Antimicrobial resistance prevalence, rates of hospitalization with septicemia and rates of mortality with sepsis in adults in different US states

Fei-Yan-Qing-Hua decoction decreases hyperinflammation by inhibiting HMGB1/RAGE signaling and promotes bacterial phagocytosis in the treatment of sepsis

ETHNOPHARMACOLOGICAL RELEVANCE

Fei-Yan-Qing-Hua decoction (FYQHD), derived from the renowned formula Ma Xing Shi Gan tang documented in Zhang Zhong Jing's "Treatise on Exogenous Febrile Disease" during the Han Dynasty, has demonstrated notable efficacy in the clinical treatment of pneumonia resulting from bacterial infection. However, its molecular mechanisms underlying the therapeutic effects remains elusive.

AIM OF THE STUDY

This study aimed to investigate the protective effects of FYQHD against lipopolysaccharide (LPS) and carbapenem-resistant Klebsiella pneumoniae (CRKP)-induced sepsis in mice and to elucidate its specific mechanism of action.

MATERIALS AND METHODS

Sepsis models were established in mice through intraperitoneal injection of LPS or CRKP. FYQHD was administered via gavage at low and high doses. Serum cytokines, bacterial load, and pathological damage were assessed using enzyme-linked immunosorbent assay (ELISA), minimal inhibitory concentration (MIC) detection, and hematoxylin and eosin staining (H&E), respectively. In vitro, the immunoregulatory effects of FYQHD on macrophages were investigated through ELISA, MIC, quantitative real-time PCR (Q-PCR), immunofluorescence, Western blot, and a network pharmacological approach.

RESULTS

The application of FYQHD in the treatment of LPS or CRKP-induced septic mouse models revealed significant outcomes. FYQHD increased the survival rate of mice exposed to a lethal dose of LPS to 33.3%, prevented hypothermia (with a rise of 3.58 °C), reduced pro-inflammatory variables (including TNF-α, IL-6, and MCP-1), and mitigated tissue damage in LPS or CRKP-induced septic mice. Additionally, FYQHD decreased bacterial load in CRKP-infected mice. In vitro, FYQHD suppressed the expression of inflammatory cytokines in macrophages activated by LPS or HK-CRKP. Mechanistically, FYQHD inhibited the PI3K/AKT/mTOR/4E-BP1 signaling pathway, thereby suppressing the translational level of inflammatory cytokines. Furthermore, it reduced the expression of HMGB1/RAGE, a positive feedback loop in the inflammatory response. Moreover, FYQHD was found to enhance the phagocytic activity of macrophages by upregulating the expression of phagocytic receptors such as CD169 and SR-A1.

CONCLUSION

FYQHD provides protection against bacterial sepsis by concurrently inhibiting the inflammatory response and augmenting the phagocytic ability of immune cells.

A sepsis treatment algorithm to improve early antibiotic de-escalation while maintaining adequacy of coverage (Early-IDEAS): A prospective observational study

BACKGROUND

Empiric antibiotic treatment selection should provide adequate coverage for potential pathogens while minimizing unnecessary broad-spectrum antibiotic use. We sought to pilot a sepsis treatment algorithm to individualize antibiotic recommendations, and thereby improve early antibiotic de-escalation while maintaining adequacy of coverage (Early-IDEAS).

METHODS

In this observational study, the Early-IDEAS decision support algorithm was derived from previous Gram- negative and Gram-positive prediction rules and models along with local guidelines, and then applied to prospectively identified consecutive adults within 24 hours of suspected sepsis. The primary outcome was the proportion of patients for whom de-escalation of the primary antibiotic regimen was recommended by the algorithm. Secondary outcomes included: (1) proportion of patients for whom escalation was recommended; (2) number of recommended de-escalation steps along a pre-specified antibiotic cascade; and (3) adequacy of therapy in patients with culture-confirmed infection.

RESULTS

We screened 578 patients, of whom 107 eligible patients were included. The Early-IDEAS treatment recommendation was informed by Gram-negative models in 76 (71%) patients, Gram-positive rules in 64 (59.8%), and local guidelines in 27 (25.2%). Antibiotic de-escalation was recommended in almost half of all patients (n = 52, 48.6%), with a median of 2 steps down the a priori antibiotic treatment cascade. No treatment change was recommended in 45 patients (42.1%), and escalation was recommended in 10 (9.3%). Among the 17 patients with positive blood cultures, both the clinician prescribed regimen and the algorithm recommendation provided adequate coverage for the isolated pathogen in 12 patients (70.6%), (p = 1). Among the 25 patients with positive relevant, non-blood cultures, both the clinician prescribed regimen and the algorithm recommendation provided adequate coverage in 20 (80%), (p = 1).

CONCLUSION

An individualized decision support algorithm in early sepsis could lead to substantial antibiotic de-escalation without compromising adequate antibiotic coverage.

Indigenous food sources as vectors of Escherichia coli and antibiotic resistance

The contamination of surface waters by fecal bacteria, measured by the number of Escherichia coli, is a significant public health issue. When these bacteria are also resistant to antimicrobials, infections are more complicated to treat. While water is regularly tested at recreational sites, wild-harvested foods, known as mahinga kai by the indigenous Māori people of Aotearoa New Zealand, are commonly overlooked as a source of exposure to potential pathogens and antimicrobial resistance (AMR). We investigate two likely sources of risk from harvesting aquatic wild foods. The first is water contact, and the second is contact with/ingestion of the harvest. We used E. coli as a proxy for microbial water quality at harvesting sites. Two popular mahinga kai species were also harvested and assessed. We found antibiotic-resistant bacteria on watercress (Nasturtium officinale) and cockles (Austrovenus stutchburyi). One-third of E. coli isolates were conjugative donors of at least one resistance phenotype. Tank experiments were used to track the internalization of E. coli by Greenshell/lip mussels (Perna canaliculus). Greenshell mussels kept at environmentally relevant concentrations of E. coli were colonized to levels considered unsafe for human consumption in 24 h. Finally, we measured horizontal gene transfer between bacteria within the shellfish, what we termed 'intra-shellular' conjugation. The transmission frequency of plasmid RP4 was significantly higher in mussels than in water alone. Our results indicate that shellfish could promote the dissemination of antibiotic resistance. They highlight the need to limit or reduce human pathogenic bacteria where food is gathered.

Increase in the community circulation of ciprofloxacin-resistant Escherichia coli despite reduction in antibiotic prescriptions

BACKGROUND

Community circulating gut microbiota is the main reservoir for uropathogenic Escherichia coli, including those resistant to antibiotics. Ciprofloxacin had been the primary antibiotic prescribed for urinary tract infections, but its broad use has been discouraged and steadily declined since 2015. How this change in prescriptions affected the community circulation of ciprofloxacin-resistant E. coli is unknown.

METHODS

We determined the frequency of isolation and other characteristics of E. coli resistant to ciprofloxacin in 515 and 1604 E. coli-positive fecal samples collected in 2015 and 2021, respectively. The samples were obtained from non-antibiotic-taking women of age 50+ receiving care in the Kaiser Permanente Washington healthcare system.

RESULTS

Here we show that despite a nearly three-fold drop in the prescription of ciprofloxacin between 2015 and 2021, the rates of gut carriage of ciprofloxacin-resistant E. coli increased from 14.2 % to 19.8% (P = .004). This is driven by a significant increase of isolates from the pandemic multi-drug resistant clonal group ST1193 (1.7% to 4.2%; P = .009) and isolates with relatively few ciprofloxacin-resistance determining chromosomal mutations (2.3% to 7.4%; P = .00003). Though prevalence of isolates with the plasmid-associated ciprofloxacin resistance dropped (59.0% to 30.9%; P = 2.7E-06), the isolates co-resistance to third generation cephalosporins has increased from 14.1% to 31.5% (P = .002).

CONCLUSIONS

Despite reduction in ciprofloxacin prescriptions, community circulation of the resistant uropathogenic E. coli increased with a rise of co-resistance to third generation cephalosporins. Thus, to reduce the rates of urinary tract infections refractory to antibiotic treatment, greater focus should be on controlling the resistant bacteria in gut microbiota.

Is patients' rurality associated with in-hospital sepsis death in US hospitals?

Background

The focus of this study was to explore the association of patients' rurality and other patient and hospital-related factors with in-hospital sepsis mortality to identify possible health disparities across United States hospitals.

Methods

The National Inpatient Sample was used to identify nationwide sepsis patients (n = 1,977,537, weighted n = 9,887,682) from 2016 to 2019. We used multivariate survey logistic regression models to identify predictors for how patients' rurality is associated with in-hospital death.

Findings

During the study periods, in-hospital death rates among sepsis inpatients continuously decreased (11.3% in 2016 to 9.9% in 2019) for all rurality levels. Rao-Schott Chi-Square tests demonstrated that certain patient and hospital factors had varied in-hospital death rates. Multivariate survey logistic regressions suggested that rural areas, minorities, females, older adults, low-income, and uninsured patients have higher odds of in-hospital mortality. Further, specific census divisions like New England, Middle Atlantic, and East North Central had greater in-hospital sepsis death odds.

Conclusion

Rurality was associated with increased in-hospital sepsis death across multiple patient populations and locations. Further, rurality in New England, Middle Atlantic, and East North Central locations is exceptionally high odds. In addition, minority races in rural areas also have an increased odds of in-hospital death. Therefore, rural healthcare requires a more significant influx of resources and should also include assessing patient-related factors.

Increase in the Rate of Gut Carriage of Fluoroquinolone-Resistant Escherichia coli despite a Reduction in Antibiotic Prescriptions

Background : Fluoroquinolone use for urinary tract infections has been steadily declining. Gut microbiota is the main reservoir for uropathogenic Escherichia coli but whether the carriage of fluoroquinolone-resistant E. coli has been changing is unknown. Methods . We determined the frequency of isolation and other characteristics of E. coli nonsuceptible to fluoroquinolones (at ³0.5 mg/L of ciprofloxacin) in 515 and 1605 E. coli -positive fecal samples collected in 2015 and 2021, respectively, from non-antibiotic- taking women of age 50+ receiving care in the Seattle area Kaiser Permanente Washington healthcare system. Results . Between 2015 and 2021 the prescription of fluoroquinolones dropped nearly three-fold in the study population. During the same period, the rates of gut carriage of fluoroquinolone-resistant E. coli increased from 14.4 % to 19.9% (P=.005), driven by a significant increase of isolates from the recently emerged, pandemic multi-drug resistant clonal group ST1193 (1.7% to 4.3%; P=.007) and those with an incomplete set of or no fluoroquinolone-resistance determining mutations (2.3% to 7.5%; P<.001). While prevalence of the resistance-associated mobile genes among the isolates dropped from 64.1% to 32.6% (P<.001), co-resistance to third generation cephalosporins has increased 21.5% to 33.1%, P=.044). Conclusion . Despite reduction in fluoroquinolone prescriptions, gut carriage of fluoroquinolone-resistant uropathogenic E. coli increased with a rise of previously sporadic lineages and co-resistance to third generation cephalosporins. Thus, to reduce the rates of antibiotic resistant urinary tract infections, greater focus should be on controlling the gut carriage of resistant bacteria.

Sepsis: emerging pathogens and antimicrobial resistance in Ethiopian referral hospitals

Background

Sepsis due to multidrug resistant (MDR) bacteria is a growing public health problem mainly in low-income countries.

Methods

A multicenter study was conducted between October 2019 and September 2020 at four hospitals located in central (Tikur Anbessa and Yekatit 12), southern (Hawassa) and northern (Dessie) parts of Ethiopia. A total of 1416 patients clinically investigated for sepsis were enrolled. The number of patients from Tikur Anbessa, Yekatit 12, Dessie and Hawassa hospital was 501, 298, 301 and 316, respectively. At each study site, blood culture was performed from all patients and positive cultures were characterized by their colony characteristics, gram stain and conventional biochemical tests. Each bacterial species was confirmed using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI TOF). Antimicrobial resistance pattern of bacteria was determined by disc diffusion. Logistic regression analysis was used to assess associations of dependent and independent variables. A p-value < 0.05 was considered as statistically significant. The data was analyzed using SPSS version 25.

Results

Among 1416 blood cultures performed, 40.6% yielded growth. Among these, 27.2%, 0.3% and 13.1%, were positive for pathogenic bacteria, yeast cells and possible contaminants respectively. Klebsiella pneumoniae (26.1%), Klebsiella variicola (18.1%) and E. coli (12.4%) were the most frequent. Most K. variicola were detected at Dessie (61%) and Hawassa (36.4%). Almost all Pantoea dispersa (95.2%) were isolated at Dessie. Rare isolates (0.5% or 0.2% each) included Leclercia adecarboxylata, Raoultella ornithinolytica, Stenotrophomonas maltophilia, Achromobacter xylosoxidans, Burkholderia cepacia, Kosakonia cowanii and Lelliottia amnigena. Enterobacteriaceae most often showed resistance to ampicillin (96.2%), ceftriaxone (78.3%), cefotaxime (78%), cefuroxime (78%) and ceftazidime (76.4%). MDR frequency of Enterobacteriaceae at Hawassa, Tikur Anbessa, Yekatit 12 and Dessie hospital was 95.1%, 93.2%, 87.3% and 67.7%, respectively. Carbapenem resistance was detected in 17.1% of K. pneumoniae (n = 111), 27.7% of E. cloacae (n = 22) and 58.8% of Acinetobacter baumannii (n = 34).

Conclusion

Diverse and emerging gram-negative bacterial etiologies of sepsis were identified. High multidrug resistance frequency was detected. Both on sepsis etiology types and MDR frequencies, substantial variation between hospitals was determined. Strategies to control MDR should be adapted to specific hospitals. Standard bacteriological services capable of monitoring emerging drug-resistant sepsis etiologies are essential for effective antimicrobial stewardship.

Prescribing for different antibiotic classes across age groups in the Kaiser Permanente Northern California population in association with influenza incidence, 2010-2018

There is limited information on the volume of antibiotic prescribing that is influenza-associated, resulting from influenza infections and their complications (such as streptococcal pharyngitis). We estimated that for the Kaiser Permanente Northern California population during 2010-2018, 3.4% (2.8%-4%) of all macrolide prescriptions (fills), 2.7% (2.3%-3.2%) of all aminopenicillin prescriptions, 3.1% (2.4%-3.9%) of all 3rd generation cephalosporins prescriptions, 2.2% (1.8%-2.6%) of all protected aminopenicillin prescriptions and 1.3% (1%-1.6%) of all quinolone prescriptions were influenza-associated. The corresponding proportions were higher for select age groups, e.g. 4.3% of macrolide prescribing in ages over 50 years, 5.1% (3.3%-6.8%) of aminopenicillin prescribing in ages 5-17 years and 3.3% (1.9%-4.6%) in ages <5 years was influenza-associated. The relative contribution of influenza to antibiotic prescribing for respiratory diagnoses without a bacterial indication in ages over 5 years was higher than the corresponding relative contribution to prescribing for all diagnoses. Our results suggest a modest benefit of increasing influenza vaccination coverage for reducing prescribing for the five studied antibiotic classes, particularly for macrolides in ages over 50 years and aminopenicillins in ages <18 years, and the potential benefit of other measures to reduce unnecessary antibiotic prescribing for respiratory diagnoses with no bacterial indication, both of which may contribute to the mitigation of antimicrobial resistance.

Rhamnetin, a Natural Flavonoid, Ameliorates Organ Damage in a Mouse Model of Carbapenem-Resistant Acinetobacter baumannii-Induced Sepsis

In sepsis, the persistence of uncontrolled inflammatory response of infected host cells eventually leads to severe lung and organ failure and, ultimately, death. Carbapenem-resistant Acinetobacter baumannii (CRAB), causative bacteria of sepsis and lung failure in acute cases, belongs to a group of critical pathogens that cannot be eradicated using the currently available antibiotics. This underlines the necessity of developing new modes of therapeutics that can control sepsis at the initial stages. In this study, we investigated the anti-inflammatory activities in vitro and in vivo and the antiseptic effects of rhamnetin, a naturally occurring flavonoid. We found that among its isoforms, the potency of rhamnetin was less explored but rhamnetin possessed superior anti-inflammatory activity with least cytotoxicity. Rhamnetin showed significant anti-inflammatory effects in lipopolysaccharide-, CRAB-, and Escherichia coli (E. coli)-stimulated mouse macrophages by inhibiting the release of interleukin-6 and nitric oxide. In a mouse model of sepsis infected with clinically isolated CRAB or E. coli, rhamnetin significantly reduced the bacterial burden in the organs. In addition, normalized pro-inflammatory cytokine levels in lung lysates and histological analysis of lung tissue indicated alleviation of lung damage. This study implies that a potent natural product such as rhamnetin could be a future therapeutic for treating carbapenem-resistant gram-negative sepsis.

Photothermally responsive chitosan-coated iron oxide nanoparticles for enhanced eradication of bacterial biofilms

This work developed a pH/NIR responsive antibacterial agent (CS-FeNPs) composed of chitosan (CS) and Fe₃O₄ nanoparticles (FeNPs). CS triggers bacterial attraction through surface charge, while Fe acts as a photothermal agent (PTA). The CS-Fe NPs exhibited antibacterial and antibiofilm activity against both bacteria (G+/G-). However, higher activity was observed against bacteria (G-) due to electrostatic interactions. The CS-FeNPs bind with the bacterial membrane through electrostatic interactions and disturb bacterial cells. Later, in an acidic environment, CS-FeNPs bind with bacterial membrane, and NIR irradiation leads the antibacterial activity. CS-FeNPs exhibited a potential photothermal conversion efficiency (η) of 21.53 %. Thus, it converts NIR irradiation into heat to kill the bacterial pathogen. The CS-FeNPs were found to be less cytotoxic with great antibacterial efficiency on planktonic bacteria and their biofilm, which indicates that they deserve to develop potential and safe treatment strategies for the treatment of bacterial infections.

Aminoglycoside-mimicking carbonized polymer dots for bacteremia treatment

Bacteremia and associated bacterial sepsis are potentially fatal and occur when the host response to microbial invasion is impaired or compromised. This motivated us to develop carbonized polymer dots (CPDs_Man/AA) from a mixture of mannose (Man) and positively charged amino acids [AAs; lysine, arginine (Arg), or histidine] through a one-step mild pyrolysis procedure, which effectively inhibited drug-resistant bacterial strains isolated from septic patients. The as-prepared CPDs_Man/AA showed broad-spectrum antibacterial activity, including multidrug-resistant bacteria, even in human plasma. The minimal inhibitory concentration of CPDs_Man/Arg is ca. 1.0 μg mL^-1, which is comparable to or lower than those of other tested antibiotics (e.g., ampicillin, gentamicin, and vancomycin). In addition to directly disrupting bacterial membranes, the CPDs_Man/Arg feature a structure similar to aminoglycoside antibiotics that could bind to 16S rRNA, thereby blocking bacterial protein synthesis. In vitro cytotoxic and hemolytic assays demonstrated the high biocompatibility of the CPDs_Man/AA. In addition, in vivo studies on methicillin-resistant Staphylococcus aureus-infected mice treated with the CPDs_Man/Arg showed a significant decrease in mortality-even better than that of antibiotics. Overall, the synthesis of the CPDs_Man/AA is cost-efficient, straightforward, and effective for treating bacteremia. The polymeric features of the CPDs_Man/Arg, including cationic charges and specific groups, can be recognized as a safe and broad-spectrum biocide to lessen our reliance on antibiotics to treat systemic bacterial infections in the future.

Study of the Antimicrobial Activity of the Chinese Dong Ethnic Minority Medicine, Madeng’ai

The overuse of antibiotics has contributed to the emergence of multidrug-resistant bacteria, which poses a challenging task for clinical therapy. Thus, new agents with antibiotic efficacy against multidrug-resistant infections are needed. The traditional Dong ethnic minority medicines have emerged as a new source for prodrug selection. Among them, Madeng'ai (PotentillafreynianaBornm) is widely used by the folk for anti-infection and wound healing, although the mechanisms remain unclear. In this study, the antimicrobial activities of Dong medicine Madeng'ai were evaluated both in vitro and in vivo. S. aureus, E. coli, E. faecalis, P. aeruginosa, K. pneumoniae, and A. baumannii were cultured in LB media, different concentrations of Madeng'ai powder solution were added to the LB agar plates to evaluate minimal inhibitory concentration. An animal study was performed on a mouse excisional wound model combined with bacterial solution injection in the wound area. After Madeng'ai or PBS treatment, hematoxylin and eosin analysis were used for pathological analysis of skin tissues from the infected area. Madeng'ai powder solution over 2 mg/mL concentration completely inhibited E. coli growth. At 4.0 mg/mL, Madeng'ai significantly inhibited the growth of E. faecalis, Pseudomonas aeruginosa (PAE), Klebsiella pneumoniae, and Acinetobacter baumannii. The mouse model revealed that Madeng'ai could suppress the growth of MRSA and PAE and accelerate healing of cutaneous wounds. Madeng'ai, a newly discovered Dong ethnic minority medicine possesses considerable antimicrobial activity against both human normal pathogenic bacteria and multiresistance bacteria such as Pseudomonas aeruginosa, S. aureus, and Acinetobacter baumannii. Therefore, Madeng'ai has great potential for further study and clinical application.

Global Distribution of O Serotypes and Antibiotic Resistance in Extraintestinal Pathogenic Escherichia coli Collected From the Blood of Patients With Bacteremia Across Multiple Surveillance Studies

BACKGROUND

Extraintestinal pathogenic Escherichia coli (ExPEC) is the leading cause of bacteremia worldwide, with older populations having increased risk of invasive bacterial disease. Increasing resistance to first-line antibiotics and emergence of multidrug-resistant (MDR) strains represent major treatment challenges. ExPEC O serotypes are key targets for potential multivalent conjugate vaccine development. Therefore, we evaluated the O serotype distribution and antibiotic resistance profiles of ExPEC strains causing bloodstream infections across 4 regions.

METHODS

Blood culture isolates from patients aged ≥60 years collected during 5 retrospective E. coli surveillance studies in Europe, North America, Asia-Pacific, and South America (2011-2017) were analyzed. Isolates were O serotyped by agglutination; O genotyping was performed for nontypeable isolates. Antimicrobial susceptibility testing was also conducted.

RESULTS

Among 3217 ExPEC blood culture isolates, the most ubiquitous O serotype was O25 (n = 737 [22.9%]), followed by O2, O6, O1, O75, O15, O8, O16, O4, O18, O77 group, O153, O9, O101/O162, O86, and O13 (prevalence of ≥1%). The prevalence of these O serotypes was generally consistent across regions, apart from South America; together, these 16 O serotypes represented 77.6% of all ExPEC bacteremia isolates analyzed. The overall MDR frequency was 10.7%, with limited variation between regions. Within the MDR subset (n = 345), O25 showed a dominant prevalence of 63.2% (n = 218).

CONCLUSIONS

Predominant O serotypes among ExPEC bacteremia isolates are widespread across different regions. O25 was the most prevalent O serotype overall and particularly dominant among MDR isolates. These findings may inform the design of multivalent conjugate vaccines that can target the predominant O serotypes associated with invasive ExPEC disease in older adults.

Accuracy of Direct Antimicrobial Susceptibility of Gram-Negative Bacteria from Positive Blood Cultures using MicroScan System and Value of Using Expert Rules for β-Lactam Agents

Direct antimicrobial susceptibility testing (AST) of positive blood cultures with Gram-negative bacteria produces results within 24 h, compared to 48 to 96 h with conventional methods. Positive clinical blood cultures were studied, supplemented with contrived blood cultures inoculated with a spectrum of resistant isolates. Bacterial inocula used for direct AST were quantitated. Direct AST was performed using MicroScan NM43 trays inoculated directly from positive blood cultures (100 μL in 25 mL water) and incubated using a WalkAway instrument, with trays read after 16 h. Reference AST was performed the following day from growth on solid medium using the same trays. Agreement of AST results between direct and reference methods, with and without the use of three expert rules for β-lactams, was evaluated using FDA categorical agreement criteria. Of 86 specimens tested (41 clinical specimens and 45 contrived specimens), the mean bacterial load in positive blood cultures was 8.98 log₁₀ CFU/mL. Fifteen isolates contained extended-spectrum β-lactamases, and 27 contained carbapenemases. Of 1,985 pairs of AST categorical results for 25 antimicrobials, 55.0% were susceptible, 4.7% intermediate, and 40.4% resistant by reference testing. Overall categorical agreement was 92.3%, with 5.3% minor errors, 1.9% major errors, and 0.4% very major errors. Agreement was higher for non-β-lactam agents (95.8%) than for β-lactam agents (90.3%; P < 0.0001). Application of expert rules increased agreement for β-lactam agents to 94.6%. The methods used achieved the study goal of producing accurate, cost-effective AST results directly from positive blood cultures using MicroScan trays with a 16-h incubation time without the need for additional testing. Use of three expert β-lactam rules improved accuracy.

Diagnostic Testing for Sepsis: A Systematic Review of Economic Evaluations

Introduction: Sepsis is a serious and expensive healthcare problem, when caused by a multidrug-resistant (MDR) bacteria mortality and costs increase. A reduction in the time until the start of treatment improves clinical results. The objective is to perform a systematic review of economic evaluations to analyze the cost-effectiveness of diagnostic methods in sepsis and to draw lessons on the methods used to incorporate antimicrobial resistance (AMR) in these studies. Material and Methods: the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the Consolidated Health Economic Evaluation Reporting standards (CHEERS) checklist was used to extract the information from the texts. Results: A total of 16 articles were found. A decision model was performed in 14. We found two ways to handle resistance while modelling: the test could identify infections caused by a resistant pathogen or resistance-related inputs, or outcomes were included (the incidence of AMR in sepsis patients, antibiotic use, and infection caused by resistant bacterial pathogens). Conclusion: Using a diagnostic technique to detect sepsis early on is more cost-effective than standard care. Setting a direct relationship between the implementation of a testing strategy and the reduction of AMR cases, we made several assumptions about the efficacy of antibiotics and the length-of-stay of patients.

Trends in urinary tract infection hospitalization in older adults in Spain from 2000-2015

Objective

To analyze trends in urinary tract infection hospitalization (cystitis, pyelonephritis, prostatitis and non-specified UTI) among patients over 65 years in Spain from 2000–2015.

Methods

We conducted a retrospective observational study using the Spanish Hospitalization Minimum Data Set (CMBD), with codifications by the International Classification of Diseases (ICD-9). We collected data on sex, age, type of discharge, main diagnosis, comorbid diagnosis, length of stay, and global cost. All the hospitalizations were grouped by age into three categories: 65–74 years old, 75–84 years old, and 85 years old and above. In the descriptive statistical analysis, crude rates were defined as hospitalizations per 1,000 inhabitants aged ≥65. To identify trends over time, we performed a Joinpoint regression.

Results

From 2000–2015, we found 387,010 hospitalizations coded as UTIs (54,427 pyelonephritis, 15,869 prostatitis, 2643 cystitis and 314,071 non-specified UTI). The crude rate of hospitalization for UTIs between 2000 and 2015 ranged from 2.09 in 2000 to 4.33 in 2015 Rates of hospitalization were higher in men than in women, except with pyelonephritis. By age group, higher rates were observed in patients aged 85 years or older, barring prostatitis-related hospitalizations. Joinpoint analyses showed an average annual percentage increase (AAPC) in incidence rates of 4.9% (95% CI 3.2;6.1) in UTI hospitalizations. We observed two joinpoints, in 2010 and 2013, that found trends of 5.5% between 2000 and 2010 (95% CI 4.7;6.4), 1.5% between 2010 and 2013 (95% CI -6.0;9.6) and 6.8% between 2013 and 2015 (95% CI -0.3;14.4).

Conclusions

The urinary infection-related hospitalization rate in Spain doubled during the period 2000–2015. The highest hospitalization rates occurred in men, in the ≥85 years old age group, and in non-specified UTIs. There were increases in all types of urinary tract infection, with non-specified UTIs having the greatest growth. Understanding these changing trends can be useful for health planning.

Dysregulation of human beta-defensin-3 expression in the peripheral blood of patients with sepsis

Objectives:

Sepsis is a serious medical condition caused by the body’s systemic inflammatory response to infections. The antimicrobial peptides, human beta-defensins, play a key role in modulating host immune responses, and aberrant expression of human beta-defensins has been implicated in many infections and inflammatory diseases. However, little is known about the expression of human beta-defensin-3 in systemic infectious diseases.

Methods:

We investigated the gene expression and protein level of human beta-defensin-3 in peripheral whole blood from 107 participants—67 patients with sepsis and 40 healthy controls—and evaluated the feasibility of human beta-defensin-3 as an indicator for sepsis. Total RNA was extracted from peripheral blood samples, and relative mRNA expression of human beta-defensin-3 was determined by reverse transcription-quantitative polymerase chain reaction. Plasma concentration of human beta-defensin-3 was measured by enzyme-linked immunosorbent assay. Pearson’s correlation analysis was performed to assess the relationship between human beta-defensin-3 mRNA and protein levels. Receiver operating characteristic analysis was performed to evaluate the value of human beta-defensin-3 as a biomarker for sepsis.

Results:

Human beta-defensin-3 mRNA expression was significantly downregulated in sepsis patients compared to controls (p = 0.001). The mean fold change of mRNA expression (±standard error) was 0.82 ± 0.63 in sepsis patients and 1.39 ± 1.09 in controls. Plasma concentration of human beta-defensin-3 (pg/mL) was significantly lower in sepsis patients compared to healthy controls (p = 0.039). The mean protein concentration (±standard error) was 539.6 ± 39.4 in sepsis patients and 715.5 ± 53 in controls. There was a significant correlation between human beta-defensin-3 mRNA expression and the corresponding protein level in sepsis patients (r = 0.358, p = 0.04), but not in healthy controls (r = 0.124, p = 0.51). For discriminating sepsis patients from healthy controls, the area under the receiver operating characteristic curve was 0.722 (95% confidence interval: 0.597–0.847, p = 0.002) for human beta-defensin-3 mRNA and 0.689 (95% confidence interval: 0.557–0.827, p = 0.009) for human beta-defensin-3 protein.

Conclusion:

This is the first study to show the downregulation of human beta-defensin-3 gene expression and protein level in sepsis, which may contribute to the complex immunological imbalance in sepsis. The significant correlation between human beta-defensin-3 mRNA expression and protein concentration suggests that mRNA expression could be used to predict protein level. Our study also showed a potential role of human beta-defensin-3 as a blood-based biomarker for sepsis. More studies on the clinical significance of human beta-defensin-3 in sepsis could further support a biomarker development.

Lipoplexes to Deliver Oligonucleotides in Gram-Positive and Gram-Negative Bacteria: Towards Treatment of Blood Infections

Bacterial resistance to antibiotics threatens the ability to treat life-threatening bloodstream infections. Oligonucleotides (ONs) composed of nucleic acid mimics (NAMs) able to inhibit essential genes can become an alternative to traditional antibiotics, as long as they are safely transported in human serum upon intravenous administration and they are carried across the multilayered bacterial envelopes, impermeable to ONs. In this study, fusogenic liposomes were considered to transport the ONs and promote their internalization in clinically relevant bacteria. Locked nucleic acids and 2′-OMethyl RNA were evaluated as model NAMs and formulated into DOTAP–DOPE liposomes followed by post-PEGylation. Our data showed a complexation stability between the post-PEGylated liposomes and the ONs of over 82%, during 24 h in native human serum, as determined by fluorescence correlation spectroscopy. Quantification by a lipid-mixing assay showed that liposomes, with and without post-PEGylation, fused with all bacteria tested. Such fusion promoted the delivery of a fraction of the ONs into the bacterial cytosol, as observed by fluorescence in situ hybridization and bacterial fractionation. In short, we demonstrated for the first time that liposomes can safely transport ONs in human serum and intracellularly deliver them in both Gram-negative and -positive bacteria, which holds promise towards the treatment of bloodstream infections.

Burden of Antimicrobial Resistance: Compared to What?

The increased focus on the public health burden of antimicrobial resistance (AMR) raises conceptual challenges, such as determining how much harm multidrug-resistant organisms do compared to what, or how to establish the burden. Here, we present a counterfactual framework and provide guidance to harmonize methodologies and optimize study quality. In AMR-burden studies, 2 counterfactual approaches have been applied: the harm of drug-resistant infections relative to the harm of the same drug-susceptible infections (the susceptible-infection counterfactual); and the total harm of drug-resistant infections relative to a situation where such infections were prevented (the no-infection counterfactual). We propose to use an intervention-based causal approach to determine the most appropriate counterfactual. We show that intervention scenarios, species of interest, and types of infections influence the choice of counterfactual. We recommend using purpose-designed cohort studies to apply this counterfactual framework, whereby the selection of cohorts (patients with drug-resistant, drug-susceptible infections, and those with no infection) should be based on matching on time to infection through exposure density sampling to avoid biased estimates. Application of survival methods is preferred, considering competing events. We conclude by advocating estimation of the burden of AMR by using the no-infection and susceptible-infection counterfactuals. The resulting numbers will provide policy-relevant information about the upper and lower bound of future interventions designed to control AMR. The counterfactuals should be applied in cohort studies, whereby selection of the unexposed cohorts should be based on exposure density sampling, applying methods avoiding time-dependent bias and confounding.

Can the Cecal Ligation and Puncture Model Be Repurposed To Better Inform Therapy in Human Sepsis?

A recent report by the National Institutes of Health on sepsis research has implied there is a trend to move away from mouse models of sepsis. The most commonly used animal model to study the pathogenesis of human sepsis is cecal ligation and puncture (CLP) in mice. The model has been the mainstay of sepsis research for decades and continues to be considered the gold standard to inform novel pathways of sepsis physiology and its therapeutic direction. As there have been many criticisms of the model, particularly regarding its relevance to human disease, how this model might be repurposed to be more reflective of the human condition begs discussion. In this piece, we compare and contrast the mouse microbiome of the CLP model to the emerging science of the microbiome of human sepsis and discuss the relevance for mice to harbor the specific pathogens present in the human microbiome during sepsis, as well as an underlying disease process to mimic the characteristics of those patients with undesirable outcomes. How to repurpose this model to incorporate these "human factors" is discussed in detail and suggestions offered.

The association of a reduced susceptibility to moxifloxacin in causative Clostridium (Clostridioides) difficile strain with the clinical outcome of patients

OBJECTIVES

To investigate the relationship between Clostridium (Clostridioides) difficile strain characteristics and C. difficile infection (CDI) outcome.

METHODS

Between October and December 2017, 16 hospitals collected epidemiological data according to the European Centre for Disease Prevention and Control (ECDC) surveillance protocol for CDI. C. difficile isolates were characterized by ribotyping, toxin genes detection and antibiotic susceptibility testing to metronidazole, vancomycin and moxifloxacin.

RESULTS

The overall mean CDI incidence density was 4.5 [95% CI 3.6-5.3] cases per 10,000 patient-days. From the 433 CDI cases, 330 (76.2%) were healthcare-associated, 52 (12.0%) cases were community-associated or of unknown origin and 51 (11.8%) CDI cases recurrent; a complicated course of CDI was reported in 65 cases (15.0%). Eighty-eight (20.3%) of patients died and 59 of them within 30 days after the CDI diagnosis. From the 379 C. difficile isolates, the most prevalent PCR ribotypes were 001 (n = 127, 33.5%) and 176 (n = 44, 11.6%). A total of 186 (49.1%) isolates showed a reduced susceptibility to moxifloxacin (> 4 mg/L) and 96.4% of them had Thr82Ile in the GyrA. Nineteen isolates revealed reduced susceptibility to metronidazole and two isolates to vancomycin (> 2 mg/L). A fatal outcome was associated with a reduced susceptibility to moxifloxacin, the advanced age of the patients and a complicated course of CDI (p<0.05). No association between ribotype, binary toxin and a reduced susceptibility to moxifloxacin and complicated course or recurrent CDI was found.

CONCLUSIONS

A reduced susceptibility to moxifloxacin, in causative C. difficile strains was associated with fatal outcome of the patients, therefore it is an important marker in surveillance of CDI.

Incidence and mortality of hospital- and ICU-treated sepsis: results from an updated and expanded systematic review and meta-analysis

Purpose

To investigate the global burden of sepsis in hospitalized adults by updating and expanding a systematic review and meta-analysis and to compare findings with recent Institute for Health Metrics and Evaluation (IHME) sepsis estimates.

Methods

Thirteen electronic databases were searched for studies on population-level sepsis incidence defined according to clinical criteria (Sepsis-1, -2: severe sepsis criteria, or sepsis-3: sepsis criteria) or relevant ICD-codes. The search of the original systematic review was updated for studies published 05/2015–02/2019 and complemented by a search targeting low- or middle-income-country (LMIC) studies published 01/1979–02/2019. We performed a random-effects meta-analysis with incidence of hospital- and ICU-treated sepsis and proportion of deaths among these sepsis cases as outcomes.

Results

Of 4746 results, 28 met the inclusion criteria. 21 studies contributed data for the meta-analysis and were pooled with 30 studies from the original meta-analysis. Pooled incidence was 189 [95% CI 133, 267] hospital-treated sepsis cases per 100,000 person-years. An estimated 26.7% [22.9, 30.7] of sepsis patients died. Estimated incidence of ICU-treated sepsis was 58 [42, 81] per 100,000 person-years, of which 41.9% [95% CI 36.2, 47.7] died prior to hospital discharge. There was a considerably higher incidence of hospital-treated sepsis observed after 2008 (+ 46% compared to the overall time frame).

Conclusions

Compared to results from the IHME study, we found an approximately 50% lower incidence of hospital-treated sepsis. The majority of studies included were based on administrative data, thus limiting our ability to assess temporal trends and regional differences. The incidence of sepsis remains unknown for the vast majority of LMICs, highlighting the urgent need for improved epidemiological sepsis surveillance.

Electronic supplementary material

The online version of this article (10.1007/s00134-020-06151-x) contains supplementary material, which is available to authorized users.

The relation between prescribing of different antibiotics and rates of mortality with sepsis in US adults

BACKGROUND

Antibiotic use contributes to the rates of sepsis and the associated mortality, particularly through lack of clearance of resistant infections following antibiotic treatment. At the same time, there is limited information on the effects of prescribing of some antibiotics vs. others on subsequent sepsis and sepsis-related mortality.

METHODS

We used a multivariable mixed-effects model to relate state-specific rates of outpatient prescribing overall for oral fluoroquinolones, penicillins, macrolides, and cephalosporins between 2014 and 2015 to state-specific rates of mortality with sepsis (ICD-10 codes A40-41 present as either underlying or contributing causes of death on a death certificate) in different age groups of US adults between 2014 and 2015, adjusting for additional covariates and random effects associated with the ten US Health and Human Services (HHS) regions.

RESULTS

Increase in the rate of prescribing of oral penicillins by 1 annual dose per 1000 state residents was associated with increases in annual rates of mortality with sepsis of 0.95 (95% CI (0.02,1.88)) per 100,000 persons aged 75-84y, and of 2.97 (0.72,5.22) per 100,000 persons aged 85 + y. Additionally, the percent of individuals aged 50-64y lacking health insurance, as well as the percent of individuals aged 65-84y who are African-American were associated with rates of mortality with sepsis in the corresponding age groups.

CONCLUSIONS

Our results suggest that prescribing of penicillins is associated with rates of mortality with sepsis in older US adults. Those results, as well as the related epidemiological data suggest that replacement of certain antibiotics, particularly penicillins in the treatment of different syndromes should be considered with the aim of reducing the rates of severe outcomes, including mortality related to bacterial infections.

Salmonella Typhimurium biofilm disruption by a human antibody that binds a pan-amyloid epitope on curli

Bacterial biofilms, especially those associated with implanted medical devices, are difficult to eradicate. Curli amyloid fibers are important components of the biofilms formed by the Enterobacteriaceae family. Here, we show that a human monoclonal antibody with pan-amyloid-binding activity (mAb 3H3) can disrupt biofilms formed by Salmonella enterica serovar Typhimurium in vitro and in vivo. The antibody disrupts the biofilm structure, enhancing biofilm eradication by antibiotics and immune cells. In mice, 3H3 injections allow antibiotic-mediated clearance of catheter-associated S. Typhimurium biofilms. Thus, monoclonal antibodies that bind a pan-amyloid epitope have potential to prevent or eradicate bacterial biofilms.

Curli amyloid fibers are important components of bacterial biofilms formed by E. coli and Salmonella. Here, Tursi et al. show that a human monoclonal antibody with pan-amyloid binding activity can disrupt biofilms formed by Salmonella Typhimurium in vitro and in vivo.

Mathematical modelling for antibiotic resistance control policy: do we know enough?

BACKGROUND

Antibiotics remain the cornerstone of modern medicine. Yet there exists an inherent dilemma in their use: we are able to prevent harm by administering antibiotic treatment as necessary to both humans and animals, but we must be mindful of limiting the spread of resistance and safeguarding the efficacy of antibiotics for current and future generations. Policies that strike the right balance must be informed by a transparent rationale that relies on a robust evidence base.

MAIN TEXT

One way to generate the evidence base needed to inform policies for managing antibiotic resistance is by using mathematical models. These models can distil the key drivers of the dynamics of resistance transmission from complex infection and evolutionary processes, as well as predict likely responses to policy change in silico. Here, we ask whether we know enough about antibiotic resistance for mathematical modelling to robustly and effectively inform policy. We consider in turn the challenges associated with capturing antibiotic resistance evolution using mathematical models, and with translating mathematical modelling evidence into policy.

CONCLUSIONS

We suggest that in spite of promising advances, we lack a complete understanding of key principles. From this we advocate for priority areas of future empirical and theoretical research.

Levels of outpatient prescribing for four major antibiotic classes and rates of septicemia hospitalization in adults in different US states - a statistical analysis

BACKGROUND

Rates of sepsis/septicemia hospitalization in the US have risen significantly during recent years. Antibiotic resistance and use may contribute to those rates through various mechanisms, including lack of clearance of resistant infections following antibiotic treatment, with some of those infections subsequently devolving into sepsis. At the same time, there is limited information on the effect of prescribing of certain antibiotics vs. others on the rates of septicemia and sepsis-related hospitalizations and mortality.

METHODS

We used multivariable linear regression to relate state-specific rates of outpatient prescribing overall for oral fluoroquinolones, penicillins, macrolides, and cephalosporins between 2011 and 2012 to state-specific rates of septicemia hospitalization (ICD-9 codes 038.xx present anywhere on a discharge diagnosis) in each of the following age groups of adults: (18-49y, 50-64y, 65-74y, 75-84y, 85 + y) reported to the Healthcare Cost and Utilization Project (HCUP) between 2011 and 2012, adjusting for additional covariates, and random effects associated with the ten US Health and Human Services (HHS) regions.

RESULTS

Increase in the rate of prescribing of oral penicillins by 1 annual dose per 1000 state residents was associated with increases in annual septicemia hospitalization rates of 0.19 (95% CI (0.02,0.37)) per 10,000 persons aged 50-64y, of 0.48(0.12,0.84) per 10,000 persons aged 65-74y, and of 0.81(0.17,1.40) per 10,000 persons aged 74-84y. Increase by 1 in the percent of African Americans among state residents in a given age group was associated with increases in annual septicemia hospitalization rates of 2.3(0.32,4.2) per 10,000 persons aged 75-84y, and of 5.3(1.1,9.5) per 10,000 persons aged over 85y. Average minimal daily temperature was positively associated with septicemia hospitalization rates in persons aged 18-49y, 50-64y, 75-84y and over 85y.

CONCLUSIONS

Our results suggest positive associations between the rates of prescribing for penicillins and the rates of hospitalization with septicemia in US adults aged 50-84y. Further studies are needed to better understand the potential effect of antibiotic replacement in the treatment of various syndromes, including the potential impact of the recent US FDA guidelines on restriction of fluoroquinolone use, as well as the potential effect of changes in the practices for prescribing of penicillins on the rates of sepsis-related hospitalization and mortality.

Rise in mortality involving poisoning by medicaments other than narcotics, including poisoning by psychotropic drugs in different age/racial groups in the US

BACKGROUND

Increase in mortality involving poisoning, particularly by narcotics, is known to have been one of the factors that affected life expectancy in the US during the last two decades, especially for white Americans and Native Americans. However, the contribution of medicaments other than narcotics to mortality in different racial/age groups is less studied.

METHODS

We regressed annual rates of mortality involving poisoning by medicaments but not narcotics/psychodysleptics (ICD-10 codes T36-39.xx or T41-50.8 but not T40.xx present as either underlying or contributing causes of death), as well as annual rates of mortality for certain subcategories of the above, including mortality involving poisoning by psychotropic drugs but not narcotics/psychodysleptics (ICD-10 codes T43.xx but not T40.xx present as either underlying or contributing causes of death) in different age/racial groups for both the 2000-2011 period and the 2011-2017 period against calendar year.

RESULTS

Annual numbers of deaths involving poisoning by medicaments but not narcotics/psychodysleptics grew from 4,332 between 2000-2001 to 11,401 between 2016-2017, with the growth in the rates of those deaths being higher for the 2011-2017 period compared to the 2000-2011 period. The largest increases in the rates of mortality involving poisoning by medicaments but not narcotics/psychodysleptics were in non-elderly Non-Hispanic Native Americans, followed by Non-Hispanic whites. Most of those increases came from increases in the rates of mortality involving poisoning by psychotropic medications; the latter rates grew for the period of 2015-2017 vs. 2000-2002 by factors ranging from 2.75 for ages 35-44y to 5.37 for ages 55-64y.

CONCLUSIONS

There were major increases in mortality involving poisoning by non-narcotic, particularly psychotropic medicaments, especially in non-elderly non-Hispanic whites and Native Americans. Our results support the need for a comprehensive evaluation of the effect of psychotropic medications on health-related outcomes, including mortality for causes other than poisoning, and the impact of medication misuse.