An overview of nosocomial infections, including the role of the microbiology laboratory

Prevalence and Risk Factors of Healthcare-Associated Infections among Hospitalized Pediatric Patients: Point Prevalence Survey in Thailand 2021

BACKGROUND

Healthcare-associated infections (HAIs) pose a grave threat to patient safety, morbidity, and mortality, contributing to antimicrobial resistance. Thus, we estimated the point prevalence, risk factors, types, and pathogens of HAIs in hospitalized pediatric patients.

METHODS

A point prevalence survey (PPS) of HAIs in hospitalized pediatric patients < 18 years old was conducted from March to May 2021. Outcomes, risk factors, and types of HAIs associated with HAIs in 41 hospitals across Thailand were collected.

RESULTS

The prevalence of HAIs was 3.9% (95% CI 2.9-5.0%) (56/1443). By ages < 1 month, 1 month-2 years, 2-12 years, and 12-18 years, the prevalence of HAIs was 4.2%, 3.3%, 4.1%, and 3.0%, respectively (p = 0.80). Significant independent risk factors were extended hospital length of stay (LOS) and central venous catheter (CVC) use. Compared to an LOS of <4 days, LOSs of 4-7 days, 8-14 days, and >14 days had adjusted odds ratios (aORs) of 2.65 (95% CI 1.05, 6.68), 5.19 (95% CI 2.00, 13.4), and 9.03 (95% CI 3.97, 20.5), respectively. The use of a CVC had an aOR of 2.45 (95% CI 1.06-5.66). Lower respiratory tract infection (LRTI) was the most common HAI type (46.4%: 26/56). The highest prevalence of HAIs was predominantly observed in LRTI diagnoses, with the highest among these in the <1 month age category at 2.3% (17/738).

CONCLUSION

The prevalence of HAIs in hospitalized pediatric patients was 3.9%. Extended LOS and use of CVC were HAI risk factors. A strategy for reducing LOS and reviewing insertion indications or the early planned removal of a CVC was implemented. The surveillance of HAIs stands as a cornerstone and fundamental component of IPC, offering invaluable insights that enhance hospital IPC interventions aimed at preventing HAIs.

Use of Biomaterials in 3D Printing as a Solution to Microbial Infections in Arthroplasty and Osseous Reconstruction

The incidence of microbial infections in orthopedic prosthetic surgeries is a perennial problem that increases morbidity and mortality, representing one of the major complications of such medical interventions. The emergence of novel technologies, especially 3D printing, represents a promising avenue of development for reducing the risk of such eventualities. There are already a host of biomaterials, suitable for 3D printing, that are being tested for antimicrobial properties when they are coated with bioactive compounds, such as antibiotics, or combined with hydrogels with antimicrobial and antioxidant properties, such as chitosan and metal nanoparticles, among others. The materials discussed in the context of this paper comprise beta-tricalcium phosphate (β-TCP), biphasic calcium phosphate (BCP), hydroxyapatite, lithium disilicate glass, polyetheretherketone (PEEK), poly(propylene fumarate) (PPF), poly(trimethylene carbonate) (PTMC), and zirconia. While the recent research results are promising, further development is required to address the increasing antibiotic resistance exhibited by several common pathogens, the potential for fungal infections, and the potential toxicity of some metal nanoparticles. Other solutions, like the incorporation of phytochemicals, should also be explored. Incorporating artificial intelligence (AI) in the development of certain orthopedic implants and the potential use of AI against bacterial infections might represent viable solutions to these problems. Finally, there are some legal considerations associated with the use of biomaterials and the widespread use of 3D printing, which must be taken into account.

Current Development of Thiazole-Containing Compounds as Potential Antibacterials against Methicillin-Resistant Staphylococcus aureus

The emergence of multi-drug-resistant bacteria is threatening to human health and life around the world. In particular, methicillin-resistant Staphylococcus aureus (MRSA) causes fatal injuries to human beings and serious economic losses to animal husbandry due to its easy transmission and difficult treatment. Currently, the development of novel, highly effective, and low-toxicity antimicrobials is important to combat MRSA infections. Thiazole-containing compounds with good biological activity are widely used in clinical practice, and appropriate structural modifications make it possible to develop new antimicrobials. Here, we review thiazole-containing compounds and their antibacterial effects against MRSA reported in the past two decades and discuss their structure-activity relationships as well as the corresponding antimicrobial mechanisms. Some thiazole-containing compounds exhibit potent antibacterial efficacy in vitro and in vivo after appropriate structural modifications and could be used as antibacterial candidates. This Review provides insights into the development of thiazole-containing compounds as antimicrobials to combat MRSA infections.

In silico and structural investigation of sulfonamides targeting VraSR two component system in methicillin-resistant Staphylococcus aureus

Drug-resistant Staphylococcus aureus strains are global health concerns. Several studies have shown that these strains can develop defences against cell wall antibiotics such as β-lactams, glycopeptides and daptomycin which target cell wall biosynthesis. The coordination of these responses have been associated with two component system (TCS) regulated by histidine kinase protein (VraS) and its cognate regulator VraR which influences the target DNA upon signal recognition. Computer-based screening methods, predictions and simulations have emerged as more efficient and quick ways to identify promising new compound leads from large databases against emerging drug targets thus allowing prediction of small select set of molecules for further validations. These combined approaches conserve valuable time and resources. Due to methicillin resistance, sulfonamide-derivative medications have been found to be effective treatment strategy to treat S. aureus infections. The current study used ligand-based virtual screening (LBVS) to identify powerful sulfonamide derivative inhibitors from an antibacterial compound library against VraSR signaling components, VraS and VraR. We identified promising sulfonamide derivative [compound 5: (4-[(1-{[(3,5-Dimethoxyphenyl)Carbamoyl]Methyl}-2,4-Dioxo-1,2,3,4-Tetrahydroquinazolin-3-Yl)Methyl]-N-[(Furan-2-Yl)Methyl]Benzamide)] with reasonable binding parameters of -31.38 kJ/mol and ΔGbind score of -294.32 kJ/mol against ATP binding domain of sensor kinase VraS. We further identified four compounds N1 (PCID83276726), N3 (PCID83276757), N9 (PCID3672584), and N10 (PCID20900589) against VraR DNA binding domain (VraRC) with ΔGbind energies of -190.27, -237.54, -165.21, and -190.88 kJ/mol, respectively. Structural and simulation analyses further suggest their stable interactions with DNA interacting residues and potential to disrupt DNA binding domain dimerization; therefore, it is prudent to further investigate and characterize them as VraR dimer disruptors and inhibit other promoter binding site. Interestingly, the discovery of drugs that target VraS and VraR may open new therapeutic avenues for drug-resistant S. aureus. These predictions based on screening, simulations and binding affinities against VraSR components hold promise for opening novel therapeutic avenues against drug-resistant S. aureus and present opportunities for repositioning efforts. These efforts aim to create analogs with enhanced potency and selectivity against two-component signaling systems that significantly contribute to virulence in MRSA or VRSA. These analyses contribute valuable insights into potential avenues for combating antibiotic-resistant S. aureus through computationally driven drug discovery strategies.Communicated by Ramaswamy H. Sarma.

Optimized preparation pipeline for emergency phage therapy against Pseudomonas aeruginosa at Yale University

Bacteriophage therapy is one potential strategy to treat antimicrobial resistant or persistent bacterial infections, and the year 2021 marked the centennial of Felix d'Hérelle's first publication on the clinical applications of phages. At the Center for Phage Biology & Therapy at Yale University, a preparatory modular approach has been established to offer safe and potent phages for single-patient investigational new drug applications while recognizing the time constraints imposed by infection(s). This study provides a practical walkthrough of the pipeline with an Autographiviridae phage targeting Pseudomonas aeruginosa (phage vB_PaeA_SB, abbreviated to ΦSB). Notably, a thorough phage characterization and the evolutionary selection pressure exerted on bacteria by phages, analogous to antibiotics, are incorporated into the pipeline.

Prevalence and risk factors of post-cholecystectomy surgical site infections

Objectives

The objectives of this study were to measure the prevalence of post-cholecystectomy surgical site infection and identify the associated risk factors and their association with its prevalence.

Method

A cross-sectional analytical study including all patients who underwent cholecystectomy in the period from January 2021 to March 2022. The data sheet was filled with records of the patients, and some questions were asked of the patients directly. Many risk factors were assessed and measured in their association with the development of postoperative SSI.

Results

One hundred seventy-two patients with a mean age of 46.41±13.37 participated in the study. Thirty-five (20.3%) of them were males, and 137 (79.7%) were females. Open cholecystectomy 121 (70.3%) was done more than laparoscopic cholecystectomy 51 (29.7%). The most common indication for cholecystectomy was found to be both cholecystitis and cholelithiasis (53.5%). Out of 172 patients, postoperative wound infection [surgical site infection (SSI)] developed in 29 (16.9%) patients. Of these, 8 (27.6%) were males, while 21 (72.4%) were females, with a mean age of 46.38 (SD=14.12) years. Prophylactic antibiotics intraoperatively and therapeutic antibiotics postoperatively were found to decrease the risk of developing SSI [P=0.005, odds ratio (OR)=0.073] (P=0.012, OR=0.153), respectively. However, hospital stay after surgery (<1 week) was also found to decrease the risk (P=0.001, OR=0.179).

Conclusions

The prevalence of post-cholecystectomy SSI is high despite a small sample size in comparison with other studies. Prophylactic antibiotics and short hospital stays have an important role in decreasing the risk of developing postoperative SSI.

Predicting Superficial Surgical Site Infections: A Study of the Risk Factors and an Assessment Scale From Western India

Introduction Superficial surgical site infections (SSSIs) are very common nosocomial infections that can complicate a range of surgeries, resulting in increased morbidity and mortality, and an overall decreased benefit of surgical interventions, along with exorbitant expenditure of healthcare resources. An assessment scale could help in the segregation of the high-risk patient population, and appropriate resources could be directed toward them. Methods A prospective observational study was carried out in a tertiary care hospital in Western India with 200 participants. Certain probable preoperative, intraoperative, and postoperative risk factors for SSSIs were assessed for significance of association, and each patient was given a score according to the assessment scale. The predictive power of the scale was calculated. Results Body mass index (BMI), preoperative laboratory investigations, and preoperative hospital stay showed a significant association with the complication. Clean-contaminated wounds had a higher incidence of postoperative SSSIs as compared to clean wounds. Postoperatively, fever and the presence of open drains predisposed the patient to complications. The assessment scale was found to have a positive predictive value of 40.94% and a negative predictive value (NPV) of 86.30%. Conclusion The factors that could significantly prevent the development of SSSIs are normal preoperative laboratory investigations, less than three days of preoperative hospital stay, and avoiding the use of open drains. The high NPV of the assessment scale means that it can be used as a screening tool to segregate high-risk patients.

Antibiotic choices among healthcare professionals for enterococcal bacteremia with patterns of resistance and risk factors of mortality, in settings of poor antibiotic stewardship program - a five-year retrospective cohort study

BACKGROUND

Enterococcal bacteremia has become prevalent in the recent decade, especially in hospitalized patients. Moreover, the rise in resistance patterns against antibiotic drugs regarding enterococci infection, such as cephalosporins, ampicillin and vancomycin, is prevailing. The major driving force behind this is the incongruous use of antibiotics with a minor contribution from environmental stressors which calls for vigilant and prudent administration of evidence-based antibiotics.

METHODS

A retrospective study was conducted from January 1 2017 until December 31 2021, at the tertiary care center, Dr Ziauddin Hospital in Karachi, Pakistan.

RESULTS

Our research revealed ampicillin resistance in 87 (63.5%), with an estimated 25 (18.8%) mortality. Male gender 19 (76%) and vancomycin resistance 13 (52%) were associated with increased mortality. Furthermore, appropriate antibiotic therapy reduced the risk of death compared with inappropriate and excessive use of antibiotics 10 (40%) vs. 15 (60%) vs. 20 (80%) respectively. Targeted therapy with amoxicillin/clavulanic acid was associated with lower mortality 1 (4%) and higher discharge rates 34 (32.1%). On Kaplan-Meier survival, targeted therapy with amoxicillin/clavulanic acid was associated with shorter hospital stays and prolonged survival. UTI was found as the most common source of enterococcal bacteremia 57 (41.6%), followed by respiratory 21 (15.3%) and intra-abdominal 13 (9.5%). In 26 (19%) patients, no identifiable source of infection was found.

CONCLUSION

Vancomycin resistance and male gender were found independent risk factors for mortality. The use of inappropriate antibiotics significantly increases mortality in these patients. The appropriate antibiotic therapy reduces the risk of death. Furthermore, overuse of antibiotics didn't reduce mortality; instead increased the financial burden and chances of developing multi-drug resistant strains of other organisms by increasing hospital stays of patients.

Surgical Site Bacterial Infection in a General Hospital, Al-Jouf Region, Saudi Arabia: A Retrospective Study

Background Surgical site infection (SSI) is a major healthcare problem with a great impact on patient morbidity, mortality, and healthcare cost all over the world. It accounts for 20% of healthcare-associated infections (HAIs), with higher frequency in low- and middle-income countries where it affects about 30% of the patients undergoing surgery. Aim The current study aims to assess the prevalence of SSI in a general hospital in Sakaka, Al-Jouf region, Saudi Arabia. The types of bacteria causing SSI were also determined. Subjects and methods A retrospective cross-sectional study was done by reviewing the hospital records of patients who got SSI during the period between 2020 and 2022. Data collection was done during 2022 and 2023 after taking ethical approval and permission from the hospital management. Results The number of patients who underwent surgical procedures during 2020, 2021, and 2022 were 689, 867, and 1119, respectively. Most of the cases were cholecystectomy and appendectomy. The cases that developed surgical site infection after cholecystectomy and/or appendectomy during 2021 and 2022 were 15.45% and 9.29% cases, respectively, and they were mainly associated with appendectomy. A culture and sensitivity test revealed methicillin-resistant Staphylococcus aureus (MRSA) and Klebsiella pneumonia. Nearly all patients have received ciprofloxacin for seven days and improved with treatment. Conclusion The number of cases that developed SSI has decreased gradually due to the application of infection control measures and strict follow-up.

Machine learning-based prediction of hospital prolonged length of stay admission at emergency department: a Gradient Boosting algorithm analysis

Objective

This study aims to develop and compare different models to predict the Length of Stay (LoS) and the Prolonged Length of Stay (PLoS) of inpatients admitted through the emergency department (ED) in general patient settings. This aim is not only to promote any specific model but rather to suggest a decision-supporting tool (i.e., a prediction framework).

Methods

We analyzed a dataset of patients admitted through the ED to the "Sant"Orsola Malpighi University Hospital of Bologna, Italy, between January 1 and October 26, 2022. PLoS was defined as any hospitalization with LoS longer than 6 days. We deployed six classification algorithms for predicting PLoS: Random Forest (RF), Support Vector Machines (SVM), Gradient Boosting (GB), AdaBoost, K-Nearest Neighbors (KNN), and logistic regression (LoR). We evaluated the performance of these models with the Brier score, the area under the ROC curve (AUC), accuracy, sensitivity (recall), specificity, precision, and F1-score. We further developed eight regression models for LoS prediction: Linear Regression (LR), including the penalized linear models Least Absolute Shrinkage and Selection Operator (LASSO), Ridge and Elastic-net regression, Support vector regression, RF regression, KNN, and eXtreme Gradient Boosting (XGBoost) regression. The model performances were measured by their mean square error, mean absolute error, and mean relative error. The dataset was randomly split into a training set (70%) and a validation set (30%).

Results

A total of 12,858 eligible patients were included in our study, of whom 60.88% had a PloS. The GB classifier best predicted PloS (accuracy 75%, AUC 75.4%, Brier score 0.181), followed by LoR classifier (accuracy 75%, AUC 75.2%, Brier score 0.182). These models also showed to be adequately calibrated. Ridge and XGBoost regressions best predicted LoS, with the smallest total prediction error. The overall prediction error is between 6 and 7 days, meaning there is a 6-7 day mean difference between actual and predicted LoS.

Conclusion

Our results demonstrate the potential of machine learning-based methods to predict LoS and provide valuable insights into the risks behind prolonged hospitalizations. In addition to physicians' clinical expertise, the results of these models can be utilized as input to make informed decisions, such as predicting hospitalizations and enhancing the overall performance of a public healthcare system.

Effective screening methods to prevent surgical site infections in orthopedic surgery: an observational study

BACKGROUND

The bacterial source of surgical-site infections (SSIs) can have either endogenous and/or exogenous origins, and some studies have revealed that endogenous transmission is an important pathway for SSIs in orthopedic surgery. However, since the frequency of SSIs is low (0.5-4.7%), screening all surgery patients is labor-intensive and cost-prohibitive. The goal of this study was to better understand how to improve the efficacy of nasal culture screening in preventing SSIs.

METHODS

Nasal cultures for 1616 operative patients over a 3-year period were evaluated for the presence of nasal bacterial microbiota and the species identity. We also investigated the medical factors that influence colonization and evaluated the ratio of agreement between nasal cultures and SSI-causing bacteria.

RESULTS

In a survey of 1616 surgical cases, 1395 (86%) were normal microbiota (NM), 190 (12%) were MSSA carriers, and 31 (2%) were MRSA carriers. The risk factors for MRSA carriers were significantly higher than the NM group in patients with a history of hospitalization (13 [41.9%], p = 0.015), patients who had been admitted to a nursing facility (4 [12.9%], p = 0.005), and patients who were > 75 years of age (19 [61.3%], p = 0.021). The incidence of SSIs was significantly higher in the MSSA group (17/190 [8.4%]) than the NM group (10/1395 [0.7%], p = 0.00). The incidence of SSIs in the MRSA group (1/31 [3.2%]) tended to be higher than that in the NM group, but there was no statistically significant difference (p = 0.114). The concordance rate between causative bacteria of SSI and species present in nasal cultures was 53% (13/25 cases).

CONCLUSIONS

The results of our study suggest screening patients with a history of past hospitalization, a history of admission in a long-term care facility, and older than 75 to reduce SSIs.

TRIAL REGISTRATION

This study was approved by the institutional review board of the authors' affiliated institutions (the ethics committee of Sanmu Medical Center, 2016-02).

Prevalence and Risk Factors of Surgical Site Infections in a Teaching Medical College in the Trichy District of India

Introduction Surgical site infection (SSI) remains a common and widespread problem, which contributes to significant morbidity and mortality, prolongs hospital stays, and consequently increases healthcare costs. The current study aimed to assess the prevalence of SSI and its associated risk factors among patients who underwent any surgical intervention in a tertiary care center in Trichy, Tamil Nadu, India. Methodology This was a hospital-based, cross-sectional study that was carried out over a period of one year in Trichy, Tamil Nadu, India. All adult patients of both genders older than 16 years who underwent surgery were included. Patients who underwent second surgery at the same site for any reason, patients on immunosuppressant therapy or immunodeficiency disease, patients on antibiotics already, and patients with infection elsewhere were excluded. After 48 hours of surgery, if there was evidence of wound infection, then the patient was considered to have SSI. The data obtained were analyzed using SPSS (Statistical Package for the Social Sciences) version 21 (IBM Corp., Armonk, NY). Results A total of 2076 patients underwent different types of surgeries. The prevalence of SSIs during the study period was 5.6% (n = 2076). SSIs were more common in abdominal surgeries (61.2%). Patients aged 16-24 years have a higher risk of getting SSI than other age groups (p = 0.040). Males have a higher risk of getting SSI than females (p = 0.022). Patients who underwent emergency surgery have a higher risk of getting SSI than those who underwent elective surgery (p = 0.025). Those with diabetes had a higher risk of getting SSI than those who were non-diabetics (p ≤ 0.0001). Conclusion SSIs were more common in abdominal surgeries. Patients who are male, younger in age, had emergency surgery, have diabetes, and have had a long hospital stay are at a higher risk of developing SSIs after any kind of surgery.

Assessment of Prevalence and Diversity of Antimicrobial Resistant Escherichia coli from Retail Meats in Southern California

Retail meat products may serve as reservoirs and conduits for antimicrobial resistance, which is frequently monitored using Escherichia coli as indicator bacteria. In this study, E. coli isolation was conducted on 221 retail meat samples (56 chicken, 54 ground turkey, 55 ground beef, and 56 pork chops) collected over a one-year period from grocery stores in southern California. The overall prevalence of E. coli in retail meat samples was 47.51% (105/221), with E. coli contamination found to be significantly associated with meat type and season of sampling. From antimicrobial susceptibility testing, 51 isolates (48.57%) were susceptible to all antimicrobials tested, 54 (51.34%) were resistant to at least 1 drug, 39 (37.14%) to 2 or more drugs, and 21 (20.00%) to 3 or more drugs. Resistance to ampicillin, gentamicin, streptomycin, and tetracycline were significantly associated with meat type, with poultry counterparts (chicken or ground turkey) exhibiting higher odds for resistance to these drugs compared to non-poultry meats (beef and pork). From the 52 E. coli isolates selected to undergo whole-genome sequencing (WGS), 27 antimicrobial resistance genes (ARGs) were identified and predicted phenotypic AMR profiles with an overall sensitivity and specificity of 93.33% and 99.84%, respectively. Clustering assessment and co-occurrence networks revealed that the genomic AMR determinants of E. coli from retail meat were highly heterogeneous, with a sparsity of shared gene networks.

Carbapenem-resistant Pseudomonas aeruginosa infections in critically ill children: Prevalence, risk factors, and impact on outcome in a large tertiary pediatric hospital of China

Background and aims

Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a major cause of healthcare-associated infections worldwide, but comprehensive study of clinical characteristics for CRPA infections among critically ill children remains limited in China. The objective of this study was to determine the epidemiology, risk factors, and clinical outcomes of CRPA infections among critically ill pediatric patients in a large tertiary pediatric hospital in China.

Methods

A retrospective case-control study of patients with P. aeruginosa infections was conducted in the three intensive care units (ICUs) of Shanghai Children's Medical Center from January 2016 to December 2021. All patients with CRPA infection in the ICUs were enrolled as case patients. Patients with carbapenem-susceptible P. aeruginosa (CSPA) infection were randomly selected as control patients in a ratio of 1:1. Clinical characteristics of those inpatients were reviewed through the hospital information system. Univariate and multivariate analyses were performed to evaluate risk factors associated with the development of CRPA infections and mortality of P. aeruginosa infections.

Results

A total of 528 cases of P. aeruginosa infection in the ICUs were enrolled in the 6-year study. The prevalence of CRPA and MDRPA (multidrug-resistance P. aeruginosa) was 18.4 and 25.6%, respectively. Significant risk factors related to CRPA infection were the length of hospitalization >28 days (OR = 3.241, 95% CI 1.622-6.473, p = 0.001), receiving invasive operations (OR = 2.393, 95% CI 1.196-4.788, p = 0.014) and a blood transfusion (OR = 7.003, 95% CI 2.416-20.297, p < 0.001) within 30 days before infection. Conversely, birth weight ≥2,500 g (OR = 0.278, 95% CI 0.122-0.635, p = 0.001) and breast nursing (OR = 0.362, 95% CI 0.168-0.777, p = 0.009) were significant protective factors against CRPA infections. The in-hospital mortality rate was 14.2%, and no difference in mortality was observed between patients with CRPA and CSPA infections. Platelet < 100 × 10⁹/L (OR = 5.729, 95% CI 1.048-31.308, p = 0.044) and serum urea <3.2 mmol/L (OR = 5.173, 95% CI 1.215-22.023, p = 0.026) were independent predictors for the mortality due to P. aeruginosa infection.

Conclusions

Our findings provide insights into CRPA infections among critically ill children in China. They provide guidance in identifying patients that may be at high risk for a resistant infection and emphasize the importance of antimicrobial stewardship and infection control in hospitals.

Nano-functionalization and evaluation of antimicrobial activity of Tinospora cordifolia against the TolB protein of Pseudomonas aeruginosa - An antibacterial and computational study

Introduction

Antibacterial drug resistance, brought on by the overuse of antibiotics, is one of the biggest threats to human health. It is crucial to consider cutting-edge strategies, such as herbal remedies, to control multidrug-resistant (MDR) bacteria.

Methods

This study evaluated the phytochemical, antioxidant and antibacterial properties of the various Tinospora cordifolia extracts. Functionalization of the isolated active compound was done using gold (Au) and silver (Ag) nanoparticles (NPs). Further, to understand the interaction of the isolated class, Cordifolisides, with its target, various in-silico methods were used.

Results and Discussion

The plant was reported from the Charaideo district of Assam, whose methanolic stem extract showed the maximum activity towards the nosocomial pathogen Pseudomonas aeruginosa. Consequently, the active compound was isolated and characterized as belonging to the class Cordifoliside using NMR. The AuNPs and AgNPs functionalized isolates showed enhanced antimicrobial activity against P. aeruginosa compared to the unfunctionalized isolate. The most reactive compound, Cordifoliside C was determined using Density Functional Theory (DFT) analysis, whose interactions with the TolB protein were studied using molecular docking methods, which revealed good binding interactions of Cordifoliside C with the TolB protein.

Conclusion

This study offers enormous potential for drug design and might be used as a pipeline to address the urgent problem of multidrug-resistance in bacteria. Graphical Abstract.

Evaluation of Polyphenolic Composition and Antimicrobial Properties of Sanguisorba officinalis L. and Sanguisorba minor Scop

The most widespread Sanguisorba species are Sanguisorba officinalis L. and Sanguisorba minor Scop. which are also found in the Romanian flora and classified as medicinal plants because of hemostatic, antibacterial, antitumor, antioxidant and antiviral activities. This study aimed to characterize and compare Sanguisorba species in order to highlight which species is more valuable according to phenolic profile and antimicrobial activity. Based on high-performance liquid chromatography equipped with photodiode array detection and mass spectrometry (electrospray ionization) (HPLC-DAD-MS (ESI⁺)) analysis, it was evident that the ethanol extract obtained from the leaves of S. minor Scop. contains the highest content of phenolic compounds at 160.96 mg/g p.s., followed by the flower and root extract (131.56 mg/g dw and 121.36 mg/g dw, respectively). While in S. officinalis, the highest amount of phenols was recorded in the root extract (127.06 mg/g), followed by the flower and leaves extract (102.31 mg/g and 81.09 mg/g dw, respectively). Our results show that among the two species, S. minor Scop. is richer in phenolic compounds compared with the S. officinalis L. sample. In addition, the antimicrobial potential of each plant organ of Sanguisorba species was investigated. The ethanol extract of S. minor Scop. leaves exhibited better antibacterial activity against all of the bacteria tested, especially on Staphylococcus aureus, with an inhibition zone of 15.33 ± 0.83 mm. Due to the chemical composition and antimicrobial effect, the Sanguisorba species can be used as food supplements with beneficial effects on human health.

Plasmid parB contributes to uropathogenic Escherichia coli colonization in vivo by acting on biofilm formation and global gene regulation

The endogenous plasmid pUTI89 harbored by the uropathogenic Escherichia coli (UPEC) strain UTI89 plays an important role in the acute stage of infection. The partitioning gene parB is important for stable inheritance of pUTI89. However, the function of partitioning genes located on the plasmid in pathogenesis of UPEC still needs to be further investigated. In the present study, we observed that disruption of the parB gene leads to a deficiency in biofilm formation in vitro. Moreover, in a mixed infection with the wild type strain and the parB mutant, in an ascending UTI mouse model, the mutant displayed a lower bacterial burden in the bladder and kidneys, not only at the acute infection stage but also extending to 72 hours post infection. However, in the single infection test, the reduced colonization ability of the parB mutant was only observed at six hpi in the bladder, but not in the kidneys. The colonization capacity in vivo of the parB-complemented strain was recovered. qRT-PCR assay suggested that ParB could be a global regulator, influencing the expression of genes located on both the endogenous plasmid and chromosome, while the gene parA or the operon parAB could not. Our study demonstrates that parB contributes to the virulence of UPEC by influencing biofilm formation and proposes that the parB gene of the endogenous plasmid could regulate gene expression globally.

Non-invasive biomedical sensors for early detection and monitoring of bacterial biofilm growth at the point of care

Bacterial infections have long been a serious global health issue. Biofilm formation complicates matters even more. The biofilm's extracellular polymeric substances (EPSs) matrix protects bacteria from the host's immune responses, yielding strong adhesion and drug resistance as the biofilm matures. Early bacterial biofilm detection and bacterial biofilm growth monitoring are crucial to treating biofilm-associated infections. Current detection methods are highly sensitive but not portable, are time-consuming, and require expensive equipment and complex operating procedures, limiting their use at the point of care. Therefore, there is an urgent need to develop affordable, on-body, and non-invasive biomedical sensors to continuously monitor and detect early biofilm growth at the point of care through personalized telemedicine. Herein, recent advances in developing non-invasive biomedical sensors for early detection and monitoring bacterial biofilm growth are comprehensively reviewed. First, biofilm's life cycle and its impact on the human body, such as biofilm-associated disease and infected medical devices, are introduced together with the challenges of biofilm treatment. Then, the current methods used in clinical and laboratory settings for biofilm detection and their challenges are discussed. Next, the current state of non-invasive sensors for direct and indirect detection of bacterial biofilms are summarized and highlighted with the detection parameters and their design details. Finally, commercially available products, challenges of current devices, and the further trend in biofilm detection sensors are discussed.

Pattern of Post-Operative Infections Among Oral Cavity Cancer Patients in a Tertiary Care Cancer Centre: A Prospective Study

Surgical site infections (SSIs) constitute a major problem among patients who undergo surgery for oral cancer and remain a substantial cause of morbidity, prolonged hospitalization and death. The aim of this study was to assess the microbial spectrum of post-operative wound infections and to assess the outcome of appropriate antibiotic usage in patients who underwent surgery for oral cancer. This was a prospective observational study done in a tertiary care cancer hospital. Patients who underwent surgery for cancers of the oral cavity during the period January 2014 to December 2016 were included in the study. The spectrum of infections, risk factors, microbial profile, antibiotic susceptibility pattern, treatment given and outcome were assessed. A total of 1431 patients who underwent surgery for cancers of the oral cavity during the study period were followed up. SSIs were noticed in 118 (8%) post-operative cases. This included 55 (76.4%) incisional SSIs and 17 (23.6%) organ/space SSIs. Culture of the surgical site in 72 infected patients yielded a total of 122 isolates. Thirty patients (41.6%) had polymicrobial infections. Gram-negative bacterial isolates (70.5%) outnumbered gram-positive bacterial isolates (27%). Majority of the patients (48 patients-66.6%) were in stage IV disease. Successful management of patients with bacterial infections depends on early identification of bacterial pathogens and selection of an effective antibiotic against the organism. Judicial use of antibiotics is also very essential to prevent the development of drug resistance.

Prevalence and microbiological and genetic characteristics of multidrug-resistant Pseudomonas aeruginosa over three years in Qatar

OBJECTIVES

Antimicrobial resistance (AMR) is a global priority with significant clinical and economic consequences. Multidrug-resistant (MDR) Pseudomonas aeruginosa is one of the major pathogens associated with significant morbidity and mortality. In healthcare settings, the evaluation of prevalence, microbiological characteristics, as well as mechanisms of resistance is of paramount importance to overcome associated challenges.

METHODS

Consecutive clinical specimens of P. aeruginosa were collected prospectively from 5 acute-care and specialized hospitals between October 2014 and September 2017, including microbiological, clinical characteristics and outcomes. Identification and antimicrobial susceptibility test were performed using the BD Phoenix identification and susceptibility testing system, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), and minimum inhibitory concentration (MIC) test strips. Overall, 78 selected MDR P. aeruginosa isolates were processed for whole-genome sequencing (WGS).

RESULTS

The overall prevalence of MDR P. aeruginosa isolates was 5.9% (525 of 8,892) and showed a decreasing trend; 95% of cases were hospital acquired and 44.8% were from respiratory samples. MDR P. aeruginosa demonstrated >86% resistance to cefepime, ciprofloxacin, meropenem, and piperacillin-tazobactam but 97.5% susceptibility to colistin. WGS revealed 29 different sequence types: 20.5% ST235, 10.3% ST357, 7.7% ST389, and 7.7% ST1284. ST233 was associated with bloodstream infections and increased 30-day mortality. All ST389 isolates were obtained from patients with cystic fibrosis. Encoded exotoxin genes were detected in 96.2% of isolates.

CONCLUSIONS

MDR P. aeruginosa isolated from clinical specimens from Qatar has significant resistance to most agents, with a decreasing trend that should be explored further. Genomic analysis revealed the dominance of 5 main clonal clusters associated with mortality and bloodstream infections. Microbiological and genomic monitoring of MDR P. aeruginosa has enhanced our understanding of AMR in Qatar.

Risk factors of surgical site infection in elective laparotomy in a tertiary care center: an observational study

INTRODUCTION

Surgical site infections (SSI) encompass 20-25% of all hospital-acquired infections with their prevalence ranging from 2.5 to 41.9% across the world. Prevalence and risk factors of SSI vary greatly between countries and between healthcare institutions within a country. There is limited data on the pattern and risk factors of SSI in the Indian healthcare scenario. This study is an attempt to identify risk factors of SSI in patients who underwent elective laparotomy in the general surgery department of a tertiary care hospital in India.

METHODOLOGY

This is an observational cross-sectional retrospective study, conducted over 5 years from January 1, 2015, to December 31, 2019. A total of 112 patients who underwent elective laparotomy in the department of general surgery, were enrolled in the study. Data collection was done from hospital case records and discharge summaries of patients.

RESULTS AND DISCUSSION

Out of the 112 patients, a total of 16 patients (14.29%) developed surgical site infections. Preoperative serum total protein (W-465.500, P 0.012) and length of hospital stay (W=1235.000, P≤0.001) were found to have a significant association with surgical site infection. Age, gender, smoking, comorbidity, class of surgical wound and, preoperative albumin did not show any significant association with the development of SSI. Escherichia coli was the predominant organism isolated in culture.

CONCLUSION

Measures to curtail SSI can only be adopted after a thorough understanding of its prevalence and predictors. The characteristics and pattern of SSI will help identify prevalent organisms, their resistance pattern and will aid in formulating antibiotic policy tailor-made for the healthcare institution.

Mutations in AR or SRD5A2 Genes: Clinical Findings, Endocrine Pitfalls, and Genetic Features of Children with 46,XY DSD

OBJECTIVE

Androgen insensivity syndrome (AIS) and 5α-reductase deficiency (5α-RD) present with indistinguishable phenotypes among the 46,XY disorders of sexual development (DSD) that usually necessitate molecular analyses for the definitive diagnosis in the prepubertal period. The aim was to evaluate the clinical, hormonal and genetic findings of 46,XY DSD patients who were diagnosed as AIS or 5α-RD.

METHODS

Patients diagnosed as AIS or 5α-RD according to clinical and hormonal evaluations were investigated. Sequence variants of steroid 5-α-reductase type 2 were analyzed in cases with testosterone/dihydrotestosterone (T/DHT) ratio of ≥20, whereas the androgen receptor (AR) gene was screened when the ratio was <20. Stepwise analysis of other associated genes were screened in cases with no causative variant found in initial analysis. For statistical comparisons, the group was divided into three main groups and subgroups according to their genetic diagnosis and T/DHT ratios.

RESULTS

A total of 128 DSD patients from 125 non-related families were enrolled. Birth weight SDS and gestational weeks were significantly higher in 5α-RD group than in AIS and undiagnosed groups. Completely female phenotype was higher in all subgroups of both AIS and 5α-RD patients than in the undiagnosed subgroups. In those patients with stimulated T/DHT <20 in the prepubertal period, stimulated T/DHT ratio was significantly lower in AIS than in the undiagnosed group, and higher in 5α-RD. Phenotype associated variants were detected in 24% (n=18 AIS, n=14 5α-RD) of the patients, revealing four novel AR variants (c.94G>T, p.Glu32*, c.330G>C, p.Leu110=; c.2084C>T, p.Pro695Leu, c.2585_2592delAGCTCCTG, p.(Lys862Argfs*16), of these c.330G>C with silent status remained undefined in terms of its causative effects.

CONCLUSION

T/DHT ratio is an important hormonal criterion, but in some cases, T/DHT ratio may lead to diagnostic confusion. Molecular diagnosis is important for the robust diagnosis of 46,XY DSD patients. Four novel AR variants were identified in our study.

An Evaluation of the Effect of the Use of N95 Respirators by Surgical Teams on Early Surgical Site Infections in Orthopedic Cases

Background

Surgical site infections (SSIs) are seen in the postoperative period in orthopedic and traumatology clinics. Just as in all surgical clinics, SSIs lead to patient dissatisfaction with the results, prolong the length of stay in the hospital, and increase treatment costs. SSIs are known to occur as a result of wound contamination through inoculation of microorganisms found mainly in the air or in the surgical area. Because of the coronavirus disease 2019 pandemic, N95 masks have been widely used in the operating rooms of our hospital by nurses, residents, and surgeons since March 2020. This study aims to evaluate the effect of N95 respirator use by the surgical team on SSIs determined in patients operated on in our clinic compared to surgical mask use.

Methodology

In this retrospective study, the use of N95 respirators by the surgical team was compared with the use of surgical masks to evaluate the effect on SSIs in patients operated on in our clinic. Two groups were formed of patients operated on by the surgical team wearing surgical masks between February 2019 and February 2020 and those operated on with the surgical team using N95 respirators between March 2020 and March 2021. Each patient was diagnosed with postoperative SSIs by two different surgeons in the same clinic and by an infection clinic specialist based on clinical and laboratory findings.

Results

A total of 1,486 patients were examined; 729 patients in February 2019-February 2020 period (Group 1) and 757 in March 2020-March 2021 period (Group 2). In total, 124 and 104 patients were excluded from the first and second groups, respectively, for various reasons, including revision surgery, open fractures, diabetes, smoking, peripheral vascular disease, or other comorbidities that could affect infection rates. SSIs were determined in 35 patients in Group 1 and 13 patients in Group 2. The SSI rates in the second period in both types of procedures (arthroplasty and trauma surgeries) were determined to be significantly lower.

Conclusions

Because of the use of intraoperative N95 respiratory masks by surgical teams in orthopedics and traumatology procedures, the number of SSIs decreased significantly compared to the use of surgical masks.

Structural insights into DNA binding domain of vancomycin‐resistance‐associated response regulator in complex with its promoter DNA from Staphylococcus aureus

In Staphylococcus aureus, vancomycin-resistance-associated response regulator (VraR) is a part of the VraSR two-component system, which is responsible for activating a cell wall-stress stimulon in response to an antibiotic that inhibits cell wall formation. Two VraR-binding sites have been identified: R1 and R2 in the vraSR operon control region. However, the binding of VraR to a promoter DNA enhancing downstream gene expression remains unclear. VraR contains a conserved N-terminal receiver domain (VraR_N ) connected to a C-terminal DNA binding domain (VraR_C ) with a flexible linker. Here, we present the crystal structure of VraR_C alone and in complex with R1-DNA in 1.87- and 2.0-Å resolution, respectively. VraR_C consisting of four α-helices forms a dimer when interacting with R1-DNA. In the VraR_C -DNA complex structure, Mg²⁺ ion is bound to Asp194. Biolayer interferometry experiments revealed that the addition of Mg²⁺ to VraR_C enhanced its DNA binding affinity by eightfold. In addition, interpretation of NMR titrations between VraR_C with R1- and R2-DNA revealed the essential residues that might play a crucial role in interacting with DNA of the vraSR operon. The structural information could help in designing and screening potential therapeutics/inhibitors to deal with antibiotic-resistant S. aureus via targeting VraR.

Patient Safety Culture and Its Associated Factors: A Situational Analysis among Nurses in Katsina Public Hospitals, Northwest Nigeria

Background: Patient safety involves identifying, assessing, and managing patient-related risks and occurrences to improve patient care and reduce patient harm. In Nigeria, there is a lack of studies on patient safety culture, especially in the northern part of the country. This study aimed to determine the levels and factors that contribute to nurses’ negative perceptions of patient safety culture in public health facilities. Methodology: A total of 460 nurses were surveyed across 21 secondary health facilities using the Hospital Survey on Patient Safety Culture, and the response rate was 93.5%. Descriptive statistics and multiple logistic regression were used to analyze the data. Results: The results showed that 59.8% of the respondents were female, and 42.6% were within the age range of 30–39 years old. Most of them (48.3%) had spent 1–5 years working in the hospital. Three out of 12 composite measures had higher negative responses (staffing—30.5%, non-punitive response to error—42.8%, and frequency of events reported—43.1%). A multiple logistic regression analysis affirmed that all three variables, in addition to organizational learning, were significant associated with overall negative perceptions of patient safety culture, with 3.15, 1.84, 2.26, and 2.39 odds ratios, respectively. Conclusion: The results revealed that four critical areas of patient safety required improvement; therefore, intervention is recommended to minimize unnecessary patient harm and medical expenses.

The effect of first- and third-generation prophylactic antibiotics on hospitalization and medical expenditures for cardiac surgery

BACKGROUND

This study investigated the efficacy of first-generation (cefazolin) and third-generation (ceftizoxime) prophylactic antibiotics in patients undergoing cardiac surgery and the incidence of surgical site infections, hospitalizations, and medical costs.

METHODS

All adult patients (≥ 20 years) undergoing cardiac surgery at one hospital from January 01, 2009, to December 31, 2016, were included in this study. A single prophylactic antibiotic was administered at a dose of 1 g within one hour of the surgical incision and for three days after surgery at eight-hour intervals. After propensity score matching, 194 patients in each antibiotic prophylaxis group (first-generation vs third-generation) were analyzed. Among the 388 patients, the incidence of surgical site infections was compared according to the type of prophylactic antibiotic, and risk factors were evaluated by chi-squared tests followed by multivariate logistic regression analysis.

RESULTS

The incidence of deep surgical site infections was significantly lower in the first-generation group (5.7%) than in the third-generation group (16.5%). The pathogens isolated from the surgical infection sites were similarly distributed in both groups. However, the prevalence of highly infectious gram-positive bacteria was more than that of gram-negative bacteria (67% vs 23%). The preoperative hospitalization duration, mean operation time, and ventilator use time were similar in both groups, but the postoperative hospitalization duration was significantly shorter in the first-generation group (25.5 days) than in the third-generation group (29.8 days). In addition, the medical costs were lower in the first-generation group (20,594 USD) than in the third-generation group (26,488 USD).

CONCLUSION

In conclusion, the first-generation prophylactic antibiotic was better than the third-generation in reducing surgical site infection rates, hospitalization length, and medical expenditures.

Effects of Tylosin, a Direct-Fed Microbial and Feedlot Pen Environment on Phenotypic Resistance among Enterococci Isolated from Beef Cattle Feces

In two sequential replicates (n = 90 and n = 96 feedlot finisher cattle, respectively) we measured the impact of an Enterococcus faecium-based probiotic (DFM) and an altered feedlot pen environment on antimicrobial resistance among fecal enterococci in cattle fed (or, not fed) the macrolide tylosin. Diluted fecal samples were spiral-plated on plain and antibiotic-supplemented m-Enterococcus agar. In the first replicate, tylosin significantly (p < 0.05) increased the relative quantity of erythromycin-resistant enterococci. This effect was diminished in cattle fed the DFM in conjunction with tylosin, indicating a macrolide susceptible probiotic may help mitigate resistance. A similar observed effect was not statistically significant (p > 0.05) in the second replicate. Isolates were speciated and resistance phenotypes were obtained for E. faecium and E. hirae. Susceptible strains of bacteria fed as DFM may prove useful for mitigating the selective effects of antibiotic use; however, the longer-term sustainability of such an approach remains unclear.

Development and validation of a simple and sensitive LC-MS/MS method for the quantification of cefazolin in human plasma and its application to a clinical pharmacokinetic study

Cefazolin is widely used during surgery to prevent surgical site infections (SSIs). Although cefazolin redosing is often needed due to its short half-life, the appropriate redosing schedule remains controversial and there is limited information on cefazolin disposition following repeated doses during surgery. In parallel with an ongoing cefazolin redosing clinical study, we have developed and fully validated a simple and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of cefazolin in human plasma. A simple protein precipitation was used for sample preparation. MS/MS analysis was performed using multiple reaction monitoring (MRM) under a positive ionization mode. The lower limit of quantification (LLOQ) for cefazolin was evaluated at 0.25 µg/mL and a linearity ranging from 0.25 to 300 µg/mL. Accuracy was ≤ 114.3% for quality controls and ≤ 118.2% for LLOQ; intra-day and inter-day precision ranging from 1.9% to 14.2% for all quality controls and LLOQ. Matrix effect, extraction recovery, stability testing, dilution integrity, hemolysis effects and whole blood stability have all been investigated. A total of 17 parameters were validated and passed their validation criteria. The method was applied in the quantification of cefazolin in clinical plasma samples and was able to successfully determine the concentrations in patients undergoing various surgeries. In comparison with other prior published methods, our method has a simple sample preparation combined with a short analysis run time, a wide dynamic range and low limit of quantification, and is a fully validated assay that abides by FDA guidance.

Synthesis, microbiological evaluation and structure activity relationship analysis of linezolid analogues with different C5-acylamino substituents

Antimicrobial resistance and lack of new antibiotics to treat multidrug-resistant (MDR) bacteria is a significant public health problem. There is a discovery void and the pipeline of new classes of antibiotics in clinical development is almost empty. Therefore, it is important to understand the structure activity relationships (SAR) of current chemical classes as that can help the drug discovery community in their efforts to develop new antibiotics by modifying existing antibiotic classes. We studied the SAR of the C5-acylaminomethyl moiety of the linezolid, an oxazolidinone antibiotic, by synthesizing 25 compounds containing various aromatic, heteroaromatic and aliphatic substitutions. Our findings suggest that this position is highly important for the function of this antibiotic class, since only smaller non-polar fragments are tolerated at this position while larger and polar ones lead to a decrease in activity compared to linezolid. Our findings have led us to construct a structure activity relationship, around the C5-acylaminomethyl moiety of linezolid, that provides valuable insight into the function of the oxazolidinone class of antibiotics.

Comparison of Efficacy of Povidone-Iodine, Ethanol, and an Aerosol Formulation of Silver Sulfadiazine in Controlling Microbial Burden on Sutures From Clean Surgeries

In the surgical suture, the implanted thread can be a source of microbial contamination. Implanted materials are frequently described as being substrates prone for biofilm development provoking surgical site infections. Treatment of postsurgical wounds with different topical antimicrobial agents is a current practice applied to every patient. However, to date, there is little evidence on the efficacy of different antiseptic treatments on suture materials in preventing environmental or skin bacterial adhesion and further infection. Here, the authors compared the ability of an aerosol formulation of silver sulfadiazine, vitamin A, and lidocaine (AF-SSD) and of two of the most frequently used topical treatments, povidone-iodine and ethanol, in eradicating or controlling the microbial contamination of suture threads in patients who have undergone clean surgeries. Postsurgical suture threads treated with AF-SSD showed a significantly reduced proportion of contaminated samples containing viable microbial cells compared with those treated with povidone-iodine or ethanol. Furthermore, those samples that were positive for bacterial growth showed a lesser number of viable cells in AF-SSD-treated sutures than those treated with povidone-iodine or ethanol. Confocal laser scanning microscopy showed that AF-SSD-treated postsurgical sutures presented significantly less attached microbial cells than povidone-iodine and ethanol, with scarce observable microbial cells on the surface of the suture. Taken together, the results suggest that treatment with AF-SSD is more effective than the other two antiseptics, and there is a potential for improvement in reducing the microbial burden of implanted materials such as the suture thread.

In vitro and in vivo evaluation of gentamicin sulphate-loaded PLGA nanoparticle-based film for the treatment of surgical site infection

The study focuses on the in vitro and in vivo evaluation of the developed gentamicin sulphate (GS)-loaded poly lactic-co-glycolic acid (PLGA) nanoparticle (PNP)-based pullulan film (PNP-F). Sterilization being an essential pre-requisite for the dosage form was carried out using ethylene oxide. Post-sterilization, PNP-F was evaluated for mechanical properties, percentage drug loading, antimicrobial effectiveness study, test for sterility and in vitro dissolution study using Strat-M® membrane. In vitro dissolution study revealed that GS gradually released from PNP-F and the highest cumulative percentage drug release was found to be 86.76 ± 0.03% at 192 h. Wound healing assay was performed to study the effect of PNP-F over migratory potential of dermal fibroblast cells (NIH-3T3) in the presence of micro-organisms, Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA). PNP-F inhibited the growth of PA and SA, allowing the growth of fibroblast cells indicating its suitability for application. In vivo study of surgical site was performed by superficial incision model in Wistar rats. Measurement of in vivo incision healing confirmed faster wound healing in the incision which received PNP-F compared to marketed cream containing GS. Graphical abstract.

Nosocomial Infection

OBJECTIVE

The first 70 years of critical care can be considered a period of "industrial revolution-like" advancement in terms of progressing the understanding and care of critical illness. Unfortunately, like the industrial revolution's impact on the environment, advancing ICU care of increasingly elderly, immunosuppressed, and debilitated individuals has resulted in a greater overall burden and complexity of nosocomial infections within modern ICUs. Given the rapid evolution of nosocomial infections, the authors provide an updated review.

DATA SOURCES AND STUDY SELECTION

We searched PubMed and OVID for peer-reviewed literature dealing with nosocomial infections in the critically ill, as well as the websites of government agencies involved with the reporting and prevention of nosocomial infections. Search terms included nosocomial infection, antibiotic resistance, microbiome, antibiotics, and intensive care.

DATA EXTRACTION AND DATA SYNTHESIS

Nosocomial infections in the ICU setting are evolving in multiple domains including etiologic pathogens plus novel or emerging pathogens, prevalence, host risk factors, antimicrobial resistance, interactions of the host microbiome with nosocomial infection occurrence, and understanding of pathogenesis and prevention strategies. Increasing virulence and antimicrobial resistance of nosocomial infections mandate increasing efforts toward their prevention.

CONCLUSIONS

Nosocomial infections are an important determinant of outcome for patients in the ICU setting. Systematic research aimed at improving the prevention and treatment of nosocomial infections is still needed.

Profiling of bacterial bloodstream infections in hematological and oncological patients based on a comparative survival analysis

Bloodstream infections (BSI) are a frequent complication in patients with hematological and oncological diseases. However, the impact of different bacterial species causing BSI and of multiple BSI remains incompletely understood. We performed a retrospective study profiling 637 bacterial BSI episodes in hematological and oncological patients. Based on the 30-day (30d) overall survival (OS), we analyzed different types of multiple BSI and grouped BSI-associated bacteria into clusters followed by further assessment of clinical and infection-related characteristics. We discovered that polymicrobial BSI (different organisms on the first day of a BSI episode) and sequential BSI (another BSI before the respective BSI episode) were associated with a worse 30d OS. Different bacterial groups could be classified into three BSI outcome clusters based on 30d OS: favorable (FAV) including mainly common skin contaminants, Escherichia spp. and Streptococcus spp.; intermediate (INT) including mainly Enterococcus spp., vancomycin-resistant Enterococcus spp., and multidrug-resistant gram-negative bacteria (MDRGN); and adverse (ADV) including MDRGN with an additional carbapenem-resistance (MDRGN+CR). A polymicrobial or sequential BSI especially influenced the outcome in the combination of two INT cluster BSI. The presence of a polymicrobial BSI and the assignment into the BSI outcome clusters were identified as independent risk factors for 30d mortality in a Cox multivariate regression analysis. The assignment to a BSI outcome cluster and the differentiated perspective of multiple BSI open new insights into the prognosis of patients with BSI and should be further validated in other patient cohorts.

Growth of Staphylococcus epidermidis on the Surface of Teatcups from Milking Parlours

The growth of two Staphylococcus epidermidis isolates (one biofilm-forming and one not) on teatcups for cattle (made of rubber) or sheep (made of silicone) were assessed in nine multiplicates for 24 h post-smearing on the teatcup surface. Staphylococci were smeared on an area of 0.0003142 m² on the material and their growth and expansion further on were monitored for 24 h. There were no differences in the frequency of recoveries between the two isolates (p > 0.82 for all comparisons). There were more recoveries from sheep teatcups than from cattle teatcups: 1280/1728 (74.1%) versus 942/1728 (54.5%), for both isolates (p < 0.0001). Significance was observed only 6 h to 15 h after smearing (p < 0.0001 for all comparisons). The median speed of linear dissemination of the isolates was 0.00000021 m s⁻¹ on cattle teatcups and 0.00000033 m s⁻¹ on sheep teatcups (p < 0.0001). The increased growth and faster expansion of staphylococci on silicone teatcups raise important points from a clinical viewpoint. The model could be used in the testing of staphylococcal growth in the material of milking parlours in various conditions.

Risk Factors for Enterococcal Intra-Abdominal Infections and Outcomes in Intensive Care Unit Patients

Background: To investigate the risk factors for enterococcal intra-abdominal infections (EIAIs) and the association between EIAIs and outcomes in intensive care unit (ICU) patients. Methods: We reviewed retrospectively the records of patients with intra-abdominal infections admitted to the Department of Critical Care Medicine at Nanfang Hospital, Southern Medical University, China, from January 2011 to December 2018. Patients with intra-abdominal infections were divided into enterococcal and non-enterococcal groups based on whether enterococci were isolated from intra-abdominal specimens. Results: A total of 431 patients with intra-abdominal infections were included, of whom 119 were infected with enterococci and 312 were infected with non-enterococci. Enterococci were isolated in 27.6% of patients, accounting for 24.5% (129/527) of all clinical bacterial isolates. Post-operative abdominal infection (adjusted odds ratio [OR], 2.361; p = 0.004), intestinal infection (adjusted OR, 2.703; p < 0.001), Mannheim Peritonitis Index score (MPI; adjusted OR, 1.052; p = 0.015), and use of antibiotic agents within the previous 90 days (adjusted OR, 1.880; p = 0.025) were associated with an increased risk of EIAIs. Compared with patients without enterococcal infection, ICU patients with enterococcal infection had a higher risk of failure of initial clinical therapy (49.6% vs. 24.2%; p < 0.001) and longer hospital stays (33 days [19, 48] vs. 18 days [12, 29]; p < 0.001). Enterococcal infection was associated with increased 28-day mortality, in-hospital mortality, and ICU mortality. However, no difference was found in length of ICU stay between the two groups. Additionally, there was no difference in ICU mortality, hospital mortality, or 28-day mortality in patients infected with enterococcus who did or did not receive empirical anti-enterococcal therapy. Conclusion: Post-operative abdominal infection, intestinal infection, MPI score, and use of antibiotic agents within the previous 90 days were independent risk factors for enterococcal infection. Enterococcal infection was associated with reduced short-term survival in ICU patients.

Antimicrobial Properties of the Ag, Cu Nanoparticle System

Microbes, including bacteria and fungi, easily form stable biofilms on many surfaces. Such biofilms have high resistance to antibiotics, and cause nosocomial and postoperative infections. The antimicrobial and antiviral behaviors of Ag and Cu nanoparticles (NPs) are well known, and possible mechanisms for their actions, such as released ions, reactive oxygen species (ROS), contact killing, the immunostimulatory effect, and others have been proposed. Ag and Cu NPs, and their derivative NPs, have different antimicrobial capacities and cytotoxicities. Factors, such as size, shape and surface treatment, influence their antimicrobial activities. The biomedical application of antimicrobial Ag and Cu NPs involves coating onto substrates, including textiles, polymers, ceramics, and metals. Because Ag and Cu are immiscible, synthetic AgCu nanoalloys have different microstructures, which impact their antimicrobial effects. When mixed, the combination of Ag and Cu NPs act synergistically, offering substantially enhanced antimicrobial behavior. However, when alloyed in Ag-Cu NPs, the antimicrobial behavior is even more enhanced. The reason for this enhancement is unclear. Here, we discuss these results and the possible behavior mechanisms that underlie them.

Los teléfonos móviles como potencial vehículo de infección en un entorno hospitalario

ResumenEl objetivo de este artículo es investigar el posible papel desempeñado por los teléfonos móviles como depósitos de colonización bacteriana y los factores de riesgo que ésta conlleva en un ambiente hospitalario. Entre enero de 2013 y marzo de 2014 examinamos a 226 miembros del personal de un hospital regional de Australia (146 médicos y 80 estudiantes de medicina). Los principales resultados de interés se relacionaron con los tipos de microorganismos y la cantidad de contaminación encontrados en los teléfonos móviles. Este estudio mostró la existencia de un alto nivel de contaminación bacteriana (n = 168/226, 74%) en los teléfonos móviles de los funcionarios de un hospital de atención terciaria, aislándose organismos similares en la mano dominante del personal y en sus teléfonos móviles. Mientras que la mayoría de los organismos aislados pertenecía a la flora cutánea normal, un pequeño porcentaje era potencialmente patógeno (n = 12/226, 5%). Además, se encontró que ser miembro subalterno del personal médico constituía un factor de riesgo para un importante crecimiento microbiano (OR 4.00, 95% CI 1.54, 10.37). Sólo 31% (70/226) de los participantes en el estudio informó que limpiaba sus teléfonos regularmente y sólo 21% (47/226) reportó que usa toallitas con alcohol para la limpieza de su teléfono. Este estudio demuestra que los teléfonos móviles son potenciales vehículos de bacterias patógenas en un ambiente hospitalario. Sólo una minoría de participantes informó que limpia su teléfono regularmente. Deberían elaborarse y aplicarse directrices de desinfección utilizando toallitas con alcohol.

Prospective Analysis of Hand Infection Rates in Elective Soft Tissue Procedures of the Hand: The Role of Preoperative Antibiotics

Background: The purpose of this study was to evaluate the efficacy of prophylactic antimicrobial prophylaxis in elective hand surgery in preventing postoperative infection. Methods: Between 2009 and 2012, we performed a multicenter trial in which patients undergoing elective hand surgeries were categorized into an antibiotic or control group depending on the center they were enrolled in. Surgical site infections were defined according to the Centers for Diseases Control and Prevention. Results: In total, 434 patients were included: 257 did not receive antibiotics (control) and 177 received antibiotics at a mean age of 61.0 years. In the control group, comorbidities were more common with 23.7% (61/257) in comparison to the antibiotics group with 14.1% (25/177). Only one surgical site infection in each group was identified. One wound was opened surgically, and an antimicrobial treatment was indicated in both cases. In addition, we observed four complications in the control group and three complications in the antibiotics group which required conservative management. No significant differences in the two cohorts in infection rate (0.006% vs 0.003%, χ² = 0.07, P > .05) and complication rate (2.8% vs 1.6%, χ² = 0.01, P > .05) were found. Conclusions: Our prospective multicenter trial showed no significant difference in infection rate in elective hand surgery whether antibiotics were administered preoperatively or not.

High Number of Door Openings Increases the Bacterial Load of the Operating Room

Background: Operating room (OR) traffic and door openings have emerged as potential modifiable risk factors for the development of surgical site infections. Methods: This study compared the microbial load of a Control OR without traffic versus a Simulated OR with the traffic in a typical orthopedic surgery case. Air particle counts and colony forming units (CFUs) were measured. A novel iOS app was developed to provide real-time door counts. Results: There were 1,862 particles >5.0 mcm in the Simulated OR compared with 56 in the Control OR. The CFUs from plates in the Simulated OR ranged from 4-22 (on brain heart infusion [BHI] agar), 2-266 (on mannitol salt agar [MSA]), and 1-19 (on Pseudomonas isolation agar [PIA]), while all plates in the Control OR grew 0-1 CFUs. Conclusions: High number of door openings leads to more airborne bacteria in the OR and viable bacterial on OR surfaces. The increased bacterial load throughout the OR was independent of distance from the door.

Correlation between Nosocomial Carriage of Vancomycin-Resistant Enterococci and Antimicrobial Use in Taiwan

A rapid increase of nosocomial vancomycin-resistant enterococci (VRE) from 23.3% in 2009 to 44.5% in 2018 among all the medical centers in Taiwan was found. The aim of the study was to explore the relationship between antimicrobial usage and prevalence of VRE. We conducted the study between January 2010 and December 2019 in a tertiary teaching hospital in Taiwan. Antibiotic consumption was expressed as defined daily doses (DDDs) per 1,000 patient-days (PDs). The trend in antibiotic consumption and VRE prevalence were analyzed by regression analysis with yearly data. Pearson's correlation analysis was used to determine the relationship between antibiotic consumption and the prevalence of VRE. The total consumption of antibiotics increased significantly from 450.6 DDDs/1,000 PDs in 2010 to 520.1 DDDs/1,000 PDs in 2019 (P = 0.013). Positive correlations were found between the prevalence of vancomycin-resistant Enterococcus faecium and the consumption of amoxicillin/clavulanate, vancomycin, and carbapenems, which included meropenem (P < 0.05). The increase in total VRE prevalence was significantly correlated with increased consumption of vancomycin and carbapenems, which included meropenem (P < 0.05). This 10-year study in a hospital demonstrated changes in antimicrobial use, which may have affected VRE prevalence in the hospital. We found a rise in nosocomial VRE prevalence was associated with the use of specific antimicrobial agents.

A comparative study on production of extracellular hydrolytic enzymes of Candida species isolated from patients with surgical site infection and from healthy individuals and their co-relation with antifungal drug resistance

BACKGROUND

Surgical site infection (SSI) is a crucial dilemma of surgery. Patients with SSIs not only face difficulty in treatment but also bear extra cost with high mortality rate. Resistant strains of Candida have emerged as an important nosocomial pathogen. Proteinase and phospholipase are exo- enzymes of Candida species, have importance with respect to their contribution in diseases. This study focused on prevalence of Candida species in surgical wound, their resistance to antifungal drugs, co-relation of these resistance with virulence potential of Candida species and comparison of production level of exo-enzymes of Candida species isolated from patients with SSIs and healthy individuals to highlights their role in SSIs.

RESULTS

A total of (n = 555) swab samples were investigated. (n = 450) samples were collected from patients with SSIs and (n = 105) were collected from healthy individuals. Samples were subjected for the identification of Candida species which were subsequently investigated for antifungal susceptibility, MICs and enzymatic activity of Candida species. Out of 128 strains of Candida spp. isolated from SSIs, 54(42.18%) were identified as C. albicans followed by C. glabrata 32(25%), C. parapsilosis 17(13.28%), C. krusei 13(10.16%) and C. tropicalis 12(9.38%). C. albicans isolates showed 100% susceptibility to voriconazole and amphotericin B followed by itraconazole 98% and fluconazole 89%. Out of 6 fluconazole resistant C. albicans 5(83.33%) were able to produce phospholipase while out of 48 fluconazole-susceptible strains 17(35.42%) were found to be phospholipase producer. Out of 54 C. albicans isolated from surgical wound 46(85.18%) and 49(90.74%) were found to be phospholipase and proteinase producer respectively, whereas out of 20 C. albicans isolates from healthy subjects 14(70%) produce proteinase and 12(60%) produce phospholipase. There were significant statistical differences found between the level of enzyme production by C. albicans, in relation to both sites (P = 0.014).

CONCLUSION

Study revealed that prevalence of Candida species is high in SSIs. Phospholipase and proteinase activity were more pronounced in Candida Species from surgical wound in contrast to species from healthy individuals suggests these enzymes may have been responsible for the severity of infection in surgical wound patients.

Are Stethoscopes, Coats, and Pagers Potential Sources of Healthcare Associated Infections?

We conducted a study to determine the rate of bacterial colonization of stethoscopes, coats, and pagers of residents at a pediatric residency training program as compared to that of badges, sleeves, and pagers of non-patient care staff (control group). Among 213 cultures obtained from 71 residents, 27 potential pathogens were isolated from 22 residents (27/213, 12.7%) as compared to 10 potential pathogens out of 162 samples obtained from 54 control participants (10/162, 6.2%) (P = .0375). The most common pathogen isolated from residents and control participants was methicillin sensitive Staphylococcus aureus (MSSA). The source of positive cultures among the residents was the stethoscope (8/22, 36.3%), pager (8/22, 36.3%), and coat sleeve (11/22, 50%). The rates of colonization with potential pathogens were higher among residents than control participants and about 12% of residents’ stethoscopes, coats and pagers were colonized with bacterial pathogens. These are potential sources of nosocomial transmission of pathogenic organisms.

LAW Trial - The Impact of Local Anesthetics Infiltration in Surgical Wound for Gastrointestinal Procedures (LAW): A Double-Blind, Randomized Controlled Trial

INTRODUCTION AND AIMS

Prior studies have suggested that infiltration of local anesthetics reduce the rate of surgical site infections (SSIs). Opioid usage has become an epidemic. Some analgesic modalities, such as epidural analgesia and transversus abdominis plane block are associated with shorter length of stay and lower opioid use. The aim of our study was to assess the relationship between local infiltration of bupivacaine with rates of SSI and pain control.

MATERIALS AND METHODS

We conducted a prospective, double-blinded randomized controlled trial in patients who underwent open major gastrointestinal procedures from July 2016 to June 2017. Patients were divided into two groups based on administration of 0.5% bupivacaine (n = 30) (group 1) or placebo (n = 30) (control group). Outcomes evaluated were SSI, postoperative opioid requirements and pain scores.

RESULTS

Patients in the bupivacaine group required a lower dose of epidural analgesia during the first 24 h (5.3 mcg/kg/h vs. 6.4 mcg/kg/h; p = 0.05). Opioid requirement was shorter in the bupivacaine group (3.5 ± 2.3 days vs. 5.7 ± 2.9 days; p = 0.01). No difference was found between groups in terms of SSI rates (0% vs. 6.7%, p = 0.49).

CONCLUSIONS

There is no clear association between bupivacaine infiltration and reduction of SSI rate according to our study. Wound bupivacaine infiltration is associated with a lower dose of epidural infusion and opioid requirements.

Biomimetic Functional Surfaces towards Bactericidal Soft Contact Lenses

The surface with high-aspect-ratio nanostructure is observed to possess the bactericidal properties, where the physical interaction between high-aspect-ratio nanostructure could exert sufficient pressure on the cell membrane eventually lead to cell lysis. Recent studies in the interaction mechanism and reverse engineering have transferred the bactericidal capability to artificial surface, but the biomimetic surfaces mimicking the topographical patterns on natural resources possess different geometrical parameters and surface properties. The review attempts to highlight the recent progress in bactericidal nanostructured surfaces to analyze the prominent influence factors and cell rupture mechanism. A holistic approach was utilized, integrating interaction mechanisms, material characterization, and fabrication techniques to establish inclusive insights into the topographical effect and mechano-bactericidal applications. The experimental work presented in the hydrogel material field provides support for the feasibility of potentially broadening applications in soft contact lenses.

Antioxidant and antibacterial effects of medicinal plants and their stick-type medicinal concentrated beverages

Nine medicinal plants and their stick-type medicinal concentrated beverages (SMCB-I and SMCB-II) with different combination ratio were evaluated on antioxidant, nitric oxide (NO) inhibitory, and antibacterial effects against pathogenic bacteria involved in respiratory system illnesses. Antioxidant activity was high in Syzygium aromaticum, Pueraria lobata, Plantago asiatica, and Kalopanax pictus which have higher contents of total phenolics and total flavonoids. The NO inhibitory activity was high in Syzygium aromaticum, Plantago asiatica, and Glycyrrhiza uralensis. Syzygium aromaticum, Plantago asiatica, Kalopanax pictus and Glycyrrhiza uralensis showed higher antibacterial activity than the other five medicinal plants against Staphylococcus aureus, Corynebacterium diphtheriae, and Mycobacterium sp. SMCB-II exhibited higher antioxidant, NO inhibitory, and antibacterial effects than SMCB-I, since Syzygium aromaticum, Pueraria lobata, and Kalopanax pictus were only used for the production of SMCB-II. The SMCBs would be expected to contribute to an easy-to-carry, easy-to-consume, and high value-added health beverage for the modern people.

Risk Factors for Carbapenem-Resistant Pseudomonas aeruginosa, Zhejiang Province, China

Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a public health concern worldwide, but comprehensive analysis of risk factors for CRPA remains limited in China. We conducted a retrospective observational study of carbapenem resistance in 71,880 P. aeruginosa isolates collected in Zhejiang Province during 2015–2017. We analyzed risk factors for CRPA, including the type of clinical specimen; the year, season, and region in which it was collected; patient information, including age, whether they were an outpatient or inpatient, and whether inpatients were in the intensive care unit or general ward; and the level of hospital submitting isolates. We found CRPA was more prevalent among isolates from patients >60 years of age and in inpatients, especially in intensive care units. In addition, specimen types and seasons in which they were collected were associated with higher rates of CRPA. Our findings can help hospitals reduce the spread of P. aeruginosa and optimize antimicrobial drug use.

Sepsis secondary to multifocal Enterococcus faecium infection: A case report

INTRODUCTION

Nosocomial Enterococcus faecium (E faecium) infections are common among immunocompromised patients; however, sepsis caused by E faecium is rarely encountered in the clinical setting.

PATIENT CONCERNS

A 69-year-old woman with a previous history of tuberculosis (TB), developed symptoms of recurrent fever, paroxysmal cough, and exertional dyspnea for over 2 months before she presented to the hospital.

DIAGNOSIS

The patient was initially misdiagnosed with recurrent TB, and did not respond to anti-TB therapy. Culture results of blood, endotracheal necrotic tissue, and urine confirmed a diagnosis of multifocal E faecium infection.

INTERVENTIONS

On definitive diagnosis, the patient received intensive antimicrobial combination treatment with linezolid, teicoplanin, caspofungin, and voriconazole on the basis of antimicrobial susceptibility results.

OUTCOMES

After transient improvement, the patient's condition deteriorated due to secondary infections, and the patient died after discharge against medical advice.

CONCLUSION

E faecium bacteremia may cause sepsis in immunocompromised patients, and has a high mortality rate. Careful pathogen detection and early initiation of treatment is crucial to good patient outcome.