Comparison of virulence factors and R plasmids of Salmonella spp. isolated from healthy and ill swine

Simmons, Karen; Wooley, Richard E.; Brown, John

doi:10.1128/aem.54.3.760-767.1988

Cited by 19 publications

(4 citation statements)

References 18 publications

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“…These classes of antimicrobial agents are normally administered to poultry in Greece either as therapeutic agents or in subtherapeutic doses in premixed form. As has been shown previously, such regimens increase the susceptibility to infections due to antimicrobial agent-resistant strains of Salmonella (24,29,30), thus aggravating the cost of potential treatment. Ampicillin resistance presents an additional problem not restricted to veterinary and food industry concerns, since, after 1991, the highest rates of resistance of human as well as animal isolates were to ampicillin.…”

Section: Discussionmentioning

confidence: 90%

Molecular epidemiology of antibiotic resistance of Salmonella enteritidis during a 7-year period in Greece

et al. 1997

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A significant increase in the frequency of isolation of Salmonella enteritidis has been observed during recent years in Greece, parallelled by an increasing rate of resistance of this organism to antibiotics. A substantial proportion of ampicillin-and doxycycline-resistant isolates exhibited cross-resistance to drugs of other classes, such as sulfonamides and streptomycin. Isolates of human origin were overall less resistant than those of animal or food-feed origin. Indeed, strains associated with animal infections were characterized by the highest rates of resistance to several antibiotics. These phenotypic data were correlated with genotypic information concerning two distinct populations: isolates from all sources that were resistant only to ampicillin, the drug toward which resistance rates were highest, and a control group of sensitive isolates. Ampicillin resistance was due to a 34-MDa conjugative plasmid. DNA fingerprinting by macrorestriction of genomic DNA revealed two types, A and B, common to both ampicillin-resistant and-sensitive strains, with 80 to 90% of strains being of type A. However, a third type, C, was specific for the sensitive population, representing 17% of those strains. Therefore, although the majority of resistant isolates were genetically related to sensitive ones, there existed a susceptible clone which had not acquired any resistance traits.

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Section: Discussionmentioning

confidence: 90%

Molecular epidemiology of antibiotic resistance of Salmonella enteritidis during a 7-year period in Greece

et al. 1997

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“…Our data showed that 35% Salmonella isolates ( n = 32) were positive for cib among 92 isolates examined [68]. Ability of colicin production may provide competitive colonization advantage to pathogen including Salmonella [69, 70].…”

Section: Discussionmentioning

confidence: 99%

Global transcriptomic analyses of Salmonella enterica in Iron-depleted and Iron-rich growth conditions

Khajanchi

Grim

et al. 2019

BMC Genomics

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Background Salmonella enterica possess several iron acquisition systems, encoded on the chromosome and plasmids. Recently, we demonstrated that incompatibility group (Inc) FIB plasmid-encoded iron acquisition systems (Sit and aerobactin) likely play an important role in persistence of Salmonella in human intestinal epithelial cells (Caco-2). In this study, we sought to determine global transcriptome analyses of S. enterica in iron-rich (IR) and iron-depleted (ID) growth conditions. Results The number of differentially-expressed genes were substantially higher for recipient (SE819) ( n = 966) and transconjugant (TC) ( n = 945) compared to the wild type (WT) (SE163A) ( n = 110) strain in ID as compared to IR growth conditions. Several virulence-associated factors including T3SS, flagellin, cold-shock protein ( cspE ), and regulatory genes were upregulated in TC in ID compared to IR conditions. Whereas, IS1 and acrR / tetR transposases located on the IncFIB plasmid, ferritin and several regulatory genes were downregulated in TC in ID conditions. Enterobactin transporter ( entS ), iron ABC transporter ( fepCD ), colicin transporter, IncFIB-encoded enolase, cyclic di-GMP regulator ( cdgR ) and other regulatory genes of the WT strain were upregulated in ID compared to IR conditions. Conversely, ferritin, ferrous iron transport protein A ( feoA ), IncFIB-encoded IS1 and acrR / tetR transposases and ArtA toxin of WT were downregulated in ID conditions. SDS-PAGE coupled with LC-MS/MS analyses revealed that siderophore receptor proteins such as chromosomally-encoded IroN and, IncFIB-encoded IutA were upregulated in WT and TC in ID growth conditions. Both chromosome and IncFIB plasmid-encoded SitA was overexpressed in WT, but not in TC or recipient in ID conditions. Increased expression of flagellin was detected in recipient and TC, but not in WT in ID conditions. Conclusion Iron concentrations in growth media influenced differential gene expressions both at transcriptional and translational levels, including genes encoded on the IncFIB plasmid. Limited iron availability within the host may promote pathogenic Salmonella to differentially express subsets of genes encoded by chromosome and/or plasmids, facilitating establishment of successful infection. Electronic supplementary material The online version of this article (10.1186/s12864-019-5768-0) contains supplementary material, which is available to authorized users.

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“…Plates were incubated for 24 and 48 hours at 37 C and examined for growth around the wells. 13 Bacterial resistance to chicken complement-Chicken plasma was obtained from 7-week-old chickens that were negative for Salmonella antibodies.17 The lytic activity of chicken complement on the test organisms was monitored by the inoculation of 20 f-il of the test organism containing 5 x 106 colony-forming units into 1 ml of chicken plasma and 1 ml of heat-inactivated plasma (56 C for 30 minutes).17'18 Suspensions were placed in a quantitative, automated systemd and bacterial lysis or growth was recorded by changes in optical density every 15 minutes for 240 minutes.17 '18 Mannose-sensitive hemagglutination tests-The ability of the test strains to hemagglutinate erythrocytes was tested in 96-well round-bottom micro titration plates with a 3% suspension of guinea pig or chicken erythrocytes in a 0.85% NaCl solution. Combinations of 25 JJL!…”

Section: Methodsmentioning

confidence: 99%

“…Plasmid screening-Plasmids were isolated from the test organisms by the method of Kado and Liu.20 Plasmid DNA was then analyzed by agarose gel electrophoresis. 13 Bacterial matings and selection of transconjugants-The R plasmids were transferred by mixing 0.2 ml of exponentially grown donor cells with 1.8 ml of an overnight culture of recipient cells in antibiotic medium 3e broth. Mixtures were incubated at 25 C, 37 C, and 42 C for 18 hours.…”

Section: Methodsmentioning

confidence: 99%

Comparison of phenotypic characteristics of Salmonella spp isolated from healthy and ill (infected) chickens

Nolan,

Wooley,

Brown

et al. 1991

ajvr

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Summary Phenotypic characteristics of 12 paired, Salmonella serotypes isolated from healthy and ill chickens were compared. Variables compared included antibiotic resistance profiles, production of colicins and siderophores, mannose-sensitive hemagglutination of erythrocytes, resistance to serum complement, carbon source utilization, presence and transmissibility of R plasmids, and invasiveness in primary chicken kidney cell culture. Differences were found between pairs for utilization of carbon sources, mannose-sensitive hemagglutination of erythrocytes, and invasiveness in cell culture.

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Comparison of virulence factors and R plasmids of Salmonella spp. isolated from healthy and ill swine

Cited by 19 publications

References 18 publications

Molecular epidemiology of antibiotic resistance of Salmonella enteritidis during a 7-year period in Greece

Molecular epidemiology of antibiotic resistance of Salmonella enteritidis during a 7-year period in Greece

Global transcriptomic analyses of Salmonella enterica in Iron-depleted and Iron-rich growth conditions

Comparison of phenotypic characteristics of Salmonella spp isolated from healthy and ill (infected) chickens

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