S. M. Rafiqul Islam

Klebsiella pneumoniae (KPN) infections pose heightened risks in the geriatric population due to weakened immunity, prevalent comorbidities, potential exposure in long-term care settings, and increased likelihood of antibiotic resistance (ABR). The study focused on the prevalence and antibiotic resistance of KPN infections, the presence of ABR genes in KPN, and the genomic characterization of KPN obtained from geriatric patients in Chattogram. A total of 543 specimens were collected from four hospitals in Chattogram, along with demographic data from hospital records. Genomic DNA was extracted from multi-drug-resistant (MDR) KPN, and the presence of ABR genes , bla _TEM-1 , sul-1 , aadB , bla _NDM-1 , bla _SHV-11 , and phoE was identified. To characterize the KPN genomes, two MDR KPN isolates were subjected to whole-genome sequencing (WGS), and the data were analyzed using bioinformatics tools to identify genomic determinants of ABR. KPN exhibited high resistance to ceftazidime (96%), cefuroxime (92%), and cefixime (83%), but sensitivity to colistin (79%) and amikacin (75%). MDR KPN was mostly detected in sputum (36%) and urine (27%) specimens, where the prevalence of ABR genes, blaTEM-1 , sul1 , aadB , blaNDM-1 , and blaSHV-11 were 28.2%, 17%, 6.17%, 56%, and 48% of these strains, respectively. These genomes exhibited distinct profiles for sequence types, ST420 and ST277 in Kpn007 and Kpn016, respectively, and ABR genes ( qnrS1 , blaCTX-M-15 , and blaSHV-27 ), virulence factors ( ybt , iuc1 , iro1 ), and contained both K (K20, K46) and O antigens (O1, O3b). MDR KPN in the geriatric population poses a serious health concern due to their increased vulnerability to infections and limited treatment options, requiring careful management. IMPORTANCE: Multidrug resistance (MDR) and the hypervirulence nature of Klebsiella pneumoniae (KPN) in geriatric patients pose a critical health concern in nosocomial infections worldwide and result in high clinical complexity and mortality. The study investigated the factors for KPN infections and analyzed antimicrobial resistance profiles. More than 60% of Klebsiella pneumoniae isolates from geriatric patients were resistant to third- and fourth-generation cephalosporins, and most isolates carried bla _NDM-1 and bla _SHV-11 genes. Analyzing whole genomes of two KPNs, Kpn007 (ST277) was identified as a hypervirulent strain with aerobactin and yersinia siderophores, contributing to virulence, and Kpn016 (ST420) carried fluoroquinolone ( qnrS1 ), ESBL ( bla _CTX-M-15 and bla _SHV-27 ) resistance. Both genomes contained K antigens (K20 and K46) and O antigens (O1 and O3b).

The coastal waters of Bangladesh support rich aquatic biodiversity, including the commercially important shrimp Penaeus monodon. However, antimicrobial resistance (AMR) poses a growing threat to aquaculture, ecosystem stability, and human health. In this study, we investigated bacterial AMR profiles and characterized the gut microbiomes of wild (Natural) and cultured P. monodon from the northern Bay of Bengal, Bangladesh. Culture-based and biochemical methods were used to identify bacterial pathogens of shrimp shells, and antimicrobial susceptibility was assessed using the disc diffusion method. Shotgun metagenomic sequencing was used to characterize gut microbial diversity and identify antibiotic resistance genes (ARGs). All Klebsiella isolates were resistant to ampicillin (100%) and showed high resistance to azithromycin (83%) and nitrofurantoin (73%). Pseudomonas isolates were 93.10% resistant to ampicillin, whereas Vibrio isolates had notable resistance to azithromycin (71.05%) and colistin (63.16%). Metagenomic analysis revealed comparable alpha diversity between wild and cultured shrimp, with Vibrio being predominant in both groups and V. parahaemolyticus as the most abundant species. Cultured shrimp harbored greater microbial diversity, including additional genera such as Shewanella, Lactococcus, and Enterobacter. A total of 30 ARGs were detected, primarily associated with β-lactams and tetracycline resistance. Cultured shrimp exhibited a broader ARG spectrum, reflecting potential anthropogenic impacts on aquaculture practices. These findings suggest that cultured shrimp environments can serve as reservoirs of resistant bacteria and ARGs. Therefore, improved antimicrobial stewardship and regular monitoring are essential to curb the spread of AMRs in marine ecosystems.

The emergence of multidrug-resistant Klebsiella pneumoniae (Kpn) is a global concern due to the increasing rate of mortality and hospital cost burden in the affected population. This study reports the whole-genome sequences of nine multidrug-resistant Kpn from a hospital in Chattogram city of Bangladesh.

The white spot syndrome virus (WSSV) is a causative agent of white spot disease (WSD) in crustaceans, especially in cultivated black tiger shrimp ( Penaeus monodon ), leading to significant economic losses in the aquaculture sector. The present study describes four whole genome sequences of WSSV obtained from coastal regions of Bangladesh.

Background The host-microbe interactions are complex, dynamic and context-dependent. In this regard, migratory fish species like hilsa shad (Tenualosa ilisha), which migrates from seawater to freshwater for spawning, provides a unique system for investigating the microbiome under an additional change in fish’s habitat. This work was undertaken to detect taxonomic variation of microbiome and their function in the migration of hilsa. Methods and results The study employed 16S rRNA amplicon-based metagenomic analysis to scrutinize bacterial diversity in hilsa gut, skin mucus and water. Thus, a total of 284 operational taxonomic units (OTUs), 9 phyla, 35 orders and 121 genera were identified in all samples. More than 60% of the identified bacteria were Proteobacteria with modest abundance (> 5%) of Firmicutes, Bacteroidetes and Actinobacteria. Leucobacter in gut and Serratia in skin mucus were the core bacterial genera, while Acinetobacter, Pseudomonas and Psychrobacter exhibited differential compositions in gut, skin mucus and water. Conclusions Representative fresh-, brackish- and seawater samples of hilsa habitats were primarily composed of Vibrio, Serratia and Psychrobacter, and their diversity in seawater was significantly higher (P < 0.05) than freshwater. Overall, salinity and water microbiota had an influence on the microbial composition of hilsa shad, contributing to host metabolism and adaptation processes. This pioneer exploration of hilsa gut and skin mucus bacteria across habitats will advance our insights into microbiome assembly in migratory fish populations.

Populations of different South Asian nations including Bangladesh reportedly have a high risk of developing diabetes in recent years. This study aimed to investigate the differences in the gut microbiome of COVID‐19‐positive participants with or without type 2 diabetes mellitus (T2DM) compared with healthy control subjects. Microbiome data of 30 participants with T2DM were compared with 22 age‐, sex‐, and body mass index (BMI)‐matched individuals. Clinical features were recorded while fecal samples were collected aseptically from the participants. Amplicon‐based (16S rRNA) metagenome analyses were employed to explore the dysbiosis of gut microbiota and its correlation with genomic and functional features in COVID‐19 patients with or without T2DM. Comparing the detected bacterial genera across the sample groups, 98 unique genera were identified, of which 9 genera had unique association with COVID‐19 T2DM patients. Among different bacterial groups, Shigella (25%), Bacteroides (23.45%), and Megamonas (15.90%) had higher mean relative abundances in COVID‐19 patients with T2DM. An elevated gut microbiota dysbiosis in T2DM patients with COVID‐19 was observed while some metabolic functional changes correlated with bidirectional microbiome dysbiosis between diabetes and non‐diabetes humans gut were also found. These results further highlight the possible association of COVID‐19 infection that might be linked with alteration of gut microbiome among T2DM patients.

Yogurt is one of the most frequently consumed dairy products for nutritional benefits. Although yogurt is enriched with probiotics, it is susceptible to spoilage because of the presence of pathogenic microbes. Spoiled yogurt if consumed can cause food-borne diseases. This study aimed to assess the nutritional composition and microbiome diversity in yogurt manufactured in Bangladesh. Microbial diversity was analyzed through high-throughput sequencing of bacterial 16S rRNA gene and fungal internal transcribed spacer (ITS) region. From nutritional analysis, significantly (P < 0.05) higher pH, fat, moisture, total solid and solid-non-fat contents (%) were observed in sweet yogurt. Following the classification of Illumina sequences, 84.86% and 72.14% of reads were assigned to bacterial and fungal genera, respectively, with significantly higher taxonomic richness in sour yogurt prepared from buffalo. A significant difference in bacterial (P_permanova = 0.001) and fungal (P_permanova = 0.013) diversity between sweet and sour yogurt was recorded. A total of 76 bacterial and 70 fungal genera were detected across these samples which were mostly represented by Firmicutes (92.89%) and Ascomycota (98%) phyla, respectively. This is the first study that accentuates nutritional profiles and microbiome diversity of Bangladeshi yogurt which are crucial in determining both active and passive health effects of yogurt consumption in individuals.