A5003125714- Salmonella and Campylobacter epidemiology
- Viral gastroenteritis research and epidemiology
- Bacteriophages and microbial interactions
- Escherichia coli research studies
- Vibrio bacteria research studies
- Genomics and Phylogenetic Studies
- Listeria monocytogenes in Food Safety
- Bacterial Genetics and Biotechnology
- Plant Pathogenic Bacteria Studies
- Probiotics and Fermented Foods
- Trace Elements in Health
- Veterinary medicine and infectious diseases
- Antibiotic Resistance in Bacteria
- Aquaculture disease management and microbiota
- Infant Nutrition and Health
- Animal Nutrition and Physiology
- Bacterial biofilms and quorum sensing
- Clostridium difficile and Clostridium perfringens research
- Postharvest Quality and Shelf Life Management
- Metal Extraction and Bioleaching
- Peripheral Neuropathies and Disorders
- Plant Pathogens and Fungal Diseases
- Plant-Microbe Interactions and Immunity
- Digestive system and related health
- Child Nutrition and Water Access
United States Department of Agriculture
2015-2025
Agricultural Research Service
2016-2025
Western Regional Research Center
2013-2024
Arizona Western College
2024
University of Arizona
2024
Belmont University
2022
University of the Witwatersrand
2018
Deakin University
2011
Washington State University
2008
U.S. National Poultry Research Center
1999
Sequencing and comparative genome analysis of four strains Campylobacter including C. lari RM2100, upsaliensis RM3195, coli RM2228 has revealed major structural differences that are associated with the insertion phage- plasmid-like genomic islands, as well variations in lipooligosaccharide complex. Poly G tracts longer, greater number, show variability than other species. Many genes involved host colonization, racR/S, cadF, cdt, ciaB, flagellin genes, conserved across species, but appear to...
A survey was initiated to determine the prevalence of Salmonella enterica in environment and around Monterey County, CA, a major agriculture region United States. Trypticase soy broth enrichment cultures samples soil/sediment (n = 617), water 252), wildlife 476), cattle feces 795), preharvest lettuce spinach 261) tested originally for presence pathogenic Escherichia coli were kept frozen storage later used test S. enterica. multipathogen oligonucleotide microarray employed identify subset...
Deletions which removed rfa genes involved in lipopolysaccharide (LPS) core synthesis were constructed vitro and inserted into the chromosome by linear transformation. The deletion delta rfa1, rfaGPBI, resulted a truncated LPS containing two heptose residues but no hexose deep rought phenotype including decreased expression of major outer membrane proteins, hypersensitivity to novobiocin, resistance phage U3. In addition, rfa1 loss flagella pili mucoid colony morphology. Measurement...
Arcobacter butzleri is a member of the epsilon subdivision Proteobacteria and close taxonomic relative established pathogens, such as Campylobacter jejuni Helicobacter pylori. Here we present complete genome sequence human clinical isolate, A. strain RM4018.Arcobacter Campylobacteraceae, but majority its proteome most similar to those Sulfuromonas denitrificans Wolinella succinogenes, both members Helicobacteraceae, deep-sea vent Epsilonproteobacteria Sulfurovum Nitratiruptor. In addition,...
ABSTRACT We describe a multiplex PCR assay to identify and discriminate between isolates of Campylobacter coli , jejuni lari upsaliensis . The C. isolate F38011 lpxA gene, encoding UDP- N -acetylglucosamine acyltransferase, was identified by sequence analysis an expression plasmid that restored wild-type lipopolysaccharide levels in Escherichia strain SM105 [ (Ts)]. With oligonucleotide primers developed the nearly full-length amplicons were amplified from additional 11 20 16 five nucleotide...
This study extends current understanding of the genetic diversity among L. monocytogenes from various food products and processing environments. Application WGS-based strategies facilitated tracking this pathogen importance to human health along production chain while providing insights into pathogenic potential for some isolates recovered. These analyses enabled grouping selected three putative virulence categories according their genotypes with informing selection phenotypic assessment...
Antimicrobial resistant (AMR) Campylobacter is a global health threat, however there limited information on genomic determinants of resistance in low- and middle-income countries. We evaluated AMR using collection whole genome sequenced jejuni C. coli isolates from Iquitos, Peru. two pediatric cohort studies enriched with that demonstrated to ciprofloxacin azithromycin were mined for determinants. The gyrA mutation leading the Thr86Ile amino acid change was only associated fluoroquinolone...
Campylobacter jejuni strains exhibit significant variation in the genetic content of lipooligosaccharide (LOS) biosynthesis loci with concomitant differences LOS structure. The C. have been grouped into six classes based on gene and organization. Utilizing PCR amplifications genes from these loci, we were able to classify a majority (80%) 123 that included 39 Penner serotype reference strains. We found particular class was not always associated specific serotype, 14 16 Guillain-Barré...
ABSTRACT Analysis of the complete genomic sequence Campylobacter jejuni strain RM1221 identified four large elements, - i ntegrated e lements (CJIEs), that were absent from C. NCTC 11168. To further investigate diversity , we conducted a comparative analysis collection 67 and 12 coli strains isolated various geographical locations clinical veterinary sources. Utilizing PCR, demonstrated 55% examined positive for at least one RM1221-like element 27% two or more these CJIEs. Furthermore, many...
ABSTRACT Campylobacter jejuni , a spiral-shaped gram-negative bacterium, is leading bacterial cause of human food-borne illness. Acute disease associated with C. invasion the intestinal epithelium. Further, maximal host cell requires secretion proteins termed antigens (Cia). As bile acids are known to alter pathogenic behavior other gastrointestinal pathogens, we hypothesized that virulence potential may be triggered by acid deoxycholate (DOC). In support this hypothesis, culturing...
ABSTRACT Harvesting and processing of leafy greens inherently cause plant tissue damage, creating niches on leaves that human pathogens can exploit. We previously demonstrated Escherichia coli O157:H7 (EcO157) multiplies more rapidly shredded than intact (M. T. Brandl, Appl. Environ. Microbiol. 74: 5285-5289, 2008). To investigate how EcO157 cells adapt to physicochemical conditions in injured lettuce tissue, we used microarray-based whole-genome transcriptional profiling characterize gene...
Fresh vegetables have been recurrently associated with salmonellosis outbreaks, and Salmonella contamination of retail produce has correlated positively the presence soft rot disease. We observed that population sizes enterica serovar Typhimurium SL1344 increased 56-fold when inoculated alone onto cilantro leaves, versus 2,884-fold coinoculated Dickeya dadantii, a prevalent pathogen macerates plant tissue. A similar trend in S. populations was for soft-rotted lettuce leaves. Transcriptome...
Abstract Background Although serotype O157:H7 is the predominant enterohemorrhagic Escherichia coli (EHEC), outbreaks of non-O157 EHEC that cause severe foodborne illness, including hemolytic uremic syndrome have increased worldwide. In fact, serotypes are now estimated to over half all Shiga toxin-producing (STEC) cases, and infections frequently associated with O26, O45, O103, O111, O121, O145. Currently, there no complete genomes for O145 in public databases. Results We determined genome...
Campylobacter jejuni promotes commensalism in the intestinal tracts of avian hosts and diarrheal disease humans, yet components environments recognized as spatial cues specific for different regions by bacterium to initiate interactions either host are mostly unknown. By analyzing a C. acetogenesis mutant defective converting acetyl coenzyme A (Ac-CoA) acetate commensal colonization young chicks, we discovered evidence vivo microbiota-derived short-chain fatty acids (SCFAs) organic that...
The diarrheal pathogen Campylobacter jejuni and other gastrointestinal bacteria encounter changes in osmolarity the environment, through exposure to food processing, upon entering host organisms, where osmotic adaptation can be associated with virulence. In this study, growth profiles, transcriptomics, phenotypic, mutant, single-cell analyses were used explore effects of hyperosmotic stress on C. jejuni. Increased inhibition correlated increased concentration, both ionic nonionic stressors...
Modern agriculture has dramatically changed the distribution of animal species on Earth. Changes to host ecology have a major impact microbiota, potentially increasing risk zoonotic pathogens being transmitted humans, but intensive livestock production host-associated bacteria rarely been studied. Here, we use large isolate collections and comparative genomics techniques, linked phenotype studies, understand timescale genomic adaptations associated with proliferation most common food-born...
Akkermansia muciniphila is a mucin-degrading bacterium found in the human gut and often associated with positive health. However, despite being detected by as early 1 month of age, little known about role infant gut. Human milk oligosaccharides (HMOs) are abundant components structurally similar to that comprise mucin, preferred growth substrate human-associated Akkermansia. A limited subset intestinal bacteria has been shown grow well on HMOs mucin. We therefore examined ability genomically...
Tn10 insertions were selected on the basis of resistance to lipopolysaccharide (LPS)-specific bacteriophage U3. The majority these located in a 2-kilobase region within rfa locus, gene cluster about 18 kb that contains genes for LPS core biosynthesis. rfa::Tn10 all exhibited deep rough phenotype included hypersensitivity hydrophobic antibiotics, reduction major outer membrane proteins, and production truncated LPS. These mutations complemented by Clarke-Carbon plasmid known complement...
The lipooligosaccharide (LOS) biosynthesis region is one of the more variable genomic regions between strains Campylobacter jejuni. Indeed, eight classes LOS loci have been established previously based on gene content and organization. In this study, we characterize additional analyze various mechanisms that result in changes to structures. To gain further insights into diversity C. jejuni region, sequenced 15 possessed was distinct from classes. This analysis identified 11 new exhibited...
Curli are adhesive fimbriae of Enterobacteriaceae and involved in surface attachment, cell aggregation, biofilm formation. Here, we report that both inter- intrastrain variations curli production widespread enterohemorrhagic Escherichia coli O157:H7. The relative proportions curli-producing variants (C(+)) curli-deficient (C(-)) an E. O157:H7 population varied depending on the growth conditions. In derived from 2006 U.S. spinach outbreak strains, shift between C(+) C(-) subpopulations...
Salmonella cycles between host and nonhost environments, where it can become an active member of complex microbial communities. The role fungi in the environmental adaptation enteric pathogens remains relatively unexplored. We have discovered that S. enterica Typhimurium rapidly attaches to forms biofilms on hyphae common fungus, Aspergillus niger. Several serovars displayed a similar interaction, whereas other bacterial species were unable bind fungus. Bacterial attachment chitin, major...
Campylobacter jejuni is well known for synthesizing ganglioside mimics within the glycan component of its lipooligosaccharide (LOS), which have been implicated in triggering Guillain-Barré syndrome. We now confirm that this pathogen capable a much broader spectrum host glycolipid/glycoprotein LOS. P blood group and paragloboside (lacto-N-neotetraose) antigen mimicry exhibited by RM1221, strain isolated from poultry source. RM1503, gastroenteritis-associated strain, expresses lacto-N-biose...
ABSTRACT Enteropathogenic Escherichia coli (EPEC) continues to be a leading cause of mortality and morbidity in children around the world. Two EPEC genomes have been fully sequenced: those O127:H6 strain E2348/69 (United Kingdom, 1969) O55:H7 CB9615 (Germany, 2003). The serotype is recent precursor virulent enterohemorrhagic E. O157:H7. To explore diversity better understand clonal evolution O157:H7, we sequenced RM12579 (California, 1974), which was collected 1 year before first U.S....
The Campylobacter lari group is a phylogenetic clade within the epsilon subdivision of Proteobacteria and part thermotolerant spp., division genus that includes human pathogen jejuni. C. currently composed five species (C. lari, insulaenigrae, volucris, subantarcticus, peloridis), as well strains termed urease-positive thermophilic (UPTC) other lari-like strains. Here we present complete genome sequences 11 strains, including species, four UPTC strain isolated in this study. subsp. RM2100...
Campylobacter jejuni produces a polysaccharide capsule that is the major determinant of Penner serotyping scheme. This passive slide agglutination typing system was developed in early 1980's and recognized for over two decades as gold standard C. typing. A preliminary multiplex PCR technique covering 17 serotypes previously order to replace this classic Here we report completion technology able identify all 47 types known jejuni. The number represented within 35. We have applied method...