Molecular Genetics Commons^™

Molecular Genetic Studies Of Horses, Especially With Reference To Aggrecan And Dwarfism, John Edmund Eberth

Theses and Dissertations--Veterinary Science

This work consists of studies on dwarfism in Miniature horses and a study on breakdowns in Thoroughbreds in relation to gene aggrecan. A correction of the description and designation of D3 dwarf variant in aggrecan (ACAN) from the master’s thesis Chondrodysplasia-like dwarfism in the Miniature horse (2013). Commercial sequencing showed previous sequencing reads presented an artifact and not a single base deletion. Analysis showed a single base missense mutation in exon 8 identified as D3* was the actual cause. Multiple alleles of ACAN associated with chondrodysplastic dwarfism in Miniature horses by Eberth et al. (2018), corrected the …

Use Of Molecular Genetics To Investigate Population Structure And Swayback In Horses, Navid Yousefimashouf

Theses and Dissertations--Veterinary Science

The present research incorporated molecular genetic methods to 1) investigate the genetic basis of Juvenile Onset Lordosis or Swayback in the American Saddlebred horses; and 2) conduct a population genetic study to compare the Persian Kurdish, Persian Arabian and American Thoroughbred horse populations.

Juvenile-onset lordosis, or swayback, is a condition in horses where the conformational topline back curvature drops significantly within the first two years of life. The trait has a higher prevalence in Saddlebreds (5%). Prior research on them quantified the trait using a Measurement of Back Contour (MBC), defining an MBC of >7.0 centimeters as swayback, and8.0) MBC …

Species-Specific Microsymbiont Discrimination Mediated By A Medicago Receptor Kinase, Xiaocheng Yu

Theses and Dissertations--Plant and Soil Sciences

Legumes form a mutualistic partnership with nitrogen-fixing bacteria to meet their nitrogen requirements. This collaboration leads to the development of root nodules, offering an ideal environment for the bacteria to convert atmospheric nitrogen into ammonia. A salient aspect of this symbiotic relationship is host range specificity, such that nodulation capacity and nitrogen fixation efficiency differ significantly between different host-bacterial combinations. Understanding the genetic basis of this specificity could pave the way for strategies to overcome the host range barrier. Sinorhizobium meliloti and Sinorhizobium medicae are two closely related species that display differential symbiotic behaviors with legume plants of the Medicago …

Can Testing The Environment For Severe Acute Respiratory Coronavirus Virus 2 (Sars-Cov-2) Be A Signal For Coronavirus Disease 2019 (Covid-19) Cases Among Nursing Home Staff?, Gabrielle M. Gussin, Raveena D. Singh, Izabela Coimbra Ibraim, Raheeb Saavedra, Thomas T. Tjoa, Micaila Curtis, Kristine P. Nguyen, Ilhem Messaoudi, Susan S. Huang

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Prior to widespread COVID-19 vaccination, nursing homes were required to perform comprehensive weekly testing of staff. After the vaccine became available, testing became symptom-based for vaccinated staff despite continued waves of different severe acute respiratory coronavirus virus 2 (SARS-CoV-2) variants. Nursing homes need pragmatic, affordable strategies to identify SARS-CoV-2–positive staff because financial and job-related pressures drive reluctance to disclose mild symptoms. We sought to determine whether positive environmental samples for SARS-CoV-2 could serve as trigger for comprehensive staff testing in lieu of weekly testing of all staff.

Correlates Of Sars-Cov-2 Anti-Rbd Igg Antibody Titers Among Persons Experiencing Homelessness In Los Angeles, Adeline Nyamathi, Sanghyuk S. Shin, Brianna M. Doratt, Alexandria Jones-Patten, Benissa Salem, Lillian Gelberg, Darlene Lee, Dana Garfin, Kartik Yadav, Alicia H. Chang, Kathryn White, Nicholas Arce, Ilhem Messaoudi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Objectives: People experiencing homelessness (PEH) have been especially impacted by the COVID-19 pandemic, likely due to increased vulnerabilities stemming from chronic diseases, substance use, and mental health conditions.

Design: A case–control study to assess the presence of antibodies against SARS-CoV-2 among PEH and associations with key variables.

Sample: A convenience sample of 97 PEH in Skid Row, Los Angeles.

Measurements: A structured questionnaire assessing socio-demographic, mental health, drug and alcohol use, health care access, pandemic stress, and other COVID-19-specific questions.

Results: We found high anti-receptor binding domain (RBD) IgG titers among five of 15 PEH who reported no prior COVID-19 …

Maternal Obesity Blunts Antimicrobial Responses In Fetal Monocytes, Suhas Sureshchandra, Brianna M. Doratt, Norma Mendza, Oleg Varlamov, Monica Rincon, Nicole E. Marshall, Ilhem Messaoudi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Maternal pre-pregnancy (pregravid) obesity is associated with adverse outcomes for both mother and offspring. Amongst the complications for the offspring is increased susceptibility and severity of neonatal infections necessitating admission to the intensive care unit, notably bacterial sepsis and enterocolitis. Previous studies have reported aberrant responses to LPS and polyclonal stimulation by umbilical cord blood monocytes that were mediated by alterations in the epigenome. In this study, we show that pregravid obesity dysregulates umbilical cord blood monocyte responses to bacterial and viral pathogens. Specifically, interferon-stimulated gene expression and inflammatory responses to respiratory syncytial virus (RSV) and E. coli were significantly …

Sars-Cov-2 Infection And Seroconversion Rates In Healthcare Providers Prior To Covid-19 Vaccine Rollout, Sanghyuk S. Shin, Miriam Bender, Delphine C. Malherbe, Hannah Vasquez, Brianna M. Doratt, Ilhem Messaoudi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Objective: A 6-month longitudinal surveillance study of asymptomatic healthcare providers (HCP) was carried out at a large urban academic medical center in the United States to assess whether their job occupation with higher exposure risks to SARS-CoV-2 would equate with higher risk of contracting COVID-19 at the beginning of the pandemic before COVID-19 vaccines were available.

Methods: A longitudinal cohort study design was used to collect and analyze immunological and virological monitoring data and self-report survey assessments of personal protective equipment (PPE) availability, adherence to infection control guidelines, and time spent on COVID-19 wards.

Results: Among 289 eligible participants, SARS-CoV-2 …

Single-Dose Vsv-Based Vaccine Protects Cynomolgus Macaques From Disease After Taï Forest Virus Infection, Paige Fletcher, Kyle L. O'Donnell, Brianna M. Doratt, Delphine C. Malherbe, Chad S. Clancy, Joseph F. Rhoderick, Friederike Feldmann, Patrick W. Hanley, Thomas G. Ksiazek, Thomas W. Geisbert, Ilhem Messaoudi, Andrea Marzi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Taï Forest virus (TAFV) is a lesser-known ebolavirus that causes lethal infections in chimpanzees and is responsible for a single human case. Limited research has been done on this human pathogen; however, with the recent emergence of filoviruses in West Africa, further investigation and countermeasure development against this virus is warranted. We developed a vesicular stomatitis virus (VSV)-based vaccine expressing the TAFV glycoprotein as the viral antigen and assessed it for protective efficacy in nonhuman primates (NHPs). Following a single high-dose vaccination, NHPs developed antigen-specific binding and neutralizing antibodies as well as modest T cell responses. Importantly, all vaccinated NHPs …

Transcriptional Profiling Of Immune Responses In Nhps After Low-Dose, Vsv-Based Vaccination Against Marburg Virus, Cecilia A. Prator, Brianna M. Doratt, Kyle L. O'Donnell, Justin Lack, Amanda N. Pinski, Stacy M. Ricklefs, Craig A. Martens, Ilhem Messaoudi, Andrea Marzi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Infection with Marburg virus (MARV), the causative agent of Marburg virus disease (MVD), results in haemorrhagic disease and high case fatality rates (>40%) in humans. Despite its public health relevance, there are no licensed vaccines or therapeutics to prevent or treat MVD. A vesicular stomatitis virus (VSV)-based vaccine expressing the MARV glycoprotein (VSV-MARV) is currently in clinical development. Previously, a single 10 million PFU dose of VSV-MARV administered 1–5 weeks before lethal MARV challenge conferred uniform protection in nonhuman primates (NHPs), demonstrating fast-acting potential. Additionally, our group recently demonstrated that even a low dose VSV-MARV (1000 PFU) protected NHPs …

Selective Gsk3b Overexpression In Medial Prefrontal Cortex Camkiia Cells Produces Sex-Specific Changes In Ethanol Self-Administration, Anxiety-Like Behavior, And Working Memory, Sam Gottlieb, Zachary Tatom, Michael F. Miles

Graduate Research Posters

Background: Glycogen synthase kinase 3 beta (Gsk3b) is central in a gene network regulated by ethanol in mouse medial prefrontal cortex (mPFC). GSK3B abundance/activity modulations regulate ethanol consumption, suggesting GSK3B could be a target in treating alcohol use disorder. However, the critical cell type in this ethanol response is not yet known, nor have sex differences in GSK3B modulations been fully investigated. Here we report results of GSK3B overexpression selectively in CamKIIa⁺ mPFC cells on multiple behaviors.

Methods: Mice underwent stereotaxic injections to overexpress GSK3B in mPFC CamKIIa⁺ cells or control virus (n=4-6/sex/virus). We assayed working …

Generation Of Chimeric Rhinoviruses Presenting Sars-Cov-2 Broadly Neutralizing Epitopes And Their Antigenicity Characterization, Danish Ansari

Biotechnology Theses

The global COVID pandemic is not yet fully under control as there were over 21 million new cases of SARS-CoV-2 infections and over 50,000 deaths globally as of January of 2022. A heavily mutated variant of concern, Omicron is responsible for most of these cases which demands an urgency for a new vaccine. NIH reports over 180 vaccine candidates that use various strategies currently in development. However, a recurring concern with these vaccines is that the continuous viral mutations decrease the efficacy of vaccines. Therefore, we proposed to construct a human rhinovirus (HRV) based chimeric virus containing highly conserved, broadly …

Cell Signaling And Stress Response In The Yeast Saccharomyces Cerevisiae: A Study Of Snf1, Scott E. Arbet Ii

Graduate Theses, Dissertations, and Problem Reports (ETD)

Saccharomyces cerevisiae are yeast that are unicellular eukaryotic organisms that are well studied as a model organism for understanding fundamental cellular processes. The ability of yeast to sense nutrient availability is crucial for their survival, growth, and reproduction. Yeast cells use various mechanisms to sense and respond to nutrient availability, including transporter-mediated uptake, receptor-mediated signaling, and sensing of metabolites. The subcellular localization of nutrient-sensing components is crucial for yeast function in nutrient sensing and signaling. Protein complexes, such as the AMP-activated protein kinase (AMPK) pathway, in nutrient sensing and response, as well as the downstream effects of these pathways …

Elucidation Of The Role Of Agouti-Signaling Protein Throughout Folliculogenesis And Early Embryonic Development In Cattle, Heather L. Chaney

Graduate Theses, Dissertations, and Problem Reports (ETD)

The oocyte expresses certain genes during folliculogenesis to regulate the acquisition of oocyte competence. Oocyte competence, which refers to the presence of imperative molecular factors in the oocyte that are critical for high oocyte quality, is directly related to the ability of the oocyte to result in a successful pregnancy following fertilization. Over the past few decades, the development and optimization of assisted reproductive technologies, particularly in vitrofertilization, have enabled the beef and dairy industries to advance cattle genetics and productivity. However, only approximately 40% of bovine embryos will develop to the blastocyst stage in vitro. In addition, bovine embryos …

The Investigation Of Novel Bovine Oocyte-Specific Long Non-Coding Rnas And Their Roles In Oocyte Maturation And Early Embryonic Development, Jaelyn Zoe Current

Graduate Theses, Dissertations, and Problem Reports (ETD)

Early embryonic loss is a significant factor in livestock species' infertility, resulting in an economic deficit. In cattle, the in vivo fertilization rate is ~90%, with an average calving rate of about 55%, indicating an embryonic-fetal mortality rate of roughly 35%. Further, 70-80% of total embryonic loss in cattle occurs during the first three weeks after insemination, particularly between days 7-16. Growing evidence indicates that the oocyte plays an active role in regulating critical aspects of the reproductive process required for successful fertilization, embryo development, and pregnancy. However, defining oocyte quality remains enigmatic. Recently, many have abandoned the notion that …

Placing The Evolutionary History Of Desmognathus Salamanders In Context: A Phylogeographic Approach, Kara Jones

Theses and Dissertations--Biology

Patterns of genetic variation do not arise in a vacuum but are instead shaped by the interplay between evolutionary forces and ecological constraints. Here, I use a phylogeographic approach to examine the role that ecology played in lineage divergence in the Desmognathus quadramaculatus species complex (Family: Plethodontidae), which consists of three nominal species: D. quadramaculatus, D. marmoratus, and D. folkertsi. Previous phylogenetic studies have shown that individuals from these species do not form clades based on phenotype. My approach to reconciling phylogenetic discordance was two-fold, using (1) genome-wide markers to provide insight into the …

Dna Methylation And The Response To Infection In Introduced House Sparrows, Melanie Gibson

College of Graduate Studies: Theses & Dissertations

Epigenetics is the study of molecular modification of a genome without changing its base pairs. The most studied type of epigenetic mechanism is DNA methylation, which is capable of turning a gene “on” or “off.” Epigenetic potential is the capacity to which an individual can have methylation on its genome. The more CpGs available, the greater the epigenetic potential. In invasive species, genetic variation has been observed to be paradoxical: not much of it exists on a genomic level, but epigenetically, phenotypic variation can occur. The focus on shift in gene expression in this study is on Toll-Like Receptor 4 …

Molecular Analysis Of Epigenetic Memory Of Stress Establishment And Long-Term Maintenance In A Perennial Woody Plant, Jia Wen Tan

Theses and Dissertations--Plant and Soil Sciences

Plants adapt to extreme environmental conditions through physiological adaptations, which are usually transient. Recent research has suggested that environmental conditions can activate a memory of stress that can result in a primed response to subsequent stress events. While the effect of priming has been observed in many plants, the underlying mechanisms are puzzling and seldom studied. A large body of research has been developed in the last decade linking response to stress, stress priming, and memory of stress with epigenetic mechanisms. This understanding of plant epigenetics has opened the door to the application of epigenetics to crop improvement, such as …

Effects Of The Otx2ecr2 Enhancer & Prox1 Overexpression In Murine Retina Development, Erick J. Subillaga

Dissertations and Theses

There is a large subset of retinal progenitor cells that upregulate the OTX2 gene in the developing retina of the mouse. OTX2 is a homeobox transcription factor important for the development of photoreceptors and bipolar cells. If OTX2 is knocked out, photoreceptors and bipolar cells fail to differentiate. In order for OTX2 to be activated in certain retinal populations, it requires the activity of an enhancer called OTX2ECR2. Past studies demonstrated that retinal progenitor cells that had activity of OTX2ECR2 turned into horizontal cells, which require OTX2 for cell genesis and survival, and photoreceptors which require OTX2 for cell …

Novel Strategies In Head And Neck Tumor Therapy; Contribution Of Senescence In Therapy Response, And Resistance Development After Cisplatin Treatment, Fereshteh Ahmadinejad

Theses and Dissertations

Therapeutic outcomes achieved in head and neck squamous cell carcinoma (HNSCC) patients by concurrent cisplatin-based chemoradiotherapy initially reflect both tumor regression and tumor stasis. However, local, and distant metastasis and disease relapse as well as cisplatin-induced resistance are common in HNSCC patients. In the current work, we demonstrate that cisplatin treatment induces senescence in both p53 wild- type HN30 and p53 mutant HN12 head and neck cancer models. We also show that tumor cells can escape from senescence both in vitro and in vivo. We further established a cisplatin-resistant cell line from HN30 parental cell line that underwent brief senescence …

Examining Genetically-Informed Etiologic Models Of Co-Occurring Posttraumatic Stress Disorder And Recreational Cannabis Use Among College Students, Terrell A. Hicks

Theses and Dissertations

The college years encompass a period of increased risk recreational cannabis use (RCU), as well as a time of increased risk for trauma exposure and developing posttraumatic stress disorder (PTSD). Given the high co-occurrence between RCU and PTSD, and the potentially negative consequences of the two (e.g., worse academic outcomes), there is a need to understand the etiologic mechanisms of these commonly co-occurring conditions. Two primary phenotypic models exist: self-medication model (i.e., PTSD to RCU) and the high-risk model (i.e., RCU to PTSD). To date, there are two existing studies longitudinally examining the etiologic models proposed to explain co-occurring RCU …

Host-Microbe Interactions In Non-Native Estuarine Anemones: Biogeography And Temperature, Parker K. Lund

Cal Poly Humboldt theses and projects

Non-native species are increasing in prevalence around the world, resulting in negative economic and ecological impacts. However, the broad distributions of non-native species also offer a system for investigating the response of host-associated microbial communities to environmental factors across a range of ecological scales. At the broadest scale, I investigated the geography of microbial communities in the non-native estuarine anemone Diadumene lineata on the west coast of the United States of America. Across latitudes, microbial community composition was very similar and displayed a high percentage of Klebsiella spp. at all sites. However, the communities in California tended to exhibit higher …

Extension Of The Ergot Alkaloid Gene Cluster, Samantha Joy Fabian

Graduate Theses, Dissertations, and Problem Reports (ETD)

Specialized metabolites produced by fungi impact human health. A large portion of the pharmaceuticals currently on the market are derived from metabolites biosynthesized by microbes. Ergot alkaloids are a class of fungal metabolites that are important in the interactions of environmental fungi with insects and mammals and also are used in the production of pharmaceuticals. In animals, ergot alkaloids can act as partial agonists or antagonists at receptors for 5-hydroxytryptamine (serotonin), dopamine, and noradrenaline as ergot alkaloids have chemical structures similar to those neurotransmitters. Therefore, they affect insects and mammals that consume them and can be used to produce drugs …

Heat Shock Protein 90 (Hsp90) System In Health And Disease., Daniella Munezero

Graduate Theses, Dissertations, and Problem Reports (ETD)

Cells rely on heat shock proteins (HSP) to facilitate and regulate the folding of the substrate proteins into their native state, and degradation if misfolding cannot be prevented. HSP90, a member of the HSP family, is a potential target for treatment of cancer and neurodegenerative diseases. Unfortunately, several clinical trials for cancer treatment have been discontinued due to cell toxicity accompanying HSP90 inhibition. HSP90 has four distinct but structurally similar paralogs. HSP90 inhibitors target all the paralogs despite increasing proof of functional differences among the paralogs. Understanding the in vivo function of HSP90 and the role played by each paralog …

Dna Transfer And Persistence On Non-Porous Surfaces Submerged In Spring Water [Preliminary Study], Morgan L.. Korzik, Josep De Alcaraz-Fossoul, Michael S. Adamowicz, David San Pietro

Forensic Science: Faculty Publications

Submerged items are often thought to lack evidentiary value. However, previous studies have shown the ability to recover DNA from submerged porous items for upwards of six weeks. The crevices or interweaving fibers in porous items are thought to protect DNA from being washed away. It is hypothesized that, because non-porous surfaces do not have the same traits that might aid in DNA retention, then DNA quantities and the number of donor alleles recovered would decrease over longer submersion periods. Additionally, it is hypothesized that DNA quantity and the number of alleles would be negatively affected by flow conditions. Neat …

Use Of Foreign Edna Tracers To Resolve Site- And Time-Specific Edna Distributions In Natural Streams, Braden A. Herman

Cal Poly Humboldt theses and projects

Substantial uncertainty in how to interpret eDNA observations motivates a need for a technique to effectively and efficiently measure of system- and time-specific eDNA distributions. Using a technique to robustly calibrate eDNA dynamics in a given system would improve established eDNA methods such as presence and absence and has the potential to refine estimates of organism abundance using eDNA concentration that are less well understood. Particles of eDNA are present in a wide variety of size and type resulting in varying transport dynamics, persistence, decay, among others. This variation likely makes eDNA transport more complex than that of conservative tracers …

Microbial Communities In The Guana Tolomato Matanzas National Estuarine Research Reserve: An Assessment Of The Responses Of Spartina Alterniflora Epiphytes To Nitrogen Enrichment, And A Characterization Of Benthic Cyanobacterial Diversity, Anne C. Hurley

UNF Graduate Theses and Dissertations

Elevated nitrogen and phosphorus inputs from anthropogenic sources, which can lead to significant increases in algal biomass and changes in algal community composition, poses a serious threat to estuarine ecosystems worldwide. While numerous studies have addressed the impacts of nutrient enrichment on epiphytic algae in seagrass habitats, few have investigated potential nutrient-driven changes to epiphytes on emergent salt marsh plants, such as Spartina alterniflora. Epiphytic microalgae on S. alterniflora play an important role in food availability in salt marsh ecosystems, and epiphytic nitrogen-fixing cyanobacteria also provide an important source of nitrogen for salt marsh consumers. The first study included …

White-Tailed Deer In A Winter-Wonderland: Long-Term Deer Yard Use And Methodological Considerations For Ungulate Fecal Dna Metabarcoding, Melanie A. Ottino

Dissertations, Master's Theses and Master's Reports

Northern white-tailed deer (Odocoileus virginianus) mitigate the increased energetic costs of severe winter conditions through obligate migration to densely congregated areas with abundant conifer cover, a behavior referred to as yarding. “Deer yards” in the Western Upper Peninsula (UP) of Michigan are principally located within the reduced snowpack and increased ambient temperature microclimates of densely canopied eastern hemlock (Tsuga canadensis) stands, but specific drivers of long-term site fidelity and utilization are largely uncharacterized. As an important game species of high economic and cultural value and a keystone herbivore with critical impact of plant community composition and structure, identifying winter yarding …

Sequencing Antisense Transcriptome Of Populus Through Antisense/Sense Transcript Pair Enrichment, Emma V. Burke

Dissertations, Master's Theses and Master's Reports

Past transcriptome research on plants focused primarily on protein coding genes, and only recently researchers began looking into the non-protein coding regions that may play significant roles in gene regulation. Antisense RNA transcripts that are found naturally in the cell share complementary sequence with sense transcripts and have been shown to regulate expression of their sense counterparts. Since antisense RNA has been largely under-studied and difficult to sequence because of their low relative abundance, new methods are needed to target antisense RNA for efficient genome-wide profiling. To address this gap in methods to efficiently and cost effectively enrich antisense RNA …

Morphological And Genetic Analysis Of The Root System In Two American Grapevines (Vitis Species), Parinaz Mohtasebi

Graduate Theses/Dissertations

The North American grapes species Vitis rupestris Scheele and Vitis riparia Michx have been the pillars of rootstock breeding for many decades. Though a large body of viticultural knowledge has been accumulated on their impact on grafted scions, the genetic basis of their root system architecture (RSA) has received limited scientific attention. In this study, I generated and analyzed adventitious root systems from dormant cuttings of 22 V. riparia and 19 V. rupestris accessions, as well as 162 interspecific F1 hybrid progeny from a cross between V. rupestris (♀) and V. riparia (♂). I photographed the roots and then extracted …

การศึกษารูปแบบของยีน Mgrb และความชุกของยีน Mcr-1 ถึง Mcr-10 ใน Escherichia Coli และ Klebsiella Pneumoniae ที่ดื้อยา Colistin จากสิ่งส่งตรวจของผู้ป่วยในโรงพยาบาลเลิดสิน, ขวัญชนม์ เจียรกิติวณิช

Chulalongkorn University Theses and Dissertations (Chula ETD)

การดื้อยา colistin มีแนวโน้มเพิ่มสูงขึ้นในเชื้อแบคทีเรียกลุ่ม Enterobacterales เนื่องมาจากการนำยา colistin กลับมาใช้ในการรักษาเชื้อดื้อยาหลายขนาน โดยเฉพาะอย่างยิ่งเชื้อแบคทีเรียแกรมลบที่ดื้อยา carbapenem ประกอบกับการถ่ายทอดยีน mobile colistin-resistant (mcr) ผ่านทาง plasmid ซึ่งส่งผลให้การแพร่ระบาดของเชื้อดื้อยา colistin เกิดขึ้นในวงกว้างอย่างรวดเร็ว สถานการณ์เชื้อกลุ่ม Enterobacterales ที่ดื้อยา colistin ในประเทศไทยกำลังเป็นที่สนใจ เนื่องมาจากเริ่มพบอัตราเชื้อดื้อยาที่สูงขึ้นอย่างต่อเนื่องทั้งในภาคการปศุสัตว์และในโรงพยาบาล การศึกษาครั้งนี้ได้ศึกษาลักษณะจีโนมของเชื้อ E. coli และ K. pneumoniae ที่ดื้อยา colistin ที่เพาะแยกได้จากผู้ป่วยของโรงพยาบาลเลิดสิน กรุงเทพมหานคร ในช่วงระหว่างเดือนตุลาคม พ.ศ. 2564 ถึงเดือนกันยายน พ.ศ. 2565 และศึกษาความสัมพันธ์และการกระจายตัวของเชื้อในแผนกต่างๆ ของโรงพยาบาล เชื้อที่เก็บได้ทั้งหมดจำนวน 54 ตัวอย่าง ประกอบด้วยเชื้อ E. coli และ K. pneumoniae จำนวน 14 และ 40 ตัวอย่าง ตามลำดับ ซึ่งให้ผลดื้อยา colistin เมื่อทดสอบด้วยเครื่องอัตโนมัติ Sensititre™ Gram Negative MIC Plate เชื้อส่วนใหญ่เพาะแยกจากปัสสาวะ (46.30%, p-value=0.38) และเสมหะ (29.63%, p-value=0.63) โดยเพาะแยกเชื้อได้จากผู้ป่วยใน (81.48%) มากกว่าผู้ป่วยนอก (18.52%) อย่างมีนัยสำคัญ (p-value=0.000) ภายหลังนำเชื้อทั้งหมดไปวิเคราะห์ลำดับเบสด้วยเทคนิค Illumina whole genome sequencing (WGS) สามารถจำแนกสายพันธุ์ของเชื้อได้อย่างมีประสิทธิภาพ โดยเชื้อ E. coli และ K. pneumoniae มีรูปแบบยีนก่อโรคที่แตกต่างกันอย่างเห็นได้ชัด และพบยีน blaCTX-M, blaTEM, blaOXA ,blaSHV ,ยีน aac, ยีน qnr …