Displaying publications 201 - 220 of 243 in total

Abstract:
Sort:
  1. Fulltext Melioidotic osteomyelitis treated with antibiotic-calcium hydroxyapatite composite: case report with four-year follow-up
    Ng WM, Kwan MK, Merican AM
    Singapore Med J, 2006 Jan;47(1):71-4.
    PMID: 16397726
    Melioidosis is caused by an infection by Burkholderia pseudomallei. Osteomyelitis is a recognised manifestation of melioidosis but Burkholderia pseudomallei is a relatively rare aetiological agent in musculoskeletal infections. We report a 32-year-old diabetic man with septicaemia due to melioidotic infection of the spleen, liver and distal femur. The osteomyelitis relapsed despite being treated with the standard radical debridement and insertion of gentamycinimpregnated polymethylmetacrylate (PMMA) beads, followed by an optimal antibiotic therapy. The PMMA-gentamycin beads were then removed. The bone defect was debrided and packed with calcium hydroxyapatite blocks filled with ceftazidime powder. The osteomyelitis was successfully treated and the patient remained free of infection four years postoperatively. Computed tomography demonstrated successful incorporation of the calcium hydroxyapatite into host bone.
    Matched MeSH terms: Burkholderia pseudomallei/isolation & purification
  2. Expression and purification of a recombinant scFv towards the exotoxin of the pathogen, Burkholderia pseudomallei
    Lim KP, Li H, Nathan S
    J Microbiol, 2004 Jun;42(2):126-32.
    PMID: 15357306
    A single chain variable fragment (scFv) specific towards B. pseudomallei exotoxin had previously been generated from an existing hybridoma cell line (6E6AF83B) and cloned into the phage display vector pComb3H. In this study, the scFv was subcloned into the pComb3X vector to facilitate the detection and purification of expressed antibodies. Detection was facilitated by the presence of a hemagglutinin (HA) tag, and purification was facilitated by the presence of a histidine tag. The culture was grown at 30 degrees C until log phase was achieved and then induced with 1 mM IPTG in the absence of any additional carbon source. Induction was continued at 30 degrees C for five h. The scFv was discerned by dual processes-direct enzyme-linked immunosorbent assays (ELISA), and Western blotting. When compared to E. coli strains ER2537 and HB2151, scFv expression was observed to be highest in the E. coli strain Top10F'. The expressed scFv protein was purified via nickel-mediated affinity chromatography and results indicated that two proteins a 52 kDa protein, and a 30 kDa protein were co-purified. These antibodies, when blotted against immobilized exotoxin, exhibited significant specificity towards the exotoxin, compared to other B. pseudomallei antigens. Thus, these antibodies should serve as suitable reagents for future affinity purification of the exotoxin.
    Matched MeSH terms: Burkholderia pseudomallei/immunology*; Burkholderia pseudomallei/metabolism
  3. Fulltext Glycogen synthase kinase-3β inhibition improved survivability of mice infected with Burkholderia pseudomallei
    Tay TF, Maheran M, Too SL, Hasidah MS, Ismail G, Embi N
    Trop Biomed, 2012 Dec;29(4):551-67.
    PMID: 23202600
    The disease melioidosis, caused by the soil bacteria Burkholderia pseudomallei, often manifests as acute septicemia with high fatality. Glycogen synthase kinase-3β (GSK3β) plays a key role during the inflammatory response induced by bacteria. We used a murine model of acute melioidosis to investigate the effects of LiCl, a GSK3 inhibitor on experimental animal survivability as well as TNF-α, IL-1β, IFN-γ, IL-10 and IL-1Ra cytokine levels in blood, lung, liver and spleen of B. pseudomallei-infected mice. Our results showed that administration of 100 μg/g LiCl improved survivability of mice infected with 5 X LD50 of B. pseudomallei. Bacterial counts in spleen, liver and lungs of infected mice administered with LiCl were lower than non-treated controls. Our data also revealed that GSK3β is phosphorylated in the spleen, liver and lung of animals infected with B. pseudomallei. However in infected animals administered with LiCl, higher levels of pGSK3 were detected in the organs. Levels of proinflammatory cytokines (TNF-α, IL-1β and IFN-γ) and anti-inflammatory cytokines (IL-10 and IL-1Ra) in sera and organs tested were elevated significantly following B. pseudomallei infection. With GSK3β inhibition, pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β) were significantly decreased in all the samples tested whilst the levels of anti-inflammatory cytokines, IL-10 (spleen and lung) and IL-1Ra (spleen, liver and sera) were further elevated. This study represents the first report implicating GSK3β in the modulation of cytokine production during B. pseudomallei infection thus reiterating the important role of GSK3β in the inflammatory response caused by bacterial pathogens.
    Matched MeSH terms: Burkholderia pseudomallei/isolation & purification; Burkholderia pseudomallei/pathogenicity*
  4. Fulltext Development of multiplex real-time PCR for the rapid detection of five bacterial causes of community acquired pneumonia
    Al-Marzooq F, Imad MA, How SH, Kuan YC
    Trop Biomed, 2011 Dec;28(3):545-56.
    PMID: 22433883 MyJurnal
    Establishing a microbial diagnosis for patients with community-acquired pneumonia (CAP) is still challenging and is often achieved in only 30-50% of cases. Polymerase chain reaction (PCR) has been shown to be more sensitive than conventional microbiological methods and it could help to increase the microbial yield for CAP patients. This study was designed to develop, optimize and evaluate multiplex real-time PCR as a method for rapid differential detection of five bacterial causes of CAP namely Streptococcus pneumoniae, Burkholderia pseudomallei and atypical bacterial pathogens, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella pneumophila. Duplex and triplex real-time PCR assays were developed using five sets of primers and probes that were designed based on an appropriate specific gene for each of the above CAP pathogens. The performance of primers for each organism was tested using SYBR Green melt curve analysis following monoplex realtime PCR amplification. Monoplex real-time PCR assays were also used to optimize each primers-probe set before combining them in multiplex assays. Two multiplex real-time PCR assays were then optimized; duplex assay for the differential detection of S. pneumoniae and B. pseudomallei, and triplex assay for the atypical bacterial pathogens. Both duplex and triplex real-time PCR assays were tested for specificity by using DNA extracted from 26 related microorganisms and sensitivity by running serial dilutions of positive control DNAs. The developed multiplex real-time PCR assays shall be used later for directly identifying CAP causative agents in clinical samples.
    Matched MeSH terms: Burkholderia pseudomallei/genetics; Burkholderia pseudomallei/isolation & purification
  5. Fulltext Delayed activation of host innate immune pathways in streptozotocin-induced diabetic hosts leads to more severe disease during infection with Burkholderia pseudomallei
    Chin CY, Monack DM, Nathan S
    Immunology, 2012 Apr;135(4):312-32.
    PMID: 22136109 DOI: 10.1111/j.1365-2567.2011.03544.x
    Diabetes mellitus is a predisposing factor of melioidosis, contributing to higher mortality rates in diabetics infected with Burkholderia pseudomallei. To investigate how diabetes alters the inflammatory response, we established a streptozotocin (STZ) -induced diabetic murine acute-phase melioidosis model. Viable B. pseudomallei cells were consistently detected in the blood, liver and spleen during the 42-hr course of infection but the hyperglycaemic environment did not increase the bacterial burden. However, after 24 hr, granulocyte counts increased in response to infection, whereas blood glucose concentrations decreased over the course of infection. A genome-wide expression analysis of the STZ-diabetic murine acute melioidosis liver identified ~1000 genes whose expression was altered in the STZ-diabetic mice. The STZ-diabetic host transcriptional response was compared with the normoglycaemic host transcriptional response recently reported by our group. The microarray data suggest that the presence of elevated glucose levels impairs the host innate immune system by delaying the identification and recognition of B. pseudomallei surface structures. Consequently, the host is unable to activate the appropriate innate immune response over time, which may explain the increased susceptibility to melioidosis in the STZ-diabetic host. Nevertheless, a general 'alarm signal' of infection as well as defence programmes are still triggered by the STZ-diabetic host, although only 24 hr after infection. In summary, this study demonstrates that in the face of a B. pseudomallei acute infection, poor glycaemic control impaired innate responses during the early stages of B. pseudomallei infection, contributing to the increased susceptibility of STZ-induced diabetics to this fatal disease.
    Matched MeSH terms: Burkholderia pseudomallei/pathogenicity*
  6. Fulltext Incidence, risk factors and clinical epidemiology of melioidosis: a complex socio-ecological emerging infectious disease in the Alor Setar region of Kedah, Malaysia
    Hassan MR, Pani SP, Peng NP, Voralu K, Vijayalakshmi N, Mehanderkar R, et al.
    BMC Infect Dis, 2010;10:302.
    PMID: 20964837 DOI: 10.1186/1471-2334-10-302
    Melioidosis, a severe and fatal infectious disease caused by Burkholderia pseudomallei, is believed to an emerging global threat. However, data on the natural history, risk factors, and geographic epidemiology of the disease are still limited.
    Matched MeSH terms: Burkholderia pseudomallei/isolation & purification*
  7. Fulltext Melioidotic septic arthritis: a case report and literature review
    Raja NS
    J Microbiol Immunol Infect, 2007 Apr;40(2):178-82.
    PMID: 17446969
    Burkholderia pseudomallei, the causative agent of melioidosis, is endemic in southeast Asia and northern Australia. In recent years, the incidence of melioidosis has increased worldwide. Septic arthritis is a rare but well-recognized manifestation of melioidosis. Patients with underlying medical conditions, such as diabetes mellitus, renal impairment, cirrhosis, and malignancy are at greater risk. The presentations of melioidotic septic arthritis often mimic other disease processes and patients may not always be clinically septic. We present a case of septic arthritis due to B. pseudomallei in a 66-year-old male with diabetes mellitus presenting with a history of fever and ankle swelling. Follow-up ankle X-ray showed soft tissue swelling. Synovial fluid and blood samples grew B. pseudomallei. The patient improved gradually after parenteral administration of ceftazidime (2 g 8-hourly) and cotrimoxazole (1440 mg 8-hourly). He was discharged on oral cotrimoxazole (1440 mg 12-hourly), doxycycline (100 mg 12-hourly), and chloramphenicol (500 mg 6-hourly) for 6 months. This case highlights the possible occurrence of melioidotic septic arthritis, and the importance of prompt initiation of appropriate antimicrobials to achieve good outcomes.
    Study site: Emergency department, University of Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
    Matched MeSH terms: Burkholderia pseudomallei/isolation & purification*
  8. Selective media and real-time PCR improves diagnosis of melioidosis in community-acquired pneumonia in a low-incidence setting in Kuala Lumpur, Malaysia
    Subakir H, Chong YM, Chan YF, Hasan MS, Jamaluddin MFH, Pang YK, et al.
    J Med Microbiol, 2020 Jan;69(1):49-51.
    PMID: 31750812 DOI: 10.1099/jmm.0.001108
    Introduction.Burkholderia pseudomallei (melioidosis) is an important cause of community-acquired pneumonia (CAP) in the tropics. Selective medium is recommended for laboratory diagnosis with non-sterile respiratory samples, while PCR is not routinely used due to variable reported performance. The effectiveness of these diagnostic modalities varies by site.Aim. To compare selective media and real-time PCR (qPCR) with routine media in detecting B. pseudomallei in CAP respiratory samples in a low-incidence setting in Kuala Lumpur, Malaysia.Methodology. Respiratory samples were routinely cultured on blood, chocolate and MacConkey agar (RESP-ROUTINE), and compared to culture on selective Ashdown medium (RESP-SELECTIVE) and qPCR. The gold standard was routine culture of B. pseudomallei from any site (ALL-ROUTINE).Results.B. pseudomallei was detected in 8/204 (3.9 %) samples. Overall sensitivity rates differed (P=0.03) for qPCR (100%), RESP-SELECTIVE (87.5%) and RESP-ROUTINE (50%). There was a trend towards lower median days to positive culture for RESP-SELECTIVE (1 day) compared to RESP-ROUTINE (2 days, P=0.08) and ALL-ROUTINE (2 days, P=0.06). Reagent costs for each additional detection were USD59 for RESP-SELECTIVE and USD354 for PCR.Conclusions. In a low-incidence setting, selective culture of respiratory samples on Ashdown was more sensitive and allowed quicker identification than routine media, at reasonable cost. Blood cultures are critical, confirming four cases missed by routine respiratory culture. Selective medium is useful in early pneumonia (pre-sepsis) and resource-limited settings where blood cultures are infrequently done. Real-time PCR is costly, but highly sensitive and useful for high-risk patients with diabetes, cancer or immunosuppressants, or requiring ventilation or intensive care.
    Matched MeSH terms: Burkholderia pseudomallei/isolation & purification*
  9. Fulltext Regulatory role of GSK3β in the activation of NF-κB and modulation of cytokine levels in Burkholderia pseudomallei-infected PBMC isolated from streptozotocin-induced diabetic animals
    Maniam P, Nurul Aiezzah Z, Mohamed R, Embi N, Hasidah MS
    Trop Biomed, 2015 Mar;32(1):36-48.
    PMID: 25801253
    Increased susceptibility of diabetics to melioidosis, a disease caused by the Burkholderia pseudomallei bacterium is believed to be attributed to dysfunction of the innate immune system. However, the underlying mechanism of the innate susceptibility is not well-understood. Glycogen synthase kinase-3β (GSK3β) plays an important role in the innate inflammatory response caused by bacterial pathogens. The present study was conducted to investigate the effects of GSK3β inhibition by LiCl on levels of pro- and anti-inflammatory cytokines; and the activity of transcription factor NF-κB in B. pseudomallei-infected peripheral blood mononuclear cells (PBMC) derived from diabetic-induced and normal Sprague Dawley rats. In addition, the effects of LiCl on intracellular bacterial counts were also investigated. Infection of PBMC from diabetic and normal rats with B. pseudomallei resulted in elevated levels of cytokines (TNF-α, IL-12 and IL-10) and phosphorylation of NF-κB in both cell types. Intracellular bacterial counts decreased with time in both cell types during infection. However bacterial clearance was less prominent in diabetic PBMC. Burkholderia pseudomallei infection also caused inactivation (Ser9 phosphorylation) of GSK3β in normal PBMC, an effect absent in infected diabetic PBMC. Inhibition of GSK3β by LiCl lowered the levels of pro-inflammatory cytokines (TNF-α and IL-12) in both normal and diabetic PBMC. Similarly, phosphorylated NF- κB (pNF-κB) levels in both cell types were decreased with LiCl treatment. Also, LiCl was able to significantly decrease the intracellular bacterial count in normal as well as diabetic PBMC. Interestingly, the levels of anti-inflammatory cytokine IL-10 in both normal and diabetic PBMC were further elevated with GSK3β inhibition. More importantly, GSK3β in infected diabetic PBMC was inactivated as in their non-diabetic counterparts upon LiCl treatment. Taken together, our results suggest that inhibition of dysregulated GSK3β in diabetic PBMC resulted in the inactivation of NF-κB and modulation of inflammatory cytokine levels. This is evidence that dysregulation of GSK3β is a contributing factor in the molecular basis of innate dysfunction and susceptibility of diabetic host to melioidosis infection.
    Matched MeSH terms: Burkholderia pseudomallei/immunology*
  10. A 5-year retrospective study of melioidosis cases treated in a district specialist hospital
    Tang RY, Lim SH, Lam JE, Nurasykin S, Eileen T, Chan YW
    Med J Malaysia, 2019 12;74(6):472-476.
    PMID: 31929471
    INTRODUCTION: Melioidosis is caused by Burkholderia pseudomallei, a gram-negative aerobic bacillus, found in the soil and surface water. Treating melioidosis has been a challenge in district hospitals due to high usage of broad spectrum antibiotics and prolonged hospitalisation. This study is to review the patients' demography, clinical presentations and microbiological data.

    METHODS: A 5-year retrospective study was carried out on patients admitted with culture positive for melioidosis from year 2013 to 2017 in Hospital Teluk Intan, Perak.

    RESULTS: There were a total of 46 confirmed cases of melioidosis. Majority of the patients were working in the agricultural and farming (28.6%), and factories (25.7%). Thirty-one patients had diabetes mellitus (71.1%). Presentations of patients with melioidosis included pneumonia (54.3%), skin and soft tissue infection (19.6%), deep abscesses (15.2%) and bone and joint infections (13%). An average of 5.8 days was needed to confirm the diagnosis of melioidosis via positive culture. However, only 39.4% of these patients were started on ceftazidime or carbapenem as the empirical therapy. The intensive care unit (ICU) admission rate for melioidosis was 46% and the mortality rate was 52%. Our microbial cultures showed good sensitivity towards cotrimoxazole (97.1%), ceftazidime (100%) and carbapenem (100%).

    CONCLUSION: Melioidosis carries high mortality rate, especially with lung involvement and bacteremia. Physicians should have high clinical suspicion for melioidosis cases to give appropriate antimelioidosis therapy early.

    Matched MeSH terms: Burkholderia pseudomallei/isolation & purification
  11. Fulltext Honeycomb and necklace signs in liver abscesses secondary to melioidosis
    Ong SCL, Alemam MMM, Zakaria NA, Abdul Halim NA
    BMJ Case Rep, 2017 Oct 19;2017.
    PMID: 29054959 DOI: 10.1136/bcr-2017-222342
    Melioidosis is endemic in Southeast Asia and tropical Australia with varying clinical features from benign skin lesions to fatal septicaemia. Imaging plays an important role in evaluation of the melioid liver abscesses. A 45-year-old man with underlying diabetes presented with fever and lethargy for 2 weeks and abdominal pain for 2 days. His liver was enlarged on examination. Blood investigations revealed mild leucocytosis and raised liver enzymes. Ultrasound showed multiple multiloculated hypoechoic lesions throughout the liver and spleen. CT of abdomen confirmed that some liver lesions were made up of asymmetric locules of varying sizes (honeycomb sign), while others had hypodense centre with small symmetric peripheral locules in radial fashion (necklace sign). Blood culture was positive for Burkholderia pseudomallei He was subsequently treated with ceftazidime for a month followed by oral trimethoprim-sulfamethoxazole for 3 months. Follow-up CT of abdomen a month after diagnosis and treatment showed resolving hepatic and splenic lesions.
    Matched MeSH terms: Burkholderia pseudomallei/isolation & purification
  12. Isolations of enteric pathogens from synanthropic flies trapped in downtown Kuala Lumpur
    Sulaiman S, Othman MZ, Aziz AH
    J Vector Ecol, 2000 Jun;25(1):90-3.
    PMID: 10925800
    Four species of synanthropic flies were trapped in downtown Kuala Lumpur: Chrysomya megacephala, Chrysomya rufifacies, Musca domestica, and Musca sorbens. Burkholderia pseudomallei, the organism causing melioidosis, was the dominant bacteria isolated from Chrysomya megacephala. Klebsiella oxytoca, commonly associated with nosocomial infections, was commonly isolated from Chrysomya megacephala, Musca domestica, and Musca sorbens. Aeromonas hydrophila, the bacteria causing gastroenteritis, was predominantly isolated from Chrysomya megacephala and also from Musca domestica and Musca sorbens. A total of 18 bacterial species was isolated from the synanthropic flies trapped. Burkholderia pseudomallei had been reported for the first time.
    Matched MeSH terms: Burkholderia pseudomallei/isolation & purification
  13. Fulltext Melioidosis: Clinical impact and public health threat in the tropics
    Perumal Samy R, Stiles BG, Sethi G, Lim LHK
    PLoS Negl Trop Dis, 2017 May;11(5):e0004738.
    PMID: 28493905 DOI: 10.1371/journal.pntd.0004738
    This review briefly summarizes the geographical distribution and clinical impact of melioidosis, especially in the tropics. Burkholderia pseudomallei (a gram-negative bacterium) is the major causative agent for melioidosis, which is prevalent in Singapore, Malaysia, Thailand, Vietnam, and Northern Australia. Melioidosis patients are increasingly being recognized in other parts of the world. The bacteria are intrinsically resistant to many antimicrobial agents, but prolonged treatment, especially with combinations of antibiotics, may be effective. Despite therapy, the overall case fatality rate of septicemia in melioidosis remains significantly high. Intracellular survival of the bacteria within macrophages may progress to chronic infections, and about 10% of patients suffer relapses. In the coming decades, melioidosis will increasingly afflict travelers throughout many global regions. Clinicians managing travelers returning from the subtropics or tropics with severe pneumonia or septicemia should consider acute melioidosis as a differential diagnosis. Patients with open skin wounds, diabetes, or chronic renal disease are at higher risk for melioidosis and should avoid direct contact with soil and standing water in endemic regions. Furthermore, there are fears that B. pseudomallei may be used as a biological weapon. Technological advancements in molecular diagnostics and antibiotic therapy are improving the disease outcomes in endemic areas throughout Asia. Research and development efforts on vaccine candidates against melioidosis are ongoing.
    Matched MeSH terms: Burkholderia pseudomallei/pathogenicity*
  14. Fulltext Molecular evidence of Burkholderia pseudomallei genotypes based on geographical distribution
    Zulkefli NJ, Mariappan V, Vellasamy KM, Chong CW, Thong KL, Ponnampalavanar S, et al.
    PeerJ, 2016;4:e1802.
    PMID: 26998408 DOI: 10.7717/peerj.1802
    Background. Central intermediary metabolism (CIM) in bacteria is defined as a set of metabolic biochemical reactions within a cell, which is essential for the cell to survive in response to environmental perturbations. The genes associated with CIM are commonly found in both pathogenic and non-pathogenic strains. As these genes are involved in vital metabolic processes of bacteria, we explored the efficiency of the genes in genotypic characterization of Burkholderia pseudomallei isolates, compared with the established pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) schemes. Methods. Nine previously sequenced B. pseudomallei isolates from Malaysia were characterized by PFGE, MLST and CIM genes. The isolates were later compared to the other 39 B. pseudomallei strains, retrieved from GenBank using both MLST and sequence analysis of CIM genes. UniFrac and hierachical clustering analyses were performed using the results generated by both MLST and sequence analysis of CIM genes. Results. Genetic relatedness of nine Malaysian B. pseudomallei isolates and the other 39 strains was investigated. The nine Malaysian isolates were subtyped into six PFGE profiles, four MLST profiles and five sequence types based on CIM genes alignment. All methods demonstrated the clonality of OB and CB as well as CMS and THE. However, PFGE showed less than 70% similarity between a pair of morphology variants, OS and OB. In contrast, OS was identical to the soil isolate, MARAN. To have a better understanding of the genetic diversity of B. pseudomallei worldwide, we further aligned the sequences of genes used in MLST and genes associated with CIM for the nine Malaysian isolates and 39 B. pseudomallei strains from NCBI database. Overall, based on the CIM genes, the strains were subtyped into 33 profiles where majority of the strains from Asian countries were clustered together. On the other hand, MLST resolved the isolates into 31 profiles which formed three clusters. Hierarchical clustering using UniFrac distance suggested that the isolates from Australia were genetically distinct from the Asian isolates. Nevertheless, statistical significant differences were detected between isolates from Malaysia, Thailand and Australia. Discussion. Overall, PFGE showed higher discriminative power in clustering the nine Malaysian B. pseudomallei isolates and indicated its suitability for localized epidemiological study. Compared to MLST, CIM genes showed higher resolution in distinguishing those non-related strains and better clustering of strains from different geographical regions. A closer genetic relatedness of Malaysian isolates with all Asian strains in comparison to Australian strains was observed. This finding was supported by UniFrac analysis which resulted in geographical segregation between Australia and the Asian countries.
    Matched MeSH terms: Burkholderia pseudomallei
  15. Fulltext Curcumin rescues Caenorhabditis elegans from a Burkholderia pseudomallei infection
    Eng SA, Nathan S
    Front Microbiol, 2015;6:290.
    PMID: 25914690 DOI: 10.3389/fmicb.2015.00290
    The tropical pathogen Burkholderia pseudomallei requires long-term parenteral antimicrobial treatment to eradicate the pathogen from an infected patient. However, the development of antibiotic resistance is emerging as a threat to this form of treatment. To meet the need for alternative therapeutics, we proposed a screen of natural products for compounds that do not kill the pathogen, but in turn, abrogate bacterial virulence. We suggest that the use of molecules or compounds that are non-bactericidal (bacteriostatic) will reduce or abolish the development of resistance by the pathogen. In this study, we adopted the established Caenorhabditis elegans-B. pseudomallei infection model to screen a collection of natural products for any that are able to extend the survival of B. pseudomallei infected worms. Of the 42 natural products screened, only curcumin significantly improved worm survival following infection whilst not affecting bacterial growth. This suggested that curcumin promoted B. pseudomallei-infected worm survival independent of pathogen killing. To validate that the protective effect of curcumin was directed toward the pathogen, bacteria were treated with curcumin prior to infection. Worms fed with curcumin-treated bacteria survived with a significantly extended mean-time-to-death (p < 0.0001) compared to the untreated control. In in vitro assays, curcumin reduced the activity of known virulence factors (lipase and protease) and biofilm formation. To determine if other bacterial genes were also regulated in the presence of curcumin, a genome-wide transcriptome analysis was performed on curcumin-treated pathogen. A number of genes involved in iron acquisition and transport as well as genes encoding hypothetical proteins were induced in the presence of curcumin. Thus, we propose that curcumin may attenuate B. pseudomallei by modulating the expression of a number of bacterial proteins including lipase and protease as well as biofilm formation whilst concomitantly regulating iron transport and other proteins of unknown function.
    Matched MeSH terms: Burkholderia pseudomallei
  16. Fulltext Melioidosis transfusion transmitted infection in beta thalassemia patient’s
    Sahrol Nizam Bin Abu Bakar, Al-Afiq Alias, Masrah Tata
    Malaysian Journal of Medicine and Health Sciences, 2019;15(106):100-100.
    MyJurnal
    Introduction:Transfusion Transmitted Infections is occurring worldwide. The common organisms related reported in literature were Human Immunodefiency Virus, Hepatitis B and C Virus, bacterial contamination and Malaria par-asites. Meanwhile, Melioidosis is endemic disease in Malaysia and especially Sabah. Mortality due to Melioidosis septicaemia was also high. It ranges between 60%-80%. In Sabah, 74% of Thalassemia children were diagnosed with Bacteraemia Melioidosis and 50% had died due to the organisms. The incidence of Melioidosis Transfusion Transmitted Infection is rarely reported in the literature. Case Description: A 17-year-old girl was diagnosed having Beta thalassemia major since 5 years old and splenectomised 8 years ago. Currently on prophylaxis Penicillin and Ex-jade. She was admitted into hospital for monthly blood transfusion. Two days prior to admission, patient complained of having sore throat and cough but no fever and other complained. On examination, the tonsil enlarged and was treated as exudative tonsillitis. She was transfused with 2 pint packed cells within 2 days. No transfusion reaction noted. Day seven admission, she had high grade fever and redness of the right hand cannulation site and was treated as right hand cellulitis with intravenous Cloxacillin. Full blood count shows Total White Cell count was 24.9 x109 /L, Haemoglobin level was 9.3 g/dl and Platelets was 462x109/L. Blood for culture and sensitivity was taken and Chest X-ray noted haziness over the left mid and lower zone of the lung and was treated as Hospital Acquired Pneumonia. She was referred to tertiary hospital for further management. Her conditioned deteriorated and died at the casualty unit in the tertiary hospital. Blood culture was positive for Burkholderia pseudomallei. The case was reported to Dis-trict health office for further investigation. Blood donor tracing was done and was positive for Melioidosis through Elisa Antibody titre IgM for Melioidosis (1:320). The patient’s house and school were visited and investigated. All environmental samples were negative for Burkholderia pseudomallei. Conclusion: Its shows a relationship between blood donations infected with Burkholderia pseudomallei causing mortality of Beta Thalassemia patients. It is highly recommended to screen all blood products for communicable disease fatal organisms.
    Matched MeSH terms: Burkholderia pseudomallei
  17. Fulltext Experimental exposure of Burkholderia pseudomallei crude culture filtrate upregulates PD-1 on T lymphocytes
    Menon N, Mariappan V, Vellasamy KM, Samudi C, See JX, Ganesh PS, et al.
    Access Microbiol, 2020;2(5):acmi000110.
    PMID: 32974575 DOI: 10.1099/acmi.0.000110
    Burkholderia pseudomallei is the causative agent for melioidosis. Because of its intracellular nature, the bacterium is capable of replicating within a plethora of eukaryotic cell lines. B. pseudomallei can remain dormant within host cells without symptoms for years, causing recrudescent infections. Here, we investigated the pathogenesis mechanism behind the suppression of T cell responses by B. pseudomallei . Peripheral blood mononuclear cells (1×106 cells/well) isolated by Ficoll Paque (Sigma-Aldrich) density gradient centrifugation were incubated with optimized concentrations of bacterial crude culture filtrate antigens (CFAs) (10 ug ml-1) and heat-killed bacteria [1 : 10 multiplicity of infection (m.o.i.)]. Following incubation, cells were investigated for surface expression of coinhibitory molecules by flow cytometry. We found that B. pseudomallei induced the upregulation of programmed death 1 (PD-1), a molecule responsible for T cell exhaustion, on T cells in vitro following exposure to crude CFAs of B. pseudomallei . This upregulation of PD-1 probably contributes to poor immune surveillance and disease pathogenesis.
    Matched MeSH terms: Burkholderia pseudomallei
  18. Fulltext The relationship between bacterial sources and genotype to the antimicrobial resistance pattern of Burkholderia pseudomallei
    Sadiq MA, Hassan L, Aziz SA, Zakaria Z, Musa HI, Amin MM
    Vet World, 2018 Nov;11(10):1404-1408.
    PMID: 30532493 DOI: 10.14202/vetworld.2018.1404-1408
    Background: Melioidosis is a fatal emerging infectious disease of both man and animal caused by bacteria Burkholderia pseudomallei. Variations were suggested to have existed among the different B. pseudomallei clinical strains/genotypes which may implicate bacterial susceptibility and resistance toward antibiotics.

    Aim: This study was designed to determine whether the phenotypic antibiotic resistance pattern of B. pseudomallei is associated with the source of isolates and the genotype.

    Materials and Methods: A collection of 111 B. pseudomallei isolates from veterinary cases of melioidosis and the environments (soil and water) were obtained from stock cultures of previous studies and were phylogenetically characterized by multilocus sequence typing (ST). The susceptibility to five antibiotics, namely meropenem (MEM), imipenem, ceftazidime (CAZ), cotrimoxazole (SXT), and co-amoxiclav (AMC), recommended in both acute and eradication phases of melioidosis treatment were tested using minimum inhibitory concentration antibiotics susceptibility test.

    Results: Majority of isolates were susceptible to all antibiotics tested while few resistant strains to MEM, SXT, CAZ, and AMC were observed. Statistically significant association was found between resistance to MEM and the veterinary clinical isolates (p<0.05). The likelihood of resistance to MEM was significantly higher among the novel ST 1130 isolates found in veterinary cases as compared to others.

    Conclusion: The resistance to MEM and SXT appeared to be higher among veterinary isolates, and the novel ST 1130 was more likely to be resistant to MEM as compared to others.

    Matched MeSH terms: Burkholderia pseudomallei
  19. Fulltext Encapsulating peritoneal sclerosis associated with Burkholderia pseudomallei peritonitis
    Aulia Z, Wan Ali WASR, Shahar MA
    Saudi J Kidney Dis Transpl, 2018 12 28;29(6):1484-1487.
    PMID: 30588983 DOI: 10.4103/1319-2442.248318
    Burkholderia pseudomallei is a known motile organism in soil. Its infection is usually described in immunocompromised patients. It inflicts serious infection with high mortality and morbidity rate. We report a rare case of an end-stage renal disease patient on regular continuous ambulatory peritoneal dialysis (PD) who developed melioidosis PD peritonitis. Within a short period of time, she developed encapsulating peritoneal sclerosis evidenced by the intraoperative findings of intraabdominal cocooning. Choice and duration of antibiotic are important for proper eradication of the organism. Early diagnosis and treatment of both conditions also may improve the prognoses.
    Matched MeSH terms: Burkholderia pseudomallei
  20. Fulltext Genomic and RT-qPCR analysis of trimethoprim-sulfamethoxazole and meropenem resistance in Burkholderia pseudomallei clinical isolates
    Schnetterle M, Gorgé O, Nolent F, Boughammoura A, Sarilar V, Vigier C, et al.
    PLoS Negl Trop Dis, 2021 Feb;15(2):e0008913.
    PMID: 33592059 DOI: 10.1371/journal.pntd.0008913
    BACKGROUND: Melioidosis is an endemic disease in southeast Asia and northern Australia caused by the saprophytic bacteria Burkholderia pseudomallei, with a high mortality rate. The clinical presentation is multifaceted, with symptoms ranging from acute septicemia to multiple chronic abscesses. Here, we report a chronic case of melioidosis in a patient who lived in Malaysia in the 70s and was suspected of contracting tuberculosis. Approximately 40 years later, in 2014, he was diagnosed with pauci-symptomatic melioidosis during a routine examination. Four strains were isolated from a single sample. They showed divergent morphotypes and divergent antibiotic susceptibility, with some strains showing resistance to trimethoprim-sulfamethoxazole and fluoroquinolones. In 2016, clinical samples were still positive for B. pseudomallei, and only one type of strain, showing atypical resistance to meropenem, was isolated.

    PRINCIPAL FINDINGS: We performed whole genome sequencing and RT-qPCR analysis on the strains isolated during this study to gain further insights into their differences. We thus identified two types of resistance mechanisms in these clinical strains. The first one was an adaptive and transient mechanism that disappeared during the course of laboratory sub-cultures; the second was a mutation in the efflux pump regulator amrR, associated with the overexpression of the related transporter.

    CONCLUSION: The development of such mechanisms may have a clinical impact on antibiotic treatment. Indeed, their transient nature could lead to an undiagnosed resistance. Efflux overexpression due to mutation leads to an important multiple resistance, reducing the effectiveness of antibiotics during treatment.

    Matched MeSH terms: Burkholderia pseudomallei
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links