sodium-morrhuate and Osteomyelitis

Hematogenous osteomyelitis was produced in the tibia or the mandible of rats by drilling a hole into the bone, injecting sodium morrhuate, and inoculating Staphylococcus aureus Phillips into the femoral vein. Animals were sacrificed after 2 weeks and examined. The infection was characterized grossly and radiographically by bone deformation, histopathologically by a characteristic suppurative reaction, and microbiologically by the recovery of S. aureus Phillips from the infected tissue. These findings indicate that the model mimics human osteomyelitis with respect to its inflammatory bone changes. In contrast to earlier rat models in which bacteria were injected directly into the bone, this new experimental model allows study of the initiating events of osteomyelitis such as bacterial attachment and might assist as a model for both prophylactic and therapeutic trials.

Topics: Animals; Antibodies, Bacterial; Disease Models, Animal; Female; Humans; Injections, Intravenous; Liver; Mandible; Osteomyelitis; Radiography; Rats; Rats, Wistar; Sodium Morrhuate; Spleen; Staphylococcal Infections; Staphylococcus aureus; Tibia

The rabbit model of osteomyelitis introduced by C.W. Norden, based on injection of an infecting solution (Staphylococcus aureus, sodium morrhuate) into the tibia, was studied at 4.7 Tesla with a time-efficient chemical shift selective imaging technique, Chemical Shift Specific Slice Selection (C4S). The evolution of the disease over several weeks was followed on water-selective, fat-selective, and sum images obtained simultaneously with this imaging sequence. Experiments were performed either on different groups of rabbits at different times after infection with subsequent sacrifice of the animal and microbiological analysis of the infected tibia or on the same group of animals imaged several times after infection. Associated analysis of the water and fat selective images revealed marrow modifications very early (Day 5 after inoculation) demonstrating the high sensitivity of the employed imaging technique. Later on, bone modifications were best identified on the sum images. Additional experiments performed on animals injected with a noninfecting solution containing only sodium morrhuate showed however that the sclerosing agent alone can yield images similar to those produced by infection at early stages after inoculation. Therefore, the Norden model would not be suitable for monitoring quantitatively outcome of therapy by magnetic resonance imaging. It is however well adapted for the evaluation and optimization of MRI techniques or protocols intended to detect early changes of bone marrow produced by septic or aseptic infarct.

Topics: Adipose Tissue; Animals; Body Water; Bone Marrow; Disease Models, Animal; Evaluation Studies as Topic; Female; Image Enhancement; Image Processing, Computer-Assisted; Infarction; Magnetic Resonance Imaging; Muscle, Skeletal; Osteomyelitis; Rabbits; Reproducibility of Results; Sodium Morrhuate; Staphylococcal Infections; Staphylococcus aureus; Thrombosis; Tibia; Time Factors

Ampicillin/sulbactam was used for the treatment of experimental osteomyelitis due to Staphylococcus aureus in rabbits. Treatment with 200 mg/kg (ampicillin) three times a day sterilized 40% of infected rabbit bones. The results of 4 weeks of treatment with ampicillin/sulbactam for chronic experimental staphylococcal osteomyelitis were comparable to those obtained previously with cephalothin and with oxacillin in previous studies and were not as good as those with clindamycin alone or combination therapy that included rifampin.

Topics: Ampicillin; Animals; Chronic Disease; Disease Models, Animal; Drug Therapy, Combination; Microbial Sensitivity Tests; Osteomyelitis; Rabbits; Sodium Morrhuate; Staphylococcal Infections; Sulbactam

Arachidonic acid was used as a facilitating agent in experimental rat Staphylococcus aureus osteomyelitis and compared with the more commonly used agent, sodium morrhuate. The injection of arachidonic acid or sodium morrhuate and S. aureus into rat tibiae caused increased quantitative bacterial bone counts, gross bone pathology, roentgenographic changes, and weight loss. The doses required to produce these changes appeared to be lower for arachidonic acid.

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Culture Techniques; Disease Models, Animal; Osteomyelitis; Radiography; Rats; Sodium Morrhuate; Staphylococcal Infections; Staphylococcus aureus

We describe here a Sprague-Dawley rat model for chronic osteomyelitis. Staphylococcus aureus and sodium morrhuate were implanted by either microdrilling or direct needle injection into the tibiae of rats. Of 107 rats, 87 (81%) developed osteomyelitis when a high-speed drill was used for implantation, and 27 (51%) of 53 rats developed osteomyelitis by direct needle inoculation (chi square = 9.81, P less than 0.01). Demonstrated histopathological changes included the presence of resorption bays filled with osteoclasts. Quantitative microbiological monitoring of tibial count confirmed disease chronicity, yielding stable numbers of CFU (10(6.29 +/- 0.27) ) of S. aureus over 70 days. Infected animals became anemic and lost weight. The erythrocyte sedimentation rates and leukocyte counts were not elevated. Roentgenograms provided the best correlation with the number of organisms in infected tibiae (r2 = 0.80). Rats with infected tibiae were treated with either oxacillin (120 mg/kg per day) or ceftriaxone (50 mg/kg per day). Treatment over 14 or 28 days reduced S. aureus counts in tibiae but did not reliably sterilize infected bones, suggesting that this model was resistant to prolonged antimicrobial therapy.

Topics: Animals; Anti-Bacterial Agents; Disease Models, Animal; Osteomyelitis; Radiography; Rats; Rats, Inbred Strains; Sodium Morrhuate; Staphylococcus aureus

A surgical procedure allowed the placement of a silicone rubber catheter in the marrow cavity of the tibia of a rabbit and also allowed the introduction of a sclerosing agent (sodium morrhuate) and cells of Staphylococcus aureus. Osteomyelitis developed in 60% of the animals so treated, and the infecting microorganism was recovered from the infected tibias of the animals that developed this disease. All blood cultures taken 24 h after the infection were negative for S. aureus. Radiological findings consisted of osteolytic changes, the occurrence of sequestration and periosteal reactions, and sclerosis in the infected bones. Sections of bone prepared for histological examination confirmed the diagnosis of osteomyelitis. Transmission and scanning electron microscopy of samples of bone marrow, bone chips, and the catheters taken from the infected tibiae revealed gram-positive cocci embedded in a very extensive matrix of ruthenium red-staining glycocalyx adhering to the bone and the implanted catheter. It is proposed that this extensive glycocalyx served a protective function for the bacteria and was important in bacterial adherence and thus played an important role in bacterial persistence and the development of osteomyelitis in these rabbits.

Topics: Adhesiveness; Animals; Bone Marrow; Catheterization; Disease Models, Animal; Male; Osteomyelitis; Rabbits; Ruthenium Red; Sodium Morrhuate; Staphylococcal Infections; Staphylococcus aureus; Tibia

An experimental model of chronic osteomyelitis caused by Pseudomonas aeruginosa was established with use of techniques identical to those employed previously with Staphylococcus. Infection of bone was consistently produced, but the disease was less severe than that seen with Staphylococcus. There were lower mortality, decreased severity of infection as demonstrated by X ray, and less evidence of sequestrum formation with P. aeruginosa than with Staphylococcus. Carbenicillin was used alone and in combination with sisomicin in the treatment of experimental pseudomonas osteomyelitis. The combination, when administered for four weeks, was significantly more effective than either agent alone.

Topics: Animals; Carbenicillin; Disease Models, Animal; Drug Evaluation, Preclinical; Drug Therapy, Combination; Gentamicins; Humans; Kidney; Male; Microbial Sensitivity Tests; Osteomyelitis; Pseudomonas aeruginosa; Pseudomonas Infections; Radiography; Sisomicin; Sodium Morrhuate

Topics: Aminoglycosides; Animals; Autopsy; Carbenicillin; Disease Models, Animal; Drug Therapy, Combination; Gentamicins; Leukocyte Count; Necrosis; Osteomyelitis; Pseudomonas aeruginosa; Pseudomonas Infections; Rabbits; Radiography; Sodium Morrhuate; Time Factors