Aminul Islam

Background: The prevalence of dengue in Bangladesh has markedly risen, resulting in the most lethal epidemic in 2023 and persistently elevated levels in 2024. Regardless of stringent control measures, dengue persists with comorbidities in Dhaka City. This research explored the correlation between laboratory findings and clinical parameters with severe dengue infection. Methods: A case–control study was performed on 435 dengue patients (145 cases with severe dengue and 290 controls with non-severe dengue) hospitalized in medical college hospitals in Dhaka City from July to December 2024. Participants were matched by age (±5 years), sex, and admission date (±2 weeks). Univariate and multivariable logistic regression analyses were conducted to find out factors associated with dengue severity. Results: Comorbidities, such as chronic pulmonary disease (AOR: 2.14; 95% confidence interval (CI): 0.90–5.10), were associated with an increased odds of severe dengue. Symptoms such as abdominal pain (AOR: 2.30; 95% CI: 1.45–3.68), lethargy (AOR: 2.70; 95% CI: 1.35–5.47), and nausea (AOR: 2.21; 95% CI: 1.15–4.22) were associated with increased dengue infection severity. Severe dengue cases exhibited an elevation in serum creatinine, ALT, AST, and pulse rate, but total bilirubin, albumin, and globulin levels were associated with a reduced odds of severity. Conclusion: This study delineates characteristics associated with severe dengue infection, including comorbidities, such as chronic pulmonary disease, and signs and symptoms, such as abdominal pain, lethargy, and nausea. Laboratory results indicating higher serum creatinine, liver enzymes, and pulse rate, coupled with decreased total bilirubin, albumin, and globulin, were significantly associated with severity. These findings emphasize the significance of early surveillance, especially in patients with comorbidities, and offer critical insights for enhancing the management of severe dengue. Future studies should investigate the transition from non-severe to severe dengue.

Background: Foodborne illnesses caused by enterotoxigenic Bacillus cereus represent a significant public health concern globally. Rapid and simple detection methods are needed, particularly in resource-limited settings where conventional laboratory infrastructure is lacking. This study aimed to develop and validate a loop-mediated isothermal amplification (LAMP) assay targeting three major enterotoxin genes ( nheA , cytK , and entFM ) for the rapid detection of enterotoxigenic B . cereus in food and feed samples from Bangladesh. Methods: LAMP primers for the nheA gene were newly designed, while cytK and entFM primers were adapted from previous studies. Reaction conditions were optimized using B . cereus ATCC 14579. Analytical sensitivity was determined using serial dilutions of pure culture, spiked milk, and genomic DNA. Specificity was assessed against 20 bacterial strains, including Bacillus species and non- Bacillus foodborne pathogens. The assay was validated on 30 field samples (feed, milk, and eggs) and compared with conventional PCR. Results: Optimal LAMP amplification was achieved at 64°C for 40 min. The limit of detection was 100 fg/µL for genomic DNA, 9 × 10 ² CFU/mL for pure culture, and 9 × 10 ³ CFU/mL for spiked milk—approximately 10,000-fold more sensitive than conventional PCR. The assay showed 100% specificity for enterotoxigenic Bacillus species, with no cross-amplification of non-target bacteria. In field samples, LAMP detected enterotoxin genes in 73.3% (22/30) for nheA , 53.3% (16/30) for cytK , and 80.0% (24/30) for entFM , compared to 63.3% (19/30), 40.0% (12/30), and 70.0% (21/30) by PCR, respectively. Overall diagnostic sensitivity and specificity against PCR were 96.1% and 66.7%, respectively, with substantial agreement (κ = 0.62). Conclusion: Although LAMP assays for individual B . cereus toxin genes have been described previously, this study represents the first application of this specific nheA - cytK - entFM LAMP panel in the Bangladeshi food and feed context, providing a regionally relevant, field-deployable method for food safety monitoring.

Objective: To assess the prevalence of Staphylococcus aureus and antimicrobial resistance patterns, with particular emphasis on methicillin resistance, among isolates from street-vended tomato sauces in Dhaka, Bangladesh. Results: Among 104 street-vended tomato sauce samples, 83 (79.8%; 95% Cl: 71.1–86.4%) were S. aureus isolates confirmed. Of these, 38 (45.8%) identified as methicillin-resistant Staphylococcus aureus , 5 (6.0%) vancomycin-resistant S. aureus , 55 (66.3%) multidrug resistance, and 2 (2.4%) extensively drug-resistant. The multiple antibiotic resistance (MAR) index ranged from 0.08 to 0.75 (mean ± SD = 0.38 ± 0.12), with 60 (72.3%) isolates exceeding the high-risk threshold (≥ 0.2). Methicillin-Resistant isolates showed significantly higher index values than susceptible isolates ( p = 0.003). Co-resistance observed between oxacillin-cefoxitin (φ = 1.00) and meropenem-amikacin (φ = 0.96). Elevated resistance index values were more frequently observed among isolates from slum and transport-hub areas.

Cronobacter sakazakii is an emerging foodborne pathogen that has gained increasing global attention due to its association with severe infections in neonates, particularly meningitis, sepsis, and necrotizing enterocolitis. These infections are often associated with contaminated powdered infant formula (PIF), a nonsterile but commonly used alternative to breast milk. We conducted a systematic review using the PRISMA approach and registered it in PROSPERO to synthesize current scientific knowledge on the detection, pathogenic mechanisms, antimicrobial resistance, and mitigation strategies of C. sakazakii . A total of 82 research articles published between 2009 and 2024 were included. The findings highlight the bacterium′s ability to survive under harsh environmental conditions, including desiccation, osmotic stress, and heat, making it a persistent contaminant in food production. Virulence is driven by several genetic determinants, including outer membrane proteins ( OmpA and OmpX ), invasion‐associated genes ( InvA and cpa ), and iron acquisition systems. Sequence types ST4 and ST1 are consistently linked to neonatal infections and show strong biofilm‐forming potential, increasing the risk of recurring contamination in manufacturing environments. The review compares conventional culture‐based detection methods with advanced molecular techniques such as polymerase chain reaction (PCR), multilocus sequence typing (MLST), and aptamer‐based biosensors, highlighting the need for rapid, cost‐effective, and accurate diagnostic tools. While most strains retain antibiotic susceptibility, emerging resistance to β ‐lactams, macrolides, and cephalothin has been reported, varying by geographic region and strain type. The LED‐based decontamination, citral treatments, and antimicrobial packaging materials are promising avenues for prevention. Furthermore, this review underscores the importance of enhanced regulatory oversight, standardized protocols, and public awareness regarding the safe preparation and handling of infant formula, considering the vulnerability of infants. Continued interdisciplinary research and international collaboration are warranted, ensuring microbiological safety and protecting infant health.