Periprosthetic Tissue Culture Research Articles

Sonication protocols and their contributions to the microbiological diagnosis of implant-associated infections: a review of the current scenario.

Addressing the existing problem in the microbiological diagnosis of infections associated with implants and the current debate about the real power of precision of sonicated fluid culture (SFC), the objective of this review is to describe the methodology and analyze and compare the results obtained in current studies on the subject. Furthermore, the present study also discusses and suggests the best parameters for performing sonication. A search was carried out for recent studies in the literature (2019-2023) that addressed this research topic. As a result, different sonication protocols were adopted in the studies analyzed, as expected, and consequently, there was significant variability between the results obtained regarding the sensitivity and specificity of the technique in relation to the traditional culture method (periprosthetic tissue culture - PTC). Coagulase-negative Staphylococcus (CoNS) and Staphylococcus aureus were identified as the main etiological agents by SFC and PTC, with SFC being important for the identification of pathogens of low virulence that are difficult to detect. Compared to chemical biofilm displacement methods, EDTA and DTT, SFC also produced variable results. In this context, this review provided an overview of the most current scenarios on the topic and theoretical support to improve sonication performance, especially with regard to sensitivity and specificity, by scoring the best parameters from various aspects, including sample collection, storage conditions, cultivation methods, microorganism identification techniques (both phenotypic and molecular) and the cutoff point for colony forming unit (CFU) counts. This study demonstrated the need for standardization of the technique and provided a theoretical basis for a sonication protocol that aims to achieve the highest levels of sensitivity and specificity for the reliable microbiological diagnosis of infections associated with implants and prosthetic devices, such as prosthetic joint infections (PJIs). However, practical application and additional complementary studies are still needed.

Dithiotreitol and Next Generation Sequencing of Bacterial 16S rRNA Shows Similar Diagnostic Security as Periprosthetic Tissue Cultures to Diagnose PJI

Dithiotreitol and Next Generation Sequencing of Bacterial 16S rRNA Shows Similar Diagnostic Security as Periprosthetic Tissue Cultures to Diagnose PJI

The role of sonication in the diagnosis of periprosthetic joint infection in total shoulder arthroplasty

An increased sensitivity of sonication compared to periprosthetic tissue cultures in the diagnosis of periprosthetic joint infection (PJI) of hip and knee arthroplasty has been reported. The goal of this study was to determine if there is also an added value of implant sonication in the diagnosis of PJI in total shoulder arthroplasty (TSA). A retrospective analysis of patients who underwent removal of their TSA combined with sonication of the implant for suspicion of PJI between April 2009 and August 2017 was performed. The diagnosis of PJI was based on the major criteria described by Parvizi. We calculated sensitivity, specificity, predictive values, likelihood ratios and diagnostic accuracy for sonication cultures in comparison with periprosthetic tissue cultures. Data from 41 patients were analysed. Standard synovial fluid cultures combined with intraoperative periprosthetic tissue cultures had a sensitivity of 95%, specificity of 95% and total accu- racy of 95%. Sonication cultures had a sensitivity of 91%, specificity of 68% and total accuracy of 80%. Six patients had negative standard cultures but positive sonication cultures. In patients with only one positive standard culture, the pathogen of the sonication culture corresponded to the pathogen of the positive soft tissue culture. We found a possible added value of sonication of TSA in the diagnosis of PJI in conjunction with standard intraoperative cultures. In some patients with suspicion of low-grade TSA infection, sonication could identify a possible causal microorganism despite negative standard cultures.

Direct Prosthetic Joint Infection Diagnosis from Sonication Fluid Inoculated in Blood Culture Bottles by Direct MALDI-TOF Mass Spectrometry

An accurate and fast microbiological diagnosis is key for a proper management and results when facing prosthetic joint infection (PJI). The purpose of this study is to assess the role of direct Matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry (MS) for early identification of the pathogens causing PJI from sonication fluid inoculated in blood culture bottles (BCB-SF). This prospective multicentric study included 107 consecutive patients from February 2016 to February 2017. Among them, 71 prosthetic joint revision surgeries were undergone for aseptic and 36 for septic reasons. Prostheses were sonicated and the resulting fluid inoculated into blood culture bottles, regardless the suspicion for infection. We assessed the diagnostic performance of direct MALDI-TOF MS identification of the pathogens in BCB-SF and compared it with periprosthetic tissue and conventional sonication fluid cultures. The sensitivity of direct MALDI-TOF MS of BCB-SF (69%) was higher compared to conventional sonication fluid (69% vs. 64%, p > 0.05) or intraoperative tissue cultures (69% vs. 53%, p = 0.04), especially for patients receiving antimicrobial treatment. This approach also reduced the time for identification but the specificity was compromised (100% vs. 94%) and polymicrobial infections were missed. In conclusion, BCB-SF improves the sensitivity and reduces the time of PJI diagnosis when used in combination with conventional cultures under strict sterility conditions.

Antimicrobial effect of methylene blue in microbiologic culture to diagnose periprosthetic joint infection: an in vitro study

BackgroundAs one of the major diagnostic criteria in Musculoskeletal Infection Society, the microbiological diagnosis of periprosthetic joint infection (PJI) performed by analyzing periprosthetic tissue culture is recommended. The goal of this study was to determine if methylene blue (MB) has antibacterial effects that might interfere with microbial culture in vitro.MethodsEight isolates of reference strains of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Streptococcus pyogenes, and Candida albicans were incubated appropriately on blood agar, China blue agar, or Sabouraud’s agar plates at 35 ℃. (Streptococci were cultured in a CO2-rich atmosphere.) Each bacterial suspension was formed by 50-fold dilution before the test MB was added. For each strain, bacterial suspension was divided into 3 groups (5 samples each) exposed either MB 0.1%, MB 0.05% or sterile non-bacteriostatic 0.45% saline. The antimicrobial property of MB was determined by measuring the bacterial density on agar plates incubated for 24 h and comparing it with controls unexposed to MB.ResultsExposure to MB 0.1% or MB 0.05% negatively affected microbial viability in vitro. Of the diluted form of MB exposure, reference strains of S. hominis and A. baumannii resulted in fewer colony-forming units compared with the sterile saline control. MB concentration was significantly negatively correlated with CFU counts of S. hominis and A. baumannii strains. The antibacterial property of MB 0.1% or MB 0.05% appears to affect the ability to culture the organism in in vitro assays.ConclusionMB 0.1% or MB 0.05% has strong antimicrobial activities against some commonly encountered bacterial strains in PJI in vitro. To further evaluate its potential antibacterial usefulness in clinical applications, the next studies are needed to assess the ability of MB to affect the ability to culture the pathogens in vivo, especially in periprosthetic tissue.

The Function of Sonication in the Diagnosis of Periprosthetic Joint Infection After Total Knee Arthroplasty.

Periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) is a serious adverse event. Culturing of samples of periprosthetic tissue is the standard technique utilized for the microbiological diagnosis of PJI. However, this technique is neither sensitive nor specific since in PJI the microorganisms are usually in a biofilm on the surface of the prosthesis. The objective of this paper is to know the role of sonication in the diagnosis of PJI after TKA. Sonication consists in taking samples of bacteria from biofilms adhered to the prosthetic surface. The reported sensitivity for the diagnosis of PJI of the periprosthetic tissue cultures and sonicate fluid cultures is 54% and 75%, apiece. The specificity is 98% and 87%, respectively. In conclusion, the sonication technique is a dependable test for the diagnosis of PJI after TKA with a greater sensitivity and specificity than the conventional periprosthetic tissue cultures. Sonication of polyethylene liners, rather than the whole prosthesis, has been reported to be sufficient for diagnosis of prosthetic joint infection.

Assessment of Microbiological and Clinical Findings of Two-Stage Revision Arthroplasty Performed Due to Prosthetic Joint Infection.

Two-stage revision arthroplasty remains the main surgical strategy for the treatment of prosthetic joint infections (PJI). Sonicate fluid culture has improved sensitivity compared to standard periprosthetic tissue culture, but its usefulness is questionable during the second stage of revision arthroplasty. Twenty-seven patients with prosthetic joint infection were investigated. Tissue and sonicate fluid cultures were examined to detect bacteria on the removed spacer during the second stage of exchange arthroplasty. Microbiological findings were analyzed and patients were assessed within an average of 5 years follow up. Tissue cultures in second-stage revision arthroplasties were positive in 6/27 cases (22.2%) growing CNS in 4 cases (14.8%), Staphylococcus aureus in 1 case (3.7%), and Enterococcus faecalis in 1 case (3.7%). In 3 cases (11.1%) infection was identified as a result of a sonication procedure. Clinical failures at final follow-up were recorded in 4 (14.8%) patients, with reinfection noted in 3 of them. Arthrodesis and spacer exchange followed by suppressive antibiotic therapy were performed in 2 cases. 1. Tissue cultures remain the gold standard in diagnosis of PIJ although a negative culture does not rule out the presence of bacteria on spacers removed during second stage revision for PJI. 2. Sonication appears to have limited ability to detect persistent infection before reimplantation and was not associated with recurrent infection; however, it can be considered a complementary method that could make it possible to identify new microorganisms and facilitate the selection of appropriate treatment options. 3. The positive results of sonication should be interpreted as the detection of actual pathogens in the light of the clinical, microbiological and histopathological data, especially for patients with immunodeficiency.

Positivity Trends of Bacterial Cultures from Cases of Acute and Chronic Periprosthetic Joint Infections.

Background: There is no clear distinction in the literature regarding the positivity trends of bacterial cultures in acute and chronic prosthetic joint infections. Methods: We prospectively included in this study all consecutive patients, aged over 18 years, that were hospitalized from September 2016 through December 2019, that underwent a joint arthroplasty revision surgery. Results: Forty patients were included in our analysis, 11 acute/acute hematogenous and 29 chronic PJIs. We were able to identify all strains of acute/acute hematogenous PJIs within 3 days, whereas this took 8 days for chronic PJIs. Sonication fluid cultures increased the positivity rate and helped in identifying rare pathogens such as Ralstonia pickettii from chronic PJIs, but also increased the number of identified strains from acute PJIs. Culturing synovial fluid in our study did not seem to have a clear benefit compared to sonication fluid and periprosthetic tissue cultures. Conclusion: There was a different positivity trend in bacterial cultures. Empiric broad-spectrum antibiotic therapy can be re-evaluated after 3 days for acute PJIs. A prolonged incubation time, especially in the case of chronic PJIs, is mandatory; however, extending the incubation period beyond 14 days would not further improve the ability to identify microorganisms.

Experience With the Use of the MicroDTTect Device for the Diagnosis of Low-Grade Chronic Prosthetic Joint Infections in a Routine Setting.

Background: In prosthetic joint infections (PJIs), identification of the causative microorganisms is critical to successfully adapt and optimize treatment. However, microbiological diagnosis of PJIs remains a challenge notably because bacteria are embedded in biofilm adhered to the prosthetic material. Recently, dithiothreitol (DTT) treatment of prosthesis has been proposed as a new strategy to release bacteria from biofilm and to improve the yield of microbiological diagnosis. In this study, we evaluated the interest of a commercial device using DTT, the MicroDTTect system (Heraeus, Hanau, Germany), for the diagnosis of low-grade chronic PJIs, compared to the conventional culture of periprosthetic tissue (PPT) samples.Methods: Twenty patients undergoing a surgery procedure for removal of prosthetic material because of a suspicion of low-grade PJI without pre-operative microbiological documentation were included (NCT04371068). Bacteriological results using the fluid obtained after prosthesis treatment with the MicroDTTect system were compared to results obtained with conventional culture of PPT samples.Results: All the bacteria considered as responsible for PJIs recovered from culture of PPT samples were also detected using the MicroDTTect device. For one patient, an additional bacterial isolate (Staphylococcus haemolyticus) suspected to be involved in a polymicrobial PJI was identified using DTT treatment. Time to positivity of the cultures was also reduced using the MicroDTTect system, notably in case of Cutibacterium acnes infection. However, probable bacterial contaminants were found (MicroDTTect system, n = 5; PPT samples, n = 1).Conclusion: This study showed that DTT treatment of the prosthetic component using the MicroDTTect device could improve the microbiological diagnosis of low-grade PJIs.

The utility of dithiothreitol treatment of periprosthetic tissues and explanted implants in the diagnosis of prosthetic joint infection

PurposeThe methods used for the processing of periprosthetic tissues and explanted implants to improve culture outcome especially in biofilm mediated prosthetic joint infections (PJIs) are still debated upon. Studies have reported that Dithiothreitol (DTT) pretreatment of infected devices gives similar results as sonication. However, none of them evaluated the DTT treatment of periprosthetic tissues and explanted implants in the same cohort. We evaluated the diagnostic utility of DTT treatment of periprosthetic tissue and explanted implants, as compared to the normal saline treatment of periprosthetic tissues and sonication of explanted implants for the diagnosis of PJI. MethodsSeventy-three revision arthroplasty cases were prospectively included in this study. Three to five tissue specimens and the explanted implants were collected from each patient. Periprosthetic tissue samples were processed by both normal saline and DTT treatments. Explanted implants were subjected to both DTT treatment and sonication. Musculoskeletal Infection Society (MSIS) PJI criteria was used as the reference standard for the diagnosis of PJI. ResultsOf the 73 cases enrolled, 34 had PJI and 39 were aseptic failures. The sensitivity of DTT treated periprosthetic tissue culture (PTC) and saline treated PTC was similar (66.6% vs 58.8%, P = 0.25). The specificity of both was 100%. Sonication and DTT treatment of explanted implants showed comparable sensitivity (85.3% vs 82.4%) and specificity (100% vs 97.4%), P > 0.99. Compared to DTT treated PTC, culture of DTT treated explanted implants significantly improved the diagnosis of PJI (P = 0.03). ConclusionsWe could verify that DTT can be used to improve culture outcome in laboratories where biofilm detaching sonication techniques are not available for infected implants. In addition, we showed that it is possible to use DTT for treating tissue biopsies, but larger studies are required to confirm our findings.

Sonication improves microbiologic diagnosis of periprosthetic elbow infection.

Periprosthetic joint infection (PJI) is a relatively frequent and oftentimes devastating complication after total elbow arthroplasty (TEA). Its microbiologic diagnosis is usually based on periprosthetic tissue culture (hereafter referred to as tissue culture), but the sensitivity of tissue culture is variable. Although implant sonication culture has been shown to be superior to tissue culture for the diagnosis of hip and knee PJI, only a single small study (of fewer than 10 infected implants) has assessed sonication for PJI diagnosis after elbow arthroplasty. We retrospectively analyzed 112 sonicate fluid cultures from patients who underwent revision of a TEA at a single institution between 2007 and 2019, comparing results to those of tissue cultures. We excluded patients who had fewer than 2 tissues submitted for culture. Using the Infectious Diseases Society of America guidelines to define PJI, there were 49 infected and 63 non-infected cases. Median ages in the PJI and non-infected groups were 66 and 61 years, respectively. In the non-infected group, 65% were female vs. 63% in the PJI group. We reviewed clinical characteristics and calculated the sensitivity and specificity of tissue compared with sonicate fluid culture. In addition, we compared the sensitivity of tissue culture to the combination of tissue and sonicate fluid culture. The most common pathogens were coagulase-negative Staphylococcus sp (49%), followed by Staphylococcus aureus (12%). Sensitivity of tissue culture was 63%, and sensitivity of sonicate fluid culture was 76% (P = .109). Specificity of tissue culture was 94% and specificity of sonicate fluid culture was 100%. Sensitivity of sonicate fluid culture in combination with tissue culture was 84% (P = .002 compared to tissue culture alone). In this study, we found that the combination of sonicate fluid and tissue culture had a greater sensitivity than tissue culture alone for microbiologic diagnosis of PJI after TEA.

324. Implant Sonication Improves Microbiologic Diagnosis of Elbow Prosthetic Joint Infection

BackgroundWith a reported incidence of up to 12%, periprosthetic joint infection (PJI) is a frequent complication of total elbow arthroplasty (TEA). Its microbiologic diagnosis is usually based on periprosthetic tissue culture (hereafter referred to as tissue culture), despite the poor sensitivity of this technique. Although implant sonication cultures have been shown to be superior to tissue cultures for hip and knee PJI diagnosis, only a single small study (including fewer than 10 infected implants) has assessed sonication of elbow arthroplasties.MethodsWe retrospectively analysed 116 sonicate fluid cultures from patients who underwent revision of a TEA at our Institution between 2007 and 2019, comparing results to tissue cultures. Nine elbows who had fewer than 2 tissue samples obtained during surgery were excluded. Using the IDSA guidelines to define PJI, there were 46 infected cases and 61 aseptic failures. We reviewed clinical characteristics and calculated the sensitivity and specificity of periprosthetic tissue culture compared to culture of samples obtained by implant sonication. In addition, we compared the sensitivity of tissue culture to the combination of tissue and sonicate fluid culture.ResultsA total of 107 elbows were included. Median ages in the aseptic failure and PJI groups were 60 and 67 years, respectively. Gender distribution was similar for both groups (PJI group 62% females; aseptic group 65% females). The most common pathogens were coagulase negative Staphylococcus species (66%), followed by Staphylococcus aureus (18%). The sensitivity of tissue culture was 63% and the sensitivity of sonicate fluid culture was 76% (p=0.14). The specificity of tissue culture was 86% and the specificity of sonicate fluid culture was 100%. Sensitivity of sonicate fluid culture in combination with tissue culture was 91% (p=0.045).Table. Comparison of tests for microbiologic diagnosis of PJI ConclusionThe combination of sonicate fluid culture and tissue culture had a greater sensitivity than tissue culture alone for microbiologic diagnosis of elbow TEA infection.Disclosures Joachin Sanchez-Sotelo, M.D, PhD, Elsevier (Other Financial or Material Support, Publishing Royalties)Exactech (Consultant)Oxford Univerity Press (Other Financial or Material Support, Publishing Royalties)Stryker (Grant/Research Support)Wright (Consultant) Robin Patel, MD, Accelerate Diagnostics (Grant/Research Support)CD Diagnostics (Grant/Research Support)Contrafect (Grant/Research Support)Curetis (Consultant)GenMark Diagnostics (Consultant)Heraeus Medical (Consultant)Hutchison Biofilm Medical Solutions (Grant/Research Support)Merck (Grant/Research Support)Next Gen Diagnostics (Consultant)PathoQuest (Consultant)Qvella (Consultant)Samsung (Other Financial or Material Support, Dr. Patel has a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, and a patent on an anti-biofilm substance issued.)Selux Dx (Consultant)Shionogi (Grant/Research Support)Specific Technologies (Consultant)

A comparative study of heterogeneous antibiotic resistance of microbial populations in conventional periprosthetic tissue cultures and sonication fluid cultures of orthopaedics explanted prostheses.

"Heterogeneity" describes a phenomenon where subpopulations of seemingly isogenic bacteria exhibit a range of susceptibilities to a particular antibiotic. We aim to investigate the frequency of heterogeneity among microbes isolated from infected prostheses, and its possible correlation with microbial resistance. Between May 2014 and June 2019, we investigated 234 patients, at our institution, undergoing revision arthroplasty because of loosening of the prostheses or because of periprosthetic joint infection. All patients had periprosthetic tissue culture, sonication of prosthesis and direct inoculation of Sonication fluid into blood culture bottles. We assessed the presence of heterogeneity among all pathogens isolated from infected prostheses. Using standard non-microbiological criteria to determine periprosthetic joint infection, it was found that 143 patient (61.1%) had aseptic loosening while 91 patients (38.9%) had periprosthetic joint infection. Comparing the two methods, the results of our study showed that the method of sonication was significantly more sensitive than tissue culture [91% (83-96) vs. 43% (33-54); p < 0.005]. In this study, heterogeneity was reported in 15 cases, 16.5% of all infections and 6.4% in the total population. In our study, Staphylococcus epidermidis was the most commonly isolated strain followed by Staphylococcus aureus, at a rate of 35.2% and 19.8%, respectively. Antibiotics in which the microorganisms exhibited heterogeneous bacterial behavior most frequently were Gendamicin (5.3%), Vancomycin (4.9%). There is increasing evidence that heterogeneity can lead to therapeutic failure and that the detection of this phenotype is a prerequisite for a proper antibiotic choice to have a successful therapeutic effect.

Patient-Related Factors Affecting the Sensitivity of Sonication of Removed Hip and Knee Implants Against Conventional Tissue Cultures for Diagnosis of Prosthetic Joint Infections

Despite its decreasing incidence, prosthesis-related infections remain a research, diagnostic, therapeutic and cost-related problem. Our study aim was to compare the diagnostic accuracy of conventional periprosthetic tissue culture and culture of sonication fluid of the explanted hardware and to investigate the role of patientrelated factors affecting the sensitivity of the sonication method. We investigated 70 patients undergoing revision hip or knee arthroplasty, at our institution. Patients’ medical history and demographic characteristics were recorded. We compared the culture of samples obtained by sonication of explanted hip and knee prostheses with conventional culture of periprosthetic tissue for the microbiological diagnosis of prosthetic-joint infection. Thirty-two patients had septic loosening and 38 aseptic loosening (48 hip prostheses and 22 knee prostheses). The sensitivities of sonication fluid culture and conventional tissue cultures were 81.25% and 56.25%, respectively (p-value = 0.043). The sensitivity of the sonication method was statistically higher in obese, diabetic patients, with age above 60, in uncemented arthroplasties and in arthroplasties because of primary osteoarthritis (p-values &lt; 0.05). The sonication method has a greater sensitivity than the conventional periprosthetic tissue cultures for the periprosthetic infections, especially in obese, diabetic patients, with age above 60, in uncemented arthroplasties and in arthroplasties because of primary osteoarthritis.

The role of implant sonication in the diagnosis of periprosthetic shoulder infection

The aim of this study was to investigate the validity of implant sonication fluid cultures in the diagnosis of shoulder periprosthetic joint infection (PJI) compared with tissue culture. This was a retrospective case-control study analyzing all patientswho underwent a revision surgery for any kind of suspected septic or aseptic event due to failed shoulder arthroplasty at our institution between July 2014 and December 2018. The diagnostic validity of implant sonication was analyzed on the basis of the last proposed definition criteria of the International Consensus Meeting and compared with standard tissue cultures. Of the 72 patients, a total of 28 (38.9%) were classified as infected. Of the 28 infected patients, 20 (71.4%) had an identified organism by tissue cultures, and Cutibacterium acnes was the most commonly isolated pathogen. The sensitivities of sonicate fluid (≥50 CFU/mL) and periprosthetic tissue culture for the diagnosis of periprosthetic shoulder infection were 36% and 61% (P = .016), and the specificities were 97.7% and 100% (P > .99), respectively. If no cutoff value was used in sonication culture, the sensitivity increased to 75% whereas the specificity dropped to 82%. Although there was no significant difference in sensitivity between tissue culture and the no-cutoff sonication fluid culture (61% vs. 75%, P = .125), the specificity of tissue culture was significantly higher (100% vs. 82%, P= .01). Tissue culture showed a higher sensitivity and specificity than implant sonication in the diagnosis of shoulder PJI and should remain the gold standard for microbiological diagnosis of shoulder PJI.

Sonication of retrieved implants improves sensitivity in the diagnosis of periprosthetic joint infection

BackgroundSonication is a valuable tool in the diagnosis of periprosthetic joint infections (PJI). However, conditions and definition criteria for PJI vary among studies. The aim of this study was to determine the diagnostic performance (i.e., specificity, sensitivity) of sonicate fluid culture (SFC) against periprosthetic tissue culture (PTC), when using European Bone and Joint Infection Society (EBJIS) criteria.MethodsFrom March 2017 to April 2018, 257 implants were submitted for sonication. PJI was defined according to the EBJIS criteria as well as according to the International Consensus Meeting criteria of 2018 (ICM 2018). Only cases with at least one corresponding tissue sample were included. Samples were cultured using traditional microbiological plating techniques. Sensitivity and specificity were determined using two-by-two contingency tables. McNemar’s test was used to compare proportions among paired samples. Subgroup analysis was performed dividing the cohort according to the site of PJI, previous antibiotic treatment, and time of manifestation. Prevalence of pathogens was determined for all patients as well as for specific subgroups.ResultsAmong the 257 cases, 145 and 112 were defined as PJI and aseptic failure, respectively. When using the EBJIS criteria, the sensitivity of SFC and PTC was 69.0 and 62.8%, respectively (p = .04). Meanwhile, the specificity was 90.2 and 92.9%, respectively (p = .65). When adopting ICM 2018 criteria, the sensitivity of SFC and PTC was 87.5 and 84.4% (p = .63) respectively, while the specificity was 85.1 and 92.5% (p = .05), respectively. The most commonly identified pathogens were coagulase-negative staphylococci (26% overall), while 31% of PJI were culture-negative and 9% polymicrobial.ConclusionsSFC exhibited significantly greater sensitivity versus PTC when using the EBJIS criteria. Nevertheless, the diagnosis of PJI remains a difficult challenge and different diagnostic tools are necessary to optimize the outcome.

A Clinico-Microbiological Study of Prosthetic Joint Infections in an Indian Tertiary Care Hospital: Role of Universal 16S rRNA Gene Polymerase Chain Reaction and Sequencing in Diagnosis.

Background:We determined the magnitude and clinico-microbiological profile of prosthetic joint infection (PJI) at a tertiary hospital. The diagnostic potential of 16S rRNA gene polymerase chain reaction (PCR) and sequencing on periprosthetic tissue samples was evaluated for the diagnosis of PJI.Materials and Methods:This ambispective cohort study consisted of patients who underwent primary or revision hip or knee arthroplasty from June 2013 to June 2017. The patients were classified as either infected or noninfected according to criteria set out by the musculoskeletal infection society (MSIS). Three to five periprosthetic tissue samples were collected from each patient for culture and 16S rRNA gene PCR sequencing.Results:Hundred and six patients were diagnosed to have PJI as per the MSIS Criteria. The cumulative incidence of PJI at our Institute at the end of 36 months was 1.1% (95% confidence interval [CI]: 0.59–2.91). Microorganisms were isolated by periprosthetic tissue culture (PTC) in 84 patients (sensitivity: 79% and specificity: 100%). Gram-negative aerobes were most frequently isolated (61%). Polymicrobial infections were present in 8.3% of cases. The most common infecting microorganism was Staphylococcus aureus (19.5%). Multidrug resistance and methicillin resistance were noted in 54% and 34% of bacterial isolates, respectively. The sensitivity and specificity of 16S rRNA PCR of periprosthetic tissue was 86% (95% CI: 74.9–89.9) and 100% (95% CI: 94.7–100), respectively. Periprosthetic tissue 16S rRNA PCR was more sensitive than PTC (P = 0.008), although both were 100% specific (P = 0.99).Conclusions:The incidence of PJI at our Institute compares well with other published reports. Contrary to previous reports, a predominance of Gram-negative PJI's was found. The preponderance of multidrug-resistant organisms in PJI's is worrisome. The high sensitivity and specificity of the 16S PCR assay used in our study support its use in culture-negative PJI suspected cases.

Microbiology analysis of periprothetic joint infection post total hip and knee arthroplasty of 9 centers in Beijing between 2014 and 2016

Objective: To investigate the microbiological test, antibiotic sensitivity and surgical treatment of periprosthetic joint infection(PJI) cases in post total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients. Methods: A retrospective cross-sectional survey was conducted on 318 patients who underwent THA or TKA in 9 clinical centers in Beijing from January 2014 to December 2016.The data of microbiology, antibiotic sensitivity and surgical treatment were collected.The average age of patients was (62.3±13.1) years old (range: 21-86 years old), including 145 males and 173 females.The body mass index was (25.6±3.8) kg/m (2) (range: 15.6-38.1 kg/m(2)). Results: In total, 318 patients had microorganisms detected by periprosthetic tissue culture or synovial fluid culture, 209 cases (65.7%) had Gram-positive bacteria, 29 cases (9.1%) had Gram-negative bacteria, 10 cases (3.1%) had fungi, 3 cases (0.9%) had non-tuberculous mycobacteria, 72 cases (22.6%) were negative, 69 cases (21.7%) had methicillin-resistant bacteria. The antibiotic sensitivity results showed that the overall resistance rate of penicillin, cefuroxime, amoxicillin+clavulanic acid was 79.9%, 69.9%, and 68.1%, respectively; meropenem, vancomycin, and linezolid resistance rate was 0. For the treatment methods of hip and knee PJI, two-stage revision surgery acounted for 72.9% (108/148) and 64.1% (109/170), respectively. One-stage revision surgery accounted for 21.6% (32/148) and 7.6% (13/170), and open debridement surgery accounted for 4.7%(7/148) and 26.4% (45/170). Conclusions: Gram-positive bacteria was still the main pathogen of PJI.The methicillin-resistant bacteria and rare bacteria should be payed attention to. The Majority of hip and knee PJI cases were treated by two-stage revision surgery.

Culture of periprosthetic tissue in blood culture bottles for diagnosing periprosthetic joint infection

BackgroundThe purpose of this meta-analysis was to evaluate the diagnostic accuracy of periprosthetic tissue culture in blood culture bottles (BCB) for periprosthetic joint infection (PJI).MethodsPubMed, Web of Science, and Embase were systematically searched for eligible studies evaluating the diagnostic performance of periprosthetic tissue culture in BCB for the diagnosis of PJI. The pooled data were analysed by Meta-Disc software.ResultsFour studies with a total of 1071 patients were included in this meta-analysis. The summarized estimates showed that periprosthetic tissue culture in BCB may be of great value in PJI diagnosis with a pooled sensitivity of 0.70 (95% confidence interval [CI]; 0.66–0.75), specificity of 0.97 (95% CI: 0.95–0.98); positive likelihood ratio (PLR) of 20.98 (95% CI: 11.52–38.2); negative likelihood ratio (NLR) of 0.28 (95% CI: 0.20–0.40); and diagnostic odds ratio (DOR) of 92.26 (95% CI: 43.93–193.78).ConclusionsThe present meta-analysis showed that periprosthetic tissue in BCB improves the results of microorganism cultures, with a sensitivity of 70% and a specificity of 97%. However, more large-scale, well-performed studies are needed to verify our findings.

Sonication of removed implants improves microbiological diagnosis of postoperative spinal infections.

In total joint replacement, culturing of the sonication fluid of removed implants has proven to be more sensitive than conventional periprosthetic tissue culture for the microbiological diagnosis of prosthetic joint infection. However, its role in postoperative spinal implant infection (PSII) is not well investigated. Therefore, the aim of this study was to determine the validity of sonication in detecting infection following instrumented spine surgery. In this prospective controlled consecutive cohort study, patients undergoing spinal revision between September 2016 and March 2018 were analyzed. In all patients sonication of removed spinal implants and at least one peri-implant tissue culture were performed. Demographic data, including age, gender, clinical manifestation, comorbidities, laboratory values (CRP and blood leukocytes), were recorded. Microorganisms causing PSII were documented. Sensitivity and specificity of sonication and peri-implant tissue culture were evaluated. A total of 118 patients were included. PSII was diagnosed in 35 patients, representing 29.6% of the study cohort. Sensitivities of tissue and sonication fluid culture were 65.7% (95% confidence interval (CI) 48.6-80.0) and 94.3% (95% CI 85.7-100) (p value = 0.002) and specificities 96.4% (95% CI 91.6-100) and 98.8% (95% CI 96.4-100), respectively. The most common microorganisms found in PSII were coagulase-negative Staphylococci and Propionibacterium acnes. Eleven PSIIs were detected only by sonicate fluid culture. Culture of samples obtained by spinal implant sonication was more sensitive than conventional peri-implant tissue culture for the microbiological diagnosis of PSII. Therefore, sonication should be used as a routine tool in the diagnostic workup of PSII. These slides can be retrieved under Electronic Supplementary Material.