Broad-range 16 s rDNA PCR in synovial fluid does not improve the diagnostic performance of septic arthritis in native joints in adults: cross-sectional single-center study in 95 patients

Assessment and diagnosis of the acute hot joint: a systematic review and meta-analysis

OBJECTIVES

Prompt diagnosis of septic arthritis (SA) in acute native hot joints is essential for avoiding unnecessary antibiotics and hospital admissions. We evaluated the utility of synovial fluid (SF) and serum tests in differentiating causes of acute hot joints.

METHODS

We performed a systematic literature review of diagnostic testing for acute hot joints. Articles were included if studying ≥1 serum or SF test(s) for an acute hot joint, compared with clinical assessment and SF microscopy and culture. English-language articles only were included, without date restriction. The following were recorded for each test, threshold and diagnosis: sensitivity, specificity, positive/negative predictive values and likelihood ratios. For directly comparable tests (i.e. identical fluid, test and threshold), bivariate random-effects meta-analysis was used to pool sensitivity, specificity, and areas under the curves.

RESULTS

A total of 8443 articles were identified, and 49 were ultimately included. Information on 28 distinct markers in SF and serum, differentiating septic from non-septic joints, was extracted. Most had been tested at multiple diagnostic thresholds, yielding a total of 27 serum markers and 156 SF markers. Due to heterogeneity of study design, outcomes and thresholds, meta-analysis was possible for only eight SF tests, all differentiating septic from non-septic joints. Of these, leucocyte esterase had the highest pooled sensitivity [0.94 (0.70, 0.99)] with good pooled specificity [0.74 (0.67, 0.81)].

CONCLUSION

Our review demonstrates many single tests, individually with diagnostic utility but suboptimal accuracy for exclusion of native joint infection. A combination of several tests with or without a stratification score is required for optimizing rapid assessment of the hot joint.

An update on recent progress of the epidemiology, etiology, diagnosis, and treatment of acute septic arthritis: a review

Acute septic arthritis is on the rise among all patients. Acute septic arthritis must be extensively assessed, identified, and treated to prevent fatal consequences. Antimicrobial therapy administered intravenously has long been considered the gold standard for treating acute osteoarticular infections. According to clinical research, parenteral antibiotics for a few days, followed by oral antibiotics, are safe and effective for treating infections without complications. This article focuses on bringing physicians up-to-date on the most recent findings and discussions about the epidemiology, etiology, diagnosis, and treatment of acute septic arthritis. In recent years, the emergence of antibiotic-resistant, particularly aggressive bacterial species has highlighted the need for more research to enhance treatment approaches and develop innovative diagnosis methods and drugs that might combat better in all patients. This article aims to furnish radiologists, orthopaedic surgeons, and other medical practitioners with contemporary insights on the subject matter and foster collaborative efforts to improve patient outcomes. This review represents the initial comprehensive update encompassing patients across all age groups.

Atypical Staphylococcal Septic Arthritis in a Native Hip: A Case Report and Review

Septic arthritis is a synovial fluid and joint tissue infection with significant morbidity and mortality risk if not diagnosed and treated promptly. The most common pathogen to cause septic arthritis is Staphylococcus aureus, a Gram-positive bacterium. Although diagnostic criteria are in place to guide the diagnosis of staphylococcal septic arthritis, there is a lack of adequate sensitivity and specificity. Some patients present with atypical findings which make it difficult to diagnose and treat in time. In this paper, we present the case of a patient with an atypical presentation of recalcitrant staphylococcal septic arthritis in a native hip complicated by uncontrolled diabetes mellitus and tobacco usage. We review current literature on diagnosing S. aureus septic arthritis, novel diagnostic technique performance to guide future research and assist clinical suspicion, and current S. aureus vaccine development for at-risk patients.

Evaluation of the MRSA/SA ELITe MGB Assay for the Detection of Staphylococcus aureus in Bone and Joint Infections

Bone and joint infections represent a potentially devastating complication of prosthetic orthopedic joint replacement, thus requiring both rapid and appropriate antibiotic treatment. Staphylococcus aureus is one of the most common pathogens involved in this pathology. Being able to assert its presence is the first step of efficient patient management. This monocenter study evaluated the MRSA/SA ELITe MGB assay for the molecular detection of S. aureus and methicillin-resistant S. aureus (MRSA) in bone and joint biopsy specimens and synovial fluids. This test, together with conventional techniques, including standard cultures and the 16S rRNA amplification assay, was performed on 208 successive perioperative samples collected prospectively for 1 year obtained from 129 patients. Using conventional techniques, we detected a microbial pathogen in 76 samples from 58 patients, 40 of which were identified as S. aureus. The limit of detection (LOD) of the MRSA/SA ELITe MGB assay was experimentally determined for bone and joint biopsy specimens and synovial fluids using negative samples spiked with S. aureus ATCC 43300. The sensitivities of S. aureus detection with the MRSA/SA ELITe MGB assay were 82.5% (33/40 samples) and 97.5% (39/40 samples) using the manufacturer's LOD and an experimentally determined LOD, respectively. Interestingly, using the osteoarticular specific LOD, 15 additional samples were determined to be positive for S. aureus DNA with the MRSA/SA ELITe MGB assay; in all cases, these samples were obtained from patients considered to be infected with S. aureus according to their clinical and microbiological records. The results were available within 24 h, which could help to expedite therapeutic decisions.

Pseudoseptic Arthritis in a Patient With Psoriasis

A 42-year-old male with a history of untreated psoriasis and a previous episode of presumed left knee septic arthritis developed sudden onset of left knee pain, swelling, and a moderate effusion. The pathogen could not be isolated despite extensive inflammation seen in synovial fluid (SF) and synovial tissue biopsy. Whether this is culture-negative septic arthritis or pseudo-septic arthritis is the enigma, given the limited sensitivity of current available SF microbiologic testing. We present a challenging and stimulating case with no current guidelines for an optimal empiric antibiotic regimen or anti-inflammatory therapy.

What are the best diagnostic tests for diagnosing bacterial arthritis of a native joint? : a systematic review of 27 studies

AIMS

This study aimed to answer two questions: what are the best diagnostic methods for diagnosing bacterial arthritis of a native joint?; and what are the most commonly used definitions for bacterial arthritis of a native joint?

METHODS

We performed a search of PubMed, Embase, and Cochrane libraries for relevant studies published between January 1980 and April 2020. Of 3,209 identified studies, we included 27 after full screening. Sensitivity, specificity, area under the curve, and Youden index of diagnostic tests were extracted from included studies. We grouped test characteristics per diagnostic modality. We extracted the definitions used to establish a definitive diagnosis of bacterial arthritis of a native joint per study.

RESULTS

Overall, 28 unique diagnostic tests for diagnosing bacterial arthritis of a native joint were identified. The following five tests were deemed most useful: serum ESR (sensitivity: 34% to 100%, specificity: 23% to 93%), serum CRP (sensitivity: 58% to 100%, specificity: 0% to 96%), serum procalcitonin (sensitivity: 0% to 100%, specificity: 68% to 100%), the proportion of synovial polymorphonuclear cells (sensitivity: 42% to 100%, specificity: 54% to 94%), and the gram stain of synovial fluid (sensitivity: 27% to 81%, specificity: 99% to 100%).

CONCLUSION

Diagnostic methods with relatively high sensitivities, such as serum CRP, ESR, and synovial polymorphonuclear cells, are useful for screening. Diagnostic methods with a relatively high specificity, such as serum procalcitonin and synovial fluid gram stain, are useful for establishing a diagnosis of bacterial arthritis. This review helps to interpret the value of various diagnostic tests for diagnosing bacterial arthritis of a native joint in clinical practice. Cite this article: Bone Joint J 2021;103-B(12):1745-1753.

Coinfection of Clostridium perfringens and Escherichia coli in gas-producing perianal abscess diagnosed by 16S rDNA sequencing: a case report

BACKGROUND

Gas-producing perianal abscess raises the possibility of clostridial infection, with Clostridium perfringens being the most common causative agent, which is highly lethal if untreated timely. As the treatment of clostridial infections often differs from that of non-clostridial infections, which they may closely resemble, the importance of accurate pathogenic organism identification cannot be overemphasized. The 16S rDNA of bacteria is highly conserved within a species and among species of the same genus but demonstrates substantial variation between different species, thus making it a suitable genomic candidate for bacterial detection and identification.

CASE PRESENTATION

Here, we report the case of a 53-year-old patient who was admitted to the hospital for a gas-producing perianal abscess. The patient was managed with ceftizoxime and ornidazole and then received debridement and drainage at the lesion on the second day after admission. The bacterial cultures of the patient isolates from the debridement showed a coinfection of Escherichia coli and Enterococcus faecium. Although perianal redness and swelling subsided obviously after the surgery, the patient was febrile to 38.3℃ with his left upper thigh red and swollen, aggravated with tenderness and crepitus. Considering insufficient debridement and the risk of incorrect identification of pathogens, a second debridement and drainage were performed 4 days after the primary operation, and 16S rDNA sequencing of the isolates implicated Clostridium perfringens infection. Given the discrepancies in diagnostic results and the treatment outcomes, Enterococcus faecium was identified as sample contamination, and a diagnosis of coinfection of Clostridium perfringens and Escherichia coli in gas-producing perianal abscess was confirmed. The patient was then successfully treated with meropenem and vancomycin and was discharged at 27 days of admission.

CONCLUSIONS

This case represents the first report of coinfection of both clostridial and non-clostridial organisms in gas-producing perianal abscess and the first case reporting the use of 16S rDNA sequencing in the diagnosis of perianal abscess. Timely pathogen identification is critical for treating gas-producing perianal abscess and an antibiotic regimen covering both aerobic and anaerobic organisms is recommended before true pathogens are identified.

Detection of bacterial DNA in synovial fluid in dogs with arthritis: a comparison between bacterial culture and 16S rRNA polymerase chain reaction

Background

Septic arthritis (SA) is a serious condition in dogs that requires a prompt diagnosis and treatment to minimize long-term joint pathology. Although bacterial detection in synovial fluid (SF) through culture or cytology is often performed to confirm diagnosis, the sensitivity of these tests is low. The need for a reliable diagnostic tool to confirm the presence of bacteria in SF in humans has led to the increased use of 16S rRNA (i.e., ribosomal RNA) gene sequencing by polymerase chain reaction (16S rRNA PCR). The aim of this prospective clinical study was to compare the sensitivity and specificity of 16S rRNA PCR with bacterial culture on blood agar plates after pre-incubation of SF in paediatric blood bacterial culture bottles to identify bacteria in dogs with clinical signs of SA and to investigate the usefulness of these methods as diagnostic tools.

Results

Ten dogs with clinical signs of SA, nine with osteoarthritis (OA, control group) and nine with clinical signs of immune-mediated polyarthritis (IMPA, second control group) were examined. Bacterial culture was positive in seven of 10 dogs with clinical SA, of which only two were positive by 16S rRNA PCR. The sensitivity of 16S rRNA PCR and bacterial culture analysis for dogs with clinical SA were 20% and 70%, respectively. All SF samples collected from control group (n = 9) and second control group (n = 14) animals were negative on culture, and 16S rRNA PCR rendered a specificity of 100%.

Conclusions

Our study showed a lower sensitivity of 16S rRNA PCR than bacterial culture for dogs with clinical SA. Our findings suggest that there is currently no advantage in using 16S rRNA PCR as a diagnostic tool for dogs with clinical SA. Furthermore, our study indicates that pre-incubation in paediatric blood bacterial culture bottles before bacterial cultivation on blood agar plates might enhance bacterial culture sensitivity compared to other culture methods.

Elaboration of a new synovial predictive score of septic origin for acute arthritis on the native joint (RESAS)

OBJECTIVE

To establish a new predictive score for the diagnosis of septic arthritis (SA) according to different synovial fluid (SF) variables.

METHODS

First, we analysed the different clinical, biological and SF variables associated with the diagnosis of SA (according to the Newman's criteria) in a monocentric cohort of acute arthritis (<30 days) (n = 233) (SYNOLACTATE cohort). A new score predictive of SA (RESAS) was created using the independent discriminant variables after multivariate analysis. A value was attributed to each variable of the score according to the weighting based on their likelihood ratio for the diagnosis of SA. RESAS performance was then tested on the first cohort (internal validation) and then checked on a second independent cohort (n = 70) (external validation).

RESULTS

After multivariate analysis, four independent variables of the SF were included for RESAS: (i) purulent SF or white blood cells count ≥70 000/mm3; (ii) absence/presence of crystals; (iii) lactate; and (iv) glucose synovial level. RESAS ranged between -4 and +13 points. The performance of RESAS to predicted SA was excellent with area under the curve (AUC)=0.928 (0.877-0.980) in internal validation and AUC=0.986 (0.962-1.00) in external validation. For a RESAS threshold ≥+4, SA was diagnosed with Se=56.0% (0.371-0.733), Sp=98.1% (0.952-0.993), LR+=29.1 (10.4-81.6) in the first cohort and with Se=91.7% (0.646-0.985), Sp=98.3% (0.909-0.997), LR+=53.2 (7.56-373) in the second cohort.

CONCLUSION

RESAS is a new composite score of four SF variables with excellent performance to predicted SA in acute arthritis population.

Moraxella nonliquefaciens septic arthritis in an immunocompetent child: A case report

A 2-year-old, previously healthy, male presented with an insidious history of intermittent left knee pain and edema who had been evaluated in the emergency department on multiple occasions with unremarkable imaging and normal laboratory results. On the day of presentation, he had mild edema of the left knee and inability to bear weight. Synovial fluid analysis showed an elevated white cell count with neutrophil predominance and mildly elevated inflammatory markers, consistent with septic arthritis. He underwent knee arthrotomy with irrigation and debridement and was initiated on broad spectrum antibiotics. Cultures were negative, polymerase chain reaction for MRSA and Kingella kingae were negative. He was started on a fifth-generation cephalosporin with resolution of symptoms, marked clinical improvement and normalization of inflammatory markers. The identification of the etiologic agent was possible due to detection of bacterial 16S rRNA gene amplification by PCR for Moraxella nonliquefaciens in the synovial fluid. He completed a course of 3 weeks of parenteral antibiotics at home with full recovery.

2020 French recommendations on the management of septic arthritis in an adult native joint

Septic arthritis (SA) in an adult native joint is a rare condition but a diagnostic emergency due to the morbidity and mortality and the functional risk related to structural damage. Current management varies and the recommendations available are dated. The French Rheumatology Society (SFR) Bone and Joint Infection Working Group, together with the French Language Infectious Diseases Society (SPILF) and the French Orthopaedic and Trauma Surgery Society (SOFCOT) have worked according to the HAS methodology to devise clinical practice recommendations to diagnose and treat SA in an adult native joint. One new focus is on the importance of microbiological documentation (blood cultures and joint aspiration) before starting antibiotic treatment, looking for differential diagnoses (microcrystal detection), the relevance of a joint ultrasound to guide aspiration, and the indication to perform a reference X-ray. A cardiac ultrasound is indicated only in cases of SA involving Staphylococcus aureus, oral streptococci, Streptococcus gallolyticus or Enterococcus faecalis, or when infective endocarditis is clinically suspected. Regarding treatment, we stress the importance of medical and surgical collaboration. Antibiotic therapies (drugs and durations) are presented in the form of didactic tables according to the main bacteria in question (staphylococci, streptococci and gram-negative rods). Probabilistic antibiotic therapy should only be used for patients with serious symptoms. Lastly, non-drug treatments such as joint drainage and early physical therapy are the subject of specific recommendations.