@article{levine_apperson_levin_kelly_kakumanu_ponnusamy_sutton_salger_caldwell_szempruch_2017, title={Stable Transmission of Borrelia burgdorferi Sensu Stricto on the Outer Banks of North Carolina}, volume={64}, ISSN={1863-1959}, url={http://dx.doi.org/10.1111/zph.12302}, DOI={10.1111/zph.12302}, abstractNote={SummaryThe spirochaete (Borrelia burgdorferi) associated with Lyme disease was detected in questing ticks and rodents during a period of 18 years, 1991–2009, at five locations on the Outer Banks of North Carolina. The black‐legged tick (Ixodes scapularis) was collected at varied intervals between 1991 and 2009 and examined for B. burgdorferi. The white‐footed mouse (Peromyscus leucopus), house mouse (Mus musculus) marsh rice rat (Oryzomys palustris), marsh rabbit (Sylvilagus palustris), eastern cottontail (Sylvilagus floridanus) and six‐lined racerunner (Cnemidophorus sexlineatus) were live‐trapped, and their tissues cultured to isolate spirochaetes. Borrelia burgdorferi isolates were obtained from questing adult I. scapularis and engorged I. scapularis removed from P. leucopus, O. palustris and S. floridanus. The prevalence of B. burgdorferi infection was variable at different times and sites ranging from 7 to 14% of examined questing I. scapularis. Mitochondrial (16S) rRNA gene phylogenetic analysis from 65 adult I. scapularis identified 12 haplotypes in two major clades. Nine haplotypes were associated with northern/Midwestern I. scapularis populations and three with southern I. scapularis populations. Sixteen isolates obtained from tick hosts in 2005 were confirmed to be B. burgdorferi by amplifying and sequencing of 16S rRNA and 5S‐23S intergenic spacer fragments. The sequences had 98–99% identity to B. burgdorferi sensu stricto strains B31, JD1 and M11p. Taken together, these studies indicate that B. burgdorferi sensu stricto is endemic in questing I. scapularis and mammalian tick hosts on the Outer Banks of North Carolina.}, number={5}, journal={Zoonoses and Public Health}, publisher={Wiley}, author={Levine, J. F. and Apperson, C. S. and Levin, M. and Kelly, T. R. and Kakumanu, M. L. and Ponnusamy, L. and Sutton, H. and Salger, S. A. and Caldwell, J. M. and Szempruch, A. J.}, year={2017}, month={Aug}, pages={337–354} } @article{caldwell_pérez-díaz_sandeep_simunovic_harris_osborne_hassan_2015, title={Mitochondrial DNA Fragmentation as a Molecular Tool to Monitor Thermal Processing of Plant-Derived, Low-Acid Foods, and Biomaterials}, volume={80}, ISSN={0022-1147}, url={http://dx.doi.org/10.1111/1750-3841.12937}, DOI={10.1111/1750-3841.12937}, abstractNote={AbstractCycle threshold (Ct) increase, quantifying plant‐derived DNA fragmentation, was evaluated for its utility as a time‐temperature integrator. This novel approach to monitoring thermal processing of fresh, plant‐based foods represents a paradigm shift. Instead of using quantitative polymerase chain reaction (qPCR) to detect pathogens, identify adulterants, or authenticate ingredients, this rapid technique was used to quantify the fragmentation of an intrinsic plant mitochondrial DNA (mtDNA) gene over time‐temperature treatments. Universal primers were developed which amplified a mitochondrial gene common to plants (atp1). These consensus primers produced a robust qPCR signal in 10 vegetables, 6 fruits, 3 types of nuts, and a biofuel precursor. Using sweet potato (Ipomoea batatas) puree as a model low‐acid product and simple linear regression, Ct value was highly correlated to time‐temperature treatment (R2 = 0.87); the logarithmic reduction (log CFU/mL) of the spore‐forming Clostridium botulinum surrogate, Geobacillus stearothermophilus (R2 = 0.87); and cumulative F‐value (min) in a canned retort process (R2 = 0.88), all comparisons conducted at 121 °C. D121 and z‐values were determined for G. stearothermophilus ATCC 7953 and were 2.71 min and 11.0 °C, respectively. D121 and z‐values for a 174‐bp universal plant amplicon were 11.3 min and 9.17 °C, respectively, for mtDNA from sweet potato puree. We present these data as proof‐of‐concept for a molecular tool that can be used as a rapid, presumptive method for monitoring thermal processing in low‐acid plant products.}, number={8}, journal={Journal of Food Science}, publisher={Wiley}, author={Caldwell, Jane M. and Pérez-Díaz, Ilenys M. and Sandeep, KP and Simunovic, Josip and Harris, Keith and Osborne, Jason A. and Hassan, Hosni M.}, year={2015}, month={Jul}, pages={M1804–M1814} } @article{caldwell_pérez-díaz_harris_hassan_simunovic_sandeep_2015, title={Mitochondrial DNA Fragmentation to Monitor Processing Parameters in High Acid, Plant-Derived Foods}, volume={80}, ISSN={0022-1147}, url={http://dx.doi.org/10.1111/1750-3841.13139}, DOI={10.1111/1750-3841.13139}, abstractNote={AbstractMitochondrial DNA (mtDNA) fragmentation was assessed in acidified foods. Using quantitative polymerase chain reaction, Ct values measured from fresh, fermented, pasteurized, and stored cucumber mtDNA were determined to be significantly different (P > 0.05) based on processing and shelf‐life. This indicated that the combination of lower temperature thermal processes (hot‐fill at 75 °C for 15 min) and acidified conditions (pH = 3.8) was sufficient to cause mtDNA fragmentation. In studies modeling high acid juices, pasteurization (96 °C, 0 to 24 min) of tomato serum produced Ct values which had high correlation to time‐temperature treatment. Primers producing longer amplicons (approximately 1 kb) targeting the same mitochondrial gene gave greater sensitivity in correlating time‐temperature treatments to Ct values. Lab‐scale pasteurization studies using Ct values derived from the longer amplicon differentiated between heat treatments of tomato serum (95 °C for <2 min). MtDNA fragmentation was shown to be a potential new tool to characterize low temperature (<100 °C) high acid processes (pH < 4.6), nonthermal processes such as vegetable fermentation and holding times of acidified, plant‐derived products.}, number={12}, journal={Journal of Food Science}, publisher={Wiley}, author={Caldwell, Jane M. and Pérez-Díaz, Ilenys M. and Harris, Keith and Hassan, Hosni M. and Simunovic, Josip and Sandeep, K.P.}, year={2015}, month={Nov}, pages={M2892–M2898} } @article{nawalakhe_shi_vitchuli_noar_caldwell_breidt_bourham_zhang_mccord_2013, title={Novel atmospheric plasma enhanced chitosan nanofiber/gauze composite wound dressings}, volume={129}, ISSN={0021-8995}, url={http://dx.doi.org/10.1002/app.38804}, DOI={10.1002/app.38804}, abstractNote={AbstractElectrospun chitosan nanofibers were deposited onto atmospheric plasma treated cotton gauze to create a novel composite bandage with higher adhesion, better handling properties, enhanced bioactivity, and moisture management. Plasma treatment of the gauze substrate was performed to improve the durability of the nanofiber/gauze interface. The chitosan nanofibers were electrospun at 3–7% concentration in trifluoroacetic acid. The composite bandages were analyzed using peel, gelbo flex, antimicrobial assay, moisture vapor transmission rate, X‐ray photoelectron spectroscopy (XPS), absorbency, and air permeability tests. The peel test showed that plasma treatment of the substrate increased the adhesion between nanofiber layers and gauze substrate by up to four times. Atmospheric plasma pretreatment of the gauze fabric prior to electrospinning significantly reduced degradation of the nanofiber layer due to repetitive flexing. The chitosan nanofiber layer contributes significantly to the antimicrobial properties of the bandage. Air permeability and moisture vapor transport were reduced due to the presence of a nanofiber layer upon the substrate. XPS of the plasma treated cotton substrate showed formation of active sites on the surface, decrease in carbon content, and increase in oxygen content as compared to the untreated gauze. Deposition of chitosan nanofibers also increased the absorbency of gauze substrate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013}, number={2}, journal={Journal of Applied Polymer Science}, publisher={Wiley}, author={Nawalakhe, Rupesh and Shi, Quan and Vitchuli, Narendiran and Noar, Jesse and Caldwell, Jane M. and Breidt, Frederick and Bourham, Mohamed A. and Zhang, Xiangwu and McCord, Marian G.}, year={2013}, month={Feb}, pages={916–923} } @article{shi_vitchuli_nowak_jiang_caldwell_breidt_bourham_zhang_mccord_2012, title={Multifunctional and durable nanofiber-fabric-layered composite for protective application}, volume={128}, ISSN={0021-8995}, url={http://dx.doi.org/10.1002/app.38465}, DOI={10.1002/app.38465}, abstractNote={AbstractA multifunctional and durable nanofiber‐fabric‐layered composite (NFLC) material was prepared by depositing electrospun Ag/PAN hybrid nanofibers onto a Nylon/cotton 50: 50 fabric substrate. The NFLCs showed excellent aerosol barrier efficiency and good air/moisture permeability. In addition, they showed excellent antibacterial efficiency by completely inhibiting the growth of both Gram‐negative E. coli and Gram‐positive S. aureus. The interfacial adhesion between the nanofiber layer and fabric substrate was significantly improved by atmospheric plasma pretreatment of the substrate. The resultant NFLCs showed excellent resistance to peeling, twisting, and flexing forces. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013}, number={2}, journal={Journal of Applied Polymer Science}, publisher={Wiley}, author={Shi, Quan and Vitchuli, Narendiran and Nowak, Joshua and Jiang, Shan and Caldwell, Jane M. and Breidt, Frederick and Bourham, Mohamed and Zhang, Xiangwu and McCord, Marian}, year={2012}, month={Sep}, pages={1219–1226} } @article{shi_vitchuli_nowak_caldwell_breidt_bourham_zhang_mccord_2011, title={Durable antibacterial Ag/polyacrylonitrile (Ag/PAN) hybrid nanofibers prepared by atmospheric plasma treatment and electrospinning}, volume={47}, ISSN={["1873-1945"]}, url={https://publons.com/publon/3117884/}, DOI={10.1016/j.eurpolymj.2011.04.002}, abstractNote={Durable antibacterial Ag/polyacrylonitrile (Ag/PAN) hybrid nanofibers were prepared by atmospheric plasma treatment and electrospinning. Atmospheric helium plasma treatment was first used to reduce the AgNO3 precursor in pre-electrospinning solutions into metallic silver nanoparticles, followed by electrospinning into continuous and smooth nanofibers with Ag nanoparticles embedded in the matrix. SEM, TEM, and EDX spectra were used to study the structure and surface elemental composition of the nanofibers. Silver nanoparticles, with diameters ranging between 3 and 6 nm, were found to be uniformly dispersed in the nanofiber matrix. The Ag/PAN nanofibers exhibited slow and long-lasting silver ion release, which provided robust antibacterial activity against both Gram-positive Bacillus cereus and Gram-negative Escherichia coli microorganisms.}, number={7}, journal={EUROPEAN POLYMER JOURNAL}, author={Shi, Quan and Vitchuli, Narendiran and Nowak, Joshua and Caldwell, Jane M. and Breidt, Frederick and Bourham, Mohamed and Zhang, Xiangwu and McCord, Marian}, year={2011}, month={Jul}, pages={1402–1409} } @article{vitchuli_shi_nowak_kay_caldwell_breidt_bourham_mccord_zhang_2011, title={Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning-electrospraying hybrid process for use in protective applications}, volume={12}, ISSN={["1468-6996"]}, url={https://publons.com/publon/3117882/}, DOI={10.1088/1468-6996/12/5/055004}, abstractNote={Abstract ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99%) against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95%) against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning–electrospraying hybrid process are promising material candidates for protective applications.}, number={5}, journal={SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS}, author={Vitchuli, Narendiran and Shi, Quan and Nowak, Joshua and Kay, Kathryn and Caldwell, Jane M. and Breidt, Frederick and Bourham, Mohamed and McCord, Marian and Zhang, Xiangwu}, year={2011}, month={Oct} } @article{shi_vitchuli_nowak_noar_caldwell_breidt_bourham_mccord_zhang_2011, title={One-step synthesis of silver nanoparticle-filled nylon 6 nanofibers and their antibacterial properties}, volume={21}, ISSN={["1364-5501"]}, url={https://publons.com/publon/274770/}, DOI={10.1039/c1jm11492a}, abstractNote={A novel and facile one-step approach to in situ synthesize silver nanoparticle-filled nylon 6 nanofibers by electrospinning is reported. The method does not need post-treatments and can be carried out at ambient conditions without using additional chemicals. It employs the electrospinning solvent as a reducing agent for in situ conversion of AgNO3 into silver nanoparticles during the solution preparation. The resultant silver nanoparticle-filled nylon 6 hybrid nanofibers show an excellent fibrous structure (fiber diameter at 50–150 nm), with narrow size 2–4 nm silver nanoparticles uniformly dispersed throughout the nylon 6 matrix. DSC analysis shows that the in situ incorporation of silver nanoparticles increased the Tg and crystallinity of the resultant nanofibers. These silver nanoparticle-filled nylon 6 nanofibers exhibit a steady and long-lasting silver ion release behavior, and robust antibacterial activity against both Gram-positive B. cereus and Gram-negative E. coli microorganisms.}, number={28}, journal={JOURNAL OF MATERIALS CHEMISTRY}, author={Shi, Quan and Vitchuli, Narendiran and Nowak, Joshua and Noar, Jesse and Caldwell, Jane M. and Breidt, Frederick and Bourham, Mohamed and McCord, Marian and Zhang, Xiangwu}, year={2011}, pages={10330–10335} } @article{breidt_caldwell_2011, title={Survival of Escherichia coli O157:H7 in cucumber fermentation brines}, volume={76}, DOI={10.1111/j.1750-3841.2011.02045.x}, abstractNote={Abstract:  Bacterial pathogens have been reported on fresh cucumbers and other vegetables used for commercial fermentation. The Food and Drug Administration currently has a 5‐log reduction standard for E. coli O157:H7 and other vegetative pathogens in acidified pickle products. For fermented vegetables, which are acid foods, there is little data documenting the conditions needed to kill acid resistant pathogens. To address this knowledge gap, we obtained 10 different cucumber fermentation brines at different stages of fermentation from 5 domestic commercial plants. Cucumber brines were used to represent vegetable fermentations because cabbage and other vegetables may have inhibitory compounds that may affect survival. The 5‐log reduction times for E. coli O157:H7 strains in the commercial brines were found to be positively correlated with brine pH, and ranged from 3 to 24 d for pH values of 3.2 to 4.6, respectively. In a laboratory cucumber juice medium that had been previously fermented with Lactobacillus plantarum or Leuconostoc mesenteroides (pH 3.9), a 5‐log reduction was achieved within 1 to 16 d depending on pH, acid concentration, and temperature. During competitive growth at 30 °C in the presence of L. plantarum or L. mesenteroides in cucumber juice, E. coli O157:H7 cell numbers were reduced to below the level of detection within 2 to 3 d. These data may be used to aid manufacturers of fermented vegetable products determine safe production practices based on fermentation pH and temperature.Practical Application:  Disease causing strains of the bacterium E. coli may be present on fresh vegetables. Our investigation determined the time needed to kill E. coli in cucumber fermentation brines and how E. coli strains are killed in competition with naturally present lactic acid bacteria. Our results showed how brine pH and other brine conditions affected the killing of E. coli strains. These data can be used by producers of fermented vegetable products to help assure consumer safety.}, number={3}, journal={Journal of Food Science}, author={Breidt, F. and Caldwell, J. M.}, year={2011}, pages={M198–203} } @article{caldwell_levine_2009, title={Domestic wastewater influent profiling using mitochondrial real-time PCR for source tracking animal contamination}, volume={77}, ISSN={0167-7012}, url={http://dx.doi.org/10.1016/j.mimet.2008.11.007}, DOI={10.1016/j.mimet.2008.11.007}, abstractNote={Real-time PCR amplifying mammalian and avian mitochondrial DNA (mtDNA) was developed to characterize domestic and light industrial wastewater influent from two municipal wastewater treatment facilities (WWTF) over a 24-week period. Influent samples were assayed with species-specific primers and dual-labeled probes for human, bovine, swine, dog, cat, Canada goose and white-tailed deer to detect and quantify eukaryotic mtDNA contributors to local municipal wastewaters. Human (mean = 9.6 × 104 copies/ml) and dog (mean = 5.3 × 102 copies/ml) mtDNA were detected in all 24 samples (12 samples/site). Bovine and swine mtDNA were detected sporadically and at lower levels than human mtDNA, means = 3.0 × 104 and 9.5 × 102 copies/ml, respectively. Domestic cat, Canada goose and white-tailed deer were detected only once in 24 samples. Mitochondrial DNA concentrations were compared to other bacterial, chemical and spectrophotometric parameters. Human mtDNA was positively correlated with ammonia concentration (P = 0.01) and initial OD600 reading (P = 0.02) at one WWTF. Bovine mtDNA was positively correlated with biological oxygen demand (BOD) (P = 0.02), final DNA concentration (P = 0.03), initial and final humic acid concentrations (P = 0.01, P = 0.01), and final OD600 (P = 0.03) at one WWTF and total suspended solids (TSS) (P = 0.04, P = 0.09) at both facilities. Fecal coliforms were not positively or negatively correlated with mtDNA concentrations of any species assayed. For source tracking purposes, a combination of human (105 copies/ml) and dog mtDNA signal (102 copies/ml) could be indicative of municipal domestic wastewater contamination of environmental waters.}, number={1}, journal={Journal of Microbiological Methods}, publisher={Elsevier BV}, author={Caldwell, Jane M. and Levine, Jay F.}, year={2009}, month={Apr}, pages={17–22} } @article{caldwell_raley_levine_2007, title={Mitochondrial Multiplex Real-Time PCR as a Source Tracking Method in Fecal-Contaminated Effluents}, volume={41}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/es062912s}, DOI={10.1021/es062912s}, abstractNote={Multiplex real-time PCR amplifying fecal mitochondrial DNA (mtDNA) combined with rapid, crude DNA preparations are promising additions to surface water source tracking methods. Amplification of eukaryotic mitochondrial DNA identifies the fecal source directly and can be used in conjunction with other intestinal microbial methods to characterize effluents. Species-specific primers and dual-labeled probes for human, swine, and bovine NADH dehydrogenase subunit 5 (ND5) genes were created for multiplex real-time PCR in feces and effluent slurries. The linear range of the multiplex assay was 10(2)-10(7) mtDNA copies for human, bovine, and swine effluent in combination (equal volumes). PCR amplification efficiencies for bovine, human, and swine mtDNA when assayed in combination were 93, 107, and 92% respectively. Linear regression correlation coefficients (r2) were 0.99 for all standard curves except for human mtDNA in combination (r2 = 0.95). Multiplex amplification of bovine, human, and swine mtDNA (ND5) exhibited no cross-reactions between the effluents from three species of interest. Also, no cross-reactions were observed with effluents of other vertebrates: sheep, goat, horse, dog, cat, Canada goose, broiler, layer, turkey, and tilapia. Performed as a blind test, the PCR operator was able to correctly identify all but two effluent challenge samples (10/12 or 83% correct) with no false positives (22/22 or 100% correct). The multiplex assay had a tendency to detect the species of highest mtDNA concentration only. Better detection of all three species in a combination of human, bovine, and swine effluents was accomplished by running each real-time PCR primer/ probe set singly. Real-time PCR detection limit was calculated as 2.0 x 10(6) mitochondrial copies or 0.2 g of human feces per 100 mL effluent. Some carry-over mtDNA PCR signal from consumed beef, but not pork, was found in feces of human volunteers.}, number={9}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Caldwell, Jane M. and Raley, Morgan E. and Levine, Jay F.}, year={2007}, month={May}, pages={3277–3283} } @article{caldwell_hassan_2002, title={Azotobacter chroococcum does not contain sodA or its gene product Mn-superoxide dismutase}, volume={48}, ISSN={["1480-3275"]}, DOI={10.1139/W02-003}, abstractNote={Azotobacter chroococcum and Azotobacter vinelandii grown in Burk medium with 1% mannitol (BM) or in BM supplemented with 2.2 mg/mL ammonium acetate (BM+N) were found to have only iron-containing and CuZn-containing superoxide dismutase. Furthermore, genomic DNA from A. chroococcum and A. vinelandii were subjected to polymerase chain reaction analysis using sodA- and sodB-specific primers and yielded only a sodB product. These results dispute the assertion by Buchanan and Lees (Can. J. Microbiol. 26: 441–447, 1980) that A. chroococcum contains Mn-superoxide dismutase.Key words: FeSOD, Cu-ZnSOD, MnSOD, Azotobacter chroococcum, Azotobacter vinelandii.}, number={2}, journal={Canadian Journal of Microbiology}, author={Caldwell, J. and Hassan, H.M.}, year={2002}, month={Feb}, pages={183–187} }