Exploration of agr types, virulence-associated genes, and biofilm formation ability in Staphylococcus aureus isolates from hemodialysis patients with vascular access infections.

Introduction: Staphylococcus aureus, is a pathogen commonly encountered in both community and hospital settings. Patients receiving hemodialysis treatment face an elevated risk of vascular access infections (VAIs) particularly Staphylococcus aureus, infection. This heightened risk is attributed to the characteristics of Staphylococcus aureus, , enabling it to adhere to suitable surfaces and form biofilms, thereby rendering it resistant to external interventions and complicating treatment efforts. Methods: Therefore this study utilized PCR and microtiter dish biofilm formation assay to determine the difference in the virulence genes and biofilm formation among in our study collected of 103 Staphylococcus aureus, isolates from hemodialysis patients utilizing arteriovenous grafts (AVGs), tunneled cuffed catheters (TCCs), and arteriovenous fistulas (AVFs) during November 2013 to December 2021. Results: Our findings revealed that both MRSA and MSSA isolates exhibited strong biofilm production capabilities. Additionally, we confirmed the presence of agr types and virulence genes through PCR analysis. The majority of the collected isolates were identified as agr type I. However, agr type II isolates displayed a higher average number of virulence genes, with MRSA isolates exhibiting a variety of virulence genes. Notably, combinations of biofilm-associated genes, such as eno-clfA-clfB-fib-icaA-icaD and eno-clfA-clfB-fib-fnbB-icaA-icaD, were prevalent among Staphylococcus aureus, isolates obtained from vascular access infections. Discussion: These insights contribute to a better understanding of the molecular characteristics associated with Staphylococcus aureus, infections in hemodialysis patients and provided more targeted and effective treatment approaches.

Pseudomonas aeruginosa Infections Are Associated with Infection Recurrence in Arteriovenous Grafts Treated with Revision.

Background and Objectives: This study was conducted to investigate whether Pseudomonas aeruginosa (PA) infections of arteriovenous grafts (AVGs) recur more frequently than other bacterial infections following treatment with revision. Materials and Methods: Operative procedures, including total excision, subtotal excision, and revision, were performed on 60 patients to treat 65 AVG infections. Final outcomes were classified as no infection recurrence, infection recurrence, and death without prior recurrence. In the competing risk setting, the cumulative incidence was estimated using the cumulative incidence function and Gray's test, and the associations between outcomes and different variables were estimated using a subdistribution hazard (SDH) model. Results: Comparing AVG infections with and without recurrence, PA infection was not associated with a higher risk of infection recurrence (p = 0.13); however, the first operative procedure type was associated with infection recurrence (p = 0.04). AVGs with PA infection were associated with a higher total number of surgical interventions (p < 0.05) than AVGs without PA infection. Regarding the cumulative incidences of outcomes, for AVGs treated with subtotal excision or revision, the cumulative incidence of recurrent infection was 3.3-fold higher for those with PA infection than without one year after the first surgery. However, when AVGs were treated with revision alone, the cumulative incidence was 4.1-fold. After excluding AVGs treated with total excision, the SDH model was applied, obtaining a hazard ratio for infection recurrence of 16.05 (p = 0.02) for AVGs with PA infection compared with AVGs without PA infection. No other variables were significantly associated with infection recurrence. Conclusions: For subtotal resection and revision, AVGs infected with PA had a higher recurrence rate than those infected with other species. However, revision surgery may aggravate the recurrence rate.

Insight into the Clonal Lineage and Antimicrobial Resistance of Staphylococcus aureus from Vascular Access Infections before and during the COVID-19 Pandemic.

Patients receiving hemodialysis are at risk of vascular access infections (VAIs) and are particularly vulnerable to the opportunistic pathogen Staphylococcus aureus. Hemodialysis patients were also at increased risk of infection during the COVID-19 pandemic. Therefore, this study determined the change in the molecular and antibiotic resistance profiles of S. aureus isolates from VAIs during the pandemic compared with before. A total of 102 S. aureus isolates were collected from VAIs between November 2013 and December 2021. Before the pandemic, 69 isolates were collected, 58%, 39.1%, and 2.9% from arteriovenous grafts (AVGs), tunneled cuffed catheters (TCCs), and arteriovenous fistulas (AVFs), respectively. The prevalence of AVG and TCC isolates changed to 39.4% and 60.6%, respectively, of the 33 isolates during the pandemic. Sequence type (ST)59 was the predominant clone in TCC methicillin-resistant S. aureus (MRSA) and AVG-MRSA before the pandemic, whereas the predominant clone was ST8 in AVG-MRSA during the pandemic. ST59 carrying the ermB gene was resistant to clindamycin and erythromycin. By contrast, ST8 carrying the msrA gene was exclusively resistant to erythromycin. The ST distribution for different VAIs changed from before to during the pandemic. The change in antibiotic resistance rate for different VAIs was closely related to the distribution of specific STs.

The role of venous pressure variability during hemodialysis in the prediction of impending arteriovenous graft occlusion.

BACKGROUND: Elevated venous pressure during hemodialysis (VPHD) is associated with arteriovenous graft (AVG) stenosis. This study investigated the role of VPHD variations in the prediction of impending AVG occlusion. METHODS: Data were retrieved from 118 operations to treat AVG occlusion (occlusion group) and 149 operations to treat significant AVG stenosis (stenosis group). In addition to analyzing the VPHD values for the three hemodialysis (HD) sessions prior to the intervention, VPHD values were normalized to mean blood pressure (MBP), blood flow rate (BFR), BFR × MBP, and BFR2 × MBP to yield ratios for analysis. The coefficient of variation (CV) was used to measure relative variations. RESULTS: The within-group comparisons for both groups revealed no significant differences in the VPHD mean and CV values among the three HD sessions prior to intervention. However, the CVs for VPHD/MBP, VPHD/(BFR × MBP), and VPHD/(BFR2 × MBP) exhibited significant elevation in the occlusion group during the last HD session prior to intervention compared with both the penultimate and antepenultimate within-group HD data (p < 0.05). In the receiver operating characteristic curve analysis, the CV for VPHD/(BFR2 × MBP) was the only parameter able to discriminate between the last and the penultimate HD outcomes (p < 0.001). According to a multivariate analysis, after controlling for covariates, CV for VPHD/(BFR2 × MBP) >8.76% was associated with a higher risk of AVG thrombosis (odds ratio: 3.17, p < 0.001). CONCLUSIONS: Increasing the variation in VPHD/(BFR2 × MBP) may increase the probability of AVG occlusion.

Do the Paths of Sequential Vein Grafts Influence the Outcomes of Coronary Artery Bypass Surgeries?

BACKGROUND: The use of a sequential vein graft (SVG) in coronary artery bypass grafting (CABG) in multi-vessel coronary disease is common. This study aimed to investigate the influence of the paths of SVGs on the outcomes of CABG. METHODS: From January 2011 to June 2017, 126 patients underwent elective isolated CABG. If the path of the SVG was from the aorta to the right coronary artery (RCA)/ posterior descending artery (PDA) to the left circumflex artery (LCX)/obtuse marginal artery (OM), the patients were included in Group R. If the path was from the aorta to the LCX/OM to the RCA/PDA, the patients were included in Group L. The in-hospital and follow-up outcomes were analyzed. RESULTS: Group R had 69 patients, and Group L had 57 patients. Univariate analysis showed that Group L had a higher number of grafts (P < .001) and less aortic cross-clamping time (P < .001) and total bypass time (P = .001). Otherwise, Group L had 14 patients (19.3%), who received first diagonal branch (D1) bypass grafting, while Group R had none (P < .001). In the multivariate analysis, in- hospital mortality from heart failure, postoperative acute kidney injury, medium-term mortality, and readmission for cardiac incidents were not associated with the SVG path. CONCLUSION: The SVG path from the aorta to the LCX/OM to the RCA/PDA facilitated the additional D1 bypass grafting, but the outcomes for this approach were not significantly different from those for the other path.

Does Interhospital Transfer Influence the Outcomes of Patients Receiving Surgery for Acute Type A Aortic Dissection? Type A Aortic Dissection: Is Transfer Hazardous or Beneficial?

INTRODUCTION: The progression of acute type A aortic dissection may cause immediate death, such that, in the event of its diagnosis, emergency surgery is indicated. Relatedly, an interhospital transfer may prolong the time from diagnosis to surgery. This study therefore investigated how interhospital transfers impact surgical outcomes for acute type A aortic dissection. MATERIALS AND METHODS: After excluding those patients who received deferred surgery for acute type A aortic dissection, 112 patients who received emergency surgery for the condition at our hospital from January 2011 to January 2018 were enrolled. These patients were divided into two groups, one consisting of the patients who were sent directly to our emergency department (group 1) and the other consisting of the patients who were transferred from another hospital after first being diagnosed with type A aortic dissection (group 2). The collected data included the patient demographics, clinical characteristics, operative findings and methods, postoperative outcomes, latest follow-up time, and most recent status. RESULTS: There were 59 patients in group 1 and 53 patients in group 2. Univariate analysis revealed that group 1 had significantly more patients with a previous stroke (p = 0.007). Moreover, the average length of time from receiving a computed tomography (CT) scan to entering the operating room (OR) was shorter for the group 1 patients (p < 0.001). However, except for the incidence of postoperative acute kidney injury (14.5% versus 33.3%, p = 0.024), there was no statistical difference between the groups in terms of the operative findings and outcomes, such as hypotension before cardiopulmonary bypass, hemopericardium, other complications, and survival rate. Multivariate analysis showed that the independent predictors of hospital mortality included age > 61.5 years (p = 0.017), respiratory rate upon admission > 18.5 breaths/minute (p = 0.046), and total bypass time > 265.6 minutes (p = 0.015). For the patients who survived to discharge, log-rank analysis demonstrated similar cumulative survival rates for the two groups (p = 0.62). Further multivariate analysis showed that the risk of death after discharge was associated with the interval between the CT scan and OR entry (hazard ratio = 0.97 per minute; 95% confidence interval, 0.950-0.998; p = 0.037). CONCLUSION: In this study, it was found that interhospital transfer did not influence the surgical outcomes of patients with acute type A aortic dissection. As such, it can be concluded that the transfer of the patients with type A aortic dissection to tertiary hospitals with experienced cardiac surgical teams may not increase the surgical risk.

[Quality of life and associated factors in patients with heart failure].

BACKGROUND: Heart failure is a chronic and exacerbating disease, which often significantly decreases patient quality of life (QOL). Treatments continue to focus on alleviating the physical symptoms of this disease, and data on QOL factors are limited. PURPOSE: The purpose of this study was to explore QOL and associated factors in patients with heart failure. METHODS: A cross-sectional and correlational research design was conducted using the Kansas City Cardiomyopathy Questionnaire, Beck Depression Inventory-II, and the World Health Organization Quality of Life Assessment. A convenience sample of 200 patients aged 20 years old or above and diagnosed with heart failure were recruited from one medical center and one regional teaching hospital in southern Taiwan. Data were analyzed using SPSS 14.0 software. RESULTS: Results found (1) participants had an average QOL index score of 63.0 (moderate); (2) significant differences in QOL scores for the variables of marriage, occupation type, monthly family income, concomitant diabetes/hypertension, number of complications, and treatment type; (3) participants had an average index score for symptoms of 54.1 (moderate) that was significantly correlated with QOL; (4) a majority of participants were classified in NYHA Class II, mean score of depression was 9.13±6.25 (normal), and functional status and depression were significantly related to QOL; and (5) 59.3% of QOL variance was explained by depression, symptoms and family income per month. CONCLUSIONS: This study may help health professionals to understand relationships among symptoms, functional status, depression and QOL in heart failure patients. It may also provide healthcare professionals evidence-based data necessary to further improve symptoms, functional status and depression in heart failure patients, and thus significantly improve QOL in patients with heart failure.