NONGONOCOCCAL BACTERIAL ARTHRITIS

Nontyphoidal salmonella septic arthritis in A patient with systemic lupus erythematosus: A case report

We report a case of septic arthritis in a 43-year-old female patient. Despite initial treatment with ceftriaxone for Nontyphoidal Salmonella based on blood and joint fluid culture results, the shoulder joint pain worsened. Suspected systemic lupus erythematosus associated synovitis did not respond to immunosuppressive therapy including methylprednisolone, hydroxychloroquine and methotrexate. Subsequent radiograph revealed a shoulder joint abscess, leading to arthroscopic joint debridement. Ceftriaxone was administered post-operatively until analgesic efficacy was attained. This case highlights the significance of accurate diagnosis and appropriate treatment for nontyphoidal Salmonella septic arthritis.

The Effect of Crystal Arthropathy on the Diagnostic Criteria of Native Septic Arthritis

INTRODUCTION

Distinguishing between septic arthritis and crystal arthropathy flares can be challenging. The purpose of this study was to determine how the presence of synovial crystals affects the diagnostic criteria of septic arthritis.

METHODS

A retrospective review identified patients undergoing joint aspirations to rule out native septic arthritis. Differences between septic arthritis presenting with and without synovial crystals were analyzed. A receiver-operating characteristic curve was plotted for laboratory markers to determine the area under the curve, or diagnostic accuracy, for septic arthritis and to evaluate thresholds that maximized sensitivity and specificity.

RESULTS

There were 302 joint aspirations in 267 patients. Septic arthritis was diagnosed in 17.9% (54/302). Patients with synovial crystals were less likely to have septic arthritis (4.2% [5/119] vs. 26.8% [49/183], P < 0.0001). Septic arthritis in patients with no synovial crystals was associated with fever and a higher synovial white blood cell (WBC) count, synovial polymorphonuclear cell percentage (PMN%), serum WBC, and C-reactive protein (CRP) ( P < 0.05). Septic arthritis in patients with synovial crystals was only associated with inability to bear weight and a higher synovial WBC and CRP ( P < 0.05). Synovial PMN% was considered nondiagnostic of septic arthritis (area under the curve 0.56) in patients with crystals while synovial WBC and CRP had acceptable (0.76) and excellent (0.83) diagnostic utility, respectively. The WBC and CRP value thresholds that maximized sensitivity and specificity for septic arthritis were greater in patients with crystals (21,600 vs. 17,954 cells/μL and 125 vs. 69 mg/L, respectively).

DISCUSSION

The presence of synovial crystals reduced the likelihood of septic arthritis and altered the laboratory diagnostic criteria. PMN% was nondiagnostic in the setting of synovial crystals.

IL-4 deficiency decreases mortality but increases severity of arthritis in experimental group B Streptococcus infection

IL-4 is an anti-inflammatory cytokine that inhibits the onset and severity in different experimental arthritis models. Group B streptococci (GBS) have been recognized as an ever-growing cause of serious invasive infections in nonpregnant adults. Septic arthritis is a clinical manifestation of GBS infection. To investigate the role of IL-4 in experimental GBS infection, IL-4 deficient or competent mice were inoculated with 1 × 10⁷ GBS/mouse. Mortality, appearance of arthritis, GBS growth in the organs, and local and systemic cytokine and chemokine production were examined. IL-4−/− mice showed lower mortality rates but increased severity of arthritis and exhibited a lower microbial load in blood, kidneys, and joints than wt mice. Increased local levels of IL-1 β, IL-6, TNF-α, MIP-1α, and MIP-2 accompanied the more severe arthritis in IL-4−/− mice. Our results suggest a detrimental role of IL-4 in GBS sepsis, whereas it plays a beneficial effect on GBS-induced arthritis.

Arthritis in the intensive care unit

Acute arthritis in critically ill patients may be caused by local or systemic infection, by a flare of chronic joint disease such as rheumatoid or crystal-associated arthritis, or by less common entities such as hemarthrosis. Diagnosis requires analysis of synovial fluid, and appropriate treatment is based on its findings. Prompt diagnosis and treatment are usually necessary to prevent the significant morbidity associated with these conditions.

Septic arthritis due to Streptococcus sanguis

We report an unusual case of septic arthritis due to Streptococcus sanguis, a member of the viridans group of streptococci that are part of the normal flora of the mouth and upper respiratory tract. Our patient had severe underlying periodontal disease, which likely contributed to his joint sepsis through hematogenous spread. Although viridans streptococci are rare causes of septic arthritis in native joints, they should be considered in the setting of severe periodontal disease.

Role of ultrasound in musculoskeletal infections

Ultrasound is able to play a key role in the management of musculoskeletal soft tissue infections. It is an easily accessible imaging modality that can be used immediately after plain radiographs have been obtained. Quick diagnosis is essential in the clinical setting of musculoskeletal infection because delay can lead to significant morbidity. In addition to its diagnostic capabilities, US offers a safe, real-time, and convenient technique to perform immediately a guided-needle aspiration of any suspicious fluid collection. US provides the most efficient way to document quickly an infection of the musculoskeletal soft tissues and to identify the offending micro-organism.

Musculoskeletal infections: US manifestations

One of the most important prognostic factors in patients with musculoskeletal infections is the delay in establishing therapy. Early diagnosis of septic arthritis requires analysis of joint fluid. Ultrasonography (US) is a rapid, portable, sensitive technique for confirming the presence of joint effusions. The study can be easily repeated for follow-up of lesions. US allows real-time guidance of fluid aspiration and can reduce the risk of contaminating other anatomic compartments, especially in the hands, wrists, and feet. Radiography provides complementary information and should be performed in conjunction with US. US is the imaging modality of choice for diagnosis of superficial abscesses. Dynamic compression with the US probe and color Doppler imaging can facilitate detection of superficial abscesses. US may help in the early diagnosis of osteomyelitis by demonstrating subperiosteal or juxtacortical fluid collections and by providing guidance for aspiration of these collections. Evaluation of osseous involvement requires additional imaging; a US examination with normal results does not allow exclusion of bone infection. US is not degraded by metallic artifact and may be useful in cases of osteomyelitis complicating metallic fixation in an extremity. After initial radiography, US can play an important role in the management of musculoskeletal infections.

Occurrence of HLA-B27 tissue antigen in patients with purulent arthritis caused by Staphylococcus aureus or beta-haemolytic streptococci

The HLA-B27 tissue antigen is associated with reactive arthritis caused by different bacterial infections but its occurrence in purulent arthritis has not been studied earlier. We analysed the frequency of HLA-B27 in patients with culture proven purulent arthritis caused by Staphylococcus aureus or beta-haemolytic streptococci. The study included 41 patients treated during the years 1979-96 (15 female and 26 male) with a mean age of 52 years (range 16-80 years). HLA-B27 was found in 24% (9/37) of the tested patients compared with 14% in the healthy Finnish population, but the difference was not statistically significant (P < 0.50). No statistical difference in disease activity according to febrile days or duration of the disease could be found between HLA-B27 positive and negative patients. We conclude that HLA-B27 is not a risk factor for purulent arthritis, and when present it has no significant modifying effect on the clinical picture of purulent arthritis.

Staphylococcus aureus-Induced Septic Arthritis and Septic Death Is Decreased in IL-4-Deficient Mice: Role of IL-4 as Promoter for Bacterial Growth

Lack of IL-4 has been shown to be protective in some experimental models of infectious diseases in mice such as cutaneous leishmaniasis. At the same time IL-4, together with other Th2 cytokines, including IL-10 and IL-13, is known as an anti-inflammatory cytokine with the potential to down-regulate proinflammatory cytokine production. To investigate the role of IL-4 in experimental Staphylococcus aureus-induced and T lymphocyte-mediated arthritis, IL-4-deficient C57BL/6 mice (IL-4−/−) and their congenic controls (IL-4+/+) were inoculated with a toxic shock syndrome toxin-1-producing S. aureus strain. In IL-4+/+ mice, arthritis peaked 14 days after bacterial inoculation, whereas, at that time, IL-4−/− mice displayed significantly less frequent (p &lt; 0.05) joint inflammation. Paralleling lower frequency of arthritis, IL-4-deficient mice showed a decreased bacterial burden in joints (p = 0.014) and kidneys (p = 0.029), as well as lower infection-triggered weight decrease and mortality. In vitro, IL-4 inhibited intracellular killing of S. aureus in infected macrophages, without affecting phagocytosis. This finding may explain the enhanced staphylococcal clearance observed in IL-4−/− mice in vivo. Our results suggest that IL-4 and IL-4-dependent Th2 responses promote septic arthritis and sepsis-related mortality by inhibition of bacterial clearance during S. aureus infection.

Staphylococcal septic arthritis: antibiotic and nonsteroidal anti-inflammatory drug treatment in a rabbit model

This study evaluated the effects of combining antibiotic therapy with the application of a nonsteroidal anti-inflammatory drug on the degradation of articular cartilage for an animal model of Staphylococcal septic arthritis. Rabbits were infected intra-articularly with Staphylococcus aureus. Antibiotic treatment started 18 hours after infection and continued for 7 days. Treatment with the nonsteroidal anti-inflammatory drug naproxen sodium started 24 hours before infection and continued for either 3 or 7 weeks. The cartilage matrix of uninfected and infected knees was quantified by analysis of glycosaminoglycan and collagen content. Three weeks after infection, the combined treatment of the nonsteroidal anti-inflammatory drug and antibiotics reduced the loss of glycosaminoglycan and collagen from the cartilage of the infected knee by 15 and 30%, respectively, compared with antibiotic treatment alone. Continuing treatment with naproxen sodium for 7 weeks reduced the loss of collagen by 50% when compared with antibiotic treatment alone. The longer period of treatment with naproxen sodium showed little further effect on the loss of glycosaminoglycan than that observed for the 3-week treatment. Treatment with this drug and antibiotics reduced swelling of the knee and levels of prostaglandin E2 in the synovial fluid. The data support the hypothesis that decreasing post-infectious inflammation by adding the drug to a standard antibiotic regimen reduces cartilage damage from Staphylococcal septic arthritis.

Association between high antistaphylolysin and teichoic acid antibody titres with rheumatic syndromes

To analyse which rheumatic syndromes are associated with serological evidence of recent Staphylococcus aureus infection, we studied retrospectively 44 adult patients, gathered between 1979-1990, having an acute arthritis syndrome or an exacerbation in their chronic rheumatic disease and simultaneously a high antistaphylolysin (ASTA > 4,0) and/or high teichoic acid antibody titre (TAA > 8). Patients with septic arthritis or endoprosthetic infections were not included. 25 patients had arthritis/arthralgia associated with a known rheumatic disease, 9 patients had reactive arthritis and 8 patients had arthralgia. The frequency of HLA-B27 in tested patients was significantly higher in the whole patient group than in the healthy Finnish population (43% v 14%, p < 0.001). It is concluded that high ASTA and/or TAA titres are associated with various acute rheumatic syndromes including reactive arthritis.

Septic arthritis

Septic arthritis is a medical emergency that can lead to significant morbidity and mortality. Prompt recognition and treatment are critical to ensuring a good prognosis. Thus, this article reviews the clinical presentation, microbiology, diagnostic workup, and outcome of nonprosthetic joint infections.