Definitive and Indeterminate Pseudomonas aeruginosa Infection in Adults with Community-acquired Pneumonia: A Prospective Observational Study

New Guidelines for Severe Community-acquired Pneumonia

In 2023, the new European guidelines on severe community-acquired pneumonia, providing clinical practice recommendations for the management of this life-threatening infection, characterized by a high burden of mortality, morbidity, and costs for the society. This review article aims to summarize the principal evidence related to eight different questions covered in the guidelines, by also highlighting the future perspectives for research activity.

Respiratory pathogenic microbial infections: a narrative review

Respiratory infectious diseases have long been recognised as a substantial global healthcare burden and are one of the leading causes of death worldwide, particularly in vulnerable individuals. In the post COVID-19 era, there has been a surge in the prevalence of influenza virus A and other multiple known viruses causing cold compared with during the same period in the previous three years, which coincided with countries easing COVID-19 restrictions worldwide. This article aims to review community-acquired respiratory illnesses covering a broad spectrum of viruses, bacteria, and atypical microorganisms and focuses on the cluster prevalence of multiple known respiratory pathogens in China, thereby providing effective prevention and control measures.

Antibiotic resistance profiles and associated factors of Pseudomonas Infections among patients admitted to large tertiary care hospital from a developing country

BACKGROUND

Pseudomonas infections are among the most common infections encountered in hospitalized patients, especially those with chronic illnesses or an immunocompromised state. Management of these infections has become challenging due to increased antibiotic resistance. Therefore, this study examines the antibiotic resistance profiles of Pseudomonas spp. and the associated factors among patients admitted to a large tertiary hospital in a developing country.

METHODS

This retrospective observational chart review study assessed patients admitted to a large tertiary hospital in a developing country with a positive culture growth of Pseudomonas from anybody site. Antibiotic susceptibility of the isolated Pseudomonas and patient characteristics were studied from the start of 2021 to the end of 2022. The study ground consisted of 185 patients.

RESULTS

The study included 185 patients with positive Pseudomonas isolates. Males constituted 54.6% of the sample, while 45.4% were females. The median age of the patients was 53 years. Patient comorbidities and risk factors for Pseudomonas infection and multidrug resistance were assessed. Antibiotic resistance to the Pseudomonas regimens showed the highest resistance to meropenem and ciprofloxacin (23.4%, similarly) among isolates of Pseudomonas aeruginosa. Multidrug resistance (MDR) was found in 108 (58.4%) isolates. The most commonly used antibiotic for treatment was piperacillin-tazobactam, accounting for 33.3% of cases, followed by aminoglycosides at 26.6%.

CONCLUSIONS

Pseudomonas aeruginosa isolates were resistant to meropenem and ciprofloxacin. Over half of the isolates were multidrug-resistant, which was worrying. Piperacillin-tazobactam and aminoglycosides were the most often utilized antibiotics, highlighting the significance of susceptibility testing. Implementing antimicrobial stewardship programs and infection control measures can help reduce drug resistance and improve outcomes in Pseudomonas infections.

Epidemiological, Microbiological, and Clinical Characteristics of Multi-Resistant Pseudomonas aeruginosa Isolates in King Fahad Medical City, Riyadh, Saudi Arabia

Increasing rates of serious multi-drug resistant (MDR) Pseudomonas aeruginosa infections have been reported globally, including in Saudi Arabia. This retrospective study investigates the epidemiological, microbiological, and clinical characteristics of multi-resistant P. aeruginosa (n3579 clinical isolates) in King Fahad Medical City, Riyadh, Saudi Arabia (2019–2021). Information on antimicrobial susceptibility and medical history was collected from the hospital database. P. aeruginosa infections occurred in 55.6% of males and 44.4% of females, and P. aeruginosa was more prevalent in children than in adults. Our analysis showed that P. aeruginosa had the highest sensitivity to amikacin (92.6%) and greatest resistance to aztreonam (29.8%), imipenem (29.5%), ceftazidime (26.1%), meropenem (25.6%), and cefepime (24.3%). MDR and extensively drug resistant (XDR) strains were more prevalent in male than female patients. Female patients showed higher rates of infection with pan-drug resistant (PDR) strains. Respiratory samples contained the majority of resistant isolates. Septic shock and liver disease were strongly correlated with mortality in the ICU patient group after analysing the relative risk associated with mortality. Our study emphasises the threat of multi-resistant P. aeruginosa in Saudi Arabia (and potentially the Middle East) and highlights important sources and contexts of infection that inhibit its effective control and clinical management.

Clinical relevance of bronchiectasis in patients with community-acquired pneumonia

BACKGROUND

Data regarding the clinical characteristics and treatment outcomes of patients with community-acquired pneumonia (CAP) and bronchiectasis (BE) are rare. This study aims to elucidate the clinical relevance of BE in patients with CAP.

METHODS

Patients hospitalized with CAP in a single center were retrospectively analyzed and divided into significant BE (BE with ≥ 3 lobes or cystic BE on computed tomography) and control groups. Clinical and microbiological characteristics were compared between the two groups.

RESULTS

In the final analysis, 2112 patients were included, and 104 (4.9%) had significant BE. The significant BE group exhibited a higher prevalence of sputum production, dyspnea, and complicated parapneumonic effusion or empyema than the control group. Pseudomonas aeruginosa was more frequently isolated in the significant BE group than in the control group, whereas Mycoplasma pneumoniae was less commonly identified. Length of hospital stay (LOS) was significantly longer in the significant BE group than the control group (12 [8-17] days vs. 9 [6-13] days, p < 0.001). In contrast, 30-day and in-hospital mortality rates did not significantly differ between the two groups. Furthermore, significant BE was an independent predictor of prolonged hospitalization in two models based on CURB-65 and pneumonia severity index.

CONCLUSIONS

Significant BE occurred in approximately 5% of patients with CAP and was more likely to be associated with sputum, dyspnea, complicated parapneumonic effusion or empyema, and isolation of P. aeruginosa. Significant BE was an independent predictor of LOS in patients with CAP.

Bacterial Patterns and Empiric Antibiotic Use in COPD Patients With Community-Acquired Pneumonia

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is strongly associated with the development of community-acquired pneumonia (CAP). Limited data are available on risk factors for difficult to manage bacteria such as Pseudomonas aeruginosa in COPD patients with CAP. Our objective was to assess the microbiological patterns associated with risk factors that determine empiric antibiotic therapy in hospitalized COPD patients with CAP.

METHODS

We performed a secondary data analysis of an international, multicenter, observational, point-prevalence study involving hospitalized COPD patients with CAP from March to June 2015. After identifying the risk factors associated with different microorganisms, we developed a scoring system to guide decision-making about empiric anti-pseudomonal antibiotic therapy in this population.

RESULTS

We enrolled 689 hospitalized COPD patients with CAP with documented microbiological testing. The most frequent microorganisms isolated were Streptococcus pneumoniae (8%) and Gram-negative bacteria (8%), P. aeruginosa (7%) and Haemophilus influenzae (3%). We developed a scoring system incorporating the variables independently associated with P. aeruginosa that include a previous P. aeruginosa isolation or infection (OR 14.2 [95%CI 5.7-35.2]), hospitalization in the past 12 months (OR 3.7 [1.5-9.2]), and bronchiectasis (OR 3.2 [1.4-7.2]). Empiric anti-pseudomonal antibiotics were overutilized in COPD patients with CAP. The new scoring system has the potential to reduce empiric anti-pseudomonal antibiotic use from 54.1% to 6.2%.

CONCLUSIONS

COPD patients with CAP present different microbiological profiles associated with unique risk factors. Anti-pseudomonal treatment is a critical decision when selecting empiric antibiotic therapy. We developed a COPD scoring system to guide decision-making about empiric anti-pseudomonal antibiotic therapy.

Impact of Pseudomonas aeruginosa coverage on the prognosis of elderly patients with community-acquired pneumonia

BACKGROUND

Although the 2019 American Thoracic Society and Infectious Diseases Society of America guidelines for community-acquired pneumonia (CAP) recommend the use of antibiotics with Pseudomonas aeruginosa coverage for patients with prior sputum isolation of P. aeruginosa, further research is needed to confirm its clinical outcomes. This study aimed to assess the impact of the use of antibiotics with P. aeruginosa coverage on mortality in elderly CAP patients with sputum isolation of P. aeruginosa.

METHODS

We retrospectively included consecutive elderly patients who were hospitalized for CAP and P. aeruginosa-positive sputum culture. The association between the use of antibiotics with P. aeruginosa coverage and 28-day mortality was assessed based on propensity score to reduce selection bias.

RESULTS

A total of 216 patients were included, and 68 (31%) of them were treated with antibiotics with P. aeruginosa coverage. The number of patients treated with antibiotics with P. aeruginosa coverage was significantly higher among nonsurvivors than among survivors. After adjustment using propensity score, the association between the use of antibiotics with P. aeruginosa coverage and the 28-day mortality was found to be statistically nonsignificant (odds ratio 2.182, 95% confidence interval 0.732-6.508, p = 0.162).

CONCLUSIONS

The use of antibiotics with P. aeruginosa coverage in elderly CAP patients with sputum isolation of P. aeruginosa did not improve their prognosis. A randomized control study is required to identify cases that should be treated with antibiotics covering P. aeruginosa.