Inflammatory turmoil within: an exploration of autoinflammatory disease genetic underpinnings, clinical presentations, and therapeutic approaches.

Systemic autoinflammatory diseases (SAIDs) arise from dysregulated innate immune system activity, which leads to systemic inflammation. These disorders, encompassing a diverse array of genetic defects classified as inborn errors of immunity, are significant diagnostic challenges due to their genetic heterogeneity and varied clinical presentations. Although recent advances in genetic sequencing have facilitated pathogenic gene discovery, approximately 40% of SAIDs patients lack molecular diagnoses. SAIDs have distinct clinical phenotypes, and targeted therapeutic approaches are needed. This review aims to underscore the complexity and clinical significance of SAIDs, focusing on prototypical disorders grouped according to their pathophysiology as follows: (i) inflammasomopathies, characterized by excessive activation of inflammasomes, which induces notable IL-1ß release; (ii) relopathies, which are monogenic disorders characterized by dysregulation within the NF-κB signaling pathway; (iii) IL-18/IL-36 signaling pathway defect-induced SAIDs, autoinflammatory conditions defined by a dysregulated balance of IL-18/IL-36 cytokine signaling, leading to uncontrolled inflammation and tissue damage, mainly in the skin; (iv) type I interferonopathies, a diverse group of disorders characterized by uncontrolled production of type I interferons (IFNs), notably interferon α, ß, and ε; (v) anti-inflammatory signaling pathway impairment-induced SAIDs, a spectrum of conditions characterized by IL-10 and TGFß anti-inflammatory pathway disruption; and (vi) miscellaneous and polygenic SAIDs. The latter group includes VEXAS syndrome, chronic recurrent multifocal osteomyelitis/chronic nonbacterial osteomyelitis, Schnitzler syndrome, and Still's disease, among others, illustrating the heterogeneity of SAIDs and the difficulty in creating a comprehensive classification. Therapeutic strategies involving targeted agents, such as JAK inhibitors, IL-1 blockers, and TNF inhibitors, are tailored to the specific disease phenotypes.

Microbiological characterization of neuropathic diabetic foot infection: a retrospective study at a Portuguese tertiary hospital.

Diabetic foot infection imposes a significant burden and is the major cause of nontraumatic limb amputation. Adequate patient management with effective antibiotic therapy is crucial.This retrospective cohort study aimed to characterize the microbiology and resistance patterns of moderate to severe neuropathic diabetic foot infection in patients hospitalized at a tertiary referral hospital between January 2020 and June 2023. Deep tissue specimens from ulcers were collected for culture.Sixty inpatients were included (62% male, mean age 59.1 ± 11.5 years). Osteomyelitis was present in 90% of the patients. Among 102 microorganisms (average of 1.91 ± 1.25 pathogens per patient), 60.8% were gram-positive bacteria, 31.4% were gram-negative, 3.92% were anaerobic bacteria, and 3.92% were fungi. Staphylococcus aureus (19%) and Enterococcus faecium (17%) were the most common. Pseudomonas aeruginosa (8%) and bacteria of the Enterobacterales family (24%) accounted for all the isolated gram-negative bacteria. Sixteen percent of Staphylococcus aureus and 67% of coagulase-negative Staphylococci were resistant to methicillin. Resistance to ampicillin was found in 11% of Enterococci. All Pseudomonas aeruginosa isolates were sensitive to piperacillin-tazobactam, ceftazidime, or cefepime. Among the Enterobacterales, resistance rates were 35% for piperacillin-tazobactam, 38% for ceftazidime, 21% for cefepime, and 13% for carbapenems.Although the prevalence of methicillin-resistant staphylococci was lower than that in other studies, carbapenem resistance among gram-negative bacteria warrants attention. This study highlights the importance of understanding local epidemiology for effective diabetic foot infection management and resistance mitigation.

Analysis of Pathogen Distribution and Antimicrobial Resistance in Bone and Joint Infections Among Young Children.

BACKGROUND: This study aimed to analyze the distribution of pathogens and antimicrobial resistance in bone and joint infections (BJIs) among children under four years old. METHODS: A retrospective analysis was conducted on the clinical data of children under four years old who received inpatient treatment for BJIs at the Children's Hospital of Soochow University between January 2016 and December 2022. Results of bacterial culture and antimicrobial resistance were analyzed. RESULTS: Among the 131 patients, 52 (39.7%) showed positive bacterial culture results. There were Gram-positive (G+) bacteria detected in 38 strains (73.07%), Gram-negative (G-) bacteria in 12 strains (23.08%), and fungi in 2 strains (3.85%). Thirty-one strains of Staphylococcus aureus (S. aureus) were detected (59.62%), including 7 MRSA strains (22.58%). The resistance rate of G+ bacteria to penicillin was 72.97%, while resistance to erythromycin and clindamycin was approximately 50%. No resistance was found against linezolid, vancomycin, and teicoplanin. G- bacteria showed a sensitivity of 100% to carbapenems, including meropenem, ertapenem, and imipenem, a resistance rate of 91.67% to ampicillin-sulbactam, and relatively high resistance rates to compound sulfamethoxazole, ampicillin/sulbactam, and piperacillin. CONCLUSIONS: Regional variations existed in the distribution of pathogens and antimicrobial resistance in children under four years old with BJIs. In our hospital, the most common pathogen is S. aureus, with MRSA accounting for approximately one-fourth of all S. aureus patients. Additionally, extended-spectrum ß-lactamase (ESBL)-producing G- bacteria have been identified, underscoring the importance of careful consideration during empirical antibiotic therapy.

Cryptococcal Osteomyelitis of the Patella: A Case Report.

CASE: A 38-year-old woman presented to our clinic with right knee pain and difficulty ambulating. After cultures were obtained, a cryptococcal infection of the patella was identified. Subsequent workup revealed previously undiagnosed HIV/AIDS and a disseminated cryptococcal infection. CONCLUSION: Over a 20-month course, the patient was treated with fluconazole and antiretroviral therapy with very limited medication compliance. The disseminated infection caused cutaneous, hepatic, and cerebral complications. Eventually, compliance improved, and a final procedure to obtain post-treatment cultures and apply antifungal bone matrix was completed. The patient cleared the infection and will likely require lifetime antifungal treatment.

Successful conservative management of advanced pyogenic sternoclavicular joint arthritis with osteomyelitis and pulmonary infiltration: a case report.

BACKGROUND: Sternoclavicular joint arthritis is a rare condition that poses considerable diagnostic and therapeutic challenges, leading to severe complications and a high mortality rate. Although surgical interventions are often considered necessary for advanced cases, some reports have suggested that conservative management with antibiotic therapy can be effective in certain cases. However, to our knowledge, there are no reports of successful conservative treatment in cases exhibiting aggressive spread. This report highlights a case of advanced sternoclavicular joint arthritis with bone destruction and pulmonary infiltration, successfully treated conservatively with outpatient antibiotic therapy. CASE PRESENTATION: A 58-year-old Japanese male presented with a 1-month history of left-sided shoulder pain. Contrast-enhanced computed tomography showed abscess formation and clavicular bone destruction, with infiltrative shadows suggesting lung involvement. The diagnosis of sternoclavicular joint arthritis was made, and outpatient oral antibiotic therapy was initiated. The patient exhibited a marked reduction in inflammatory marker levels and symptoms, and antibiotic therapy was discontinued after 3 weeks, with no recurrence observed at a 4-month follow-up. CONCLUSIONS: This case highlights that conservative management with antibiotics can be effective for treating advanced sternoclavicular joint arthritis, emphasizing the need for individualized management and further research into non-surgical treatment options.

The clinical significance of inflammatory biomarkers, IL6 cytokine, and systemic immune inflammatory index in rabbit model of acute and chronic Methicillin-resistant Staphylococcus epidermidis-induced osteomyelitis.

Infections are a major complication of open fractures and fracture fixation. In this study, an innovative bioactive medical device was used to experimentally treat MRSE-induced osteomyelitis in rabbit tibia. This paper investigates the clinical significance of inflammatory biomarkers (NLR, PLR, MLR and PMR), SII and IL-6 and assesses their role in the development of osteomyelitis. The main objective is to identify the utility of hematological reports derived from neutrophils, leukocytes, monocytes and platelets in the evolution of implant-related osteomyelitis and the estimation of treatment efficiency. In particular, this study compares the response of these inflammatory markers to different treatments in the presence or absence of bioactive materials and/or topical antibiotics over time. The analysis of the threads showed that NLR, PLR and SII had high values in the acute phase of the disease, so that after chronicization, they decrease. The animals treated with vancomycin nano-functionalized peptide-enriched silk fibroin-coated implants showed lower levels of inflammatory biomarkers compared to the other groups (empty implants and peptide-enriched silk fibroin-coated implants). NLR, PLR and SII, complemented by IL-6 can be used as fairly accurate biomarkers for the diagnosis of osteomyelitis.

Tricalcium phosphate-loaded injectable hydrogel as a promising osteogenic and bactericidal teicoplanin-delivery system for osteomyelitis treatment: An in vitro and in vivo investigation.

Osteomyelitis is an inflammation of bone tissue usually caused by pyogenic bacteria. The most recurrent clinical approach consists of bone debridement followed by parenteral administration of antibiotics. However, systemic antibiotic treatment has limitations regarding absorption rate and bioavailability over time. The main challenge of osteomyelitis treatment consists of coupling the persistent infection treatment with the regeneration of the bone debrided. In this work, we developed an injectable drug delivery system based on poloxamer 407 hydrogel containing undoped Mg, Zn-doped tricalcium phosphate (ß-TCP), and teicoplanin, a broad-spectrum antibiotic. We evaluated how the addition of teicoplanin and ß-TCP affected the micellization, gelation, particle size, and surface charge of the hydrogel. Later, we studied the hydrogel degradation and drug delivery kinetics. Finally, the bactericidal, biocompatibility, and osteogenic properties were evaluated through in vitro studies and confirmed by in vivo Wistar rat models. Teicoplanin was found to be encapsulated in the corona portions of the hydrogel micelles, yielding a bigger hydrodynamics radius. The encapsulated teicoplanin showed a sustained release over the evaluated period, enough to trigger antibacterial properties against Gram-positive bacteria. Besides, the formulations were biocompatible and showed bone healing ability and osteogenic properties. Finally, in vivo studies confirmed that the proposed locally injected formulations yielded osteomyelitis treatment with superior outcomes than parenteral administration while promoting bone regeneration. In conclusion, the presented formulations are promising drug delivery systems for osteomyelitis treatment and deserve further technological improvements.

Ruthenibacterium lactatiformans isolated from a human blood culture: a first report.

BACKGROUND: Ruthenibacterium lactatiformans, a Gram-stain-negative, rod-shaped, obligate anaerobic bacterium of the Oscillospiraceae family, has not been previously reported in human infections. This study reports the first case of bacteraemia and potential vertebral osteomyelitis caused by Ruthenibacterium lactatiformans. CASE PRESENTATION: An 82-year-old man with a history of diabetes, chronic renal failure, and prior spinal surgery for spondylolisthesis and spinal stenosis presented with fever and lower back pain. Magnetic resonance imaging revealed multiple vertebral osteomyelitis lesions. Initial blood cultures identified methicillin-resistant Staphylococcus aureus (MRSA), which prompted vancomycin treatment. However, repeated blood cultures not only confirmed persistent MRSA, but also detected Gram-negative bacilli (GNB). Despite surgical removal of the spinal hardware and antimicrobial therapy, the patient's osteomyelitis worsened, necessitating transfer for further management. Subsequent analysis using 16S rRNA gene sequencing identified the GNB as Ruthenibacterium lactatiformans. CONCLUSIONS: This is the first documented instance of human infection with Ruthenibacterium lactatiformans, signifying its pathogenic potential in vertebral osteomyelitis. The involvement of anaerobic bacteria and the possibility of polymicrobial infections complicate the diagnosis and treatment of vertebral osteomyelitis. This report underscores the need for caution when identifying the causative organism and selecting an appropriate treatment.

Safety of rezafungin as a long-term treatment option in two patients with complicated fungal infections: two cases from Lecco Hospital (Italy).

Rezafungin is an echinocandin characterized by a long elimination half-life which allows for weekly administration. It has been recently approved for the treatment of candidemia. Few data are available about the long-term use of rezafungin and its use for deep infections like endocarditis and osteomyelitis. We describe our experience with its prolonged use in two azole-resistant Candida infections: a case of sacral osteomyelitis and a prosthetic valve endocarditis also involving a thoracic endovascular aneurysm repair.

Unique Presentation of Asymptomatic Bacteriuria, Vertebral Osteomyelitis, and Iliopsoas Abscess Due to Klebsiella pneumonia in a 73-Year-Old Man with Type 2 Diabetes Mellitus on Empagliflozin.

BACKGROUND Sodium-glucose co-transporter 2 inhibitors (SGLT2), such as empagliflozin, used to treat type 2 diabetes mellitus (DM), can increase the risk of infections, including urinary tract infections and osteomyelitis, especially in elderly patients. The use of SGLT2 inhibitors has been increasing dramatically in the last few years. Therefore, their adverse effects and complications have also been increasing. Herein, this report describes a 73-year-old man with type 2 DM treated with empagliflozin presenting with asymptomatic bacteriuria, vertebral osteomyelitis and iliopsoas abscess due to Klebsiella pneumoniae. CASE REPORT We report a 73-year-old man with DM on empagliflozin who presented with back pain of 1-month duration with elevated inflammatory markers. On lumbar spine magnetic resonance imaging (MRI), he was found to have lumbar vertebral osteomyelitis and left iliopsoas abscess. His symptoms were improved with abscess drainage and antimicrobial therapy. The source of infection was most likely asymptomatic bacteriuria, which may have been secondary to empagliflozin treatment, as evidenced by the urine, the blood, the bone and abscess cultures revealing growth of Klebsiella pneumoniae with the same susceptibility profile. CONCLUSIONS This particular case reinforces the significance of potential complications of DM and SGLT2 inhibitors' adverse effects, especially the increased risk of infections, and can aid clinicians in expanding the differential and enabling them to reach an accurate diagnosis and appropriate management. Although vertebral osteomyelitis is a less common cause of back pain, physicians should keep it in the differential diagnosis whenever a patient's back pain is chronic and associated with motor weakness.

Destructive Cryptococcal Osteomyelitis Mimicking Tuberculous Spondylitis.

BACKGROUND Cryptococcosis is an opportunistic fungal infection that typically occurs in patients with compromised immune systems, primarily affecting the respiratory and central nervous systems. However, cryptococcal osteomyelitis is a rare manifestation of cryptococcal infection, characterized by nonspecific clinical features. Here, we present a case of vertebral cryptococcal osteomyelitis in a middle-aged woman and discuss diagnostic approaches. CASE REPORT A 56-year-old woman presented with lower back pain and limited mobility, without fever, and with a history of pulmonary tuberculosis. Physical examination revealed enlarged lymph nodes and tenderness in the thoracic vertebrae. A computed tomography-guided biopsy confirmed granulomatous inflammation caused by Cryptococcus, with abundant 10 µm spherical microbial spores. After 4 weeks of treatment with amphotericin B and fluconazole, symptoms and lesions improved. Upon discharge, the patient was prescribed oral fluconazole. Follow-up examinations showed a stable condition and a negative serum cryptococcal capsular polysaccharide antigen test. CONCLUSIONS Given the rarity and lack of specificity of clinical features of cryptococcal spondylitis, clinicians encountering similar presentations should consider tuberculous spondylitis and spinal tumors as differential diagnoses. Additionally, tissue biopsy of the affected vertebral bodies should be performed early to establish the type of vertebral infection, aiding in diagnosis, treatment, and prognosis.

Chronic recurrent multifocal osteomyelitis: Case report and review of the literature.

BACKGROUNDS: Chronic recurrent multifocal osteomyelitis (CRMO) is a rare inflammatory disease. OBJECTIVE: This report aims to analyze the clinical characteristics of CRMO and enhance clinicians' comprehension. We present 3 atypical cases, highlighting their unique clinical features, diagnostic challenges, and effective treatment strategies. METHODS: We retrieved 3 CRMO cases in our hospital from September 2019 to August 2022. The clinical features were analyzed retrospectively, and relevant literatures were reviewed. RESULTS: All 3 cases initially presented with bone pain, normal leucocyte counts, negative rheumatoid factors and no signs of sclerotic or hyperostotic lesions. Case 1, a 12-year-old girl, exhibited concurrent acne on the forehead and historic necrotizing lymphadenitis, a previously unreported association with CRMO. Case 2, a 14-year-old boy, tested positive for human leukocyte antigen-B27 and displayed scoliosis along with multifocal osteomyelitis. Case 3, a 9-year-old girl, presented with scoliosis, and chest computed tomography revealed changes in the T8 vertebral body, initially suggesting Langerhans cell histiocytosis. Bone biopsy was conducted in case 1 and case 3, revealing chronic inflammation. All 3 cases affected long bones, pelvis, and vertebra, involving 8, 6 and 5 bones, respectively, identified by magnetic resonance imaging. Genetic analysis was undertaken in cases 1 and 2 but no pathogenic mutations were identified. Upon the confirmation of a CRMO diagnosis, all patients were initiated on a treatment regimen comprising nonsteroidal anti-inflammatory drugs and tumor necrosis factor-α inhibitors. In cases 1 and 2, due to the severity of their bone pain, they were also administered to disease-modifying anti-rheumatic drugs, specifically methotrexate. All 3 patients achieved remission of bone pain. To gain a more comprehensive understanding of CRMO, we conducted a thorough review of relevant literature. CONCLUSION: CRMO is a rare autoinflammatory bone disorder with diverse clinical presentations and a lack of specific laboratory tests, which leads to potency to misdiagnosis or delayed diagnosis. By raising awareness and improving diagnostic criteria, physicians are now better equipped to identify CRMO. We contribute to share our understanding of CRMO by presenting 3 cases with untypical clinical features, highlighting the importance of recognizing this rare condition for timely and effective management.

Chronic Diffuse Sclerosing Osteomyelitis of the Mandible: The Use of Bisphosphonates as a Treatment for a Rare and Challenging Condition.

Chronic diffuse sclerosing osteomyelitis is a very rare condition, described as a non-suppurative, inflammatory disease of the bone and characterized by a proliferative endosteal reaction, which clinically reveals itself with cyclic pain of the jaw and swelling. We reported two clinical cases, where patients suffered recurrent swelling and pain at the mandible irradiating to the preauricular area, denying any previous trauma or significant medical history. Odontogenic causes were excluded. An initial treatment with antibiotics and NSAIDs temporarily relieved the symptoms without complete resolution, prompting further investigations. After a comprehensive array of diagnostic tools (X-rays, CT scans, scintigraphy, bone biopsy, serum markers), both patients were diagnosed with chronic diffuse sclerosing osteomyelitis of the mandible. Bisphosphonates (clodronate and zolendronate) with different treatment schemes were used to treat the condition, until a full recovery from symptoms was reported. Bisphosphonates could therefore represent an effective option in managing this rare but impactful condition. Further research is warranted to better understand the underlying mechanisms of the disease and to optimize treatment strategies.

[Therapeutic effect of calcaneal beak-like fracture secondary to calcaneal osteomyelitis caused by diabetic foot].

OBJECTIVE: To explore clinical effect of vancomycin calcium sulfate combined with internal fixation on calcaneal beak-like fracture secondary to calcaneal osteomyelitis caused by diabetic foot. METHODS: From April 2018 to October 2021, a retrospective analysis was performed on 5 patients with calcaneal bone osteomyelitis secondary to diabetic foot, including 2 males and 3 females, aged from 48 to 60 years old;diabetes course ranged from 5 to 13 years;the courses of diabetic foot disease ranged from 18 to 52 days;5 patients were grade Ⅲ according to Wagner classification. All patients were treated with debridement, vancomycin bone cement implantation, negative pressure aspiration at stageⅠ, vancomycin calcium sulfate and internal fixation at stageⅡfor calcaneal beak-like fracture. Surgical incision and fracture healing time were recorded, and the recurrence of osteomyelitis was observed. American Orthopedic Foot Andankle Society (AOFAS) score and exudation at 12 months after operation were evaluated. RESULTS: Five patients were successfully completed operation without lower extremity vascular occlusion, and were followed up for 16 to 36 months. The wound healing time after internal fixation ranged from 16 to 26 days, and healing time of fractures ranged from 16 to 27 weeks. AOFAS score ranged from 65 to 91 at 12 months after operation, and 2 patients got excellent result, 2 good and 1 fair. Among them, 1 patient with skin ulcer on the back of foot caused by scalding at 5 months after operation (non-complication), was recovered after treatment;the wound leakage complication occurred in 2 patients, and were recovered after dressing change. No osteomyelitis or fracture occurred in all patients. CONCLUSION: Vancomycin calcium sulfate with internal fixation in treating calcaneal osteomyelitis secondary to calcaneal osteomyelitis caused by diabetic foot could not only control infection, but also promote fracture healing, and obtain good clinical results.

Malassezia restricta as an unexpected cause of infectious osteomyelitis diagnosed by metagenomic sequencing: a case report and literature review.

BACKGROUND: Malassezia restricta, a lipophilic and lipodependent yeast belonging to the basidiomycetes group, is an opportunistic fungal pathogen associated with various skin diseases, including seborrheic dermatitis and dandruff. Typically, Malassezia infection in neonates manifests as fungemia or hematogenous dissemination to the bone or lungs. However, vertebral osteomyelitis caused by these fungi is rarely reported owing to non-specific clinical presentations and laboratory/imaging findings. The Pathogen Metagenomics Sequencing (PMseq) technique enables direct high-throughput sequencing of infected specimens, facilitating the rapid and accurate detection of all microorganisms in clinical samples through comprehensive reports. CASE PRESENTATION: A 52-year-old male was admitted to our hospital on July 20, 2022 with a 3-month history of ambulatory difficulties and localized low back pain. Magnetic Resonance Imaging (MRI) examination of the spinal column revealed irregular bone destruction affecting the L2, L3, and L5 vertebral bodies. Additionally, low T1 and high T2 intensity lesions were observed at the intervertebral discs between L3 and L5. The presumptive diagnosis of tuberculous spondylitis was made based on the imaging findings, despite negative results in all mycobacterium tests. However, the patient exhibited no improvement after receiving regular anti-tuberculosis treatment for 3 months. Subsequent MRI revealed an expansive abnormal signal within the vertebral body, leading to progressive bone destruction. The absence of spinal tuberculosis or other infective microorganisms was confirmed through culture from blood and pathological tissue from the L4 vertebral body. Subsequently, PMseq was performed on the specimens, revealing M. restricta as the predominant pathogen with the highest relative abundance value. The pathological examination revealed the presence of fungal mycelium in the L4 vertebral body, with positive findings on periodic Schiff-methenamine and periodic acid-Schiff staining. The anti-tuberculosis treatment was discontinued, and an antifungal combination of fluconazole and voriconazole was administered. All symptoms were resolved after 7 consecutive months of treatment, and the patient was able to ambulate autonomously. Vertebral lesions were reduced on MRI during the 13-month follow-up. CONCLUSIONS: M. restricta is not a commonly recognized pathogen associated with infectious vertebral osteomyelitis. However, PMseq can aid in diagnosis, timely treatment, and decision making for some non-specific infectious diseases.

P. aeruginosa infection of the ulna, a rare complication after arterial puncture.

Pseudomonas aeruginosa, a Gram-negative bacterium known to induce severe infections, is seldomly reported in scientific literature as a contributor of osteomyelitis. In this case report, a 71-year-old woman exhibited recurring infections and enduring forearm pain. A subsequent MRI revealed osteomyelitis in the distal ulna, linked to an arterial blood gas sample taken months earlier. Despite undergoing multiple extended courses of antibiotic treatment, the patient eventually underwent surgery on her left forearm. Biopsy cultures conclusively confirmed the presence of P. aeruginosa.

A Case Report of Brodie's Abscess of the Cuboid Treated by Anatomic Antibiotic-Cement Spacer.

Background: A case of chronic osteomyelitis with Brodie's abscess of the cuboid caused by a wooden foreign body penetrating the plantar foot. Total cuboidectomy was carried out with implantation of an anatomically molded antibiotic-impregnated cement spacer with culture-specific postoperative intravenous antibiotics. At six months of follow-up, the patient was completely asymptomatic without evidence of a recurrence of infection. Final radiographs also didn't show spacer migration or surrounding bone erosions. The spacer obviated the need for any foot fusion which preserved foot biomechanics. The patient didn't need to use any braces or insoles. Conclusion: Osteomyelitis should always be on the differential list of lytic lesions of the tarsal bones, especially if there is a history of prior foot trauma. In this case, cuboid excision and placement of an antibiotic-impregnated cement spacer provided sustained relief of symptoms without evidence of recurrence or complications for six months.Level of Evidence: V.

Naringin exerts antibacterial and anti-inflammatory effects on mice with Staphylococcus aureus-induced osteomyelitis.

Osteomyelitis is an invasive bone infection that can lead to severe pain and even disability, posing a challenge for orthopedic surgery. Naringin can reduce bone-related inflammatory conditions. This study aimed to elucidate the function and mechanism of naringin in a Staphylococcus aureus-induced mouse model of osteomyelitis. Femurs of S. aureus-infected mice were collected after naringin administration and subjected to microcomputed tomography to analyze cortical bone destruction and bone loss. Bacterial growth in femurs was also assessed. Proinflammatory cytokine levels in mouse femurs were measured using enzyme-linked immunosorbent assays. Pathological changes and bone resorption were analyzed using hematoxylin and eosin staining and tartrate-resistant acid phosphatase staining, respectively. Quantitative reverse transcription polymerase chain reaction and western blot analysis were used to quantify the messenger RNA and protein expression of osteogenic differentiation-associated genes in the femurs. The viability of human bone marrow-derived stem cells (hBMSCs) was determined using cell counting kit-8. Alizarin Red S staining and alkaline phosphatase staining were performed to assess the formation of mineralization nodules and bone formation in vitro. Notch signaling-related protein levels in femur tissues and hBMSCs were assessed using western blot analysis. Experimental results revealed that naringin alleviated S. aureus-induced cortical bone destruction and bone loss in mice by increasing the bone volume/total volume ratio. Naringin suppressed S. aureus-induced bacterial growth and inflammation in femurs. Moreover, it alleviated histopathological changes, inhibited bone resorption, and increased the expression of osteogenic markers in osteomyelitic mice. It increased the viability of hBMSCs and promoted their differentiation and bone mineralization in vitro. Furthermore, naringin activated Notch signaling by upregulating the protein levels of Notch1, Jagged1, and Hes1 in the femurs of model mice and S. aureus-stimulated hBMSCs. In conclusion, naringin reduces bacterial growth, inflammation, and bone resorption while upregulating the expression of osteogenic markers in S. aureus-infected mice and hBMSCs by activating Notch signaling.