Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
1.
J Med Educ Curric Dev ; 10: 23821205231217894, 2023.
Article in English | MEDLINE | ID: mdl-38106517

ABSTRACT

OBJECTIVES: Medical schools considering longitudinal integrated clerkships (LICs) have access to literature that provides recommendations for planning, implementation, and sustainability. However, LIC development and implementation remain notoriously challenging. University of Utah's LIC development process was informed by the documented experiences of long-established LIC programs. A literature gap was identified pertaining to more recently implemented LICs. The aim of this study was to explore the experiences of faculty in the early stages of LIC development. METHODS: Thirteen representatives from eight LICs implemented after 2015 participated in 2 Zoom focus groups (5 participated in the first and the other 8 participated in the second). Participants were asked questions to assess key supports, barriers, and recommendations. Following the focus groups, participants were asked to rank the responses based on their level of importance. RESULTS: Highest ranked supports included stakeholder and partner involvement; a dedicated coordinator or team; and strong, committed leadership. Highest ranked barriers included difficulty recruiting preceptors and clinical sites; underestimation of the amount of work required to coordinate the LIC; and challenges in providing the needed faculty development. Top recommendations for new LICs included investing in the needs of clinical partners; staffing or assigning a dedicated coordinator early in the development and implementation process; and frequent communication with all stakeholders. CONCLUSION: Despite variation among the types of new LICs represented, there was consensus among participants on the importance of key supports, barriers, and recommendations. Knowledge of these factors can help new schools plan and allocate resources during their LIC development process. Participants found the focus group process and follow-up discussions useful and have formed an ongoing workgroup which meets quarterly.

2.
Acad Pediatr ; 23(2): 351-358, 2023 03.
Article in English | MEDLINE | ID: mdl-35863738

ABSTRACT

BACKGROUND: Current breastfeeding guidelines promote initiating breastfeeding ≤1 h after birth to establish long-term breastfeeding. Previous studies dichotomized initiation to ≤1 h versus subsequent hours combined. There are limited data evaluating the effect of initiation in each subsequent hour on breastfeeding duration. Our objective was to evaluate the association between breastfeeding initiated at ≤1 h versus the subsequent 23 hours after birth and outpatient breastfeeding duration. METHODS: In this retrospective cohort study, we analyzed real-time, discretely documented electronic health record (EHR) breastfeeding data for 3315 infants born at a university center and followed to age ≥12 mo at 27 university primary care clinics. The primary outcome was breastfeeding duration. The exposure variable was hour of breastfeeding initiation within 24 h postnatally. Data were analyzed by univariable and multivariable linear regression separately for infants born by vaginal versus cesarean delivery. RESULTS: In adjusted models, initiating breastfeeding during each hour from age >1 to ≤6 h and during ages >6 to ≤24 h was not associated with decreased breastfeeding duration versus initiating breastfeeding at ≤1 h after birth for infants born via vaginal or cesarean delivery. CONCLUSIONS: Delaying breastfeeding initiation to >1 to ≤24 h after birth is not associated with decreased breastfeeding duration compared with initiating breastfeeding at ≤1 h after birth. Integration of breastfeeding measures into inpatient and outpatient EHR discrete data fields may clarify best practices that support long-term breastfeeding as a public health imperative.


Subject(s)
Breast Feeding , Outpatients , Infant , Female , Pregnancy , Humans , Retrospective Studies , Linear Models
3.
Matern Child Health J ; 26(2): 397-406, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34633615

ABSTRACT

OBJECTIVES: Despite known health benefits of breastfeeding, the Navajo have low reported frequency of breastfeeding initiation and support. We evaluated breastfeeding frequencies and practices in the predominately Navajo community of rural San Juan County, Utah, to identify factors that affect breastfeeding decisions and duration. METHODS: We performed retrospective chart review for 135 infants aged 0 to 12 months, and surveys of 85 mothers of infants aged 0 to 2 years, and eight primary care providers. We characterized demographic factors using counts/percentages and medians/inter-quartile ranges, and compared mothers who breastfed for 6 months or less versus greater than 6 months. RESULTS: In 96 infants with complete feeding documentation, 86 infants (90%) received some breast milk and 36 infants (38%) were exclusively breastfed at age 2 months. In 67 infants with complete feeding documentation at ≥ 6 months, 22 infants (33%) were exclusively breastfed 6 months. Most mothers knew about breastfeeding benefits. In 56 mothers whose infants were aged ≥ 6 months at the time of the survey, breastfeeding for more than 6 months had been planned by 44 mothers (79%) but performed by only 29 mothers (52%). Mothers who breastfed for > 6 months were more likely to have been influenced by WIC and less likely to have introduced formula at an early age. Barriers to breastfeeding included maternal pain, latch difficulties, and concerns about inadequate milk supply. Primary care providers reported limited confidence in providing breastfeeding support but would support telehealth-driven interventions. CONCLUSIONS FOR PRACTICE: Practical, culturally sensitive interventions, including telehealth and improved provider education, may improve breastfeeding outcomes and community health in this underserved population.


Subject(s)
Breast Feeding , Milk, Human , Attitude , Female , Humans , Infant , Mothers , Retrospective Studies , Utah
5.
Acad Pediatr ; 18(2): 196-199, 2018 03.
Article in English | MEDLINE | ID: mdl-29180296

ABSTRACT

OBJECTIVE: To determine whether the 2011 guidelines for universal routine screening for dyslipidemia in children aged 9 to 11 years, published by the Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents and National Heart, Lung, and Blood Institute, are being followed by pediatric primary-care providers. METHODS: Retrospective data were obtained for 63,951 well-child visits (WCV) in children aged 9 to 11 years from 2 health care systems and 1 insurance program from 2009 to 2015. The proportion of WCV that had a lipid panel or total cholesterol test performed within 1 year of the visit was compared for 2009-2011 versus 2013-2015. Associations between demographic variables and lipid screening were evaluated with logistic regression. The frequency of tested children who had abnormal lipid results was evaluated. RESULTS: Only 3.5% of 9- to 11-year WCV had lipid tests performed in association with the visit before and after the guidelines. Of those tested, 43% had an abnormal lipid result. CONCLUSIONS: Utah clinicians rarely follow guidelines for universal lipid screening of children aged 9 to 11. This represents a missed opportunity to identify children at risk for early-onset cardiovascular disease.


Subject(s)
Dyslipidemias/diagnosis , Guideline Adherence/statistics & numerical data , Pediatricians , Physicians, Primary Care , Child , Dyslipidemias/epidemiology , Female , Hispanic or Latino , Humans , Logistic Models , Male , Mass Screening , Medicaid , Multivariate Analysis , Pediatric Obesity/epidemiology , Practice Guidelines as Topic , Retrospective Studies , United States , Utah/epidemiology
6.
Clin Pediatr (Phila) ; 56(14): 1286-1290, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28006979

ABSTRACT

In 2011, an expert National Institutes of Health panel published the "Integrated Guidelines for CV Health and Risk Reduction in Children and Adolescents," which recommended screening all children aged 9 to 11 years for dyslipidemia. It is unknown if this guideline is being followed. We surveyed members of the Utah chapter of the American Academy of Pediatrics to determine whether they performed universal lipid screening at well-child visits (WCV) on their patients at 9,10, or 11 years and how comfortable they were with evaluating and/or managing children with dyslipidemia. Of the 118 respondents who practiced primary care, only 18 (15%) screened all children at WCV; 86 (73%) tested "some," most commonly children who were obese or had a positive family history. 18% were unfamiliar with the guidelines; 28% were familiar with the guidelines but felt they were "inappropriate;" 98 (84%) of the respondents said they were "very or somewhat comfortable" evaluating children with dyslipidemia.


Subject(s)
Dyslipidemias/diagnosis , Guideline Adherence/statistics & numerical data , Mass Screening/statistics & numerical data , Office Visits/statistics & numerical data , Pediatricians/statistics & numerical data , Child , Female , Humans , Male , Surveys and Questionnaires , Utah
8.
Fish Shellfish Immunol ; 26(6): 858-63, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19345267

ABSTRACT

Moritella viscosa is the causative agent of winter ulcer disease in salmonids reared in North-Atlantic countries. In this study the effects of selected M. viscosa antigens on cytotoxicity and pro-inflammatory gene expression in an Atlantic salmon (Salmo salar Linnaeus) macrophage-like cell line (SHK-1) were examined. SHK-1 cells were stimulated with live and heat-killed bacterial cells, extracellular products (ECP) and an extracellular vibriolysin, termed MvP1. Following incubation, cytotoxicity and expression levels of interleukin-1 beta (IL-1 beta) and interleukin-8 (IL-8) were examined at different time points. Both live M. viscosa cells and ECP were cytotoxic, but neither heat-killed cells, nor the MvP1 peptidase caused cell death. Expression levels of both IL-1 beta and IL-8 increased significantly after stimulation with live cells, but heat-killed cells only caused increased IL-8 expression. ECP did not affect IL-1 beta expression, but did stimulate IL-8 expression. The isolated MvP1 peptidase stimulated both IL-1 beta and IL-8 expression at the highest concentration tested. This study reveals a difference in the induction of pro-inflammatory gene expression in salmon SHK-1 cells between live and heat-killed M. viscosa cells, and also that an unknown secreted factor is the main stimulant of IL-beta and IL-8 expression.


Subject(s)
Antigens, Bacterial/immunology , Fish Diseases/microbiology , Moritella/immunology , Salmo salar , Vibrio Infections/veterinary , Animals , Cell Line , Cell Survival/immunology , Fish Diseases/immunology , Gene Expression , Interleukin-1beta/biosynthesis , Interleukin-1beta/genetics , Interleukin-1beta/immunology , Interleukin-8/biosynthesis , Interleukin-8/genetics , Interleukin-8/immunology , Macrophages , Metalloendopeptidases/immunology , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Vibrio Infections/immunology , Vibrio Infections/microbiology
9.
Fish Shellfish Immunol ; 26(1): 91-108, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19038557

ABSTRACT

To investigate the immunological responses of turbot to nodavirus infection or pIC stimulation, we constructed cDNA libraries from liver, kidney and gill tissues of nodavirus-infected fish and examined the differential gene expression within turbot kidney in response to nodavirus infection or pIC stimulation using a turbot cDNA microarray. Turbot were experimentally infected with nodavirus and samples of each tissue were collected at selected time points post-infection. Using equal amount of total RNA at each sampling time, we made three tissue-specific cDNA libraries. After sequencing 3230 clones we obtained 3173 (98.2%) high quality sequences from our liver, kidney and gill libraries. Of these 2568 (80.9%) were identified as known genes and 605 (19.1%) as unknown genes. A total of 768 unique genes were identified. The two largest groups resulting from the classification of ESTs according to function were the cell/organism defense genes (71 uni-genes) and apoptosis-related process (23 uni-genes). Using these clones, a 1920 element cDNA microarray was constructed and used to investigate the differential gene expression within turbot in response to experimental nodavirus infection or pIC stimulation. Kidney tissue was collected at selected times post-infection (HPI) or stimulation (HPS), and total RNA was isolated for microarray analysis. Of the 1920 genes studied on the microarray, we identified a total of 121 differentially expressed genes in the kidney: 94 genes from nodavirus-infected animals and 79 genes from those stimulated with pIC. Within the nodavirus-infected fish we observed the highest number of differentially expressed genes at 24 HPI. Our results indicate that certain genes in turbot have important roles in immune responses to nodavirus infection and dsRNA stimulation.


Subject(s)
Adjuvants, Immunologic/pharmacology , Fish Diseases/immunology , Flatfishes/immunology , Gene Expression Regulation/drug effects , Nodaviridae/physiology , Polynucleotides/pharmacology , RNA Virus Infections/veterinary , Animals , Expressed Sequence Tags , Fish Diseases/virology , Flatfishes/virology , Gills/immunology , Kidney/immunology , Liver/immunology , Molecular Sequence Data , Oligonucleotide Array Sequence Analysis , RNA Virus Infections/immunology
10.
BMC Genomics ; 9: 427, 2008 Sep 18.
Article in English | MEDLINE | ID: mdl-18801193

ABSTRACT

BACKGROUND: Aeromonas salmonicida subsp. salmonicida is a Gram-negative bacterium that is the causative agent of furunculosis, a bacterial septicaemia of salmonid fish. While other species of Aeromonas are opportunistic pathogens or are found in commensal or symbiotic relationships with animal hosts, A. salmonicida subsp. salmonicida causes disease in healthy fish. The genome sequence of A. salmonicida was determined to provide a better understanding of the virulence factors used by this pathogen to infect fish. RESULTS: The nucleotide sequences of the A. salmonicida subsp. salmonicida A449 chromosome and two large plasmids are characterized. The chromosome is 4,702,402 bp and encodes 4388 genes, while the two large plasmids are 166,749 and 155,098 bp with 178 and 164 genes, respectively. Notable features are a large inversion in the chromosome and, in one of the large plasmids, the presence of a Tn21 composite transposon containing mercury resistance genes and an In2 integron encoding genes for resistance to streptomycin/spectinomycin, quaternary ammonia compounds, sulphonamides and chloramphenicol. A large number of genes encoding potential virulence factors were identified; however, many appear to be pseudogenes since they contain insertion sequences, frameshifts or in-frame stop codons. A total of 170 pseudogenes and 88 insertion sequences (of ten different types) are found in the A. salmonicida genome. Comparison with the A. hydrophila ATCC 7966T genome reveals multiple large inversions in the chromosome as well as an approximately 9% difference in gene content indicating instances of single gene or operon loss or gain.A limited number of the pseudogenes found in A. salmonicida A449 were investigated in other Aeromonas strains and species. While nearly all the pseudogenes tested are present in A. salmonicida subsp. salmonicida strains, only about 25% were found in other A. salmonicida subspecies and none were detected in other Aeromonas species. CONCLUSION: Relative to the A. hydrophila ATCC 7966T genome, the A. salmonicida subsp. salmonicida genome has acquired multiple mobile genetic elements, undergone substantial rearrangement and developed a significant number of pseudogenes. These changes appear to be a consequence of adaptation to a specific host, salmonid fish, and provide insights into the mechanisms used by the bacterium for infection and avoidance of host defence systems.


Subject(s)
Aeromonas salmonicida/genetics , Fishes/microbiology , Genome, Bacterial , Aeromonas hydrophila/genetics , Aeromonas salmonicida/pathogenicity , Animals , DNA Transposable Elements , Evolution, Molecular , Sequence Analysis, DNA
11.
Infect Immun ; 76(4): 1445-55, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18212071

ABSTRACT

Aeromonas salmonicida subsp. salmonicida, a bacterial pathogen of Atlantic salmon, has no visible pili, yet its genome contains genes for three type IV pilus systems. One system, Tap, is similar to the Pseudomonas aeruginosa Pil system, and a second, Flp, resembles the Actinobacillus actinomycetemcomitans Flp pilus, while the third has homology to the mannose-sensitive hemagglutinin pilus of Vibrio cholerae. The latter system is likely nonfunctional since eight genes, including the gene encoding the main pilin subunit, are deleted compared with the orthologous V. cholerae locus. The first two systems were characterized to investigate their expression and role in pathogenesis. The pili of A. salmonicida subsp. salmonicida were imaged using atomic force microscopy and Tap- and Flp-overexpressing strains. The Tap pili appeared to be polar, while the Flp pili appeared to be peritrichous. Strains deficient in tap and/or flp were used in live bacterial challenges of Atlantic salmon, which showed that the Tap pilus made a moderate contribution to virulence, while the Flp pilus made little or no contribution. Delivery of the tap mutant by immersion resulted in reduced cumulative morbidity compared with the cumulative morbidity observed with the wild-type strain; however, delivery by intraperitoneal injection resulted in cumulative morbidity similar to that of the wild type. Unlike the pili of other piliated bacterial pathogens, A. salmonicida subsp. salmonicida type IV pili are not absolutely required for virulence in Atlantic salmon. Significant differences in the behavior of the two mutant strains indicated that the two pilus systems are not redundant.


Subject(s)
Aeromonas salmonicida/metabolism , Aeromonas salmonicida/pathogenicity , Fimbriae Proteins/metabolism , Fimbriae, Bacterial/metabolism , Fish Diseases/microbiology , Salmo salar/microbiology , Aeromonas salmonicida/genetics , Animals , Bacterial Adhesion , Fimbriae Proteins/genetics , Mutation , Virulence
12.
Fish Shellfish Immunol ; 23(5): 1095-106, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17658271

ABSTRACT

The cell envelope of Aeromonas salmonicida contains a lipopolysaccharide (LPS) essential for the physical integrity and functioning of bacterial cell membrane. Using a recently developed in-source fragmentation technique, we screened 39 typical and atypical isolates of A. salmonicida and established their O-chain polysaccharide structure by capillary electrophoresis-mass spectrometry (CE-MS), compositional and linkage analyses and comparison to the previously determined O-chain polysaccharide structure of A. salmonicida strain A449. These studies have demonstrated that A. salmonicida isolates fall into three distinct structural types, types A-C, based on chemical structures of their respective O-chain polysaccharide components. Subsequent immunoblotting and serological studies with salmon polyclonal antisera produced to formalin-fixed cells of A. salmonicida strains A449, N4705 and 33659 representing three structural types A-C revealed that variations in the O-chain polysaccharide structure have led to significant serological differences between strains belonging to type A and non-type A, where non-type A species include chemically separated structural types B and C. Due to the presence of common antigenic determinants shared by their respective O-chain polysaccharide components, serological cross-reactions were observed between A. salmonicida strains belonging to structural types B and C. These findings suggest the possibility of developing LPS-based classification system of A. salmonicida sub-species consisting of two serologically distinct types, type A and non-type A.


Subject(s)
Aeromonas salmonicida/chemistry , Aeromonas salmonicida/classification , Lipopolysaccharides/chemistry , Aeromonas salmonicida/isolation & purification , Aeromonas salmonicida/metabolism , Animals , Antibodies, Bacterial/metabolism , Enzyme-Linked Immunosorbent Assay , Fish Diseases/immunology , Fish Diseases/microbiology , Gram-Negative Bacterial Infections/immunology , Gram-Negative Bacterial Infections/microbiology , Gram-Negative Bacterial Infections/veterinary , Immune Sera/metabolism , Immunoblotting , Lipopolysaccharides/metabolism , Mass Spectrometry , Salmon/immunology , Serotyping
13.
BMC Genomics ; 7: 43, 2006 Mar 07.
Article in English | MEDLINE | ID: mdl-16522207

ABSTRACT

BACKGROUND: Aeromonas salmonicida has been isolated from numerous fish species and shows wide variation in virulence and pathogenicity. As part of a larger research program to identify virulence genes and candidates for vaccine development, a DNA microarray was constructed using a subset of 2024 genes from the draft genome sequence of A. salmonicida subsp. salmonicida strain A449. The microarray included genes encoding known virulence-associated factors in A. salmonicida and homologs of virulence genes of other pathogens. We used microarray-based comparative genomic hybridizations (M-CGH) to compare selected A. salmonicida sub-species and other Aeromonas species from different hosts and geographic locations. RESULTS: Results showed variable carriage of virulence-associated genes and generally increased variation in gene content across sub-species and species boundaries. The greatest variation was observed among genes associated with plasmids and transposons. There was little correlation between geographic region and degree of variation for all isolates tested. CONCLUSION: We have used the M-CGH technique to identify subsets of conserved genes from amongst this set of A. salmonicida virulence genes for further investigation as potential vaccine candidates. Unlike other bacterial characterization methods that use a small number of gene or DNA-based functions, M-CGH examines thousands of genes and/or whole genomes and thus is a more comprehensive analytical tool for veterinary or even human health research.


Subject(s)
Aeromonas salmonicida/genetics , Genetic Variation , Virulence Factors/genetics , Aeromonas salmonicida/classification , Aeromonas salmonicida/isolation & purification , Aeromonas salmonicida/pathogenicity , Animals , Fish Diseases/microbiology , Fishes , Genomics/methods , Gram-Negative Bacterial Infections/microbiology , Oligonucleotide Array Sequence Analysis
15.
Vet Immunol Immunopathol ; 109(1-2): 183-7, 2006 Jan 15.
Article in English | MEDLINE | ID: mdl-16112748

ABSTRACT

Toll-like receptors (TLRs) are involved in the innate immune response against microbial pathogens in vertebrates and insects. The extracellular region of a TLR recognizes pathogen-associated molecules, while the intracellular region initiates the signaling pathway leading to immune response. Membrane-bound TLRs have been found in most vertebrates, but few soluble forms have been reported. A novel transcript corresponding to a portion of a soluble TLR was identified in liver of infected Atlantic salmon. The complete coding sequence of this TLR was obtained and BLASTN analysis showed the highest sequence identity to a recently described full-length cDNA sequence of a soluble TLR5 from rainbow trout (GenBank Accession No.: ). The deduced protein is 40% identical to the mammalian counterpart of the leucine-rich repeat (LRR)/LRR-like motifs of TLR5. Based on the structure of human TLRs, it contains 21 LRRs with conserved LxxLxLxxNx*xx*xxxxFxxL pattern. Since TLR5 is essential for the recognition of bacterial flagellins, we hypothesize that flagellin and perhaps some other pathogen-derived factors from Aeromonas salmonicida bind to this soluble TLR through an unknown binding domain within the LRR.


Subject(s)
Aeromonas salmonicida/immunology , Fish Diseases/microbiology , Furunculosis/veterinary , Gram-Negative Bacterial Infections/veterinary , RNA, Messenger/genetics , Salmo salar/genetics , Toll-Like Receptor 5/genetics , Amino Acid Motifs , Amino Acid Sequence , Animals , Base Sequence , Fish Diseases/genetics , Fish Diseases/immunology , Furunculosis/immunology , Furunculosis/microbiology , Gram-Negative Bacterial Infections/genetics , Gram-Negative Bacterial Infections/immunology , Gram-Negative Bacterial Infections/microbiology , Molecular Sequence Data , RNA, Bacterial/chemistry , RNA, Bacterial/genetics , RNA, Messenger/immunology , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Sequence Alignment , Toll-Like Receptor 5/immunology
16.
Fish Shellfish Immunol ; 18(5): 393-415, 2005 May.
Article in English | MEDLINE | ID: mdl-15683917

ABSTRACT

To investigate the response of Atlantic halibut to vaccination and pathogen exposure, a cDNA library was constructed from liver, kidney and spleen mRNA collected following vaccination against Vibrio anguillarum and Aeromonas salmonicida. After sequencing 1114 clones 1072 (96.23%) readable sequences were obtained of which 106 sequences are the first reported from the fish. Of these, 182 clones (16.98%) contained cell/organism defence genes including immunoglobulin light chain, MHC class I and II, interferon consensus sequence binding protein, B-cell receptor-associated protein, early B-cell factor, 10 complement components, heat shock protein 70 and 90, antimicrobial peptides hepcidin type 1 and 2, and CC chemokine (macrophage inflammatory protein-1 beta-like chemokine, MIP-1beta). Expression of MIP-1beta-like was elevated in the kidney and spleen at 1, 2, 7 and 14 days post vaccination. Functional genes involved in cellular processes of hematopoietic tissues were also identified. These results indicate that this cDNA library contains many important genes involved in the immune response, making it an important resource for studying the response of Atlantic halibut to vaccination or pathogen exposure.


Subject(s)
Aeromonas salmonicida , Expressed Sequence Tags , Fish Diseases/prevention & control , Flounder/genetics , Furunculosis/veterinary , Vaccination/veterinary , Vibrio Infections/veterinary , Amino Acid Sequence , Animals , Computational Biology , DNA Primers , Fish Diseases/microbiology , Furunculosis/prevention & control , Gene Library , Immunity/genetics , Kidney/immunology , Kidney/metabolism , Liver/immunology , Liver/metabolism , Molecular Sequence Data , Reverse Transcriptase Polymerase Chain Reaction , Sequence Alignment , Sequence Analysis, DNA , Spleen/immunology , Spleen/metabolism , Vibrio Infections/prevention & control
17.
Eur J Biochem ; 271(22): 4507-16, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15560791

ABSTRACT

Aeromonas salmonicida is a pathogenic aquatic bacterium and the causal agent of furunculosis in salmon. In the course of this study, it was found that when grown in vitro on tryptic soy agar, A. salmonicida strain 80204-1 produced a capsular polysaccharide with the identical structure to that of the lipopolysaccharide O-chain polysaccharide. A combination of 1D and 2D NMR methods, including a series of 1D analogues of 3D experiments, together with capillary electrophoresis-electrospray MS (CE-ES-MS), compositional and methylation analyses and specific modifications was used to determine the structure of these polysaccharides. Both polymers were shown to be composed of linear trisaccharide repeating units consisting of 2-acetamido-2-deoxy-D-galacturonic acid (GalNAcA), 3-[(N-acetyl-L-alanyl)amido]-3,6-dideoxy-D-glucose[3-[(N-acetyl-L-alanyl)amido]-3-deoxy-D-quinovose, Qui3NAlaNAc] and 2-acetamido-2,6-dideoxy-D-glucose (2-acetamido-2-deoxy-D-quinovose, QuiNAc) and having the following structure: [-->3)-alpha-D-GalpNAcA-(1-->3)-beta-D-QuipNAc-(1-->4)-beta-D-Quip3NAlaNAc-(1-]n, where GalNAcA is partly presented as an amide and AlaNAc represents N-acetyl-L-alanyl group. CE-ES-MS analysis of CPS and O-chain polysaccharide confirmed that 40% of GalNAcA was present in the amide form. Direct CE-ES-MS/MS analysis of in vivo cultured cells confirmed the formation of a novel polysaccharide, a structure also formed in vitro, which was previously undetectable in bacterial cells grown within implants in fish, and in which GalNAcA was fully amidated.


Subject(s)
Aeromonas salmonicida/chemistry , Bacterial Capsules/chemistry , O Antigens/chemistry , Aeromonas salmonicida/genetics , Aeromonas salmonicida/growth & development , Aeromonas salmonicida/immunology , Bacterial Capsules/immunology , Carbohydrate Conformation , Carbohydrate Sequence , Molecular Sequence Data , Nuclear Magnetic Resonance, Biomolecular/methods , O Antigens/immunology , Spectrometry, Mass, Electrospray Ionization/methods
18.
Mar Biotechnol (NY) ; 5(6): 545-54, 2003.
Article in English | MEDLINE | ID: mdl-14508654

ABSTRACT

Commercially available human complementary DNA microarrays were used to compare differential expression in the livers of Atlantic salmon ( Salmo salar) infected with Aeromonas salmonicida and of healthy fish. Complementary DNA probes were prepared from total RNA isolated from livers of control salmon and infected salmon by reverse transcription in the presence of (33)P-dCTP and independently hybridized to human GENE-FILTERS GF211 microarrays. Of the 4131 known genes on the microarray, 241 spots gave clearly detectable signals using labeled RNA from the control salmon liver. Of these, 4 spots were consistently found to have a greater than 2-fold increase in infected salmon compared with controls when using the same pair of filters to generate hybridization data from triplicates. These up-regulated genes were ADP/ATP translocase (AAT2), Na(+)/K(+) ATPase, acyloxyacyl hydrolase (AOAH), and platelet-derived growth factor (PDFG-A). A BlastN search revealed an AAT2 homolog from Atlantic salmon, and a reverse transcriptase polymerase chain reaction assay using primers based on this sequence confirmed its up-regulation (approx. 1.8-fold) during early infection. This work demonstrates the feasibility of using human microarrays to facilitate the discovery of differentially expressed genes in Atlantic salmon, for which no homologous microarrays are available.


Subject(s)
Aeromonas , Fish Diseases/microbiology , Gram-Negative Bacterial Infections/veterinary , Oligonucleotide Array Sequence Analysis/methods , Salmo salar/genetics , Up-Regulation , Amino Acid Sequence , Animals , Carboxylic Ester Hydrolases/genetics , DNA Primers , Databases, Genetic , Fish Diseases/genetics , Gene Expression Profiling , Humans , Liver/chemistry , Mitochondrial ADP, ATP Translocases/genetics , Molecular Sequence Data , Platelet-Derived Growth Factor/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Sodium-Potassium-Exchanging ATPase/genetics
SELECTION OF CITATIONS
SEARCH DETAIL
...