Melioidosis is caused by community-acquired gram-negative bacillus Burkholderia pseudomallei which resides in soil and water. It was first described in 1912 in Burma and 1927 in Sri Lanka. Melioidosis presents with non-specific clinical and biochemical findings. Diagnosis is confirmed by the isolation of bacteria in cultures or demonstrating antibody response. Once the diagnosis is made, patients are managed with a course of intravenous antibiotics followed by a long course of oral antibiotics. Even with antibiotic treatments, most patients do not achieve complete recovery which results in chronic disease. Prolonged antibiotic therapy makes patients less compliant with treatment. Here we present a 50-year-old Sri Lankan male with diabetes mellitus presented with low-grade fever and back pain. He was found to have multiple abscesses involving the liver, spleen and left psoas muscle. Initially, he was evaluated for tuberculosis and later only melioidosis was diagnosed. The patient was managed with guided aspiration of abscesses and intravenous antibiotics. Subsequently, the patient defaulted on all treatments. It is important to consider melioidosis as a differential diagnosis in immunocompromised patients presented with multiple abscesses. It is important to maintain a registry for follow-up melioidosis patients to prevent becoming chronic melioidosis patients and to save healthcare costs.

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Melioidosis is a zoonotic disease, with its outbreaks being rare and indicative of an unusual concurrence of extreme climate and natural environmental factors. An outbreak of melioidosis cases emerged in Hainan following Typhoon \"Dianmu\" from October to December 2021, presenting an opportunity to identify the environmental sources of infection for these cases due to its nature as a well-defined point-source cluster. To investigate the relationship between the occurrence of these melioidosis cases and the environment, we extracted the entire genome of 25 clinical strains and conducted MLST typing, followed by whole genome sequencing and analysis of molecular genetic information for four ST46 genotypes from these strains. Phylogenetic and evolutionary relationships between Hainan sequence types (STs) and those found in other endemic regions were analyzed using IslandPath-DIMO, PHASTER, e-BURST, PHYLOViZ, and the maximum likelihood method. Notably, a total of 25 clinical strains were identified, encompassing 12 STs (ST46, ST1105, ST1991, ST30, ST1992, ST50, ST164, ST55, ST70, ST1993, ST1545, and ST58), with ST1991, ST1992, and ST1993 being newly discovered subtypes. PHYLOViZ clustering analysis divided the strains into two groups (A and B), both closely related to the Asian region. Phylogenetic tree analysis further revealed that most of the strains in this study were closely related to those found in Australia and Thailand. Analysis of patient information and visits to their residences suggested that contaminated water sources might be the primary source of infection during this outbreak. Our findings underscore that extreme weather events, such as typhoons, significantly increase the infection rate of B. pseudomallei, along with its genetic diversity, necessitating additional prevention strategies to control these B. pseudomallei infections.

Background We studied the clinical features and treatment outcome of patients with melioidosis in our hospital. Methods We did this retrospective observational chart review over a period of 7 years between December 2014 and February 2022. Results There were 59 cases and 23 deaths attributable to melioidosis over the study period. The age range was 5 to 74 years and 48 (81.3%) were men. The comorbid conditions included diabetes mellitus (68%), alcoholism (11.8%), pulmonary tuberculosis (6.7%) and chronic kidney disease (5%). Over three-fourths of patients (78%) presented during the rainy season (June to December) and were acute presentations (44 [75%]). The most common sites were liver and spleen, followed by the musculoskeletal system, skin, soft tissues, lungs and brain. Of the 21 (36%) patients with septic shock, 16 (76%) died. On the contrary, of 38 (64%) patients without septic shock, only 11% died. Of the 27 (47%) admitted to ICU, 11 (41%) died. In ICU, 18 (67%) were ventilated. Of the 23 (39%) deaths overall, median time from admission to death was 4 days. There were no relapses in the 42% patients followed up for 2-6 months. Conclusions The epidemiology of melioidosis is similar to other endemic areas with preponderance of men. There was a temporal association with the monsoon season and a higher number of acute cases. The differences included a higher proportion of deep visceral abscesses and musculo-skeletal involvement compared to lung involvement.

Melioidosis is an emerging tropical infectious disease in travelers. We present a case of travel related melioidosis in a 65-year-old man with chronic obstructive pulmonary disease and end stage renal disease following a two-week business trip to Thailand and attendance of the Songkran festival. This case emphasizes that vigilance, heightened clinical suspicion, and use of appropriate microbiology diagnostic tools are of paramount importance for a timely diagnosis and successful management. With the ever-increasing global travel, infectious diseases specialists, microbiologists, and public health professionals are constantly challenged by unfamiliar infections in returned travelers.

BACKGROUND: Melioidosis, a disease induced by Burkholderia pseudomallei, poses a significant health threat in tropical areas where it is endemic. Despite the availability of effective treatments, mortality rates remain notably elevated. Many risk factors are associated with mortality. This study aims to develop a scoring system for predicting the in-hospital mortality from melioidosis using readily available clinical data.
METHODS: The data were collected from Surin Hospital, Surin, Thailand, during the period from April 2014 to March 2017. We included patients aged 15 years and above who had cultures that tested positive for Burkholderia pseudomallei. The clinical prediction rules were developed using significant risk factors from the multivariable analysis.
RESULTS: A total of 282 patients with melioidosis were included in this study. In the final analysis model, 251 patients were used for identifying the significant risk factors of in-hospital fatal melioidosis. Five factors were identified and used for developing the clinical prediction rules, and the factors were as follows: qSOFA ≥ 2 (odds ratio [OR] = 2.39, p= 0.025), abnormal chest X-ray findings (OR = 5.86, p < 0.001), creatinine ≥ 1.5 mg/dL (OR = 2.80, p = 0.004), aspartate aminotransferase ≥50 U/L (OR = 4.032, p < 0.001), and bicarbonate ≤ 20 mEq/L (OR = 2.96, p = 0.002). The prediction scores ranged from 0 to 7. Patients with high scores (4-7) exhibited a significantly elevated mortality rate exceeding 65.0% (likelihood ratio [LR+] 2.18, p < 0.001) compared to the low-risk group (scores 0-3) with a lower mortality rate (LR + 0.18, p < 0.001). The area under the receiver operating characteristic curve (AUC) was 0.84, indicating good model performance.
CONCLUSIONS: This study presents a simple scoring system based on easily obtainable clinical parameters to predict in-hospital mortality in melioidosis patients. This tool may facilitate the early identification of high-risk patients who could benefit from more aggressive treatment strategies, potentially improving clinical decision-making and patient outcomes.

Background:Burkholderia pseudomallei, the causative agent of melioidosis, is highly genetically recombinant, resulting in significant genomic diversity. Multiple virulence factors have been associated with specific disease presentations. To date, there are limited data relating to genomic diversity and virulence factors associated with melioidosis cases in North Queensland, Australia. Aim: To describe the genetic diversity of B. pseudomallei and identify virulence factors associated with clinical risk factors and patient outcomes. Methods: Whole genome sequencing of clinical isolates was performed and analysed with clinical data obtained from a retrospective melioidosis cohort study. Results: Fifty-nine distinct sequence types (STs) were identified from the 128 clinical isolates. Six STs comprised 64/128 (50%) isolates. Novel STs accounted for 38/59 (64%) STs, with ST TSV-13 as the most prevalent (n = 7), and were less likely to possess an LPS A genotype or YLF gene cluster (p < 0.001). These isolates were most likely to be found outside the inner city (aOR: 4.0, 95% CI: 1.7-9.0, p = 0.001). ST TSV-13 was associated with increased mortality (aOR: 6.1, 95% CI: 1.2-30.9, p = 0.03). Patients with a history of alcohol excess were less likely to be infected by fhaB3 (aOR 0.2, 95% CI: 0.1-0.7, p = 0.01) or YLF (aOR: 0.4, 95% CI: 0.2-0.9, p = 0.04) positive isolates. Conclusions: There are a significant number of novel sequence types in Townsville, Australia. An emerging novel ST appears to have an association with geographic location and mortality. Ongoing investigation is required to further understand the impact of this ST on the Townsville region.

Melioidosis is a potentially severe disease caused by the gram-negative soil-dwelling bacterium called Burkholderia pseudomallei. The true breadth of the distribution of this tropical pathogen is starting to emerge with environmental and clinical isolates frequently characterized in new countries and regions. Even so, isolates, clinical cases, and genetic data from the continent of Africa remain scant. We previously confirmed the presence of B. pseudomallei in the environment of Ghana, unmasking a new area of endemicity for this pathogen. Here, we describe the genetic characteristics of isolates obtained from that environmental survey. Twenty-one isolates were subjected to whole genome sequencing and found to represent three discrete sequence types (ST), one of which was novel, and designated ST2058. Phylogenetic analysis places this novel isolate within a B. pseudomallei clade that includes genomes derived from the Americas, although it is closely related to a sub-clade that includes isolates from Africa. Importantly, phenotypic characterization demonstrates common features including API 20NE profiles and B. pseudomallei CPS to support existing diagnostics, and susceptibility to standard of care antibiotics often used in the clinical management of melioidosis. These findings add to our knowledge about the presence and distribution of B. pseudomallei in Africa and represent the first published genomes out of Ghana.

Melioidosis caused by Burkholderia pseudomallei is an infectious disease with a high mortality rate. In acute melioidosis, sepsis is a major cause of death among patients. Once the bacterium enters the bloodstream, immune system dysregulation ensues, leading to cytokine storms. In contrast to B. pseudomallei, a closely related but non-virulent strain B. thailandensis has rarely been reported to cause cytokine storms or death in patients. However, the mechanisms in which the virulent B. pseudomallei causes sepsis are not fully elucidated. It is well-documented that monocytes play an essential role in cytokine production in the bloodstream. The present study, therefore, determined whether there is a difference in the innate immune response to B. pseudomallei and B. thailandensis during infection of primary human monocytes and THP-1 monocytic cells by investigating pyroptosis, an inflammatory death pathway known to play a pivotal role in sepsis. Our results showed that although both bacterial species exhibited a similar ability to invade human monocytes, only B. pseudomallei can significantly increase the release of cytosolic enzyme lactate dehydrogenase (LDH) as well as the increases in caspase-1 and gasdermin D activations in both cell types. The results were consistent with the significant increase in IL-1β and IL-18 production, key cytokines involved in pyroptosis. Interestingly, there was no significant difference in other cytokine secretion, such as IL-1RA, IL-10, IL-12p70, IL-15, IL-8, and IL-23 in cells infected by both bacterial species. Furthermore, we also demonstrated that ROS production played a crucial role in controlling pyroptosis activation during B. pseudomallei infection in primary human monocytes. These findings suggested that pyroptosis induced by B. pseudomallei in the human monocytes may contribute to the pathogenesis of sepsis in acute melioidosis patients.

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