value of moxifloxacin is influenced by the causative pathogens involved and resistance patterns. Therefore, it may be advisable to identify patient subgroups in which treatment with moxifloxacin is cost-effective and should be recommended by guidelines.