Antibiotics for treatment of acute exacerbation of chronic obstructive pulmonary disease: a network meta-analysis

Harnessing Graphene-Modified Electrode Sensitivity for Enhanced Ciprofloxacin Detection

Increased evidence has documented a direct association between Ciprofloxacin (CFX) intake and significant disruption to the normal functions of connective tissues, leading to severe health conditions (such as tendonitis, tendon rupture and retinal detachment). Additionally, CFX is recognized as a potential emerging pollutant, as it seems to impact both animal and human food chains, resulting in severe health implications. Consequently, there is a compelling need for the precise, swift and selective detection of this fluoroquinolone-class antibiotic. Herein, we present a novel graphene-based electrochemical sensor designed for Ciprofloxacin (CFX) detection and discuss its practical utility. The graphene material was synthesized using a relatively straightforward and cost-effective approach involving the electrochemical exfoliation of graphite, through a pulsing current, in 0.05 M sodium sulphate (Na2SO4), 0.05 M boric acid (H3BO3) and 0.05 M sodium chloride (NaCl) solution. The resulting material underwent systematic characterization using scanning electron microscopy/energy dispersive X-ray analysis, X-ray powder diffraction and Raman spectroscopy. Subsequently, it was employed in the fabrication of modified glassy carbon surfaces (EGr/GC). Linear Sweep Voltammetry studies revealed that CFX experiences an irreversible oxidation process on the sensor surface at approximately 1.05 V. Under optimal conditions, the limit of quantification was found to be 0.33 × 10-8 M, with a corresponding limit of detection of 0.1 × 10-8 M. Additionally, the developed sensor's practical suitability was assessed using commercially available pharmaceutical products.

Prevalence of multi-antimicrobial resistant non-typhoidal Salmonella isolated from filth flies at wet markets in Klang, Malaysia, and their survival in the simulated gastric fluid

Filth flies at wet markets can be a vector harbouring multiple antimicrobial-resistant (MAR) nontyphoidal Salmonella (NTS), and such strains are a significant threat to public health as they may cause severe infections in humans. This study aims to investigate the prevalence of antimicrobial-resistant NTS, especially Salmonella Enteritidis and S. Typhimurium harboured by filth flies at wet markets, and investigate their survival in the simulated gastric fluid (SGF). Filth flies (n = 90) were captured from wet markets in Klang, Malaysia, and processed to isolate Salmonella spp. The isolates (n = 16) were identified using the multiplex-touchdown PCR and assessed their antimicrobial susceptibility against 11 antimicrobial agents. Finally, three isolates with the highest MAR index were subjected to SGF survival tests. It was observed that 17.8 % of flies (n = 16/90) harbouring Salmonella, out of which 10 % (n = 9/90) was S. Enteritidis, 2.2 % (n = 2/90) was S. Typhimurium, and 5.6 % was unidentified serotypes of Salmonella enterica subsp. I. 43.8 % (n = 7/16) were confirmed as MAR, and they were observed to be resistant against ampicillin, chloramphenicol, kanamycin, streptomycin, and nalidixic acid. Three strains, F35, F75, and F85 demonstrated the highest MAR index and were able to survive (>6-log10) in the SGF (180 min), indicating their potential virulence and invasiveness. This study provides significant insights into the prevalence and severity of MAR nontyphoidal Salmonella harboured by filth flies in wet markets, which may help inform strategies for controlling the spread and outbreak of foodborne disease.

Towards Antibiotic Synthesis in Continuous-Flow Processes

Continuous-flow chemistry has become a mainstream process and a notable trend among emerging technologies for drug synthesis. It is routinely used in academic and industrial laboratories to generate a wide variety of molecules and building blocks. The advantages it provides, in terms of safety, speed, cost efficiency and small-equipment footprint compared to analog batch processes, have been known for some time. What has become even more important in recent years is its compliance with the quality objectives that are required by drug-development protocols that integrate inline analysis and purification tools. There can be no doubt that worldwide government agencies have strongly encouraged the study and implementation of this innovative, sustainable and environmentally friendly technology. In this brief review, we list and evaluate the development and applications of continuous-flow processes for antibiotic synthesis. This work spans the period of 2012-2022 and highlights the main cases in which either active ingredients or their intermediates were produced under continuous flow. We hope that this manuscript will provide an overview of the field and a starting point for a deeper understanding of the impact of flow chemistry on the broad panorama of antibiotic synthesis.

Azithromycin Versus Beta-lactams in Hospitalized Patients with Acute Exacerbations of COPD

BACKGROUND

There is a lack of data comparing azithromycin to alternative antibiotic choices in managing COPD exacerbations, making appropriate antibiotic selection controversial.

OBJECTIVE

To compare treatment failure in hospitalized patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) receiving azithromycin or beta-lactams.

DESIGN

Retrospective, multicenter cohort study using logistic regression for multivariable analysis. Patients were included if they were at least 18 years old, admitted with AECOPD, and received at least two consecutive days of either a beta-lactam or azithromycin. Patients were excluded if they received concomitant azithromycin and beta-lactam antibiotics during the first 2 days, had a history of other severe underlying pulmonary diseases, pregnancy, COVID-19, alpha-1 antitrypsin deficiency, or received a corticosteroid for a diagnosis other than COPD.

PARTICIPANTS

Five hundred ninety-five patients were included, of which 428 (72%) received azithromycin and 167 patients (28%) received a beta-lactam.

MAIN MEASURES

The primary endpoint was treatment failure rate in patients receiving azithromycin versus beta-lactams, which was a composite endpoint defined as in-hospital mortality, admission to intensive care, initiation of invasive mechanical ventilation, initiation of a new antibiotic, steroid therapy escalation, or readmission due to AECOPD within 30 days.

KEY RESULTS

The composite primary outcome occurred in 84 patients (19.6%) in the azithromycin group and 54 (32.3%) in the beta-lactam group (p<0.01). The difference in the composite outcome was a result of higher rates of new antibiotics during admission (12.6% vs 4.2%; p<0.01) and higher readmission within 30 days (19.3% vs 12.4%; p=0.032). After controlling for potential confounders, beta-lactams continued to demonstrate a higher risk for treatment failure (OR, 2.30; 95% CI, 1.46-3.63). There was no difference in adverse effects between the groups.

CONCLUSION

Azithromycin was associated with less treatment failure in AECOPD which was driven by lower readmission rates and prescription of new antimicrobials.

Meta-analysis of sputum microbiome studies identifies airway disease-specific taxonomic and functional signatures

Introduction. Studying taxonomic and functional signatures of respiratory microbiomes provide a better understanding of airway diseases.Gap Statement. Several human airway metagenomics studies have identified taxonomic and functional features restricted to a single disease condition and the findings are not comparable across airway diseases due to use of different samples, NGS platforms, and bioinformatics databases and tools.Aim. To study the microbial taxonomic and functional components of sputum microbiome across airway diseases and healthy smokers.Methodology. Here, 57 whole metagenome shotgun sequencing (WMSS) runs coming from the sputum of five airway diseases: asthma, bronchiectasis, chronic obstructive pulmonary diseases (COPD), cystic fibrosis (CF), tuberculosis (TB), and healthy smokers as the control were reanalysed using a common WMSS analysis pipeline.Results. Shannon's index (alpha diversity) of the healthy smoker group was the highest among all. The beta diversity showed that the sputum microbiome is distinct in major airway diseases such as asthma, COPD and cystic fibrosis. The microbial composition based on differential analysis showed that there are specific markers for each airway disease like Acinetobacter bereziniae as a marker for COPD and Achromobacter xylosoxidans as a marker of cystic fibrosis. Pathways and metabolites identified from the sputum microbiome of these five diseases and healthy smokers also show specific markers. 'ppGpp biosynthesis' and 'purine ribonucleosides degradation' pathways were identified as differential markers for bronchiectasis and COPD. In this meta-analysis, besides bacteria kingdom, Aspergillus fumigatus was detected in asthma and COPD, and Roseolovirus human betaherpesvirus 7 was detected in COPD. Our analysis showed that the majority of the gene families specific to the drug-resistant associated genes were detected from opportunistic pathogens across all the groups.Conclusion. In summary, the specific species in the sputum of airway diseases along with the microbial features like specific gene families, pathways, and metabolites were identified which can be explored for better diagnosis and therapy.

Prevalence, Pattern, Risks Factors and Consequences of Antibiotic Resistance in COPD: A Systematic Review

A concern of antibiotic use in chronic obstructive pulmonary disease (COPD) is the emergence and propagation of antimicrobial resistance (AMR). A systematic review was conducted to determine prevalence, pattern, risk factors and consequences of AMR in COPD. Bibliographic databases were searched from inception to November 2020, with no language restrictions, including studies of any design that included patients with COPD and reported prevalence and pattern of AMR. 2748 unique titles and abstracts were identified, of which 63 articles, comprising 26,387 patients, met inclusion criteria. Forty-four (69.8%) studies were performed during acute exacerbation. The median prevalence of AMR ranged from 0-100% for Pseudomonas aeruginosa, Moraxella catarrhalis, Klebsiella pneumoniae and Acinetobacter baumannii. Median resistance rates of H influenzae and S pneumoniae were lower by comparison, with maximum rates ≤40% and ≤46%, respectively, and higher for Staphylococcus aureus. There was a trend towards higher rates of AMR in patients with poorer lung function and greater incidence of previous antibiotic exposure and hospitalisation. The impact of AMR on mortality was unclear. Data regarding antimicrobial susceptibility testing techniques and the impact of other risk factors or consequences of AMR were variable or not reported. This is the first review to systematically unify data regarding AMR in COPD. AMR is relatively common and strategies to optimise antibiotic use could be valuable to prevent the currently under-investigated potential adverse consequences of AMR.Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2021.2000957 .

Effectiveness of empirical anti-pseudomonal antibiotics for recurrent COPD exacerbation: a multicenter retrospective cohort study

Although frequent chronic obstructive pulmonary disease (COPD) exacerbation has been associated with the isolation of Pseudomonas aeruginosa (PA) in sputum cultures, it remains unknown whether the empirical use of anti-pseudomonal antibiotics can improve outcomes in patients with frequent COPD exacerbations. This multicenter retrospective cohort study evaluated whether the empirical use of anti-pseudomonal antibiotics improves the length of the hospital stay in patients with recurrent COPD exacerbation (≥ 2 admissions from April 1, 2008 to July 31, 2020). For statistical analysis, a log-linked Gamma model was used. Parameters were estimated using a generalized estimating equation model with an exchangeable correlation structure accounting for repeated observations from a single patient. Covariates included age, body mass index, home oxygen therapy use, respiratory rate, heart rate, oxygen use on admission, mental status, systemic steroid use, activities of daily living, and the number of recurrences. Hospital-specific effects were specified as fixed effects. In total, 344 patients and 965 observations of recurrent COPD exacerbations were selected. Anti-pseudomonal antibiotics were used in 173 patients (18%). The estimated change in the length of the hospital stay between anti-pseudomonal and non-anti-pseudomonal antibiotics groups was 0.039 days [95% confidence interval; - 0.083, 0.162]. Anti-pseudomonal antibiotics could not shorten the length of the hospital stay.

Serum cortisol levels and adrenal gland size in patients with chronic obstructive pulmonary disease

OBJECTIVE

To determine the clinical significance of serum Cortisol (Cor) levels and adrenal gland size in patients with chronic obstructive pulmonary disease (COPD).

METHODS

We assigned 80 patients with COPD admitted to our hospital to an observation group, and 80 healthy individuals to a control group. Serum Cor, C-reactive protein (CRP) level, and adrenal gland size were measured. Patients with COPD were divided into several subgroups according to BODE (BMI, Obstruction, Dyspnea, Exercise capacity) indexes and forced expiratory volume in the first second (FEV1), and Cor levels and adrenal gland size were compared between subgroups. The Pearson Correlation was used to analyze correlations of adrenal gland size and Cor levels with partial pressure of oxygen (PaO₂), partial pressure of carbon dioxide (PaCO₂), FEV1, forced vital capacity (FVC), and FEV1/FVC. After 30 days' follow-up, the patients were allocated into good-prognosis group and poor-prognosis group. The clinical value of Cor levels in predicting prognosis was estimated by the receiver operating characteristic (ROC) curve.

RESULTS

Increased serum CRP levels were found in the observation group, while Cor levels and adrenal gland diameter were decreased (P<0.05 for each comparison). In the observation group, an increase in BODE index or decrease in FEV1 led to decreased Cor levels and adrenal gland diameter, as well as increased CRP levels (P<0.05, each comparison). Correlation analysis showed that adrenal gland diameter and Cor levels were positively correlated with PaO₂, FEV1, FVC, and FEV1/FVC, but negatively correlated with PaCO₂. The ROC curve indicated that Cor levels were valuable in predicting the prognosis (AUC>0.7, P<0.05).

CONCLUSION

Cor levels and adrenal gland size are closely associated with the severity of COPD, and Cor levels are predictive of prognosis.

Clinical Significance of Procalcitonin, C-Reactive Protein, and Interleukin-6 in Helping Guide the Antibiotic Use for Patients with Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Background

Currently, standards of antibiotic use in acute exacerbations of chronic obstructive pulmonary disease (AECOPD) patients are controversial.

Objective

The aim of the present study was to analyze the value of procalcitonin (PCT), C-reactive protein (CRP), and interleukin-6 (IL-6) levels to guide the antibiotic treatment of AECOPD patients.

Methods

A total of 371 patients with COPD or AECOPD were included in the study. Clinical and laboratory data were obtained at admission, 325 AECOPD patients and 46 sCOPD patients treated with antibiotics. The receiver operating curve (ROC) was used to evaluate the relationship between CRP, PCT, and IL-6.

Results

This study included medical record/case control 1, the COPD group (n = 46) and the AECOPD group (n = 325), and medical record control 2, the nonchanged antibiotic group (n = 203) and the changed antibiotic group (n = 61). In case 1, CRP, PCT, and IL-6 levels in the AECOPD group were higher than that in the control group (P < 0.05), while the result of ROC showed that IL-6 had higher AUC values (0.773) and higher sensitivity (71.7%) than other indicators. The specificity of PCT (93.5%) is higher than other indicators. In case 2, ROC curve results showed that the AUC value of IL-6 (0.771) was slightly higher than PCT and CRP. The sensitivity (85.2%) and specificity (65.5%) of CRP were higher than other indicators.

Conclusions

IL-6 and PCT were elevated in AECOPD patients, resulting in a higher diagnostic value for AECOPD. CRP had a higher diagnostic value for antibiotic use in AECOPD patients.

Efficacy and Safety of Different Doses of Systemic Corticosteroids in COPD Exacerbation

BACKGROUND

Although systemic corticosteroids (SCS) have long been used to treat patients with COPD exacerbation, the recommended dose remains controversial. We aimed to perform a meta-analysis and an indirect treatment comparison to investigate the efficacy and safety of different doses of SCS in subjects with COPD exacerbation.

METHODS

Studies were identified by searching different databases for randomized controlled trials that investigated the efficacy and safety of SCS with placebo in subjects with exacerbation of COPD. The different doses of SCS were assigned to low-dose (ie, initial dose ≤ 40 mg prednisone equivalent/d [PE/d]), medium-dose (initial dose = 40-100 mg PE/d, and high-dose (initial dose > 100 mg PE/d) groups. The indirect treatment comparison was performed between low-, medium-, and high-dose SCS groups.

RESULTS

Twelve trials with 1,375 participates were included. Compared to placebo, the risk of treatment failure was lower in the low-dose SCS groups (risk ratio 0.61 [95% CI 0.43-0.88], P = .007) and high-dose SCS groups (risk ratio 0.64 [95% CI 0.48-0.85], P = .002); the FEV₁ was significantly improved in low-dose (mean difference 0.09 [95% CI 0.06-0.12], P < .001), medium-dose (mean difference 0.23 [95% CI 0.02-0.44], P = .036), and high-dose SCS groups (mean difference 0.09, [95% CI 0.03-0.15], P < .001, respectively). Regarding safety, the incidence of hyperglycemia was higher in high-dose SCS groups versus placebo (risk ratio 2.52 [95% CI 1.13-5.62], P = .02). The indirect comparison between low-, medium-, and high-dose SCS found that the risk of treatment failure and changes in FEV₁ were similar between these doses of SCS.

CONCLUSIONS

This meta-analysis indicates that low-dose SCS (initial dose ≤ 40 mg PE/d) was sufficient and safer for treating subjects with COPD exacerbation, and it was noninferior to higher doses of SCS (initial dose > 40 mg PE/d) in improving FEV₁ and reducing the risk of treatment failure. However, our findings need to be verified in head-to-head randomized controlled trials.

Impact of antibiotic choice on readmission in adults experiencing an acute COPD exacerbation

PURPOSE

The impact of antibiotic therapy in managing acute chronic obstructive pulmonary disease (COPD) exacerbations requiring hospitalization remains unclear. We conducted a study to assess the impact of antibiotic therapy on the rate of 30-day readmission after discharge from a hospital stay for an acute COPD exacerbation. Additional study outcomes analyzed included the effects of antibiotic therapy on hospital length of stay, in-hospital mortality, 90-day and 12-month readmission rates, and time to next COPD exacerbation.

METHODS

The study was an institutional review board-approved, retrospective, observational review of adult patients at a tertiary academic medical center. The medical records of patients 18 years of age or older who were hospitalized for an acute COPD exacerbation between January 2008 and December 2014 were evaluated. Included patients were stratified by receipt of guideline-appropriate, guideline-inappropriate, or no antibiotic therapy. Nonparametric data were analyzed using the Kruskal-Wallis test (nonparametric) and categorical data via χ 2 test, respectively.

RESULTS

Three hundred twenty-five subjects were included; there were no significant differences in baseline characteristics in the 3 study groups. Sixty-eight percent of patients (n = 223) received antibiotics. The percentage of patients readmitted within 30 days did not differ between cohorts: 11.9% (appropriate therapy) vs 13.2% (nonappropriate therapy) vs 12.2% (no antibiotics) (P = 0.95 for all comparisons). Additionally, no detectable differences in 90-day or 12-month readmission rate, length of hospital day, or in-hospital mortality were found. However, a trend toward increased time to next COPD exacerbation was noted in those receiving antibiotics vs no antibiotics (352 days vs 192 days, P = 0.07).

CONCLUSION

Treatment of COPD exacerbations with antibiotics did not impact readmission rates, length of hospital stay, in-hospital mortality, or time to next exacerbation. More investigation is warranted to assess the effect of antibiotics on time to next exacerbation, as well as comparative effectiveness between antibiotic classes.

Antibiotics for COPD exacerbations: does drug or duration matter? A primary care database analysis

Introduction

Antibiotics are routinely given to people with chronic obstructive pulmonary disease (COPD) presenting with lower respiratory tract infection (LRTI) symptoms in primary care. Population prescribing habits and their consequences have not been well-described.

Methods

We conducted a retrospective analysis of antibiotic prescriptions for non-pneumonic exacerbations of COPD from 2010 to 2015 using the UK primary care Optimum Patient Care Research Database. As a proxy of initial treatment failure, second antibiotic prescriptions for LRTI or all indications within 14 days were the primary and secondary outcomes, respectively. We derived a model for repeat courses using univariable and multivariable logistic regression analysis.

Results

A total of 8.4% of the 9042 incident events received further antibiotics for LRTI, 15.5% further courses for any indication. Amoxicillin and doxycycline were the most common index and second-line drugs, respectively (58.7% and 28.7%), mostly given for 7 days. Index drugs other than amoxicillin, cardiovascular disease, pneumococcal vaccination and more primary care consultations were statistically significantly associated with repeat prescriptions for LRTI (p<0.05). The ORs and 95% CIs were: OR 1.28, 95% CI 1.10 to 1.49; OR 1.37, 95% CI 1.13 to 1.66; OR 1.33, 95% CI 1.14 to 1.55 and OR 1.05, 95% CI 1.02 to 1.07, respectively. Index duration, inhaled steroid use and exacerbation frequency were not statistically significant. The derived model had an area under the curve of 0.61, 95% CI 0.59 to 0.63.

Discussion

The prescription of multiple antibiotic courses for COPD exacerbations was relatively common-one in twelve patients receiving antibiotics for LRTI had a further course within 2 weeks. The findings support the current preference for amoxicillin as index drug within the limitations of this observational study. Further clinical trials to determine best practice in this common clinical situation appear required.

Time to NIV and mortality in AECOPD hospital admissions: an observational study into real world insights from National COPD Audits

Background

Randomised control trial (RCT)-derived survival figures for acute exacerbation of chronic obstructive pulmonary disease admissions managed with non-invasive ventilation (NIV) have not been replicated in UK clinical audits. Subsequent guidelines have emphasised the need for timely NIV application.

Methods

Data from the 2008 and 2014 national chronic obstructive pulmonary disease audits was used to analyse the association between time to NIV and mortality.

Results

1032 patients received NIV in 2008, and 1612 in 2014. Overall mortality rates reduced between the audits from 24.9% in 2008 to 16.8% in 2014 but time to NIV lengthened. In 2014, 20.9% of patients received NIV within 60 min versus 24.9% in 2008 (p=0.001). The proportion of patients receiving NIV between 3 and 24 hours increased from 31.3% in 2008 to 39% in 2014 (p=0.001). Patients admitted with hypercapnic acidotic respiratory failure who received NIV within 3 hours had lower in-patient mortality than those who received NIV between 3 and 24 hours, 15.9% versus 18.4%, but this did not reach statistical significance (p=0.425), but acidotic patients receiving NIV >24 hours after admission had significantly higher mortality (28.9%, p=0.002). A second cohort admitted with hypercapnia but normal range pH, who developed later acidosis, had higher mortality (24.6%), compared with those acidotic on admission (18% p≤0.001) and an extremely high mortality when NIV was given >24 hours after admission (42.6%).

Conclusion

Survival rates for those treated with NIV has improved between the two audits but remains lower than reported in RCTs. Patients who developed acidosis after admission and received NIV later in the hospital stay have even higher mortality and deserve further study and clinical attention.

Long-term macrolide treatment for the prevention of acute exacerbations in COPD: a systematic review and meta-analysis

Background

Acute exacerbation of COPD (AECOPD) is associated with an increased hospitalization and mortality. Azithromycin and erythromycin are the recommended drugs to reduce the risk of exacerbations. However, the most suitable duration of therapy and drug-related adverse events are still a matter of debate. The aim of this meta-analysis was to assess the current evidence regarding the efficacy and safety of long-term macrolide treatment for COPD.

Materials and methods

We comprehensively searched PubMed, Embase, the Cochrane Library, and the Web of Science and performed a systematic review and cumulative meta-analysis of all randomized controlled trials (RCTs) and retrospective studies.

Results

Eleven RCTs and one retrospective study including a total of 2,151 cases were carried out. Long-term macrolide treatment significantly reduced the total number of cases with one or more exacerbations (OR=0.40; 95% CI=0.24–0.65; P<0.01) and the rate of exacerbations per patient per year (risk ratio [RR]=0.60; 95% CI=0.45–0.78; P<0.01). Subgroup analyses showed that the minimum duration for drug efficacy for both azithromycin and erythromycin therapy was 6 months. In addition, macrolide therapy could improve the St George Respiratory Questionnaire (SGRQ) total score (P<0.01) but did not achieve the level of clinical significance. The frequency of hospitalizations was not significantly different between the treatment and control groups (P=0.50). Moreover, chronic azithromycin treatment was more likely to increase adverse events (P<0.01).

Conclusion

Prophylactic azithromycin or erythromycin treatment has a significant effect in reducing the frequency of AECOPD in a time-dependent manner. However, long-term macrolide treatment could increase the occurrence of adverse events and macrolide resistance. Future large-scale, well-designed RCTs with extensive follow-up are required to identify patients in whom the benefits outweigh risks.

Antibiotics for exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Many patients with an exacerbation of chronic obstructive pulmonary disease (COPD) are treated with antibiotics. However, the value of antibiotics remains uncertain, as systematic reviews and clinical trials have shown conflicting results.

OBJECTIVES

To assess effects of antibiotics on treatment failure as observed between seven days and one month after treatment initiation (primary outcome) for management of acute COPD exacerbations, as well as their effects on other patient-important outcomes (mortality, adverse events, length of hospital stay, time to next exacerbation).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library, MEDLINE, Embase, and other electronically available databases up to 26 September 2018.

SELECTION CRITERIA

We sought to find randomised controlled trials (RCTs) including people with acute COPD exacerbations comparing antibiotic therapy and placebo and providing follow-up of at least seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened references and extracted data from trial reports. We kept the three groups of outpatients, inpatients, and patients admitted to the intensive care unit (ICU) separate for benefit outcomes and mortality because we considered them to be clinically too different to be summarised as a single group. We considered outpatients to have a mild to moderate exacerbation, inpatients to have a severe exacerbation, and ICU patients to have a very severe exacerbation. When authors of primary studies did not report outcomes or study details, we contacted them to request missing data. We calculated pooled risk ratios (RRs) for treatment failure, Peto odds ratios (ORs) for rare events (mortality and adverse events), and mean differences (MDs) for continuous outcomes using random-effects models. We used GRADE to assess the quality of the evidence. The primary outcome was treatment failure as observed between seven days and one month after treatment initiation.

MAIN RESULTS

We included 19 trials with 2663 participants (11 with outpatients, seven with inpatients, and one with ICU patients).For outpatients (with mild to moderate exacerbations), evidence of low quality suggests that currently available antibiotics statistically significantly reduced the risk for treatment failure between seven days and one month after treatment initiation (RR 0.72, 95% confidence interval (CI) 0.56 to 0.94; I² = 31%; in absolute terms, reduction in treatment failures from 295 to 212 per 1000 treated participants, 95% CI 165 to 277). Studies providing older antibiotics not in use anymore yielded an RR of 0.69 (95% CI 0.53 to 0.90; I² = 31%). Evidence of low quality from one trial in outpatients suggested no effects of antibiotics on mortality (Peto OR 1.27, 95% CI 0.49 to 3.30). One trial reported no effects of antibiotics on re-exacerbations between two and six weeks after treatment initiation. Only one trial (N = 35) reported health-related quality of life but did not show a statistically significant difference between treatment and control groups.Evidence of moderate quality does not show that currently used antibiotics statistically significantly reduced the risk of treatment failure among inpatients with severe exacerbations (i.e. for inpatients excluding ICU patients) (RR 0.65, 95% CI 0.38 to 1.12; I² = 50%), but trial results remain uncertain. In turn, the effect was statistically significant when trials included older antibiotics no longer in clinical use (RR 0.76, 95% CI 0.58 to 1.00; I² = 39%). Evidence of moderate quality from two trials including inpatients shows no beneficial effects of antibiotics on mortality (Peto OR 2.48, 95% CI 0.94 to 6.55). Length of hospital stay (in days) was similar in antibiotic and placebo groups.The only trial with 93 patients admitted to the ICU showed a large and statistically significant effect on treatment failure (RR 0.19, 95% CI 0.08 to 0.45; moderate-quality evidence; in absolute terms, reduction in treatment failures from 565 to 107 per 1000 treated participants, 95% CI 45 to 254). Results of this trial show a statistically significant effect on mortality (Peto OR 0.21, 95% CI 0.06 to 0.72; moderate-quality evidence) and on length of hospital stay (MD -9.60 days, 95% CI -12.84 to -6.36; low-quality evidence).Evidence of moderate quality gathered from trials conducted in all settings shows no statistically significant effect on overall incidence of adverse events (Peto OR 1.20, 95% CI 0.89 to 1.63; moderate-quality evidence) nor on diarrhoea (Peto OR 1.68, 95% CI 0.92 to 3.07; moderate-quality evidence).

AUTHORS' CONCLUSIONS

Researchers have found that antibiotics have some effect on inpatients and outpatients, but these effects are small, and they are inconsistent for some outcomes (treatment failure) and absent for other outcomes (mortality, length of hospital stay). Analyses show a strong beneficial effect of antibiotics among ICU patients. Few data are available on the effects of antibiotics on health-related quality of life or on other patient-reported symptoms, and data show no statistically significant increase in the risk of adverse events with antibiotics compared to placebo. These inconsistent effects call for research into clinical signs and biomarkers that can help identify patients who would benefit from antibiotics, while sparing antibiotics for patients who are unlikely to experience benefit and for whom downsides of antibiotics (side effects, costs, and multi-resistance) should be avoided.

Molecular epidemiology and antimicrobial susceptibility of human Clostridium difficile isolates from a single institution in Northern China

Because the epidemiology of Clostridium difficile infection (CDI) is region-specific, the present study was undertaken to examine the epidemiology of C difficile outbreaks in Beijing, China.Eighty nonduplicate isolates were collected from March, 2016 to December, 2016. The molecular type and phylogenetic analysis were evaluated by multilocus sequence typing (MLST). The minimum inhibitory concentrations (MICs) for 11 antibiotics and the resistance mechanisms were investigated.Sixty-five toxigenic strains (81.25%), including 22 tcdABCDT strains (27.5%) and 43 tcdABCDT strains (53.75%), and also 15 nontoxigenic strains (tcdABCDT; 18.75%) were detected. MLST identified 21 different sequence types (STs), including 2 novel types (ST409 and ST416). All isolates were susceptible to metronidazole, vancomycin, fidaxomicin, piperacillin/tazobactam, and meropenem, and all were effectively inhibited by emodin (MICs 4-8 μg/mL). The resistance rates to rifaximin, ceftriaxone, clindamycin, erythromycin, and ciprofloxacin were 8.75%, 51.25%, 96.25%, 81.25%, and 96.25%, respectively; 81.25% (65/80) of isolates were multidrug-resistant. Amino acid mutations in GyrA and/or GyrB conferred quinolone resistance. One novel amino acid substitution, F86Y in GyrA, was found in 1 CIP-intermediate strain. The erm(B) gene played a key role in mediating macrolide-lincosamide-streptogramin B (MLSB) resistance. Erm(G) was also found in erm(B)-negative strains that were resistant to both erythromycin and clindamycin. RpoB mutations were associated with rifampin resistance, and 2 new amino mutations were identified in 1 intermediate strain (E573A and E603N).Regional diversity and gene heterogeneity exist in both the ST type and resistant patterns of clinical C difficile isolates in Northern China.