Assessment of Biofilm Forming Capability and Antibiotic Resistance in Proteus mirabilis Colonizing Indwelling Catheter.

<b>Background and Objective:</b> Urinary tract infections from the use of an indwelling urinary catheter are one of the most common infections caused by <i>Proteus mirabilis</i>. Due to their biofilm-producing capacity and the increasing antimicrobial resistance in this microorganism, this study aimed to determine the prevalence, biofilm-producing capacity, antimicrobial resistance patterns, multidrug resistance and plasmid mediated resistance of the recovered isolates. <b>Materials and Methods:</b> A total of 50 urinary samples were collected from May to August, 2018 from patients on indwelling urinary catheters. Using routine microbiological and biochemical methods, 37 <i>P. mirabilis</i> were isolated. Biofilm forming capability was determined among the isolates using the tube method while antimicrobial susceptibility and plasmid curing were also performed. <b>Results:</b> All isolates were biofilm producers with 17(46%) being moderate producers while 20(54%) were strong biofilm formers. The study isolates exhibited a high resistance rate to empiric antibiotics, including ceftazidime (75.8%), cefuroxime (54.5%), ampicillin (69.7%) and amoxicillin-clavulanic acid (51.5%). Low resistance was seen in the fluoroquinolones, gentamicin and nitrofurantoin. Plasmid curing experiment revealed that most isolates lost their resistance indicating that resistance was borne on plasmids. Plasmid carriage is likely the reason for the high MDR rate of 56.8% observed. <b>Conclusion:</b> These findings necessitate the provision of infection control programs which will guide and implement policies.

[Cuff Shaving in Recurrent Exit-Site Infections in a Patient on Peritoneal Dialysis].

In patients on peritoneal dialysis, the cutaneous emergency (exit-site) represents a potential access route to the peritoneum; consequently, it can become a site for microbial infections. These infections, initially localized to the exit-site, may spread to the peritoneum causing peritonitis, which is the most common cause of drop-out from peritoneal dialysis and transition to hemodialysis. Peritoneal catheters have dacron caps which have the function of counteracting the traction of the catheter itself and at the same time acting as a barrier for microorganisms, preventing the spread towards the peritoneum. Despite this, the same dacron cap can represent a sort of nest for microorganisms to colonize and, with the formation of a biofilm that facilitates their proliferation, make the same organisms impervious to antibiotic therapy and even resistance to them. The most effective tool for monitoring the health status of the exit-site is represented by the objective examination. This examination, through the use of well-defined scales, helps to provide a pathological score of the exit, facilitating the implementation of necessary precautions. In the presence of recurrent exit-site infections, from both Gram positive and Gram negative bacteria, minimally invasive surgical therapy is a valid approach to break this vicious circle. It helps avoid subjecting the patient to the removal of the peritoneal catheter, temporary transition to hemodialysis with the insertion of a central venous catheter, and subsequent repositioning of another peritoneal catheter. We propose the case of a recurrent Staphylococcus Aureus infection resolved after cuff shaving of the exit-site.

Catheter salvage or removal in catheter-related bloodstream infections with Staphylococcus aureus in children with chronic intestinal failure receiving home parenteral nutrition and the use of prophylactic taurolidine catheter lock solution: A descriptive cohort study.

BACKGROUND: Children with chronic IF require long-term home parenteral nutrition (HPN), administered through a central venous catheter. Catheter-related bloodstream infection (CRBSI) with Staphylococcus aureus is known to be a serious infection with a high mortality rate and risk of complications. A standardized protocol on the management of S aureus CRBSIs in children receiving HPN is lacking. The aim of this study is to evaluate the effectiveness and safety of the current management in an HPN expertise center in the Netherlands. METHODS: We performed a retrospective descriptive cohort study between 2013 and 2022 on children 0-18 years of age with chronic IF requiring long-term HPN. Our primary outcomes were the incidence of S aureus CRBSI per 1000 catheter days, catheter salvage attempt rate, and successful catheter salvage rate. Our secondary outcomes included complications and mortality. RESULTS: A total of 74 patients (39 male; 53%) were included, covering 327.8 catheter years. Twenty-eight patients (38%) had a total of 52 S aureus CRBSIs, with an incidence rate of 0.4 per 1000 catheter days. The catheter salvage attempt rate was 44% (23/52). The successful catheter salvage rate was 100%. No relapse occurred, and no removal was needed after catheter salvage. All complications that occurred were already present at admission before the decision to remove the catheter or not. No patients died because of an S aureus CRBSI. CONCLUSION: Catheter salvage in S aureus CRBSIs in children receiving HPN can be attempted after careful consideration by a multidisciplinary team in an HPN expertise center.

Bacteremia due to Leuconostoc species: A 13-year single-center case series.

INTRODUCTION: Leuconostoc spp. are facultatively anaerobic Gram-positive cocci involved in cases of hospital-acquired bacteremia, mainly in immunocompromised hosts. The available data is scarce due to its uncommon presentation. METHODS: We describe all the episodes of Leuconostoc spp. bacteremia in a third level hospital in a 13-year period (2008-2021). RESULTS: Four cases of clinically relevant bacteremia were detected. All cases were categorized as catheter-related. The following risk factors were found: previous glycopeptide therapy (75%), use of parenteral nutrition (100%) and cancer (75%). All isolates showed susceptibility to beta-lactams. Catheter removal was performed and wide spectrum antimicrobials were administered, with clinical response in all cases except one. DISCUSSION: Apart from cancer and glycopeptide exposure, disruption of skin barrier and gastrointestinal conditions were identified as risk factors, as it was concordantly underlined in other case series. Susceptibility to beta-lactams is usually maintained. Catheter removal and administration of an active antibacterial therapy seem to be the best approach for Leuconostoc spp. catheter-related bacteremia.

7295 elderly hospitalized patients with catheter-associated urinary tract infection: a case-control study.

BACKGROUND: Catheter-associated urinary tract infection (CAUTI) ranks second among nosocomial infections in elderly patients after lung infections. Improper treatment can lead to death. This study analysed the risk factors, pathogen distribution, clinical characteristics and outcomes of CAUTI in elderly inpatients with a large sample size to provide evidence for clinical prevention and control. METHODS: Based on the HIS and LIS, a case‒control study was conducted on all hospitalized patients with indwelling urinary catheters ≥ 60 years old from January 1, 2019, to December 31, 2022, and the patients were divided into the CAUTI group and the non-CAUTI group. RESULTS: CAUTI occurred in 182 of 7295 patients, and the infection rate was 3.4/per 1000 catheter days. Urine pH ≥ 6.5, moderate dependence or severe dependence in the classification of self-care ability, age ≥ 74 years, male sex, hospitalization ≥ 14 days, indwelling urinary catheter ≥ 10 days, diabetes and malnutrition were independent risk factors for CAUTI (P < 0.05). A total of 276 strains of pathogenic bacteria were detected in urine samples of 182 CAUTI patients at different times during hospitalization. The main pathogens were gram-negative bacteria (n = 132, 47.83%), followed by gram-positive bacteria (n = 91, 32.97%) and fungi (n = 53, 19.20%). Fever, abnormal procalcitonin, positive urinary nitrite and abnormal urination function were the clinical characteristics of elderly CAUTI patients (P < 0.001). Once CAUTI occurred in elderly patients, the hospitalization days were increased by 18 days, the total hospitalization cost increased by ¥18,000, and discharge all-cause mortality increased by 2.314 times (P<0.001). CONCLUSION: The situation of CAUTI in the elderly is not optimistic, it is easy to have a one-person multi-pathogen infection, and the proportion of fungi infection is not low. Urine pH ≥ 6.5, moderate or severe dependence on others and malnutrition were rare risk factors for elderly CAUTI in previous studies. Our study analysed the clinical characteristics of CAUTI in the elderly through a large sample size, which provided a reliable basis for its diagnosis and identified the adverse outcome of CAUTI.

[Prevention of the development of catheter-associated urinary system infections in the early postoperative period].

BACKGROUND: Bladder catheterization is a common medical manipulation that is associated with the risk of complications, including catheter-associated urinary tract infection (CAUTI), which accounts for 80% of all nosocomial infections of the urological profile. AIM: To evaluate the combined use of the biologically active additive Uronext and ceftriaxone in the prevention of the development of CAUTI in the early postoperative period in 120 patients aged 20-80 years with a Foley indwelling catheter. MATERIALS AND METHODS: The patients were divided into 2 groups: in group I (n=60), D-mannose with cranberry extract and vitamin D3 as part of Uronext dietary supplement was administered orally in the form of sachets 48 hours before surgery and after surgery until urethral catheter was placed, as well as intravenous ceftriaxone 1000 mg 2 hours before surgery and in the postoperative period within 7 days. In group II (n=60), ceftriaxone monotherapy was prescribed in a similar way. RESULTS: According to the results of bacteriological examination of the removed urinary catheter on 3-7 days in Uronext group, bacterial growth was absent in 40 patients (66.67%, p<0.05), versus 23 cases (38.33%) in the control group. CONCLUSIONS: The data obtained confirm the efficiency of the use of the biologically active additive Uronext in combination with an antibacterial drug, which allows to recommend this scheme in patients with an indwelling urinary catheter for the prevention of the development of CAUTI.

A mixed-methods evaluation on the efficacy and perceptions of needleless connector disinfectants.

OBJECTIVE: Optimizing needleless connector hub disinfection practice is a key strategy in central-line-associated bloodstream infection (CLABSI) prevention. In this mixed-methods evaluation, 3 products with varying scrub times were tested for experimental disinfection followed by a qualitative nursing assessment of each. METHODS: Needleless connectors were inoculated with varying concentrations of Staphylococcus epidermidis, Pseudomonas aeruginosa, and Staphylococcus aureus followed by disinfection with a 70% isopropyl alcohol (IPA) wipe (a 15-second scrub time and a 15-second dry time), a 70% IPA cap (a 10-second scrub time and a 5-second dry time), or a 3.15% chlorhexidine gluconate with 70% IPA (CHG/IPA) wipe (a 5-second scrub time and a 5-second dry time). Cultures of needleless connectors were obtained after disinfection to quantify bacterial reduction. This was followed by surveying a convenience sample of nursing staff with intensive care unit assignments at an academic tertiary hospital on use of each product. RESULTS: All products reduced overall bacterial burden when compared to sterile water controls, however the IPA and CHG/IPA wipes were superior to the IPA caps when product efficacy was compared. Nursing staff noted improved compliance with CHG/IPA wipes compared with the IPA wipes and the IPA caps, with many preferring the lesser scrub and dry times required for disinfection. CONCLUSION: Achieving adequate bacterial disinfection of needleless connectors while maximizing healthcare staff compliance with scrub and dry times may be best achieved with a combination CHG/IPA wipe.

Risk factors of infection of totally implantable venous access port: A retrospective study.

BACKGROUND: Infection is the most frequent complication associated with the use of totally implantable venous access port (TIVAP). This retrospective study was conducted to determine the risk factors affecting TIVAP-related infection. METHODS: A total of 1406 patients implanted with TIVAP at our center were included in this retrospective study. Incidence of perioperative infection, patient characteristics and bacteriologic data were retrieved and analyzed. Univariable analyses and multiple logistic regression analyses were used to determine the risk factors. RESULTS: Overall, 72 (5.1%) patients had perioperative infection, and TIVAP was finally removed from 12 (0.85%) patients. There was significantly more hematologic malignancy in the infection group, compared to the non-infection group. Patients with chemotherapy and infection within 30 days before operation also had more infections. There were more inpatients in the infection group than in the non-infection group. The rate of hematoma was higher in the infected patients. Multivariate logistic analysis revealed that hematoma (OR 5.695, p < 0.001), preoperative hospital stay (⩾14d) (OR 2.945, p < 0.001), history of chemotherapy (OR 2.628, p = 0.002), history of infection (within 30 days) (OR 4.325, p < 0.001) were independent risk factor for infection. CONCLUSIONS: This study demonstrated that hematoma, preoperative hospital stay (⩾14d), history of chemotherapy and history of infection (within 30 days) are independent risk factor for all patients.

TIVAP-related infection due to Gram-negative aerobic bacilli: should TIVAP stay or should it go?

We aimed to describe the outcome of totally implantable venous-access port (TIVAP)-related infections due to Gram-negative aerobic bacilli (Pseudomonas aeruginosa and other Pseudomonas spp., Acinetobacter spp., and Stenotrophomonas maltophilia), or GNAB, and assess the safety of conservative treatment. We conducted a retrospective study in a French teaching hospital, from January 2016 to December 2020, including adult patients treated for TIVAP-related infection due to GNAB. Success of conservative treatment was defined as a functional TIVAP 3 months after infection with no recurrence. We performed a bivariate analysis and analyzed causes for treatment failure. We included 68 patients (53 TIVAP-related bloodstream infections, 11 TIVAP-related infections, and 4 probable TIVAP-related infections) due to GNAB, mostly P. aeruginosa (50/68, 74%). TIVAP removal was initially decided for 49/68 patients (72%). Among the 19/68 (28%) patients with conservative treatment (all for infections caused by P. aeruginosa), 5/19 (26%) had successful treatment, 7/19 (37%) experienced failure (without sepsis or septic shock), 6/19 (32%) died within 3 months without TIVAP removal and no signs of infection recurrence, and 1 patient had TIVAP removal as it was no longer required. TIVAP-related infections caused by GNAB frequently require TIVAP removal. Conservative treatment can be performed in selected patients with a non-complicated infection caused by P. aeruginosa, who can benefit from the continuation of antineoplastic chemotherapy or palliative care. Treatment failures were not associated with sepsis or septic shock.

Tunneled catheter-related bacteremia in hemodialysis patients: incidence, risk factors and outcomes. A 14-year observational study.

BACKGROUND: Tunneled catheter-related bacteremia represents one of the major complications in patients on hemodialysis, and is associated with increased morbidity and mortality. This study aimed to evaluate the incidence of tunneled catheter-related bacteremia and, secondly, to identify possible factors involved in the first episode of bacteremia. METHODS: This is a retrospective study of all tunneled catheters inserted between 1 January, 2005 and 31 December, 2019. Data on patients with a tunneled catheter were analyzed for comorbidities, catheter characteristics, microbiological culture results and variables related to the first episode of bacteremia. Patient outcomes were also assessed. RESULTS: In the 14-year period under study, 406 tunneled catheters were implanted in 325 patients. A total of 85 cases of tunneled catheter-related bacteremia were diagnosed, resulting in an incidence of 0.40 per 1000 catheter days (81.1% after 6 months of implantation). The predominant microorganisms isolated were Gram-positive organisms: Staphylococcus epidermidis (48.4%); Staphylococcus aureus (28.0%). We found no significant differences in time to catheter removal for infections or non-infection-related reasons. The jugular vein, the Palindrome® catheter, and being the first vascular access were protective factors for the first episode of bacteremia. The 30-day mortality rate from the first tunneled catheter-related bacteremia was 8.7%. CONCLUSIONS: The incidence of bacteremia in our study was low and did not seem to have a relevant impact on catheter survival. S. epidermidis was the most frequently isolated microorganism, followed by S. aureus. We identified Palindrome® catheter, jugular vein, and being the first vascular access as significant protective factors against tunneled catheter-related bacteremia.

Transient Bacteremia Promotes Catheter-Related Central Venous Thrombosis through Neutrophil Extracellular Traps.

Formation of intravenous catheter-related thrombosis leads to central venous stenosis in patients requiring renal replacement therapy or chemotherapy infusion, yet the triggers or mechanisms remain unclear, especially in patients without symptoms of infection. In this study, we found that neutrophil extracellular traps (NETs) could be detected in the fibrin sheaths from dialysis patients without clinical manifestations of infection. Confocal microscopy revealed bacteria imbedded in NETs in the fibrin sheaths. Thirty-nine of 50 (78%) fibrin sheath specimens contained bacteria detectable by 16S ribosomal RNA genome typing with a predominance of Staphylococcus aureus (69%). In rat models, transient bacteremia of S. aureus induced NETs in enlarged fibrin sheaths, and treatment with DNase I alone significantly reduced both NET and fibrin sheath formation surrounding the catheter. Therefore, transient bacteremia could be a silent trigger that induces NET-related immunothrombosis enhancing catheter-related central venous stenosis.

Epidemiology, management, and prevention of exit site infections in peritoneal dialysis patients.

Exit site infection (ESI) is a leading complication of peritoneal dialysis (PD), at an incidence of 0.6 episodes per year in the United States, and a major risk factor for catheter removal and peritonitis. An estimated 20% of all peritonitis cases are preceded by an ESI, with up to 50% of Staphylococcus aureus peritonitis associated with ESI. Gram-negative ESIs are less associated with succeeding peritonitis than their gram-positive counterparts, though when present, are associated with a lower peritonitis cure rate. The rate of catheter removal for refractory ESI is relatively highest in ESI due to mycobacteria (up to 40%), S. aureus (35%), Pseudomonas aeruginosa (28%), followed by Corynebacterium, Serratia, and fungi. In review of relevant literature, we found no prophylactic benefit of dressings over nondressings, specific antiseptics over normal saline, or topical honey over topical antibiotic prophylaxis, and thus recommend individualized exit site hygiene. We found topical gentamicin effective for prevention of most ESIs, including gram-negative ESIs, and thus recommend consideration of prophylactic topical gentamicin in areas of high gram-negative peritonitis incidence. With long-term use, observational studies detect up to 25% of gram-positive and 14% of gram-negative ESIs may be mupirocin and gentamicin resistant, respectively. We review empiric and targeted ESI management, including indications for ultrasound, anti-VMRSA, anti-Pseudomonal, and anti-mycobacterial antibiotic use, and catheter removal. We recommend further investigation into the earlier use of second-line treatment agents and the utility of treating post-infectious exit site colonization as avenues to decrease refractory and repeat ESI.

EDTA and Taurolidine Affect Pseudomonas aeruginosa Virulence In Vitro-Impairment of Secretory Profile and Biofilm Production onto Peritoneal Dialysis Catheters.

Peritoneal catheter-associated biofilm infection is reported to be the main cause of refractory peritonitis in peritoneal dialysis patients. The application of antimicrobial lock therapy, based on results on central venous catheters, may be a promising option for treatment of biofilm-harboring peritoneal catheters. This study investigated the effects of two lock solutions, EDTA and taurolidine, on an in vitro model of Pseudomonas aeruginosa biofilm-related peritoneal catheter infection. Silicone peritoneal catheters were incubated for 24 h with a bioluminescent strain of P. aeruginosa. Then, serial dilutions of taurolidine and/or EDTA were applied (for 24 h) once or twice onto the contaminated catheters, and P. aeruginosa viability/persistence were evaluated in real time up to 120 h using a Fluoroskan reader. On selected supernatants, high-performance liquid chromatography mass spectrometry (HPLC-MS) analysis was performed to measure the production of autoinducers (AI), phenazines, and pyocyianines. Taurolidine alone or in combination with EDTA caused a significant decrease of bacterial load and biofilm persistence on the contaminated catheters. The treatment did not lead to the sterilization of the devices, yet it resulted in a substantial destructuration of the catheter-associated P. aeruginosa biofilm. HPLC-MS analysis showed that the treatment of biofilm-harboring catheters with taurolidine and EDTA also affected the secretory activity of the pathogen. EDTA and taurolidine affect P. aeruginosa biofilm produced on peritoneal catheters and profoundly compromise the microbial secretory profile. Future studies are needed to establish whether such lock solutions can be used to render peritoneal catheter-related infections more susceptible to antibiotic treatment. IMPORTANCE An in vitro model allows studies on the mechanisms by which the lock solutions exert their antimicrobial effects on catheter-associated biofilm, thus providing a better understanding of the management of devise-associated infections.

Indwelling Urinary Catheter and Dementia Are Associated with Enterococcal Urinary Tract Infections in Hospitalized Patients.

BACKGROUND: The recent increase in enterococcal urinary tract infections (EUTI) and the potential morbidity and mortality associated with inappropriate antimicrobial treatment underscores the need for early risk assessment and institution of appropriate empirical antimicrobial therapy. OBJECTIVES: To identify high-risk features associated with hospitalized patients with EUTI. METHODS: Demographic, clinical, laboratory, and bacteriological data of 285 patients hospitalized with UTI during 2016 were retrieved from the computerized database of Shamir Medical Center. Patients were divided into two groups: EUTI and non-EUTI (NEUTI), according to the presence or absence of enterococcus in the urine culture. The features of the two groups were compared. RESULTS: We obtained 300 urine cultures from 285 patients. Of the total, 80 patients (26.6%) had EUTI and 220 patients (73.3%) had NEUTI. A higher prevalence of urinary multi-bacterial cultures was found in EUTI compared to NEUTI patients (P < 0.01). Higher prevalence of permanent indwelling urinary catheter and dementia were found in hospitalized patients with community-acquired EUTI and nosocomial EUTI respectively (P = 0.02, P = 0.016) compared to patients with NEUTI. CONCLUSIONS: Indwelling urinary catheter and dementia are risk factors for EUTI in patients with community and hospital acquired infection, respectively.

Characteristics of infective endocarditis in a cancer population.

BACKGROUND: Infective endocarditis (IE) is more common in patients with cancer as compared with the general population. Due to an immunocompromised state, the need for invasive procedures, hypercoagulability and the presence of indwelling catheters, patients with cancer are particularly predisposed to the development of IE. OBJECTIVES: Limited information exists about IE in patients with cancer. We aimed to evaluate the characteristics of patients with cancer and IE at our tertiary care centre, including a comparison of the microorganisms implicated and their association with mortality. METHODS: A retrospective chart review of patients with cancer who had echocardiography for suspicion of endocarditis was conducted. A total of 56 patients with a confirmed diagnosis of cancer and endocarditis, based on the modified Duke criteria, were included in the study. Baseline demographics, risk factors for developing IE, echocardiography findings, microbiology and mortality data were analysed. RESULTS: Following the findings of vegetations by echocardiography, the median survival time was 8.5 months. Staphylococcus aureus was the most common organism identified as causing endocarditis. The mitral and aortic valves were the most commonly involved sites of endocarditis. Patients with S. aureus endocarditis (SAE) had a significantly poorer survival when compared with patients without SAE (p=0.0217) over the 12-month period from diagnosis of endocarditis. CONCLUSIONS: Overall survival of patients with cancer and endocarditis is poor, with a worse outcome in patients with SAE.

Repeat exit site infection in peritoneal dialysis patient with polycythemia vera - a case report.

BACKGROUND: Infectious complications of peritoneal dialysis (PD) remain a common cause of catheter loss and discontinuation of PD. Exit site infection (ESI) constitutes a significant risk factor for PD-related peritonitis and determination of predisposing states is relevant. We here present a case of repeat ESI due to Pseudomonas aeruginosa in a PD patient with skin changes in the course of polycythemia vera (PV). CASE PRESENTATION: A 73-year-old PD patient with chronic kidney disease secondary to renal amyloidosis and ankylosing spondylitis, presented to the nephrology unit with signs of ESI. In 2006 he was diagnosed with PV and since then has was successfully treated with hydroxyurea; however, he reported recurrent episodes of developing skin nodules in the course of the disease. Exit site swab yielded Pseudomonas aeruginosa and the infection developed in the ulcerated PV nodule that appeared in exit site 2 weeks earlier. Patient was treated with intraperitoneal amikacin and oral ciprofloxacin, however, due to neurological complications, the treatment had to be interrupted and finally catheter was removed. Similar episode of ESI with Pseudomonas aeruginosa developed in the patient two years earlier and also required catheter removal. CONCLUSION: This is the first case report demonstrating the development of ESI on the polycythemia vera skin lesion in this area. Skin manifestations of PV might be a predisposing factor to ESI in PD patients.

Marine Microbial-Derived Antibiotics and Biosurfactants as Potential New Agents against Catheter-Associated Urinary Tract Infections.

Catheter-associated urinary tract infections (CAUTIs) are among the leading nosocomial infections in the world and have led to the extensive study of various strategies to prevent infection. However, despite an abundance of anti-infection materials having been studied over the last forty-five years, only a few types have come into clinical use, providing an insignificant reduction in CAUTIs. In recent decades, marine resources have emerged as an unexplored area of opportunity offering huge potential in discovering novel bioactive materials to combat human diseases. Some of these materials, such as antimicrobial compounds and biosurfactants synthesized by marine microorganisms, exhibit potent antimicrobial, antiadhesive and antibiofilm activity against a broad spectrum of uropathogens (including multidrug-resistant pathogens) that could be potentially used in urinary catheters to eradicate CAUTIs. This paper summarizes information on the most relevant materials that have been obtained from marine-derived microorganisms over the last decade and discusses their potential as new agents against CAUTIs, providing a prospective proposal for researchers.

An ex vivo model of medical device-mediated bacterial skin translocation.

The skin is a barrier and part of the immune system that protects us from harmful bacteria. Because indwelling medical devices break this barrier, they greatly increase the risk of infection by microbial pathogens. To study how these infections can be prevented through improved clinical practices and medical device technology, it is important to have preclinical models that replicate the early stages of microbial contamination, ingress, and colonization leading up to infection. At present, there are no preclinical ex vivo models specifically developed to simulate conditions for indwelling medical devices. Translocation of pathogens from outside the body across broken skin to normally sterile internal compartments is a rate-limiting step in infectious pathogenesis. In this work, we report a sensitive and reproducible ex vivo porcine skin-catheter model to test how long antimicrobial interventions can delay translocation. Skin preparation was first optimized to minimize tissue damage. The presence of skin dramatically decreased bacterial migration time across the polyurethane catheter interface from > 96 h to 12 h. Using visual colony detection, fluorescence, a luminescent in vitro imaging system, and confocal microscopy, the model was used to quantify time-dependent differences in translocation for eluting and non-eluting antimicrobial catheters. The results show the importance of including tissue in preclinical biofilm models and help to explain current gaps between in vitro testing and clinical outcomes for antimicrobial devices.

A comparison of the efficacy of normal saline and Savlon solutions in periurethral cleaning to reduce catheter-associated bacteriuria: A randomized control trial.

OBJECTIVE: Catheter-associated urinary tract infection (CAUTI) is a common nosocomial infection. However, there has been no randomized control trial (RCT) comparing the efficacy of periurethral cleaning solutions for reducing CAUTI. This study aimed to compare the efficacy of normal saline solution (NSS) and Savlon solution. METHODS: A non-inferiority cross-over RCT was conducted to compare the 2 solutions by the incidence of significant bacteriuria (SB) on day 5 after Foley catheterization. Patients admitted to a tertiary referral hospital from June 2018 to August 2019 participated in the study. The acceptable prespecified non-inferiority margin was 10%. RESULTS: There were 265 and 275 patients in the NSS and Savlon groups, respectively. The incidence of CAUTI was 2.65/1000 catheter-days, and the median duration of catheterization was 5 days (IQR 4, 7). There was no significant difference between the incidence of SB in the NSS and Savlon groups, as indicated by the adjusted difference of 0.6 (95% CI: -3.1-4.2). CONCLUSION: This study was the first RCT in patients from multiple hospital units to compare the efficacy of the 2 solutions in the periurethral cleaning process. The study demonstrated non-inferiority of NSS to Savlon solution. THAI CLINICAL TRIALS REGISTRY STUDY ID: TCTR20180518001.

The microbial biofilm composition on peripherally inserted central catheters: A comparison of polyurethane and hydrophobic catheters collected from paediatric patients.

BACKGROUND: Peripherally inserted central catheters are susceptible to microbial colonisation and subsequent biofilm formation, leading to central line-associated bloodstream infection, a serious peripherally inserted central catheter-related complication. Next-generation peripherally inserted central catheter biomaterials, such as hydrophobic materials (e.g. Endexo®), may reduce microbial biofilm formation or attachment, consequently reducing the potential for central line-associated bloodstream infection. METHODS: Within a randomised controlled trial, culture-dependent and culture-independent methods were used to determine if the biomaterials used in traditional polyurethane peripherally inserted central catheters and hydrophobic peripherally inserted central catheters impacted microbial biofilm composition. This study also explored the impact of other clinical characteristics including central line-associated bloodstream infection, antibiotic therapy and dwell time on the microbial biofilm composition of peripherally inserted central catheters. RESULTS: From a total of 32 patients, one peripherally inserted central catheter was determined to be colonised with Staphylococcus aureus, and on further analysis, the patient was diagnosed with central line-associated bloodstream infection. All peripherally inserted central catheters (n = 17 polyurethane vs n = 15 hydrophobic) were populated with complex microbial communities, including peripherally inserted central catheters considered non-colonised. The two main microbial communities observed included Staphylococcus spp., dominant on the colonised peripherally inserted central catheter, and Enterococcus, dominant on non-colonised peripherally inserted central catheters. Both the peripherally inserted central catheter biomaterial design and antibiotic therapy had no significant impact on microbial communities. However, the diversity of microbial communities significantly decreased with dwell time. CONCLUSION: More diverse pathogens were present on the colonised peripherally inserted central catheter collected from the patient with central line-associated bloodstream infection. Microbial biofilm composition did not appear to be affected by the design of peripherally inserted central catheter biomaterials or antibiotic therapy. However, the diversity of the microbial communities appeared to decrease with dwell time.