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Full-Text Articles in Life Sciences

Complete Dna Sequence, Comparative Genomics, And Prevalence Of An Inchi2 Plasmid Occurring Among Extraintestinal Pathogenic Escherichia Coli Isolates, Timothy J. Johnson, Yvonne Wannemuehler, Jennifer A. Scaccianoce, Sara J. Johnson, Lisa K. Nolan Nov 2006

Complete Dna Sequence, Comparative Genomics, And Prevalence Of An Inchi2 Plasmid Occurring Among Extraintestinal Pathogenic Escherichia Coli Isolates, Timothy J. Johnson, Yvonne Wannemuehler, Jennifer A. Scaccianoce, Sara J. Johnson, Lisa K. Nolan

Veterinary Microbiology and Preventive Medicine Publications

We have sequenced a large plasmid that occurs among avian pathogenicEscherichia coli isolates. This plasmid, pAPEC-O1-R, is a 241,387-bp IncHI2 plasmid which is cotransmissible via bacterial conjugation with a ColBM virulence plasmid, encodes resistance to eight antimicrobial agents, and appears to occur at low rates among extraintestinal E. coli isolates.


Occurrence Of Pathogenicity Island Iapec-O1 Genes Among Escherichia Coli Implicated In Avian Colibacillosis, Subhashinie Kariyawasam, Timothy J. Johnson, Chitrita Debroy, Lisa K. Nolan Sep 2006

Occurrence Of Pathogenicity Island Iapec-O1 Genes Among Escherichia Coli Implicated In Avian Colibacillosis, Subhashinie Kariyawasam, Timothy J. Johnson, Chitrita Debroy, Lisa K. Nolan

Veterinary Microbiology and Preventive Medicine Publications

Colibacillosis caused by avian pathogenic Escherichia coli (APEC) is a leading cause of economic loss to the poultry industry worldwide. The ability of APEC to cause disease is determined by certain virulence markers, some of which are located on pathogenicity islands (PAIs). We recently described one such PAI in an APEC O1:K1 strain (APEC-O1). This PAI, termed PAI IAPEC-O1, carries the genes of the pap operon, a region similar to the tiainvasion determinant of enterotoxigenic E. coli; ireA, a gene that encodes an iron-responsive element; and a novel 1.5-kb region, ORF 54. Here, the occurrence of ...


Complete Dna Sequence Of A Colbm Plasmid From Avian Pathogenic Escherichia Coli Suggests That It Evolved From Closely Related Colv Virulence Plasmids, Timothy J. Johnson, Sara J. Johnson, Lisa K. Nolan Aug 2006

Complete Dna Sequence Of A Colbm Plasmid From Avian Pathogenic Escherichia Coli Suggests That It Evolved From Closely Related Colv Virulence Plasmids, Timothy J. Johnson, Sara J. Johnson, Lisa K. Nolan

Veterinary Microbiology and Preventive Medicine Publications

Avian pathogenic Escherichia coli (APEC), an extraintestinal pathogenic E. colicausing colibacillosis in birds, is responsible for significant economic losses for the poultry industry. Recently, we reported that the APEC pathotype was characterized by possession of a set of genes contained within a 94-kb cluster linked to a ColV plasmid, pAPEC-O2-ColV. These included sitABCD, genes of the aerobactin operon, hlyF, iss, genes of the salmochelin operon, and the 5′ end ofcvaB of the ColV operon. However, the results of gene prevalence studies performed among APEC isolates revealed that these traits were not always linked to ColV plasmids. Here, we ...


Fitness Of Antimicrobial-Resistant Campylobacter And Salmonella, Qijing Zhang, Orhan Sahin, Patrick F. Mcdermott, Sophie Payot Jun 2006

Fitness Of Antimicrobial-Resistant Campylobacter And Salmonella, Qijing Zhang, Orhan Sahin, Patrick F. Mcdermott, Sophie Payot

Veterinary Microbiology and Preventive Medicine Publications

Campylobacter and Salmonella are the most commonly reported bacterial causes of human foodborne infections, and increasing proportions of these pathogens become resistant to medically important antimicrobial agents, imposing a burden on public health. Acquisition of resistance to antibiotics affects the adaptation and evolution of Salmonella and Campylobacter in various environments. Many resistance-conferring mutations entail a biological fitness cost, while others (e.g. fluoroquinolone resistance in Campylobacter) have no cost or even enhanced fitness. In Salmonella, the fitness disadvantage due to antimicrobial resistance can be restored by acquired compensatory mutations, which occur both in vitro and in vivo. The compensated or ...


Virulence Genotyping Of Salmonella Spp. With Multiplex Pcr, Jerod A. Skyberg, Catherine M. Logue, Lisa K. Nolan Mar 2006

Virulence Genotyping Of Salmonella Spp. With Multiplex Pcr, Jerod A. Skyberg, Catherine M. Logue, Lisa K. Nolan

Veterinary Microbiology and Preventive Medicine Publications

The purpose of this study was to develop a multiplex polymerase chain reaction (PCR) protocol useful in the virulence genotyping of Salmonella spp. with the idea that genotyping could augment current Salmonella characterization and typing methods. Seventeen genes associated with Salmonella invasion, fimbrial production, toxin production, iron transport, and intramacrophage survival were targeted by three PCR reactions. Most of these genes are required for full Salmonella virulence in a murine model, and many are also located onSalmonella pathogenicity islands (PAIs) and are associated with type III secretion systems (TTSSs). Once the success of procedures that used positive and negative ...


The Pap Operon Of Avian Pathogenic Escherichia Coli Strain O1:K1 Is Located On A Novel Pathogenicity Island, Subhashinie Kariyawasam, Timothy J. Johnson, Lisa K. Nolan Jan 2006

The Pap Operon Of Avian Pathogenic Escherichia Coli Strain O1:K1 Is Located On A Novel Pathogenicity Island, Subhashinie Kariyawasam, Timothy J. Johnson, Lisa K. Nolan

Veterinary Microbiology and Preventive Medicine Publications

We have identified a 56-kb pathogenicity island (PAI) in avian pathogenicEscherichia coli strain O1:K1 (APEC-O1). This PAI, termed PAI IAPEC-O1, is integrated adjacent to the 3′ end of the pheV tRNA gene. It carries putative virulence genes of APEC (pap operon), other E. coli genes (tia and ireA), and a 1.5-kb region unique to APEC-O1. The kps gene cluster required for the biosynthesis of polysialic acid capsule was mapped to a location immediately downstream of this PAI.


Dna Sequence Of A Colv Plasmid And Prevalence Of Selected Plasmid-Encoded Virulence Genes Among Avian Escherichia Coli Strains, Timothy J. Johnson, Kylie E. Siek, Sara J. Johnson, Lisa K. Nolan Jan 2006

Dna Sequence Of A Colv Plasmid And Prevalence Of Selected Plasmid-Encoded Virulence Genes Among Avian Escherichia Coli Strains, Timothy J. Johnson, Kylie E. Siek, Sara J. Johnson, Lisa K. Nolan

Veterinary Microbiology and Preventive Medicine Publications

olV plasmids have long been associated with the virulence of Escherichia coli, despite the fact that their namesake trait, ColV production, does not appear to contribute to virulence. Such plasmids or their associated sequences appear to be quite common among avian pathogenic E. coli (APEC) and are strongly linked to the virulence of these organisms. In the present study, a 180-kb ColV plasmid was sequenced and analyzed. This plasmid, pAPEC-O2-ColV, possesses a 93-kb region containing several putative virulence traits, including iss, tsh, and four putative iron acquisition and transport systems. The iron acquisition and transport systems include those encoding aerobactin ...