Biofilm Formation in <em>Acinetobacter Baumannii</em>: Genotype-Phenotype Correlation

Strains of Acinetobacter baumannii are commensal and opportunistic pathogens that have emerged as problematic hospital pathogens due to its biofilm formation ability and multiple antibiotic resistances. The biofilm-associated pathogens usually exhibit dramatically decreased susceptibility to antibiotics. This study was aimed to investigate the correlation of biofilm-forming ability, antibiotic resistance and biofilm-related genes of 154 A. baumannii isolates which were collected from a teaching hospital in Taiwan. Biofilm-forming ability of the isolates was evaluated by crystal violet staining and observed by scanning electron microscopy. Antibiotic susceptibility was determined by disc diffusion method and minimum inhibitory concentration; the biofilm-related genes were screened by polymerase chain reaction. Results showed that among the 154 tested isolates, 15.6% of the clinical isolates were weak biofilm producers, while 32.5% and 45.4% of them possessed moderate and strong biofilm formation ability, respectively. The experimental results revealed that the multiple drug resistant isolates usually provided a higher biofilm formation. The prevalence of biofilm related genes including bap, blaPER-1, csuE and ompA among the isolated strains was 79.2%, 38.3%, 91.6%, and 68.8%, respectively. The results indicated that the antibiotic resistance, the formation of biofilm and the related genes were significantly correlated. The results of this study can effectively help to understand the antibiotic resistant mechanism and provides the valuable information to the screening, identification, diagnosis, treatment and control of clinical antibiotic-resistant pathogens

Comparison of tunneled central venous catheters and native arteriovenous fistulae by evaluating the mortality and morbidity of patients with prevalent hemodialysis

Purpose: We examined the association between catheter use for maintenance hemodialysis (HD) and mortality/hospitalization in a cohort of patients with prevalent HD. Methods: In this study, 70 HD patients with tunneled cuffed central venous catheters (TCVCs) from a Taiwanese HD center during 2014–2016 were enrolled and compared with 70 matched HD patients with native arteriovenous fistulae (AVF). The compared variables included demographic parameters and laboratory and dialysis-related indices. Cox regression analysis was used to assess the risk of mortality/hospitalization within a year. Results: Low baseline serum albumin levels were found in patients with TCVCs (3.64 g/dL vs 3.79 g/dL, p = 0.030). The mortality rates of patients with AVF and TCVCs were 14 per 1000 patients and 171 per 1000 patients, respectively. Infection was the leading cause of mortality/hospitalization in patients with TCVCs. Using multivariate analyses, the risk of death was found to be significantly higher in patients with TCVCs than in those with AVF (Hazard ratio [HR] 12.15, 95% CI 1.16–127.17; p = 0.037). Patients with TCVC also had a higher hospitalization rate (HR 1.33, 95% CI 0.71–2.49; p = 0.369) (not statistically significant). Conclusion: Catheter use for maintenance HD was associated with increased all-cause mortality. Keywords: Tunneled catheter, Arteriovenous fistula, Mortality, Hemodialysi

Changes in Serum Concentrations of Fibroblast Growth Factor 23 and Soluble Klotho in Hemodialysis Patients after Total Parathyroidectomy

Background. We examined the changes in circulating fibroblast growth factor 23 (FGF23) and Klotho concentrations in hemodialysis patients after parathyroidectomy (PTX). Methods. We enrolled a cohort of hemodialysis patients who received PTX. Postoperatively, patients received calcium supplements and/or vitamin D analogue (calcitriol) to maintain serum calcium within 7.0–8.0 mg/dL. Information on clinical parameters including bone-mineral metabolic variables was collected pre-PTX and on days 5 and 90 after PTX. Concomitantly, serum full-length FGF23 and α-Klotho levels were measured. The relationship between FGF23 and clinical parameters was analyzed by single linear regression. Results. Forty-six participants (33 women; 13 men) were enrolled in the study. Their mean age was 56.49 years. Serum FGF23 and α-Klotho concentrations were elevated on days 5 and 90 after PTX compared to baseline (p>0.05). Serum FGF23 concentrations negatively correlated with serum calcium concentrations pre-PTX (Beta -0.31; R2 0.0949; p=0.040), day 5 post-PTX (Beta -0.31; R2 0.0982; p=0.036), and day 90 post-PTX (Beta -0.39; R2 0.1528; p=0.008). Conclusions. There was no change in circulating FGF23 and Klotho concentrations after PTX in hemodialysis patients given postoperative calcium supplements and/or vitamin D analogue. Serum FGF23 concentrations pre-PTX and at days 5 and 90 after PTX were inversely related to serum calcium concentrations

Identifying the Association of Time-Averaged Serum Albumin Levels with Clinical Factors among Patients on Hemodialysis Using Whale Optimization Algorithm

Time-averaged serum albumin (TSA) is commonly associated with clinical outcomes in hemodialysis (HD) patients and considered as a surrogate indicator of nutritional status. The whale optimization algorithm-based feature selection (WOFS) model could address the complex association between the clinical factors, and could further combine with regression models for application. The present study aimed to demonstrate an optimal multifactor TSA-associated model, in order to interpret the complex association between TSA and clinical factors among HD patients. A total of 829 HD patients who met the inclusion criteria were selected for analysis. Monthly serum albumin data tracked from January 2009 to December 2013 were converted into TSA categories based on a critical value of 3.5 g/dL. Multivariate logistic regression was used to analyze the association between TSA categories and multiple clinical factors using three types of feature selection models, namely the fully adjusted, stepwise, and WOFS models. Five features, albumin, age, creatinine, potassium, and HD adequacy index (Kt/V level), were selected from fifteen clinical factors by the WOFS model, which is the minimum number of selected features required in multivariate regression models for optimal multifactor model construction. The WOFS model yielded the lowest Akaike information criterion (AIC) value, which indicated that the WOFS model could achieve superior performance in the multifactor analysis of TSA for HD patients. In conclusion, the application of the optimal multifactor TSA-associated model could facilitate nutritional status monitoring in HD patients

Prevalence of Carbapenem Resistance Genes among <i>Acinetobacter baumannii</i> Isolated from a Teaching Hospital in Taiwan

The problem of antibiotic-resistant strains has become a global public issue; antibiotic resistance not only limits the choice of treatments but also increases morbidity, mortality and treatment costs. The multi-drug resistant Acinetobacter baumannii is occurring simultaneously in hospitals and has become a major public health issue worldwide. Although many medical units have begun to control the use of antibiotics and paid attention to the issue of drug resistance, understanding the transmission pathways of clinical drug-resistant bacteria and drug-resistant mechanisms can be effective in real-time control and prevent the outbreak of antibiotic-resistant pathogens. In this study, a total of 154 isolates of Acinetobacter baumannii obtained from Chia-Yi Christian Hospital in Taiwan were collected for specific resistance genotyping analysis. Ten genes related to drug resistance, including blaOXA-51-like, blaOXA-23-like, blaOXA-58-like, blaOXA-24-like, blaOXA-143-like, tnpA, ISAba1, blaPER-1, blaNDM and blaADC, and the repetitive element (ERIC2) were selected for genotyping analysis. The results revealed that 135 A. baumannii isolates (87.6%) carried the blaOXA-51-like gene, 4.5% of the isolates harbored the blaOXA-23-like gene, and 3.2% of the isolates carried the blaOXA-58-like gene. However, neither the blaOXA-24-like nor blaOXA-143-like genes were detected in the isolates. Analysis of ESBL-producing strains revealed that blaNDM was not found in the test strains, but 38.3% of the test isolates carried blaPER-1. In addition, blaADC, tnpA and ISAba1genes were found in 64.9%, 74% and 93% of the isolates, respectively. Among the carbapenem-resistant strains of A. baumannii, 68% of the isolates presenting a higher antibiotic resistance carried both tnpA and ISAba1 genes. Analysis of the relationship between their phenotypes (antibiotic resistant and biofilm formation) and genotypes (antibiotic-resistant genes and biofilm-related genes) studied indicated that the bap, ompA, ISAba1and blaOXA-51 genes influenced biofilm formation and antibiotic resistance patterns based on the statistical results of a hierarchical clustering dendrogram. The analysis of the antibiotic-resistant mechanism provides valuable information for the screening, identification, diagnosis, treatment and control of clinical antibiotic-resistant pathogens, and is an important reference pointer to prevent strains from producing resistance

Multivariate logistic regression model for PCa risk.

Multivariate logistic regression model for PCa risk.</p

Subgroup analysis results for younger patients aged under 70 years (n = 109).

(a) Nomogram for PCa risk prediction of benign prostatic hyperplasia patients. (b) The predicted probability versus actual probability of the proposed model for PCa with 250 and 500 resampling using the bootstrap method. (c) Comparison results of predictive performance between the proposed model and single risk factors of PCa. PCa, prostate cancer. OE, Occupational exposure. HPV, human papillomavirus. FH score, Family history severity score. (TIF)</p

The predictive performance of proposed model for PCa risk in all patients.

(a) Nomogram for PCa risk prediction of benign prostatic hyperplasia patients. (b) The predicted probability versus actual probability of proposed model for PCa with 250 and 500 resampling using bootstrap method. (c) Comparison results of predictive performance between proposed model and single risk factors of PCa. PCa, prostate cancer. OE, Occupational exposure. HPV, human papillomavirus. FH score, Family history severity score.</p

Characteristics of study cohort.

BackgroundBenign prostatic hyperplasia (BPH) is common in aging Asian males and is associated with an excess risk of developing prostate cancer (PCa). However, discussions about socially-sensitive experiences such as sexual activity, which can significantly predict PCa risk, may be considered stigmatized in Asian culture. This study aimed to develop a predictive model for PCa risk in Asian males with BPH using non-socially-sensitive information.MethodsA cross-sectional case-control study, with PCa patients as the cases and remaining as the controls, was conducted on a cohort of Taiwanese males with BPH from four medical institutions. Patients who met the inclusion criteria were enrolled, excluding those aged over 86 years or who had received human papillomavirus (HPV) vaccination. Non-socially-sensitive variables such as obesity, occupational exposure, HPV infection, and PCa family history score (FH score) were included in a fully adjusted logistic regression model, and depicted using a nomogram.ResultsAmong 236 BPH patients, 45.3% had PCa. Obesity, occupational exposure, HPV infection, and family history of PCa were significantly associated with PCa risk. The FH score (OR = 1.89, 95% CI = 1.03–3.47, P = 0.041) had the highest impact, followed by HPV infection (OR = 1.47, 95% CI = 1.03–2.11, P = 0.034), occupational exposure (OR = 1.32, 95% CI = 1.15–1.51, P P = 0.005). The nomogram accurately depicted the predictive risk, and the model demonstrated robust performance compared to individual factors. In addition, the subgroup analysis results showed elderly age group could obtain more favorable predictive performance in our proposed model (AUC = 0.712).ConclusionThis non-socially-sensitive predictive model for PCa risk in Taiwanese males with BPH integrates multiple factors that could provide acceptable PCa risk-predictive performance, especially for elderly BPH patients over 70 years, aiding clinical decision-making and early cancer detection.</div