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Multidrug-resistant bacteria, particularly extended-spectrum-beta-lactamase-producing (ESBL) bacteria, pose a significant global public health challenge. Klebsiella pneumoniae (KPN) is frequently implicated in cases of this resistance. This study aimed to investigate the presence of drug and metal resistance genes in clinical K. pneumoniae isolate Kp04 and comparative genomics of clinical KPN isolates characterized from Bangladesh. A total of 12 isolates were collected. Disk-diffusion assay showed that all five isolates were resistant to 14 out of 21 tested antibiotics and sensitive to only three—tigecycline, imipenem, and meropenem. KPN Kp04 was positive for both blaSHV and blaCTX-M ESBL genes in PCR. All five isolates produced PCR amplicons of the correct size for ampicillin (ampC), tetracycline (tetC), fluoroquinolone (qnrS), and aminoglycoside (aadA) resistance genes. The whole genome of Kp04 was sequenced using the MiSeq Platform (V3 kit, 2 × 300 cycles). We utilized different databases to detect Antibiotic-Resistant Genes (ARGs), virulence factor genes (VFGs), and genomic functional features of the Kp04 strain. Whole-genome sequencing identified 75 ESBL, virulence, and multiple drug-resistant (MDR) genes including blaSHV, tetA, oqxA, oqxB, aadA, sul1-5, and mphA in KPN Kp04 isolate. Pan-genomic analysis of 43 Bangladeshi KPN isolates showed similarities between Dhaka and Chattogram isolates regarding virulence and antibiotic-resistant genes. Our results indicate the transmission of similar virulent KPN strains in Dhaka and Chattogram. This study would provide valuable information about drug sensitivity, antibiotic, and metal resistance features of K. pneumoniae circulated among hospitalized patients in Bangladeshi megacities. [ABSTRACT FROM AUTHOR]

Microplastics (MPs), small synthetic particles, have emerged as perilous chemical pollutants in aquatic habitats, causing grave concerns about their disruptive effects on ecosystems. The fauna and flora inhabiting these specific environments consume these MPs, unwittingly introducing them into the intricate web of the food chain. In this comprehensive evaluation, the current methods of identifying MPs are amalgamated and their profound impacts on marine and freshwater ecosystems are discussed. There are many potential risks associated with MPs, including the dangers of ingestion and entanglement, as well as internal injuries and digestive obstructions, both marine and freshwater organisms. In this review, the merits and limitations of diverse identification techniques are discussed, including spanning chemical analysis, thermal identification, and spectroscopic imaging such as Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and fluorescent microscopy. Additionally, it discusses the prevalence of MPs, the factors that affect their release into aquatic ecosystems, as well as their plausible impact on various aquatic ecosystems. Considering these disconcerting findings, it is imperative that appropriate measures should be taken to assess the potential risks of MP pollution, protect aquatic life and human health, and foster sustainable development. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Nanocellulose has a wide range of applications in the field of functional materials, and it has piqued the interest of researchers for some time. This is because nanocellulose inherits the advantages of environmental friendliness and easy availability of plant cell walls in nature, as well as the unique morphology of nanostructures. This review presents four types of nanocellulose including cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), regenerated nanocellulose (RNC) and bacterial cellulose (BC), introduces the different preparation routes and their mechanisms, analyzes the advantages and drawbacks between these approaches, and summarizes the potential applications in the field of functional materials such as reinforced composite materials, biomedical materials, soft templates, and optical materials. Finally, future development directions are proposed including further enrichment of nanocellulose raw materials, improvement of preparation methods to adapt to more diversified raw materials, and classification of products according to their morphology and properties to improve the use efficiency. [ABSTRACT FROM AUTHOR]