A Real Pain: Diagnostic Quandaries and Septic Arthritis

The accuracy and diagnostic value of gram staining joint aspirates in suspected joint infections

BACKGROUND

Septic arthritis is a debilitating condition with prolonged treatment and adverse outcomes. A gram stain is often performed from the joint aspirate sample, followed by a definitive culture. In our study, we assessed the accuracy of gram staining for suspected septic arthritis and explored factors associated with positive culture growth and false negatives in the gram stain.

METHODS

We retrospectively reviewed joint aspirates performed from 2015-2021 at a major trauma centre. Aspirates not cultured for septic arthritis were excluded. Data collected included aspirate site, gram stain and culture result delay, patient demographics, orthopaedic/rheumatological history, and comorbidities. Outcomes measured were gram stain sensitivity and specificity. Factors influencing positive cultures and false negative gram stain results were analysed using logistic regression.

RESULTS

Of 408 joint aspirates meeting the criteria, 37 did not undergo initial gram staining. Gram stain sensitivity was 30.4%, specificity was 97.6%. The delay from aspirate to definitive gram stain and culture results was 1.1 and 5.4 days, respectively Logistic regression identified that prosthetic joint(p = 0.007), past joint infections(p = 0.006), arthritis(p < 0.001), hypertension(p = 0.007), diabetes(p = 0.019) were positively associated with positive cultures. Past joint infections(p = 0.004) were positively associated with false negative gram stain results. Patients on antibiotics during the aspirate had a higher risk of false negative gram stain results (OR = 5.538, 95%CI, 2.802-10.948; p < 0.001).

CONCLUSIONS

In conclusion, the initial gram stain has limited sensitivity and caution should be exercised when interpreting negative results. Vigilance is crucial when the highlighted comorbidities or antibiotic use are present, to assess patients with potential joint infections.

Potential value of a rapid syndromic multiplex PCR for the diagnosis of native and prosthetic joint infections: a real-world evidence study

Introduction: The BIOFIRE Joint Infection (JI) Panel is a diagnostic tool that uses multiplex-PCR testing to detect microorganisms in synovial fluid specimens from patients suspected of having septic arthritis (SA) on native joints or prosthetic joint infections (PJIs). Methods: A study was conducted across 34 clinical sites in 19 European and Middle Eastern countries from March 2021 to June 2022 to assess the effectiveness of the BIOFIRE JI Panel. Results: A total of 1527 samples were collected from patients suspected of SA or PJI, with an overall agreement of 88.4 % and 85 % respectively between the JI Panel and synovial fluid cultures (SFCs). The JI Panel detected more positive samples and microorganisms than SFC, with a notable difference on Staphylococcus aureus, Streptococcus species, Enterococcus faecalis, Kingella kingae, Neisseria gonorrhoeae, and anaerobic bacteria. The study found that the BIOFIRE JI Panel has a high utility in the real-world clinical setting for suspected SA and PJI, providing diagnostic results in approximately 1 h. The user experience was positive, implying a potential benefit of rapidity of results' turnover in optimising patient management strategies. Conclusion: The study suggests that the BIOFIRE JI Panel could potentially optimise patient management and antimicrobial therapy, thus highlighting its importance in the clinical setting.

Exploring the Utility of Multiplex Infectious Disease Panel Testing for Diagnosis of Infection in Different Body Sites: A Joint Report of the Association for Molecular Pathology, American Society for Microbiology, Infectious Diseases Society of America, and Pan American Society for Clinical Virology

The use of clinical molecular diagnostic methods for detecting microbial pathogens continues to expand and, in some cases, supplant conventional identification methods in various scenarios. Analytical and clinical benefits of multiplex molecular panels for the detection of respiratory pathogens have been demonstrated in various studies. The use of these panels in managing different patient populations has been incorporated into clinical guidance documents. The Association for Molecular Pathology's Infectious Diseases Multiplex Working Group conducted a review of the current benefits and challenges to using multiplex PCR for the detection of pathogens from gastrointestinal tract, central nervous system, lower respiratory tract, and joint specimens. The Working Group also discusses future directions and novel approaches to detection of pathogens in alternate specimen types, and outlines challenges associated with implementation of these multiplex PCR panels.

Prevotella bivia Septic Arthritis in an Immunocompetent Adult: A Case Report and Review of Literature

Septic arthritis is a medical emergency that requires prompt diagnosis to prevent long-term intra-articular complications. Prevotella bivia is an anaerobic gram-negative rod which has been infrequently reported to cause septic arthritis. We present a 49-year-old female that presented with spontaneous left knee pain and swelling without history of insult to the knee. She was initially misdiagnosed with patellar tendinitis and gout but later underwent joint aspiration due to worsening symptoms, which demonstrated 60 800/µL nucleated cells with a polymorphonuclear burden consistent with septic arthritis. Arthroscopy with irrigation and drainage was subsequently performed, and the patient was started on empiric antibiotics while awaiting cultures. Cultures grew Prevotella bivia, and antibiotics were deescalated to ertapenem alone followed by oral metronidazole. Prevotella species as a source of septic arthritis is rare, and its occurrence in a patient without known insult to the knee is even more uncommon. It is essential that it is recognized to treat appropriately and prevent long-term loss of function in the joint.

Synovial microflora of large joints in patients of a multidisciplinary hospital

Relevance. There is no doubt that microorganisms participate in occurrence and development of septic process in joints. However, the issue of etiological significance of each agent remains controversial, because, in spite of the general trends, indicating the participation of numerous microorganisms in the development of articular pathology, each result of microbiological analysis concerns only a specific case in the territorial and clinical aspects. The aim of the study - microbiological research of synovial fluid obtained from knee joint during synovitis after its aspiration in patients of various departments of the Stavropol Regional Clinical Hospital. Materials and Methods . There were studied 198 samples of synovial fluid. Primary inoculation of puncture was performed with subsequent isolation, identification of the cultures by mass spectrometry and assessment of their antibiotic sensitivity by discodiffusion method. Results and Discussion . 11 cultures of bacterial pathogens were isolated. Gram-positive cocci - 82 %, of which 77.8 % - microorganisms of Staphylococcus genus (44.4 % S.aureus , 33.4 % S.epidermidis ), 22.2 % - other gram-positive cocci: one strain of each, Enterococcus faecium and Streptococcus mitis . Gram-negative pathogens are represented by K.neumoniae and P.aeruginosa with a total content of 18 %. Highly virulent microorganisms S.aureus , K.neumoniae and P.aeruginosa are isolated from the synovial fluid of patients of the surgical departments (orthopedotraumatological No. 1, No. 2) and the rheumatological department. Microorganisms with low virulence E.faecium , S.mitis and S.epidermidis are isolated from synovial fluid of patients of various departments. No obvious resistance of isolated pathogens to antimicrobial drugs has been registered. Conclusion . The presence and species affiliation of the microorganisms identified in synovial fluid allows predicting their etiological significance in development of septic process in joints. Their role as causative agents of nosocomial infections typical for a medical institution is not excluded. The presence of articular pathology in each of the examined departments dictates the need for a clear understanding of the importance of timely and high-quality joint aspiration followed by microbiological examination in almost all patients with damage of large joints, including patients without clinical signs of septic arthritis. Such an approach that makes it possible to identify a greater number of causative agents of septic arthritis and quickly evaluate the dynamics of their antimicrobial resistance should become an obligatory part of a comprehensive research and treatment of a patient with arthritis in multi-fi eld hospitals.

Case Report of a Diagnosed Septic Hip Joint Treated with a 2-Stage Hip Arthroplasty

Introduction

Identifying and determining appropriate treatment of adult hip septic arthritis (SA) can be quite challenging. Although rare, the annual incidence of this diagnosis is approximately 8 cases per 100,000 patients. The timing of patient symptoms is wide spread. The presentation may be acute, subacute, or even chronic, and moreover, the disease process may be masked by an underlying etiology. Once diagnosed, SA requires rapid and aggressive treatment.

Case Report

A 67-year-old patient presented with left hip pain. Physical examination shifted the differential diagnosis from osteoarthritis to a possible septic joint. Elevated inflammatory markers were revealed. Joint aspiration was obtained, which demonstrated rare Group G streptococcus. Two-stage hip arthroplasty was performed. Intra-operative cultures still reveal no growth of bacteria, and the patient is progressing well.

Conclusion

Adult septic hip arthritis is a rare diagnosis. Hence, a proper history, physical examination, infectious laboratory workup is important. The treatment of the condition is based on the duration of symptoms and the physician's clinical gestalt.

A Prospective Study to Assess the Optimal Incubation Times for Culture and Aerobic Bacterial Profile in Prosthetic Joint Infections

Introduction With an increase in the number of total joint arthroplasties, the count of prosthetic joint infections (PJIs) is also increasing and has become a nightmare for an orthopaedic surgeon. Microbiological diagnosis is important for administering definitive antimicrobial treatment. Negative culture reports hamper patient management and prolonged incubation periods have increased the culture yield but at the risk of culture contamination in conventional microbiology settings. Thus, we aimed to optimize the best incubation time for culture and the aerobic bacterial profile of PJIs.

Material and Methods Over a year, samples from clinically suspected PJI patients were collected and processed for culture using standard techniques. The samples were incubated for up to 10 days with daily subculturing on to solid media. The bacterial isolates were identified and antibiotic susceptibility was performed.

Results Out of 200 patients, 105 were included in the study and samples were collected in triplicate. In 70 cases culture was positive and 35 were culture negative PJIs. Mean incubation days to culture positivity was 3.6 days with 97.14% culture positivity seen by the seventh day of incubation. Twenty-four percent methicillin-resistant Staphylococcus aureus , and more than 50% extended spectrum β lactamase producing Klebsiella pneumoniae and Escherichia coli were isolated.

Discussion Culture positivity in PJIs provides definitive evidence of infection and guides the treatment. Increasing the incubation times can help in maximizing the culture yield, and we found that 97.14% pathogens grew within 7 days of incubation. Prolonging it further would not provide an added advantage especially in a resource-constraint setting.

A Case of Septic Arthritis Caused by Staphylococcus schleiferi

Septic arthritis leads to significant hospital burden in the United States adult patient population. Bacteria are the leading cause of septic arthritis with Staphylococcus aureus being the most common. Of the staphylococcal species, Staphylococcus ​​​​​​​schleiferi, primarily found in carnivores, rarely causes septic arthritis. We here report the presentation, diagnosis, treatment, and discharge of a 39-year-old male with S. schleiferi septic arthritis. Due to biochemical similarities, S. schleiferi are commonly misidentified as S. aureus, and correct identification is increasingly relevant for the selection of appropriate therapy due to the rise in cases of multidrug-resistant microorganisms.

Novel therapeutic interventions towards improved management of septic arthritis

Septic arthritis (SA) represents a medical emergency that needs immediate diagnosis and urgent treatment. Despite aggressive treatment and rapid diagnosis of the causative agent, the mortality and lifelong disability, associated with septic arthritis remain high as close to 11%. Moreover, with the rise in drug resistance, the rates of failure of conventional antibiotic therapy have also increased. Among the etiological agents frequently isolated from cases of septic arthritis, Staphylococcus aureus emerges as a dominating pathogen, and to worsen, the rise in methicillin-resistant S. aureus (MRSA) isolates in bone and joint infections is worrisome. MRSA associated cases of septic arthritis exhibit higher mortality, longer hospital stay, and higher treatment failure with poorer clinical outcomes as compared to cases caused by the sensitive strain i.e methicillin-sensitive S. aureus (MSSA).

In addition to this, equal or even greater damage is imposed by the exacerbated immune response mounted by the patient’s body in a futile attempt to eradicate the bacteria. The antibiotic therapy may not be sufficient enough to control the progression of damage to the joint involved thus, adding to higher mortality and disability rates despite the prompt and timely start of treatment. This situation implies that efforts and focus towards studying/understanding new strategies for improved management of sepsis arthritis is prudent and worth exploring.

The review article aims to give a complete insight into the new therapeutic approaches studied by workers lately in this field. To the best of our knowledge studies highlighting the novel therapeutic strategies against septic arthritis are limited in the literature, although articles on pathogenic mechanism and choice of antibiotics for therapy, current treatment algorithms followed have been discussed by workers in the past. The present study presents and discusses the new alternative approaches, their mechanism of action, proof of concept, and work done so far towards their clinical success. This will surely help to enlighten the researchers with comprehensive knowledge of the new interventions that can be used as an adjunct therapy along with conventional treatment protocol for improved success rates.

Rapid pathogen detection by metagenomic next-generation sequencing of infected body fluids

We developed a metagenomic next-generation sequencing (mNGS) test using cell-free DNA from body fluids to identify pathogens. The performance of mNGS testing of 182 body fluids from 160 patients with acute illness was evaluated using two sequencing platforms in comparison to microbiological testing using culture, 16S bacterial PCR and/or 28S-internal transcribed ribosomal gene spacer (28S-ITS) fungal PCR. Test sensitivity and specificity of detection were 79 and 91% for bacteria and 91 and 89% for fungi, respectively, by Illumina sequencing; and 75 and 81% for bacteria and 91 and 100% for fungi, respectively, by nanopore sequencing. In a case series of 12 patients with culture/PCR-negative body fluids but for whom an infectious diagnosis was ultimately established, seven (58%) were mNGS positive. Real-time computational analysis enabled pathogen identification by nanopore sequencing in a median 50-min sequencing and 6-h sample-to-answer time. Rapid mNGS testing is a promising tool for diagnosis of unknown infections from body fluids.

Diagnosis and management of sternoclavicular joint infections: a literature review

The sternoclavicular joint (SCJ) is anatomically and clinically significant considering its proximity to important neuro-vascular structures like the subclavian vessels and the phrenic nerve. Infections of this joint masquerade multiple disorders, delay diagnosis and spread to the bone and deep tissues. There is no standardized workup and treatment protocol for sternoclavicular joint infections (SCJI) as defined in literature. Here, we review the existing literature to understand the current knowledge of the diagnosis and treatment of SCJI. We searched English publications in PubMed and included clinical trials, case reports, case series, retrospective cohort studies, literature and systematic reviews after excluding non-infectious etiology of SCJ pathologies. There are many risk factors for SCJI, such as immunocompromised status, intravenous drug use, trauma and arthropathies. But a large percentage of patients with disease have none of these risk factors. SCJIs can present with fever, joint swelling, immobility, and rarely with vocal cord palsy or dysphagia. While Staphylococcus aureus causes over 50% of SCJI cases, other pathogens such as Pseudomonas and Mycobacterium are frequently seen. When diagnosed early, the infection can be medically managed with antibiotics or joint aspirations. Most cases of SCJI, however, are diagnosed after extensive spread to soft tissue and bones requiring en-bloc resection with or without a muscle flap. Complications of undertreatment can range from simple abscess formation to mediastinitis, even sepsis. SCJIs are rare but serious infections prompting early detection and interventions. Most cases of SCJI treated adequately show complete resolution in months while retaining maximum functionality. Key features of proper healing include aggressive physiotherapy to prevent adhesive shoulder capsulitis and decreased range of motion.

Suspected Septic Sacroiliitis Following Recent Cesarean Section Under Spinal Anesthesia

Septic sacroiliitis is sacroiliac (SI) joint inflammation secondary to microbial invasion of the synovial space characterized by tenderness over the sacroiliac joint, difficulty walking, and lower back pain that can radiate to the buttocks. Clinicians can easily overlook septic sacroiliitis as a potential diagnosis due to its rare occurrence and non-specific symptoms. A 30-year-old female (G2P2A0) who presented acutely to the ED nine days after an uncomplicated Cesarean section performed under spinal anesthesia. The patient experienced progressive lancinating, electric-shock pain originating from the coccyx radiating to the right buttock and lower back with the inability to bear weight. MRI pelvis demonstrated edematous changes of the right SI joint, indicative of septic sacroiliitis. Patient's condition improved after empiric intravenous antibiotics and was discharged home on the continued intravenous course. Rapid empiric administration of intravenous antibiotics may have prevented the onset of severe complications of an infective SI joint.

Ruptured Appendicitis and Retrocecal Abscess Masquerading as Knee Pain in a Pediatric Patient: A Case Report

BACKGROUND

Knee pain has a variety of etiologies in the pediatric population, including septic arthritis, osteomyelitis, fracture, ligamentous injury, and neoplasms. Extrinsic sources of knee pain may also be intra-abdominal, although abdominal pathology is much more likely to manifest as hip or proximal thigh musculature pain.

CASE REPORT

A 5-year-old healthy male presented with atraumatic right knee pain, discomfort with weightbearing, fever, and elevated inflammatory laboratory markers. Physical examination and magnetic resonance imaging findings of the knee were benign, leading to low clinical suspicion for knee septic arthritis. Blood cultures were positive for a gastrointestinal organism, Granulicatella adiacens, suggesting abdominal pathology leading to referred pain. Ultrasound evaluation and computed tomography (CT) of the abdomen revealed a large abscess secondary to perforated appendicitis, which was treated with CT-guided drainage and i.v. antibiotics. The patient's musculoskeletal pain subsided with treatment of the appendicitis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Acute appendicitis may present as knee pain, with other signs and symptoms mimicking septic arthritis, such as fever, inability to bear weight, and elevated inflammatory markers. Considering an array of differential diagnoses in pediatric patients with apparent knee septic arthritis is crucial to prevent delay in diagnosis of alternative infectious sources.