Burkholderia pseudomallei in Soil, US Virgin Islands, 2019.
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ABSTRACT:
SUBMITTER: Stone NE
PROVIDER: S-EPMC7588534 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Phylogenetic analysis of a clinical isolate associated with subclinical Burkholderia pseudomallei infection revealed probable exposure in the British Virgin Islands, where reported infections are limited. Clinicians should consider this geographic distribution when evaluating possible infection among persons with compatible travel history.
| S-EPMC8632167 | biostudies-literature
Project description:Melioidosis, caused by the soil-dwelling bacterium Burkholderia pseudomallei, is predicted to be endemic in Nigeria but is only occasionally reported. This report documents the systematic identification of the presence of B. pseudomallei and B. thailandensis in the soil across multiple states in Nigeria.
| S-EPMC10124662 | biostudies-literature
Project description:Burkholderia pseudomallei is the etiologic agent of melioidosis, a significant cause of morbidity and mortality where this infection is endemic. Genomic differences among strains of B. pseudomallei are predicted to be one of the major causes of the diverse clinical manifestations observed among patients with melioidosis. The purpose of this study was to examine the role of genomic islands (GIs) as sources of genomic diversity in this species.We found that genomic islands (GIs) vary greatly among B. pseudomallei strains. We identified 71 distinct GIs from the genome sequences of five reference strains of B. pseudomallei: K96243, 1710b, 1106a, MSHR668, and MSHR305. The genomic positions of these GIs are not random, as many of them are associated with tRNA gene loci. In particular, the 3' end sequences of tRNA genes are predicted to be involved in the integration of GIs. We propose the term "tRNA-mediated site-specific recombination" (tRNA-SSR) for this mechanism. In addition, we provide a GI nomenclature that is based upon integration hotspots identified here or previously described.Our data suggest that acquisition of GIs is one of the major sources of genomic diversity within B. pseudomallei and the molecular mechanisms that facilitate horizontally-acquired GIs are common across multiple strains of B. pseudomallei. The differential presence of the 71 GIs across multiple strains demonstrates the importance of these mobile elements for shaping the genetic composition of individual strains and populations within this bacterial species.
| S-EPMC2612704 | biostudies-literature
Project description:BackgroundBurkholderia pseudomallei is a Gram-negative bacterium found in soil and water in many tropical countries. It causes melioidosis, a potentially fatal infection first described in 1911 in Myanmar. Melioidosis is a common cause of sepsis and death in South and South-east Asia, but it is rarely diagnosed in Myanmar. We conducted a nationwide soil study to identify areas where B. pseudomallei is present.Methodology/principal findingsWe collected soil samples from 387 locations in all 15 states and regions of Myanmar between September 2017 and June 2019. At each site, three samples were taken at each of three different depths (30, 60 and 90 cm) and were cultured for B. pseudomallei separately, along with a pooled sample from each site (i.e. 10 cultures per site). We used a negative binomial regression model to assess associations between isolation of B. pseudomallei and environmental factors (season, soil depth, soil type, land use and climate zones). B. pseudomallei was isolated in 7 of 15 states and regions. Of the 387 sites, 31 (8%) had one or more positive samples and of the 3,870 samples cultured, 103 (2.7%) tested positive for B. pseudomallei. B. pseudomallei was isolated more frequently during the monsoon season [RR-2.28 (95% CI: 0.70-7.38)] and less in the hot dry season [RR-0.70 (95% CI: 0.19-2.56)] compared to the cool dry season, and in the tropical monsoon climate zone [RR-2.26; 95% CI (0.21-6.21)] compared to the tropical dry winter climate zone. However, these associations were not statistically significant. B. pseudomallei was detected at all three depths and from various soil types (clay, silt and sand). Isolation was higher in agricultural land (2.2%), pasture land (8.5%) and disused land (5.8%) than in residential land (0.4%), but these differences were also not significant.Conclusion/significanceThis study confirms a widespread distribution of B. pseudomallei in Myanmar. Clinical studies should follow to obtain a better picture of the burden of melioidosis in Myanmar.
| S-EPMC8143414 | biostudies-literature
Project description:BACKGROUND:Melioidosis, caused by Burkholderia pseudomallei, is an endemic disease in Bangladesh. No systematic study has yet been done to detect the environmental source of the organism and its true extent in Bangladesh. The present study attempted to isolate B. pseudomallei in soil samples and to determine its seroprevalence in several districts in Bangladesh. METHODOLOGY AND RESULTS:Soil samples were collected from rural areas of four districts of Bangladesh from where culture confirmed melioidosis cases were detected earlier. Multiple soil samples, collected from 5-7 sampling points of 3-5 sites of each district, were cultured in Ashdown selective media. Suspected colonies of B. pseudomallei were identified by biochemical and serological test, and by polymerase chain reaction (PCR) using 16s rRNA specific primers. Blood samples were collected from 940 healthy individuals of four districts to determine anti- B. pseudomallei IgG antibody levels by indirect enzyme linked immunosorbent assay (ELISA) using sonicated crude antigen. Out of 179 soil samples, B. pseudomallei was isolated from two samples of Gazipur district which is located 58 km north of capital Dhaka city. Both the isolates were phenotypically identical, arabinose negative and showed specific 550bp band in PCR. Out of 940 blood samples, anti- B. pseudomallei IgG antibody, higher than the cut-off value (>0.8), was detected in 21.5% individuals. Seropositivity rate was 22.6%-30.8% in three districts from where melioidosis cases were detected earlier, compared to 9.8% in a district where no melioidosis case was either detected or reported (p<0.01). Seropositivity increased with the advancement of age from 5.3% to 30.4% among individuals aged 1-10 years and > 50 years respectively. The seropositivity rates were 26.0% and 20.6% in male and female respectively, while it was 20-27% among different occupational groups. No significant association was observed with gender (?2 = 3.441, p = 0.064) or any occupational group (?2 = 3.835, p = 0.280). CONCLUSION:This is the first study demonstrating the presence of B. pseudomallei in the environmental (soil) samples of Bangladesh. It also suggested that a large proportion of people, residing in these districts, were exposed to the organism.
| S-EPMC4714902 | biostudies-literature
Project description:The resilience of Burkholderia pseudomallei, the causative agent of melioidosis, was evaluated in control soil microcosms and in soil microcosms containing NaCl or FeSO4 at 30°C. Iron (Fe(II)) promoted the growth of B. pseudomallei during the 30-day observation, contrary to the presence of 1.5% and 3% NaCl. Scanning electron micrographs of B. pseudomallei in soil revealed their morphological alteration from rod to coccoid and the formation of microcolonies. The smallest B. pseudomallei cells were found in soil with 100 ?M FeSO4 compared with in the control soil or soil with 0.6% NaCl (P < 0.05). The colony count on Ashdown's agar and bacterial viability assay using the LIVE/DEAD(®) BacLight(™) stain combined with flow cytometry showed that B. pseudomallei remained culturable and viable in the control soil microcosms for at least 120 days. In contrast, soil with 1.5% NaCl affected their culturability at day 90 and their viability at day 120. Our results suggested that a low salinity and iron may influence the survival of B. pseudomallei and its ability to change from a rod-like to coccoid form. The morphological changes of B. pseudomallei cells may be advantageous for their persistence in the environment and may increase the risk of their transmission to humans.
| S-EPMC4703280 | biostudies-literature
Project description:BackgroundMelioidosis is a frequently fatal infectious disease caused by the soil dwelling Gram-negative bacterium Burkholderia pseudomallei. Environmental sampling is important to identify geographical distribution of the organism and related risk of infection to humans and livestock. The aim of this study was to evaluate spatial distribution of B. pseudomallei in soil and consider the implications of this for soil sampling strategies.Methods and findingsA fixed-interval sampling strategy was used as the basis for detection and quantitation by culture of B. pseudomallei in soil in two environmental sites (disused land covered with low-lying scrub and rice field) in northeast Thailand. Semivariogram and indicator semivariogram were used to evaluate the distribution of B. pseudomallei and its relationship with range between sampling points. B. pseudomallei was present on culture of 80/100 sampling points taken from the disused land and 28/100 sampling points from the rice field. The median B. pseudomallei cfu/gram from positive sampling points was 378 and 700 for the disused land and the rice field, respectively (p = 0.17). Spatial autocorrelation of B. pseudomallei was present, in that samples taken from areas adjacent to sampling points that were culture positive (negative) for B. pseudomallei were also likely to be culture positive (negative), and samples taken from areas adjacent to sampling points with a high (low) B. pseudomallei count were also likely to yield a high (low) count. Ranges of spatial autocorrelation in quantitative B. pseudomallei count were 11.4 meters in the disused land and 7.6 meters in the rice field.ConclusionsWe discuss the implications of the uneven distribution of B. pseudomallei in soil for future environmental studies, and describe a range of established geostatistical sampling approaches that would be suitable for the study of B. pseudomallei that take account of our findings.
| S-EPMC2879387 | biostudies-literature
Project description:Burkholderia pseudomallei, as a saprophytic bacterium that can cause a severe sepsis disease named melioidosis, has preserved several extra genes in its genome for survival. The sequenced genome of the organism showed high diversity contributed mainly from genomic islands (GIs). Comparative genome hybridization (CGH) of 3 clinical and 2 environmental isolates, using whole genome microarrays based on B. pseudomallei K96243 genes, revealed a difference in the presence of genomic islands between clinical and environmental isolates. The largest GI, GI8, of B. pseudomallei was observed as a 2 sub-GI named GIs8.1 and 8.2 with distinguishable %GC content and unequal presence in the genome. GIs8.1, 8.2 and 15 were found to be more common in clinical isolates. A new GI, GI16c, was detected on chromosome 2. Presences of GIs8.1, 8.2, 15 and 16c were evaluated in 70 environmental and 64 clinical isolates using PCR assays. A combination of GIs8.1 and 16c (positivity of either GI) was detected in 70% of clinical isolates and 11.4% of environmental isolates (P<0.001). Using BALB/c mice model, no significant difference of time to mortality was observed between K96243 isolate and three isolates without GIs under evaluation (P>0.05). Some virulence genes located in the absent GIs and the difference of GIs seems to contribute less to bacterial virulence. The PCR detection of 2 GIs could be used as a cost effective and rapid tool to detect potentially virulent isolates that were contaminated in soil.
| S-EPMC3365882 | biostudies-literature
Project description:Burkholderia pseudomallei is a soil-dwelling bacterium and the cause of melioidosis, which kills an estimated 89,000 people per year worldwide. Agricultural workers are at high risk of infection due to repeated exposure to the bacterium. Little is known about the soil physicochemical properties associated with the presence or absence of the organism. Here, we evaluated the soil physicochemical properties and presence of B. pseudomallei in 6,100 soil samples collected from 61 rice fields in Thailand. The presence of B. pseudomallei was negatively associated with the proportion of clay, proportion of moisture, level of salinity, percentage of organic matter, presence of cadmium, and nutrient levels (phosphorus, potassium, calcium, magnesium, and iron). The presence of B. pseudomallei was not associated with the level of soil acidity (P = 0.54). In a multivariable logistic regression model, the presence of B. pseudomallei was negatively associated with the percentage of organic matter (odds ratio [OR], 0.06; 95% confidence interval [CI], 0.01 to 0.47; P = 0.007), level of salinity (OR, 0.06; 95% CI, 0.01 to 0.74; P = 0.03), and percentage of soil moisture (OR, 0.81; 95% CI, 0.66 to 1.00; P = 0.05). Our study suggests that B. pseudomallei thrives in rice fields that are nutrient depleted. Some agricultural practices result in a decline in soil nutrients, which may impact the presence and amount of B. pseudomallei bacteria in affected areas.ImportanceBurkholderia pseudomallei is an environmental Gram-negative bacillus and the cause of melioidosis. Humans acquire the disease following skin inoculation, inhalation, or ingestion of the bacterium in the environment. The presence of B. pseudomallei in soil defines geographic regions where humans and livestock are at risk of melioidosis, yet little is known about the soil properties associated with the presence of the organism. We evaluated the soil properties and presence of B. pseudomallei in 61 rice fields in East, Central, and Northeast Thailand. We demonstrated that the organism was more commonly found in soils with lower levels of organic matter and nutrients, including phosphorus, potassium, calcium, magnesium, and iron. We also demonstrated that crop residue burning after harvest, which can reduce soil nutrients, was not uncommon. Some agricultural practices result in a decline in soil nutrients, which may impact the presence and amount of B. pseudomallei bacteria in affected areas.
| S-EPMC5118919 | biostudies-literature
Project description:Within 8 months, 3 children from 1 family in northern Vietnam died from melioidosis. Burkholderia pseudomallei of the same sequence type, 541, was isolated from clinical samples, borehole water, and garden and rice field soil. Boreholes should be properly constructed and maintained to avoid B. pseudomallei contamination.
| S-EPMC9328891 | biostudies-literature