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Background/objectives: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder associated with gut dysbiosis. To investigate the association between gut microbiota and T2DM in a Saudi Arabian population., Methods: We conducted a comparative analysis of fecal microbiota from 35 individuals, including both T2DM patients and healthy controls. 16S rRNA gene sequencing was employed to characterize the microbial community structure., Results: Our findings revealed significant differences in microbial composition between the two groups. The T2DM group exhibited a higher abundance of Firmicutes and lower levels of Bacteroidetes compared to the healthy control group. At the genus level, T2DM patients showed a decrease in butyrate-producing bacteria such as Bacteroides and Akkermansia, while an increase in Ruminococcus and Prevotella was observed. Additionally, the T2DM group had a higher abundance of Faecalibacterium, Agathobacter, and Lachnospiraceae, along with a lower abundance of Bacteroides., Conclusions: These results suggest that alterations in gut microbiota composition may contribute to the development of T2DM in the Saudi Arabian population. Further large-scale studies are needed to validate these findings and explore potential therapeutic interventions targeting the gut microbiome.

We have used multiple sequencing approaches to sequence the genome of a volunteer from Saudi Arabia. We use the resulting data to generate a de novo assembly of the genome, and use different computational approaches to refine the assembly. As a consequence, we provide a contiguous assembly of the complete genome of an individual from Saudi Arabia for all chromosomes except chromosome Y, and label this assembly KSA001. We transferred genome annotations from reference genomes to fully annotate KSA001, and we make all primary sequencing data, the assembly, and the genome annotations freely available in public databases using the FAIR data principles. KSA001 is the first telomere-to-telomere-assembled genome from a Saudi individual that is freely available for any purpose., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background Autoimmune hepatitis (AIH) is a chronic liver disorder caused by the immune system targeting liver cells. The etiology of AIH remains undefined. Therefore, we aim to explore the relationship between cigarette smoking and AIH.  Methods A retrospective study was done at the Department of Medicine, King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. Forty-six inpatients and outpatients managed at KAUH from 2016 to 2021 and diagnosed with AIH were included. Data about patients' age, gender, smoking state, type of liver disease, and any other autoimmune disease were collected. Results In all, 10.9% (n = 5) of patients were active smokers, and 60.0% (n = 3) used cigarettes. The median number of cigarettes smoked per day was 17, while 56.5% (n = 26) had a positive family history of smoking, and 41.3% (n = 19) were passive smokers. Of them, 39.1% (n = 18) had at least one complication of AIH, such as liver cirrhosis, which is the most frequent complication (61.1%; n = 11), followed by esophageal varices (22.2%; n = 4), liver fibrosis (5.6%; n = 1), and fatty liver (5.6%; n = 1). The presence of any complication was not associated with patients' demographics or smoking status. On the other hand, liver cirrhosis was significantly higher among currently active smokers. Conclusion No relationship was found between smoking and the AIH outcomes. Future multi-center studies on larger samples are needed., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Research Ethics Committee of King Abdulaziz University issued approval HA-02-J-008. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Alarawi et al.)

Background: Escherichia coli is a common cause of biofilm-associated urinary tract infections (UTIs). Biofilm formation in E. coli is responsible for various indwelling medical device-associated infections, including catheter-associated urinary tract infections (CAUTIs). This study aimed to reduce biofilm formation of E. coli ATCC 25922 by knocking out genes involved in quorum sensing (QS) (luxS) and adhesion (fimH and bolA) using the CRISPR/Cas9-HDR approach., Method: Single-guide RNAs (sgRNAs) were designed to target luxS, fimH and bolA genes. Donor DNA for homologous recombination was constructed to provide accurate repairs of double-strand breaks (DSBs). A biofilm quantification assay (crystal violet assay) was performed to quantify the biofilm formation of mutant and wild-type strains. Morphological changes in biofilm architecture were confirmed by scanning electron microscopy (SEM). Further application of the biofilm formation of mutant and wild-type strains on urinary catheter was tested., Results: Crystal violet assay showed that the biofilm formation of ΔfimH, ΔluxS, and ΔbolA strains was significantly reduced compared to the wild-type strain (P value<0.001). The percentage of biofilm reduction of mutant strains was as follows: ΔluxS1 77.51 %, ΔfimH1 78.37 %, ΔfimH2 84.17 %, ΔbolA1 78.24 %, and ΔbolA2 75.39 %. Microscopic analysis showed that all mutant strains lack extracellular polymeric substances (EPS) production compared to the wild-type strain, which was embedded in its EPS matrix. The adherence, cell aggregation, and biofilm formation of wild-type strain on urinary catheters were significantly higher compared to ΔfimH, ΔluxS and ΔbolA strains., Conclusion: Altogether, our results demonstrated that the knockout of luxS, fimH, and bolA genes reduced EPS matrix production, which is considered the main factor in the development, maturation, and maintenance of the integrity of biofilm. This pathway could be a potential strategy to disrupt E. coli biofilm-associated UTIs. This study suggests that CRISPR/Cas9-HDR system may provide an efficient and site-specific gene editing approach that exhibits a possible antibiofilm strategy through intervention with the QS mechanism and adhesion property to suppress biofilm formation associated with UTI catheter infections., Competing Interests: Conflict of interests The authors declare no conflict of interest., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Vitamin D deficiency is a significant global health issue. It is prevalent in chronic kidney disease (CKD) patients, which is an important cause of death among children. Many studies have found a link between low vitamin D status in CKD patients and cardiovascular disease (CVD) risk factors. However, there are no data on this relationship in children with CKD in Saudi Arabia., Aims: We aimed to demonstrate this association among children with CKD admitted to the King Abdulaziz University Hospital (KAUH) in Jeddah, Saudi Arabia., Materials and Methods: Data were collected between June and August 2020 from a convenience sample of pediatric patients., Results: In total, 153 pediatric patients with CKD stages 2-5 were admitted to the KAUH between 2010 and 2019, and 67.3% had CKD stage 5. Approximately 4.6% and 10.5% of the participants were overweight or obese, respectively. Patients who fell into the lower 25-hydroxyvitamin D (25[OH]D) tertile were older, had higher body mass index (BMI) values, and had higher blood pressure than those in the upper two tertiles; however, these differences were not statistically significant. There was a significant inverse association of 25(OH)D levels with BMI, blood pressure, and serum creatinine levels., Conclusions: The results of this retrospective study suggest that patients with CKD and lower vitamin D levels have a higher BMI and blood pressure and are therefore at higher risk of developing CVD. Future prospective studies with a larger sample size are needed to confirm these findings. Randomized clinical trials are also needed to investigate the effect of sufficient vitamin D status on reducing CVD in patients with CKD., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Fayoumi et al.)

The demand for novel, robust microbial biocatalysts for use in industrial and pharmaceutical applications continues to increase rapidly. As a result, there is a need to develop advanced tools and technologies to exploit the vast metabolic potential of unculturable microorganisms found in various environments. Single-cell and functional metagenomics studies can explore the enzymatic potential of entire microbial communities in a given environment without the need to culture the microorganisms. This approach has contributed substantially to the discovery of unique microbial genes for industrial and medical applications. Functional metagenomics involves the extraction of microbial DNA directly from environmental samples, constructing expression libraries comprising the entire microbial genome, and screening of the libraries for the presence of desired phenotypes. In this study, lipolytic enzymes from the Red Sea were targeted. A high-throughput single-cell microfluidic platform combined with a laser-based fluorescent screening bioassay was employed to discover new genes encoding lipolytic enzymes. Analysis of the metagenomic library led to the identification of three microbial genes encoding lipases based on their functional similarity and sequence homology to known lipases. The results demonstrated that microfluidics is a robust technology that can be used for screening in functional metagenomics. The results also indicate that the Red Sea is a promising, under-investigated source of new genes and gene products., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Global climate change together with growing desertification is leading to increased dust emissions to the atmosphere, drawing attention to possible impacts on marine ecosystems receiving dust deposition. Since microorganisms play important roles in maintaining marine homeostasis through nutrient cycling and carbon flow, detrimental changes in the composition of marine microbiota in response to increased dust input could negatively impact marine health, particularly so in seas located within the Global Dust Belt. Due to its strategic location between two deserts and unique characteristics, the Red Sea provides an attractive semi-enclosed "megacosm" to examine the impacts of large dust deposition on the vastly diverse microbiota in its exceptionally warm oligotrophic waters., Results: We used culture-independent metagenomic approaches to assess temporal changes in the Red Sea microbiota in response to two severe sandstorms, one originated in the Nubian Desert in the summer 2016 and a second one originated in the Libyan Desert in the spring 2017. Despite differences in sandstorm origin and meteorological conditions, both sandstorms shifted bacterial and Archaeal groups in a similar mode. In particular, the relative abundance of autotrophic bacteria declined while those of heterotrophic bacteria, particularly Bacteroidetes, and Archaea increased. The changes peaked within six days from the start of sandstorms, and the community recovered the original assemblage within one month., Conclusion: Our results suggest that increased dust emission with expanding desertification could lead to undesirable impacts in ocean function, enhancing heterotrophic processes while reducing autotrophic ones, thereby affecting the marine food web in seas receiving dust deposition., (© 2022. The Author(s).)

Monitoring the changes that occur to water during distribution is vital to ensure water safety. In this study, the biological stability of reverse osmosis (RO) produced drinking water, characterized by low cell concentration and low assimilable organic carbon, in combination with chlorine disinfection was investigated. Water quality at several locations throughout the existing distribution network was monitored to investigate whether microbial water quality changes can be identified. Results revealed that the water leaving the plant had an average bacterial cell concentration of 10 3 cells/mL. A 0.5-1.5 log increase in bacterial cell concentration was observed at locations in the network. The residual disinfectant was largely dissipated in the network from 0.5 mg/L at the treatment plant to less than 0.1 mg/L in the network locations. The simulative study involving miniature distribution networks, mimicking the dynamics of a distribution network, fed with the RO produced chlorinated and non-chlorinated drinking water revealed that distributing RO produced water without residual disinfection, especially at high water temperatures (25-30 °C), poses a higher chance for water quality change. Within six months of operation of the miniature network fed with unchlorinated RO produced water, the adenosine triphosphate (ATP) and total cell concentration (TCC) in the pipe biofilm were 4 × 10 2 pg ATP/cm 2 and 1 × 10 7 cells/ cm 2 . The low bacterial cell concentration and organic carbon concentration in the RO-produced water did not prevent biofilm development inside the network with and without residual chlorine. The bacterial community analysis using 16S ribosomal RNA (rRNA) gene sequencing revealed that mesophilic bacteria with higher temperature tolerance and bacteria associated with oligotrophic, nutrient-poor conditions dominated the biofilm, with no indication of the existence of opportunistic pathogenic species. However, chlorination selected against most bacterial groups and the bacterial community that remained was mainly the bacteria capable of surviving disinfection regimes. Biofilms that developed in the presence of chlorine contained species classified as opportunistic pathogens. These biofilms have an impact on shaping the water quality received at the consumer tap. The presence of these bacteria on its own is not a health risk indicator; viability assessment and qPCRs targeting genes specific to the opportunistic pathogens as well as quantitative microbiological risk assessment (QMRA) should be included to assess the risk. The results from this study highlight the importance of implementing multiple barriers to ensure water safety. Changes in water quality detected even when high-quality disinfected RO-produced water is distributed highlight microbiological challenges that chlorinated systems endure, especially at high water temperatures., (Copyright © 2021. Published by Elsevier Ltd.)

Background: Cellulolytic microorganisms are considered a key player in the degradation of plant biomass in various environments. These microorganisms can be isolated from various environments, such as soils, the insect gut, the mammalian rumen and oceans. The Red Sea exhibits a unique environment in terms of presenting a high seawater temperature, high salinity, low nutrient levels and high biodiversity. However, there is little information regarding cellulase genes in the Red Sea environment. This study aimed to examine whether the Red Sea can be a resource for the bioprospecting of microbial cellulases by isolating cellulase-producing microorganisms from the Red Sea environment and characterizing cellulase genes., Results: Three bacterial strains were successfully isolated from the plankton fraction and the surface of seagrass. The isolated strains were identified as Bacillus paralicheniformis and showed strong cellulase activity. These results suggested that these three isolates secreted active cellulases. By whole genome sequencing, we found 10 cellulase genes from the three isolates. We compared the expression of these cellulase genes under cellulase-inducing and non-inducing conditions and found that most of the cellulase genes were generally upregulated during cellulolysis in the isolates. Our operon structure analysis also showed that cellulase genes form operons with genes involved in various kinds of cellular reactions, such as protein metabolism, which suggests the existence of crosstalk between cellulolysis and other metabolic pathways in the bacterial isolates. These results suggest that multiple cellulases are playing important roles in cellulolysis., Conclusions: Our study reports the isolation and characterization of cellulase-producing bacteria from the Red Sea. Our whole-genome sequencing classified our three isolates as Bacillus paralicheniformis, and we revealed the presence of ten cellulase orthologues in each of three isolates' genomes. Our comparative expression analysis also identified that most of the cellulase genes were upregulated under the inducing conditions in general. Although cellulases have been roughly classified into three enzyme groups of beta-glucosidase, endo-β-1,4-glucanase and exoglucanase, these findings suggest the importance to consider microbial cellulolysis as a more complex reaction with various kinds of cellulase enzymes., (© 2021. The Author(s).)

Droplet microfluidic techniques have shown promising outcome to study single cells at high throughput. However, their adoption in laboratories studying "-omics" sciences is still irrelevant due to the complex and multidisciplinary nature of the field. To facilitate their use, here we provide engineering details and organized protocols for integrating three droplet-based microfluidic technologies into the metagenomic pipeline to enable functional screening of bioproducts at high throughput. First, a device encapsulating single cells in droplets at a rate of ∼250 Hz is described considering droplet size and cell growth. Then, we expand on previously reported fluorescence-activated droplet sorting systems to integrate the use of 4 independent fluorescence-exciting lasers (i.e., 405, 488, 561, and 637 nm) in a single platform to make it compatible with different fluorescence-emitting biosensors. For this sorter, both hardware and software are provided and optimized for effortlessly sorting droplets at 60 Hz. Then, a passive droplet merger is also integrated into our pipeline to enable adding new reagents to already-made droplets at a rate of 200 Hz. Finally, we provide an optimized recipe for manufacturing these chips using silicon dry-etching tools. Because of the overall integration and the technical details presented here, our approach allows biologists to quickly use microfluidic technologies and achieve both single-cell resolution and high-throughput capability (>50,000 cells/day) for mining and bioprospecting metagenomic data., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Corrosion in pipelines and reservoir tanks in oil plants is a serious problem in the global energy industry because it causes substantial economic losses associated with frequent part replacement and can lead to potential damage to entire crude oil fields. Previous studies revealed that corrosion is mainly caused by microbial activities in a process currently termed microbiologically influenced corrosion or biocorrosion. Identifying the bacteria responsible for biocorrosion is crucial for its suppression. In this study, we analyzed the microbial communities present at corrosion sites in oil plant pipelines using comparative metagenomic analysis along with bioinformatics and statistics. We analyzed the microbial communities in pipelines in an oil field in which groundwater is used as injection water. We collected samples from four different facilities in the oil field. Metagenomic analysis revealed that the microbial community structures greatly differed even among samples from the same facility. Treatments such as biocide administration and demineralization at each location in the pipeline may have independently affected the microbial community structure. The results indicated that microbial inspection throughout the pipeline network is essential to prevent biocorrosion at industrial plants. By identifying the bacterial species responsible for biocorrosion, this study provides bacterial indicators to detect and classify biocorrosion. Furthermore, these species may serve as biomarkers to detect biocorrosion at an early stage. Then, appropriate management such as treatment with suitable biocides can be performed immediately and appropriately. Thus, our study will serve as a platform for obtaining microbial information related to biocorrosion to enable the development of a practical approach to prevent its occurrence., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)