Antibiotic Suppression Research Articles

Cutibacterium acnes periprosthetic joint infections.

Cutibacterium acnes (C. acnes; previously known as Propionibacterium acnes or P. acnes) periprosthetic hip and knee infections are under-reported. While culture contamination with C. acnes occurs, true infections are important to recognize and treat. We sought to describe the demographics and treatment outcomes of patients with C. acnes periprosthetic joint infections (PJIs) of the hip and knee. Patients with C. acnes PJI between January 2005 and December 2018 were retrospectively reviewed utilizing the institutional total joint registry. Patients with monomicrobial PJI and two or more positive cultures were considered to have true C. acnes PJI. Patients with polymicrobial infection or with only one positive culture were excluded. This resulted in 35 PJIs (21 hips and 14 knees); the patients' mean age was 63 years (35 to 84) and 15 (43%) were female. Mean follow-up was five years (1 to 14). The median time to positive culture was five days (IQR 5 to 6) and median synovial fluid cell count was 22,583 cells (IQR 15,200 to 53,231). The median ESR was 25 mm/hr (IQR 7 to 37), and CRP was 15 mg/l (IQR 3 to 29). Of the 35 PJIs, 18 (51%) were treated with chronic antibiotic suppression without surgical intervention, and the remainder were treated with two-stage exchange arthroplasty. The two-year survival free of any revision was 94%. Four patients failed treatment due to symptomatic infection, with three treated with two-stage exchange and one treated with irrigation and debridement with modular component exchange for a survival rate of 89% and 83% at two and five years, respectively. Laboratory evidence of C. acnes PJI in this cohort was typical compared to more conventional organisms. Cultures grew more quickly than previously thought in patients with C. acnes PJI. Treatment with two-stage exchange or chronic antibiotic suppression alone both had few treatment failures at mid-term follow-up.

Outcomes of the Subsequent Periprosthetic Joint Infection Revisions after a Failed Debridement, Antibiotics and Implant Retention: A Multicentric Study of 197 Patients.

Background: The impact of prior unsuccessful debridement, antibiotics, and implant retention (DAIR) procedures on subsequent revisions is uncertain, with conflicting evidence. Despite 85% consensus against the second DAIR procedure following the 2018 International Consensus Meeting, a 2020 study reported high success rates for the aforementioned second DAIR procedure. Methods: We conducted a multicenter observational study reviewing data from patients with failed DAIR procedures between 2005 and 2021. Patients diagnosed with acute periprosthetic joint infection of the hip or knee were included, following ICM criteria. Failure was defined as uncontrolled infection leading to additional surgeries, prosthesis removal, infection-related mortality, or suppressive antibiotic therapy. Demographic, surgical, and microbiological variables were recorded. Results: Among 197 patients from 10 institutions with failed DAIR procedures were included: 88 (44.7%) received a second DAIR, 21 (10.7%) underwent one-stage revision, and 77 (39.1%) underwent two-stage revision. One-stage revision success rate was 76.2%, with no identified predictors of failure. Two-stage revision success rate was 79.3%; factors associated with failure included polymicrobial infections (p = 0.025) and revision procedures (p = 0.049). Second DAIR success rate was 54.5%; factors associated with failure included non-specialized surgical teams in the first DAIR (p = 0.034), non-exchange of mobile components (p = 0.0038), polymicrobial infections (p = 0.043), and antibiotic resistance (p = 0.035). Excluding patients with these risk factors increased the success rate to 83.3%. Conclusions: Second DAIR's overall success rate was 54.5%, significantly increasing to 83.3% when excluding patients with identified risk factors. These findings suggest considering second DAIR in carefully selected patients without these risk factors. Our study found success rates of 76.2% and 79.3% for one- and two-stage revisions, respectively, aligning closely with published data.

Clinical impact of the use of chronic suppressive antibiotics against recurrent ventricular assist device infections.

Ventricular assist device infections (VADIs) are a significant complication leading to hospital readmissions. However, the risk factors and optimal preventive strategies for VADI remain unclear. This study investigated the effectiveness of chronic suppressive antibiotic therapy in patients with VADI. We found that the use of chronic suppressive antibiotic therapy was associated with a reduction in the risk of VADI recurrence with few adverse reactions. Our findings suggest the potential benefit of chronic suppressive antibiotics in preventing infections in selected cases. Our findings are relevant for the management of patients with ventricular assist devices awaiting heart transplantation, providing valuable insights for clinical practice.

Evaluation of KLIC and CRIME80 scores for analysis of the risk of failure of the debridement, antibiotics and implant retention procedure in acute postoperative periprosthetic joint infections of the knee

Objectives The primary objective of the study was to evaluate the efficiency of KLIC and CRIME80 scores in assessing the risk of failure of the Debridement, Antibiotics and Implant Retention (DAIR) procedure for the treatment of acute postoperative periprosthetic joint infection after total knee arthroplasty (TKA). Secondary objectives included determining the failure rate of DAIR and identifying factors related to DAIR treatment failure. Methods A retrospective study was conducted with patients undergoing DAIR within 30 days post-TKA or TKA revision at a specialized SUS hospital for high-complexity orthopedic surgeries. Patient records were evaluated to collect the necessary information for score assessment. Procedure failures were considered if re-intervention was required within 60 days, death occurred within 60 days, or if suppressive antibiotic therapy was needed. Results The study included 17 patients undergoing the DAIR procedure. 52% of infections were caused by Staphylococcus aureus, and 29% occurred after revision surgery. Six (35%) patients experienced DAIR failure, and the mortality rate was 11%. Patients who failed had a higher score on the KLIC score (p<0.0001). Regarding the CRIME80 score, only 33% of those with a score of less than 3 experienced procedure failure. Results also showed that for patients with a KLIC score between 2,5 and 5, the presence of a comorbidity or risk factor resulted in DAIR failure. Additionally, 100% of patients with chronic kidney disease experienced treatment failure, with 66% of them progressing to death. Conclusion Our results demonstrated that the KLIC and CRIME80 scores proved to be effective methods in predicting the likelihood of failure in the treatment of acute postoperative periprosthetic joint infection with DARI and patients in intermediate KLIC groups with comorbidities are subject to a higher chance of failure.

Undiagnosed Periprosthetic Infections in First-Time Aseptic Revision Hip Arthroplasties.

Background: Unexpected infections diagnosed after intraoperative cultures in aseptic revision hip arthroplasties are infrequent, but the features and outcomes of culture-positive cases are still poorly understood. A single-center retrospective study was conducted to assess the following: (1) the incidence, (2) the profile of the cases, and (3) the outcomes of the revision hips performed for presumed aseptic reasons that became septic after intraoperative cultures. Methods: Instances of first-time aseptic revision hips (a retrospective cohort study) in the hospital database were reviewed. The revisions with the isolation of two phenotypically identical microorganisms in the intraoperative cultures were selected. The profile (bacteria, pre-operative markers) and the outcomes of the revisions (survival rates, complications, reasons for re-revision) were assessed. Results: Out of 424 cases of presumed aseptic revision hip arthroplasty, 19 patients (4.48%) were classified as septic. Staphylococcus epidermidis (9, 47.37%) was the most frequent microorganism. In three patients (15.8%), C-reactive protein and erythrocyte sedimentation rate values were higher, and in only one case (5.26%), C-reactive protein values and the white blood cell count were elevated. An antibiotic therapy was administered in every case. At a mean follow-up of 3.72 ± 2.18 years, three patients (15.79%) experienced complications (dislocation, pain without loosening, chronic suppressive antibiotic therapy) and two patients (10.53%) required re-revision for septic relapse (same microorganisms). The survival rate of the cohort was 89.47% (95% CI: 64.08-97.26) at 2 and 4 years. Conclusions: Missed periprosthetic infections rarely occurred in presumed aseptic revision hips. However, the outcomes are fair, and septic relapses are not uncommon.

Performance of the GeneXpert® MRSA/SA SSTI Test in Periprosthetic Joint Infections: Rate of failure, Outcomes and Risk Factors

BackgroundThe GeneXpert® MRSA/SA SSTI test allows early detection of methicillin-resistant staphylococci in intraoperative samples of prosthetic joint infections (PJI) in order to stop early broad-spectrum antibiotics. Questions/Purpose(1) What is the rate of false-negative GeneXpert® MRSA/SA SSTI test results? (2) Does a false-negative GeneXpert® MRSA/SA SSTI test result increase the risk of treatment failure for the patient with a PJI? (3) What are the risk factors of a false-negative result? MethodA retrospective study was carried out to compare all GeneXpert® assays to conventional cultures in prosthetic joint infections from April 1st, 2012 to October 1st, 2016. False-negative (FN) results (absence of methicillin-resistant staphylococci (MRS) with GeneXpert® test, but presence in the culture) were identified. We compared the rate of treatment failure between FN results and other test results and we established the risk factors of having a FN result. ResultsAmong the 612 GeneXpert® results, the rate of FN results was 3.6 % (22/612). We found a significant increase in treatment failures for prosthetic joint infection with a FN result with 14 treatment failures (14/22) compared to 198 treatment failures (198/590) in the other test results (OR, 2.1; 95 % CI, 1.3-3.4, p = 0.0019). Not considering suppressive antibiotics as a treatment failure, we found no significant difference in the rate of treatment failures between the false-negative tests and the other tests (OR, 1.36; 95 % CI, 0.66-2.81, p = 0.41). Tobacco use (OR, 3.8; 95 % CI, 1.4-10.3, p = 0.004), ASA classification (OR, 2,4; 95 % CI, 0.9-6.9, p = 0.064), history of infection in the joint (OR, 3.2; 95 % CI, 1.2-9.6, p = 0.007), chronic infections (OR, 3.2; 95 % CI, 0.8-17.5, p = 0.01) and polymicrobial infections (OR, 3.2; 95 % CI, 1.1-9.2, p < 0.0001) were risk factors for a FN result. ConclusionGeneXpert® tests in prosthetic joint infections showed a low rate of FN results. An increased risk of treatment failures was observed in FN results only when long-term use of suppressive antibiotics was considered as treatment failure. Level of evidenceIII; Diagnostic retrospective case control study.

Estimation of two-year hospital costs of hip and knee periprosthetic joint infection treatments using activity-based costing.

Our aim was to estimate the total costs of all hospitalizations for treating periprosthetic joint infection (PJI) by main management strategy within 24 months post-diagnosis using activity-based costing. Additionally, we investigated the influence of individual PJI treatment pathways on hospital costs within the first 24 months. Using admission and procedure data from a prospective observational cohort in Australia and New Zealand, Australian Refined Diagnosis Related Groups were assigned to each admitted patient episode of care for activity-based costing estimates of 273 hip PJI patients and 377 knee PJI patients. Costs were aggregated at 24 months post-diagnosis, and are presented in Australian dollars. The mean cost per hip and knee PJI patient was $64,585 (SD $53,550). Single-stage revision mean costs were $67,029 (SD $47,116) and $80,063 (SD $42,438) for hip and knee, respectively. Two-stage revision costs were $113,226 (SD $66,724) and $122,425 (SD $60,874) for hip and knee, respectively. Debridement, antibiotics, and implant retention in hips and knees mean costs were $53,537 (SD$ 39,342) and $48,463 (SD $33,179), respectively. Suppressive antibiotic therapy without surgical management mean costs were $20,296 (SD $8,875) for hip patients and $16,481 (SD $6,712) for knee patients. Hip patients had 16 different treatment pathways and knee patients had 18 treatment pathways. Additional treatment, episodes of care, and length of stay contributed to substantially increased costs up to a maximum of $369,948. Treating PJI incurs a substantial cost burden, which is substantially influenced by management strategy. With an annual PJI incidence of 3,900, the cost burden would be in excess of $250 million to the Australian healthcare system. Treatment pathways with additional surgery, more episodes of care, and a longer length of stay substantially increase the associated hospital costs. Prospectively monitoring individual patient treatment pathways beyond initial management is important when quantifying PJI treatment cost. Our study highlights the importance of optimizing initial surgical treatment, and informs treating hospitals of the resources required to provide care for PJI patients.

Outpatient parenteral antimicrobial therapy for patients with Enterococcus faecalis endocarditis using continuous infusion IV benzylpenicillin plus IV ceftriaxone.

Many patients with Enterococcus faecalis endocarditis are clinically stable and able to leave hospital before completing antibiotic treatment, but data are lacking regarding some outpatient treatment options. To assess the outcomes for adults with E. faecalis endocarditis receiving outpatient parenteral antimicrobial therapy (OPAT) with continuous infusion IV benzylpenicillin plus bolus/continuous infusion IV ceftriaxone. We retrospectively reviewed adults who received at least 2 weeks duration of OPAT for E. faecalis endocarditis with the above treatment regimen in the Auckland and Christchurch regions between July 2019 and September 2022. Forty-four patients met inclusion criteria. Fifteen were female (34%). The median age was 80 (IQR 71.5 to 84) years. Twenty-two (50%) had prosthetic valve (PV), 15 (34%) native valve (NV), 3 (7%) NV and/or cardiac implantable electronic device (CIED) infection, 3 (7%) PV and/or CIED infection, and 1 (2%) repaired valve endocarditis. Patients received a median of 16.5 days inpatient and 28 days OPAT antibiotic treatment. The 12 month outcome was cure (n = 25; 57%), antibiotic suppression (n = 9; 20%), relapse (n = 2; 5%; both possible) or death (n = 8; 18%). Compared with a historical cohort treated with OPAT continuous infusion IV benzylpenicillin plus bolus IV gentamicin, there was no difference in the relapse rate. This study adds to the accumulating evidence supporting the treatment of E. faecalis endocarditis with OPAT continuous infusion IV benzylpenicillin plus bolus/continuous infusion IV ceftriaxone. This is an option for patients requiring further antibiotic treatment at the time of hospital discharge.

Dalbavancin-resistant Staphylococcus epidermidis in vivo selection following a prosthetic joint infection: phenotypic and genomic characterization.

Dalbavancin is a lipoglycopeptide antibiotic with a wide spectrum of activity against Gram-positive bacteria, including MDR isolates. Its pharmacokinetic properties and administration patterns could be useful for the treatment of bone and joint infections, especially prosthetic joint infections (PJIs). We report the case of an 80-year-old man who experienced an acute periprosthetic joint infection of his right total knee arthroplasty (TKA). A DAIR procedure was done with tissue sampling, which allowed identification of a linezolid-resistant MDR S. epidermidis (LR-MDRSE) strain. The patient was then treated with dalbavancin (four injections). We studied the phenotypic and genomic evolution of the strains and plasma through concentrations of dalbavancin at different points in time. After four injections (1500 mg IV) of dalbavancin over a 6 month period, the dalbavancin MIC increased 4-fold. Calculated fAUC0-24/MIC ratios were 945, 1239 and 766.5, respectively, at Days 49, 71 and 106, assuming an MIC of 0.032 mg/L. The PFGE dendrogram revealed 97% similarity among all the isolates. These results suggest acquisition by the S. epidermidis strain of dalbavancin resistance when the patient underwent dalbavancin treatment. A 4-amino-acid deletion in the walK gene coinciding with the emergence of phenotypic resistance was revealed by WGS without any other relevant indels. Despite dalbavancin treatment with pharmacokinetic management, emerging dalbavancin resistance in S. epidermidis was observed, resulting in treatment failure. This outcome led to a prosthesis revision and long-term suppressive antibiotic therapy, with no recurrence of PJI after an 18 month follow-up.

Effectiveness of temocillin in treatment of non-urinary tract infections caused by ESBL-producing Enterobacterales and risk factors for failure.

To describe the real-life use of temocillin for non-urinary tract infections, to assess its effectiveness in infections caused by ESBL-producing Enterobacterales, and to identify risk factors for treatment failure. Retrospective multicentric study in 14 tertiary care hospitals, including all patients who received at least one dose of temocillin for ESBL infections from 1 January 2016 to 31 December 2021 for non-urinary tract infections. Failure was a composite criterion defined within 28 day follow-up by persistence or reappearance of signs of infection, and/or switch to suppressive antibiotic treatment and/or death from infection. Logistic regression with univariable and multivariable analysis was performed to identify risks associated with failure. Data on 163 infection episodes were collected; 133 were due to ESBL-producing Enterobacterales and 128 were included in the effectiveness analysis. Median (IQR) age was 61 (53-70) years and 61.7% of patients were male. Main indications were lower respiratory tract infection (LRTI; 28.9%), intra-abdominal infections (IAI; 28.1%) and cutaneous infections (12.5%). The main bacteria involved were Klebsiella pneumoniae (48.4%), Escherichia coli (25.0%) and Enterobacter cloacae (24.2%). Polymicrobial infections occurred in 45.3% of cases. Temocillin was used as monotherapy in 86/128 (67.2%). Failure was found in 36/128 (28.1%) cases. In multivariable analysis, the only factor associated with failure was initial severity of the episode [adjusted OR 3.0 (95% CI: 1.06-8.69)]. During non-urinary tract infections, the main use of temocillin was for LRTIs and IAIs due to ESBL-producing E. coli and K. pneumoniae. The main risk factor for failure was initial severity of the disease.

Contribution of gut microbiota to biodegradation of polystyrene in Tenebrio molitor larvae: Microbiome under antibiotic suppression of Gram-positive, Gram-negative, and fungal microbes

The discovery of plastic biodegradation by insects such as Tenebrio molitor larvae has been well known, however, understanding of the roles of larval gut microorganisms is still very limited. The contribution of the gut microbes belonging to respective Gram-positive (G+), Gram-negative (G−), and fungal (F) groups remains unclear. In this study, we tested polystyrene (PS) biodegradation by T. molitor larvae under three selective antibiotics i.e., gentamicin sulfate (GMS) against G− bacteria, ampicillin (AMP) against G+ bacteria and nystatin (NS) against fungi. The larvae consumed and biodegraded PS foams with Mn 86.381 kDa and Mw 181.176 kDa under antibiotic suppressions at reduced rates versus control (CK) with a sequence of CK>GMS>AMP>NS group. Specifically, only NS group showed a significant decreased in consumption compared to the control. The gut microbial counts decreased with GMS, AMP, or NS addition during the PS feeding. The respective gut microbial counts decreased by 103 to 104 with GMS, AMP, or NS addition PS feeding. Analyses of DSC, TGA, FTIR confirmed oxidation and biodegradation in the presence of antibiotics. The ingested PS polymers were depolymerized and mass reduction with negative influence in the order of NS<AMP<GMS. The negative impact of antibiotic suppression on PS biodegradation process was as follows: anti-fungi reagent > anti-G+ bacteria > anti- G− bacteria. Changes in chemical functional groups are probably related to certain gut microbes, such as the fungal genus of Candida, and bacterial genera of unclassified Enterobacteriaceae and Lactobacillus. Our findings provided new insights into the mechanisms of the biodegradation of plastics in insects.

Comparing costs associated with management of antibiotic-recalcitrant recurrent urinary tract infections for one year pre- and post-electrofulguration.

To quantify and compare recurrent urinary tract infection costs between 1 year before and 1 year after electrofulguration. Following IRB approval, a well-characterized cohort of non-neurogenic women with >3 symptomatic urinary tract infections(UTIs)/year, a negative upper and lower urinary tract evaluation, and inflammatory bladder lesions (cystitis) on office cystoscopy who underwent fulguration of these lesions was analyzed. Cost of visits, imaging, labs, and medications were summed for 1-year pre- and post-fulguration using the Medicare Physician Fee Schedule, local pharmacy pricing, and institutional expenses. Before fulguration, all patients underwent clinic visit, noninvasive flow study, and flexible cystoscopy, and post-fulguration, 6-week follow-up visit and 6-month cystoscopy. Ninety-threewomen met study criteria (mean age 64), with 100% 1-year follow-up. Before fulguration, 73% of patients used daily antibiotic suppression, 6% self-start antibiotics, and 5% postcoital prophylaxis. Some also used vaginal estrogens (17%), urinary analgesics (13%), and cranberry or d-mannose supplements (7%). At 1 year post-fulguration, 82% had 0-1 infections and no cystoscopy evidence of cystitis, while 14% required additional fulguration for new cystitis sites and recurrent infections. Patients had on average 0.7 infections in the 1-year post-fulguration, which was significantly lower than pre-fulguration (p < 0.05). Mean 1-year pre-fulguration cost was $1328 (median $1071, range $291-$5564). Mean 1-year post-fulguration cost was $617 (median $467, range $275-$4580). On average, post-fulguration costs were $710 lower than pre-EF (p < 0.05). For women with antibiotic-refractory recurrent urinary tract infections and cystoscopy evidence of cystitis, fulguration was associated with a significant reduction in UTI-related costs in the 1-year post-fulguration.

The Impact of Culture Negativity on the Outcomes of Revision Total Knee Arthroplasty for Chronic PJI.

Culture-positive (CP) and culture-negative (CN) periprosthetic joint infections (PJI) remain a crucial area of research; however, current studies comparing these infections rely on unstandardized outcome reporting tools. Our study aimed to compare the outcomes of two-stage revision of CP and CN PJI using the standardized Musculoskeletal Infection Society (MSIS) outcome reporting tool. We retrospectively reviewed 138 patients who were diagnosed with PJI and indicated for two-stage revision total knee arthroplasty (rTKA). The majority of patients in both CP and CN cohorts achieved infection control without the need for reoperation (54.1% and 62.5%, respectively). There was a significant difference in the overall distribution of MSIS outcomes (p = 0.043), with a significantly greater rate of CN patients falling into Tier 1 (infection control without the use of suppressive antibiotics) (52.5% versus 29.6%, p = 0.011). There was also a significant difference in the distribution of septic versus aseptic reoperations after 2nd stage (p = 0.013), with more CP reoperations being septic and more CN reoperations being aseptic. The duration from first to second stage was significantly shorter in the CN cohort (p = 0.002). While overall infection control was similar between cohorts, these data suggest that the outcomes of two-stage rTKA are favorable in cases of CN PJI.

Cefadroxil is an option for Gram-positive bone and joint infections in adults

Background: Oral antimicrobial therapy for osteoarticular infections in adults is increasingly adopted; however, the preponderance of published data and experience with oral antibiotics involves agents such as fluoroquinolones, trimethoprim-sulfamethoxazole, and clindamycin. Data supporting the use of narrower-spectrum, stewardship-friendly oral antibiotics with favorable toxicities profiles (e.g. cefadroxil) are needed. Methods: We report a case series of adults who underwent surgery for monomicrobial Gram-positive osteomyelitis, native joint septic arthritis (NJSA), prosthetic joint infection (PJI), or other orthopedic hardware infection at our institution from January 2019 through January 2022 and who subsequently received at least two weeks of oral cefadroxil. We excluded patients who had polymicrobial infection or curative amputation, or who received cefadroxil only as suppressive antibiotic therapy (SAT). Our primary outcome of interest was treatment success during followup, defined as freedom from death, unplanned surgery for infection, or readmission for worsening infection. Results: We identified 22 patients who received cefadroxil for primary treatment of osteoarticular infection. The mean age was 57.6 years, mean weight 98.6 kg, 68% were male, and none had peripheral vascular disease. Infections included PJI in 12, NJSA in 8, osteomyelitis in 7, and other hardware infections in 5; some patients had multiple infectious syndromes. Methicillin-susceptible Staphylococcus aureus (MSSA) was the most common pathogen (73%), followed by streptococci (18%), other methicillin-susceptible staphylococci (14%), and Cutibacterium acnes (5%). Half of patients received 120kg who had device infections with MSSA, two of which were managed with implant retention, suggesting pharmacokinetic/pharmacodynamic factors and biofilm burden could influence treatment outcome. Limitations of this study include its small sample size, noncomparative nature, lengthy initial intravenous antibiotic durations, and limited durations of followup. These data suggest cefadroxil merits investigation for adult osteoarticular infection in larger comparative (and ideally, prospective randomized) studies.

Understanding the Ecological Robustness and Adaptability of the Gut Microbiome in Plastic-Degrading Superworms (Zophobas atratus) in Response to Microplastics and Antibiotics.

Recent discoveries indicate that several insect larvae are capable of ingesting and biodegrading plastics rapidly and symbiotically, but the ecological adaptability of the larval gut microbiome to microplastics (MPs) remains unclear. Here, we described the gut microbiome assemblage and MP biodegradation of superworms (Zophobas atratus larvae) fed MPs of five major petroleum-based polymers (polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate) and antibiotics. The shift of molecular weight distribution, characteristic peaks of C═O, and metabolic intermediates of residual polymers in egested frass proved depolymerization and biodegradation of all MPs tested in the larval intestines, even under antibiotic suppression. Superworms showed a wide adaptation to the digestion of the five polymer MPs. Antibiotic suppression negatively influenced the survival rate and plastic depolymerization patterns. The larval gut microbiomes differed from those fed MPs and antibiotics, indicating that antibiotic supplementation substantially shaped the gut microbiome composition. The larval gut microbiomes fed MPs had higher network complexity and stability than those fed MPs and antibiotics, suggesting that the ecological robustness of the gut microbiomes ensured the functional adaptability of larvae to different MPs. In addition, Mantel's test indicated that the gut microbiome assemblage was obviously related to the polymer type, the plastic degradability, antibiotic stress, and larval survival rate. This finding provided novel insights into the self-adaptation of the gut microbiome of superworms in response to different MPs.

The Use of Long-term Antibiotics for Suppression of Bacterial Infections.

Suppressive antibiotic therapy is prescribed when a patient has an infection that is presumed to be incurable by a defined course of therapy or source control. The cohort receiving suppressive antibiotic therapy is typically highly comorbid and the infections often involve retained prosthetic material. In part due to a lack of clear guidelines regarding the use of suppressive antibiotics, and in part due to the complex nature of the infections in question, patients are often prescribed suppressive antibiotics for extremely long, if not indefinite, courses. The risks of prolonged antibiotic exposure in this context are not fully characterized, but they include adverse drug effects ranging from mild to severe, the development of antibiotic-resistant organisms, and perturbations of the gastrointestinal microbiome. In this narrative review we present the available evidence for the use of suppressive antibiotic therapy in 4 common indications, examine the gaps in the current literature, and explore the known and potential risks of this therapy. We also make suggestions for improving the quality of evidence in future studies, particularly by highlighting the need for a standardized term to describe the use of long courses of antibiotics to suppress hard-to-treat infections.

Dalbavancin as suppressive therapy for implant-related infections: a case series with therapeutic drug monitoring and review of the literature.

Implant-related infections may need suppressive antibiotic therapy (SAT). We describe a SAT strategy using dalbavancin with therapeutic drug monitoring (TDM). This is a retrospective bicentric study of patients with implant-related infection who received dalbavancin SAT between January 2021 and September 2023. Fifteen patients were included. Median number of injections was 4 (IQR: 2-7). Median time between two reinjections was 57days (IQR 28-82). Dalbavancin plasma concentrations were above 4mg/L for 97.9% of dosages (93/95) and above 8mg/L for 85% (81/95). These results support the use of dalbavancin SAT for implant-related infections.

Variation in North American Infectious Disease Specialists' Practice Regarding Oral and Suppressive Antibiotics for Adult Osteoarticular Infections: Results of an Emerging Infections Network (EIN) Survey.

Osteoarticular infections (OAIs) are commonly treated with prolonged intravenous (IV) antimicrobials. The Oral versus Intravenous Antibiotics for Bone and Joint Infection (OVIVA) trial demonstrated that oral (PO) antibiotics are noninferior to IV antibiotics in the treatment of OAIs. We surveyed infectious disease (ID) physicians about their use of PO antibiotics in the treatment of OAIs. An Emerging Infection Network survey with 9 questions regarding antibiotic prescribing for the treatment of OAIs was sent to 1475 North American ID physicians. The questions were mostly multiple choice and focused on the use of definitive oral antibiotic therapy (defined as oral switch within 2 weeks of starting antibiotics) and chronic suppressive antibiotic therapy (SAT). Of the 413 physicians who reported treating OAIs, 91% used oral antibiotics at least sometimes and 31% used them as definitive therapy, most often for diabetic foot osteomyelitis and native joint septic arthritis. The oral antibiotics most frequently used for OAIs included trimethoprim-sulfamethoxazole, doxycycline/minocycline, and linezolid for Staphylococcus aureus, amoxicillin/cefadroxil/cephalexin for streptococci, and fluoroquinolones for gram-negative organisms. The most common rationales for not transitioning to oral antibiotics included nonsusceptible pathogens, comorbidities preventing therapeutic drug levels, and concerns about adherence. SAT use was variable but employed by a majority in most cases of periprosthetic joint infection managed with debridement and implant retention. North American ID physicians utilize oral antibiotics and SAT for the management of OAIs, although significant practice variation exists. Respondents voiced a need for updated guidelines.

No differences in outcomes with stopping or continuing antibiotic suppression in periprosthetic joint infections.

The data on long-term antibiotic use following debridement, antibiotics, and implant retention (DAIR) for treatment of periprosthetic joint infections are limited. In this single-center retrospective study, we show that patients with eventual cessation of antibiotic suppression after DAIR had similar outcomes to those who remained on chronic antibiotic suppression.

CAN WE PREDICT DAIR FAILURE IN PJI? EXTERNAL VALIDATION OF THE KLIC AND CRIME80 SCORES

IntroductionDebridement, antibiotics irrigation and implant retention (DAIR) is a common management strategy for hip and knee prosthetic joint infections (PJI). However, failure rates remain high, which has led to the development of predictive tools to help determine success. These tools include KLIC and CRIME80 for acute-postoperative (AP) and acute haematogenous (AH) PJI respectively. We investigated whether these tools were applicable to a Waikato cohort.MethodWe performed a retrospective cohort study that evaluated patients who underwent DAIR between January 2010 and June 2020 at Waikato Hospital. Pre-operative KLIC and CRIME80 scores were calculated and compared to success of operation. Failure was defined as: (i) need for further surgery, (ii) need for suppressive antibiotics, (iii) death due to the infection. Logistic regression models were used to calculate the area under the curve (AUC).Results117 eligible patients underwent DAIR, 53 in the AP cohort and 64 in the AH cohort. Failure rate at 2 years post-op was 43% in the AP cohort and 59% in the AH cohort. In the AP cohort a KLIC score of &lt;4 had a DAIR failure rate of 28.6%, while those who scored ³4 had a failure rate of 72.2% (p=0.002). In the AH cohort a CRIME80 score of &lt;3 had a DAIR failure rate of 48% while those who scored ³3 had a 100% failure rate (p&lt;0.001).DiscussionThis study represents the first external validation of the KLIC and CRIME80 scores for predicting DAIR failure in an Australasian population. The results indicate that both KLIC and CRIME80 scoring tools are valuable aids for the clinician seeking to determine the optimal management strategy in patients with AP or AH PJI.