Lavage of contaminated surfaces: an in vitro evaluation of the effectiveness of different systems

INTRODUCTION

Lavage is an effective, additive therapeutic procedure with a broad application in surgery. In addition to irrigation with the conventional syringe, the pulsed jet lavage system is used. The effectiveness of bacterial reduction depends on, among other things, the irrigation pressure. Complications of high-irrigation pressure in bone and joint surgery are intramedullary seeding of bacteria, visible damage of the bone, or delayed healing of the fracture by lavage of the fracture zone. The purpose of this in vitro study was to evaluate the effectiveness of mechanical irrigation on several surfaces using different systems of irrigation.

MATERIALS AND METHODS

Four different test surfaces (nonbiological surfaces: sterilized bone cement and titanium osteosynthesis plates; biological surfaces: gamma-irradiated bovine muscle and cancellous bone) were contaminated with a defined suspension of different bacterial species (Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa). The samples were irrigated with three different systems (conventional 50-ml plastic syringe, manual pump irrigator, jet lavage) in a standardized, randomized experimental setup. After irrigation of the sample the amount of residual bacteria (colony-forming units) was determined.

RESULTS

An effective bacterial reduction was achieved with the use of irrigation regardless of the system that was used and surface that was cleaned. On average P. aeruginosa was reduced around log 1.907, E. faecalis around log 1.666 and S. aureus around log 1.506. On biological surfaces, a reduction around log 0.801 for muscle and around log 1.738 for bone samples was achieved independent of the system that was used for irrigation. For the titanium surface a reduction of log 1.652 compared with log 2.580 for the bone cement surface was demonstrated. Statistical analysis showed that mechanical lavage resulted in a significant reduction of all tested bacterial species on the surfaces. The best bacterial reduction was achieved with the manual pump irrigator (P = 0.06). The results demonstrate that the manual pump irrigator achieved significantly better bacterial reduction (P = 0.039) on "biological surfaces" (bone and muscle) compared with nonbiological surfaces (titanium and cement).

CONCLUSION

The results show that irrigation is an effective technique for bacterial reduction on contaminated surfaces. A remarkable finding was the limited bacterial reduction of Staphylococcus aureus from gamma-sterilized muscle. The use of a continuous manual pump irrigator showed a greater reduction of bacteria contamination compared with the other means of irrigation investigated. In conclusion, the manual continuous irrigation system proved to be practical, economical and effective in reducing the bacterial load on various surfaces.

A plasmid-encoded nicotinamidase (PncA) is essential for infectivity of Borrelia burgdorferi in a mammalian host

Borrelia burgdorferi, a spirochaete that causes Lyme borreliosis, contains 21 linear and circular plasmids thought to be important for survival in mammals or ticks. Our results demonstrate that the gene BBE22 encoding a nicotinamidase is capable of replacing the requirement for the 25 kb linear plasmid lp25 during mammalian infection. Transformation of B. burgdorferi lacking lp25 with a shuttle vector containing the lp25 gene BBE22 (pBBE22) restored infectivity in mice to a level comparable to that of wild-type Borrelia. This complementation also restored the growth and host adaptation of lp25-B. burgdorferi in dialysis membrane chambers (DMCs) implanted in rats. A single Cys to Ala conversion at the putative active site of BBE22 abrogated the ability of pBBE22 to re-establish infectivity or growth in DMCs. Additional Salmonella typhimurium complementation studies and enzymatic analysis demonstrated that the BBE22 gene product has nicotinamidase activity and is most probably required for the biosynthesis of NAD. These results indicate that some plasmid-encoded products fulfil physiological functions required in the enzootic cycle of pathogenic Borrelia.

Lyme disease (Lyme borreliosis)

Lyme borreliosis (Lyme disease) is a systemic infectious disease with a wide spectrum of symptoms affecting the skin, the heart, and the nervous and musculoskeletal systems. Lyme borreliosis is caused by the spirochaete Borrelia burgdorferi and transmitted by ticks. The disease occurs in endemic pockets with an incidence of from 50 to more than 100 cases per 100,000 inhabitants. Despite increasing knowledge about the virulence factors of the spirochaetes and the immune response of the host, many aspects of the pathogenesis, for example of chronic treatment-resistant disease, are still a matter of debate. The diagnosis is based on clinical findings and confirmed by serology. Diagnostic problems arise from patients with non-specific symptoms and a positive IgG serology. In about 80% of the patients, the disease can be cured by adequate antibiotic therapy. Evidence-based guidelines for treatment have been recently published. The only vaccine to prevent Lyme disease, licensed in the USA, has been discontinued due to disappointing sales despite good efficacy and tolerability.

Geographically specific infections and arthritis, including rheumatic syndromes associated with certain fungi and parasites, Brucella species and Mycobacterium leprae

This overview is designed to introduce the reader to the broad spectrum of rheumatic syndromes associated with certain fungal and parasitic diseases, brucellosis and leprosy. Musculoskeletal disorders caused by fungi are uncommon and difficult to diagnose, particularly in the early stages. Deep fungal infections involve-in order of frequency-bone, soft tissues and joints. Rare but well-defined rheumatic syndromes occur in a variety of parasitic diseases. Brucellosis remains a major challenge to both human public health and clinical acumen in many countries today. The arthritis of leprosy deserves wider recognition and study as it contributes to disability and may hold clues to the mechanism of inflammation in other rheumatic disorders. All of the above may afflict residents in endemic areas and occasionally appear far from the source of origin in travellers or migrants, and usually cause diagnostic confusion.

Arthritis associated with enteric infection

Reactive arthritis is classically seen following infection with enteric pathogens such as Yersinia, Salmonella, Campylobacter and Shigella. Inflammatory arthritis has also been described following other enteric infection with organisms such as Clostridium difficile, Brucella and Giardia. Furthermore, arthritis is seen in Whipple's disease, caused by the actinomycete Tropheryma whippelii. This chapter reviews the current understanding of these conditions (with the exception of Brucella, which is discussed in a subsequent chapter). The epidemiology is reviewed, and the contribution of both host and organism to the aetiology and pathogenesis is discussed with particular discussion of the role of HLA-B27 in host susceptibility. Recent work exploring evidence for traffic of pathogenic organisms to the joint is highlighted. A practical approach to the diagnosis and management of the condition is then formulated based, where possible, on clinical trial evidence.

[Bronchopneumonia and polyarthritis due to Mycoplasma bovis in a calf]

This case report describes gross lesions and histopathological findings in a 3-months-old calf originating from a feedlot with approximately 400 cattle. In this animal and additional 14 cattle of similar age, which were kept together in the same stable, swollen joints had occurred suddenly. The examination of this calf showed that a severe polyarthritis induced by haematogenous spread of Mycoplasma bovis following bronchopenumonia was present, which was characterised by necrotising lesions of the joint capsules and severe cartilage erosions.

Gonococcal arthritis

Gonococcal arthritis results from blood dissemination of Neisseria gonorrhoeae from primary sexually acquired mucosal infection. The disease has become rare in Western countries since the introduction of effective control programmes, but it still needs to be recognized promptly to avoid systemic, potentially life-threatening involvement, destructive changes associated with chronic arthritis and spread of the infection. Sexually active women are predominantly affected. Clinical features include polyarthralgia, sometimes migratory, tenosynovitis, arthritis, constitutional symptoms and skin lesions, which are mild and easily unnoticed. True arthritis occurs in less than 50% of cases. Primary mucosal infection may be asymptomatic.N. gonorrhoeae is a fragile micro-organism which is difficult to culture. Sampling of blood, synovial fluid, skin lesion, genito-urinary tract, pharynx and rectum must be performed before starting antibiotics. Samples should be plated immediately on fresh, pre-warmed appropriate media and sent quickly to the laboratory. Culture of N. gonorrhoeae is of tremendous importance not only for definite diagnosis but also for determination of drug susceptibility. When culture is negative, rapid response to antimicrobial treatment will allow a probable diagnosis. Penicillin resistance has developed worldwide in recent years, and penicillin is no longer the initially recommended antibiotic for gonococcal arthritis. Patients should be started on a third-generation cephalosporin and later switched to ampicillin or penicillin only when sensitivity to these antimicrobials has been demonstrated. Oral therapy substitutes the intravenous or intramuscular route after signs and symptoms have improved, in order to complete 7 days of antimicrobial therapy. Effusions should be aspirated until disappearance. Purulent effusions are rare but may require longer antibiotic treatment. The patient's sexual partner must be examined and treated. Patients should be tested and eventually treated for Chlamydia, syphilis and HIV, and educated about the sexual mode of transmission and means of preventing sexually transmitted diseases.

[Mycoplasma synoviae-associated amyloid arthropathy in white leghorns: case report]

Under field circumstances amyloid arthropathy was nerve recorded in white layers, while experimentally their brown counterparts were found to be more susceptible to the induction of amyloid arthropathy, although articular amyloid was found in a few white leghorns. In the present manuscript the first field case of amyloid arthropathy in white layers associated with Mycoplasma synoviae is reported. In the same house where the white birds were housed, brown layers were present. The condition was much more severe in the latter chickens. The different susceptibility between both breeds is discussed in view of previously performed research.

Current status of pathogenetic mechanisms in staphylococcal arthritis

Interactions between staphylococci and the joint tissues of the host lead typically to rapidly progressing and highly destructive processes. Staphylococci possess a vast arsenal of components and products that contribute to the pathogenesis of joint infection. Occasionally these compounds have overlapping activities and act either in concert or alone. Host responsiveness to staphylococcal infection displays an even more complex pattern. Most of the cells and molecules that participate in the innate immune system protect the host against bacteria. However, the staphylococci have developed systems that counteract endogenous protective mechanisms. Interestingly, certain cells and molecules of the acquired immune system potentiate the severity of infection by triggering exaggerated responses to the staphylococcal danger signals. This review deals with the intricate host-bacterium interactions that occur during experimental septic arthritis, and outlines potential preventive and treatment modalities.

Role of macrophages in experimental group B streptococcal arthritis

Septic arthritis is a clinical manifestation of group B Streptococcus (GBS) infection in both neonates and adults. Because macrophages are known to participate in tissue injury, the role of this cell population in GBS-induced arthritis was investigated. Mice were rendered monocytopenic by administration of etoposide, a drug that selectively depletes the monocyte/macrophage population and then injected with GBS (1 x 10(7) colony-forming units per mouse). Appearance of arthritis, mortality, GBS growth in the organs, and local and systemic cytokine production were examined. Etoposide-treated mice had a significantly less severe arthritis than control animals. Histopathological analysis of the joints confirmed clinical observations. Decreased joint levels of the proinflammatory cytokines interleukin 1 (IL-1) beta and IL-6 accompanied the less severe development of arthritis in monocytopenic mice. In contrast, mortality was increased in the etoposide-treated mice compared with controls. Monocytopenic mice exhibited elevated bacterial load in the blood and kidneys at all time points examined. These results indicate that lack of macrophages leads to less severe joint lesions, but also results in impaired clearance of bacteria, and consequent enhancement of mortality rates.

Role of bacteriophage MAV1 as a mycoplasmal virulence factor for the development of arthritis in mice and rats

The lysogenic bacteriophage MAV1 has been shown to be a virulence factor for the development of arthritis in rats infected with Mycoplasma arthritidis. In the present study, arthritis was evaluated by histopathologic examination to demonstrate that MAV1 is a virulence factor not only in the rat but also in the mouse. Specifically, the MAV1 lysogen 158L3-1 was more virulent than the nonlysogen strain 158 in DBA/2NCr, C3H/HeNCr, C3H/HeJ, and C3Smn.CB17-Prkdc(scid)/J mice, as well as in LEW rats.

Borrelia burgdorferi and its tropisms for adhesion molecules in the joint

Borrelia burgdorferi, the spirochete that causes Lyme disease, has evolved elegant strategies for interacting with its mammalian hosts. Among them are several distinct mechanisms of adhesion to cells and extracellular matrix components. The mammalian receptors for B. burgdorferi that have been most thoroughly studied, and for which candidate bacterial ligands have been identified, are decorin, fibronectin, glycosaminoglycans, and beta3-chain integrins. This diversity of adhesion mechanisms allows B. burgdorferi to infect multiple tissues, including the synovial tissues of the joints.

The beneficial effect of interleukin-12 on arthritis induced by group B streptococci is mediated by interferon-gamma and interleukin-10 production

OBJECTIVE

To assess the effect of interleukin-12 (IL-12) administration on the evolution of systemic infection and septic arthritis induced by group B streptococci (GBS) in mice.

METHODS

CD1 mice were inoculated intravenously with arthritogenic strain 1/82 of type IV GBS. Exogenous murine IL-12 was administered intraperitoneally 18 hours or 5 days after infection with 1 x 10(7) GBS, at doses ranging from 0.5 to 2.5 microg per mouse. Mice were monitored daily for survival and for signs of arthritis. In a subsequent set of experiments, mice were killed at selected times for examination of bacterial clearance, histopathologic changes in the joints, and cytokine production.

RESULTS

IL-12 administration before the onset of clinical signs had a beneficial effect on GBS-induced arthritis and was clearly dose-dependent. The 2.5-microg dose per mouse totally prevented death from GBS-induced arthritis. The decrease in pathology was associated with a reduction of the bacterial burden and a change in the cytokine profile. In particular, systemic and joint levels of interferon-gamma (IFN gamma) and IL-10 significantly increased in mice treated with IL-12, whereas a decrease in IL-6 and IL-1 beta production was observed. The beneficial effects of IL-12, in terms of the incidence and severity of articular lesions, were reversed by coadministration of anti-IFN gamma or anti-IL-10-neutralizing antibodies.

CONCLUSION

The findings of this study demonstrate that IL-12 is important in controlling the cytokine production that leads to the evolution of GBS-induced experimental arthritis. The amelioration of articular lesions is mostly attributable to IL-12-induced IFN gamma, but with a relevant participation of IL-12-induced IL-10.

Role of osteopontin in murine Lyme arthritis and host defense against Borrelia burgdorferi

Several genetic loci in the mouse have been identified that regulate the severity of Lyme arthritis. The region of chromosome 5 including the osteopontin (OPN) gene (Opn) has been identified in intercross populations of C3H/HeN x C57BL/6 and C3H/HeJ x BALB/cAnN mice. OPN is of particular interest as it is involved in the maintenance and remodeling of tissue during inflammation, it regulates production of interleukin-10 (IL-10) and IL-12 (cytokines implicated in Lyme arthritis), it is necessary for host control of certain bacterial infections, and mice displaying different severities of Lyme arthritis possess different alleles of the OPN gene. Macrophages and splenocytes from OPN-deficient mice on mixed C57BL/6J-129S or inbred 129S backgrounds were stimulated with the Pam(3)Cys modified lipoprotein from Borrelia burgdorferi, OspA. OPN was not required for OspA-induced cytokine production; however, macrophages from 129S-Opn(-/-) mice displayed a reduced level of IL-10 production. OPN was also not required for resistance to severe arthritis, as B. burgdorferi-infected 129S-Opn(-/-) mice developed mild arthritis, as did their wild-type littermates. Arthritis was more severe in OPN-deficient mice on the mixed C57BL/6J-129S backgrounds than in inbred mice of either strain. This increase was most likely due to a gene(s) closely linked to Opn on chromosome 5 in conjunction with other randomly assorting genes. Deficiency in OPN did not influence the numbers of spirochetes in tissues from B. burgdorferi-infected mice, indicating OPN is not part of the host defense to this pathogen. Interestingly, there was no alteration in the B. burgdorferi-specific antibody isotypes in OPN-deficient mice, indicating that its effect on helper T-cell responses is not relevant to the host response to B. burgdorferi.

Low molecular weight heparin aggravates infectious arthritis triggered by Staphylococcus aureus

PURPOSE

Staphylococcus aureus is responsible for the majority of wound infections in clean surgical procedures that involve implantation of foreign material, grafts or prosthetic devices. The aim of the study was to assess the effect of low molecular weight heparin on the development and progression of S. aureus arthritis.

MATERIALS AND METHODS

The murine model of hematogenously acquired septic arthritis was used injecting intravenously toxic shock syndrome toxin-1 (TSST-1) producing S. aureus of LS-1 strain. Mice lacking prosthetic implants were treated with intraperitoneal injections of low molecular weight heparin, used routinely as anti-thrombotic prophylaxis following joint prosthetic surgery. Evaluation of arthritis was performed clinically and histopathologically. In addition, the effect of low molecular weight heparin on T cell dependent and independent inflammation was assessed.

RESULTS

Seven days after inoculation with bacteria 18 out of 19 low molecular weight heparin treated mice displayed clinical symptoms of arthritis as compared to 9 out of 23 control animals (p < 0.05), and the severity of arthritis, expressed as arthritic index, was 2.6+/-0.5 versus 1.6+/-0.5 (p = 0.05). The histopathological examination confirmed the clinical findings showing that both inflammation and joint destruction were more substantial in heparin treated animals.

CONCLUSION

Our findings indicate that the routine anti-coagulation treatment with heparin contributes to more severe course of joint infection.

Molecular epidemiology of unilateral amyloid arthropathy in broiler breeders associated with Enterococcus faecalis

Although symmetrical polyarticular amyloidosis has been described extensively in brown layers, spontaneous unilateral amyloid arthropathy has not been described previously in chickens. Birds from nine flocks of broiler parent stock (PS) had unilateral lameness associated with severe swelling of the left hock joint and the caudal aspect of the metatarsus. Gross pathology was restricted to the left hock joint and the left digital flexor tendons in almost all cases, suggesting an association with administration of Marek's disease vaccine. Amyloid deposits were found in 83% (25/30) of affected joints by histological examination of Congo red stained sections. Systemic amyloidosis, involving mainly the liver and spleen, was found in 59% (10/17) of birds. Enterococcus faecalis was isolated from joints in 77% (23/30) of cases and Staphylococcus aureus was isolated from the joint in one case (1/30). Thirty-five E. faecalis isolates from joints, tendons and blood samples from birds in five affected PS flocks were compared using pulsed-field gel electrophoresis (PFGE) to separate genomic fragments after digestion with SmaI. All but one isolate had identical or closely related restriction endonuclease digestion (RED) patterns that were very similar to a known arthropathic and amyloidogenic E. faecalis isolate. A further 30 E. faecalis isolates from seven grandparent stock (GPS) flocks and two isolates from two unaffected PS flocks of the same genetic background were analysed by PFGE. Among these isolates, 11 originating from four GPS flocks had RED patterns identical to or closely related to the reference amyloid-inducing strain. Moreover, one E. faecalis isolate from amyloidotic joints of brown layers housed in California, USA was included in the analysis and appeared to be identical to the reference strain. This study showed that the E. faecalis isolates involved in these outbreaks of unilateral amyloid arthropathy in broiler breeders belonged to the same clone as that responsible for outbreaks in brown layers.

Protection against tick-transmitted Lyme disease in dogs vaccinated with a multiantigenic vaccine

In an effort to develop a safe and effective vaccine for the prevention of Lyme borreliosis that addresses concerns raised over currently available vaccines, dogs were vaccinated twice with a multiantigenic preparation of Borrelia burgdorferi, strain N40, on days 0 and 20 of the experiment. About 70 and 154 days after the first immunization, dogs were challenged by exposing them to field-collected Ixodes scapularis ticks harboring B. burgdorferi. Vaccinated dogs were completely protected from infection by all criteria utilized to assess infection, developed high-titer anti-B. burgdorferi serum antibodies and growth inhibitory activity which persisted for over 200 days, and did not demonstrate any untoward consequence of vaccination. Serum absorption experiments revealed that borreliacidal and most likely protective antibodies in dogs receiving the multiantigenic preparation were not only elicited against the OspA antigen, but were also produced against additional yet to be determined targets on B. burgdorferi organisms. These data demonstrate that a multiantigenic vaccine is effective in preventing Lyme disease transmitted via the natural vector.

Mycoplasma hyosynoviae arthritis in grower-finisher pigs

The aetiology of acute lameness in pigs 3-5 months of age in nine Danish herds with high incidences of lameness was investigated. Eighty-seven acutely lame pigs, that exhibited lameness of varying degree in the hind legs, were selected. Non-lame pigs were matched on pen, sex and weight. The lame pigs had soft fluctuating joint swellings (odds ratio (OR), 7.21; 95% confidence interval (CI), 3.41-15.47). No indication of suppurative arthritis was observed. Joint infection with Mycoplasma hyosynoviae was found by culture in 20% (17 of 86) of the lame pigs and in 8% (seven of 83) of the non-lame pigs. Lameness and joint infection with M. hyosynoviae were significantly associated. Other ordinary bacteria were not found in any case. Macroscopic osteochondrotic lesions were observed at slaughter in 47% (37 of 78) of the previously lame pigs and in 35% (55 of 158) of an enlarged group without history of lameness. The cubital joints were most frequently affected and a history of hind leg lameness was not statistically associated with osteochondrotic lesions at slaughter (OR, 1.69; 95% CI, (1.94-3.05), or joint infection with M. hyosynoviae at slaughter (OR, 0.88; 95% CI, 0.31-2.40). Arthritis due to M. hyosynoviae infection was the primary cause of acute and severe lameness in grower-finisher pigs. Moreover, M. byosynoviae was isolated from joints of several pigs without signs of lameness. This suggests that M. hyosynoriae may be present in joints without provoking clinical illness. The mean daily incidence of treatments due to lameness in the herds was 5.4 per 1,000 pigs. Joint disease implied 30-90 min extra labour for surveillance and treatment every day per 1,000 pigs, and 5% of the affected individuals were euthanized due to lameness. The average daily weight gains in the selected pigs until slaughter seemed unaffected by the lameness.

Molecular typing of strains of staphylococcus aureus isolated from bone and joint lesions in lame broilers by random amplification of polymorphic DNA

A study was conducted to investigate the relationship between the presence of localized bacterial infection and lameness in broiler fowl (Gallus gallus domesticus). Isolation of bacteria from the proximal femur, proximal tibia, and tibiotarsus from broilers with lameness revealed a probable association between lameness and the presence of Staphlylococcus aureus. Other potential pathogens, including Escherichia coli and DNase-negative staphylococci, were also isolated from sound and lame birds, and their association with pathologies causing lameness was less well defined. After trials with a set of twenty 10-base oligonucleotide primers, a pair of primers giving optimal performance was selected. The S. aureus isolates were typed by random amplification of polymorphic DNA (RAPD) by using the pair of 10-mer primers, and groupings were defined by banding patterns after agarose gel electrophoresis. The putative RAPD groupings may provide a basis for epidemiological studies of S. aureus in broiler production systems.

Detection of Mycobacterium tuberculosis group organisms in human and mouse joint tissue by reverse transcriptase PCR: prevalence in diseased synovial tissue suggests lack of specific association with rheumatoid arthritis

Infection with mycobacterial species, including Mycobacterium tuberculosis, has long been implicated in the etiopathology of rheumatoid arthritis (RA) on the basis of clinical and pathological similarities between tuberculosis and RA. Despite evidence of immune responses to mycobacterial antigens in RA patient synovial fluid, cross-reactivity between these and host joint antigens, and the presence of M. tuberculosis protein antigen in RA synovial fluid, a definite causal association with RA has not been shown. Previous studies from our laboratory using reverse transcriptase PCR (RT-PCR) of bacterial rRNAs have shown RA synovium to be colonized by a diverse range of bacteria, most of commensal origin. However, M. tuberculosis group organism (MTG) RNA sequences were found in one RA patient tissue. Since this was considered of sufficient interest to warrant further investigation, we devised a M. tuberculosis-specific nested RT-PCR test which could be used for detection of MTG in a mixed pool of bacterial crDNAs. This test was used to investigate the distribution of MTG in RA synovial tissue and also non-RA arthritis and healthy control tissues and was also used to examine the tissue distribution of MTG in an acute and chronic model of M. tuberculosis infection in the BALB/c mouse. MTG sequences were found in a high proportion of RA patient synovial tissues but also in non-RA arthritis control tissues at lower frequency. This likely reflects trafficking of persistent M. bovis BCG to inflamed joint tissue, irrespective of cause. MTG were not found in healthy synovial tissue or the tissue of patients with undifferentiated arthritis. In both the acute and chronic models of infection in BALB/c mice, M. tuberculosis was also found to have trafficked to joint tissues, however, no signs of inflammation, arthritis, or pathology associated with M. tuberculosis infection was seen. These combined results would argue against a specific causal role of MTG in RA-like arthritis; however, their role as adjuvant in immune dysfunction in an innately susceptible host cannot be excluded.

Septic arthritis of the spine facet joint: early positive diagnosis on magnetic resonance imaging. Review of two cases

We report two cases of septic arthritis of the spine facet joint in two patients with no previous medical history. Clinical symptoms were consistent with a spondylodiscitis. Blood cultures were positive for Staphylococcus aureus. The infection was initially shown and precisely localised with magnetic resonance imaging, despite an initially negative or aspecific bone scintigraphy. Magnetic resonance imaging of the spine demonstrated infection involving the epidural space and paraspinal musculature and enhancement of the infected thoracic and lumbar facet joint after gadolinium injection.

Role of IL-12 in Staphylococcus aureus-triggered arthritis and sepsis

The present study demonstrates that endogenous production of IL-12 is crucial for survival in Staphylococcus aureus-induced arthritis in mice. Staphylococcal load is enhanced in several organs, because of lack of IL-12. This might be due to decreased production of IFN-gamma in IL-12-deficient mice. Although IL-12-deficient mice were exposed to higher staphylococcal load, they demonstrated no increased severity of arthritis as compared with control animals.

Chronic destructive oligoarthritis associated with Propionibacterium acnes in a female patient with acne vulgaris: septic-reactive arthritis?

Propionibacterium acnes is an anaerobic bacillus implicated in certain chronic arthritides. This report describes an HLA-B27+ 17-year-old woman with acne vulgaris who presented with rapidly destructive arthritis in the left shoulder as well as an evolving left subclavicular adenopathy. One year later, arthritis was detected in the left knee; the inflammatory synovial fluid was sterile. Growth of P acnes was observed in cultures of the shoulder synovium and lymph nodes, but polymerase chain reaction was negative for Borrelia, Chlamydia, and Ureaplasma DNA. Three months of treatment with amoxicillin and rifampicin led to clinical disappearance of the oligoarthritis, but arthritis recurred in the left knee after discontinuation of therapy. On biopsy, bacteria were undetectable in the knee synovium, but chronic arthritis was evident histologically. Antibiotics were reintroduced for 12 months and were again effective against the clinical symptoms. Although the asymmetry, histologic features, arthritis-acne association, and genetic predisposition of this chronic destructive oligoarthritis would seem to indicate a reactive arthropathy, the isolation of P acnes from 2 distinct specimens prompted us to propose calling this a case of septic-reactive arthritis, which is further supported by the absence of progression after antibiotic therapy and the persistence of the rheumatism. To our knowledge, this is the first demonstration of the efficacy of prolonged antibiotic therapy on the joint manifestations of chronic rheumatism associated with acne.

Interleukin-4 (IL-4) and IL-13 signaling pathways do not regulate Borrelia burgdorferi-induced arthritis in mice: IgG1 is not required for host control of tissue spirochetes

Previous studies have suggested that interleukin-4 (IL-4) has a protective effect in host defense to Borrelia burgdorferi infection, both in limiting the severity of arthritis and in controlling spirochete numbers in tissues, and a mapping study revealed suggestive linkage to a cluster of genes on mouse chromosome 11, including the genes for IL-4 and IL-13. In contrast, other studies have questioned the importance of IL-4. In this study the involvement of IL-4 in murine Lyme disease was examined in C57BL/6J and BALB/cJ mice with targeted disruptions in the IL-4 gene, the IL-4Ralpha chain gene, or both. A spectrum of arthritis severity was seen in BALB/cJ mice, and ablation of IL-4, IL-4Ralpha, or both had no effect on the overall severity of arthritis as determined by joint swelling and histopathology. Wild-type C57BL/6J mice exhibited mild to moderate arthritis, and ablation of IL-4 again had no effect on arthritis severity. IL-4- and IL-4Ralpha-deficient mice produced extremely low levels of immunoglobulin G1 (IgG1) and showed increased production of IgG2b. This shift in immunoglobulin isotype had no effect on the host's ability to control spirochete growth in either strain of mouse, as determined by PCR detection of B. burgdorferi DNA from heart and ankle tissues. In summary, the IL-4-IL-4Ralpha pathway, including IL-13 signaling, neither limits arthritis severity nor is required for control of spirochete growth during B. burgdorferi infection of mice. Furthermore, the IgG1 isotype is not required to control B. burgdorferi cell numbers in tissues. These findings suggest the host defense against B. burgdorferi infection is not dependent on the Th1-Th2 paradigm of T-cell responses.

Pyarthrosis in patients with rheumatoid arthritis: a detailed analysis of 10 cases and literature review

OBJECTIVES

1) To analyze the clinical features and outcome of patients with rheumatoid arthritis and pyarthrosis seen in a rheumatology department during a 9-year period; 2) To review the available literature about this association in the last decade.

METHODS

From the database of our department, we collected all hospitalized cases of infectious arthritis in native joints between January 1990 and December 1998. In 10 cases (27%), pyarthrosis occurred in patients with rheumatoid arthritis. A detailed analysis of each patient was performed. The literature was reviewed by using MEDLINE from 1990 to 1999.

RESULTS

The mean age of patients was 63.2 years; six were female. Most patients had long-standing disease and poor functional class, and all received glucocorticoid treatment. Mean diagnostic delay was 7.3 days. Causative organisms were Staphylococcus aureus (4 cases), gram-negative bacilli (3 cases), anaerobic bacteria (2 cases), and Streptococcus pneumoniae (n = 1). Two patients died. In all but two patients who survived, joint function worsened.

CONCLUSIONS

Rheumatoid arthritis is a relevant host-related risk factor for septic arthritis. Pyarthrosis in these patients is associated with considerable morbidity and mortality.

An outbreak of erysipelas in 2-day-old poults

Systemic erysipelas infection was seen in 2-to-4-day-old poults from three separate ranches owned by the same company. The affected poults were all from the same breeder source; poults from other breeder sources were seemingly unaffected. Mortality increased on days 2 and 3, ranging from 2% to 8.5%. Birds submitted were dehydrated and very weak, with one half of the poults submitted having died during transport to the lab. Gross lesions included swollen, congested livers and spleens, as well as hemorrhagic breast muscle in one case. Toes were swollen and reddish-purple in color. The poults had been toe-trimmed during hatchery processing using a commercial microwave. Histologically, periportal inflammation with heterophilic infiltration in the liver was noted. Spleens showed hyalinization of arteries, lymphoid depletion, and necrosis. Toe joints showed purulent synovitis and cellulitis. Gram stains done on impression smears of liver and spleen showed rare to moderate numbers of small gram-positive rods. Erysipelothrix rhusiopathiae was isolated from 18 of 22 livers cultured, five of six toe joints cultured, and from the yolk sac in two birds.

Pyogenic arthritis in adults

Septic arthritis has shown no change in incidence, and despite advances in antimicrobial therapy is often responsible for residual functional impairment and for a high mortality rate among debilitated patients. Risk factors include older age, diabetes mellitus, rheumatoid arthritis, immunodeficiency, and a preexisting joint disease (e.g., rheumatoid arthritis) to which the symptoms of septic arthritis are sometimes ascribed. Staphylococcus aureus contributes over two-thirds of identified organisms; a range of streptococci and gram-negative bacilli are next in frequency. The most common site is the knee, followed by the hip and shoulder. Over 10% of patients have polyarticular involvement reflecting bacteremia and diminished resistance to infection; (over 50% of polyarticular forms occur in rheumatoid arthritis patients). Prosthetic joint infection is becoming increasingly common; chronic forms due to intraoperative contamination and resulting in septic loosening should be distinguished from acute hematogenous infection in which emergency treatment can allow to salvage the prosthesis. Demonstration of the organism in the joint is the key to the diagnosis. Joint aspiration should be performed on an emergency basis, if needed after identification of radiographic landmarks or under ultrasonographic guidance. Seeding the fluid on blood culture flasks immediately after aspiration increases the yield. Antibiotics should be started as soon as the microbiological specimens have been collected. When aspiration is difficult (hip) or inadequate, arthroscopic drainage usually makes arthrotomy unnecessary. Early antiinflammatory therapy (nonsteroidal antiinflammatory drugs, systemic or local glucocorticoids, anticytokines, and antiinflammatory cytokines) are being considered as tools for limiting joint damage; their efficacy and safety will first have to be established in animal studies.

Reactive arthritis

Reactive arthritis is one of the spondyloarthropathy family of clinical syndromes. The clinical features are those shared by other members of the spondyloarthritis family, though it is distinguished by a clear relationship with a precipitating infection. Susceptibility to reactive arthritis is closely linked with the class 1 HLA allele B27; it is likely that all sub-types pre-dispose to this condition. The link between HLA B27 and infection is mirrored by the development of arthritis in HLA B27-transgenic rats. In this model, arthritis does not develop in animals maintained in a germ-free environment. Infections of the gastrointestinal, genitourinary and respiratory tract appear to provoke reactive arthritis and a wide range of pathogens has now been implicated. Although mechanistic parallels may exist, reactive arthritis is distinguished from Lyme disease, rheumatic fever and Whipple's disease by virtue of the distinct clinical features and the link with HLA B27. As in these conditions both antigens and DNA of several micro-organisms have been detected in joint material from patients with reactive arthritis. The role of such disseminated microbial elements in the provocation or maintenance of arthritis remains unclear. HLA B27-restricted T-cell responses to microbial antigens have been demonstrated and these may be important in disease pathogenesis. The importance of dissemination of bacteria from sites of mucosal infection and their deposition in joints has yet to be fully understood. The role of antibiotic therapy in the treatment of reactive arthritis is being explored; in some circumstances, both the anti-inflammatory and anti-microbial effects of certain antibiotics appear to be valuable. The term reactive arthritis should be seen as a transitory one, reflecting a concept which may itself be on the verge of replacement, as our understanding of the condition develops. Nevertheless it appropriately describes arthritis that is associated with demonstrable infection at a distant site without traditional evidence of sepsis at the affected joint(s). Although several forms of disease could be described as "reactive", particularly acute rheumatic fever, post-meningococcal septicaemia arthritis and Lyme disease, in clinical practice the term is restricted to an acute spondyloarthritis, usually, but not exclusively, linked to acute genitourinary or gastrointestinal infection. A proportion of patients fulfil criteria for Reiter's Syndrome [1].

Mycobacterium kansasii septic arthritis: French retrospective study of 5 years and review

Septic arthritis due to Mycobacterium kansasii is rare; only 40 cases have been published. A French national inquiry revealed the occurrence of 10 new cases between 1992 and 1997 (8 men and 2 women: mean age, 37 years; range, 25-54 years). Seven had an underlying condition: AIDS (n=4), chronic skin psoriasis and AIDS (n=2), or a renal transplant (n=1). Trauma to the joint, use of intra-articular corticosteroid(s) 1 month to 2 years after the event, and chronic skin psoriasis were risk factors. The mean interval between appearance of the first symptoms of arthritis and the diagnosis was 5 months. Monarthritis was localized to the knee (n=4), wrist (n=3), finger (n=1), elbow (n=1), or ankle (n=1). The main diagnostic procedure was culture of a synovial biopsy specimen. In all cases, debridement was associated with antimycobacterial treatment. Three patients died of AIDS during treatment, and another is still undergoing treatment; the other 6 patients were cured. M. kansasii infection should be considered in all cases of indolent arthritis with any of the following risk factors: local trauma, local or systemic corticosteroid therapy, chronic skin psoriasis, and immunodepression, especially that due to human immunodeficiency virus infection.

Septic arthritis due to Streptococcus pneumoniae in Nottingham, United Kingdom, 1985-1998

Pneumonia and meningitis are the 2 most frequent manifestations of Streptococcus neumoniae infection. Pneumococcal septic arthritis is considered to be relatively uncommon. Between 1985 and 1998, 32 (8. 2%) of 389 cases of septic arthritis seen in the 2 hospitals in Nottingham, United Kingdom, were due to S. pneumoniae. Six of 7 children with pneumococcal septic arthritis were aged <2 years. Of the 25 adults, 20 (80%) were aged >60 years, 11 (44%) had concomitant pneumococcal infection elsewhere, and 23 (92%) had articular or nonarticular diseases and/or other risk factors. In the elderly, a lack of febrile response was striking. S. pneumoniae was isolated from blood and joint cultures in >70% of cases, and gram-positive diplococci were seen in the joint fluids of 90% of patients. The mean duration of antimicrobial therapy for adults was twice as long as that for children. Eight (32%) of the adults died.

The clinical spectrum of osteoarticular tuberculosis in non-human immunodeficiency virus patients in a defined area of northwestern Spain (1988-1997)

OBJECTIVE

To examine the frequency and clinical manifestations of osteoarticular tuberculosis in non-human immunodeficiency virus (HIV) patients during the past 10 years in a northwestern area of Spain.

METHODS

The charts of all patients older than 14 years of age, not HIV-infected, and diagnosed as having osteoarticular tuberculosis at the Xeral-Calde Hospital from 1988 through 1997 were reviewed. All patients were residents of the region of Lugo. The diagnosis of osteoarticular tuberculosis was made on the basis of a positive culture for Mycobacterium tuberculosis from synovial fluid, joint tissue or paravertebral abscess or by histological findings of caseating granulomas in biopsied tissue.

RESULTS

Thirty-two HIV-negative patients (20 men and 12 women) were diagnosed with osteoarticular tuberculosis. The average annual incidence rate of osteoarticular tuberculosis in the combined (male and female) non-HIV population > or = 15 years of age was 15.68/million (95% CI: 10.25; 21.11); males 20.02/million (95% CI: 11.25; 28.79); females 11.52/million (95% CI: 5.00; 18.03). The age at the time of diagnosis was 60.8 +/- 17.5 years. Peripheral monoarthritis was observed in 16 of the 32 cases. The knee was the most frequent site of peripheral tuberculous arthritis (31%), but involvement of the non-weight-bearing joints (50%) was also common. Spondylitis involving the lower thoracic and upper lumbar vertebrae (31%) and unilateral sacroiliitis (19%) were less commonly observed. In general, patients with osteoarticular tuberculosis had a long duration of symptoms of the disease prior to the diagnosis (median: 5.5 months). The tuberculin skin test was negative in 3 cases. Chest radiograph was abnormal in only 6 of 32 patients (19%). The ESR (mean +/- SD) at the time of diagnosis was 55.7 +/- 29.0 mm/hr. Computed tomography was very useful in detecting early involvement of the sacroiliac joints and in defining the extent of the abscesses and the severity of the involvement in patients with spondylitis. All patients received chemotherapy for tuberculosis. None of them suffered relapses of tuberculosis.

CONCLUSION

Tuberculosis is a major source of osteoarticular complications in northwestern Spain. The prevailing low level of clinical suspicion may explain the long delay to the diagnosis in most patients. A greater awareness of the possibility of this severe complication, especially in the elderly people or in high-risk populations, would be advisable.

Staphylococcus aureus-induced inflammation and bone destruction in experimental models of septic arthritis

Staphylococcus aureus is the most common cause of septic arthritis. This disease often leads to severe joint destruction and high mortality. An experimental model of S. aureus arthritis has been developed to study the course of inflammation and joint destruction, to elucidate the role of bacterial and host factors for joint pathology and mortality, and to develop therapeutical and preventive devices against septic arthritis and sepsis. Results show that the innate immune system is crucial in defending the host against staphylococcal infection while components of the specific immune system, T and B lymphocytes and their products, are detrimental to the host, mediating joint destruction and increasing mortality rates. Staphylococcal capsule polysaccharides, toxins, cell wall-attached adhesins and possibly also the chromosomal DNA are virulence determinants in S. aureus arthritis. Several vaccine candidates have recently been described which protects against staphylococcal infections, e.g. staphylococcal surface polysaccharides, enterotoxins devoid of their superantigenic properties and collagen adhesin. There are also new approaches suggested for treatment of ongoing infections, such as the combined use of antibiotics and corticosteroids.

Destructive knee joint infection caused by Peptostreptococcus micros: importance of early microbiological diagnosis

Peptostreptococcus micros is a commensal of the oral cavity and the genitourinary tract that rarely causes serious infections. A case of a destructive knee joint infection with rapid progress caused by P. micros is presented. The significance of the microbiological findings was initially not acknowledged, which contributed to a nonsuccessful clinical outcome.

Septic and aseptic arthritis: a continuum?

This chapter considers the likelihood that a wide spectrum of infection-provoked arthritis exists, ranging from overt sepsis to apparently aseptic chronic arthritis in which very small numbers of causal bacteria can be detected only by using highly sensitive techniques. It asks whether joints are, as conventionally held, normally devoid of micro-organisms and how to judge the significance of bacteria detected within apparently sterile joints. Through a consideration of known septic, probably infective and apparently aseptic forms of arthritis, a set of criteria for attributing causality to putative arthritogenic micro-organisms is proposed.

The detection of DNA from a range of bacterial species in the joints of patients with a variety of arthritides using a nested, broad-range polymerase chain reaction

OBJECTIVE

Bacteria have been implicated in the pathogenesis of many types of inflammatory arthritides. The aim of this study was to identify any bacterial DNA in synovial fluid (SF) from patients with a range of inflammatory arthritides.

METHODS

A highly sensitive, broad-range, nested polymerase chain reaction (PCR) protocol targeting the bacterial 16S rRNA gene was designed and applied to SF from 65 patients with a range of rheumatic diseases.

RESULTS

Bacterial DNA was detected in 26 SF samples, including eight from patients with rheumatoid arthritis and five with juvenile arthritides. PCR products were identified by sequencing and searching of bacterial genomic databases; 'best fits' included Haemophilus influenzae, Bordetella and Yersinia.

CONCLUSIONS

These finding suggest an association between bacterial infection and inflammatory arthritides in some patients. Further research is required to determine the role of these organisms in the pathogenesis and whether such patients might respond to prolonged antibiotic therapy.

The use of pulsed field gel electrophoresis to investigate the epidemiology of Staphylococcus aureus infection in commercial broiler flocks

Pulsed field gel electrophoresis (PFGE) analysis of SmaI restriction patterns was used to type 109 isolates of Staphylococcus aureus collected from broiler farms and hatcheries in Northern Ireland. Forty-seven isolates from clinical conditions in broilers and 62 strains from hatcheries, were examined. The PFGE patterns demonstrated a similarity between 85% of strains from clinical sources and 71% of the hatchery isolates. The association of disease with the predominant strain type and presence of these same strains in the hatchery, indicates that the hatchery is a potential source of the infection for clinical broiler disease.

Role of group B streptococcal capsular polysaccharides in the induction of septic arthritis

The ability of different serotypes of group B streptococci (GBS) to induce septic arthritis in mice was compared. Types II, III, IV, V, VI and VII GBS were investigated. A highly capsulate strain of type III GBS, COH1, and its mutants, COH1-11 (lacking capsular sialic acid) and COH1-13 (non-capsulate), obtained by transposon insertional mutagenesis, were used to assess the role of type-specific polysaccharide on the induction of arthritis. At an intravenous dose of 10(7) cfu/mouse, reference strains of types II, III, IV, VI and VII and type III strain COH1 induced arthritis with an incidence ranging from 70 to 90%. For type V and strain COH1-11, 10(8) cfu/mouse was required to obtain a 50% incidence of arthritis; lesions were not evident with strain COH1-13. The presence of the capsule played a major role in the induction of GBS septic arthritis. The presence and amount of sialic acid in capsular polysaccharide influenced the incidence of articular lesions. The bacterial dose affected the manifestations of arthritis; the less virulent strains of GBS also induced articular lesions when an adequate number of micro-organisms reached the joints.

Experimental infection of the human granulocytic ehrlichiosis agent in horses

Human blood collected from two patients from Westchester County, New York with human granulocytic ehrlichia (HGE) infection was inoculated into two ponies. Inoculated ponies developed clinical signs similar to a previous report (Madigan et al., 1995). Histopathological changes involved follicular hyperplasia of lymphoid tissues. HGE DNA was detected by PCR in muscle, fascia, peritoneum, and adrenal gland after the ponies produced a high level of antibodies to HGE. We suggest that HGE may reside in poorly vascularized connective tissues, where the antibodies may have some difficulties to penetrate, resulting in persistent infection. Since HGE and E. equi cause very similar diseases in both humans and horses, they may be the same organism with minor genetic differences.

[The characteristics of the causative agents of suppurative-inflammatory complications in hemophiliacs]

Morphological-cultural and physiological-biochemical properties of 24 strains of microorganisms agents of pyo-inflammatory complications of different localization in patients with hemophilia have been studied. Microorganisms strains presented by the following species: Staphylococcus aureus, S. epidermidis, S. saprophyticus, Proteus vulgaris, P. morganii, Hafnia alvei, Serratia marcescens, have been identified. It was found out that in monoculture staphylococci prove to be the leading etiological agent (60.9%), gram-negative enterobacteria (52.2%) and bacterial associations (8.7%) occur more rarely. Special attention was paid to the study of resistance of antibiotics, circulation and pathogenicity factors that had a direct effect on the main disease severity. It was ascertained that high activity of enzymes and presence of pathogenicity factors were the peculiarities of microorganisms isolated from pyo-septic sites in patients with hemophilia. All the strains possessed multiple resistance to antibiotics.

Heterogeneity of staphylococci and other bacteria isolated from six-week-old broiler chickens

In broiler operations, various health problems develop during the final 2 wk of the growing period, resulting in increased mortality and condemnation losses. At this stage, sickly birds were found to be systemically infected by various bacteria regardless of varied clinical signs, and the purpose of this study was to carry out thorough microbiological investigations on this problem. Thirty-one 6-wk-old broilers showing signs of illness were obtained from three farms, and bacterial isolations were carried out from the blood, liver, and hock joint. Bacteria were isolated from 87, 90, and 71% of the blood, liver, and hock joint samples, respectively. Mean bacterial counts in log10 of the blood (per milliliter) and liver (per gram) were 2.15 and 2.93, respectively. Among 132 bacterial isolates, major species were Staphylococcus (60%), Corynebacterium (18%), Escherichia coli (5%), and Stomatococcus (4%). Among 79 Staphylococcus isolates, 77 were coagulase-negative. Major species of staphylococci were S. lentus (19%), S. simulans (18%), S. cohnii (13%), S. gallinarum (10%), and S. captis (7%). In addition, six species of gram-positive and five species of gram-negative organisms were isolated. Thus, the apparent systemic infections were not caused by predominant pathogenic bacterial species, and adequately described as mixed infections. There were some significant relationships between isolated bacterial species and sampling sites, suggesting that certain organisms were abundant in the environment of a particular poultry house. These results indicate that systemic infections in market age broilers are caused by mixed bacterial species and suggest that they are caused by suppressed host antibacterial systems rather than pathogenic factors of microorganisms.

Genotypic and phenotypic analysis of Mycoplasma fermentans strains isolated from different host tissues

A correlation was found between the expression of a specific Mycoplasma fermentans surface antigen (Pra, proteinase-resistant antigen) and the site of isolation of the organism from the infected host. Strains which expressed Pra were most frequently associated with cells of bone marrow origin, and strains which lacked expression of Pra were most commonly isolated from the respiratory tract, genital tract, and arthritic joints, i.e., epithelial cell surfaces. Pra was previously shown to be resistant to degradation by proteinases and was hypothesized to play a protective role at the organism surface and perhaps to influence which host tissue site was colonized by the organism. The methods used for this phenotyping scheme required isolation and growth of the mycoplasma in quantities sufficient for immunoblot analysis using monoclonal antibodies. We wanted to determine a more rapid and less cumbersome technique to supplement this method for determining the Pra phenotype directly in clinical specimens. Here we describe PCR studies to investigate the movement of a previously identified M. fermentans insertion sequence (IS)-like element. These data showed a correlation between a specific IS genotype and the Pra+ phenotype. Production of a 160-bp product using a single set of IS-based primers was associated with expression of Pra. The genomic IS location resulting in the 160-bp product was determined by using Southern blot analysis and was found to be a stable insertion site characteristic of genotype I strains. Additional analyses of sequences within and flanking the IS insertion sites revealed another pair of PCR primer sites which resulted in the consistent production of a 450-bp amplicon. The stability of this site was dependent on the absence of the IS-like element between the primer sites. The production of this 450-bp amplicon correlated with the Pra mutant phenotype and was characteristic of genotype II strains. The data showed that the sequence within the IS may be unstable and that reliable genotyping sequences are more easily found in the stable genomic sites which flank the IS element.

Tuberculosis of contralateral costo-transverse joints

We present a case of multifocal tuberculosis of contralateral costo-transverse joints. Even in countries where tuberculosis is common, extrapulmonary multifocal infection is uncommon. Furthermore, a bilateral, symmetric distribution is distinctly unusual. The index of suspicion for tuberculosis should increase when the patient is from a country where tuberculosis is endemic or when a history of AIDS is present.

Use of antibiotic-impregnated polymethyl methacrylate in horses with open or infected fractures or joints: 19 cases (1987-1995)

OBJECTIVE

To evaluate the clinical efficacy of antibiotic-impregnated polymethyl methacrylate (PMMA) in horses with open or infected fractures or joints in which internal fixation or external coaptation devices were used.

DESIGN

Retrospective case series.

ANIMALS

19 horses in which antibiotic-impregnated PMMA was used as part of the treatment regimen.

PROCEDURES

Medical records of each horse were reviewed, and owners and trainers were contacted to provide additional information.

RESULTS

Musculoskeletal problems in these horses included 10 fractures of long bones, 2 comminuted phalangeal fractures, 5 joint injuries, and 2 chronically septic joints in which ankylosis was stimulated. Nine horses had open fractures, 8 had closed wounds and developed infection after internal fixation of fractures, and 2 had chronically septic joints. Bony union was achieved in 15 of 19 horses. Twelve horses were discharged from the hospital and survived long term. Gentamicin sulfate, tobramycin sulfate, amikacin sulfate, and cefazolin sodium were used in PMMA.

CLINICAL IMPLICATIONS

Use of antibiotic-impregnated PMMA provided high local concentrations of antibiotics and should be considered in the treatment of horses with open fractures and acute and chronic bone and joint infections.