@article{faith_kim_azizoglu_kathariou_czuprynski_2012, title={Purine Biosynthesis Mutants (purA and purB) of Serotype 4b Listeria monocytogenes Are Severely Attenuated for Systemic Infection in Intragastrically Inoculated A/J Mice}, volume={9}, ISSN={["1556-7125"]}, DOI={10.1089/fpd.2011.1013}, abstractNote={In this study, we demonstrate that purA and purB transposon mutants of serotype 4b Listeria monocytogenes were severely impaired in their ability to colonize the gastrointestinal tract and cause systemic infection of the spleen, liver, and gallbladder following intragastric inoculation of A/J mice. The mutant strains were also impaired in their ability to multiply within Caco-2 human intestinal epithelial cells. Neither mutant was affected in resistance to synthetic gastric fluid (pH 4.5). These findings indicate that purine biosynthesis is critical for gastrointestinal virulence of L. monocytogenes serotype 4b in mice.}, number={5}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Faith, Nancy G. and Kim, Jae-Won and Azizoglu, Reha and Kathariou, Sophia and Czuprynski, Charles}, year={2012}, month={May}, pages={480–486} }
 @article{cheng_kim_lee_siletzky_kathariou_2010, title={DNA Probes for Unambiguous Identification of Listeria monocytogenes Epidemic Clone II Strains}, volume={76}, ISSN={["1098-5336"]}, DOI={10.1128/aem.03064-09}, abstractNote={ABSTRACT
          
            Listeria monocytogenes
            epidemic clone II (ECII) strains have been responsible for two major multistate outbreaks of food-borne listeriosis in the United States, but their prevalence and ecology remain poorly understood. In this study, we describe DNA probes that unambiguously identify this clonal group. These probes were able to differentiate ECII strains of outbreak, sporadic, or environmental origin from other
            L. monocytogenes
            strains of the same serotype (4b).
          }, number={9}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Cheng, Ying and Kim, J. -W. and Lee, S. and Siletzky, R. M. and Kathariou, S.}, year={2010}, month={May}, pages={3061–3068} }
 @article{gundogdu_lucovsky_chung_kim_nordlund_2009, title={Application of non-linear optical second harmonic generation and X-ray absorption and spectroscopies to defect related properties of Hf silicate and Hf Si oxynitride gate dielectrics}, volume={86}, ISSN={["1873-5568"]}, DOI={10.1016/j.mee.2009.03.004}, abstractNote={Three different Hf oxide based dielectrics have emerged as viable candidates for applications in advanced ULSI devices. This article focuses on two of these: (i) phase separated Hf silicates with (i) 70-85% nano-crystalline HfO2 with a nano-grain size <2nm, and 15-30% ~2nm non-crystalline SiO2 inclusions, and (ii) Hf Si oxynitride alloys, the most promising of which has a composition, (HfO2)0.3(SiO2)0.3(Si3N4)0.4 designated as 3/3/4 Hf SiON. X-ray absorption spectroscopy has been applied to identification of defect associated with vacancy structures in phase separated silicates, and network disruption defects in the Hf Si oxynitrides. Optical second harmonic generation is introduced in this article for the first time as a non-invasive approach for detecting macroscopic strain, that is shown to be absent in these low defect density dielectrics, the phase separated Hf silicates, and Hf Si oxynitrides, but present in HfO2 films, and Hf silicates with lower HfO2 content, e.g., the 40% HfO2 film of this article.}, number={7-9}, journal={MICROELECTRONIC ENGINEERING}, author={Gundogdu, K. and Lucovsky, G. and Chung, K-B. and Kim, J. -W. and Nordlund, D.}, year={2009}, pages={1654–1657} }
 @article{lucovsky_chung_kim_norlund_2009, title={Spectroscopic differentiation between O-atom vacancy and divacancy defects, respectively, in TiO2 and HfO2 by X-ray absorption spectroscopy}, volume={86}, ISSN={["0167-9317"]}, DOI={10.1016/j.mee.2009.03.005}, abstractNote={Defect state features have been detected in second derivative O K edge spectra for thin films of nano-crystalline TiO2 and HfO2. Based on soft X-ray photoelectron band edge spectra, and the occurrence of occupied band edge 4f states in Gd(Sc,Ti)O3, complementary spectroscopic features have been confirmed in the pre-edge (<530 eV) and vacuum continuum (>545 eV) regimes of O K edge spectra. Qualitatively similar spectral features have been obtained for thin films of HfO2 and TiO2, and these have been assigned to defect states associated with vacancies. The two electrons/removed O-atom are not distributed uniformly over the TM atoms defining the vacancy geometry, but instead are localized in equivalent d-states: a d2 state for a Ti monovacancy and a d4 state for a Hf divacancy. This new model for electronic structure provides an unambiguous way to differentiate between monovacancy and divacancy arrangements, as well as immobile (or fixed) and mobile vacancies.}, number={7-9}, journal={MICROELECTRONIC ENGINEERING}, author={Lucovsky, G. and Chung, K-B and Kim, J. -W. and Norlund, D.}, year={2009}, pages={1676–1679} }
 @article{kim_kathariou_2009, title={Temperature-Dependent Phage Resistance of Listeria monocytogenes Epidemic Clone II}, volume={75}, ISSN={["1098-5336"]}, DOI={10.1128/AEM.02480-08}, abstractNote={ABSTRACT
          
            Listeria monocytogenes
            epidemic clone II (ECII) has been responsible for two multistate outbreaks in the United States in 1998-1999 and in 2002, in which contaminated ready-to-eat meat products (hot dogs and turkey deli meats, respectively) were implicated. However, ecological adaptations of ECII strains in the food-processing plant environment remain unidentified. In this study, we found that broad-host-range phages, including phages isolated from the processing plant environment, produced plaques on ECII strains grown at 37°C but not when the bacteria were grown at lower temperatures (30°C or below). ECII strains grown at lower temperatures were resistant to phage regardless of the temperature during infection and subsequent incubation. In contrast, the phage susceptibility of all other tested strains of serotype 4b (including epidemic clone I) and of strains of other serotypes and
            Listeria
            species was independent of the growth temperature of the bacteria. This temperature-dependent phage susceptibility of ECII bacteria was consistently observed with all surveyed ECII strains from outbreaks or from processing plants, regardless of the presence or absence of cadmium resistance plasmids. Phages adsorbed similarly on ECII bacteria grown at 25°C and at 37°C, suggesting that resistance of ECII strains grown at 25°C was not due to failure of the phage to adsorb. Even though the underlying mechanisms remain to be elucidated, temperature-dependent phage resistance may represent an important ecological adaptation of
            L. monocytogenes
            ECII in processed, cold-stored foods and in the processing plant environment, where relatively low temperatures prevail.
          }, number={8}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Kim, Jae-Won and Kathariou, Sophia}, year={2009}, month={Apr}, pages={2433–2438} }
 @article{kim_siletzky_kathariou_2008, title={Host Ranges of Listeria-Specific Bacteriophages from the Turkey Processing Plant Environment in the United States}, volume={74}, ISSN={["1098-5336"]}, DOI={10.1128/AEM.01282-08}, abstractNote={ABSTRACT
          
            Even though at least 400
            Listeria
            phages have been isolated from various sources, limited information is available on phages from the food processing plant environment. Phages in the processing plant environment may play critical roles in determining the
            Listeria
            population that becomes established in the plant. In this study, we pursued the isolation of
            Listeria
            -specific phages from environmental samples from four turkey processing plants in the United States. These environmental samples were also utilized to isolate
            Listeria
            spp. Twelve phages were isolated and classified into three groups in terms of their host range. Of these, nine (group 1) showed a wide host range, including multiple serotypes of
            Listeria monocytogenes
            , as well as other
            Listeria
            spp. (
            L. innocua
            ,
            L. welshimeri
            ,
            L. seeligeri
            , and
            L. ivanovii
            ). The remaining phages mostly infected
            L. monocytogenes
            serotype 4b as well as
            L. innocua
            ,
            L. ivanovii
            , and/or
            L. welshimeri
            . All but one of the strains of the serotype 4b complex (4b, 4d, 4e) from the processing plant environment could be readily infected by the wide-host-range phages isolated from the environment of the processing plants. However, many strains of other serotypes (1/2a [or 3a] and 1/2b [or 3b]), which represented the majority of
            L. monocytogenes
            strains isolated from the environmental samples, were resistant to infection by these phages. Experiments with two phage-resistant strains showed reduced phage adsorption onto the host cells. These findings suggest that phage resistance may be an important component of the ecology of
            L. monocytogenes
            in the turkey processing plants.
          }, number={21}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Kim, Jae-Won and Siletzky, Robin M. and Kathariou, Sophia}, year={2008}, month={Nov}, pages={6623–6630} }