The presence of skin bacteria in the sternal wound and contamination of implantation materials during cardiac surgery.

BACKGROUND: Sternal wound infections (SWIs) and aortic graft infections (AGIs) are serious complications after cardiac surgery. Staphylococcus aureus and coagulase-negative staphylococci are the most common causes of SWIs, whereas AGIs are less studied. AGIs may occur from contamination during surgery or postoperative haematogenous spread. Skin commensals, such as Cutibacterium acnes, are present in the surgical wound; however, their ability to cause infection is debated. AIM: To investigate the presence of skin bacteria in the sternal wound and to evaluate their potential to contaminate surgical materials. METHODS: Fifty patients undergoing coronary artery bypass graft surgery and/or valve replacement surgery at Örebro University Hospital from 2020 to 2021 were included. Cultures were collected from skin and subcutaneous tissue at two timepoints during surgery, and from pieces of vascular graft and felt that were pressed against subcutaneous tissue. The most common bacterial isolates were tested for antibiotic susceptibility with disc diffusion and gradient tests. FINDINGS: Cultures from skin had bacterial growth in 48% of patients at surgery start and in 78% after 2 h, and cultures from subcutaneous tissue were positive in 72% and 76% of patients, respectively. The most common isolates were C. acnes and S. epidermidis. Cultures from surgical materials were positive in 80-88%. No difference in susceptibility was found for S. epidermidis isolates at surgery start compared with after 2 h. CONCLUSION: The results suggest that skin bacteria are present in the wound and may contaminate surgical graft material during cardiac surgery.

Evidence-based optimisation of empirical antibiotic regimens in paediatric complicated appendicitis: a retrospective study of 94 patients.

BACKGROUND: Acute appendicitis is the most frequent surgical emergency in the paediatric population. Complicated appendicitis accounts for 30% of cases and is inextricably linked to postoperative infectious complications. A study at our institution showed that amoxicillin-clavulanate resistant Escherichia coli in complicated appendicitis was significantly linked to postoperative infectious complications. These findings led to a change in the empirical antibiotic protocol (amoxicillin-clavulanate changed to ceftriaxone + metronidazole as of 2017), intending to reduce postoperative infectious complications in complicated appendicitis in our institution. AIM OF THE STUDY: This study aimed to analyse the microbiology and resistance profiles of pathogens of complicated appendicitis at our institution since implementing the new antibiotic protocol and the postoperative infectious complications rate. METHODS: We designed a retrospective comparative cohort study. During the defined study period (01 January 2017 to 31 July 2020), medical records were analysed for cases of acute appendicitis, complicated appendicitis and postoperative infectious complications, retaining only those who fulfilled inclusion criteria. Postoperative outcomes, microbiology and antibiotic resistance of peritoneal swabs were analysed. RESULTS: During the study period, 95 patients presented with a complicated appendicitis, and 11 (12%) developed postoperative infectious complications. The most frequent pathogens found in complicated appendicitis were E. coli (66%), Streptococcus anginosus (45%), and Bacteroides fragilis (22%). Pseudomonas aeruginosa was present in 17% of complicated appendicitis. Pathogens involved in postoperative infectious complications mirrored the distribution found in complicated appendicitis without postoperative infectious complications. Antibiotic susceptibility analysis showed that 10 (15%) of E. coli strains were resistant to amoxicillin-clavulanate but sensitive to ceftriaxone + metronidazole, with only one strain responsible for causing a postoperative infectious complication. Six additional strains of E. coli (9%) were resistant to amoxicillin-clavulanate and our empirical antibiotic regimen but were not associated with an increase in postoperative infectious complications. Compared with our previous study, there was a decrease in postoperative infectious complications from 16% to 12%. Postoperative infectious complications caused by amoxicillin-clavulanate-resistant E. coli decreased from 28% to 9%. CONCLUSION: This retrospective study demonstrated a decrease in the rate of postoperative infectious complications due to amoxicillin-clavulanate-resistant E. coli in complicated appendicitis. These findings accentuate the need to implement evidence-based treatment protocols based on local microbiology profiles and resistance rates to optimise post-operative antibiotics in complicated appendicitis.

Infectious complications after surgery for perihilar cholangiocarcinoma: A single Western center experience.

BACKGROUND: The aim of this study was to analyze the risk factors for surgical infectious complications and the outcomes of patients undergoing surgery for perihilar cholangiocarcinoma according to the microbiological examinations. METHODS: Patients who underwent surgery for perihilar cholangiocarcinoma in the last decade were enrolled, and all clinical and microbiological data were collected from a retrospective monocentric database. Univariate and multivariate analyses were performed distinguishing patients who developed at least 1 surgical infectious complication (surgical site infections, acute bacterial cholangitis, bacteremia). RESULTS: A total of 98 patients were included. Among patients who developed surgical infectious complications (51%), many preoperative characteristics were significantly more frequent: American Society of Anesthesiologists score ≥3 (P = .026), neutrophil-to-lymphocyte ratio ≥3.4 (P = .001), endoscopic sphincterotomy (P = .032), ≥2 biliary drainage procedures (P = .013), acute cholangitis (P = .012), multidrug resistant (P = .009), and ≥3 microorganisms' detection (P = .042); whereas during the postoperative period, surgical infectious complications were associated to increased incidence of intensive care unit readmission (P = .031), major complications (P < .001), posthepatectomy liver failure (P = .005), ascites (P = .008), biliary leakage (P = .008), 90-day readmission (P = .003), and prolonged length of hospital stay (P < .001). At the multivariate analysis 3 independent preoperative risk factors for surgical infectious complications were identified: neutrophil-to-lymphocyte ratio ≥3.4 (P = .004), endoscopic sphincterotomy (P = .009), and acute cholangitis (P = .013). The presence of multidrug-resistance in the perioperative biliary cultures was related to postoperative multidrug-resistant species from all cultures (P < .001) and organ/space and incisional-surgical site infections (P ≤ .044). CONCLUSION: Infective complications after surgery for perihilar cholangiocarcinoma worsen the short-term outcomes. A careful microbiological surveillance should be carried out in all cases to prevent and promptly treat surgical infectious complications.

Kidney Transplantation From Deceased Donors With Bloodstream Infection: A Multicenter Retrospective Study.

BACKGROUND: The use of organs from donors with infection is limited because of the possibility of transmission. We aimed to investigate the transmission after deceased donor transplantation with bloodstream infection (BSI). METHODS: A retrospective study of patients undergoing kidney or pancreas transplantation at five tertiary centers in Korea from January 2009 and November 2019 was performed. We analyzed the outcomes after transplantation from deceased donors with BSI. RESULTS: Eighty-six recipients received transplantation from 69 donors with BSI. The most common isolated pathogens from donors were Gram-positive bacteria (72.0%), followed by Gram-negative bacteria (22.7%), and fungi (5.3%). Appropriate antimicrobial agents were used in 47.8% of donors before transplantation. Transmission occurred only in 1 of 83 recipients (1.2%) from bacteremic donors and 1 of 6 recipients (16.7%) from fungemic donors. One-year patient and graft survival was 97.5%and 96.3%, respectively. There was no significant difference in graft and patient survival between patients who received organs from infected donors and noninfected donors. CONCLUSION: Using organs from donors with bacteremia seems to be a safe option with low transmission risk. The overall prognosis of using organs from donors with BSI is favorable.

Infectious risks in patients treated with extracorporeal photopheresis for graft-versus-host disease: A retrospective cohort study.

BACKGROUND: Infections are common with significant mortality and morbidity in patients with graft-versus-host disease (GvHD). Extracorporeal photopheresis (ECP) is an advantageous treatment option for patients with GvHD because it is not immunosuppressive. The objective of this study was to assess the rate of infections and to determine risk factors in patients with GvHD. MATERIALS AND METHODS: In a single-center cohort, we retrospectively collected data on infectious episodes by evaluating the clinical records of patients with GvHD treated by ECP since 2011. RESULTS: A total of 47 patients were included in this study. At ECP initiation, there were 10 patients with acute GvHD and 37 with chronic GvHD. At the final follow-up, 200 infectious episodes were diagnosed in 91.5% of patients with an average follow-up of 25.9 months (ie, 1.97 infections per patient per year). Most episodes had positive outcomes as there was no death related to infections, and only six infections required long-term treatment. Higher dose of corticosteroids at the initiation of ECP was significantly associated with a shorter onset of the first infection (hazard ratio [HR] = 2.05; 95% confidence interval [CI] [1.17, 3.57]; P = .013). Unrelated donor transplants were significantly associated with a lower rate of infection (HR = 0.61; 95% CI [0.39, 0.95]; P = .028). CONCLUSION: The results of our study suggest that ECP is associated with a low infection rate and an optimal clinical efficacy. Thus, ECP is still a suitable treatment for GvHD. Yet, a future study with a larger cohort will be necessary to deepen the identification of risk factors for infection.

Antimicrobial Selection for Transurethral Procedures Across the United States: A State-by-State Antibiogram Evaluation.

OBJECTIVE: To evaluate optimal regimens for perioperative antimicrobial prophylaxis in transurethral procedures by examining antimicrobial susceptibility patterns in the United States. MATERIALS AND METHODS: Through several methods, we attempted to attain an antibiogram for each state. We focused on microbes known to cause infections after transurethral surgeries and antibiotics referred to in current or prior recommendations and compared susceptibility rates across states using Kruskal Walis tests and the Dwass, Steel, Critchlow-Fligner tests. We also examined susceptibility to (non-ceftazidime) third generation cephalosporins. RESULTS: Data is included from 40 states. For each microbe studied, there was significant variability in sensitivity to antibiotics studied. Current first line recommendations for antimicrobial prophylaxis include first generation cephalosporins with 82%, 80%, and 87% mean coverage for E coli, Proteus, and Klebsiella respectively and trimethoprim-sulfamethoxazole with 74%, 80%, and 93% coverage, respectively. Susceptibility to aminoglycosides is 91%, 92%, and 96%, respectively and to third generation cephalosporin, it is 92%, 99%, and 94%. CONCLUSION: Current first line recommended antimicrobials for prophylaxis in transurethral procedures provide overall poor predicted coverage based on our database of antibiograms. Alternatives exist that have higher predicted susceptibility, though clinical significance of this and risk of resultant antimicrobial resistance is unknown. Urologists should consider local patterns when selecting antimicrobial prophylaxis for their patients.

Oral/oesophageal candidiasis is a risk factor for severe infection after kidney transplantation.

AIM: Bacterial and fungal infections are serious, life-threatening conditions after kidney transplantation. The development of oral/oesophageal candidiasis after kidney transplantation is not a reported risk factor for subsequent severe infection. This study was performed to investigate the relationship between oral/oesophageal candidiasis after kidney transplantation and the development of subsequent infection requiring hospitalization. METHODS: This retrospective study included 522 consecutive patients who underwent kidney transplantation at Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital from 1 January 2010 to 1 February 2019. Ninety-five percentage of patients were living donor transplant recipients. Visual examination was performed to detect oral candidiasis, beginning immediately after kidney transplantation; upper gastrointestinal endoscopy was performed 8-10 months after kidney transplantation. Twenty-five patients developed candidiasis (Candida-onset group) and 497 did not (non-Candida-onset group). The follow-up periods were 67 (37-86) months in the Candida-onset group and 55 (34-89) months in the non-Candida-onset group. Severe infection was defined as bacterial or fungal infection requiring hospitalization; viral infections were excluded. RESULTS: Severe infection developed in 9/25 (36%) patients in the Candida-onset group and in 77/497 (15%) patients in the non-Candida-onset group (p = .006). Binomial logistic analysis revealed that Candida infection (odds ratio [OR] 2.53, 95% confidence interval [CI] 1.06-6.06; p = .037) and use of rituximab (OR 1.81, 95% CI 1.12-2.93; p = .016) were significant predictors of subsequent severe infection. CONCLUSION: Oral/oesophageal candidiasis is a risk factor for severe infection after kidney transplantation and suggests an over-immunosuppressive state, which should prompt evaluation of immunosuppression.

A CASE REPORT OF CHRONIC ENDOPHTHALMITIS SECONDARY TO AQUAMICROBIUMterrae.

PURPOSE: Chronic postoperative endophthalmitis is a known complication of cataract surgery. Here, we report a case of chronic endophthalmitis following uncomplicated cataract surgery secondary to the atypical bacterium Aquamicrobium terrae . METHODS: Retrospective case report of a single patient with endophthalmitis secondary to A. terrae. RESULTS: A 61-year-old healthy patient presented with recurrent iridocyclitis following uncomplicated cataract surgery. Repeated attempts to taper off topical steroid eyedrops were unsuccessful. Anterior chamber paracentesis cultures and vitrectomy cultures grew the same gram-negative bacillus, A. terrae , on six different occasions. The patient was treated initially with a series of intravitreal ceftazidime injections and adjuvant oral minocycline with recurrence of inflammation necessitating pars plana vitrectomy with intraocular lens removal and total capsulectomy. Inflammatory episodes recurred until residual capsule fragments were ablated using endoscopic vitrectomy. Since ablation over 18 months ago, no further recurrences have occurred and the patient has excellent visual outcome. CONCLUSION: A. terrae is a gram-negative bacillus recovered from polluted soil. This is the first case of postoperative endophthalmitis secondary to A. terrae and the first description of human infection caused by this newly identified microbe.

When amputation is not the end of the challenge: A successful therapy for osteomyelitis and soft tissue infection in a patient with type 1 diabetes.

Infection is a common complication in patients with diabetic foot ulcer, leading to lower extremities amputation and healing failure. In this article, we report the case of a 39-year-old man with diabetes who developed a severe soft tissue infection and osteomyelitis after experiencing a major amputation for wet gangrene of both the foot and the ankle.

Are Cutibacterium acnes present at the end of primary shoulder prosthetic surgeries responsible for infection? Prospective study.

The purpose of this study was to investigate if the C. acnes present at the end of a primary shoulder arthroplasty could be responsible for shoulder arthroplasty infection. Prospective study includes patients undergoing primary shoulder arthroplasty from January 2015 until December 2018. From all the patients included, 5 to 12 tissue samples were obtained and were specifically cultured to detect the presence of C. acnes. DNA was extracted from the C acnes isolated colonies and Whole Genome Sequencing (WGS) analysis was done. A cohort of 156 patients was finally included. In twenty-seven patients, the C. acnes was present at the end of the primary surgery. Two of these patients developed a C. acnes periprosthetic shoulder infection at 6 and 4 months after the primary surgery. WGS of C. acnes isolated colonies showed that all the revision-surgery isolates clustered near to the corresponding primary-surgery isolates compared to the other independent bacterial colonies. (99.89% of similarity). C. acnes present at the end of the primary surgery can be the cause of early or delayed periprosthetic joint infections in shoulder arthroplasty.

Resistance to Antibiotics in Plankton and Biofilm Cultures of Pseudomonas aeruginosa Clinical Strains.

Biofilms formed by Pseudomonas aeruginosa strains isolated from biomaterial of patients with implant-associated infection are characterized by much higher resistance to antibiotics of various classes than plankton cultures of these strains. The concentrations of antibiotics causing the death of 90% of P. aeruginosa biofilm (MIC90) was 2-6 µg/ml for fluoroquinolones, 267-356 µg/ml for cephalosporins, and 92-215 µg/ml for amikacin, which significantly (p<0.05) differed from MIC90 for plankton cultures that did not exceed 0.8 µg/ml for fluoroquinolones, 19 µg/ml for cephalosporins, and 3 µg/ml for amikacin. The degree of the microbial biofilm maturity also affected antibiotic resistance.

A 45-Year-Old Man With Acute Chest Pain, Fever, and Dyspnea After Tooth Extraction.

CASE PRESENTATION: A 45-year-old Japanese man underwent wisdom tooth extraction. He developed right chest pain 2 days later, followed by continuous fever with dyspnea 2 weeks after the tooth extraction, and then came to our hospital. He complained of cough and purulent sputum.

Prospective Activity of PLG0206, an Engineered Antimicrobial Peptide, on Chronic Periprosthetic Joint Infection Total Knee Arthroplasty Components Ex Vivo: The Knee Explant Analysis (KnEA) Study.

PLG0206 is an engineered antimicrobial peptide that has completed phase 1 clinical studies. A prospective study was completed on explanted implants from chronic periprosthetic joint infections (n = 17). At a concentration of 1 mg/mL for 15 min, there was a mean 4-log10 reduction (range, 1 to 7) in the bacterial CFU identified from the implants. IMPORTANCE Chronically infected prosthetics of the knee were exposed to PLG0206, an engineered antimicrobial peptide, at a concentration of 1 mg/mL for 15 min. A mean 4-log10 reduction (range, 1 to 7) in the number of bacteria occurred, which may translate to improved clinical outcomes for persons with prosthetic joint infection of the knee.

Case report of the first cured patient with Mycobacterium Chimaera infection following cardiac valve replacement in the mainland of China.

BACKGROUND: Mycobacterium chimaera infections subsequent to cardiac surgery are related to contaminated heater-cooler devices, with high mortality. Nevertheless, few studies have been reported in Asia. CASE PRESENTATION: We described the case of a 55-year-old man with Mycobacterium chimaera infection following cardiac surgery in the mainland of China. He was diagnosed with endocarditis caused by Mycobacterium chimaera subsequent to open heart surgery. Metagenomic next-generation sequencing (mNGS) and 16S rRNA gene PCR analysis were used to identify potential pathogens. The patient underwent redo valve replacement surgery and received combination therapy with azithromycin, ethambutol, linezolid, and amikacin. No signs of relapse were observed during the 11-month follow-up visit. CONCLUSIONS: This is the first documented case of Mycobacterium chimaera infection following cardiac surgery in the mainland of China and the first documented transnational imported case worldwide. Moreover, mNGS is a novel diagnostic technology that can guide antimicrobial therapy prior to obtaining fluid/tissue culture results for Mycobacterium chimaera, providing a new approach for the detection of potential Mycobacterium chimaera infection.

Recent Strategies to Combat Infections from Biofilm-Forming Bacteria on Orthopaedic Implants.

Biofilm-related implant infections (BRII) are a disastrous complication of both elective and trauma orthopaedic surgery and occur when an implant becomes colonised by bacteria. The definitive treatment to eradicate the infections once a biofilm has established is surgical excision of the implant and thorough local debridement, but this carries a significant socioeconomic cost, the outcomes for the patient are often poor, and there is a significant risk of recurrence. Due to the large volumes of surgical procedures performed annually involving medical device implantation, both in orthopaedic surgery and healthcare in general, and with the incidence of implant-related infection being as high as 5%, interventions to prevent and treat BRII are a major focus of research. As such, innovation is progressing at a very fast pace; the aim of this study is to review the latest interventions for the prevention and treatment of BRII, with a particular focus on implant-related approaches.

Population Pharmacokinetics and Dosing Optimization of Vancomycin in Pediatric Liver Transplant Recipients.

Methicillin-resistant Staphylococcus aureus infections are a significant cause of morbidity and mortality in pediatric liver transplant (LT) recipients. Physiological changes following LT may affect vancomycin pharmacokinetics; however, appropriate dosing to achieve sufficient drug exposure (i.e., 24-h area under the concentration-time curve [AUC24]/MIC ≥ 400) in pediatric LT recipients has not been reported. This retrospective pharmacokinetics study of LT recipients aged <18 years utilized data on patient characteristics with vancomycin concentrations and dosing information obtained from electronic medical records. Population pharmacokinetics analysis was conducted by nonlinear mixed-effects modeling with the Phoenix NLME software. Potential covariates were screened with univariate and multivariate analysis. Monte Carlo simulations were performed using the final model to explore appropriate dosing. The study included 270 pharmacokinetics profiles encompassing 1,158 concentrations measured in 161 patients. The median age was 13.3 (interquartile range, 7.6 to 53.5) months, serum creatinine (sCr) was 0.16 (0.12 to 0.23) mg/dl, and days from LT (DFLT) was 17 (6 to 31). Multivariate analysis demonstrated that lower sCr and shorter DFLT were associated with higher clearance. By post hoc estimation, the average clearance and volume of distribution were 0.18 liters/h/kg and 1.01 liters/kg, respectively. The Monte Carlo simulations revealed that only 16% of patients achieved an AUC24/MIC of ≥400 with the assumed vancomycin MIC of 1 µg/ml. DFLT and sCr were significant covariates for vancomycin clearance in pediatric LT recipients. Standard vancomycin dosing may be insufficient, and higher or more frequent dosing may be required to achieve an AUC24/MIC of ≥400 in pediatric LT recipients with normal renal function. IMPORTANCE We evaluated vancomycin pharmacokinetics in pediatric LT recipients and developed a population pharmacokinetics model by considering various factors that might account for alterations in vancomycin pharmacokinetics. Our analyses revealed that lower serum creatinine levels and a shorter duration from the day of LT were associated with higher vancomycin clearance and led to subtherapeutic drug exposure. We also performed Monte Carlo simulations to determine the appropriate dosing strategy in pediatric LT recipients, which revealed that a standard vancomycin dosing might be insufficient and that higher or more frequent dosing might be necessary to achieve an AUC24/MIC of ≥400 in pediatric LT recipients with normal renal function. To the best of our knowledge, this is the first study to assess vancomycin pharmacokinetics in pediatric LT recipients by population pharmacokinetics analysis.

First Isolation of Exiguobacterium aurantiacum in Serbia.

Exiguobacterium aurantiacum is isolated from a variety of environmental samples but rarely from patients. The aim of the study was to represent isolation of unusual bacterial strains that could cause infection in patients. Final identification was performed using matrix-assisted description/ionization time-of-flight mass spectrometry (MALDI-TOF). Two isolates strains of E. aurantiacum were isolated, one isolate from distilled water used during surgical treatment and the second one from a patient with bacteremia after radical prostatectomy, both sensitive to all tested antimicrobials. Environmental strains could cause infection, especially in immunocompromised patients; therefore, rare bacteria testing is required, in which identification special assistance is provided by an automated system MALDI-TOF.

Case Report: Invasive Sinusitis due to Sporothrix Brasiliensis in a Renal Transplant Recipient.

Sporotrichosis is usually a subcutaneous infection caused by thermodimorphic fungi of the genus Sporothrix. The disease occurs worldwide, but endemic areas are located in tropical and subtropical regions. The epidemiology of sporotrichosis in Brazil is peculiar because of the cat's entry in the chain of transmission of this mycosis, associated with Sporothrix brasiliensis, the most virulent species in the genus. Sinusitis caused by Sporothrix species is unusual and may be underdiagnosed or confused with other fungal etiologies, like mucormycosis. We report a case of sinusitis due to a Sporothrix species in a 6-year renal transplant recipient. Direct examination of smears of exudate of the sinus specimen (aspirate, biopsy) revealed budding yeasts and cigar-shaped cells. Sporothrix was subsequently recovered from the patient's exudate culture and identified as S. brasiliensis using species-specific polymerase chain reaction, and she was successfully treated with antifungal therapy. Her parents also developed the disease a week later, both only cutaneous involvement. Sporotrichosis sinusitis is a rare disease, even in immunocompromised patients. Diagnosis is crucial, and benefits from good epidemiological history.

Infectious complications after tracheoplasty for congenital tracheal stenosis: a retrospective comparative study.

PURPOSE: The factors related to infectious complications after tracheoplasty for congenital tracheal stenosis (CTS) remain unclear; we, therefore, assessed these factors in this study. METHODS: We divided 47 patients who underwent slide tracheostomy and tracheal resection for CTS between May 2016 and December 2020 into an infected group and a non-infected group. Their characteristics were compared between groups. Results are presented as the median (range) or incidence. RESULTS: Infectious complications were observed in 12 patients (25.5%). Empyema and mediastinitis were seen in 5 cases (10.6%). There was a significant difference in the following factors in the infected and non-infected groups, respectively: weight, 5457 (2868-20,750) g and 6554 (2275-20,800) g (p = 0.025); surgical time, 575.5 (313-646) min and 349 (270-651) min (p < 0.001); extracorporeal circulation time, 303.5 (186-610) min and 216 (117-478) min (p = 0.001); and postoperative intubation time, 13 (7-28) days, and 6 (5-22) days (p < 0.001). Age, malnutrition, cardiovascular comorbidities, and preoperative methicillin-resistant Staphylococcus aureus detection were not significantly different between the two groups. CONCLUSION: There were a few serious infectious complications and no perioperative deaths. Attention should be paid to low body weight, long surgical and extracorporeal circulation time, and intubation time in relation to infectious complications.