Deposits on the intraluminal surface and bacterial growth in central venous catheters

Risk factors of lower respiratory tract infection caused by Stenotrophomonas maltophilia: Systematic review and meta-analysis

Objective

To systematically evaluate the risk factors of lower respiratory tract infection caused by Stenotrophomonas maltophilia for better clinical treatment.

Methods

PubMed, Embase, the Cochrane Library, Web of Science, China Journal full-text Database (CNKI), Wanfang Database (WanFang Data), VIP (VIP), and China Biomedical Literature Database (CBM) were selected and published by June 2022 about the risk factors of lower respiratory tract infection of S. maltophilia. Two researchers independently screened the literature, extracted data, and quality evaluation according to the inclusion and exclusion criteria. RevMan 5.4 software was used for meta-analysis.

Results

A total of 18 articles were included, including 10 in English and 8 in Chinese. Meta analysis showed that the risk factors of lower respiratory tract infection caused by S. maltophilia included disease severity, hospitalization days, use of glucocorticoids, invasive procedures, use of broad-spectrum antibiotics and use of more than 3 Antibiotics. The OR values of patients with hospitalization, mechanical ventilation, use of more than 3 Antibiotics, endotracheal intubation and tracheotomy were the highest. Specific hospitalization days (OR = 14.56, 95% CI: 6.12~23.01), mechanical ventilation (OR = 14.16, 95% CI: 5.85~34.3), use of more than 3 Antibiotics (OR = 6.21, 95% CI: 1.24~31.14), tracheal intubation (OR = 6.07, 95% CI: 1.97~3.64), tracheotomy (OR = 3.77, 95% CI: 1.09~13.04).

Conclusion

There are many risk factors for lower respiratory tract infection of S. maltophilia, which can occur in patients with severe illness, high APACHE-II score, invasive procedures, and the need for broad-spectrum antibiotics. In terms of the host, these patients are characterized by impaired immune function, severe illness and long-term hospitalization, which objectively leads to the infection of S. maltophilia. Therefore, strengthening the monitoring, prevention and control of patients with risk factors of S. maltophilia infection is conducive to reducing the risk of infection and death.

A large amount of microscopic precipitates are inevitably injected during infusion therapy without an in-line filter

Infusion route problems can have a significant impact on hemodynamics in children with severe heart failure. Here, we report the case of a 13-year-old girl with dilated cardiomyopathy. Her condition fluctuated due to frequent occlusion of the central venous catheter (CVC) route. However, a quick check revealed no apparent abnormalities in the CVC, infusion route, in-line filter or infusion pump. Scanning electron microscopy revealed that dobutamine and heparin had crystallized and that the in-line filter membrane was occluded. This case emphasizes the importance of proper infusion route management in pediatric patients with severe heart failure. Even drugs that are used daily may form microscopic crystals at several concentrations and administration rates. Without an in-line filter, microscopic particles are injected into the body, and there is no evidence that the injected crystals do not cause permanent damage.

Electrically-responsive antimicrobial coatings based on a tetracycline-loaded poly(3,4-ethylenedioxythiophene) matrix

The growth of bacteria and the formation of complex bacterial structures on biomedical devices is a major challenge in modern medicine. The aim of this study was to develop a biocompatible, conducting and antibacterial polymer coating applicable in biomedical engineering. Since conjugated polymers have recently aroused strong interest as controlled delivery systems for biologically active compounds, we decided to employ a poly(3,4-ethylenedioxythiophene) (PEDOT) matrix to immobilize a powerful, first-line antibiotic: tetracycline (Tc). Drug immobilization was carried out simultaneously with the electrochemical polymerization process, allowing to obtain a polymer coating with good electrochemical behaviour (charge storage capacity of 19.15 ± 6.09 mC/cm²) and high drug loading capacity (194.7 ± 56.2 μg/cm²). Biological activity of PEDOT/Tc matrix was compared with PEDOT matrix and a bare Pt surface against a model Gram-negative bacteria strain of Escherichia coli with the use of LIVE/DEAD assay and SEM microscopy. Finally, PEDOT/Tc was shown to serve as a robust electroactive coating exhibiting antibacterial activity.

Microbiome signatures in neonatal central line associated bloodstream infections

Neonates are at high risk for central line associated bloodstream infections (CLABSI). Biofilm formation is universal on indwelling catheters but why some biofilms seed the bloodstream to cause CLABSI is not clearly understood. With the objective to test the hypothesis that catheter biofilm microbiome in neonates with CLABSI differs than those without infection, we prospectively enrolled neonates (n = 30) with infected and uninfected indwelling central catheters. Catheters were collected at the time of removal, along with blood samples and skin swabs at the catheter insertion sites. Microbiomes of catheter biofilms, skin swabs and blood were evaluated by profiling the V4 region of the bacterial 16S rRNA gene using Illumina MiSeq sequencing platform. The microbial DNA load was higher from catheter biofilms of CLABSI patients without differences in alpha diversity when compared to that of the non-CLABSI neonates. Proteus and unclassified Staphylococcaceae were more abundant in infected catheter biofilms while Bradyrhizobium, Cloacibacterium, and Sphingomonas were more abundant in the uninfected catheters. A blood microbiome was detected in uninfected samples. The blood microbiome in CLABSI neonates clustered separately from the uninfected blood samples in beta diversity plots. We found that the microbiome signature in catheter biofilm and blood of neonates with CLABSI is different than the microbiomes of non-CLABSI neonates.

Taurolidine-citrate-heparin lock reduces catheter-related bloodstream infections in intestinal failure patients dependent on home parenteral support: a randomized, placebo-controlled trial

Background: In patients with intestinal failure who are receiving home parenteral support (HPS), catheter-related bloodstream infections (CRBSIs) inflict health impairment and high costs.Objective: This study investigates the efficacy and safety of the antimicrobial catheter lock solution, taurolidine-citrate-heparin, compared with heparin 100 IE/mL on CRBSI occurrence.Design: Forty-one high-risk patients receiving HPS followed in a tertiary HPS unit were randomly assigned in a double-blinded, placebo-controlled trial. External, stratified randomization was performed according to age, sex, and prior CRBSI incidence. The prior CRBSI incidence in the study population was 2.4 episodes/1000 central venous catheter (CVC) days [95% Poisson confidence limits (CLs): 2.12, 2.71 episodes/1000 CVC days]. The maximum treatment period was 2 y or until occurrence of a CRBSI or right-censoring because of CVC removal. The exact permutation tests were used to calculate P values for the log-rank tests.Results: Twenty patients received the taurolidine-citrate-heparin lock and 21 received the heparin lock, with 9622 and 6956 treatment days, respectively. In the taurolidine-citrate-heparin arm, no CRBSIs occurred, whereas 7 CRBSIs occurred in the heparin arm, with an incidence of 1.0/1000 CVC days (95% Poisson CLs: 0.4, 2.07/1000 CVC days; P = 0.005). The CVC removal rates were 0.52/1000 CVC days (95% Poisson CLs: 0.17, 1.21/1000 CVC days) and 1.72/1000 CVC days (95% Poisson CLs: 0.89, 3.0/1000 CVC days) in the taurolidine-citrate-heparin and heparin arm, respectively, tending to prolong CVC survival in the taurolidine arm (P = 0.06). Costs per treatment year were lower in the taurolidine arm (€2348) than in the heparin arm (€6744) owing to fewer admission days related to treating CVC-related complications (P = 0.02).Conclusions: In patients with intestinal failure who are life dependent on HPS, the taurolidine-citrate-heparin catheter lock demonstrates a clinically substantial and cost-beneficial reduction of CRBSI occurrence in a high-risk population compared with heparin. This trial was registered at clinicaltrials.gov as NCT01948245.

Infection risks associated with peripheral vascular catheters

BACKGROUND

Peripheral vascular catheters (PVC) are the most frequently used invasive medical devices in hospitals, with 330 million sold each year in the USA alone. One in three UK inpatients at any one time has at least one PVC in situ according to the Scottish National Prevalence survey.

METHOD

A narrative review of studies describing the infection risks associated with PVCs.

RESULTS

It is estimated that 30-80% of hospitalised patients receive at least one PVC during their hospital stay. Despite their prevalence, PVCs are not benign devices, and the high number of PVCs inserted annually has resulted in serious catheter-related bloodstream infections and significant morbidity, prolonged hospital stay and increased healthcare system costs. To date, PVC infections have been under-evaluated. Most studies focus on central venous catheter rather than PVC-associated bloodstream infections. Risks associated with PVC infection must be addressed to reduce patient morbidity and associated costs of prolonged hospital admission and treatment.

DISCUSSION

This article discusses the sources and routes of PVC-associated infection and outlines known effective prevention and intervention strategies.

Biofilm-based infections in long-term care facilities

The recent trend in the early admittance to long-term care facilities (LTCFs) of severely injured patients transferred from general hospitals has given a new dynamic to the incidence of healthcare-associated infections, including biofilm-based infections related to the implant of urinary and intravascular catheters, and the onset of pressure ulcers. Catheter-associated urinary tract infections lead in most of the surveys on LTCFs, approximately 80% of urinary tract infections in these settings being due to the short- or long-term insertion of a urinary catheter. Furthermore, the implantation of intravascular catheters is often responsible for catheter-related bloodstream infections caused by the development of an intraluminal biofilm. Pressure ulcers, frequently occurring in bedridden patients admitted to LTCFs, are also susceptible to infection by biofilm-growing aerobic and anaerobic bacteria, the biofilm formation on the wound being the main reason for its delayed healing.

Genotypic study documents divergence in the pathogenesis of bloodstream infection related central venous catheters in neonates

Objective

To investigate the pathogenesis of bloodstream infection by Staphylococcus epidermidis, using the molecular epidemiology, in high-risk neonates.

Methods

We conducted a prospective study of a cohort of neonates with bloodstream infection using central venous catheters for more than 24 h. “National Healthcare Safety Network” surveillance was conducted. Genotyping was performed by DNA fingerprinting and mecA genes and icaAD were detected by multiplex-PCR.

Results

From April 2006 to April 2008, the incidence of bloodstream infection and central venous catheter-associated bloodstream infection was 15.1 and 13.0/1000 catheter days, respectively, with S. epidermidis accounting for 42.9% of episodes. Molecular analysis was used to document the similarity among six isolates of bloodstream infection by S. epidermidis from cases with positive blood and central venous catheter tip cultures. Fifty percent of neonates had bloodstream infection not identified as definite or probable central venous catheter-related bloodstream infection. Only one case was considered as definite central venous catheter-related bloodstream infection and was extraluminally acquired; the remaining were considered probable central venous catheter-related bloodstream infections, with one probable extraluminally and another probable intraluminally acquired bloodstream infection. Additionally, among mecA+ and icaAD+ samples, one clone (A) was predominant (80%). A polyclonal profile was found among sensitive samples that were not carriers of the icaAD gene.

Conclusions

The majority of infections caused by S. epidermidis in neonates had an unknown origin, although 33.3% appeared to have been acquired intraluminally and extraluminally. We observed a polyclonal profile between sensitive samples and a prevalent clone (A) between resistant samples.

Should prophylactic thrombolysis be routine in clinical practice? Evidence from an autopsy case of septicemia

Background

Central venous catheters provide easy access for intravenous infusion and nutrition, but they can bring about complications such as catheter-related infections. Infected central venous catheters often cause nosocomial bloodstream infections with high morbidity and mortality. However, most of the morphological data that have been published are derived from in vitro and in vivo studies and few reports of direct evidence obtained from patient-derived samples have been described. Here we present visual evidence of catheter-related candidemia. To our knowledge, this is the first reported conventional histopathological evidence of a Candida-infected intraluminal thrombus in a patient’s central venous catheter.

Case presentation

A 62-year-old Japanese female with obstructive jaundice, gastrointestinal bleeding, and liver metastasis from pancreatic head cancer was given an implantable subcutaneous central venous port for nutrition and chemotherapy administration. High fever ensued on day 16 after the central venous port insertion and blood cultures revealed Candida albicans. Although the patient was given 300 mg/day of fosfluconazole according to the suggestion of the infection control team, she died from respiratory failure. Postmortem computed tomography revealed findings consistent with acute respiratory distress syndrome, suggesting that the patient’s course was complicated by catheter-related sepsis. Autopsy revealed a subcutaneous abscess around the port, from which C. albicans was cultured. However, no catheter-adherent thrombus, thrombosis of the great central veins, or endocardial vegetations were detected in the patient. Histological analysis revealed scattered abscesses in several organs including lungs and kidneys. Hyaline membrane formation and Candida colonies were found in the lungs. The central venous port tube, together with the part of the subclavian vein into which it had been inserted, was involved in an intraluminal fibrin thrombus containing neutrophils and macrophages, indicating that the thrombus existed while the patient was alive. Histopathological examination following use of the periodic acid-Schiff reagent and the Grocott stain revealed scattered Candida in the thrombus.

Conclusions

Prophylactic thrombolysis should be encouraged to prevent central venous catheter-related candidiasis in clinical practice.

Central venous catheter-related infections in hematology and oncology: 2012 updated guidelines on diagnosis, management and prevention by the Infectious Diseases Working Party of the German Society of Hematology and Medical Oncology

BACKGROUND

Cancer patients are at increased risk for central venous catheter-related infections (CRIs). Thus, a comprehensive, practical and evidence-based guideline on CRI in patients with malignancies is warranted.

PATIENTS AND METHODS

A panel of experts by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) has developed a guideline on CRI in cancer patients. Literature searches of the PubMed, Medline and Cochrane databases were carried out and consensus discussions were held.

RESULTS

Recommendations on diagnosis, management and prevention of CRI in cancer patients are made, and the strength of the recommendation and the level of evidence are presented.

CONCLUSION

This guideline is an evidence-based approach to the diagnosis, management and prevention of CRI in cancer patients.

Field emission scanning electron microscopy of biofilm-growing bacteria involved in nosocomial infections

Scanning electron microscopy (SEM) provides useful information on the shape, size, and localization within the biofilm of single bacteria as well as on the steps of biofilm formation process, on bacterial interactions, and on production of extracellular polymeric substances.When biofilms are constituted by microbial species involved in health care-associated infections, information provided by SEM can be fruitfully used not only for basic researches but also for diagnostic purposes.The protocols currently used in our laboratory for biofilm investigation by SEM are reported here. Particularly, the procedures to fix, dehydrate, and metalize in vitro-developed biofilms or ex vivo clinical specimens colonized by biofilm-growing microorganisms are described as well as the advantages of the observation of these samples by field emission scanning electron microscopy.

An organoselenium compound inhibits Staphylococcus aureus biofilms on hemodialysis catheters in vivo

Colonization of central venous catheters (CVCs) by pathogenic bacteria leads to catheter-related bloodstream infections (CRBSIs). These colonizing bacteria form highly antibiotic-resistant biofilms. Staphylococcus aureus is one of the most frequently isolated pathogens in CRBSIs. Impregnating CVC surfaces with antimicrobial agents has various degrees of effectiveness in reducing the incidence of CRBSIs. We recently showed that organoselenium covalently attached to disks as an antibiofilm agent inhibited the development of S. aureus biofilms. In this study, we investigated the ability of an organoselenium coating on hemodialysis catheters (HDCs) to inhibit S. aureus biofilms in vitro and in vivo. S. aureus failed to develop biofilms on HDCs coated with selenocyanatodiacetic acid (SCAA) in either static or flowthrough continuous-culture systems. The SCAA coating also inhibited the development of S. aureus biofilms on HDCs in vivo for 3 days. The SCAA coating was stable and nontoxic to cell culture or animals. This new method for coating the internal and external surfaces of HDCs with SCAA has the potential to prevent catheter-related infections due to S. aureus.