Mortality attributable to carbapenem-resistant Pseudomonas aeruginosa bacteremia: a meta-analysis of cohort studies

Penicillin-binding protein 3 sequence variations reduce susceptibility of Pseudomonas aeruginosa to β-lactams but inhibit cell division

BACKGROUND

β-lactam antibiotics, which inhibit penicillin-binding protein 3 (PBP3) that is required for cell division, play a key role in treating P. aeruginosa infections. Some sequence variations in PBP3 have been associated with β-lactam resistance but the effects of variations on antibiotic susceptibility and on cell division have not been quantified. Antibiotic efflux can also reduce susceptibility.

OBJECTIVES

To quantify the effects of PBP3 variations on β-lactam susceptibility and cell morphology in P. aeruginosa.

METHODS

Nineteen PBP3 variants were expressed from a plasmid in the reference strain P. aeruginosa PAO1 and genome engineering was used to construct five mutants expressing PBP3 variants from the chromosome. The effects of the variations on β-lactam minimum inhibitory concentration (MIC) and cell morphology were measured.

RESULTS

Some PBP3 variations reduced susceptibility to a variety of β-lactam antibiotics including meropenem, ceftazidime, cefepime and ticarcillin with different variations affecting different antibiotics. None of the tested variations reduced susceptibility to imipenem or piperacillin. Antibiotic susceptibility was further reduced when PBP3 variants were expressed in mutant bacteria overexpressing the MexAB-OprM efflux pump, with some variations conferring clinical levels of resistance. Some PBP3 variations, and sub-MIC levels of β-lactams, reduced bacterial growth rates and inhibited cell division, causing elongated cells.

CONCLUSIONS

PBP3 variations in P. aeruginosa can increase the MIC of multiple β-lactam antibiotics, although not imipenem or piperacillin. PBP3 variations, or the presence of sub-lethal levels of β-lactams, result in elongated cells indicating that variations reduce the activity of PBP3 and may reduce bacterial fitness.

Risk factors and molecular epidemiology of intestinal colonization by carbapenem-resistant Gram-negative bacteria in patients with hematological diseases: a multicenter case‒control study

Patients with hematological diseases are considered to be at high risk for intestinal colonization by carbapenem-resistant Gram-negative bacteria (CR-GNB). However, the epidemiological data regarding risk factors and molecular characteristics of intestinal colonized CR-GNB isolates in this population are insufficient in China. A multicenter case‒control study involving 4,641 adult patients with hematological diseases from 92 hospitals across China was conducted. Following culture of collected rectal swabs, mass spectrometry and antimicrobial susceptibility tests were performed to identify GNB species and CR phenotype. Risk factors were assessed through retrospective clinical information. Whole-genome sequencing was used to analyze the molecular characteristics of CR-GNB isolates. This trial is registered with ClinicalTrials.gov as NCT05002582. Our results demonstrated that among 4,641 adult patients, 10.8% had intestinal colonization by CR-GNB. Of these, 8.1% were colonized by carbapenem-resistant Enterobacterales (CRE), 2.6% were colonized by carbapenem-resistant Pseudomonas aeruginosa (CRPA), and 0.3% were colonized by carbapenem-resistant Acinetobacter baumannii (CRAB). The risk factors for CR-GNB colonization include male gender, acute leukemia, hematopoietic stem cell transplantation, β-lactam antibiotic usage, and the presence of non-perianal infections within 1 week. Compared with CRPA-colonized patients, patients using carbapenems were more likely to be colonized with CRE. NDM was the predominant carbapenemase in colonized CRE. This study revealed a high CR-GNB intestinal colonization rate among adult patients with hematological diseases in China, with CRE being the predominant one. Notably, a significant proportion of CRE exhibited metallo-β-lactamase production, indicating a concerning trend. These findings emphasize the importance of active screening for CR-GNB colonization in patients with hematological diseases.IMPORTANCECarbapenem-resistant Gram-negative bacteria (CR-GNB) has emerged as a significant threat to public health. Patients with hematological diseases are at high risk of CR-GNB infections due to their immunosuppressed state. CR-GNB colonization is an independent risk factor for subsequent infection. Understanding the risk factors and molecular characteristics of CR-GNB associated with intestinal colonization in patients with hematological diseases is crucial for empirical treatment, particularly in patients with febrile neutropenia. However, the epidemiology data are still insufficient, and our study aims to determine the intestinal colonization rate of CR-GNB, identify colonization risk factors, and analyze the molecular characteristics of colonized CR-GNB isolates.

Molecular characterization of extensively drug-resistant hypervirulent Pseudomonas aeruginosa isolates in China

BACKGROUND

Recently, extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) isolates have been increasingly detected and posed great challenges to clinical anti-infection treatments. However, little is known about extensively resistant hypervirulent P. aeruginosa (XDR-hvPA). In this study, we investigate its epidemiological characteristics and provide important basis for preventing its dissemination.

METHODS

Clinical XDR-PA isolates were collected from January 2018 to January 2023 and identified using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry; antibiotic susceptibility testing was performed by broth microdilution method, and minimum inhibitory concentrations (MICs) were evaluated. Virulence was evaluated using the Galleria mellonella infection model; molecular characteristics, including resistance genes, virulence genes, and homology, were determined using whole-genome sequencing.

RESULTS

A total of 77 XDR-PA strains were collected; 47/77 strains were XDR-hvPA. Patients aged > 60 years showed a significantly higher detection rate of XDR-hvPA than of XDR-non-hvPA. Among the 47 XDR-hvPA strains, 24 strains carried a carbapenemase gene, including blaGES-1 (10/47), blaVIM-2 (6/47), blaGES-14 (4/47), blaIMP-45 (2/47), blaKPC-2 (1/47), and blaNDM-14 (1/47). ExoU, exoT, exoY, and exoS, important virulence factors of PA, were found in 31/47, 47/47, 46/47, and 29/47 strains, respectively. Notably, two XDR-hvPA simultaneously co-carried exoU and exoS. Six serotypes (O1, O4-O7, and O11) were detected; O11 (19/47), O7 (13/47), and O4 (9/47) were the most prevalent. In 2018-2020, O4 and O7 were the most prevalent serotypes; 2021 onward, O11 (16/26) was the most prevalent serotype. Fourteen types of ST were detected, mainly ST235 (14/47), ST1158 (13/47), and ST1800 (7/47). Five global epidemic ST235 XDR-hvPA carried blaGES and showed the MIC value of ceftazidime/avibactam reached the susceptibility breakpoint (8/4 mg/L).

CONCLUSIONS

The clinical detection rate of XDR-hvPA is unexpectedly high, particularly in patients aged > 60 years, who are seemingly more susceptible to contracting this infection. Clonal transmission of XDR-hvPA carrying blaGES, which belongs to the global epidemic ST235, was noted. Therefore, the monitoring of XDR-hvPA should be strengthened, particularly for elderly hospitalized patients, to prevent its spread.

Incidence, antimicrobial resistance and mortality of Pseudomonas aeruginosa bloodstream infections among hospitalized patients in China: a retrospective observational multicenter cohort study from 2017 to 2021

Background

Pseudomonas aeruginosa (P. aeruginosa) accounts for high antimicrobial resistance and mortality rates of bloodstream infections (BSIs). We aim to investigate incidence, antimicrobial resistance and risk factors for mortality of P. aeruginosa BSIs among inpatients.

Methods

A retrospective cohort study were conducted at two tertiary hospitals in 2017-2021. Medical and laboratory records of all inpatients diagnosed with P. aeruginosa BSIs were reviewed. A generalized linear mixed model was used to identify risk factors for mortality.

Results

A total of 285 patients with P. aeruginosa BSIs were identified. Incidence of P. aeruginosa BSIs fluctuated between 2.37 and 3.51 per 100,000 patient-days over the study period. Out of 285 P. aeruginosa isolates, 97 (34.04%) were carbapenem-resistant (CR) and 75 (26.32%) were multidrug-resistant (MDR). These isolates showed low resistance to aminoglycosides (9.51-11.62%), broad-spectrum cephalosporins (17.19-17.61%), fluoroquinolones (17.25-19.43%), and polymyxin B (1.69%). The crude 30-day mortality rate was 17.89% (51/285). Healthcare costs of patients with MDR/CR isolates were significantly higher than those of patients with non-MDR/CR isolates (P < 0.001/=0.002). Inappropriate definitive therapy [adjusted odds ratio (aOR) 4.47, 95% confidence interval (95% CI) 1.35-14.77; P = 0.014], ICU stay (aOR 2.89, 95% CI: 1.26-6.63; P = 0.012) and corticosteroids use (aOR 2.89, 95% CI: 1.31-6.41; P = 0.009) were independently associated with 30-day mortality.

Conclusion

Incidence of P. aeruginosa BSIs showed an upward trend during 2017-2020 but dropped in 2021. MDR/CR P. aeruginosa BSIs are associated with higher healthcare costs. Awareness is required that patients with inappropriate definitive antimicrobial therapy, ICU stay and corticosteroids use are at higher risk of death from P. aeruginosa BSIs.

Safety and pharmacokinetics of SPR206 in subjects with varying degrees of renal impairment

SPR206 is a novel polymyxin derivative with potent in vitro activity against susceptible and multidrug-resistant strains of Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Enterobacter species. SPR206 is eliminated renally. The safety, tolerability, and pharmacokinetics (PK) of SPR206 were evaluated in healthy subjects with normal renal function (Cohort 1) and subjects with varying degrees of renal impairment (RI) (Cohorts 2-4) or end-stage renal disease (ESRD) on hemodialysis (HD) (Cohort 5). Subjects in Cohorts 1-4 received a 100-mg intravenous (IV) dose of SPR206. Subjects in Cohort 5 received a 100-mg IV dose within 2 h after HD on day 1 and 1 h before HD on day 5. Safety and PK analyses included 37 subjects. Mostly mild but no serious treatment-related adverse events were reported. Systemic exposure to SPR206 increased as renal function decreased, with mean area under the concentration-time curve from time 0 to the last quantifiable concentration (AUC0-last) values 39% to 239% greater in subjects with RI vs healthy subjects. Mean plasma clearance (CL) of SPR206 decreased with decreasing renal function (29% to 76% lower vs healthy subjects). In subjects with ESRD, AUC0-last decreased by 51%, and CL increased by 92% for dialyzed vs nondialyzed conditions. SPR206 was excreted in urine within 12 h in healthy subjects and subjects with mild RI (Cohort 2) but was prolonged in those with moderate and severe RI (Cohorts 3 and 4, respectively). In summary, SPR206 was generally safe and well tolerated, and the PK of SPR206 was well characterized in subjects with RI.

Carbapenem-Resistant Pseudomonas aeruginosa Spondylodiscitis Treated with Ceftazidime-Avibactam: A Case Report with Literature Review

Pyogenic spondylodiscitis (PS) is a highly morbid and potentially fatal bacterial infection with an increasing incidence in recent decades. Its diagnosis and treatment are challenging, especially with the expansion of multidrug- or extensively drug-resistant bacteria. We report a rare case of PS caused by carbapenem-resistant Pseudomonas aeruginosa (CRPA) that was treated with ceftazidime-avibactam (C/A). The choice of C/A therapy was based on the patient's bacterial sensitivity profile and intolerance to the initial therapeutic regimen (polymyxin B and meropenem). The total antimicrobial treatment time was seven weeks. The evolution of the clinical course met the cure criteria, which was characterized by remission of signs and symptoms, normalization of inflammatory markers, and radiological improvement over 18 months of clinical follow-up. This is a rare case of CRPA spondylodiscitis that responded to C/A treatment.

Clinical Characteristics and Prognosis of Bloodstream Infection with Carbapenem-Resistant Pseudomonas aeruginosa in Patients with Hematologic Malignancies

Objective

To analyze the clinical characteristics and prognostic risk factors of carbapenem-resistant Pseudomonas aeruginosa (CRPA) bloodstream infections in patients with hematologic malignancies.

Methods

Medical records and drug susceptibility data of patients with hematologic malignancies complicated by CRPA bloodstream infections admitted to the Cancer Hospital of Zhengzhou University between January 1, 2018, and December 31, 2022, were retrospectively analyzed.

Results

A total of 64 patients were included in the study, with a mortality rate of 37.5% (24/64) at 28 days after the occurrence of CRPA bloodstream infection. In Cox regression analysis, an absolute neutrophil count <0.5×109/L at discharge (HR 0.039, 95% CI 0.006 ~ 0.258, p=0.001), admission to the intensive care unit (HR 7.546, 95% CI 1.345 ~ 42.338, p= 0.022), and a higher Pitt bacteremia score (HR 0.207, 95% CI 0.046 ~ 0.939, p = 0.041) were independent risk factors associated with 28-day mortality. Survival analysis showed that patients receiving ceftazidime-avibactam-based (HR 0.368, 95% CI 0.107~ 1.268, p = 0.023) or polymyxin B (HR 2.561, 95% CI 0.721 ~ 9.101, p = 0.015) therapy had a higher survival rate.

Conclusion

Patients with hematologic neoplasms had high mortality from CRPA bloodstream infections, and admission to the intensive care unit, higher Pitt bacteremia score (PBS) scores, granulocyte deficiency, and granulocyte deficiency at discharge were independently associated with higher mortality. Early anti-infective treatment with ceftazidime-avibactam or polymyxin B may improve the clinical prognosis of patients.

Pharmacokinetics of SPR206 in Plasma, Pulmonary Epithelial Lining Fluid, and Alveolar Macrophages following Intravenous Administration to Healthy Adult Subjects

SPR206 is a next-generation polymyxin being developed for the treatment of multidrug-resistant (MDR) Gram-negative infections. This Phase 1 bronchoalveolar lavage (BAL) study was conducted to evaluate SPR206's safety and pharmacokinetics in plasma, pulmonary epithelial lining fluid (ELF), and alveolar macrophages (AM) in healthy volunteers. Subjects received a 100 mg intravenous (IV) dose of SPR206 infused over 1 h every 8 h for 3 consecutive doses. Each subject underwent 1 bronchoscopy with BAL at 2, 3, 4, 6, or 8 h after the start of the third IV infusion. SPR206 concentrations in plasma, BAL, and cell pellet were measured with a validated LC-MS/MS assay. Thirty-four subjects completed the study and 30 completed bronchoscopies. Mean SPR206 peak concentrations (Cmax) in plasma, ELF, and AM were 4395.0, 735.5, and 860.6 ng/mL, respectively. Mean area under the concentration-time curve (AUC0-8) for SPR206 in plasma, ELF, and AM was 20120.7, 4859.8, and 6026.4 ng*h/mL, respectively. The mean ELF to unbound plasma concentration ratio was 0.264, and mean AM to unbound plasma concentration ratio was 0.328. Mean SPR206 concentrations in ELF achieved lung exposures above the MIC for target Gram-negative pathogens for the entire 8-h dosing interval. Overall, SPR206 was well tolerated; 22 subjects (64.7%) reported at least 1 treatment-emergent adverse event (TEAE). Of the 40 reported TEAEs, 34 (85.0%) were reported as mild in severity. The most frequent TEAEs were oral paresthesia (10 subjects [29.4%]) and nausea (2 subjects [5.9%]). This study demonstrates pulmonary penetration of SPR206 and supports further development of SPR206 for the treatment of patients with serious infections caused by MDR Gram-negative pathogens.

Mixed strain pathogen populations accelerate the evolution of antibiotic resistance in patients

Antibiotic resistance poses a global health threat, but the within-host drivers of resistance remain poorly understood. Pathogen populations are often assumed to be clonal within hosts, and resistance is thought to emerge due to selection for de novo variants. Here we show that mixed strain populations are common in the opportunistic pathogen P. aeruginosa. Crucially, resistance evolves rapidly in patients colonized by multiple strains through selection for pre-existing resistant strains. In contrast, resistance evolves sporadically in patients colonized by single strains due to selection for novel resistance mutations. However, strong trade-offs between resistance and growth rate occur in mixed strain populations, suggesting that within-host diversity can also drive the loss of resistance in the absence of antibiotic treatment. In summary, we show that the within-host diversity of pathogen populations plays a key role in shaping the emergence of resistance in response to treatment.

Assessment of mortality-related risk factors and effective antimicrobial regimens for treatment of bloodstream infections caused by carbapenem-resistant Pseudomonas aeruginosa in patients with hematological diseases

Background

Infections caused by carbapenem-resistant Pseudomonas aeruginosa (CRPA) are related to higher mortality. The objective of this study was to explore clinical outcomes of CRPA bacteremia, identify risk factors and also, compare the efficacy of traditional and novel antibiotic regimens.

Methods

This retrospective study was conducted at a blood diseases hospital in China. The study included hematological patients who were diagnosed with CRPA bacteremia between January 2014 and August 2022. The primary endpoint was all-cause mortality at day 30. Secondary endpoints included 7-day and 30-day clinical cure. Multivariable Cox regression analysis was employed to identify mortality-related risk factors.

Results

100 patients infected with CRPA bacteremia were included and 29 patients accepted allogenic-hematopoietic stem cell transplantation. 24 received ceftazidime-avibactam (CAZ-AVI)-based therapy and 76 received other traditional antibiotics. 30-day mortality was 21.0%. Multivariable cox regression analysis showed neutropenia >7 days after bloodstream infections (BSI) (P=0.030, HR: 4.068, 95%CI: 1.146~14.434), higher Pitt bacteremia score (P<0.001, HR:1.824, 95%CI: 1.322~2.517), higher Charlson comorbidity index (P=0.01, HR: 1.613, 95%CI: 1.124~2.315) and bacteremia due to multidrug-resistant Pseudomonas aeruginosa (MDR-PA) (P=0.024, HR:3.086, 95%CI: 1.163~8.197) were identified as independent risk factors of 30-day mortality. After controlling for confounders, an additional multivariable cox regression analysis revealed definitive regimens containing CAZ-AVI were associated with lower mortality in CRPA bacteremia (P=0.016, HR: 0.150, 95%CI: 0.032~0.702), as well as in MDR-PA bacteremia (P=0.019, HR: 0.119, 95%CI: 0.020~0.709).

Conclusions

For patients with hematological diseases and CRPA bacteremia, 30-day mortality rate was 21.0% (21/100). Neutropenia >7 days after BSI, higher Pitt bacteremia score, higher Charlson comorbidity index and bacteremia due to MDR-PA increased 30-day mortality. CAZ-AVI-based regimens were effective alternatives for bacteremia due to CRPA or MDR-PA.

In Vivo Development of Aztreonam Resistance in Meropenem-Resistant Pseudomonas aeruginosa Owing to Overexpression of the blaPDC-16

The rapid acquisition of antibiotic resistance of Pseudomonas aeruginosa has been a complex problem in clinics. Two meropenem-resistant P. aeruginosa isolates were collected from the same patient on May 24, 2021, and June 4, 2021, respectively. The first was susceptible to aztreonam, while the second displayed resistance. This study aimed to identify the genetic differences between two P. aeruginosa isolates and uncover alterations formed by the within-host bacterial evolution leading to aztreonam resistance during therapy. Strains were subjected to antimicrobial susceptibility testing using the broth microdilution method. Genomic DNAs were obtained to identify their genetic differences. The relative mRNA levels of β-lactam-resistance genes were determined by real-time PCR. Both isolates belonged to ST 773 high-risk clones with the same antibiotic resistance genes, eliminating the possibility of horizontally obtaining resistance genes. Reverse transcription (RT)-PCR results showed that the blaPDC-16 mRNA level in the second one was about 1,500 times higher than that in the first one. When 3-aminophenyl boronic acid was added, the second strain recovered its susceptibility to aztreonam, which confirmed that the overexpression of blaPDC-16 was the main reason for the isolate's resistance to aztreonam. Compared to the first strain, the second showed a single amino acid substitution in AmpR located upstream of blaPDC-16, which may contribute to the upregulation of blaPDC-16 and lead to aztreonam resistance. AmpR plays an essential role in regulating antibiotic resistance in P. aeruginosa, and there is a need to be alert to clinical treatment failures associated with mutations in ampR. IMPORTANCE Pseudomonas aeruginosa is notorious for being highly resistant to antimicrobial agents. In this study, two P. aeruginosa strains isolated from the same patient with different susceptibility to aztreonam were used to illustrate the within-host resistance evolution process of P. aeruginosa. Both isolates, which belonged to a ST773 high-risk clone, had the same β-lactam resistance genes (blaPDC-16, blaIMP-45, blaOXA-1, and blaOXA-395), which means the second isolate might have been derived from the first isolate by gaining aztreonam resistance via mutations associated with aztreonam resistance relative genes. Subsequently, we found that mutation in ampR may be the cause of aztreonam resistance in the second isolate. Mutation in ampR leads to its loss of control over blaPDC-16, allowing overexpression of blaPDC-16 and further resistance to aztreonam. This study revealed that ampR plays an essential role in regulating antibiotic resistance in P. aeruginosa. There is a need to be alert to clinical treatment failures associated with mutations in ampR.

Clinical impact and early prediction of carbapenem-resistant Pseudomonas aeruginosa bacteraemia in allogeneic hematopoietic stem cell transplantation recipients

OBJECTIVE

Although antipseudomonal agents are administered in high-risk patients, no reports have focused on the risk of carbapenem-resistant (CR) Pseudomonas aeruginosa bacteraemia in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients.

METHODS

We retrospectively studied a cohort of adult allo-HSCT recipients with P. aeruginosa bacteraemia, focusing on a comparison between carbapenem-sensitive (CS) and CR P. aeruginosa after initiating conditioning chemotherapy at our institute between January 2005 and December 2020. The incidence, all-cause 30-d mortality of P. aeruginosa bacteraemia, and risk factors for carbapenem resistance among patients with P. aeruginosa bacteraemia in allo-HSCT recipients were evaluated.

RESULTS

Forty-eight patients with P. aeruginosa bacteraemia were included, with an incidence of 3.84/100 recipients (CS = 1.92 vs. CR = 1.92). The all-cause 30-d mortality was significantly higher in CR P. aeruginosa bacteraemia (CS = 4.2% vs. CR = 39.1%; P = 0.003). The factor significantly associated with CR P. aeruginosa bacteraemia was carbapenem use for at least 3 d within 30 d before the onset of bacteraemia (odds ratio = 8.92; 95% confidence interval: 1.35-58.90). Inappropriate antimicrobial selection was significantly more frequent in CR P. aeruginosa bacteraemia (CS = 0% vs. CR = 29.2%; P ˂ 0.009).

CONCLUSION

Empirical combination therapy with reference to antimicrobial susceptibility profiles in each institution should be considered when CR P. aeruginosa bacteraemia is suspected in allo-HSCT recipients based on the risk of carbapenem exposure.

Treatment of severe multi-drug resistant Pseudomonas aeruginosa infections

Pseudomonas aeruginosa is the microorganism most frequently involved in the main ICU-acquired infections, with special importance in ventilator associated pneumonia. Its importance lies, in addition to its high incidence in critically ill patients, in the severity of the infections it causes and in the difficulty of its antimicrobial treatment, directly related to the high percentage of resistance to antibiotics classically considered first-line. New active antibiotics have recently been developed against Pseudomonas aeruginosa, even against multi-drug resistant strains. This review analyzes both the differential characteristics of Pseudomonas aeruginosa infections and the new therapeutic options, focusing on multi-drug resistant Pseudomonas aeruginosa.

Faecal carriage of multidrug-resistant bacteria and associated risk factors: results from a point prevalence study

OBJECTIVES

Since 2003, incidences of carbapenemase-producing Gram-negative bacilli (CP-GNB) and vancomycin-resistant Enterococcus faecium (VRE) have steadily increased in France. We therefore conducted a point prevalence study to estimate carriage rates of CP-GNB, VRE and ESBL-producing Enterobacterales (ESBL-PE) and associated risk factors.

METHODS

Between September 2019 and January 2020, all inpatients hospitalized on a given day in 11 teaching hospitals in the Paris urban area were eligible. Patient interviews and rectal swab screening results were recorded by dedicated nurses. The swabs were plated onto selective chromogenic media and processed using the GeneXpert® system.

RESULTS

Of 2396 patients, 364 (15.2%) yielded at least one multiresistant bacterial isolate, including 29 CP-GNB carriers (1.2%), 13 VRE carriers (0.5%) and 338 ESBL-PE carriers (14%). In 15 patients (4.4% of ESBL-PE carriers and 36.6% of CP-GNB/VRE carriers), concomitant CP-GNB/VRE and ESBL-PE carriage was observed. In 7/29 CP-GNB and 7/13 VRE carriers, carbapenemase production and vanA in the screening samples was only detected with Xpert® tests. The OXA-48 gene was predominant in 13/34 CP-GNB isolates from 29 carriers. From the 338 ESBL-PE carriers, 372 isolates were recovered, mainly Escherichia coli (61.2%). Among 379 children, 1.1% carried a CP-GNB/VRE strain, and 12.4% carried an ESBL strain. Previous hospitalization outside mainland France, previous antimicrobial treatment and previous ESBL-PE carriage were the main risk factors associated with CP-GNB and/or VRE carriage.

CONCLUSIONS

The low CP-GNB and VRE prevalence likely reflects the French policy to limit intrahospital spread of CP-GNB and VRE strains.

Clinical data from studies involving novel antibiotics to treat multidrug-resistant Gram-negative bacterial infections

Multidrug-resistant (MDR) Gram-negative bacteria (GNB) are a critical threat to healthcare worldwide, worsening outcomes and increasing mortality among infected patients. Carbapenemase- and extended-spectrum β-lactamase-producing Enterobacterales, as well as carbapenemase-producing Pseudomonas and Acinetobacter spp., are common MDR pathogens. To address this threat, new antibiotics and combinations have been developed. Clinical trial findings support several combinations, notably ceftazidime-avibactam (CZA, a cephalosporin-β-lactamase inhibitor combination) which is effective in treating complicated urinary tract infections (cUTI), complicated intra-abdominal infections and hospital-acquired and ventilator-associated pneumonia caused by GNBs. Other clinically effective combinations include meropenem-vaborbactam (MVB), ceftolozane-tazobactam (C/T) and imipenem- relebactam (I-R). Cefiderocol is a recent siderophore β-lactam antibiotic that is useful against cUTIs caused by carbapenem-resistant Enterobacterales (CRE) and is stable against many β-lactamases. CRE are a genetically heterogeneous group that vary in different world regions and are a substantial cause of infections, among which Klebsiella pneumoniae are the most common. Susceptible CRE infections can be treated with fluoroquinolones, aminoglycosides or fosfomycin, but alternatives include CZA, MVB, I-R, cefiderocol, tigecycline and eravacycline. MDR Acinetobacter baumannii and Pseudomonas aeruginosa are increasingly common pathogens producing a range of different carbapenemases, and infections are challenging to treat, often requiring novel antibiotics or combinations. Currently, no single agent can treat all MDR-GNB infections, but new β-lactam-β-lactamase inhibitor combinations are often effective for different infection sites, and, when used appropriately, have the potential to improve outcomes. This article reviews clinical studies investigating novel β-lactam approaches for treatment of MDR-GNB infections.

Pseudomonas aeruginosa Community-Onset Bloodstream Infections: Characterization, Diagnostic Predictors, and Predictive Score Development-Results from the PRO-BAC Cohort

Community-onset bloodstream infections (CO-BSI) caused by gram-negative bacilli are common and associated with significant mortality; those caused by Pseudomonas aeruginosa are associated with worse prognosis and higher rates of inadequateempirical antibiotic treatment. The aims of this study were to describe the characteristics of patients with CO-BSI caused by P. aeruginosa, to identify predictors, and to develop a predictive score for P. aeruginosa CO-BSI. Materials/methods: PROBAC is a prospective cohort including patients >14 years with BSI from 26 Spanish hospitals between October 2016 and May 2017. Patients with monomicrobial P. aeruginosa CO-BSI and monomicrobial Enterobacterales CO-BSI were included. Variables of interest were collected. Independent predictors of Pseudomonas aeruginosa CO-BSI were identified by logistic regression and a prediction score was developed. Results: A total of 78patients with P. aeruginosa CO-BSI and 2572 with Enterobacterales CO-BSI were included. Patients with P. aeruginosa had a median age of 70 years (IQR 60−79), 68.8% were male, median Charlson score was 5 (IQR 3−7), and 30-daymortality was 18.5%. Multivariate analysis identified the following predictors of CO-BSI-PA [adjusted OR (95% CI)]: male gender [1.89 (1.14−3.12)], haematological malignancy [2.45 (1.20−4.99)], obstructive uropathy [2.86 (1.13−3.02)], source of infection other than urinary tract, biliary tract or intra-abdominal [6.69 (4.10−10.92)] and healthcare-associated BSI [1.85 (1.13−3.02)]. Anindex predictive of CO-BSI-PA was developed; scores ≥ 3.5 showed a negative predictive value of 89% and an area under the receiver operator curve (ROC) of 0.66. Conclusions: We did not find a good predictive score of P. aeruginosa CO-BSI due to its relatively low incidence in the overall population. Our model includes variables that are easy to collect in real clinical practice and could be useful to detect patients with very low risk of P. aeruginosa CO-BSI.

The Economic Impact of Carbapenem Resistant-Non Lactose Fermenter and Enterobacteriaceae Infections on Hospital Costs in Dr. Soetomo General Academic Hospital Surabaya, Indonesia

Background: Carbapenem resistant-non lactose fermenter (CR-NLF) and Carbapenem resistant-Enterobacteriaceae (CR-E) bacterial infections are likely to be a global threat to people’s health. However, studies on the economic impacts according to the hospital setting are very scarce. The study aimed to explore the impact of CR-NLF (Acinetobacter baumannii = CRAB) & Pseudomonas aeruginosa = CRPA) and CR-E (Escherichia coli = CREC) & Klebsiella pneumoniae = CRKP) infections on hospital costs from a payer perspective among patients admitted to Dr.Soetomo Hospital, Surabaya, Indonesia. Methods: In the retrospective case-control study, medical records of all included patients hospitalized during 2018−2021 were reviewed for CRAB, CRPA, CREC, CRKP, and carbapenem sensitive (CSAB, CSPA, CSEC, CSKP) were collected. We retrieved the data of age, gender, clinical specimen, dates of admission, and discharge status. The outcomes of interest were hospital length of stay and hospitalization cost. Results: The cost for CR-NLFs infections was higher than carbapenem sensitive, $3026.24 versus $1299.28 (p < 0.05). There was no significant difference between CR-E against carbapenem sensitive. It showed that the highest impact of the cost was CRAB, followed by CRPA, CRKP, and CREC. The bed, antibiotics, pharmacy, and diagnostic costs of CR-NLFIs were significantly higher than CR-E. Conclusion: This study showed that the hospital cost and expenditure of CR-NLFs per patient were higher than CS. The hospital cost per patient for CR-NLF was higher than CR-E.

Emergence of High Prevalence of Extended-Spectrum Beta-Lactamase and Carbapenemase-Producing Enterobacteriaceae Species among Patients in Northwestern Ethiopia Region

Background. World Health Organization identified some Enterobacteriaceae as superbugs because of their high production and spread of extended-spectrum beta-lactamases (ESBL) and carbapenemases. Moreover, their resistance against commonly prescribed antibiotics left few choices of drugs to treat infection. This study is aimed at determining the magnitude of ESBL and carbapenemase-producing Enterobacteriaceae pathogens and their antimicrobial resistance pattern. Materials and Methods. A hospital-based cross-sectional study was carried out from February to April 2019 in the Northwestern Ethiopia region. A total of 384 patients presumptive for bacterial infections were conveniently enrolled in the study. Specimens were collected and processed following standard bacteriological procedures. Drug susceptibility tests were performed using disk diffusion technique. ESBL and carbapenemase enzymes were tested by double disk diffusion and modified carbapenem inhibition methods, respectively. The data obtained were analyzed using SPSS version 22 software, and descriptive statistics were summarized in tables and graphs. Results. Out of 384 clinical specimens processed 100 (26%) were culture positive for Enterobacteriaceae. The proportion of Enterobacteriaceae infection was relatively higher among in-patients 86 (32.6%) than out-patients 14 (11.7%). Overall, Escherichia coli 35 (9.1%) was the leading isolate followed by Klebsiella pneumoniae 31 (8.1%). Klebsiella pneumoniae 15 (15.6%) was the most frequent isolate from bloodstream infection and is the leading isolate from intensive care unit patients 15 (38.3%). Overall, 44 (44%) of Enterobacteriaceae were extended-spectrum beta-lactamase producers. Among them, Citrobacter spp. was the leading one 4 (80%) followed by Enterobacter cloacae 6 (60%) and K. pneumoniae 18 (58.1%). Furthermore, 6 (6%) of Enterobacteriaceae were carbapenemase-producers, in which 5 (50%) of E. cloacae and 3 (9.7%) of K. pneumoniae had highest percentage. Conclusions. ESBL and carbapenemase-producing isolates of Enterobacteriaceae are alarmingly spreading in the study area. Thus, improving the infection prevention strategy and further screening at the national level is recommended to develop the optimal use of antibiotics.

Pseudomonas aeruginosa Pneumonia: Evolution of Antimicrobial Resistance and Implications for Therapy

Pseudomonas aeruginosa (PA), a non-lactose-fermenting gram-negative bacillus, is a common cause of nosocomial infections in critically ill or debilitated patients, particularly ventilator-associated pneumonia (VAP), and infections of urinary tract, intra-abdominal, wounds, skin/soft tissue, and bloodstream. PA rarely affects healthy individuals, but may cause serious infections in patients with chronic structural lung disease, comorbidities, advanced age, impaired immune defenses, or with medical devices (e.g., urinary or intravascular catheters, foreign bodies). Treatment of pseudomonal infections is difficult, as PA is intrinsically resistant to multiple antimicrobials, and may acquire new resistance determinants even while on antimicrobial therapy. Mortality associated with pseudomonal VAP or bacteremias is high (> 35%) and optimal therapy is controversial. Over the past three decades, antimicrobial resistance (AMR) among PA has escalated globally, via dissemination of several international multidrug resistant "epidemic" clones. We discuss the importance of PA as a cause of pneumonia including health care-associated pneumonia, hospital-acquired pneumonia, VAP, the emergence of AMR to this pathogen, and approaches to therapy (both empirical and definitive).

β-lactam Resistance in Pseudomonas aeruginosa: Current Status, Future Prospects

Pseudomonas aeruginosa is a major opportunistic pathogen, causing a wide range of acute and chronic infections. β-lactam antibiotics including penicillins, carbapenems, monobactams, and cephalosporins play a key role in the treatment of P. aeruginosa infections. However, a significant number of isolates of these bacteria are resistant to β-lactams, complicating treatment of infections and leading to worse outcomes for patients. In this review, we summarize studies demonstrating the health and economic impacts associated with β-lactam-resistant P. aeruginosa. We then describe how β-lactams bind to and inhibit P. aeruginosa penicillin-binding proteins that are required for synthesis and remodelling of peptidoglycan. Resistance to β-lactams is multifactorial and can involve changes to a key target protein, penicillin-binding protein 3, that is essential for cell division; reduced uptake or increased efflux of β-lactams; degradation of β-lactam antibiotics by increased expression or altered substrate specificity of an AmpC β-lactamase, or by the acquisition of β-lactamases through horizontal gene transfer; and changes to biofilm formation and metabolism. The current understanding of these mechanisms is discussed. Lastly, important knowledge gaps are identified, and possible strategies for enhancing the effectiveness of β-lactam antibiotics in treating P. aeruginosa infections are considered.

Clinical characteristics and risk factors for mortality in children with Pseudomonas aeruginosa bacteraemia: A retrospective review at a paediatric tertiary centre

AIM

The objective of this study was to describe clinical features and to assess the risk factors associated with mortality in Pseudomonas aeruginosa bacteraemia in a tertiary Japanese paediatric care hospital.

METHODS

Patients diagnosed with P. aeruginosa bacteraemia at our hospital between 2007 and 2018 were analysed in a retrospective case series. Inadequate initial therapy for P. aeruginosa bacteraemia was defined as initial treatment without antipseudomonal antibiotics or an administration of antipseudomonal agent to which the causative strain was resistant. Bacteraemia-related death was defined as all deaths occurring within 7 days after the onset of bacteraemia.

RESULTS

Overall, 41 patients with 42 P. aeruginosa bacteraemia episodes were identified. The most common underlying condition was malignancy (27%), followed by congenital heart disease (20%) and preterm birth (17%). Among the 42 P. aeruginosa clinical isolates, 24% were resistant to at least one of the antipseudomonal agents and 10% were resistant to more than one agent. The susceptibility levels for piperacillin, fourth-generation cephalosporins and ciprofloxacin were higher than that for carbapenems. Bacteraemia-related death was observed in 43% of episodes. The 30-day all-cause mortality was 50% (standard error 8%). Neonates, intensive care, mechanical ventilation, afebrile episodes, septic shock, hypoxia, renal injury and inadequate initial therapy were associated with bacteraemia-related death episodes.

CONCLUSIONS

We found that childhood P. aeruginosa bacteraemia is still a high mortality disease. Our results imply the importance of the identification of high-risk patients and the establishment of adequate empirical antibiotic therapy.

Development of a rapid and sensitive analytical system for Pseudomonas aeruginosa based on reverse transcription quantitative PCR targeting of rRNA molecules

For Pseudomonas aeruginosa (PA), infection control and appropriate antimicrobial treatment have become important issues. Diagnosis is critical in managing PA infection, but conventional methods are not highly accurate or rapid. We developed a new PA quantification system based on 23S rRNA-targeted reverse transcription quantitative PCR (RT-qPCR). We confirmed that RT-qPCR can quantify PA directly from clinical samples quickly (within 6 h) and with high sensitivity (blood, 1 cell/mL; stool, 100 cells/g) and without cross-reaction. Also, under antibiotic treatment, PA viable counts detected by this system correlated well with the inflammatory response of infected Caco-2 cells compared to other methods such as culturing and qPCR. Next, we utilized this system on fecal samples collected from 65 septic ICU patients and 44 healthy volunteers to identify ICU infection status. We confirmed that the PA detection ratio in ICU patients was significantly higher than that in healthy volunteers (49.2% vs. 13.6%, P < 0.05). Additionally, we monitored drug-resistant PA in 4 ICU patients by this system. The trends in PA counts accurately reflected various treatment backgrounds such as antibiotic use and mechanical ventilator use. Our results suggest that this RT-qPCR system is beneficial for the early diagnosis and evaluation of appropriate antibacterial treatment and may be a useful tool in combating PA infection.

Pyocin-mediated antagonistic interactions in Pseudomonas spp. isolated in James Ross Island, Antarctica

Interactions within bacterial communities are frequently mediated by the production of antimicrobial agents. Despite the increasing interest in research of new antimicrobials, studies describing antagonistic interactions among cold-adapted microorganisms are still rare. Our study assessed the antimicrobial interactions of 36 Antarctic Pseudomonas spp. and described the genetic background of these interactions in selected strains. The overall bacteriocinogeny was greater compared to mesophilic Pseudomonas non-aeruginosa species. R-type tailocins were detected on transmission electron micrographs in 16 strains (44.4%); phylogenetic analysis of the corresponding gene clusters revealed that the P. prosekii CCM 8878 tailocin was related to the Rp3 group, whereas the tailocin in Pseudomonas sp. CCM 8880 to the Rp4 group. Soluble antimicrobials were produced by eight strains (22.-2%); gene mining found pyocin L homologues in the genomes of P. prosekii CCM 8881 and CCM 8879 and pyocin S9-like homologues in P. prosekii CCM 8881 and Pseudomonas sp. CCM 8880. Analysis of secretomes confirmed the production of all S- and L-type pyocin genes. Our results suggest that bacteriocin-based inhibition plays an important role in interactions among Antarctic soil bacteria, and these native, cold-adapted microorganisms could be a promising source of new antimicrobials.

Complicated carbapenem-resistant infections: a treatment pathway analysis in Italian sites

INTRODUCTION

Efforts to curb a growing prevalence of carbapenem resistance are prominent worldwide and especially in countries where high levels of carbapenem resistance are reported, such as Italy. Complicated infections, including complicated urinary tract infections (cUTI), complicated intra-abdominal infections (cIAI), and hospital-acquired/ventilator-associated bacterial pneumonia (HABP/VABP), are often caused by carbapenem-resistant Gram-negative (CRGN) bacteria and as such, these infection sites and their causative bacteria are important areas of focus for healthcare practitioners seeking to follow good antimicrobial stewardship practices. The aim of this study was to assess the clinical management and associated clinical and economic outcomes of patients with cUTI, cIAI, and HABP/VABP resulting from CRGN bacteria in Italy.

METHODS

We first conducted a hospital survey focusing on Gram-negative infections and their antibacterial susceptibility profile in four participating Italian hospitals. The second part of the study involved a non-interventional, retrospective single cohort chart review of 100 patients with cUTI, cIAI, or HABP/VABP caused by CRGN bacteria, in which patient characteristics, index hospitalization characteristics, infection characteristics, patient outcomes, treatment pathways, and healthcare resource use were assessed.

RESULTS

The hospital survey demonstrated carbapenem resistance in approximately 17% of complicated infections, mostly associated with Acinetobacter baumannii. The non-interventional, retrospective cohort component showed that complicated CRGN infections were hospital- or healthcare-acquired in 99.0% of cases and were most often caused by Klebsiella pneumoniae (66.0%). Despite the carbapenem-resistant nature of the included infections, carbapenems were used in 19.0% of patients as empirical therapy, in 43.0% as late empirical (i.e. immediately before receipt of susceptibility test results), and in 64.0% as targeted therapy (post-susceptibility test result receipt). Colistin was used in 61.0% of patients after susceptibility results were available. High clinical and economic burden was evident, with the average length of hospital stay being greater than 50 days, clinical cure achievement in only 43.0% of patients, and an overall mortality rate of 65.0% by the end of the follow-up period.

CONCLUSION

Our results reflect the considerable burden associated with complicated CRGN infections in Italy and the limitations in current treatment strategies. Our study pinpoints potential areas for improvement. For example, regular and detailed local surveillance and state of the art microbial diagnostic capabilities might aid and hasten clinical decision-making and facilitate improved antimicrobial stewardship when treating complex CRGN infections. New therapeutic options which more appropriately address CRGN infections may assist in improving outcomes which are important to both patients and healthcare providers.

Single- and Multiple-Ascending Dose Study of the Safety, Tolerability, and Pharmacokinetics of the Polymyxin Derivative, SPR206

Carbapenem-resistant Acinetobacter baumannii and Enterobacterales are identified as urgent threats, and multidrug-resistant (MDR) Pseudomonas aeruginosa and extended-spectrum beta-lactamase (ESBL)-producing pathogens are identified as serious threats by the Centers for Disease Control and Prevention (CDC). SPR206 is a novel polymyxin derivative with potent in vitro and in vivo activity against A. baumannii, P. aeruginosa, and multiple clinically important species of Enterobacterales, including multidrug- and extensively drug-resistant strains. This was a first-in-human (FIH) double-blind, placebo-controlled, single-, and multiple-ascending-dose study of the safety, tolerability, and pharmacokinetics (PK) of SPR206 in 94 healthy subjects. Following intravenous (i.v.) administration (1-h infusion) at single doses of 10 mg to 400 mg and multiple doses of 25 mg to 150 mg every 8 h (q8h) for 7 days and 100 mg q8h for 14 days, SPR206 was generally safe and generally well tolerated. While the incidence of adverse events increased with dose, most were of mild severity. Systemic exposure (maximum concentration of drug in serum [C_max] and area under the concentration-time curve [AUC]) to SPR206 was approximately dose proportional, time to peak concentrations ranged from 1.1 to 1.3 h, and half-life ranged from 2.4 to 4.1 h. No appreciable accumulation occurred with repeated dosing of SPR206, and trough concentrations suggest that steady state was achieved by day 2. Urinary excretion of unchanged SPR206 was dose dependent across single- (SAD) and multiple-ascending-dose (MAD) cohorts, and the percentage of dose excreted as SPR206 was up to >50%. Importantly, no evidence of nephrotoxicity was observed over 14 days of 100 mg q8h dosing of SPR206; a dosing regimen anticipated to exceed requirements for clinical efficacy. (This study has been registered at ClinicalTrials.gov under identifier NCT03792308.)

Biomarker screening and validation for the differentiation of bloodstream infection from adult-onset Still's disease: A prospective cohort study

OBJECTIVES

Distinguishing between bloodstream infection (BSI) and adult-onset Still's disease (AOSD) is challenging in practice due to similarities in their clinical and laboratory characteristics. We aimed to identify biomarkers in a prospective cohort of patients with BSI and AOSD for differential diagnosis and prognosis prediction.

METHODS

Sixty-four individuals were enrolled in the training set (37 with BSI, 17 with AOSD, and 10 healthy controls). Furthermore, 86 individuals were enrolled in the validation cohort (67 with BSI and 19 with AOSD). Clinical and laboratory data were collected. Blood samples were stimulated using bacteria-specific antigens and levels of several cytokines were detected in the supernatant via Luminex or enzyme-linked immunosorbent assay.

RESULTS

Escherichia coli and Klebsiella pneumoniae were the pathogens most frequently responsible for BSI. In the training cohort, the incidence of rash, arthralgia, myalgia, sore throat, lymphadenopathy, leukocytosis, and hyperferritinemia was higher in patients with AOSD than in those with BSI. Procalcitonin was significantly higher in patients with BSI than that in those with AOSD. Interleukin (IL)-6, IL-17A, C-X3-C motif chemokine ligand (CX3CL)-1, and C-X-C motif chemokine ligand 10 (CXCL10) levels were higher in patients with BSI than in those with AOSD. IL-18 was higher among patients with AOSD than in those with BSI. A decision tree analysis showed that a combination of plasma IL-18 and ferritin levels can be used to distinguish BSI from AOSD (diagnostic accuracy: 97.67%, sensitivity: 96.15%, specificity: 100%). Plasma IL-18 levels were positively correlated with ferritin, and were decreased after treatment in both BSI and ASOD groups.

CONCLUSIONS

Plasma IL-18 and ferritin levels can be used to differentiate BSI from AOSD. IL-18 may be a potential biomarker for prognosis prediction in BSI and AOSD.

In vitro synergy of ceftolozane/tazobactam in combination with fosfomycin or aztreonam against MDR Pseudomonas aeruginosa

OBJECTIVES

Carbapenem-resistant Pseudomonas aeruginosa (CR-PSA) imposes great limitations on empirical therapeutic choices, which are further complicated by metallo-β-lactamase production. This study evaluated in vitro antimicrobial synergy of ceftolozane/tazobactam in combination with aztreonam and fosfomycin against MDR PSA.

METHODS

MICs were determined by broth microdilution and gradient strips. The effect of ceftolozane/tazobactam+aztreonam and ceftolozane/tazobactam+fosfomycin combinations were tested against 27 MDR PSA isolates carrying blaSPM-1 (n = 13), blaIMP (n = 4), blaVIM (n = 3), blaGES-1 (n = 2) and blaCTX-M-like (n = 2), and 3 isolates with no acquired β-lactamase production detected by gradient diffusion strip crossing (GDSC). Six genetically unrelated SPM-1-producing isolates were also evaluated by time-kill analysis (TKA).

RESULTS

All CR-PSA isolates harbouring blaSPM-1, blaGES-1 and blaIMP-1 were categorized as resistant to ceftolozane/tazobactam, meropenem and fosfomycin, with 70% being susceptible to aztreonam. Synergism for ceftolozane/tazobactam+fosfomycin and ceftolozane/tazobactam+aztreonam combinations was observed for 88.9% (24/27) and 18.5% (5/27) of the isolates by GDSC, respectively. A 3- to 9-fold reduction in ceftolozane/tazobactam MICs was observed, depending on the combination. Ceftolozane/tazobactam+fosfomycin was synergistic by TKA against one of six SPM-1-producing isolates, with additional non-synergistic bacterial density reduction for another isolate. Aztreonam peak concentrations alone demonstrated a ≥3 log10 cfu/mL reduction against all six isolates, but all strains were within the susceptible range for the drug. No antagonism was observed.

CONCLUSIONS

In the context of increasing CR-PSA and the genetic diversity of resistance mechanisms, new combinations and stewardship strategies may need to be explored in the face of increasingly difficult to treat pathogens.

A meta-analysis of antibiotic resistance rates in Pseudomonas aeruginosa isolated in blood cultures in Turkey between 2007 and 2017

OBJECTIVE:

The prevalence of Pseudomonas aeruginosa has remained stable in recent years, and resistant strains has increased dramatically. In this meta-analysis, we aimed to analyze the P. aeruginosa strains isolated from blood cultures in Turkey during the last 11 years and to reveal their antimicrobial susceptibility.

METHODS:

Data collected between 2007 and 2017 were divided into two groups as Group-1; 2007–2011 and Group-2; 2012–2017. The differences in antibiotic resistance rates between Group-1 and Group-2 were analyzed. The study data were included according to PRISMA criteria, then meta-analysis was performed.

RESULTS:

A total of 30 study data from 25 studies were included in the study. The prevalence rate of meropenem (MEM) resistance in P. aeruginosa in Turkey was 25.1% (95% Cl: 20.65–29.83) according to a meta-analysis of 637 isolates. MEM resistance rates in Group-1 and Group-2 were 23.4% (95% Cl: 18.34–28.99) and 29.3% (95% Cl: 21.23–38.23), respectively. The prevalence rate of imipenem (IMP) resistance in P. aeruginosa in Turkey was 26.8% (%95 Cl: 23.40–30.35) according to a meta-analysis of 1421 isolates. IMP resistance rates in Group-1 and Group-2 were 26.2% (95% Cl: 22.41–30.27) and 28.4% (95% Cl: 21.57–35.88), respectively. Ciprofloxacin (CIP) resistance rate was 27.04% (95% Cl: 21.88–32.52) in 1388 isolates. CIP resistance rates in Group-1 and Group-2 were 30.8% (95% Cl: 24.35–37.56) and 18.6% (95% Cl: 10.72–28.11), respectively. The prevalence rate of piperacillin-tazobactam (TZP) resistance in P. aeruginosa in Turkey was 29.2% (95% Cl: 21.058–38.088) according to a meta-analysis of 1030 isolates. TZP resistance rates in Group-1 and Group-2 were 26.1% (95% Cl: 17.76–35.31) and 38.2% (95% Cl: 18.48–60.27), respectively.

CONCLUSION:

There is a remarkable increase in resistance rates in P. aeruginosa to MEM and TZP in Turkey due to frequent use. Other antibiotics with antipseudomonal effect should be prioritized in the treatment of these infections.

Highlights Regarding the Use of Metallic Nanoparticles against Pathogens Considered a Priority by the World Health Organization

The indiscriminate use of antibiotics has facilitated the growing resistance of bacteria, and this has become a serious public health problem worldwide. Several microorganisms are still resistant to multiple antibiotics and are particularly dangerous in the hospital and nursing home environment, and to patients whose care requires devices, such as ventilators and intravenous catheters. A list of twelve pathogenic genera, which especially included bacteria that were not affected by different antibiotics, was released by the World Health Organization (WHO) in 2017, and the research and development of new antibiotics against these genera has been considered a priority. The nanotechnology is a tool that offers an effective platform for altering the physicalchemical properties of different materials, thereby enabling the development of several biomedical applications. Owing to their large surface area and high reactivity, metallic particles on the nanometric scale have remarkable physical, chemical, and biological properties. Nanoparticles with sizes between 1 and 100 nm have several applications, mainly as new antimicrobial agents for the control of microorganisms. In the present review, more than 200 reports of various metallic nanoparticles, especially those containing copper, gold, platinum, silver, titanium, and zinc were analyzed with regard to their anti-bacterial activity. However, of these 200 studies, only 42 reported about trials conducted against the resistant bacteria considered a priority by the WHO. All studies are in the initial stage, and none are in the clinical phase of research.

Colistin Dosing Regimens against Pseudomonas aeruginosa in Critically Ill Patients: An Application of Monte Carlo Simulation

Our aims are to assess various colistin dosing regimens against Pseudomonas aeruginosa (P. aeruginosa) infection in critically ill patients and to propose an appropriate regimen based on microbiological data. A Monte Carlo simulation was performed using the published colistin’s pharmacokinetic parameters of critically ill patients, the published pharmacodynamic target from a mouse thigh infection model, and the minimum inhibitory concentration (MIC) results from a Vietnamese hospital. The probability of target attainment (PTA) of 80% and cumulative fraction of response (CFR) of 90% were used to evaluate the efficacy of each regimen. Of 121 P. aeruginosa laboratory datasets, the carbapenem-resistant P. aeruginosa (CRPA) and the colistin-resistant P. aeruginosa rates were 29.8% and 0.8%, respectively. MIC_50,90 were both 0.5 mg/L. The simulated results showed that at MIC of 2 mg/L, most regimens could not reach the PTA target, particularly in patients with normal renal function (Creatinine clearance (CrCl) ≥ 80 mL/min). At MIC of 0.5 mg/L and 1 mg/L, current recommendations still worked well. On the basis of these results, aside from lung infection, our study recommends three regimens against P. aeruginosa infection at MIC of 0.5 mg/L, 1 mg/L, and 2 mg/L. In conclusion, higher total daily doses and fractionated colistin dosing regimens could be the strategy for difficult-to-acquire PTA cases, while a less aggressive dose might be appropriate for empirical treatment in settings with low MIC_50/90.

Retrospective Data Insight into the Global Distribution of Carbapenemase-Producing Pseudomonas aeruginosa

This study aimed to determine the global distribution and molecular characteristics of carbapenemase-producing Pseudomonas aeruginosa isolates. A total of 328 (11.1%, 328/2953) carbapenemase-producing P. aeruginosa isolates from humans were obtained from public databases as of October 2019. Of which, the bla_VIM and bla_IMP genes were the most prevalent carbapenemases in the P. aeruginosa isolates. These carbapenemase-producing P. aeruginosa isolates possessed 34 distinct sequence types (STs) and six predominated: ST357, ST823, ST308, ST233, ST175 and ST111. The ST357 and ST823 isolates were primarily found detected in Asia and all ST175 isolates were found in Europe. The ST308, ST233 and ST111 isolates were spread worldwide. Further, all ST823 isolates and the majority of ST111, ST233 and ST175 isolates carried bla_VIM but ST357 isolates primarily carried bla_IMP. ST308 isolates provide a key reservoir for the spread of bla_VIM, bla_IMP and bla_NDM. WGS analysis revealed that ST111 carried a great diversity of ARG types (n = 23), followed by ST357 (n = 21), ST308 (n = 19), ST233 (n = 18), ST175 (n = 14) and ST823 (n = 10). The ST175 isolates carried a more diversity and frequent of aminoglycoside ARGs, and ST233 isolates harbored more tetracycline ARGs. Our findings revealed that different carbapenem resistance genes were distributed primarily in variant STs of P. aeruginosa isolates, these isolates also possessed an extensive geographical distribution that highlights the need for surveillance studies that detect carbapenemase-producing P. aeruginosa isolates in humans.

Risk Factors and Outcomes of Antibiotic-resistant Pseudomonas aeruginosa Bloodstream Infection in Adult Patients With Acute Leukemia

BACKGROUND

Pseudomonas aeruginosa (PA) bloodstream infection (BSI) is a common complication in patients with acute leukemia (AL), and the prevalence of antibiotic-resistant strains poses a serious problem. However, there is limited information regarding antibiotic resistance, clinical characteristics, and outcomes of PA BSI in AL patients. This study explored characteristics associated with the clinical outcomes of AL patients with PA BSI and analyzed factors associated with BSI caused by multidrug-resistant (MDR) or carbapenem-resistant strains.

METHODS

This single-center retrospective study enrolled hospitalized AL patients who developed PA BSI during January 2014-December 2019. The Kaplan-Meier method was used to plot survival curves. Multivariate logistic regression analyses were also performed.

RESULTS

Of 293 eligible patients with PA BSI, 55 (18.8%) received inappropriate empirical antibiotic therapy within 48 hours of BSI onset, whereas up to 65.8% MDR-PA BSI patients received inappropriate empirical treatment. The 30-day mortality rate was 8.5% for all patients. However, the 30-day mortality rates were 28.9% and 5.5% in MDR-PA BSI and non-MDR-PA BSI patients, respectively (P < .001). On multivariate analysis, previous use of quinolones (odds ratio [OR], 5.851 [95% confidence interval {CI}, 2.638-12.975]) and piperacillin/tazobactam (OR, 2.837 [95% CI, 1.151-6.994]) were independently associated with MDR-PA BSI; and MDR-PA BSI (OR, 7.196 [95% CI, 2.773-18.668]), perianal infection (OR, 4.079 [95% CI, 1.401-11.879]), pulmonary infection (OR, 3.028 [95% CI, 1.231-7.446]), and age ≥55 years (OR, 2.871 [95% CI, 1.057-7.799]) were independent risk factors for 30-day mortality.

CONCLUSIONS

MDR increases mortality risk in PA BSI patients, and previous antibiotic exposure is important in MDR-PA BSI development. Rational antibiotic use based on local antimicrobial susceptibility and clinical characteristics can help reduce antibiotic resistance and mortality.

Whole Genome Sequencing of Ceftolozane-Tazobactam and Ceftazidime-Avibactam Resistant Pseudomonas aeruginosa Isolated from a Blood Stream Infection Reveals VEB and Chromosomal Metallo-Beta Lactamases as Genetic Determinants: A Case Report

Pseudomonas aeruginosa is a common gram-negative bacillus in nosocomial settings. Consideration of this organism is important due to its potential to acquire multi-drug resistance through various mechanisms causing severe infections, particularly in immunocompromised hosts. Here, we present a challenging case of a blood stream infection caused by a drug-resistant strain of P. aeruginosa in a debilitated young patient. A 31-year-old male patient with a complex history of multiple trauma following a vehicle accident that required several surgical interventions, is plagued by persistent bacteremia. An extensively drug-resistant strain of P. aeruginosa was repeatedly isolated that continued to grow in the patient's blood cultures despite treatment with meropenem and colistin for an extended period. In addition to phenotypic characterization, the complete genome of the strain was sequenced and a genomic view was provided regarding its antimicrobial resistance (AMR) patterns, efflux pump genes, virulence determinants, phageomic signals, and genomic islands. The strain belongs to sequence type ST357 with dominant Class A (VEB), Class B, Class C (PDC-11) and D (OXA-10, OXA-50) β-lactamases, and injectosomes (type III secretion system) known to mediate high virulence. The pool of extended spectrum β-lactamases genes and the upregulated chromosomal efflux system are likely to account for the extended resistance pattern in this strain. In light of the global spread of ST357 isolates, it is essential to continue monitoring their resistance patterns and evaluate effective epidemiological tools to define the genetic determinants of emerging resistance. Intensified infection control measures are continuously required to stop dissemination of such strains in an institution where susceptible hosts are at risk of acquiring them.

Broad spectrum antimicrobial activity of dispirooxindolopyrrolidine fused acenaphthenone heterocyclic hybrid against healthcare associated microbial pathogens (HAMPs)

BACKGROUND

Healthcare-associated infections (HAI) are prime health task worldwide and issue of patient safety besides intensifying antimicrobial drug resistance. It is essential to formulate structurally fascinating novel, active and cost-effective anti-microbial drugs possessing a peculiar way of action and capable of overcoming the resistance to effectively combat this disease.

MATERIALS AND METHODS

The synthesized spiro-heterocyclic hybrids (SHHs) were elucidated through spectroscopic analysis and were assessed for their in vitro antimicrobial activity by agar diffusion method and minimal inhibitory concentration (MIC) value was also determined. In addition, antioxidant potential was also evaluated through DPPH radical scavenging assays.

RESULTS

The novel class of SHHs 4a and 4b displayed significant antibacterial activity against selected healthcare associated microbial pathogens (HAMPs). In addition, SHH 4b showed potent antioxidant properties.

CONCLUSION

Antibacterial and antifungal activity of dispirooxindolopyrrolidine fused acenaphthenone heterocyclic hybrids were examined. Interestingly, SHH 4b exhibited potent antimicrobial activity against selected HAMPs. Further, these compounds were also showed potent antioxidant properties. These results revealed that SHH 4b is a promising lead for the development of new antimicrobial drugs.

Carbapenem Antibiotics for the Empiric Treatment of Nosocomial Pneumonia: A Systematic Review and Meta-analysis

BACKGROUND

Previous meta-analyses suggested that treating hospital-acquired pneumonia (HAP), including ventilator-associated pneumonia (VAP), with empiric carbapenems was associated with lower mortality rates but higher rates of clinical failure for pseudomonal pneumonia. This study was an updated meta-analysis with sensitivity analyses and meta-regression to better understand the impact of carbapenem use in HAP/VAP.

RESEARCH QUESTION

What is the efficacy of carbapenems for empiric treatment of nosocomial pneumonia?

STUDY DESIGN AND METHODS

Databases were searched for randomized controlled studies evaluating empiric treatment for HAP and/or VAP, and studies were included comparing carbapenem- vs non-carbapenem-containing regimens. The primary outcome was all-cause mortality. Secondary outcomes included subgroup stratification and resistance development.

RESULTS

Of 9,140 references, 20 trials enrolling 5,489 patients met inclusion criteria. For mortality, carbapenem use had a risk ratio (RR) of 0.84 (95% CI, 0.74-0.96; P = .01). Stratified according to VAP proportion (< 33%, 33%-66%, and > 66%), RRs were 0.95 (95% CI, 0.77-1.17; P = .66), 0.78 (95% CI, 0.57-1.07; P = .13), and 0.81 (95% CI, 0.65-0.99; P = .04), respectively. Stratified according to severity, only groups with Acute Physiology and Chronic Health Evaluation II scores < 14 and between 14 and 17 showed mortality benefit (RRs of 0.64 [95% CI, 0.45-0.92; P = .01] and 0.77 [95% CI, 0.61-0.97; P = .03]). Meta-regression did not show an association between Pseudomonas prevalence and mortality (P = .44). Carbapenem use showed a trend toward developing resistance (RR, 1.40; 95% CI, 0.95-2.06; P = .09) and a 96% probability of resistance emergence.

INTERPRETATION

Carbapenem-based empiric regimens were associated with lower mortality rates compared with non-carbapenems, largely driven by trials of VAP. The mortality effect was not observed in trials with high disease severity and was not associated with Pseudomonas. The mortality difference was observed mainly in studies that used ceftazidime as control. There was a trend toward increasing resistance associated with carbapenems.

TRIAL REGISTRY

International Prospective Register of Systematic Reviews; No. CRD42018093602; URL: https://www.crd.york.ac.uk/prospero/.

Prevalence of bacteriocins and their co-association with virulence factors within Pseudomonas aeruginosa catheter isolates

Urinary tract infections represent common nosocomial infectious diseases. Bacteriocin production has been recently described as a putative virulence factor in these infections but studies focusing particularly on Pseudomonas aeruginosa are not available. Therefore, we assessed the prevalence of the bacteriocin genes, their co-occurrence and their co-association with previously detected virulence factors in a set of 135 P. aeruginosa strains from catheter-associated urinary tract infections (CAUTIs). The overall bacteriocinogeny reached 96.3 % with an average of 3.6 genes per strain. The most frequently detected determinants were the encoded pyocins S4 (76.3 %), R (69.6 %), and S2 (67.4 %). A statistically significant co-occurrence and a negative relationship were observed between several pyocin types. Particular pyocins exhibited associations with biofilm formation, production of pyochelin, pyocyanin, antibiotic-degrading enzymes, overall strain susceptibility and resistance, and motility of the strain. Co-occurrence of the pyocins S2 and S4 (p<<0.0001; Z = 13.15), both utilizating the ferripyoverdine receptor FpvAI, was found but no relation to pyoverdine production was detected. A negative association (p = 0.0047; Z=-2.83) was observed between pyochelin and pyocin S5 utilising the ferripyochelin receptor FptA. Pairwise assays resulted in 52.1 % inhibition which was equally distributed between soluble and particle types of antimicrobials. In conclusion, pyocin determinants appear to be important characteristics of CAUTI-related P. aeruginosa isolates and could contribute to their urovirulence.

The Effect of Host Immunity on Predicting the Mortality of Carbapenem-Resistant Organism Infection

Carbapenem-resistant organisms (CROs) are associated with considerable mortality clinically. There is a lack of effective tool to predict individual prognosis. We aim to determine if host immunity can be utilized to predict the prognosis of patients infected with CRO. From December 2018 to August 2019, we recruited CRO-infected patients to evaluate risk factors for 30-day mortality. Clinical, routine laboratory, immune and microbiological features were investigated and subjected to univariate and multivariate analyses. The final predictive models were established based on the regression coefficients of multivariate logistic regression. A total of 127 CRO-infected patients were enrolled in our study, including 85 survivors and 42 non-survivors. The number and IFN-γ producing ability of lymphocytes were remarkably decreased in non-survivors. The number of IFN-γ⁺CD4⁺ T cells could effectively predict 30-day mortality of CRO infection. Its area under the receiver operating characteristic (ROC) curve, sensitivity, specificity and accuracy, were 0.889 (95% confidence interval [CI], 0.834-0.945), 81.0, 80.0, and 80.3%, respectively. In multivariate analysis of laboratory parameters, IFN-γ⁺CD4⁺ T cell number and creatinine concentration were selected for the 2-marker model to predict prognosis fleetly. Its area under the ROC curve, sensitivity, specificity and accuracy were 0.894 (95% CI, 0.841-0.947), 83.3, 82.4, and 82.7%, respectively. Impaired lymphocyte function was an important factor to affect the outcome of CRO-infected patients. A 2-marker model based on the combination of IFN-γ⁺CD4⁺ T cell number and creatinine showed good performance in predicting the prognosis of CRO infection.

Mortality associated with carbapenem-susceptible and Verona Integron-encoded Metallo-β-lactamase-positive Pseudomonas aeruginosa bacteremia

Background

Studies on various Gram-negative bacteria suggest that resistance to carbapenem antibiotics is responsible for increased mortality in patients; however, results are not conclusive. We first assessed the 28-day in-hospital all-cause mortality in patients with Verona Integron-encoded Metallo-β-lactamase-positive Pseudomonas aeruginosa (VIM-PA) bacteremia compared to patients with VIM-negative, carbapenem-susceptible P. aeruginosa (CS-PA) bacteremia. Second, we identified determinants for mortality and survival.

Methods

All patients with a positive blood culture with VIM-PA or CS-PA between January 2004 and January 2016 were included. Kaplan-Meier survival curves were constructed, and survivors and non-survivors were compared on relevant clinical parameters using univariate analyses, and multivariable analyses using a Cox-proportional hazard model.

Results

In total, 249 patients were included, of which 58 (23.3%) died. Seventeen out of 40 (42.5%) patients with VIM-PA died, compared to 41 out of 209 (19.6%) patients with CS-PA (difference = 22.9%, P-value = 0.001). Assumed acquisition of the bacterium at the intensive care unit was significantly associated with mortality (HR = 3.32, 95%CI = 1.60–6.87), and having had adequate antibiotic therapy in days 1–14 after the positive blood culture was identified as a determinant for survival (HR = 0.03, 95%CI = 0.01–0.06). VIM-PA vs CS-PA was not identified as an independent risk factor for mortality.

Conclusions

The crude mortality rate was significantly higher in patients with a VIM-PA bacteremia compared to patients with a CS-PA bacteremia; however, when analyzing the data in a multivariable model this difference was non-significant. Awareness of the presence of P. aeruginosa in the hospital environment that may be transmitted to patients and rapid microbiological diagnostics are essential for timely administration of appropriate antibiotics. Acquisition of P. aeruginosa should be prevented, independent of resistance profile.

Simultaneous Infection with Enterobacteriaceae and Pseudomonas aeruginosa Harboring Multiple Carbapenemases in a Returning Traveler Colonized with Candida auris

We report our clinical experience treating a critically ill patient with polymicrobial infections due to multidrug-resistant Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa in a 56-year-old woman who received health care in India and was also colonized by Candida auris A precision medicine approach using whole-genome sequencing revealed a multiplicity of mobile elements associated with NDM-1, NDM-5, and OXA-181 and, supplemented with susceptibility testing, guided the selection of rational antimicrobial therapy.

Length of stay, cost, and mortality of healthcare-acquired bloodstream infections in children and neonates: A systematic review and meta-analysis

OBJECTIVE

To estimate the attributable mortality, length of stay (LOS), and healthcare cost of pediatric and neonatal healthcare-acquired bloodstream infections (HA-BSIs).

DESIGN

A systematic review and meta-analysis.

METHODS

A systematic search (January 2000-September 2018) was conducted in PubMed, Cochrane, and CINAHL databases. Reference lists of selected articles were screened to identify additional studies. Case-control or cohort studies were eligible for inclusion when full text was available in English and data for at least 1 of the following criteria were provided: attributable or excess LOS, healthcare cost, or mortality rate due to HA-BSI. Study quality was evaluated using the Critical Appraisal Skills Programme Tool (CASP). Study selection and quality assessment were conducted by 2 independent researchers, and a third researcher was consulted to resolve any disagreements. Fixed- or random-effect models, as appropriate, were used to synthesize data. Heterogeneity and publication bias were evaluated.

RESULTS

In total, 21 studies were included in the systematic review and 13 studies were included in the meta-analysis. Attributable mean LOS ranged between 4 and 27.8 days; healthcare cost ranged between $1,642.16 and $160,804 (2019 USD) per patient with HA-BSI; and mortality rate ranged between 1.43% and 24%. The pooled mean attributable hospital LOS was 16.91 days (95% confidence interval [CI], 13.70-20.11) and the pooled attributable mortality rate was 8% (95% CI, 6-9). A meta-analysis was not conducted for cost due to lack of eligible studies.

CONCLUSIONS

Pediatric HA-BSIs have a significant impact on mortality, LOS, and healthcare cost, further highlighting the need for implementation of HA-BSI prevention strategies.

Prevalence of healthcare-associated infections and antimicrobial use in China: Results from the 2018 point prevalence survey in 189 hospitals in Guangdong Province

BACKGROUND

Limited data on healthcare-associated infections (HAIs) are available from the developing world, thus a point prevalence survey was conducted to determine the prevalence of HAIs and antimicrobial use in Guangdong Province, China.

METHODS

A standardized methodology for point prevalence surveys on HAIs and antimicrobial use has been developed by the Chinese Nosocomial Infection Control and Quality Improvement Center. The prevalence of HAIs, antimicrobial use, and baseline hospital-level variables were collected in 189 hospitals from June 2017 to May 2018.

RESULTS

Of 5 868 147 patients, 72 976 had one or more HAIs (1.24%), with 82 700 distinct HAIs. The prevalence rates of device-associated infections, including ventilator-associated pneumonia, catheter-associated urinary tract infection, and central line-associated bloodstream infection were 7.92, 2.06, and 0.63 per 1000 catheter-days, respectively. A total of 10 591 (0.18%) HAIs caused by multidrug-resistant organisms were identified. Carbapenem non-susceptibility rates were highest in Acinetobacter species (53.86%) and Pseudomonas aeruginosa (21.60%). Forty-six percent (2 712 258/5 868 147) of inpatients were receiving at least one antimicrobial during this survey.

CONCLUSIONS

This survey indicated the relatively lower prevalence of HAIs but higher antimicrobial using in Guangdong Province compared with other mid to low-income and high-income countries. Further studies are warranted to elucidate which HAI-related indicators are the best measures of HAI performance and thus allow improvements leading to better patient outcomes.

Plasmid evolution in carbapenemase-producing Enterobacteriaceae: a review

Carbapenem-resistant Enterobacteriaceae (CRE) have been listed by the WHO as high-priority pathogens owing to their high association with mortalities and morbidities. Resistance to multiple β-lactams complicates effective clinical management of CRE infections. Using plasmid typing methods, a wide distribution of plasmid replicon groups has been reported in CREs around the world, including IncF, N, X, A/C, L/M, R, P, H, I, and W. We performed a literature search for English research papers, published between 2013 and 2018, reporting on plasmid-mediated carbapenem resistance. A rise in both carbapenemase types and associated plasmid replicon groups was seen, with China, Canada, and the United States recording a higher increase than other countries. bla_KPC was the most prevalent, except in Angola and the Czech Republic, where OXA-181 (n = 50, 88%) and OXA-48-like (n = 24, 44%) carbapenemases were most prevalent, respectively; bla_KPC-2/3 accounted for 70% (n = 956) of all reported carbapenemases. IncF plasmids were found to be responsible for disseminating different antibiotic resistance genes worldwide, accounting for almost 40% (n = 254) of plasmid-borne carbapenemases. bla_CTX-M , bla_TEM , bla_SHV , bla_OXA-1/9 , qnr, and aac-(6')-lb were mostly detected concurrently with carbapenemases. Most reported plasmids were conjugative but not present in multiple countries or species, suggesting limited interspecies and interboundary transmission of a common plasmid. A major limitation to effective characterization of plasmid evolution was the use of PCR-based instead of whole-plasmid sequencing-based plasmid typing.

The Clinical and Economic Impact of Antibiotic Resistance in China: A Systematic Review and Meta-Analysis

Antibiotic resistance (ABR) is one of the biggest threats to global health, especially in China. This study aims to analyze the published literature on the clinical and economic impact of ABR or multi-drug resistant (MDR) bacteria compared to susceptible bacteria or non-infection, in mainland China. English and Chinese databases were searched to identify relevant studies evaluating mortality, hospital stay, and hospital costs of ABR. A meta-analysis of mortality was performed using a random effects model. The costs were converted into 2015 United States (US) dollars. Of 13,693 studies identified, 44 eligible studies were included. Twenty-nine investigated the impact of ABR on hospital mortality, 37 were focused on hospital stay, and 21 on hospital costs. Patients with ABR were associated with a greater risk of overall mortality compared to those with susceptibility or those without infection (odds ratio: 2.67 and 3.29, 95% confidence interval: 2.18–3.26 and 1.71–6.33, p < 0.001 and p < 0.001, respectively). The extra mean total hospital stay and total hospital cost were reported, ranging from 3 to 46 days, and from US$238 to US$16,496, respectively. Our study indicates that ABR is associated with significantly higher mortality. Moreover, ABR is not always, but usually, associated with significantly longer hospital stay and higher hospital costs.

Perceived differences between intensivists and infectious diseases consultants facing antimicrobial resistance: a global cross-sectional survey

To identify differences in perception on multi-drug-resistant (MDR) organisms and their management at intensive care units (ICU). A cross-sectional survey was conducted. A proposal addressing a pathogen priority list (PPL) for ICU, arising from the TOTEM study, was compared with a sample of global experts in infections in critically ill patients. The survey was responded by 129 experts. Globally, ESBL Enterobacteriaceae, followed by carbapenem-resistant Acinetobacter baumannii and carbapenem-resistant Klebsiella pneumoniae, were the main concerns. Some differences in opinion were identified between 63 (49%) ICU physicians (ICU/anesthesiology) and 43 (33%) infectious disease consultants (ID physicians/microbiologists). The pathogens most concerning in the ICU for intensivists were ESBL Enterobacteriaceae (38%) versus carbapenem-resistant A. baumannii (48.3%) for ID consultants, (p < 0.05). Increasing number of ID consultants over intensivists (26% vs 14%) reported difficulty in choosing initial therapy for carbapenem-resistant A. baumannii. For intensivists, the urgent measures to limit development of antibiotic resistance were headed by cohort measures (26.3%) versus increasing nurse/patient ratio (32.5%) for ID consultants, (p < 0.05). Regarding effectiveness to prevent MDR development and spread, education programs (42.4%) were the priority for intensivists versus external consultation (35.7%) for ID consultants. Finally, both groups agreed that carbapenem resistance was the most pressing concern (> 70%) regarding emerging resistance. Differences in priorities regarding organisms, infection control practices, and educational priorities were visualized between ID/clinical microbiologists and ICU/anesthesiologists. Multi-disciplinary collaboration is required to achieve best care for ICU patients with severe infections.