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Cationic zinc (II) phthalocyanine nanoemulsions for photodynamic inactivation of resistant bacterial strains. Photodiagnosis Photodyn Ther 2021; 34:102301. [PMID: 33894372 DOI: 10.1016/j.pdpdt.2021.102301] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 03/22/2021] [Accepted: 04/16/2021] [Indexed: 01/05/2023]
Abstract
BACKGROUND The growing emergence of microbial resistance to antibiotics represents a worldwide challenge. Antimicrobial photodynamic inactivation (aPDI) has been introduced as an alternative technique, especially when combined with nanotechnology. Therefore, this study was designed to investigate the therapeutic merits of combined aPDI and nanoemulsion in infections caused by resistant bacterial strains. METHODS Cationic zinc (II) phthalocyanine nanoemulsions (ZnPc-NE) were prepared using isopropyl myristate (IPM) as oil phase, egg phosphatidylcholine (egg PC) as emulsifier, and N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB). Nanoemulsions were characterized for particle size, polydispersity, zeta potential, viscosity, and skin deposition. The in-vitro aPDI was investigated on human resistant pathogens; gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and gram-negative Multidrug-resistant strain of Escherichia coli (MDR E. coli), under different experimental conditions. In addition, in-vivo model of abrasion wound infected by MDR E. coli was induced in rats to investigate the therapeutic potential of the selected formulation. RESULTS It was evident that the selected ZnPc formulation (20 % IPM, 2 % egg PC and 0.5 % CTAB) displayed a particle size of 209.9 nm, zeta potential +73.1 mV, and 23.66 % deposition of ZnPc in skin layers. Furthermore, the selected formulation combined with light achieved almost 100 % eradication of the two bacterial strains, with superior bacterial load reduction and wound healing propertiesin-vivo, compared to either the nanoemulsion formulation or laser alone. CONCLUSION ZnPc nanoemulsion improved antimicrobial photodynamic therapy in inactivating resistant bacterial infections and provided a promising therapeutic means of treating serious infections, and hence could be applied in diseases caused by other bacterial strains.
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Wilson BK, Holland BP, Step DL, Jacob ME, VanOverbeke DL, Richards CJ, Nagaraja TG, Krehbiel CR. Feeding wet distillers grains plus solubles with and without a direct-fed microbial to determine performance, carcass characteristics, and fecal shedding of Escherichia coli O157:H7 in feedlot heifers1. J Anim Sci 2016; 94:297-305. [DOI: 10.2527/jas.2015-9601] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Tokel O, Yildiz UH, Inci F, Durmus NG, Ekiz OO, Turker B, Cetin C, Rao S, Sridhar K, Natarajan N, Shafiee H, Dana A, Demirci U. Portable microfluidic integrated plasmonic platform for pathogen detection. Sci Rep 2015; 5:9152. [PMID: 25801042 PMCID: PMC4371189 DOI: 10.1038/srep09152] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/26/2015] [Indexed: 01/22/2023] Open
Abstract
Timely detection of infectious agents is critical in early diagnosis and treatment of infectious diseases. Conventional pathogen detection methods, such as enzyme linked immunosorbent assay (ELISA), culturing or polymerase chain reaction (PCR) require long assay times, and complex and expensive instruments, which are not adaptable to point-of-care (POC) needs at resource-constrained as well as primary care settings. Therefore, there is an unmet need to develop simple, rapid, and accurate methods for detection of pathogens at the POC. Here, we present a portable, multiplex, inexpensive microfluidic-integrated surface plasmon resonance (SPR) platform that detects and quantifies bacteria, i.e., Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) rapidly. The platform presented reliable capture and detection of E. coli at concentrations ranging from ~10(5) to 3.2 × 10(7) CFUs/mL in phosphate buffered saline (PBS) and peritoneal dialysis (PD) fluid. The multiplexing and specificity capability of the platform was also tested with S. aureus samples. The presented platform technology could potentially be applicable to capture and detect other pathogens at the POC and primary care settings.
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Affiliation(s)
- Onur Tokel
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Umit Hakan Yildiz
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Stanford University School of Medicine, Canary Center at Stanford for Cancer Early Detection, Palo Alto, CA, USA
| | - Fatih Inci
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Stanford University School of Medicine, Canary Center at Stanford for Cancer Early Detection, Palo Alto, CA, USA
| | - Naside Gozde Durmus
- Department of Biochemistry, Stanford School of Medicine, Stanford, CA, USA
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, USA
| | - Okan Oner Ekiz
- UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey
| | - Burak Turker
- UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey
| | - Can Cetin
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Shruthi Rao
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Kaushik Sridhar
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Nalini Natarajan
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Hadi Shafiee
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Aykutlu Dana
- UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey
| | - Utkan Demirci
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Stanford University School of Medicine, Canary Center at Stanford for Cancer Early Detection, Palo Alto, CA, USA
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Jacob ME, Bai J, Renter DG, Rogers AT, Shi X, Nagaraja TG. Comparing real-time and conventional PCR to culture-based methods for detecting and quantifying Escherichia coli O157 in cattle feces. J Food Prot 2014; 77:314-9. [PMID: 24490927 DOI: 10.4315/0362-028x.jfp-13-304] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Detection of Escherichia coli O157 in cattle feces has traditionally used culture-based methods; PCR-based methods have been suggested as an alternative. We aimed to determine if multiplex real-time (mq) or conventional PCR methods could reliably detect cattle naturally shedding high (≥10(4) CFU/g of feces) and low (∼10(2) CFU/g of feces) concentrations of E. coli O157. Feces were collected from pens of feedlot cattle and evaluated for E. coli O157 by culture methods. Samples were categorized as (i) high shedders, (ii) immunomagnetic separation (IMS) positive after enrichment, or (iii) culture negative. DNA was extracted pre- and postenrichment from 100 fecal samples from each category (high shedder, IMS positive, culture negative) and subjected to mqPCR and conventional PCR assays based on detecting three genes, rfbE, stx1, and stx2. In feces from cattle determined to be E. coli O157 high shedders by culture, 37% were positive by mqPCR prior to enrichment; 85% of samples were positive after enrichment. In IMS-positive samples, 4% were positive by mqPCR prior to enrichment, while 43% were positive after enrichment. In culture-negative feces, 7% were positive by mqPCR prior to enrichment, and 40% were positive after enrichment. The proportion of high shedder-positive and culture-positive (high shedder and IMS) samples were significantly different from mqPCR-positive samples before and after enrichment (P < 0.01). Similar results were observed for conventional PCR. Our data suggest that mqPCR and conventional PCR are most useful in identifying high shedder animals and may not be an appropriate substitute to culture-based methods for detection of E. coli O157 in cattle feces.
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Affiliation(s)
- M E Jacob
- Department of Population Health and Pathobiology, North Carolina State University, 1060 William Moore Drive, College of Veterinary Medicine, Raleigh, North Carolina 27607, USA.
| | - J Bai
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, 1800 Denison Avenue, Manhattan, Kansas 66506, USA
| | - D G Renter
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, 1800 Denison Avenue, Manhattan, Kansas 66506, USA
| | - A T Rogers
- Department of Population Health and Pathobiology, North Carolina State University, 1060 William Moore Drive, College of Veterinary Medicine, Raleigh, North Carolina 27607, USA
| | - X Shi
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, 1800 Denison Avenue, Manhattan, Kansas 66506, USA
| | - T G Nagaraja
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, 1800 Denison Avenue, Manhattan, Kansas 66506, USA
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Tasoglu S, Gurkan UA, Wang S, Demirci U. Manipulating biological agents and cells in micro-scale volumes for applications in medicine. Chem Soc Rev 2013; 42:5788-808. [PMID: 23575660 PMCID: PMC3865707 DOI: 10.1039/c3cs60042d] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Recent technological advances provide new tools to manipulate cells and biological agents in micro/nano-liter volumes. With precise control over small volumes, the cell microenvironment and other biological agents can be bioengineered; interactions between cells and external stimuli can be monitored; and the fundamental mechanisms such as cancer metastasis and stem cell differentiation can be elucidated. Technological advances based on the principles of electrical, magnetic, chemical, optical, acoustic, and mechanical forces lead to novel applications in point-of-care diagnostics, regenerative medicine, in vitro drug testing, cryopreservation, and cell isolation/purification. In this review, we first focus on the underlying mechanisms of emerging examples for cell manipulation in small volumes targeting applications such as tissue engineering. Then, we illustrate how these mechanisms impact the aforementioned biomedical applications, discuss the associated challenges, and provide perspectives for further development.
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Affiliation(s)
- Savas Tasoglu
- Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Division of Biomedical Engineering and Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Umut Atakan Gurkan
- Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Division of Biomedical Engineering and Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - ShuQi Wang
- Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Division of Biomedical Engineering and Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Utkan Demirci
- Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Division of Biomedical Engineering and Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Harvard-MIT Health Sciences and Technology, Cambridge, MA, USA
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Wang S, Inci F, Chaunzwa TL, Ramanujam A, Vasudevan A, Subramanian S, Chi Fai Ip A, Sridharan B, Gurkan UA, Demirci U. Portable microfluidic chip for detection of Escherichia coli in produce and blood. Int J Nanomedicine 2012; 7:2591-600. [PMID: 22679370 PMCID: PMC3368510 DOI: 10.2147/ijn.s29629] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Pathogenic agents can lead to severe clinical outcomes such as food poisoning, infection of open wounds, particularly in burn injuries and sepsis. Rapid detection of these pathogens can monitor these infections in a timely manner improving clinical outcomes. Conventional bacterial detection methods, such as agar plate culture or polymerase chain reaction, are time-consuming and dependent on complex and expensive instruments, which are not suitable for point-of-care (POC) settings. Therefore, there is an unmet need to develop a simple, rapid method for detection of pathogens such as Escherichia coli. Here, we present an immunobased microchip technology that can rapidly detect and quantify bacterial presence in various sources including physiologically relevant buffer solution (phosphate buffered saline [PBS]), blood, milk, and spinach. The microchip showed reliable capture of E. coli in PBS with an efficiency of 71.8% ± 5% at concentrations ranging from 50 to 4,000 CFUs/mL via lipopolysaccharide binding protein. The limits of detection of the microchip for PBS, blood, milk, and spinach samples were 50, 50, 50, and 500 CFUs/mL, respectively. The presented technology can be broadly applied to other pathogens at the POC, enabling various applications including surveillance of food supply and monitoring of bacteriology in patients with burn wounds.
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Affiliation(s)
- ShuQi Wang
- Bio-Acoustic-MEMS in Medicine Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02139, USA
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Inclusion of dried or wet distillers' grains at different levels in diets of feedlot cattle affects fecal shedding of Escherichia coli O157:H7. Appl Environ Microbiol 2010; 76:7238-42. [PMID: 20817807 DOI: 10.1128/aem.01221-10] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Our objectives were to evaluate the prevalence of Escherichia coli O157:H7 in cattle fed diets supplemented with 20 or 40% dried distillers' grains (DG) (DDG) or wet DG (WDG) and assess whether removing DG from diets before slaughter affected fecal shedding of E. coli O157:H7. Eight hundred forty steers were allocated to 70 pens (12 steers/pen). Treatments were no DG (control), 20% DDG or WDG, and 40% DDG or WDG, and each was replicated in 14 pens. In phase 1, eight floor fecal samples were collected from each pen every 2 weeks for 12 weeks for isolation of E. coli O157:H7 and detection of high shedders. In phase 2, half of the pens with DG were transitioned to the no-DG control diet, and pen floor fecal samples were collected weekly from all pens for 4 weeks. During phase 1, prevalence of E. coli O157:H7 was 20.8% and 3.2% for high shedders. The form of DG had no significant effect on fecal E. coli O157:H7 shedding. The prevalence levels of E. coli O157:H7 and the numbers of high shedders were not different between diets with 0 or 20% DG; however, cattle fed 40% DG had a higher prevalence and more high shedders than cattle fed 0 or 20% DG (P ≤ 0.05). During phase 2, overall and high-shedder prevalence estimates were 3.3% and <0.1%, respectively, and there were no differences between those for different DG forms and inclusion levels or when DG was removed from diets. The form of DG had no impact on E. coli O157:H7; however, fecal shedding was associated with the DG inclusion level.
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Jacob ME, Renter DG, Nagaraja TG. Animal- and truckload-level associations between Escherichia coli O157:H7 in feces and on hides at harvest and contamination of preevisceration beef carcasses. J Food Prot 2010; 73:1030-7. [PMID: 20537257 DOI: 10.4315/0362-028x-73.6.1030] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cattle feces and hides contribute to carcass contamination with Escherichia coli O157:H7, ultimately impacting beef safety. Primary objectives of our cross-sectional study were to evaluate associations among fecal, hide, and preevisceration carcass prevalence of E. coli O157:H7 and to assess factors affecting carcass contamination. Fecal, hide, and preevisceration carcass samples were collected from up to 32 cattle on each of 45 truckloads presented to a midwestern U.S. abattoir. Enrichment and selective culture were used to assess fecal, hide, and carcass prevalence, and direct plating was used to identify cattle shedding high levels of E. coli O157:H7 in feces. Fecal, hide, and carcass prevalence of E. coli O157:H7 within truckload were significantly correlated (P < 0.05) with each other. Enriched fecal sample prevalence was 13.8%, and high shedder prevalence was 3.3%; 38.5% of hides and 10.5% of carcasses were positive for E. coli O157:H7. We used logistic regression to assess animal- and truckload-level variables affecting the probability of carcasses testing positive for E. coli O157:H7. All truckload-level predictors significantly affected the probability of an E. coli O157:H7-positive carcass, including presence of a high shedder within the truckload (odds ratio [OR] = 4.0; confidence interval [CI], 1.6 to 10.1), high (>25%) within-truckload fecal prevalence (OR = 19.3; CI, 4.7 to 79.0), and high (>50%) within-truckload hide prevalence (OR = 7.7; CI, 3.1 to 19.6). The only significant animal-level predictor was having a positive hide (OR = 1.6; CI, 1.0 to 2.6). Our results suggest that preharvest interventions for reducing E. coli O157:H7 contamination of carcasses should focus on truckload (cohort)-level and hide mitigation strategies.
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Affiliation(s)
- M E Jacob
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506-5606, USA
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Dodd CC, Renter DG, Fox JT, Shi X, Sanderson MW, Nagaraja T. Genetic Relatedness ofEscherichia coliO157 Isolates from Cattle Feces and Preintervention Beef Carcasses. Foodborne Pathog Dis 2010; 7:357-65. [DOI: 10.1089/fpd.2009.0415] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Charles C. Dodd
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - David G. Renter
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - J. Trent Fox
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - Xiaorong Shi
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - Michael W. Sanderson
- Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | - T.G. Nagaraja
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
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Fox JT, Renter DG, Sanderson MW, Nutsch AL, Shi X, Nagaraja TG. Associations between the presence and magnitude of Escherichia coli O157 in feces at harvest and contamination of preintervention beef carcasses. J Food Prot 2008; 71:1761-7. [PMID: 18810859 DOI: 10.4315/0362-028x-71.9.1761] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To quantify associations at slaughter between Escherichia coli O157 carcass contamination, fecal-positive animals, and high-shedding animals within truckloads of finished cattle, we sampled up to 32 cattle from each of 50 truckloads arriving at a commercial abattoir in the Midwest United States during a 5-week summer period. Carcass swab samples collected pre-evisceration and fecal samples collected postevisceration were matched within animals and analyzed for the presence of E. coli O157, using enrichment, immunomagnetic separation, and plating on selective media (IMS). In addition, a direct plating procedure was performed on feces to identify high-shedding animals. E. coli O157 was isolated from 39 (2.6%) of 1,503 carcass samples in 15 (30%) truckloads, and 127 (8.5%) of 1,495 fecal samples in 37 (74%) truckloads. Fifty-five (3.7%) high-shedding animals were detected from 26 (52%) truckloads. Truckload high-shedder (Spearman rank-order correlation coefficient [r(s)] = 0.68), IMS-positive (r(s) = 0.48), and combined fecal (r(s) = 0.61) prevalence were significantly correlated with carcass prevalence. The probability of isolating E. coli O157 from a carcass was not significantly associated with the high-shedder or fecal IMS status of the animal from which the carcass was derived. However, the probability of carcass contamination was significantly associated with all truckload-level measures of fecal E. coli O157, particularly whether or not a high shedder was present within the truckload (odds ratio = 16.2; 95% confidence interval, 6.3-43.6). Our results suggest that high shedders within a truckload at slaughter could be a target for mitigation strategies to reduce the probability of preevisceration carcass contamination.
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Affiliation(s)
- J T Fox
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506-5606, USA
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