Improving in vivo models of fracture fixation associated osteomyelitis

This project’s aim was to create new experimental models in small animals for the investigation of infections related to bone fracture fixation implants. Animal models are essential in orthopaedic trauma research and this study evaluated new implants and surgical techniques designed to improve standardisation in these experiments, and ultimately to minimise the number of animals needed in future work. This study developed and assessed procedures using plates and inter-locked nails to stabilise fractures in rabbit thigh bones. Fracture healing was examined with mechanical testing and histology. The results of this work contribute to improvements in future small animal infection experiments.

Propionibacterium acnes and Staphylococcus lugdunensis Cause Pyogenic Osteomyelitis in an Intramedullary Nail Model in Rabbits

Propionibacterium acnes and coagulase-negative staphylococci (CoNS) are opportunistic pathogens implicated in prosthetic joint and fracture fixation device-related infections. The purpose of this study was to determine whether P. acnes and the CoNS species Staphylococcus lugdunensis, isolated from an "aseptically failed" prosthetic hip joint and a united intramedullary nail-fixed tibial fracture, respectively, could cause osteomyelitis in an established implant-related osteomyelitis model in rabbits in the absence of wear debris from the implant material. The histological features of P. acnes infection in the in vivo rabbit model were consistent with localized pyogenic osteomyelitis, and a biofilm was present on all explanted intramedullary (IM) nails. The animals displayed no outward signs of infection, such as swelling, lameness, weight loss, or elevated white blood cell count. In contrast, infection with S. lugdunensis resulted in histological features consistent with both pyogenic osteomyelitis and septic arthritis, and all S. lugdunensis-infected animals displayed weight loss and an elevated white blood cell count despite biofilm detection in only two out of six rabbits. The differences in the histological and bacteriological profiles of the two species in this rabbit model of infection are reflective of their different clinical presentations: low-grade infection in the case of P. acnes and acute infection for S. lugdunensis. These results are especially important in light of the growing recognition of chronic P. acnes biofilm infections in prosthetic joint failure and nonunion of fracture fixations, which may be currently reported as "aseptic" failure. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Uncommon mandibular osteomyelitis in a cat caused by Nocardia africana

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microbiota associated with chronic osteomyelitis of the jaws

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

GARRES OSTEOMYELITIS - A CASE-REPORT

This is a case report of Garre's osteomyelitis caused by infection from a lower left molar which was successfully managed by root treatment following several unsuccessful attempts with antibiotic therapy alone. After 18 months there was complete resolution of the bony lesion.

Garré's osteomyelitis: a case report.

This is a case report of Garré's osteomyelitis caused by infection from a lower left molar which was successfully managed by root treatment following several unsuccessful attempts with antibiotic therapy alone. After 18 months there was complete resolution of the bony lesion.

Garre's osteomyelitis associated with a fistula: a case report.

A report of Garre's osteomyelitis of the mandible associated with a fistula is presented. Elimination of pulpal periapical infection through endodontic therapy was shown to be an effective treatment. The total bone healing was observed one year later.

Marginal resection for treatment of mandibular osteomyelitis associated with osteopetrosis: Case report

Osteopetrosis (OP) is a rare hereditary disorder characterized by a dysfunction of the osteoclasts that impairs bone resorption, which together with the normal osteoblastic activity forms intense bone sclerosis with reduction of marrow. A common complication that arises, most frequently, as a result of tooth extraction is mandibular osteomyelitis. There is no consensus on the literature about the treatment of this infection in an osteopetrotic patient, therefore, the purpose of this paper is to report a case of marginal resection for treatment of mandibular osteomyelitis in an osteopetrotic patient and discuss relevant features of this procedure. © 2010 European Association for Cranio-Maxillo-Facial Surgery.

Deforming mandibular osteomyelitis in a cow caused by Trueperella pyogenes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exogenous bacterial osteomyelitis in 52 dogs: a retrospective study of etiology and in vitro antimicrobial susceptibility profile (2000-2013)

Background: Most clinical cases of osteomyelitis in dogs involve infectious agents, especially bacteria and fungi. The characterization of these microorganisms may aid in the prevention and treatment of disease.Objective: The aim of this study was to evaluate retrospectively microbiological cultures and in vitro antimicrobial susceptibility profile of isolates from 52 cases of bacterial osteomyelitis in long bones of dogs over 2000-2013. In 78% of the cases injuries were caused by a motor vehicle accident, but there were a few cases of dog bites (17%) and ascending infection due to pododermatitis (5%).Animals and methods: The isolated microorganisms were identified based on conventional phenotypic methods. In vitro disk diffusion test was performed using 30 different antimicrobials.Results: The isolates were obtained from femur (28%), humerus (16%), tibia (31%), and radius/ulna (25%). Among 52 cases, culture was positive in 88% of cases. Thirteen genus of different species of microorganisms were isolated. The most common microorganisms isolated were Staphylococcus spp. and Escherichia coli followed by Streptococcus spp., enteric bacteria, Corynebacterium sp. and anaerobic bacteria. In 42% of cases cultures were mixed. The most effective drugs against isolated bacteria were amoxicillin and clavulanate potassium (79%) followed by ceftriaxone (69%). High-resistance rates were documented against azithromycin (80%), penicillin (59%), and clindamycin (59%).Conclusions: The present study highlights diverse etiologic agents in cases of infectious bacterial osteomyelitis, with predominance of Staphylococcus genus, and reinforces the importance of obtaining cultures and susceptibility profiles given the high rates of antimicrobial resistance.

Canine osteomyelitis caused by Leishmania sp

Leishmaniasis is a disease emerging or re-emerging worldwide distribution (Sousa, 2008), a major impact on public health. The canine visceral leishmaniasis is an infectious parasitic zoonosis of worldwide distribution (Troncarelli, 2009), caused by a flagellate protozoan called Leishmania chagasi (Costard, 2009). Osteomyelitis can develop when the parasite reaches the bone tissue of the host via blood or continuity of adjacent soft tissue infection (Baltenperger, 2004). The histopathology of the lesions has 100% specificity when viewing the amastigote form of the parasite (Feitosa et al., 2000). A dog breed poodle, female, five years, with chronic lameness four months ago was attended by a veterinary, proceeded to the general clinical examination, radiographic evaluation of the hindquarters and the laboratory tests of enzyme immunoassay (ELISA) and indirect immunofluorescence (RIFI) for Leishmania sp. On examination, besides the enlargement of lymph nodes, the animal showed pain on flexion and extension of hind limbs. In radiographic lytic bone lesions were observed in bilateral ischial board and greater trochanter of the femur, suggestive of osteomyelitis. In specific laboratory tests for diagnosis of leishmaniasis ELISA reagent and RIFI reagent 1:40. As recommended by the Ministry of Health, the animal was euthanized. No macroscopic findings were reported during the necropsy, usually associated with leishmaniasis. The ischium bone fragments were sent for histopathological examination. There was intense proliferation of mononuclear inflammatory cells, mainly macrophages and lymphocytes. Amastigotes of Leishmania sp, were identified in the cytoplasm of some macrophages and bone tissue. In endemic areas for canine leishmaniasis, dogs with a history of intermittent lameness, and radiographic lytic bone lesions suggestive of osteomyelitis should be directed to realization of the histopathology and serologic tests for the differential diagnosis of Leishmania sp. Even without evidence of cutaneous or visceral lesions, usually associated with this disease.

Chronic osteomyelitis of the maxilla and mandible: microbiological and clinical aspects

Osteomyelitis of the mandible and maxilla are common in developing countries and their treatment may be long-standing and difficult. Thus, the aim of this study was to discuss the main biological aspects of the chronic osteomyelitis of the jaws of especial interest for dental team. These infections are associated with a complex microbiota composed mainly by anaerobic bacteria, sometimes associated with microorganisms originated from the skin and digestive tract. These data suggest that chronic osteomyelitis of the mandible and maxilla should be treated as anaerobic infections in most cases. In addition, local surgical treatments are relevant in the therapy outcome, associated to the use of antimicrobial agents, and the failure to accomplish them is a major cause of treatment failure.