Sabir Hossain

Landfill leachates in rapidly urbanizing regions like Dhaka present a complex ecological challenge owing to the concurrent buildup of heavy metals and plastic waste. Despite the severity of this pollution, the role of indigenous multi-functional bacteria in mitigating these mixed contaminants remains poorly understood. This research sought to isolate and characterize bacteria resistant to heavy metals and capable of degrading plastics from the Aminbazar and Matuail landfills and evaluate their bioremediation potential. Physicochemical analysis confirmed extreme contamination, with heavy metal levels (Pb, Cr, Cd, Cu) significantly exceeding WHO safety limits. Out of 81 isolates, nearly half exhibited multi-metal resistance and polyethylene (PE) degradation capacity. Statistical analysis showed a significant correlation between plastic degradation and multi-metal tolerance, suggesting a linked evolutionary adaptation. Enzymatic assays confirmed enzymes (e.g., urease, catalase, citrate and esterase) as drivers of both plastic degradation and heavy metal tolerance in leading isolates. Molecular screening identified the resistance genes pbrA and alkB , while the high prevalence of Class 1 integrons (80% in pbrA -positive isolates) points to a high potential for horizontal gene transfer in these environments. Furthermore, MALDI-TOF MS identified the functional isolates as Bacillus sp. with FTIR verifying the contribution of specific cell-surface functional groups to metal biosorption. These results underscore the promise of native Bacillus strains as promising agents for the development of sustainable, integrated biotechnologies for landfill restoration and complex waste management.

Antibiotic-resistant Pseudomonas aeruginosa is a common nosocomial pathogen all over the world. We detected the presence of P. aeruginosa in 22% (53 out of 238) of the test samples collected from patients with infections including secondary wound infections, abscesses and urinary tract infections admitted to two academic hospitals in Bangladesh. Resistance to carbapenems (imipenem, and meropenem) was present among 30% (16 out of 53) of these clinical P. aeruginosa isolates, which is more than 2-fold higher compared to that of previous studies. Such a rapid increase in carbapenem resistance was mediated by metallo-β-lactamase (MBL). Expression of MBL was detected in 90% (14 out of 16) of these resistant isolates. Molecular analyses revealed that the carbapenem-resistant isolates carried at least one of the MBL variants, either bla- VIM or bla -NDM-1. All the bla- NDM-1 positives carried a 0.5 MDa plasmid. ERIC-PCR revealed the highly heterogeneous nature of the P. aeruginosa isolates indicating multiple sources of infection within the hospital. However, the majority of XDR isolates belonged to a single cluster of drug-resistant bacterial infections. These findings indicate that Metallo-β-lactamase (MBL) mediated resistance to carbapenem in P. aeruginosa poses a serious threat to the spread of infections among hospitalized patients.

Background: Chronic obstructive pulmonary disease (COPD) is the most prevalent long-term respiratory condition. Patients with COPD experience detrimental effects of COVID-19 infection. Objective: To figure out whether COPD is a risk factor influencing the progression of COVID-19 and to explore the clinical value of laboratory biomarkers to assess the severity of COVID-19 in patients with COPD comorbidity. Methods: In total, 1572 participants aged 35 to 70 years were enrolled to a tertiary hospital in Bangladesh between March 2022 and October 2022. Participants were categorized into four groups: (1) control, (2) COPD, (3) COVID-19, and (4) COVID-19 with COPD, and blood levels of clinical laboratory markers were assessed to analyze how these markers differ among the study groups. Results: COVID-19 patients with COPD had a significantly lower level of sodium (131.81 ± 2.8 mmol/L) and calcium (1.91 ± 0.28 mmol/L), and a significantly higher level of NT-proBNP (568.45 ± 207.40 pg/mL), bilirubin (1.34 ± 0.54 mg/dL), fibrinogen (577.27 ± 145.24 mg/dL), D-dimer (2.97 ± 2.25 μg/mL), C-reactive protein (71.08 ± 62.42 mg/L), interleukin-6 (166.47 ± 174.39 pg/mL), and procalcitonin (0.25 ± 0.30 ng/mL) compared to other study groups patients (p < 0.0001). In addition, the GOLD 4 group demonstrated significantly altered clinical parameters among COVID-19 patients with COPD. Furthermore, NT-proBNP, interleukin 6, D-dimer, C-reactive protein, and fibrinogen demonstrated excellent diagnostic performance in predicting disease severity among the COVID-19 patients with COPD, with a cut-off value of 511.2 pg/mL, 51.375 pg/mL, 1.645 μg/mL, 40.2 mg/L, and 510 mg/dL, respectively. Our results also indicate that inflammatory markers had significant positive correlations with the biochemical and coagulation markers in the COVID-19 patients suffering with COPD (p < 0.0001). Conclusions: NT-proBNP, interleukin 6, D-dimer, C-reactive protein, and fibrinogen are the most potential parameters for differentiating severe cases of COVID-19.

The study was designed to investigate the effect of both the duration of storage and treatments (lemon, mustrard and garlic) methods on minerals (Ca, P, Fe, Mn, Cu, Mg and Zn) value of smoked hilsa in six selected regions (Chandpur, Barisal, Patuakhali, Bhola, Shariatpur and Cox’s Bazar). Minerals (Ca, P, Fe, Mn, Cu, Mg and Zn) composition was increased by treatments but gradually decreased variedly with duration of storage smoked hilsa. The calcium (Ca), phosphorus (P), iron (Fe), manganese (Mn), copper (Cu) magnesium (Mg) and zinc (Zn) were found 910.55±11.79 to 853.57±11.09 mg/100g, 228.53±4.37 to 83.60±8.75 mg/100g, 12.45±0.97 to 7.07±1.85 mg/100g, 21.58±0.48 to 7.89±0.75 mg/100g, 3.15±0.16 to 0.90±0.05 mg/100g, 60.54±10.66 to 36.31±1.85 mg/100g and 2.97±0.10 to 0.92±0.02 mg/100g respectively. Generally, the minerals reduced more in the first month of storage. The results suggest that storage period to be a negative effect on the minearls values of smoked hilsa. Hence, smoked hilsa should be consumed while fresh and if it is to be stored, the period must be as short as possible to provide optimal levels of minerals.