Burkholderia pseudomallei: Its Detection in Soil and Seroprevalence in Bangladesh

Abstract

BackgroundMelioidosis, 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 ResultsSoil 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 (χ2 = 3.441, p = 0.064) or any occupational group (χ2 = 3.835, p = 0.280).ConclusionThis 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.

Seroprevalence of Burkholderia pseudomallei among Adults in Coastal Areas in Southwestern India

“…These results are consistent with several studies that also showed higher disease rates among males compared to females [ 12 , 22 ]. In contrast, a recent report from Bangladesh described a similar seropositivity in both genders [ 23 ]. A difference in immunity to melioidosis between genders is unclear.…”

Melioidosis in Bangladesh: A Clinical and Epidemiological Analysis of Culture-Confirmed Cases

“…The survey recorded 28.9% positivity for B. pseudomallei through an indirect haemagglutination assay among 1244 adult febrile patients [ 41 ]. However, another study reported 22.6% to 30.8% seropositivity in three districts (Gazipur, Mymensingh, and Sylhet) where melioidosis cases were detected earlier, compared to 9.8% in a district (Kishoreganj) where no melioidosis cases were either detected or reported ( p < 0.01) [ 42 ]. The same study found no significant difference among different occupational groups (χ 2 = 3.835, p = 0.280) [ 42 ].…”

“…However, another study reported 22.6% to 30.8% seropositivity in three districts (Gazipur, Mymensingh, and Sylhet) where melioidosis cases were detected earlier, compared to 9.8% in a district (Kishoreganj) where no melioidosis cases were either detected or reported ( p < 0.01) [ 42 ]. The same study found no significant difference among different occupational groups (χ 2 = 3.835, p = 0.280) [ 42 ]. Over 88% (23/26) of cases in Bangladesh had a definitive history of soil exposure ( Table 2 ).…”

Socio-demographic, Clinical and Laboratory Characteristics of Melioidosis: Four-Year Experience of Managing Consecutive 11 Cases in a Tertiary Care Hospital of Bangladesh

“…7 Furthermore, a delay in diagnosis and treatment with inappropriate antimicrobials may result in case fatality rates exceeding 70%. 9,10 Since the isolation of the bacterium in the soil of Gazipur district, Bangladesh in 2013, 11 there have been an increasing number of reported cases of melioidosis in Bangladesh. [12][13][14][15][16][17][18][19] This observational study is the first of its kind to focus on describing the clinical features, diagnostic proofs, treatment and outcome of melioidosis cases in Bangladesh.…”