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Higgins C, Huber L. Rhodococcus equi: challenges to treat infections and to mitigate antimicrobial resistance. J Equine Vet Sci 2023:104845. [PMID: 37295760 DOI: 10.1016/j.jevs.2023.104845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/01/2023] [Accepted: 06/03/2023] [Indexed: 06/12/2023]
Abstract
Rhodococcus equi, a gram-positive facultative intracellular pathogen and a soil saprophyte, is one of the most common causes of pneumonia in young foals. It poses a threat to the economy in endemic horse-breeding farms and to animal welfare annually. Many farms use thoracic ultrasonographic screening and antimicrobial treatment of subclinically affected foals as a preventive measure against severe R. equi infections. The wide use antimicrobials to treat subclinically affected foals has contributed to the emergence of multidrug resistant (MDR)-R. equi in both clinical isolates from sick foals and in the environment of horse-breeding farms. Alternatives to treat foals infected with MDR-R. equi are scarce and the impact of the emergence of MDR-R. equi in the environment of farms is still unknown. The aim of this review is to discuss the emergence of MDR-R. equi in the United States and the challenges faced to guide antimicrobial use practices. Reduction of antimicrobial use at horse-breeding farms is essential for the preservation of antimicrobial efficacy and, ultimately, human, animal, and environmental health.
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Affiliation(s)
- Courtney Higgins
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, 1130 Wire Road, Auburn, Alabama, USA 36832.
| | - Laura Huber
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, 1130 Wire Road, Auburn, Alabama, USA 36832.
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2
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Qiao Y, Li Y, Ye Y, Yu Y, Wang W, Yao K, Zhou M. Gallium-Based Nanoplatform for Combating Multidrug-Resistant Pseudomonas aeruginosa and Postoperative Inflammation in Endophthalmitis Secondary to Cataract Surgery. ACS APPLIED MATERIALS & INTERFACES 2022; 14:51763-51775. [PMID: 36373472 DOI: 10.1021/acsami.2c15834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Postcataract endophthalmitis (PCE), a devastating complication following cataract surgeries, is one of the most crucial diseases causing irreversible eye blindness. Pseudomonas aeruginosa (PA), a multiple-drug-resistance (MDR) pathogen, always leads to uncontrolled infection and severe inflammation in PCE that can be difficult to treat by antibiotics. Therefore, it is urgent to develop new feasible strategies composed of both antibacterial and anti-inflammatory capabilities. Here, we report a multifunctional non-antibiotic nanoplatform (Ga-mSiO2-BFN) comprised of clinically approved gallium, mesoporous silica, and bromfenac (BFN) as a co-modified release system to simultaneously eradicate MDR-PA infection and cure inflammation for PCE. The released gallium ions can disrupt bacterial iron metabolism. Meanwhile, the simultaneously released BFN can suppresses the inflammation both postoperation and postinfection of PCE. In the PCE rabbit model, the slit-lamp dispersion and retro-illumination micrograph, ophthalmic clinical grading, and etiological histopathology analysis demonstrated that Ga-mSiO2-BFN could eradicate the MDR infection and alleviate the secondary inflammation from MDR-PA infection. Moreover, both cellular biocompatibility and in vivo animal model application verified the biocompatibility. A potential antibacterial mechanism implicated in the antibacterial action was demonstrated by comprehensive assays of iron antagonism evolutionary curve, colony autofluorescence, polymerase chain reaction, and electron microscopy, showing a repressing siderophore peptide pyoverdine, pyoverdine synthetase D, and interfering with bacterial DNA synthesis. All composites of our nanoplatform were FDA approved, making the Ga-mSiO2-BFN as a potentially promising therapeutic approach for treating MDR-PA in PCE accompanying satisfactory prognosis and prospects for clinical translations.
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Affiliation(s)
- Yue Qiao
- Eye Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou 310009, China
| | - Yangyang Li
- Institute of Translational Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Women's Reproductive Health Research of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Yang Ye
- Eye Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou 310009, China
| | - Yinhui Yu
- Eye Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou 310009, China
| | - Wei Wang
- Eye Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou 310009, China
| | - Ke Yao
- Eye Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou 310009, China
| | - Min Zhou
- Eye Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Institute of Translational Medicine, Zhejiang University, Hangzhou 310029, China
- Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou 310009, China
- Research Center for Life Science and Human Health, Binjiang Institute of Zhejiang University, Hangzhou 310053, China
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3
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Bordin AI, Huber L, Sanz M, Cohen N. Rhodococcus equi Foal Pneumonia: Update on Epidemiology, Immunity, Treatment, and Prevention. Equine Vet J 2022; 54:481-494. [PMID: 35188690 DOI: 10.1111/evj.13567] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/03/2022] [Accepted: 02/17/2022] [Indexed: 11/25/2022]
Abstract
Pneumonia in foals caused by the bacterium Rhodococcus equi has a worldwide distribution and is a common cause of disease and death for foals. The purpose of this narrative review is to summarise recent developments pertaining to the epidemiology, immune responses, treatment, and prevention of rhodococcal pneumonia of foals. Screening tests have been used to implement earlier detection and treatment of foals with presumed subclinical R. equi pneumonia to reduce mortality and severity of disease. Unfortunately, this practice has been linked to the emergence of antimicrobial resistant R. equi in North America. Correlates of protective immunity for R. equi infections of foals remain elusive, but recent evidence indicates that innate immune responses are important both for mediating killing and orchestrating adaptive immune responses. A macrolide antimicrobial in combination with rifampin remains the recommended treatment for foals with R. equi pneumonia. Great need exists to identify which antimicrobial combination is most effective for treating foals with R. equi pneumonia and to limit emergence of antimicrobial-resistant strains. In the absence of an effective vaccine against R. equi, passive immunisation remains the only commercially-available method for effectively reducing the incidence of R. equi pneumonia. Because passive immunisation is expensive, labour-intensive, and carries risks for foals, great need exists to develop alternative approaches for passive and active immunisation.
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Affiliation(s)
- Angela I Bordin
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, 77843-4475, USA
| | - Laura Huber
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, 36849, USA
| | - Macarena Sanz
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, 99164-6610, USA
| | - Noah Cohen
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, 77843-4475, USA
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4
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Shaw SD, Arroyo LG, zur Linden A, Allen C, Giraldo A, Cohen ND. Medical management of a large intra‐abdominal mass caused by
Rhodococcus equi
in a foal. EQUINE VET EDUC 2021. [DOI: 10.1111/eve.13389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- S. D. Shaw
- Department of Clinical Studies Ontario Veterinary College University of Guelph Guelph OntarioCanada
| | - L. G. Arroyo
- Department of Clinical Studies Ontario Veterinary College University of Guelph Guelph OntarioCanada
| | - A. zur Linden
- Department of Clinical Studies Ontario Veterinary College University of Guelph Guelph OntarioCanada
| | - C. Allen
- Allen Equine Services Etobicoke OntarioCanada
| | - A. Giraldo
- Department of Clinical Studies Ontario Veterinary College University of Guelph Guelph OntarioCanada
| | - N. D. Cohen
- Department of Large Animal Clinical Sciences College of Veterinary Medicine Texas A&M University College Station Texas USA
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Le Corre S, Janes J, Slovis NM. Multiple extra‐pulmonary disorders associated with
Rhodococcus equi
infection in a 2‐month‐old foal. EQUINE VET EDUC 2021. [DOI: 10.1111/eve.13279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- S. Le Corre
- Hagyard Equine Medical Institute Lexington Kentucky USA
| | - J. Janes
- University of Kentucky Veterinary Diagnostic Laboratory Lexington Kentucky USA
| | - N. M. Slovis
- Hagyard Equine Medical Institute Lexington Kentucky USA
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Antimicrobial Selection for the Equine Practitioner. Vet Clin North Am Equine Pract 2021; 37:461-494. [PMID: 34243881 DOI: 10.1016/j.cveq.2021.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antimicrobial drugs play an important, often central, role in the therapeutic management of mature horses and foals with a variety of illnesses, including those requiring critical care. Antimicrobial use must be based on rational principles involving thorough patient evaluation and sound clinical judgment that indicate a high likelihood that the patient has a bacterial infection and that antimicrobials are indicated to promote recovery. The aim of antimicrobial treatment is to inflict an insult on infecting bacteria sufficient to kill the organism or render it susceptible to inactivation by natural host defenses or the local microenvironment without adversely affecting the patient.
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Huber L, Giguère S, Hart KA, Slovis NM, Greiter ME, Dailey CA, Cohen ND. Association between antimicrobial treatment of subclinical pneumonia in foals and selection of macrolide- and rifampicin-resistant Rhodococcus equi strains at horse-breeding farms in central Kentucky. J Am Vet Med Assoc 2021; 258:648-653. [PMID: 33683955 DOI: 10.2460/javma.258.6.648] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare soil concentrations of macrolide- and rifampicin-resistant Rhodococcus equi strains (MRRE) on horse-breeding farms that used thoracic ultrasonographic screening (TUS) to identify foals with subclinical pneumonia combined with subsequent administration of macrolides and rifampin to affected foals (TUS farms) versus soil concentrations on farms that did not (non-TUS farms), determine whether the combined use of TUS and antimicrobial treatment of subclinically affected foals was associated with soil concentration of MRRE, and assess whether there were temporal effects on soil concentrations of MRRE during the foaling season. SAMPLES 720 soil samples and 20 completed questionnaires from 20 horse-breeding farms (10 TUS farms and 10 non-TUS farms) in central Kentucky. PROCEDURES A questionnaire was used to gather information from participating farms about their 2019 foaling season. Soil samples were collected during January, March, May, and July 2019 for bacterial culture and antimicrobial susceptibility testing to identify any isolates of MRRE. Results were compared for TUS farms versus non-TUS farms. Linear mixed-effects modeling was used to evaluate for potential associations between the soil concentration of MRRE and the use of TUS. RESULTS Overall, the sum of the mean soil concentrations of MRRE was significantly higher for TUS farms (8.85 log10-transformed CFUs/g) versus non-TUS farms (7.37 log10-transformed CFUs/g). CONCLUSIONS AND CLINICAL RELEVANCE Our findings indicated that farms that use TUS to identify foals with subclinical pneumonia for antimicrobial treatment select for antimicrobial-resistant R equi strains. Because prognosis is worse for foals infected with resistant versus nonresistant strains of R equi, prudent use of antimicrobials to treat foals with subclinical pulmonary lesions attributed to R equi is recommended.
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Epidemiology and Molecular Basis of Multidrug Resistance in Rhodococcus equi. Microbiol Mol Biol Rev 2021; 85:85/2/e00011-21. [PMID: 33853933 DOI: 10.1128/mmbr.00011-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The development and spread of antimicrobial resistance are major concerns for human and animal health. The effects of the overuse of antimicrobials in domestic animals on the dissemination of resistant microbes to humans and the environment are of concern worldwide. Rhodococcus equi is an ideal model to illustrate the spread of antimicrobial resistance at the animal-human-environment interface because it is a natural soil saprophyte that is an intracellular zoonotic pathogen that produces severe bronchopneumonia in many animal species and humans. Globally, R. equi is most often recognized as causing severe pneumonia in foals that results in animal suffering and increased production costs for the many horse-breeding farms where the disease occurs. Because highly effective preventive measures for R. equi are lacking, thoracic ultrasonographic screening and antimicrobial chemotherapy of subclinically affected foals have been used for controlling this disease during the last 20 years. The resultant increase in antimicrobial use attributable to this "screen-and-treat" approach at farms where the disease is endemic has likely driven the emergence of multidrug-resistant (MDR) R. equi in foals and their environment. This review summarizes the factors that contributed to the development and spread of MDR R. equi, the molecular epidemiology of the emergence of MDR R. equi, the repercussions of MDR R. equi for veterinary and human medicine, and measures that might mitigate antimicrobial resistance at horse-breeding farms, such as alternative treatments to traditional antibiotics. Knowledge of the emergence and spread of MDR R. equi is of broad importance for understanding how antimicrobial use in domestic animals can impact the health of animals, their environment, and human beings.
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9
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Huber L. Medical management of
Rhodococcus equi
infections: A clinical epidemiology perspective. EQUINE VET EDUC 2020. [DOI: 10.1111/eve.13417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- L. Huber
- Institute of Environmental Decisions Health Geography and Policy Group ETH Zürich Zürich Switzerland
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10
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Quantitative proteomic reveals gallium maltolate induces an iron-limited stress response and reduced quorum-sensing in Pseudomonas aeruginosa. J Biol Inorg Chem 2020; 25:1153-1165. [DOI: 10.1007/s00775-020-01831-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 10/21/2020] [Indexed: 01/12/2023]
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11
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Rakowska A, Cywinska A, Witkowski L. Current Trends in Understanding and Managing Equine Rhodococcosis. Animals (Basel) 2020; 10:E1910. [PMID: 33081047 PMCID: PMC7603097 DOI: 10.3390/ani10101910] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 01/19/2023] Open
Abstract
The aim of this review was to summarize studies on equine rhodococcosis over the last decade. For many years Rhodococcus equi has remained one of the major health challenges in the equine breeding industry worldwide. Recently, many novel approaches and ideas have been described and some of them were initially implemented into the clinical practice. This study reviews a variety of new information about neonatal susceptibility, clinical appearance, considered and applied diagnostic procedures and treatment alternatives, factors limiting accurate prognosis, ideas regarding environmental management and prophylaxis considerations. Although multiple research were conducted, the main problems such as high morbidity and mortality, a lack of reliable prevention strategies and treatment limitations are still unresolved and require further scientific effort.
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Affiliation(s)
- Alicja Rakowska
- Department of Veterinary Epidemiology and Economics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-787 Warszawa, Poland;
| | - Anna Cywinska
- Department of Pathology and Veterinary Diagnostics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 1, 02-787 Warszawa, Poland;
| | - Lucjan Witkowski
- Department of Veterinary Epidemiology and Economics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-787 Warszawa, Poland;
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Álvarez-Narváez S, Berghaus LJ, Morris ERA, Willingham-Lane JM, Slovis NM, Giguere S, Cohen ND. A Common Practice of Widespread Antimicrobial Use in Horse Production Promotes Multi-Drug Resistance. Sci Rep 2020; 10:911. [PMID: 31969575 PMCID: PMC6976650 DOI: 10.1038/s41598-020-57479-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/21/2019] [Indexed: 02/07/2023] Open
Abstract
The practice of prophylactic administration of a macrolide antimicrobial with rifampin (MaR) to apparently healthy foals with pulmonary lesions identified by thoracic ultrasonography (i.e., subclinically pneumonic foals) is common in the United States. The practice has been associated epidemiologically with emergence of R. equi resistant to MaR. Here, we report direct evidence of multi-drug resistance among foals treated with MaR. In silico and in vitro analysis of the fecal microbiome and resistome of 38 subclinically pneumonic foals treated with either MaR (n = 19) or gallium maltolate (GaM; n = 19) and 19 untreated controls was performed. Treatment with MaR, but not GaM, significantly decreased fecal microbiota abundance and diversity, and expanded the abundance and diversity of antimicrobial resistance genes in feces. Soil plots experimentally infected with Rhodococcus equi (R. equi) and treated with MaR selected for MaR-resistant R. equi, whereas MaR-susceptible R. equi out-competed resistant isolates in GaM-treated or untreated plots. Our results indicate that MaR use promotes multi-drug resistance in R. equi and commensals that are shed into their environment where they can persist and potentially infect or colonize horses and other animals.
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Affiliation(s)
- S Álvarez-Narváez
- Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, Ga, USA
| | - L J Berghaus
- Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, Ga, USA
| | - E R A Morris
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - J M Willingham-Lane
- Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, Ga, USA
| | - N M Slovis
- Hagyard Equine Medical Institute, Lexington, KY, USA
| | - S Giguere
- Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, Ga, USA
| | - N D Cohen
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA.
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GAPDH, rhbC, and vapA gene expression in Rhodococcus equi cultured under different iron concentrations. Microb Pathog 2019; 139:103885. [PMID: 31790793 DOI: 10.1016/j.micpath.2019.103885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/07/2019] [Accepted: 11/21/2019] [Indexed: 11/22/2022]
Abstract
The ability of Rhodococcus equi to survive in macrophages and cause pneumonia in foals depends on vapA and rhbC genes, which produce the virulence-associated protein A (VapA) and the rhequichelin siderophore, respectively. Virulent R. equi acquires Fe from transferrin by unknown mechanisms. Our objectives were to determine the role of GAPDH in Fe homeostasis, to further characterize GAPDH, rhbC, and vapA expression under iron homeostasis, and to document the occurrence of rhbC gene in R. equi isolates. Therefore, vapA + R. equi was cultured under excessive, physiologic, and restricted iron concentrations, and quantitative culture and gene expression were performed. The relative expression of GAPDH, rhbC, and vapA after 48 h of culture were analyzed by qPCR. To determine the rhbC occurrence, total DNA was extracted from R. equi isolated from foals with clinical rhodococcosis (n = 22), healthy horses (feces, n = 16; nasal swab, n = 9), soil (n = 6), and 2 ATCC reference strains. Conventional PCR was performed to identify genus/species, vapA, and rhbC genes. Iron restriction proportionally decreased R. equi growth rates, and induced high expression of both GAPDH and vapA. The putative role of GAPDH in R. equi iron homeostasis should be further investigated. rhbC was significantly up-regulated under both Fe excess and critical starvation. The rhbC gene was identified in all clinical isolates and soil, but it was absent in 2 isolates from healthy horses, suggesting that rhequichelin is not required for R. equi nasal and intestinal colonization.
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Rocha JN, Dangott LJ, Mwangi W, Alaniz RC, Bordin AI, Cywes-Bentley C, Lawhon SD, Pillai SD, Bray JM, Pier GB, Cohen ND. PNAG-specific equine IgG 1 mediates significantly greater opsonization and killing of Prescottella equi (formerly Rhodococcus equi) than does IgG 4/7. Vaccine 2019; 37:1142-1150. [PMID: 30691984 PMCID: PMC8314964 DOI: 10.1016/j.vaccine.2019.01.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 02/04/2023]
Abstract
Prescottella equi (formerly Rhodococcus equi) is a facultative intracellular bacterial pathogen that causes severe pneumonia in foals 1-6 months of age, whereas adult horses are highly resistant to infection. We have shown that vaccinating pregnant mares against the conserved surface polysaccharide capsule, β-1 → 6-linked poly-N-acetyl glucosamine (PNAG), elicits opsonic killing antibody that transfers via colostrum to foals and protects them against experimental infection with virulent. R. equi. We hypothesized that equine IgG1 might be more important than IgG4/7 for mediating protection against R. equi infection in foals. To test this hypothesis, we compared complement component 1 (C1) deposition and polymorphonuclear cell-mediated opsonophagocytic killing (OPK) mediated by IgG1 or IgG4/7 enriched from either PNAG hyperimmune plasma (HIP) or standard plasma. Subclasses IgG1 and IgG4/7 from PNAG HIP and standard plasma were precipitated onto a diethylaminoethyl ion exchange column, then further enriched using a protein G Sepharose column. We determined C1 deposition by enzyme-linked immunosorbent assay (ELISA) and estimated OPK by quantitative microbiologic culture. Anti-PNAG IgG1 deposited significantly (P < 0.05) more C1 onto PNAG than did IgG4/7 from PNAG HIP or subclasses IgG1 and IgG4/7 from standard plasma. In addition, IgG1 from PNAG HIP mediated significantly (P < 0.05) greater OPK than IgG4/7 from PNAG HIP or IgG1 and IgG4/7 from standard plasma. Our findings indicate that anti-PNAG IgG1 is a correlate of protection against R. equi in foals, which has important implications for understanding the immunopathogenesis of R. equi pneumonia, and as a tool for assessing vaccine efficacy and effectiveness when challenge is not feasible.
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Affiliation(s)
- Joana N Rocha
- College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 660 Raymond Stotzer Pkwy, College Station, TX 77843-4475, United States.
| | - Lawrence J Dangott
- Protein Chemistry Laboratory, Texas A&M University, 300 Olsen Blvd, College Station, TX 77843, United States.
| | - Waithaka Mwangi
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, 1800 Denison Ave, Manhattan, KS 66506, United States.
| | - Robert C Alaniz
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health and Science Center, 206 Olsen Blvd, College Station, TX 77845, United States.
| | - Angela I Bordin
- College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 660 Raymond Stotzer Pkwy, College Station, TX 77843-4475, United States.
| | - Colette Cywes-Bentley
- Harvard Medical School, Brigham & Women's Hospital, 181 Longwood Ave, Boston, MA 02115, United States.
| | - Sara D Lawhon
- College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 660 Raymond Stotzer Pkwy, College Station, TX 77843-4475, United States.
| | - Suresh D Pillai
- National Center for Electron Beam Research-IAEA Collaborative Centre for Electron Beam Technology, Texas A&M University, 400 Discovery Dr, College Station, TX 77845, United States.
| | - Jocelyne M Bray
- College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 660 Raymond Stotzer Pkwy, College Station, TX 77843-4475, United States
| | - Gerald B Pier
- Harvard Medical School, Brigham & Women's Hospital, 181 Longwood Ave, Boston, MA 02115, United States.
| | - Noah D Cohen
- College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 660 Raymond Stotzer Pkwy, College Station, TX 77843-4475, United States.
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15
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Topical treatment with gallium maltolate reduces Treponema pallidum subsp. pertenue burden in primary experimental lesions in a rabbit model of yaws. PLoS Negl Trop Dis 2019; 13:e0007076. [PMID: 30601824 PMCID: PMC6331133 DOI: 10.1371/journal.pntd.0007076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 01/14/2019] [Accepted: 12/12/2018] [Indexed: 12/22/2022] Open
Abstract
Background Gallium is a semi-metallic element known since the 1930s to have antimicrobial activity. This activity stems primarily from gallium's ability to mimic trivalent iron and disrupt specific Fe(III)-dependent pathways, particularly DNA synthesis (due to inhibition of ribonucleotide reductase). Because of its novel mechanism of action, gallium is currently being investigated as a new antibacterial agent, particularly in light of the increasing resistance of many pathogenic bacteria to existing antibiotics. Gallium maltolate (GaM) is being developed as an orally and topically administrable form of gallium. Yaws is a neglected tropical disease affecting mainly the skin and skeletal system of children in underprivileged settings. It is currently the object of a WHO-promoted eradication campaign using mass administration of the macrolide azithromycin, an antibiotic to which the yaws agent Treponema pallidum subsp. pertenue has slowly begun to develop genetic resistance. Methods Because yaws transmission is mainly due to direct skin contact with an infectious skin lesion, we evaluated the treponemicidal activity of GaM applied topically to skin lesions in a rabbit model of yaws. Treatment efficacy was evaluated by measuring lesion diameter, treponemal burden in lesion aspirates as determined by dark field microscopy and amplification of treponemal RNA, serology, and immunohistochemistry of biopsied tissue samples. Results Our results show that topical GaM was effective in reducing treponemal burden in yaws experimental lesions, particularly when applied at the first sign of lesion appearance but, as expected, did not prevent pathogen dissemination. Conclusion Early administration of GaM to yaws lesions could reduce the infectivity of the lesions and thus yaws transmission, potentially contributing to current and future yaws control campaigns. Yaws is a neglected tropical disease affecting children in underprivileged countries, transmitted through direct skin contact with an active lesion. This infection, although rarely fatal, can lead to disfigurement and serious disability. The World Health Organization is currently conducting a yaws eradication effort that employs mass administration of azithromycin, an antibiotic against which the yaws pathogen has slowly begun to develop genetic resistance. Because this phenomenon has the potential to undermine the eradication effort, we investigated the antimicrobial activity of gallium maltolate, which has a novel mechanism of action, against the yaws pathogen. Our initial results show that topical application of gallium maltolate has significant treponemicidal activity, and suggest that this compound might find an application in the effort to eradicate yaws. Future studies will evaluate whether oral administration of gallium maltolate is as effective as the antibiotics currently approved for yaws treatment to clear systemic infection.
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16
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Giguère S, Cohen ND. Controversies in therapy of infections caused byRhodococcus equiin foals. EQUINE VET EDUC 2017. [DOI: 10.1111/eve.12870] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- S. Giguère
- University of Georgia; Athens Georgia USA
| | - N. D. Cohen
- Texas A&M University; College Station Texas USA
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Oyama MA, Ellenberg SS, Shaw PA. Clinical Trials in Veterinary Medicine: A New Era Brings New Challenges. J Vet Intern Med 2017; 31:970-978. [PMID: 28557000 PMCID: PMC5508340 DOI: 10.1111/jvim.14744] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 03/17/2017] [Accepted: 04/20/2017] [Indexed: 12/27/2022] Open
Abstract
Randomized clinical trials (RCTs) are among the most rigorous ways to determine the causal relationship between an intervention and important clinical outcome. Their use in veterinary medicine has become increasingly common, and as is often the case, with progress comes new challenges. Randomized clinical trials yield important answers, but results from these studies can be unhelpful or even misleading unless the study design and reporting are carried out with care. Herein, we offer some perspective on several emerging challenges associated with RCTs, including use of composite endpoints, the reporting of different forms of risk, analysis in the presence of missing data, and issues of reporting and safety assessment. These topics are explored in the context of previously reported veterinary internal medicine studies as well as through illustrative examples with hypothetical data sets. Moreover, many insights germane to RCTs in veterinary internal medicine can be drawn from the wealth of experience with RCTs in the human medical field. A better understanding of the issues presented here can help improve the design, interpretation, and reporting of veterinary RCTs.
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Affiliation(s)
- M A Oyama
- Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA.,Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - S S Ellenberg
- Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.,Division of Biostatistics, Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - P A Shaw
- Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.,Division of Biostatistics, Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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Giguère S. Treatment of Infections Caused by Rhodococcus equi. Vet Clin North Am Equine Pract 2017; 33:67-85. [DOI: 10.1016/j.cveq.2016.11.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Wright S. Highlights of recent clinically relevant papers. EQUINE VET EDUC 2015. [DOI: 10.1111/eve.12474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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