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

Objective: The aim of this study is to characterise the clinical and microbiological profile of adult patients treated at our orthopaedic unit with septic arthritic between 2006 and 2017. Materials and Methods: A total of 70 patients who were admitted with a diagnosis of septic arthritis between 2006 and 2017 were included in the study. The patients' clinical and epidemiological characteristics were surveyed; microbiological profile and the complications relating to the patients' treatment were identified. Results: Septic arthritis was more common among males (83%). About 75% of the patients presented with a history of fever. The knee was the most commonly affected joint (71%), followed by the hip. While C-reactive protein was found to be consistently >75, total blood white blood cell (WBC) counts were found not to be reflective of the presence of infection with a mean WBC count of only 13,561/cu.mm, and Gram stain examination had a poor sensitivity of 47%. Among the co-morbidities, the most prevalent association was with diabetes mellitus. The infectious agent most frequently isolated was Staphylococcus aureus(42.85%). The antibiotic sensitivity pattern has evolved since the early years, with resistant strains becoming increasingly prevalent. Unusually, high incidence of streptococci was noted (30%), contrary to the published literature. One-third of the patients had multi-resistant organisms. Septic arthritis left 70% of the patients with a significant residual disability at 6 months follow-up and had 4.25% mortality. Conclusion: Changing sensitivity patterns of microbes in septic arthritis point to a need for reconsidering empirical antibiotic therapy. Joint damage following infection can lead to significant disability.

Equine or porcine synovial fluid as a novel ex vivo model for the study of bacterial free-floating biofilms that form in human joint infections.

Bacterial invasion of synovial joints, as in infectious or septic arthritis, can be difficult to treat in both veterinary and human clinical practice. Biofilms, in the form of free-floating clumps or aggregates, are involved with the pathogenesis of infectious arthritis and periprosthetic joint infection (PJI). Infection of a joint containing an orthopedic implant can additionally complicate these infections due to the presence of adherent biofilms. Because of these biofilm phenotypes, bacteria within these infected joints show increased antimicrobial tolerance even at high antibiotic concentrations. To date, animal models of PJI or infectious arthritis have been limited to small animals such as rodents or rabbits. Small animal models, however, yield limited quantities of synovial fluid making them impractical for in vitro research. Herein, we describe the use of ex vivo equine and porcine models for the study of synovial fluid induced biofilm aggregate formation and antimicrobial tolerance. We observed Staphylococcus aureus and other bacterial pathogens adapt the same biofilm aggregate phenotype with significant antimicrobial tolerance in both equine and porcine synovial fluid, analogous to human synovial fluid. We also demonstrate that enzymatic dispersal of synovial fluid aggregates restores the activity of antimicrobials. Future studies investigating the interaction of bacterial cell surface proteins with host synovial fluid proteins can be readily carried out in equine or porcine ex vivo models to identify novel drug targets for treatment of prevention of these difficult to treat infectious diseases.

Recurrent arthritis caused by Candida parapsilosis: a case report and literature review.

BACKGROUND: Candida arthritis is extremely rare and also represents a major challenge of diagnosis and treatment. Here we reported a rare case of recurrent arthritis caused by Candida parapsilosis. CASE PRESENTATION: A 56-year-old Chinese male suffered from recurrent pain and swelling in his right knee after several times of "small needle-knife" acupuncture and corticosteroid injection of the joint. Candida parapsilosis was cultured in his synovial fluid and identified by sequencing of its Internal Transcribed Spacer (ITS) gene. Here we present the radiological characteristics, arthroscopic pictures, and synovium pathology of this patient. Also, blood test and chemical analysis of his synovial fluid were listed as well as the ITS sequence of this Candida species identified. The patient underwent thorough arthroscopic debridement and then set on fluconazole 400 mg daily for 12 months. His symptoms resolved and no relapse was observed on the last follow-up. Additionally, a brief but comprehensive review of C. parapsilosis arthritis episodes from past to now were studied. CONCLUSION: With the detailed clinical information reported in this case and our literature review, we hope they would add to our knowledge of C. parapsilosis arthritis - its clinical settings, laboratory features, radiological characteristics, arthroscopic findings and experience of management.

Optimized testing for C. trachomatis DNA in synovial fluid samples in clinical practice.

AIM: No standardized polymerase chain reaction (PCR) assay is available for detection of Chlamydia trachomatis (C. tr.) in synovial fluid (SF) for diagnostic use in clinical practice. This study tested the performance of two optimized molecular biology methods, to determine which is best suited for detecting C. tr. in SF clinical samples from patients with various rheumatologic diseases. METHODS: Two DNA extraction methods, i.e., (1) alkaline lysis and (2) QIAEX II Gel Extraction Kit® + cetyltrimethylammonium bromide (CTAB; Qiagen, Hilden, Germany), and C. tr.-omp1-152 bp PCR were tested in SF samples from a total of 329 patients with the following diagnoses: reactive arthritis (ReA; n = 10, 4 patients had posturethritic ReA), undifferentiated arthritis (UA; n = 66), rheumatoid arthritis (RA; n = 169), psoriatic arthritis (PSA; n = 12), and osteoarthritis (OA) n = 72. RESULTS: In SF samples, C. tr.-omp1-152 bp PCR in combination with alkaline lysis DNA extraction allowed detection of more C. tr.-positive samples: 3/10 (30%) ReA patients (all with posturethritic ReA) and 20/66 (38%) UA patients were positive, compared to the 0/10 (0%) patients with ReA and 1/66 (2%) with UA detected using the QIAEX II Gel Extraction Kit® + CTAB. Moreover, 2/12 (17%) SF samples from PSA patients tested positive with alkaline lysis. All samples from patients with OA and RA tested negative. CONCLUSION: Alkaline lysis in combination with C. tr.-omp1-152 bp PCR emerged as the most sensitive method for identification of C. tr. in clinical SF samples.

Isolation of Brucella melitensis from a human case of chronic additive polyarthritis.

Brucellar arthritis remains under diagnosed owing to non-specific clinical manifestations. Here, we report isolation of Brucella melitensis from synovial fluid of 5th metatarsophalangeal joint of a 39-year-old lady having unusually chronic asymmetric, additive, peripheral polyarthritis. This isolation was confirmed by Bruce-Ladder polymerase chain reaction (PCR). The patient had a history of contact with an aborted goat. Rose Bengal Plate Agglutination Test (RBPT) and Standard Tube Agglutination Test (SAT) were positive for Brucella-specific antibodies both for patient and in contact with sheep and goats. The patient was treated with doxycycline and rifampicin for 16 weeks and was recovered fully.

Cathodic Electrical Stimulation Combined With Vancomycin Enhances Treatment of Methicillin-resistant Staphylococcus aureus Implant-associated Infections.

BACKGROUND: Effective treatments for implant-associated infections are often lacking. Cathodic voltage-controlled electrical stimulation has shown potential as a treatment of implant-associated infections of methicillin-resistant Staphylococcus aureus (MRSA). QUESTIONS/PURPOSES: The primary purpose of this study was to (1) determine if cathodic voltage-controlled electrical stimulation combined with vancomycin therapy is more effective at reducing the MRSA bacterial burden on the implant, bone, and synovial fluid in comparison to either treatment alone or no treatment controls. We also sought to (2) evaluate the histologic effects of the various treatments on the surrounding bone; and to (3) determine if the cathodic voltage-controlled electrical stimulation treatment had an effect on the mechanical properties of the titanium implant as a result of possible hydrogen embrittlement. METHODS: Thirty-two adult male Long-Evans rats (Harlan Laboratories, Indianapolis, IN, USA) with surgically placed shoulder titanium implants were infected with a clinical strain of MRSA (NRS70). One week after infection, eight animals received a treatment of cathodic voltage-controlled electrical stimulation at -1.8 V versus Ag/AgCl for 1 hour (STIM), eight received vancomycin twice daily for 1 week (VANCO), eight received the cathodic voltage-controlled electrical stimulation and vancomycin therapy combined (STIM + VANCO), and eight served as controls with no treatment (CONT). Two weeks after initial infection, the implant, bone, and synovial fluid were collected for colony-forming unit (CFU) enumeration, qualitative histological analysis by a pathologist blinded to the treatments each animal received, and implant three-point bend testing. RESULTS: The implant-associated CFU enumerated from the STIM + VANCO (mean, 3.7 × 10(3); SD, 6.3 × 10(3)) group were less than those from the CONT (mean, 1.3 × 10(6); SD, 2.8 × 10(6); 95% confidence interval [CI] of difference, -4.3 × 10(5) to -9.9 × 10(3); p < 0.001), STIM (mean, 1.4 × 10(6); SD, 2.0 × 10(6); 95% CI of difference, -2.1 × 10(6) to -1.8 × 10(3); p = 0.002), and VANCO (mean, 5.8 x 10(4); SD, 5.7 × 10(4); 95% CI of difference, -6.4 × 10(4) to -1.7 × 10(4); p < 0.001) group. The bone-associated CFU enumerated from the STIM + VANCO group (6.3 × 10(1); SD, 1.1 × 10(2)) were less than those from the CONT (mean, 2.8 × 10(5); SD, 4.8 × 10(5); 95% CI of difference, -9.4 × 10(4) to -5.0 × 10(3); p < 0.001) and STIM (mean, 2.6 × 10(4); SD, 2.5 × 10(4); 95% CI of difference, -4.1 × 10(4) to -1.6 × 10(3); p < 0.001) groups. The VANCO group (4.3 × 10(5); SD, 6.3 × 10(2)) also had lower bone-associated CFU as compared with the CONT (mean 95% CI of difference, -9.3 × 10(4) to -4.5 × 10(3); p < 0.001) and STIM (95% CI of difference, -4.0 × 10(4) to -1.5 × 10(3); p < 0.001) groups. In comparison to the synovial fluid CFU enumerated from the CONT group (mean, 3.3 × 10(4); SD, 6.0 × 10(4)), lower synovial CFU were reported for both the STIM + VANCO group (mean, 4.6 × 10(1); SD, 1.2 × 10(2); 95% CI of difference, -4.9 × 10(3) to -3.0 × 10(2); p < 0.001) and the VANCO group (mean, 6.8 × 10(1); SD, 9.2 × 10(1); 95% CI of difference, -4.9 × 10(3) to -2.8 × 10(2); p = 0.007). The histological analysis showed no discernable deleterious effects on the surrounding tissue as a result of the treatments. No brittle fracture occurred during mechanical testing and with the numbers available, no differences in implant flexural yield strength were detected between the groups. CONCLUSIONS: In this rodent model, cathodic voltage-controlled electrical stimulation combined with vancomycin is an effective treatment for titanium implant-associated infections showing greater than 99.8% reduction in bacterial burden on the implant, surrounding bone, and synovial fluid as compared with the controls and the stimulation alone groups. CLINICAL RELEVANCE: Cathodic voltage-controlled electrical stimulation combined with vancomycin may enable successful treatment of titanium orthopaedic implant-associated infections with implant retention. Future studies will focus on optimization of the stimulation parameters for complete eradication of infection and the ability to promote beneficial host tissue responses.

Bacteria and Toll-like receptor and cytokine mRNA expression profiles associated with canine arthritis.

The major forms of inflammatory canine arthritis are immune-mediated arthritis (IMA) and septic arthritis (SA), although some cases of cruciate disease (CD) are associated with significant levels of synovitis. In this study, the bacteria associated with canine arthritis were identified and mRNA expression levels of Toll-like receptors (TLRs) and pro-inflammatory cytokines determined. Of the 40 synovial fluid samples analysed, bacteria were isolated from 12 samples by culture (2 CD, 10 SA) and detected in 4 samples (3 CD, 1 SA) using culture-independent methods. Statistically significant increases in TLR2, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-12 mRNA expression were seen in all disease groups compared to normal controls. All disease groups had decreased mRNA expression of other TLRs compared to normal controls, but this did not reach statistical significance. Synovial fluid cell counts revealed that the highest number and proportion of mononuclear cells and neutrophils were found in the IMA and SA samples, respectively. Age had an effect on the TLR and cytokine mRNA expression profiles: TNF-α (p=0.043) and IL-12 (p=0.025) mRNA expression was increased and TLR4 mRNA expression was reduced (p=0.033) in dogs up to 4 years of age compared to older animals. In the 10 SA samples from which bacteria were isolated, statistically significant increases in TLR2, TLR7, TNF-α and IL-6 mRNA expression were observed. It is concluded that canine arthritis is associated with increased mRNA levels of pro-inflammatory cytokines, which could in some cases be mediated by bacteria through activation of TLR2.

Septic arthritis of the hip in a Cambodian child caused by multidrug-resistant Salmonella enterica serovar Typhi with intermediate susceptibility to ciprofloxacin treated with ceftriaxone and azithromycin.

Septic arthritis is a rare complication of typhoid fever. A 12-year-old boy without pre-existing disease attended a paediatric hospital in Cambodia with fever and left hip pain. A hip synovial fluid aspirate grew multidrug-resistant Salmonella enterica ser. Typhi with intermediate susceptibility to ciprofloxacin. Arthrotomy, 2 weeks of intravenous ceftriaxone and 4 weeks of oral azithromycin led to resolution of symptoms. The optimum management of septic arthritis in drug-resistant typhoid is undefined.

Ureaplasma parvum prosthetic joint infection detected by PCR.

We describe the first reported case of Ureaplasma parvum prosthetic joint infection (PJI) detected by PCR. Ureaplasma species do not possess a cell wall and are usually associated with colonization and infection of mucosal surfaces (not prosthetic material). U. parvum is a relatively new species name for certain serovars of Ureaplasma urealyticum, and PCR is useful for species determination. Our patient presented with late infection of his right total knee arthroplasty. Intraoperative fluid and tissue cultures and pre- and postoperative synovial fluid cultures were all negative. To discern the pathogen, we employed PCR coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). Our patient's failure to respond to empirical antimicrobial treatment and our previous experience with PCR/ESI-MS in culture-negative cases of infection prompted us to use this approach over other diagnostic modalities. PCR/ESI-MS detected U. parvum in all samples. U. parvum-specific PCR testing was performed on all synovial fluid samples to confirm the U. parvum detection.

Diagnóstico clínico y de laboratorio de la artritis gonocócica: a propósito de un caso / Clinical and laboratory diagnosis of gonococcal arthritis: presentation of a case

Introducción. La artritis gonocócica es una patología infrecuente en países de Europa occidental. Conseguir un diagnóstico temprano es vital para evitar una diseminación sistémica potencialmente fatal. Un caso en el trabajo rutinario de nuestro laboratorio, nos invita a realizar una breve revisión sobre la fisiopatología y el diagnóstico de la enfermedad. Observación clínica. Varón de 64 años, con fiebre, poliartralgias, e inflamación en tobillo derecho. Se procede a artrococentesis obteniendo muestra de líquido sinovial, con resultados analíticos sugerentes de artritis infecciosa, verificada mediante cultivo con aislamiento de N. gonorrhoeae, que el antibiograma muestra sensible a penicilina y ceftriaxona. Discusión. La infección diseminada de N. gonorrhoeae (DGI) incluye signos como poliartralgias, tenosinovitis y dermatitis. Ciertos casos pueden cursar además con artritis monoarticular, asociada a cultivos positivos de líquido sinovial, aunque hemocultivos negativos. Los elevados índices de resistencia a penicilina y tetraciclina, obligan a recomendar ceftriaxona i.v. como tratamiento de elección. Conclusión. La artritis gonocócica puede cursar en pacientes sin lesiones en la mucosa genitourinaria. Se asocia comúnmente a hemocultivos negativos. Solo el aislamiento del microorganismo en líquido sinovial permite un diagnóstico definitivo (AU)

Introduction. Gonococcal arthritis is an uncommon disease in western European countries. Obtaining an early diagnosis is essential to prevent potentially fatal dissemination. A case in the routine work of our laboratory led us to present a short review of the pathophysiology and diagnosis of the disease. Clinical observation. A 64 year-old male with, a fever, multiple joint pains, and inflammation in the right ankle. A sample of synovial fluid was obtained by arthrocentesis, with analytical results suggestive of infectious arthritis. This was confirmed by a culture, with the isolation of N. gonorrhoeae, which the antibiogram showed susceptibility to penicillin and ceftriaxone. Discussion. Disseminated N. gonorrhoeae infection includes signs such as, multiple joint pains, tenosynovitis and dermatitis. Certain cases can also present with, single joint arthritis, combined with positive synovial fluid cultures, although with negative blood cultures. The elevated rates of resistance to penicillin and tetracycline require recommending IV ceftriaxone as the treatment of choice. Conclusion. Gonococcal arthritis can occur in patients without lesions in the genitourinary mucosa. It is commonly associated with negative blood cultures. Only the isolation of the microorganism in synovial fluid enables a definitive diagnosis to be made (AU)

The fate of acutely inflamed joints with a negative synovial fluid culture.

PURPOSE: The purpose of this study was to evaluate the management and fate of acutely inflamed joints with a negative synovial fluid culture. METHODS: Between January and December 2009, all the patients who presented to our institution with an acutely inflamed joint and were subjected to microbiological assessment of their synovial fluid, were included in the study. Patients with a positive synovial fluid culture, a prosthetic joint replacement in situ and where an aspirate was obtained for a rheumatological diagnosis were excluded. This cohort was then divided into two groups depending on whether a diagnosis could be established through the course of their treatment. Group I included patients in whom a diagnosis could be established and group II included patients in whom a diagnosis could not be established. A thorough review of the patients' medical records and the hospital database was performed. Following this, a database consisting of the patient demographics, clinical features, investigations, treatment and outcome was created. RESULTS: A total of 144 patients met the inclusion criteria (group I: 95, group II: 49). The most commonly affected joint in both the groups was the knee. The average time to presentation was shorter in group II. Clinical findings at presentation were comparable in both groups. However, inflammatory markers were more likely to be raised in group II in comparison with group I. Eighty-two percent of group II required antibiotic treatment compared with 15% of group I. The mean duration of antibiotic treatment in group I was ten days and in group II was 26 days. Mean hospital stay differed significantly between the two groups, with group II being more than twice as long as compared with group I (p=0.001). The rate of mortality was also higher in group II (8.2%, p=0.03). CONCLUSION: Our study shows that patients presenting with an acutely inflamed joint and a negative synovial fluid culture in whom a diagnosis cannot be established during their hospital stay have a longer hospital stay and an increased rate of mortality as compared with patients in whom a diagnosis can be established.

The role of human xanthine oxidoreductase (HXOR), anti-HXOR antibodies, and microorganisms in synovial fluid of patients with joint inflammation.

This work is to investigate the levels of human xanthine oxidoreductase (HXOR), its antibodies, and microorganisms in synovial fluid of patients with untreated rheumatoid joint diseases. Synovial fluids were collected from sixty-four patients with rheumatoid joint diseases. Sixty-four age-matched individuals were included as control. Xanthine oxidoreductase (XOR) proteins level and anti-XOR antibodies were determined in the blood and synovial fluid, using human XOR as antigen, by enzyme-linked immunosorbent (ELISA) assay. Synovial fluids were cultured for bacteria and fungi. The titers of XOR protein in the synovial fluid of patients with rheumatoid arthritis were 90.43 ± 23.37 µg/ml (mean ± SD, n = 29) and up to 62.42 ± 8.74 µg/ml (mean ± SD, n = 35) in other joint inflammation. Anti-HXOR antibodies titers in patients were 167.72 ± 23.64 µg/ml, n = 64, which was significantly higher in rheumatoid arthritis patients. The results indicated that anti-HXOR antibodies in synovial fluids have a protective role as high concentrations against XOR were detected in inflammatory arthritis. These antibodies play a role in eliminating XOR from synovial fluids. However, immune complex formation could activate complement and participate in propagating the inflammatory cycle. Synovial aspirate ordinary microbial cultures were negative for any bacteria or fungi, but that does not exclude organisms of special culture requirements.

Seasonal variation in detection of bacterial DNA in arthritic stifle joints of dogs with cranial cruciate ligament rupture using PCR amplification of the 16S rRNA gene.

An underappreciated cause and effect relationship between environmental bacteria and arthritis may exist. Previously, we found that stifle arthritis in dogs was associated with the presence of environmental bacteria within synovium. Cranial cruciate ligament rupture (CCLR) is often associated with stifle arthritis in dogs. We now wished to determine whether seasonal variation in detection of bacterial material may exist in affected dogs, and to also conduct analyses of both synovium and synovial fluid. We also wished to analyze a larger clone library of the 16S rRNA gene to further understanding of the microbial population in the canine stifle. Synovial biopsies were obtained from 117 affected dogs from January to December 2006. Using PCR, synovium and synovial fluid were tested for Borrelia burgdorferi and Stenotrophomonas maltophilia DNA. Broad-ranging 16S rRNA primers were also used and PCR products were cloned and sequenced for bacterial identification. Overall, 41% of arthritic canine stifle joints contained bacterial DNA. Detection of bacterial DNA in synovial fluid samples was increased, when compared with synovium (p<0.01). Detection rates were highest in the winter and spring and lowest in the summer period, suggesting environmental factors influence the risk of translocation to the stifle. Organisms detected were predominately Gram's negative Proteobacteria, particularly the orders Rhizobiales (32.8% of clones) and Burkholderiales (20.0% of clones), usually as part of a polymicrobial population. PCR-positivity was inversely correlated with severity of arthritis assessed radiographically and with dog age. Bacterial translocation to the canine stifle may be associated with changes to the indoor environment.

Broad-range PCR, cloning and sequencing of the full 16S rRNA gene for detection of bacterial DNA in synovial fluid samples of Tunisian patients with reactive and undifferentiated arthritis.

INTRODUCTION: Broad-range rDNA PCR provides an alternative, cultivation-independent approach for identifying bacterial DNA in reactive and other form of arthritis. The aim of this study was to use broad-range rDNA PCR targeting the 16S rRNA gene in patients with reactive and other forms of arthritis and to screen for the presence of DNA from any given bacterial species in synovial fluid (SF) samples. METHODS: We examined the SF samples from a total of 27 patients consisting of patients with reactive arthritis (ReA) (n = 5), undifferentiated arthritis (UA) (n = 9), rheumatoid arthritis (n = 7), and osteoarthritis (n = 6) of which the latter two were used as controls. Using broad-range bacterial PCR amplifying a 1400 bp fragment from the 16S rRNA gene, we identified and sequenced at least 24 clones from each SF sample. To identify the corresponding bacteria, DNA sequences were compared to the EMBL (European Molecular Biology Laboratory) database. RESULTS: Bacterial DNA was identified in 20 of the 27 SF samples (74, 10%). Analysis of a large number of sequences revealed the presence of DNA from more than one single bacterial species in the SF of all patients studied. The nearly complete sequences of the 1400 bp were obtained for most of the detected species. DNA of bacterial species including Shigella species, Escherichia species, and other coli-form bacteria as well as opportunistic pathogens such as Stenotrophomonas maltophilia and Achromobacter xylosoxidans were shared in all arthritis patients. Among pathogens described to trigger ReA, DNA from Shigella sonnei was found in ReA and UA patients. We also detected DNA from rarely occurring human pathogens such as Aranicola species and Pantoea ananatis. We also found DNA from bacteria so far not described in human infections such as Bacillus niacini, Paenibacillus humicus, Diaphorobacter species and uncultured bacterium genera incertae sedis OP10. CONCLUSIONS: Broad-range PCR followed by cloning and sequencing the entire 16S rDNA, allowed the identification of the bacterial DNA environment in the SF samples of arthritic patients. We found a wide spectrum of bacteria including those known to be involved in ReA and others not previously associated with arthritis.

Identification of nanobacteria in human arthritic synovial fluid by method validated in human blood and urine using 200 nm model nanoparticles.

Earlier we introduced a biosensor for the identification of nanobacteria in water drops. Here, we generalize its principle and apply it to identify nanobacteria in synovial fluid from a patient with osteoarthritis. Results indicate the prevalence of nanobacteria in the synovial fluid. The identification method is applicable to body fluids such as unfiltered human blood and urine, is independent of culturing procedures, and permits for a rapid detection of nanoparticles in liquid drops. In view of increasing clinical evidence on a contribution of nanobacteria in disease, their reported detection in HIV-infected people in South Africa, laboratory experiments indicating the excretion of viable (i.e., propagating) nanobacteria from humans via urine, the use of human excreta in agricultural irrigation, models predicting an injection of nanoaerosols contained in irrigation water enriched with human excreta into the atmosphere, and the identification of nanobacteria in the terrestrial atmosphere, promote the identification method described in this work to an important tool to monitor nanobacteria in body fluids and environmental samples.

Synovial fluid analysis and bacterial findings in arthritic joints of juvenile male camel (Camelus dromedarius) calves.

Eighteen synovial fluid samples from 11 male dromedarian calves, 9-12 month old, were analysed cytologically and bacteriologically. Calves were lame and all joints were grossly swollen. The mean +/- SD of total nucleated cell count was 7970 +/- 5000 cells/microl (range 2800-20,000 cells/microl). Polymorphonuclear (PMN) leucocytes were the predominant cell type. The mean +/- SD of absolute and percentages of each cell type were as follows: PMN leucocytes 5518 +/- 3600 cells/microl and 68 +/- 19%, monocytes/macrophages 1600 +/- 1120 cells/microl and 26 +/- 17%, lymphocytes 830 +/- 140 cells/microl and 8 +/- 7%, and red blood cell 350 +/- 130 cells/microl. The mean +/- SD of total protein concentration was 3.5 +/- 1 g/dl (range 2.5-5 g/dl). The most commonly isolated bacteria were non-haemolytic streptococci spp., followed by Arcanobacterium pyogenes and Staphylococcus aureus. No bacterial growth was obtained in eight samples and non-revealed Mycoplasma spp.

Gross synovial fluid analysis in the differential diagnosis of joint effusion.

AIMS: To develop an objective and easy to complete standardised questionnaire for documentation of synovial fluid (SF) gross appearance and use it in the assessment of patients presenting to the rheumatology service with a joint effusion. METHODS: A standardised questionnaire to record the gross appearance of SF was developed. Interobserver error in recorded observations and direct gross analysis of synovial fluid between four observers was calculated in a pilot study. In a prospective study over 8 months, SF gross analysis and cell count were documented in all patients presenting with a joint effusion. Fusch Rosenthal manual counting chamber was used for calculating SF cell counts. RESULTS: There was good interobserver agreement on direct gross analysis and between questionnaire assessors (mean kappa 0.889). 80 SF samples were collected. Gross analysis was performed in all samples and cell count in 72. Of the specimens thought to be inflammatory on gross analysis, 31% were found to be non-inflammatory based on cell count; however, 12 of these patients had an established inflammatory arthritis. Gross analysis had a sensitivity of 94% and specificity of 58% when used to determine whether SF is inflammatory or non-inflammatory. The positive and negative predictive values were 0.69 and 0.91 respectively. CONCLUSIONS: SF cell count did not add any information when SF gross analysis suggested a non-inflammatory process. Gross analysis was better than cell count to determine a potentially septic joint fluid. Further work needs to be done on the value of SF cell counts if gross analysis suggests the fluid to be inflammatory.

Distribution of Mycoplasma pneumoniae and Mycoplasma salivarium in the synovial fluid of arthritis patients.

By use of a very sensitive nested PCR method targeting part of the strongly conserved mycoplasmal 16S RNA genes, Mycoplasma pneumoniae was found in the synovial fluid of 19/24 (79%) of rheumatoid arthritis patients, 6/6 (100%) of patients with nonrheumatoid inflammatory arthritis, and 8/10 (80%) of osteoarthritis patients attending the rheumatology clinic for drainage of joint effusions. It was not found in the synovial exudates of 13 people attending the orthopedic clinic with traumatic knee injuries or undergoing surgery for knee replacement. However, M. pneumoniae was detected in 2/4 synovial biopsy specimens from orthopedic patients with traumatic knee injuries. M. pneumoniae was associated with the increased synovial fluids found in arthritic flares but was not found in the synovial fluids of trauma patients. Mycoplasma salivarium occurred sporadically. Mycoplasma fermentans had previously been isolated from patients with inflammatory cellular infiltrates, such as rheumatoid arthritis, but it was not detected for osteoarthritic patients from either clinic. It is possible that these organisms may contribute to chronic inflammation within the joints.