Hot topics on vertebral osteomyelitis from the International Society of Antimicrobial Chemotherapy

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.

The importance of the bacterial spectrum in the clinical diagnostics and management of patients with spontaneous pyogenic spondylodiscitis and isolated spinal epidural empyema: a 20-year cohort study at a single spine center

BACKGROUND

Personalized clinical management of spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE) is challenging due to limited evidence of microbiologic findings and their clinical impact during the clinical course of the disease. We aimed to characterize clinico-microbiological and imaging phenotypes of SD and ISEE to provide useful insights that could improve outcomes and potentially modify guidelines.

METHODS

We performed chart review and collected data on the following parameters: bacterial antibiogram-resistogram, type of primary spinal infection, location of spinal infection, source of infection, method of detection, clinical complications (sepsis, septic embolism, and endocarditis), length of hospital and intensive care unit (ICU) stay, relapse rate, and disease-related mortality in patients with proven pyogenic SD and ISEE treated surgically in a university hospital in Germany between 2002 and 2022.

RESULTS

We included data from 187 patients (125 SD, 66.8% and 62 ISEE, 33.2%). Gram-positive bacteria (GPB) were overall more frequently detected than gram-negative bacteria (GNB) (GPB: 162, 86.6% vs. GNB: 25, 13.4%, p < 0.001). Infective endocarditis was caused only by GPB (GPB: 23, 16.5% vs. GNB: 0, 0.0%, p = 0.046). Methicillin-susceptible Staphylococcus aureus was the most frequently isolated strain (MSSA: n = 100, 53.5%), occurred more frequently in the cervical spine compared to other bacteria (OB) (MSSA: 41, 41.0% vs. OB: 18, 20.7%, p = 0.004) and was most frequently detected in patients with skin infection as the primary source of infection (MSSA: 26, 40.6% vs. OB: 11, 16.7%, p = 0.002). Streptococcus spp. and Enterococcus spp. (SE: n = 31, 16.6%) were more often regarded as the cause of endocarditis (SE: 8, 27.6% vs. OB: 15, 11.4%, p = 0.037) and were less frequently detected in intraoperative specimens (SE: 19, 61.3% vs. OB: 138, 88.5%, p < 0.001). Enterobacterales (E: n = 20, 10.7%) were identified more frequently in urinary tract infections (E: 9, 50.0% vs. OB: 4, 3.6%, p < 0.001). Coagulase-negative Staphylococci (CoNS: n = 20, 10.7%) were characterized by a lower prevalence of sepsis (CoNS: 4, 20.0% vs. OB: 90, 53.9%, p = 0.004) and were more frequently detected in intraoperative specimens (CoNS: 20, 100. 0% vs. OB: 137, 82.0%, p = 0.048). Moreover, CoNS-associated cases showed a shorter length of ICU stay (CoNS: 2 [1-18] days vs. OB: 6 [1-53] days, median [interquartile range], p = 0.037), and occurred more frequently due to foreign body-associated infections (CoNS: 8, 61.5% vs. OB: 15, 12.8%, p = 0.008). The presence of methicillin-resistant Staphylococcus aureus (MRSA) prolonged hospital stay by 56 [24-58] days and ICU stay by 16 [1-44] days, whereas patients with Pseudomonas aeruginosa spent only 20 [18-29] days in the hospital and no day in the ICU 0 [0-5] days.

CONCLUSIONS

Our retrospective cohort study identified distinct bacterial-specific manifestations in pyogenic SD and ISEE regarding clinical course, neuroanatomic targets, method of pathogen detection, and sources of infection. The clinico-microbiological patterns varied depending on the specific pathogens.

Efficacy of posterior fixation and bone graft fusion for treatment of lumbar brucellosis spondylitis

The purpose of this study is to verify whether early stage patients with single-segment lumbar Brucella spondylitis can still be cured through simple posterior fixation and bone grafting, even without debridement. A retrospective study was conducted on 63 patients diagnosed with single-segment lumbar brucellosis spondylitis, who underwent posterior-only debridement (or not), bone grafting, and instrumentation from June 2016 to June 2019. Group A comprised 34 patients who did not undergo debridement, while group B comprised 29 patients who underwent debridement. The clinical data and imaging results of the patients were compared between the 2 groups to evaluate the clinical effects of debridement or not. Both groups of patients completed at least 1 year of follow-up. The group A had significantly lower values for operation time, blood loss, and hospital stay compared to the group B (P < .05). There were no significant differences between the 2 groups in terms of erythrocyte sedimentation rate, C-reactive protein, visual analogue scores, improvement of Japanese Orthopaedic Association Evaluation of treatment score, and Cobb angle. The bone fusion rate was 92% (31 patients) in group A and 96% (28 patients) in group B, with no significant difference between the 2 groups (P > .05). In summary, these findings suggest that posterior fixation and bone graft fusion are effective treatments for single-segment lumbar brucellosis spondylitis in early stages even without debridement. Importantly, these procedures offer several benefits, such as minimal trauma, short operation times, rapid postoperative recovery, and favorable bone graft fusion outcomes.

Laboratory diagnostics for primary spinal infections in pediatric and adult populations: a narrative review

Primary spinal infection (PSI) is a generic term covering a heterogeneous group of infections that can affect the vertebral body, intervertebral disks, the content of the medullary cavity, and adjacent paraspinal tissues. Patients' characteristics can vary significantly, notably according to their age, and some of these characteristics undoubtedly play a primordial role in the occurrence of a PSI and in the type of offending pathogen. Before approaching the subject of laboratory diagnostics, it is essential to define the characteristics of the patient and their infection, which can then guide the physician toward specific diagnostic approaches. This review critically examined the roles and usefulness of traditional and modern laboratory diagnostics in supporting clinicians' decision-making in cases of pediatric and adult primary spinal infection (PSI). It appears impossible to compare PSIs in children and adults, whether from an epidemiological, clinical, bacteriological, or biological perspective. The recipients are really too different, and the responsible germs are closely correlated to their age. Secondly, the interpretation of traditional laboratory blood tests appears to contribute little guidance for clinicians attempting to diagnose a PSI. Biopsy or needle aspiration for bacterial identification remains a controversial subject, as the success rates of these procedures for identifying causative organisms are relatively uncertain in pediatric populations.Using nucleic acid amplification assays (NAAAs) on biopsy samples has been demonstrated to be more sensitive than conventional cultures for diagnosing PSI. Recent advances in next-generation sequencing (NGS) are particularly interesting for establishing a microbiological diagnosis of a PSI when standard cultures and NAAAs have failed to detect the culprit. We can even imagine that plasma metagenomic NGS using plasma (known as "liquid biopsy") is a diagnostic approach that can detect not only pathogens circulating in the bloodstream but also those causing focal infections, and thus eliminate the need for source sample collection using costly invasive surgical procedures.

Advances in diagnosis and management of atypical spinal infections: A comprehensive review

Atypical spinal infections (ASIs) of the spine are a challenging pathology to management with potentially devastating morbidity and mortality. To identify patients with atypical spinal infections, it is important to recognize the often insidious clinical and radiographic presentations, in the setting of indolent and smoldering organism growth. Trending of inflammatory markers, and culturing of organisms, is essential. Once identified, the spinal infection should be treated with antibiotics and possibly various surgical interventions including decompression and possible fusion depending on spine structural integrity and stability. Early diagnosis of ASIs and immediate treatment of debilitating conditions, such as epidural abscess, correlate with fewer neurological deficits and a shorter duration of medical treatment. There have been great advances in surgical interventions and spinal fusion techniques for patients with spinal infection. Overall, ASIs remain a perplexing pathology that could be successfully treated with early diagnosis and immediate, appropriate medical, and surgical management.

[Spondylodiscitis]

Spondylodiscitis is a severe infectious disease of the spine that affects the intervertebral discs and adjacent vertebrae. It can lead to nonspecific pain, limited mobility, and destruction of spinal structures. Various pathogens, such as bacteria, fungi, or parasites, can trigger the disease. An early diagnosis and targeted treatment are crucial to reduce the risk of serious complications. Magnetic resonance imaging (MRI) with contrast agent and blood tests are essential for the diagnosis and assessing the course of the disease. The treatment includes conservative and surgical approaches. Conservative treatment consists of a minimum 6‑week antibiotic course and immobilization of the affected area. Surgical interventions, along with several weeks of antibiotic therapy, are indicated for instabilities or complications in order to eliminate the infection focus and to restore spinal stability.

Cervical Spinal Epidural Abscess: Diagnosis, Treatment, and Outcomes: A Case Series and a Literature Review

Although recent diagnostic and management methods have improved the prognosis of cervical epidural abscesses, morbidity and mortality remain significant. The purpose of our study is to define the clinical presentation of cervical spinal epidural abscess, to determine the early clinical outcome of surgical treatment, and to identify the most effective diagnostic and treatment approaches. Additionally, we analyzed studies regarding cervical epidural abscesses and performed a review of the literature. In this study, four patients with spinal epidural abscess were included. There were three men and one woman with a mean age of 53 years. Three patients presented with motor deficits, and one patient was diagnosed incidentally through spinal imaging. All the patients had fever, and blood cultures were positive. Staphylococcus aureus was the most common organism cultured from abscesses. All patients underwent a surgical procedure, and three patients recovered their normal neurological functions, but one remained with mild neurological disability that was resolved two years postoperatively. The mean follow-up period was 12 months, and no deaths occurred in this series. Furthermore, we identified 85 studies in the literature review and extracted data regarding the diagnosis and management of these patients. The timely detection and effective management of this condition are essential for minimizing its associated morbidity and mortality.

Individualized Pharmaceutical Care for Antifungal Therapy in a Patient with Aspergillus tubingensis Spondylitis After Discontinuation of Rifampicin: A Case Report

Aspergillus tubingensis spondylitis (AS) is a rare spinal infectious disease with severe clinical symptoms and a challenging diagnosis. Treatment of AS is challenging due to its prolonged duration, substantial side effects, and complex drug-drug interactions. However, there is a lack of experience in individualized pharmaceutical care of AS by clinical pharmacists, especially in the presence of rifampicin, which has sustained liver enzyme induction after discontinuation. Our case described an immunocompetent patient infected with Aspergillus tubingensis spondylitis. Clinical pharmacists proposed an individualized treatment regimen for AS, after considering the effects of sustained liver enzyme induction of rifampicin (after discontinuation) on voriconazole, and utilized caspofungin as a bridge-connection scheme. We also paid attention to changes in indicators during treatment and managed adverse reactions. Therapeutic drug monitoring of voriconazole was also used to optimize the dosing regimen. With the individualized pharmaceutical care of clinical pharmacists and the efforts of clinicians, the patient's incision healed well after 33 days of hospitalization, and she was discharged with significant improvement. Therefore, individualized pharmaceutical care by a clinical pharmacist can help optimize the treatment of Aspergillus tubingensis spondylitis. In clinical practice, drug-drug and drug-diet interactions may affect voriconazole efficacy, and individualized dose adjustment using therapeutic drug monitoring (TDM) is critical to improve efficacy and reduce adverse reactions.

2022 SPILF - Clinical Practice guidelines for the diagnosis and treatment of disco-vertebral infection in adults

These guidelines are an update of those made in 2007 at the request of the French Society of Infectious Diseases (SPILF, Société de Pathologie Infectieuse de Langue Française). They are intended for use by all healthcare professionals caring for patients with disco-vertebral infection (DVI) on spine, whether native or instrumented. They include evidence and opinion-based recommendations for the diagnosis and management of patients with DVI. ESR, PCT and scintigraphy, antibiotic therapy without microorganism identification (except for emergency situations), therapy longer than 6 weeks if the DVI is not complicated, contraindication for spinal osteosynthesis in a septic context, and prolonged dorsal decubitus are no longer to be done in DVI management. MRI study must include exploration of the entire spine with at least 2 orthogonal planes for the affected level(s). Several disco-vertebral samples must be performed if blood cultures are negative. Short, adapted treatment and directly oral antibiotherapy or early switch from intravenous to oral antibiotherapy are recommended. Consultation of a spine specialist should be requested to evaluate spinal stability. Early lifting of patients is recommended.

Antibiotic Cement Utilization for the Prophylaxis and Treatment of Infections in Spine Surgery: Basic Science Principles and Rationale for Clinical Use

Antibiotic bone cement (ABC) is an effective tool for the prophylaxis and treatment of osteomyelitis due to the controlled, sustained release of local antibiotics. ABC has been proven to be effective in the orthopedic fields of arthroplasty and extremity trauma, but the adoption of ABC in spine surgery is limited. The characteristics of ABC make it an optimal solution for treating vertebral osteomyelitis (VO), a serious complication following spine surgery, typically caused by bacterial and sometimes fungal and parasitic pathogens. VO can be devastating, as infection can result in pathogenic biofilms on instrumentation that is dangerous to remove. New techniques, such as kyphoplasty and novel vertebroplasty methods, could amplify the potential of ABC in spine surgery. However, caution should be exercised when using ABC as there is some evidence of toxicity to patients and surgeons, antibiotic allergies, bone cement structural impairment, and possible development of antibiotic resistance. The purpose of this article is to describe the basic science of antibiotic cement utilization and review its usage in spine surgery.

Extensive retroperitoneal multiloculated abscesses after open cholecystectomy associated with bile leak: a case report

Retroperitoneal abscesses are rare and life-threatening. The incidence of abscesses after open cholecystectomies is <1% disregarding location. Eleven cases reporting post-cholecystectomy retroperitoneal abscesses were archived on PubMed, seven associated with gallstone retaining or spillage. Hereby, we present a case of extensive retroperitoneal multiloculated abscesses after open cholecystectomy complicated with bile leak, while no gallstone was noted. Early evaluation for retroperitoneal abscesses is critical if the patient does not clinically improve after cholecystectomy. Early treatment with drainage of the abscesses, antibiotics, and ERCP intervention to achieve source control can greatly improve the clinical outcome.

PMMA-Cement-PLIF Is Safe and Effective as a Single-Stage Posterior Procedure in Treating Pyogenic Erosive Lumbar Spondylodiscitis—A Single-Center Retrospective Study of 73 Cases

Background: Surgical treatment for erosive pyogenic spondylodiscitis of the lumbar spine is challenging as, following debridement of the intervertebral and bony abscess, a large and irregular defect is created. Sufficient defect reconstruction with conventional implants using a posterior approach is often impossible. Therefore, we developed the “Cement-PLIF”, a single-stage posterior lumbar procedure, combining posterior lumbar interbody fusion (PLIF) with defect-filling using antibiotic-loaded polymethylmethacrylate (PMMA). This study first describes and evaluates the procedure’s efficacy, safety, and infection eradication rate. Radiological implant stability, bone-regeneration, sagittal profile reconstruction, procedure-related complications, and pre-existing comorbidities were further analyzed. Methods: A retrospective cohort study analyzing 73 consecutive patients with a minimum of a one-year follow-up from 2000–2017. Patient-reported pain levels and improvement in infectious serological parameters evaluated the clinical outcome. Sagittal profile reconstruction, anterior bone-regeneration, and posterior fusion were analyzed in a.p. and lateral radiographs. A Kaplan–Meier analysis was used to determine the impact of pre-existing comorbidities on mortality. Pre-existing comorbidities were quantified using the Charlson-Comorbidity Index (CCI). Results: Mean follow-up was 3.3 (range: 1–16; ±3.2) years. There was no evidence of infection persistence in all patients at the one-year follow-up. One patient underwent revision surgery for early local infection recurrence (1.4%). Five (6.9%) patients required an early secondary intervention at the same level due to minor complications. Radiological follow-up revealed implant stability in 70/73 (95.9%) cases. Successful sagittal reconstruction was demonstrated in all patients (p < 0.001). There was a significant correlation between Kaplan–Meier survival and the number of pre-existing comorbidities (24-months-survival: CCI ≤ 3: 100%; CCI ≥ 3: 84.6%; p = 0.005). Conclusions: The Cement-PLIF procedure for pyogenic erosive spondylodiscitis is an effective and safe treatment as evaluated by infection elimination, clinical outcome, restoration, and maintenance of stability and sagittal alignment.

Osteomyelitis of the spine: treatments and future directions

BACKGROUND

Osteomyelitis of the spine is a serious condition that has been increasing with the intravenous drug pandemic and aging population. Multiple different organisms can cause osteomyelitis and mainstay of treatment is early recognition and antibiotics. The course can sometimes be indolent leading to delayed presentations. Once suspected, comprehensive workup and initiation of management should be employed. In rare circumstances, surgical evacuation or deformity correction is indicated. Continued antibiotic treatment should be considered post-operatively.

METHODS

Emerging treatment solutions are being developed to help target osteomyelitis in a more effective manner. In this review, we highlight the epidemiology and pathophysiology of spinal osteomyelitis. We overview the diagnostic workup and treatment options. Finally, we present new options that are currently being investigated and are on the near horizon.

CONCLUSION

This review offers a user friendly resource for clinicians and researchers regarding osteomyelitis of the spine and will serve as a catalyst for further discovery.

Lumbar infection caused by Mycobacterium paragordonae: A case report

BACKGROUND

Mycobacterium paragordonae (M. paragordonae), a slow-growing, acid-resistant mycobacterial species, was first isolated from the sputum of a lung infection patient in South Korea in 2014. Infections caused by M. paragordonae are rare.

CASE SUMMARY

Herein, we report the case of a 53-year-old patient who presented with fever and low back pain. Lumbar nuclear magnetic resonance imaging revealed the destruction of the lumbar vertebra with peripheral abscess formation. After anti-infective and diagnostic anti-tuberculosis treatment, the patient had no further fever, but the back pain was not relieved. Postoperatively, the necrotic material was sent for pathological examination, and all tests related to tuberculosis were negative, but pus culture suggested nontuberculous mycobacteria. The necrotic tissue specimens were subjected to metagenomic next-generation sequencing, which indicated the presence of M. paragordonae. Finally, the infecting pathogen was identified, and the treatment plan was adjusted. The patient was in good condition during the follow-up period.

CONCLUSION

M. paragordonae, a rare nontuberculous mycobacterium, can also cause spinal infections. In the clinic, it is necessary to identify nontuberculous mycobacteria for spinal infections similar to Mycobacterium tuberculosis.

Preclinical models of vertebral osteomyelitis and associated infections: Current models and recommendations for study design

Spine-related infections, such as vertebral osteomyelitis, discitis, or spondylitis, are rare diseases that mostly affect adults, and are usually of hematogenous origin. The incidence of this condition has gradually risen in recent years because of increases in spine-related surgery and hospital-acquired infections, an aging population, and intravenous (IV) drug use. Spine infections are most commonly caused by Staphylococcus aureus, while other systemic infections such as tuberculosis and brucellosis can also cause spondylitis. Various animal models of vertebral osteomyelitis and associated infections have been investigated in mouse, rat, chicken, rabbit, dog, and sheep models by hematogenous and direct inoculation in surgery, each with their strengths and limitations. This review is the first of its kind to concisely analyze the various existing animal models used to reproduce clinically relevant models of infection. Spine-related infection models must address the unique anatomy of the spine, the avascular nature of its structures and tissues and the consequences of tissue destruction such as spinal cord compression. Further investigation is necessary to elucidate the specific mechanisms of host-microbe response to inform antimicrobial therapy and administration techniques in a technically demanding body cavity. Small-animal models are not suitable for large instrumentation, and difficult IV access thwarts antibiotic administration. In contrast, large-animal models can be implanted with clinically relevant instrumentation and are resilient to repeat procedures to study postoperative infection. A canine model of infection offers a unique opportunity to design and investigate antimicrobial treatments through recruitment a rich population of canine patients, presenting with a natural disease that is suitable for randomized trials.

A Detailed Analysis of Clinical Features and Outcomes of Patients with Pyogenic Spondylodiscitis Presenting without Axial Back Pain

Study design: Retrospective analysis of a single institution prospective, longitudinal database of spinal pyogenic infections. Diagnosis of pyogenic spondylodiscitis (PS) can be challenging. Although presenting symptoms are often non-specific, acute non-remitting axial back pain is the most striking feature. Nevertheless, several authors have reported on the uncommon occurrence of patients with PS without axial back pain. The aim of this study was to characterize presenting symptoms, causative agents, comorbidities, and treatment outcomes of patients presenting with painless pyogenic spondylodiscitis. A total of 214 patients diagnosed with PS were reviewed; patients were divided into two groups: patients presenting with no axial back pain (no pain group, n = 16), and patients presenting with axial back pain (control group, n = 198). Analyzed data comprised general demographics, presenting symptoms, comorbidities, spinal infection location, and amount of spinal involvement. While average age (62.4 vs. 65.0) and sex distribution was similar between the two groups, a significant diagnostic delay was noted in the control group (53 vs. 17 days, p < 0.001). Patients in the no pain group were more likely IV drug abusers or have had liver failure/cirrhosis. Anatomic distribution (i.e., cervical vs thoracolumbar) of the infection did not differ between the two groups, but a higher number of post-surgical infections was noted in the no pain group (37.5 vs. 15.6%, p = 0.026). E. coli and Pseudomonas spp. were more commonly seen in no pain group patients, and mortality was also higher in this group (12.5 vs. 6.0%, p = 0.004).

Population pharmacokinetics and Monte Carlo simulation for dosage optimization of fosfomycin in the treatment of osteoarticular infections in patients without renal dysfunction

Background: Fosfomycin is gaining interest in the treatment of complex osteoarticular infections (OI) due to MDR pathogens.Objective: The aims were to conduct population pharmacokinetics of fosfomycin in a cohort of OI patients receiving 16g/daily by intermittent (II) or continuous infusion (CI), and to carry out Monte Carlo simulations for dosage optimization in the treatment of these infections.Methods: Patients underwent blood sampling on day 5 of therapy (2-3 serial samples). Population pharmacokinetics and Monte Carlo simulations were performed to define the probability of target attainment (PTA) of 70% T>MIC, and the cumulative fraction of response (CFR) against common OI pathogens with dosages of 8, 12, 16, and 20g/day administered by II, extended-infusion (EI) or CI.Results: Forty-eight patients were recruited. A two-compartment open model with infusion input and first-order elimination was developed. Estimated creatinine clearance (CL_CR) was included as covariate in the final model. Monte Carlo simulations showed that optimal PTAs and CFRs (≥90%) may be achieved in three different classes of renal function by administering a daily dosage of: 2g q6h by II against S. aureus, E. coli, ESBL-producing E. Coli and MRSA; 8g by CI against CoNS, K. pneumoniae and ESBL-producing K. pneumoniae; 12g by CI against P. aeruginosa, and 16g by CI against KPC-producing K. pneumoniae Conclusion: Our study provides a strong rationale for considering fosfomycin dosages of  8-16 g daily by CI in several clinical scenarios for OI patients. Feasibility of administration by CI in an elastomeric pump makes fosfomycin a candidate for OPAT programs.

Population pharmacokinetics of dalbavancin and dosing consideration for optimal treatment of adult patients with staphylococcal osteoarticular infections

Background: Dalbavancin is gaining interest in the treatment of complex osteoarticular (OA) infections.Objective: To conduct a population pharmacokinetic analysis of dalbavancin in a prospective cohort of adult patients with Gram-positive OA infections and to identify optimal dosing regimens for long term-treatment.Methods: Non-linear mixed-effects modelling was performed with Monolix. Monte Carlo simulations were performed with six dalbavancin regimens (1500mg at day 1; 1000mg at day 1 plus 500mg at day 8; 1500mg at day1 and 8; 1500mg at day1 and 8 plus 500, 1000 or 1500mg at day 36) to assess the PTA of three pharmacodynamic target of fAUC_24h/MIC against S. aureus (>27.1, 53.3 and 111.1). Cumulative fraction of response (CFR) was calculated against MIC distribution of both MRSA and MSSA as well. Desirable PTAs and CFRs were ≥90%.Results: Fifteen patients provided 120 plasma concentrations. Most (73.3%) had prosthetic joint infections. Clinical cure rate was 87%. A two-compartment model with linear elimination well described the data. No covariate was retained in the final model. Pharmacokinetic dalbavancin estimates were 0.106L/h for CL and 36.4L for V_ss The tested dosing regimens granted desirable CFRs against S. aureus at the most effective PK/PD target for a period ranging 3-to-9 weeks. Conclusion: Giving a two 1500mg dosing regimen of dalbavancin one week apart may ensure efficacy against both MSSA and MRSA up to 5 weeks in patients with OA infections. Clinical assessment at that time may allow for considering whether or not an additional dose should be administered for prolonging effective treatment.

Microbiologic Diagnosis of Pyogenic Spondylitis

Pyogenic spondylitis requires long-term antibiotics treatment and identification of the etiologic microorganism is essential. The first test in the microbiologic diagnosis of pyogenic spondylitis is a blood culture. Any microorganisms that grow in blood culture are highly likely to be the etiological microorganisms of pyogenic spondylitis. If the microbial etiology cannot be defined by the blood culture, a needle biopsy is performed on the inflamed tissues. Here, it is recommended that paraspinal tissues, rather than spinal tissues, are collected to increase the positive rate in tissue culture. If the microbial etiology cannot be defined by the first needle biopsy, another needle biopsy may be performed. The collected tissue sample is used in culture tests on bacteria and mycobacteria as well as pathological tests. If tuberculous spondylitis is suspected, polymerase chain reaction is carried out to detect Mycobacterium tuberculosis. In the case that the etiological microorganisms cannot be identified, the data of the patient regarding age, sex, vertebrae involved, history of spinal surgery or procedure, previous or concurrent urinary tract or intra-abdominal infection are analyzed. Based on this the most probable microbial etiology is determined to select the antibiotics to be used in the empiric treatment.

Efficacy of Daptomycin-Containing Regimen for Treatment of Staphylococcal or Enterococcal Vertebral Osteomyelitis: A Prospective Clinical Experience

Vertebral osteomyelitis (VO) is a compelling clinical entity for clinicians, because of its insidious and indolent course that makes diagnosis difficult. A concern is reported about the choice of antibiotic regimens, duration of therapy, and criteria to switch to oral therapy. We conducted a prospective observational study. All consecutive hospitalized patients with a confirmed diagnosis of VO caused by staphylococcal or enterococcal strains were analyzed. The primary endpoint was the analysis of clinical cure at the end of therapy. A propensity score for receiving therapy with daptomycin was added to the model. During the study period, 60 episodes of confirmed VO were observed. The main etiology of infection was methicillin-resistant Staphylococcus aureus (29%). Overall, clinical failure at end of therapy was reported in 11 (18.3%) patients. Logistic regression analysis, after propensity score, showed that >2 vertebrae involved (OR 2.4, CI95% 1.12–5.24, p = 0.002) and inadequate drainage of infection (OR 4.8, CI95% 2.45–8.51, p < 0.001) were independently associated with failure of therapy, while the use of a daptomycin-containing-regimen (OR 0.15, CI 95% 0.04–0.46, p < 0.001) with clinical cure. VO caused by staphylococcal or enterococcal strains is associated with an important rate of clinical failure. Daptomycin-containing regimen was strongly associated with clinical cure. Considering that over 70% of VO etiology is caused by Gram-positive strains but the etiology of infection is obtained in about 75% of cases, these data may help physicians to choose the appropriate antibiotic regimen.

Tuberculous and Brucellar Spondylodiscitis: Comparative Analysis of Clinical, Laboratory, and Radiological Features

Study Design

This was a retrospective study.

Purpose

The aim was to compare the clinical, laboratory, radiological, and evolutionary features of tuberculous spondylodiscitis (TS) and brucellar spondylodiscitis (BS).

Overview of Literature

Clinical presentation of spondylodiscitis varies according to the underlying etiology, among which brucellosis and tuberculosis represent the primary cause, in endemic countries. Only a few studies have compared the characteristics between TS and BS.

Methods

A retrospective study was conducted using the data of all patients hospitalized for TS and BS in the infectious diseases department between 1991 and 2018.

Results

Among a total of 117 patients, 73 had TS (62.4%) and 44 had BS (37.6%). Females were significantly more affected with TS than males (56.2% vs. 22.7%, p<0.001). Fever (72.7% vs. 45.2%, p=0.004) and sweating (72.7% vs. 47.9%, p=0.009) were significantly more frequent among patients with BS. The median erythrocyte sedimentation rate was significantly higher in the TS group (median, 70 mm/hr; interquartile range [IQR], 45–103 mm/hr) than in the BS group (median, 50 mm/hr; IQR, 16–75 mm/hr) (p=0.003). Thoracic involvement was significantly more frequent in the TS group (53.4% vs. 34.1%, p=0.04), whereas lumbar involvement was significantly more frequent in the BS group (72.7% vs. 49.3%, p=0.01). Initial imaging findings revealed significantly higher frequencies of posterior vertebral arch involvement, vertebral compaction, and spinal cord compression in the TS group. Percutaneous abscess drainage (20.5% vs. 2.3%, p=0.005) and surgical treatment (17.8% vs. 2.3%, p=0.01) were more frequently indicated in the TS group, with a significant difference.

Conclusions

A combination of clinical, laboratory, and radiological features can be used to distinguish between TS and BS while these patients await diagnosis confirmation.

Diagnosis and Treatment of Retroperitoneal Infection

Background: Retroperitoneal infection is a persistent and widespread infectious disease that is difficult to treat. It is usually caused by secondary complications such as inflammation, damage, or perforation of adjacent organs in the retroperitoneal space. Pathogenic bacteria invade the retroperitoneal space through retroperitoneal and interstitial organs, peripheral tissue, and the blood. As a result, infections mostly arise from severe acute pancreatitis, acute colonic diverticulitis, inflammatory bowel disease, kidney abscess, and biliary tract injury. Initially manifested by the presence of lumbago, this disease spreads easily, is persistent, and is often misdiagnosed. Methods: Review and synthesis of pertinent literature and guidelines pertaining to abdominal infection and retroperitoneal infection. Results: Recent data indicate that mortality rates associated with retroperitoneal infection have been increasing annually. Early diagnosis and treatment have been shown to improve the prognosis. In the early stage, infection is insidious and lacks typical symptoms, and is primarily diagnosed with computed tomography (CT). Strategies that control the source of infection, rational use of antibiotic agents, and nutritional interventions are the primary approaches to treat the infections. Emergence of minimally invasive drainage technologies, including the ultrasound/CT-guided puncture and drainage, percutaneous nephroscope puncture and drainage, and drainage using a catheter through an abdominal puncture device (trocar) have shortened the treatment cycle and disease burden. However, current diagnosis and treatment for retroperitoneal infection are not sufficiently effective because some patients do not show typical clinical manifestations. Moreover, sensitivity and specificity of available auxiliary examination methods are not supported by sufficient evidence-based medical research. Additionally, there are no uniform standards on the timing of surgical intervention and treatment options. Therefore, we summarized the progresses on current diagnosis and treatment approaches for retroperitoneal infection.

Aspergillus spondylitis: case series and literature review

BACKGROUND

Spinal fungal infections, especially spinal Aspergillus infections, are rare in the clinic. Here, we introduce the clinical features, diagnosis, treatment, and prognoses of 6 cases of Aspergillus spondylitis.

METHODS

We retrospectively analysed the complete clinical data of patients with Aspergillus spondylitis treated in our hospital from January 2013 to January 2020.

RESULTS

Aspergillus fumigatus was isolated in 4 cases, and Aspergillus spp. and Aspergillus niger were isolated in 1 case each. All six patients reported varying degrees of focal spinal pain; one patient reported radiating pain, one patient experienced bowel dysfunction and numbness in both lower limbs, and three patients had fever symptoms. One case involved the thoracic spine, one case involved the thoracolumbar junction, and 4 cases involved the lumbar spine. Three patients were already in an immunosuppressed state, and three patients entered an immunosuppressed state after spinal surgery. All six patients were successfully cured, and five required surgery. Of the 5 patients who underwent surgical treatment, 2 had spinal cord compression symptoms, and 3 had spinal instability. At the end of follow-up, 1 patient reported left back pain and 1 patient reported left limb numbness.

CONCLUSION

The clinical manifestations of Aspergillus spondylitis are non-specific, and the diagnosis depends on typical imaging findings and microbiological and histopathological examination results. When there is no spinal instability, spinal nerve compression symptoms, or progressive deterioration, antifungal therapy alone may be considered. If spinal instability, spinal nerve compression, or epidural abscess formation is present, surgery combined with antifungal therapy is recommended.

Spinal Infections: An Update

Spinal infection poses a demanding diagnostic and treatment problem for which a multidisciplinary approach with spine surgeons, radiologists, and infectious disease specialists is required. Infections are usually caused by bacterial microorganisms, although fungal infections can also occur. The most common route for spinal infection is through hematogenous spread of the microorganism from a distant infected area. Most patients with spinal infections diagnosed in early stages can be successfully managed conservatively with antibiotics, bed rest, and spinal braces. In cases of gross or pending instability, progressive neurological deficits, failure of conservative treatment, spinal abscess formation, severe symptoms indicating sepsis, and failure of previous conservative treatment, surgical treatment is required. In either case, close monitoring of the patients with spinal infection with serial neurological examinations and imaging studies is necessary.