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Oslan SNH, Yusoff AH, Mazlan M, Lim SJ, Khoo JJ, Oslan SN, Ismail A. Comprehensive approaches for the detection of Burkholderia pseudomallei and diagnosis of melioidosis in human and environmental samples. Microb Pathog 2022; 169:105637. [PMID: 35710088 DOI: 10.1016/j.micpath.2022.105637] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 06/06/2022] [Accepted: 06/10/2022] [Indexed: 11/16/2022]
Abstract
Melioidosis is endemic in Southeast Asia and northern Australia. The causative agent of melioidosis is a Gram-negative bacterium, Burkholderia pseudomallei. Its invasion can be fatal if melioidosis is not treated promptly. It is intrinsically resistant to a variety of antibiotics. In this paper, we present a comprehensive overview of the current trends on melioidosis cases, treatments, B. pseudomallei virulence factors, and molecular techniques to detect the bacterium from different samples. The clinical and microbial diagnosis methods of identification and detection of B. pseudomallei are commonly used for the rapid diagnosis and typing of strains, such as polymerase chain reaction or multi-locus sequence typing. The genotyping strategies and techniques have been constantly evolving to identify genomic loci linked to or associated with this human disease. More research strategies for detecting and controlling melioidosis should be encouraged and conducted to understand the current situation. In conclusion, we review existing diagnostic methodologies for melioidosis detection and provide insights on prospective diagnostic methods for the bacterium.
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Affiliation(s)
- Siti Nur Hazwani Oslan
- Faculty of Food Science and Nutrition, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia.
| | - Abdul Hafidz Yusoff
- Gold Rare Earth and Material Technopreneurship Centre (GREAT), Faculty of Bioengineering and Technology, Universiti Malaysia Kelantan, Jeli Campus, Jeli, 17600, Kelantan, Malaysia.
| | - Mazlina Mazlan
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, 43400 UPM, Serdang, Selangor, Malaysia.
| | - Si Jie Lim
- Enzyme Technology and X-Ray Crystallography Laboratory, VacBio 5, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia; Enzyme and Microbial Technology (EMTech) Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
| | - Jing Jing Khoo
- Tropical Infectious Diseases Research and Education Centre (TIDREC), High Impact Research Building, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Siti Nurbaya Oslan
- Enzyme Technology and X-Ray Crystallography Laboratory, VacBio 5, Institute of Bioscience, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia; Enzyme and Microbial Technology (EMTech) Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia; Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
| | - Aziah Ismail
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia.
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2
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Odogwu NM, Olayemi OO, Omigbodun AO. The vaginal microbiome of sub-Saharan African women: revealing important gaps in the era of next-generation sequencing. PeerJ 2020; 8:e9684. [PMID: 32879794 PMCID: PMC7441984 DOI: 10.7717/peerj.9684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/18/2020] [Indexed: 12/14/2022] Open
Abstract
Accurate characterization of the vaginal microbiome remains a fundamental goal of the Human Microbiome project (HMP). For over a decade, this goal has been made possible deploying high-throughput next generation sequencing technologies (NGS), which indeed has revolutionized medical research and enabled large-scale genomic studies. The 16S rRNA marker-gene survey is the most commonly explored approach for vaginal microbial community studies. With this approach, prior studies have elucidated substantial variations in the vaginal microbiome of women from different ethnicities. This review provides a comprehensive account of studies that have deployed this approach to describe the vaginal microbiota of African women in health and disease. On the basis of published data, the few studies reported from the African population are mainly in non-pregnant post pubertal women and calls for more detailed studies in pregnant and postnatal cohorts. We provide insight on the use of more sophisticated cutting-edge technologies in characterizing the vaginal microbiome. These technologies offer high-resolution detection of vaginal microbiome variations and community functional capabilities, which can shed light into several discrepancies observed in the vaginal microbiota of African women in an African population versus women of African descent in the diaspora.
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Affiliation(s)
- Nkechi Martina Odogwu
- Pan African University of Life and Earth Science Institute, Department of Obstetrics and Gynecology, University College Hospital, University of Ibadan, Ibadan, Oyo, Nigeria
| | - Oladapo O. Olayemi
- Department of Obstetrics and Gynecology, College of Medicine, University College Hospital, University of Ibadan, Ibadan, Oyo, Nigeria
| | - Akinyinka O. Omigbodun
- Department of Obstetrics and Gynecology, College of Medicine, University College Hospital, University of Ibadan, Ibadan, Oyo, Nigeria
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3
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Abstract
The causative agent of melioidosis, Burkholderia pseudomallei, a tier 1 select agent, is endemic in Southeast Asia and northern Australia, with increased incidence associated with high levels of rainfall. Increasing reports of this condition have occurred worldwide, with estimates of up to 165,000 cases and 89,000 deaths per year. The ecological niche of the organism has yet to be clearly defined, although the organism is associated with soil and water. The culture of appropriate clinical material remains the mainstay of laboratory diagnosis. Identification is best done by phenotypic methods, although mass spectrometric methods have been described. Serology has a limited diagnostic role. Direct molecular and antigen detection methods have limited availability and sensitivity. Clinical presentations of melioidosis range from acute bacteremic pneumonia to disseminated visceral abscesses and localized infections. Transmission is by direct inoculation, inhalation, or ingestion. Risk factors for melioidosis include male sex, diabetes mellitus, alcohol abuse, and immunosuppression. The organism is well adapted to intracellular survival, with numerous virulence mechanisms. Immunity likely requires innate and adaptive responses. The principles of management of this condition are drainage and debridement of infected material and appropriate antimicrobial therapy. Global mortality rates vary between 9% and 70%. Research into vaccine development is ongoing.
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Affiliation(s)
- I Gassiep
- Pathology Queensland, Townsville Hospital, Townsville, Queensland, Australia
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - M Armstrong
- Pathology Queensland, Townsville Hospital, Townsville, Queensland, Australia
| | - R Norton
- Pathology Queensland, Townsville Hospital, Townsville, Queensland, Australia
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
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4
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Tang Y, Rasschaert G, Yu L, Chilton C, Baert L. Evaluation of Whole Genome Mapping as a Fast and Automated Molecular Epidemiological Tool for the Study of Cronobacter spp. in Powdered Infant Formula Processing Facilities. J Food Prot 2017; 80:1443-1450. [PMID: 28782998 DOI: 10.4315/0362-028x.jfp-17-029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cronobacter has been identified as the causative agent of outbreaks or sporadic cases of meningitis, necrotizing enterocolitis, and septicemia associated with powdered infant formula. Food processing environments may provide a possible contamination route. The purpose of this study was to evaluate whole genome mapping (WGM) as a fast and automated molecular epidemiological method for characterizing Cronobacter spp. in the processing environment. This is the first study indicating the applicability of WGM to Cronobacter. WGM was compared with ribotyping, which is often used as an automated typing tool, and with pulsed-field gel electrophoresis, which is a well-known and highly discriminating tool that is also based on restriction site analysis. The comparison of the three tools was carried out on a subset of Cronobacter isolates collected from 2011 to 2014 through a monitoring program. The performance characteristics of WGM have not yet been described; therefore, in the current study its performance was evaluated based on five criteria: typeability, reproducibility, stability, epidemiological concordance, and the discrimination power. WGM was shown to produce typeable, reproducible, and stable results. With a similar cut-off of 98%, WGM was shown to have a discriminatory power equivalent to pulsed-field gel electrophoresis and higher than ribotyping. Future studies are needed to confirm the indicated cut-off level of 98%.
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Affiliation(s)
- Yanjie Tang
- 1 Nestlé Research Center, Nestec Ltd., Vers-Chez-les-Blanc, CH-1000 Lausanne 26, Switzerland; and
| | - Geertrui Rasschaert
- 2 Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Brusselsesteenweg 370, 9090, Melle, Belgium
| | - Liping Yu
- 1 Nestlé Research Center, Nestec Ltd., Vers-Chez-les-Blanc, CH-1000 Lausanne 26, Switzerland; and
| | - Claire Chilton
- 1 Nestlé Research Center, Nestec Ltd., Vers-Chez-les-Blanc, CH-1000 Lausanne 26, Switzerland; and
| | - Leen Baert
- 1 Nestlé Research Center, Nestec Ltd., Vers-Chez-les-Blanc, CH-1000 Lausanne 26, Switzerland; and
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5
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Vangay P, Fugett EB, Sun Q, Wiedmann M. Food microbe tracker: a web-based tool for storage and comparison of food-associated microbes. J Food Prot 2013; 76:283-94. [PMID: 23433376 DOI: 10.4315/0362-028x.jfp-12-276] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Large amounts of molecular subtyping information are generated by the private sector, academia, and government agencies. However, use of subtype data is limited by a lack of effective data storage and sharing mechanisms that allow comparison of subtype data from multiple sources. Currently available subtype databases are generally limited in scope to a few data types (e.g., MLST. net) or are not publicly available (e.g., PulseNet). We describe the development and initial implementation of Food Microbe Tracker, a public Web-based database that allows archiving and exchange of a variety of molecular subtype data that can be cross-referenced with isolate source data, genetic data, and phenotypic characteristics. Data can be queried with a variety of search criteria, including DNA sequences and banding pattern data (e.g., ribotype or pulsed-field gel electrophoresis type). Food Microbe Tracker allows the deposition of data on any bacterial genus and species, bacteriophages, and other viruses. The bacterial genera and species that currently have the most entries in this database are Listeria monocytogenes, Salmonella, Streptococcus spp., Pseudomonas spp., Bacillus spp., and Paenibacillus spp., with over 40,000 isolates. The combination of pathogen and spoilage microorganism data in the database will facilitate source tracking and outbreak detection, improve discovery of emerging subtypes, and increase our understanding of transmission and ecology of these microbes. Continued addition of subtyping, genetic or phenotypic data for a variety of microbial species will broaden the database and facilitate large-scale studies on the diversity of food-associated microbes.
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Affiliation(s)
- Pajau Vangay
- Department of Food Science, Cornell University, Ithaca, NY 14853, USA
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6
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Xie X, Liang J, Pu T, Xu F, Yao F, Yang Y, Zhao YL, You D, Zhou X, Deng Z, Wang Z. Phosphorothioate DNA as an antioxidant in bacteria. Nucleic Acids Res 2012; 40:9115-24. [PMID: 22772986 PMCID: PMC3467049 DOI: 10.1093/nar/gks650] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Diverse bacteria contain DNA with sulfur incorporated stereo-specifically into their DNA backbone at specific sequences (phosphorothioation). We found that in vitro oxidation of phosphorothioate (PT) DNA by hydrogen peroxide (H(2)O(2)) or peracetic acid has two possible outcomes: DNA backbone cleavage or sulfur removal resulting in restoration of normal DNA backbone. The physiological relevance of this redox reaction was investigated by challenging PT DNA hosting Salmonella enterica cells using H(2)O(2). DNA phosphorothioation was found to correlate with increasing resistance to the growth inhibition by H(2)O(2). Resistance to H(2)O(2) was abolished when each of the three dnd genes, required for phosphorothioation, was inactivated. In vivo, PT DNA is more resistant to the double-strand break damage caused by H(2)O(2) than PT-free DNA. Furthermore, sulfur on the modified DNA was consumed and the DNA was converted to PT-free state when the bacteria were incubated with H(2)O(2). These findings are consistent with a hypothesis that phosphorothioation modification endows DNA with reducing chemical property, which protects the hosting bacteria against peroxide, explaining why this modification is maintained by diverse bacteria.
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Affiliation(s)
- Xinqiang Xie
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai 200030, People's Republic of China
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7
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Inglis TJJ, O'Reilly L, Merritt AJ, Levy A, Heath CH, Heath C. The aftermath of the Western Australian melioidosis outbreak. Am J Trop Med Hyg 2011; 84:851-7. [PMID: 21633018 DOI: 10.4269/ajtmh.2011.10-0480] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Melioidosis became a notifiable disease in Western Australia (WA) 2 years after the West Kimberley melioidosis outbreak. Two cases of melioidosis caused by the outbreak genotype of Burkholderia pseudomallei (National Collection of Type Cultures [NCTC] 13177) occurred in 1998 and 1999 in persons who visited the outbreak location at the time. No other infections caused by the outbreak strain have been recorded in WA since that time, despite an average of four culture-positive cases per year. Sporadic cases of melioidosis often follow tropical storms and cyclones during summer, and they have been detected outside the endemic area when cyclones travel far inland. In 2007, environmental isolates resembling NCTC 13177 were found 500 km east of the outbreak location after unusually severe weather. Recent whole-genome analysis places NCTC 13177 genetically close to other Australian isolates. Additional biogeographic and ecological studies are needed to establish the relative importance of environmental cofactors in disease pathogenesis.
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Affiliation(s)
- Timothy J J Inglis
- Division of Microbiology and Infectious Diseases, PathWest Laboratory Medicine, Nedlands, WA 6009, Australia.
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8
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9
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Susceptibility of Vibrio parahaemolyticus to tris-dependent DNA degradation during pulsed-field gel electrophoresis. J Clin Microbiol 2009; 47:870-1. [PMID: 19129409 DOI: 10.1128/jcm.02306-08] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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10
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Pingault NM, Lehmann D, Bowman J, Riley TV. A comparison of molecular typing methods for Moraxella catarrhalis. J Appl Microbiol 2007; 103:2489-95. [PMID: 17850316 DOI: 10.1111/j.1365-2672.2007.03536.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS Three molecular typing techniques were examined to determine which method was the most discriminatory in order to perform epidemiological typing of Moraxella catarrhalis. METHODS AND RESULTS Twenty-five Mor. catarrhalis isolates obtained from nasopharyngeal aspirates collected from Aboriginal and non-Aboriginal children were subjected to random amplified polymorphic DNA (RAPD) analysis, automated ribotyping and pulsed field gel electrophoresis (PFGE). RAPD analysis determined two Mor. catarrhalis types, automated ribotyping with PstI determined four Mor. catarrhalis ribogroups and PFGE analysis with NotI determined 21 pulse field groups within the 25 isolates examined. CONCLUSIONS Analysis of discrimination index and typeability demonstrated that PFGE is the most discriminatory method for typing Mor. catarrhalis. SIGNIFICANCE AND IMPACT OF THE STUDY This study confirms that PFGE is the most appropriate molecular tool for the epidemiological study of Mor. catarrhalis.
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Affiliation(s)
- N M Pingault
- School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Perth, WA, Australia
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11
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Duangsonk K, Gal D, Mayo M, Hart CA, Currie BJ, Winstanley C. Use of a variable amplicon typing scheme reveals considerable variation in the accessory genomes of isolates of Burkholderia pseudomallei. J Clin Microbiol 2006; 44:1323-34. [PMID: 16597858 PMCID: PMC1448637 DOI: 10.1128/jcm.44.4.1323-1334.2006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Melioidosis, a disease caused by the bacterium Burkholderia pseudomallei, is endemic in southeast Asia and northern Australia. We used suppression subtractive hybridization (SSH) to identify sequences that varied between two B. pseudomallei isolates from Australia and determined the distribution of 45 SSH-derived sequences among a panel of B. pseudomallei and B. thailandensis isolates. Sequences exhibiting variable prevalence were included in a variable amplicon typing (VAT) scheme designed to score the presence or absence of 14 PCR amplicons. VAT analysis was carried out with 48 isolates from Thailand, which were typed by multilocus sequence typing (MLST), and 44 isolates from Australia of known MLST type. The VAT scheme could be used to divide the 48 isolates from Thailand into 23 VAT types and the 44 isolates from Australia into 36 VAT types. Some of the sequences included in the VAT scheme were more commonly PCR positive among isolates from Australia than among isolates from Thailand, and vice versa. No isolate from Australia was PCR positive for genomic island 11 or a putative transposase sequence, whereas four SSH-derived sequences were far more prevalent among the Australian isolates. Analysis based on the VAT scheme indicated that the isolates clustered into groups, some of which were mainly or exclusively from one geographical origin. One cluster included Australian isolates that were mostly associated with severe disease, including rare neurological melioidosis, suggesting that the content of the accessory genome may play an important role in determining the clinical manifestation of the disease.
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Affiliation(s)
- Kwanjit Duangsonk
- Division of Medical Microbiology, University of Liverpool, Duncan Building, Daulby Street, Liverpool L69 3GA, United Kingdom.
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12
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Merritt A, Inglis TJJ, Chidlow G, Harnett G. PCR-based identification of Burkholderia pseudomallei. Rev Inst Med Trop Sao Paulo 2006; 48:239-44. [PMID: 17086309 DOI: 10.1590/s0036-46652006000500001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Accepted: 06/02/2006] [Indexed: 11/21/2022] Open
Abstract
DNA amplification techniques are being used increasingly in clinical laboratories to confirm the identity of medically important bacteria. A PCR-based identification method has been in use in our centre for 10 years for Burkholderia pseudomallei and was used to confirm the identity of bacteria isolated from cases of melioidosis in Ceará since 2003. This particular method has been used as a reference standard for less discriminatory methods. In this study we evaluated three PCR-based methods of B. pseudomallei identification and used DNA sequencing to resolve discrepancies between PCR-based results and phenotypic identification methods. The established semi-nested PCR protocol for B. pseudomallei 16-23s spacer region produced a consistent negative result for one of our 100 test isolates (BCC #99), but correctly identified all 71 other B. pseudomallei isolates tested. Anomalous sequence variation was detected at the inner, reverse primer binding site for this method. PCR methods were developed for detection of two other B. pseudomallei bacterial metabolic genes. The conventional lpxO PCR protocol had a sensitivity of 0.89 and a specificity of 1.00, while a real-time lpxO protocol performed even better with sensitivity and specificity of 1.00, and 1.00. This method identified all B. pseudomallei isolates including the PCR-negative discrepant isolate. The phaC PCR protocol detected the gene in all B. pseudomallei and all but three B. cepacia isolates, making this method unsuitable for PCR-based identification of B. pseudomallei. This experience with PCR-based B. pseudomallei identification methods indicates that single PCR targets should be used with caution for identification of these bacteria, and need to be interpreted alongside phenotypic and alternative molecular methods such as gene sequencing.
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Affiliation(s)
- Adam Merritt
- Division of Microbiology & Infectious Diseases, PathWest Laboratory Medicine WA, QEII Medical Centre, Nedlands, Australia
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13
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Leclair D, Pagotto F, Farber JM, Cadieux B, Austin JW. Comparison of DNA fingerprinting methods for use in investigation of type E botulism outbreaks in the Canadian Arctic. J Clin Microbiol 2006; 44:1635-44. [PMID: 16672387 PMCID: PMC1479196 DOI: 10.1128/jcm.44.5.1635-1644.2006] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pulsed-field gel electrophoresis (PFGE), randomly amplified polymorphic DNA (RAPD) analysis, and automated ribotyping were compared for epidemiological typing of Clostridium botulinum type E using clinical and food isolates associated with four botulism outbreaks occurring in the Canadian Arctic. All type E strains previously untypeable by PFGE, even with the use of a formaldehyde fixation step, could be typed by the addition of 50 microM thiourea to the electrophoresis running buffer. Digestion with SmaI or XhoI followed by PFGE was used to link food and clinical isolates from four different type E botulism outbreaks and differentiate them from among 39 group II strains. Strain differentiation was unsuccessful with the automated ribotyping system, producing a single characteristic EcoRI fingerprint common to all group II strains. RAPD analysis of C. botulinum group II strains was not consistently reproducible with primer OPJ-6 or OPJ-13, apparently discriminating between epidemiologically related strains. A modified PFGE protocol was judged to be the most useful method for typing epidemiologically related C. botulinum type E strains, based on its ability to type all strains reproducibly and with an adequate level of discrimination.
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Affiliation(s)
- Daniel Leclair
- Bureau of Microbial Hazards, Health Products and Food Branch, Food Directorate, Health Canada, Tunney's Pasture, PL 2204A2, Ottawa, Ontario, Canada K1A 0L2
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14
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Abstract
Melioidosis, caused by the gram-negative saprophyte Burkholderia pseudomallei, is a disease of public health importance in southeast Asia and northern Australia that is associated with high case-fatality rates in animals and humans. It has the potential for epidemic spread to areas where it is not endemic, and sporadic case reports elsewhere in the world suggest that as-yet-unrecognized foci of infection may exist. Environmental determinants of this infection, apart from a close association with rainfall, are yet to be elucidated. The sequencing of the genome of a strain of B. pseudomallei has recently been completed and will help in the further identification of virulence factors. The presence of specific risk factors for infection, such as diabetes, suggests that functional neutrophil defects are important in the pathogenesis of melioidosis; other studies have defined virulence factors (including a type III secretion system) that allow evasion of killing mechanisms by phagocytes. There is a possible role for cell-mediated immunity, but repeated environmental exposure does not elicit protective humoral or cellular immunity. A vaccine is under development, but economic constraints may make vaccination an unrealistic option for many regions of endemicity. Disease manifestations are protean, and no inexpensive, practical, and accurate rapid diagnostic tests are commercially available; diagnosis relies on culture of the organism. Despite the introduction of ceftazidime- and carbapenem-based intravenous treatments, melioidosis is still associated with a significant mortality attributable to severe sepsis and its complications. A long course of oral eradication therapy is required to prevent relapse. Studies exploring the role of preventative measures, earlier clinical identification, and better management of severe sepsis are required to reduce the burden of this disease.
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Affiliation(s)
- Allen C Cheng
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia
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15
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Cheng AC, Currie BJ. Melioidosis: epidemiology, pathophysiology, and management. Clin Microbiol Rev 2005. [PMID: 15831829 DOI: 10.1128/cmr.18.2.383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023] Open
Abstract
Melioidosis, caused by the gram-negative saprophyte Burkholderia pseudomallei, is a disease of public health importance in southeast Asia and northern Australia that is associated with high case-fatality rates in animals and humans. It has the potential for epidemic spread to areas where it is not endemic, and sporadic case reports elsewhere in the world suggest that as-yet-unrecognized foci of infection may exist. Environmental determinants of this infection, apart from a close association with rainfall, are yet to be elucidated. The sequencing of the genome of a strain of B. pseudomallei has recently been completed and will help in the further identification of virulence factors. The presence of specific risk factors for infection, such as diabetes, suggests that functional neutrophil defects are important in the pathogenesis of melioidosis; other studies have defined virulence factors (including a type III secretion system) that allow evasion of killing mechanisms by phagocytes. There is a possible role for cell-mediated immunity, but repeated environmental exposure does not elicit protective humoral or cellular immunity. A vaccine is under development, but economic constraints may make vaccination an unrealistic option for many regions of endemicity. Disease manifestations are protean, and no inexpensive, practical, and accurate rapid diagnostic tests are commercially available; diagnosis relies on culture of the organism. Despite the introduction of ceftazidime- and carbapenem-based intravenous treatments, melioidosis is still associated with a significant mortality attributable to severe sepsis and its complications. A long course of oral eradication therapy is required to prevent relapse. Studies exploring the role of preventative measures, earlier clinical identification, and better management of severe sepsis are required to reduce the burden of this disease.
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Affiliation(s)
- Allen C Cheng
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia
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16
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Sprague LD, Neubauer H. Melioidosis in animals: a review on epizootiology, diagnosis and clinical presentation. ACTA ACUST UNITED AC 2005; 51:305-20. [PMID: 15525357 DOI: 10.1111/j.1439-0450.2004.00797.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Melioidosis, an infectious disease caused by Burkholderia pseudomallei is an emerging disease with high impact on animals and man. In different animal species, the clinical course varies and delayed diagnosis poses risks for the dissemination of the agent in non-endemic areas. Not only migration and transport of animals around the world but also tourism increases the risk that melioidosis can leave its endemic boundaries and establish itself elsewhere. Detection of the agent is a major challenge, as the agent has to be handled in laboratories of biosafety level 3 and test kits are not yet commercially available. Veterinarians and doctors should be aware of melioidosis not only as an agent of public interest but also in terms of a bioterrorist attack. The aim of this review is to describe the agent, its aetiology, the manifestation in a variety of animal species as well as to describe diagnostic procedures, typing techniques and countermeasures.
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Affiliation(s)
- L D Sprague
- Klinik und Poliklinik für Strahlentherapie und Radiologische Onkologie der TU München, Klinikum rechts der Isar, Ismaningerstr. 22, 81675 München, Germany.
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17
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Inglis TJJ, Rodrigues F, Rigby P, Norton R, Currie BJ. Comparison of the susceptibilities of Burkholderia pseudomallei to meropenem and ceftazidime by conventional and intracellular methods. Antimicrob Agents Chemother 2004; 48:2999-3005. [PMID: 15273112 PMCID: PMC478517 DOI: 10.1128/aac.48.8.2999-3005.2004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The effect of the two antibiotics ceftazidime and meropenem on a collection of 46 Burkholderia pseudomallei isolates representing clinical and environmental sources across northern Australia was investigated by using a series of in vitro test methods. The susceptibility testing methods used included Kirby-Bauer disk diffusion, Etest MIC, broth microdilution MIC, and a modification of the microdilution method in which Acanthamoeba cells were added to simulate the effect of a professional phagocytic cell on test outcome. In a semiquantitative validation coculture series, the majority of bacteria were intracellular up to a multiplicity of infection of 10 bacteria to one ameba. The optical density and bacterial count (log10 CFU/ml) correlated across the range tested (r2 = 0.77; P < 0.0001). Susceptibility test results were compared against clinical outcomes. The MICs of ceftazidime were consistently higher than those of meropenem by all three methods. The MICs of both agents were significantly higher when Acanthamoeba trophozoites were added to the broth microdilution method. Conventional and intracellular MIC results were consistent for clinical isolates from the Western Australian outbreak cluster despite the wide variety of clinical outcomes. Further development of the intracellular MIC method is expected to help assess the efficacy of antimicrobial agents on this bacterial species in an intracellular setting.
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Affiliation(s)
- T J J Inglis
- The Division of Microbiology and Infectious Diseases, Western Australian Centre for Pathology and Medical Research, Nedlands, Western Australia, Australia.
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18
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Abstract
PURPOSE OF REVIEW Burkholderia pseudomallei, the causative agent of melioidosis and a potential biological weapon, is still unfamiliar in some areas where sporadic cases are being reported among travelers. This review highlights findings in 2002-2003 and is an extension of a recent review by Dance. RECENT FINDINGS The allele profiles of B. pseudomallei are distinguishable from avirulent Burkholderia thailandensis, but Burkholderia mallei is a clone of B. pseudomallei. Capsule and a type III protein secretion apparatus enable B. pseudomallei to survive intracellular killing and facilitate intercellular spread. A strong antibody response to infection is useful for monitoring disease activity. A mutant that is auxotrophic in the branched chain amino acid biosynthetic pathway has been found to be attenuated and protective. A new selective media is useful for isolation from contaminated specimens and the environment. Molecular techniques have been developed to distinguish B. pseudomallei from B. thailandensis and B. mallei as well as for serological diagnosis. Classification of the clinical manifestation is proposed to facilitate global communication, and will be useful to compare the efficacies of new regimens and adjunctive immunomodulatory therapies, such as granulocyte colony-stimulating factor and activated protein C for septicemic melioidosis. SUMMARY Study of pathogenesis and intracellular survival of B. pseudomallei is advancing and may lead to better methods of therapy and vaccine production. New antimicrobial agents and immunomodulators are being studied to shorten the duration of treatment in the acute and maintenance phases, reduce the high mortality rate in septicemic melioidosis, and prevent relapses.
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Affiliation(s)
- Amorn Leelarasamee
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkoknoi, Bangkok 10700, Thailand
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19
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Inglis TJJ, Aravena-Roman M, Ching S, Croft K, Wuthiekanun V, Mee BJ. Cellular fatty acid profile distinguishes Burkholderia pseudomallei from avirulent Burkholderia thailandensis. J Clin Microbiol 2004; 41:4812-4. [PMID: 14532228 PMCID: PMC254375 DOI: 10.1128/jcm.41.10.4812-4814.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia pseudomallei, the cause of melioidosis, can be distinguished from the closely related but nonpathogenic Burkholderia thailandensis by gas chromatography (GC) analysis of fatty acid derivatives. A 2-hydroxymyristic acid derivative (14:0 2OH) was present in 95% of B. pseudomallei isolates and no B. thailandensis isolates. GC mass spectrophotometry confirmed that 2-hydroxymyristic acid was present in B. pseudomallei. GC-fatty acid methyl ester analysis may be useful in distinguishing these two closely related species.
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Affiliation(s)
- Timothy J J Inglis
- Division of Microbiology and Infectious Diseases, Western Australian Centre for Pathology and Medical Research, Nedlands, Western Australia, Australia.
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20
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Howard K, Inglis TJJ. The effect of free chlorine on Burkholderia pseudomallei in potable water. WATER RESEARCH 2003; 37:4425-4432. [PMID: 14511713 DOI: 10.1016/s0043-1354(03)00440-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Chlorine is widely used in public water supplies to provide a disinfection barrier. The effect of chlorine disinfection on the water-borne pathogen Burkholderia pseudomallei was assessed using multiple techniques. After exposure to chlorine viable bacteria were undetectable by conventional plate count techniques; however, persistence of B. pseudomallei was verified by flow cytometry and bacteria were recoverable following a simple one-step broth procedure. The minimum residual chlorine concentration and contact time as prescribed by potable water providers in Australia was insufficient to reduce a B. pseudomallei population by more than 2 log(10). Chlorine had a bacteriostatic effect only on B. pseudomallei; viable bacteria were recovered from water containing up to 1000 ppm free chlorine. This finding has practical implications for water treatment in regions where B. pseudomallei is endemic. Future work to assess the effect of alternative water disinfection processes either singly or in sequence is necessary.
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Affiliation(s)
- Kay Howard
- Division of Microbiology and Infectious Diseases, Western Australian Centre for Pathology and Medical Research, Locked Bag 2009, WA 6909, Nedlands, Australia.
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21
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Sauders BD, Fortes ED, Morse DL, Dumas N, Kiehlbauch JA, Schukken Y, Hibbs JR, Wiedmann M. Molecular subtyping to detect human listeriosis clusters. Emerg Infect Dis 2003; 9:672-80. [PMID: 12781006 PMCID: PMC3000145 DOI: 10.3201/eid0906.020702] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We analyzed the diversity (Simpson's Index, D) and distribution of Listeria monocytogenes in human listeriosis cases in New York State (excluding New York City) from November 1996 to June 2000 by using automated ribotyping and pulsed-field gel electrophoresis (PFGE). We applied a scan statistic (p<or=0.05) to detect listeriosis clusters caused by a specific Listeria monocytogenes subtype. Among 131 human isolates, 34 (D=0.923) ribotypes and 74 (D=0.975) PFGE types were found. Nine (31% of cases) clusters were identified by ribotype or PFGE; five (18% of cases) clusters were identified by using both methods. Two of the nine clusters (13% of cases) corresponded with investigated multistate listeriosis outbreaks. While most human listeriosis cases are considered sporadic, highly discriminatory molecular subtyping approaches thus indicated that 13% to 31% of cases reported in New York State may represent single-source clusters. Listeriosis control and reduction efforts should include broad-based subtyping of human isolates and consider that a large number of cases may represent outbreaks.
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Affiliation(s)
- Brian D. Sauders
- Wadsworth Center, New York State Department of
Health, Albany, New York, USA
- Cornell University, Ithaca, New York, USA
| | | | - Dale L. Morse
- Wadsworth Center, New York State Department of
Health, Albany, New York, USA
- University at Albany, Albany, New York,
USA
| | - Nellie Dumas
- Wadsworth Center, New York State Department of
Health, Albany, New York, USA
| | - Julia A. Kiehlbauch
- Wadsworth Center, New York State Department of
Health, Albany, New York, USA
| | | | - Jonathan R. Hibbs
- Wadsworth Center, New York State Department of
Health, Albany, New York, USA
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22
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Mair M. Publications of Interest. Biosecur Bioterror 2003. [DOI: 10.1089/15387130360514869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Michael Mair
- Center for Civilian Biodefense Strategies, Johns Hopkins University
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