-
Emerging Infectious Diseases Mar 2024In 2019, a melioidosis case in Maryland, USA, was shown to have been acquired from an ornamental fish tank contaminated with Burkholderia pseudomallei bacteria, likely...
In 2019, a melioidosis case in Maryland, USA, was shown to have been acquired from an ornamental fish tank contaminated with Burkholderia pseudomallei bacteria, likely derived from Southeast Asia. We investigated the presence of B. pseudomallei in ornamental fish tanks in the endemic area of Vientiane, Laos.
Topics: Animals; Laos; Burkholderia pseudomallei; Melioidosis; Bacteria; Fishes
PubMed: 38407187
DOI: 10.3201/eid3003.231674 -
Veterinary World Jan 2024, a highly pathogenic bacterium responsible for melioidosis, exhibits ecological ubiquity and thrives within soil and water reservoirs, posing significant infection...
BACKGROUND AND AIM
, a highly pathogenic bacterium responsible for melioidosis, exhibits ecological ubiquity and thrives within soil and water reservoirs, posing significant infection risks to humans and animals through direct contact. The aim of this study was to elucidate the genetic diversity and prevalence patterns of sequence types (STs) across a global spectrum and to understand the relationships between strains isolated from different sources.
MATERIALS AND METHODS
We performed a systematic review and meta-analysis in this study. Extensive research was carried out across three comprehensive databases, including PubMed, Scopus, and ScienceDirect with data collected from 1924 to 2023.
RESULTS
A total of 40 carefully selected articles contributed 2737 isolates attributed to 729 distinct STs and were incorporated into the systematic review. Among these, ST46 emerged as the most prominent, featuring in 35% of the articles and demonstrating a dominant prevalence, particularly within Southeast Asia. Moreover, ST51 consistently appeared across human, animal, and environmental studies. Subsequently, we performed a meta-analysis, focusing on nine specific STs: ST46, ST51, ST54, ST70, ST84, ST109, ST289, ST325, and ST376. Surprisingly, no statistically significant differences in their pooled prevalence proportions were observed across these compartments for ST46, ST70, ST289, ST325, and ST376 (all p > 0.69). Conversely, the remaining STs, including ST51, ST54, ST84, and ST109, displayed notable variations in their prevalence among the three domains (all p < 0.04). Notably, the pooled prevalence of ST51 in animals and environmental samples surpassed that found in human isolates (p < 0.01).
CONCLUSION
To the best of our knowledge, this study is the first systematic review and meta-analysis to investigate the intricate relationships between STs and their sources and contributes significantly to our understanding of diversity within the One Health framework.
PubMed: 38406370
DOI: 10.14202/vetworld.2024.26-36 -
Cureus Jan 2024Melioidosis is an uncommon bacterial infection that is endemic to countries like Southeast Asia and Northern Australia but less common in temperate zones than when seen...
Melioidosis is an uncommon bacterial infection that is endemic to countries like Southeast Asia and Northern Australia but less common in temperate zones than when seen in returned travelers. This disease can affect almost every organ, with the lung being the most common organ to be involved. Here, we present a 21-year-old diabetic male who came with complaints of fever, nonproductive cough, and sore throat with grade III-IV shortness of breath. Laboratory investigations revealed hypokalemia and isolates of on blood culture and sensitivity. High-resolution computed tomography (HRCT) of the chest showed widespread, variable-sized nodules with central cavitations diffusely scattered in bilateral lungs.
PubMed: 38371114
DOI: 10.7759/cureus.52409 -
CMAJ : Canadian Medical Association... Feb 2024
Topics: Humans; Melioidosis; Anti-Bacterial Agents; Arthritis, Infectious
PubMed: 38316453
DOI: 10.1503/cmaj.230902 -
Vaccine: X Mar 2024There are no licensed vaccines to protect vulnerable populations from the potentially fatal tropical infection, melioidosis, despite its causative agent, being endemic...
There are no licensed vaccines to protect vulnerable populations from the potentially fatal tropical infection, melioidosis, despite its causative agent, being endemic in tropical and subtropical regions. A promising vaccine candidate, BpOmpW protected mice from melioidosis infection for up to 81 days and stimulated robust interferon gamma responses in CD4, CD8, NK and NKT cells. In order to progress to human studies, selection of an adjuvant with an acceptable human safety profile that stimulates appropriate correlates of protection is essential. Here we demonstrate that the CAF01 vaccine adjuvant elicits optimal immune correlates of protection when administered with our BpOmpW vaccine. Specifically, we demonstrate that CAF01 administered with BpOmpW elicits robust Th1 responses, with potent IFN-γ responses in CD4 and CD8 T cells and NKT cells, in addition to Th17 and Th2 responses. This formulation will be particularly effective in protecting susceptible populations including people with type 2 diabetes from melioidosis.
PubMed: 38303776
DOI: 10.1016/j.jvacx.2024.100438 -
Microbiology Spectrum Mar 2024and are Gram-negative, soil-dwelling bacteria that are found in a wide variety of environmental niches. While is the causative agent of melioidosis in humans and...
and are Gram-negative, soil-dwelling bacteria that are found in a wide variety of environmental niches. While is the causative agent of melioidosis in humans and animals, members of the complex typically only cause disease in immunocompromised hosts. In this study, we report the identification of strains isolated from either patients or soil in Laos and Thailand that express a -like 6-deoxyheptan capsular polysaccharide (CPS). These strains were initially identified based on their positive reactivity in a latex agglutination assay that uses the CPS-specific monoclonal antibody (mAb) 4B11. Mass spectrometry and sequencing confirmed the identity of these isolates as (formerly genomovar I). Total carbohydrates extracted from cell pellets reacted with CPS-specific mAbs MCA147, 3C5, and 4C4, but did not react with the lipopolysaccharide-specific mAb Pp-PS-W. Whole genome sequencing of the isolates revealed the presence of genes demonstrating significant homology to those comprising the CPS biosynthetic gene cluster. Collectively, our results provide compelling evidence that strains expressing the same CPS as co-exist in the environment alongside . Since CPS is a target that is often used for presumptive identification of , it is possible that the occurrence of these unique strains may complicate the diagnosis of melioidosis.IMPORTANCE, the etiologic agent of melioidosis, is an important cause of morbidity and mortality in tropical and subtropical regions worldwide. The 6-deoxyheptan capsular polysaccharide (CPS) expressed by this bacterial pathogen is a promising target antigen that is useful for rapidly diagnosing melioidosis. Using assays incorporating CPS-specific monoclonal antibodies, we identified both clinical and environmental isolates of that express the same CPS antigen as . Because of this, it is important that staff working in melioidosis-endemic areas are aware that these strains co-exist in the same niches as and do not solely rely on CPS-based assays such as latex-agglutination, AMD Plus Rapid Tests, or immunofluorescence tests for the definitive identification of isolates.
Topics: Animals; Humans; Burkholderia pseudomallei; Melioidosis; Burkholderia cepacia; Polysaccharides; Antibodies, Monoclonal; Soil
PubMed: 38299821
DOI: 10.1128/spectrum.03321-23 -
Journal of Global Infectious Diseases 2023
PubMed: 38292688
DOI: 10.4103/jgid.jgid_46_23 -
Infection and Immunity Mar 2024Melioidosis is a disease that is difficult to treat due to the causative organism, being inherently antibiotic resistant and it having the ability to invade, survive,...
Melioidosis is a disease that is difficult to treat due to the causative organism, being inherently antibiotic resistant and it having the ability to invade, survive, and replicate in an intracellular environment. Combination therapy approaches are routinely being evaluated in animal models with the aim of improving the level of protection and clearance of colonizing bacteria detected. In this study, a subunit vaccine layered with the antibiotic finafloxacin was evaluated against an inhalational infection with in Balb/c mice. Groups of mice vaccinated, infected, and euthanized at antibiotic initiation had a reduced bacterial load compared to those that had not been immunized. In addition, the subunit vaccine provided a synergistic effect when it was delivered with a CpG ODN and finafloxacin was initiated at 48 h post-challenge. Vaccination was also shown to improve the outcome, in a composite measure of survival and clearance. In summary, layering a subunit vaccine with the antibiotic finafloxacin is a promising therapeutic alternative for use in the treatment of infections.
Topics: Animals; Mice; Burkholderia pseudomallei; Mice, Inbred BALB C; Melioidosis; Anti-Bacterial Agents; Vaccination; Vaccines, Subunit; Disease Models, Animal
PubMed: 38289122
DOI: 10.1128/iai.00455-23 -
Biomolecules Jan 2024Questions about which reactive oxygen species (ROS) or reactive nitrogen species (RNS) can escape from the mitochondria and activate signals must be addressed. In this...
Mitochondria Play Essential Roles in Intracellular Protection against Oxidative Stress-Which Molecules among the ROS Generated in the Mitochondria Can Escape the Mitochondria and Contribute to Signal Activation in Cytosol?
Questions about which reactive oxygen species (ROS) or reactive nitrogen species (RNS) can escape from the mitochondria and activate signals must be addressed. In this study, two parameters, the calculated dipole moment (debye, D) and permeability coefficient (Pm) (cm s), are listed for hydrogen peroxide (HO), hydroxyl radical (•OH), superoxide (O), hydroperoxyl radical (HO•), nitric oxide (•NO), nitrogen dioxide (•NO), peroxynitrite (ONOO), and peroxynitrous acid (ONOOH) in comparison to those for water (HO). O is generated from the mitochondrial electron transport chain (ETC), and several other ROS and RNS can be generated subsequently. The candidates which pass through the mitochondrial membrane include ROS with a small number of dipoles, i.e., HO, HO•, ONOOH, •OH, and •NO. The results show that the dipole moment of •NO is 0.35 D, indicating permeability; however, •NO can be eliminated quickly. The dipole moments of •OH (1.67 D) and ONOOH (1.77 D) indicate that they might be permeable. This study also suggests that the mitochondria play a central role in protecting against further oxidative stress in cells. The amounts, the long half-life, the diffusion distance, the Pm, the one-electron reduction potential, the p, and the rate constants for the reaction with ascorbate and glutathione are listed for various ROS/RNS, •OH, singlet oxygen (O), HO, O, HO•, •NO, •NO, ONOO, and ONOOH, and compared with those for HO and oxygen (O). Molecules with negative electrical charges cannot directly diffuse through the phospholipid bilayer of the mitochondrial membranes. Short-lived molecules, such as •OH, would be difficult to contribute to intracellular signaling. Finally, HO• and ONOOH were selected as candidates for the ROS/RNS that pass through the mitochondrial membrane.
Topics: Reactive Oxygen Species; Hydrogen Peroxide; Cytosol; Nitrogen Dioxide; Oxidative Stress; Nitric Oxide; Peroxynitrous Acid; Oxygen; Mitochondria
PubMed: 38275757
DOI: 10.3390/biom14010128 -
JAC-antimicrobial Resistance Feb 2024In 2022, WHO released the WHO AWaRe (Access, Watch, Reserve) antibiotic book to promote the rational use of antibiotics. Here, we review the AWaRe antibiotic book from... (Review)
Review
In 2022, WHO released the WHO AWaRe (Access, Watch, Reserve) antibiotic book to promote the rational use of antibiotics. Here, we review the AWaRe antibiotic book from the perspective of implementation in low-resource settings, using the Lao PDR (Laos) as a case study. Not all recommendations in the AWaRe antibiotic book match the epidemiology of infectious diseases and antimicrobial susceptibility patterns in Laos and other low- and middle-income countries (LMICs), e.g. melioidosis, rickettsial disease and leptospirosis are common causes of sepsis and febrile illness in Laos but do not feature in the AWaRe book. Conversely, some infectious diseases like -associated diarrhoea are in the AWaRe antibiotic book but rarely considered in Laos with no diagnostic tests available. Only 29/39 antibiotics in the AWaRe book are available in Laos, with no Reserve group antimicrobials available. The AWaRe book stimulates countries such as Laos to consider alternative diagnoses and include additional antimicrobials in the national essential medicines list (NEML). However, it should be updated to include regional important pathogens that are not included. Comprehensive antibiotic use guidelines alone might not assure appropriate use or control overuse of antibiotics. Access to antibiotics is challenging in low-resource settings in terms of unavailability in the country (low demand or small market size), patchy access, especially for those living in remote areas, and unaffordability. All these systemic factors can contribute to inappropriate use of antibiotics. Improved access to antibiotics, strengthening diagnostic capacity and promoting antibiotic stewardship should be combined.
PubMed: 38259905
DOI: 10.1093/jacamr/dlae004