Intraoperative Culture Results Research Articles

Does hydrogen peroxide help mitigate the incidence of Cutibacterium acnes in cervical spine surgeries?

Background: Surgical site infection (SSI) is a common yet serious complication of cervical spine surgery. While initially thought to be clinically insignificant, Cutibacterium acnes (C. acnes) is an important cause of infection. The purpose of this study was to investigate the ability of an hydrogen peroxide (H2O2) application during standard pre-surgical skin preparation to reduce the burden of C. acnes in patients undergoing cervical spine surgery. Methods: This was a retrospective review of prospectively collected data. Subjects were randomly assigned to either standard surgical preparation plus H2O2 (experimental) or without H2O2 (control). Pre-scrub, post-scrub, and dermal cultures were obtained to assess the C. acnes burden after cultures on an aerobic and anaerobic growth medium were held for 21 days. Multivariate analysis was conducted to determine factors associated with presence of C. acnes. Outcome measures included the results of intraoperative cultures and the development of a SSI within 90 days post-operatively. Results: Patients (n=86) undergoing elective two- or three-level fusion via anterior approach were included. Prior to application of the antiseptic solution, 65% (28/43) of the experimental cohort and 77% (33/43) of the control cohort had positive C. acnes cultures (p=0.34). Following application of antiseptic solution, there were no differences in positive C. acnes culture rates between the experimental and control cohorts in the epidermal (30% versus 28%, p=1.00) or dermal (40% versus 42%, p=1.00) cultures. No differences in the rates of C. acnes eradication from pre-antiseptic to post-antiseptic application occurred for epidermal (p= 1.00) or dermal (p= 1.00) skin layers. None of the factors were associated with positive C. acnes epidermal cultures on multivariable logistic regression analysis (p> 0.05). Conclusions: While there is potential for H2O2 to reduce the positive culture rate of C. acnes in cervical spine patients, no difference was seen when compared to standard surgical skin preparation.

Clinical relevance of positive intraoperative bacterial culture in tibial plateau leveling osteotomy in dogs: a retrospective study

BackgroundTibial plateau leveling osteotomy (TPLO) belongs to the most frequently used surgical method for the treatment of cranial cruciate ligament rupture in dogs. Surgical site infection (SSI) is one of the possible postoperative complications. The aim of this study was to evaluate the diagnostic value of intraoperative bacterial culture as a tool for the detection of intraoperative bacterial contamination progressing to infection development in canine TPLO. Electronic patient records from dogs who underwent TPLO between January 2018 to December 2020 were retrospectively reviewed. Intraoperative bacterial culture results, used antimicrobial drugs and presence of SSI were recorded.ResultsNinety-eight dogs were included in the study. SSI rate was 10.2%. All dogs who developed SSI (n = 10) had negative intraoperative bacterial cultures. None of the dogs with positive intraoperative bacterial culture (n = 6) developed SSI. The most cultured bacteria causing SSI was Staphylococcus pseudintermedius (n = 4).ConclusionsIntraoperative bacterial culture in dogs undergoing TPLO is not suitable as a predictor of surgical site infection.

The microbiology of periprosthetic joint infections as revealed by sonicate cultures in Korea: Routine use of fungal and mycobacterial cultures is necessary?

Although sonication is a valuable diagnostic tool for periprosthetic joint infections (PJI), it is not commonly utilized. We analyzed sonicate and intraoperative tissue culture results obtained from three hospitals to define the microbial etiology of PJIs in Korea. Furthermore, we investigated necessity of conducting regular fungal and mycobacterial cultures. We retrospectively analyzed data for patients with suspected orthopedic-related infections between 2017 and 2022, who had undergone prostheses removal surgery. We included 193 patients with suspected PJIs, and bacterial (n = 193), fungal (n = 193), and mycobacterial (n = 186) cultures were conducted on both sonicate and intraoperative tissue samples. The diagnosis of PJI was based on the European Bone and Joint Infection Society (EBJIS) criteria. Out of 193 patients, 121 (62.7%) had positive sonicate cultures, while 112 (58.0%) had positive periprosthetic tissue cultures. According to EBJIS criteria, a total of 181 patients were diagnosed with PJI, and 141 patients received microbiological confirmation through sonicate fluid culture or tissue culture. Of the 181 patients, 28 were classified with acute PJI (within 3 months of implantation) and 153 with chronic PJI. Among 141 patients, staphylococci were the most common organisms, accounting for 51.8% of cases, followed by Gram-negative organisms (15.6%), fungus (8.5%), and mycobacteria (3.5%). Nearly 91.7% of fungal isolates were Candida species, which also grew in bacterial cultures. In total, 11 cases cultured positive only in tissue culture, whereas 20 cases cultured positive only in sonicate culture. The antibiotic treatment plans were adjusted according to culture results. Utilizing sonicate culture has greatly assisted in identifying pathogens responsible for chronic indolent PJIs, allowing suitable antimicrobial treatment. Based on few cases involving non-Candida and mycobacterial infections, it appears that routine fungal and mycobacterial cultures may not be necessary.

The Value of Preoperative Ultrasound-Determined Fluid Film and Joint Aspiration in Revision Hip Arthroplasty

BackgroundData regarding the diagnostic value of ultrasound (US)–determined fluid film and joint aspiration prior to revision total hip arthroplasty for suspected periprosthetic joint infections (PJIs) are limited. This study aimed to analyze the value of US-determined fluid film, characterized the preoperative and intraoperative microbiological spectrum and resistance patterns, and compared the concordance between preoperative synovial fluid and intraoperative culture results. MethodsWe analyzed 366 US examinations from 324 patients prior to revision total hip arthroplasty. Selected cases were grouped into clearly infected, noninfected, and inconclusive cohorts, according to the International Consensus Meeting 2018 Criteria. For US-determined fluid film <1 mm, no aspiration was performed based on our institutional protocol. Patients were grouped into no aspiration (144 of 366; [39.3%]), dry tap (21 of 366; [5.7%]), and a successful tap (201 of 366; [54.9%]). The microbiological spectrum and antibiograms were compared between preoperative and intraoperative results. ResultsThe absence of US-determined fluid film showed no correlation with the presence of a hip PJI. Overall, 31.9% cases of the no-aspiration group had a PJI. In total, 13.5% discrepancies were found between successful taps and intraoperative cultures. The most prevalent microorganisms in preoperative synovial fluid were Staphylococcus epidermidis and Staphylococcus aureus (20.8%), while intraoperatively S. epidermidis (26.3%) and Cutibacterium acnes (14.5%) were leading. Additional microorganisms were identified in 32.5% of intraoperative cultures. There were no differences between resistance patterns of preoperative and intraoperative concordant microorganisms. ConclusionsAbsence of US-determined fluid film cannot rule out the presence of a hip PJI. Combined microbiological results from hip US aspirations and subsequent surgical procedures are crucial to design an effective treatment for suspected hip PJI.

Management of nonpurulent wound drainage following spinal surgery: is empiric oral antibiotic treatment appropriate?

BACKGROUND CONTEXTPostoperative incisional concerns including nonpurulent drainage are relatively common following spine surgery. Evidence-based management protocols are lacking. PURPOSEThe purpose of this study is to determine if prescribing empiric oral antibiotics for nonpurulent wound drainage is beneficial for the prevention of chronic infection or reoperation. STUDY DESIGNRetrospective chart review. PATIENT SAMPLEPatients calling the office with postsurgical wound concerns. OUTCOME MEASURESNot applicable. METHODSIn a large, multisurgeon, spine surgery practice, a review of the communications log showed that 298 patients called or messaged the office with a concern regarding postoperative nonpurulent wound drainage. Patients were prescribed empiric oral antibiotics based on surgeon preference. Patients who received empiric oral antibiotic treatment (AbxTx) were propensity matched to patients who did not (No AbxTx) based on sex, age, BMI, ASA grade, smoking status, prior spine surgery, anatomic location, and number of surgical levels. The number of patients requiring surgical intervention (debridement) and/or developing a chronic infection was determined. RESULTSOral antibiotics were prescribed for 112 of the 298 (38%) patients with reports of nonpurulent drainage. Demographic and surgical characteristics of the two matched cohorts were similar. Although there were more patients in the AbxTx group who required surgical intervention (n=17, 17%) compared to the No AbxTx group (n=9, 9%), this difference was not statistically significant (p=.139). The intra-operative culture results showed no growth in 94% (16/17) of the AbxTx group vs 67% (6/9) of the No AbxTx group (p=.103). One patient in each group required a return to the operating room within the year after the initial surgical debridement for management of chronic infection. CONCLUSIONIn this large series (n=298) of patients with nonpurulent wound drainage following spine surgery, 87% resolved without the need for surgical intervention. Empiric oral antibiotics did not reduce the need for surgical intervention or the development of a chronic infection. In addition to the added cost, potential adverse reactions, development of resistant organisms, and inaccurate labeling of surgical site infection; empiric oral antibiotics may lead to a negative intraoperative culture for those requiring surgical intervention impacting the ability to prescribe a specific antibiotic regimen.

Systemic Manifestation of Periprosthetic Joint Infection Is Associated With Increased In-Hospital Mortality.

Introduction Periprosthetic joint infection (PJI) is one of the most devastating complications of total joint arthroplasty. Systemic symptoms of infection may indicate a patient who is at a higher risk of serious complications. The goal of this study was to determine if systemic symptoms of infection in the setting of PJI were associated with greater in-hospital mortality. Materials and methods We used our institutional database to identify all patients urgently treated for deep PJI from 2002-2012. Records were reviewed to collect demographics, surgical data, vital signs prior to surgical intervention, blood and intraoperative culture results, preoperative intensive care unit (ICU) admissions, and deaths that occurred during the hospital admission. Patients were classified as having systemic inflammatory response syndrome (SIRS) based on the criteria established by the American College of Chest Physicians and the Society of Critical Care Medicine. Results During the 10-year timeframe of our study, 484 patients were treated emergently for deep infection, with 130 (27%) meeting SIRS criteria preoperatively and 31 (6%) of the patients with SIRS having positive blood cultures. Patients with positive blood cultures and SIRS demonstrated a higher in-hospital mortality rate (p < 0.001). Neither SIRSnor SIRS with positive blood cultures were associated with ICU admission. Discussion Occasionally, PJI can spread beyond the affected joint, showing physical symptoms of systemic illness and bacteremia. This study demonstrates that patients with SIRS and positive blood cultures are at an increased risk of in-hospital mortality. These patients should be monitored closely before definitive treatment in order to minimize their mortality risk.

Inflammatory response in confirmed non-diabetic foot and ankle infections: A case series with normal inflammatory markers.

The distinction between foot and ankle wound healing complications as opposed to infection is crucial for the appropriate and efficacious allocation of antibiotic therapy. Multiple reports have focused on the diagnostic accuracy of different inflammatory markers, however, mainly in the diabetic population. To evaluate the diagnostic accuracy of white cell count (WCC) and C-reactive protein (CRP) as diagnostic tools for this distinction in the non-diabetic cohort. Data was reviewed from a prospectively maintained Infectious Diseases Unit database of 216 patients admitted at Leicester University Hospitals-United Kingdom with musculoskeletal infections over the period between July 2014 and February 2020 (68 mo). All patients with confirmed diagnosis of diabetes were excluded while only those with confirmed microbiological or clinical diagnosis of foot or ankle infection were included in our study. For the included patients, we retrospectively retrieved the inflammatory markers (WCCs and CRP) at the time of presentation. Values of CRP 0-10 mg/L and WCC 4.0-11.0 × 109/L were considered normal. After exclusion of patients with confirmed diabetes, 25 patients with confirmed foot or ankle infections were included. All infections were confirmed microbiologically with positive intra-operative culture results. 7 (28%) patients with osteomyelitis (OM) of the foot, 11 (44%) with OM of the ankle, 5 (20%) with ankle septic arthritis and 2 (8%) patients with post-surgical wound infection were identified. Previous bony surgery was identified in 13 (52%) patients, either a corrective osteotomy or an open reduction and internal fixation for a foot or ankle fracture with the infection developing on top of the existing metalwork. 21 (84%) patients did have raised inflammatory markers while 4 (16%) patients failed to mount an inflammatory response even with subsequent debridement and removal of metal work. CRP sensitivity was 84%, while WCC sensitivity was only 28%. CRP has a relatively good sensitivity in the diagnosis of foot and ankle infections in non-diabetic patients, whereas WCC is a poor inflammatory marker in the detection of such cases. In presence of clinically high level of suspicion of foot or ankle infection, a normal CRP should not rule out the diagnosis of OM.

Will Preoperative Synovial Fluid Antigen Testing Change Our Clinical Practice?

Commentary In their article, Toler et al. evaluated the diagnostic performance of a recently launched synovial fluid antigen test for the preoperative diagnosis of periprosthetic joint infection (PJI). The test is of great interest because identifying the causative microorganism prior to the surgical procedure is important in guiding surgical decision-making and starting targeted antimicrobial treatment as soon as possible. Toler et al. demonstrated a high concordance between synovial fluid culture and the antigen test. Moreover, in culture-negative synovial fluids, the test identified a microorganism in 49% of cases. However, from a clinical point of view, there are important limitations that should be taken into consideration. With regard to how the test will guide antibiotic treatment, the following shortcomings should be taken into account. A limited number of species (i.e., Staphylococcus, Enterococcus, and Candida species) are included in the test, as noted in the article, and it is important to keep in mind that the reference test used to calculate the diagnostic accuracy was a positive synovial fluid culture for the included species. A comparison with intraoperative tissue cultures was not performed, and, because the sensitivity of synovial culture is poor, an infection cannot be ruled out in the case of a negative antigen test. Therefore, empirical antibiotic treatment should still be administered in the case of a negative antigen test when a PJI is suspected. In the case of a positive test, it is important to realize that, in addition to the inclusion of a limited number of species that can be detected, the test only identifies species on a genus level. Because the antibiotic treatments for methicillin-sensitive staphylococci compared with methicillin-resistant staphylococci and for Enterococcus faecalis compared with Enterococcus faecium are different, their identification on a genus level cannot fully target antibiotic treatment. Other tests that overcome this limitation are available, such as the recently launched multiplex polymerase chain reaction (PCR) for bone and joint infections1. The BioFire Joint Infection PCR Panel provides a rapid diagnosis (i.e., within 1 hour), includes more genera and identifies pathogens on a species level, and detects resistance genes, which may better guide antimicrobial treatment1. Also, other microorganisms not detected by the PCR test may be involved. According to the literature, around 30% to 40% of PJIs are polymicrobial in nature, with an even higher incidence observed in early postoperative and chronic infections with a sinus tract2,3. Consequently, empirical antibiotic treatment cannot be easily narrowed in the case of a positive antigen test either. With regard to how the test will help us in surgical decision-making, some experts in the field have advocated a 2-stage exchange instead of 1-stage exchange for PJI caused by difficult-to-treat microorganisms such as enterococci and Candida4,5. Therefore, isolating these species prior to the surgical procedure may guide surgical decision-making. However, in the total cohort in the study by Toler et al., Candida species already grew on synovial fluid culture in 338 cases and Enterococcus species grew on culture in 465 cases. More rapid identification that the antigen provides is not needed in chronic infections, as one has time to wait for the final culture results. In the remaining preoperative samples with negative synovial fluid cultures, the antigen test detected Candida in an additional 142 cases and enterococci in an additional 188 cases. If these extra cases were to be considered to represent real infections, rather than false-positives as stated by Toler et al., only 0.3% of candidal infections and 0.4% of enterococcal infections from the total cohort of patients will have been missed when solely relying on preoperative cultures of synovial fluid. This low percentage of missed infections makes one wonder whether the number needed to test is really justified. Last but not least, Toler et al. analyze their results according to whether the preoperative diagnosis, according to the 2018 International Consensus Meeting, was positive or negative, but the inconclusive cases (7.5% of the total cohort) are not included in the final analysis, although these are the cases that are most clinically challenging. Based on the above-mentioned limitations and the way that the results are analyzed, it seems that the evaluated antigen test will not change our daily clinical practice in a large number of cases. Additional analyses, particularly comparisons with the final postoperative diagnosis and intraoperative culture results, are needed to define the role of this test in the diagnostic workup.

What is the concordance rate of preoperative synovial fluid aspiration and intraoperative biopsy in detecting periprosthetic joint infection of the shoulder ?

The accuracy of preoperative synovial fluid culture for microbe detection in shoulder periprosthetic joint infection (PJI) is poorly described. To evaluate the utility of preoperative culture data for early pathogen identification for shoulder PJI, we determined the concordance between preoperative synovial fluid culture results and intraoperative tissue culture results. Fifty patients who met the 2014 Musculoskeletal Infection Society criteria for shoulder PJI between January 2016 and December 2019 were retrospectively reviewed for clinical and demographic data. This cohort of patients was divided in two groups based on the concordance between preoperative and intraoperative culture results. The pathogens identified on preoperative and intraoperative cultures were classified as high-virulence or low-virulence. Student's t tests and Mann-Whitney U tests were used as appropriate for continuous variables and chi-square and Fisher's exact tests were used as appropriate for categorical variables. Concordance between preoperative aspiration and intraoperative tissue culture was identified in 28 patients out of 50 (56%). Preoperative cultures positive for Gram-positive species were more likely to be concordant than discordant (p=0.015). Preoperative cultures positive for Cutibacterium acnes were more likely to be concordant with intraoperative cultures (p=0.022). There were more patients with polymicrobial infection in discordant group compared to concordant group (p<0.001). No statistically significant correlation between preoperative serum CRP level and intraoperative category of bacteria was reported. Staphylococcus aureus and coagulase-negative Staphylococci were associated with high specificity and negative predictive value (NPV). Preoperative cultures positive for Cutibacterium acnes demonstrated sensitivity, specificity, positive predictive value (PPV) and NPV lower than 0.8. Gram-negative pathogens demonstrated the highest sensitivity (1) and specificity (1), while polymicrobial infections exhibited the lowest sensitivity and PPV. Preoperative synovial fluid aspiration for shoulder PJI poorly predicts intraoperative culture results, with discordance of 44%. More favorable concordance was observed for monomicrobial preoperative cultures, particularly for Gram-negative organisms and methicillin-sensitive Staphylococcus aureus. The overall high rate of discordance between preoperative and intraoperative culture may prompt surgeons to base medical and surgical management on patient history and other factors and avoid relying solely on preoperative synovial fluid culture data.

Allogenic bone grafts and postoperative surgical site infection: are positive intraoperative swab cultures predictive for a higher infectious risk?

In spine surgery, allogenic bone grafts are often required to ensure bone fusion, however, the main concern regarding their use is the infection risk: therefore, an intraoperative swab for culture test is performed. The cost-effectiveness of these swabs and their influence on the patients' postoperative course have often been questioned. This study aims at determining whether positive spine allograft culture results are predictive of an increased risk of surgical site infection and whether they influence the surgeon's choices in postoperative management.The records of 340 patients who received allogenic bone graft during spinal fusion surgery in our institution were reviewed, for a total of 677 allografts. Each graft was swabbed intraoperatively. All patients were followed clinically for postoperative complications. Infection was diagnosed based on clinical data, blood tests and radiographic images, all assessed by an infectious disease specialist.Only 4 of the 677 allografts used (0.6%) resulted positive at the intraoperative swab culture. Three cultures were positive for Staphylococcus epidermidis and one culture for S. warneri. No clinical infection occurred in any of these patients. Twenty-eight of the 340 patients (8.2%) developed an infection, but none of them had a positive intraoperative swab culture. The most common microbiologic pathogen isolated from this cohort was S. aureus.According to our series, intraoperative swab culture results were not predictive for higher risk of infection and did not affect the clinical behavior of the surgeons in postoperative management.

Reliability of Inflammatory Markers as a Diagnostic Tool for Non-Diabetic Foot and Ankle Infections: Case Series Study

Category: Other; Ankle; Basic Sciences/Biologics; Hindfoot; Midfoot/Forefoot; Trauma Introduction/Purpose: The distinction between foot and ankle wound healing complications as opposed to infection is crucial for the appropriate and efficacious allocation of antibiotic therapy. Multiple reports have focused on the diagnostic accuracy of different inflammatory markers, however, mainly in the diabetic population. Our aim was to evaluate the diagnostic accuracy of white cell count (WCC) and C-reactive protein (CRP) as diagnostic tools for this distinction in the non-diabetic cohort. Methods: Data were reviewed from a prospectively maintained Infectious Disease Unit database of 216 patients admitted at Leicester University Hospitals - the United Kingdom with musculoskeletal infections over the period between July 2014 and February 2020 (68 months). All patients with a confirmed diagnosis of diabetes were excluded while only those with a confirmed microbiological or clinical diagnosis of foot or ankle infection were included in our study. For the included patients, we retrospectively retrieved the inflammatory markers (WCCs and CRP) at the time of presentation and during the perioperative period for debridement. Values of CRP 0-10 mg/L and WCC 4.0-11.0 x109 /L were considered normal. Results: After the exclusion of patients with confirmed diabetes, 25 patients with confirmed foot or ankle infections were included. All infections were confirmed microbiologically with positive intra-operative culture results. 7 (28%) patients with osteomyelitis (OM) of the foot, 11 (44%) with OM of the ankle, 5 (20%) with ankle septic arthritis, and 2 (8%) patients with post- surgical wound infection were identified. Previous bony surgery was identified in 52% (n=13), either a corrective osteotomy or an open reduction and internal fixation (ORIF) for a foot or ankle fracture with the infection developing on top of the existing metalwork. 84% (n=21) did have raised inflammatory markers while 16% (n=4) failed to mount an inflammatory response even with subsequent debridement and removal of metalwork. CRP sensitivity was 84%, while WCC sensitivity was only 28%. Conclusion: CRP has relatively good sensitivity in the diagnosis of foot and ankle infections in non-diabetic patients, whereas WCC is a poor inflammatory marker in the detection of such cases. In presence of a clinically high level of suspicion of foot or ankle infection, a normal CRP should not rule out the diagnosis of OM.

Role of joint aspiration before re-implantation in patients with a cement spacer in place.

BACKGROUNDThe usefulness of a mandatory joint aspiration before re-implantation in patients with a cement spacer already in place is unclear.AIMTo evaluate the role of culturing synovial fluid obtained by joint aspiration before re-implantation in patients who underwent a two-stage septic revision.METHODSA retrospective observational study was conducted, including patients that underwent a two-stage septic revision (hip or knee) from 2010 to 2017. After the first stage revision and according to intraoperative culture results, all patients were treated with an antibiotic protocol for 6-8 wk. Following 2 wk without antibiotics, a culture of synovial fluid was obtained. The results of these cultures were recorded and compared with cultures obtained during re-implantation surgery.RESULTSForty-one patients (20 hip and 21 knee spacers) were included in the final analysis. In 39 cases, the culture of synovial fluid was negative, while in the remaining 2 cases (knee spacers) no analysis was possible due to dry tap. In 5 of the patients, two or more intraoperative cultures taken during the re-implantation surgery were positive.CONCLUSIONWe found no evidence to support mandatory joint aspiration before re-implantation in patients with a cement spacer in place.

The first case report of thorn-induced Alternaria alternata infection of the hand in an immunocompetent host

BackgroundFungal infection secondary to a penetrating plant thorn injury in upper extremities is infrequently reported especially in immunocompetent hosts. Alternaria is a dematicaceous hyphomycete, commonly found in decay and plant pathogens, and Alternaria alternata has been regarded as the most frequent species among more than 400 s of its species. This case is the first report of thorn-induced Alternaria alternata infection of the hand in an immunocompetent host.Case presentationA 47-year-old male patient was admitted to our institution with persistent pain and swelling of the right hand even after a prior surgical removal of a previous thorn injury. Upon impression of abscess, chronic extensor tenosynovitis, and septic arthritis at the 3rd metacarpophalangeal joint based on advanced imaging, the patient underwent surgical incision and drainage. Intraoperative culture, biopsy, and gene molecular sequencing results revealed fungal infection with Alternaria alternata. Postoperatively, the patient was treated with oral itraconazole (200 mg q 12 h) for nine consecutive months.ConclusionsWe report the first case of chronic extensor tenosynovitis and septic arthritis of the hand with Alternaria alternata after a thorn injury in an immunocompetent host. Despite rare incidences of fungal extensor tenosynovitis and septic arthritis, the current case strongly suggests a careful examination of social history and surgical debridement along with a prolonged use of appropriate anti-fungal agents in thorn injuries.

Oral and IV Antibiotic Administration After Single-Stage Revision Shoulder Arthroplasty: Study of Survivorship and Patient-Reported Outcomes in Patients without Clear Preoperative or Intraoperative Infection.

Following revision shoulder arthroplasty, postoperative antibiotics are selected before the results of intraoperative cultures become available. We determined infection-free survival, revision-free survival, complications, and patient-reported outcomes for patients selected to receive oral or intravenous (IV) antibiotics after revision arthroplasty. This study included 92 patients who had revision shoulder arthroplasty. IV antibiotics were administered if the surgeon had a high index of suspicion for infection, and oral antibiotics were given if there was a low suspicion. Antibiotic therapy was modified based on intraoperative culture results. Patient-reported outcomes and adverse events were documented at a mean of 4.1 years. In selecting antibiotic therapy, surgeons correctly predicted the presence or absence of multiple positive cultures of specimens from the revision surgery in 72% of the 92 cases. Subsequent re-revision surgery was required in 17 (18%) of the patients; 8 of these 17 patients had ≥2 positive cultures at re-revision. Patients who initially received IV antibiotics and those who initially received oral antibiotics had similar revision-free (p = 0.202) and infection-free (p = 0.155) survivorship. Patients requiring a change from oral to IV antibiotics based on positive cultures had similar survivorship compared with those initially treated with IV antibiotics. The IV and oral antibiotic groups had similar postoperative Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES), and satisfaction scores. Patients receiving IV antibiotics had a higher rate of antibiotic-related adverse events. Post-revision antibiotic therapy was associated with an infection-free survival rate of 91% at a mean of >4 years of follow-up. Infection-free survival, revision-free survival, and patient-reported outcomes were similar in high-risk patients placed on IV antibiotics and low-risk patients placed on oral antibiotics. Further study is needed to define the indications for IV or oral antibiotics after revision arthroplasty. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

How does pre-operative antimicrobial treatment influence the intra-operative culture results and infectious complications in patients with positive baseline bladder urine culture undergoing ureteroscopic lithotripsy?

We investigated how pre-operative antimicrobial treatment influenced intra-operative culture (IC) results and infectious complications in patients with positive pre-operative bladder urine culture (PBUC) undergoing ureteroscopic lithotripsy. We assessed 162 patients undergoing ureteroscopic lithotripsy from April 2019 to March 2020. Based on PBUC findings, they were divided into positive and negative PBUC groups. We administered pre-operative antimicrobial treatment to the positive PBUC group and only peri-operative antimicrobial prophylaxis to the negative PBUC group. We examined intra-operative cultures (ICs), including bladder urine culture, renal pelvic urine culture and stone culture, in all cases. We studied the association between the results of PBUC, ICs and infectious complications in both groups. A total of 67 and 95 patients had positive and negative PBUC, respectively. In the positive PBUC group, 19 (28.4%) patients still had positive bladder urine culture after the antibiotic treatment. Positive ICs (43.3% vs. 3.2%, p < 0.001) and post-operative fever (16.4% vs. 2.0%, p = 0.001) were more common in the positive PBUC group than in the negative PBUC group. In the positive PBUC group, 11 patients had a post-operative fever, regardless of the ICs results (6 positive ICs and 5 negative ICs). Furthermore, antimicrobial-resistant bacteria were detected from ICs in 5 patients with positive PBUC, including 4 suffering from a post-operative fever. Although the effect of pre-operative antimicrobial treatment is not definitive, to avoid serious infectious complications, we should recognize high-risk patients and perform more careful infection control based on the pre- and intra-operative culture results.

Clinical Significance of Intraoperative Bile Culture in Surgery Including Bile Duct Resection

It is widely accepted that intraoperative bacterial infection may potentially result in a worse postoperative outcomes. The purpose of this study is to analyze the microbiology of intraoperative bile smear culture test and the correlation between the results of culture and postoperative outcomes in bile duct resection operation. Methods: The data was prospectively collected from 235 patients who underwent bile duct resection at Samsung Medical Center for one year from October 2018 to September 2019. The diseases included in the data are periampullary cancer, gallbladder cancer, hilar cholangiocarcionoma, and intrahepatic cholangiocarcinoma. Intraoperative bile smear test was performed in operation, and the included operation was pancreaticoduodenectomy and liver resection surgery with bile duct resection. Specimens were obtained from culture swab of bile drained during bile duct resection. Results: Of the 235 patients, microorganism was isolated in 141 patients (60%). The predominant microorganisms grown from the intraoperative bile cultures were Enterococcus faecalis (38 cultures, 27.0%), Enterococcus faecium (32 cultures, 22.7%), Klebsiella pneumoniae and Enterobacter cloacae (28 cultures, 19.9%). In postoperative complication, the positive results of intraoperative bile cultures was related with Clavien-Dindo Classification≥Ⅲ (OR3.117, 95%CI:1.498-6.485, p=0.002). Also, it was a risk factors for occurrence of surgical site infection (OR3.266, 95%CI:1.237-8.621, p=0.013) and intra-abdominal abscess (OR1.145, 95%CI:1.057-1.240, p=0.003). In addition, the incidence of postoperative pancreatic fistula was increased in patients with microorganisms grown in bile (OR1.974, 95%CI:1.098-3.549, p=0.022). Conclusions: Smear positivity of intraoperative bile fluid is associated with occurrence of major complication. It was risk factor for surgical site infection and intra-abdominal abscess.

Intraoperative Bacterial Contamination and Activity of Different Antimicrobial Prophylaxis Regimens in Primary Knee and Hip Replacement.

Surgical antimicrobial prophylaxis (SAP) is important for the prevention of prosthetic joint infections (PJIs) and must be effective against the microorganisms most likely to contaminate the surgical site. Our aim was to compare different SAP regimens (cefazolin, cefuroxime, or vancomycin, alone or combined with gentamicin) in patients undergoing total knee (TKA) and hip (THA) arthroplasty. In this preclinical exploratory analysis, we analyzed the results of intraoperative sample cultures, the ratio of plasma antibiotic levels to the minimum inhibitory concentrations (MICs) for bacteria isolated at the surgical wound and ATCC strains, and serum bactericidal titers (SBT) against the same microorganisms. A total of 132 surgical procedures (68 TKA, 64 THA) in 128 patients were included. Cultures were positive in 57 (43.2%) procedures (mostly for coagulase-negative staphylococci and Cutibacterium spp.); the rate was lower in the group of patients receiving combination SAP (adjusted OR 0.475, CI95% 0.229–0.987). The SAP regimens evaluated achieved plasma levels above the MICs in almost all of intraoperative isolates (93/94, 98.9%) and showed bactericidal activity against all of them (SBT range 1:8–1:1024), although SBTs were higher in patients receiving cefazolin and gentamicin-containing regimens. The potential clinical relevance of these findings in the prevention of PJIs remains to be determined.

Influence of Klebsiella pneumoniae and quinolone treatment on prognosis in patients with pancreatic cancer.

An increasing body of evidence suggests that microbiota may promote progression of pancreatic ductal adenocarcinoma (PDAC). It was hypothesized that gammaproteobacteria (such as Klebsiella pneumoniae) influence survival in PDAC, and that quinolone treatment may attenuate this effect. This was a retrospective study of patients from the Massachusetts General Hospital (USA) and Ludwig-Maximilians-University (Germany) who underwent preoperative treatment and pancreatoduodenectomy for locally advanced or borderline resectable PDAC between January 2007 and December 2017, and for whom a bile culture was available. Associations between tumour characteristics, survival data, antibiotic use and results of intraoperative bile cultures were investigated. Survival was analysed using Kaplan-Meier curves and Cox regression analysis. Analysis of a total of 211 patients revealed that an increasing number of pathogen species found in intraoperative bile cultures was associated with a decrease in progression-free survival (PFS) (-1·9 (95 per cent c.i. -3·3 to -0·5) months per species; P=0·009). Adjuvant treatment with gemcitabine improved PFS in patients who were negative for K. pneumoniae (26·2 versus 15·3 months; P =0·039), but not in those who tested positive (19·5 versus 13·2 months; P =0·137). Quinolone treatment was associated with improved median overall survival (OS) independent of K. pneumoniae status (48·8 versus 26·2 months; P =0·006) and among those who tested positive for K. pneumoniae (median not reached versus 18·8 months; P =0·028). Patients with quinolone-resistant K. pneumoniae had shorter PFS than those with quinolone-sensitive K. pneumoniae (9·1 versus 18·8 months; P =0·001). K. pneumoniae may promote chemoresistance to adjuvant gemcitabine, and quinolone treatment is associated with improved survival.

Detecting the presence of bacteria in low-volume preoperative aspirated synovial fluid by metagenomic next-generation sequencing

ObjectivesPreoperative diagnosis is important for patients who need revision surgery due to PJI. Microbial culture plays an important role in PJI diagnosis, but the sensitivity of cultures is low when the sample amount is limited or when a patient is treated with antibiotics before sample collection. In this study, metagenomic next-generation sequencing (mNGS) was used to detect bacteria in preoperative puncture synovial fluid samples from patients with suspected PJI, and the preoperative and intraoperative culture results were compared to estimate its diagnostic efficiency. MethodsFrom July 2016 to December 2018, patients with suspected PJI who underwent prosthetic joint revision surgery were included, and the results of those who had been tested by preoperative synovial fluid culture and mNGS were obtained. The demographic characteristics, medical history, laboratory test results, culture results, and mNGS results of each patient were recorded. Then, the efficiency of preoperative synovial fluid mNGS was compared to that of synovial fluid culture for diagnosing PJI. ResultsA total of 37 patients were included, and 24 patients (25 joints) were diagnosed with PJI. The sensitivity, specificity, and accuracy of preoperative synovial fluid mNGS were 92%, 91.7%, and 83.7%, respectively. The sensitivity, specificity, and accuracy of preoperative synovial fluid culture were 52%, 91.7%, and 43.7%, respectively. ConclusionsWith a low volume of synovia (1 ml), mNGS can be performed with higher sensitivity and specificity compared to synovial culture. Thus, mNGS can be a useful supplemental method to improve diagnostic efficiency during the preoperative period.

The Importance Of Multi-site Intra-operative Tissue Sampling In The Diagnosis Of Hip And Knee Periprosthetic Joint Infection - Results From A Single Centre Study.

Introduction: The primary aim of this study was to determine whether the tissue type and anatomical location of intra-operative samples influences the accuracy of culture in the diagnosis of periprosthetic joint infection (PJI). The secondary aim was to create a predictive model of PJI using other known patient variables.Methods: A retrospective cohort of 3460 intra-operative samples from 887 patients was identified. The data was then analysed to compare intra-operative culture results (positive or negative) to the chosen gold standard of clinical diagnosis made by the treating team (infected or non-infected prosthetic joint). The intra-operative samples were grouped according to their labelling at the time of collection.Results: No single tissue type or anatomical location had both high sensitivity and specificity. The highest specificity for an anatomical location was hip bursa with 100%, for tissue type it was synovium with 93%. Sensitivity was highest in the anatomical locations for hip capsule (68%) and in the tissue types for pus (83%). Data analysis was performed to create a model for PJI and identified pre-operative predictors of PJI (increased white cell count, knee joint and non-revision surgery) which when used in combination with intra-operative culture results increased the sensitivity.Conclusion: Sample type and anatomical location influenced the reliability of the diagnosis of PJI however, no single sample type had higher diagnostic accuracy than samples combined thereby highlighting the necessity of obtaining multiple intra-operative samples in the diagnosis of PJI. The variation in predictive values of tissue types as well as improvement in sensitivity when combined with patient factors indicates that types of intra-operative sampling and the overall diagnostic pathway should vary depending on the individual case.