Percutaneous Fluoroscopic-Guided Celiac Plexus Approach: Results in a Pig Cadaveric Model.

Celiac plexus block (CPB) and neurolysis (CPN) are used for pain management in people suffering from abdominal tumours or chronic pancreatitis. The fluoroscopically guided approach common in human medicine has not been described in veterinary settings. The aim of this study was to describe a fluoroscopic approach to the celiac plexus (CP) in fresh pig cadavers. Twelve animals were included in the procedure. Cadavers were positioned in sternal position and, under fluoroscopic guidance, a Chiba needle was inserted parasagittal at 6 cm from the spinal midline at the level of the last thoracic vertebra. From the left side, the needle was directed medio-ventrally with a 45° angle towards the T15 vertebral body; once the vertebral body was contacted, the needle was advanced 1 cm ventrally towards the midline. Iodinated contrast was injected to confirm the location. Following this, 2 mL of dye (China ink) was injected. A laparotomy was performed, and dyed tissue was dissected and prepared for both histochemical and immunohistochemical techniques. In 10 out of 12 samples submitted for histological evaluation, nervous tissue belonging to CP was observed. Fluoroscopy guidance allows for feasible access to the CP in swine cadavers in this study. Further studies are warranted to determine the efficacy of this technique in swine and other veterinary species.

Wastewater-based epidemiology applied at the building-level reveals distinct virome profiles based on the age of the contributing individuals.

BACKGROUND: Human viruses released into the environment can be detected and characterized in wastewater. The study of wastewater virome offers a consolidated perspective on the circulation of viruses within a population. Because the occurrence and severity of viral infections can vary across a person's lifetime, studying the virome in wastewater samples contributed by various demographic segments can provide valuable insights into the prevalence of viral infections within these segments. In our study, targeted enrichment sequencing was employed to characterize the human virome in wastewater at a building-level scale. This was accomplished through passive sampling of wastewater in schools, university settings, and nursing homes in two cities in Catalonia. Additionally, sewage from a large urban wastewater treatment plant was analysed to serve as a reference for examining the collective excreted human virome. RESULTS: The virome obtained from influent wastewater treatment plant samples showcased the combined viral presence from individuals of varying ages, with astroviruses and human bocaviruses being the most prevalent, followed by human adenoviruses, polyomaviruses, and papillomaviruses. Significant variations in the viral profiles were observed among the different types of buildings studied. Mamastrovirus 1 was predominant in school samples, salivirus and human polyomaviruses JC and BK in the university settings while nursing homes showed a more balanced distribution of viral families presenting papillomavirus and picornaviruses and, interestingly, some viruses linked to immunosuppression. CONCLUSIONS: This study shows the utility of building-level wastewater-based epidemiology as an effective tool for monitoring the presence of viruses circulating within specific age groups. It provides valuable insights for public health monitoring and epidemiological studies.

Surveillance of SARS-CoV-2 in sewage from buildings housing residents with different vulnerability levels.

During the last three years, various restrictions have been set up to limit the transmission of the Coronavirus Disease (COVID-19). While these rules apply at a large scale (e.g., country-wide level) human-to-human transmission of the virus that causes COVID-19, the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), occurs at a small scale. Different preventive policies and testing protocols were implemented in buildings where COVID-19 poses a threat (e.g., elderly residences) or constitutes a disruptive force (e.g., schools). In this study, we sampled sewage from different buildings (a school, a university campus, a university residence, and an elderly residence) that host residents of different levels of vulnerability. Our main goal was to assess the agreement between the SARS-CoV-2 concentration in wastewater and the policies applied in these buildings. All buildings were sampled using passive samplers while 24 h composite samples were also collected from the elderly residence. Results showed that passive samplers performed comparably well to composite samples while being cost-effective to keep track of COVID-19 prevalence. In the elderly residence, the comparison of sampling protocols (passive vs. active) combined with the strict clinical testing allowed us to compare the sensitivities of the two methods. Active sampling was more sensitive than passive sampling, as the former was able to detect a COVID-19 prevalence of 0.4 %, compared to a prevalence of 2.2 % for passive sampling. The number of COVID-19-positive individuals was tracked clinically in all the monitored buildings. More frequent detection of SARS-CoV-2 in wastewater was observed in residential buildings than in non-residential buildings using passive samplers. In all buildings, sewage surveillance can be used to complement COVID-19 clinical testing regimes, as the detection of SARS-CoV-2 in wastewater remained positive even when no COVID-19-positive individuals were reported. Passive sampling is useful for building managers to adapt their COVID-19 mitigation policies.

Evaluation and perceptions of a nursing discharge plan among nurses from different healthcare settings in Spain.

PURPOSE: The exchange of information between different healthcare settings through a nursing discharge plan is essential for safe care. However, the factors contributing to achieving the most efficient exchange have not been well studied. This study aimed to evaluate and explore the perceptions of a nursing discharge plan from the perspective of nurses in different healthcare settings. METHODS: A mixed methods approach comprising a specifically designed ad hoc questionnaire (n = 437) and a focus group session (n = 8). FINDINGS: Overall, 66.1% out of 437 nurses, and especially those working in nursing homes, were satisfied with the nursing discharge plan. Lack of time to complete the report and poor information about both nursing diagnoses and patients' social assessment were identified as problem areas. Some proposals emerged from the focus group: providing sufficient time for its completion, giving the nursing discharge plan a more flexible structure permitting more open-ended responses, requiring more information to be provided about the social and psychological situation of the patients, training nurses to use standardized language to avoid possible misinterpretations, and getting nurses from the different health care settings to work together in designing continuity of care plans. Elderly and low-income patients are found to need greater attention when filling out nursing discharge plans. CONCLUSIONS: The study has revealed key aspects that need to be improved and some recommendations in implementing the nursing discharge plan in our health area. These include that there should be more time provided to complete the NDP, and also specific details regarding the format, structure, content of the information that is communicated, and the prioritization of the patient profile.

Online breast-feeding support groups as a community asset in Lebanon after Beirut explosion.

OBJECTIVE: Breast-feeding rates are unsatisfactory in Lebanon. Social media groups could play an important role in promoting breast-feeding in normal conditions and post crisis. The aim of this study is to identify breast-feeding challenges, facilitators and assets and to describe how community assets via social media could build community resilience to pandemic's and disaster's effects. DESIGN: A two-phase qualitative content analysis was performed on posts and comments collected from a Facebook breast-feeding support group. Data were categorised into themes, categories and subcategories. SETTING: Posts and comments retrieved from a Facebook breast-feeding support group in Lebanon during the month of August 2020. PARTICIPANTS: Group members: mothers who breastfed, breast-feeding mothers and group admins that are lactation consultants. RESULTS: In phase one, breast-feeding 'Challenges' identified were lack of support from peers and family, lack of supportive policies, lack of knowledge and maternal stress related to political instability, COVID-19 and economic crisis. 'Assets and facilitators' included community support and donations. In phase two, analysis revealed how assets were being used on social media platform to build community resilience post crisis, through access to social support in challenging times, community engagement, material resources and transformative potential. CONCLUSION: Challenges faced during breast-feeding were diminished due to the support and assets received on a Facebook breast-feeding support group, and social media has been shown to be an important community asset implicated in empowering women to breastfeed and to build community resilience in moments of crisis.

Assessing Nurses' Satisfaction with Continuity of Care and the Case Management Model as an Indicator of Quality of Care in Spain.

Chronic diseases are treated and cared for in different healthcare settings. Continuity of care and the case management model facilitate the integration of processes and care levels. However, there is little evidence regarding the satisfaction of nurses with this model. The purpose of this study was to examine nurses' satisfaction with continuity of care and the case management model. A cross-sectional study was conducted. An ad hoc questionnaire was administrated to 437 Spanish nurses from the three health care settings that responded. This included items on socio-demographics, employment relationship, and satisfaction with continuity of care and case management. Descriptive analysis and linear regression models were performed. In total, 96.1% of the nurses expressed a high level of satisfaction with continuity of care and 80.7% with the case management model. Nurses in a primary care setting reported the greatest satisfaction with the case management model (B = 0.146, 95% CI = 0.139-0.694, p = 0.003). The nurses' higher perception of patient satisfaction was associated with greater satisfaction with continuity of care (B = 0.466, 95% CI = -0.367-0.533, p < 0.000). Nurses identified the case management model as an optimal facilitator of continuity of care. While satisfaction with continuity is high, strategies are needed to improve it in primary care centers and aged care homes.

Effectiveness of a training intervention to improve communication between/awareness of team roles: A randomized clinical trial.

BACKGROUND: Interprofessional teamwork training of nursing undergraduates is essential to improving healthcare. The absence of clear role definitions and poor interprofessional communications have been listed as the main reasons behind abandonment of the profession by recently graduated nurses. PURPOSE: The aim of this parallel randomized clinical trial was to evaluate the impact of Situation-Background-Assessment-Recommendation (SBAR) role-play training on interprofessional teamwork skills (role-related and communication-related) and non-technical skills (patient assessment, patient intervention, patient safety, and critical thinking). METHOD: The intervention group were taught teamwork skills, role and task assignment skills, and use of the SBAR worksheet in a 1-hour role-play training session, while the control group received conventional lecture-based training. Teamwork and non-technical skills were then assessed in high-fidelity simulation scenarios using the KidSIM Team Performance Scale (teamwork skills) and the Clinical Simulation Evaluation Tool (non-technical skills). Cohen's d (d) was used to examine effect size differences. RESULTS: Compared to the control group, the intervention group improved in 4 teamwork items - 'verbalize out loud' (p < 0.001, d = 0.99), 'paraphrase' (p < 0.001, d = 0.77), 'cross-monitoring' (p < 0.001, d = 0.72), and 'role clarity' (p = 0.002, d = 0.66) - and in a single non-technical skill (patient intervention: p = 0.004, d = 0.66), while also reporting greater confidence in performing patient assessments (p = 0.02, d = 0.56). CONCLUSIONS: Role-play and SBAR training for undergraduate nurses improved patient intervention, enhanced information sharing in an interprofessional team, and raised awareness of their own and other team members' roles.

Healthy Ageing in Place: Enablers and Barriers from the Perspective of the Elderly. A Qualitative Study.

BACKGROUND: Most elderly people wish to grow old at their own homes. The sociodemographic characteristics; home and neighbourhood conditions; and the social services support and networks are determinants in the possibility of "ageing in place". The present study aimed to explore the ageing in place phenomenon, as well as the enablers and barriers that interact in a healthy ageing from the perspective of the elderly connected to local entities. METHODS: A generic qualitative design was proposed in the Health Region of Girona in Catalonia (Spain). Seventy-one elderly people were purposefully selected. Six focus groups were conducted, and data were thematically analysed. RESULTS: Three key themes were generated: (1) Participants experienced ageing differently. The physical and mental health, the family environment and financial stability were key elements for life quality. (2) The perception of the elderly's role in the community depended on their age, health status and attitude towards life. (3) The participants identified several enablers and barriers to healthy ageing in place. CONCLUSIONS: The promotion of older people's autonomy and wellbeing, together with the creation of an active network of health and social services, may improve the possibility for elderly to age at home and avoid or delay institutionalisation.

Dispositional Optimism, Burnout and Their Relationship with Self-Reported Health Status among Nurses Working in Long-Term Healthcare Centers.

The mental health of nurses working in long-term healthcare centers is affected by the care they provide to older people with major chronic diseases and comorbidity and this in turn affects the quality of that care. The aim of the study was to investigate dispositional optimism, burnout and self-reported health among nurses working in long-term healthcare centers. A descriptive, cross-sectional survey design was used. Survey questionnaires were distributed in 11 long-term health care centers (n = 156) in Catalonia (Spain). The instruments used were LOT-R (dispositional optimism), MBI (burnout) and EuroQol EQ-5D (self-reported health). Bivariate analyses and multivariate linear regression models were used. Self-reported health correlated directly with dispositional optimism and inversely with emotional exhaustion and cynicism. Better perceived health was independently associated with greater dispositional optimism and social support, lower levels of emotional exhaustion level and the absence of burnout. Dispositional optimism in nurses is associated with a greater perception of health and low levels of emotional exhaustion.

Eosinophilic COPD Patients Display a Distinctive Serum miRNA Profile From Asthma and Non-eosinophilic COPD.

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) are common chronic airway diseases that may overlap in some individuals. Asthma COPD overlap (ACO) is a heterogeneous conditions that includes smoking-asthma (SA) and COPD with eosinophilia (COPDe). MicroRNAs (miRNA) are regulators of gene expression with a great potential as biomarkers. OBJECTIVES: The objective of this study was to identify distinctive miRNA signatures in patients from the whole spectrum of chronic obstructive bronchial disease (SA, COPDe, non-smoking asthmatics (NSA), and COPD) that could serve as diagnostic biomarkers or describe differential molecular mechanisms with potential therapeutic implications. METHODS: From a previously characterized cohort of ACO, COPD and asthma patients, we selected a discovery group of 40 patients for miRNA expression profiling by means of microarray technology. Differential expression of miRNAs were validated by quantitative PCR in the complete cohort (n=274). RESULTS: Thirty differentially expressed miRNAs (eBAYES p<0.05, fold change ≥2) were found among the different groups of patients regarding COPDe: 19 COPD-vs-COPDe, 13 NSA-vs-COPDe, 11 SA-vs-COPDe. A characteristic down-regulated miRNA expression pattern was identified in COPDe patients. Differential expression of miR-619-5p and miR-4486 in COPDe patients were validated in the complete cohort (n=274). CONCLUSIONS: We postulate that COPDe patients show a characteristic expression profile of miRNAs distinctive from asthma and COPD. Also that SA and COPDe patients, which have been typically clustered in the ACO group, display distinct molecular events.

Relationship between sense of coherence, health and work engagement among nurses.

AIM: To examine the sense of coherence among registered nurses and its relationship with health and work engagement. BACKGROUND: Sense of coherence is a global orientation to view life as structured, manageable and meaningful and have the capacity to cope with stressful situations. A high sense of coherence score indicates that an individual can understand, manage and attribute meaning to events in his or her life as well as in the work environment. Registered nurses face many workplace stressors that may be easier to manage with a strong sense of coherence; however, the effect of this score on their self-reported health status and work engagement remains unknown. METHODS: In a cross-sectional study, 109 registered nurses working in a long-term care setting responded to a self-administered questionnaire. Social support, work-related family conflicts, sense of coherence, self-reported health status and work engagement variables were analysed using multiple linear regression models. RESULTS: Nurses with a high sense of coherence score reported no work-related family conflicts (mean difference -6.91; 95% CI -10.65 to -3.18; p = .000), better health (r = .408) and greater work engagement (r = .223), compared to their peers with lower sense of coherence. The association between sense of coherence and self-reported health was confirmed by linear regression modelling (ß = .276, p = .003). CONCLUSIONS: Nurses with a higher sense of coherence had better health and greater work engagement. The work engagement variable showing the highest association with sense of coherence was dedication. IMPLICATIONS FOR NURSING MANAGEMENT: Implementing interventions that increase sense of coherence among nurses can increase commitment to their work, to the institution and to building more engaged teams.

The intrinsic resistome of Klebsiella pneumoniae.

Molecular epidemiology studies aiming at understanding the acquisition of antimicrobial resistance by clinical isolates of Klebsiella pneumoniae are regularly published; however, information on the genes that contribute to its characteristic phenotype of resistance to antibiotics (intrinsic resistome) is scarce. To fill this gap, a K. pneumoniae transposon mutant library was screened and 171 mutants presenting changes in their susceptibility to antibiotics were selected, in which the transposon insertion site was determined in 75. Twenty-seven mutants for which insertion points had been previously identified were included in the analysis. A total of 102 mutants were selected for further studies. In 70 mutants the transposon was inserted in a gene with a known function, whilst in 19 the insertion occurred in genes encoding proteins with unknown functions and 13 insertions occurred in intergenic regions. Moreover, 87 of the insertions were localised in the chromosome, with 15 insertions located in the two plasmids carried by this strain. Whereas some of the mutated genes are already known to be involved in antimicrobial resistance (ampG, acrB, tolC), several of them are involved in regular processes of bacterial physiology, including K. pneumoniae virulence. Together with results published for other organisms, these results support that determinants involved in basic processes of bacterial physiology may contribute to antimicrobial resistance. These findings also indicate that, besides acquired resistance genes, plasmids may harbour other genes belonging to their backbone that can also be involved in resistance.

Prevalence and related factors of Active and Healthy Ageing in Europe according to two models: Results from the Survey of Health, Ageing and Retirement in Europe (SHARE).

BACKGROUND: Active and Healthy Ageing (AHA) is the process of optimizing opportunities related to health, participation, and safety in order to improve quality of life. The approach most often used to measure AHA is Rowe and Kahn's Satisfactory Ageing model. Nonetheless, this model has limitations. One of the strategic objectives of the WHO Global Strategy and Action Plan (2016) is to improve Healthy Ageing measurement. Our objectives were to compare two models of assessing AHA and further compare the results by country and sociodemographic variables. METHODS: This was a cross-sectional, observational analysis of a representative sample of the general population aged 50 years and older in Europe. The data analysed were obtained by the Study of Health, Ageing and Retirement in Europe (SHARE). The dependent variable was AHA and its dimensions, measured using the Rowe and Kahn AHA model (AHA-B) and the authors' model based on the WHO definition (AHA-BPS). A descriptive analysis and multivariate models of binary logistical regression were developed. RESULTS: The sample consisted of 52,641 participants (mean age 65.24 years [SD = 10.18; Range = 50-104], 53.2% women). Healthy Ageing prevalence in the AHA-B model was 23.5% (95%CI = 23.1%-23.9%). In the AHA-BPS model, this prevalence was 38.9%. In both models, significant variations were observed between countries, and were distributed along a north-western to south-eastern gradient. The sociodemographic variables associated with the absence of AHA were advanced age, female sex, death of spouse, low educational level, lack of employment, and low financial status. Comparing the two models, the strength of association between absence of AHA and advanced age (85 years and older) was four times greater in the AHA-B model. CONCLUSIONS: Our results showing differences between these two models provide evidence that the AHA-BPS model does not penalize older age and is more likely to characterize AHA from a health promotion perspective.

Potential applications of lipid peroxidation products - F4-neuroprostanes, F3-neuroprostanesn-6 DPA, F2-dihomo-isoprostanes and F2-isoprostanes - in the evaluation of the allograft function in renal transplantation.

F4-neuroprostanes, F3-neuroprostanesn-6 DPA, and F2-dihomo-isoprostanes, metabolites of non-enzymatic lipid peroxidation of polyunsaturated fatty acids [docosahexaenoic acid, n-6 docosapentanoic acid, and adrenic acid respectively], have become important biomarkers for oxidative stress in several diseases like epilepsy and alzheimer. These biomarkers and the 15-F2t-isoprostane (also known as 8-iso-PGF2α), a F2-isoprostane isomer measured as reference oxidative marker at systemic level, were analyzed by UHPLC-QqQ-MS/MS in the urine of 60 renal recipients from cadaveric donors of the Nephrology Unit of the University Hospital Virgen de la Arrixaca, at six different times during the first six months after renal transplantation, and were compared with a control group of 60 healthy subjects from the same hospital. A total of 11 metabolites were analyzed and different patterns were observed. A tendency to decrease was observed in three metabolites (4-epi-4-F3t- NeuroPn-6 DPA, ent-7(RS)-7-F2t-dihomo-IsoP, and ent-7(S)-7-F2t-dihomo-IsoP) and in our reference oxidative marker (15-F2t-IsoP) when kidney function improved and the excretion of urine proteins decreased. These results suggest that these three biomarkers of oxidative stress could be useful to assess renal function in the postransplant phase. Unfortunately, little is known about this kind of biomarker in this cohort of patients, so further investigation would be required in the clinical field to clarify the relationship between oxidative stress and the graft function, as well as the usefulness of these biomarkers as rejection markers.

Nursing student and professor perceptions and assessments of the achievement of practicum competencies: A mixed method approach.

Within the context of the European Higher Education Area's requirement of competency-based assessments, the objective of the present study was to evaluate the Nursing Degree Practicum experience at the University of Girona (Spain) and ascertain student and faculty perceptions of the degree of competency achieved as a result of the practicum. This cross-sectional, descriptive, study combined quantitative analysis of a questionnaire and qualitative analysis of focus group comments. In the quantitative part of the study, 163 fourth-year nursing students completed the questionnaire; the qualitative analysis was derived from a focus group of 5 students and 5 professors. On the questionnaire, overall practicum evaluation was 8.39 on a 10-point Likert scale; scores evaluating the nurse mentor/instructor and nursing professor were 8.43 and 7.98, respectively. The geriatrics practicum experience received the lowest overall score (7.81), while the surgical practicum received the lowest score on the adequacy of knowledge acquired in the classroom in previous courses (5.54). The best scores were earned by the mental health and intensive/emergency care practicum experiences (a mean of 9.05 and 8.70, respectively). Students and professors in the focus group agreed that the practicum met the Nursing degree program's competency goals, highlighting practical activity as the best methodology to evaluate competencies. Participants highlighted the importance of reflective practice and the role of the nurse mentor/instructor in student learning, and indicated that it is essential for the university and the health care centers where students take practicum courses to maintain a strong relationship and good communication. Finally, feedback from the nurse mentor/instructor and Nursing professor was very important to students, both to motivate them and to help them learn.

Reducing health inequities affecting immigrant women: a qualitative study of their available assets.

BACKGROUND: Immigrant women often experience health inequities, whether for reasons of gender, country of origin, or socioeconomic status. The view of immigrant women has always focussed on their needs, without taking into account their available assets. A salutogenic approach incorporating an assets analysis could provide a new perspective on the design of health promotion interventions to reduce health inequities. The study objective was to identify the assets of this group of women as a necessary first step in changing the paradigm used in such health promotion interventions. METHODS: This qualitative study combined focus groups, in-depth interviews, and a photovoice session. The aim was to describe the assets of this group, based on Antonovsky's salutogenic approach and assets model. Qualitative results were interpreted with a phenomenological focus, identifying each individual's internal, community, and institutional assets. RESULTS: The self awareness of skills was linked to a person's description of herself as being optimistic, having religious beliefs, and having motivations and objectives in life, for herself, her family or her children. Being motivated helped the women to persist in doing or learning things that could be useful in confronting difficult situations. Another selfawareness skill was feeling useful to others, whether this was due to religious beliefs about their role in life or to the importance of the mutual support of interpersonal relationships. CONCLUSIONS: High optimism, strong capacity for struggle and self-initiative, the importance of religious beliefs, social support, and concern for their children's future were described as assets of immigrant women. Identification of these assets allows us to develop more in-depth knowledge and better tools for health promotion programs and policies intended to reduce health inequities in this population of immigrant women.

The evaluation of reflective learning from the nursing student's point of view: A mixed method approach.

BACKGROUND: Adapting university programmes to European Higher Education Area criteria has required substantial changes in curricula and teaching methodologies. Reflective learning (RL) has attracted growing interest and occupies an important place in the scientific literature on theoretical and methodological aspects of university instruction. However, fewer studies have focused on evaluating the RL methodology from the point of view of nursing students. OBJECTIVES: To assess nursing students' perceptions of the usefulness and challenges of RL methodology. DESIGN: Mixed method design, using a cross-sectional questionnaire and focus group discussion. METHODS: The research was conducted via self-reported reflective learning questionnaire complemented by focus group discussion. RESULTS: Students provided a positive overall evaluation of RL, highlighting the method's capacity to help them better understand themselves, engage in self-reflection about the learning process, optimize their strengths and discover additional training needs, along with searching for continuous improvement. Nonetheless, RL does not help them as much to plan their learning or identify areas of weakness or needed improvement in knowledge, skills and attitudes. Among the difficulties or challenges, students reported low motivation and lack of familiarity with this type of learning, along with concerns about the privacy of their reflective journals and about the grading criteria. CONCLUSIONS: In general, students evaluated RL positively. The results suggest areas of needed improvement related to unfamiliarity with the methodology, ethical aspects of developing a reflective journal and the need for clear evaluation criteria.

Deciphering tissue-induced Klebsiella pneumoniae lipid A structure.

The outcome of an infection depends on host recognition of the pathogen, hence leading to the activation of signaling pathways controlling defense responses. A long-held belief is that the modification of the lipid A moiety of the lipopolysaccharide could help Gram-negative pathogens to evade innate immunity. However, direct evidence that this happens in vivo is lacking. Here we report the lipid A expressed in the tissues of infected mice by the human pathogen Klebsiella pneumoniae. Our findings demonstrate that Klebsiella remodels its lipid A in a tissue-dependent manner. Lipid A species found in the lungs are consistent with a 2-hydroxyacyl-modified lipid A dependent on the PhoPQ-regulated oxygenase LpxO. The in vivo lipid A pattern is lost in minimally passaged bacteria isolated from the tissues. LpxO-dependent modification reduces the activation of inflammatory responses and mediates resistance to antimicrobial peptides. An lpxO mutant is attenuated in vivo thereby highlighting the importance of this lipid A modification in Klebsiella infection biology. Colistin, one of the last options to treat multidrug-resistant Klebsiella infections, triggers the in vivo lipid A pattern. Moreover, colistin-resistant isolates already express the in vivo lipid A pattern. In these isolates, LpxO-dependent lipid A modification mediates resistance to colistin. Deciphering the lipid A expressed in vivo opens the possibility of designing novel therapeutics targeting the enzymes responsible for the in vivo lipid A pattern.

Functional Genomic Screen Identifies Klebsiella pneumoniae Factors Implicated in Blocking Nuclear Factor κB (NF-κB) Signaling.

Klebsiella pneumoniae is an etiologic agent of community-acquired and nosocomial pneumonia. It has been shown that K. pneumoniae infections are characterized by reduced early inflammatory response. Recently our group has shown that K. pneumoniae dampens the activation of inflammatory responses by antagonizing the activation of the NF-κB canonical pathway. Our results revealed that K. pneumoniae capsule polysaccharide (CPS) was necessary but not sufficient to attenuate inflammation. To identify additional Klebsiella factors required to dampen inflammation, we standardized and applied a high-throughput gain-of-function screen to examine a Klebsiella transposon mutant library. We identified 114 mutants that triggered the activation of NF-κB. Two gene ontology categories accounted for half of the loci identified in the screening: metabolism and transport genes (32% of the mutants) and envelope-related genes (17%). Characterization of the mutants revealed that the lack of the enterobactin siderophore was linked to a reduced CPS expression, which in turn underlined the NF-κB activation induced by the mutant. The lipopolysaccharide (LPS) O-polysaccharide and the pullulanase (PulA) type 2 secretion system (T2SS) are required for full effectiveness of the immune evasion. Importantly, these factors do not play a redundant role. The fact that LPS O-polysaccharide and T2SS mutant-induced responses were dependent on TLR2-TLR4-MyD88 activation suggested that LPS O-polysaccharide and PulA perturbed Toll-like receptor (TLR)-dependent recognition of K. pneumoniae. Finally, we demonstrate that LPS O-polysaccharide and pulA mutants are attenuated in the pneumonia mouse model. We propose that LPS O-polysaccharide and PulA T2SS could be new targets for the design of new antimicrobials. Increasing TLR-governed defense responses might provide also selective alternatives for the management of K. pneumoniae pneumonia.