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Frontiers in Veterinary Science 2023
PubMed: 37901106
DOI: 10.3389/fvets.2023.1303556 -
Trends in Microbiology Jan 2024is a Gram negative, facultative intracellular bacterium that resides in the rhizosphere of tropical soils. causes melioidosis, which is transmitted by cutaneous entry,...
is a Gram negative, facultative intracellular bacterium that resides in the rhizosphere of tropical soils. causes melioidosis, which is transmitted by cutaneous entry, ingestion, or inhalation of contaminated soil or water. Infection with can cause a wide array of clinical symptoms such as pneumonia, bone, joint, skin, genitourinary, and central nervous system infections, as well as parotid abscesses in children. Mammalian virulence is linked to the intracellular life cycle, which begins with attachment and internalization by host cells. can infect a wide range of eukaryotic cells, including macrophages, monocytes, and neutrophils, as well as nonphagocytic cells. Once internalized, a type 3 secretion system (T3SS) facilitates escape from the phagosome, and the bacteria replicate in the cytoplasm. Autotransporter protein BimA mediates actin polymerization, enabling to spread, cell to cell, using actin-based motility. This process, coupled with the activity of a type 6 secretion system (T6SS-5), results in host membrane fusion and the formation of multinucleated giant cells. Capsule polysaccharides also contribute to virulence and evasion of host innate immunity. Treatment of infections is complicated by the organism’s intrinsic resistance to multiple classes of antimicrobials, largely due to an abundance of efflux pumps and reduced outer membrane permeability. While is commonly associated with endemic ‘hotspots’ in southeast Asia and northern Australia, there is increasing evidence that it is likely endemic in a large range of tropical and subtropical areas, including regions in Africa, South America, the Middle East, Central America, and the Caribbean. Soil and climate conditions favorable for survival are also found in additional areas worldwide. Consequently, it is important for clinical and public health laboratories located outside of high-endemicity areas to be aware of , as well as for improved diagnostic and reporting methods.
Topics: Burkholderia pseudomallei; Burkholderia
PubMed: 37634974
DOI: 10.1016/j.tim.2023.07.008 -
The American Journal of Tropical... Jun 2023
Topics: Humans; Burkholderia pseudomallei; Melioidosis
PubMed: 37160279
DOI: 10.4269/ajtmh.23-0223 -
Frontiers in Cellular and Infection... 2024Animal models of infectious disease often serve a crucial purpose in obtaining licensure of therapeutics and medical countermeasures, particularly in situations where... (Review)
Review
Animal models of infectious disease often serve a crucial purpose in obtaining licensure of therapeutics and medical countermeasures, particularly in situations where human trials are not feasible, i.e., for those diseases that occur infrequently in the human population. The common marmoset (), a Neotropical new-world (platyrrhines) non-human primate, has gained increasing attention as an animal model for a number of diseases given its small size, availability and evolutionary proximity to humans. This review aims to (i) discuss the pros and cons of the common marmoset as an animal model by providing a brief snapshot of how marmosets are currently utilized in biomedical research, (ii) summarize and evaluate relevant aspects of the marmoset immune system to the study of infectious diseases, (iii) provide a historical backdrop, outlining the significance of infectious diseases and the importance of developing reliable animal models to test novel therapeutics, and (iv) provide a summary of infectious diseases for which a marmoset model exists, followed by an in-depth discussion of the marmoset models of two studied bacterial infectious diseases (tularemia and melioidosis) and one viral infectious disease (viral hepatitis C).
Topics: Animals; Humans; Callithrix; Disease Models, Animal; Communicable Diseases; Tularemia; Bacterial Infections
PubMed: 38465237
DOI: 10.3389/fcimb.2024.1340017 -
PLoS Neglected Tropical Diseases Nov 2023Neglected tropical diseases (NTDs) affect most impoverished communities in developing countries, like Myanmar in Southeast Asia. NTDs have been understudied and...
BACKGROUND
Neglected tropical diseases (NTDs) affect most impoverished communities in developing countries, like Myanmar in Southeast Asia. NTDs have been understudied and underreported in Myanmar.
METHODS
A systematic review of published and grey literature (1900-2023) on neglected tropical diseases (NTDs) in Myanmar was conducted. The literature search included five international databases: PubMed, EMBASE, Ovid Global Health, and Web of Science Core Collection and one national database: the Myanmar Central Biomedical Library (locally published papers and grey literature). The selection criteria included articles with all types of study designs of current or previous infections conducted in humans, that reported NTDs, recognised by WHO, US CDC, and listed in PLoS NTDs. We included melioidosis and rickettsioses which we consider also meet the definition of an NTD.
RESULTS
A total of 5941 records were retrieved and screened, of which, 672 (11%) met the selection criteria and were included in this review. Of the included articles, 449 (65%) were published after 2000 and 369 (55%) were from two regions (Yangon and Mandalay) of Myanmar. Of the included articles, 238 (35%) reported bacterial NTDs, 212 (32%) viral NTDs, 153 (23%) helminth NTDs, 25 (4%) protozoal NTDs and 39 (6%) reported more than one aetiology. Based on reported frequency in descending order, the bacterial NTDs were leprosy, Escherichia coli enteritis, salmonellosis, cholera, shigellosis, melioidosis, leptospirosis and rickettsioses; the viral NTDs were dengue, chikungunya and Japanese encephalitis virus (JEV) infection; the protozoal NTDs were amoebiasis, giardiasis and leishmaniasis, and the helminth NTDs were ascariasis, trichuriasis, hookworm disease, filariasis and strongyloidiasis.
CONCLUSION
This review summarises NTDs reported in Myanmar over the past 100 years. The findings suggest that most NTDs are likely to be under reported, especially from the majority of the country which is far from academic centres. Research capacity building together with strengthening of laboratory systems would lead to better understanding of the true burden of NTDs in Myanmar.
TRIAL REGISTRATION
PROSPERO registration ID: CRD42018092627.
Topics: Animals; Humans; Myanmar; Melioidosis; Ascariasis; Helminths; Neglected Diseases; Tropical Medicine; Encephalitis, Japanese; Rickettsia Infections
PubMed: 37910592
DOI: 10.1371/journal.pntd.0011706 -
The International Journal of... Oct 2023Melioidosis is a potentially life-threatening infection caused by the Gram-negative bacillus . Mediastinal melioidosis has a range of clinical presentations, making it... (Review)
Review
Melioidosis is a potentially life-threatening infection caused by the Gram-negative bacillus . Mediastinal melioidosis has a range of clinical presentations, making it difficult to diagnose: we therefore reviewed the evidence on the clinical characteristics, radiological features and invasive diagnostic modalities or interventions. An electronic search was conducted on three databases (PubMed, SCOPUS, Google Scholar) from November to December 2022. The initial search yielded 120 results, of which 34 studies met the inclusion criteria, but only 31 full-texts were retrievable. Among these, 4 were cohort studies, 26 case reports or series and 1 a conference abstract. The four main themes covered were mediastinal melioidosis as a diagnostic dilemma, unexpected complications, invasive interventions or an accompanying thoracic feature. Radiological manifestations included matting, necrosis and abscess-like collection. Severe presentations of mediastinal melioidosis included superior vena cava obstruction, sinus tract formation and pericardial tamponade. Transbronchial needle aspiration was the most common invasive diagnostic modality. Further research is needed to understand the relationship between the thoracic features of melioidosis on patient prognosis, its relationship to melioidosis transmission and potential preventive measures.
Topics: Humans; Burkholderia pseudomallei; Melioidosis; Radiography; Vena Cava, Superior
PubMed: 37749834
DOI: 10.5588/ijtld.23.0079 -
PLoS Neglected Tropical Diseases Jun 2023This systematic review and network meta-analysis (NMA) aimed to compare the efficacy of all available treatments for severe melioidosis in decreasing hospital mortality... (Meta-Analysis)
Meta-Analysis
BACKGROUND
This systematic review and network meta-analysis (NMA) aimed to compare the efficacy of all available treatments for severe melioidosis in decreasing hospital mortality and to identify eradication therapies with low disease recurrence rates and minimal risk of adverse drug events (AEs).
METHODOLOGY
Relevant randomized controlled trials (RCT) were searched from Medline and Scopus databases from their inception until July 31, 2022. RCTs that compared the efficacy between treatment regimens for severe melioidosis or eradication therapy of melioidosis, measured outcomes of in-hospital mortality, disease recurrence, drug discontinuation, or AEs, were included for review. A two-stage NMA with the surface under the cumulative ranking curve (SUCRA) was used to estimate the comparative efficacy of treatment regimens.
PRINCIPAL FINDINGS
Fourteen RCTs were included in the review. Ceftazidime plus granulocyte colony-stimulating factor (G-CSF), ceftazidime plus trimethoprim-sulfamethoxazole (TMP-SMX), and cefoperazone-sulbactam plus TMP-SMX had a lower mortality rate than other treatments and were ranked as the top three most appropriate treatments for severe melioidosis with the SUCRA of 79.7%, 66.6%, and 55.7%, respectively. However, these results were not statistically significant. For eradication therapy, treatment with doxycycline monotherapy for 20 weeks was associated with a significantly higher risk of disease recurrence than regimens containing TMP-SMX (i.e.,TMP-SMX for 20 weeks, TMP-SMX plus doxycycline plus chloramphenicol for more than 12 weeks, and TMP-SMX plus doxycycline for more than 12 weeks). According to the SUCRA, TMP-SMX for 20 weeks was ranked as the most efficacious eradication treatment (87.7%) with the lowest chance of drug discontinuation (86.4%), while TMP-SMX for 12 weeks had the lowest risk of AEs (95.6%).
CONCLUSION
Our results found a non-significant benefit of ceftazidime plus G-CSF and ceftazidime plus TMP-SMX over other treatments for severe melioidosis. TMP-SMX for 20 weeks was associated with a lower recurrence rate and minimal risk of adverse drug events compared to other eradication treatments. However, the validity of our NMA may be compromised by the limited number of included studies and discrepancies in certain study parameters. Thus, additional well-designed RCTs are needed to improve the therapy of melioidosis.
Topics: Humans; Trimethoprim, Sulfamethoxazole Drug Combination; Melioidosis; Doxycycline; Ceftazidime; Network Meta-Analysis; Granulocyte Colony-Stimulating Factor; Drug-Related Side Effects and Adverse Reactions
PubMed: 37307278
DOI: 10.1371/journal.pntd.0011382