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- Complement resistance (6)
- Virulence (6)
- Avian colibacillosis (5)
- Iss (5)
- Avian Escherichia coli (4)
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- Escherichia coli (4)
- Analysis of plasmids (2)
- Embryo lethality (2)
- Virulence factors (2)
- Avian (1)
- Cellulitis (1)
- Chicken (1)
- Colibacillosis challenge model (1)
- Colicin V (1)
- Colisepticemia (1)
- Complement-resistance assays (1)
- Embryo lethality assay (1)
- Flow cytometry (1)
- Monoclonal antibody development (1)
- Pathogenic avian Escherichia coli (1)
- Phagocytosis resistance (1)
- R plasmid (1)
- Tsh (1)
- Viable counts (1)
Articles 1 - 25 of 25
Full-Text Articles in Medicine and Health Sciences
Prediction Of Chicken Embryo Lethality With The Avian Escherichia Coli Traits Complement Resistance, Colicin V Production, And Presence Of The Increased Serum Survival Gene Cluster (Iss), Penelope S. Gibbs, John J. Maurer, Lisa K. Nolan, Richard E. Wooley
Prediction Of Chicken Embryo Lethality With The Avian Escherichia Coli Traits Complement Resistance, Colicin V Production, And Presence Of The Increased Serum Survival Gene Cluster (Iss), Penelope S. Gibbs, John J. Maurer, Lisa K. Nolan, Richard E. Wooley
Lisa K. Nolan
Differentiating between virulent and avirulent avian Escherichia coli isolates continues to be a problem for poultry diagnostic laboratories and the study of colibacillosis in poultry. The ability of a laboratory to conduct one simple test that correlates with virulence would simplify studies in these areas; however, previous studies have not enabled researchers to establish such a test. In this study, the occurrence of certain phenotypic and genotypic traits purported to contribute to avian E. coli virulence in 20 avian E. coli isolates was correlated with the results of embryo challenge studies. This analysis was undertaken in an effort to determine …
Characterization Of Integron Mediated Antimicrobial Resistance In Salmonella Isolated From Diseased Swine, David G. White, Shaohua Zhao, Patrick F. Mcdermott, Sherry Ayers, Sharon Friedman, Julie Sherwood, Missy Breider-Foley, Lisa K. Nolan
Characterization Of Integron Mediated Antimicrobial Resistance In Salmonella Isolated From Diseased Swine, David G. White, Shaohua Zhao, Patrick F. Mcdermott, Sherry Ayers, Sharon Friedman, Julie Sherwood, Missy Breider-Foley, Lisa K. Nolan
Lisa K. Nolan
Forty-two Salmonella isolates obtained from diseased swine were genetically characterized for the presence of specific antimicrobial resistance mechanisms. Twenty of these isolates were characterized as S. Typhimurium DT104 strains. Pulsed-field gel electrophoresis was used to determine genetic relatedness and revealed 20 distinct genetic patterns among the 42 isolates. However, all DT104 isolates fell within 2 closely related genetic clusters. Other Salmonella isolates were genetically grouped together according to serotype. All DT104 isolates displayed the penta-resistance phenotype to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline. Resistance to sulfamethoxazole, tetracycline, streptomycin, kanamycin, and ampicillin was most common among the non-DT104 Salmonella isolates. All …
Monoclonal Antibodies To Avian Escherichia Coli Iss, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Thomas R. Gustad, Erick D. Handegard, Michael Robinson, Lisa K. Nolan
Monoclonal Antibodies To Avian Escherichia Coli Iss, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Thomas R. Gustad, Erick D. Handegard, Michael Robinson, Lisa K. Nolan
Lisa K. Nolan
Escherichia coli infections are a major problem for the poultry industry in the United States. Yet, the virulence mechanisms operative in avian E. coli are poorly understood. In the present studies, monoclonal antibodies (MAbs) have been generated that may facilitate study of the pathogenesis of avian colibacillosis. These MAbs are directed against the Iss protein because results from our laboratory have shown that the possession of iss DNA sequences is strongly correlated with the E. coli implicated in avian colibacillosis. As part of an overall effort to explore the role of iss/Iss in colibacillosis pathogenesis, Iss protein has been purified, …
Complement Resistance, As Determined By Viable Count And Flow Cytometric Methods, And Its Association With The Presence Of Iss And The Virulence Of Avian Escherichia Coli, Lisa K. Nolan, Catherine W. Giddings, Shelley M. Horne, Curt Doetkott, Penelope S. Gibbs, Richard E. Wooley, Steven L. Foley
Complement Resistance, As Determined By Viable Count And Flow Cytometric Methods, And Its Association With The Presence Of Iss And The Virulence Of Avian Escherichia Coli, Lisa K. Nolan, Catherine W. Giddings, Shelley M. Horne, Curt Doetkott, Penelope S. Gibbs, Richard E. Wooley, Steven L. Foley
Lisa K. Nolan
Previous work in our labs has shown that avian Escherichia coli virulence is correlated with resistance to complement. Also, our studies have revealed that the presence of the increased serum survival gene (iss), known to contribute to the complement resistance and virulence of mammalian E. coli, may predict the virulent nature of an avian E. coli isolate. This relationship warrants further research, but further clarification of the relationship among virulence, complement resistance, and iss sequences requires use of complement susceptibility assays. Such assays, unfortunately, are labor-intensive, expensive, and difficult to perform. In the present study, the results of two complement …
Location Of Increased Serum Survival Gene And Selected Virulence Traits On A Conjugative R Plasmid In An Avian Escherichia Coli Isolate, Timothy J. Johnson, Catherine W. Giddings, Shelley M. Horne, Penelope S. Gibbs, Richard E. Wooley, Jerod Skyberg, Pam Olah, Ronda Kercher, Julie S. Sherwood, Steven L. Foley, Lisa K. Nolan
Location Of Increased Serum Survival Gene And Selected Virulence Traits On A Conjugative R Plasmid In An Avian Escherichia Coli Isolate, Timothy J. Johnson, Catherine W. Giddings, Shelley M. Horne, Penelope S. Gibbs, Richard E. Wooley, Jerod Skyberg, Pam Olah, Ronda Kercher, Julie S. Sherwood, Steven L. Foley, Lisa K. Nolan
Lisa K. Nolan
Avian colibacillosis is a costly disease for the poultry industry. The mechanisms of virulence employed by the etiologic agent of this disease remain ill defined. However, accumulated evidence suggests that complement resistance and the presence of the increased serum survival gene (iss) in an avian Escherichia coli isolate may be indicative of its ability to cause disease. This association of iss with the E. coli implicated in avian disease may mean that iss and/or, perhaps, the genes associated with it are important contributors to avian E. coli virulence. For this reason, we have begun a search for iss's location in …
Virulence Factors Of Escherichia Coli From Cellulitis Or Colisepticemia Lesions In Chickens, J. S. Jeffrey, Lisa K. Nolan, K. H. Tonooka, S. Wolfe, C. W. Giddings, S. M. Horne, S. L. Foley, A. M. Lynne, J. O. Ebert, L. M. Elijah, G. Bjorklund, S. J. Pfaff-Mcdonough, R. S. Singer, C. Doetkott
Virulence Factors Of Escherichia Coli From Cellulitis Or Colisepticemia Lesions In Chickens, J. S. Jeffrey, Lisa K. Nolan, K. H. Tonooka, S. Wolfe, C. W. Giddings, S. M. Horne, S. L. Foley, A. M. Lynne, J. O. Ebert, L. M. Elijah, G. Bjorklund, S. J. Pfaff-Mcdonough, R. S. Singer, C. Doetkott
Lisa K. Nolan
This study was designed to compare virulence factors of cellulitis-derived Escherichia coli to colisepticemic E. coli in order to clarify whether E. coli associated with cellulitis comprise a unique subset of pathogenic E. coli. Isolates were tested for serotype, capsule, aerobactin production, colicin production, the presence of the iss gene, and serum resistance. Untypable isolates made up the greatest percentage of each group. Serotypes O2 and O78 were the most commonly identified among both groups of isolates. No statistical differences in the distribution of aerobactin or colicin production, capsule, or iss gene were observed between groups. Cluster analysis showed that …
Cloning And Sequencing Of The Iss Gene From A Virulent Avian Escherichia Coli, Shelley M. Horne, Samantha J. Pfaff-Mcdonough, Catherine W. Giddings, Lisa K. Nolan
Cloning And Sequencing Of The Iss Gene From A Virulent Avian Escherichia Coli, Shelley M. Horne, Samantha J. Pfaff-Mcdonough, Catherine W. Giddings, Lisa K. Nolan
Lisa K. Nolan
Control of colibacillosis is important to the poultry industry. We have found that the presence of a gene for increased serum survival, iss, is strongly correlated with Escherichia coli isolated from birds with colibacillosis. Therefore, the iss gene and its protein product, Iss, are potential targets for detection and control of avian colibacillosis. The iss gene was amplified from a virulent avian E. coli isolate and sequenced. The sequences of the gene and the predicted protein product were compared with those of iss from a human E. coli isolate and lambda bor. The iss gene from the avian E. coli …
Iss From A Virulent Avian Escherichia Coli, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Michael Robinson, Lisa K. Nolan
Iss From A Virulent Avian Escherichia Coli, Steven L. Foley, Shelley M. Horne, Catherine W. Giddings, Michael Robinson, Lisa K. Nolan
Lisa K. Nolan
No single characteristic of virulent avian Escherichia coli has been identified that can be exploited in colibacillosis detection protocols. Research in our lab suggests a strong association between the presence of an iss DNA sequence with an isolate's disease-causing ability. The study presented here focuses on the techniques used in the expression, purification, and characterization of avian E. coli Iss protein. In brief, iss was cloned into an expression vector, the construct was transformed into a protease-deficient E. coli, and expression was induced. The protein was expressed as a glutathione-S-transferase (GST) fusion and purified by affinity chromatography. The GST portion …
Complement Resistance-Related Traits Among Escherichia Coli Isolates From Apparently Healthy Birds And Birds With Colibacillosis, Samantha J. Pfaff-Mcdonough, Shelley M. Horne, Catherine W. Giddings, Jessica O. Ebert, Curt Doetkott, M. Herbert Smith, Lisa K. Nolan
Complement Resistance-Related Traits Among Escherichia Coli Isolates From Apparently Healthy Birds And Birds With Colibacillosis, Samantha J. Pfaff-Mcdonough, Shelley M. Horne, Catherine W. Giddings, Jessica O. Ebert, Curt Doetkott, M. Herbert Smith, Lisa K. Nolan
Lisa K. Nolan
In this study, 294 Escherichia coli isolates from birds with colibacillosis were collected from disease outbreaks throughout the United States and were compared with 75 fecal E. coli isolates of apparently healthy chickens by their possession of several purported virulence genes, resistance to rough-lipopolysaccharide-specific bacteriophages (rLPSr), and elaboration of capsule. Traits were selected for study on the basis of their association with complement resistance. The genes targeted in this study included those encoding colicin V (cvaC) and the outer membrane proteins TraT (traT), OmpA (ompA), and Iss (iss). No significant differences were found between the two groups of isolates in …
Further Characterization Of A Complement-Sensitive Mutant Of A Virulent Avian Escherichia Coli Isolate, Theodore J. Kottom, Lisa K. Nolan, Michael Robinson, John Brown, Tom Gustad, Shelley M. Horne, Catherine W. Giddings
Further Characterization Of A Complement-Sensitive Mutant Of A Virulent Avian Escherichia Coli Isolate, Theodore J. Kottom, Lisa K. Nolan, Michael Robinson, John Brown, Tom Gustad, Shelley M. Horne, Catherine W. Giddings
Lisa K. Nolan
An attempt was made to characterize the mechanism of complement resistance operating in a virulent avian Escherichia coli isolate. Using flow cytometry to detect antibody to C3, we found that there was significantly more antibody bound to a complement-sensitive mutant of this wild type than to the parent organism, suggesting that more C3 subunits were bound to the wild type. Neither the wild type nor the mutant degraded C3. Further, the mutant was phagocytosed to a significantly greater degree than the wild type by cultured phagocytes in the presence of C5-deficient serum. These data suggest that the wild type is …
Decreased Intracellular Survival Of An Fkpa Mutant Of Salmonella Typhimurium Copenhagen, Shelley M. Horne, Theodore J. Kottom, Lisa K. Nolan, Kevin D. Young
Decreased Intracellular Survival Of An Fkpa Mutant Of Salmonella Typhimurium Copenhagen, Shelley M. Horne, Theodore J. Kottom, Lisa K. Nolan, Kevin D. Young
Lisa K. Nolan
The fkpA gene of Salmonella typhimurium encodes a protein similar to the macrophage infectivity potentiator (Mip) proteins of Legionella pneumophila and Chlamydia trachomatis. Because Mip proteins enhance the ability of these intracellular pathogens to survive within macrophages and epithelial cells, we tested whether the product of the fkpA gene would have the same effect on the intracellular growth of a virulent strain of S. typhimurium. By a series of P22 transductions, the fkpA gene of S. typhimurium Copenhagen was replaced with the inactive fkpA1::omega-Cm gene from Escherichia coli, creating the mutant S. typhimurium KY32H1. The Copenhagen and KY32H1 strains were …
Large Plasmids Of Avian Escherichia Coli Isolates, Dawn M. Doetkott, Lisa K. Nolan, Catherine W. Giddings, David L. Berryhill
Large Plasmids Of Avian Escherichia Coli Isolates, Dawn M. Doetkott, Lisa K. Nolan, Catherine W. Giddings, David L. Berryhill
Lisa K. Nolan
The plasmid DNA of 30 Escherichia coli isolates from chickens was extracted and examined using techniques designed to isolate large plasmids. This plasmid DNA was examined for the presence of certain known virulence-related genes including cvaC, tra7 and some aerobactin-related sequences. Seventeen of the 30 isolates contained from one to four plasmids greater than 50 kb in size. Eleven of these 17 strains possessed plasmids greater than 100 kb in size. Therefore, E. coli isolates of chickens frequently contain large plasmids, and many of these plasmids are likely to contain virulence related sequences.
Analysis Of Plasmids Cloned From A Virulent Avian Escherichia Coli And Transformed Into Escherichia Coli Dh5Α, Richard E. Wooley, Penelope S. Gibbs, Harry W. Dickerson, John Brown, Lisa K. Nolan
Analysis Of Plasmids Cloned From A Virulent Avian Escherichia Coli And Transformed Into Escherichia Coli Dh5Α, Richard E. Wooley, Penelope S. Gibbs, Harry W. Dickerson, John Brown, Lisa K. Nolan
Lisa K. Nolan
Three of four plasmids from a virulent wild-type avian Escherichia coli were cloned or transformed into an avirulent laboratory recipient E. coli DH5a and tested for the ability to confer a virulence phenotype. The three plasmids transformed into E. coli DH5a were 5, 6, and 56 kb. A fourth plasmid of 64 kb was not successfully transformed. Parameters used to measure virulence included presence of type 1 pili and a smooth lipopolysaccharide (LPS) layer, motility, production of Colicin V, resistance to host complement, and embryo lethality. The 5-kb plasmid encoded for ampicillin resistance, whereas the 6-kb plasmid encoded for tetracycline …
Invasion Of Caco-2 Cells By Salmonella Typhimurium (Copenhagen) Isolates From Healthy And Sick Chickens, Theodore J. Kottom, Lisa K. Nolan, John Brown
Invasion Of Caco-2 Cells By Salmonella Typhimurium (Copenhagen) Isolates From Healthy And Sick Chickens, Theodore J. Kottom, Lisa K. Nolan, John Brown
Lisa K. Nolan
In a previous study, Salmonella isolates of sick birds were distinguished from those of apparently healthy birds by their high degree of invasion of tissue culture cells. In this study, a single pair of Salmonella isolates was examined to determine the source of this observed difference in invasion. When isolates were allowed to invade Caco-2 cells for 8 hours, the isolate from the sick bird (S) appeared to invade in greater numbers than did the isolate from the healthy bird (H). However, when invasion was distinguished from intracellular growth/survival, it was found that H invaded in greater numbers than S, …
Phenotypic Expression Of Recombinant Plasmids Pkt107 And Phk11 In An Avirulent Avian Escherichia Coli, Richard E. Wooley, Lisa K. Nolan, John Brown, Penelope S. Gibbs, Denise I. Bounous
Phenotypic Expression Of Recombinant Plasmids Pkt107 And Phk11 In An Avirulent Avian Escherichia Coli, Richard E. Wooley, Lisa K. Nolan, John Brown, Penelope S. Gibbs, Denise I. Bounous
Lisa K. Nolan
An avirulent wild-type avian Escherichia coli strain (Av) was electrotransformed with plasmids coding for complement resistance (pKT107) and Colicin V (ColV) production (pHK11) in order to study the effects of complement resistance and ColV production on virulence. Transformants were also compared with the wild type for embryo lethality, uptake by macrophages, motility, growth rate, plasmid content, and hemolysis. Growth rates and complement resistance patterns of strain Av and transformant Av+pHK1 1 were similar, but Av+pHK11 caused a significantly greater number of deaths in embryos and acquired motility. Transformant Av+pKT107 had a lower rate of phagocytosis, a slower growth rate, and …
Characterization Of An Avirulent Mutant Of A Virulent Avian Escherichia Coli Isolate, Lisa K. Nolan, Richard E. Wooley, Catherine W. Giddings, John Brown
Characterization Of An Avirulent Mutant Of A Virulent Avian Escherichia Coli Isolate, Lisa K. Nolan, Richard E. Wooley, Catherine W. Giddings, John Brown
Lisa K. Nolan
A virulent, complement-resistant avian Escherichia co/lisolate and its avirulent, complement-sensitive, transposon-insertion mutant were compared for the purpose of revealing structures associated with complement resistance. Both had a smooth lipopolysaccharide layer, contained traT, and lacked a capsule, but the mutant possessed a 16.2-kilodalton outer-membrane protein (OMP) not present in the wild-type. This protein may be the product of a coding region interrupted by transposon insertion. Such results suggest that an OMP greater than 16.2 kilodaltons in size may be responsible for the complement resistance and virulence of this wild-type E. coli.
Effect Of Normal Intestinal Flora Of Chickens On Colonization By Virulent Colicin V-Producing, Avirulent, And Mutant Colicin V-Producing Avian Escherichia Coli, Richard E. Wooley, John Brown, Penelope S. Gibbs, Lisa K. Nolan, Kathy R. Turner
Effect Of Normal Intestinal Flora Of Chickens On Colonization By Virulent Colicin V-Producing, Avirulent, And Mutant Colicin V-Producing Avian Escherichia Coli, Richard E. Wooley, John Brown, Penelope S. Gibbs, Lisa K. Nolan, Kathy R. Turner
Lisa K. Nolan
Colonization of the intestinal tracts of newly hatched chicks with Escherichia coli was attempted by swabbing test organisms onto the air-shell of 19-day-old embryos. Test organisms consisted of two virulent E. coli isolates, one avirulent isolate, and one laboratory-derived mutant of the avirulent isolate carrying a recombinant plasmid coding for Colicin V production. Chicks were cultured weekly for 3 weeks for total E. coliand for the test organisms using selective media. Control chicks were sampled on weeks 1 and 5, and the normal E. coli intestinal microflora were examined for the production of colicins. The two virulent E. coli isolates …
Association Of K-1 Capsule, Smooth Lipopolysaccharides, Trat Gene, And Colicin V Production With Complement Resistance And Virulence Of Avian Escherichia Coli, Richard E. Wooley, Lisa K. Nolan, John Brown, Penelope S. Gibbs, Catherine W. Giddings, Kathy S. Turner
Association Of K-1 Capsule, Smooth Lipopolysaccharides, Trat Gene, And Colicin V Production With Complement Resistance And Virulence Of Avian Escherichia Coli, Richard E. Wooley, Lisa K. Nolan, John Brown, Penelope S. Gibbs, Catherine W. Giddings, Kathy S. Turner
Lisa K. Nolan
A group of complement-resistant, virulent avian Eschberichia coli isolates were compared with a group of complement-sensitive, avirulent avian isolates for the presence of K-1 capsule, smooth lipopolysaccharides (LPS), the traT gene, and Colicin V (ColV) production. These parameters were selected because of their reported association with complement resistance and virulence in E. coli. Lethality in chicken embryos has also been shown to be correlated with virulence of avian E. colifor chickens. The complement-resistant, virulent E. coli isolates did not possess a K-1 capsule. Production of ColV and the presence of smooth LPS were significantly correlated with embryo lethality. There was …
Failure Of The Congo Red Dye Uptake Test To Discriminate Between Virulent And Avirulent Avian Escherichia Coli, Kathy R. Spears, Richard E. Wooley, John Brown, Lisa K. Nolan
Failure Of The Congo Red Dye Uptake Test To Discriminate Between Virulent And Avirulent Avian Escherichia Coli, Kathy R. Spears, Richard E. Wooley, John Brown, Lisa K. Nolan
Lisa K. Nolan
Twenty avian Escherichia coli isolates from normal and diseased chickens were compared by use of three virulence tests. These tests included the uptake of Congo red dye, an embryo lethality test, and a quantitative microtiter complement resistance test. A direct correlation was seen between the results of the complement resistance test and the embryo lethality test. The results of the Congo red test did not correlate with the two other tests.
Relationship Of Complement Resistance And Selected Virulence Factors In Pathogenic Avian Escherichia Coli, Richard E. Wooley, Kathy R. Spears, John Brown, Lisa K. Nolan, Oscar J. Fletcher
Relationship Of Complement Resistance And Selected Virulence Factors In Pathogenic Avian Escherichia Coli, Richard E. Wooley, Kathy R. Spears, John Brown, Lisa K. Nolan, Oscar J. Fletcher
Lisa K. Nolan
Complement resistance, antibiotic resistance profiles, and virulence profiles of 80 Escherichia coli isolates from the intestines of normal chickens (40 isolates) and chickens diagnosed as having colisepticemia (40 isolates) were compared. Differences were observed between the two groups for antibiotic resistance, siderophore production, presence of type 1 pili, complement resistance, motility, and size of plasmids. The systemic isolates were more likely to have siderophores and type 1 pili, and to be complement-resistant and motile than were the intestinal isolates. No differences between the two groups were observed for colicin production. Further comparison of the 10 most complement-resistant isolates from the …
Characteristics Of Conjugative R-Plasmids From Pathogenic Avian Escherichia Coli, Richard E. Wooley, Kathy R. Spears, Lisa K. Nolan, John Brown, Mark A. Dekich
Characteristics Of Conjugative R-Plasmids From Pathogenic Avian Escherichia Coli, Richard E. Wooley, Kathy R. Spears, Lisa K. Nolan, John Brown, Mark A. Dekich
Lisa K. Nolan
Three of four virulent avian Escherichia coli isolates transferred a single large molecular-weight R-plasmid to two recipient E. coli strains. Antibiotic resistances transferred included streptomycin (two isolates) and streptomycin-tetracycline-sulfa (one isolate). Production of colicin and siderophores, complement resistance, and embryo lethality present in the virulent isolates were not transferred to recipient organisms. From the results, it appears that the R-plasmids of these virulent avian E. coli are not associated with virulence.
Comparison Of A Complement Resistance Test, A Chicken Embryo Lethality Test, And The Chicken Lethality Test For Determining Virulence Of Avian Escherichia Coli, Lisa K. Nolan, Richard E. Wooley, John Brown, Kathy R. Spears, H. W. Dickerson, Mark Dekich
Comparison Of A Complement Resistance Test, A Chicken Embryo Lethality Test, And The Chicken Lethality Test For Determining Virulence Of Avian Escherichia Coli, Lisa K. Nolan, Richard E. Wooley, John Brown, Kathy R. Spears, H. W. Dickerson, Mark Dekich
Lisa K. Nolan
Results with four pathogenic avian Escherichia coli isolates and one avirulent isolate in a complement resistance test, a chicken lethality test, and a chicken embryo lethality test were compared. Results of the complement resistance test with these isolates were highly correlated to results of the chicken lethality test of virulence. The chicken embryo test yielded results that were of a medium positive correlation with the chicken lethality results. The results of the complement resistance and chicken embryo lethality tests were highly correlated.
Transposon Mutagenesis Used To Study The Role Of Complement Resistance In The Virulence Of An Avian Escherichia Coli Isolate, Lisa K. Nolan, Richard E. Wooley, Richard K. Cooper
Transposon Mutagenesis Used To Study The Role Of Complement Resistance In The Virulence Of An Avian Escherichia Coli Isolate, Lisa K. Nolan, Richard E. Wooley, Richard K. Cooper
Lisa K. Nolan
The role of complement resistance in the virulence of an avian Escherichia coli isolate was examined with transposon mutagenesis. A suicide plasmid containing a kanamycin-encoding mini-transposon was used to transform a virulent complement-resistant avian E. coli isolate. A less resistant mutant was identified that contained a transposon insertion in a plasmid and in the chromosome. This loss of complement resistance was associated with a drop in virulence in an embryo assay. No other phenotypic changes were detected in the mutant. These results suggest that complement resistance is associated with the virulence of this organism.
Comparison Of A Quantitative Microtiter Method, A Quantitative Automated Method, And The Plate-Count Method For Determining Microbial Complement Resistance, Margie D. Lee, Richard E. Wooley, John Brown, Kathy R. Spears, Lisa K. Nolan, Emmett B. Shotts Jr.
Comparison Of A Quantitative Microtiter Method, A Quantitative Automated Method, And The Plate-Count Method For Determining Microbial Complement Resistance, Margie D. Lee, Richard E. Wooley, John Brown, Kathy R. Spears, Lisa K. Nolan, Emmett B. Shotts Jr.
Lisa K. Nolan
A quantitative microtiter method for determining the degree of complement resistance or sensitivity of microorganisms is described. The microtiter method is compared with a quantitative automated system and the standard plate-count technique. Data were accumulated from 30 avian Escherichia coli isolates incubated at 35 C with either chicken plasma or heat-inactivated chicken plasma. Analysis of data generated by the automated system and plate-count techniques resulted in a classification of the microorganisms into three groups: those sensitive to the action of complement; those of intermediate sensitivity to the action of complement; and those resistant to the action of complement. Although the …
Comparison Of Chicken Plasma And Guinea Pig Serum In A Quantitative Microtiter Method Of Determining Microbial Complement Resistance, Richard E. Wooley, John Brown, Kathy R. Spears, Lisa K. Nolan
Comparison Of Chicken Plasma And Guinea Pig Serum In A Quantitative Microtiter Method Of Determining Microbial Complement Resistance, Richard E. Wooley, John Brown, Kathy R. Spears, Lisa K. Nolan
Lisa K. Nolan
Y. A quantitative microtiter method using chicken plasma is described for determining the degree of complement resistance or sensitivity of avian Escherichia coli isolates. Results obtained with the microtiter method using chicken plasma were compared with results obtained using commercially available standardized guinea pig serum as the source of complement. The test organisms consisted of five isolates of E. coli isolated from chickens. Three isolates were from flocks with colisepticemia; one was from a flock with omphalitis; and one isolate was a non-pathogenic control. Data were accumulated from the five avian E. coli isolates incubated at 35 C with either …