Pulsed-Field Gel Electrophoresis Diversity of Human and Bovine Clinical Salmonella Isolates

Soyer, Yeşim
Schoonmaker-Bopp, Dainna J.
Root, Timothy P.
Warnick, Lorin D.
McDonough, Patrick L.
Dumas, Nellie B.
Groehn, Yrjo T.
Wiedmann, Martin
Pulsed-field gel electrophoresis (PFGE) characterization of 335 temporally and spatially matched clinical, bovine, and human Salmonella enterica subsp. enterica isolates revealed 167 XbaI PFGE patterns. These isolates were previously classified into 51 serotypes and 73 sequence types, as determined by multilocus sequence typing. Discriminatory power of PFGE (Simpson's index, D = 0.991) was considerably higher than that of multilocus sequence typing (D = 0.920) or serotyping (D = 0.913). Although 128 PFGE types each only represented a single isolate, 8 PFGE types represented > 4 isolates, including (i) three serotype Enteritidis and Heidelberg patterns that were only identified among human isolates, (ii) two PFGE patterns (each representing serotypes Bardo and Newport) that were significantly more common among bovine isolates as compared with human isolates; (iii) two PFGE types that each includes two serotypes (4,5,12:i:- and Typhimurium; Thompson and 1,7:-:1,5); and (iv) one PFGE type that includes eight Typhimurium isolates from humans and cattle. Characterization of isolates collected over multiple farm visits indicated that given specific PFGE types persisted over time on 11 farms. On an additional seven farms, isolates with a given sequence type represented multiple PFGE type, which typically only differed by < 3 bands, suggesting PFGE type diversification during strain persistence. Sixteen PFGE types were isolated from 2 or more farms, including two widely distributed serotype Newport-associated PFGE types each found on 10 farms. In six instances two or three human isolates collected in the same county in the same or consecutive months represented the same subtypes, suggesting small human case clusters. PFGE-based characterization and surveillance of human and animal isolates can provide improved understanding of Salmonella diversity and epidemiology, including identification of possible host-associated and common, widely distributed PFGE types.


Multilocus sequence typing supports the hypothesis that cow- and human-associated Salmonella isolates represent distinct and overlapping populations
Alcaine, S. D.; Soyer, Yeşim; Warnick, L. D.; Su, W. -L.; Sukhnanand, S.; Richards, J.; Fortes, E. D.; McDonough, P.; Root, T. P.; Dumas, N. B.; Grohn, Y.; Wiedmann, M. (American Society for Microbiology, 2006-12-01)
A collection of 179 human and 156 bovine clinical Salmonella isolates obtained from across New York state over the course of I year was characterized using serotyping and a multilocus sequence typing (MLST) scheme based on the sequencing of three genes (fimA, manB, and mdh). The 335 isolates were differentiated into 52 serotypes and 72 sequence types (STs). Analyses of bovine isolates collected on different farms over time indicated that specific subtypes can persist over time on a given farm; in particular...
High hydrostatic pressure induced inactivation kinetics of e. coli o157:h7 and s. aureus in carrot juice and analysis of cell volume change
Pilavtepe, Mutlu; Alpas, Hami; Department of Food Engineering (2007)
The main objective of this study was to determine the pressure induced inactivation mechanism of pressure-resistant Escherichia coli O157:H7 933 and Staphylococcus aureus 485 in a low acid food. Firstly, inactivation curves of pathogens were obtained at 200 to 400 MPa at 40ºC in peptone water and carrot juice. First-order and Weibull models were fitted and Weibull model described the inactivation curves of both pathogens more accurately than first-order model, revealing that food systems could exhibit eithe...
Characterization of extracellular beta-lactamases from penicillin G-resistant cells of Streptococcus thermophilus
Chirica, LC; Güray, Nülüfer Tülün; Gültekin, Güzin Candan; Bozoglu, F (International Association for Food Protection, 1998-07-01)
In this study, biochemical properties of two extracellular beta-lactamases produced by penicillin-resistant Streptococcus thermophilus cells were investigated. Both beta-lactamases showed specificity for penicillins but not for cephaloridins. The p-lactamases exhibited different affinities for penicillin G. The one with the higher molecular weight (F1) had a K(m) value of 3.44 mu M and a V(max), value of 8.33, mu mol/min/mg of protein, whereas the beta-lactamase with the lower molecular weight (FII) had a K...
Evaluation of high hydrostatic pressure sensitivity of Staphylococcus aureus and Escherichia coli O157 : H7 by differential scanning calorimetry
Alpas, Hami; BOZOGLU, F; KALETUNC, G (Elsevier BV, 2003-11-01)
Differential scanning calorimetry (DSC) was used to evaluate the relative high hydrostatic pressure (HHP) resistances of bacterial strains from Staphylococcus aureus and Escherichia coli O157:H7 in vivo. The total apparent enthalpy change and thermal stability were two DSC parameters used to compare bacterial strains of untreated control and pressure-treated bacteria. DSC thermograms indicated that ribosomal denaturation appears to be a major factor in cell death by both thermal and high pressure treatments...
Preparation of cross-linked tyrosinase aggregates
Aytar, Burcu Selin; Bakir, Ufuk (Elsevier BV, 2008-02-01)
Tyrosinase from mushroom was immobilized as a cross-linked enzyme aggregate (CLEA) via precipitation with ammonium sulfate and cross-linking with glutaraldehyde. The effects of precipitation and cross-linking on CLEA activity were investigated and the immobilized tyrosinase was characterized. Sixty percent ammonium sulfate saturation and 2% glutaraldehyde were used; a 3-h cross-linking reaction at room temperature, at pH 7.0 was performed; particle sizes of the aggregates were reduced; consequently, 100% ac...
Citation Formats
Y. Soyer et al., “Pulsed-Field Gel Electrophoresis Diversity of Human and Bovine Clinical Salmonella Isolates,” FOODBORNE PATHOGENS AND DISEASE, pp. 707–717, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/38037.