Thesis (Master of Science in Biotechnology)

Permanent URI for this collectionhttps://hdl.handle.net/10361/28397

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Post infection serosurveillance study of foot and mouth disease using NSP 3AB3 as antigen by DIVA ELISA
(BRAC University, 2012-08) Bhattacherjee, Sanjoy Chandra; Choudhury, Naiyyum; Department of Mathematics and Natural Sciences
Foot and mouth disease (FMD) remains a tremendous problem in developing countries like Bangladesh where proper vaccination strategy was maintained haphazardly to protect the disease stature. Sometimes animals become infected but do not show any clinical symptoms and constantly shed virus and become the most important source of disease spread. Affected animals, through their mouth secretions, milk and semen secretions as well as from their infected hooves shed virus into the environment which can spread 300km in water course and 60km by air. FMD vaccine is produced from structural protein of the FMD virus and but in case of live viral infection, antibodies produced in the cattle body are against structural and non-structural protein. DIVA ELISA test is a serological test, which has been devised to determine the immune status of animals form the basis of understanding that it could differentiate infected from vaccinated animals. Tests have been devised to use non-structural proteins (NSP) of FMDV since it is only on infection that antibodies are produced against such proteins. This study through DIVA ELISA testing was conducted to show the clinical status of different crossbreed cattle and native/indigenous cattle to determine carrier status and to observe the effect of vaccination against FMD in different organized and unorganized dairy farms in different districts of Bangladesh after a severe outbreak recorded at the end of 2011. For this purpose, 218 cattle sera were collected from various regions, where cattle are reared. Serum sample were divided into three groups depending on the vaccination history. Blood samples were collected from the infected animals, susceptible animals and disease free animals during or/after infection. The study was conducted to find out if any, relevance between breed and vaccination status, to reveal antibody response against 3AB3 non-structural protein between native and crossbreed cattle and to explore any relevant significant relationship between breed and non-structural protein 3AB3. There was significant relevance found between vaccination and breed preference than other criteria set to conduct the test. People were more curious to vaccinate cross breed cattle than native cattle. Presently, such tests are at the heart of confirming whether an organized farm is free from FMD virus (replication) even where there is no observed clinical disease which is vital to trade issues, milk and meat production in live animals and animal products. What is apparent from this work and other data is that the criteria for selecting cutoffs as to whether animals are positive or negative have to be re-assessed. Another finding is that the tests are very useful at the herd level, but due to the measured diagnostic uncertainly, are not so useful at the single animal level in tune with most serological testing. Single ELISA systems using NSP for screening are powerful tools for assessing infection in a herd since they only require a single test, but are best backed up by confirmatory tests.
Open Access
Isolation of mobile colistin-resistance (mcr) gene-harboring gram-negative bacteria from chicken droppings in Dhaka
(BRAC University, 2025-10) Fatima, Nayara Noor E; Deen, Nadia Sultana; Department of Mathematics and Natural Sciences
The use of antibiotics in poultry industries across low and middle-income countries is increasing rapidly, contributing to the emergence of antibiotic resistance and leading to a public health threat. This study aimed to investigate the prevalence of Mobile Colistin Resistance (mcr) genes in Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii isolated from the fecal samples of broiler chickens in Dhaka city. A total of 100 fresh poultry droppings were collected from 8 different raw markets in Dhaka. The samples were processed and streaked onto HiCrome UTI Agar to presumptively isolate E. coli and K. pneumoniae and Leeds Acinetobacter Agar for A. baumannii. The isolates were further confirmed by polymerase chain reaction (PCR). Detection of mcr genes was performed by employing two sets of multiplex PCR targeting mcr-1 to mcr-5, and mcr-6 to mcr-10. A total of 84 E. coli and 14 K. pneumoniae isolates were confirmed by PCR. The mcr-3 gene was the most abundant, being present in 83.7% of isolates, among which 74 were from E. coli and 8 from K. pneumoniae. The mcr-8 gene was the second most prevalent, being present in 40 (40.8%) isolates, among which 39 were from E. coli, and 1 from K. pneumoniae. None of the isolates tested positive for mcr-2, mcr-4, mcr-5 or mcr-10. Co-occurrence of two or more mcr gene variants occurred in 41.8% of E. coli isolates. Phenotypic colistin resistance was conducted on 15 E. coli isolates using the broth microdilution method to measure the minimum inhibitory concentration, and 14 isolates showed resistance to colistin. Discrepancies were observed between phenotypic and genotypic resistance to colistin. To our knowledge, this study marks the first report of mcr-3 in Bangladeshi poultry, and the first report of mcr-6, mcr-8, and mcr-9 in Bangladesh overall. The high prevalence of various mcr genes, notably mcr-3 and mcr-8, indicated industrial poultry as a potential source of multidrug-resistant pathogens.
Open Access
The impact of maternal diet, lifestyle, & environmental exposures during pregnancy on Autism spectrum disorder in children
(BRAC University, 2026-03) Jahan, Israt; Haque, Munima; Department of Mathematics and Natural Sciences
Autism Spectrum Disorder (ASD) is a complicated illness that is classified as a neurodevelopmental disorder that is influenced by a variety of factors, including genetics, environment, nutrition, and lifestyle. There is an increasing amount of evidence that suggests that the food and lifestyle behaviors of the mother, as well as the environmental exposures to which she is subjected during pregnancy, have a significant influence on determining how the brain of the fetus develops and may even be a contributing factor to the risk of autism. This study investigates the effects of prenatal dietary patterns, micronutrient deficiencies, metabolic conditions, maternal stress, physical activity, exposure to toxins, air pollution, heavy metals, and household dangers on a global scale. The review also explores how these elements interact with one another to affect the development of autism spectrum disorder. Due to its high population density and vulnerability to environmental threats, Bangladesh confronts several specific problems. Among them are starvation, contamination by heavy metals, industrial pollution, widespread pesticide use, degraded air quality in urban areas, and inadequate waste management. These elements may lead to an inequitable rise in the likelihood that children will acquire developmental problems. This analysis synthesizes literature from both national and global contexts to identify the most important factors that determine the risk of autism in relation to the mother's health and environment. The review also highlights research gaps in Bangladesh and offers potential avenues for future scientific study and legislation. According to the findings, to reduce the incidence of ASD, there is a need for extensive maternal health programs, more control over the environment, improved prenatal nutrition initiatives, and interventions at the community level. To effectively detect and decrease the risk factors of autism in the populations of South Asia, it is necessary to take important efforts, such as enhancing data collection and participating in epidemiological research in Bangladesh.
Open Access
Vitamin D status and associated biochemical profiles among rickshaw pullers in Dhaka, Bangladesh: a cross-sectional study
(BRAC University, 2026-02) Saiyan, Zwad Al; Hossain, Mahboob; Department of Mathematics and Natural Sciences
Vitamin D deficiency is highly prevalent in South Asia despite abundant sunlight, and outdoor workers are often assumed to be protected due to prolonged sun exposure. This cross-sectional study assessed vitamin D status and associated biochemical parameters among 152 male rickshaw pullers in Dhaka, Bangladesh. Data were collected through interviews, anthropometric measurements, and biochemical analyses. Serum 25-hydroxyvitamin D was measured using chemiluminescence immunoassay. Vitamin D insufficiency was observed in 43.4% of participants, while 56.6% had sufficient levels; no participants were deficient. The mean serum vitamin D concentration was 31.39 ± 7.61 ng/mL. Vitamin D levels were not significantly associated with socio-demographic, occupational, or lifestyle factors. Dyslipidemia was common, with elevated triglycerides and total cholesterol observed in 36.8% and 34.2% of participants, respectively. Smoking was significantly associated with higher triglyceride levels (p = 0.004). Regarding electrolytes, potassium levels were within the normal range for all participants. However, calcium abnormalities were frequent, with 40.8% below and 23.7% above the normal range, while mild deviations were also observed for chloride and CO₂ levels. Despite extensive sun exposure, vitamin D insufficiency remains prevalent, highlighting the need for integrated occupational health interventions.
Open Access
Effect of temperature and heavy metals on biofilm formation of Vibrio cholerae
(BRAC University, 2026) Rahman, Bushra; Naser, Iftekhar Bin; Department of Mathematics and Natural Sciences
Vibrio cholerae, is a waterborne pathogen capable of persisting in aquatic environments through its ability to form biofilms, which allow survival, transmission, and increased resistance. Environmental temperature fluctuation and heavy metals play critical roles in influencing biofilm development. This review discusses current research showing that temperature and heavy metals are two of the most important abiotic factors influencing V. cholerae biofilm development, architecture, and importance to public health. Temperature is one of the key regulators that dictate the planktonic–biofilm transition. Generally low to moderate temperatures (15–25 °C) promote V. cholerae biofilm, and this correlates with an increase in intracellular c-di-GMP, activation of the regulatory network, activation of cold-adaptation pathways, and increased expression of adhesive proteins, e.g. MSHA pili and GbpA. These responses support V. cholerae attachment and survival in seawater during seasonal transitional periods. The exposure to heavy metals such as Cd, Cu, Pb, Zn, Ni, Hg, and As imposes oxidative stress, destabilization of the cellular membrane, and inhibition of multiple enzymes. Vibrio cholerae can manage its level of toxicity by regulating it through a collection of metal responsive regulators. In addition, toxic metal stress frequently selects for enhanced EPS production, thicker biofilms, and co-selection of metal tolerance, biofilm proficiency, and potentially antimicrobial resistance. The review suggests that temperature acts as a primary regulatory factor, while metal toxicity would function solely as a selective pressure for regulating biofilm architecture. The survival strategy of bacteria may interact synergistically in cholera endemic estuaries where there are both seasonal temperature increases, along with increased industrial discharge, VBNC transitions, and outbreak timing. Notable knowledge gaps include limited experiments on temperature and heavy metals affecting V. cholerae biofilm formation and persistence in aquatic ecosystems. Therefore, it needs to resolve molecular cross-talk between metal stress signalling, quorum sensing, and temperature-controlled c-di-GMP pathways. Integrating metal monitoring for cholera, WASH interventions, and the need for implementation of One Health frameworks as methods for reducing the persistence of the environmental reservoir and the potential for outbreaks.
Open Access
Genomic landscape of hypervirulent Klebsiella pneumoniae (hvKp) in Bangladesh: comparative analysis with global hvKp lineages
(BRAC University, 2026-01) Sharma, Arnob; Haque, Fahim Kabir Monjurul; Department of Mathematics and Natural Sciences
Hypervirulent Klebsiella pneumonia (hvKp) has emerged as a major global public health concern due to its ability to cause severe, invasive infections and its increasing convergence with antimicrobial resistance (AMR). While hvKp has been extensively studied in East and Southeast Asia, genomic data from South Asia, particularly Bangladesh remain limited. This thesis presents a comprehensive comparative genomic analysis of hvKp isolates from Bangladesh in a global context, focusing on population structure, virulence determinants, antimicrobial resistance profiles, and capsular diversity. Using publicly available whole-genome sequencing data from the Pathogen Watch platform, a total of 20,430 K. pneumoniae genomes were analyzed, including 601 isolates from Bangladesh. Hypervirulent strains were defined using established genomic markers, primarily the presence of the aerobactin (iuc) locus, ensuring high specificity. Comparative analyses were conducted between Bangladeshi and global isolates using sequence typing, virulence scoring, resistance burden metrics, and multivariate statistical approaches. The results reveal that the K. pneumoniae population in Bangladesh represents a limited subset of global diversity, dominated by a small number of enriched sequence types, notably ST11, ST16, ST48, and ST147. Hypervirulent strains accounted for only 4.5% of Bangladeshi isolates, substantially lower than the global average. Bangladeshi hvKp exhibited strong enrichment of key virulence loci, including aerobactin, yersiniabactin, and rmpA/rmpA2, but showed lower prevalence of colibactin compared to global hvKp populations. Although Bangladeshi hvKp isolates demonstrated high levels of multidrug resistance—particularly to aminoglycosides, fluoroquinolones, and sulfonamides—the prevalence of carbapenem-resistant hvKp remained low. Capsular and O-antigen analyses identified a distinctive regional serotype profile dominated by K20, K2, and O1 variants, differing markedly from global patterns. Multivariate analyses confirmed that Bangladeshi hvKp form a genetically constrained 5 cluster with limited virulence–AMR convergence. Overall, this study highlights Bangladesh as being in an early epidemiological phase of hvKp evolution, presenting a critical opportunity for targeted surveillance, antimicrobial stewardship, and region-specific intervention strategies before the widespread emergence of highly resistant hypervirulent clones
Open Access
Comparative microbiological and antibiotic resistance analysis of street-vended fruit juice and ice
(BRAC University, 2026-01) Nasreen, Shamima; Monjurul Haque, Fahim Kabir; Department of Mathematics and Natural Sciences
Street-vended fruit juices are widely consumed in urban Bangladesh, yet their microbiological safety remains a concern. The study evaluated the quality and antimicrobial resistance of bacterial pathogens in 20 samples of street-vended fruit juices and ice in Dhaka, Bangladesh. Sixty-six isolates, including Escherichia coli (n=11), Klebsiella pneumoniae (n=20) and Vibrio spp. (n=35), were confirmed. Out of the 20 samples, 50% of the samples had total aerobic counts exceeding the recommended safety limits. Klebsiella spp. and Escherichia coli exceedance of microbiological limits was reported in 55% of samples each, whilst Vibrio spp. contamination was over regulatory levels in each sample (100%), indicating a significant issue to the community. Kirby-Bauer Disk Diffusion, which is a phenotypic susceptibility testing, showed a wide level of resistance to a large proportion of Amoxicillin (60% in ice; 41.3% in juice). It is interesting to note that isolates derived by juices were more resistant to the carbapenem Imipenem (32.6%) than those derived by ice (10%). On the other hand, Levofloxacin and Norfloxacin had 100 percent efficacy in all the samples. Such results point to the high public health hazard urging tightening of the hygiene policies and the education of the vendors to reduce the foodborne AMR pathogens.
Open Access
Health implications of non-ionizing radiation from the home appliances in Dhaka city
(BRAC University, 2025-10) Mollika, Faria Sultana; Haque, Munima; Department of Mathematics and Natural Sciences
Modern science gave rise to the invention of various technologies and incorporated several electronics, electrical appliances, and devices into our daily lives, leaving us exposed to non-ionizing radiation (NIR). Despite a large number of studies on NIR, limited work has been done to examine its effects from home appliances in Dhaka city. Hence, this study aims to bridge that gap by measuring various Electromagnetic fields (EMF) sources from the domestic environment, focusing on magnetic fields, electric fields, and radio frequency. The study also focused on health issues and awareness among 67 households. Measurements were taken for 1009 appliances and devices. And the health outcomes were assessed through a well-structured questionnaire. The results showed that magnetic field exposure was highest near fans and iron machines, while electric field levels peaked around microwaves, multiple plugs, and refrigerators. Radio frequency exposure was dominated by Wi-Fi routers, mobile phones, and laptops. However, all the values remained well below the international safety threshold. There were some common health issues reported, which are stress, mental health problems, vision problems, cognitive issues, cancer, etc. Even though there was not much conclusive evidence, as no lab tests were done to confirm the relation between biological issues and non-ionizing radiation, it can be inferred that there are some connections between constant exposure to EMF and issues such as cancer, stress, and psychological problems. Public education, safe appliance design, further experiment, and longitudinal research are recommended.
Open Access
Prevalence, molecular characterization and antibiotic-resistance pattern of Salmonella spp. in aquaculture supply chain in Bangladesh
(BRAC University, 2025-02) Tamanna, Sadia; Naser, Iftekhar Bin; Department of Mathematics and Natural Sciences
Salmonella represents a persistent global health threat, primarily causing food-borne infections through contaminated animal-derived products, including poultry, eggs, and fish. In developing countries like Bangladesh, Salmonella is increasingly found as a diarrhea-causing agent. Despite its significance, systematic detection and monitoring of Salmonella within Bangladesh's aquaculture supply chain remains poorly understood, necessitating a comprehensive investigation into its prevalence and characteristics. The study examined 794 samples, a total of 400 fish samples (Pangas and Tilapia species) fish tank water (n=206) and cutting board swabs(n=188) were collected from various points along the supply chain including ponds(n=120), wholesale markets(n=100), and retail markets(n=574). Standard microbiological culture methods and molecular identification techniques were employed, with PCR analysis targeting the invasion (invA) marker gene. The investigation included detection of clinically relevant virulence genes (avrA, ssaQ, sodC1, bcfC) and antimicrobial susceptibility testing against 20 antibiotics using the Kirby-Bauer Disc Diffusion method. Analysis revealed that 32% (258/794) of fish samples tested positive for Salmonella species, with the highest incidence observed in retail markets 37%( n=211/574) followed by wholesale markets 23%(n=23/100) and ponds 20%(n=24/120).For environmental samples, Salmonella spp. Was detected in 35% of fish tank water samples and 38% of cutting board swab samples. Nalidixic acid and Tetracycline showed 10-11% resistance in both fish samples where as other antibiotics (Gentamycin, Pipeperacillin/Tazobactum, Meropenem, Ertapenem showed resistance within (0-3)% as well as Cefepime showed 0% resistaNce. Virulence gene analysis identified bcfC as the most prevalent gene (77%), followed by ssaQ (74%), avrA (69%) and sodC1(46%). The findings highlight the significant burden of Salmonella species within Bangladesh's Tilapia and Pangas aquaculture value chain. The study emphasizes the critical need for implementing a comprehensive One Health approach that integrates public health, aquaculture sector practices, and environmental health considerations. These results underscore the importance of developing and implementing effective risk reduction strategies in Bangladesh's aquaculture sector to ensure public health safety and sustainable aquaculture practices.
Open Access
CRISPR precision and its paradox: a deep dive into off- target effects
(BRAC University, 2025-05) Sultana, Samia; Naser, Iftekar Bin; Department of Mathematics and Natural Sciences
CRISPR-Cas9 has revolutionized genome editing, providing researchers with a powerful tool to precisely alter DNA sequences in a wide range of organisms. Its ability to specifically target and modify genes has unlocked opportunities in diverse fields, including medicine, agriculture, and basic scientific research. This thesis explores the dual aspects of CRISPR-Cas9: its wide-ranging applications and the challenges posed by off-target effects, along with the innovative strategies that scientists have developed to address these issues. The usefulness of CRISPR-Cas9 lies in its simplicity and versatility. In medicine, it has been applied to correct genetic mutations responsible for diseases such as sickle cell anemia, Duchenne muscular dystrophy, and some cancers. In agriculture, it has been used to develop drought-resistant crops, enhance nutritional content, and combat plant diseases. CRISPR-Cas9 is also a vital tool for studying gene functions and creating disease models in research. These capabilities highlight its transformative potential to solve complex problems and drive innovation across disciplines. However, the technology is not without its limitations. Off-target effects—where CRISPR edits unintended regions of the genome—pose significant challenges. These unintended changes can disrupt vital genes, lead to harmful mutations, or even cause genomic instability, making it a critical issue for clinical and agricultural applications. Off-target effects are influenced by several factors, including the design of the guide RNA, chromatin accessibility, and similarities between target and non-target sequences. To overcome these challenges, scientists have developed several strategies to enhance the precision of CRISPR-Cas9. High-fidelity Cas9 variants, such as SpCas9-HF1 and eSpCas9, have been engineered to reduce off-target activity. Bioinformatics tools now allow for the design of highly specific guide RNAs, minimizing the risk of off-target binding. Delivery methods, such as ribonucleoprotein complexes (RNPs), help reduce the duration of Cas9 activity, further limiting unintended edits. In addition, newer genome-editing tools like base editors and prime editors provide even greater accuracy by allowing single-nucleotide changes or small insertions without causing double-stranded breaks in DNA. (Ansori ANM, et al. 2023). This thesis delves into the mechanisms of CRISPR-Cas9’s off-target effects, the factors that influence them, and the innovative methods developed to address these issues. By exploring both the immense potential and the current challenges of CRISPR technology, this research contributes to the ongoing efforts to improve its safety and reliability. Ultimately, the findings aim to support the development of CRISPR-based solutions that are not only effective but also safe for widespread use in medicine, agriculture, and scientific research.
Open Access
Genetic innovations in environmental restoration: the power of rDNA technology
(BRAC University, 2025-05) Hany, Umma; Naser, Iftekhar Bin; Department of Mathematics and Natural Sciences
Innovative approaches in bioremediation have become necessary due to recent environmental difficulties, and recombinant DNA technology is developing as a game-changing alternative for environmental restoration. By improving the genetic capacity of microorganisms to more effectively break down environmental contaminants, genetic engineering approaches have transformed conventional bioremediation procedures. Researchers have successfully altered microbes to express particular genes that target different environmental toxins using rDNA technology. Increased tolerance to environmental stresses, improved substrate selectivity, and improved degradation pathways are the outcomes of these alterations. When it comes to decomposing harmful substances including heavy metals, herbicides, industrial waste products, and persistent organic pollutants (POPs), the modified microorganisms work exceptionally well. The creation of specialised bacterial strains with various degradative capacities is very important. These strains can handle many contaminants at once because they have recombinant plasmids that include genes for different catabolic enzymes. These organisms' ability to survive and function in harsh environments has also been enhanced by the introduction of stress- tolerance genes, which increases their suitability for in-situ bioremediation applications. Recent developments have concentrated on creating durable genetic constructs that sustain their improved capabilities throughout several generations and optimising gene expression systems. Monitoring capabilities have been further enhanced by the incorporation of biosensor genes, which enable real-time evaluation of biodegradation processes. Along with cutting treatment durations and expenses, these advancements have greatly improved the bioremediation procedures' dependability and efficiency. There are still issues with the release of genetically modified organisms into the environment and the possible ecological effects of doing so. Suicide genes and containment tactics that restrict bacterial survival outside of specified locations are being developed as part of ongoing research to solve these issues. In the future, new gene combinations will be investigated, and synthetic biology concepts will be used to develop more complex and regulated bioremediation systems. This review paper investigates the role of recombinant DNA (rDNA) technology in advancing bioremediation techniques. It explores the genetic modification of microorganisms to improve their efficiency in degrading or detoxifying environmental pollutants, focusing on applications, challenges, and future prospects.
Open Access
Approaches to breast cancer treatment
(BRAC University, 2023-01) Shourav, Md. Burhan Uddin; Naser, Iftekar Bin; Department of Mathematics and Natural Sciences
Breast cancer remains a significant global health concern, ranking as the second leading cause of cancer-related deaths among women worldwide. This review article aims to provide a comprehensive overview of the current understanding of breast cancer causes and treatments. The etiology of breast cancer is multifactorial, involving complex interactions between genetic, hormonal, environmental, and lifestyle factors. Key risk factors include age, reproductive history, genetic predisposition (particularly BRCA1/2 mutations), breast density, and lifestyle choices such as alcohol consumption and obesity. Understanding these risk factors is crucial for developing effective prevention strategies and identifying high-risk individuals. Significant advancements have been made in breast cancer treatment over recent decades. Surgical approaches have evolved to favor breast-conserving therapy and sentinel lymph node biopsy when appropriate. Radiotherapy techniques have improved, offering better dose distribution and organat- risk sparing. Chemotherapy regimens have been refined, with the advent of multiparameter gene expression assays helping to guide treatment decisions. Hormone therapy remains a cornerstone for hormone receptor-positive cancers, with recent developments in overcoming resistance. Targeted therapies, particularly for HER2-positive breast cancers, have dramatically improved outcomes for specific subtypes. Emerging treatment modalities, such as immunotherapy and antibody-drug conjugates, show promise in expanding therapeutic options, especially for difficult-to-treat subtypes like triplenegative breast cancer. Additionally, novel drug delivery systems, including nanoparticle-based approaches, are being explored to enhance treatment efficacy and reduce side effects. Despite these advances, challenges persist in optimizing treatment regimens, managing side effects, and addressing treatment resistance. Ongoing research focuses on personalized medicine approaches, combination therapies, and strategies to overcome resistance mechanisms. This review synthesizes current knowledge on breast cancer causes and treatments, highlighting recent achievements, ongoing challenges, and areas of progress. By providing this comprehensive overview, we aim to inform future research directions and improvements in patient care.
Open Access
Significance of comorbidities among COVID-19 patients as determinants of fatality in South Asia
(BRAC University, 2023-12) Nahreen, Ashfia; Siddiqee, Mahbubul Hasan; Department of Mathematics and Natural Sciences
Several comorbidities have been reported to be associated with SARS-CoV-2 related severity and mortality. However, there has been considerable variation in the prevalence estimates of these underlying conditions and their effects on COVID-19 morbidity and mortality in prior studies. This thesis aimed to review all published literature to determine these differences in the prevalence of comorbidities in South Asia. A search was conducted using PubMed, Scopus and Google Scholar to include all COVID-19 studies published between January 1st, 2020 to December 21st, 2022 reporting comorbidities with severity and mortality in three South Asian countries- namely, Bangladesh, India and Pakistan. Of 91 studies with 48908 participants, the most prevalent comorbidity among the overall population was diabetes (30.83%), hypertension (30.38%), cardiovascular diseases (9.75%) and chronic kidney diseases (8.06%). The presence of these comorbidities resulted in more COVID-19 severity and mortality, while presence of multiple comorbidities aggravated the condition even further. In patients with pre-existing diabetes and hypertension, a patient’s condition deteriorated further when another comorbidity was present, mainly cardiovascular diseases and chronic kidney diseases. The study found that there were significant differences in the prevalence of comorbidities and the effect they had on disease severity and mortality across different geographical regions. In Bangladesh and India, the highest mortality was seen in diabetic patients infected with COVID-19 (61.23% and 49.25% respectively), whereas, in Pakistan, the highest mortality was seen in hypertensive patients infected with COVID-19 (63.69%). This study highlighted that the male gender, older age and comorbidities owned strong epidemiological evidence of associations with the severity and prognosis of COVID-19. Most frequent comorbidities reported in association with disease severity were diabetes, followed by hypertension and cardiovascular diseases. The data obtained from this study portrays the significant impact that the presence of pre-existing comorbidities had on the outcome of COVID-19 infection in Bangladesh, India and Pakistan. The study suggests that COVID-19 control strategies should be tailored according to comorbidities, age, and gender differences, and should take into account the specific geographical location to effectively stratify the risk and implement control measures. This study can also help to identify the gaps in the healthcare system and help to address the systemic issues that are leading to high mortality rates in these countries. From the public health perspective, this systematic review can help policymakers to better allocate resources and develop targeted interventions to improve the outcome of COVID-19 infection among these high-risk populations.
Open Access
A comparative analysis of the regulatory systems between the Philippines and Bangladesh for approving biotech crops
(BRAC University, 2023) Anonna, Eera Ashrafy; Islam, Aparna; Department of Mathematics and Natural Sciences
Many countries have adopted Genetically Engineered (GE) crops and their products. Before cultivation, these crops must go through a regulatory approval system, which varies from country to country. Here, the regulatory process of the Philippines, a mega GE crop cultivating country from Asia, is analyzed. The National Committee on Biosafety of the Philippines (NCBP) was established in 1990, whereas the approval process was established in 2002. The Philippines ratified the Cartagena Protocol on Biosafety (CPB) in 2006. The first GE crop approval came in December 2002. Till date, GE approval was given for many events, of which some are for commercial cultivation and the others are for FFP. In 2021, the Philippines became the first country to approve the cultivation of Golden Rice. In Bangladesh, Bt Eggplant was approved in 2013 and Golden rice is also under regulatory pipeline. With similar crop events, the Philippines being South-Asian pioneer in GE crop approvals, the regulatory system of the Philippines was compared with the regulatory system of Bangladesh. The Biosafety guidelines of Bangladesh established the regulatory committees involved in the GE crop approvals in Bangladesh. The National Biosafety Framework (2007) later detailed the policies and approval process. Both countries have implemented the CPB in their National Biosafety Frameworks. With the vast experience of GE crop approval and cultivation, nowadays, the Philippine approval process has brought several changes.
Open Access
Characterization of pathogenic Escherichia coli isolated from fresh vegetables of Dhaka city
(2022-09) Moon, Unmilita Das; Haque, Fahim Kabir Monjurul; Department of Mathematics and Natural Sciences
Escherichia coli (E. coli) is generally harmless bacteria that resides in the intestines of humans and animals and maintains intestinal health. This benign intestinal resident is also a highly adaptable and frequently lethal infection. Vegetables are susceptible to E. coli contamination from pre-harvest through post-harvest. This study aims to determine the frequency of the virulence gene and the antibiotic resistance of E. coli in fresh vegetables gathered from various areas of Dhaka. Of 250 vegetable samples, 101 (40.4%) included E. coli. Dhanmondi had the most positive isolates (12.87%) and followed by Rampura (11.88%), Farmgate (9.9%), Uttara (9.9%), Gulshan-1(7.92%), Gulshan-2 (7.92%), Banani (7.92%), Khilgoan (7.92%), Mirpur (6.94%), Mohakhali (5.94%), Mohammadpur (5.94%), and Bashundhara (4.95%). The highest percentage of positive isolates in Tomato was 52.0%. Respectively, followed by Capsicum (51.85%), Carrot (51.35%), Coriander (47.61%), Cabbage (44%), Cucumber (40.9%), Green Chili (36.84%), Mint (31.81%), Spring Onion (21.42%), Lettuce (20.83%). From the antibiotic susceptibility test, 95.04% of isolates showed multi-drug resistance (MDR). Moreover, the pathogenicity of 40 bacteria out of 101 isolates was evaluated through PCR, and 26 (65%) of the 40 isolates were confirmed positive for pathogenicity. According to these findings, there is a considerable cause for worry for the residents of the Dhaka region since there is a significant threat to human health. As a realization of these findings, it became clear that there is a compelling need to raise public awareness regarding the hygienic practices that should be followed while selling and purchasing fresh produce.
Open Access
Are we exposing ourselves to UTI causing Escherichia coli? appraisal on the virulence factors and antibiotic resistant trend among clinical and washroom water isolates
(BRAC University, 2023-09) Khan, Nabila; Haque, Fahim Kabir Monjurul; Department of Mathematics and Natural Sciences
One of the most prevalent bacterial infectious diseases that cause significant morbidity and cost-effective health issues is urinary tract infection (UTI). The most frequent cause of UTIs, uropathogenic Escherichia coli (UPEC), is a type of extraintestinal pathogenic E. coli that exhibits extremely diverse virulence factors and capable of multi-drug resistance (MDR). This study aimed to assess the prevalence of the virulence factors and antibiotic resistant pattern among clinical and washroom water isolates of UPEC. From a tertiary diagnostic center, a total of 126 urine samples from UTI patients and total 20 washroom water samples from domestic and public washrooms were collected within a same time period in Dhaka city, Bangladesh. The samples were cultured on MacConkey agar after that DNA of suspected E. coli isolates were extracted for Real-Time PCR and confirmed by using ECO primer. A total of 85 isolates from clinical and a total of 38 isolates from non-clinical isolates were confirmed as E. coli and further the virulence genes were detected using virulence gene primers of fimH, papC, hly, cnf, iucC, and fyuA for both, clinical and non-clinical isolates. Antibiotic susceptibility test was performed for both, clinical and non-clinical isolates, using amoxicillin (AML) (10 μg), ciprofloxacin (CIP) (5 μg), ceftriaxone (CRO) (30 μg), azithromycin (AZM) (15 μg), cefexime (CFM) (5 μg), norfloxacin (NOR) (10 μg), nitrofurantoin (F) (300 μg), cefuroxime (CXM) (30 μg), meropenem (MEM) (10 μg), and cefepime (FEP) (30 μg). Hemolysin production was also observed for both, clinical and non-clinical isolates. According to results, among six virulence markers of pathogenicity-associated island (PAI), in both clinical and non-clinical isolates, fimH was found in highest percentage 80% and 52.63%, respectively. Moreover, cnf gene was found in least percentage, 7.06% and 2.63% for both clinical and non-clinical isolates, respectively. In case of antibiotic susceptibility pattern, the highest resistance against amoxicillin was observed 92.94% and 63.16%, in clinical and non-clinical isolates, respectively. Moreover, the lowest resistance was seen against meropenem, 57.65% in clinical isolates and 50% in non-clinical isolates. Blood Agar hemolysis pattern among clinical and non-clinical isolates showed 58.82% clinical isolates and 31.58% non-clinical isolates exhibited β-hemolytic pattern. Public water supplies in Dhaka, Bangladesh, are frequently contaminated with E. coli strains with virulence factors that cause UTIs and multi-drug resistance patterns. In metropolitan settings, the transmission of plasmids and resistant gene to bacteria through the supply water acts as a major risk to public health. This quick evaluation of bacterial pathogenicity may help healthcare providers treat patients with urinary tract infections more effectively.
Open Access
Proteome-wide screening for designing a multi-epitope vaccine against emerging pathogen Campylobacter jejuni using immunoinformatics approaches
(BRAC University, 2025-01) Alsaied, Mariam; Haque, Munima; Department of Mathematics and Natural Sciences
Campylobacter jejuni (C. jejuni) is a leading cause of bacterial gastroenteritis worldwide, often resulting in severe complications such as Guillain-Barré syndrome and reactive arthritis. The rising prevalence of antibiotic-resistant strains underscores the urgent need for alternative preventive measures, such as vaccines. This study employs a comprehensive immunoinformatics approach to design a multi-epitope vaccine targeting C. jejuni. Out of the 1,800 proteins in the C. jejuni proteome, the major outer membrane protein (MOMP) was identified as the most antigenic candidate, with a VaxiJen score of 0.5059. MOMP was further analyzed to predict cytotoxic T lymphocyte (CTL) and helper T lymphocyte (HTL) epitopes, using tools such as NetCTL, IEDB, and VaxiJen. The selected epitopes were evaluated for immunogenicity, allergenicity, and toxicity, ensuring their suitability for vaccine development. Additionally, linear B-cell epitopes (LBL) were predicted to induce humoral immunity. The identified CTL and HTL epitopes were also analyzed for global population coverage, achieving significant inclusivity across diverse HLA alleles. The proposed vaccine construct integrates these epitopes to stimulate robust cellular and humoral immune responses, offering a promising candidate for further experimental validation. This study highlights the potential of computational methods in accelerating vaccine design and provides a framework for addressing the significant global burden of C. jejuni infections.
Open Access
The prevalence, risk factors, diagnosis & treatment of osteoporosis in Bangladesh
(BRAC University, 2025-02) Bulbuli, Naima Hasan; Haque, Munima; Department of Mathematics and Natural Sciences
Osteoporosis is a debilitating condition affecting over 200 million individuals worldwide, characterized by reduced bone mass and increased susceptibility to fractures. In Bangladesh, the prevalence is alarmingly high, particularly among women and the elderly, yet it remains underdiagnosed and poorly understood. This review synthesizes data from global and regional studies, highlighting the critical role of lifestyle, nutrition, and awareness in influencing osteoporosis outcomes. Analysis reveals that approximately 35% of Bangladeshi adults suffer from osteoporosis, with an additional 40% classified as having osteopenia Factors such as low calcium intake, insufficient vitamin D levels, and sedentary lifestyles are prevalent, affecting over 70% of the population Notably, only 30% of individuals are aware of osteoporosis and its prevention, underscoring the urgent need for targeted public health interventions. This paper emphasizes the importance of comprehensive strategies integrating nutrition education, community outreach, and accessible screening programs. By addressing these factors, Bangladesh can mitigate the growing burden of osteoporosis and improve the quality of life for its population. This review provides a foundation for developing evidence-based policies and interventions tailored to the country’s unique socio-cultural context. Keywords:
Open Access
Drug-resistance and virulence in Campylobacter jejuni: insights from clinical, poultry, and wastewater interfaces
(BRAC University, 2025-02) Khatun, Ayesha; Naser, Iftekhar Bin; Department of Mathematics and Natural Sciences
Campylobacter jejuni is a leading cause of human gastrointestinal infections, primarily transmitted through the consumption of undercooked poultry, the main reservoir of Campylobacter species, and via cross-contaminated food and water. The emergence of multidrug-resistant (MDR) C. jejuni due to resistance to various antimicrobial agents poses significant global health risks. This research aims to characterize antimicrobial resistance patterns and virulence genes of C. jejuni from clinical, poultry and wastewater interfaces in Bangladesh. In this study, fifteen C. jejuni isolates were cultured on CHROMagar plates and subjected to phenotypic testing, polymerase chain reaction, and antimicrobial resistance assessment. The Kirby–Bauer disc diffusion method was used to evaluate resistance to nine antibiotic classes, while minimum inhibitory concentrations for ciprofloxacin, erythromycin, and tetracycline were determined by E-test. The isolates showed 100% resistance to ciprofloxacin and erythromycin; 93% to sulfamethoxazole, azithromycin, nalidixic acid, and ampicillin; 87% to ceftriaxone; 73% to cefuroxime; 67% to gentamicin, cefoxitin, and cefixime; 60% to tetracycline; 47% to ampicillin and chloramphenicol; 27% to imipenem; and 7% to amikacin. All isolates were resistant to more than four antibiotic classes, with wastewater isolates showing the highest resistance rates. Resistance to macrolides and fluoroquinolones, which are critical antibiotics for the treatment of Campylobacteriosis, was observed in all isolates. Virulence genes, including flaA, racR, cdtA, cdtC, gyrB, parC, and wlaN were investigated using gene-specific PCR. All five wastewater and clinical isolates assessed positive for flaA and parC. The genes racR, cdtA, and cdtC were present in four clinical isolates, while chicken isolates exhibited racR (1/5), cdtA (1/5), and cdtC (4/5). The wlaN gene was detected in one clinical, two chicken, and three wastewater isolates, while the gyrB gene was found in one wastewater and two chicken isolates. Overall, virulence gene prevalence was cdtA (53%), flaA (47%), wlaN (40%), cdtC (33%), racR (33%), parC (33%), and gyrB (20%). In Bangladesh, widespread self-medication with antibiotics and treatment failures due to resistance exacerbate the problem. However, MDR C. jejuni and their resistance patterns at the clinical-poultry-wastewater interface remain poorly studied. This study provided valuable insights into the antimicrobial resistance profiles and virulence determinants of MDR C. jejuni, a significant contributor to diarrheal mortality in Bangladesh, thereby enhancing understanding of its pathogenesis and implications for public health.
Open Access
Evaluation of Hyperhomocysteinemia and MTHFR C677T gene polymorphism as independent risk factors of ischemic stroke among Bangladeshis
(BRAC University, 2025-01) Raymond, Mugenyi; Deen, Nadia Sultana; Department of Mathematics and Natural Sciences
Stroke remains a leading cause of death and disability worldwide. This study investigated the relationship between hyperhomocysteinemia (HHcy) and MTHFR C677T gene polymorphism as independent risk factors of Ischemic stroke (IS) in Bangladesh. Blood samples and clinical data were collected from 30 IS patients (>18 years old) and 30 healthy controls. Levels of plasma homocysteine and other biochemical parameters were measured using an automated analyzer, and their relationship with HHcy was determined. DNA was extracted from blood using QIAamp DNA blood kits, and the MTHFR C677T gene polymorphism was genotyped using PCR-RFLP. The prevalence of HHcy was higher in IS patients (30%) than in healthy controls (6.67%), and the difference was statistically significant (p-value = 0.02095). The associations between HHcy and IS traditional risk factors were not statistically significant, suggesting that HHcy could influence IS outcomes through mechanisms independent of conventional risk factors. Unique dietary patterns modulating ischemic stroke risk were also identified. Participants eating fish less than three times a week were higher in numbers among IS patients (16.67%) than in controls (0%), and the observed difference in proportions was statistically significant (p-value = 0.0261). The T allele was more prevalent in individuals with HHcy (27.3 %) than in those without HHcy (16.3%), while the C allele dominated in those without HHcy (83.7 %) compared to the hyperhomocysteinemic individuals (72.7%). Similarly, the TT genotype was more prevalent in the HHcy group (9.1%) than in the non-HHcy group (2%). The CT genotype also dominated in the HHcy group (36.4%) compared to the non-HHcy group (28.6%). The high frequencies of the T allele and the TT genotype in individuals with HHcy compared to those without HHcy Indicate that predisposition to the MTHFR C677T polymorphism may result in hyperhomocysteinemia. These findings emphasize the need for routine homocysteine screening, maintenance of a healthy diet, and the necessity for genetic testing for the C677T mutation in the MTHFR gene for early detection and management of these critical IS risk factors. Future large-scale interventional studies are recommended to fully understand the complex interactions between hyperhomocysteinemia and MTHFR polymorphisms in the pathogenesis of ischemic stroke.

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