The role of anaerobes in patients with ventilator-associated pneumonia and aspiration pneumonia: a prospective study

Therapy of Aspiration: Out-of-Hospital and In-Hospital-Acquired

Therapeutic considerations for aspiration pneumonia prioritize the risk of multidrug-resistant organisms. This involves integrating microbiological insights with each patient's unique risk profile, including the location at the time of aspiration, and whether it occurred in or out of the hospital. Our understanding of the microbiology of aspiration pneumonia has also evolved, leading to a reassessment of anaerobic bacteria as the primary pathogens. Emerging research shows a predominance of aerobic pathogens, in both community and hospital-acquired cases. This shift challenges the routine use of broad-spectrum antibiotics targeting anaerobes, which can contribute to antibiotic resistance and complications such as Clostridium difficile infections-concerns that are especially relevant given the growing issue of antimicrobial resistance. Adopting a comprehensive, patient-specific approach that incorporates these insights can optimize antibiotic selection, improve treatment outcomes, and reduce the risk of resistance and adverse effects.

Is There a Role for Bronchoscopy in Aspiration Pneumonia?

Aspiration represents the passage of oropharyngeal content to the lower respiratory tract. The interplay between the host and the aspirate proprieties determines the subsequent aspiration syndrome. A low pH, typical of gastric aspirate, favors chemical pneumonitis, whereas an increased bacterial inoculum causes aspiration pneumonia. About a quarter of patients with aspiration pneumonitis will develop a bacterial superinfection during the course of recovery. While antibiotic therapy is indicated for aspiration pneumonia, supportive care remains the cornerstone of treatment in aspiration pneumonitis. However, the overlapping clinical features of these syndromes lead to initiation of antimicrobial therapy in most cases of aspiration. Bronchoscopy can aid in clinical decision-making by direct airway visualization and also by providing access to a series of emerging biomarkers. Invasive microbiological studies increase diagnostic yield and enable a tailored antibiotic treatment. In conjunction with stewardship programs, invasive sampling and novel molecular diagnostics can decrease the amount of inappropriate antibiotic therapy. In the context of foreign body aspiration, bronchoscopy represents both diagnostic and treatment gold standard.

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Causes of death in mucopolysaccharidoses

Mucopolysaccharidoses are inherited metabolic diseases caused by mutations in genes encoding enzymes required for degradation of glycosaminoglycans. A lack or severe impairment of activity of these enzymes cause accumulation of GAGs which is the primary biochemical defect. Depending on the kind of the deficient enzyme, there are 12 types and subtypes of MPS distinguished. Despite the common primary metabolic deficit (inefficient GAG degradation), the course and symptoms of various MPS types can be different, though majority of the diseases from the group are characterized by severe symptoms and significantly shortened live span. Here, we analysed the frequency of specific, direct causes of death of patients with different MPS types, the subject which was not investigated comprehensively to date. We examined a total of 1317 cases of death among MPS patients, including 393 cases of MPS I, 418 cases of MPS II, 232 cases of MPS III, 45 cases of MPS IV, 208 cases of MPS VI, and 22 cases of MPS VII. Our analyses indicated that the most frequent causes of death differ significantly between MPS types, with cardiovascular and respiratory failures being predominant in MPS I, MPS II, and MPS VI, neurological deficits in MPS III, respiratory issues in MPS IV, and hydrops fetalis in MPS VII. Results of such studies suggest what specific clinical problems should be considered with the highest priority in specific MPS types, apart from attempts to correct the primary causes of the diseases, to improve the quality of life of patients and to prolong their lives.

Bacterial profiles detected in ventilator-associated pneumonia in Japan: A systematic review

The primary objective of this study was to identify the predominant organisms associated with ventilator-associated pneumonia (VAP) in Japan. Studies on VAP conducted in Japan were systematically reviewed, and seven studies with a total of 374 cases were included. The detection rate of each bacterium and multidrug-resistant (MDR) pathogen was analyzed using the inverse variance method. Pseudomonas aeruginosa was identified as the predominant pathogen in 29.2 % of cases, followed by methicillin-resistant Staphylococcus aureus (MRSA) (12.0 %), and Klebsiella spp. (9.5 %). An integrated analysis revealed a detection rate of 57.8 % (95 % confidence interval: 48.7%-66.8 %) for MDR pathogens. This review highlights P. aeruginosa and MRSA as the predominant VAP-associated organisms in Japan, with a significant prevalence of MDR pathogens. This analysis provides valuable insights based on the regional distribution of bacteria detected in VAP, which is critical for selecting appropriate empirical therapy.

Aspiration Pneumonia

Aspiration pneumonia is a lower respiratory tract infection that results from inhalation of foreign material, often gastric and oropharyngeal contents. It is important to distinguish this from a similar entity, aspiration with chemical pneumonitis, as treatment approaches may differ. An evolving understanding of the human microbiome has shed light on the pathogenesis of aspiration pneumonia, suggesting that dysbiosis, repetitive injury, and inflammatory responses play a role in its development. Risk factors for aspiration events involve a complex interplay of anatomical and physiological dysfunctions in the nervous, gastrointestinal, and pulmonary systems. Current treatment strategies have shifted away from anaerobic organisms as leading pathogens. Prevention of aspiration pneumonia primarily involves addressing oropharyngeal dysphagia, a significant risk factor for aspiration pneumonia, particularly among elderly individuals and those with cognitive and neurodegenerative disorders.

Pleural Empyema Caused by Streptococcus intermedius and Fusobacterium nucleatum: A Distinct Entity of Pleural Infections

BACKGROUND

Many community-acquired pleural infections are caused by facultative and anaerobic bacteria from the human oral microbiota. The epidemiology, clinical characteristics, pathogenesis, and etiology of such infections are little studied. The aim of the present prospective multicenter cohort study was to provide a thorough microbiological and clinical characterization of such oral-type pleural infections and to improve our understanding of the underlying etiology and associated risk factors.

METHODS

Over a 2-year period, we included 77 patients with community-acquired pleural infection, whereof 63 (82%) represented oral-type pleural infections. Clinical and anamnestic data were systematically collected, and patients were offered a dental assessment by an oral surgeon. Microbial characterizations were done using next-generation sequencing. Obtained bacterial profiles were compared with microbiology data from previous investigations on odontogenic infections, bacteremia after extraction of infected teeth, and community-acquired brain abscesses.

RESULTS

From the oral-type pleural infections, we made 267 bacterial identifications representing 89 different species. Streptococcus intermedius and/or Fusobacterium nucleatum were identified as a dominant component in all infections. We found a high prevalence of dental infections among patients with oral-type pleural infection and demonstrate substantial similarities between the microbiology of such pleural infections and that of odontogenic infections, odontogenic bacteremia, and community-acquired brain abscesses.

CONCLUSIONS

Oral-type pleural infection is the most common type of community-acquired pleural infection. Current evidence supports hematogenous seeding of bacteria from a dental focus as the most important underlying etiology. Streptococcus intermedius and Fusobacterium nucleatum most likely represent key pathogens necessary for establishing the infection.

Antimicrobial resistance pattern of anaerobic bacteria causing lower respiratory tract infections

BACKGROUND

Anaerobes are normal flora of the human body. However, they can cause serious infections in humans. Anaerobic bacteria are known to cause respiratory infections like pneumonia and acute exacerbation of chronic lower airway infections. These are often missed due to the complexity of their isolation and identification. Hence, this study aimed to study anaerobes causing respiratory tract infections and determine their antibiotic susceptibility.

MATERIALS & METHODS

Clinical specimens such as bronchial aspirates and pleural aspirates collected from patients with respiratory diseases attending Vallabhbhai Patel Chest Institute were processed, the anaerobes isolated were identified, and their susceptibilities to various groups of antimicrobials were studied using standard microbiological methods.

RESULTS

Three hundred and fourteen patients were included in the study, 154 males and 160 females. Of these 314 patients, 148 (47%) yielded anaerobes in their clinical samples. Seventy patients had more than one type of anaerobic organism. Hence, 235 isolates were recovered belonging to as many as 17 genera. The MIC of seven antibiotics on 154 isolates was tested. The isolates belonged mostly to the genera Bacteroides, Prevotella, Veillonella, and Actinomyces. Variable resistance was observed to most classes of antibiotics by many genera.

CONCLUSIONS

Metronidazole is commonly used against anaerobes, but the study showed that the isolates were 20-30% resistant to the antibiotic. Starting this as an empirical therapy might lead to treatment failure.

Management of pneumonia in the critically ill

Pneumonias continue to be major public health issues and are commonly encountered in the intensive care setting. The most common types of pneumonia leading to critical illness include severe community acquired pneumonia, hospital acquired pneumonia, and ventilator associated pneumonia. Early evaluation, diagnosis, and escalation to appropriate levels of care are imperative to improving survival. Treatment remains challenging with the need to balance antibiotic stewardship and minimizing patient harm. As evidenced in the most recent society guidelines, the identification of risk factors for severe disease and the causative pathogens are crucial in guiding the most appropriate therapy.

The Clinical Significance of Anaerobic Coverage in the Antibiotic Treatment of Aspiration Pneumonia: A Systematic Review and Meta-Analysis

INTRODUCTION

Aspiration pneumonia is increasingly recognised as a common condition. While antibiotics covering anaerobes are thought to be necessary based on old studies reporting anaerobes as causative organisms, recent studies suggest that it may not necessarily benefit prognosis, or even be harmful. Clinical practice should be based on current data reflecting the shift in causative bacteria. The aim of this review was to investigate whether anaerobic coverage is recommended in the treatment of aspiration pneumonia.

METHODS

A systematic review and meta-analysis of studies comparing antibiotics with and without anaerobic coverage in the treatment of aspiration pneumonia was performed. The main outcome studied was mortality. Additional outcomes were resolution of pneumonia, development of resistant bacteria, length of stay, recurrence, and adverse effects. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed.

RESULTS

From an initial 2523 publications, one randomised control trial and two observational studies were selected. The studies did not show a clear benefit of anaerobic coverage. Upon meta-analysis, there was no benefit of anaerobic coverage in improving mortality (Odds ratio 1.23, 95% CI 0.67-2.25). Studies reporting resolution of pneumonia, length of hospital stay, recurrence of pneumonia, and adverse effects showed no benefit of anaerobic coverage. The development of resistant bacteria was not discussed in these studies.

CONCLUSION

In the current review, there are insufficient data to assess the necessity of anaerobic coverage in the antibiotic treatment of aspiration pneumonia. Further studies are needed to determine which cases require anaerobic coverage, if any.

Diagnosis and treatment of stroke associated pneumonia: Qualitative exploration of clinicians’ practice

<b>Background:</b> Establishing and implementing a gold standard criteria for diagnosing and treating stroke-associated pneumonia (SAP) would have a significant positive impact on stroke outcomes and antibiotic stewardship. This study aimed to qualitatively explore current diagnostic and treatment practice for SAP among clinicians.<br /> <b>Methods: </b>A qualitative study was employed to conduct semi-structured interviews at the tertiary-care Jordan University Hospital. A purposive sampling technique was employed to recruit the participants, including respiratory consultants (n=3) and residents (n=9) practicing in the internal medicine wards and intensive care unit, where stroke patients are treated. The interviews were audio-recorded, transcribed verbatim, translated, and analyzed thematically using framework analysis.<br /> <b>Results:</b> Clinicians expressed their experiences, which were organized into two themes and eight emerged sub-themes: Terminology and diagnostic approach of SAP involved; no definite terminology, reliance on both clinical evidence and X-ray findings to decide, reliance on clinical evidence alone to suspect SAP and initiate empirical therapy, and SAP overdiagnosis. The treatment strategies include early treatment of SAP, treating SAP the same as CAP/HAP, predominant anaerobes coverage, and SAP overtreatment.<br /> <b>Conclusion:</b><i> </i>Our findings show a wide range of physician-based diagnostic and treatment approaches for SAP, with clinical criteria serving as the main driver for antibiotic initiation. Standard validated algorithmic-based criteria need to be established and implemented.

The association between empiric antimicrobial therapy and the risk of clinical failure in critically ill patients with aspiration pneumonia

WHAT IS KNOWN AND OBJECT

Aspiration pneumonia is a clinically important infectious process that can result in increased morbidity and mortality. Empiric antimicrobial therapy with activity against anaerobes has been a standard practice based on previous studies, which isolated anaerobes from respiratory cultures. Recent studies have failed to identify anaerobes as causative pathogens, however, these studies did not assess patient outcomes based on the presence or absence of anaerobic coverage.

METHODS

This retrospective cohort study evaluated patients at least 18 years of age requiring mechanical ventilation diagnosed with aspiration pneumonia between 1 October 2020 and 31 July 2021. The primary outcome was the incidence of clinical failure. Secondary outcomes included the time to clinical failure, the incidence of Clostridioides difficile infections and development of multidrug-resistant infections, as well as time on mechanical ventilation and intensive care unit length of stay.

RESULTS

A total of 141 patients were included with 83 patients initially receiving anaerobic coverage and 58 patients treated without anaerobic coverage. There was no difference in the incidence of clinical failure between cohorts (18.1% vs. 22.4%; p = 0.41). There was a statistically significant difference in anaerobic escalations with more escalations in the cohort without anaerobic coverage (0% vs. 20.7%; p < 0.0001). Patients initially treated with drugs with anaerobic activity had a higher incidence of multidrug resistant infections on current admission (7.2% vs. 0%; p = 0.04) and a longer length of intensive care unit stay.

WHAT IS NEW AND CONCLUSION

In critically ill adults with aspiration pneumonia, our study found no difference in clinical failure based on the presence or absence of empiric anaerobic coverage adding to evolving literature suggesting that anaerobic coverage is not routinely warranted in this patient population. Interpretation of the results needs to consider, however, that the retrospective design led to the inclusion of sicker patients in the anaerobic cohort. The frequency of empiric anaerobic coverage demonstrates the need for a prospective randomized control trial to confirm these findings.

Nosocomial Pneumonia in the Mechanically Ventilated Patient

Ventilator-associated pneumonia (VAP) is a common complication occurring in critically ill patients who are mechanically ventilated and is the leading cause of nosocomial infection-related death. Etiologic agents for VAP widely differ based on the population of intensive care unit patients, duration of hospital stay, and prior antimicrobial therapy. VAP due to multidrug-resistant pathogens is associated with the highest morbidity and mortality, likely due to delays in appropriate antimicrobial treatment. International guidelines are currently available to guide diagnostic and therapeutic strategies. VAP can be prevented through various pharmacological and non-pharmacological interventions, which are more effective when grouped as bundles. When VAP is clinically suspected, diagnostic strategies should include early collection of respiratory samples to guide antimicrobial therapy. Empirical treatment should be based on the most likely etiologic microorganisms and antibiotics likely to be active against these microorganisms. Response to therapy should be reassessed after 3 to 5 days and antimicrobials adjusted or de-escalated to reduce the burden of the disease. Finally, considering that drug resistance is increasing worldwide, several novel antibiotics are being tested to efficiently treat VAP in the coming decades.

Stroke and Pneumonia: Mechanisms, Risk Factors, Management, and Prevention

A stroke is a cerebrovascular medical emergency characterized by the sudden loss of neurological function due to interruption to the blood supply. A serious and common complication of stroke is pneumonia. This review article outlined various studies in order to understand the pathogenesis pathways that lead to the development of stroke-associated pneumonia, as well as therapeutic and preventive options to reduce pneumonia. The article looked for risk factors that increase the risk of developing pneumonia among stroke patients. In addition, it has reviewed various therapeutic modalities, such as postural modifications, pharmacological treatment, and other unique treatments, in an attempt to find which of them are efficient to decrease the occurrence of pneumonia and which of them are not. The article also attempts to emphasize the importance of early screening for dysphagia among stroke patients and demonstrates the importance of preventive strategies that can be easily implemented, such as routine oral care and behavioral modifications.

Significance of Antimicrobial Prophylaxis for the Prevention of Early-Onset Pneumonia After Radical Esophageal Cancer Resection: A Retrospective Analysis of 356 Patients Undergoing Thoracoscopic Esophagectomy

BACKGROUND

Postoperative pneumonia is a common complication after esophagectomy and is associated with a high mortality rate. Although many randomized, controlled trials have been conducted on the prevention of postoperative pneumonia, little attention has been paid to the efficacy of antimicrobial prophylaxis. The purpose of this study was to investigate the impact of antimicrobial prophylaxis on the prevention of postoperative pneumonia.

METHODS

Data of patients with esophageal cancer who underwent thoracoscopic esophagectomy between 2016 and 2020 were collected. Early-period patients received cefazolin (CEZ) per protocol as antimicrobial prophylaxis (n = 250), and later-period patients received ampicillin/sulbactam (ABPC/SBT) (n = 106) because of the unavailability of CEZ in Japan. The incidence of pneumonia was compared between treatments in this quasi-experimental setting. Pneumonia detected by routine computed tomography (CT) on postoperative Days 5-6 was defined as early-onset pneumonia, and pneumonia that developed later was defined as late-onset pneumonia.

RESULTS

The incidence of early-onset pneumonia was significantly lower (3.8% vs. 13.6%, P = 0.006), and the median length of postoperative hospital stay was significantly shorter (17 vs. 20 days, P < 0.001) in the ABPC/SBT group than in the CEZ group. The incidence of late-onset pneumonia was similar between groups (9.4% vs. 10.0%, P = 0.870). The incidence of Clostridioides difficile infections and the incidence of multidrug-resistant organisms were similar between groups. Multivariate analyses consistently showed the superiority of ABPC/SBT to CEZ in preventing early-onset pneumonia (odds ratio: 0.20, P = 0.006).

CONCLUSIONS

ABPC/SBT after esophagectomy was better at preventing early-onset pneumonia compared with CEZ and was feasible regarding the development of antimicrobial resistance.

Successful management of aspiration pneumopathy without antimicrobial agents: 14 dogs (2014-2021)

OBJECTIVES

To describe clinical cases of aspiration pneumonitis and pneumonia in dogs, which were successfully managed without antimicrobials.

MATERIALS AND METHODS

Retrospective case review of dogs presenting to a referral teaching hospital between February 2014 and February 2021. Cases were included when a clinical diagnosis of aspiration pneumopathy was made (requiring one or more of the following: radiographic evidence of an aspiration pneumopathy, endotracheal airway sampling consistent with aspiration and/or a positive endotracheal airway sample culture) which was not treated with antimicrobial therapy.

RESULTS

Fourteen cases were identified of which nine had respiratory signs including increased respiratory rate or effort (n=8), arterial hypoxaemia (n=2), or a clinician-determined requirement for oxygen therapy (n=4). Where haematology was performed, five of nine displayed a normal neutrophil count with toxic changes, three displayed neutrophilia and one displayed neutropenia with toxic changes. Endotracheal airway sample cytology in four cases revealed neutrophilic inflammation with bacteria, plant material, yeasts and unidentified foreign material. Where respiratory signs were present, these resolved within 12 to 36 hours.

CLINICAL SIGNIFICANCE

In this case series, immunocompetent dogs sustaining aspiration events, even with classical evidence of pneumonitis or pneumonia, have been managed successfully without antimicrobials. Radiography alone cannot be used to determine the requirement for antimicrobials. Better characterisation of the pathogenesis and clinical trajectory of aspiration pneumopathy is required, which may enable a reduction in inappropriate antimicrobial prescriptions.

Infections in Older Adults

Infections in elderly patients can prove diagnostically challenging. Age-related factors affecting the immune system in older individuals contribute to nonspecific presentations. Other age-related factors and chronic conditions have symptoms that may or may not point to an infectious diagnosis. Delay in administration of antimicrobials can lead to poor outcomes; however, unnecessary administration of antimicrobials can lead to increased morbidity and contribute to the emergence of multidrug-resistant organisms. Careful clinical assessment and consideration of patient history and risk factors is crucial. When necessary, antimicrobials should be chosen that are appropriate for the diagnosis and deescalated as soon as possible.

Aspiration Risk Factors, Microbiology, and Empiric Antibiotics for Patients Hospitalized With Community-Acquired Pneumonia

BACKGROUND

Aspiration community-acquired pneumonia (ACAP) and community-acquired pneumonia (CAP) in patients with aspiration risk factors (AspRFs) are infections associated with anaerobes, but limited evidence suggests their pathogenic role.

RESEARCH QUESTION

What are the aspiration risk factors, microbiology patterns, and empiric anti-anaerobic use in patients hospitalized with CAP?

STUDY DESIGN AND METHODS

This is a secondary analysis of GLIMP, an international, multicenter, point-prevalence study of adults hospitalized with CAP. Patients were stratified into three groups: (1) ACAP, (2) CAP/AspRF+ (CAP with AspRF), and (3) CAP/AspRF- (CAP without AspRF). Data on demographics, comorbidities, microbiological results, and anti-anaerobic antibiotics were analyzed in all groups. Patients were further stratified in severe and nonsevere CAP groups.

RESULTS

We enrolled 2,606 patients with CAP, of which 193 (7.4%) had ACAP. Risk factors independently associated with ACAP were male, bedridden, underweight, a nursing home resident, and having a history of stroke, dementia, mental illness, and enteral tube feeding. Among non-ACAP patients, 1,709 (70.8%) had CAP/AspRF+ and 704 (29.2%) had CAP/AspRF-. Microbiology patterns including anaerobes were similar between CAP/AspRF-, CAP/AspRF+ and ACAP (0.0% vs 1.03% vs 1.64%). Patients with severe ACAP had higher rates of total gram-negative bacteria (64.3% vs 44.3% vs 33.3%, P = .021) and lower rates of total gram-positive bacteria (7.1% vs 38.1% vs 50.0%, P < .001) when compared with patients with severe CAP/AspRF+ and severe CAP/AspRF-, respectively. Most patients (>50% in all groups) independent of AspRFs or ACAP received specific or broad-spectrum anti-anaerobic coverage antibiotics.

INTERPRETATION

Hospitalized patients with ACAP or CAP/AspRF+ had similar anaerobic flora compared with patients without aspiration risk factors. Gram-negative bacteria were more prevalent in patients with severe ACAP. Despite having similar microbiological flora between groups, a large proportion of CAP patients received anti-anaerobic antibiotic coverage.

Antibiotics for Aspiration Pneumonia in Neurologically Impaired Children

OBJECTIVE

To compare hospital outcomes associated with commonly used antibiotic therapies for aspiration pneumonia in children with neurologic impairment (NI).

DESIGN/METHODS

A retrospective study of children with NI hospitalized with aspiration pneumonia at 39 children's hospitals in the Pediatric Health Information System database. Exposure was empiric antibiotic therapy classified by antimicrobial activity. Outcomes included acute respiratory failure, intensive care unit (ICU) transfer, and hospital length of stay (LOS). Multivariable regression evaluated associations between exposure and outcomes and adjusted for confounders, including medical complexity and acute illness severity.

RESULTS

In the adjusted analysis, children receiving Gram-negative coverage alone had two-fold greater odds of respiratory failure (odds ratio [OR] 2.15; 95% CI: 1.41-3.27), greater odds of ICU transfer (OR 1.80; 95% CI: 1.03-3.14), and longer LOS [adjusted rate ratio (RR) 1.28; 95% CI: 1.16-1.41] than those receiving anaerobic coverage alone. Children receiving anaerobic and Gram-negative coverage had higher odds of respiratory failure (OR 1.65; 95% CI: 1.19-2.28) than those receiving anaerobic coverage alone, but ICU transfer (OR 1.15; 95% CI: 0.73-1.80) and length of stay (RR 1.07; 95% CI: 0.98-1.16) did not statistically differ. For children receiving anaerobic, Gram-negative, and P. aeruginosa coverage, LOS was shorter (RR 0.83; 95% CI: 0.76-0.90) than those receiving anaerobic coverage alone; odds of respiratory failure and ICU transfer rates did not significantly differ.

CONCLUSIONS

Anaerobic therapy appears to be important in the treatment of aspiration pneumonia in children with NI. While Gram-negative coverage alone was associated with worse outcomes, its addition to anaerobic therapy may not yield improved outcomes.

Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America

Background: This document provides evidence-based clinical practice guidelines on the management of adult patients with community-acquired pneumonia.

Methods: A multidisciplinary panel conducted pragmatic systematic reviews of the relevant research and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology for clinical recommendations.

Results: The panel addressed 16 specific areas for recommendations spanning questions of diagnostic testing, determination of site of care, selection of initial empiric antibiotic therapy, and subsequent management decisions. Although some recommendations remain unchanged from the 2007 guideline, the availability of results from new therapeutic trials and epidemiological investigations led to revised recommendations for empiric treatment strategies and additional management decisions.

Conclusions: The panel formulated and provided the rationale for recommendations on selected diagnostic and treatment strategies for adult patients with community-acquired pneumonia.

Dynamics of microbiota during mechanical ventilation in aspiration pneumonia

BACKGROUND

The emergence of multi-drug resistant pathogens is an urgent health-related problem, and the appropriate use of antibiotics is imperative. It is often difficult to identify the causative bacteria in patients with aspiration pneumonia because tracheal aspirate contains contaminants of oral bacteria. We investigated the dynamics of microbiota in mechanically ventilated patients with aspiration pneumonia to develop a treatment strategy.

METHODS

Twenty-two intubated patients with aspiration pneumonia were recruited. Saliva and tracheal aspirate of the subjects were collected at three time points: (A) within 2 h after intubation, (B) just before administration of antibiotics, and (C) 48-72 h after administration of antibiotics. The microbiota in each specimen was analyzed by using the 16S rRNA gene clone library sequencing method. Bacterial floras of the samples were analyzed by principal component analysis.

RESULTS

Principal component analysis based on the composition of genus revealed that although the changes of microbiota in the saliva from (A) to (B) were not clear, the composition of anaerobes in the tracheal aspirate (B) was lower than (A). In fact, the reduction of anaerobes, not in the saliva but in the tracheal aspirate from (A) to (B), was confirmed by incident rate ratios estimated by a multilevel Poisson regression model (p < 0.001). The extent of decrease in anaerobes was fully dependent on the time difference between the sampling of tracheal aspirate (A) and (B)-in particular, over 3 h of mechanical ventilation. This indicates that the alterations of microbiota (involving the reduction of anaerobes in the lower respiratory tract) occurred during mechanical ventilation prior to the administration of antibiotics. After the administration of antibiotics, Enterobacter spp., Corynebacterium spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Granulicatera adiacens were predominantly detected in the tracheal aspirate (C).

CONCLUSION

The microbiota of the lower respiratory tract changes dynamically during mechanical ventilation and during the administration of antibiotics in intubated patients with aspiration pneumonia. Antibiotics should be selected on the premise that dynamic changes in microbiota (involved in the reduction of anaerobes) may occur during the mechanical ventilation in these patients.

Ceftriaxone versus ampicillin/sulbactam for the treatment of aspiration-associated pneumonia in adults

Aim: To compare hospital mortality in patients with aspiration-associated pneumonia treated with ceftriaxone (CTRX) and in those treated with ampicillin/sulbactam (ABPC/SBT). Methods: From a Japanese multicentre observational study cohort of patients with pneumonia, those diagnosed with pneumonia and having at least one aspiration-related risk factor were selected. Propensity score-matching analysis was used to balance baseline characteristics of the participants and compare hospital mortality of patients treated with CTRX and those treated with ABPC/SBT. Results: Hospital mortality did not significantly differ between patients treated with CTRX and those treated with ABPC/SBT (6.6 vs 10.7%, risk difference -4.0, 95% CI [-9.4, 1.3]; p = 0.143). Conclusion: Further studies are needed to compare CTRX and ABPC/SBT treatments in patients with aspiration-associated pneumonia.

Randomized Noninferiority Trial of Cefoperazone-Sulbactam versus Cefepime in the Treatment of Hospital-Acquired and Healthcare-Associated Pneumonia

Cefoperazone, a third-generation cephamycin with broad-spectrum antibacterial activity and the ability to permeate bacterial cell membranes, is active against commonly encountered multidrug-resistant pathogens for hospital-acquired pneumonia (HAP) and health care-associated pneumonia (HCAP). To clarify the clinical effects of cefoperazone-sulbactam in the treatment of HAP and HCAP, we conducted an open-label, randomized, noninferiority trial that recruited patients aged ≥18 years suffering HAP/HCAP. Participants were randomly assigned to the cefoperazone-sulbactam (2 g of each per 12 h) or cefepime (2 g per 12 h) arm. Clinical and microbiological responses were evaluated at early posttherapy and test-of-cure visits. Recruited patients were allocated to subpopulations for intent-to-treat (n = 154), per-protocol (n = 147), and safety (n = 166) analyses. Intent-to-treat analysis demonstrated that (i) at the early posttherapy visit, 87.3% of patients receiving cefoperazone-sulbactam and 84.3% of patients receiving cefepime achieved clinical improvement or cure (risk difference of 3.0%; 95% confidence interval [CI], -9.0% to 15.0%), and (ii) at the test-of-cure visit, 73.1% of patients receiving cefoperazone-sulbactam and 56.8% of patients receiving cefepime were assessed as cured (risk difference of 16.3%; 95% CI, 0.0% to 33.0%). These results indicated the noninferiority of cefoperazone-sulbactam to cefepime, which was confirmed by per-protocol analysis. The chest radiographic consolidation/infiltration resolution rate, microbiological eradiation rate, and percentage of adverse events were comparable in both groups. Serious adverse events were rare, and none was judged to be related to the study drugs. Cefoperazone-sulbactam at 2 g every 12 h was noninferior to cefepime at 2 g every 2 h for patients with HCAP.

New bacterial growth in bronchial secretions after bronchoscopic valve implantation

Background

Bronchoscopic valve implantation is an established treatment in selected patients with severe lung emphysema. There is evidence in literature of increased bacterial colonization of various implants. So far, it is unclear if an increased bacterial colonization can also be observed after endoscopic valve therapy.

Methods

Retrospective analysis of patients with examination of the bronchial secretions for presence or change of bacterial growth before and after valve implantation.

Results

Overall, 144 patients who underwent bronchoscopic follow-up after valve implantation were included in this analysis. Prior to valve placement, only 7 out of 144 consecutive emphysema patients (5%) presented with evidence of bacterial colonization, whereas 137 patients (95%) showed no bacterial growth prior to valve placement. One hundred seven out of the 137 patients (78%) showed new bacterial growth after valve implantation. Almost 38% of the patients who presented with a new bacterial growth had evidence of Viridans streptococci, Rothia mucilaginousa and Neisseria species simultaneously, as bacterial colonization. Pathogenic bacterial growth was recorded for Staphylococcus aureus (18%), Pseudomonas aeruginosa (13%) and Stenotrophomonas maltophilia (9%) microorganisms. There was also a significant bacterial growth by Moraxella catarrhalis (26%) and anaerobic bacteria (23%), especially in patients with complete atelectasis after successful endoscopic lung volume reduction. For all of the 7 patients, the presented initial bacterial colonization showed a change in the flora after bronchoscopy valve implantation.

Conclusion

In this study we observed an increased bacterial colonization in the long term after valve implantation. This finding needs further evaluation regarding its possible clinical relevance but should be taken into consideration in the follow-up of these patients.

Anaerobic antibiotic usage for pneumonia in the medical intensive care unit

BACKGROUND AND OBJECTIVE

Pneumonia is a common admitting diagnosis in the intensive care unit (ICU). When aspiration is suspected, antibiotics to cover anaerobes are frequently used, but in the absence of clear risk factors, current guidelines have questioned their role. It is unknown how frequently these guidelines are followed.

METHODS

We conducted a single-centre observational study on practice patterns of anaerobic antibiotic use in consecutive patients admitted to the ICU with aspiration pneumonia (Asp), community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP).

RESULTS

A total of 192 patients were studied (Asp: 20, HCAP: 107, CAP: 65). Overall, 59 patients received anaerobic antibiotics (Asp: 90%, HCAP: 28%, CAP 17%) but a significant proportion of these patients did not meet criteria to receive them. Inappropriate anaerobic antibiotic use was 12/20 for Asp, 27/107 for HCAP and 9/65 for CAP. Mortality probability model III at zero hours (MPM0) score and a diagnosis of Asp were predictors of receiving inappropriate anaerobic antibiotics. Receiving inappropriate anaerobic antibiotics was associated with a longer ICU length of stay (LOS; 7 days (interquartile range (IQR): 7-21) vs 4 days (IQR:2-9), P = 0.017).

CONCLUSION

For patients in the ICU admitted with pneumonia, there is a high occurrence of inappropriately prescribed anaerobic antibiotics, the use of which was associated with a longer ICU LOS.

Aspiration Pneumonia in the Dog: A Review

OBJECTIVE

To review the human and veterinary literature pertaining to aspiration pneumonitis and pneumonia.

MATERIAL AND METHODS

Data sources included scientific reviews and original research publications from the human and veterinary literature. All reviews and studies that added to the understanding of aspiration pneumonia were included.

RESULTS

Compared to human medicine, aspiration pneumonia can be difficult to diagnose in the canine patient and is often a diagnosis of presumption. Multiple risk factors exist increasing the likelihood of aspiration pneumonia and a thorough understanding of these can aid in prevention. Treatment recommendations center primarily on supportive care, oxygen therapy and antibiotic administration.

CLINCIAL SIGNIFICANCE

Aspiration pneumonia is a common finding in the canine patient and a thorough understanding of the disease will lead to better treatment outcomes. Further studies on treatment and prevention in veterinary medicine are warranted.

New horizons in hospital acquired pneumonia in older people

Approximately 1.5% of hospital patients develop hospital acquired pneumonia. Aspiration is the major risk factor for pneumonia and is associated with reduced ability to mechanically clear respiratory pathogens into the stomach. Currently non-invasive methods of diagnosing hospital acquired pneumonia are less robust than invasive methods, and lead to over-diagnosis. Accurate diagnosis is key to surveillance, prevention and treatment of HAP, and also to improving outcomes; newer imaging modalities such as phase contrast X-ray imaging and nanoparticle enhanced magnetic resonance imaging may help. Potential preventative strategies such as systematic swallowing assessment in non-stroke patients, and interventions such as improving oral hygiene need further, robust randomised controlled trials. Antibiotics are likely to continue to be the mainstay of treatment, and new antibiotics such as ceftobiprole are likely to have a role in treating hospital acquired pneumonia. Given the spread of antimicrobial resistance, alternative treatment strategies including bacteriophages, peptides and antibodies are under investigation. Reducing the incidence of hospital acquired pneumonia could decrease length of hospital stay, reduce inappropriate antibiotic use, and both improve functional outcomes and mortality in our increasingly aged population.

Pneumonitis and pneumonia after aspiration

Aspiration pneumonitis and aspiration pneumonia are clinical syndromes caused by aspiration. These conditions are clinically significant due to their high morbidity and mortality. However, aspiration as a preceding event are often unwitnessed, particularly in cases of asymptomatic or silent aspiration. Furthermore, despite the difference in treatment approaches for managing aspiration pneumonitis and aspiration pneumonia, these two disease entities are often difficult to discriminate from one another, resulting in inappropriate treatment. The use of unclear terminologies hinders the comparability among different studies, making it difficult to produce evidence-based conclusions and practical guidelines. We reviewed the most recent studies to define aspiration, aspiration pneumonitis, and aspiration pneumonia, and to further assess these conditions in terms of incidence and epidemiology, pathophysiology, risk factors, diagnosis, management and treatment, and prevention.

Pseudomonas aeruginosa identified as a key pathogen in hospitalised children with aspiration pneumonia and a high aspiration risk

AIM

Data on the causative pathogens and optimal empirical therapy of aspiration pneumonia in children are limited. This study sought to describe the bacteriology of aspiration pneumonia in hospitalised children with a high aspiration risk.

METHODS

Respiratory tract specimens were prospectively collected using the induced sputum technique from children with a high aspiration risk who were hospitalised for aspiration pneumonia in a tertiary paediatric medical centre from 2009 to 2014. Clinical, microbiological and treatment data were recorded and analysed for each admission.

RESULTS

The cohort comprised 50 children with 235 hospital admissions. Of the 183 respiratory tract cultures performed, 110 were positive for bacteria, with 169 isolates, mostly Gram-negative. The most common Gram-negative pathogen was Pseudomonas aeruginosa. If patients had Pseudomonas aeruginosa isolation, the risk of them having the pathogen again was 81%. The multivariate analysis showed that the use of antibiotic prophylaxis and number of hospitalisations were significantly associated with Pseudomonas aeruginosa isolation.

CONCLUSION

Gram-negative bacilli, especially Pseudomonas aeruginosa, were the major causative agents of paediatric aspiration pneumonia in our study. Empiric antipseudomonas treatment should be considered, particularly in patients who are receiving antibiotic prophylaxis, have experienced recurrent hospitalisations or with previous respiratory cultures that showed Pseudomonas aeruginosa isolation.

Characteristics of Children Hospitalized With Aspiration Pneumonia

OBJECTIVES

Unlike community-acquired pneumonia (CAP), there is a paucity of data characterizing the patient demographics and hospitalization characteristics of children with aspiration pneumonia. We used a large national database of US children's hospitals to assess the patient and hospitalization characteristics associated with aspiration pneumonia and compared these characteristics to patients with CAP.

METHODS

We identified children hospitalized with a diagnosis of aspiration pneumonia or CAP at 47 hospitals included in the Pediatric Health Information System between 2009 and 2014. We evaluated whether differences exist in patient characteristics (median age and proportion of patients with a complex chronic condition), and hospital characteristics (length of stay, ICU admission, cost, and 30-day readmission rate) between children with aspiration pneumonia and CAP. Lastly, we assessed whether seasonal variability exists within these 2 conditions.

RESULTS

Over the 6-year study period, there were 12 097 children hospitalized with aspiration pneumonia, and 121 489 with CAP. Compared with children with CAP, children with aspiration pneumonia were slightly younger and more likely to have an associated complex chronic condition. Those with aspiration pneumonia had longer hospitalizations, higher rates of ICU admission, and higher 30-day readmission rates. Additionally, the median cost for hospitalization was 2.4 times higher for children with aspiration pneumonia than for children with CAP. More seasonal variation was observed for CAP compared with aspiration pneumonia hospitalizations.

CONCLUSIONS

Aspiration pneumonia preferentially affects children with medical complexity and, as such, accounts for longer and more costly hospitalizations and higher rates of ICU admission and readmission rates.

The significance of oral streptococci in patients with pneumonia with risk factors for aspiration: the bacterial floral analysis of 16S ribosomal RNA gene using bronchoalveolar lavage fluid

Background

Aspiration pneumonia has been a growing interest in an aging population. Anaerobes are important pathogens, however, the etiology of aspiration pneumonia is not fully understood. In addition, the relationship between the patient clinical characteristics and the causative pathogens in pneumonia patients with aspiration risk factors are unclear. To evaluate the relationship between the patient clinical characteristics with risk factors for aspiration and bacterial flora in bronchoalveolar lavage fluid (BALF) in pneumonia patients, the bacterial floral analysis of 16S ribosomal RNA gene was applied in addition to cultivation methods in BALF samples.

Methods

From April 2010 to February 2014, BALF samples were obtained from the affected lesions of pneumonia via bronchoscopy, and were evaluated by the bacterial floral analysis of 16S rRNA gene in addition to cultivation methods in patients with community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP). Factors associated with aspiration risks in these patients were analyzed.

Results

A total of 177 (CAP 83, HCAP 94) patients were enrolled. According to the results of the bacterial floral analysis, detection rate of oral streptococci as the most detected bacterial phylotypes in BALF was significantly higher in patients with aspiration risks (31.0 %) than in patients without aspiration risks (14.7 %) (P = 0.009). In addition, the percentages of oral streptococci in each BALF sample were significantly higher in patients with aspiration risks (26.6 ± 32.0 %) than in patients without aspiration risks (13.8 ± 25.3 %) (P = 0.002). A multiple linear regression analysis showed that an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of ≥3, the presence of comorbidities, and a history of pneumonia within a previous year were significantly associated with a detection of oral streptococci in BALF.

Conclusions

The bacterial floral analysis of 16S rRNA gene revealed that oral streptococci were mostly detected as the most detected bacterial phylotypes in BALF samples in CAP and HCAP patients with aspiration risks, especially in those with a poor ECOG-PS or a history of pneumonia.

Early-onset pneumonia after out-of-hospital cardiac arrest

Early-onset pneumonia (EOP) is a common complication after successful cardiopulmonary resuscitation. Currently, EOP diagnosis is difficult because usual diagnostic tools are blunted by the features of post-cardiac arrest syndrome and therapeutic hypothermia itself. When the diagnosis of EOP is suspected, empiric antimicrobial therapy should be considered following bronchopulmonary sampling. The onset of EOP increases the length of mechanical ventilation duration and intensive care unit stay, but its influence on survival and neurological outcome seems marginal. Therapeutic hypothermia has been recognized as an independent risk factor for this infectious complication. All together, these observations underline the need for future prospective clinical trials to better delineate pathogens and risk factors associated with EOP. In addition, there is a need for diagnostic approaches serving the accurate diagnosis of EOP.

The bacterial pneumonias: a new treatment paradigm

Pneumonia is a common disease that carries a high mortality. Traditionally, pneumonia has been classified and treated according to the setting where the pneumonia develops, namely community-acquired pneumonia, health-care-associated pneumonia, and hospital-acquired pneumonia. This classification was based on the risk of a patient being infected with a hospital-acquired drug-resistant pathogen. A new treatment paradigm has been proposed based on the risk of the patient being infected with a community-acquired drug-resistant pathogen. The risk factors for infection with a community-acquired drug-resistant pathogen include (1) hospitalization for > 2 days during the previous 90 days, (2) antibiotic use during the previous 90 days, (3) nonambulatory status, (4) tube feeds, (5) immunocompromised status, (6) use of acid-suppressive therapy, (7) chronic hemodialysis during the preceding 30 days, (8) positive methicillin-resistant Staphylococcus aureus history within the previous 90 days, and (9) present hospitalization > 2 days. This article reviews this new treatment paradigm and other issues relevant to the diagnosis and management of pneumonia based on information from MEDLINE, EMBASE, and the Cochrane Register of Controlled Trials.

Nosokomiale Pneumonie – Antibiotikatherapie und hygienische Interventionsstrategien

Die Pneumonie ist auch in unserer Zeit eine schwere Infektionskrankheit. Sie ist eine der häufigsten infektiösen Todesursachen der westlichen Industrieländer und steht an 3. Stelle unter den Infektionskrankheiten. Jede 4. ärztlich diagnostizierte Pneumonie ist nosokomial erworben. Nosokomiale Pneumonien führen neben einer verlängerten Morbidität und erhöhten Letalität zu einer Verlängerung der Krankenhausverweildauer und zu erheblichen Kosten.

Bacteriology of aspiration pneumonia in patients with acute coma

Loss of protective airway reflexes in patients with acute coma puts these patients at risk of aspiration pneumonia complicating the course of the primary disease. Available data vary considerably with regard to bacteriology, role of anaerobic bacteria, and antibiotic treatment. Our objective was to research the bacteriology of aspiration pneumonia in acute coma patients who were not pre-treated with antibiotics or hospitalized within 30 days prior to the event. We prospectively analyzed 127 patient records from adult patients admitted, intubated and ventilated to a tertiary medical intensive care unit with acute coma. Bacteriology and antibiotic resistance testing from tracheal aspirate sampled within 24 h after admission, blood cultures, ICU scores (APACHE II, SOFA), hematology, and clinical chemistry were assessed. Patients were followed up until death or hospital discharge. The majority of patients with acute coma suffered from acute cardiovascular disorders, predominantly myocardial infarction, followed by poisonings, and coma of unknown cause. In a majority of our patients, microaspiration resulted in overt infection. Most frequently S. aureus, H. influenzae, and S. pneumoniae were isolated. Anaerobic bacteria (Bacteroides spec., Fusobacteria, Prevotella spec.) were isolated from tracheal aspirate in a minority of patients, and predominantly as part of a mixed infection. Antibiotic monotherapy with a 2nd generation cephalosporin, or a 3rd generation gyrase inhibitor, was most effective in our patients regardless of the presence of anaerobic bacteria.

Aspiration-related deaths in 57 consecutive patients: autopsy study

Background

Aspiration can cause a diverse spectrum of pulmonary disorders some of which can lead to death but can be difficult to diagnose.

Patients and Methods

The medical records and autopsy findings of 57 consecutive patients in whom aspiration was the immediate cause of death at Mayo Clinic (Rochester, MN, USA) over a 9-yr period, from January 1 2004 to December 31 2012 were analyzed.

Results

The median age at death was 72 years (range, 13–95 years) and included 39 (68%) males. The most common symptom before death was dyspnea (63%) and chest radiography revealed bilateral infiltrates in the majority (81%). Most common precipitating factors for aspiration were depressed consciousness (46%) and dysphagia (44%). Aspiration-related syndromes leading to death were aspiration pneumonia in 26 (46%), aspiration pneumonitis in 25 (44%), and large airway obstruction in 6 patients (11%). Aspiration was clinically unsuspected in 19 (33%) patients. Antimicrobial therapy had been empirically administered to most patients (90%) with aspiration pneumonia and aspiration pneumonitis.

Conclusion

We conclude aspiration-related deaths occur most commonly in the elderly with identifiable risks and presenting bilateral pulmonary infiltrates. One-third of these aspiration-related pulmonary syndromes were clinically unsuspected at the time of death.

Risk factors for aspiration in community-acquired pneumonia: analysis of a hospitalized UK cohort

BACKGROUND

There is a move toward finding clinically useful "phenotypes" in community-acquired pneumonia: groups of patients displaying distinct clinical characteristics, microbiology, and prognosis. Aspiration pneumonia is an intuitive clinical phenotype; however, to date there are no recognized diagnostic criteria, and data regarding outcomes in suspected aspiration are limited.

METHODS

An observational study of 1348 patients hospitalized with community-acquired pneumonia in the United Kingdom examined both short- and long-term outcomes for patients at risk of aspiration pneumonia. Patients were defined as "at risk" in the presence of chronic neurologic disorders, esophageal disorders and dysphagia, impaired conscious level, vomiting, or witnessed aspiration. The primary outcome was 30-day mortality. Secondary outcomes included 1-year mortality, readmissions, and recurrent pneumonia within 1 year.

RESULTS

Some 13.8% of the cohort were classified as "at risk of aspiration." These patients were older (median age, 74 years [interquartile range, 60-84] vs 66 years [interquartile range, 49-77]; P < .0001) and more likely to have comorbidities (chronic liver disease 11.3% vs 3.7%, P < .0001; congestive heart failure 28% vs 17.1%, P = .0004; and stroke 26.9% vs 9.5%, P < .0001). Patients at risk of aspiration pneumonia had a poorer short-term outcome (30-day mortality 17.2% vs 7.7%, P < .0001), but after adjusting for their greater severity of illness and comorbidities this difference was not significant (odds ratio 1.05; 95% confidence interval [CI], 0.63-1.76; P = .8). However, patients with aspiration risk factors were at greater risk of poor long-term outcomes with increased 1-year mortality (hazard ratio [HR], 1.73; 95% CI, 1.15-2.58), increased risk of rehospitalization (HR, 1.52; 95% CI, 1.21-1.91), and a strong association with recurrent admissions with pneumonia (HR, 3.13; 95% CI, 2.05-4.78) after multivariable adjustment.

CONCLUSIONS

Using risk factors to identify patients at risk of aspiration pneumonia identifies a distinct clinically useful phenotype of patients with greater severity of disease and poorer long-term outcomes.

Microbiology and prognostic factors of hospital- and community-acquired aspiration pneumonia in respiratory intensive care unit

BACKGROUND

Incidence of aspiration pneumonia in hospital-acquired pneumonia and community-acquired pneumonia is high; however, many features of this disease remain imprecise. Our objective was to characterize the microbial etiology and their antibiotic resistance and to determine the prognostic factors in aspiration pneumonia among patients admitted to a respiratory intensive care unit (RICU).

METHODS

A prospective survey was conducted in 112 patients exhibiting hospital-or community-acquired aspiration pneumonia in the RICU of a provincial general hospital from 2010-2012. Bronchoalveolar lavage sampling was collected, and then followed by standard culture and drug-sensitive test. Risk factors were analyzed by multivariate logistic analysis.

RESULTS

One hundred twenty-eight strains were isolated in 94 patients, gram-negative bacilli (57.8%) was the predominant cultured microorganism, followed by fungus (28.9%) and gram-positive cocci (13.3%). The 5 main isolated bacteria demonstrated high and multiantibiotic resistance. The crude overall mortality was 43.8%, 50%, and 40%, respectively, in hospital- and community-acquired aspiration pneumonia group. Multivariate logistic analysis identified age older than 65 years, use of inotropic support, and ineffective initial therapy as independent risk factors of poor outcome.

CONCLUSIONS

The predominant pathogenic bacteria of aspiration pneumonia in patients admitted to an RICU were antibiotic-resistant bacteria, and effective initial supportive management secured better prognosis.

Anaerobes in nosocomial and community acquired pleural infections

Anaerobes are important causes of pleural space infections. The aim of the study is to evaluate the role of the anaerobic bacteria in pleural infections. The study involved 278 consecutive clinical samples sent to the Clinical Microbiology Laboratory of Tertiary Chest Hospital. Anaerobes were isolated in 39 community acquired and five nosocomial cases out of 278 anaerobic cultivations (15.8%). Total of 56 anaerobe strains were identified and 21 aerobes were accompanied to anaerobic isolates. Aerobe isolates were associated with anaerobic microorganisms in 19 cases (43.2%). Bacteroides species (21.4%) and Pseudomonas aeruginosa (33.3%) were the most common anaerobic and aerobic isolates.