Elderly patients with community-acquired pneumonia: optimal treatment strategies

Repositioning of Antibiotics in the Treatment of Viral Infections

Drug repurposing, also known as drug repositioning, is a currently tested approach by which new uses are being assigned for already tested drugs. In this case there are antibiotics that are used to combat bacterial infections. However, antibiotics are among the drugs that have been studied for possible antiviral activities. Therefore, the aim of this work is to carry out a review of the studies of antibiotics that could be repositioned for the treatment of viral infections. Among the main antibiotics that have demonstrated antiviral activity are macrolides and glycopeptides. In addition, several antibiotics from the group of tetracyclines, fluoroquinolones, cephalosporins and aminoglycosides have also been studied for their antiviral activity. These antibiotics have demonstrated antiviral activity against both RNA and DNA viruses, including the recent pandemic virus SARS-CoV-2. Some of these antibiotics were selected in addition to its antiviral activity for their immunomodulatory and anti-inflammatory properties. Of the antibiotics that present antiviral activity, in many cases the mechanisms of action are not exactly known. The use of these antibiotics to combat viral infections remains controversial and is not generally accepted, since clinical trials are required to prove its effectiveness. Therefore, there is currently no antibiotic approved as antiviral therapy. Hence is necessary to present the studies carried out on antibiotics that can be repositioned in the future as antiviral drugs.

Potential Drugs in COVID-19 Management

The SARS-CoV-2 virus first emerged in China in December 2019 and quickly spread worldwide. Despite the absence of a vaccination or authorized drug specifically developed to combat this infection, certain medications recommended for other diseases have shown potential effectiveness in treating COVID-19, although without definitive confirmation. This review aims to evaluate the existing literature on the efficacy of these medications against COVID-19. The review encompasses various potential treatments, including antiviral medications, anti-malaria and anti-rheumatic drugs, vaccines, corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs), antipyretic and analgesic medicines, antiparasitic drugs, and statins. The analysis also addresses the potential benefits and drawbacks of these medications, as well as their effects on hypertension and diabetes. Although these therapies hold promise against COVID-19, further research, including suitable product production or clinical testing, is needed to establish their therapeutic efficacy.

Detection of Pneumonia Infection by Using Deep Learning on a Mobile Platform

Pneumonia is a disease that spreads quickly and poses a serious risk to the health and well-being of its victims. An accurate biomedical diagnosis of pneumonia necessitates the use of various diagnostic tools and the evaluation of various clinical features, all of which are hindered by the lack of available experts and tools. According to the research presented here, a mobile app that uses deep learning techniques to classify whether or not a patient has pneumonia is being developed. It was hoped that a mobile application prototype for detecting pneumonia using neural networks would be developed as part of this study. The use of a high-level tool such as Create ML makes this process easier and eliminates issues such as how many layers a neural network has, initializing the model parameters, or which algorithms to use. The model can now be accessed by anyone, anywhere, via a mobile application. The dataset of more than 5,000 real images was used to train an image classification model using Create ML, a tool with a graphical interface, and there was no need for specialized knowledge.

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.

Repurposing of antibiotics for clinical management of COVID-19: a narrative review

Background

Drug repurposing otherwise known as drug repositioning or drug re-profiling is a time-tested approach in drug discovery through which new medical uses are being established for already known drugs. Antibiotics are among the pharmacological agents being investigated for potential anti-SARS-COV-2 activities. The antibiotics are used either to resolve bacterial infections co-existing with COVID-19 infections or exploitation of their potential antiviral activities. Herein, we aimed to review the various antibiotics that have been repositioned for the management of COVID-19.

Methods

This literature review was conducted from a methodical search on PubMed and Web of Science regarding antibiotics used in patients with COVID-19 up to July 5, 2020.

Results

Macrolide and specifically azithromycin is the most common antibiotic used in the clinical management of COVID-19. The other antibiotics used in COVID-19 includes teicoplanin, clarithromycin, doxycycline, tetracyclines, levofloxacin, moxifloxacin, ciprofloxacin, and cefuroxime. In patients with COVID-19, antibiotics are used for their immune-modulating, anti-inflammatory, and antiviral properties. The precise antiviral mechanism of most of these antibiotics has not been determined. Moreover, the use of some of these antibiotics against SARS-CoV-2 infection remains highly controversial and not widely accepted.

Conclusion

The heavy use of antibiotics during the COVID-19 pandemic would likely worsen antibiotic resistance crisis. Consequently, antibiotic stewardship should be strengthened in order to prevent the impacts of COVID-19 on the antibiotic resistance crisis.

The association between vitamin D deficiency and community-acquired pneumonia: A meta-analysis of observational studies

Emerging evidence has shown that vitamin D deficiency may be related with community-acquired pneumonia (CAP), but individually published studies showed inconclusive results. The aim of this study was to quantitatively summarize the association between vitamin D and the CAP.We conducted this meta-analysis though a systematic literature search of PubMed, Medline, and EMBASE up to 31 September 2018 with the following keywords 'vitamin D' or 'cholecalciferol' or '25-hydroxyvitamin D' or '25(OH)D' in combination with 'community-acquired pneumonia' or 'CAP' or 'pneumonia' with no limitations. This meta-analysis was performed following the guidelines of Meta-analysis of Observational Studies in Epidemiology. The association between vitamin D levels and CAP were measured as odds ratio (OR) and weighted mean difference (WMD). Results were combined using a random-effect or a fix-effect meta-analysis, and sensitivity analyses were conducted to explore potential factors.Eight observational studies involving 20,966 subjects were included. In this meta-analysis, CAP patients with vitamin D deficiency (serum 25(OH)D levels <20 ng/mL) experienced a significantly increased risk of CAP (odds ratio (OR) = 1.64, 95% confidence intervals (CI): 1.00, 2.67), and an obvious decrease of -5.63 ng/mL (95% CI: -9.11, -2.14) in serum vitamin D was demonstrated in CAP patients. Sensitivity analysis showed that exclusion of any single study did not materially alter the overall combined effect.The evidence from this meta-analysis indicates an association between vitamin D deficiency and an increased risk of CAP patients. However, well-designed trails are required to determine the explicit effect of vitamin D supplementation.

Pharmacokinetic-pharmacodynamic analysis of ciprofloxacin in elderly Chinese patients with lower respiratory tract infections caused by Gram-negative bacteria

Background:

Ciprofloxacin is usually used in the treatment of lower respiratory tract infections (LRTIs). Recent studies abroad have shown ciprofloxacin is inadequately dosed and might lead to worse outcomes. The aim of this study was to perform pharmacokinetic and pharmacodynamic analyses of ciprofloxacin in elderly Chinese patients with severe LRTIs caused by Gram-negative bacteria.

Methods:

From September 2012 to June 2014, as many as 33 patients were empirically administered beta-lactam and ciprofloxacin combination therapy. Patients were infused with 200 or 400 mg of ciprofloxacin every 12 h, which was determined empirically by the attending physician based on the severity of the LRTI and the patient's renal condition. Ciprofloxacin serum concentrations were determined by high-performance liquid chromatography. Bacterial culture was performed from sputum samples and/or endotracheal aspirates, and the minimum inhibitory concentrations (MICs) of ciprofloxacin were determined. The ratios of the area under the serum concentration-time curve to the MIC (AUC/MIC) and of the maximum serum concentration of the drug to the MIC (C_max/MIC) were calculated. The baseline data and pharmacokinetic parameters were compared between clinical success group and clinical failure group, bacteriologic success group and bacteriologic failure group.

Results:

Among the 33 patients enrolled in the study, 17 were infected with Pseudomonas aeruginosa, 14 were infected with Acinetobacter baumannii, and two were infected with Klebsiella pneumoniae. The mean age of the patients was 76.9 ± 6.7 years. Thirty-one patients (93.4%) did not reach the target AUC/MIC value of >125, and 29 patients (87.9%) did not reach the target C_max/MIC value of >8. The AUC/MIC and C_max/MIC ratios in the clinical success group were significantly higher than those in the clinical failure group (61.1 [31.7–214.9] vs. 10.4 [3.8–66.1], Z = −4.157; 9.6 [4.2–17.8] vs. 1.3 [0.4–4.7], Z = −4.018; both P < 0.001). The AUC/MIC and C_max/MIC ratios in the patients for whom the pathogens were eradicated were significantly higher than those in the patients without the pathogens eradicated (75.3 [31.7–214.9] vs. 10.5 [3.8–66.1], Z = −3.938; 11.4 [4.2–17.8] vs. 1.4 [0.4–5.4], Z = −3.793; P < 0.001 for both). Receiver operating characteristic curve analysis showed that the AUC/MIC and C_max/MIC values were closely associated with clinical and bacteriologic efficacies (P < 0.001 in both).

Conclusions:

Ciprofloxacin is inadequately dosed against Gram-negative bacteria, especially for those with relatively high MIC values. Consequently, the target values, AUC/MIC > 125 and C_max/MIC > 8, cannot be reached.

The usefulness of serum procalcitonin, C-reactive protein, soluble triggering receptor expressed on myeloid cells 1 and Clinical Pulmonary Infection Score for evaluation of severity and prognosis of community-acquired pneumonia in elderly patients

AIMS

To comparatively analyze the usefulness of serum procalcitonin (PCT), C-reactive protein (CRP), soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) and Clinical Pulmonary Infection Score (CPIS) for assessing the severity and prognosis of community-acquired pneumonia (CAP) in the elderly.

METHODS

A total of 214 elderly patients with CAP and 106 healthy persons were enrolled in this prospective study. On the admission day, serum inflammatory markers, including CRP, PCT, sTREM-1, and CPIS were analyzed. By severity, the CAP patients were subdivided into non-severe CAP group and severe CAP group. By outcome, the patients were classified into survival group and death group. The efficiency of three inflammatory markers and CPIS on predicting prognosis of pneumonia patients was then analyzed.

RESULTS

The serum inflammatory markers and CPIS were significantly higher in CAP patients than in healthy controls. These biomarkers and CPIS were significantly higher in patients with severe CAP than in patients with non-severe CAP. Compared with patients who would survive, these markers and CPIS were significantly higher in patients who would die. Receiver operating characteristic curve analysis showed that the area under the curve and sensitivity were higher for serum sTREM-1 than for other indicators, while the specificity of serum PCT was the highest.

CONCLUSIONS

Serum CRP, PCT, and sTREM-1 and CPIS determined on the admission day are effective indicators to evaluate the severity and prognosis of CAP in the elderly. The prognostic value of PCT and sTREM-1 is better than that of CRP and CPIS.

Results of the effectiveness of two piperacillin-tazobactam molecules in the real world

OBJECTIVE

The objective was to determine the effectiveness of two piperacillin-tazobactam molecules in terms of all-cause mortality, mortality by infection, and hospital stay.

METHODS

A cohort study was performed involving patients treated with piperacillin-tazobactam at a clinic in Colombia. The patients were divided into those who received the innovator piperacillin-tazobactam (from July to December 2014) and those who received the generic piperacillin-tazobactam (from January to June 2015). Socio-demographic, clinical (all-cause mortality, death by infection, days of hospitalization), microbiological, pharmacological, and comorbidity variables were evaluated. Multivariate analyses were performed.

RESULTS

A total of 279 patients were included: 140 treated with the innovator piperacillin-tazobactam and 139 with the generic piperacillin-tazobactam. The median age was 63 years, and 56% of the patients were male. There was no statistically significant difference in death from all causes (22.9% vs. 14.4%, p=0.069), death by infection (7.9 vs. 10.8%, p=0.399), or hospital stay (18.1±16.2 vs. 15.7±11.6 days, p=0.178) between the innovator and generic piperacillin-tazobactam, respectively.

CONCLUSIONS

The generic piperacillin-tazobactam was equivalent to the innovator piperacillin-tazobactam with regards to all-cause mortality, mortality by infection, hospital stay, and safety, and at a lower cost, which may be useful for decision-makers in hospitals.

Diagnostic utility of appetite loss in addition to existing prediction models for community-acquired pneumonia in the elderly: a prospective diagnostic study in acute care hospitals in Japan

OBJECTIVE

Diagnosis of community-acquired pneumonia (CAP) in the elderly is often delayed because of atypical presentation and non-specific symptoms, such as appetite loss, falls and disturbance in consciousness. The aim of this study was to investigate the external validity of existing prediction models and the added value of the non-specific symptoms for the diagnosis of CAP in elderly patients.

DESIGN

Prospective cohort study.

SETTING

General medicine departments of three teaching hospitals in Japan.

PARTICIPANTS

A total of 109 elderly patients who consulted for upper respiratory symptoms between 1 October 2014 and 30 September 2016.

MAIN OUTCOME MEASURES

The reference standard for CAP was chest radiograph evaluated by two certified radiologists. The existing models were externally validated for diagnostic performance by calibration plot and discrimination. To evaluate the additional value of the non-specific symptoms to the existing prediction models, we developed an extended logistic regression model. Calibration, discrimination, category-free net reclassification improvement (NRI) and decision curve analysis (DCA) were investigated in the extended model.

RESULTS

Among the existing models, the model by van Vugt demonstrated the best performance, with an area under the curve of 0.75(95% CI 0.63 to 0.88); calibration plot showed good fit despite a significant Hosmer-Lemeshow test (p=0.017). Among the non-specific symptoms, appetite loss had positive likelihood ratio of 3.2 (2.0-5.3), negative likelihood ratio of 0.4 (0.2-0.7) and OR of 7.7 (3.0-19.7). Addition of appetite loss to the model by van Vugt led to improved calibration at p=0.48, NRI of 0.53 (p=0.019) and higher net benefit by DCA.

CONCLUSIONS

Information on appetite loss improved the performance of an existing model for the diagnosis of CAP in the elderly.

Diagnosis and treatment of community-acquired pneumonia in adults: 2016 clinical practice guidelines by the Chinese Thoracic Society, Chinese Medical Association

Community‐acquired pneumonia (CAP) in adults is an infectious disease with high morbidity in China and the rest of the world. With the changing pattern in the etiological profile of CAP and advances in medical techniques in diagnosis and treatment over time, Chinese Thoracic Society of Chinese Medical Association updated its CAP guideline in 2016 to address the standard management of CAP in Chinese adults. Extensive and comprehensive literature search was made to collect the data and evidence for experts to review and evaluate the level of evidence. Corresponding recommendations are provided appropriately based on the level of evidence. This updated guideline covers comprehensive topics on CAP, including aetiology, antimicrobial resistance profile, diagnosis, empirical and targeted treatments, adjunctive and supportive therapies, as well as prophylaxis. The recommendations may help clinicians manage CAP patients more effectively and efficiently. CAP in pediatric patients and immunocompromised adults is beyond the scope of this guideline. This guideline is only applicable for the immunocompetent CAP patients aged 18 years and older. The recommendations on selection of antimicrobial agents and the dosing regimens are not mandatory. The clinicians are recommended to prescribe and adjust antimicrobial therapies primarily based on their local etiological profile and results of susceptibility testing, with reference to this guideline.

Explicit definitions of potentially inappropriate prescriptions of antibiotics in older patients: a compilation derived from a systematic review

Potentially inappropriate prescriptions (PIPs) of antibiotics (antibiotic-PIPs) are generally detected by applying implicit definitions based on expert opinion. Explicit definitions are less frequently used, even though this approach would enable the automated detection of antibiotic-PIPs in electronic health records. Here, explicit definitions of antibiotic-PIPs used in studies of older adults were systematically reviewed. The MEDLINE^®, Scopus^® and Web of Science^TM core collection databases were searched with a combination of three terms and their synonyms: 'potentially inappropriate prescription' AND 'antibiotic treatment' AND 'older patients'. Following standardised selection of publications, explicit definitions of antibiotic-PIPs were extracted and were classified into infectious diseases domains and subdomains. A total of 600 search queries identified 4270 records, 93 of which were selected for review. A total of 160 mentions of antibiotic-PIPs were found, corresponding to 62 distinct definitions in 19 infectious diseases domains. Nearly one-half of the definitions were related to upper respiratory tract infections (n = 11 definitions; 17.7%), lower respiratory tract infections (n = 8; 12.9%) and drug-drug interactions (n = 11; 17.7%). Almost 75% of definitions (n = 46) were mentioned in a single study only. Only three definitions concerned critically important antibiotics such as third-generation cephalosporins and fluoroquinolones. This systematic review identified 62 explicit definitions of antibiotic-PIPs. Most of the definitions were not found in more than one study and they varied in the degree of precision. We advocate the implementation of an expert consensus on explicit definitions of antibiotic-PIPs that correspond to today's challenges in public health.

Clinical Application of High-Resolution Computed Tomographic Imaging Features of Community-Acquired Pneumonia

Background

This article discusses the value of high-resolution computed tomography (HRCT) in the diagnosis and treatment of pulmonary infections. Lung infection caused by pathogens is an important cause of death. Traditional methods to treat lung infection involved empirical antibiotic therapy. Thin-slice CT scanning is widely used in the clinical setting, and HRCT scan can very clearly show alveolar and bronchiolar involvement of infection.

Material/Methods

In total, 178 patients with community-acquired pneumonia (CAP) were enrolled. All the patients underwent CT scan, qualified sputum, and blood samples for culture or immunological biochemical tests. CT imaging features, pathogenic bacteria, and treatment results were used for statistical analysis.

Results

In 77 patients with lobar consolidation, the rate of detection was 43.26% (77/178), and in 101 patients with lobular pneumonia it was 56.74% (101/178). In 51 patients, pathogenic bacteria were detected (28.65%, 51/178). Sixteen of 33 patients detected with bacteria had cavities (48.5%, 16/33) and 35 of 145 patients detected with bacteria had no cavities (24.1%, 35/145). The difference between the 2 groups was statistically significant (χ²=7.795, P=0.005). According to the pathogenic bacteria, 38 patients were cured (74.51%, 38/51), and according to the CT imaging features 81 patients were cured (71.05%, 81/114). No statistically significant difference was found between them (χ²=0.209, P=0.647).

Conclusions

Treatment effect of CAP based on HRCT findings is not inferior to treatment effect guided by microbial characterization.

Lower Body Mass Index is a Risk Factor for In-Hospital Mortality of Elderly Japanese Patients Treated with Ampicillin/sulbactam

Objectives: A retrospective examination was conducted to identify risk factors for in-hospital mortality of elderly patients (65 years or older) treated with the beta-lactam/beta-lactamase inhibitor combination antibiotic, ampicillin/sulbactam (ABPC/SBT). Methods: Clinical data from 96 patients who were hospitalized with infectious diseases and treated with ABPC/SBT (9 g/day or 12 g/day) were analyzed. Risk factors examined included demographic and clinical laboratory parameters. Parameter values prior to treatment and changes after treatment were compared between survivors and non-survivors. Results: The study patients had an average age of 81.9±8.4 years (±SD) and body mass index (BMI) of 19.9±4.2 kg/m². They were characterized by anemia (low hemoglobin and hematocrit levels), inflammation (high leukocyte count, neutrophil count, C-reactive protein level, and body temperature), and hepatic and renal dysfunction (high aspartate aminotransferase, alanine aminotransferase and blood urea nitrogen levels). The BMI of non-survivors, 16.2±2.9 kg/m², was lower than that of survivors, 20.4±4.1 kg/m². In addition, the hematological parameters deteriorated more remarkably, inflammation markers were not altered (or the decrease was marginal), and hepatic function was not improved, in non-survivors. Conclusions: A lower BMI value is a risk factor for in-hospital mortality of elderly patients treated with ABPC/SBT.

Guía de consenso para el abordaje de la neumonía adquirida en la comunidad en el paciente anciano

La incidencia de la neumonía adquirida en la comunidad se incrementa con la edad y se asocia a una elevada morbimortalidad debido a los cambios fisiológicos asociados al envejecimiento y a una mayor presencia de enfermedades crónicas. Debido a la importancia que tiene desde un punto de epidemiológico y pronóstico, y a la enorme heterogeneidad descrita en el manejo clínico, creemos que existía la necesidad de realizar un documento de consenso específico para este perfil de paciente. El propósito de este fue realizar una revisión de las evidencias en relación con los factores de riesgo para la etiología, la presentación clínica, el manejo y el tratamiento de la neumonía adquirida en la comunidad en los ancianos con el fin de elaborar una serie de recomendaciones específicas basadas en el análisis crítico de la literatura. Este documento es fruto de la colaboración de diferentes especialistas en representación de la Sociedad Española de Medicina de Urgencias y Emergencias (SEMES), Sociedad Española de Geriatría y Gerontología (SEGG), Sociedad Española de Quimioterapia (SEQ), Sociedad Española de Medicina Interna (SEMI), Sociedad Española de Neumología y Cirugía Torácica (SEPAR), Sociedad Española de Hospitalización a Domicilio (SEHAD) y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC).

Management of community-acquired pneumonia in older adults

Community-acquired pneumonia (CAP) is an increasing problem among the elderly. Multiple factors related to ageing, such as comorbidities, nutritional status and swallowing dysfunction have been implicated in the increased incidence of CAP in the older population. Moreover, mortality in patients with CAP rises dramatically with increasing age. Streptococcus pneumoniae is still the most common pathogen among the elderly, although CAP may also be caused by drug-resistant microorganisms and aspiration pneumonia. Furthermore, in the elderly CAP has a different clinical presentation, often lacking the typical acute symptoms observed in younger adults, due to the lower local and systemic inflammatory response. Several independent prognostic factors for mortality in the elderly have been identified, including factors related to pneumonia severity, inadequate response to infection, and low functional status. CAP scores and biomarkers have lower prognostic value in the elderly, and so there is a need to find new scales or to set new cut-off points for current scores in this population. Adherence to the current guidelines for CAP has a significant beneficial impact on clinical outcomes in elderly patients. Particular attention should also be paid to nutritional status, fluid administration, functional status, and comorbidity stabilizing therapy in this group of frail patients. This article presents an up-to-date review of the main aspects of CAP in elderly patients, including epidemiology, causative organisms, clinical features, and prognosis, and assesses key points for best practices for the management of the disease.

Inhibitor-induced conformational stabilization and structural alteration of a mip-like peptidyl prolyl cis-trans isomerase and its C-terminal domain

FKBP22, an Escherichia coli-encoded PPIase (peptidyl-prolyl cis-trans isomerase) enzyme, shares substantial identity with the Mip-like pathogenic factors, caries two domains, exists as a dimer in solution and binds some immunosuppressive drugs (such as FK506 and rapamycin) using its C-terminal domain (CTD). To understand the effects of these drugs on the structure and stability of the Mip-like proteins, rFKBP22 (a chimeric FKBP22) and CTD⁺ (a CTD variant) have been studied in the presence and absence of rapamycin using different probes. We demonstrated that rapamycin binding causes minor structural alterations of rFKBP22 and CTD⁺. Both the proteins (equilibrated with rapamycin) were unfolded via the formation of intermediates in the presence of urea. Further study revealed that thermal unfolding of both rFKBP22 and rapamycin-saturated rFKBP22 occurred by a three-state mechanism with the synthesis of intermediates. Intermediate from the rapamycin-equilibrated rFKBP22 was formed at a comparatively higher temperature. All intermediates carried substantial extents of secondary and tertiary structures. Intermediate resulted from the thermal unfolding of rFKBP22 existed as the dimers in solution, carried an increased extent of hydrophobic surface and possessed relatively higher rapamycin binding activity. Despite the formation of intermediates, both the thermal and urea-induced unfolding reactions were reversible in nature. Unfolding studies also indicated the considerable stabilization of both proteins by rapamycin binding. The data suggest that rFKBP22 or CTD⁺ could be exploited to screen the rapamycin-like inhibitors in the future.

Selection and evolution of resistance to antimicrobial drugs

The overuse and misuse of antibiotics over many years has selected a high frequency of resistance among medically important bacterial pathogens. The evolution of resistance is complex, frequently involving multiple genetic alterations that minimize biological fitness costs and/or increase the resistance level. Resistance is selected at very low drug concentrations, such as found widely distributed in the environment, and this selects for resistant mutants with a high fitness. Once resistance with high fitness is established in a community it is very difficult to reduce its frequency. Addressing the problem of resistance is essential if we are to ensure a future where we can continue to enjoy effective medical control of bacterial infections. This will require several actions including the discovery and development of novel antibiotics, the creation of a continuous pipeline of drug discovery, and the implementation of effective global antibiotic stewardship to reduce the misuse of antibiotics and their release into the environment.

Experimental evolution as an efficient tool to dissect adaptive paths to antibiotic resistance

Antibiotic treatments increasingly fail due to rapid dissemination of drug resistance. Comparative genomics of clinical isolates highlights the role of de novo adaptive mutations and horizontal gene transfer (HGT) in the acquisition of resistance. Yet it cannot fully describe the selective pressures and evolutionary trajectories that yielded today's problematic strains. Experimental evolution offers a compelling addition to such studies because the combination of replicated experiments under tightly controlled conditions with genomics of intermediate time points allows real-time reconstruction of evolutionary trajectories. Recent studies thus established causal links between antibiotic deployment therapies and the course and timing of mutations, the cost of resistance and the likelihood of compensating mutations. They particularly underscored the importance of long-term effects. Similar investigations incorporating horizontal gene transfer (HGT) are wanting, likely because of difficulties associated with its integration into experiments. In this review, we describe current advances in experimental evolution of antibiotic resistance and reflect on ways to incorporate horizontal gene transfer into the approach. We contend it provides a powerful tool for systematic and highly controlled dissection of evolutionary paths to antibiotic resistance that needs to be taken into account for the development of sustainable anti-bacterial treatment strategies.

[Update of pneumonia in the elderly]

The incidence of pneumonia increases with age and contributes to morbidity and mortality in the elderly. In our setting, pneumonia is the sixth leading cause of death and the fourth most common diagnosis at discharge from acute hospitals. This article reviews current concepts in management of pneumonia in the elderly: healthcare-associated pneumonia, aspiration and oropharyngeal dysphagia, risk stratification, and indications of radiological, microbiological and biological markers. We present current evidence on antibiotic treatment (when to start, empirical coverage, duration, new drugs and combinations) and adjuvant treatment (steroids, early mobilization, oral hygiene, prevention and treatment of aspiration and cardiac complications). We emphasize preventive aspects and considerations regarding palliative treatment.

Impaired NLRP3 inflammasome function in elderly mice during influenza infection is rescued by treatment with nigericin

The NLRP3 inflammasome is activated in the lung during influenza viral infection; however, the impact of aging on inflammasome function during influenza infection has not been examined. In this study, we show that elderly mice infected with a mouse-adapted strain of influenza produced lower levels of IL-1β during in vitro and in vivo infection. Dendritic cells from elderly mice exhibited decreased expression of ASC, NLRP3, and capase-1 but increased expression of pro-IL-1β, pro-IL-18, and pro-IL-33 compared with dendritic cells from young infected mice. Treatment with nigericin during influenza infection augmented IL-1β production, increased caspase-1 activity, and decreased morbidity and mortality in elderly mice. Our study demonstrates for the first time, to our knowledge, that during influenza viral infection, elderly mice have impaired NLRP3 inflammasome activity and that treatment with nigericin rescues NLRP3 activation in elderly hosts.