Phylogeographic characterization of Burkholderia pseudomallei isolated from Bangladesh.

BACKGROUND: Burkholderia pseudomallei possesses a diverse set of genes which encode a vast array of biological functions reflecting its clinical, ecological and phenotypic diversity. Strain variation is linked to geographic location as well as pattern of land uses. This soil-dwelling Gram-negative pathogen causes melioidosis, a tropical disease endemic in northern Australia and Southeast Asian regions including Bangladesh. Phylogeographic analyses of B. pseudomallei isolates by molecular typing techniques could be used to examine the diversity of this organism as well as to track melioidosis epidemics. METHODS: In this study, 22 B. pseudomallei isolates, of which 20 clinical and two soil isolates were analyzed, utilizing Real-time PCR assay and multilocus sequence typing (MLST). The sequences were then submitted to PubMLST database for analysis and construction of phylogenetic tree. FINDINGS: A total of 12 different sequence types (STs) that includes four novel STs were identified for the first time. Strains having STs 1005, 1007 and 56 were the most widespread STs frequently isolated in Bangladesh. ST 1005, ST 56, ST 1007 and ST 211 have been detected not only in Bangladesh but are also present in many Southeast Asian countries. SIGNIFICANCE: ST 1005 was detected in both soil and clinical samples of Gazipur. Most prevalent, ST 56 has been previously reported from Myanmar, Thailand, Cambodia and Vietnam, confirming the persistence of the genotype over the entire continent. Further large-scale study is necessary to find out the magnitude of the infection and its different reservoirs in the environment along with phylogeographic association.

Disseminated mucormycosis: An unusual case of ascites with bone marrow invasion.

Mucormycosis is a fatal invasive illness most frequently seen in immunocompromised hosts with uncontrolled diabetes, hematological malignancies, organ transplantation, or long-term steroid treatment. It has a poorer outcome than other fungal diseases due to its rapid spread and resistance to antifungal agents. We report a rare case of disseminated mucormycosis including the bone marrow, peritoneum, lung, and lymph nodes in an apparently immunocompetent 58-year-old gentleman who presented with two months of ascites and weight loss. After a thorough analysis, we found aseptate fungal hyphae in the bone marrow and ascitic fluid. In addition, a cottony white, woolly growth indicative of mucor species was seen in the ascitic fluid culture. CT scans of the chest and abdomen indicate characteristics consistent with mucor invasion. We began the patient on tablet posaconazole, but he died on the fifth day. The atypical presentation in an apparently immunocompetent patient and broad dissemination with rare bone marrow involvement emphasizes the disease's invasiveness.

Salmonellacidal antibody response to Salmonella enterica serovar Typhi in enteric fever and after vaccination with Vi capsular polysaccharide.

OBJECTIVES: Serum salmonellacidal (bactericidal) antibody could be used to detect functional capacity of antibody in patients with enteric fever and after typhoid vaccination. METHODS: Salmonellacidal antibody response was measured by colorimetric serum salmonellacidal assay from 70 acute and 11 convalescence sera of patients infected with Salmonella Typhi and Paratyphi A and also from 15 control and 6 Vi capsular polysaccharide vaccinated volunteer's sera. RESULTS: Sera from patients with typhoid and paratyphoid A showed significant (p < 0.05) levels of salmonellacidal antibody titer (549.9 ± 108.5 and 528.7 ± 187.3) compared with control (0.133 ± 0.1). Moreover, this titer increased significantly (p <0.05) in sera collected between 7 and 10 days and between 11 and 25 days of fever (titer 535.7 ± 119.2 and 794.6 ± 235.6) compared with sera collected from patients with fever for less than 7 days (136.4 ± 52.7). The mean titer significantly (p < 0.05) decreased to 5.5 ± 2.1 after 6-8 weeks onset of illness. Although, very low salmonellacidal titers (2.5 ± 1.5 and 2.3 ± 1.5) were detected after Vi CPS vaccine among the human volunteers, but mean titer was raised 15-fold from pre- to postvaccinated sera (0.166-2.5). CONCLUSION: The serum salmonellacidal antibody by colorimetric salmonellacidal assay could be used to detect acute typhoidal cases and also to monitor immune response of typhoid vaccine.

Rhino-Orbital Mucormycosis After COVID-19 Infection in a Patient With Non-Hodgkin's Lymphoma.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may be succeeded by a spectrum of complications, including invasive fungal infections (IFIs). Here, we describe a case of rhino-orbital mucormycosis in a recovered coronavirus disease-19 (COVID-19) patient with underlying non-Hodgkin's lymphoma (NHL). Our patient was normotensive, non-diabetic, presenting with multiple non-healing ulcers on different parts of the body. She received high-dose glucocorticoids and antibiotics during her severe COVID-19 illness. Three weeks following COVID-19 detection, she developed progressive rhino-orbital lesion with profuse pus formation, along with pain and redness of the left eye. Histopathology from the lesion revealed mucormycosis. She was treated with Amphotericin B. Unfortunately, the patient died after the first cycle of chemotherapy for NHL. Due to the high chance of mortality, timely clinical suspicion along with microbiological diagnosis is necessary for the early detection of infection. Strong policymaking should also be implicated to revisit the cost effectiveness of available treatments to reduce case fatality.

The Epidemiology of Melioidosis and Its Association with Diabetes Mellitus: A Systematic Review and Meta-Analysis.

Melioidosis is an under-recognized fatal disease in humans, caused by the Gram-negative bacterium Burkholderia pseudomallei. Globally, more than 35,000 human melioidosis cases have been reported since 1911. Soil acts as the natural reservoir of B. pseudomallei. Humans may become infected by this pathogen through direct contact with contaminated soil and/or water. Melioidosis commonly occurs in patients with diabetes mellitus, who increase the occurrence of melioidosis in a population. We carried out a systematic review and meta-analysis to investigate to what extent diabetes mellitus affects the patient in getting melioidosis. We selected 39 articles for meta-analysis. This extensive review also provided the latest updates on the global distribution, clinical manifestation, preexisting underlying diseases, and risk factors of melioidosis. Diabetes mellitus was identified as the predominant predisposing factor for melioidosis in humans. The overall proportion of melioidosis cases having diabetes was 45.68% (95% CI: 44.8-46.57, p < 0.001). Patients with diabetes mellitus were three times more likely to develop melioidosis than patients with no diabetes (RR 3.40, 95% CI: 2.92-3.87, p < 0.001). The other potential risk factors included old age, exposure to soil and water, preexisting underlying diseases (chronic kidney disease, lung disease, heart disease, and thalassemia), and agricultural activities. Evidence-based clinical practice guidelines for melioidosis in patients with diabetes mellitus may be developed and shared with healthcare professionals of melioidosis endemic countries to reduce morbidity.

Endemic HBV among hospital in-patients in Bangladesh, including evidence of occult infection.

Bangladesh is one of the top-ten most heavily burdened countries for viral hepatitis, with hepatitis B (HBV) infections responsible for the majority of cases. Recombinant and occult HBV infections (OBI) have been reported previously in the region. We investigated an adult fever cohort (n=201) recruited in Dhaka, to determine the prevalence of HBV and OBI. A target-enrichment deep sequencing pipeline was applied to samples with HBV DNA >3.0 log10 IU ml-1. HBV infection was present in 16/201 (8 %), among whom 3/16 (19 %) were defined as OBI (HBsAg-negative but detectable HBV DNA). Whole genome deep sequences (WGS) were obtained for four cases, identifying genotypes A, C and D. One OBI case had sufficient DNA for sequencing, revealing multiple polymorphisms in the surface gene that may contribute to the occult phenotype. We identified mutations associated with nucleos(t)ide analogue resistance in 3/4 samples sequenced, although the clinical significance in this cohort is unknown. The high prevalence of HBV in this setting illustrates the importance of opportunistic clinical screening and DNA testing of transfusion products to minimise OBI transmission. WGS can inform understanding of diverse disease phenotypes, supporting progress towards international targets for HBV elimination.

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

Melioidosis is known to occur in Bangladesh, but there are few reports about the condition in the published international literature. We set out to review all known cases of melioidosis in the country to date, using both retrospective and prospective data. A web-based literature search was conducted to identify all published case reports, original articles and conference abstracts. Cases were also included from a prospective study conducted in 2017. Fifty-one cases were identified between 1961 and 2017. Cases have been reported from sixteen out of the 64 districts of Bangladesh. The median age of the patients at presentation was 45 years (IQR 37⁻52), with a significant male (77%) predominance. Many patients (14/39; 36%) were farmers and 83% had diabetes mellitus. A skin/soft tissue abscess was the most common primary clinical presentation (13/49; 27%), followed by septic arthritis (10/49; 20%), pneumonia, and a deep-seated abscess/organ abscess (7/49; 14%). The major challenges to the diagnosis and treatment of melioidosis in Bangladesh are the lack of resources and the lack of awareness of melioidosis. Capacity development programs are urgently required to define the burden of disease and to tackle the mortality rates.

Successful treatment outcome of primary melioidosis pneumonia-a case report from Bangladesh.

BACKGROUND: Melioidosis is endemic in tropical Australia and Southeast Asian countries and its causative organism Burkholderia pseudomallei is a recognized cause of pneumonia in these regions. Recent isolation of the organism in the soil of Kapasia, Gazipur, Bangladesh has proven its exposure among the population residing in endemic areas of our country. Pneumonia is the most common presentation of melioidosis. Acute, subacute and chronic pneumonia due to B. pseudomallei can present as primary or secondary pneumonia. Treatment of such cases are challenging as well. Till date, few cases of acute and chronic pneumonia due to melioidosis occurring in local Bangladeshis as well as in returning travelers to Europe have been reported. To the best of our knowledge, this is the first reported case of primary melioidosis pneumonia declared cured after a 27 weeks of treatment regimen from Bangladesh. CASE PRESENTATION: A 43-year-old Bangladeshi gentleman, known diabetic, hypertensive, smoker, presented with the complaints of recurrent episodes of low to high grade intermittent fever, productive cough with occasional haemoptysis and 10 kg weight loss over one and half months. Poorly responding to conventional antibiotics, he was suspected as a case of pulmonary tuberculosis. Examination and investigations revealed left sided consolidation with cavitary lesion, hepato-splenomegaly and sputum analysis confirmed growth of Burkholderia pseudomallei. The patient was successfully treated as a case of primary melioidosis pneumonia. CONCLUSION: Often misdiagnosed and empirically treated as tuberculosis, untreated melioidosis pneumonia may even lead to death. Therefore, melioidosis should be suspected in appropriate clinical scenario in patients with a history of residing in or traveling to endemic areas. In Bangladesh, time has come to explore whether melioidosis should be considered as an emerging infectious disease.