Infectious complications in critically injured children

Current Knowledge and Perspectives of Phage Therapy for Combating Refractory Wound Infections

Wound infection is one of the most important factors affecting wound healing, so its effective control is critical to promote the process of wound healing. However, with the increasing prevalence of multi-drug-resistant (MDR) bacterial strains, the prevention and treatment of wound infections are now more challenging, imposing heavy medical and financial burdens on patients. Furthermore, the diminishing effectiveness of conventional antimicrobials and the declining research on new antibiotics necessitate the urgent exploration of alternative treatments for wound infections. Recently, phage therapy has been revitalized as a promising strategy to address the challenges posed by bacterial infections in the era of antibiotic resistance. The use of phage therapy in treating infectious diseases has demonstrated positive results. This review provides an overview of the mechanisms, characteristics, and delivery methods of phage therapy for combating pathogenic bacteria. Then, we focus on the clinical application of various phage therapies in managing refractory wound infections, such as diabetic foot infections, as well as traumatic, surgical, and burn wound infections. Additionally, an analysis of the potential obstacles and challenges of phage therapy in clinical practice is presented, along with corresponding strategies for addressing these issues. This review serves to enhance our understanding of phage therapy and provides innovative avenues for addressing refractory infections in wound healing.

Biological Therapy on Infected Traumatic Wounds: A Case-Control Study

Background:Traumatic wound is a great challenging issue to surgeons, because of large in size, heavily contaminated, infected and unscenic. Infection proceeded to progressive tissue necrosis, septicemia, organ failure or even death. Majority has polymicrobial infections. Bacteriohage therapy will have revolutionized in the treatment of wound. The present study was planned to evaluate the efficacy of topical bacteriophage therapy on large traumatic wounds in comparison with conventional therapy. Methods:The Study conducted from Sept. 2018 to July 2020. Samples between 12- 60 years was taken into study. Customized bacteriophage applied over the wound after serial debridement in case and conventional dressing in control. Fifty four wounded person met the clinical inclusion criteria; 27 in each group. Wound swab and tissue biopsy was taken for bacterial isolation. Isolated specific phage was applied over the wound on alternate day till the wound become sterile and fit for further definitive management. Results: A significant and rapid improvement was observed in wound healing in cases then control group. Average number of day required for complete granulation of wound and attaining sterility was half in cases then control. The hospital stay of the patients on BT was half (20days) than those on CT (40 days). The financial analysis also favours the BT over CT as only 1/third expenditure incurred in BT group as compared to CT Conclusion:Topical Bacteriophage therapy is efficient, effective to clearing the infection in shorter length of time and cost effective for infected traumatic wounds as compared to conventional dressing.

Depressed Monocytic Activity may be a Predictor for Sepsis

Introduction:

Trauma is one of the leading causes of mortality worldwide with infections as important causes of death in such patients. Bacterial infections cause activation of monocytes with excessive synthesis of pro-inflammatory cytokines. Hence, this prospective study was conducted to assess the activity of monocytes in traumatized sepsis patients using flow cytometry and to assess if they have any prognostic potential.

Materials and Methods:

A total of 16 consecutive trauma patients with sepsis and having positive blood culture were enrolled, along with four healthy controls during the period of March 2013 to July 2013. Blood from septic patients were collected on the same day when blood culture was positive and on days 2 and 5 thereafter. Surface staining for monocytes with CD14 and intracellular staining for interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) was done and results were analyzed by flow cytometer. Procalcitonin (PCT) assay was done using MiniVidas. Complete clinical follow-up was done for the patients.

Results:

Of the 16 patients, four died due to infections by various microorganisms. Isolated abdominal trauma (25%) was the most common injury among the enrolled patients of sepsis. Levels of TNF-α were significantly decreased when stimulated with lipopolysaccharide in the fatal patients as compared to the healthy controls. Patients having sepsis who survived had an increased level of TNF-α during the follow-up periods.

Conclusion:

This study showed that activity of monocytes to produce TNF-α and IL-6 were reduced in severe sepsis. Early identification of such immune-paralysis can help in earlier intervention to salvage this vulnerable trauma population.

Flagellin treatment prevents increased susceptibility to systemic bacterial infection after injury by inhibiting anti-inflammatory IL-10+ IL-12- neutrophil polarization

Severe trauma renders patients susceptible to infection. In sepsis, defective bacterial clearance has been linked to specific deviations in the innate immune response. We hypothesized that innate immune modulations observed during sepsis also contribute to increased bacterial susceptibility after severe trauma. A well-established murine model of burn injury, used to replicate infection following trauma, showed that wound inoculation with P. aeruginosa quickly spreads systemically. The systemic IL-10/IL-12 axis was skewed after burn injury with infection as indicated by a significant elevation in serum IL-10 and polarization of neutrophils into an anti-inflammatory ("N2"; IL-10(+) IL-12(-)) phenotype. Infection with an attenuated P. aeruginosa strain (ΔCyaB) was cleared better than the wildtype strain and was associated with an increased pro-inflammatory neutrophil ("N1"; IL-10(-)IL-12(+)) response in burn mice. This suggests that neutrophil polarization influences bacterial clearance after burn injury. Administration of a TLR5 agonist, flagellin, after burn injury restored the neutrophil response towards a N1 phenotype resulting in an increased clearance of wildtype P. aeruginosa after wound inoculation. This study details specific alterations in innate cell populations after burn injury that contribute to increased susceptibility to bacterial infection. In addition, for the first time, it identifies neutrophil polarization as a therapeutic target for the reversal of bacterial susceptibility after injury.

Mortality due to septicemia at a level 1 Indian trauma care centre: an epidemiological analysis

Trauma contributes to a significant proportion of mortality and morbidity in the economically productive age group of 15-45 years. Infections are the second most important cause of death in trauma patients after head injury. Despite advances in trauma care, deaths due to septicemia are increasing. An epidemiological study of septicemia-related deaths were conducted at a level 1 Trauma Centre from January 2011 to December 2011. A total of 201 patients died due to suspected septicemia. The average age of the deceased trauma victims was 35.9 years and the median length of stay in hospital before death was 27 days. In our study, a high proportion of patients had grown pathogens in significant counts from respiratory specimens (36%) and blood (23%) during ante-mortem period, which may have contributed to their fatal outcome. Infections are one of the most common and fatal complications following trauma and complicate the recovery of a significant number of injured patients.

Profile of micro-organisms in intensive care unit of a level-1 trauma centre: A retrospective study

Background:

Patients with trauma usually require highly specialized care in ICU and many times their recovery is complicated by infections. Aim of this study was to determine the profile of pathogens and their impact on outcome among these patients.

Materials and Methods:

The clinical records of 101 consecutive patients who were admitted for more than 48-hrs in ICU during Jun-Dec 2007 were analyzed.

Results:

Total of 953 samples from blood, urine, BAL or pus/collection were subjected to cultures. From 276 samples, 299 organisms were isolated. Among pathogens Candida Spp. [89 (29%)] were the most common, followed by Acinetobacter Spp. [69 (23%)], Pseudomonas Spp. [63 (21%)], Klebsiella Spp. [31 (10%)], coagulase negative Staphylococcus aureus [16 (5%)], E coli [12 (4%)], Enterobacter Spp. [7 (2%)], S aureus [6 (2%)], Enterococcus Spp. [5 (2%)], Citrobacter Spp. [2 (0.6%)], S maltophila [1 (0.3%)] and Providentia Spp. [1 (0.3%)]. For gram negative pathogens drug-resistance rates were as follows: Fluoroquinolones, 76%; 3^rd generation cephalosporins, 74%; aminoglycosides, 66%; β-lactams/β-lactamase inhibitors combinations, 64%; and carbapenems, 50%. Among these 27% of pathogens were resistant to all 5 classes of drugs. 58% of Staphylococcus aureus were methicillin-resistant whereas 85% of coagulase negative Staphylococcus were methicillin resistant. The mortality was higher among patients in whom pathogens were isolated [Odd's Ratio (OR) 0.185; 95% confidence interval (CI) 0.049-0.640; P = 0.002].

Conclusions:

Isolation of multi-drug resistant pathogens is common among trauma patients admitted in ICU and is associated with increased mortality and could impact on the consumption of hospital resources. The importance of high rate of fungal isolation needs to be studied among these patients.

Risk factors for healthcare-associated infection in pediatric intensive care units: a systematic review

A systematic review of observational studies on risk factors for healthcare-associated infection in pediatric Intensive Care Units (ICU) was carried out. Studies indexed in MEDLINE, LILACS, Cochrane, BDENF, CAPES databases published in English, French, Spanish or Portuguese between 1987 and 2006 were included and cross references added. Key words for search were 'cross infection' and 'Pediatric Intensive Care Units' with others sub-terms included. 11 studies were selected from 419 originally found: four studies had healthcare-associated infection as the main outcome without a specific site; three articles identified factors associated with lower respiratory tract infection (pneumonia or tracheitis); three articles were concerned with laboratory-confirmed bloodstream infection; and a single retrospective study analyzed urinary tract infection. The production of evidence on risk factors Paediatric ICU has not kept up the same pace of that on adult - there are few studies with adequate design and statistical analysis. The methodological diversity of the studies did not allow for a summarized measurement of risk factors.

Isolated head injury in children affects the neutrophil function and lymphocyte count

BACKGROUND

Outcomes of treatment of postinjury complications remain unsatisfactory and research continues into the impact of trauma on innate and acquired immunity. The aim of our study was to describe how head injury affects a child's immunity by measuring the neutrophil function and lymphocytes subsets.

METHODS

The peripheral blood of 16 children with head trauma (Glasgow Coma Score < or =9) was examined. The blood samples were collected on the first and on the seventh day after trauma. The production of reactive oxygen species (ROS), spontaneous and stimulated, the expression of CD11b, and the lymphocyte subpopulations were measured. The blood of healthy children was studied as control. The impact of endotracheal intubation on the examined parameters was analyzed as well.

RESULTS

Head trauma leads to the increase of leukocytosis; the total production of ROS by peripheral blood neutrophils does not change after head injury. Correction of the results according to the number of neutrophils revealed a significant decrease in ROS production by a single neutrophil. The expression of adhesion molecule CD11b did not change. Head injury in children causes the decrease of the total lymphocyte count, CD3, CD4, CD8, and natural killer cells count on both the first and the seventh postinjury day. On the seventh day the significant decrease of natural killer cells subset was observed. The CD4/CD8 ratio increased from 1.5 (the first day) to 2.5 (the seventh day). The intubation did not affect the examined parameters.

CONCLUSIONS

After head injury, total ROS production and adhesion molecule CD11b expression remained unchanged when compared with control. The study did not demonstrate evidence for neutrophil activation in patients with head injuries. The total lymphocyte count was found to be decreased and the composition of lymphocytes' subsets was deeply impaired.

One year study of bacterial and fungal nosocomial infections among patients in pediatric intensive care unit (PICU) in Alexandria

A 1-year prospective and observational study included all admissions (n=216) until 48 h after discharge to Alexandria PICU between first of May 2003 and end of April 2004. Cultures for bacteria and fungi and antibiotic sensitivity tests (19 antibiotic using Bauer-Kirby disc diffusion method) were obtained (blood, stool, urine and cerebrospinal fluid, if needed) and repeated on suspicion of NIs. All cannulae, endotracheal tube (ET) aspirates and tips, nasogastric tubes and different catheters were cultured. All PICU health care workers (HCWs) were subjected to throat and under-finger nails cultures as well as inanimate objects, both on bimonthly basis. The referral place (ward or emergency), PRISM III score, length of stay (LOS) and fate were recorded. Amongst those patients whose age ranged from 1 to 23 months, 23 per cent had NIs with infection rates of 40/1000 days. Significantly high rates of mortality, LOS and PRISM III score were encountered among patients with NIs (52 per cent vs 30 per cent; 9.4+/-4.8 vs 5.4+/-2.2 days; 14.4+/-7 vs 11.8+/-6 respectively). The descending order of frequency of NIs was blood stream infection (BSI) (47 per cent), urinary tract infection (UTI) (28 per cent), ventilator-associated pneumonia (VAP) (16 per cent) and meningitis (9 per cent). Gr-ve bacilli accounted for 76.7 per cent; Gr+ve cocci 13.3 per cent (with satisfactory sensitivity to cefepime, imipenem and meropenem) and Candida albicans 10 per cent of all NIs. The rate of NIs/1000 device days were: 18.7 per cent for BSI, 10.9 per cent for VAP and 25.5 per cent for UTI. Vulnerable age groups were >6 m for VAP and <6 m for meningitis. Multiple logistic regression analysis identified LOS, PRISM III score and referral from wards a predictors of NI acquisition (odd ratio and 95 per cent confidence interval: 1.537, 1.423-1.659; 1.073, 1.041-1.105 and 0.269, 0.178-0.406 respectively). Bimonthly cultures for HCWs isolated coagulase-ve Staphylococci, while inanimate objects isolated diphtheroids and Candida albicans.

CONCLUSION

NIs rate was high (23 per cent) mainly due to severity of condition on admission as shown by high PRISM III score value, the high PRISM III score, LOS and referral from wards were predictors of acquisition of NIs and there is a high incidence of Candida albicans infection (10 per cent of NIs).

Interleukin-6 treatment reverses apoptosis and blunts susceptibility to intraperitoneal bacterial challenge following hemorrhagic shock*

BACKGROUND

Resuscitation from hemorrhagic shock (HS) predisposes to subsequent infections. Susceptibility to infection following sepsis has been attributed to apoptosis. Interleukin (IL)-6 has been shown to have antiapoptotic properties and to decrease postresuscitation inflammation in rodent and porcine models of HS.

OBJECTIVE

The objective was to determine if HS increases host susceptibility to infection, if IL-6 administration at resuscitation reduces this susceptibility, and if changes in susceptibility to infection are accompanied by parallel changes in apoptosis.

SUBJECTS AND INTERVENTIONS

Mice were randomized into three groups-HS, sham, and no-surgery control-and each group was further randomized to receive either IL-6 (3 microg/kg; HS/IL-6) or placebo (HS/P) at the start of resuscitation. In the HS-infection protocol, each mouse was challenged intraperitoneally the next day with a sublethal dose of Staphylococcus aureus (4x107 colony-forming units); 24 hrs later, the peritoneal cavity was lavaged and the major organs were harvested for culture. In the HS-apoptosis protocol, the livers were harvested the next day and analyzed by means of the terminal deoxynucleotidyl transferase dUTP-biotin nick-end-labeling (TUNEL) assay.

RESULTS

HS/P mice had a six- to eight-fold increase in total bacterial counts in comparison with sham and control mice that was attributable to a seven- to nine-fold increase in liver burden. IL-6 treatment reduced total and liver bacterial counts in HS/IL-6 mice by 62% and 69%, respectively, to levels statistically indistinguishable from IL-6-treated sham and control mice. The number of TUNEL-positive liver cells in the HS/P group was increased eight-fold vs. that in the sham group (p=.002); IL-6 resuscitation completely reversed the HS-induced increase in TUNEL-positive cells in the HS/IL-6 group (p=.002).

CONCLUSIONS

IL-6 treatment at resuscitation eliminated the HS-mediated increase in total and liver bacterial burden and protected the liver from HS-induced apoptosis. Reduced liver apoptosis may explain the ability of IL-6 to blunt the HS-induced increase in susceptibility to bacterial challenge.

Incidence study of nosocomial infection in pediatric trauma patients

In this article we intend to describe the epidemiological profile of nosocomial infection in pediatric patients with multiple trauma. We conducted a prospective study from July to November 2003 in a pediatric teaching hospital in Barcelona. We used US Centers for Disease Control and Prevention standard criteria to define nosocomial infection. Of the 121 patients included in the study, 33% had at least one episode of nosocomial infection, with an incidence rate of 9.9 infections per 100 admissions and 1.1 infections per 100 patient-days. The most frequent episode of nosocomial infection was bacteremia. Coagulase-negative staphylococci were the most common pathogens. Nosocomial infection rates per 100 device-days were 3.2 for bacteremia, 1.6 for respiratory infection and 1.0 for urinary tract infection. These findings suggest the need to evaluate infection control measures aimed at reducing the morbidity associated with infections.

Infection control: avoiding the inevitable

Infection, while a major cause of morbidity, should not be considered an inevitable consequence of injury. Good aseptic technique, compulsive attention to detail, and thorough understanding of the points addressed in the following list of critical points are the best guarantee that infection will not add avoidable morbidity to misfortune. Critical points regarding infectious problems in care of the injured child: 1. Polymicrobial infection is the rule with 50% of isolates being mixed aerobic and anaerobic bacteria. 2. It is a misnomer to consider antibiotic use in a pediatric trauma victim as prophylactic. Antimicrobials used in this setting are best considered adjunctive. 3. The major indication for anti-infective therapy in pediatric trauma is an injury with a high probability of infection. 4. Antibiotics do not sterilize the wound or body cavity; they limit bacterial proliferation, thereby supplementing effective immune control. 5. Available studies suggest that 24 hours is as efficacious as a longer treatment duration in a purely adjunctive mode. 6. In bites inflicted by dogs and cats, Pasturella species are frequent. 7. Human bites may result in infection by Eikenella corrodens. 8. Based on this bacteriology, adjunctive intravenous ampicillin sulbactam or oral amoxicillin clavulanate are recommended for human and animal bites. 9. Tetanus prophylaxis is indicated in all significant soft tissue injuries. 10. Risk of osteomyelitis correlates directly with the extent of the associated soft tissue injury and vascular compromise. 11. The majority of infectious complications in the injured child are not a consequence of the injury itself, but rather in the treatment thereof. 12. In the injured child the most common nosocomial infection is lower respiratory followed by primary blood stream and the urinary tract. 13. The management of nosocomial pneumonia in the injured child is based on the time of diagnoses. Early evidence of pulmonary infection requires treatment with a third generation cephalosporin with or without an antistaphylococcal penicillin. Late pneumonia is treated with an aminoglycoside with or without an antipseudomonal added. 14. Catheter related infection is, in the injured child, overwhelmingly gram positive with coagulase negative staphlococcal species accounting for 30-60% of isolates. Staphlococcus aureus is responsible for an additional 15-20%. 15. The role of antibiotics in the prevention of catheter related meningitis is controversial. Recent adult studies suggest no advantage to their routine use. If utilized, they should only be employed prophylactically and not continued throughout the monitoring period. 16. Lack of response to treatment of sepsis may represent an inappropriate antimicrobial agent, improper dosage, inability to achieve adequate levels at the site of infection. (eg, CSF) fungal pathogen, and/or ongoing contamination or undrained purulent focus.