Microbiological profile of septic arthritis in adults: Lessons learnt and treatment strategies

Trained immunity of synovial macrophages is associated with exacerbated joint inflammation and damage after Staphylococcus aureus infection

OBJECTIVES

Investigate whether and which synoviocytes would acquire trained immunity characteristics that could exacerbate joint inflammation following a secondary Staphylococcus aureus infection.

METHODS

Lipopolysaccharide (LPS) and S. aureus were separately or double injected (21 days of interval) into the tibiofemoral joint cavity of male C57BL/6 mice. At different time points after these stimulations, mechanical nociception was analyzed followed by the analysis of signs of inflammation and damage in the affected joints. The trained immunity markers, including the glycolytic and mTOR pathway, were analyzed in whole tissue or isolated synoviocytes. A group of mice was treated with Rapamycin, an mTOR inhibitor before LPS or S. aureus stimulation.

RESULTS

The double LPS - S. aureus hit promoted intense joint inflammation and damage compared to single joint stimulation, including markers in synoviocyte activation, production of proinflammatory cytokines, persistent nociception, and bone damage, despite not reducing the bacterial clearance. The double LPS - S. aureus hit joints increased the synovial macrophage population expressing CX3CR1 alongside triggering established epigenetic modifications associated with trained immunity events in these cells, such as the upregulation of the mTOR signaling pathway (p-mTOR and HIF1α) and the trimethylation of histone H3. Mice treated with Rapamycin presented reduced CX3CR1+ macrophage activation, joint inflammation, and bone damage.

CONCLUSIONS

There is a trained immunity phenotype in CX3CR1+ synovial macrophages that contributes to the exacerbation of joint inflammation and damage during septic arthritis caused by S. aureus.

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.

Early Intervention in Septic Arthritis of the Hand, Optimizing Patient Outcomes in Hand Infections-A Five-Year Retrospective Study

Background and Objectives: Hand septic arthritis is a potentially debilitating condition that can significantly affect patient functionality and quality of life. Understanding the demographic, clinical, and microbiological characteristics of this condition is crucial for its effective treatment and management. This study aimed to analyze the demographic and clinical profiles of patients with hand septic arthritis, to identify common microbial pathogens, and to evaluate the impact of various factors on clinical course and treatment outcomes. Material and Methods: This cross-sectional retrospective study examined patients diagnosed with septic arthritis of the hand, focusing on their demographic data, clinical presentation, causative organisms, treatment methods, and outcomes. Data on age, sex, cause of infection, affected sites, surgical interventions, microbiological findings, and patient outcomes were also collected. Results: This study found a higher prevalence of septic arthritis in males and identified bite as the predominant cause. Staphylococcus aureus is the most common pathogen. A large number of patients did not exhibit bacterial growth, and bacterial resistance did not significantly affect the outcome. Outcomes were statistically influenced by the timing of medical presentation and the presence of comorbidities. Conclusions: Early diagnosis and intervention are critical for effective management of hand septic arthritis. This study underscores the need for a comprehensive approach that considers patient demographic and clinical characteristics to optimize treatment outcomes. Awareness and preventive measures are essential to reduce the incidence and severity of this condition.

Orthopedic Articular and Periarticular Joint Infections

Acute nontraumatic joint pain has an extensive differential. Emergency physicians must be adept at identifying limb and potentially life-threatening infection. Chief among these is septic arthritis. In addition to knowing how these joint infections typically present, clinicians need to be aware of host and pathogen factors that can lead to more insidious presentations and how these factors impact the interpretation of diagnostic tests.

Should treatment decisions in septic arthritis of the native hip joint be based on the route of infection?

Background: Surgical management of septic arthritis (SA) of the hip aims at treating the infection by either preserving, resecting or replacing the joint. In some cases, joint preservation should be attempted, whereas other cases would benefit from immediate joint resection or replacement. Prognostic factors have been proposed to guide decision-making. We hypothesized that most of these factors can be simplified to three subgroups based on the route of infection: contiguous spreading, direct inoculation or hematogenous seeding. Methods: A total of 41 patients have been treated surgically for SA of the native hip at our tertiary hospital during the last 16 years. Medical records were studied, and various patient and disease characteristics were collated. Results: Significant differences between (1) level of fitness, (2) condition of the hip joint, (3) micro-organisms and (4) chance of femoral head preservation were found for patients with SA of the native hip resulting from the three aforementioned subgroups. Femoral head resection was necessary at one point in 85 % of patients. Patients with hematogenous infections of undamaged hips had a reasonable chance (53 %) of avoiding joint resection or replacement. Hip arthroplasty was performed on 46.3 % of patients, with an infection rate of 10.5 %. Conclusion: Patients with SA of the native hip resulting from contiguous spreading, hematogenous seeding or direct inoculation differ significantly and should be considered distinct clinical entities. Route of infection is directly related to the chance of femoral head preservation and should, therefore, guide decision-making. Only patients with hematogenous infection to a previously healthy hip had the possibility of femoral head preservation.

C-reactive protein and procalcitonin use in adults in low- and middle-income countries: a narrative review

Objectives

C-reactive protein (CRP) and procalcitonin (PCT) are widely used biomarkers in high-income countries. However, evidence for their use in low- and middle-income countries (LMICs) is scant. Because many factors, including rates of endemic disease, comorbidities and genetics, may influence biomarkers' behaviour, we aimed to review available evidence generated in LMICs.

Methods

We searched the PubMed database for relevant studies within the last 20 years that originated in regions of interest (Africa, Latin America, Middle East, South Asia or South East Asia), and full-text articles involving diagnosis, prognostication and evaluation of therapeutic response with CRP and/or PCT in adults (n = 88) were reviewed and categorized in 12 predefined focus areas.

Results

Overall, results were highly heterogeneous, at times conflicting, and often lacking clinically useful cut-off values. However, most studies demonstrated higher levels of CRP/PCT in patients with bacterial versus other infections. HIV and TB patients had consistently higher levels of CRP/PCT versus controls. In addition, higher CRP/PCT levels at baseline and follow-up in HIV, TB, sepsis and respiratory tract infections were associated with poorer prognosis.

Conclusions

Evidence generated from LMIC cohorts suggests that CRP and PCT may have potential to become effective clinical guiding tools particularly in respiratory tract infections, sepsis and HIV/TB. However, more studies are needed to define potential scenarios for use and cost-effectiveness. Consensus across stakeholders regarding target conditions, laboratory standards and cut-off values would support the quality and applicability of future evidence.

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.

Two-Stage Total Hip Arthroplasty for Primary Advanced Septic Arthritis of the Hip in Adults

Background

Comparing the outcomes of debridement and total hip arthroplasty (THA) with antibiotic-loaded spacer implantation and subsequent THA for the treatment of patients affected by primary advanced septic arthritis (SA) of the hip in adults.

Methods

All of the 20 patients (20 hips) underwent two-stage surgery. Nine patients were submitted to surgical debridement first and then THA (group 1), while 11 patients were treated with antibiotic-loaded spacer and subsequent THA (group 2). Patients were evaluated based on the recurrence of infection, Harris hip score, visual analogue scale (VAS) pain score, and leg length discrepancy.

Results

No cases of infection, deep vein thrombosis, death, and loosening of the hip prosthesis were observed during follow-up. The mean follow-up time was 29.09 ± 10.80 months in group 1 and 28.22 ± 14.80 months in group 2. Before the THA surgery, the mean leg length discrepancy was 2.80 ± 2.03 cm in group 1 and 0.50 ± 0.23 cm in group 2 (P < 0.05). In the latest follow-up, the Harris hip scores of patients were 90.33 ± 4.85 in group 1 and 94.36 ± 2.34 in group 2 (P < 0.05), respectively. There was no statistically significant difference in the VAS pain score of the hip between the two groups (P > 0.05).

Conclusions

Debridement and antibiotic-loaded spacer and subsequent THA were effective in eradicating the infection for advanced SA. However, antibiotic-loaded spacer and subsequent THA was superior for effectively maintaining the length of the lower limb and function of the hip.

Treatment of MRSA infections in India: Clinical insights from a Delphi analysis

PURPOSE

International and Indian guidelines for the management of patients with methicillin-resistant Staphylococcus aureus (MRSA) infections are available, but the local guidelines are not MRSA-specific. This study aimed to provide clinical insights for the treatment of MRSA infections in India.

METHODS

We used a three-step modified Delphi method to obtain insights. Ten experts comprising infectious disease specialists, microbiologists, pulmonologists, and critical care experts agreed to participate in the analysis. In round 1, a total of 161 statements were circulated to the panel and the experts were asked to 'agree' or 'disagree' by responding 'yes' or 'no' to each statement and provide comments. The same process was used for 73 statements in round 2. Direct interaction with the experts was carried out in round 3 wherein 35 statements were discussed. At least 80% of the experts had to agree for a statement to reach concordance.

RESULTS

Eighty-eight statements in round 1, thirty-eight statements in round 2, and eight statements in round 3 reached concordance and were accepted without modification. The final document comprised 152 statements on the management of various syndromes associated with MRSA such as skin and soft tissue infections, bacteremia and endocarditis, pneumonia, bone and joint infections, and central nervous system infections.

CONCLUSIONS

This analysis will assist clinicians in India to choose an appropriate course of action for MRSA infections.

An Improved Device Clears Blockages in the Tube of Irrigation and Drainage Systems

The outflow tube may be blocked during continuous irrigation for the treatment of septic joints. Although multiple solutions have been applied to clear the blockage, there are still many disadvantages. The success rate is difficult to guarantee, and bacteria may enter the joint cavity and cause secondary infection. We designed an improved irrigation and drainage system that avoids these disadvantages and is particularly convenient to use. In addition, the improved system provides more thorough lavage and drainage and prevents joint adhesion.

Clinical Outcomes and Global Health After Joint Debridement in Adult-Onset Septic Arthritis: A Prospective Observational Study

PURPOSE

Despite several reports on risk factors for septic arthritis (SA) in adults, the outcomes on quality of life and joint function are sparsely reported. This study aimed to investigate the quality of life and joint function in adult patients treated for SA.

METHODS

This prospective observational study enrolled clinically diagnosed adult SA patients and estimated Euroqol 5-dimension 5 levels (EQ-5D-5L) questionnaire, Euroqol Visual Analog Scale (EQ-VAS) and a validated tool for joint function at 1, 3, 6 and 12 months after debridement.

RESULTS

Twenty seven patients (20 males/7 females) with 21 knees, four shoulders, and two elbows were evaluated. The mean age of the cases was 51(± 13.00) years. Three cases sustained mortality. EQ-5D-5L (P < 0.01) and EQ-VAS (P < 0.01) scores improved significantly between all time frames. Mean Knee society (P < 0.01), Shoulder QuickDASH, and Mayo elbow scores improved at all time frames. There was no difference in primary outcomes between early (< 14 days) and late (14 days or more) presentation. There was no difference in primary outcome measures between confirmed and suspected SA. Fifteen patients could ambulate without support, while 6 needed some support for walking at 1 year.

CONCLUSION

Improved outcomes can be expected in quality of life and joint function in adults' septic arthritis at the end of 1 year after surgical treatment; however, the effects of delay in presentation need to be investigated further. Isolation of the microorganism from an infected joint has no bearing on the outcome measures.

Microbiological profile of infections of the hip joint: An Indian perspective

BACKGROUND

Knowledge of the local microbiological epidemiology helps in formulating protocols for appropriate treatment of hip infections. The aim of this study was to profile the organisms cultured from infected hips.

METHODS

The microbiological profile and sensitivity pattern of organisms in eighty infected hips were reviewed.

RESULTS

Infection was secondary to arthroplasty in 35, fracture surgery in 34 and primary septic arthritis in 11. Twenty percent of the infections were polymicrobial, whereas the rest were monomicrobial. Fifty-five percent were Gram-positive, of which 45% were Staphylococcus species (36% methicillin-sensitive Staphylococcus aureus, 20% methicillin-resistant S. aureus, and 44% coagulase sensitive Staphylococcal species). All Staphylococcus species were sensitive to vancomycin, but 20% of Enterococcus species were resistant to vancomycin. One-third of the Enterococcus species and 2% of Staphylococcus species were resistant to teicoplanin. Escherichia coli (n = 10) and Pseudomonas sp. (n = 13) were the most common Gram-negative organism. Although 18% of the Gram-negative organisms were carbapenem resistant, all were sensitive to colistin.

CONCLUSION

Staphylococcus sp. was the most common pathogen found in hip infections. However, the high incidence of Gram-negative infection requires that prophylactic antibiotics cover these organisms as well. The high resistance to first-line antibiotics should be taken into consideration while making protocols. The knowledge of the microbial profile is especially important when considering arthroplasty for arthritis secondary to hip infections.