• View in gallery

    Map of Hainan Island and distribution of the 30 sequence types (STs). Map obtained from http://www.hinews.cn/news/system/2009/11/10/010605499.shtml showing the major regions in the island. The STs of 60 clinical isolates were labeled in each region in which melioidosis patients come from. The number of the strains is shown in the brackets.

  • View in gallery

    eBURST diagram of sequence types from isolates in this study. I = group 1; II = group 2; III = group 3.

  • View in gallery

    eBURST diagram comparing Burkholderia pseudomallei isolates from this study to those from the entire world. The novel sequence types (STs) in this study are highlighted green, and the existing STs are highlighted magenta.

  • 1.

    Kaestli M, Mayo M, Harrington G, Ward L, Watt F, Hill JV, Cheng AC, Currie BJ, 2009. Landscape changes influence the occurrence of the melioidosis bacterium Burkholderia pseudomallei in soil in northern Australia. PLoS Negl Trop Dis 3: e364.

    • Search Google Scholar
    • Export Citation
  • 2.

    Baker A, Tahani D, Gardiner C, Bristow KL, Greenhill AR, Warner J, 2011. Groundwater seeps facilitate exposure to Burkholderia pseudomallei. Appl Environ Microbiol 77: 72437246.

    • Search Google Scholar
    • Export Citation
  • 3.

    Rattanavong S, Wuthiekanun V, Langla S, Amornchai P, Sirisouk J, Phetsouvanh R, Moore CE, Peacock SJ, Buisson Y, Newton PN, 2011. Randomized soil survey of the distribution of Burkholderia pseudomallei in rice fields in Laos. Appl Environ Microbiol 77: 532536.

    • Search Google Scholar
    • Export Citation
  • 4.

    Limmathurotsakul D, Wuthiekanun V, Amornchai P, Wongsuwan G, Day NP, Peacock SJ, 2012. Effectiveness of a simplified method for isolation of Burkholderia pseudomallei from soil. Appl Environ Microbiol 78: 876877.

    • Search Google Scholar
    • Export Citation
  • 5.

    Vongphayloth K, Rattanavong S, Moore CE, Phetsouvanh R, Wuthiekanun V, Sengdouangphachanh A, Phouminh P, Newton PN, Buisson Y, 2012. Burkholderia pseudomallei detection in surface water in southern Laos using Moore's swabs. Am J Trop Med Hyg 86: 872877.

    • Search Google Scholar
    • Export Citation
  • 6.

    Currie BJ, Jacups SP, 2003. Intensity of rainfall and severity of melioidosis, Australia. Emerg Infect Dis 9: 15381542.

  • 7.

    Su HP, Chan TC, Chang CC, 2011. Typhoon-related leptospirosis and melioidosis, Taiwan, 2009. Emerg Infect Dis 17: 13221324.

  • 8.

    Parameswaran U, Baird RW, Ward LM, Currie BJ, 2012. Melioidosis at Royal Darwin Hospital in the big 2009–2010 wet season: comparison with the preceding 20 years. Med J Aust 196: 345348.

    • Search Google Scholar
    • Export Citation
  • 9.

    Liu X, Pang L, Sim SH, Goh KT, Ravikumar S, Win MS, Tan G, Cook AR, Fisher D, Chai LY, 2015. Association of melioidosis incidence with rainfall and humidity, Singapore, 2003–2012. Emerg Infect Dis 21: 159162.

    • Search Google Scholar
    • Export Citation
  • 10.

    Chen PS, Chen YS, Lin HH, Liu PJ, Ni WF, Hsueh PT, Liang SH, Chen C, Chen YL, 2015. Airborne transmission of melioidosis to humans from environmental aerosols contaminated with B. pseudomallei. PLoS Negl Trop Dis 9: e0003834.

    • Search Google Scholar
    • Export Citation
  • 11.

    Suputtamongkol Y, Hall AJ, Dance DA, Chaowagul W, Rajchanuvong A, Smith MD, White NJ, 1994. The epidemiology of melioidosis in Ubon Ratchatani, northeast Thailand. Int J Epidemiol 23: 10821090.

    • Search Google Scholar
    • Export Citation
  • 12.

    Hill AA, Mayo M, Kaestli M, Price EP, Richardson LJ, Godoy D, Spratt BG, Currie BJ, 2013. Melioidosis as a consequence of sporting activity. Am J Trop Med Hyg 89: 365366.

    • Search Google Scholar
    • Export Citation
  • 13.

    Doker TJ, Sharp TM, Rivera-Garcia B, Perez-Padilla J, Benoit TJ, Ellis EM, Elrod MG, Gee JE, Shieh WJ, Beesley CA, Ryff KR, Traxler RM, Galloway RL, Haberling DL, Waller LA, Shadomy SV, Bower WA, Hoffmaster AR, Walke HT, Blaney DD, 2015. Contact investigation of melioidosis cases reveals regional endemicity in Puerto Rico. Clin Infect Dis 60: 243250.

    • Search Google Scholar
    • Export Citation
  • 14.

    White NJ, 2003. Melioidosis. Lancet 361: 17151722.

  • 15.

    Cheng AC, Currie BJ, 2005. Melioidosis: epidemiology, pathophysiology, and management. Clin Microbiol Rev 18: 383416.

  • 16.

    Limmathurotsakul D, Golding N, Dance DAB, Messina JP, Pigott DM, Moyes CL, Rolim DB, Bertherat E, Day NPJ, Peacock SJ, Hay SI, 2016. Predicted global distribution of Burkholderia pseudomallei and burden of melioidosis. Nature Microbiol 1: 15.

    • Search Google Scholar
    • Export Citation
  • 17.

    Godoy D, Randle G, Simpson AJ, Aanensen DM, Pitt TL, Kinoshita R, Spratt BG, 2003. Multilocus sequence typing and evolutionary relationships among the causative agents of melioidosis and glanders, Burkholderia pseudomallei and Burkholderia mallei. J Clin Microbiol 41: 20682079.

    • Search Google Scholar
    • Export Citation
  • 18.

    Feil EJ, Li BC, Aanensen DM, Hanage WP, Spratt BG, 2004. eBURST: inferring patterns of evolutionary descent among clusters of related bacterial genotypes from multilocus sequence typing data. J Bacteriol 186: 15181530.

    • Search Google Scholar
    • Export Citation
  • 19.

    Cheng AC, Godoy D, Mayo M, Gal D, Spratt BG, Currie BJ, 2004. Isolates of Burkholderia pseudomallei from northern Australia are distinct by multilocus sequence typing, but strain types do not correlate with clinical presentation. J Clin Microbiol 42: 54775483.

    • Search Google Scholar
    • Export Citation
  • 20.

    Cheng AC, Ward L, Godoy D, Norton R, Mayo M, Gal D, Spratt BG, Currie BJ, 2008. Genetic diversity of Burkholderia pseudomallei isolates in Australia. J Clin Microbiol 46: 249254.

    • Search Google Scholar
    • Export Citation
  • 21.

    Currie BJ, Thomas AD, Godoy D, Dance DA, Cheng AC, Ward L, Mayo M, Pitt TL, Spratt BG, 2007. Australian and Thai isolates of Burkholderia pseudomallei are distinct by multilocus sequence typing: revision of a case of mistaken identity. J Clin Microbiol 45: 38283829.

    • Search Google Scholar
    • Export Citation
  • 22.

    De Smet B, Sarovich DS, Price EP, Mayo M, Theobald V, Kham C, Heng S, Thong P, Holden MTG, Parkhill J, Peacock SJ, Spratt BG, Jacobs JA, Vandamme P, Currie BJ, 2015. Whole-genome sequencing confirms that Burkholderia pseudomallei multilocus sequence types common to both Cambodia and Australia are due to homoplasy. J Clin Microbiol 53: 323326.

    • Search Google Scholar
    • Export Citation
  • 23.

    Price EP, Sarovich DS, Smith EJ, MacHunter B, Harrington G, Theobald V, Hall CM, Hornstra HM, McRobb E, Podin Y, Mayo M, Sahl JW, Wagner DM, Keim P, Kaestli M, Currie BJ, 2016. Unprecedented melioidosis cases in northern Australia caused by an Asian Burkholderia pseudomallei strain identified by using large-scale comparative genomics. Appl Environ Microbiol 82: 954963.

    • Search Google Scholar
    • Export Citation

 

 

 

 

Multilocus Sequence Typing of Clinical Isolates of Burkholderia pseudomallei Collected in Hainan, a Tropical Island of Southern China

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  • 1 Department of Clinical Laboratory, Hainan General Hospital, Haikou, People's Republic of China.
  • 2 Hainan Department, The General Hospital of the Chinese People's Liberation Army, Sanya, People's Republic of China.
  • 3 State Key Laboratory for Infectious Disease Prevention and Control, Beijing, People's Republic of China.
  • 4 National Institute for Communicable Disease Control and Prevention, Beijing, People's Republic of China.
  • 5 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.

Burkholderia pseudomallei is a gram-negative bacterium that causes melioidosis. In this study, we examined the sequence types (STs) of 60 clinical isolates from patients with melioidosis in Hainan, a tropical island in southern China. The 60 clinical isolates were resolved into 30 STs. Among the STs, ST562 was also reported in Australia, and ST90 was also reported in the United States, probably from a traveler who had previously visited Asia. In addition, six novel STs were found in this study, including ST1395, ST1396, ST1397, ST1398, ST1399, and ST1443, whereas the remaining STs were mostly shared with other southeast Asian regions. Phylogenetic analysis of 60 isolates conducted using the eBURST v3 software segregated the 30 STs into three groups and 18 singletons. Our study shows genetic diversity of 60 clinical isolates of B. pseudomallei in Hainan Island.

Introduction

Burkholderia pseudomallei is a gram-negative environmental saprophyte that causes melioidosis. This organism is commonly isolated from soil and water in endemic areas such as southeast Asia and northern tropical Australia.15 Melioidosis usually occurs in the rainy season, particularly after a rainstorm or typhoon.69 In endemic areas, the greatest risk of developing melioidosis arises from frequent exposure to contaminated soil, water, or environmental aerosols. Burkholderia pseudomallei infection may be acquired through inhalation, subcutaneous inoculation, or direct exposure of wounded skin to contaminated material.1013 Clinical presentations of melioidosis are highly variable, and can manifest as asymptomatic infection, localized skin abscesses, acute or chronic pneumonia, genitourinary, bone, and joint infections, or severe systemic sepsis with or without multiple abscesses in internal organs. Septic shock cases have a greater than 90% mortality rate.14,15 Because of the nonspecific disease presentation, lack of an available vaccine, and fear of deliberate release coupled with a high mortality rate, B. pseudomallei was upgraded to a Tier 1 select agent by the Centers for Disease Control and Prevention in October 2012 (http://www.selectagents.gov/).

Hainan Island is the largest tropical island in southern China. Situated in southeast Asia, it is close to endemic regions such as Thailand, Vietnam, Laos, and Hong Kong. Hainan has a tropical monsoon maritime climate characterized by high temperature and humidity. The rainy season of Hainan typically occurs between May and October, when frequent rainstorms and typhoons occur (http://www.weather.com.cn/hainan/qxjjj/03/341906.shtml). These factors combined have allowed Hainan to become a region of melioidosis endemicity.16

Multilocus sequence typing (MLST) has been used to characterize the population structure and diversity of B. pseudomallei; however, there is little information regarding this organism available from China (http://pubmlst.org/bpseudomallei/). Therefore, this study was conducted to analyze the sequence type (ST) diversity of clinical strains of B. pseudomallei from Hainan in China.

Materials and Methods

Ethics statement.

In this study, we anonymized the melioidosis patient data. All clinical isolates were collected during routine melioidosis laboratory diagnosis; therefore, patients did not provide written informed consent.

Clinical isolates.

A total of 60 clinical strains of B. pseudomallei were acquired from culture-confirmed melioidosis patients admitted to Hainan General Hospital, Haikou, and Hainan Department of the General Hospital of the Chinese People's Liberation Army, Sanya. Information describing the 60 strains is shown in Table 1. Glycerol stocks of B. pseudomallei were stored at −80°C.

Table 1

Clinical information and STs of 60 clinical isolates of Burkholderia pseudomallei in this study

StrainSample typeLocationOccurrenceMain clinical presentationOutcomeST
HPPH 23BloodHaikouNovember 2011SepticemiaS46
HPPH 32Bone marrowBaotingJuly 2012Septicemia, pneumoniaD46
HPPH 44Blood, secretionLedongApril 2013Septicemia, pneumonia, abscessD46
HPPH 45Blood, secretionLedongMay 2013AbscessS46
HPPH 65BloodDongfangAugust 2014Septicemia, pneumonia, abscessD46
HPPH 83SaniesHaikouJanuary 2004AbscessS46
HPPH 93SaniesChangjiangNovember 2013Septicemia, pneumonia, abscessD46
HPPH 50BloodWanningSeptember 2013Septicemia, pneumoniaD50
HPPH 55BloodHaikouFebruary 2014Septicemia, pneumoniaS50
HPPH 57Blood, saniesWanningApril 2014Septicemia, pneumonia, abscessD50
HPPH 72BloodDinganOctober 2014Septicemia, pneumoniaS50
HPPH 76SputumWanningDecember 2014PneumoniaS50
HPPH 40Blood, saniesDongfangDecember 2012Septicemia, abscessD55
HPPH 47SputumDongfangMay 2013PneumoniaS55
HPPH 51BloodDongfangSeptember 2013Septicemia, pneumonia, abscessD55
HPPH 61BloodDongfangJuly 2014Septicemia, pneumoniaD55
HPPH 92SaniesDongfangUAbscessS55
101699TissueLedongApril 2013AbscessS55
o91238BloodSanyaOctober 2012UD55
111506BloodSanyaDecember 2014US55
HPPH 53Blood, tissueWanningOctober 2013Septicemia, pneumoniaD58
HPPH 80BloodWenchangOctober 2005SepticemiaS58
HPPH 81Blood, sputumWanningOctober 2005Septicemia, pneumonia, abscessD58
141207009Blood, sputumLedongAugust 2013Septicemia, pneumoniaD58
141225021BloodSanyaUSepticemia, pneumoniaU58
o8005BloodSanyaSeptember 2013US58
HPPH 42BloodLedongJanuary 2013Septicemia, pneumonia, abscessD70
HPPH 66BloodHaikouAugust 2014Septicemia, pneumonia, abscessD70
HPPH 69BloodChangjiangSeptember 2014Septicemia, pneumoniaS90
HPPH 86SaniesDongfangUUS165
o42901SputumLedongUPneumoniaU205
HPPH 63BloodHaikouAugust 2014Septicemia, pneumonia, abscessD271
HPPH 75SaniesQionghaiOctober 2014Pneumonia, abscessS354
HPPH 77BloodDongfangDecember 2013Septicemia, pneumoniaS366
HPPH 43BloodHaikouMarch 2013Septicemia, pneumoniaD562
HPPH 48BloodTunchangJune 2013Septicemia, pneumonia, abscessD562
HPPH 58BloodDinganJuly 2014Septicemia, pneumoniaS658
HPPH 62SaniesWenchangJuly 2014AbscessS658
HPPH 54TissueDongfangDecember 2013AbscessS677
HPPH 68SaniesLingshuiSeptember 2014AbscessS677
112011SputumSanyaUUS677
o83020BloodSanyaDecember 2014Septicemia, pneumoniaD1091
HPPH 24SaniesLedongFebruary 2012Septicemia, pneumonia, abscessS1092
HPPH 21BloodDanzhouOctober 2011SepticemiaS1093
HPPH 1Blood, sputumLingaoJune 2010Septicemia, pneumoniaD1094
HPPH 4BloodSanyaOctober 2010Septicemia, pneumoniaS1095
HPPH 82BloodHaikouAugust 2003Septicemia, abscessD1096
HPPH 56SaniesChangjiangFebruary 2014PneumoniaS1098
HPPH 67SaniesWenchangSeptember 2014PneumoniaS1105
HPPH 70BloodHaikouOctober 2014Septicemia, pneumonia, abscessD1105
HPPH 85Blood, saniesWanningUSepticemia, abscessS1107
HPPH 59BloodWenchangJuly 2014SepticemiaS1325
HPPH 60BloodWenchangJuly 2014Septicemia, pneumoniaD1325
HPPH 73BloodWenchangNovember 2014Septicemia, pneumoniaD1443
HPPH 74SputumChengmaiNovember 2014PneumoniaS1443
HPPH 49SputumLedongJuly 2013PneumoniaS1395
HPPH 52BloodDinganAugust 2013PneumoniaS1396
HPPH 64BloodQionghaiAugust 2014Septicemia, pneumoniaD1397
HPPH 71BloodWenchangOctober 2014Septicemia, pneumoniaD1398
HN008_JBloodSanyaUUS1399

D = died; S = survived; STs = sequence types; U = unclear. In heavily shaded rows, STs was only found in Hainan. ST1395–1399 and ST1443 were the novel STs found in this study. ST562 was reported in both China and Australia; ST90 was also reported in the United States, probably from a traveler who had previously visited Asia.

Bacterial diversity analysis.

A total of 60 clinical isolates were typed by MLST as previously described.17 The number of alleles on seven housekeeping genes was determined by comparing the sequences to those at the B. pseudomallei MLST website (http://pubmlst.org/bpseudomallei/). The seven numbers were composed of the allelic profile of each strain, and each distinct allelic profile was assigned as a sequence type. New alleles and STs were submitted to the B. pseudomallei MLST database curator.

Phylogenetic analysis.

The relatedness among 30 STs was displayed as a dendrogram by eBURST v3 (Ed Feil, University of Bath, Bath, United Kingdom) with six shared alleles defined as a group.18 We downloaded the entire STs and allelic profiles of B. pseudomallei on the MLST website as a reference file, then compared the data with those for the 30 STs of this study as a query file by eBURST v3. The novel STs in our study are highlighted green, and the existing STs are highlighted magenta.

Results and Discussion

Information describing the 60 clinical isolates.

The 60 strains included in this study were isolated from 60 melioidosis patients in 15 different regions of Hainan excluding Basha, Qiongzhong, and Wuzhishan. All regions except Dingan, Tunchang, and Baoting were located along the coast (Figure 1). Because the population density of coastal areas was higher than that of inland areas, it remains unknown whether coastal areas are more conducive to B. pseudomallei growth and persistence than inland regions. Environmental samples of both coastal and inland areas across Hainan are needed to better understand the true ecological distribution of B. pseudomallei on this island. In Hainan, the presentations of melioidosis mainly included pneumonia, abscess formation, and septicemia. Overall, 31 of 35 patients with septicemia died (Table 1).

Figure 1.
Figure 1.

Map of Hainan Island and distribution of the 30 sequence types (STs). Map obtained from http://www.hinews.cn/news/system/2009/11/10/010605499.shtml showing the major regions in the island. The STs of 60 clinical isolates were labeled in each region in which melioidosis patients come from. The number of the strains is shown in the brackets.

Citation: The American Society of Tropical Medicine and Hygiene 95, 4; 10.4269/ajtmh.16-0280

STs of 60 clinical isolates.

The 60 clinical isolates belonged to 30 distinct STs, six of which had not been previously documented (Table 2). Among the six new STs, the gmhD locus of ST1443 was 99% similar to the allele-2 sequence, whereas the other new STs were generated by reassortment of existing alleles. These findings indicated that there was low genetic diversity within alleles, but alleles recombined frequently to form new STs. Among the 60 isolates, the loci of ace, gltB, lepA, lipA, and ndh had only three types of alleles, most of which were allele-1, but the loci of gmhD and nark had more than six alleles.

Table 2

Alleles types of six novel sequence types (STs)

STStrainLocus
acegltBgmhDlepAlipAnarKndh
1443HPPH73, HPPH7413126new1521
1395HPPH 4931281121
1396HPPH 5212611223
1397HPPH 6412131121
1398HPPH 7111311401
1399HN008_J1431143

new = new sequence, 99% similarity of allele-2.

The remaining 24 STs were reported from other southeast Asian regions except ST562, ST90, and 10 STs that were only reported in China (Table 1). ST562 was shared with Australia and ST90 with the United States. It was previously reported that isolates of B. pseudomallei from Australia and Asia were distinct by MLST.19 Even isolates from the different regions of Australia were distinct.20,21 Because B. pseudomallei had not naturally been found in the environment in the United States, ST90 was probably from a traveler who had previously visited Asia. The ST562 may also have been caused by homoplasy in the MLST loci,22 or imported strains because Hainan is known for an international tourism. In view of the high level of genetic recombination, it may be a recombinant.23

The ST distribution of 60 clinical isolates also differed (Figure 1). ST55 (eight strains), ST46 (seven strains), ST58 (six strains), and ST50 (five strains) were the most prevalent sequence types (Table 1). ST55 and ST46 were mainly found in southwest Hainan of Dongfang, Ledong, and Sanya, whereas ST58 was primarily distributed in southern Hainan and ST50 was primarily in northeastern Hainan. However, more clinical isolates and environmental samples are needed to confirm these findings.

The relatedness of 30 STs.

The 30 STs were divided into three groups and 18 singletons by eBURST. The majority of STs in the present study were singletons. With the exception of group 2, they did not form a radial expansion pattern (Figure 2). The 30 STs were compared with all of the STs present in the MLST database using eBURST (Figure 3). The results demonstrated a high level of diversity, with the 30 STs spread throughout almost all branches of the eBURST diagram.

Figure 2.
Figure 2.

eBURST diagram of sequence types from isolates in this study. I = group 1; II = group 2; III = group 3.

Citation: The American Society of Tropical Medicine and Hygiene 95, 4; 10.4269/ajtmh.16-0280

Figure 3.
Figure 3.

eBURST diagram comparing Burkholderia pseudomallei isolates from this study to those from the entire world. The novel sequence types (STs) in this study are highlighted green, and the existing STs are highlighted magenta.

Citation: The American Society of Tropical Medicine and Hygiene 95, 4; 10.4269/ajtmh.16-0280

In conclusion, the 60 clinical isolates from Hainan had a high level of diversity. Allele recombination may be an important factor leading to these diversities, and migration of humans may have also influenced the distribution of B. pseudomallei clones throughout Hainan.

  • 1.

    Kaestli M, Mayo M, Harrington G, Ward L, Watt F, Hill JV, Cheng AC, Currie BJ, 2009. Landscape changes influence the occurrence of the melioidosis bacterium Burkholderia pseudomallei in soil in northern Australia. PLoS Negl Trop Dis 3: e364.

    • Search Google Scholar
    • Export Citation
  • 2.

    Baker A, Tahani D, Gardiner C, Bristow KL, Greenhill AR, Warner J, 2011. Groundwater seeps facilitate exposure to Burkholderia pseudomallei. Appl Environ Microbiol 77: 72437246.

    • Search Google Scholar
    • Export Citation
  • 3.

    Rattanavong S, Wuthiekanun V, Langla S, Amornchai P, Sirisouk J, Phetsouvanh R, Moore CE, Peacock SJ, Buisson Y, Newton PN, 2011. Randomized soil survey of the distribution of Burkholderia pseudomallei in rice fields in Laos. Appl Environ Microbiol 77: 532536.

    • Search Google Scholar
    • Export Citation
  • 4.

    Limmathurotsakul D, Wuthiekanun V, Amornchai P, Wongsuwan G, Day NP, Peacock SJ, 2012. Effectiveness of a simplified method for isolation of Burkholderia pseudomallei from soil. Appl Environ Microbiol 78: 876877.

    • Search Google Scholar
    • Export Citation
  • 5.

    Vongphayloth K, Rattanavong S, Moore CE, Phetsouvanh R, Wuthiekanun V, Sengdouangphachanh A, Phouminh P, Newton PN, Buisson Y, 2012. Burkholderia pseudomallei detection in surface water in southern Laos using Moore's swabs. Am J Trop Med Hyg 86: 872877.

    • Search Google Scholar
    • Export Citation
  • 6.

    Currie BJ, Jacups SP, 2003. Intensity of rainfall and severity of melioidosis, Australia. Emerg Infect Dis 9: 15381542.

  • 7.

    Su HP, Chan TC, Chang CC, 2011. Typhoon-related leptospirosis and melioidosis, Taiwan, 2009. Emerg Infect Dis 17: 13221324.

  • 8.

    Parameswaran U, Baird RW, Ward LM, Currie BJ, 2012. Melioidosis at Royal Darwin Hospital in the big 2009–2010 wet season: comparison with the preceding 20 years. Med J Aust 196: 345348.

    • Search Google Scholar
    • Export Citation
  • 9.

    Liu X, Pang L, Sim SH, Goh KT, Ravikumar S, Win MS, Tan G, Cook AR, Fisher D, Chai LY, 2015. Association of melioidosis incidence with rainfall and humidity, Singapore, 2003–2012. Emerg Infect Dis 21: 159162.

    • Search Google Scholar
    • Export Citation
  • 10.

    Chen PS, Chen YS, Lin HH, Liu PJ, Ni WF, Hsueh PT, Liang SH, Chen C, Chen YL, 2015. Airborne transmission of melioidosis to humans from environmental aerosols contaminated with B. pseudomallei. PLoS Negl Trop Dis 9: e0003834.

    • Search Google Scholar
    • Export Citation
  • 11.

    Suputtamongkol Y, Hall AJ, Dance DA, Chaowagul W, Rajchanuvong A, Smith MD, White NJ, 1994. The epidemiology of melioidosis in Ubon Ratchatani, northeast Thailand. Int J Epidemiol 23: 10821090.

    • Search Google Scholar
    • Export Citation
  • 12.

    Hill AA, Mayo M, Kaestli M, Price EP, Richardson LJ, Godoy D, Spratt BG, Currie BJ, 2013. Melioidosis as a consequence of sporting activity. Am J Trop Med Hyg 89: 365366.

    • Search Google Scholar
    • Export Citation
  • 13.

    Doker TJ, Sharp TM, Rivera-Garcia B, Perez-Padilla J, Benoit TJ, Ellis EM, Elrod MG, Gee JE, Shieh WJ, Beesley CA, Ryff KR, Traxler RM, Galloway RL, Haberling DL, Waller LA, Shadomy SV, Bower WA, Hoffmaster AR, Walke HT, Blaney DD, 2015. Contact investigation of melioidosis cases reveals regional endemicity in Puerto Rico. Clin Infect Dis 60: 243250.

    • Search Google Scholar
    • Export Citation
  • 14.

    White NJ, 2003. Melioidosis. Lancet 361: 17151722.

  • 15.

    Cheng AC, Currie BJ, 2005. Melioidosis: epidemiology, pathophysiology, and management. Clin Microbiol Rev 18: 383416.

  • 16.

    Limmathurotsakul D, Golding N, Dance DAB, Messina JP, Pigott DM, Moyes CL, Rolim DB, Bertherat E, Day NPJ, Peacock SJ, Hay SI, 2016. Predicted global distribution of Burkholderia pseudomallei and burden of melioidosis. Nature Microbiol 1: 15.

    • Search Google Scholar
    • Export Citation
  • 17.

    Godoy D, Randle G, Simpson AJ, Aanensen DM, Pitt TL, Kinoshita R, Spratt BG, 2003. Multilocus sequence typing and evolutionary relationships among the causative agents of melioidosis and glanders, Burkholderia pseudomallei and Burkholderia mallei. J Clin Microbiol 41: 20682079.

    • Search Google Scholar
    • Export Citation
  • 18.

    Feil EJ, Li BC, Aanensen DM, Hanage WP, Spratt BG, 2004. eBURST: inferring patterns of evolutionary descent among clusters of related bacterial genotypes from multilocus sequence typing data. J Bacteriol 186: 15181530.

    • Search Google Scholar
    • Export Citation
  • 19.

    Cheng AC, Godoy D, Mayo M, Gal D, Spratt BG, Currie BJ, 2004. Isolates of Burkholderia pseudomallei from northern Australia are distinct by multilocus sequence typing, but strain types do not correlate with clinical presentation. J Clin Microbiol 42: 54775483.

    • Search Google Scholar
    • Export Citation
  • 20.

    Cheng AC, Ward L, Godoy D, Norton R, Mayo M, Gal D, Spratt BG, Currie BJ, 2008. Genetic diversity of Burkholderia pseudomallei isolates in Australia. J Clin Microbiol 46: 249254.

    • Search Google Scholar
    • Export Citation
  • 21.

    Currie BJ, Thomas AD, Godoy D, Dance DA, Cheng AC, Ward L, Mayo M, Pitt TL, Spratt BG, 2007. Australian and Thai isolates of Burkholderia pseudomallei are distinct by multilocus sequence typing: revision of a case of mistaken identity. J Clin Microbiol 45: 38283829.

    • Search Google Scholar
    • Export Citation
  • 22.

    De Smet B, Sarovich DS, Price EP, Mayo M, Theobald V, Kham C, Heng S, Thong P, Holden MTG, Parkhill J, Peacock SJ, Spratt BG, Jacobs JA, Vandamme P, Currie BJ, 2015. Whole-genome sequencing confirms that Burkholderia pseudomallei multilocus sequence types common to both Cambodia and Australia are due to homoplasy. J Clin Microbiol 53: 323326.

    • Search Google Scholar
    • Export Citation
  • 23.

    Price EP, Sarovich DS, Smith EJ, MacHunter B, Harrington G, Theobald V, Hall CM, Hornstra HM, McRobb E, Podin Y, Mayo M, Sahl JW, Wagner DM, Keim P, Kaestli M, Currie BJ, 2016. Unprecedented melioidosis cases in northern Australia caused by an Asian Burkholderia pseudomallei strain identified by using large-scale comparative genomics. Appl Environ Microbiol 82: 954963.

    • Search Google Scholar
    • Export Citation

Author Notes

* Address correspondence to Ling-Li Liu, Department of Clinical Laboratory, Hainan General Hospital, No. 19 Xiuhua Road, Xiuying District, Haikou 570311, People's Republic of China, E-mail: liu_lingli@126.com or Wei Li, National Institute for Communicable Disease Control and Prevention, No. 155 Changbai Road, Changping District, Beijing, 102206, People's Republic of China, E-mail: liwei@icdc.cn. † These authors contributed equally to this work.

Financial support: This work was funded by project no. Qiongwei-2013-Zizhu-059 from the Hainan Provincial Health Department and the National Natural Science Foundation of China (no. 81573208).

Authors' addresses: Xu-Ming Wang, Hua Wu, Xiao-Jun Zhou, Hong-Li Guo, Kai Xu, Tian-Jiao Li, and Ling-Li Liu, Clinical Laboratory, Hainan General Hospital, Haikou, People's Republic of China, E-mails: wxmhn1260@163.com, syjykwuhua@163.com, hainanbeilicun@163.com, 18789690990@163.com, xukaisy@163.com, ltjhnhn@163.com, and liu_lingli@126.com. Xiao Zheng and Wei Li, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, People's Republic of China, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China, and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China, E-mails: zhengxiao@icdc.cn and cdcliwei@gmail.com. Hui-Hui Kuang, The General Hospital of the Chinese People's Liberation Army, Sanya, People's Republic of China, E-mail: huiziai1988@163.com.

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