Azithromycin regulates bacterial virulence and immune response in a murine model of ceftazidime-treated Pseudomonas aeruginosa acute pneumonia

Pseudomonas aeruginosa (PA) remains one of the leading causes of nosocomial acute pneumonia. The array of virulence factors expressed by PA and the intense immune response associated with PA pneumonia play a major role in the severity of these infections. New therapeutic approaches are needed to overcome the high resistance of PA to antibiotics and to reduce the direct damage to host tissues. Through its immunomodulatory and anti-virulence effects, azithromycin (AZM) has demonstrated clinical benefits in patients with chronic PA respiratory infections. However, there is relatively little evidence in PA acute pneumonia. We investigated the effects of AZM, as an adjunctive therapy combined with ceftazidime (CAZ), in a murine model of PA acute pneumonia. We observed that the combined therapy (i) reduces the weight loss of mice 24 h post-infection (hpi), (ii) decreases neutrophil influx into the lungs at 6 and 24 hpi, while this effect is absent in a LPS-induced pneumonia or when PA is pretreated with antibiotics and mice do not receive any antibiotics, and that (iii) AZM, alone or with CAZ, modulates the expression of PA quorum sensing regulators and virulence factors (LasI, LasA, PqsE, PhzM, ExoS). Our findings support beneficial effects of AZM with CAZ on PA acute pneumonia by both bacterial virulence and immune response modulations. Further investigations are needed to clarify the exact underlying mechanisms responsible for the reduction of the neutrophils influx and to better discriminate between direct immunomodulatory properties of AZM, and indirect effects on neutrophilia resulting from bacterial virulence modulation.

Sensitivity of Legionella pneumophila to phthalates and their substitutes

Phthalates constitute a family of anthropogenic chemicals developed to be used in the manufacture of plastics, solvents, and personal care products. Their dispersion and accumulation in many environments can occur at all stages of their use (from synthesis to recycling). However, many phthalates together with other accumulated engineered chemicals have been shown to interfere with hormone activities. These compounds are also in close contact with microorganisms that are free-living, in biofilms or in microbiota, within multicellular organisms. Herein, the activity of several phthalates and their substitutes were investigated on the opportunistic pathogen Legionella pneumophila, an aquatic microbe that can infect humans. Beside showing the toxicity of some phthalates, data suggested that Acetyl tributyl citrate (ATBC) and DBP (Di-n-butyl phthalate) at environmental doses (i.e. 10-6 M and 10-8 M) can modulate Legionella behavior in terms of motility, biofilm formation and response to antibiotics. A dose of 10-6 M mostly induced adverse effects for the bacteria, in contrast to a dose of 10-8 M. No perturbation of virulence towards Acanthamoeba castellanii was recorded. These behavioral alterations suggest that L. pneumophila is able to sense ATBC and DBP, in a cross-talk that either mimics the response to a native ligand, or dysregulates its physiology.

Distribution, Consequences, and Determinants of Time to Antibiotics in Children With Community-Onset Severe Bacterial Infection: A Secondary Analysis of a Prospective Population-Based Study

OBJECTIVES

To describe the distribution, consequences and potential determinants of time to antibiotics administration in children with community-onset severe bacterial infections (COSBIs).

DESIGN

Secondary analysis of the available data from a prospective population-based study from 2009 to 2014.

SETTING

An administrative area in western France accounting for 13% of the national pediatric population.

PATIENTS

All children from 1 month to 16 years old admitted to a PICU or who died before admission and had a COSBI.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The time to antibiotics was divided into patient interval (from first signs of COSBI to the first medical consultation) and medical interval (from the first consultation to appropriate antibiotics administration). The association between the medical interval and child outcome was studied by a multinomial logistic regression model and the potential determinants of the patient and medical intervals were by a Cox proportional-hazards model. Of the 227 children included (median age 2.1 yr), 22 died (9.7%), and 21 (9.3%) had severe sequelae at PICU discharge. Median patient and medical intervals were 7.0 hours (interquartile range [IQR], 2.0-16.5 hr) and 3.3 hours (IQR, 1.1-12.2 hr), respectively. The last quartile of medical interval was not associated with death (adjusted odds ratio [aOR], 3.7; 95% CI, 0.8-17.5) or survival with severe sequelae (aOR, 1.3; 95% CI, 0.4-4.0) versus survival without severe sequelae. Patient interval was shorter in younger children (adjusted hazard ratio [aHR], 0.95; 95% CI, 0.92-0.99), and medical interval was reduced when the first consultation was conducted in a hospital (aHR, 1.5; 95% CI, 1.1-2.0) versus outpatient medicine.

CONCLUSIONS

For children with COSBI, we found no significant association between medical interval and mortality or severe sequelae. An initial hospital referral could help reduce the time to antibiotics in COSBIs.

Prevalence of a cefazolin inoculum effect associated with blaZ gene types, and clinical outcomes among methicillin-susceptible Staphylococcus aureus blood isolates of patients with infective endocarditis

OBJECTIVES

A proportion of blaZ gene-positive methicillin-susceptible Staphylococcus aureus (MSSA) strains exhibits the cefazolin inoculum effect (CInE). Its clinical impact remains uncertain but could compromise the use of cefazolin in high-burden infections. To date, no study has been conducted in France or in Europe. We aimed to assess the prevalence of CInE and its association with blaZ beta-lactamase and S. aureus protein A (spa) types, and to assess the clinical outcomes in cefazolin-treated patients for infective endocarditis whose strain exhibited a CInE.

METHODS

This was a French single-center retrospective study of 51 MSSA strains from patients of the Nantes endocarditis prospective cohort, conducted between 2013 and 2018.

RESULTS

Cefazolin MIC₅₀ at high inoculum was 2 mg/L (IQR 1-2). CInE was found in 17.6 % of tested strains. Among blaZ-positive strains (n = 44), type A beta-lactamase was predominant (n = 25, 57 %). Thirty-seven S. aureus protein A (spa) types were found. No statistical association was shown between blaZ or spa types and CInE. CInE was neither associated with a higher rate of persistent bacteremia (25 % vs 56.3 %, p = 0.58) nor with clinical failure in patients treated with cefazolin, in comparison to patients with no CInE strain (25 % vs 56.3 %, p = 0.58).

CONCLUSION

The cefazolin inoculum effect was found in a substantial number of Staphylococcus aureus strains; however, minimum inhibitory concentrations remained globally low. CInE was not associated with a higher proportion of clinical failure on treatment.

Effect of Phthalates and Their Substitutes on the Physiology of Pseudomonas aeruginosa

Phthalates are used in a variety of applications—for example, as plasticizers in polyvinylchloride products to improve their flexibility—and can be easily released into the environment. In addition to being major persistent organic environmental pollutants, some phthalates are responsible for the carcinogenicity, teratogenicity, and endocrine disruption that are notably affecting steroidogenesis in mammals. Numerous studies have thus focused on deciphering their effects on mammals and eukaryotic cells. While multicellular organisms such as humans are known to display various microbiota, including all of the microorganisms that may be commensal, symbiotic, or pathogenic, few studies have aimed at investigating the relationships between phthalates and bacteria, notably regarding their effects on opportunistic pathogens and the severity of the associated pathologies. Herein, the effects of phthalates and their substitutes were investigated on the human pathogen, Pseudomonas aeruginosa, in terms of physiology, virulence, susceptibility to antibiotics, and ability to form biofilms. We show in particular that most of these compounds increased biofilm formation, while some of them enhanced the bacterial membrane fluidity and altered the bacterial morphology.

Assessment of Factors Associated With Community-Acquired Extended-Spectrum β-Lactamase-Producing Escherichia coli Urinary Tract Infections in France

IMPORTANCE

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is considered a leading pathogen contributing to the global burden of antimicrobial resistance.

OBJECTIVE

To better understand factors associated with the heterogeneity of community-acquired ESBL-producing E coli urinary tract infections (UTIs) in France.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study performed from January 1 to December 31, 2021, was based on data collected via PRIMO (Surveillance and Prevention of Antimicrobial Resistance in Primary Care and Nursing Homes), a nationwide clinical laboratory surveillance system in France. Strains of E coli isolated from community urine samples from January 1 to December 31, 2019, from 59 administrative departments of metropolitan France were included.

MAIN OUTCOMES AND MEASURES

Quasi-Poisson regression models were used to assess the associations between several ecological factors available on government and administration websites between 2010 and 2020 (demographic population structure, living conditions, baseline health care services, antibiotic consumptions, economic indicators, animal farming density, and environmental characteristics) and the number of ESBL-producing E coli strains isolated from urine samples of individuals with community-acquired UTI in 2019.

RESULTS

Among 444 281 E coli isolates from urine samples tested in 1013 laboratories, the mean prevalence of ESBL-producing E coli was 3.0% (range, 1.4%-8.8%). In an adjusted model, the number of community-acquired ESBL-producing E coli UTIs in each department was positively associated with the percentage of children younger than 5 years (adjusted β1 coefficient, 0.112 [95% CI, 0.040-0.185]; P = .004), overcrowded households (adjusted β1 coefficient, 0.049 [95% CI, 0.034 to 0.062]; P < .001), consumption of fluoroquinolones (adjusted β1 coefficient, 0.002 [95% CI, 0.001-0.002]; P < .001), and tetracyclines (adjusted β1 coefficient, 0.0002 [0.00004 to 0.00039]; P = .02), and poultry density (adjusted β1 coefficient, 0.0001 [95% CI, 0.0001-0.0002]; P < .001). The social deprivation index (adjusted β1 coefficient, -0.115 [95% CI, -0.165 to -0.064]; P < .001) and the proportion of water surface area (adjusted β1 coefficient, -0.052 [-0.081 to -0.024]; P = .001) were negatively associated with a higher number of community-acquired ESBL-producing E coli UTIs.

CONCLUSIONS AND RELEVANCE

The findings of this cross-sectional study suggest that multiple human health, animal health, and environmental factors are associated with the occurence of community-acquired ESBL E coli UTI. Strategies to mitigate ESBL in the community should follow the One Health approach and address the role played by fluoroquinolones, tetracycline use, poultry density, overcrowded households, and preschool-aged children.

Evaluation of the French surveillance system for epidemiological surveillance of antimicrobial resistance in the community and nursing homes

Background

Antimicrobial resistance (AMR) has been widely recognized as a major public health issue, which can be addressed through effective AMR surveillance systems. In 2018, a national surveillance programme for AMR in the community and nursing homes called Mission PRIMO was established in France. It builds on an existing network called MedQual-Ville that had been monitoring AMR mainly in the west of France community since 2003.

Objectives and Methods

To evaluate the MedQual-Ville surveillance activities and to formulate practical recommendations for improvement, using a semi-quantitative evaluation framework called OASIS.

Results

The evaluation showed that MedQual-Ville is overall a well-performing surveillance system. Its major strengths rely on excellent coordination and internal communication with clinical laboratories that participate on a voluntary basis. Surveillance objectives and procedures are clear to all participants. Hence, the quality and reliability of the data being produced is very high. At this stage, the major area for improvement is representativeness, with poor coverage achieved in several densely populated areas. Besides, the utility and impact of surveillance data could be improved by strengthening communication towards end-users, especially local prescribers.

Conclusions

There is currently no European programme or guidance for AMR surveillance in the community and nursing homes. Our results partly fill this gap, by evaluating how surveillance is being performed in France and providing recommendations that could be applicable to other countries with similar health systems. This work also highlighted the relevance of OASIS for evaluation of surveillance systems in the human sector.

Interleukin-33 Deficiency Exacerbates Bone Loss Associated with Porphyromonas Gingivalis-Induced Experimental Periodontitis in Female Mice

BACKGROUND/AIMS

Interleukin 33 (IL-33) plays a significant role in immunity but its role in bone physiology and periodontitis needs to be further investigated. The aim of this study was to decipher the contribution of IL-33 to bone homeostasis under physiological conditions, and to alveolar bone loss associated with experimental periodontitis (EP) in IL-33 knockout (KO) mice and their wildtype (WT) littermates.

METHODS

The bone phenotype of IL-33 KO mice was studied in the maxilla, femur, and fifth lumbar vertebra by micro-computed tomography (micro-CT). EP was induced by a ligature soaked with the periopathogen Porphyromonas gingivalis (Pg) around a maxillary molar. Alveolar bone loss was quantified by micro-CT. The resorption parameters were assessed via toluidine blue staining on maxillary sections. In vitro osteoclastic differentiation assays using bone marrow cells were performed with or without lipopolysaccharide from Pg (LPS-Pg).

RESULTS

First, we showed that under physiological conditions, IL-33 deficiency increased the trabecular bone volume/total volume ratio (BV/TV) of the maxillary bone in male and female mice, but not in the femur and fifth lumbar vertebra, suggesting an osteoprotective role for IL-33 in a site-dependent manner. The severity of EP induced by Pg-soaked ligature was increased in IL-33 KO mice but in female mice only, through an increase in the number of osteoclasts. Moreover, osteoclastic differentiation from bone marrow osteoclast progenitors in IL-33-deficient female mice is enhanced in the presence of LPS-Pg.

CONCLUSION

Taken together, our data demonstrate that IL-33 plays a sex-dependent osteoprotective role both under physiological conditions and in EP with Pg.

Prevalence, Characteristics, and Determinants of Suboptimal Care in the Initial Management of Community-Onset Severe Bacterial Infections in Children

IMPORTANCE

Assessment of the quality of initial care is necessary to target priority actions that can reduce the still high morbidity and mortality due to community-onset severe bacterial infections (COSBIs) among children.

OBJECTIVE

To study the prevalence, characteristics, and determinants of suboptimal care in the initial management of COSBIs.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, population-based, cohort study and confidential enquiry was conducted between August 2009 and January 2014 in western France, a region accounting for 15% of the French pediatric population (1 968 474 children aged 1 month to 16 years) and including 6 pediatric intensive care units (PICUs) and 35 emergency departments. Participants included all children aged 1 month to 16 years who died before PICU admission or were admitted to a PICU with a COSBI (ie, bacterial sepsis, including meningitis, purpura fulminans, and pulmonary, osteoarticular, intra-abdominal, cardiac, and soft-tissue severe infections). Data were analyzed from March to June 2020.

EXPOSURES

Suboptimal care determined according to evaluation of 8 types of care: (1) the delay in seeking care by family, (2) the physician's evaluation of severity, (3) the patient's referral at the first consultation with signs of severity, (4) the timing and (5) dosage of antibiotic treatment, (6) the timing and (7) volume of fluid bolus administration, and (8) the clinical reassessment after fluid bolus.

MAIN OUTCOMES AND MEASURES

Two experts assessed the quality of care before death or PICU admission as optimal, possibly suboptimal, or certainly suboptimal. The consequences and determinants of certainly suboptimal care were identified with multinomial logistic regression and generalized linear mixed models.

RESULTS

Of the 259 children included (median [IQR] age, 24 [6-66] months; 143 boys [55.2%]), 27 (10.4%) died, and 25 (9.6%) had severe sequelae at PICU discharge. The quality of care was certainly suboptimal in 89 cases (34.4%). Suboptimal care was more frequent in children with sequelae (adjusted odds ratio [aOR], 5.61; 95% CI, 1.19-26.36) and less frequent in children who died (aOR, 0.16; 95% CI, 0.04-0.65) vs those surviving without sequelae. Factors independently associated with suboptimal care were age younger than 5 years (aOR, 3.15; 95% CI, 1.25-7.90), diagnosis of sepsis with no source (aOR, 5.77; 95% CI, 1.64-20.30) or meningitis (aOR, 3.39; 95% CI, 1.15-9.96) vs other severe infections, and care by a primary care physician (aOR, 3.22; 95% CI, 1.17-8.88) vs a pediatric hospital service.

CONCLUSIONS AND RELEVANCE

This study found that suboptimal care is frequent in the initial management of COSBI and is associated with severe sequelae. The paradoxical association with reduced risk of death may be explained by an insufficient adjustment on bacterial or host intrinsic factors. Management could be optimized by improving the quality of primary care, especially for young children.

Decreasing proportion of extended-spectrum beta-lactamase among E. coli infections during the COVID-19 pandemic in France

OBJECTIVES

We investigated the impact of the COVID-19 and national pandemic response on the epidemiology of Extended Spectrum Beta-Lactamase producing E. coli (ESBL-E.coli) in France.

METHODS

Individual microbiology records from clinical laboratories were analyzed between 1 January 2019 to 31 December 2020. The ESBL-E.coli rates from clinical samples of patients in primary care and nursing home residents were compared before and after the general lockdown in March 2020, according to demographic and geographical characteristics. Interrupted time series analyses were performed to detect measurable changes in the trend of ESBL-E.coli rates.

RESULTS

Records covering 793,954 E. coli isolates from 1022 clinical laboratories were analyzed. In primary care, 3.1% of E. coli isolates from clinical samples were producing ESBL before March 2020 and 2.9% since May 2020 (p < 0.001). The proportion of ESBL-E.coli decreased significantly among urine cultures, females, age categories 5-19, 40-64, > 65 year-old, and in the North, West, East and South-East regions. In nursing home, the ESBL-E.coli rate was 9.3% (monthly rate min-max: 6.5-10.5%) before March 2020 and 8.3% (7.2-9.1%) since May 2020 (p < 0.001). The reduction rate accelerated from -0.04%/month to -0.22%/month from May 2020 (p < 0.001).

CONCLUSION

Investigation of factors that led to the decreased proportion of ESBL-E.coli during the COVID-19 pandemic is urgently needed.

Local characteristics associated with higher prevalence of ESBL-producing Escherichia coli in community-acquired urinary tract infections: an observational, cross-sectional study

OBJECTIVES

The prevalence of ESBL-producing Escherichia coli (ESBL-E. coli) in community-acquired urinary tract infections (UTI) has been increasing worldwide since 2000, but with large geographical variations. The aim of this study was to determine whether the ESBL-E. coli rate in urine samples from individuals with community-acquired UTI was associated with the local socio-economic, environmental, agricultural and healthcare characteristics.

METHODS

This was a cross-sectional study in western France using data on antibiotic susceptibility of E. coli isolated from urine samples of individuals with community-acquired UTI analysed in non-hospital laboratories from 2015 to 2017. The ESBL-E. coli rate was calculated for each laboratory. Data on socio-economic characteristics, human antibiotic consumption, hospital bed density, animal farming density and percentage of agricultural land and surface water were retrieved at the municipality level and aggregated by study area. Their association with ESBL-E. coli prevalence was quantified using multivariate linear regression models with a backward selection.

RESULTS

From 358 291 E. coli isolates from urine samples tested in 92 laboratories, the mean ESBL-E. coli prevalence for the study period was 3.30%. In an adjusted model, the ESBL-E. coli rate was significantly (P < 0.05) and positively associated with the local percentage of people >65 years old, third-generation cephalosporin use (DDD/1000 inhabitants), number of hospital beds/km2, poultry density, pig density and percentage of agricultural land. Lower deprivation was associated with a higher ESBL-E. coli rate.

CONCLUSIONS

Several anthropogenic factors (primary care, hospitals and animal farming) are associated with the local ESBL-E. coli rate in community-acquired UTI. These results could contribute to improve risk management, including identification of at-risk patient groups.

Trends in antimicrobial resistance among Escherichia coli from defined infections in humans and animals

OBJECTIVES

To characterize and compare resistance trends in clinical Escherichia coli isolates from humans, food-producing animals (poultry, cattle and swine) and pets (dogs and cats).

METHODS

Antibiogram results collected between January 2014 and December 2017 by MedQual [the French surveillance network for antimicrobial resistance (AMR) in bacteria isolated from the community] and RESAPATH (the French surveillance network for AMR in bacteria from diseased animals) were analysed, focusing on resistance to antibiotics of common interest to human and veterinary medicine. Resistance dynamics were investigated using generalized additive models.

RESULTS

In total, 743 637 antibiograms from humans, 48 170 from food-producing animals and 7750 from pets were analysed. For each antibiotic investigated, the resistance proportions of isolates collected from humans were of the same order of magnitude as those from food-producing animals or pets. However, resistance trends in humans differed from those observed in pets and food-producing animals over the period studied. For example, resistance to third-generation cephalosporins and fluoroquinolones was almost always below 10% for both humans and animals. However, in contrast to the notable decreases in resistance observed in both food-producing animals and pets, resistance in humans decreased only slightly.

CONCLUSIONS

Despite several potential biases in the data, the resistance trends remain meaningful. The strength of the parallel is based on similar data collection in humans and animals and on a similar statistical methodology. Resistance dynamics seemed specific to each species, reflecting different antibiotic-use practices. These results advocate applying the efforts already being made to reduce antibiotic use to all sectors and all species, both in human and veterinary medicine.

Could Azithromycin Be Part of Pseudomonas aeruginosa Acute Pneumonia Treatment?

Azithromycin (AZM) is a 15-membered-ring macrolide that presents a broad-spectrum antimicrobial activity against Gram-positive bacteria and atypical microorganisms but suffers from a poor diffusion across the outer-membrane of Gram-negative bacilli, including Pseudomonas aeruginosa (PA). However, AZM has demonstrated clinical benefits in patients suffering from chronic PA respiratory infections, especially cystic fibrosis patients. Since the rise of multidrug-resistant PA has led to a growing need for new therapeutic options, this macrolide has been proposed as an adjunctive therapy. Clinical trials assessing AZM in PA acute pneumonia are scarce. However, a careful examination of the available literature provides good rationales for its use in that context. In fact, 14- and 15-membered-ring macrolides have demonstrated immunomodulatory and immunosuppressive effects that could be of major interest in the management of acute illness. Furthermore, growing evidence supports a downregulation of PA virulence dependent on direct interaction with the ribosomes, and based on the modulation of several key regulators from the Quorum Sensing network. First highlighted in vitro, these interesting properties of AZM have subsequently been confirmed in the animal models. In this review, we systematically analyzed the literature regarding AZM immunomodulatory and anti-PA effects. In vitro and in vivo studies, as well as clinical trials were reviewed, looking for rationales for AZM use in PA acute pneumonia.

Regulatory T Cells Expressing Tumor Necrosis Factor Receptor Type 2 Play a Major Role in CD4+ T-Cell Impairment During Sepsis

Sepsis causes inflammation-induced immunosuppression with lymphopenia and alterations of CD4+ T-cell functions that renders the host prone to secondary infections. Whether and how regulatory T cells (Treg) are involved in this postseptic immunosuppression is unknown. We observed in vivo that early activation of Treg during Staphylococcus aureus sepsis induces CD4+ T-cell impairment and increases susceptibility to secondary pneumonia. The tumor necrosis factor receptor 2 positive (TNFR2pos) Treg subset endorsed the majority of effector immunosuppressive functions, and TNRF2 was particularly associated with activation of genes involved in cell cycle and replication in Treg, probably explaining their maintenance. Blocking or deleting TNFR2 during sepsis decreased the susceptibility to secondary infection. In humans, our data paralleled those in mice; the expression of CTLA-4 was dramatically increased in TNFR2pos Treg after culture in vitro with S. aureus. Our findings describe in vivo mechanisms underlying sepsis-induced immunosuppression and identify TNFR2pos Treg as targets for therapeutic intervention.

Risk Factors of Extended-Spectrum Beta-Lactamases-Producing Escherichia coli Community Acquired Urinary Tract Infections: A Systematic Review

Purpose

The prevalence of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) has been increasing worldwide since the early 2000s. E. coli is found in 70–90% of community-acquired urinary tract infections (CA-UTIs). We performed a systematic literature review to determine the risk factors for CA-UTI caused by ESBL-EC.

Methods

We searched the MEDLINE, Cochrane Library, Embase and Web of Science databases without language or date restriction up to March 2019. Two independent reviewers selected studies with quantified risk factors for CA-UTI due to ESBL-EC, and assessed their quality using the Newcastle-Ottawa Scale.

Results

Among the 5,597 studies identified, 16 observational studies (n=12,138 patients) met the eligibility criteria. The included studies were performed in various countries, and 14/16 were published after 2012. The most relevant risk factors for CA-UTI due to ESBL-EC identified were prior use of antibiotics (odds ratio (OR) from 2.2 to 21.4), previous hospitalization (OR: 1.7 to 3.9), and UTI history (OR: 1.3 to 3.8). Two risk factors were related to environmental contamination: travelling abroad, and swimming in freshwater.

Conclusion

Our findings could allow adapting empiric antibiotic treatments according to the patient profile. Further studies are needed to quantify the relationships between CA-UTI due to ESBL-EC and the environment.

Epidemiology of invasive early-onset neonatal infection in a French administrative district: A 10-year population-based study

BACKGROUND

In light of the pending update of the French guidelines for the management of neonatal infections, knowing the current epidemiology of early-onset neonatal infection (EONI) is essential.

OBJECTIVES

The aim of this study was to assess the current epidemiology of a French administrative district population of proven EONI, including umbilical cord blood procalcitonin levels.

METHODS

We conducted a retrospective population-based study in the Nantes metropolitan area. We included all infants treated for proven EONI in the maternity, neonatology, and intensive care wards between 1 January 2006 and 31 December 2015 in the Nantes University Hospital.

RESULTS

Among the 140,502 children born during the study period, 61 cases of EONI were documented. The overall incidence of confirmed EONI was 0.43/1000 live births, with 0.23/1000 GBS (group B streptococcus) infections and 0.08/1000 Escherichia coli infections. The majority of infected newborns were full-term or late-preterm infants (67% were≥34 weeks of gestation), 88% had symptoms of EONI in the first 24h of life, most of which were respiratory. The mortality rate was 8% (in premature infants). Available in 51% of the population, the cord blood PCT value could contribute to an earlier diagnostic screening in 10% of cases but with a very low sensitivity.

CONCLUSIONS

The incidence of confirmed EONI is low in this French district. The diagnostic value of PCT umbilical blood cord should be assessed based on further studies before confirming its value. We suggest that a national registry of these rare but serious cases of EONI could contribute to monitoring the epidemiological progression as well as to optimizing our diagnostic and therapeutic strategies.

Impact of fecal microbiota transplantation on chronic recurrent pouchitis in ulcerative colitis with ileo-anal anastomosis: study protocol for a prospective, multicenter, double-blind, randomized, controlled trial

BACKGROUND

Almost 15% of patients with ulcerative colitis (UC) will require a proctocolectomy with ileal pouch-anal anastomosis (IPAA) as a result of fulminant colitis, dysplasia, cancer, or medical refractory diseases. Around 50% will experience pouchitis, an idiopathic inflammatory condition involving the ileal reservoir, responsible for digestive symptoms, deterioration in quality of life, and disability. Though the majority of initial cases of pouchitis are easily managed with a short course of antibiotics, in about 10% of cases, inflammation of the pouch becomes chronic with very few treatments available. Previous studies have suggested that manipulating the composition of intestinal flora through antibiotics, probiotics, and prebiotics achieved significant results for treating acute episodes of UC-associated pouchitis. However, there is currently no established effective treatment for chronic antibiotic-dependent pouchitis. Fecal microbiota transplantation (FMT) is a novel therapy involving the transfer of normal intestinal flora from a healthy donor to a patient with a medical condition potentially caused by the disrupted homeostasis of intestinal microbiota or dysbiosis.

METHODS

Our project aims to compare the delay of relapse of chronic recurrent pouchitis after FMT versus sham transplantation. Forty-two patients with active recurrent pouchitis after having undergone an IPAA for UC will be enrolled at 12 French centers. The patients who respond to antibiotherapy will be randomized at a ratio of 1:1 to receive either FMT or sham transplantation.

DISCUSSION

On April 30, 2014, the World Health Organization published an alarming report on antibiotic resistance. Finding an alternative medical treatment to antibiotics in order to prevent relapses of pouchitis is therefore becoming increasingly important given the risk posed by multiresistant bacteria. Moreover, if the results of this study are conclusive, FMT, which is less expensive than biologics, could become a routine treatment in the future.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03524352. Registered on 14 May 2018.

A murine model of Staphylococcus aureus infected chronic diabetic wound: A new tool to develop alternative therapeutics

Diabetic wound infection is a frequent complication that may result in limb amputation. To develop new treatment strategies in response to increasing bacterial resistance, animal models are needed. We created a diabetic mouse model with chronically infected wounds. Diabetes was induced using streptozotocin, and wounds were performed using a biopsy punch, and then infected with a clinical strain of Staphylococcus aureus. Chronification was reached by delaying healing thanks to chemical products (aminotriazole and mercaptosuccinic acid). Overall survival, as well as clinical, bacteriological and immunological data in skin, blood and spleens were collected at days 1, 7, and 14 after wounding. After a transient bacteremia proved by bacteria presence in spleen and kidneys in the first days after wounding, infected mice showed a chronic infection, with a bioburden impairing the healing process, and bacteria persistence compared to control mice. Infected mice showed gradual increasing skin levels of IL-17A compared to control mice that resulted in an IL-17/IFN-γ inbalance, pointing out a localized Th17 polarization of the immune response. Whether infected or not, the skin level of IL-10 decreased dramatically at days 1 and 7 after wounding, with an increase observed only in the control mice at day 14. After a decrease at day 1 in both groups, spleen IL-10 showed a rather steady level at days 7 and 14 in the control group compared with the decrease observed in the infected group. The spleen IL-10/IFN-γ ratio showed a systemic inflammatory response with Th1 polarization. Therefore, this model provides useful data to study wound healing. It is easy to reproduce, affordable and offers clinical and biological tools to evaluate new therapeutics.

Interleukin-22 regulates interferon lambda expression in a mice model of pseudomonas aeruginosa pneumonia

BACKGROUND

Interleukin (IL)-22 is a cytokine involved in tissue protection and repair following lung pathologies. Interferon (IFN)-λ cytokines displayed similar properties during viral infection and a synergy of action between these two players has been documented in the intestine. We hypothesize that during Pseudomonas aeruginosa challenge, IL-22 up-regulates IFN-λ and that IFN-λ exhibits protective functions during Pseudomonas aeruginosa acute pneumonia model in mice.

METHODS

Using an in vitro human alveolar epithelial cell line A549, we assessed the ability of IL-22 to enhance IFN-λ expression during infection. IFN-λ protective function was evaluated in an acute mouse pneumonia model.

RESULTS

We first demonstrated in murine lungs that only type-II alveolar cells express IL-22 receptor and that IL-22 treatment of A549 cell line up-regulates IFN-λ expression. In a murine acute pneumonia model, IL-22 administration maintained significant IFN-λ levels in the broncho-alveolar fluids whereas IL-22 neutralization abolished IFN-λ up-regulation. In vivo administration of IFN-λ during Pseudomonas aeruginosa pneumonia improves mice outcome by dampening neutrophil recruitment and decreasing epithelium damages.

DISCUSSION

We show here that IL-22 regulates IFN-λ levels during Pseudomonas aeruginosa pneumonia.

Potential Impact of Umbilical-Cord-Blood Procalcitonin-Based Algorithm on Antibiotics Exposure in Neonates With Suspected Early-Onset Sepsis

Context: The incidence of early-onset neonatal infection has greatly decreased, but a new diagnostic approach is needed to avoid overdiagnosis and overtreatment. The aim of this study was to assess the potential impact of an algorithm incorporating umbilical-cord-blood procalcitonin (PCT) level on neonatal antibiotics prescription rate as compared with current practice. Material and methods: We conducted a prospective study in three maternity wards in France. All term and preterm neonates with the usual risk factors for neonatal group B Streptococcus infection were eligible for umbilical-cord-blood PCT testing. We compared the proportion of neonates who were exposed early to antibiotics (before 6 days of life) to that of neonates for whom antibiotics prescription would be indicated according to the PCT-based algorithm. Results: Among the 3,080 neonates included, 1 neonate presented with certain infection and 38 neonates with probable infection. The global antibiotics prescription rate was 4.6% [95% confidence interval (CI), 4.1-5]. With the PCT-based algorithm, the potential decrease in prescription rate would be 1.8% (95% CI, 1.3-2.3), corresponding to a 39% (95% CI, 37.3-40.7) relative reduction in antibiotics exposure (p < 0.05). Conclusion: These results suggest that the umbilical-cord-blood PCT-based algorithm could significantly help the clinicians in their antibiotic prescription decision to decrease neonatal antibiotics exposure as compared with current practice. If validated in a larger interventional randomized study, this approach could help clinicians stratify the risk of early-onset neonatal infection and initiate early antibiotics treatment in newborns at high risk of infection while limiting the deleterious effects of useless prescriptions in non-infected newborns.

PK/PD targets of amikacin and gentamicin in ICU patients

OBJECTIVES

We aimed to evaluate the probability to achieve PK-PD targets in patients with sepsis hospitalized in the intensive care unit (ICU) after a single dose of 30mg/kg of amikacin or 8mg/kg of gentamicin.

PATIENTS AND METHODS

This single-center prospective study included 138 ICU patients with severe sepsis or septic shock with an indication for intravenous amikacin (N=89) or gentamicin (N=49). Maximum concentration (C_max) was measured 30 minutes after infusion completion. PK/PD objectives were respectively C_max≥60mg/L and ≥30mg/L for amikacin and gentamicin for empirical therapy, and a C_max/MIC ratio≥8, as per French guidelines.

RESULTS

The median Simplified Acute Physiology Score II was 43 and ICU case fatality rate was 34.8%. A causative bacterial agent was identified in 94 patients (68.1%). Three pathogens had acquired aminoglycoside resistance and 15 were naturally resistant. The targeted C_max for the first dose was achieved in 53 patients (59.6%) receiving amikacin, and one (2.2%) patient receiving gentamicin. C_max/MIC ratio≥8 was obtained in all patients infected with susceptible pathogens (N=72). Factors associated with C_max≥60mg/L of amikacin in multivariate analysis were dose per kg of adapted body weight (OR=1.39, P<0.001) and renal clearance estimated with CKD-EPI formula (OR=0.98, P=0.003).

CONCLUSIONS

Despite high doses, amikacin and gentamicin first C_max remain dramatically low in ICU patients. However, an adequate C_max/MIC ratio was reached in all patients.

Linezolid versus vancomycin cost in the treatment of staphylococcal pneumonia

OBJECTIVE

Staphylococcusaureus is involved in around 20% of nosocomial pneumonia cases. Vancomycin used to be the reference antibiotic in this indication, but new molecules have been commercialized, such as linezolid. Previous studies comparing vancomycin and linezolid were based on models. Comparing their real costs from a hospital perspective was needed.

METHODS

We performed a bicentric retrospective analysis with a cost-minimization analysis. The hospital antibiotic acquisition costs were used, as well as the laboratory test and administration costs from the health insurance cost scale. The cost of each hospital stay was evaluated using the national cost scale per diagnosis related group (DRG), and was then weighted by the stay duration.

RESULTS

Fifty-eight patients were included. All bacteria identified in pulmonary samples were S. aureus. The cost of nursing care per stay with linezolid was €234.10 (SD=91.50) vs. €381.70 (SD=184.70) with vancomycin (P=0.0029). The cost of laboratory tests for linezolid was €172.30 (SD=128.90) per stay vs. €330.70 (SD=198.40) for vancomycin (P=0.0005). The acquisition cost of linezolid per stay was not different from vancomycin based on the price of the generic drug (€54.92 [SD=20.54] vs. €40.30 [SD=22.70]). After weighting by the duration of stay observed, the mean cost per hospital stay was €47,411.50 for linezolid and €57,694.0 for vancomycin (NSD).

CONCLUSION

These results, in favor of linezolid, support other former pharmacoeconomic study based on models. The mean cost per hospitalization stay was not statistically different between the two study groups, but a trend in favor of linezolid is emerging.

Effectiveness of At-Risk Gamblers' Temporary Self-Exclusion from Internet Gambling Sites

To prevent risks associated with online gambling, many jurisdictions propose self-exclusion strategies as a part of a responsible gambling policy. To protect online gamblers, French law provides for a 7-day temporary non-reducible and voluntary self-exclusion measure that applies only to select websites. The objective of our study was to evaluate the effectiveness of this self-exclusion measure for at-risk online gamblers. It was an experimental randomized controlled trial targeted at risk prevention. The main outcomes were the money wagered and time spent gambling assessed 15 days (short-term) and 2 months (medium-term) after the implementation of the self-exclusion measure. The effectiveness of self-exclusion was also compared according to the gambling type (pure chance games, such as lottery or scratch tickets, skill and chance bank games such as sports betting or horserace betting, and skill and chance games such as poker). Sixty participants were randomly assigned to the experimental condition (n = 30; with the implementation of a self-exclusion measure) or control condition (n = 30). The randomization was stratified according to their favorite game [pure chance games (n = 20), skill and chance bank games (n = 20), and skill and chance social games (n = 20)]. The results revealed that self-exclusion had no short-term impact-but did have a medium-term impact-on gambling habits. After 2 months, the gambling-related cognitions ("illusion of control" and "the perceived inability to stop gambling") and the subscale "desire" of the Gambling Craving Scale (GACS) have decreased. Participants' opinions about the impact and effectiveness of self-exclusion were discussed. To conclude, it appeared that temporary self-exclusion is an interesting tool to protect online gamblers from excessive practices, but several modifications have to be made to improve its effectiveness and use.

A meta-analysis of outcomes of in-situ reconstruction after total or partial removal of infected abdominal aortic graft

INTRODUCTION

There is currently a lack of evidence for the relative effectiveness of partial resection (PR) and total resection (TR) before managing abdominal aortic graft infection (AGI). Most authorities agree that TR is mandatory for intracavitary AGI in patients with favorable conditions but there is an increasing number of patients with severe comorbidities for whom this approach is not suitable, resulting in a prohibitive mortality rate. The purpose of this study was to determine the most appropriate indication for TR or PR.

EVIDENCE ACQUISITION

A meta-analysis was conducted on the rates of early/late mortality, amputations and reinfection. A meta-regression was performed with eight variables: patient age, male prevalence, presence of virulent or nonvirulent organisms, urgency, omentoplasty and follow-up.

EVIDENCE SYNTHESIS

Twenty-one studies and 1052 patients were included. For TR and PR, the rates of early mortality and reinfection were 16.8% and 10.5%, 11% and 27%, respectively. For TR urgency and male gender were associated with increased rate of early mortality and male gender, PDF and virulent organisms were associated with increased risk of reinfection. For PR no statistical correlation was analyzable except for PDF with increased risk of reinfection.

CONCLUSIONS

Early mortality rates are higher for TR and reinfection rates are higher for PR. For TR early mortality increases in urgent cases and it is suggested that alternative option must be discussed, reinfection decreases in the presence of nonvirulent organisms and TR seems optimal. For TR and PR reinfection increases in presence of PDF and alternative technique may be more appropriate.

Prevalence of Haemophilus influenzae with alteration of PBP 3 sequence over a 1-year period in a French hospital: focus on a clinical failure after ceftriaxone treatment

Among 547 Haemophilus influenzae isolates recovered in our center, 45 displayed a phenotype of loss of PBP 3 affinity (8.2%). Two isolates with 6 substitutions in PBP 3 showed decreased susceptibility to third-generation cephalosporins. Clinical data revealed clinical failure after ceftriaxone treatment in a context of bronchitis in a patient with pulmonary sarcoidosis.

Vaccine-preventable severe morbidity and mortality caused by meningococcus and pneumococcus: A population-based study in France

BACKGROUND

In a context of suboptimal vaccination coverage and increasing vaccine hesitancy, we aimed to study morbidity and mortality in children related to missing or incomplete meningococcal C and pneumococcal conjugate vaccines.

METHODS

We conducted a prospective, observational, population-based study from 2009 to 2014 in a French administrative area that included all children from age 1 month to 16 years who died before admission or were admitted to an intensive care unit for a community-onset bacterial infection. Vaccine-preventable infection was defined as an infection with an identified serotype included in the national vaccine schedule at the time of infection and occurring in a non- or incompletely vaccinated child. Death and severe sequelae were studied at hospital discharge. Frequencies of vaccine-preventable morbidity and mortality caused by meningococcus and pneumococcus were calculated.

RESULTS

Among the 124 children with serotyped meningococcal (n = 75) or pneumococcal (n = 49) severe infections included (median age 26 months), 20 (16%) died and 12 (10%) had severe sequelae. Vaccine-preventable infections accounted for 18/124 infections (15%, 95% CI 9, 22), 5/20 deaths (25%, 95% CI 9, 49), and 3/12 severe sequelae cases (25%, 95% CI 0, 54). The vaccine schedule for meningococcal C and pneumococcal conjugate vaccinations was incomplete for 71/116 (61%) children targeted by at least one of these two vaccination programs.

CONCLUSIONS

Mortality and morbidity rates related to vaccine-preventable meningococcal or pneumococcal infection could be reduced by one quarter with better implementation of immunisation programs. Such information could help enhance the perception of vaccine benefits and fight vaccine hesitancy.

Is There an Association Between Use of Amoxicillin-Clavulanate and Resistance to Third-Generation Cephalosporins in Klebsiella pneumoniae and Escherichia coli at the Hospital Level?

AIMS

Amoxicillin-clavulanate is extensively used in European hospitals. Whether the hospital use of amoxicillin-clavulanate is associated with nonsusceptibility to third-generation cephalosporins (3GC) in Klebsiella pneumoniae is unknown. Our aim was to assess the relationship between the hospital use of amoxicillin-clavulanate and 3GC nonsusceptibility in K. pneumoniae and Escherichia coli.

METHODS

Yearly data of antibiotic use and 3GC nonsusceptibility in K. pneumoniae and E. coli were obtained from 33 French hospitals between 2011 and 2016. Decreased susceptibility to 3GC and Extended-Spectrum Beta-Lactamase (ESBL) production were modelled from antibiotic use with linear mixed models on years 2011 to 2015, and validated on year 2016.

RESULTS

Nonsusceptibility to 3GC increased in K. pneumoniae and E. coli. In a multivariable model that included year and use of 3GC and fluoroquinolones as explanatory variables, amoxicillin-clavulanate use was protective against 3GC nonsusceptibility in K. pneumoniae (incidence rate ratio [IRR], 0.992 [0.988-0.997]), and with ESBL production in K. pneumoniae (IRR, 0.989 [0.985-0.992]). The correlation coefficient between observed and predicted numbers of 3GC-nonsusceptible K. pneumoniae in 2016 was 0.95 (95% confidence interval, 0.89-0.98). There was no significant association between amoxicillin-clavulanate use and 3GC nonsusceptibility in E. coli.

CONCLUSION

Amoxicillin-clavulanate hospital use was protective against nonsusceptibility to 3GC in K. pneumoniae. Conversely, it was not associated with susceptibility to 3GC in E. coli. To decrease the hospital use of 3GC and fluoroquinolones, and 3GC nonsusceptibility in K. pneumoniae, it may be acceptable to increase the hospital use of amoxicillin-clavulanate. Interventional studies are necessary to confirm this hypothesis.

Tetracycline use in the community may promote decreased susceptibility to quinolones in Escherichia coli isolates

We previously found that the hospital use of tetracyclines is associated with quinolone resistance in hospital isolates of Enterobacteriaceae. Tetracyclines are heavily used in the community. Our aim was to assess whether their use in the community favors quinolone resistance in community isolates of Escherichia coli. Monthly data of community antibiotics use and E. coli quinolone resistance in a 1.3 million inhabitant French area were obtained from 2009 to 2014, and were analyzed with autoregressive integrated moving average (ARIMA) models. Quinolone use decreased from 10.1% of the total antibiotic use in 2009 to 9.3% in 2014 (trend, - 0.016; p-value < 0.0001), while tetracycline use increased from 16.5% in 2009 to 17.1% in 2014 (trend, 0.016; p < 0.0001). The mean (95% confidence interval) monthly proportions of isolates that were non-susceptible to nalidixic acid and ciprofloxacin were 14.8% (14.2%-15.5%) and 9.5% (8.8%-10.1%), respectively, with no significant temporal trend. After adjusting on quinolone use, tetracycline use in the preceding month was significantly associated with nalidixic acid non-susceptibility (estimate [SD], 0.01 [0.007]; p-value, 0.04), but not with ciprofloxacin non-susceptibility (estimate [SD], 0.01 [0.009]; p-value, 0.23). Tetracycline use in the community may promote quinolone non-susceptibility in E. coli. Decreasing both tetracycline and quinolone use may be necessary to fight against the worldwide growth of quinolone resistance.

Exoenzyme T Plays a Pivotal Role in the IFN-γ Production after Pseudomonas Challenge in IL-12 Primed Natural Killer Cells

Pseudomonas aeruginosa (PA) expresses the type III secretion system (T3SS) and effector exoenzymes that interfere with intracellular pathways. Natural killer (NK) cells play a key role in antibacterial immunity and their activation is highly dependent on IL-12 produced by myeloid cells. We studied PA and NK cell interactions and the role of IL-12 using human peripheral blood mononuclear cells, sorted human NK cells, and a human NK cell line (NK92). We used a wild-type (WT) strain of PA (PAO1) or isogenic PA-deleted strains to delineate the role of T3SS and exoenzymes. Our hypotheses were tested in vivo in a PA-pneumonia mouse model. Human NK cells or NK92 cell line produced low levels of IFN-γ in response to PA without IL-12 stimulation, whereas PA significantly increased IFN-γ after IL-12 priming. The modulation of IFN-γ production by PA required bacteria-to-cell contact. Among T3SS effectors, exoenzyme T (ExoT) upregulates IFN-γ production and control ERK activation. In vivo, ExoT also increases IFN-γ levels and the percentage of IFN-γ⁺ NK cells in lungs during PA pneumonia, confirming in vitro data. In conclusion, our results suggest that T3SS could modulate the production of IFN-γ by NK cells after PA infection through ERK activation.