Successful treatment of fulminant community-acquired Pseudomonas aeruginosa necrotizing pneumonia in a previously healthy young man

The Uncommon Suspect: Pseudomonas aeruginosa and Cavitary Lung Lesions in an Immunocompetent Patient

Cavitary lung lesions pose a formidable diagnostic challenge due to their multifaceted etiologies. While tuberculosis and other prevalent pathogens typically dominate discussions, instances of community-acquired Pseudomonas aeruginosa (P. aeruginosa) pneumonia leading to cavitation in immunocompetent individuals remain exceptionally rare. Herein, we present a compelling case of such pneumonia in a 61-year-old man with a past medical history of hypertension and coronary artery disease who presented with cough, chest pain, and subjective fever. Chest imaging revealed cavitary lung lesions, which is atypical for community-acquired pneumonia (CAP). Initial workup excluded common CAP pathogens, following which bronchoscopy with bronchoalveolar lavage (BAL) definitively diagnosed P. aeruginosa, prompting targeted antibiotic therapy. Treatment led to clinical and radiographic improvement. P. aeruginosa rarely causes CAP, especially in immunocompetent patients, and cavitary lesions further complicate diagnosis. This case highlights the importance of considering P. aeruginosa in CAP with unusual features and emphasizes the utility of bronchoscopy with BAL for diagnosis and guiding management.

A Fatal Case of Pseudomonas aeruginosa Community-Acquired Pneumonia in an Immunocompetent Patient: Clinical and Molecular Characterization and Literature Review

Rare cases of Pseudomonas aeruginosa community-acquired pneumonia (PA-CAP) were reported in non-immunocompromised patients. We describe a case of Pseudomonas aeruginosa (PA) necrotizing cavitary CAP with a fatal outcome in a 53-year-old man previously infected with SARS-CoV-2, who was admitted for dyspnea, fever, cough, hemoptysis, acute respiratory failure and a right upper lobe opacification. Six hours after admission, despite effective antibiotic therapy, he experienced multi-organ failure and died. Autopsy confirmed necrotizing pneumonia with alveolar hemorrhage. Blood and bronchoalveolar lavage cultures were positive for PA serotype O:9 belonging to ST1184. The strain shares the same virulence factor profile with reference genome PA01. With the aim to better investigate the clinical and molecular characteristics of PA-CAP, we considered the literature of the last 13 years concerning this topic. The prevalence of hospitalized PA-CAP is about 4% and has a mortality rate of 33-66%. Smoking, alcohol abuse and contaminated fluid exposure were the recognized risk factors; most cases presented the same symptoms described above and needed intensive care. Co-infection of PA-influenza A is described, which is possibly caused by influenza-inducing respiratory epithelial cell dysfunction: the same pathophysiological mechanism could be assumed with SARS-CoV-2 infection. Considering the high rate of fatal outcomes, additional studies are needed to identify sources of infections and new risk factors, along with genetic and immunological features. Current CAP guidelines should be revised in light of these results.

Young Healthy Patient With Severe COVID-19 and Fulminant Community-Acquired Pseudomonas aeruginosa Pneumonia: A Case Report

Community-acquired pneumonia (CAP) caused by Pseudomonas aeruginosa in healthy adults can rapidly lead to severe outcomes. We treated a case of P. aeruginosa-induced CAP and concurrent severe coronavirus disease (COVID-19) in a healthy 39-year-old man without other serious risk factors for severe illness except smoking. Immediately after admission, the patient developed sepsis and received intensive broad-spectrum antibacterial therapy with meropenem and vancomycin, veno-arterial extracorporeal membrane oxygenation (VAECMO), and catecholamine supplementation. Despite receiving multidisciplinary treatment, the patient died within 24 hours. P. aeruginosa with normal antimicrobial susceptibility was identified in blood and sputum cultures of samples taken at admission. Gram staining of the bacteria detected in blood cultures was suspicious for non-glucose-fermenting Gram-negative rods, including P. aeruginosa, and the antimicrobial regimen that was initiated following admission was considered effective. The patient was a plumber and a smoker, which are risk factors for P. aeruginosa-induced CAP, and the clinical course matched those in previous reports of P. aeruginosa-induced CAP, including necrotizing pneumonia with cavities and rapid progression of sepsis. Although COVID-19 can be the sole cause of septic shock, the combination of P. aeruginosa bacteremia and COVID-19 was possibly the cause of septic shock in this case. Even during an infectious disease pandemic, reviewing the patient's occupational history and comorbidities and performing blood and sputum culture tests, including Gram staining, are important for the provision of appropriate treatment.

Virulent Pseudomonas aeruginosa pneumonia in an immunocompetent adult associated with a home whirlpool bath: A case report

We present a case of life-threatening pneumonia caused by Pseudomonas aeruginosa (P. aeruginosa) in a healthy 67-year-old man. Rapid disseminated infection resulted in the right hemorrhagic pneumonia and bacteremia. Antimicrobial therapy had limited effects, radical pneumonectomy eventually resolved the prolonged infection. Concurrently, we explored the environmental factors responsible for fulminant P. aeruginosa infection. Multi-locus sequence typing demonstrated that P. aeruginosa isolated from the patient was identical to that collected from home whirlpool bath by the common virulent factor gene. Massive inhalation of contaminated aerosol and pathogen virulence may have synergistically contributed to the severity in this case.

Septic shock secondary to an acute necrotizing community-acquired pneumonia with bacteremia due to Pseudomonas aeruginosa

•

Necrotizing acute community-acquired pneumonia due to Pseudomonas aeruginosa are rare.

•

Second description of a septic shock secondary to a necrotizing CAP with bacteremia due to P. aeruginosa for which pulmonary origin was proven by bronchoalveolar lavage fluid on a patient who survived.

•

Anti-pseudomonal monotherapy may be may be a better option for older patients

•

Despite risk factors related to the host or to the bacteria, the evolution remains unpredictable.

Pseudomonas aeruginosa is an uncommon cause of necrotizing acute community-acquired pneumonia (CAP). Only thirteen cases have been previously reported in the literature. In this article, we describe a case of previously healthy 80-year-old male patient, who presented in septic shock caused by necrotizing CAP. Despite inadequate empiric antimicrobial treatment, the patient survived and was able to return to his home after three weeks of hospitalization. To the best of our knowledge, this is the second case of septic shock secondary to P. aeruginosa necrotizing CAP and bacteremia, with optimal clinical outcome. We highlight the evolution of this pathology remains unpredictable, despite the factors related to the host and the bacterium.

Community-acquired necrotizing pneumonia with bacteremia caused by Pseudomonas aeruginosa in a patient with emphysema: An autopsy case report

We report the case of a 47-year-old man with chronic obstructive pulmonary disease who was referred to our hospital for acute dyspnea. The radiologic findings revealed consolidation with a cavity in the left upper lobe of the lung. Blood/sputum cultures detected Pseudomonas aeruginosa. Despite intensive care, the patient died from respiratory failure. Autopsy revealed multiple small necrotizing cavities that had coalesced. Although P. aeruginosa is a known causative pathogen of community-acquired pneumonia in patients with structural lung disease, the radiologic findings were non-specific. Irrespective of imaging findings, P. aeruginosa should be considered a cause of community-acquired pneumonia.

Prevalence and risk factors for bloodstream infection present on hospital admission

BACKGROUND

Bloodstream infection present on hospital admission (BSI-POA) is a major cause of morbidity and mortality. The purpose of this study was to measure prevalence and describe the risk factors of patients with BSI-POA and to determine the prevalence of resistance in isolates by admission source.

METHODS

We conducted a retrospective cohort study of patients discharged from three hospitals in New York City between 2006 and 2014. BSI-POA was defined as BSI diagnosed within 48 h of hospitalisation.

RESULTS

The prevalence for BSI-POA was 5307/315,010 discharges (1.7%). The odds of being admitted with BSI-POA were greatest among patients admitted with renal failure, chronic dermatitis, malignancies and prior hospitalisation. Odds ratios and 95% confidence intervals (CI) were 2.72 (95% CI = 2.56-2.88), 2.15 (95% CI = 1.97-2.34), 1.76 (95% CI = 1.64-1.88) and 1.59 (95% CI = 1.50-1.69), respectively. The largest proportion of BSI-POA presented with Staphylococcus aureus (48.4%), followed by Enterococcus faecalis/faecium (20.3%), Klebsiella pneumoniae (16.2%), Streptococcus pneumoniae (8.7%), Pseudomonas aeruginosa (4.2%) and Acinetobacter baumannii (2.2%). Overall, 44% of those admitted from nursing homes presented with antibiotic resistant strains versus 34% from other hospitals and 31% from private homes (P = 0.002).

CONCLUSION

Understanding the risk factors of patients who present to the hospital with BSI could enable timely interventions and better patient outcomes.

Necrotizing Pseudomonas aeruginosa Community-Acquired Pneumonia: A Case Report and Review of the Literature

Lung cavities are not typically associated with community-acquired pneumonia (CAP). CAP due to P. aeruginosa is rare and even less commonly causes necrotizing pneumonia. We report a case of P. aeruginosa CAP that progressed to necrotizing pneumonia and was eventually fatal. Procalcitonin (PCT) has been well investigated in guiding antibiotic therapy (especially CAP) in adults. In this case, PCT at presentation and sequentially was negative. We discuss this caveat and present hypotheses as to the sensitivity and specificity of PCT and C-reactive protein (CRP) in these patients. To better characterize P. aeruginosa CAP, we undertook a review of cases indexed in PubMed from 2001 to 2016 (n = 9). The data reveal that risk factors for P. aeruginosa CAP include smoking, alcohol use, obstructive lung disease, sinusitis, and hot tub use. The route of infection for P. aeruginosa CAP remains unknown. One of the most interesting findings on reviewing cases was that P. aeruginosa CAP involves the right upper lobe in the vast majority. We suggest that when physicians in the community see patients with distinctly upper lobe necrotizing or cavitary pneumonia, they should consider P. aeruginosa in their differential diagnosis. Further studies are needed to clarify route of infection, role of PCT and CRP, and optimal therapy including drug and duration.

Virulence Attributes and Host Response Assays for Determining Pathogenic Potential of Pseudomonas Strains Used in Biotechnology

Pseudomonas species are opportunistically pathogenic to humans, yet closely related species are used in biotechnology applications. In order to screen for the pathogenic potential of strains considered for biotechnology applications, several Pseudomonas strains (P.aeruginosa (Pa), P.fluorescens (Pf), P.putida (Pp), P.stutzeri (Ps)) were compared using functional virulence and toxicity assays. Most Pa strains and Ps grew at temperatures between 28°C and 42°C. However, Pf and Pp strains were the most antibiotic resistant, with ciprofloxacin and colistin being the most effective of those tested. No strain was haemolytic on sheep blood agar. Almost all Pa, but not other test strains, produced a pyocyanin-like chromophore, and caused cytotoxicity towards cultured human HT29 cells. Murine endotracheal exposures indicated that the laboratory reference strain, PAO1, was most persistent in the lungs. Only Pa strains induced pro-inflammatory and inflammatory responses, as measured by elevated cytokines and pulmonary Gr-1 -positive cells. Serum amyloid A was elevated at ≥ 48 h post-exposure by only some Pa strains. No relationship was observed between strains and levels of peripheral leukocytes. The species designation or isolation source may not accurately reflect pathogenic potential, since the clinical strain Pa10752 was relatively nonvirulent, but the industrial strain Pa31480 showed comparable virulence to PAO1. Functional assays involving microbial growth, cytotoxicity and murine immunological responses may be most useful for identifying problematic Pseudomonas strains being considered for biotechnology applications.

[Two Cases of Rapidly Progressive Community-acquired Pneumonia Due to Pseudomonas aeruginosa]

Pseudomonas aeruginosa is a significant causative bacterium in hospital-acquired pneumonia and nursing and healthcare-associated pneumonia, but it seems to be rare in community-acquired pneumonia (CAP). We report two cases of severe CAP due to P. aeruginosa. Case 1: A 52-year-old man was referred to our hospital for chest and back pain. He was being treated for diabetes mellitus and had a long history of smoking. Chest images showed consolidation in the right upper lobe. Soon after hospitalization, he developed sepsis shock and died seven hours later. Case 2: A 73-year-old man with a history of heavy smoking was referred to our hospital for right chest pain. Chest images showed right upper lobe pneumonia. Although wide-spectrum antimicrobial agents were administrated, he died ten hours after admission. In both cases, there was a rapid progression to death, despite administration of a broad spectrum of antibiotics and treatment for sepsis. In cases of CAP involving the right upper lobe, the possibility of bacteremia and rapid progress should be considered.

Community-acquired Pseudomonas aeruginosa-pneumonia in a previously healthy man occupationally exposed to metalworking fluids

Although the Pseudomonas aeruginosa infection is well known and frequently found in hospitals and nursing care facilities, many cases are also reported outside these boundaries. In general, this pathogen infects debilitated patients either by comorbidities or by any form of immunodeficiency. In cases of respiratory infection, tobacco abuse seems to play an important role as a risk factor. In previously healthy patients, community-acquired pneumonia (CAP) with P. aeruginosa as the etiological agent is extremely rare, and unlike the cases involving immunocompromised or hospitalized patients, the outcome is severe, and is fatal in up to 61.1% of cases. Aerosolized contaminated water or solutions are closely linked to the development of respiratory tract infection. In this setting, metalworking fluids used in factories may be implicated in CAP involving previously healthy people. The authors report the case of a middle-aged man who worked in a metalworking factory and presented a right upper lobar pneumonia with a rapid fatal outcome. P. aeruginosa was cultured from blood and tracheal aspirates. The autopsy findings confirmed a hemorrhagic necrotizing pneumonia with bacteria-invading vasculitis and thrombosis. A culture of the metalworking fluid of the factory was also positive for P. aeruginosa. The pulsed-field gel electrophoresis showed that both strains (blood culture and metalworking fluid) were genetically indistinguishable. The authors highlight the occupational risk for the development of this P.aeruginosa-infection in healthy people.

Community-acquired, hospital-acquired, and healthcare-associated pneumonia caused by Pseudomonas aeruginosa

We describe three types of Pseudomonas aeruginosa pneumonia.

Case 1. P. aeruginosa was isolated from the blood and sputum of a 29-year-old male non-smoker who developed severe community-acquired pneumonia (CAP). Piperacillin was initially effective, but fever and lobular pneumonia with cavities developed seven days after discharge. Intravenous piperacillin/tazobactam and tobramycin were administered for four weeks, followed by oral ciprofloxacin for two weeks. He finally recovered, but developed recurrent CAP due to P. aeruginosa despite appropriate antibiotic therapy and immunocompetent status.

Case 2. P. aeruginosa was isolated from the blood and sputum of a 57-year-old woman with renal cancer who developed hospital-acquired pneumonia (HAP) after surgical treatment. She recovered after meropenem administration for four weeks.

Case 3. A 67-year-old woman with systemic sclerosis and malignant lymphoma who was followed up on an outpatient basis underwent immunosuppressive therapy. Thereafter, she developed pneumonia and was admitted to our institution where P aeruginosa was isolated from blood and sputum samples. Healthcare-associated pneumonia (HCAP) was diagnosed and effectively treated with tobramycin and ciprofloxacin.

P. aeruginosa is not only a causative pathogen of HAP and HCAP, but possibly also of CAP.

30-day mortality in UK patients with bacteraemic community-acquired pneumonia

OBJECTIVES

To determine 7 and 30-day mortality in consecutive patients with bacteraemic community-acquired pneumonia (CAP) and the association between predicted variables and likelihood of death.

METHODS

From August 2007 to July 2011, demographic, clinical and microbiological data were prospectively collected on patients with bacteraemic CAP. Patients were followed until death, hospital discharge or recovery from infection. Univariate and multivariate analysis was performed to determine the association between predictor variables and 30-day mortality.

RESULTS

7-day mortality was 61/252 [24.4%, 95% confidence interval (CI) 19.1-30.0%] and by 30 days, this had risen to 77/252 (30.6%, 95% CI 24.9-36.6%). In univariate analysis, factors associated with 30-day mortality were age, speciality within 48 h of admission, blood culture isolate and Charlson co-morbidity index (CCI). In multivariate analysis, age and CCI remained significantly associated. There was also a trend towards significance for meticillin-sensitive Staphylococcus aureus (MSSA) and Pseudomonas aeruginosa blood culture isolates compared to Streptococcus pneumoniae.

CONCLUSIONS

Overall, bacteraemic CAP was associated with high inpatient mortality. Because of their association with poor outcomes, patients with MSSA and P. aeruginosa bacteraemic CAP require further study.

[Multidisciplinary approach of ventilated necrotizing pneumonia]

Les pneumopathies infectieuses peuvent se compliquer, du fait de facteurs liés aux germes, à l’hôte ou à l’interaction entre les deux, par la survenue d’une nécrose et/ou d’une destruction du parenchyme pulmonaire. La nécrose et la destruction du parenchyme pulmonaire sont à l’origine de deux entités cliniques principales, les abcès pulmonaires et les pneumonies nécrosantes (PN). Les PN sont des entités rares mais dont le pronostic est redoutable. Elles sont caractérisées par une hépatisation diffuse, possiblement bilatérale du parenchyme pulmonaire avec cavitations et nécrose. Les PN sont généralement associées à un sepsis sévère et à une insuffisance respiratoire aiguë. Nous envisagerons la physiopathologie et le traitement médical qui comprend des mesures symptomatiques, le support des différentes défaillances d’organe, en particulier respiratoires, et le traitement antibiotique. Les indications chirurgicales et leurs modalités seront aussi détaillées. Une prise en charge multidisciplinaire associant réanimateurs, pneumologues, infectiologues, radiologues, chirurgiens et kinésithérapeutes doit permettre d’améliorer les taux de survie et surtout la qualité de vie des patients à distance d’une PN.