Multidrug-resistant pathogens in patients with pneumonia coming from the community

Bloodstream infections due to multi-drug resistant bacteria in the emergency department: prevalence, risk factors and outcomes-a retrospective observational study

Multidrug-resistant organisms (MDROs) are prevalent in patients admitted to the Emergency Department (ED) and increase the risk of inappropriate empirical antibiotic therapy. Risk stratification for MDRO infection is essential to early identify patients requiring empirical broad-spectrum antibiotic therapy, but it remains challenging for emergency physicians. This study aimed to evaluate prevalence, risk factors, and outcomes of patients admitted to the ED with a bloodstream infection (BSI) caused by MDROs. A retrospective observational study enrolling all consecutive adult patients admitted with a BSI to the ED of Niguarda Hospital, Italy, from January 2019 to December 2021 was performed. 757 patients were enrolled, 14.1% with septic shock. 156 (20%) patients had a BSI caused by MDRO: extended-spectrum beta-lactamase (ESBL) producing Enterobacterales were the most prevalent followed by methicillin-resistant Staphylococcus aureus (MRSA). Risk factors for BSI due to MDRO and specifically for ESBL were chronic renal failure (OR 2.2; 95%CI 1.4-3.6), nursing home residency (OR 4.4; 95%CI 1.9-10.2) and antibiotic therapy in the last 90-days (OR 2.6; 95%CI 1.7-4), whereas for MRSA were dialysis (OR 12.3; 95%CI 1.8-83), antibiotic therapy and/or hospital admission in the past 90-days (OR 3.6; 95%CI 1.2-10.6) and ureteral stent or nephrostomy (OR 7.8; 95%CI 1.5-40.9). Patients with BSI due to MDRO had a higher rate of inappropriate empirical antibiotic therapy (50%) and longer length of stay, but no higher in-hospital mortality. Among patients admitted to the ED with a BSI, MDROs are frequent and often associated with inappropriate empirical antibiotic therapy. Specific updated risk factors for MDRO may help clinicians to better identify patients requiring a broader antibiotic therapy in the ED, while awaiting microbiological results.

In vitro and in vivo evaluation of the biofilm-degrading Pseudomonas phage Motto, as a candidate for phage therapy

Infections caused by Pseudomonas aeruginosa are becoming increasingly difficult to treat due to the emergence of strains that have acquired multidrug resistance. Therefore, phage therapy has gained attention as an alternative to the treatment of pseudomonal infections. Phages are not only bactericidal but occasionally show activity against biofilm as well. In this study, we describe the Pseudomonas phage Motto, a T1-like phage that can clear P. aeruginosa infections in an animal model and also exhibits biofilm-degrading properties. The phage has a substantial anti-biofilm activity against strong biofilm-producing isolates (n = 10), with at least a twofold reduction within 24 h. To demonstrate the safety of using phage Motto, cytotoxicity studies were conducted with human cell lines (HEK 293 and RAW 264.7 macrophages). Using a previously established in vivo model, we demonstrated the efficacy of Motto in Caenorhabditis elegans, with a 90% survival rate when treated with the phage at a multiplicity of infection of 10.

Multidrug-Resistant Sepsis: A Critical Healthcare Challenge

Sepsis globally accounts for an alarming annual toll of 48.9 million cases, resulting in 11 million deaths, and inflicts an economic burden of approximately USD 38 billion on the United States healthcare system. The rise of multidrug-resistant organisms (MDROs) has elevated the urgency surrounding the management of multidrug-resistant (MDR) sepsis, evolving into a critical global health concern. This review aims to provide a comprehensive overview of the current epidemiology of (MDR) sepsis and its associated healthcare challenges, particularly in critically ill hospitalized patients. Highlighted findings demonstrated the complex nature of (MDR) sepsis pathophysiology and the resulting immune responses, which significantly hinder sepsis treatment. Studies also revealed that aging, antibiotic overuse or abuse, inadequate empiric antibiotic therapy, and underlying comorbidities contribute significantly to recurrent sepsis, thereby leading to septic shock, multi-organ failure, and ultimately immune paralysis, which all contribute to high mortality rates among sepsis patients. Moreover, studies confirmed a correlation between elevated readmission rates and an increased risk of cognitive and organ dysfunction among sepsis patients, amplifying hospital-associated costs. To mitigate the impact of sepsis burden, researchers have directed their efforts towards innovative diagnostic methods like point-of-care testing (POCT) devices for rapid, accurate, and particularly bedside detection of sepsis; however, these methods are currently limited to detecting only a few resistance biomarkers, thus warranting further exploration. Numerous interventions have also been introduced to treat MDR sepsis, including combination therapy with antibiotics from two different classes and precision therapy, which involves personalized treatment strategies tailored to individual needs. Finally, addressing MDR-associated healthcare challenges at regional levels based on local pathogen resistance patterns emerges as a critical strategy for effective sepsis treatment and minimizing adverse effects.

Multidrug-Resistant Bacteria on Critically Ill Patients with Sepsis at Hospital Admission: Risk Factors and Effects on Hospital Mortality

Purpose

To evaluate the effect of MDRO infection on hospital mortality and the risk factors among critically ill patients with sepsis at hospital admission.

Patients and Methods

A cross-sectional study was performed between April 2019 and May 2020, followed by a cohort to evaluate hospital mortality that prospectively included all consecutive patients 18 years or older with sepsis admitted within 48 hours of hospital admission to an adult ICU in Brazil. Patients' characteristics, blood samples within one hour of ICU admission, and microbiological results within 48h of hospital admission were collected. In addition, descriptive statistics, binary logistic regression, and propensity score matching were performed.

Results

At least one MDRO was isolated in 85 patients (9.8%). The extended-spectrum beta-lactamase-producing Enterobacterales are the most frequent organism (56.1%). Hypoxemic acute respiratory failure (OR 1.87, 95% CI 1.02-3.40, p = 0.04), Glasgow Coma Score below 15 (OR 2.57, 95% CI 1.38-4.80, p < 0.01), neoplasm (OR 2.66, 95% CI 1.04-6.82, p = 0.04) and hemoglobin below 10.0 g/dL (OR 1.82, 95% CI 1.05-3.16, p = 0.03) were associated with increased MDRO. Admission from the Emergency Department (OR 0.25, 95% CI 0.14-0.43, p < 0.01) was associated with decreased MDRO. In the multivariate analysis, MDRO at hospital admission increased hospital mortality (OR 2.80, 95% CI 1.05-7.42, p = 0.04). After propensity score-matching adjusted to age, APACHE II, SOFA, and dementia, MDRO at hospital admission was associated with significantly high hospital mortality (OR 2.80, 95% CI 1.05-7.42, p = 0.04). The E-value of adjusted OR for the effect of MDRO infection on hospital mortality was 3.41, with a 95% CI of 1.31, suggesting that unmeasured confounders were unlikely to explain the entirety of the effect.

Conclusion

MDRO infection increased hospital mortality, and MDRO risk factors should be accessed even in patients admitted to ICU within 48 hours of hospital admission.

Identification of hospitalized patients with community-acquired infection in whom treatment guidelines do not apply: a validated model

OBJECTIVES

To develop and validate a clinical model to identify patients admitted to hospital with community-acquired infection (CAI) caused by pathogens resistant to antimicrobials recommended in current CAI treatment guidelines.

METHODS

International prospective cohort study of consecutive patients admitted with bacterial infection. Logistic regression was used to associate risk factors with infection by a resistant organism. The final model was validated in an independent cohort.

RESULTS

There were 527 patients in the derivation and 89 in the validation cohort. Independent risk factors identified were: atherosclerosis with functional impairment (Karnofsky index <70) [adjusted OR (aOR) (95% CI) = 2.19 (1.41-3.40)]; previous invasive procedures [adjusted OR (95% CI) = 1.98 (1.28-3.05)]; previous colonization with an MDR organism (MDRO) [aOR (95% CI) = 2.67 (1.48-4.81)]; and previous antimicrobial therapy [aOR (95% CI) = 2.81 (1.81-4.38)]. The area under the receiver operating characteristics (AU-ROC) curve (95% CI) for the final model was 0.75 (0.70-0.79). For a predicted probability ≥22% the sensitivity of the model was 82%, with a negative predictive value of 85%. In the validation cohort the sensitivity of the model was 96%. Using this model, unnecessary broad-spectrum therapy would be recommended in 30% of cases whereas undertreatment would occur in only 6% of cases.

CONCLUSIONS

For patients hospitalized with CAI and none of the following risk factors: atherosclerosis with functional impairment; previous invasive procedures; antimicrobial therapy; or MDRO colonization, CAI guidelines can safely be applied. Whereas, for those with some of these risk factors, particularly if more than one, alternative antimicrobial regimens should be considered.

Hot topics and current controversies in community-acquired pneumonia

Community-acquired pneumonia (CAP) is one of the most common infectious diseases, as well as a major cause of death both in developed and developing countries, and it remains a challenge for physicians around the world. Several guidelines have been published to guide clinicians in how to diagnose and take care of patients with CAP. However, there are still many areas of debate and uncertainty where research is needed to advance patient care and improve clinical outcomes. In this review we highlight current hot topics in CAP and present updated evidence around these areas of controversy.

Community-acquired pneumonia is the most frequent cause of infectious death worldwide; however, there are several areas of controversy that should be addressed to improve patient care. This review presents the available data on these topics.http://bit.ly/2ShnH7A

Prevalence and risk factors for Enterobacteriaceae in patients hospitalized with community‐acquired pneumonia

BACKGROUND AND OBJECTIVE

Enterobacteriaceae (EB) spp. family is known to include potentially multidrug-resistant (MDR) microorganisms, and remains as an important cause of community-acquired pneumonia (CAP) associated with high mortality. The aim of this study was to determine the prevalence and specific risk factors associated with EB and MDR-EB in a cohort of hospitalized adults with CAP.

METHODS

We performed a multinational, point-prevalence study of adult patients hospitalized with CAP. MDR-EB was defined when ≥3 antimicrobial classes were identified as non-susceptible. Risk factors assessment was also performed for patients with EB and MDR-EB infection.

RESULTS

Of the 3193 patients enrolled with CAP, 197 (6%) had a positive culture with EB. Fifty-one percent (n = 100) of EB were resistant to at least one antibiotic and 19% (n = 38) had MDR-EB. The most commonly EB identified were Klebsiella pneumoniae (n = 111, 56%) and Escherichia coli (n = 56, 28%). The risk factors that were independently associated with EB CAP were male gender, severe CAP, underweight (body mass index (BMI) < 18.5) and prior extended-spectrum beta-lactamase (ESBL) infection. Additionally, prior ESBL infection, being underweight, cardiovascular diseases and hospitalization in the last 12 months were independently associated with MDR-EB CAP.

CONCLUSION

This study of adults hospitalized with CAP found a prevalence of EB of 6% and MDR-EB of 1.2%, respectively. The presence of specific risk factors, such as prior ESBL infection and being underweight, should raise the clinical suspicion for EB and MDR-EB in patients hospitalized with CAP.

Costunolide alleviates HKSA-induced acute lung injury via inhibition of macrophage activation

Staphylococcus aureus (S. aureus) infection leads to a severe inflammatory response and causes acute lung injury (ALI), eventually threatening human life. Therefore, it is of importance to find an agent to inhibit inflammation and reduce ALI. Here, we found that costunolide, a sesquiterpene lactone, displays anti-inflammatory effects and ameliorates heat-killed S. aureus (HKSA)-induced pneumonia. Costunolide treatment attenuated HKSA-induced murine ALI in which pulmonary neutrophil infiltration was inhibited, lung edema was decreased, and the production of pro-inflammatory cytokines was significantly reduced. In addition, costunolide dose-dependently inhibited the generation of IL-6, TNF-α, IL-1β, and keratinocyte-derived cytokine (KC), as well as the expression of iNOS, in HKSA-induced macrophages. Furthermore, costunolide attenuated the phosphorylation of p38 MAPK and cAMP response element-binding protein (CREB). Collectively, our findings suggested that costunolide is a promising agent for alleviating bacterial-induced ALI via the inhibition of the MAPK signaling pathways.

Prevalence, risk factors and outcomes of patients coming from the community with sepsis due to multidrug resistant bacteria

Background

Although previous studies showed an increasing prevalence of infections due to multi-drug resistant (MDR) bacteria in the community, specific data on sepsis are lacking. We aimed to assess prevalence, risk factors and outcomes of patients with sepsis due to MDR bacteria.

Methods

An observational, retrospective study was conducted on consecutive adult patients coming from the community and admitted to the Policlinico Hospital, Milan, Italy, with a diagnosis of sepsis between January 2011 and December 2015. Primary study outcome was in-hospital mortality.

Results

Among 518 patients, at least one MDR bacteria was isolated in 88 (17%). ESBL+ Enterobacteriaceae were the most prevalent MDR bacteria (9.7%) followed by MRSA (3.9%). Independent risk factors for sepsis due to MDR bacteria were septic shock (OR: 2.2; p = 0.002) and hospitalization in the previous 90 days (OR: 2.3; p = 0.003). Independent risk factors for sepsis due to ESBL+ bacteria were hospitalization in the previous 90 days (OR: 2.1; p = 0.02) and stroke (OR: 2.1; p = 0.04). A significantly higher mortality was detected among patients with vs. without MDR bacteria (40.2% vs. 23.1% respectively, p = 0.001). Independent risk factors for mortality among patients with sepsis were coagulation dysfunction (OR: 3.2; p = 0.03), septic shock (OR: 3.2; p = 0.003), and isolation of a MDR bacteria (OR: 4.6; p < 0.001).

Conclusion

In light of the prevalence and impact of MDR bacteria causing sepsis in patients coming from the community, physicians should consider ESBL coverage when starting an empiric antibiotic therapy in patients with specific risk factors, especially in the presence of septic shock.

Comparison of ceftazidime-avibactam and ceftolozane-tazobactam in vitro activities when tested against gram-negative bacteria isolated from patients hospitalized with pneumonia in United States medical centers (2017-2018)

Clinical isolates were consecutively collected from 70 United States medical centers in 2017-2018 and susceptibility tested by reference broth microdilution methods at a central laboratory. The most active agents against Enterobacterales (n = 3269) were ceftazidime-avibactam (99.9% susceptible), amikacin (98.7% susceptible), meropenem (97.4% susceptible), and tigecycline (94.6% susceptible), but only ceftazidime-avibactam and tigecycline retained good activity (≥90% susceptible) against carbapenem-resistant Enterobacterales (97.5% and 92.4% susceptible, respectively). The most active agents against multidrug-resistant (MDR) Enterobacterales were ceftazidime-avibactam (99.2% susceptible) and amikacin (90.9% susceptible), whereas ceftolozane-tazobactam and meropenem were active against only 53.8% and 78.1% of these organisms, respectively. Among ESBL-producing Enterobacterales (excluding carbapenemase-producing), susceptibility rates for ceftazidime-avibactam, ceftolozane-tazobactam, and meropenem were 100.0%, 84.1%, and 98.9%, respectively. Ceftazidime-avibactam and ceftolozane-tazobactam were very active against P. aeruginosa (n = 2215) and exhibited similar susceptibility rates (96.0% and 95.9% susceptible, respectively), including against meropenem-nonsusceptible (87.2% and 87.3% susceptible, respectively) and MDR (83.5% and 83.7% susceptible, respectively) isolates.

Multidrug Resistant Gram-Negative Bacteria in Community-Acquired Pneumonia

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2019. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2019. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Acquisition of Carbapenemase-Producing Enterobacteriaceae in Solid Organ Transplantation Recipients

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) can lead to life-threatening outcomes with rapid spread of the carbapenemase gene in solid organ transplantation (SOT) recipients because of limitations of available antibiotics. We examined the characteristics and importance of CPE acquisition in SOT recipients with large numbers of CPE isolates.

METHODS

Between November 2015 and October 2016, 584 CPE isolates were found in 37 recipients and verified by carbapenemase gene multiplex polymerase chain reaction (PCR). One hundred recipients with at least 2 negative results in carbapenemase PCR for stool surveillance and no CPE isolates in clinical samples were retrospectively included.

RESULTS

Most CPE isolates were Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (546, 93.5%). The most frequent transplantation organ was lung (43.3%), and the most common sample with CPE isolates other than stool was respiratory tract (22.6%). The median time between SOT and first CPE acquisition was 7 days. All-cause mortality was significantly higher in recipients with CPE than in those without CPE (24.3% vs 10.0%; P = .03). In multivariate regression analysis, stool colonization of vancomycin-resistant Enterococci and/or Clostridium difficile during 30 days before SOT (odds ratio [OR], 3.28; 95% CI, 1.24-8.68; P = .02), lung transplantation (OR, 4.50; 95% CI, 1.19-17.03; P = .03), and intensive care unit stay ≥2 weeks (OR, 6.21; 95% CI, 1.72-22.45; P = .005) were associated with acquisition of CPE.

CONCLUSIONS

Early posttransplantation CPE acquisition may affect the clinical outcome of SOT recipients. Careful screening for CPE during the early posttransplantation period would be meaningful in recipients with risk factors.

Multidrug Resistant Gram-Negative Bacteria in Community-Acquired Pneumonia

Community-acquired pneumonia (CAP) is associated with high morbidity and mortality worldwide [1]. Although several different bacteria and respiratory viruses can be responsible for CAP, Streptococcus pneumoniae (pneumococcus) remains the most common causative pathogen. A small proportion of CAP cases are caused by Gram-negative bacteria, especially Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii and Stenotrophomona maltophilia [2, 3]. The main problem concerning the treatment of Gram-negative bacterial infections is their related antibiotic resistance, reported as multidrug resistant (MDR = resistant to at least one agent in three or more groups of antibiotics), extensively drug resistant (XDR = resistant to at least one agent in all but two or fewer groups of antibiotics) and pan-drug resistant (PDR = resistant to all groups of antibiotics) [4]. This makes the clinical management of pneumonia caused by such pathogens a challenge for physicians. Taking into account the clinical severity that may be associated with CAP caused by Gram-negative bacteria (respiratory failure, bacteremia, shock, acute respiratory distress syndrome [ARDS]) the magnitude of the global health problem is tremendous.

Clinical outcomes and prognostic factors in patients directly transferred to the intensive care unit from long-term care beds in institutions and hospitals: a retrospective clinical study

Background

There has been a steady increase in the aging population and an increase in the need for long-term care beds in institutions and hospitals (LTCHs) in Korea. The aim of this study was to investigate prognosis and to identify factors contributing to mortality of critically ill patients with respiratory problems who were directly transferred to intensive care units (ICU) from LTCHs.

Methods

Following a retrospective review of clinical data and radiographic findings between July 2009 and September 2016, we included 111 patients with respiratory problems who had visited the emergency room (ER) transferred from LTCHs due to respiratory symptoms and who were then admitted to the ICU.

Results

The mean age of the 111 patients was 79 years, and 71 patients (64%) were male. Pneumonia developed in 98 patients (88.3%), pulmonary thromboembolism in 4 (3.6%) and pulmonary tuberculosis in 3 (2.7%). Overall mortality was 19.8% (22/111). Multiple-drug-resistant (MDR) pathogens (odds ratio [OR], 17.43; 95% confidence interval [CI], 1.96–155.40) and serum albumin levels < 2.15 g/dL, which were derived through ROC (sensitivity, 72.7%; specificity, 85.4%) (OR, 28.05; 95% CI, 5.47–143.75), were independent predictors for mortality. The need for invasive ventilation (OR, 2.74; 95% CI, 1.02–7.32) and history of antibiotic use within the 3 months (OR, 3.23; 95% CI, 1.32–7.90) were risk factors for harboring MDR pathogens.

Conclusions

The presence of MDR pathogens and having low serum albumin levels may be poor prognostic factors in patients with respiratory problems who are admitted to the ICU from LTCHs. A history of antibiotic use within the 3 months and the need for invasive ventilation can be helpful in choosing the appropriate antibiotics to combat MDR pathogens at the time of admission.

Validation of the prediction rules identifying drug-resistant pathogens in community-onset pneumonia

Background

Appropriate initial antibiotic treatment and avoiding administration of unnecessary broad-spectrum antibiotics are important for the treatment of pneumonia. To achieve this, assessment of risk for drug-resistant pathogens (DRPs) at diagnosis is essential.

Purpose

The aim of this study was to validate a predictive rule for DRPs that we previously proposed (the community-acquired pneumonia drug-resistant pathogen [CAP-DRP] rule), comparing several other predictive methods.

Patients and methods

A prospective observational study was conducted in hospitalized patients with community-onset pneumonia at four institutions in Japan. Pathogens identified as not susceptible to ceftriaxone, ampicillin–sulbactam, macrolides, and respiratory fluoroquinolones were defined as CAP-DRPs.

Results

CAP-DRPs were identified in 73 (10.1%) of 721 patients analyzed. The CAP-DRP rule differentiated low vs high risk of CAP-DRP at the threshold of ≥3 points or 2 points plus any of methicillin-resistant Staphylococcus aureus specific factors with a sensitivity of 0.45, specificity of 0.87, positive predictive value of 0.47, negative predictive value of 0.87, and accuracy of 0.79. Its discrimination performance, area under the receiver operating characteristic curve, was 0.73 (95% confidence interval 0.66–0.79). Specificity of the CAP-DRP rule against CAP-DRPs was the highest among the six predictive rules tested.

Conclusion

The performance of the predictive rules and criteria for CAP-DRPs was limited. However, the CAP-DRP rule yielded high specificity and could specify patients who should be treated with non-broad-spectrum antibiotics, eg, a non-pseudomonal β-lactam plus a macrolide, more precisely.

Burden and risk factors for Pseudomonas aeruginosa community-acquired pneumonia: a multinational point prevalence study of hospitalised patients

Pseudomonas aeruginosa is a challenging bacterium to treat due to its intrinsic resistance to the antibiotics used most frequently in patients with community-acquired pneumonia (CAP). Data about the global burden and risk factors associated with P. aeruginosa-CAP are limited. We assessed the multinational burden and specific risk factors associated with P. aeruginosa-CAP.We enrolled 3193 patients in 54 countries with confirmed diagnosis of CAP who underwent microbiological testing at admission. Prevalence was calculated according to the identification of P. aeruginosa Logistic regression analysis was used to identify risk factors for antibiotic-susceptible and antibiotic-resistant P. aeruginosa-CAP.The prevalence of P. aeruginosa and antibiotic-resistant P. aeruginosa-CAP was 4.2% and 2.0%, respectively. The rate of P. aeruginosa CAP in patients with prior infection/colonisation due to P. aeruginosa and at least one of the three independently associated chronic lung diseases (i.e. tracheostomy, bronchiectasis and/or very severe chronic obstructive pulmonary disease) was 67%. In contrast, the rate of P. aeruginosa-CAP was 2% in patients without prior P. aeruginosa infection/colonisation and none of the selected chronic lung diseases.The multinational prevalence of P. aeruginosa-CAP is low. The risk factors identified in this study may guide healthcare professionals in deciding empirical antibiotic coverage for CAP patients.

Pneumonia in Patients with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a frequent comorbid condition associated with increased morbidity and mortality. Pneumonia is the most common infectious disease condition. The purpose of this review is to evaluate the impact of pneumonia in patients with COPD. We will evaluate the epidemiology and factors associated with pneumonia. We are discussing the clinical characteristics of COPD that may favor the development of infections conditions such as pneumonia. Over the last 10 years, there is an increased evidence that COPD patients treated with inhaled corticosteroids are at increased risk to develp pneumonia. We will review the avaialbe information as well as the possible mechanism for this events. We also discuss the impact of influenza and pneumococcal vaccination in the prevention of pneumonia in COPD patients.

The current role of glycopeptides in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in not neutropenic adults: the viewpoint of a group of Italian experts

Staphylococcus aureus is still an important problem in clinical and therapeutic area, worldwide. In Italy, in recent years, methicillin resistance remained stable, yet considerably high, the percentage of strains of MRSA being around 40%. It was deemed interesting and timely to carry out a consensus conference using the RAND/UCLA method to collect the opinion of a group of experts in infectious diseases on the role of glycopeptides in the management of MRSA infections within several clinical scenarios and namely in pneumonia, bacteremia and endocarditis, joint replacement infections, skin and soft tissue infections, diabetic foot, abdominal infections and central nervous system infections. The scenarios proposed by the Scientific Committee have been validated by a group of experts in infectious diseases and then voted in three meetings of infectious disease specialists. The results obtained on each individual condition were analyzed and therapeutic recommendations on each of these were released.

Mortality in patients with community-onset pneumonia at low risk of drug-resistant pathogens: Impact of β-lactam plus macrolide combination therapy

BACKGROUND AND OBJECTIVE

Drug-resistant pathogen (DRP) risk stratification is important for choosing a treatment strategy for community-onset pneumonia. Evidence for benefits of non-antipseudomonal β-lactam plus macrolide combination therapy (BLM) on mortality is limited in patients at low DRP risk. Risk factors for mortality remain to be clarified.

METHODS

Post hoc analysis using a prospective multicentre study cohort of community-onset pneumonia was performed to assess 30-day differences in mortality between non-antipseudomonal β-lactam monotherapy (BL) and BLM groups. Logistic regression analysis was performed to assess the therapeutic effect and risk factors for mortality in patients at low DRP risk.

RESULTS

In total, 594 patients with community-onset pneumonia at low DRP risk (369 BL and 225 BLM) were analysed. The 30-day mortality in BL and BLM was 13.8% and 1.8%, respectively (P < 0.001). Multivariate analysis showed that BLM reduced the 30-day mortality (adjusted odds ratio: 0.28, 95% CI: 0.09-0.87) compared with BL. Independent prognostic factors for 30-day mortality included arterial partial pressure of carbon dioxide (PaCO₂ ) > 50 mm Hg, white blood cell count < 4000/mm³ , non-ambulatory status, albumin < 3.0 g/dL, haematocrit < 30%, age ≥ 80 years, respiratory rate > 25/min and body temperature < 36°C.

CONCLUSION

In patients with community-onset pneumonia at low DRP risk, BLM treatment reduced 30-day mortality compared with BL. Independent risk factors for mortality are potential confounding factors when assessing antibiotic effects in randomized clinical trials.

A Prospective One-Year Microbiologic Survey of Combined Pneumonia and Respiratory Failure

BACKGROUND

Pneumonia and respiratory failure are common problems in the intensive care unit (ICU) setting, often occurring together. The relative prevalence of pneumonia types (community acquired, hospital acquired, ventilator associated) and causative pathogens is not well described in patients with respiratory failure.

METHODS

This was a prospective observational cohort study conducted in the medical ICU (34 beds) of Barnes-Jewish Hospital, an academic referral center of 1,300 beds from January 2016-December 2016. All patients who were prospectively adjudicated to have respiratory failure and pneumonia (RFP) regardless of pneumonia type were classified into one of four microbiologic categories: pathogen negative, antibiotic-susceptible pathogen (according to ceftriaxone susceptibility), antibiotic-resistant pathogen, and viruses. The primary outcomes assessed were the hospital mortality rate and inappropriate initial antibiotic therapy (IIAT) for non-viral pathogens.

RESULTS

Among 364 consecutive patients with RFP, 63 (17.3%) had organisms that were antibiotic susceptible, 104 (28.6%) had antibiotic-resistant organisms, 118 (32.4%) were pathogen negative, and 79 (21.7%) had viral infections. For these categories, IIAT occurred in 3.2%, 21.2%, 0.8%, and 0, respectively (p < 0.001). Vasopressor-requiring shock was present in 61.9%, 72.1%, 68.6%, and 67.1%, respectively (p = 0.585), and the hospital mortality rates were 27.0%, 48.1%, 31.4%, and 36.7%, respectively (p = 0.020). Multivariable logistic regression analysis identified IIAT as an independent predictor of in-hospital death (adjusted odds ratio 5.28; 95% confidence interval 2.72-10.22; p = 0.012). Male gender, increasing Acute Physiology and Chronic Health Evaluation (APACHE) II scores, greater age, and the presence of shock also predicted death.

CONCLUSIONS

Microbiologic categorization of patients with RFP suggests that antibiotic-resistant pathogens and viruses are associated with the highest mortality rates. Vasopressor-requiring shock was common regardless of the microbiologic categorization of RFP. Future development and use of rapid diagnostics and novel therapeutics targeting specific RFP pathogens may allow more timely administration of appropriate antimicrobial therapy and enhance antibiotic stewardship practices.

The respiratory threat posed by multidrug resistant Gram-negative bacteria

Respiratory infections are a major cause of global mortality and morbidity. In recent years, an increased incidence of multidrug-resistant (MDR) Gram-negative bacteria (GNB) has been described. Microorganisms such as Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae or Acinetobacter baumannii have been identified as causative pathogens of different respiratory tract infections. Several studies have detected MDR-GNB in patients with community-acquired and nosocomial pneumonia. Furthermore, MDR-GNB have also been isolated in patients with chronic obstructive pulmonary disease and bronchiectasis having acute or chronic bronchial infection. Prevalence varies depending on the geographical area but MDR-GNB has been reported in the Asia-Pacific region, Europe and the United States, reaching rates of 70% in hospital-acquired infection. The presence of MDR-GNB has been related to poor clinical outcomes, including increased mortality, although data regarding this relationship are limited. This is probably linked to inappropriate selection of empiric antibiotic treatment; this poses a threat of widespread resistance. GNB antibiotic resistance and the absence of new antibiotics are a major concern given limited treatment options; an aspect that deserves future research. We review current literature, highlight prevalence of MDR-GNB in different respiratory infections and explore their impact on clinical outcomes.

Variation in Empiric Coverage Versus Detection of Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa in Hospitalizations for Community-Onset Pneumonia Across 128 US Veterans Affairs Medical Centers

OBJECTIVE To examine variation in antibiotic coverage and detection of resistant pathogens in community-onset pneumonia. DESIGN Cross-sectional study. SETTING A total of 128 hospitals in the Veterans Affairs health system. PARTICIPANTS Hospitalizations with a principal diagnosis of pneumonia from 2009 through 2010. METHODS We examined proportions of hospitalizations with empiric antibiotic coverage for methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PAER) and with initial detection in blood or respiratory cultures. We compared lowest- versus highest-decile hospitals, and we estimated adjusted probabilities (AP) for patient- and hospital-level factors predicting coverage and detection using hierarchical regression modeling. RESULTS Among 38,473 hospitalizations, empiric coverage varied widely across hospitals (MRSA lowest vs highest, 8.2% vs 42.0%; PAER lowest vs highest, 13.9% vs 44.4%). Detection rates also varied (MRSA lowest vs highest, 0.5% vs 3.6%; PAER lowest vs highest, 0.6% vs 3.7%). Whereas coverage was greatest among patients with recent hospitalizations (AP for anti-MRSA, 54%; AP for anti-PAER, 59%) and long-term care (AP for anti-MRSA, 60%; AP for anti-PAER, 66%), detection was greatest in patients with a previous history of a positive culture (AP for MRSA, 7.9%; AP for PAER, 11.9%) and in hospitals with a high prevalence of the organism in pneumonia (AP for MRSA, 3.9%; AP for PAER, 3.2%). Low hospital complexity and rural setting were strong negative predictors of coverage but not of detection. CONCLUSIONS Hospitals demonstrated widespread variation in both coverage and detection of MRSA and PAER, but probability of coverage correlated poorly with probability of detection. Factors associated with empiric coverage (eg, healthcare exposure) were different from those associated with detection (eg, microbiology history). Providing microbiology data during empiric antibiotic decision making could better align coverage to risk for resistant pathogens and could promote more judicious use of broad-spectrum antibiotics. Infect Control Hosp Epidemiol 2017;38:937-944.