Catheter Colonization Research Articles

Targeting outer membrane protein A (OmpA) – inhibitory effect of 2′-hydroxychalcone derivatives on Acinetobacter baumannii and Candida albicans dual-species biofilm formation

Biofilm production facilitates microbial colonization of wounds and catheters. Acinetobacter baumannii produces high levels of biofilm and causes difficult-to-treat nosocomial infections. Candida albicans is another strong biofilm producer which may facilitate A. baumannii adhesion by providing hyphae-mediated OmpA-binding sites. Here we tested the potential of 2′-hydroxychalcones to inhibit dual-species biofilm production of A. baumannii and Candida spp., and further predicted the mechanism of structure-related difference in activity. The results suggest that 2′-hydroxychalcones exhibit potent activity against Candida spp./A. baumannii dual-species biofilm production. Particularly active was trifluoromethyl-substituted derivative (p-CF3), which decreased C. albicans/A. baumannii biomass produced on vein-indwelling parts of the central venous catheterization set by up to 99%. Further, higher OmpA-binding affinity was also calculated for p-CF3, which together with demonstrated significant ompA-downregulating activity, suggests that superior antibiofilm activity of this chalcone against the tested dual-species community of A. baumannii is mediated through the OmpA.

Curcumin-Functionalized Graphene Oxide Strongly Prevents Candida parapsilosis Adhesion and Biofilm Formation.

Candida parapsilosis is the major non-C. albicans species involved in the colonization of central venous catheters, causing bloodstream infections. Biofilm formation on medical devices is considered one of the main causes of healthcare-associated infections and represents a global public health problem. In this context, the development of new nanomaterials that exhibit anti-adhesive and anti-biofilm properties for the coating of medical devices is crucial. In this work, we aimed to characterize the antimicrobial activity of two different coated-surfaces, graphene oxide (GO) and curcumin-graphene oxide (GO/CU) for the first time, against C. parapsilosis. We report the capacity of GO to bind and stabilize CU molecules, realizing a homogenous coated surface. We tested the anti-planktonic activity of GO and GO/CU by growth curve analysis and quantification of Reactive Oxigen Species( ROS) production. Then, we tested the antibiofilm activity by adhesion assay, crystal violet assay, and live and dead assay; moreover, the inhibition of the formation of a mature biofilm was investigated by a viability test and the use of specific dyes for the visualization of the cells and the extra-polymeric substances. Our data report that GO/CU has anti-planktonic, anti-adhesive, and anti-biofilm properties, showing a 72% cell viability reduction and a decrease of 85% in the secretion of extra-cellular substances (EPS) after 72 h of incubation. In conclusion, we show that the GO/CU conjugate is a promising material for the development of medical devices that are refractory to microbial colonization, thus leading to a decrease in the impact of biofilm-related infections.

Study of the effectiveness of antimicrobial dressings with chlorhexidine bigluconate in the prevention of catheter-related blood-stream infections in pediatric intensive care units

Introduction. Nosocomial infections are risk factors associated with in-hospital mortality. Among other factors, these infections are strongly associated with invasive devices. In pediatric patients, a central venous catheter (CVC) is one of the most common causes of catheter-related bloodstream infection (CRBSI).
 Background. To investigate the effectiveness of antimicrobial chlorhexidine dressings compared with standard dressings in the prevention of central venous catheter-related bloodstream infections.
 Methods. 20 children who were treated in the intensive care unit were randomly divided into two groups of 10: a group that used chlorhexidine dressings and a group that used standard dressings (comparison group). Patient care was carried out in accordance with asepsis and antisepsis rule. The primary outcomes were a comparative study of microbiological researches of peripheral blood blood culture and catheter blood sample. But the final results were cultures from the tip of the catheter (at least 5 cm) after removal of the catheter in case of clinical symptoms of KAIK or in case of planned removal of the catheter due to the lack of its further need.
 Results. Catheter colonization occurred in 3 patients in the control group (3 %) and in 2 patients in the chlorhexidine dressing group (2 %). Catheter-related bloodstream infections occurred in 3 patients in the control group (3%), and in patients in the chlorhexidine group, no microorganisms were isolated by microbiological examination of the implantation sites (0 %). Although more patients in the comparison group had catheter-related bloodstream infections, the difference in infection rates between the two groups was insignificant (P = 0.07).
 Conclusions. The use of chlorhexidine-impregnated dressings reduced the incidence of catheter-related bloodstream infections, contamination, colonization, and local catheter infection in the pediatric intensive care unit, but there was no significant difference compared with the use of standard dressings. This study needs further study in pediatric patients.

E. coli catheter-associated urinary tract infections are associated with distinctive virulence and biofilm gene determinants.

Urinary catheterization facilitates urinary tract colonization by E. coli and increases infection risk. Here, we aimed to identify strain-specific characteristics associated with the transition from colonization to infection in catheterized patients. In a single-site study population, we compared E. coli isolates from patients with catheter-associated asymptomatic bacteriuria (CAASB) to those with catheter-associated urinary tract infection (CAUTI). CAUTI isolates were dominated by a phylotype B2 subclade containing the multidrug-resistant ST131 lineage relative to CAASB isolates, which were phylogenetically more diverse. A distinctive combination of virulence-associated genes was present in the CAUTI-associated B2 subclade. Catheter-associated biofilm formation was widespread among isolates and did not distinguish CAUTI from CAASB strains. Preincubation with CAASB strains could inhibit catheter colonization by multiple ST131 CAUTI isolates. Comparative genomic analysis identified a group of variable genes associated with high catheter biofilm formation present in both CAUTI and CAASB strains. Among these, ferric citrate transport (Fec) system genes were experimentally associated with enhanced catheter biofilm formation using reporter and fecA deletion strains. These results are consistent with a variable role for catheter biofilm formation in promoting CAUTI by ST131-like strains or resisting CAUTI by lower-risk strains that engage in niche exclusion.

Structure–function correlates of fibrinogen binding by Acinetobacter adhesins critical in catheter-associated urinary tract infections

Multidrug-resistantAcinetobacter baumannii infections are an urgent clinical problem and can cause difficult-to-treat nosocomial infections. During such infections, like catheter-associated urinary tract infections (CAUTI), A. baumannii rely on adhesive, extracellular fibers, called chaperone-usher pathway (CUP) pili for critical binding interactions. The A. baumannii uropathogenic strain, UPAB1, and the pan-European subclone II isolate, ACICU, use the CUP pili Abp1 and Abp2 (previously termed Cup and Prp, respectively) in tandem to establish CAUTIs, specifically to facilitate bacterial adherence and biofilm formation on the implanted catheter. Abp1 and Abp2 pili are tipped with two domain tip adhesins, Abp1D and Abp2D, respectively. We discovered that both adhesins bind fibrinogen, a critical host wound response protein that is released into the bladder upon catheterization and is subsequently deposited on the catheter. The crystal structures of the Abp1D and Abp2D receptor-binding domains were determined and revealed that they both contain a large, distally oriented pocket, which mediates binding to fibrinogen and other glycoproteins. Genetic, biochemical, and biophysical studies revealed that interactions with host proteins are governed by several critical residues in and along the edge of the binding pocket, one of which regulates the structural stability of an anterior loop motif. K34, located outside of the pocket but interacting with the anterior loop, also regulates the binding affinity of the protein. This study illuminates the mechanistic basis of the critical fibrinogen-coated catheter colonization step in A. baumannii CAUTI pathogenesis.

Probiotic lactic acid bacteria as a means of preventing in vitro urinary catheter colonization and biofilm formation

BackgroundCatheter-associated urinary tract infections (CAUTIs) are the most common infections found in healthcare facilities. Urinary catheters predispose the development of CAUTIs by destroying natural barriers and providing a source for infection and biofilm formation (BF). This study aimed to evaluate probiotic lactic acid bacteria (LAB) as a means of preventing in vitro urinary catheter colonization and BF.MethodsCross-sectional screening, followed by an experimental study, was conducted on 120 catheterized patients admitted to the urology department in a tertiary care hospital for 7 months. The isolated and identified uropathogens were tested for their antimicrobial susceptibility patterns by the disk diffusion method according to Clinical and Laboratory Standards Institute recommendations and examined for their ability to produce biofilms using a microtiter plate (MtP) assay. Five LAB (Lactobacillus acidophilus (L. acidophilus), Bifidobacterium bifidum (B. bifidum), L. paracasei, L. pentosus, and L. plantarum) were identified and examined for preventing in vitro colonization and BF of some isolated uropathogens on Foley urinary catheter surfaces.ResultsOf the 120 samples collected, 32.5% were found to be associated with CAUTIs. Of isolated organisms, 74.4% were gram-negative bacilli, while gram-positive cocci represented 14%, and only 11.6% were of the Candida species. About two-thirds of isolated uropathogens were biofilm formers. All five probiotic strains had inhibitory effects on the growth of all the uropathogens tested but with varying intensities according to the duration of application after 2, 4, and 6 days.ConclusionsThe prevalence of CAUTIs was high, and the predominant bacterial isolates were gram-negative bacilli. Many of the studied uropathogens were biofilm formers. The bacterial isolates had a higher prevalence of resistance to commonly prescribed antimicrobial agents. Probiotics have the potential to prevent in vitro urinary catheter colonization and inhibit BF. Pre-coating urinary catheters with probiotics is recommended after ensuring the safety of probiotics’ use in vivo by carrying out further large-scale studies.

Comparative study of microbial colonization of catheters for prolonged regional anesthesia when using different fixation methods

BACKGROUND: Infectious complications related to prolonged epidural and peripheral regional anesthesia are quite rare. However, this does not exclude the necessity of strict adherence to measures aimed at preventing microbial colonization of catheters for regional anesthesia. Microbial colonization of the catheter is not always accompanied by the development of infectious complications but increases the likelihood of their occurrence.
 AIM: To determine the frequency of colonization, the qualitative and quantitative composition of the microflora depending on the various methods of fixing of the catheter and the duration of its use.
 MATERIALS AND METHODS: 76 patients from 2 to 18 years old with prolonged epidural or peripheral anesthesia were included in an comparative, prospective, randomized, single-center study. Patients were divided into the groups according to the method of catheter fixation - adhesive sticker (AS), adhesive sticker and antimicrobial coating Desitol B (AS+D) and tunneling (T). Determination of microbial contamination of catheters was carried out using classical bacteriological studies.
 RESULTS: None of the 76 patients had signs of a local or systemic infection. The difference in the frequency of colonization between the AS and T groups was statistically significant: 2 (1, n = 54) = 5.5381 (p = 0.018), between the AS and AS+D groups it was not significant. The relative risk of colonization of the skin of the catheter with adhesive fixation was 2.14 times higher than with catheter tunneling: RR = 2.14, p = 0.05 (95% CI 1.04.49). In the AS+D group, colonization of both the skin and the inner part of the catheter was observed significantly earlier than in the T group: skin part: U = 5.5; Ucr = 8 (p = 0.02); inner part: U = 5.5; Ucr = 6 (p = 0.04). The growth of Staphylococcus epidermidis (48.3%) and Staphylococcus aureus (20.7%) was fixed mainly when positive results of microbiological culture takes place.
 CONCLUSIONS: Tunneling is the preferred method of fixation of the catheter when the postoperative pain relief period is more than 3 days.

Pre-Emptive Antimicrobial Locks Decrease Long-Term Catheter-Related Bloodstream Infections in Hemodialysis Patients.

This study aimed to prove that pre-emptive antimicrobial locks in patients at risk of bacteremia decrease infection. We performed a non-randomized prospective pilot study of hemodialysis patients with tunneled central venous catheters. We drew quantitative blood cultures monthly to detect colonization. Patients with a critical catheter colonization by coagulase-negative staphylococci (defined as counts of 100-999 CFU/mL) were at high risk of developing a catheter-related bloodstream infection. We recommended antimicrobial lock for this set of patients. The nephrologist in charge of the patient decided whether to follow the recommendation or not (i.e., standard of care). We compared bloodstream infection rates between patients treated with antimicrobial lock therapy versus patients treated with the standard of care (i.e., heparin). We enrolled 149 patients and diagnosed 86 episodes of critical catheter colonization by coagulase-negative staphylococci. Patients treated with antimicrobial lock had a relative risk of bloodstream infection of 0.19 when compared with heparin lock (CI 95%, 0.11-0.33, p < 0.001) within three months of treatment. We avoided one catheter-related bloodstream infection for every ten catheter-critical colonizations treated with antimicrobial lock [number needed to treat 10, 95% CI, 5.26-100, p = 0.046]. In conclusion, pre-emptive antimicrobial locks decrease bloodstream infection rates in hemodialysis patients with critical catheter colonization.

Combined Application of Aminoglycosides and Ascorbic Acid in the Elimination of Proteus mirabilis Rods Responsible for Causing Catheter-Associated Urinary Tract Infections (CAUTIs)-A Molecular Approach.

Proteus mirabilis is a common cause of catheter-associated urinary tract infections (CAUTIs). In this study, we verified the effectiveness of amikacin or gentamicin and ascorbic acid (AA) co-therapy in eliminating uropathogenic cells, as well as searched for the molecular basis of AA activity by applying chromatographic and fluorescent techniques. Under simulated physiological conditions, a combined activity of the antibiotic and AA supported the growth (threefold) of the P. mirabilis C12 strain, but reduced catheter colonization (≤30%) in comparison to the drug monotherapy. Slight modifications in the phospholipid and fatty acid profiles, as well as limited (≤62%) 2',7'-dichlorofluorescein fluorescence, corresponding to the hydroxyl radical level, allowed for the exclusion of the hypothesis that the anti-biofilm effect of AA was related to membrane perturbations of the C12 strain. However, the reduced (≤20%) fluorescence intensity of propidium iodide, as a result of a decrease in membrane permeability, may be evidence of P. mirabilis cell defense against AA activity. Quantitative analyses of ascorbic acid over time with a simultaneous measurement of the pH values proved that AA can be an effective urine acidifier, provided that it is devoid of the presence of urease-positive cells. Therefore, it could be useful in a prevention of recurrent CAUTIs, rather than in their treatment.

Incidence of catheter-related bloodstream infections following ultrasound-guided central venous catheterization: a systematic review and meta-analysis

BackgroundUltrasonographic guidance is widely used for central venous catheterization. Several studies have revealed that ultrasound-guided central venous catheterization increases the rate of success during the first attempt and reduces the procedural duration when compared to the anatomical landmark-guided insertion technique, which could result in protection from infectious complications. However, the effect of ultrasound-guided central venous catheterization on catheter-related bloodstream infections remains unclear. We aimed to conduct a systematic review and meta-analysis to evaluate the value of ultrasound guidance in preventing catheter-related bloodstream infections and catheter colonization associated with central venous catheterization.MethodsThe Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE (via PubMed) were searched up to May 9, 2022 for randomized controlled trials (RCTs) comparing ultrasound-guided and anatomical landmark-guided insertion techniques for central venous catheterization. Risk of bias was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool for RCTs. A meta-analysis was performed for catheter-related bloodstream infections and catheter colonization, as primary and secondary outcomes, respectively.ResultsFour RCTs involving 1268 patients met the inclusion criteria and were analyzed. Ultrasound-guided central venous catheterization was associated with a slightly lower incidence of catheter-related bloodstream infections (risk ratio, 0.46; 95% confidence interval [CI], 0.16–1.32) and was not associated with a lower incidence of catheter colonization (risk ratio, 1.36; 95% CI, 0.57–3.26).ConclusionUltrasound-guided central venous catheterization might reduce the incidence of catheter-related bloodstream infections. Additional RCTs are necessary to further evaluate the value of ultrasound guidance in preventing catheter-related bloodstream infections with central venous catheterization.

Catheter-Related Bloodstream Infection With Femoral Central Access Versus Internal Jugular Access in Patients Admitting to Medical Intensive Care Unit.

BackgroundThe current research focused on studying the pattern of catheter-related bloodstream infections (CRBSI) with femoral central access versus internal jugular access in patients admitted to the medical intensive care unit (ICU).MethodsA cross-sectional study was conducted at the Department of Emergency Medicine, Shifa International Hospital, between March 4, 2022, and August 4, 2022. All individuals who presented to the ICU who needed a central venous catheter (CVC) for more than 48 hours were included. Catheter insertion was not permitted if the patient had a history of dermatitis or burns at the site of insertion or if the hemodialysis procedure necessitated the insertion of the catheter into a blood vessel. Three groups of patients were created: group A patients had been diagnosed with CRBSI; group B patients had catheter colonization (CC); and group C did not have CRBSI or CC. Standard microbiological methods were used to identify all of the bacteria collected from the cultures. All data was documented in a predefined pro forma.ResultsOverall, 20 (12.12%) patients had positive CRBSI, 68 (41.5%) had CC, and the remaining 46.3% of cultures were negative. Elderly populations were more prone to acquiring CRBSI showing a significant correlation between older age and CRBSI (p < 0.0001). CC was significantly associated with a longer duration of ICU stay, i.e., 30.3 ± 3.7 (p = 0.003). The absence of both CRBSI and CC was significantly associated with a lower duration of catheterization (11 ± 8.5 days in group C versus 22.1 ± 6.9 and 18.7 ± 7 days in groups A and B, respectively; p < 0.0001). Our study revealed a higher risk of CRBSI when the femoral access was compared to the internal jugular access (58.3% vs. 41.7%; p = 0.0008). The study did not find any significant association of CC with femoral or internal jugular access. Furthermore, a significantly higher rate of negative cultures was reported in patients with internal jugular access as compared to femoral vein access (85.8% vs. 14.2%; p = 0.007).ConclusionThe need for routinely monitoring and observing the microbiological spectrum in patients receiving care in intensive care units is highlighted by the current investigation. The patients with internal jugular vein access had a decreased incidence of CRBSI and CC, while those with femoral access experienced CRBSI more frequently. Escherichia coli and Pseudomonas aeruginosa were the most frequently isolated germs, and both were resistant to various drugs that are used today. It is essential to regularly monitor the epidemiology of CRBSI in order to adopt preventative measures for infection prevention and control, such as staff education, strict hygiene standards, and a higher nurse-to-patient ratio.

Prospective clinical study on the incidence of catheter-related complications in a neurological intensive care unit: 4 years of experience.

Over the past decades, significant efforts have been made to reduce early and late catheter-related complications in critically ill patients, using approaches based on bundles of evidence-based interventions. In this prospective clinical study, the authors evaluated the incidence of catheter-related complications in their neuro-intensive care unit during a 4-year period, adopting systematically the GAVeCeLT bundles for the insertion and management of all central venous access devices: centrally inserted central catheters (CICCs), peripherally inserted central catheters (PICCs) and femorally inserted central catheters (FICCs). All early/immediate and late complications were recorded. On 486 central lines (328 CICCs, 149 PICCs and 9 FICCs), the only clinically relevant early/immediate complication was primary tip malposition (1%). In regards late infective complications, the authors did not record any case of catheter-related bloodstream infection; though, they observed one case of central line associated blood stream infection (one CICC; 0.14/1000 catheter days), and 15 cases of catheter colonization (12 CICCs and 3 PICCs; 2.09 episodes/1000 catheter days). Late non-infective complications were few: 14 accidental dislodgments (2.9%), 18 irreversible lumen occlusions (3.7%), and no episodes of symptomatic catheter-related thrombosis or tip migration. The systematic adoption of the GAVeCeLT bundles for CVAD insertion and maintenance was associated with a minimization of catheter-related complications. The strict adherence to the recommendations included in these bundles was the major determinant for clinical success.

Combating Bacterial Biofilm Formation in Urinary Catheter by Green Silver Nanoparticle.

Urinary catheters are commonly associated with urinary tract infections. This study aims to inhibit bacterial colonisation and biofilm of urinary tract catheters. Silicon catheter pieces were varnished with green silver nanoparticles (AgNPs) using Pistacia lentiscus mastic to prevent bacterial colonisation. Pomegranate rind extract was used to synthesize AgNPs. AgNPs were characterized by UV-Vis spectroscopy, X-ray crystallography, and transmission electron microscopy (TEM). Results obtained revealed that the size of most AgNPs ranged between 15–25 nm and they took crystallised metal and oxidised forms. The amounts of released silver ions from 1 cm pieces of catheters coated with AgNPs were estimated for five days and ranged between 10.82 and 4.8 µg. AgNPs coated catheters significantly inhibited the colonisation of catheters by antibiotic-resistant clinical Gram-positive (Staphylococcus epidermidis and Staphylococcus aureus) and Gram-negative (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa) bacteria. AgNPs-varnish was more active against Gram-negative bacteria than Gram-positive bacteria. The significant inhibitory effect of coated catheters lasted for 72 h for both Gram-positive and Gram-negative bacteria. Varnishing catheters with AgNPs may help to prevent bacterial colonisation and infections.

Semi-Quantitative Assay to Measure Urease Activity by Urinary Catheter-Associated Uropathogens.

Catheter-associated urinary tract infections (CAUTIs) are one of the most common healthcare-associated infections in the US, accounting for over 1 million cases annually and totaling 450 million USD. CAUTIs have high morbidity and mortality rates and can be caused by a wide range of pathogens, making empiric treatment difficult. Furthermore, when urease-producing uropathogens cause symptomatic CAUTI or asymptomatic catheter colonization, the risk of catheter failure due to blockage increases. The enzyme urease promotes catheter blockage by hydrolyzing urea in urine into ammonia and carbon dioxide, which results in the formation of crystals that coat the catheter surface. If CAUTI is left untreated, the crystals can grow until they block the urinary catheter. Catheter blockage and subsequent failure reduces the quality of life for the chronically catheterized, as it requires frequent catheter exchanges and can promote more severe disease, including dissemination of the infection to the kidneys or bloodstream. Thus, understanding how urease contributes to catheter blockages and/or more severe disease among the broad range of urease-producing microbes may provide insights into better prevention or treatment strategies. However, clinical assays that detect urease production among clinical isolates are qualitative and prioritize the detection of urease from Proteus mirabilis, the most well-studied uropathogenic urease producer. While urease from other known urease producers, such as Morganella morganii, can also be detected with these methods, other uropathogens, including Staphylococcus aureus and Klebsiella pneumonia, are harder to detect. In this study, we developed a high throughput, semiquantitative assay capable of testing multiple uropathogens in a rapid and efficient way. We validated the assay using Jack Bean urease, the urease producing species: Proteus spp., M. morganii, K. pneumonia, and S. aureus strains, and the non-urease producer: Escherichia coli. This modified assay more rapidly detected urease-producing strains compared to the current clinical test, Christensen Urea Agar, and provided semiquantitative values that may be used to further investigate different aspects of urease regulation, production, or activity in these diverse species. Furthermore, this assay can be easily adapted to account for different environmental stimuli affecting urease production, including bacterial concentration, aeration, or addition of anti-urease compounds.

Infections and colonisation of central venous catheters in patients admitted to intensive care units at two tertiary care hospitals

Introduction: Central venous catheters (CVC) are frequently used in modern health care systems. However, CVCs are likely to get colonised with microorganisms, resulting in catheter-related blood stream infections (CRBSI). This study investigated microorganisms causing CRBSI and CVC colonisation, their antibiotic resistance, and factors associated with CRBSI in patients in the intensive care units (ICU) at the Colombo North Teaching Hospital (CNTH) and Apeksha hospital, Sri Lanka. Methods: The study included 300 adult patients in ICUs with a CVC in-situ for &gt;48 hours. Blood taken through the CVC, peripheral blood and CVC tips were cultured. Microorganisms were identified and tested for antibiotic susceptibility. Demographic factors were recorded. Results: Seventeen patients (13.1%) developed CRBSI. The CRBSI rate was 13.3 per 1,000 catheter days in CNTH while it was 10 (5.9%) cases and 5.2 per 1,000 catheter days in Apeksha hospital. In CNTH, CVC colonisation was detected in 35 (26.9%). Coagulase negative staphylococci (CoNS) were the leading cause of both CRBSI (41%) and colonisation (58%). In Apeksha hospital, Klebsiella sp. (5/10) were the predominant pathogens that caused CRBSI. Eighty-nine CVCs (52.3%) were colonised by CoNS (58%). In CNTH, CRBSI was detected more in males (14/17) (p&lt;0.05). The majority of microorganisms that caused CRBSI and CVC colonisation in both hospitals showed resistance to commonly used antibiotics. Conclusion: The CRBSI rates and the incidences were higher in CNTH. CoNS was the most common cause of CRBSI in CNTH and Gram negative bacteria in Apeksha hospital. CVC colonisation with CoNS was common in both hospitals. Antibiotic resistance was high among bacteria causing CRBSI and colonisation.

Insights on catheter-related bloodstream infections: a prospective observational study on the catheter colonization and multidrug resistance

Central venous catheter-related bloodstream infection (CRBSI) is a huge public health concern with considerable impact on mortality and health costs. A three-year observational study enrolling three tertiary hospitals located in Lisbon, Portugal, was designed to identify the major aetiological agents of CRBSI, their ability to colonize central venous catheters and their antimicrobial resistance profiles. Aetiological agents of CRBSI were identified by Vitek 2. Whole-genome sequencing was used to confirm CRBSI by the most prevalent aetiological agents and characterize their resistome. Central venous catheter colonization (namely by biofilm assembly) was monitored by scanning electron microscopy. Staphylococci were the most prevalent causative agent (36/58, 62.0%), with S.aureus and coagulase-negative S.epidermidis accounting for 24.1% and 36.2% of CRBSIs, respectively. Fifty-nine of 72 staphylococci isolates were meticillin resistant. Comparative genomic analysis of central venous catheters/haemoculture pairs of isolates revealed genomic matches for 35 of 36 pairs and a good correlation between antibiotic susceptibility phenotype and the presence of antimicrobial resistance genetic determinants. Biofilms were present on 48.6% of the central venous catheters; nevertheless, no statistically significant association was established between biofilm assembly and CRBSI, and the presence/absence of ica operon and agr groups did not correlate with biofilm phenotypes, highlighting the need for further studies to elucidate biofilms' role on this healthcare-associated infection. Whole-genome sequencing was shown to be a valuable tool to confirm CRBSI. Although more than 42.3% of the central venous catheters were colonized by staphylococci, no statistically significant association was found between CRBSI and biofilms.

Bacterial colonization, species diversity and antimicrobial susceptibility patterns of indwelling urinary catheters from postpartum mothers attending a Tertiary Hospital in Eastern Uganda.

BackgroundPostpartum urinary Catheter-Related Infections (CRIs) are a significant cause of maternal sepsis. Several studies done have reported the presence of mixed populations of bacteria with a significant increase in Extended-Spectrum Beta-Lactamase (ESBL) Enterobacteriaceae spps, Methicillin-Resistant Staphylococcus aureus (MRSA), Multi-Drug Resistant (MDR) bacteria in urine and blood cultures of catheterized patients despite the use of prophylactic antibiotics. This study aimed at determining the bacterial species diversity and susceptibility patterns of indwelling urinary catheters from postpartum mothers attending Mbale Regional Referral Hospital (MRRH).MethodsA cross-sectional study employing quantitative and qualitative was carried out in MRRH among postpartum mothers with urinary catheters and their care-takers. The purposive non-random sampling strategy was used to collect data using an interviewer-administered questionnaire for the quantitative data collection and in-depth interviews for qualitative data collection. All the data collection tools used were developed, pretested and validated. At the point of de-catheterization, Catheter tips from enrolled participants were cut about 2-3cm below the balloon aseptically into test-tube containing peptone water, sonication technique employed, and incubation done 24hours then cultured to ensure phenotypic identification. An antibiotic sensitivity test was performed using the disc diffusion method following Clinical and Laboratory Standards Institute (CLSI) guidelines. Quantitative data collected was entered in Microsoft Excel and then exported to STATA14 for statistical analysis. Thematic analysis was used to analyse and organise qualitative data by an inductive coding method using Nvivo 12 software.ResultsIn this study, 208 postpartum mothers participated, the majority of whom were caesarean section mothers of age range 20–24 years and 17 care-takers with a median age of 32 years. The prevalence of catheter tips bacterial colonisation was 98% despite 88.5% of the participants being on broad-spectrum antibiotics. The average duration of catheterisation was 2 days. All bacteria isolates were potential uro-pathogens with a mean occurrence of 2 bacteria species in each urinary catheter tip. The rates of MDR to commonly used antibiotics were high. The urinary catheter size of greater than F14 and duration of catheterization greater than 2 days were significantly associated with the number of bacterial species isolated from each sample. The maintenance care and knowledge of care-urinary catheter care among the care-takers was found sub-optimal.ConclusionThere was a high prevalence of catheter colonisation with bacterial spps diversity averaging 2 spps per sample despite use of broad spectrum antibiotics. The MDR rates were high, which calls for routine culture and sensitivity. Health workers practicing obstetric medicine need to pay attention to catheter sizes during catheterisation and its duration. Health education should be part of antenatal and postnatal care education.

Comparison of chlorhexidine impregnated dressing and standard dressing for the prevention of central-line associated blood stream infection and colonization in critically ill pediatric patients: A randomized controlled trial.

The aim of this study was to compare chlorhexidine gluconate (CHG)-impregnated dressing and standard dressing with respect to the frequency of central-line-associated bloodstream infection (CLABSI), catheter-related bloodstream infection, primary bloodstream infection, and catheter colonization in critically ill pediatric patients with short-term central venous catheters. Children who were admitted to the pediatric intensive care unit of a tertiary institution between May 2018 and December 2019 and received placement of a short-term central venous catheter were included in this single-center randomized controlled trial. Patients were grouped according to the type of catheter fixation applied. A total of 307 patients (151 CHG-impregnated dressing, 156 standard dressing), with 307 catheters (amounting to a collective total of 4,993 catheter days), were included in the study. The CHG-impregnated dressing did not significantly decrease the incidence of CLABSI (6.36 vs 7.59 per 1,000 catheter days; hazard ratio (HR): 0.93, P = 0.76), catheter related bloodstream infection (3.82 vs 4.18 per 1,000 catheter days; HR: 0.98; P = 0.98), and primary bloodstream infection (2.54 vs 3.42 catheter days; HR: 0.79; P = 0.67). The CHG-impregnated dressing significantly decreased the incidence of catheter colonization (3.82 vs 7.59 per 1,000 catheter days; HR: 0.40; P = 0.04). In both groups, the most frequent microorganisms isolated in CLABSI or catheter colonization were Gram-positive bacteria (the majority were coagulase-negative staphylococci). The use of CHG-impregnated dressing does not decrease CLABSI incidence in critically ill pediatric patients but it significantly reduced catheter colonization. Coagulase-negative staphylococci were the most common microorganisms causing CLABSI or catheter colonization.

Üç Yollu Musluk ve Split Septumlu Enjeksiyon Valfi Kullanımının Kateter Enfeksiyonu ve Kolonizasyonuna Etkileri: Yarı Deneysel Çalışma

Objective: Connectors are frequently and necessarily used in patients undergoing intravenous fluid therapy. All of the catheters and connectors may be a risk factor for catheter infections if aseptic techniques were not used. This study was conducted to determine the effect of 3-way stopcock (3WSC) and Split Septum Injection Valve (SSIV) Usage on peripheral intravenous catheter colonization and infection. Material and Methods: This is a quasi-experimental study. The sample of the study consists of 216 patients (108 control, and 108 experimental group). 3WSC was integrated to the control group and SSIV was integrated to the experiment group peripheral venous catheters. Catheters were observed for 72 hours in terms of complications such as bleeding, leakage, and phlebitis infiltration. Catheters were removed for culture sampling 72 hours after catheterization. Descriptive statistics and Pearson chi-square were used in the analysis of the data. Results: The rate of colonization was 5.6% in 3WSCs and 2.8% in SSIVs. When the colonization rates were compared, there was no statistically significant difference between 3WSCs and SSIVs about catheter colonization and infection (p>0.05). Conclusion: Both connectors can be used safely in the administration of continuous intravenous solution and drug therapy. Development of continuous in-service training programs for the prevention of catheter related blood system infections are suggested.

Thrombosis and infections of peripherally inserted central catheters in burn patients: A 3-year retrospective study and a systematic review

AimsPeripherally inserted central catheters (PICCs) are becoming common and effective in acute and critical care settings recently. Burn patients need special considerations because of restricted insertion sites, burn wounds, hyper coagulation, high infection rates and others. However, the safety of PICCs in burn patients are not well elucidated and no related protocol has been formed. This study aims to investigate the thrombosis and infections of PICCs in burn patients. MethodsThis was a single center retrospective study and a systematic review. All the burn patients with PICCs between January 1, 2018 and December 31, 2020 were included. A systematic search of Medline, PubMed, EMBASE and Web of Science was performed from inception to 4 June 2021 following PRISMA guidelines. Upper extremity vein thrombosis (UEVT) and central line-associated bloodstream infection (CLABSI) were the main outcome. ResultsA total of 85 successful PICCs in 78 patients were included. Most patients were male (79.5%), adults(80.8%) and injured by flame(74.4%). The mean TBSA was 50.3% and 76.9% of patients had TBSA more than 30%. Most PICCs were punctured once (60.0%) and inserted less than 30 days after injury (80.0%) through basilar vein (70.6%). The overall line days were 2195 days and the mean line days was 25.8 ± 18.3 days. Six PICCs were complicated by UEVT (7.1%) in 21.2 ± 17.3 days after insertion. Patients with UEVT had significantly higher rate of bacteremia and later insertions than those without UEVT. One patient developed CLABSI and the CLABSI rate was 1.2% and 0.5 per 1000 line days. Six PICCs had catheter colonization. No significant risk factors were identified. Five articles involving 293 patients and 319 PICCs were ultimately evaluated in systematic review. The overall incidence of UEVT was 3.2% and CLABSI was 6.9% in burn populations. ConclusionPICCs in burn patients had acceptable incidence of UEVT and CLABSI with relative long line durations. A standardized PICC guideline for burn patients is required to further improve the feasibility and safety of PICCs.