Genomic Diversity of Burkholderia pseudomallei Isolates,Colombia

We report an analysis of the genomic diversity of isolates of Burkholderia pseudomallei, the cause of melioidosis, recovered in Colombia from routine surveillance during 2016–2017. B. pseudomallei appears genetically diverse, suggesting it is well established and has spread across the region.     

Burkholderia pseudomallei antibodies in children, Cambodia

Antibodies to Burkholderia pseudomallei were detected in 16% of children in Siem Reap, Cambodia. This organism was isolated from 30% of rice paddies in the surrounding vicinity. Despite the lack of reported indigenous cases, melioidosis is likely to occur in Cambodia.     

Misidentification of Burkholderia pseudomallei,China

We report a case of melioidosis in China and offer a comparison of 5 commercial detection systems for Burkholderia pseudomallei. The organism was misidentified by the VITEK 2 Compact, Phoenix, VITEK mass spectrometry, and API 20NE systems but was eventually identified by the Bruker Biotyper system and 16S rRNA sequencing.     

Seroepidemiological surveillance of Burkholderia pseudomallei in Bangladesh

Melioidosis (Burkholderia pseudomallei infection) has yet to be demonstrated systematically in Bangladesh. A prospective, cross-sectional serological survey was conducted in 2010 at six Bangladeshi hospitals. Age, gender, occupation and residential address were recorded. Of 1244 patients, 359 (28.9%) were positive for B. pseudomallei by indirect haemagglutination assay. Farmers had an increased risk of seropositivity (risk ratio=1.4, 95% CI 1.0-1.8; p=0.03). There was no clear geographic clustering of seropositives. Melioidosis should be considered as a possible cause of febrile illness in Bangladesh. Further studies are needed to establish the incidence of clinical disease and distribution of environmental risk.     

Burkholderia pseudomallei in Unchlorinated Domestic Bore Water, Tropical Northern Australia

To determine whether unchlorinated bore water in northern Australia contained Burkholderia pseudomallei organisms, we sampled 55 bores; 18 (33%) were culture positive. Multilocus sequence typing identified 15 sequence types. The B. pseudomallei sequence type from 1 water sample matched a clinical isolate from a resident with melioidosis on the same property.     

Melioidosis Caused by Burkholderia pseudomallei in Drinking Water,Thailand, 2012

We identified 10 patients in Thailand with culture-confirmed melioidosis who had Burkholderia pseudomallei isolated from their drinking water. The multilocus sequence type of B. pseudomallei from clinical specimens and water samples were identical for 2 patients. This finding suggests that drinking water is a preventable source of B. pseudomallei infection.     

Nonclonal Burkholderia pseudomallei Population in Melioidosis Case Cluster,Sri Lanka

A melioidosis case cluster of 10 blood culture–positive patients occurred in eastern Sri Lanka after an extreme weather event. Four infections were caused by Burkholderia pseudomallei isolates of sequence type 594. Whole-genome analysis showed that the isolates were genetically diverse and the case cluster was nonclonal.     

Emergence of Burkholderia pseudomallei Sequence Type 562, Northern Australia

Since 2005, the range of Burkholderia pseudomallei sequence type 562 (ST562) has expanded in northern Australia. During 2005–2019, ST562 caused melioidosis in 61 humans and 3 animals. Cases initially occurred in suburbs surrounding a creek before spreading across urban Darwin, Australia and a nearby island community. In urban Darwin, ST562 caused 12% (53/440) of melioidosis cases, a proportion that increased during the study period. We analyzed 2 clusters of cases with epidemiologic links and used genomic analysis to identify previously unassociated cases. We found that ST562 isolates from Hainan Province, China, and Pingtung County, Taiwan, were distantly related to ST562 strains from Australia. Temporal genomic analysis suggested a single ST562 introduction into the Darwin region in ≈1988. The origin and transmission mode of ST562 into Australia remain uncertain.     

Burkholderia pseudomallei traced to water treatment plant in Australia

Burkholderia pseudomallei was isolated from environmental specimens 1 year after an outbreak of acute melioidosis in a remote coastal community in northwestern Australia. B. pseudomallei was isolated from a water storage tank and from spray formed in a pH-raising aerator unit. Pulsed-field gel electrophoresis confirmed the aerator and storage tank isolates were identical to the outbreak strain, WKo97.     

Burkholderia pseudomallei in Environment of Adolescent Siblings with Melioidosis,Kerala, India, 2019

In 2019, Burkholderia pseudomallei was isolated from the backyard of 2 siblings with melioidosis in Kerala, India. This finding highlights the value of healthcare providers being aware of risk for melioidosis in febrile patients, of residents taking precautions when outside, and of increasing environmental surveillance for B. pseudomallei in this region.     

Laboratory exposure to Burkholderia pseudomallei--Los Angeles, California, 2003

On July 26, 2003, the Los Angeles County Department of Health Services (LACDHS) received a report that a local clinical laboratory had isolated from specimens Burkholderia pseudomallei, a category B biologic terrorism agent and the causative organism for melioidosis, which is endemic to certain tropical areas. Because laboratory workers had manipulated cultures of the organism, CDC was asked to assist in the subsequent investigation. This report summarizes the results of that investigation, which included assessment of laboratory exposures, postexposure chemoprophylaxis, and serologic testing of exposed laboratory workers. The findings underscore the need to reinforce proper laboratory practices and the potential benefits of chemoprophylaxis after laboratory exposures.     

VNTR analysis of selected outbreaks of Burkholderia pseudomallei in Australia.

Molecular typing methods for Burkholderia pseudomallei have been successful at assigning isolates into epidemiologically related groups, but have not been able to detect differences and define evolutionary patterns within groups. Our variable number tandem repeat (VNTR) analysis of a set of 121 Australian B. pseudomallei isolates, 104 of which were associated with nine epidemiological groups, provides fine scale differentiation even among very closely related isolates. We used a Bayesian model based upon mutation accumulation patterns to define the close phylogenetic relationships within these epidemiological groups. Our results reveal that genetic diversity can exist within a very small geographic area, and that low levels of diversity can exist even within a single infection. These methods provide the ability to generate robust evolutionary hypotheses that enable tracking of B. pseudomallei in forensic and epidemiological outbreaks at fine phylogenetic scales.     

湛江地区类鼻疽伯克霍尔德菌特征与流行病学研究

目的研究类鼻疽伯克霍尔德菌与常见其他伯克霍尔德菌间病原学特点及对药物敏感性的差异，为临床诊断、检验和治疗提供参考。方法对类鼻疽伯克霍尔德菌感染病例进行流行病学研究，并将其与常见医院感染皮氏伯克霍尔德菌、洋葱伯克霍尔德菌对常用抗菌药物的药敏结果进行比较分析。结果类鼻疽伯克霍尔德菌具有两端浓染，银白色菌落形态特征。在湛江，此菌感染以遂溪、廉江、吴川为主要疫区，好发于秋季，接触疫水、农民、免疫功能低下、年龄≥50岁为易感因素。其对复方磺胺甲嗯唑、头孢哌酮／舒巴坦、米诺环素、哌拉西林及其酶抑制复合制剂、头孢他啶、亚胺培南敏感率达100％，对氨基糖苷类、喹诺酮类和非抗假单胞菌属类药敏感性较差或耐药。结论类鼻疽伯克霍尔德菌感染属热带或亚热带地区传染病，水患易导致该菌流行；细菌具有染色、菌落形态特征，对药物的敏感性具有伯克菌属共同特征，易产生耐药，建议联合用药治疗。     

Identification of an OmpW homologue in Burkholderia pseudomallei,a protective vaccine antigen against melioidosis

Burkholderia pseudomallei is the causative agent of melioidosis, which is associated with a range of clinical manifestations, including sepsis and fatal pneumonia and is endemic in Southeast Asia and Northern Australia. Treatment can be challenging and control of infection involves prolonged antibiotic therapy, yet there are no approved vaccines available to prevent infection. Our aim was to develop and assess the potential of a prophylactic vaccine candidate targeted against melioidosis. The identified candidate is the 22 kDa outer membrane protein, OmpW. We previously demonstrated that this protein was immunoprotective in mouse models of Burkholderia cepacia complex (Bcc) infections. We cloned Bp_ompW in Escherichia coli, expressed and purified the protein. Endotoxin free protein administered with SAS adjuvant protected Balb/C mice (75% survival) relative to controls (25% survival) (p < 0.05). A potent serological response was observed with IgG2a to IgG1 ratio of 6.0. Furthermore C57BL/6 mice were protected for up to 80 days against a lethal dose of B. pseudomallei and surpassed the efficacy of the live attenuated 2D2 positive control. BpompW is homologous across thirteen sequenced B. pseudomallei strains, indicating that it should be broadly protective against B. pseudomallei. In conclusion, we have demonstrated that BpOmpW is able to induce protective immunity against melioidosis and is likely to be an effective vaccine antigen, possibly in combination with other subunit antigens.