The bacterial virulence factor NleA undergoes host-mediated O-linked glycosylation.

Enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) are gastrointestinal pathogens responsible for severe diarrheal illness. EHEC and EPEC form "attaching and effacing" lesions during colonization and, upon adherence, inject proteins directly into host intestinal cells via the type III secretion system (T3SS). Injected bacterial proteins have a variety of functions but generally alter host cell biology to favor survival and/or replication of the pathogen. Non-LEE-encoded effector A (NleA) is a T3SS-injected effector of EHEC, EPEC, and the related mouse pathogen Citrobacter rodentium. Studies in mouse models indicate that NleA has an important role in bacterial virulence. However, the mechanism by which NleA contributes to disease remains unknown. We have determined that the following translocation into host cells, a serine and threonine-rich region of NleA is modified by host-mediated mucin-type O-linked glycosylation. Surprisingly, this region was not present in several clinical EHEC isolates. When expressed in C. rodentium, a non-modifiable variant of NleA was indistinguishable from wildtype NleA in an acute mortality model but conferred a modest increase in persistence over the course of infection in mixed infections in C57BL/6J mice. This is the first known example of a bacterial effector being modified by host-mediated O-linked glycosylation. Our data also suggests that this modification may confer a selective disadvantage to the bacteria during in vivo infection.

Depression, Adherence, and Functionality in Patients Undergoing Hemodialysis.

Background  Patients undergoing hemodialysis face multiple problems such as difficulties in performing daily activities, low functional capacity, non-adherence to the hemodialysis regimen, and depressive symptoms that lead to poor health outcomes. The present study aimed to assess the levels of depression, adherence, and functionality in patients undergoing hemodialysis, as well as the association between the above variables. Materials and methods In this cross-sectional study, 100 patients undergoing hemodialysis from a private hospital in Athens participated. Data were collected via the Zung Self-Rating Depression Scale, the Barthel Scale/Index, and the Greek Simplified Medication Adherence Questionnaire-Hemodialysis for the evaluation of patients' depression, functionality, and adherence to hemodialysis regimen, respectively. In addition, sociodemographic and clinical characteristics were recorded. The study was conducted during the period of December 2020 to February 2021. IBM SPSS Statistics for Windows, Version 25.0 (Released 2017. IBM Corp., Armonk, New York) was used for the statistical analysis of the data. The statistical significance level was set up at 0.05. Results Of the patients, 50% scored < 38 (possible range 20-80) in the scale pof depression, and 25% of patients scored < 34. Regarding adherence, the median value was 7 (IQR: 7-7) while 77% scored 7 (possible range of 0-8). Regarding functionality, mild dependence (score 91-99) was referred by 77% of the participants, moderate dependence (score 61-90) by 17%, and severe dependence (score 21-60) was referred by 6% of the patients. A statistically significant negative association emerged between depression and functionality (r= -0.342, p=0.001) while no significant association arised between depression and adherence (r= 0.021,p=0.836) as well as between adherence and functionality (r = 0.078, p = 0.439). Statistical significantly higher scores of depression were seen in women (ß = 3.65, p = 0.001) and elderly >70 years old (ß = 3.51, CI=0.09-6.93, p = 0.044). Statistically significantly lower functionality were referred by patients >70 years old (ß = -13.58, CI: -21.68-5.49, p = 0.001) and by patients with high depression score (ß= -0.62, 95% CI: -1.06-0.20, p = 0.005). Conclusion Patients experienced moderate to low levels of depression and high levels of adherence and functionality. The higher the functionality scores, the lower the depression scores. Demographic characteristics, such as age and gender, seem to be significant predictors of depression and functionality.

Translation, Cultural Adaptation, Validation and Internal Consistency of the Factors of Nurses Caring Behavior.

INTRODUCTION: The international literature presents a significant gap in the study of the factors affecting caring behaviors as perceived by nurses. This gap requires the study of the factors of nurses' caring behavior. AIM: The translation and the cultural adaptation of the Factors of Nurses Caring Behaviors (FNCB) scale in the Greek language, the validity, and internal consistency of the scale. METHODS: Between November- December 2019, 329 Greek nurses from six public general hospitals completed the FNCB scale consisting of 32 items rating on a 5-point Likert scale. The scale was firstly translated in the Greek language, then back-translated in the English language and culturally adapted. To investigate the construct validity of the scale, exploratory factor analysis was carried out with principal component analysis. The test-retest reliability was performed while the internal consistency was checked through Cronbach's alpha coefficient. Statistical analysis was performed via the Statistical Program SPSS version 21.0. The statistical significance level was set up at 0.05. RESULTS: The final Greek version of the FNCB Scale includes six factors which were revealed from the exploratory factor analysis: Workplace Circumstances, Workload/Management, Interest/Perceptions on Nursing Job,Nurse's Educational Background, Patient's Demographic Characteristics, and Patient's Clinical Characteristics. The internal consistency of the scale was excellent (Cronbach's alpha 0.95). CONCLUSIONS: The Greek version of the FNCB Scale is a valid and reliable questionnaire which can be used for the measure of factors affecting nurses' caring behavior.

Patient Knowledge, Adherence to the Therapeutic Regimen, and Quality of Life in Hemodialysis : Knowledge, Adherence, and Quality of Life in Hemodialysis.

The aim of this study was to investigate the effect of patients' knowledge on adherence to the hemodialysis regimen and Quality of Life (QoL) of patients undergoing hemodialysis as well as the effect of adherence on QoL. Also, the effect of demographic and clinical characteristics on the above three variables was studied. In this cross-sectional study conducted between March and May 2017, 321 patients on hemodialysis from six hemodialysis units completed the Kidney Disease Questionnaire, the GR-Simplified Medication Adherence Questionnaire and the Missoula Vitas Quality of Life Index-15 to measure the patient knowledge, the adherence to hemodialysis regimen, and the QoL, respectively. The statistical analysis was performed via the Statistical Program SPSS 19.0. The statistical significance level was set up at 0.05. The knowledge was independently associated with the overall QoL and its dimension-transcendence-with total adherence and its dimension-diet/fluid adherence. The total adherence was independently associated with overall QoL and its dimensions-symptoms and interpersonal. The educational level, the type of vascular access, and the daily number of pills were independently associated with the total adherence and the overall QoL. Patient knowledge may have an important effect on adherence and QoL. Adherence may have an important effect on QoL. Demographic and clinical characteristics play, also, a crucial role in the above variables. The findings can help nephrology nurses to quantify the extent of non-adherence in hemodialysis and poor quality of life.

The Effect of Fatigue and Pain Self- Efficacy on Health-Related Quality of Life Among Patients with Multiple Sclerosis.

INTRODUCTION: Health-related quality of life is a major issue among patients with Multiple sclerosis (MS). AIM: To explore the effect of fatigue and pain self-efficacy on health-related quality of life among patients with MS. METHODS: Between March and May 2018, 85 MS patients from a large Hospital of Athens region completed the questionnaires: a) Missoula-VITAS Quality of Life Index-15, which examines 5 dimensions of quality of life, b) Pain Self Efficacy Questionnaire which measures the pain self-efficacy that an individual perceives, c) Fatigue Assessment Scale (FAS) which measures fatigue, d) a questionnaire about the sociodemographic elements. Statistical analysis was performed using the IBM SPSS Statistics version 21. The significance level was set up to 0.001. RESULTS: Fatigue might predict the dimension of quality of life "Function" while Pain Self-Efficacy might, also, predict the dimension of quality of life "Interpersonal". A strong correlation was found between the dimensions of quality of life "Well-being" and "Transcendent" and between "Interpersonal" and Pain Self-Efficacy. The total score of fatigue was strongly correlated with Physical Fatigue and very strongly correlated with Mental Fatigue. CONCLUSION: Fatigue and Pain Self-Efficacy are important predictors of the dimensions of quality of life among patients with MS. Pain in MS has to be taken into serious consideration in every patient with MS.

The Virulence Effect of CpxRA in Citrobacter rodentium Is Independent of the Auxiliary Proteins NlpE and CpxP.

Citrobacter rodentium is a murine pathogen used to model the intestinal infection caused by Enteropathogenic and Enterohemorrhagic Escherichia coli (EPEC and EHEC), two diarrheal pathogens responsible for morbidity and mortality in developing and developed countries, respectively. During infection, these bacteria must sense and adapt to the gut environment of the host. In order to adapt to changing environmental cues and modulate expression of specific genes, bacteria can use two-component signal transduction systems (TCS). We have shown that the deletion of the Cpx TCS in C. rodentium leads to a marked attenuation in virulence in C3H/HeJ mice. In E. coli, the Cpx TCS is reportedly activated in response to signals from the outer-membrane lipoprotein NlpE. We therefore investigated the role of NlpE in C. rodentium virulence. We also assessed the role of the reported negative regulator of CpxRA, CpxP. We found that as opposed to the ΔcpxRA strain, neither the ΔnlpE, ΔcpxP nor the ΔnlpEΔcpxP strains were significantly attenuated, and had similar in vivo localization to wild-type C. rodentium. The in vitro adherence of the Cpx auxiliary protein mutants, ΔnlpE, ΔcpxP, ΔnlpEΔcpxP, was comparable to wild-type C. rodentium, whereas the ΔcpxRA strain showed significantly decreased adherence. To further elucidate the mechanisms behind the contrasting virulence phenotypes, we performed microarrays in order to define the regulon of the Cpx TCS. We detected 393 genes differentially regulated in the ΔcpxRA strain. The gene expression profile of the ΔnlpE strain is strikingly different than the profile of ΔcpxRA with regards to the genes activated by CpxRA. Further, there is no clear inverse correlation in the expression pattern of the ΔcpxP strain in comparison to ΔcpxRA. Taken together, these data suggest that in these conditions, CpxRA activates gene expression in a largely NlpE- and CpxP-independent manner. Compared to wildtype, 161 genes were downregulated in the ΔcpxRA strain, while being upregulated or unchanged in the Cpx auxiliary protein deletion strains. This group of genes, which we hypothesize may contribute to the loss of virulence of ΔcpxRA, includes T6SS components, ompF, the regulator for colanic acid synthesis, and several genes involved in maltose metabolism.

Systematic Analysis of Two-Component Systems in Citrobacter rodentium Reveals Positive and Negative Roles in Virulence.

Citrobacter rodentium is a murine pathogen used to model intestinal infections caused by the human diarrheal pathogens enterohemorrhagic and enteropathogenic Escherichia coli During infection, bacteria use two-component systems (TCSs) to detect changing environmental cues within the host, allowing for rapid adaptation by altering the expression of specific genes. In this study, 26 TCSs were identified in C. rodentium, and quantitative PCR (qPCR) analysis showed that they are all expressed during murine infection. These TCSs were individually deleted, and the in vitro and in vivo effects were analyzed to determine the functional consequences. In vitro analyses only revealed minor differences, and surprisingly, type III secretion (T3S) was only affected in the ΔarcA strain. Murine infections identified 7 mutants with either attenuated or increased virulence. In agreement with the in vitro T3S assay, the ΔarcA strain was attenuated and defective in colonization and cell adherence. The ΔrcsB strain was among the most highly attenuated strains. The decrease in virulence of this strain may be associated with changes to the cell surface, as Congo red binding was altered, and qPCR revealed that expression of the wcaA gene, which has been implicated in colanic acid production in other bacteria, was drastically downregulated. The ΔuvrY strain exhibited increased virulence compared to the wild type, which was associated with a significant increase in bacterial burden within the mesenteric lymph nodes. The systematic analysis of virulence-associated TCSs and investigation of their functions during infection may open new avenues for drug development.

THE EFFECT OF PERCEIVED SOCIAL SUPPORT ON HEMODIALYSIS PATIENTS' QUALITY OF LIFE.

BACKGROUND: Association between perceived social support and quality of life in hemodialysis patients represents a new area of interest. AIM: The aim of this study was to explore the effect of social support on the quality of life of hemodialysis patients. MATERIAL AND METHODS: In this study 258 hemodialysis patients were enrolled. Data was collected using a questionnaire which consisted of three parts: a) the Multidimensional Scale of Perceived Social Support (MSPSS) to assess perceived social support, b) the Missoula-VITAS Quality of Life Index (MVQOLI-15) to assess quality of patients' life and c) the socio-demographic, clinical and other variables of patients. To test the existence of association between quality of life and social support the correlation coefficient of Spearman was used. Multiple linear regression was performed to estimate the effect of social support on quality of life (dependent variable), adjusted for potential confounders. The analysis was performed on SPSS v20. RESULTS: Patients felt high support from significant others and family and less from friends (median 6, 6 and 4.5 respectively). Patients evaluated their quality of life in its entirety as moderate in the total and "overall quality of life" score (median 17.2 and 3 respectively). Regarding the association between social support and quality of life, results showed that the more support patients had from their significant others, family and friends, the better quality of life they had. (rho =0,395, rho =0,399 and rho=0,359, respectively). CONCLUSIONS: Understanding the relation between social support and quality of life should prompt health professionals to provide beneficial care to hemodialysis patients.

The CpxRA two-component system is essential for Citrobacter rodentium virulence.

Citrobacter rodentium is a murine intestinal pathogen used as a model for the foodborne human pathogens enterohemorrhagic Escherichia coli and enteropathogenic E. coli. During infection, these pathogens use two-component signal transduction systems to detect and adapt to changing environmental conditions. In E. coli, the CpxRA two-component signal transduction system responds to envelope stress by modulating the expression of a myriad of genes. Quantitative real-time PCR showed that cpxRA was expressed in the colon of C57BL/6J mice infected with C. rodentium. To determine whether CpxRA plays a role during C. rodentium infection, a cpxRA deletion strain was generated and found to have a colonization defect during infection. This defect was independent of an altered growth rate or a defective type III secretion system, and single-copy chromosomal complementation of cpxRA restored virulence. The C. rodentium strains were then tested in C3H/HeJ mice, a lethal intestinal infection model. Mice infected with the ΔcpxRA strain survived infection, whereas mice infected with the wild-type or complemented strains succumbed to infection. Furthermore, we found that the cpxRA expression level was higher during early infection than at a later time point. Taken together, these data demonstrate that the CpxRA two-component signal transduction system is essential for the in vivo virulence of C. rodentium. In addition, these data suggest that fine-tuned cpxRA expression is important for infection. This is the first study that identifies a C. rodentium two-component transduction system required for pathogenesis. This study further indicates that CpxRA is an interesting target for therapeutics against enteric pathogens.