Clinical characteristics and outcomes of hematogenous vertebral osteomyelitis caused by gram-negative bacteria

Infective Spondylitis in Adults: A Journey Through Diagnosis, Management, and Future Directions

Infective spondylitis is a rare but potentially devastating spinal infection that requires timely diagnosis and appropriate treatment to prevent severe complications, including neurological deficits and spinal deformity. Despite advancements in diagnostic imaging, microbiological techniques, and antimicrobial therapies, clinical challenges persist because of the disease's insidious onset, varied etiologies, and increasing antimicrobial resistance. This review article provides a comprehensive analysis of the current literature on the epidemiology, pathophysiology, diagnostic approaches, and treatment strategies for infective spondylitis.

Gram-negative rods are associated with prolonged treatment in patients with thoracolumbar pyogenic spondylitis after minimally invasive posterior fixation compared with gram-positive cocci: a multicenter retrospective cohort study

BACKGROUND

This study compared patient characteristics, clinical outcomes, and antibiotic durations between patients undergoing posterior fixation for gram-negative rods (GNR) or gram-positive cocci (GPC) thoracolumbar pyogenic spondylitis.

METHODS

In this multicenter retrospective cohort study, 53 patients who underwent minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis were categorized into a GPC or GNR group based on the identified causative organisms. Patient characteristics, surgical outcomes, and postoperative infection control were compared between the two groups to identify factors affecting antibiotic duration.

RESULTS

The patients in the GNR group (n = 14) were older (77.2 years versus 70.1 years; p = 0.008), had a higher incidence of a history of abdominal-pelvic infections (4 versus 0; p = 0.003), required longer preoperative antibiotics (5.9 weeks versus 3.0 weeks; p = 0.035), and had more unplanned additional surgeries due to poor infection control (n = 4 versus n = 1; p = 0.014) than those in the GPC group (n = 39). Furthermore, GNR infection independently predicted longer preoperative antibiotic duration (p = 0.002, β = 0.43).

CONCLUSIONS

Pyogenic spondylitis with GNR is associated with the need for prolonged antibiotic treatment and higher rates of unplanned additional surgeries due to poor infection control as compared to GPC-associated pyogenic spondylitis. Older age and a history of abdominal-pelvic infections tend to complicate the management in these patients; therefore, tailored treatment strategies are required to optimize treatment duration and minimize complications.

CLINICAL TRIAL NUMBER

Not applicable.

Clinical Characteristics of 96 Patients Presenting With Hematogenous Spinal Osteomyelitis- a Retrospective Study

OBJECTIVE

To report clinical characteristics and course of care for patients diagnosed with hematogenous spinal osteomyelitis (HVO).

METHODS

Medical records of patients presenting to two tertiary care centers with HVO were reviewed.

RESULTS

96 consecutive patients with HVO were identified. Mean follow-up was 8.9 months. Most infections occurred in the lumbar region (50.0%). Of the cultures taken, MRSA accounted for 9%; MSSA, 26%; Streptococcus species, 12%; other gram-positive bacteria, 23%; gram-negative, 17%; fungal, 2.6%; and 11.5% of cultures returned no growth. 57 patients underwent surgery. Of these, 79% of the patients had undergone a trial of empiric antibiotics (cefepime and vancomycin) of the day prior to surgery. 44% underwent secondary surgeries, typically due to a heavy wound burden of necrotic tissue and pus. Postoperative antibiotics were prescribed to all patients. 51.6% of the patients were prescribed antibiotic therapy >6 months. Overall mortality rate was 3.8%. Major cause of all deaths was septic shock. Post-infection sequelae occurred in 47.4% of patients. The most common sequelae were persistent or new sites of infection, sepsis, and abscess.

CONCLUSIONS

Diabetes, hypertension, and renal failure appear to increase the risk of post-infection sequelae and death. While non-operative management was attempted in nearly 47%, ultimately 73% had surgery. This high rate may reflect our population of patients hospitalized in a tertiary care center. Available data suggests that patients presenting with hematogenous osteomyelitis be followed closely as failure of non-operative management, and resulting morbidity, was high.

Efficacy of Additional Surgical Decompression on Functional Outcome in Pyogenic Spinal Epidural Abscess With No Neurological Deficit

Objective

The aim of this study was to investigate the efficacy of additional surgical decompression with antibiotics to treat pyogenic spinal epidural abscess (SEA) with no neurological deficits.

Methods

We retrospectively reviewed the data of patients diagnosed with spontaneous pyogenic SEA in the thoracolumbosacral area who presented with sciatica and no motor deficits in the lower extremities. The treatment took place in a single tertiary hospital. The effects of additional surgical decompression (decompressive laminectomy) and other clinical variables on functional outcome were assessed using the short form 36 (SF-36).

Results

Fifty-nine patients (49 men and 10 women, mean age 65.73±12.29 [41-89] years) were included in the analysis. Surgical decompression had been performed in 31 patients (Group S, treated with additional surgical decompression and antibiotics). There were five (15.2%, 5/33) unplanned operations to control leg sciatica among the patients with initially non-surgical plans, and 28 patients were finally treated with only antibiotics (group N-S). Group S showed a statistically significant increased cost of hospitalization compared to group N-S (15,856.37±7,952.83 vs. 10,672.62±4,654.17 US dollars, p=0.004) with no superiority of 6-month functional outcome after the completion of antibiotic treatment (53.65±4.74 vs. 51.75±7.96 SF-36 scores, p=0.266).

Conclusion

Although there is a possibility of requiring an unplanned operation to control leg sciatica during conservative antibiotic treatment, overall, additional surgical decompression in pyogenic SEA presenting with no motor deficit of the lower extremity showed increased medical burden and no greater benefit in terms of functional outcomes.

Microbes Causing Spinal Epidural Infection in Patients Who Use Drugs

Background

The incidence of spine infections has increased due to the surge in injection drug use driven by the opioid epidemic. Few recent studies have evaluated the microbiology of spinal epidural infections among people who inject drugs compared to the microbiology of such infections among the general population.

Methods

We performed a retrospective chart review to identify patients with a spinal epidural abscess or phlegmon unrelated to recent spine surgery between 2015 and 2023.

Results

Of 346 initial records, 277 met inclusion criteria for demographic analyses. Of the 229 patients with microbiologic results, details regarding possible drug use were available in 227 patients. Patients with no documented history of drug use were categorized as non-PWUD, while patients who use drugs (PWUD) were separated based on whether drug use was active or not. Patients with prior histories of injection or noninjection drug use were categorized as nonactive PWUD, while those with injection or snorting drug use reported in the past 3 months were categorized as active PWUD. Thirty-nine percent of patients with spinal epidural infection had substance use disorder. Most patients with monomicrobial cultures were infected with gram-positive, aerobic bacteria (86%). Active PWUD were more likely to have methicillin-resistant Staphylococcus aureus compared to non-PWUD (36% vs 13%, respectively, P = .002). Nonactive PWUD were more likely to have non-Escherichia coli gram-negative bacterial infections than non-PWUD (18% and 4.4%, respectively, P = .01).

Conclusions

More than 1 in 3 patients with a spinal epidural infection unrelated to recent surgery had substance use disorder. These patients are more likely to have infections due to MRSA and gram-negative bacteria other than E coli such as Serratia marcescens.

Spinal infection: Assessing comorbidities and costs to inform patient management and resource use strategies

Background

Spinal Infection (SI) is associated with various comorbidities. The interaction of these comorbidities and their impact on costs and complexity of care has not been fully assessed.

Methods

This is a retrospective cohort study of SI patients in an urban hospital system to characterize comorbidities and outcomes in adult patients with SI. Adult patients in our hospital system who were hospitalized with an initial diagnosis of SI between July 1, 2017 and June 30, 2019 were included. Outcomes measures included length of stay (LOS) of the index hospitalization for SI, charges and payments for the index hospitalization, and hospital readmissions within one year after discharge from the index hospitalization. Data was obtained by querying our Electronic Data Warehouse (EDW) using ICD-10-CM and CPT procedure codes. Spearman's correlation was used to summarize the relationships between LOS, charges, and payments. Multivariable linear regression was used to evaluate associations of demographics, comorbidities, and other factors with LOS. Multivariable Cox regression was used to evaluate associations of demographics, comorbidities, and other factors with hospital readmissions.

Results

403 patients with a first diagnosis of SI were identified. The average number of comorbidities per patient was 1.3. 294 (73%) had at least 1 medical comorbidity, and 54 (13%) had 3 or more comorbidities. The most common medical comorbidities were diabetes mellitus (26%), intravenous drug use (IVDU, 26%), and malnutrition (20%). 112 patients (28%) had a surgical site infection (SSI). DM (p<.001) and SSI (p=.016) were more common among older patients while IVDU was more common among younger patients (p<.001). Median LOS was 12 days. A larger number of medical comorbidities was associated with a longer LOS (p<.001) while the presence of a SSI was associated with a shorter LOS (p=.007) after multivariable adjustment. LOS was positively correlated with both charges (r=0.83) and payments (r=0.61). Among 389 patients discharged after the index hospitalization, 36% had a readmission within 1 year. The rate of readmission was twice as high for patients with three or more comorbidities than patients with zero comorbidities (hazard ratio: 1.95, p=.017).

Conclusions

Patients with SI often have multiple comorbidities, and the specific type of comorbidity is associated with the patient's age. The presence of multiple comorbidities correlates with initial LOS, cost of care, and readmission rate. Readmission in the first year post-discharge is high.

A retrospective review of gram-negative spinal infections in a single tertiary spinal centre over six years

Aims

Gram-negative infections are associated with comorbid patients, but outcomes are less well understood. This study reviewed diagnosis, management, and treatment for a cohort treated in a tertiary spinal centre.

Methods

A retrospective review was performed of all gram-negative spinal infections (n = 32; median age 71 years; interquartile range 60 to 78), excluding surgical site infections, at a single centre between 2015 to 2020 with two- to six-year follow-up. Information regarding organism identification, antibiotic regime, and treatment outcomes (including clinical, radiological, and biochemical) were collected from clinical notes.

Results

All patients had comorbidities and/or non-spinal procedures within the previous year. Most infections affected lumbar segments (20/32), with Escherichia coli the commonest organism (17/32). Causative organisms were identified by blood culture (23/32), biopsy/aspiration (7/32), or intraoperative samples (2/32). There were 56 different antibiotic regimes, with oral (PO) ciprofloxacin being the most prevalent (13/56; 17.6%). Multilevel, contiguous infections were common (8/32; 25%), usually resulting in bone destruction and collapse. Epidural collections were seen in 13/32 (40.6%). In total, five patients required surgery, three for neurological deterioration. Overall, 24 patients improved or recovered with a mean halving of CRP at 8.5 days (SD 6). At the time of review (two to six years post-diagnosis), 16 patients (50%) were deceased.

Conclusion

This is the largest published cohort of gram-negative spinal infections. In older patients with comorbidities and/or previous interventions in the last year, a high level of suspicion must be given to gram-negative infection with blood cultures and biopsy essential. Early organism identification permits targeted treatment and good initial clinical outcomes; however, mortality is 50% in this cohort at a mean of 4.2 years (2 to 6) after diagnosis.

Advanced Neck Dermatillomania Leading to Cervical Osteomyelitis and Epidural Abscess

Dermatillomania, a condition characterized by compulsive skin picking, can lead to tissue damage and severe infections of adjacent structures. This case report presents the first documented instance of dermatillomania-induced cervical osteomyelitis and epidural abscess. Herein, we describe the case of a 45-year-old male patient with a history of a non-healing posterior neck wound, which progressively worsened and extended to the posterior cervical spine. The patient subsequently experienced weakness and paresthesia in the left arm. Neuroimaging revealed cervical spine osteomyelitis and an associated epidural collection/phlegmon compressing the spinal cord. The abscess was evacuated via posterior laminectomy, followed by culture-guided antibiotic therapy. The presence of a chronic wound or ulcer in the setting of psychiatric comorbidities should raise suspicion of dermatillomania-induced complications. Early diagnosis is essential to guide management and prevent serious complications. Management involves a multidisciplinary approach that includes addressing behavioral abnormalities and concurrent psychiatric disorders.

Preoperative Risk Factors Affecting Outcome in Surgically Treated Pyogenic Spondylodiscitis

STUDY DESIGN

Retrospective study.

OBJECTIVE

The primary aim of this study was to investigate the predictors of severe complications in patients following surgery for pyogenic spondylodiscitis (PS) using a surgeon-maintained database. The secondary aim was to investigate the predictors of early recovery.

METHODS

We introduced a surgeon-maintained database of prospectively collected multicenter data that mainly focused on perioperative complications in 2012. Our surgeon-maintained database allows the retrospective collection of detailed data. We analyzed 143 patients who underwent surgery for PS from the 19,056 patients in the prospective surgeon-maintained database at 27 affiliated institutions between 2013 and 2017. Data relating to preoperative patient factors, infection factors, surgical factors, and pre- and postoperative blood tests was retrospectively collected. We performed multivariate regression analysis to evaluate the predictors of postoperative severe complications and early recovery in patients with PS.

RESULTS

High updated Charlson comorbidity index (uCCI), chronic pulmonary disease, diabetes, Gram-negative bacteria, pyogenic osteoarthritis, high preoperative white blood cell count, and low preoperative platelet count were significantly associated with severe complications in patients undergoing surgery for PS. A high uCCI was the sole independent negative predictor on early recovery.

CONCLUSION

Careful perioperative management is necessary if surgery is performed on patients who are at a high risk of life-threatening events.

Carbapenem-Resistant Pseudomonas aeruginosa Spondylodiscitis Treated with Ceftazidime-Avibactam: A Case Report with Literature Review

Pyogenic spondylodiscitis (PS) is a highly morbid and potentially fatal bacterial infection with an increasing incidence in recent decades. Its diagnosis and treatment are challenging, especially with the expansion of multidrug- or extensively drug-resistant bacteria. We report a rare case of PS caused by carbapenem-resistant Pseudomonas aeruginosa (CRPA) that was treated with ceftazidime-avibactam (C/A). The choice of C/A therapy was based on the patient's bacterial sensitivity profile and intolerance to the initial therapeutic regimen (polymyxin B and meropenem). The total antimicrobial treatment time was seven weeks. The evolution of the clinical course met the cure criteria, which was characterized by remission of signs and symptoms, normalization of inflammatory markers, and radiological improvement over 18 months of clinical follow-up. This is a rare case of CRPA spondylodiscitis that responded to C/A treatment.

Pyogenic spondylitis caused by Escherichia coli: A case report and literature review

BACKGROUND

Pyogenic spondylitis is often manifested as atypical low back pain and fever, which makes it easy to be confused with other diseases. Here we report a case of pyogenic spondylitis and describe the diagnosis and treatment based on the related literature.

CASE SUMMARY

The reported case suffered from pyogenic spondylitis caused by Escherichia coli and complicated with bacteremia and psoas abscess. Acute pyelonephritis was initially diagnosed due to atypical symptoms. Symptoms were improved from antibiotic treatment while developing progressive lower limb dysfunction. One month post the admission, the patient underwent anterior lumbar debridement + autogenous iliac bone graft fusion + posterior percutaneous screw-rod internal fixation, and received 6 wk of antibiotic treatment after the operation. Reexamination 4 mo post the operation showed that the patient had no evident pain in the waist, and walked well with no evident dysfunction of lower limbs.

CONCLUSION

Here we describe the application value of several imaging examinations, such as X-ray, computed tomography and magnetic resonance imaging, and certain tests like erythrocyte sedimentation rate and C-reactive protein in the clinical treatment of pyogenic spondylitis. This disease requires early diagnosis and treatment. Sensitive antibiotics should be used in early stages and surgical intervention should be taken if necessary, which may help for a speedy recovery and prevent the occurrence of severe complications.

Postoperative prolonged mechanical ventilation in patients with surgically treated pyogenic spondylodiscitis: a surrogate endpoint for early postoperative mortality

Surgical procedures with spinal instrumentation constitute a prevalent and occasionally highly indicated treatment modality in patients with pyogenic spondylodiscitis (PSD). However, surgical therapy might be associated with the need of prolonged postoperative intensive care medicine which in turn might impair intended operative benefit. Therefore, we analyzed prolonged mechanical ventilation (PMV) as an indicator variable for such intensive care treatment with regard to potential correlations with mortality in this vulnerable patient cohort. Between 2012 and 2018, 177 consecutive patients received stabilization surgery for PSD at the authors' neurosurgical department. PMV was defined as postoperative mechanical ventilation of more than 24 h. A multivariable analysis was performed to identify independent predictors for 30-day mortality. Twenty-three out of 177 patients (13%) with PSD suffered from postoperative PMV. Thirty-day mortality rate was 5%. Multivariable analysis identified "spinal empyema" (p = 0.02, odds ratio (OR) 6.2, 95% confidence interval (CI) 1.3-30.2), "Charlson comorbidity index (CCI) > 2" (p = 0.04, OR 4.0, 95% CI 1.0-15.5), "early postoperative complications (PSIs)" (p = 0.001, OR 17.1, 95% CI 3.1-96.0) and "PMV > 24 hrs" (p = 0.002, OR 13.0, 95% CI 2.7-63.8) as significant and independent predictors for early postoperative mortality. The present study indicates PMV to significantly correlate to elevated early postoperative mortality rates following stabilization surgery for PSD. These results might entail further scientific efforts to investigate PMV as a so far underestimated negative prognostic factor in the surgical treatment of PSD.

Effectiveness of oral cephalexin in antibiotic-course completion for methicillin-susceptible Staphylococcus aureus-induced bacteremic vertebral osteomyelitis

BACKGROUND

Methicillin-susceptible Staphylococcus aureus (MSSA) is the most common causative microorganism of pyogenic vertebral osteomyelitis (PVO). Although oral antimicrobial therapy with first-generation cephalosporins can treat MSSA infection, data on PVO are scarce. This study evaluated the treatment efficacy of cephalexin as oral antibiotic therapy for MSSA-induced PVO.

METHODS

This retrospective study included adult patients treated with oral cephalexin as the completing treatment for PVO with MSSA bacteremia from 2012 to 2020. Treatment effectiveness of cephalexin was evaluated by comparing improvement (5-point scale; score ≥ 4/5 indicates treatment success) in symptoms and laboratory and imaging results between intravenous antimicrobial and oral cephalexin treatment.

RESULTS

Among 15 participants (8 [53%] women; median [interquartile range, IQR], age 75 [67.5-80.5] years; Charlson Comorbidity Index 2 [0-4]), 10 (67%) had lumbar spine lesions, 12 (80%) had spinal abscesses, and 4 (27%) had remote abscesses; no patients had concomitant endocarditis. In 11 patients with normal renal function, cephalexin 1,500-2,000 mg/day was administered. Five patients (33%) underwent surgery. Median (IQR; range) duration (days) of intravenous antibiotics, cephalexin, and total treatment was 36 (32-61; 21-86), 29 (19-82; 8-251), and 86 (59-125; 37-337), respectively. Cephalexin had an 87% treatment success rate without recurrence during a median follow-up of 119 (IQR, 48.5-350) days.

CONCLUSIONS

In patients with MSSA bacteremia and PVO, antibiotic treatment completion with cephalexin is a reasonable option, even in cases with spinal abscess, if at least 3 weeks of effective intravenous antimicrobial therapy is provided.

Analysis of Clinical Factors Associated with Medical Burden and Functional Status in Pyogenic Spine Infection

Background and purpose: Pyogenic spinal infection (PSI) has recently been on the rise due to aging and increasing degenerative spinal disease related procedures. PSI requires long-term antibiotic treatment and is followed by sustained functional disability even after successful treatment. This study aimed to analyze the clinical factors associated with medical burden and functional status of PSI. Methods: This retrospective study involved patients with non-postoperative PSI of thoraco-lumbo-sacral area in a single tertiary hospital. The length/cost of hospitalization with an antibiotic therapy and severity of back pain using the short form 36 (SF-36) were defined as the medical burden and functional status, respectively. We analyzed the clinical factors associated with medical burden and functional status. Results: We enrolled 142 patients (91 males and 51 females). The length and cost of hospitalization were 55.56 ± 27.09 (7–172) days and $14,070.17 ± 9289.39 (1611.87–48,722.35), respectively. A recurrence rate of 7.7% (11/142) and significant improvement of SF-36 at six months after completion of antibiotic treatment were noted (p < 0.05). Procedure-related (OR 2.702), C-reactive protein (CRP; OR 1.062), bacteremia (OR 4.966), additional surgical treatment (OR 6.524), recurrence (OR 12.453), and paraspinal abscess (OR 5.965) for above-average length of hospitalization were observed; female (OR 4.438), CRP (OR 1.071), bacteremia (OR 4.647), additional surgical treatment (OR 6.737), recurrence (OR 22.543), and extent of lesion (OR 1.431) for above-average cost of hospitalization; leg weakness (OR 15.966), white blood cell (WBC; OR 1.116), Charlson’s comorbidity index (CCI, OR 1.485), and identification of causative bacteria (OR 2.913) for below-average initial SF-36 were observed; leg weakness (OR 7.975) and WBC (OR 1.094) for below-average 6-month SF-36 were the statistically significant clinical factors in the multivariable logistic regression analysis (p < 0.05). Conclusion: Recurrence and leg weakness were identified as the most important clinical factors for medical burden and functional status in PSI, respectively. We think that it is necessary to actively suppress recurrence and manage neurological deficits for decreasing medical burden and achieving favorable functional outcome in the treatment of PSI.

Enrichment of Bone Tissue with Antibacterially Effective Amounts of Nitric Oxide Derivatives by Treatment with Dielectric Barrier Discharge Plasmas Optimized for Nitrogen Oxide Chemistry

Cold atmospheric plasmas (CAPs) generated by dielectric barrier discharge (DBD), particularly those containing higher amounts of nitric oxide (NO) or NO derivates (NOD), are attracting increasing interest in medical fields. In the present study, we, for the first time, evaluated DBD-CAP-induced NOD accumulation and therapeutically relevant NO release in calcified bone tissue. This knowledge is of great importance for the development of new therapies against bacterial-infectious complications during bone healing, such as osteitis or osteomyelitis. We found that by modulating the power dissipation in the discharge, it is possible (1) to significantly increase the uptake of NODs in bone tissue, even into deeper regions, (2) to significantly decrease the pH in CAP-exposed bone tissue, (3) to induce a long-lasting and modulable NO production in the bone samples as well as (4) to significantly protect the treated bone tissue against bacterial contaminations, and to induce a strong bactericidal effect in bacterially infected bone samples. Our results strongly suggest that the current DBD technology opens up effective NO-based therapy options in the treatment of local bacterial infections of the bone tissue through the possibility of a targeted modulation of the NOD content in the generated CAPs.

Pyogenic spondylitis caused by Klebsiella pneumoniae: should the possibility of hypervirulent Klebsiella pneumoniae be considered?

Background

Klebsiella pneumoniae is rare but the second most common causative agent among gram-negative bacteria that cause pyogenic spondylitis. However, there are no available studies on the serotype, virulence factors, and clinical characteristics associated with K. pneumoniae-caused pyogenic spondylitis. Accordingly, we investigated the clinical characteristics of pyogenic spondylitis, K1 and K2 serotypes, and virulence factors of K. pneumoniae.

Methods

We reviewed the microbiological reports of specimens collected between January 2014 and December 2019 as well as the medical records of patients with pyogenic spondylitis caused by K. pneumoniae. We also evaluated K1 and K2 serotypes and the virulent genes rmpA, iutA, mrkD, ybtS, entB, and kfu. Strains that possessed rmpA and iutA were defined as hypervirulent K. pneumoniae.

Results

Six patients with pyogenic spondylitis caused by K. pneumoniae were enrolled in the study. The capsular serotypes K1 and K2 were present in 66.7% (4/6) of cases, and the hypervirulent strains were present in 88.3% (5/6) of cases. All patients had community-acquired infections, and all strains isolated were susceptible to antimicrobial agents. Intravenous antibiotic treatment continued for 2–7 weeks, and no patient underwent decompressive operation or surgical debridement. There was no recurrence. One patient died from pneumonia with a septic lung.

Conclusion

Hypervirulent K. pneumoniae is a rare but possible causative agent associated with pyogenic spondylitis.

Treatment Failure in Vertebral Osteomyelitis: Is it All About Staphylococcus aureus ?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim was to compare the influence of 2 common vertebral osteomyelitis (VO) causing pathogens on treatment failure within the first year of diagnosis.

SUMMARY OF BACKGROUND DATA

VO is mainly caused by Staphylococcus aureus (SA), while enterococci and streptococci (ENST) are also responsible for a significant proportion of VO, particularly in elderly patients. Data on VO caused by SA show a tendency for worse outcome, whereas data on VO caused by ENST are scarce. For this purpose, our study compares characteristics of patients with VO caused by SA or ENST in order to analyze risk factors for treatment failure.

METHODS

We conducted a retrospective monocentric study including VO patients from 2008 to 2020. Primary outcome was treatment failure defined as death or relapse within 1 year (T1). We compared patients diagnosed with VO caused by Staphylococcus aureus including MRSA to patients diagnosed with VO caused by Enterococcus and Streptococcus species, which were combined into one group. Polymicrobial infections were excluded. We employed multiple logistic regression analysis to adjust for confounding. To account for moderation, the model was repeated with an included interaction term.

RESULTS

Data of 130 VO patients (SA=95; ENST=35) were available at T1. Treatment failure occurred in 37% of SA patients and 23% of ENST patients. On multivariate analysis SA [odds ratio (OR): 3.12; 95% confidence interval (CI): 1.09-10.53; P =0.046], Charlson comorbidity index (OR: 1.31; 95% CI: 1.11-1.58; P =0.002) and infectious endocarditis (IE; OR: 4.29; 95% CI: 1.23-15.96; P =0.024) were identified as independent risk factors for treatment failure.

CONCLUSION

In our cohort every third patient with VO caused by SA or ENST dies within 1 year. Our findings indicate that patients with VO caused by SA, concomitant IE and/or a high Charlson comorbidity index score may be at elevated risk for treatment failure. These findings can be used to individualize patient care and to direct clinical surveillance. This could include echocardiography evaluating for the presence of IE in patients with VO caused by gram-positive pathogens.

Is There a Difference in Clinical Features, Microbiological Epidemiology and Effective Empiric Antimicrobial Therapy Comparing Healthcare-Associated and Community-Acquired Vertebral Osteomyelitis?

Background: Empiric antibiotic therapy for suspected vertebral osteomyelitis (VO) should be initiated immediately in severely ill patients, and might be necessary for culture-negative VO. The current study aimed to identify differences between community-acquired (CA) and healthcare-associated (HA) VO in terms of clinical presentation, causative pathogens, and antibiotic susceptibility. Methods: Cases of adult patients with VO treated at a German university orthopaedic trauma center between 2000 and 2020 were retrospectively reviewed. Patient history was used to distinguish between CA and HA VO. Susceptibility of antibiotic regimens was assessed based on antibiograms of the isolated pathogens. Results: A total of 155 patients (with a male to female ratio of 1.3; and a mean age of 66.1 ± 12.4 years) with VO were identified. In 74 (47.7%) patients, infections were deemed healthcare-associated. The most frequently identified pathogens were Staphylococcus aureus (HAVO: 51.2%; CAVO: 46.8%), and Coagulase-negative Staphylococci (CoNS, HAVO: 31.7%; CAVO: 21.3%). Antibiograms of 45 patients (HAVO: n = 22; CAVO: n = 23) were evaluated. Significantly more methicillin-resistant isolates, mainly CoNS, were found in the HAVO cohort (27.3%). The highest rate of resistance was found for cefazolin (HAVO: 45.5%; CAVO: 26.1%). Significantly higher rates of resistances were seen in the HAVO cohort for mono-therapies with meropenem (36.4%), piperacillin–tazobactam (31.8%), ceftriaxone (27.3%), and co-amoxiclav (31.8%). The broadest antimicrobial coverage was achieved with either a combination of piperacillin–tazobactam + vancomycin (CAVO: 100.0%; HAVO: 90.9%) or meropenem + vancomycin (CAVO: 100.0%; HAVO: 95.5%). Conclusion: Healthcare association is common in VO. The susceptibility pattern of underlying pathogens differs from CAVO. When choosing an empiric antibiotic, combination therapy must be considered.

Secondary Infection/Microbial Substitution in a Managed Case of Pyogenic Spondylitis

Pyogenic spondylitis is a challenging condition that requires early and accurate diagnosis for appropriate treatment. Most cases can be treated non-surgically or with minimally invasive surgical procedures; however, a combination of anterior debridement/bone grafting and posterior fixation is necessary for severe cases. We encountered a case of lumbar pyogenic spondylitis treated with anterior debridement and autogenous bone grafting after percutaneous endoscopic discectomy drainage (PEDD) with percutaneous pedicle screw (PPS) fixation. The continuous pus oozing from the PEDD drainage tube wound was characteristic in this case, and the pus was considered to be caused by secondary infection/microbial substitution. The discharge immediately stopped and healed after anterior debridement and autogenous bone grafting. Escherichia coli was first detected as the causative bacterium, and Corynebacterium amycolatum and Corynebacterium striatum were detected as the cause of secondary infection/microbial substitution. The possibility of secondary infection/microbial substitution should be considered when the clinical course worsens.

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.

Rare case of osteomyelitis caused by Gardnerella vaginalis and Streptococcus parasanguinis in a postmenopausal woman

Vertebral osteomyelitis is an infection of the vertebrae that can lead to spinal degeneration, most commonly caused by Staphylococcus aureus Here, we report an unusual case of pyogenic osteomyelitis caused by Gardnerella vaginalis and Streptococcus parasanguinis in a 61-year-old postmenopausal woman. The patient presented with a 2-week history of worsening lower back pain and fever and a recent episode of cystitis following re-engagement of sexual activity. Imaging revealed a deterioration of vertebrae discs and spinal canal stenosis at the L3-L4 levels with a formation of abscess in the right psoas muscle. Needle aspiration of the abscess identified G. vaginalis and S. parasanguinis and the patient was successfully treated with a 6-week course of ceftriaxone and metronidazole. This case describes an unusual coinfection of two pathogens that normally reside in the urogenital tract and oral cavity, respectively, and highlights the risk posed when these organisms breach the body's normal barriers.

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.

Antimicrobial therapy and assessing therapeutic response in culture-negative pyogenic vertebral osteomyelitis: a retrospective comparative study with culture-positive pyogenic vertebral osteomyelitis

Background

There are still controversies regarding the treatment and outcomes in culture-negative pyogenic vertebral osteomyelitis (PVO). The purpose of this study is to investigate the antimicrobial therapy, assessment of therapeutic response, and outcome of culture-negative PVO compared to culture-positive PVO.

Methods

A retrospective study was performed with non-surgical lumbar PVO patients. The patients were divided into two groups based on the causative bacterial identification (CN group with culture-negative PVO and CP group with culture-positive PVO). The clinical features, use of antibiotics, laboratory data, and outcomes were compared between the two groups.

Results

Seventy-three patients with 41 (56.2%) of the CN group and 32 (43.8%) of the CP group were enrolled. The CN group showed a shorter duration of parenteral antibiotics (45.88 ± 16.14 vs. 57.31 ± 24.39, p = 0.019) but a tendency of prolonged duration of total (parenteral + oral) antibiotics (101.17 ± 52.84 vs. 84.19 ± 50.29 days, p = 0.168). When parenteral antibiotics were discontinued or switched to oral antibiotics, the mean erythrocyte segmentation rate (ESR, normal range: < 25 mm/h), C-reactive protein (CRP, normal range: < 0.5 mg/dL) level, and visual analog scale (VAS) score of back pain were 42.86 ± 24.05 mm/h, 0.91 ± 1.18 mg/dL, and 4.05 ± 1.07, respectively, with no significant differences between the two groups. The recurrence rates of CN and CP groups were 7.3% (3/41) and 6.3% (2/32), respectively (p = 1.000). The presence of epidural abscess was the most significant factor for the identification of causative bacteria (p = 0.002), and there was no significant relationship between the use of empirical antibiotics before tissue culture and the causative bacterial identification (p = 0.194).

Conclusions

The CN group required a shorter duration of parenteral antibiotics than the CP group. Discontinuation of parenteral antibiotics or changing the administration route can be considered based on the values of ESR, CRP, and VAS score of back pain. The presence of epidural abscess was the most significant factor for the identification of causative bacteria.

The STAPH Score: A Predictor of Staphylococcus aureus as the Causative Microorganism of Native Vertebral Osteomyelitis

Background

Staphylococcus aureus (SA) is the most common causative microorganism in native vertebral osteomyelitis (NVO). Few studies have compared the clinical features of NVO due to SA (SA-NVO) and NVO due to other organisms (NSA-NVO). This study was conducted to validate a predictive score for SA-NVO to facilitate NVO treatment without broad-spectrum antimicrobial agents.

Methods

This retrospective study compared the clinical features of patients with SA-NVO and NSA-NVO who were diagnosed from 2004 to 2019. Univariate associations were assessed using χ ², Fisher's exact, or Mann-Whitney U test. Multivariable analysis was conducted using logistic regression. The optimal age cutoff point was determined by classification and regression tree analysis.

Results

Among 155 NVO patients, 98 (63.2%) had a microbiologically confirmed diagnosis: 40 (25.8%) with SA-NVO and 58 (37.4%) with NSA-NVO. Six predictors, either independently associated with SA-NVO or clinically relevant, were used to develop the STAPH prediction score: atopic dermatitis (Skin) (3 points); recent Trauma (2 points); Age < 67 years (1 point); Abscess (1 point); central venous Port catheter (2 points); and History of puncture (2 points). In a receiver operating characteristic analysis, the area under the curve was 0.84 (95% confidence interval, 0.76-0.91). The best cutoff point was 3. A score ≥3 had a sensitivity, specificity, positive predictive value, and negative predictive value of 58%, 84%, 84%, and 73%, respectively.

Conclusions

The STAPH score has relatively high specificity for use by clinicians to predict SA as the causative microorganism in patients with NVO until results of a confirmatory culture are available.

Microbial Etiology of Pyogenic Vertebral Osteomyelitis According to Patient Characteristics

Background

It is difficult to select an appropriate empirical antibiotic treatment regimen for patients with culture-negative pyogenic vertebral osteomyelitis (PVO). Having knowledge of the distribution of microorganisms according to patient characteristics can help clinicians make informed choices regarding empirical antibiotics. The aim of this study was to determine the microbial distribution among individuals with PVO according to their demographic and clinical characteristics.

Methods

We reviewed the medical records of patients admitted to our hospital with culture-confirmed PVO between January 2005 and December 2017 and collected data on demographics, underlying diseases, and radiographic and microbiological results. Statistical analysis was performed to identify associations between specific bacteria and specific patient characteristics.

Results

A total of 586 patients were included in the study. The prevalence of Staphylococcus aureus infections was higher in young patients than in old patients, while gram-negative bacterial infections and Enterococcus were more prevalent in older patients. Gram-negative bacterial infections were more common in women than in men (32.1% vs 16.4%; P < .05), in patients with cirrhosis than in those without (32.7% vs 21.1%; P < .05), and in patients with a solid tumor than in those without (31.0% vs 20.7%; P < .05). Methicillin-resistant S. aureus infections were more prevalent in patients with chronic renal disease than in those without (34.4% vs 14.7%; P < .05).

Conclusions

The microbial etiology of PVO varies according to patient characteristics. Patient characteristics should thus be considered when choosing empirical antibiotics in patients with culture-negative PVO.

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.

Joint EANM/ESNR and ESCMID-endorsed consensus document for the diagnosis of spine infection (spondylodiscitis) in adults

PURPOSE

Diagnosis of spondylodiscitis (SD) may be challenging due to the nonspecific clinical and laboratory findings and the need to perform various diagnostic tests including serologic, imaging, and microbiological examinations. Homogeneous management of SD diagnosis through international, multidisciplinary guidance would improve the sensitivity of diagnosis and lead to better patient outcome.

METHODS

An expert specialist team, comprising nuclear medicine physicians appointed by the European Association of Nuclear Medicine (EANM), neuroradiologists appointed by the European Society of Neuroradiology (ESNR), and infectious diseases specialists appointed by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), reviewed the literature from January 2006 to December 2015 and proposed 20 consensus statements in answer to clinical questions regarding SD diagnosis. The statements were graded by level of evidence level according to the 2011 Oxford Centre for Evidence-based Medicine criteria and included in this consensus document for the diagnosis of SD in adults. The consensus statements are the result of literature review according to PICO (P:population/patients, I:intervention/indicator, C:comparator/control, O:outcome) criteria. Evidence-based recommendations on the management of adult patients with SD, with particular attention to radiologic and nuclear medicine diagnosis, were proposed after a systematic review of the literature in the areas of nuclear medicine, radiology, infectious diseases, and microbiology.

RESULTS

A diagnostic flow chart was developed based on the 20 consensus statements, scored by level of evidence according to the Oxford Centre for Evidence-based Medicine criteria.

CONCLUSIONS

This consensus document was developed with a final diagnostic flow chart for SD diagnosis as an aid for professionals in many fields, especially nuclear medicine physicians, radiologists, and orthopaedic and infectious diseases specialists.

Comparison of pyogenic postoperative and native vertebral osteomyelitis

BACKGROUND CONTEXT

Postoperative vertebral osteomyelitis (PVO) after spinal surgery is a clinical challenge. However, there is a paucity of evidence regarding the most likely etiologic organisms to guide the choice of empirical antibiotic therapy, and previous reports of treatment outcomes for PVO are scarce.

PURPOSE

To compare the microbiology, clinical characteristics, and outcomes of pyogenic PVO with native vertebral osteomyelitis (NVO).

STUDY DESIGN

Retrospective comparative study.

PATIENT SAMPLE

Patients with microbiologically proven vertebral osteomyelitis from three university-affiliated hospitals in South Korea between January 2005 and December 2015 with follow-up of at least 12 months after completion of antibiotics or until the patient was transferred. Patients who had a spine operation in the same location within 1 year of diagnosis, and all patients with remnant implants at the time of the vertebral osteomyelitis diagnosis, were defined as having PVO. The remainder of the patients was considered to have NVO. Spinal operations included discectomy, laminectomy, arthrodesis, and instrumentation for stabilization of the spine.

OUTCOME MEASURES

Overall mortality, neurologic outcomes, treatment failure, and relapse of infection.

METHODS

Demographic data, comorbidities, presenting symptoms, microbiological data, radiographic characteristics, laboratory data (including white blood cell counts, erythrocyte sedimentation rate, and C-reactive protein), surgical treatment, and neurologic outcomes for each patient were reviewed from electronic medical records and analyzed. Mortality rate, treatment failure, and relapse of infection were calculated for the two groups. Factors associated with treatment outcome were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

The study evaluated 104 patients with PVO and 441 patients with NVO. In PVO, the most common isolate was Staphylococcus aureus (34%, n=35), followed by coagulase-negative staphylococci (31%, n=32). In NVO, the most common isolates were S. aureus (47%, n=206) and streptococci (21%, n=94). Of the staphylococci, the proportion of methicillin-resistant strains was significantly higher in PVO than that in NVO (75% vs. 39%, p<.001). The proportion of patients with gram-negative bacilli was 14% in PVO and 20% in NVO. Pre-existing or synchronous nonspinal infection was observed more frequently in NVO than in PVO (33% vs. 13%, p<.001). Although the duration of antibiotic use was similar in both groups, surgery for infection control was performed more frequently in PVO. The mortality rate was similar in both groups. However, the treatment failure and relapse rates at 12 months were higher in the PVO group (23% vs. 13%, p=.009; 14% vs. 7%, p=.028, respectively). Methicillin-resistant S.aureus was significantly associated with treatment failure or relapse via logistic regression (odds ratio 3.01, 95% confidence interval [1.71-5.32], p<.001; odds ratio 2.78, 95% confidence interval [1.40-5.49], p=.003).

CONCLUSIONS

Coverage of methicillin-resistant staphylococci should be considered when prescribing empirical antibiotics for PVO. Although surgery was performed more often in PVO than NVO, the treatment failure and relapse rates at 12 months were higher in PVO.

Selection of an appropriate empiric antibiotic regimen in hematogenous vertebral osteomyelitis

Background

Empiric antibiotic therapy for suspected hematogenous vertebral osteomyelitis (HVO) should be initiated immediately in seriously ill patients and may be required in those with negative microbiological results. The aim of this study was to inform the appropriate selection of empiric antibiotic regimens for the treatment of suspected HVO by analyzing antimicrobial susceptibility of isolated bacteria from microbiologically proven HVO.

Method

We conducted a retrospective chart review of adult patients with microbiologically proven HVO in five tertiary-care hospitals over a 7-year period. The appropriateness of empiric antibiotic regimens was assessed based on the antibiotic susceptibility profiles of isolated bacteria.

Results

In total, 358 cases of microbiologically proven HVO were identified. The main causative pathogens identified were methicillin-susceptible Staphylococcus aureus (33.5%), followed by methicillin-resistant S. aureus (MRSA) (24.9%), Enterobacteriaceae (19.3%), and Streptococcus species (11.7%). Extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and anaerobes accounted for only 1.7% and 1.4%, respectively, of the causative pathogens. Overall, 73.5% of isolated pathogens were susceptible to levofloxacin plus rifampicin, 71.2% to levofloxacin plus clindamycin, and 64.5% to amoxicillin-clavulanate plus ciprofloxacin. The susceptibility to these oral combinations was lower in cases of healthcare-associated HVO (52.6%, 49.6%, and 37.6%, respectively) than in cases of community-acquired HVO (85.8%, 84.0%, and 80.4%, respectively). Vancomycin combined with ciprofloxacin, ceftriaxone, ceftazidime, or cefepime was similarly appropriate (susceptibility rates of 93.0%, 94.1%, 95.8%, and 95.8%, respectively).

Conclusions

Based on our susceptibility data, vancomycin combined with a broad-spectrum cephalosporin or fluoroquinolone may be appropriate for empiric treatment of HVO. Fluoroquinolone-based oral combinations may be not appropriate due to frequent resistance to these agents, especially in cases of healthcare-associated HVO.

Factors associated with sequelae after treatment of hematogenous pyogenic vertebral osteomyelitis

OBJECTIVES

Functional disability may persist after completing treatment for hematogenous pyogenic vertebral osteomyelitis (HPVO). The objective of this study was to identify factors associated with residual sequelae after treatment of HPVO.

METHODS

We conducted a retrospective study of patients diagnosed with HPVO at 5 tertiary-care hospitals between January 2005 and December 2012. Sequelae were defined as an inability to walk without assistance, bladder/bowel incontinence, and/or unresolved pain that required analgesic therapy at 12 months after completing the HPVO treatment.

RESULTS

Of the 279 patients with microbiologically proven HPVO, 79 (28.3%) had sequelae at 12 months posttherapy. Independent risk factors for sequelae were neurologic deficit (adjusted odds ratio [aOR], 3.38), recurrence within 12 months (aOR, 2.45), age ≥ 65 years (aOR, 2.05), C-reactive protein level ≥ 10 mg/dL (aOR, 2.01), and epidural/paravertebral abscess (aOR, 2.00). Among 58 patients with neurologic deficit, sequelae rates differed according to the surgical strategy, as follows: 28.6% (early surgery [<48 h]), 55.0% (delayed surgery [≥48 h]), and 66.7% (no surgery) (P = 0.03). Among the 170 patients with abscess, early drainage (<72 h) was an independent protective factor for sequelae (aOR, 0.35). The 12-month recurrence rates differed according to the total duration of antibiotic treatment, as follows: 20.5% (4-6 weeks), 18.4% (6-8 weeks), and 5.2% (≥8 weeks) (P < 0.001).

CONCLUSIONS

A substantial proportion of patients with HPVO experienced sequelae after completing treatment. Early surgery for neurologic deficit, early drainage of abscess, and antibiotic therapy of appropriate duration to reduce recurrence may prevent development of sequelae in patients with HPVO.

Osteoarticular Infections Following Open or Penetrating Trauma in Children in the Post-Community-Acquired Methicillin-resistant Staphylococcus aureus Era: The Impact of Enterobacter cloacae

BACKGROUND

Most cases of pediatric osteoarticular infections (OAIs) are hematogenous in nature and caused by Staphylococcus aureus. OAI in children can also occur through direct inoculation of microorganisms secondary to penetrating or open trauma. No studies in the United States have evaluated the microbiology or outcomes of trauma-related OAI (TROAI) in children in the era of community-acquired methicillin-resistant S. aureus (CA-MRSA).

METHODS

Cases were identified from the inpatient infectious diseases consultation database at Texas Children's Hospital from January 2011 to December 2016. TROAI cases were those in which OAI developed following a clear history of penetrating trauma, open fracture, crush injury or traumatic amputation. Only cases with radiographic evidence of bone abscess, gross appearance of infection at the time of surgery and/or positive cultures from bone or joint were included. Complications included recurrence of infection, pathologic fracture or chronic osteomyelitis.

RESULTS

During the study period, 692 consultations for OAI were performed, with 34 meeting inclusion criteria. In 68%, at least 1 organism was isolated, and the most commonly isolated organisms were S. aureus (32% overall, 21% MRSA) and Enterobacter cloacae (24%). Polymicrobial infections occurred in 38% of patients. Eighty-five percentage of patients had at least 1 surgical procedure, and 38% underwent ≥ 2 procedures. Eighty-two percentage of patients were discharged on oral therapy. Complications developed in 15% of patients and were more commonly associated with E. cloacae (80% vs. 14%, P = 0.007) and fungi (P = 0.03).

CONCLUSION

TROAI are relatively uncommon in children but cause significant morbidity. While MRSA contributes substantially to TROAI, the highly diverse microbiology emphasizes the importance of obtaining cultures for microbiologic diagnosis and management. Clinicians should be aware of the frequency of E. cloacae in TROAI and its high risk for sequelae.

Analysis of infectious spondylodiscitis: 7-years data

Objective:

Infectious spondylodiscitis (SD) is an infectious disease that is rare and difficult to diagnose due to its non-specific clinical features. In this study, we aimed to describe the clinical and diagnostic features of infectious spondylodiscitis.

Methods:

All patients who were diagnosed with SD at our hospital during a 7-year period from January 1, 2011 through December 31, 2017 were included in the study. Spondylodiscitis is divided into the following three types: pyogenic, tuberculous, and brucellar. Clinical and laboratory data were collected retrospectively from the medical records of the patients.

Results:

Of the 118 patients, 66 (55.9%) were female, 81 (68.6%) had pyogenic SD (PSD), 21 (17.8%) had tuberculous SD (TSD), and 16 (13.6%) had brucellar SD (BSD). The mean age was 59.3 ± 14.6 years. Leucocytosis was significantly higher in patients with PSD (p=0.01) than in patients with other types of SD. Thoracic involvement (47.6%) was significantly higher in patients with TSD (p=0.005) than in other patients. Sacral involvement (12.5%) was significantly higher in patients with BSD (p=0.01) than in other patients. Paravertebral abscess formation (42.8%) occurred most frequently in patients with TSD. Microbiologic agents were defined in 50% (18/36) of the surgical specimens and in 12.5% of the fine needle aspiration biopsy (FNAB) specimens. Staphylococcus aureus was the most common microbiological agent in patients with PSD. Spinal surgery was defined as a risk factor for PSD (p = 0.0001). Binary logistic regression analysis revealed that female gender, thoracic involvement and night sweats were the predictive markers for TSD (OR 4.5 [95% CI 1.3-15.3] and OR 5 [95% CI 1.7-14.6]).

Conclusion:

PSD is the most frequent form of SD. Leucocytosis is most common in patients with PSD. Thoracic involvement and paraspinal abscess were prominent in patients with TSD. Sacral involvement was most common in patients with BSD. Thoracic involvement, female gender and night sweats were the predictive markers for TSD. The microbiological culture positivity rate was higher in surgical specimens compared to FNAB specimens. The need for surgical treatment was most common in patients with TSD.

Development of Organic-Inorganic Hybrid Optical Gas Sensors for the Non-Invasive Monitoring of Pathogenic Bacteria

Hybrid optical gas sensors, based on different organic and inorganic materials, are proposed in this paper, with the aim of using them as optical artificial nose systems. Three types of organic and inorganic dyes, namely zinc-porphyrin, manganese-porphyrin, and zinc-phthalocyanine, were used as gas sensing materials to fabricate a thin-film coating on glass substrates. The performance of the gas sensor was enhanced by a thermal treatment process. The optical absorption spectra and morphological structure of the sensing films were confirmed by UV-Vis spectrophotometer and atomic force microscope, respectively. The optical gas sensors were tested with various volatile compounds, such as acetic acid, acetone, ammonia, ethanol, ethyl acetate, and formaldehyde, which are commonly found to be released during the growth of bacteria. These sensors were used to detect and discriminate between the bacterial odors of three pathogenic species (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) grown in Luria-Bertani medium. Based on a pattern recognition (PARC) technique, we showed that the proposed hybrid optical gas sensors can discriminate among the three pathogenic bacterial odors and that the volatile organic compound (VOC) odor pattern of each bacterium was dependent on the phase of bacterial growth.

Analysis of mortality in a cohort of 650 cases of bacteremic osteoarticular infections

OBJECTIVES

The mortality of patients with bacteremic osteoarticular infections (B-OAIs) is poorly understood. Whether certain types of OAIs carry higher mortality or interventions like surgical debridement can improve prognosis, are unclarified questions.

METHODS

Retrospective analysis of a prospective cohort of patients with B-OAIs treated at a teaching hospital in Barcelona (1985-2014), analyzing mortality (30-day case-fatality rate). B-OAIs were categorized as peripheral septic arthritis or other OAIs. Factors influencing mortality were analyzed using logistic regression models. The association of surgical debridement with mortality in patients with peripheral septic arthritis was evaluated with a multivariate logistic regression model and a propensity score matching analysis.

RESULTS

Among 650 cases of B-OAIs, mortality was 12.2% (41.8% of deaths within 7 days). Compared with other B-OAI, cases of peripheral septic arthritis were associated with higher mortality (18.6% vs 8.3%, p < 0.001). In a multiple logistic regression model, peripheral septic arthritis was an independent predictor of mortality (adjusted odds ratio [OR] 2.12; 95% CI: 1.22-3.69; p = 0.008). Cases with peripheral septic arthritis managed with surgical debridement had lower mortality than those managed without surgery (14.7% vs 33.3%; p = 0.003). Surgical debridement was associated with reduced mortality after adjusting for covariates (adjusted OR 0.23; 95% CI: 0.09-0.57; p = 0.002) and in the propensity score matching analysis (OR 0.81; 95% CI: 0.68-0.96; p = 0.014).

CONCLUSIONS

Among patients with B-OAIs, mortality was greater in those with peripheral septic arthritis. Surgical debridement was associated with decreased mortality in cases of peripheral septic arthritis.

Clinical characteristics, treatments, and outcomes of hematogenous pyogenic vertebral osteomyelitis, 12-year experience from a tertiary hospital in central Taiwan

BACKGROUND

In Taiwan, studies about hematogenous pyogenic vertebral osteomyelitis (HPVO) are limited. We conducted a retrospective study to evaluate the clinical presentations, treatment, and outcomes of patients with the diagnosis of HPVO.

METHOD

This 12.5-year retrospective study included patients with a diagnosis of HPVO. Medical records of all HPVO patients were thoroughly reviewed and their clinical data were analyzed by the SPSS software.

RESULT

414 HPVO cases were included and the mean age was 61.6 ± 13.4 years. The mean duration of symptoms was 29 ± 35.3 days and pain over the affected site was reported by most patients (86.0%). Gram-positive bacteria, especially Staphylococcus aureus (162/399 = 40.6%), were the main HPVO pathogens. Escherichia coli (42/399 = 10.5%) was the most common gram-negative isolate. Surgery was performed in 68.8% of cases and the mean duration of total antibiotic treatment was 104.7 ± 77.7 days. All-cause mortality and recurrence rates were 6.3% and 18.8%, respectively. In multivariate analysis, polymicrobial infection (OR: 4.154, 95% CI: 1.039-16.604, p = 0.044), multiple vertebral body involvement (OR: 2.202, 95% CI: 1.088-4.457, p = 0.028), abscess formation treated with antibiotics alone (OR: 2.912, 95% CI: 1.064-7.966, p = 0.037), and the duration of antimicrobial treatment less than 4 weeks (OR: 3.737, 95% CI: 1.195-11.683, p = 0.023) were associated with HPVO recurrence.

CONCLUSION

In Taiwan, HPVO mainly affected the elderly and S. aureus remained the most common HPVO pathogen. In patients with risk factors associated with HPVO recurrence, a longer duration (≥6 weeks) of antimicrobial therapy is suggested.

Spondylodiscitis Caused by Enterobacter agglomerans

All over the globe, the incidence of vertebral infection is rising. Nowadays, compared to tuberculous variety, pyogenic spondylodiscitis incidence is high. The increase in the susceptible population and improved diagnostics summatively contributed to this. In clinical grounds, differentiation of pyogenic and tuberculous spondylodiscitis is well defined. Enterobacter agglomerans is a hospital contaminant and associated with infections in immunocompromised individuals and intravenous lines. It causes a wide array of infections. Enterobacter agglomerans spondylodiscitis is unusual and there are, around the globe, only less than 31 suspected cases that have been previously reported. Enterobacter agglomerans histology mimics tuberculous rather than pyogenic spondylodiscitis. A 65-year-old farming lady, while being in hospital, developed sudden onset spastic paraparesis with hyperreflexia. Later blood culture revealed Enterobacter agglomerans with 41-hour incubation in 99.9% probability from Ramel identification system. Her initial ESR was 120 mm/first hour. Isolate was susceptible to ciprofloxacin and intravenous followed with oral therapy shows a drastic ESR fall and improved clinical response. Differentiation of tuberculous and pyogenic spondylodiscitis is very much important in management point of view. Therefore, blood culture has a role in diagnosis of spondylodiscitis. ESR can be used as important inflammatory marker in monitoring the response to treatment. Retrospectively, ESR would aid in reaching a definitive diagnosis.

Rare cause of back pain: Staphylococcus aureus vertebral osteomyelitis complicated by recurrent epidural abscess and severe sepsis

An epidural abscess represents a rare acute medical emergency, with a reported incidence of 2.5/10 000 hospital admissions annually. The clinical features include fever, spinal pain, radiating nerve root pain and leg weakness. When sepsis is present, prompt recognition is required to initiate appropriate antimicrobial therapy and surgical decompression. We present the case of a man aged 68 years presenting to the emergency department with a 3-day history of fever, low back, right hip and leg pain. He was hypoxic, tachycardic and hypotensive. He required intubation and ventilation. An MRI spine confirmed a posterior epidural abscess from T12 to L4. Blood cultures revealed Staphylococcus aureus He started treatment with linezolid and underwent incision and drainage. He remained septic and 8 days later, a repeat MRI spine showed a peripherally enhancing posterior epidural collection from L2/L3 to L4/L5, consistent with a recurrent epidural abscess. Further drainage was performed. He developed bilateral knee pain requiring washout. His right knee synovial biopsy cultured S. aureus He continued treatment with linezolid for 6 weeks until his C reactive protein was 0.8 ng/L. He started neurorehabilitation. 10 weeks later, he became feverish with lumbar spine tenderness. An MRI spine showed discitis of the L5/S1 endplate. A CT-guided biopsy confirmed discitis and osteomyelitis. Histology was positive for S. aureus and he started treatment with oral linezolid. After 19 days, he was discharged with 1 week of oral linezolid 600 mg 2 times per day, followed by 1 further week of oral clindamycin 600 mg 4 times daily. This case report reinforces the importance of maintaining a high clinical suspicion, with a prompt diagnosis and combined medical and surgical treatment to prevent adverse outcomes in this patient cohort. With spinal surgical services centralised, physicians may not encounter this clinical diagnosis more often in day-to-day hospital medical practice. The unique aspect of this case is the persistence and then the recurrence (despite 6 weeks of antimicrobial therapy and a second debridement) of S. aureus infection. Furthermore, the paucity of clinical recommendations and the controversy regarding the adequate duration of antimicrobial therapy are notable features of this case.

Comparison of gram-negative and gram-positive hematogenous pyogenic spondylodiscitis: clinical characteristics and outcomes of treatment

Background

To the best of our knowledge, no study has compared gram-negative bacillary hematogenous pyogenic spondylodiscitis (GNB-HPS) with gram-positive coccal hematogenous pyogenic spondylodiscitis (GPC-HPS) regarding their clinical characteristics and outcomes.

Methods

From January 2003 to January 2013, 54 patients who underwent combined antibiotic and surgical therapy in the treatment of hematogenous pyogenic spondylodiscitis were included.

Results

Compared with 37 GPC-HPS patients, the 17 GNB-HPS patients were more often found to be older individuals, a history of cancer, and a previous history of symptomatic urinary tract infection. They also had a less incidence of epidural abscess formation compared with GPC-HPS patients from findings on magnetic resonance imaging (MRI). Constitutional symptoms were the primary reasons for initial physician visits in GNB-HPS patients whereas pain in the affected spinal region was the most common manifestation in GPC-HPS patients at initial visit. The clinical outcomes of GNB-HPS patients under combined surgical and antibiotic treatment were not different from those of GPC-HPS patients. In multivariate analysis, independent predicting risk factors for GNB-HPS included a malignant history and constitutional symptoms and that for GPC-HPS was epidural abscess.

Conclusions

The clinical manifestations and MRI presentations of GNB-HPS were distinguishable from those of GPC-HPS.

Reduced ability to work both before and after infectious spondylodiscitis in working-age patients

BACKGROUND

As little is known about the ability to work in patients with infectious spondylodiscitis, we compared the relation between the workforce before infection with that of a reference population and described the patients' ability to work after infection including predictors of return to work (RTW).

METHODS

We identified all patients aged 20-57 years treated for infectious spondylodiscitis January 1994-May 2009 at hospitals in Funen County, Denmark. The work status of each week from 2 years before until 2 years after index date was compared with that of a reference population. Time to RTW was described using cumulative incidence curves and univariate cause-specific Cox-regression analyses (hazard ratios - HRs).

RESULTS

Of 112 identified patients, 8 (7%) died within the first year and 48 (43%) were part of the workforce 1 year before index. Through the entire observation period, the patients had lower affiliation to the workforce compared with the reference population. During the observation period, the proportion of patients on permanent disability pension increased from 24% to 38% and the proportion of self-supporters decreased from 58% to 33%. Seventy-three per cent of the patients being part of the workforce 1 year before index returned to the workforce within the 2 year follow-up. Main predictor of RTW was being part of the workforce 1 year before index (HR = 7.8; CI: 2.4-25.3).

CONCLUSIONS

Patients with infectious spondylodiscitis were less likely to be part of the workforce before infection compared with a reference population and infection further lowered their ability to RTW.

Vertebral osteomyelitis in adults: an update

INTRODUCTION

The incidence of vertebral osteomyelitis is increasing, attributed to an ageing population with inherent co-morbidities and improved case ascertainment.

SOURCES OF DATA

References were retrieved from the PubMed database using the terms 'vertebral osteomyelitis' and 'spondylodiscitis' between January 1, 2009 and April 30, 2014 published in English as checked in May 2014 (>1000 abstracts checked).

AREAS OF AGREEMENT

Blood cultures and whole spine imaging with magnetic resonance imaging are essential investigations. Thorough debridement is the mainstay of surgical management, although placing metalwork in active infection is becoming increasingly common.

AREAS OF CONTROVERSY

The extent of pursuing spinal biopsies to determine aetiology, antimicrobial choices and duration, monitoring the response to treatment, and surgical techniques and timing all vary widely in clinical practice with heterogeneous studies limiting comparisons. Surgery, rather than conservative approaches, is being proposed as the default management choice, because it can, in carefully selected patients, offer faster reduction in pain scores and improved quality of life.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies are needed to define the most effective technique for spinal biopsies to maximize determining aetiology. High-quality trials are required to provide an evidence base for both the medical and surgical management of vertebral osteomyelitis, including challenging medical management as the default option.

Neurologic Complications, Reoperation, and Clinical Outcomes After Surgery for Vertebral Osteomyelitis

STUDY DESIGN

A consecutive retrospective cohort study from 2008 to 2013 at a single tertiary-care institution was conducted.

OBJECTIVE

The aim of the study was to characterize recovery from pain and neurologic deficit after surgery for vertebral osteomyelitis (VO), and identify incidence of postoperative adverse events.

SUMMARY OF BACKGROUND DATA

A minority of patients with VO require surgery. Although prior studies have characterized outcomes after medical management, the morbidity after surgery is poorly defined.

METHODS

The primary outcome was change from baseline in a Modified McCormick Scale (MMS, 1-5 scale), whereas secondary outcomes included reoperation and change in self-reported pain Visual Analog Scale (VAS, 0-10 scale). MMS and VAS were collected throughout the postoperative course as surrogates for neurologic function and degree of pain. Intraoperative, short-term postoperative (<30 d), and long-term neurologic complications were recorded. New-onset neurologic deficits in the postoperative period were considered neurologic complications.

RESULTS

Fifty patients were included; a majority (52%) presented with a neurologic deficit. The median length of follow-up was 18 months. A statistically significant improvement in MMS was observed by 12 months postoperatively, whereas an improvement in VAS was observed by 3 months. The mean improvement in MMS at last follow-up was 0.35, whereas the mean improvement in VAS was 3.40. One quarter of patients required reoperation. At 24 months postoperatively, 10% died, 26% underwent reoperation, 42% experienced a neurologic complication, and 60% experienced at least one of these 3 adverse events.

CONCLUSION

This is the first study to investigate neurologic complications, reoperation, and pain in a longitudinal manner after surgery for VO. We observed statistically significant improvements in MMS and VAS in the postoperative period. Despite these improvements, the 24-month incidence of overall adverse events was 60%. Patients and clinicians should be aware of the clinical improvement but high incidence of adverse events after surgical management of VO.

LEVEL OF EVIDENCE

4.

Timing and prognosis of surgery for spinal epidural abscess: A review

Background:

The nonsurgical versus surgical management of spinal epidural abscesses (SEAs) remains controversial. Even with the best preoperative screening for multiple risk factors, high nonoperative failure rates are attended by considerable morbidity (e.g., irreversible paralysis) and mortality. Therefore, the focus remains on early surgery.

Methods:

Most papers promote early recognition of the clinical triad (e.g., fever [50%], spinal pain [92–100%], and neurological deficits [47%]) for SEA. They also identify SEA-related risk factors for choosing nonsurgical versus surgical approaches; advanced age (>65 or 80), diabetes (15–30%), cancer, intravenous drug abuse (25%), smoking (23%), elevated white blood cell count (>12.5), high C-reactive protein >115, positive blood cultures, magnetic resonance imaging/computed tomographic documented cord compression, and significant neurological deficits (e.g., 19–45%).

Results:

Surgical options include: decompressions, open versus minimally invasive biopsy/culture/irrigation, or fusions. Up to 75% of SEA involve the thoracolumbar spine, and 50% are located ventrally. Wound cultures are positive in up to 78.8% of cases and are often (60%) correlated with positive blood cultures. The most typical offending organism is methicillin resistant Staphylococcus aureus, followed by methicillin sensitive S. aureus. Unfortunately, the failure rates for nonoperative treatment of SEA remain high (e.g., 41–42.5%), contributing to significant morbidity (22% risk of permanent paralysis), and mortality (3–25%).

Conclusion:

The vast majority of studies advocated early surgery to achieve better outcomes for treating SEA; this avoids high failure rates (41–42.5%) for nonoperative therapy, and limits morbidity/mortality rates.

Susceptibility Pattern of Microorganisms Isolated by Percutaneous Needle Biopsy in Nonbacteremic Pyogenic Vertebral Osteomyelitis

Pyogenic vertebral osteomyelitis (VO) is diagnosed according to several lines of evidence: clinical, biological, radiological, and histological. Definitive diagnosis requires the isolation of a causative pathogen or histological confirmation. The aim of our study was to describe the microorganisms isolated by percutaneous needle biopsy (PNB) and to analyze their susceptibility patterns, in order to assess the possibility of empirical combination therapy for the treatment of nonbacteremic patients without resorting to PNB. Based on a French prospective multicenter study of 351 patients with VO, we compiled clinical, biological, and radiological findings for 101 patients with microbiologically confirmed VO. Based on antibiotic susceptibility testing of PNB isolated pathogens, the suitabilities of four antibiotic combinations were analyzed: ofloxacin plus rifampin, levofloxacin plus rifampin, ciprofloxacin plus clindamycin, and ciprofloxacin plus amoxicillin-clavulanate. The main causative pathogens identified were coagulase-negative Staphylococcus spp. (26% of isolates), followed by Staphylococcus aureus (21%), Streptoccocus spp. (13%), and enterobacteria (21%). Empirical antibiotic combination therapy was effective in nearly 75% of cases, and the different combinations gave similar results, except for ofloxacin-rifampin, which was effective in only 58% of cases. A "perfect" empirical antibiotic therapy does not exist. If PNB is not possible, a combination of a fluoroquinolone with clindamycin or rifampin can be used, but the high risk of microbiological failure does not allow the exclusion of PNB. (This study has been registered with EudraCT, number 2006-000951-18, and ClinicalTrials.gov, number NCT00764114.).