Bacterial septic arthritis in adults

HPLC Analysis, Optimization of Extraction Conditions and Biological Evaluation of Corylopsis coreana Uyeki Flos

A method for the separation and quantification of three flavonoids and one isocoumarin by reverse-phase high performance liquid chromatography (HPLC) has been developed and validated. Four constituents present in a crude ethanolic extract of the flowers of Coryloposis coreana Uyeki, were analyzed. Bergenin, quercetin, quercitrin and isosalipurposide were used as calibration standards. In the present study, an excellent linearity was obtained with an r² higher than 0.999. The chromatographic peaks showed good resolution. In combination with other validation data, including precision, specificity, and accuracy, this method demonstrated good reliability and sensitivity, and can be conveniently used for the quantification of bergenin, quercetin, quercitrin and isosalipurposide in the crude ethanolic extract of C. coreana Uyeki flos. Furthermore, the plant extracts were analyzed with HPLC to determine the four constituents and compositional differences in the extracts obtained under different extraction conditions. Several extracts of them which was dependent on the ethanol percentage of solvent were also analyzed for their antimicrobial and antioxidant activities. One hundred % ethanolic extract from C. coreana Uyeki flos showed the best antimicrobial activity against the methicillin-resistant Staphylococcus aureus (MRSA) strain. Eighty % ethanolic extract showed the best antioxidant activity and phenolic content. Taken of all, these results suggest that the flower of C. coreana Uyeki flos may be a useful source for the cure and/or prevention of septic arthritis, and the validated method was useful for the quality control of C. coreana Uyeki.

Staphylococcus aureus-Associated Musculoskeletal Infections

Musculoskeletal infections caused by Staphylococcus aureus are among the most difficult-to-treat infections. S. aureus osteomyelitis is associated with a tremendous disease burden through potential for long-term relapses and functional deficits. Although considerable advances have been achieved in diagnosis and treatment of osteomyelitis, the management remains challenging and impact on quality of life is still enormous. S. aureus acute arthritis is relatively seldom in general population, but the incidence is considerably higher in patients with predisposing conditions, particularly those with rheumatoid arthritis. Rapidly destructive course with high mortality and disability rates makes urgent diagnosis and treatment of acute arthritis essential. S. aureus pyomyositis is a common disease in tropical countries, but it is very seldom in temperate regions. Nevertheless, the cases have been increasingly reported also in non-tropical countries, and the physicians should be able to timely recognize this uncommon condition and initiate appropriate treatment. The optimal management of S. aureus-associated musculoskeletal infections requires a strong interdisciplinary collaboration between all involved specialists.

A novel method for a fast diagnosis of septic arthritis using mid infrared and deported spectroscopy

OBJECTIVE

To assess the ability of mid infrared deported spectroscopy to discriminate synovial fluids samples of septic arthritis patients from other causes of joint effusion.

METHODS

Synovial fluids obtained from patients with clinically suspected arthritis were collected, analysed and classified according to standard diagnostic procedures as septic or non-septic. A spectroscopic analysis on synovial fluid samples was then performed using a coiled optical fiber made with chalcogenide glass. After a factorial analysis of the normalized spectra and the computation of a Fisher test used to select the most relevant components, a logistic regression model was fitted, allowing to attribute a score between 0 - non-septic -, and 1 - septic.

RESULTS

In a first phase, we analysed the synovial fluids from 122 different synovial fluids including 6 septic arthritis among arthritis of various origins. Septic synovial fluids were identified with a sensitivity of 95.8% and a specificity of 93.9% and an AUROC of 0.977. The analysis of an independent set of samples (n=42, including two septic arthritis) gave similar values.

CONCLUSIONS

Our data strongly supports the interest of mid infrared deported spectroscopy, which could be used potentially at point of care, for a rapid and easy diagnosis of septic arthritis. Now, the precision of the diagnosis must be evaluated through a multicentric study on a larger panel of patients.

Native Joint Septic Arthritis: Epidemiology, Clinical Features, and Microbiological Causes in a New Zealand Population

Objective.

To determine the epidemiology, clinical features, and microbiology of adult native joint septic arthritis in Canterbury, New Zealand, over a 5-year period in individuals with and without an underlying rheumatic disorder.

Methods.

Patients with native joint septic arthritis were identified retrospectively and classified by Newman’s criteria. The clinical characteristics were described and comparisons made between those with and without underlying rheumatic disease.

Results.

Two hundred forty-eight cases of native joint septic arthritis (mean age 60, range 16–97 yrs) were identified with an overall incidence rate of 12.0/100,000/year (95% CI 10.6–13.6). Yearly incidence increased with age to a maximum of 73.4/100,000 in those > 90 years of age. Septic arthritis was iatrogenic in 16.9% of cases while 27% had an underlying inflammatory arthritis including gout (14.9%), calcium pyrophosphate disease (8.5%), and rheumatoid arthritis (4%). Few patients were taking immunosuppressant therapy, with just 1 taking a biological agent. Staphylococcus aureus was the most commonly identified organism. Those with underlying inflammatory arthritis were significantly older (73.6 yrs vs 55.6 yrs; p < 0.001), more likely to be female (55.2% vs 26.0%; p < 0.001), and to have septic polyarthritis (16.4% vs 4.4%; p = 0.002). The 30-day mortality was 2%, increasing to 6% at 90 days.

Conclusion.

The incidence of septic arthritis in Canterbury, New Zealand, is higher than in previous studies. Crystal arthropathy commonly coexisted with infection although autoimmune arthritis and immunosuppression was less of a factor than anticipated.

Spontaneous septic arthritis of the pubic symphysis in an afebrile patient

Septic arthritis is a rare infection usually involving the knee or hip but can infrequently affect less obvious joints such as the pubic symphysis.Risk factors for septic arthritis include joint repair or replacement surgery, systemic infection, intravenous recreational drug use, and alcoholism.We present the case of a 48-year-old man with a final diagnosis of septic arthritis of the pubic symphysis who had no risk factors besides alcoholism. The presentation was unusual in that the patient was afebrile,and the infection seemed to be spontaneous. The infecting pathogen was identified as Streptococcus anginosus or S constellatus, both being normal intestinal flora. Infection by either bacterium is rare in septic arthritis.

Clinical manifestations and bacteriological features of culture-proven Gram-negative bacterial arthritis

BACKGROUND/PURPOSE

To investigate the clinical manifestations and bacteriological features of culture-proven, Gram-negative bacterial arthritis.

METHODS

This study was conducted at the Chi Mei Medical Center, a 1300-bed teaching hospital located in southern Taiwan. Patients with synovial fluid cultures positive for Gram-negative bacilli (GNB) during the period January 2009 to May 2014 were identified from the hospital's computerized microbiology database.

RESULTS

During the study period, a total of 48 patients with culture-confirmed, GNB septic arthritis were identified. In the majority of patients (n = 33, 68.8%), the knee was the most commonly involved joint. The most common causative pathogen was Pseudomonas spp. (n = 16, 33.3%), followed by Escherichia coli (n = 13, 28.1%). Among the 29 clinical isolates of Enterobacteriaceae, eight (27.6%) were resistant to ceftriaxone and six (20.7%) were resistant to cefpirome. Three E. coli isolates and three Klebsiella pneumoniae isolates were extended-spectrum beta-lactamase producers (n = 6, 20.7%). Among the nonfermenting GNB (NFGNB), 21.1% were resistant to ceftazidime, 21.1% were resistant to ciprofloxacin, 26.3% were resistant to piperacillin-tazobactam, and 15.8% were resistant to imipenem. The overall mortality rate was 10.4%, and the significant risk factors for death were concomitant bacteremia [odds ratio (OR): 14.6, 95% confidence interval (CI): 1.9-115.2, p = 0.011] and liver cirrhosis (OR: 20.0, 95% CI: 2.4-169.9, p = 0.006).

CONCLUSION

Approximately 25% of cases of septic arthritis were due to GNB and resistance to commonly used antimicrobial agents was common. Liver cirrhosis and concomitant bacteremia were significant risk factors for death.

Utilization of Hyaluronate and Incidence of Septic Knee Arthritis in Adults: Results from the Korean National Claim Registry

Background

Septic arthritis of the knee has been reported recently in adult patients who were administered hyaluronate. We evaluated the incidence of septic knees and the utilization of hyaluronate in the Korean adult population using nationwide data from the Health Insurance Review and Assessment Service (HIRA).

Methods

All new admissions to the clinics or hospitals for septic knees were recorded in the HIRA database which was established by the Korean government and covers the Korean population using the International Classification of Diseases-10 revision code. We evaluated the incidence of septic arthritis of the knees in the population above 50 years of age. Hyaluronate prescription data was also collected from the HIRA database.

Results

In 2012, the incidence of septic knees was 2.7 per 100,000 persons in men and 4.2 per 100,000 persons in women, respectively. The age-adjusted incidence of septic knees increased by 6.7% per year (95% confidence interval, 3.3 to 10.1), and the annual number of prescriptions of hyaluronate increased about 1.5-fold during the study period.

Conclusions

Cautious aseptic technique is required when hyaluronate is administered in adult patients with osteoarthritis of the knee due to the concerns of the risk of septic arthritis.

M, Wu Y, Spahr C, Gonella G, Xu B, Dai HL. Gram's Stain Does Not Cross the Bacterial Cytoplasmic Membrane

For well over a century, Hans Christian Gram's famous staining protocol has been the standard go-to diagnostic for characterizing unknown bacteria. Despite continuous and ubiquitous use, we now demonstrate that the current understanding of the molecular mechanism for this differential stain is largely incorrect. Using the fully complementary time-resolved methods: second-harmonic light-scattering and bright-field transmission microscopy, we present a real-time and membrane specific quantitative characterization of the bacterial uptake of crystal-violet (CV), the dye used in Gram's protocol. Our observations contradict the currently accepted mechanism which depicts that, for both Gram-negative and Gram-positive bacteria, CV readily traverses the peptidoglycan mesh (PM) and cytoplasmic membrane (CM) before equilibrating within the cytosol. We find that not only is CV unable to traverse the CM but, on the time-scale of the Gram-stain procedure, CV is kinetically trapped within the PM. Our results indicate that CV, rather than dyes which rapidly traverse the PM, is uniquely suited as the Gram stain.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Septic arthritis in immunocompetent and immunosuppressed hosts

Septic arthritis has long been considered an orthopedic emergency. Historically, Neisseria gonorrhoeae and Staphylococcus aureus have been the most common causes of septic arthritis worldwide but in the modern era of biological therapy and extensive use of prosthetic joint replacements, the spectrum of microbiological causes of septic arthritis has widened considerably. There are also new approaches to diagnosis but therapy remains a challenge, with a need for careful consideration of a combined medical and surgical approach in most cases.

Polyarticular Septic Arthritis in an Immunocompetent Adult: A Case Report and Review of the Literature

Septic arthritis is a clinical emergency requiring prompt diagnosis and treatment to avoid significant morbidity and mortality. Polyarticular septic arthritis (PASA) accounts for 15% of all infectious arthritides and rarely occurs in immunocompetent adults. Staphylococcus aureus is the most commonly isolated organism, with infection primarily affecting knees, shoulders, elbows, and hips. The morbidity associated with PASA is very high, and mortality in treated cases of PASA may be as high as 50% of cases. We report a case of PASA with associated epidural abscess in a healthy adult male, who presented with complaints of arthralgia and limited range of motion of his left shoulder, wrist, and ankle. He also presented with low back pain and motor weakness associated with an epidural abscess spanning L2-S1, with multilevel vertebral osteomyelitis. Surgical washout of the affected joints as well as decompressive laminectomies was performed, and he received a standard course of intravenous antibiotics. Staphylococcus aureus was isolated from joint aspirations and from blood cultures. The patient had a full neurological and functional recovery postoperatively with no sequelae. To the best of our knowledge this is the only case report of Staphylococcus aureus PASA with concomitant epidural abscess in an immunocompetent adult.

Infections and arthritis

Bacteria, viruses, fungi, and parasites can all cause arthritis of either acute or chronic nature, which can be divided into infective/septic, reactive, or inflammatory. Considerable advances have occurred in diagnostic techniques in the recent decades resulting in better treatment outcomes in patients with infective arthritis. Detection of emerging arthritogenic viruses has changed the epidemiology of infection-related arthritis. The role of viruses in the pathogenesis of chronic inflammatory arthritides such as rheumatoid arthritis is increasingly being recognized. We discuss the various causative agents of infective arthritis and emphasize on the approach to each type of arthritis, highlighting the diagnostic tests, along with their statistical accuracy. Various investigations including newer methods such as nucleic acid amplification using polymerase chain reaction are discussed along with the pitfalls in interpreting the tests.

An outbreak of joint and cutaneous infections caused by non-tuberculous mycobacteria after corticosteroid injection

OBJECTIVES

An outbreak of joint and cutaneous infections among patients who had been injected at a single clinic in South Korea was investigated.

METHODS

In this retrospective case-control study, 61 cases were diagnosed based on symptoms and signs of septic arthritis or cutaneous infection that developed after injections at the clinic between April and September 2012; 64 controls were investigated by administering questionnaires on risk factors and analyzing the clinic medical records. An environmental investigation was performed, and clinical specimens of the cases were analyzed by pulsed-field gel electrophoresis.

RESULTS

All cases were injected with triamcinolone. A greater number of triamcinolone injections (adjusted odds ratio 4.3, 95% confidence interval 1.5-12.1 for six or more visits, compared with one or two visits) was associated with the development of an infection. In the clinic, only the triamcinolone injection was prepared by mixing with lidocaine and normal saline, and an alcohol swab was prepared using boiled tap water by members of the clinic staff. Although injected medications and environmental cultures were not found to be responsible, a single strain of Mycobacterium massiliense was isolated from the affected sites of 16 cases.

CONCLUSIONS

Repeated injection of triamcinolone contaminated with NTM from the clinic environment may have caused this post-injection outbreak.

High Prevalence of Methicillin-Resistant Staphylococcus aureus among Patients with Septic Arthritis Caused by Staphylococcus aureus

BACKGROUND

This study investigated the clinical characteristics of patients with septic arthritis caused by Staphylococcus aureus and tried to identify the risk factors for methicillin-resistant S. aureus (MRSA) arthritis.

METHODS

Between January 2008 and December 2011, patients with septic arthritis caused by S. aureus were identified from the computerized databases of a regional hospital and a medical center in southern Taiwan. The medical records of these patients were retrospectively reviewed.

RESULTS

A total of 93 patients with S. aureus arthritis were identified, and MRSA arthritis was found in 38 (40.9%) cases. The mean age of the patients was 58 years, and 86 (92.5%) episodes were classified as community-acquired infections. Diabetes mellitus (n = 41, 44.1%) was the most common underlying disease, followed by chronic kidney disease and liver cirrhosis. Patients with MRSA arthritis were more frequently elderly and found in the setting of healthcare-associated infection than patients with methicillin-susceptible S. aureus (MSSA) infections. No other significant differences in clinical manifestations and outcomes were noted between these two groups of patients. Overall, the in-hospital mortality rate was 5.4%, and diabetes mellitus was the only risk factor for mortality.

CONCLUSIONS

MRSA is emerging in the setting of community-acquired septic arthritis. MRSA septic arthritis is more likely to develop in the elderly and in healthcare-associated infections than MSSA septic arthritis.

Poor adherence to guidelines on early management of acute hot swollen joint(s): an evaluation of clinical practice and implications for training

BACKGROUND

Synovial fluid analysis is an indispensable investigation to attain a diagnosis in a patient with acute hot swollen joint(s), septic arthritis in particular. A delay in appropriate early management results in serious undesired consequences.

METHODS

We evaluated clinical practice at two teaching hospitals including 81 patients. We analysed medical records, laboratory pathology results and discharge summaries with regard to documentation of joint aspiration, blood cultures, antibiotic treatment and specialist referral. We then conducted a survey of 140 medical trainees to evaluate their self-reported competence at managing the acute hot swollen joint.

RESULTS

We found that synovial aspiration and blood cultures were performed in only 42(52%) and 30(37%) patients, respectively, not in accord with current guidelines. Given trainee doctors are responsible for the early management of acute hot swollen joint(s), our survey reveal low self-reported levels of competence and confidence at managing acute hot swollen joint(s) in 72(52%) and 37(27%) respondents, respectively. Furthermore, 101(75%) trainees indicated a need for more training in joint aspiration. We also report that 13 of 15 hospitals surveyed in London and South East UK do not provide specific training on the management of the hot swollen joint and joint aspiration as part of their induction programme.

CONCLUSIONS

Early management of patients with hot swollen joint(s) to perform synovial fluid aspiration and blood cultures are not being done in accordance with guidelines. We suggest that the medical trainee curricula should incorporate joint aspiration skills as an 'essential procedure', to improve the trainee doctor's confidence and competence at managing acute hot swollen joint(s) to improve adherence to guidelines, and consequently, patient outcomes.

Complicated septic arthritis after knee arthroscopy in a 75-year-old man with osteoarthritis and a popliteal cyst

A 75-year-old man presented in shock secondary to septic arthritis of the knee. The patient, with a known history of knee osteoarthritis, was treated elsewhere for mechanical locking symptoms and effusion with arthroscopic debridement, and developed septic arthritis, which disseminated to the leg and foot after a tear in the capsule, and a ruptured pyogenic popliteal cyst. Open debridement of the knee joint, and drainage of the abscesses of the leg and foot, were performed. Antibiotic-loaded cement beads were left in the residual space. Debridement was repeated and cement beads removed after 4 days, and finally the infection was eradicated without any serious consequences for the patient. There is debate over arthroscopic intervention for osteoarthritic knees. The presence of a popliteal cyst, which is a rather common finding in the latter, could be related to a significant number of complications, such as septic arthritis.

Septic arthritis due to methylcyllin-resistant Staphylococcus aureus in adults

INTRODUCTION

Septic arthritis due to methylcyllin resistant Staphylococcus aureus (MRSA) is a serious infection that has increased in incidence in the past 10years.

METHODS

We conducted a retrospective study (1984-2011) in which a description of the clinical and epidemiological characteristics of MRSA arthritis in adults was performed and then compared to native joint infections caused by MRSA vs. methylcyllin sensitive Staphylococcus aureus (MSSA).

RESULTS

Fourteen MRSA infections were included (7 native joint, 5 prosthetic and 2 bursae). No case was polyarticular. There was significant comorbidity, although none was associated to rheumatoid arthritis. Seven patients had bacteremia. Four required surgical treatment. Six died. When comparing the 7 patients with native joint MRSA infection with the 17 cases caused by MSSA, no significant differences in risk factors were seen, except more malignancies in the MRSA group. The infection was polyarticular in 7 cases (41%) of the MSSA group. Bacteremia was more frequent in the MRSA group (71.4 vs 58.8%). Empirical antibiotic was useful in 28.6% of MRSA cases versus 100% of MSSA cases. There was a greater tendency to associated mortality in MRSA arthritis (57.1% vs 17.6%, P=.07).

CONCLUSIONS

MRSA septic arthritis is a serious condition that occurs in the elderly and patients with high comorbidity. It is usually monoarticular, with positive blood cultures and higher mortality than MSSA arthritis. In patients at risk, vancomycin empiric antibiotic therapy is indicated.

Case study: a case of debilitating gout in the 1st metatarsophalangeal joint

Gout is a painful arthritic condition that affects many people worldwide. The disease has been associated with hyperuricaemia and life style risk factors such as obesity, alcohol intake, meat and seafood consumption. We present a case of a 67-year-old male with a history of gout, who attended the clinic with a painful 1st metatarsophalangeal joint, which had progressively worsened in pain, mobility and deformity in the last 20 years. Although lifestyle changes had been advised by the GP some years earlier such as a low purine based diet, management had only consisted of NSAID's, which had not significantly improved symptoms. Surgical excision of chalky white material from around the 1st metatarsophalangeal joint rendered the patient symptom free with increased mobility after 6 weeks. Histopathology confirmed the excised tissue as gouty tophus. Following this, the patient was placed on allopurinol, a xanthine oxidase inhibitor to prevent recurrent attacks. This case study highlights the importance of early recognition and prophylactic management in gout sufferers. In joints where the disease process is well-established surgical excision of the gouty tophus may help mitigate further disease progression, and restore quality of life to individuals.

Sternoclavicular septic arthritis due to methicillin-resistant Staphylococcus aureus in a patient with a suprapubic catheter

We report a case of a 74-year-old man who presented to the emergency department with a 1-week history of fever. He had a meatal stenosis and had a suprapubic catheter for 10 months, and had a recent hospitalisation for urosepsis with bacteraemia due to methicillin-resistant Staphylococcus aureus after manipulation of the catheter. Clinical examinations were performed in the emergency department and the patient was hospitalised with the diagnosis of recurrent urinary tract infection. The following day, we noticed the development of a mass in the left sternoclavicular joint with inflammatory signs and excruciating pain. Ultrasonographic findings led to the diagnosis of left sternoclavicular synovitis, and methicillin-resistant S. aureus grew in blood cultures leading to the diagnosis of sternoclavicular septic arthritis. Treatment with vancomycin and gentamicin was started and maintained for 4 weeks with complete resolution of symptoms and no complications or sequelae.

A retrospective study of septic arthritis in a tertiary hospital in West Texas with high rates of methicillin-resistant Staphylococcus aureus infection

Septic arthritis is an important concern for rheumatologists in the evaluation of joint disease. Very few studies have addressed the microbiologic epidemiology and outcomes of septic arthritis in the USA since the year 2000. We performed a retrospective study of septic arthritis in a tertiary hospital in West Texas from the year 2000 to 2013. We recorded data on patient demographics, microbiologic etiology, treatment patterns, and outcomes. The most common causative organisms were Staphylococcus aureus and Streptococcus spp. Methicillin-resistant Staphylococcus aureus (MRSA) caused septic arthritis in 22.6 % of the cases. MRSA septic arthritis was associated with low rates of adequate empiric antimicrobial therapy. The mortality due to sepsis in our study was 5.5 %. Patients with septic arthritis had a mean length of stay of 13.5 ± 12.1 days and required 2.1 ± 1.4 joint operations. Many patients (29.2 %) had readmissions due to complications, and these patients had high rates of home health utilization and transfers to other facilities post hospital discharge. In our logistic regression analysis model, factors associated with poor outcomes in septic arthritis were MRSA, older age, and prosthetic joint infection. Septic arthritis is associated with significant mortality, morbidity, and health care costs, and more studies are needed to improve outcomes, especially considering the increasing rates of MRSA as the pathogen.

Clinical and epidemiological differences between septic arthritis of the knee and hip caused by oxacillin-sensitive and -resistant s. aureus

OBJECTIVE

To establish the risk factors for joint infection by oxacillin-resistant Staphylococcus aureus (MRSA) using clinical and epidemiological data.

METHODS

All septic arthritis cases of the knee and hip diagnosed and treated in our institution from 2006 to 2012 were evaluated retrospectively. Only patients with cultures identified as microbial agents were included in the study. The clinical and epidemiological characteristics of the patients were analyzed, seeking the differences between populations affected by MRSA and oxacillin-sensitive Staphylococcus aureus (MSSA).

RESULTS

S. aureus was isolated in thirty-five patients (46.0%) in our total sample, 25 in the knee and 10 in the hip. Of these 35 patients, 22 presented with MSSA and 13 presented with MRSA. Provenance from a health service-related environment, as described by the Centers for Disease Control and Prevention, was the only variable associated with oxacillin-resistant strains of this bacterium (p = 0.001).

CONCLUSION

Provenance from a health service-related environment was associated with a higher incidence of MRSA-related septic arthritis, suggesting that this agent should be considered in the initial choice of antibiotic treatment. Previous surgeries of the knee or affected limb and the absence of leukocytes might also be related to infection with this agent.

Predictors of treatment failure and mortality in native septic arthritis

The aims of this study are to analyse the characteristics of septic arthritis stratified by age and to identify the predictors of treatment failure and mortality in septic arthritis. A retrospective single-centre study was conducted in patients with native septic arthritis between 1994 and 2012. The primary outcome was treatment failure. Secondary outcomes included mortality, complications, endocarditis, bacteraemia, hospital readmission and the duration of the hospital stay. Logistic regression analyses with a propensity score were performed to identify the predictors of response and mortality. Additional analyses were performed according to age and the initial treatment (surgery or conservative). A total of 186 patients were studied. The median (interquartile range) age was 64 (46, 74) years, and the percentage of male patients was 68.9%. A logistic regression analysis showed that Staphylococcus aureus infection [OR 2.39 (1.20-4.77), p = 0.013], endocarditis [OR 4.74 (1.16-19.24), p = 0.029] and the involvement of joints difficult to access with needle drainage [OR 2.33 (1.06-5.11), p = 0.034] predict treatment failure and that age [OR 1.27 (1.07 = 1.50), p = 0.005], the leucocyte count at baseline [OR 1.01 (1.00-1.02), p = 0.023], bacteraemia [OR 27.66 (1.39-551.20), p = 0.030], diabetes mellitus [OR 15.33 (1.36-172.67), p = 0.027] and chronic renal failure [OR 81.27 (3.32-1990.20), p = 0.007] predict mortality. No significant differences in treatment failure by age were found. In septic arthritis, the predictors of mortality and the predictors of treatment failure differ. The predictors of treatment failure concern local factors and systemic complications, whereas conditions related to the host's immune competence, such as age and comorbidities that hamper the host's response, predict mortality.

Surgical therapy of extensive knee joint empyema: mid-term results after two-stage versus one-stage procedures

PURPOSE

Untreated knee joint empyema leads to rapid destruction of the joint and, thus far, has proven challenging to treat. This study presents data obtained after one- versus two-stage surgical approaches. Specifically, clinical outcome, complication rate, re-infection rate, duration of operation, and hospital stay are reported.

METHODS

Between 2006 and 2010, 67 patients with extensive knee joint empyema underwent surgical therapy. Patients underwent either a two-stage surgical approach with open joint treatment for 7-10 days or a one-stage procedure with primary closure of the knee joint after radical debridement.

RESULTS

The two-stage procedure was performed on 36 patients, whereas the one-stage procedure was performed on 31 patients. Infection duration prior to the index procedure ranged from 3 days to 55 months (two-stage: ~5 months, one-stage: ~2.4 months). The groups did not differ significantly in demographic group characteristics. Hospital stay and duration of operation were significantly (p < 0.01) reduced in the one-stage group compared to the two-stage group (31.1 ± 10.6 vs. 23.4 ± 14.4 days and 105 ± 32 vs. 68 ± 18 min, respectively). Functional outcome improved in both groups from the pre- to post-operative period, but did not differ significantly between groups.

CONCLUSION

The one-stage open surgical approach produced similar results to the two-stage approach in the treatment of extensive knee joint empyemas. However, by waiving the open joint treatment concept, duration of hospital stay and operation time could be significantly reduced.

LEVEL OF EVIDENCE

III.

Community Acquired Chronic Arthritis due to Pseudomonas aeruginosa in a Previously Healthy Pregnant Woman

Septic arthritis caused by Pseudomonas aeruginosa is uncommon in the immunocompetent population, despite its occurrence in younger patients with open injuries and in intravenous drug abusers. Here we report a case of septic arthritis caused by P. aeruginosa. This case is unique for several reasons. First, it is a case of septic arthritis in a pregnant woman with no traditional risk factors reported in the literature including history of prior traumatic events, hospitalisation, or chronic underlying disease. She was suspected of having transient osteoporosis associated with pregnancy to involve both hip joints. Second, this is the first reported case of a community acquired chronic septic arthritis due to P. aeruginosa involving large joints of both upper and lower extremities. The patient was treated successfully with a combination of ceftazidime and amikacin for 4 weeks followed by oral ciprofloxacin 750 mg twice daily for 8 weeks.

The potential use of microcalorimetry in rapid differentiation between septic arthritis and other causes of arthritis

Current diagnostic methods in differentiating septic from non-septic arthritis are time-consuming (culture) or have limited sensitivity (Gram stain). Microcalorimetry is a novel method that can rapidly detect microorganisms by their heat production. We investigated the accuracy and time to detection of septic arthritis by using microcalorimetry. Patients older than 18 years of age with acute arthritis of native joints were prospectively included. Synovial fluid was aspirated and investigated by Gram stain, culture and microcalorimetry. The diagnosis of septic arthritis and non-septic arthritis were made by experienced rheumatologists or orthopaedic surgeons. Septic arthritis was diagnosed by considering the finding of acute arthritis together with findings such as positive Gram stain or positive culture of synovial fluid or positive blood culture. The sensitivity and specificity for diagnosing septic arthritis and the time to positivity of microcalorimetry were determined. Of 90 patients (mean age 64 years), nine had septic arthritis, of whom four (44 %) had positive Gram stain, six (67 %) positive synovial fluid culture and four (44 %) had positive blood culture. The sensitivity of microcalorimetry was 89 %, the specificity was 99 % and the mean detection time was 5.0 h (range, 2.2-8.0 h). Microcalorimetry is an accurate and rapid method for the diagnosis of septic arthritis. It has potential to be used in clinical practice in diagnosing septic arthritis.

Oral Antimicrobial Therapy: Efficacy and Safety for Methicillin-Resistant Staphylococcus aureus Infections and Its Impact on the Length of Hospital Stay

Background

Carefully switching from intravenous to oral antibiotic therapy has shown to reduce treatment costs and lengths of hospital stay as well as increase safety and comfort in patients with infections. The aim of this study was to compare the clinical efficacy and safety between the patients treated with glycopeptides (case group), and the patients given oral antibiotics, as the initial or step-down therapy (control group), in the treatment of patients with methicillin-resistant Staphylococcus aureus (MRSA) infection.

Materials and Methods

A multicenter observational study was retrospectively performed in 7 teaching hospitals in Korea from January to December 2012. The study included adult patients (≥ 18 years) with infection caused by MRSA isolates, susceptible to clindamycin, erythromycin, and ciprofloxacin. The primary end point was treatment outcome, including all-cause mortality and switching of antibiotics. Drug-related adverse events and the lengths of hospital stay were also compared between the two treatment groups.

Results

During the study period, 107 patients (43 cases and 64 controls) with MRSA infections were enrolled from the participating hospitals. The most common sites of MRSA infection were skin and soft tissue (n = 28) and bone and joint (n = 26). The median Charlson comorbidity index (P = 0. 560), the frequency of severe sepsis (P = 0.682) or thrombocytopenia (P = 1.000), and median level of serum C-reactive protein (P = 0.157) at the onset of MRSA infections were not significantly different between the case and control groups. The oral antibiotics most frequently prescribed in the case group, were fluoroquinolones (n = 29) and clindamycin (n = 8). The median duration of antibiotic treatment (P = 0.090) and the occurrence of drug-related adverse events (P = 0.460) did not reach statistically significant difference between the two groups, whereas the total length of hospital stay after the onset of MRSA infection was significantly shorter in the case group than the control group [median (interquartile range), 23 days (8-41) vs. 32 days (15-54), P = 0.017]. In multivariate analyses, the type of antibiotic used was not an independent risk factor for treatment failure. The statistically significant factors associated with treatment failure included underlying hepatic diseases, prior receipt of antibiotics, and foreign body retention.

Conclusions

This study indicates that oral antibiotic therapy with active agents against MRSA isolates can be considered as the initial or step-down therapy for the treatment of MRSA infections and also reduce the length of hospital stay.

Sacroilitis: an unusual cause for a common presentation

Inflammatory arthritis and sacroilitis are common presentations to rheumatology clinics. Owing to the physiological changes of pregnancy, the first presentation can be post partum with back pain and an accompanying oligoarthritis or polyarthritis. We present a woman with lower back pain who demonstrated clinical and radiological features consistent with sacroilitis and an inflammatory arthritis but was found to have an unusual presentation of another common cause of arthritis.

Determinants of methicillin-susceptible Staphylococcus aureus native bone and joint infection treatment failure: a retrospective cohort study

Background

Although methicillin-susceptible Staphylococcus aureus (MSSA) native bone and joint infection (BJI) constitutes the more frequent clinical entity of BJI, prognostic studies mostly focused on methicillin-resistant S. aureus prosthetic joint infection. We aimed to assess the determinants of native MSSA BJI outcomes.

Methods

Retrospective cohort study (2001–2011) of patients admitted in a reference hospital centre for native MSSA BJI. Treatment failure determinants were assessed using Kaplan-Meier curves and binary logistic regression.

Results

Sixty-six patients (42 males [63.6%]; median age 61.2 years; interquartile range [IQR] 45.9–71.9) presented an acute (n = 38; 57.6%) or chronic (n = 28; 42.4%) native MSSA arthritis (n = 15; 22.7%), osteomyelitis (n = 19; 28.8%) or spondylodiscitis (n = 32; 48.5%), considered as “difficult-to-treat” in 61 cases (92.4%). All received a prolonged (27.1 weeks; IQR, 16.9–36.1) combined antimicrobial therapy, after surgical management in 37 cases (56.1%). Sixteen treatment failures (24.2%) were observed during a median follow-up period of 63.3 weeks (IQR, 44.7–103.1), including 13 persisting infections, 1 relapse after treatment disruption, and 2 super-infections. Independent determinants of treatment failure were the existence of a sinus tract (odds ratio [OR], 5.300; 95% confidence interval [CI], 1.166–24.103) and a prolonged delay to infectious disease specialist referral (OR, 1.134; 95% CI 1.013–1.271).

Conclusions

The important treatment failure rate pinpointed the difficulty of cure encountered in complicated native MSSA BJI. An early infectious disease specialist referral is essential, especially in debilitated patients or in presence of sinus tract.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-443) contains supplementary material, which is available to authorized users.

Evaluation of a real-time PCR assay for simultaneous detection of Kingella kingae and Staphylococcus aureus from synovial fluid in suspected septic arthritis

Direct plating of synovial fluid (SF) on agar-based media often fails to identify pathogens in septic arthritis (SA). We developed a PCR assay for the simultaneous detection of Kingella kingae and Staphylococcus aureus from SF to evaluate molecular detection in SF and to estimate the incidence of K. kingae in SA in North America. The assay was based on detection of the cpn60 gene of K. kingae and the spa gene of S. aureus in multiplex real-time PCR. K. kingae was identified in 50% of patients between 0 and 5 yr of age (n=6) but not in any patients >18 yr old (n=105). Direct plating of SF on agar-based media failed to detect K. kingae in all samples. The PCR assay was inferior to the culture-based method for S. aureus, detecting only 50% of culture-positive cases. Our findings suggest that K. kingae is a common pathogen in pediatric SA in North America, in agreement with previous reports from Europe. PCR-based assays for the detection of K. kingae may be considered in children with SA, especially in those with a high degree of clinical suspicion.

Clinical results after arthroscopic treatment for septic arthritis of the elbow joint

PURPOSE

The purpose of this study was to examine clinical findings of septic arthritis of the elbow joint in a series of immunocompetent patients and to evaluate the outcomes after arthroscopic treatment.

METHODS

Between October 2006 and January 2012, 11 patients with septic arthritis of the elbow underwent arthroscopic surgery. History, laboratory findings, and radiologic findings were reviewed. Functional outcomes were evaluated using the Mayo Elbow Performance Score (MEPS).

RESULTS

The study included 5 men and 6 women with a mean age of 45 years. An underlying medical disease was present in 1 patient (diabetes). Staphylococcus aureus was the most common organism identified (5 patients). There was 1 reoperation and no complications related to the arthroscopic procedure. Eight of 11 patients had excellent results assessed by MEPS at the final follow-up. The mean MEPS was 94.5 at the final follow-up.

CONCLUSIONS

Septic arthritis of the elbow joint can occur in otherwise healthy patients without pre-existing elbow disease. Arthroscopic irrigation and synovectomy are safe and effective in patients with septic arthritis and result in good functional outcomes.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Septic arthritis: patients with or without isolated infectious agents have similar characteristics

PURPOSE

Septic arthritis can be disabling and life-threatening, requiring prompt diagnosis and treatment. The infectious agent is not always identified in these patients. We revaluate septic arthritis cases discharged from our department, describing the affected population, causative microorganisms and antibiotic therapy used, and characterised differences between patients with and without isolated pathogenic agents.

METHODS

Sixty-eight septic arthritis patients were included in this study. Diagnosis was based on clinical findings, and/or the presence of joint purulent material, and/or bacterial pathogen isolation from joint fluid/synovial membrane/blood cultures and response to antibiotics. Data analysis was performed using SPSS 20.

RESULTS

Patients had a mean age of 61.1 ± 18.8 years, without sex predominance. 26.5 % had an infection ≤ 15 days before septic arthritis diagnosis. Besides previous infection, 57.4 % had ≥ 1 risk factors for septic arthritis, most commonly pharmacological immunosuppression (20.6 %), diabetes mellitus type 2 (19.1 %) and rheumatoid arthritis (17.6 %). The knee was the most often affected (54.3 %). Only 39.7 % presented fever from clinical onset until hospital admission (mean 13.4 ± 18.9 days). Leucocytosis was present in 45.6 % of patients, elevated erythrocyte sedimentation rate (ESR) in 75 % and elevated C-reactive protein (CRP) in 97.1 %. 5.9 % had articular damage attributable to septic arthritis. An infectious agent was isolated in 41.2 % of patients, with Staphylococcus aureus being the most frequent. 38.7 % of synovial fluid and 23.5 % of synovial membrane cultures were positive. Patients with an identified infectious agent have no significant differences other than more days of hospitalisation (p = 0.003) and in-hospital antibiotic treatment (p = 0.017).

CONCLUSION

Synovial fluid and synovial membrane cultures more often identified pathogens compared to blood or urine cultures. Patients with and without an identified infectious agent have similar demographic, clinical, laboratory and radiographic characteristics.

Antimicrobial-related severe adverse events during treatment of bone and joint infection due to methicillin-susceptible Staphylococcus aureus

Prolonged antimicrobial therapy is recommended for methicillin-susceptible Staphylococcus aureus (MSSA) bone and joint infections (BJI), but its safety profile and risk factors for severe adverse events (SAE) in clinical practice are unknown. We addressed these issues in a retrospective cohort study (2001 to 2011) analyzing antimicrobial-related SAE (defined according to the Common Terminology Criteria for Adverse Events) in 200 patients (male, 62%; median age, 60.8 years [interquartile range {IQR}, 45.5 to 74.2 years]) with MSSA BJI admitted to a reference regional center with acute (66%) or chronic arthritis (7.5%), osteomyelitis (9.5%), spondylodiscitis (16%), or orthopedic device-related infections (67%). These patients received antistaphylococcal therapy for a median of 26.6 weeks (IQR, 16.8 to 37.8 weeks). Thirty-eight SAE occurred in 30 patients (15%), with a median time delay of 34 days (IQR, 14.75 to 60.5 days), including 10 patients with hematologic reactions, 9 with cutaneomucosal reactions, 6 with acute renal injuries, 4 with hypokalemia, and 4 with cholestatic hepatitis. The most frequently implicated antimicrobials were antistaphylococcal penicillins (ASP) (13 SAE/145 patients), fluoroquinolones (12 SAE/187 patients), glycopeptides (9 SAE/101 patients), and rifampin (7 SAE/107 patients). Kaplan-Meier curves and stepwise binary logistic regression analyses were used to determine the risk factors for the occurrence of antimicrobial-related SAE. Age (odds ratio [OR], 1.479 for 10-year increase; 95% confidence interval [CI], 1.116 to 1.960; P = 0.006) appeared to be the only independent risk factor for SAE. In patients receiving ASP or rifampin, daily dose (OR, 1.028; 95% CI, 1.006 to 1.051; P = 0.014) and obesity (OR, 8.991; 95% CI, 1.453 to 55.627; P = 0.018) were associated with the occurrence of SAE. The high rate of SAE and their determinants highlighted the importance of the management and follow-up of BJI, with particular attention to be paid to older persons, especially for ASP dosage, and to rifampin dose adjustment in obese patients.

Rapid in situ chondrocyte death induced by Staphylococcus aureus toxins in a bovine cartilage explant model of septic arthritis

OBJECTIVE

To assess in situ chondrocyte viability following exposure to a laboratory strain and clinical isolates of Staphylococcus aureus.

METHODS

Bovine cartilage explants were cultured in the presence of S. aureus 8325-4 (laboratory strain), clinical S. aureus isolates or non-infected culture medium of pH values 7.4, 6.4 and 5.4. All clinical isolates were isolated from the joint aspirates of patients presenting with S. aureus-induced septic arthritis (SA). At designated time points, in situ chondrocyte viability was assessed within defined regions-of-interest in the axial and coronal plane following live- and dead-cell image acquisition using the fluorescent probes 5-chloromethylfluorescein diacetate (CMFDA) and propidium iodide (PI), respectively, and confocal laser-scanning microscopy (CLSM). Cartilage water content, following S. aureus 8325-4 exposure, was obtained by measuring cartilage wet and dry weights.

RESULTS

S. aureus 8325-4 and clinical S. aureus isolates rapidly reduced in situ chondrocyte viability (>45% chondrocyte death at 40 h). The increased acidity, observed during bacterial culture, had a minimal effect on chondrocyte viability. Chondrocyte death commenced within the superficial zone (SZ) and rapidly progressed to the deep zone (DZ). Simultaneous exposure of SZ and DZ chondrocytes to S. aureus 8325-4 toxins found SZ chondrocytes to be more susceptible to the toxins than DZ chondrocytes. Cartilage water content was not significantly altered compared to non-infected controls.

CONCLUSIONS

Toxins released by S. aureus have a rapid and fatal action on in situ chondrocytes in this experimental model of SA. These data advocate the prompt and thorough removal of bacteria and their toxins during the treatment of SA.

Spontaneous septic arthritis in a patient without trauma, coinfection, or immunosuppression

Septic arthritis is a rare infection, most often affecting the knee and hip [1]. Infections are often secondary to joint repair or replacement surgery, systemic infection, or intravenous recreational drug use [1,2].Diabetes, rheumatoid arthritis, hepatic dysfunction, and immunosuppression are common risk factors [1,2]. Although septic arthritis can occur spontaneously, such occurrences are rare. We report a case of a previously healthy 54-year-old woman with no known risk factors presenting to a freestanding emergency department with 5 days of shoulder pain.