Molecular Investigations of a Locally Acquired Case of Melioidosis in Southern AZ, USA

Abstract

Melioidosis is caused by Burkholderia pseudomallei, a Gram-negative bacillus, primarily found in soils in Southeast Asia and northern Australia. A recent case of melioidosis in non-endemic Arizona was determined to be the result of locally acquired infection, as the patient had no travel history to endemic regions and no previous history of disease. Diagnosis of the case was confirmed through multiple microbiologic and molecular techniques. To enhance the epidemiological analysis, we conducted several molecular genotyping procedures, including multi-locus sequence typing, SNP-profiling, and whole genome sequence typing. Each technique has different molecular epidemiologic advantages, all of which provided evidence that the infecting strain was most similar to those found in Southeast Asia, possibly originating in, or around, Malaysia. Advancements in new typing technologies provide genotyping resolution not previously available to public health investigators, allowing for more accurate source identification.

Whole Genome Sequence Typing to Investigate the Apophysomyces Outbreak following a Tornado in Joplin, Missouri, 2011

“…Whole genome sequencing also provides robust and comprehensive data for use in further comparative genomic explorations of the extraordinary virulence/host susceptibility, particularly in immunocompetent hosts; antifungal resistance properties; and strain to strain genomic variations that may govern the aforementioned factors.Additionally, WGS data can be compared among the various Mucorales genera and with non-Mucorales genera to allow further insight into novel mechanisms of virulence and potential targets for antifungal drugs in this group of human fungal pathogens. WGST has been used in other fungal and bacterial disease investigations [19], [20], [23], [31]. For this study, we developed the first population structure for Apophysomyces based on whole genome analysis, and provide an initial genomic view of this fungus in a natural setting.…”

Rapid and robust phylotyping of spa t003, a dominant MRSA clone in Luxembourg and other European countries

“…WGST has been previously used for advanced molecular typing of MRSA [20,21], as well as for other bacteria [22,23] and fungal pathogens [24-26]. WGST has proven to be far superior to other typing methodologies for determining genetic assignment (genotype) and phylogenetic relatedness (phylotype), given its ability to interrogate genome-wide character states.…”

Clinical features and outcome of patients with cutaneous melioidosis during a nosocomial outbreak in a temperate region of Australia

“…Autochthonous cases from non–endemic areas have also been described. As we have done in the present case series, where there are cryptic cases, the geographical region of origin can be inferred from MLST typing of the organism, without an apparent environmental source …”

“…As we have done in the present case series, where there are cryptic cases, the geographical region of origin can be inferred from MLST typing of the organism, without an apparent environmental source. 12 Nosocomial outbreaks of other environmental Gramnegative organisms where contamination of antiseptics and disinfectants are the major source have been described. 13 Like other environmental Gramnegative organisms, B. pseudomallei will tolerate a wide range of nutrient-free aqueous environments.…”