Risk factors for nosocomial burn wound infection caused by multidrug resistant Acinetobacter baumannii

Pyrogallol loaded chitosan-based polymeric hydrogel for controlling Acinetobacter baumannii wound infections: Synthesis, characterization, and topical application

Antibacterial hydrogels have emerged as a promising approach for wound healing, owing to their ability to integrate antibacterial agents into the hydrogel matrix. Benefiting from its remarkable antibacterial and wound-healing attributes, pyrogallol has been introduced into chitosan-gelatin for the inaugural development of an innovative antibacterial polymeric hydrogel tailored for applications in wound healing. Hence, we observed the effectiveness of pyrogallol in inhibiting the growth of A. baumannii, disrupting mature biofilms, and showcasing robust antioxidant activity both in vitro and in vivo. In addition, pyrogallol promoted the migration of human epidermal keratinocytes and exhibited wound healing activity in zebrafish. These findings suggest that pyrogallol holds promise as a therapeutic agent for wound healing. Interestingly, the pyrogallol-loaded chitosan-gelatin (Pyro-CG) hydrogel exhibited enhanced mechanical strength, stability, controlled drug release, biodegradability, antibacterial activity, and biocompatibility. In vivo results established that Pyro-CG hydrogel promotes wound closure and re-epithelialization in A. baumannii-induced wounds in molly fish. Therefore, the prepared Pyro-CG polymeric hydrogel stands poised as a potent and promising agent for wound healing with antibacterial properties. This holds considerable promise for the development of effective therapeutic interventions to address the increasing menace of A. baumannii-induced wound infections.

Fibrous matrices facilitate pleurocidin killing of wound associated bacterial pathogens

Conventional wound infection treatments neither actively promote wound healing nor address the growing problem of antibacterial resistance. Antimicrobial peptides (AMPs) are natural defense molecules, released from host cells, which may be rapidly bactericidal, modulate host-immune responses, and/or act as endogenous mediators for wound healing. However, their routine clinical use has hitherto been hindered due to their instability in the wound environment. Here we describe an electrospun carrier system for topical application of pleurocidin, demonstrating sufficient AMP release from matrices to kill wound-associated pathogens including Acinetobacter baumannii and Pseudomonas aeruginosa. Pleurocidin can be incorporated into polyvinyl alcohol (PVA) fiber matrices, using coaxial electrospinning, without major drug loss with a peptide content of 0.7% w/w predicted sufficient to kill most wound associated species. Pleurocidin retains its activity on release from the electrospun fiber matrix and completely inhibits growth of two strains of A. baumannii (AYE; ATCC 17978) and other ESKAPE pathogens. Inhibition of P. aeruginosa strains (PAO1; NCTC 13437) is, however, matrix weight per volume dependent, with only larger/thicker matrices maintaining complete inhibition. The resulting estimation of pleurocidin release from the matrix reveals high efficiency, facilitating a greater AMP potency. Wound matrices are often applied in parallel or sequentially with the use of standard wound care with biocides, therefore the presence and effect of biocides on pleurocidin potency was tested. It was revealed that combinations displayed additive or modestly synergistic effects depending on the biocide and pathogens which should be considered during the therapy. Taken together, we show that electrospun, pleurocidin-loaded wound matrices have potential to be investigated for wound infection treatment.

Infections in Pediatric Patients With Burn Injury: 6 Years of Experience

BACKGROUND

This study aimed to determine the frequency of bloodstream and wound infections and their possible risk factors in hospitalized children with burn injury.

METHODS

We performed this retrospective descriptive study from 2015 to 2021. The study subjects consisted of all the pediatric patients hospitalized in the burn unit, from whom microorganisms were isolated either from blood or wound culture samples.

RESULTS

We detected a total of 142 microorganisms from 97 blood culture samples and 45 wound culture samples. Among the 115 patients, 44 (38.3%) were females and 71 (61.7%) were males, with a median age of 21 months (interquartile range: 14-39 months). Gram-positive bacteria were the most common causative agents of bloodstream infections in patients with burns (54.6%), followed by Gram-negative bacteria (32.9%) and fungi (12.3%). Gram-negative bacteria were the most common causative agent of wound infections (86.7%). Prolonged hospitalization positively correlated with the extent of the burn surface area (P: 0.031), degree of burn (P: 0.001), use of central venous catheter (P: 0.028), and intensive care unit stay (P: 0.044). Independent risk factors for Gram-negative bacteremia and Gram-negative wound infections were the extent of the burn surface area (P: 0.018), degree of burn (P: 0.024) and intensive care unit stay (P: 0.023). The independent risk factor for fungemia was prolonged hospitalization (P: 0.026).

CONCLUSIONS

To reduce infections, minimizing invasive procedures using a multidisciplinary approach would be beneficial, especially in patients who have a large burn surface area and are expected to have a long hospital stay.

Biomimetic Neutrophil Nanotoxoids Elicit Potent Immunity against Acinetobacter baumannii in Multiple Models of Infection

Acinetobacter baumannii is a leading cause of antibiotic-resistant nosocomial infections with high mortality rates, yet there is currently no clinically approved vaccine formulation. During the onset of A. baumannii infection, neutrophils are the primary responders and play a major role in resisting the pathogen. Here, we design a biomimetic nanotoxoid for antivirulence vaccination by using neutrophil membrane-coated nanoparticles to safely capture secreted A. baumannii factors. Vaccination with the nanotoxoid formulation rapidly mobilizes innate immune cells and promotes pathogen-specific adaptive immunity. In murine models of pneumonia, septicemia, and superficial wound infection, immunization with the nanovaccine offers significant protection, improving survival and reducing signs of acute inflammation. Lower bacterial burdens are observed in vaccinated animals regardless of the infection route. Altogether, neutrophil nanotoxoids represent an effective platform for eliciting multivalent immunity to protect against multidrug-resistant A. baumannii in a wide range of disease conditions.

Development and Clinical Application of a Recombinase Polymerase Amplification-Lateral Flow Strip Assay for Detection of Carbapenem-Resistant Acinetobacter baumannii

Acinetobacter baumannii is a worldwide, primary cause of respiratory tract infections, septicemia, urinary apparatus infections, and secondary meningitis. It can be fatal. Rapid and accurate detection methods are needed to control the spread of carbapenem-resistant A. baumannii (CRAB). Current molecular diagnostic methods are limited and not suitable for on-site detection. In this study, an isothermal detection method using recombinase polymerase amplification (RPA) combined with a lateral flow strip (LFS) was developed to target the bla_OXA-51 and bla_OXA-23 genes of A. baumannii. The reaction was completed in about 40 min at 37°C. This method can also effectively distinguish A. baumannii and CRAB. The limit of detection of 10⁰-10¹ CFU/reaction was equal to that of other detection methods. The detection accuracy was equal to that of the qPCR method with the use of clinical samples. The RPA-LFS assay is portable, rapid, and accurate and could replace existing detection methods for on-site detection of A. baumannii and CRAB.

Investigations on the Wound Healing Potential of Tilapia Piscidin (TP)2-5 and TP2-6

Wound healing is a highly orchestrated process involving many cell types, such as keratinocytes, fibroblasts and endothelial cells. This study aimed to evaluate the potential application of synthetic peptides derived from tilapia piscidin (TP)2, TP2-5 and TP2-6 in skin wound healing. The treatment of HaCaT keratinocytes with TP2-5 and TP2-6 did not cause cytotoxicity, but did enhance cell proliferation and migration, which could be attributed to the activation of epidermal growth factor receptor signaling. In CCD-966SK fibroblasts, although TP2-5 (31.25 μg/mL) and TP2-6 (125 μg/mL) showed cytotoxic effects, we observed the significant promotion of cell proliferation and migration at low concentrations. In addition, collagen I, collagen III, and keratinocyte growth factor were upregulated by the peptides. We further found that TP2-5 and TP2-6 showed pro-angiogenic properties, including the enhancement of human umbilical vein endothelial cell (HUVEC) migration and the promotion of neovascularization. In a murine model, wounds treated topically with TP2-5 and TP2-6 were reduced by day 2 post-injury and healed significantly faster than untreated wounds. Taken together, these findings demonstrate that both TP2-5 and TP2-6 have multifaceted effects when used as topical agents for accelerating wound healing.

Methylene Blue-Mediated Antimicrobial ​Photodynamic Therapy Against Clinical Isolates of Extensively Drug Resistant ​Gram-Negative Bacteria Causing Nosocomial Infections in Thailand, An In Vitro Study

BACKGROUND/PURPOSE

Some multidrug-resistant gram-negative bacteria as a global threat have been recently prioritized for research and development of new treatments. We studied the efficacy of methylene blue-mediated antimicrobial photodynamic therapy (MB-aPDT) for the reduction of extensively drug-resistant Acinetobacter baumannii (XDR-AB) and Pseudomonas aeruginosa (XDR-PS) and multidrug-resistant Klebsiella pneumoniae (MDR-KP) isolated in a university hospital setting in Thailand.

METHOD

Two isolates of each selected bacterium were collected, XDR-AB1 and AB2, XDR- PS1 and PS2, and MDR-KP1 and KP2. Three triplicate experiments using various MB concentrations alone, various red light fluences alone, as well as the selected non-toxic doses of MB and fluences of red light combined as MB-aPDT were applied on each selected isolate. The colonies were counted [colony forming units (CFU)/ml]. Estimation of the lethal treatment dose defined as reduction of > 2 log₁₀ in CFU/ml compared with untreated bacteria.

RESULT

There were generally negligible changes in the viable counts of the bacterial suspensions treated with all the MB concentrations (p > 0.05). In the second experiment with the only red light treatments, at fluences higher than 2 J/cm, reduction trend in viable counts across all the isolates was observed. Only for MDR-KP1, however, the lethal dose was achieved with the highest fluence of red light (80 J/cm). With the concentration of MB, 50 and 150 mg/L in the third experiment (MB-aPDT), the greater bacterial reduction was observed in all clinical isolates leading to their lethal viable cell reduction when escalating the light fluence to 80 J/cm.

CONCLUSIONS

MB-aPDT evidently killed the selected XDR and MDR-gram negative bacteria. In highly drug-resistant crisis era, MB-aPDT could be a promising option, particularly for local infections and infection complicating chronic wounds.

Risk Factors for Extensively Drug-Resistant Acinetobacter baumannii in Neonatal Patients

Introduction Extensively drug-resistant Acinetobacter baumannii infections (XDRABIs) are significant causes of mortality and morbidity in neonatal patients due to the treatment difficulties and limitations. In the present study, we aimed to evaluate the characteristics and risk factors for XDRABIs acquisition during hospitalization.

Methods We investigated the risk factors of health care-associated infections (HC-AIs) caused by multidrug-resistant A. baumannii in the four neonatal units between January 2008 and December 2018. The patients and the control group's data and culture results were recorded and analyzed on a daily basis.

Results A total of 70 patients infected with XDRABIs and 118 control patients were included in the study. Univariate analysis showed that prematurity, gestation age, birth weight, mechanical ventilation, parenteral nutrition, transfusion, use of glycopeptides, and aminoglycosides were significantly associated with XDRABIs. In the univariate analysis, gestation age, mechanical ventilation, transfusion, parenteral nutrition, use of glycopeptides, carbapenems, and aminoglycosides were significantly associated with mortality. In the multiple logistic regression analysis, gestation age (p = 0.034), transfusion (p < 0.001), and use of glycopeptides (p = 0.019) were determined to be independent predictors of mortality in newborn infants with XDRABIs (R-square = 0.546).

Conclusion Determination of the risk factors, avoiding invasive procedures, rational use of antibiotics will lead to a decrease in the mortality and morbidity rates related to XDRABIs.

Incidence, impact and risk factors for multidrug-resistant organisms (MDRO) in patients with major trauma: a European Multicenter Cohort Study

INTRODUCTION

The burden of MDRO in health systems is a global issue, and a growing problem. We conducted a European multicenter cohort study to assess the incidence, impact and risk factors for multidrug-resistant organisms in patients with major trauma. We conducted this study because the predictive factors and effects of MDRO in severely injured patients are not yet described. Our hypothesis is that positive detection of MDRO in severely injured patients is associated with a less favorable outcome.

METHODS

Retrospective study of four level-1 trauma centers including all patients after major trauma with an injury severity score (ISS) ≥ 9 admitted to an intensive care unit (ICU) between 2013 and 2017. Outcome was measured using the Glasgow outcome scale (GOS).

RESULTS

Of 4131 included patients, 95 (2.3%) had a positive screening for MDRO. Risk factors for MDRO were male gender (OR 1.73 [95% CI 1.04-2.89]), ISS (OR 1.01 [95% CI 1.00-1.03]), PRBC's given (OR 1.73 [95% CI 1.09-2.78]), ICU stay > 48 h (OR 4.01 [95% CI 2.06-7.81]) and mechanical ventilation (OR 1.85 [95% CI 1.01-3.38]). A positive MDRO infection correlates with worse outcome. MDRO positive cases GOS: good recovery = 0.6%, moderate disability = 2.1%, severe disability = 5.6%, vegetative state = 5.7% (p < 0.001).

CONCLUSIONS

MDRO in severely injured patients are rare but associated with a worse outcome at hospital discharge. We identified potential risk factors for MDRO in severely injured patients. Based on our results, we recommend a standardized screening procedure for major trauma patients.

Innovations in Infection Prevention and Treatment

Background: Patients with large, acute burn injuries are a major challenge for clinicians. The loss of skin barrier protection against micro-organisms combined with the induced immunosuppression after burn injury makes this population especially vulnerable to infection. For burn-injured patients who survive immediate management considerations and burn resuscitation after acute injury, sepsis remains the primary cause of death. The purpose of this article is to describe current strategies and innovations in burn sepsis prevention and management. Methods: This work reviews the current understanding of the systemic inflammatory response to burn injury and burn sepsis as well as current strategies in insolation and infection prevention, newer burn unit design strategies in the context of infection prevention, and novel therapies being considered in topical antimicrobial wound care management. Results: A review of burn sepsis is key to understanding current paradigms and innovation in burn management and prevention. Key management principles begin from the time of injury and persist throughout the patient's hospital course. This includes use of personal protective equipment, burn unit design considerations, and knowledge of critical care principles such as central venous catheter management strategies. Innovations on wound dressing types, forms, and use have been key to better controlling burn wound sepsis and improving wound healing. Products incorporating nanotechnology, novel anions, oxygen, and even light have been key to introducing previously unconsidered methods to fight or prevent infection. Conclusion: Understanding the pathophysiology and source identification of sepsis from burn wounds has been a key contributor in developing innovative prevention and therapeutic strategies in burn management. The emergence of drug-resistant pathogens and the difficulty of systemic antibiotic agents to reach poorly vascularized wounds have further reinforced the need to anticipate management strategies moving forward. A proactive, multidisciplinary approach is necessary to minimize the morbidity and mortality associated with infection control.

Transfusion and Infections in the Burn Patient

Background: Blood product transfusion has historically been utilized after major burn injury in the resuscitative as well as the acute phase. Transfusion has been implicated in infection and immunosuppression in many disease states. Recommendations for blood product transfusion has varied, but several landmark studies have helped define optimal burn transfusion strategies with respect to infection. The purpose of this article is to review the evidence describing the relation between transfusion and infection in burn injury during different phases of burn treatment to identify optimal transfusion strategies and suggest future targets for transfusion research in burns. Methods: This article presents the history, current status, and future research directions related to blood and blood product transfusion in burn injury. Results: Patients with burns are subject to infectious complications resulting from the loss of skin and burn-related immunosuppression. The use of blood in burn treatment has varied during both the resuscitative phase and the acute treatment phase. Whole-blood use in resuscitation was replaced with crystalloid infusion. Future trials are examining the role of plasma and albumin in burn resuscitation. A randomized prospective multicenter transfusion trial was able to decrease transfusion by 50% with no change in infection. Further examination of the role of hemostatic resuscitation in burn excision may help to better define transfusion goals. Conclusions: Blood product transfusion in burn injury has varied throughout the last century. Although advances in the understanding of blood transfusion in burn injury have occurred, initiatives to define optimal care better are required.

Trends in microbial profile of burn patients following an event of dust explosion at a tertiary medical center

Background

Microbial infection is the main cause of increased morbidity and mortality in burn patients, especially infections caused by multiple drug-resistant organisms (MDRO). The purpose of this study was to explore major microbial trends in burn patients.

Methods

This retrospective study was conducted at burn wards and intensive care units, where burn patients were admitted following an event of dust explosion. Data were collected for a number of variables including severity of burns, demographic and clinical characteristics, laboratory data, and therapeutic devices.

Results

A total of 1132 specimens were collected from 37 hospitalized burn patients with mean TBSA of 46.1%.The most commonly isolated species were Staphylococcus spp. (22.4%). The highest rate of antibiotic resistance was observed in carbapenem–resistant A. baumannii (14.6%), followed by methicillin-resistant S. aureus (11.3%). For each additional 10% TBSA, the isolation of MDRO increased 2.58–17.57 times (p < 0.05); for each additional 10% of the third-degree burn severity, the risk of MDRO significantly decreased by 47% (95% CI, 0.38–0.73, p < 0.001) by Cox model.

Conclusions

The proportion of overall microbial isolates increased with the increase in TBSA and duration of time after burns. The extent of TBSA was the most important factor affecting MDRO.

Evaluation of synergistic effect of tazobactam with meropenem and ciprofloxacin against multi-drug resistant Acinetobacter baumannii isolated from burn patients in Tehran

Background:Acinetobacter baumannii is an increasingly important cause of nosocomial infections worldwide. In addition to the intrinsic resistance of Acinetobacter baumannii to many antibiotics, available treatment approaches with older antibiotics are significantly associated with an increase in multiresistant strains. The aim of this study was to evaluate the synergistic effect of tazobactam with meropenem and ciprofloxacin against carbapenems and drug resistant Acinetobacter baumannii isolated from burn patients in a tertiary burn center in Tehran.

Materials and methods: In this study, a total of 47 clinical isolates of A. baumannii were included from burn patients admitted to the Shahid Motahari Burns Hospital, Tehran, from June 2018 to August 2018. The disk diffusion method was used to determine resistance patterns. The synergistic effect of tazobactam with meropenem and ciprofloxacin was evaluated by determining the MIC. A PCR assay was performed to determine bla_OXA-40-like, bla_OXA-58-like and bla_OXA-24-like.

Results: Antibiotic susceptibility testing revealed that all of the isolates were resistant to meropenem and ciprofloxacin. The MIC values decreased in the cases of combined use of ciprofloxacin and meropenem with tazobactam. The bla_OXA-24-like gene was the predominant carbapenemase gene (93.6%), followed by bla_OXA-40-like, which was detected in 48.9% of isolates. None of the A. baumannii isolates harbored the bla_OXA-58-like gene.

Conclusions: Based on in-vitro antimicrobial susceptibility in the current study, the MIC of tazobactam combined with meropenem or ciprofloxacin have been shown to be variable. Furthermore, the data acquired from such in vitro conditions should be confirmed by reliable results from sufficiently controlled clinical trials.

Modifiable risk factors for multidrug-resistant Gram-negative infection in critically ill burn patients: a systematic review and meta-analysis

BACKGROUND

We conducted a systematic review and meta-analysis to identify potentially modifiable risk factors for multidrug-resistant Gram-negative colonization or infection in critically ill burn patients.

METHODS

A systematic search was conducted of PubMed, Embase, CINAHL, Web of Science and Central (Cochrane). Risk factors including antibiotic use and hospital interventions were summarized in a random-effects meta-analysis. Risk of publication bias was assessed using the Grading of Recommendations Assessment, Development and Evaluation method and funnel plots.

RESULTS

A total of 11 studies met the inclusion criteria. We identified several potentially modifiable risk factors and were able to grade their importance based on effect size. Related to prior antibiotic exposure, extended-spectrum cephalosporins (pooled odds ratio (OR) 7.00, 95% confidence interval (CI) 2.77-17.67), carbapenems (pooled OR 6.65, 95% CI 3.49-12.69), anti-pseudomonal penicillins (pooled OR 4.23, 95% CI 1.23-14.61) and aminoglycosides (pooled OR 4.20, 95% CI 2.10-8.39) were most significant. Related to hospital intervention, urinary catheters (pooled OR 11.76, 95% CI 5.03-27.51), arterial catheters (pooled OR 8.99, 95% CI 3.84-21.04), mechanical ventilation (pooled OR 5.49, 95% CI 2.59-11.63), central venous catheters (pooled OR 4.26, 95% CI 1.03-17.59), transfusion or blood product administration (pooled OR 4.19, 95% CI 1.48-11.89) and hydrotherapy (pooled OR 3.29, 95% CI 1.64-6.63) were most significant.

CONCLUSION

Prior exposure to extended-spectrum cephalosporins and carbapenems, as well as the use of urinary catheters and arterial catheters pose the greatest threat for infection or colonization with multidrug-resistant Gram-negative organisms in the critically ill burn patient population.

Incidence and mortality of healthcare-associated infections in hospitalized patients with moderate to severe burns

PURPOSE

This study was to examine the incidence of different types, and isolated pathogens, of healthcare-associated infections (HAIs), and also to determine their prognostic factors for mortality.

METHODS

Prospective surveillance was conducted in a medical center from 2005 through to 2016. Multiple logistic regression analysis was performed to assess prognostic factors of mortality.

RESULTS

A total of 709 patients with moderate to severe burns were hospitalized. There were 83 patients (11.7%) with HAIs (158 episodes) and 203 isolated pathogens. The most common HAI types were bloodstream infection (BSI) at 39.2% (8.7% of all patients) and central line-associated BSI (mean 4.8 per 1000 central line days). Overall, S. aureus (13.8%) were the most common isolated pathogens, while the most commonly found type of multidrug-resistant pathogen was carbapenems-resistant Enterobacteriaceae (23%). The crude mortality rate was 15.7%, and the independent factors (p < .05) for mortality were BSI (Odds ratio [OR] 2.70), intensive care unit (OR 5.19) and total body surface area with full-thickness injuries ≥50% (OR 5.22).

CONCLUSIONS

Burn patients with BSI were the most common HAI sites, and this was an independent factor for mortality. Effective integrated care and appropriate infection control can reduce the incidence of infection and death.

Infection Prevention: Unique Aspects of Burn Units

BACKGROUND

Infection is a common complication of burn injury caused by the loss of skin (the primary defense against micro-organisms) as well as burn-induced immunosuppression. Essentially, survival after burn injury is determined by whether wound healing or infection predominates. The purpose of this article is to describe how burn unit structure and design may impact the incidence of infection after burn injury.

METHODS

This article describes the special considerations for burn unit structure and design based on burn pathophysiology, including burn-related immunosuppression and wound treatment. Particular emphasis is placed on how burn unit design should consider the immunosuppressed state of the burn patient.

RESULTS

Because many of the factors that promote wound healing also promote infection, burn unit design must prioritize infection prevention, including segregation and containment, environment layout and function, room cleaning, and isolation. Burn centers should have dedicated facilities with separation of patients, specialized room environment/equipment, and cleaning and wound care disinfection capabilities, with particular attention paid to surfaces, ventilation, temperature control, and patient movement to the operating room, radiology, and therapy.

CONCLUSIONS

Because of the high infection potential associated with burn injury, burn units require meticulous attention to design and function to minimize patient infection risk.

Molecular identification and genotyping of Acinetobacter baumannii isolated from burn patients by PCR and ERIC-PCR

BACKGROUND

Acinetobacter baumannii is one of the most important agents of hospital infections. Rapid and accurate identification and genotyping of A. baumannii is very important, especially in burn hospitals in order to prevent the spread of related nosocomial infections and to further epidemiological studies.

MATERIAL AND METHODS

For two months, 82 A. baumannii isolates were collected from burn wound swabs of patients in a major burn hospital in Tehran. A. baumannii isolates were identified by conventional microbiological test and polymerase chain reaction (PCR) using the primers of blaOXA-51 gene, while the genetic linkage of A. baumannii isolates was investigated by enterobacterial repetitive intragenic consensus (ERIC)-PCR technique. Similarity, a cut-off of ⩾ 95% was considered for classifying the genotypes.

RESULTS

The molecular test (PCR) confirmed 97.56% of phenotypic results for the detection of A. baumannii isolates. ERIC-PCR results revealed 14 different ERIC patterns (ERIC-types) including 11 common types and three unique types.

CONCLUSION

Our findings show that we can simply and quickly detect A. baumannii isolates by PCR using blaOXA genes and genetic diversity by ERIC-PCR, respectively. These rapid and simple techniques for the routine screening and identification of clinical A. baumannii isolates could be useful with epidemic potential.

Risk factors for multidrug-resistant Gram-negative infection in burn patients

BACKGROUND

Infection with multidrug-resistant (MDR) Gram-negative organisms leads to poorer outcomes in the critically ill burn patient. The aim of this study was to identify the risk factors for MDR Gram-negative pathogen infection in critically ill burn patients admitted to a major tertiary referral intensive care unit (ICU) in Australia.

METHODS

A retrospective case-control study of all adult burn patients admitted over a 7-year period was conducted. Twenty-one cases that cultured an MDR Gram-negative organism were matched with 21 controls of similar age, gender, burn size and ICU stay. Multivariable conditional logistic regression was used to individually assess risk factors after adjusting for Acute Burn Severity Index. Adjusted odds ratios (ORs) were reported. P-values < 0.25 were considered as potentially important risk factors.

RESULTS

Factors increasing the risk of MDR Gram-negative infection included superficial partial thickness burn size (OR: 1.08; 95% confidence interval (CI): 1.01-1.16; P-value: 0.034), prior meropenem exposure (OR: 10.39; 95% CI: 0.96-112.00; P-value: 0.054), Gram-negative colonization on admission (OR: 9.23; 95% CI: 0.65-130.15; P-value: 0.10) and escharotomy (OR: 2.66; 95% CI: 0.52-13.65; P-value: 0.24). For cases, mean age was 41 (SD: 13) years, mean total body surface area burned was 47% (SD: 18) and mean days in ICU until MDR specimen collection was 17 (SD: 10) days.

CONCLUSION

Prior meropenem exposure, Gram-negative colonization on admission, escharotomy and superficial partial thickness burn size may be potentially important factors for increasing the risk of MDR Gram-negative infection in the critically ill burn patient.

Impact of relocation and environmental cleaning on reducing the incidence of healthcare-associated infection in NICU

BACKGROUND

Hospital environment remains a risk for healthcare-associated infections (HAIs). This was a prospective study to evaluate the comprehensive impact of relocating a neonatal intensive care unit (NICU) to a new facility and improved environmental cleaning practice on the presence of methicillin-resistant Staphylococcus aureus (MRSA) on inanimate surfaces and the incident rate of HAIs.

METHODS

New environmental cleaning measures were adopted after the NICU was moved to a new and better-designed location. The effect of moving and the new environmental cleaning practice was investigated by comparing the positive number of MRSA on ward surfaces and the incidence density of HAIs between the baseline and intervention periods.

RESULTS

Only 2.5% of environmental surfaces were positive for MRSA in the intervention period compared to 44.0% in the baseline period (P<0.001). Likewise, the total incident rate of HAIs declined from 16.8 per 1000 cot-days to 10.0 per 1000 cot-days (P<0.001).

CONCLUSION

The comprehensive measures of relocating the NICU to a new facility design with improved environmental cleaning practice are effective and significantly reduce the incidence of HAIs.

Risk Factors for Health Care-Associated Bloodstream Infections in a Neonatal Intensive Care Unit

Background

Healthcare-associated bloodstream infections (HCA-BSI) are a major cause of morbidity and mortality in neonatal intensive care units (NICUs).

Objectives

We aimed to determine the causative organisms and risk factors of HCA-BSIs in NICUs.

Methods

This study was performed between January 2011 and December 2014 in the neonatal intensive care unit of Dicle university, Turkey. The study consisted of 126 patients (infected group) with positive blood culture and 126 randomly selected patients (uninfected control group) with negative blood culture after four days of hospitalization.

Results

We found that the most common causative agents isolated from nosocomial infections (NIs) were 20.7% Staphylococcus epidermidis, 26.7% Klebsiella spp., and 13.3% Acinetobacter spp. Incidences of low gestational age, low birth weight, vaginal birth type, and long length of hospitalization were higher in the infected neonates than in the uninfected neonates. In the univariate analysis, surgical operation, ventriculoperitoneal shunt, use of umbilical catheter, nasogastric or orogastric tube, urinary catheter, mechanical ventilation, surfactant treatment, erythrocyte transfusion, plasma transfusion, thrombocyte transfusion, total parenteral nutrition infusion, intracranial hemorrhage, length of hospital stay, fifth-minute Apgar score, and total parenteral nutrition time were significantly associated with NIs. In the multiple logistic regression analysis, fifth-minute Apgar, use of erythrocyte transfusion and surgical operation were found as the independent risk factors for HCA-BSI.

Conclusions

This study determined the causative organisms and risk factors of HCA-BSIs in NICUs.

Determining the Independent Risk Factors and Mortality Rate of Nosocomial Infections in Pediatric Patients

The objective of this study was to determine the rate, independent risk factors, and outcomes of healthcare-associated infections in pediatric patients. This study was performed between 2011 and 2014 in pediatric clinic and intensive care unit. 86 patients and 86 control subjects were included in the study. Of 86 patients with nosocomial infections (NIs), there were 100 NIs episodes and 90 culture growths. The median age was 32.0 months. The median duration of hospital stay of the patients was 30.0 days. The most frequent pathogens were Coagulase-negative Staphylococcus, Acinetobacter spp., Klebsiella spp., and Candida spp. Unconsciousness, prolonged hospitalization, transfusion, mechanical ventilation, use of central venous catheter, enteral feeding via a nasogastric tube, urinary catheter, and receiving carbapenems and glycopeptides were found to be significantly higher in NIs patients. Multivariate logistic regression analysis showed prolonged hospitalization, neutropenia, and use of central venous catheter and carbapenems as the independent risk factors for NIs. In the univariate analysis, unconsciousness, mechanical ventilation, enteral feeding, use of enteral feeding via a nasogastric tube, H₂ receptor blockers, and port and urinary catheter were significantly associated with mortality. In the multiple logistic regression analysis, only mechanical ventilation was found as an independent predictor of mortality in patients with NIs.

A Multicenter Evaluation of Blood Culture Practices, Contamination Rates, and the Distribution of Causative Bacteria

BACKGROUND

The prognostic value of blood culture testing in the diagnosis of bacteremia is limited by contamination.

OBJECTIVES

In this multicenter study, the aim was to evaluate the contamination rates of blood cultures as well as the parameters that affect the culture results.

MATERIALS AND METHODS

Sample collection practices and culture data obtained from 16 university/research hospitals were retrospectively evaluated. A total of 214,340 blood samples from 43,254 patients admitted to the centers in 2013 were included in this study. The blood culture results were evaluated based on the three phases of laboratory testing: the pre-analytic, the analytic, and the post-analytic phase.

RESULTS

Blood samples were obtained from the patients through either the peripheral venous route (64%) or an intravascular catheter (36%). Povidone-iodine (60%) or alcohol (40%) was applied to disinfect the skin. Of the 16 centers, 62.5% have no dedicated phlebotomy team, 68.7% employed a blood culture system, 86.7% conducted additional studies with pediatric bottles, and 43.7% with anaerobic bottles. One center maintained a blood culture quality control study. The average growth rate in the bottles of blood cultures during the defined period (1259 - 26,400/year) was 32.3%. Of the growing microorganisms, 67% were causative agents, while 33% were contaminants. The contamination rates of the centers ranged from 1% to 17%. The average growth time for the causative bacteria was 21.4 hours, while it was 36.3 hours for the contaminant bacteria. The most commonly isolated pathogens were Escherichia coli (22.45%) and coagulase-negative staphylococci (CoNS) (20.11%). Further, the most frequently identified contaminant bacteria were CoNS (44.04%).

CONCLUSIONS

The high contamination rates were remarkable in this study. We suggest that the hospitals' staff should be better trained in blood sample collection and processing. Sterile glove usage, alcohol usage for disinfection, the presence of a phlebotomy team, and quality control studies may all contribute to decreasing the contamination rates. Health policy makers should therefore provide the necessary financial support to obtain the required materials and equipment.

Risk factors for the acquisition of imipenem-resistant Acinetobacter baumannii in a burn unit: An appraisal of the effect of colonization pressure

Imipenem-resistant Acinetobacter baumannii (IRAB) is a major threat for critically ill patients, including those admitted to burn units. Recent studies have suggested that colonization pressure (the proportion of patients or patient-days harbouring the pathogen of interest) is an important driver of the risk for acquisition of multidrug-resistant organisms. With that in mind, we conducted a cohort study, enrolling 208 patients admitted to a burn unit from November 2008 through December 2009. The outcome of interest was the acquisition of IRAB. In addition to the usual risk factors, we assessed the impact of colonization pressure. The number of wound excisions (odds ratio (OR) 12.06, 95% confidence interval (CI) 2.82-51.64) and the number of antimicrobials used (OR 22.82, 95% CI 5.15-101.19) were significant risk factors for the outcome of interest. On the other hand, colonization pressure (measured for whole time of exposure or up to the last 14, 7, or 3 days) was not associated with the risk for IRAB acquisition.