Osteomyelitis and Septic Arthritis Due to Burkholderia pseudomallei: A 10-Year Retrospective Melioidosis Study From South China

Outcomes of Adjunctive Therapy with Open Arthrotomy for Patients with Septic Arthritis Due to Melioidosis: A Retrospective Study

Melioidosis is a potentially fatal infection caused by the bacterium Burkholderia pseudomallei. Septic arthritis caused by this infection is uncommon and difficult to treat. The role of adjunctive open arthrotomy in this type of infection has not yet been elucidated. We conducted a retrospective study of patients with microbiologically confirmed melioidosis between January 2002 and December 2022. Patients with a clinical condition of septic arthritis and positive cultures for B. pseudomallei were included. Comparisons were made between patients who received adjunctive therapy with open arthrotomy with conventional standard treatment and those who did not in terms of clinical outcomes and hospital expenditures. Of the 478 patients diagnosed with melioidosis microbiological confirmation, 81 patients had septic arthritis, accounting for 17% of cases. Among these patients, only 36 (44%) underwent adjunctive therapy with open arthrotomy. The 14-day and 30-day in-hospital mortality and length of hospital stays of patients who underwent adjunctive therapy with open arthrotomy were more favorable than those of patients who did not receive adjunctive therapy with open arthrotomy; however, the difference was not statistically significant. Patients who underwent adjunctive therapy with open arthrotomy had lower hospital expenditures (antimicrobial and non-antimicrobial costs) than those who did not undergo open arthrotomy. Adjunctive therapy with open arthrotomy for patients with septic arthritis due to melioidosis was associated with favorable clinical outcomes and significantly lower hospital expenditures.

Sphingolipid-Induced Bone Regulation and Its Emerging Role in Dysfunction Due to Disease and Infection

The human skeleton is a metabolically active system that is constantly regenerating via the tightly regulated and highly coordinated processes of bone resorption and formation. Emerging evidence reveals fascinating new insights into the role of sphingolipids, including sphingomyelin, sphingosine, ceramide, and sphingosine-1-phosphate, in bone homeostasis. Sphingolipids are a major class of highly bioactive lipids able to activate distinct protein targets including, lipases, phosphatases, and kinases, thereby conferring distinct cellular functions beyond energy metabolism. Lipids are known to contribute to the progression of chronic inflammation, and notably, an increase in bone marrow adiposity parallel to elevated bone loss is observed in most pathological bone conditions, including aging, rheumatoid arthritis, osteoarthritis, and osteomyelitis. Of the numerous classes of lipids that form, sphingolipids are considered among the most deleterious. This review highlights the important primary role of sphingolipids in bone homeostasis and how dysregulation of these bioactive metabolites appears central to many chronic bone-related diseases. Further, their contribution to the invasion, virulence, and colonization of both viral and bacterial host cell infections is also discussed. Many unmet clinical needs remain, and data to date suggest the future use of sphingolipid-targeted therapy to regulate bone dysfunction due to a variety of diseases or infection are highly promising. However, deciphering the biochemical and molecular mechanisms of this diverse and extremely complex sphingolipidome, both in terms of bone health and disease, is considered the next frontier in the field.

Chitosan-Based Smart Biomaterials for Biomedical Applications: Progress and Perspectives

Over the past decade, smart and functional biomaterials have escalated as one of the most rapidly emerging fields in the life sciences because the performance of biomaterials could be improved by careful consideration of their interaction and response with the living systems. Thus, chitosan could play a crucial role in this frontier field because it possesses many beneficial properties, especially in the biomedical field such as excellent biodegradability, hemostatic properties, antibacterial activity, antioxidant properties, biocompatibility, and low toxicity. Furthermore, chitosan is a smart and versatile biopolymer due to its polycationic nature with reactive functional groups that allow the polymer to form many interesting structures or to be modified in various ways to suit the targeted applications. In this review, we provide an up-to-date development of the versatile structures of chitosan-based smart biomaterials such as nanoparticles, hydrogels, nanofibers, and films, as well as their application in the biomedical field. This review also highlights several strategies to enhance biomaterial performance for fast growing fields in biomedical applications such as drug delivery systems, bone scaffolds, wound healing, and dentistry.

Risk Factors for Melioidosis Mortality and Epidemics: A Multicentre, 10-Year Retrospective Cohort Study in Northern Hainan

INTRODUCTION

Burkholderia pseudomallei is a gram-negative environmental bacterium and aetiological agent of melioidosis, a tropical infectious disease with diverse clinical presentations. We aimed to describe the epidemiological and clinical characteristics of melioidosis in northern Hainan and to determine the meteorological factors affecting its morbidity.

METHODS

We conducted a retrospective, multicentre, observational cohort study of 90 patients with melioidosis admitted to four general hospitals in northern Hainan from 2010 to 2020. Epidemiological, clinical presentation, laboratory and treatment outcome data were collected and analysed. The monthly incidence of melioidosis and meteorological data, including precipitation, temperature, humidity, air pressure and wind speed, for the same period were collected to analyse the relationship between meteorological factors and the incidence of melioidosis.

RESULTS

Of the 90 patients included in the study, 79 (87.78%) were male. Patient age ranged from 10 to 81 years old, but most patients, namely, 78 (86.67%), were middle-aged and elderly people aged 41-81 years old. Forty-six patients (51.11%) were farmers. The number of cases increased significantly after 2014, with the highest numbers occurring in 2014 and 2016. The highest number of cases occurred in summer and autumn and were associated with abundant rainfall, and 58 cases (64.44%) occurred from July to December. The patients showed diverse presentations and abnormal laboratory parameters: 69 patients (76.67%) had a history of diabetes mellitus; bacteremia was present in 50 patients (55.56%), sepsis was present in 39 patients (43.33%) and pneumonia in 19 patients (21.11%). An average high-sensitivity C-reactive protein (hs-CRP) level of 149.57 ± 13.65 mg/L and a median procalcitonin (PCT) level of 1.31 (0.39, 6.21) ng/mL were observed. Among all the cases, 21 (23.33%) were identified as acute infections, 51 (56.67%) as subacute infections and 18 (20.00%) as chronic infections. Six patients (6.67%) died of illness; five of these patients were male, and five of these patients were middle-aged and elderly patients. The monthly average precipitation was significantly positively correlated with the monthly average incidence of melioidosis (r = 0.74, P < 0.01).

CONCLUSION

Male patients, farmers and especially middle-aged and elderly individuals with a history of diabetes mellitus accounted for most of the patients. The majority of cases were concentrated in coastal areas. Most cases of melioidosis occurred during the rainy seasons, and the monthly average precipitation was an independent factor affecting the average monthly incidence of melioidosis.

Chronic Splenic Melioidosis in a Patient with Fever of Unknown Origin Diagnosed by Metagenomics Next-Generation Sequencing: An Emerging Cause and Literature Review

Introduction

Human melioidosis is an emerging infectious disease in tropical areas of China, and chronic melioidosis can be a rare cause of fever of unknown origin (FUO). Timely diagnosis may improve the prognosis of melioidosis.

Case Presentation

We report a case of melioidosis with splenic abscesses caused by Burkholderia pseudomallei in a 57-year-old man, who presented with FUO. Positron emission tomography/computed tomography (PET/CT) revealed multiple hypermetabolic lesions in the spleen. The spleen biopsy was conducted and metagenomics next-generation sequencing (mNGS) of the spleen specimen identified the presence of B. pseudomallei, confirming the diagnosis of melioidosis. Antimicrobial treatment was initiated with intravenous meropenem, followed by oral faropenem. During the follow-up, the patient was in good condition except having a low-grade fever occasionally. A splenectomy was performed, and subsequent culture and mNGS of the spleen pus were both positive for B. pseudomallei. Histopathological characteristics of chronic splenic melioidosis were noted.

Conclusion

Melioidosis is a serious endemic disease, and it is critical to raise awareness about this disease.

Layered and integrated medical countermeasures against Burkholderia pseudomallei infections in C57BL/6 mice

Burkholderia pseudomallei, the gram-negative bacterium that causes melioidosis, is notoriously difficult to treat with antibiotics. A significant effort has focused on identifying protective vaccine strategies to prevent melioidosis. However, when used as individual medical countermeasures both antibiotic treatments (therapeutics or post-exposure prophylaxes) and experimental vaccine strategies remain partially protective. Here we demonstrate that when used in combination, current vaccine strategies (recombinant protein subunits AhpC and/or Hcp1 plus capsular polysaccharide conjugated to CRM197 or the live attenuated vaccine strain B. pseudomallei 668 ΔilvI) and co-trimoxazole regimens can result in near uniform protection in a mouse model of melioidosis due to apparent synergy associated with distinct medical countermeasures. Our results demonstrated significant improvement when examining several suboptimal antibiotic regimens (e.g., 7-day antibiotic course started early after infection or 21-day antibiotic course with delayed initiation). Importantly, this combinatorial strategy worked similarly when either protein subunit or live attenuated vaccines were evaluated. Layered and integrated medical countermeasures will provide novel treatment options for melioidosis as well as diseases caused by other pathogens that are refractory to individual strategies, particularly in the case of engineered, emerging, or re-emerging bacterial biothreat agents.

Critical approach to atypical spectrum of melioidosis: a case-series based literature review

Melioidosis is an emerging infectious disease with highest predominance in Southeast Asia, but it has a significantly lower incidence across other parts of the globe. The most common systemic involvement seen in melioidosis is pulmonary, followed by multiple visceral and cutaneous abscesses. Infrequently, melioidosis manifests with atypical presentations such as spontaneous bacterial peritonitis (SBP), acute pyogenic meningitis or septic arthritis. Our primary case discusses an extremely rare presentation of melioidosis with SBP. There have not been any cases of SBP reported secondary to melioidosis infection. The second case exhibits development of acute pyogenic meningitis from haematogenous dissemination of this organism, while the final case demonstrates musculoskeletal melioidosis as an uncommon presentation. Of note, this case series also discusses the guidelines of management of melioidosis and illustrates the tremendous impact of appropriate and timely antibiotic therapy on mortality and morbidity secondary to melioidosis.

Osteoarticular melioidosis: a retrospective cohort study of a neglected disease

INTRODUCTION

Patients with melioidosis can present with a combination of fever, respiratory distress and focal involvement. Focal involvement of bone and joint is, however, rare in patients with melioidosis. This study aimed to characterize patients with osteoarticular melioidosis.

PATIENTS AND METHODS

This was a retrospective review of records of all adult patients diagnosed with culture-positive osteoarticular melioidosis over three years. The clinical, laboratory and treatment details were recorded in a predefined case-record form and analyzed.

RESULTS

Of the 11 patients with osteoarticular melioidosis, 55% (n=6) had concurrent pulmonary involvement. The patients were classified as isolated osteomyelitis (n=3), isolated arthritis (n=3), and both osteomyelitis and septic arthritis (n=5). Of eight patients with joint involvement, 87.5% had monoarthritis. A single bone was involved in 75% of the patients with bone involvement (n=8). Concomitant myositis was seen in 36.4% (n=4) of the cases. Local debridement of the involved bone or joint was done in 54.5% (n=6) of the cases. Combination therapy with ceftazidime/meropenem and cotrimoxazole was predominantly used as intensive therapy for a mean of 3+1.3 weeks. Monotherapy with cotrimoxazole was used as eradication therapy for a mean of 4.6+2 months. Except for one patient with recurrent disease and one death, all patients were declared cured at the end of therapy.

CONCLUSION

Osteoarticular melioidosis should be suspected in high-risk individuals from endemic areas with single bone or joint involvement and surrounding myositis. Early diagnosis and prompt initiation of therapy is key to a favourable response.