Community acquired pneumonia: assessment and treatment

Molecular characterization of Staphylococcus aureus isolates derived from severe pneumonia: a retrospective monocentre study

BACKGROUND

Staphylococcus aureus is endowed with a repertoire of virulence factors potentially implicated in its pathogenicity and ability to cause invasive disease. The main objective of this study was to describe the bacterial genotype, including virulence genes and affiliation to clonal complexes (CCs), encountered in severe pneumonia.

METHODS

DNA microarray was used to analyse 18 S. aureus isolates from patients hospitalized with severe pneumonia between 2017 and 2019.

RESULTS

Among 18 S. aureus isolates, 14 were methicillin-susceptible S. aureus (MSSA), and 4 methicillin-resistant S. aureus (MRSA). There were 14 community-acquired, 3 healthcare-associated, and 1 hospital-acquired infections. Different radiological presentations were observed: necrotizing pneumonia (n = 8, 44%), alveolar consolidation (n = 7, 39%), alveolar-interstitial infiltrates (n = 3, 17%). Sixteen patients (89%) required ICU hospitalization, 13 (72%) an invasive mechanical ventilation, and 12 (67%) a vasopressor support. Mortality affected 6 patients (33%). Panton-Valentine leukocidin (PVL), staphylococcal enterotoxins, toxic shock syndrome toxine-1 (TSST-1) encoding genes were documented in nine (50%), 12 (67%), one (6%) of the isolates, respectively. Accessory regulator gene group I was the most reported (n = 9, 50%) and was found in five deaths. The majority of isolates were affiliated to CC152 (n = 6), followed by CC15 (n = 3), CC45 (n = 2), CC30 (n = 2), CC1 (n = 2), CC8 (n = 1), CC9 (n = 1), and CC25 (n = 1). All the CC152 isolates were PVL-positive.

CONCLUSION

CC152-PVL positive S. aureus strains were the most prevalent in severe pneumonia. Other virulence gene profiles were found coupled to additional clonal lineages. A genotyping strategy contributes to describe the current circulating strains and bacterial genetic backgrounds.

Evaluation of severity scoring systems in patients with severe community acquired pneumonia

BACKGROUND

The aim of this study was to evaluate the ability of severity scoring systems to predict 30-day mortality in patients with severe community-acquired pneumonia.

METHODS

The study included 98 patients aged ≥18 years with community acquired pneumonia hospitalized at the Intensive Care Unit of the University Clinic for Infectious Diseases in Skopje, Republic of North Macedonia, during a 3-year period. We recorded demographic, clinical and common biochemical parameters. Five severity scores were calculated at admission: CURB 65 (Confusion, Urea, Respiratory Rate, Blood pressure, Age ≥65 years), SCAP (Severe Community Acquired Pneumonia score), SAPS II (Simplified Acute Physiology Score), SOFA (Sequential Organ Failure Assessment Score) and MPM (Mortality Prediction Model). Primary outcome variable was 30-day in-hospital mortality.

RESULTS

The mean age of the patients was 59.08 ± 15.76 years, predominantly males (68%). The overall 30-day mortality was 52%. Charlson Comorbidity index was increased in non-survivors (3.72 ± 2.33) and was associated with the outcome. All severity indexes had higher values in patients who died, that showed statistical significance between the analysed groups. The areas under curve (AUC) values of the five scores for 30-day mortality were 0.670, 0.732, 0,726, 0.785 and 0.777, respectively.

CONCLUSION

Widely used severity scores accurately detected patients with pneumonia that had increased risk for poor outcome, but none of them individually demonstrated any advantage over the others.

Prognostic factors of severe community-acquired staphylococcal pneumonia in France

PURPOSE

Staphylococcus aureus causes severe forms of community-acquired pneumonia (CAP), namely staphylococcal pleuropneumonia in young children and staphylococcal necrotising pneumonia in older patients. Methicillin resistance and the Panton-Valentine leukocidin (PVL) toxin, as well as less specific factors, have been associated with poor outcome in severe CAP, but their roles are unclear.

METHODS

A prospective multicentre cohort study of severe staphylococcal CAP was conducted in 77 paediatric and adult intensive care units in France between January 2011 and December 2016. After age-clustering, risk factors for mortality, including pre-existing conditions, clinical presentation, laboratory features, strain genetic lineage, PVL, other virulence factors and methicillin resistance were assessed using univariate and multivariable Cox and LASSO (least absolute shrinkage and selection operator) regressions.

RESULTS

Out of 163 included patients, aged 1 month to 87 years, 85 (52.1%) had PVL-positive CAP; there were 20 (12.3%) patients aged <3 years (hereafter "toddlers"), among whom 19 (95%) had PVL-positive CAP. The features of PVL-positive CAP in toddlers matched with the historical description of staphylococcal pleuropneumonia, with a lower mortality (three (15%) out of 19) compared to PVL-positive CAP in older patients (31 (47%) out of 66). Mortality in older patients was predicted by PVL-positivity (hazard ratio (HR) 1.81, 95% CI 1.03-3.17) and methicillin resistance (HR 2.37, 95% CI 1.29-4.34) independently from S. aureus lineages and the presence of other determinants of virulence.

CONCLUSION

PVL was associated with staphylococcal pleuropneumonia in toddlers and was a risk factor for mortality in older patients with severe CAP, independently of methicillin resistance, S. aureus genetic background and other virulence factors.

Effect of daily manual toothbrushing with 0.2% chlorhexidine gel on pneumonia-associated pathogens in adults living with profound neuro-disability

Purpose

To investigate the effect of daily toothbrushing with 0.2 % chlorhexidine digluconate (CHX) on the colonization of dental plaque by pathogens associated with pneumonia amongst non-ventilated adults with a neuro-disability.

Methodology

Forty-nine patients living in long-term care were recruited. Daily toothbrushing with 0.2 % CHX gel was conducted for 48 weeks. Plaque accumulation was assessed and microbiological sampling was undertaken every 6 weeks.

Results

At any one time point at least 65 % (n=32) of subjects were found to harbour respiratory pathogens. Although there were significant changes in the proportion of individuals colonized over time with Gram-negative bacilli and Pseudomonas aeruginosa, the changes were not sustained. By week 48 there was no significant difference from the levels that had been recorded at baseline.

Conclusions

Bacteria known to be causal in pneumonia are present and colonize the dental plaque of non-ventilated adults with a neuro-disability. Daily toothbrushing with 0.2 % CHX gel did not produce a sustained reduction in intra-oral respiratory pathogen counts after 48 weeks.

Fulminant Staphylococcal Infections

Fulminant staphylococcal infection indicates an explosive, intense, and severe infection occurring in a patient whose previous condition and antecedent would never have caused any anticipation of life-threatening development. This includes necrotizing pneumonia, necrotizing fasciitis, and to some extent toxic shock syndrome and infective endocarditis. In the three former diseases, toxin production plays a major role whereas in the latter (fulminant presentation of infective endocarditis), association with any particular toxinic profile has never been demonstrated. This article reviews the clinical, pathophysiological, and therapeutic aspects of these diseases.

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.

Real life management of community-acquired Pneumonia in adults in the Gulf region and comparison with practice guidelines: a prospective study

Background

Very few data exist on the management of community-acquired pneumonia (CAP) in patients admitted to hospitals in the Gulf region. The objectives of this study were to describe treatment patterns for CAP in 38 hospitals in five Gulf countries (United Arab Emirates, Kuwait, Bahrain, Oman, and Qatar) and to compare the findings to the most recent Infectious Diseases Society of America (IDSA) / American Thoracic Society (ATS) guidelines.

Methods

This was a prospective, observational study conducted between January 2009 and February 2011. Adult patients hospitalised (excluding intensive care units) for CAP and subsequently discharged were included. Data were collected retrospectively at hospital discharge, and prospectively during two follow-up visits. Data on medical history, mortality-risk scores, diagnostic criteria, antibiotic treatment, isolated pathogens and clinical and radiographic outcomes were collected. Care practices were compared to the IDSA/ATS guidelines.

Results

A total of 684 patients were included. The majority (82.9 %) of patients were classified as low risk for mortality (pneumonia severity index II and III). The majority of patients fulfilled criteria for treatment success at discharge, although only 77.6 % presented a normalised leukocyte count. Overall, the management of CAP in Gulf countries is in line with the IDSA/ATS guidelines. This applied to the diagnosis of CAP, to the identification of high-risk CAP patients, to the identification of etiologic agent responsible for CAP and to the type of treatment despite the fact that combinations of antimicrobial agents were not consistent with the guidelines in 10 % of patients. In all patients, information about Gram’s staining was not captured as recommended by the IDSA/ATS and in the majority of patients (>85 %) chest radiography was not systematically performed at the post-discharge follow-up visits.

Discussion

The management of CAP in the Gulf region is globally in line with current IDSA/ATS guidelines, although rates of pathogen characterisation and post-discharge follow-up need to be improved.

Conclusion

Compliance with established guidelines should be encouraged in order to improve the management of the disease in this region.