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Klose SM, De Souza DP, Devlin JM, Bushell R, Browning GF, Vaz PK. A "plus one" strategy impacts replication of felid alphaherpesvirus 1, Mycoplasma and Chlamydia, and the metabolism of coinfected feline cells. mSystems 2024:e0085224. [PMID: 39315777 DOI: 10.1128/msystems.00852-24] [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: 07/08/2024] [Accepted: 09/05/2024] [Indexed: 09/25/2024] Open
Abstract
Coinfections are known to play an important role in disease progression and severity. Coinfections are common in cats, but no coinfection studies have investigated the in vitro dynamics between feline viral and bacterial pathogens. In this study, we performed co-culture and invasion assays to investigate the ability of common feline bacterial respiratory pathogens, Chlamydia felis and Mycoplasma felis, to replicate in and invade into Crandell-Rees feline kidney cells. We subsequently investigated how coinfection of these feline cells with each bacterium (C. felis or M. felis) and the common feline viral pathogen, felid alphaherpesvirus 1 (FHV-1), affects replication of each agent in this cell culture system. We also investigated the metabolic impact of each co-pathogen using metabolomic analysis of infected and coinfected cells. C. felis was able to invade and replicate in CRFKs, while M. felis had little capacity to invade. During coinfection, FHV-1 replication was minimally affected by the presence of either bacterial pathogen, but bacterial replication kinetics were more affected, particularly in M. felis. Both C. felis and M. felis replicated to higher levels in the presence of a secondary pathogen. Coinfections resulted in reprogramming of the glycolysis pathway, the pentose phosphate pathway, and the tricarboxylic acid cycle. The distinct metabolic profiles of coinfected cells compared to those of cells infected with just one of these three pathogens, as well as the impact of coinfections on viral or bacterial load, suggest strong interactions between these three pathogens and possible synergistic mechanisms enhancing virulence that need further investigation.IMPORTANCEIn the natural world, respiratory pathogens coexist within their hosts, but their dynamics and interactions remain largely unexplored. Herpesviruses, mycoplasmas, and chlamydias are common and significant causes of acute and chronic respiratory and system disease in animals and people, and these diseases are increasingly found to be polymicrobial. This study investigates how coinfection of feline cells between three respiratory pathogens of cats impact each other as well as the host innate metabolic response to infection. Each of these pathogens have been implicated in the induction of feline upper respiratory tract disease in cats, which is the leading cause of euthanasia in shelters. Understanding how coinfection impacts co-pathogenesis and host responses is critical for improving disease management.
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Affiliation(s)
- Sara M Klose
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, University of Melbourne, Melbourne, Victoria, Australia
| | - David P De Souza
- Metabolomics Australia, Bio21 Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Joanne M Devlin
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, University of Melbourne, Melbourne, Victoria, Australia
| | - Rhys Bushell
- Department of Veterinary Clinical Sciences, Melbourne Veterinary School, University of Melbourne, Melbourne, Victoria, Australia
| | - Glenn F Browning
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, University of Melbourne, Melbourne, Victoria, Australia
| | - Paola K Vaz
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, University of Melbourne, Melbourne, Victoria, Australia
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Lewin AC, Hicks SK, Carter RT. A review of evidence-based management of infectious ocular surface disease in shelter-housed domestic cats. Vet Ophthalmol 2023; 26 Suppl 1:47-58. [PMID: 36749144 DOI: 10.1111/vop.13063] [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: 11/11/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 02/08/2023]
Abstract
Infectious ocular surface disease (IOSD) is a common problem in shelter-housed domestic cats and has a widespread negative impact on animal welfare. While the common etiological agents are well-described, addressing IOSD in large groups of animals presents a management challenge to the clinician and logistical challenges to shelter employees. Treatments, diagnostics, and prevention strategies that are effective in privately owned or experimental animals may be impractical or ineffective in the shelter environment. This review article focuses on the relative prevalence of etiological agents in feline IOSD, practical diagnostic testing protocols, prevention strategies, and treatment of IOSD in shelter-housed cats. Discrepancies between experimental laboratory-based studies and clinical trials assessing therapeutics for treatment of feline herpes virus are highlighted. Further high-quality clinical trials are necessary to determine optimal preventative and therapeutic protocols for IOSD in shelter-housed cats.
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Affiliation(s)
- Andrew C Lewin
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Sarah K Hicks
- Shelter Medicine Program University of Wisconsin-Madison, School of Veterinary Medicine, Madison, Wisconsin, USA
| | - Renee T Carter
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
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Covert JC, Thomasy SM, Kado-Fong H, Kon LN, Kass PH, Reilly CM, Lappin MR, Margulies BJ, Maggs DJ. Pilot Study of the Safety and Tolerability of a Subconjunctival Penciclovir Implant in Cats Experimentally Infected with Herpesvirus. J Ocul Pharmacol Ther 2019; 35:38-49. [DOI: 10.1089/jop.2018.0043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- Jill C. Covert
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, California
| | - Sara M. Thomasy
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, California
- Veterinary Medical Teaching Hospital, University of California-Davis, Davis, California
| | - Helen Kado-Fong
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, California
| | - Leslie N. Kon
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, California
| | - Philip H. Kass
- Department of Population Health and Reproduction, and University of California-Davis, Davis, California
| | - Christopher M. Reilly
- Department of Pathology Microbiology and Immunology, University of California-Davis, Davis, California
| | - Michael R. Lappin
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Barry J. Margulies
- Towson University Herpes Virus Laboratory, Department of Biological Sciences, Towson University, Towson, Maryland
| | - David J. Maggs
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, California
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Thomasy SM, Maggs DJ. A review of antiviral drugs and other compounds with activity against feline herpesvirus type 1. Vet Ophthalmol 2016; 19 Suppl 1:119-30. [PMID: 27091747 DOI: 10.1111/vop.12375] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Feline herpesvirus type 1 (FHV-1) is a common and important cause of ocular surface disease, dermatitis, respiratory disease, and potentially intraocular disease in cats. Many antiviral drugs developed for the treatment of humans infected with herpesviruses have been used to treat cats infected with FHV-1. Translational use of drugs in this manner ideally requires methodical investigation of their in vitro efficacy against FHV-1 followed by pharmacokinetic and safety trials in normal cats. Subsequently, placebo-controlled efficacy studies in experimentally inoculated animals should be performed followed, finally, by carefully designed and monitored clinical trials in client-owned animals. This review is intended to provide a concise overview of the available literature regarding the efficacy of antiviral drugs and other compounds with proven or putative activity against FHV-1, as well as a discussion of their safety in cats.
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Affiliation(s)
- Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, 95616, USA
| | - David J Maggs
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, 95616, USA
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Bol S, Bunnik EM. Lysine supplementation is not effective for the prevention or treatment of feline herpesvirus 1 infection in cats: a systematic review. BMC Vet Res 2015; 11:284. [PMID: 26573523 PMCID: PMC4647294 DOI: 10.1186/s12917-015-0594-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 11/05/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Feline herpesvirus 1 is a highly contagious virus that affects many cats. Virus infection presents with flu-like signs and irritation of ocular and nasal regions. While cats can recover from active infections without medical treatment, examination by a veterinarian is recommended. Lysine supplementation appears to be a popular intervention (recommended by > 90 % of veterinarians in cat hospitals). We investigated the scientific merit of lysine supplementation by systematically reviewing all relevant literature. METHODS NCBI's PubMed database was used to search for published work on lysine and feline herpesvirus 1, as well as lysine and human herpesvirus 1. Seven studies on lysine and feline herpesvirus 1 (two in vitro studies and 5 studies with cats), and 10 publications on lysine and human herpesvirus 1 (three in vitro studies and 7 clinical trials) were included for qualitative analysis. RESULTS There is evidence at multiple levels that lysine supplementation is not effective for the prevention or treatment of feline herpesvirus 1 infection in cats. Lysine does not have any antiviral properties, but is believed to act by lowering arginine levels. However, lysine does not antagonize arginine in cats, and evidence that low intracellular arginine concentrations would inhibit viral replication is lacking. Furthermore, lowering arginine levels is highly undesirable since cats cannot synthesize this amino acid themselves. Arginine deficiency will result in hyperammonemia, which may be fatal. In vitro studies with feline herpesvirus 1 showed that lysine has no effect on the replication kinetics of the virus. Finally, and most importantly, several clinical studies with cats have shown that lysine is not effective for the prevention or the treatment of feline herpesvirus 1 infection, and some even reported increased infection frequency and disease severity in cats receiving lysine supplementation. CONCLUSION We recommend an immediate stop of lysine supplementation because of the complete lack of any scientific evidence for its efficacy.
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Affiliation(s)
- Sebastiaan Bol
- Department of Botany and Plant Sciences, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA.
| | - Evelien M Bunnik
- Department of Cell Biology and Neuroscience, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA.
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Cave NJ, Dennis K, Gopakumar G, Dunowska M. Effects of physiologic concentrations of l-lysine on in vitro replication of feline herpesvirus 1. Am J Vet Res 2014; 75:572-80. [PMID: 24866513 DOI: 10.2460/ajvr.75.6.572] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the effects of various concentrations of l-lysine on in vitro replication of feline herpesvirus 1 (FHV-1). SAMPLE Cultures of Crandell-Rees feline kidney (CRFK) cells. PROCEDURES CRFK cells were inoculated with FHV-1 and maintained in media with 20 combinations of l-arginine and l-lysine concentrations. Changes in cell viability were monitored by continuous measurement of electrical impedance of cultured cells and by observation of viral cytopathic effects. Viral load was determined by use of quantitative PCR assay in supernatants obtained from infected cultures at specified time points. RESULTS Increases in l-lysine concentration had no effect on the kinetics of cell death in FHV-1-infected cultures. There was also no significant effect (r(2) < 0.1) on viral DNA load for l-arginine concentrations ≥ 12 μg/mL There was a significant effect of increases in l-lysine concentration on viral DNA load in media supplemented with 6 μg of l-arginine/mL (mean ± SD slope, -4,641 ± 1,626 units; adjusted r(2) = 0.45). However, the difference between the lowest (1 × 10(6.28) copies/μL) and highest (1 × 10(6.86) copies/μL) FHV-1 DNA load in these media was < 1 logarithm. CONCLUSIONS AND CLINICAL RELEVANCE The difference in FHV-1 DNA load was unlikely to be biologically important. Various l-lysine concentrations did not inhibit in vitro replication of FHV-1 at l-arginine concentrations sufficient to maintain cell growth. This conclusion was consistent with results of other studies in which investigators have not detected a consistently beneficial effect when l-lysine is administered to FHV-1-infected cats.
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Affiliation(s)
- Nicholas J Cave
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North 4410, New Zealand
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Friedl Y, Schulz B, Knebl A, Helps C, Truyen U, Hartmann K. Efficacy of passively transferred antibodies in cats with acute viral upper respiratory tract infection. Vet J 2014; 201:316-21. [DOI: 10.1016/j.tvjl.2014.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 04/22/2014] [Accepted: 05/02/2014] [Indexed: 11/28/2022]
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Maes R. Felid herpesvirus type 1 infection in cats: a natural host model for alphaherpesvirus pathogenesis. ISRN VETERINARY SCIENCE 2012; 2012:495830. [PMID: 23762586 PMCID: PMC3671728 DOI: 10.5402/2012/495830] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 10/20/2012] [Indexed: 11/23/2022]
Abstract
Feline herpesvirus 1 (FeHV-1) is an alphaherpesvirus that causes feline viral rhinotracheitis, an important viral disease of cats on a worldwide basis. Acute FeHV-1 infection is associated with both upper respiratory and ocular signs. Following the acute phase of the disease lifelong latency is established, primarily in sensory neuronal cells. As is the case with human herpes simplex viruses, latency reactivation can result in recrudescence, which can manifest itself in the form of serious ocular lesions. FeHV-1 infection in cats is a natural host model that is useful for the identification of viral virulence genes that play a role in replication at the mucosal portals of entry or are mediators of the establishment, maintenance, or reactivation of latency. It is also a model system for defining innate and adaptive immunity mechanisms and for immunization strategies that can lead to better protection against this and other alphaherpesvirus infections.
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Affiliation(s)
- Roger Maes
- Departments of Pathobiology and Diagnostic Investigation and Microbiology and Molecular Genetics, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
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Infectious Diseases. THE CAT 2012. [PMCID: PMC7161403 DOI: 10.1016/b978-1-4377-0660-4.00033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Respiratory and Thoracic Medicine. THE CAT 2012. [PMCID: PMC7158197 DOI: 10.1016/b978-1-4377-0660-4.00030-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
PRACTICAL RELEVANCE Feline herpesvirus-1 (FHV-1) is a major cause of feline morbidity. Following exposure to the virus, virtually all cats become persistently infected and many of these will develop recrudescent disease on one or more occasions during their lifetime. Acute ocular herpetic disease manifests as conjunctivitis, corneal ulceration and keratitis, and can be severe and painful. Repeated bouts of recrudescent ocular disease can lead to progressive corneal pathology that can be ultimately blinding in affected cats. GLOBAL IMPORTANCE FHV-1 has a worldwide distribution, with reported exposure rates in some cat populations of up to 97%. As such it is a significant cause of clinical disease in the global cat population. PATIENT GROUP Young and adolescent cats are most at risk of acute primary disease, and the vast majority of these will become persistently infected. Around half of all persistently infected cats will shed virus at some stage in their life and these may develop recrudescent ocular disease. CLINICAL CHALLENGES Treatment of FHV-1 ocular disease is challenging. Antiviral medications may be expensive, and require good owner and patient compliance. Clinical responses in patients can be variable. Selecting the appropriate therapeutic approach requires good clinical judgement, with assessment of factors such as severity and stage of clinical disease, patient and owner compliance, and financial considerations. EVIDENCE BASE Although a wide range of antiviral treatments is available, few have been tested in controlled clinical trials. Therapeutic decisions are, therefore, often based on results of in vitro studies, case-based reports and anecdote. Large, masked, controlled clinical trials are required in order to determine the efficacy of the antiviral drugs currently available to treat FHV-1.
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Affiliation(s)
- David Gould
- Manor Farm Business Park, Higham Gobion, Hertfordshire SG5 3HR, UK.
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13
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Abstract
PRACTICAL RELEVANCE Corneal ulcers in cats (ulcerative keratitis) are a common presenting complaint, and are a frequent sequela to feline herpesvirus (FHV-1) infection. In fact, it is fair to assume an FHV-1 aetiology until proven otherwise. In practice, therefore, many cases of corneal ulceration can be treated medically, but treatment can frequently be challenging, with the need to tailor therapy carefully to the type of ulcer, the individual cat and its temperament. PATIENT GROUP All age groups and breeds can suffer with ulcerative keratitis although some breeds are over-represented for some types of corneal ulceration. EVIDENCE BASE The scientific literature on feline ulcerative keratitis is extensive, particularly that related to FHV-1 infection. This article reviews the medical treatment options for corneal ulceration in cats with reference to the current evidence base.
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Affiliation(s)
- Claudia Hartley
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK.
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Jackson JC, Duodu KG, Holse M, Lima de Faria MD, Jordaan D, Chingwaru W, Hansen A, Cencic A, Kandawa-Schultz M, Mpotokwane SM, Chimwamurombe P, de Kock HL, Minnaar A. The morama bean (Tylosema esculentum): a potential crop for southern Africa. ADVANCES IN FOOD AND NUTRITION RESEARCH 2010; 61:187-246. [PMID: 21092905 DOI: 10.1016/b978-0-12-374468-5.00005-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The morama bean is an underutilized leguminous oilseed native to the Kalahari Desert and neighboring sandy regions of Botswana, Namibia, and South Africa (Limpopo, North-West, Gauteng, and Northern Cape provinces), and forms part of the diet of the indigenous population in these countries. It is also known as gemsbok bean, moramaboontjie, elandboontjie, braaiboonjie, marama, marumana, tsi, tsin, gami, and ombanui. It is reported as an excellent source of good quality protein (29-39%); its oil (24-48%) is rich in mono- and di-unsaturated fatty acids and contains no cholesterol. Morama is a good source of micronutrients such as calcium, iron, zinc, phosphate, magnesium, and B vitamins including folate. It is also reported to be a potential source of phytonutrients including phenolic compounds (e.g., tannins), trypsin inhibitors, phytates, and oligosaccharides, components which have been shown in other foods to contribute to health in particular, prevention of noncommunicable diseases such as cardiovascular diseases, diabetes, and some cancers. From a nutritional and health perspective, the morama bean has potential commercial value as a cash crop and value-added products, particularly in the communities where it is found.
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Affiliation(s)
- Jose C Jackson
- Centre for Scientific Research, Indigenous Knowledge and Innovation (CESRIKI), University of Botswana, Botswana.
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Drazenovich TL, Fascetti AJ, Westermeyer HD, Sykes JE, Bannasch MJ, Kass PH, Hurley KF, Maggs DJ. Effects of dietary lysine supplementation on upper respiratory and ocular disease and detection of infectious organisms in cats within an animal shelter. Am J Vet Res 2009; 70:1391-400. [PMID: 19878022 DOI: 10.2460/ajvr.70.11.1391] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine within a cat shelter effects of dietary lysine supplementation on nasal and ocular disease and detection of nucleic acids of Chlamydophila felis, feline calicivirus (FCV), and feline herpesvirus (FHV-1). ANIMALS 261 adult cats. PROCEDURES Cats were fed a diet containing 1.7% (basal diet; control cats) or 5.7% (supplemented diet; treated cats) lysine for 4 weeks. Plasma concentrations of lysine and arginine were assessed at the beginning (baseline) and end of the study. Three times a week, cats were assigned a clinical score based on evidence of nasal and ocular disease. Conjunctival and oropharyngeal swab specimens were tested for FHV-1, FCV, and C felis nucleic acids once a week. RESULTS Data were collected from 123, 74, 59, and 47 cats during study weeks 1, 2, 3, and 4, respectively. By study end, plasma lysine concentration in treated cats was greater than that in control cats and had increased from baseline. There was no difference between dietary groups in the proportion of cats developing mild disease. However, more treated cats than control cats developed moderate to severe disease during week 4. During week 2, FHV-1 DNA was detected more commonly in swab specimens from treated versus control cats. CONCLUSIONS AND CLINICAL RELEVANCE Dietary lysine supplementation in the amount used in our study was not a successful means of controlling infectious upper respiratory disease within a cat shelter. Rather, it led to increases in disease severity and the incidence of detection of FHV-1 DNA in oropharyngeal or conjunctival mucosal swab specimens at certain time points.
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Affiliation(s)
- Tracy L Drazenovich
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA
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Rees TM, Lubinski JL. Oral supplementation with L-lysine did not prevent upper respiratory infection in a shelter population of cats. J Feline Med Surg 2008; 10:510-3. [PMID: 18547855 PMCID: PMC11271227 DOI: 10.1016/j.jfms.2008.03.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2008] [Indexed: 11/18/2022]
Abstract
Cats in animal shelters are highly susceptible to infection by feline herpesvirus (FHV) by virtue of their stress and close proximity to other cats. Animal shelters take several different approaches to prevent FHV-related upper respiratory infections (URIs), including empirically treating all cats with L-lysine, a supplement believed to prevent the replication of FHV and, therefore, manifestations of herpesvirus infections. In this study we tested oral supplementation of L-lysine as a means to prevent URIs. One hundred and forty-four cats were treated with L-lysine in a small amount of canned food once daily. A 'no treatment' group of 147 cats received no lysine during the course of the study. The development of conjunctivitis or URI was tracked between the two groups. In all measures, there was no effect between the two groups, suggesting that lysine was not able to prevent URI or conjunctivitis in our shelter situation. Cats entering shelters encounter stressors that may make them more susceptible to FHV reactivation or infection. Infection control and control of fomite transmission are also key to keeping cats healthy in a group housing situation. The finding that lysine did not prevent URI in this animal shelter suggests that shelters may better use their resources by finding ways to decrease stress among their feline population, focusing on proper infection control measures, and limiting fomite transmission of disease.
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Affiliation(s)
- Tina M Rees
- Humane Society of Indianapolis, 7929 N Michigan Road, Indianapolis, IN 46268, USA.
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Opinion of the Scientific Panel on Additives and Products or Substances used in Animal Feed on the safety and efficacy of L-lysine sulphate (Vitalys®Liquid and Dry) for all animal species. EFSA J 2007. [DOI: 10.2903/j.efsa.2007.522] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Low HC, Powell CC, Veir JK, Hawley JR, Lappin MR. Prevalence of feline herpesvirus 1, Chlamydophila felis, and Mycoplasma spp DNA in conjunctival cells collected from cats with and without conjunctivitis. Am J Vet Res 2007; 68:643-8. [PMID: 17542698 DOI: 10.2460/ajvr.68.6.643] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To use PCR assays to determine the prevalence of feline herpesvirus 1 (FHV-1), Chlamydophila felis, and Mycoplasma spp DNA in conjunctival cells collected from cats with and without conjunctivitis; to compare results of conventional and real-time fluorogenic PCR assays for amplification of FHV-1 DNA; and to determine whether copy numbers of FHV-1 DNA are correlated with conjunctivitis. ANIMALS 55 cats with active conjunctivitis, 39 healthy cats that never had conjunctivitis, and 32 cats with a history of conjunctivitis that had been resolved for at least 3 months. PROCEDURES Samples were obtained by rolling cotton-tipped applicators on the ventral conjunctiva of awake cats treated topically with proparacaine. The DNA was extracted from the swab specimens and assessed in PCR assays to detect DNA of FHV-1 (fluorogenic PCR assay and conventional PCR assay), Mycoplasma spp (conventional PCR assay), and C felis (conventional PCR assay). RESULTS Overall prevalence rates of FHV-1, C felis, and Mycoplasma spp as assessed by the conventional PCR assays were 6.7%, 3.2%, and 9.6%, respectively. Percentage concordance between conventional PCR and fluorogenic PCR assays for FHV-1 was 92.5%. There were no significant differences among the 3 groups of cats for the mean copy number of FHV-1 divided by the copy number of glyceraldehyde-3-phosphate dehydrogenase. CONCLUSIONS AND CLINICAL RELEVANCE Mycoplasma spp were the most prevalent organism detected and was associated with conjunctivitis. This study could not confirm that there are increased copy numbers of FHV-1 DNA in cats with conjunctivitis, compared with the copy numbers for cats without conjunctivitis.
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Affiliation(s)
- Heather C Low
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
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Maggs DJ, Sykes JE, Clarke HE, Yoo SH, Kass PH, Lappin MR, Rogers QR, Waldron MK, Fascetti AJ. Effects of dietary lysine supplementation in cats with enzootic upper respiratory disease. J Feline Med Surg 2007; 9:97-108. [PMID: 17055313 PMCID: PMC10832735 DOI: 10.1016/j.jfms.2006.08.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2006] [Indexed: 10/24/2022]
Abstract
To determine the effectiveness of dietary lysine supplementation in cats with enzootic upper respiratory disease (URD), 50 cats were fed a ration containing 11 or 51 g lysine/kg diet for 52 days. Food intake, body weight, clinical signs, plasma amino acid concentrations and presence of Chlamydophila felis or feline herpesvirus (FHV)-1 DNA within the conjunctival fornix were assessed. Food and lysine intake of both dietary groups decreased between days 17 and 22, coinciding with peak disease and viral presence. Mean disease score for cats fed the supplemented ration (0.94) was higher than for those fed the basal diet (0.21); however, this could be attributed to a small subset of male cats which demonstrated fighting behavior that may have contributed to stress within that cage. FHV-1 DNA was detected on 12 occasions in six cats receiving the supplemented diet and on one occasion in one cat fed the basal diet. C felis DNA was never detected. Mean plasma arginine concentration was lower and plasma lysine concentration was higher in supplemented cats. Mean plasma arginine concentration declined throughout the study in both dietary groups. Data from the present study raise important questions but do not permit a definitive conclusion regarding the efficacy of dietary lysine supplementation in cats with enzootic URD.
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Affiliation(s)
- David J Maggs
- Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA 95616, USA.
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Gaskell R, Dawson S, Radford A, Thiry E. Feline herpesvirus. Vet Res 2007; 38:337-54. [PMID: 17296160 DOI: 10.1051/vetres:2006063] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Accepted: 12/14/2006] [Indexed: 11/14/2022] Open
Abstract
Feline herpesvirus (FHV-1; felid herpesvirus 1 (FeHV-1)) is an alphaherpesvirus of cats closely related to canine herpesvirus-1 and phocine herpesvirus-1. There is only one serotype of the virus and it is relatively homogenous genetically. FeHV-1 is an important cause of acute upper respiratory tract and ocular disease in cats. In addition, its role in more chronic ocular disease and skin lesions is increasingly being recognised. Epidemiologically, FeHV-1 behaves as a typical alphaherpesvirus whereby clinically recovered cats become latently infected carriers which undergo periodic episodes of virus reactivation, particularly after a stress. The primary site of latency is the trigeminal ganglion. Conventional inactivated and modified-live vaccines are available and protect reasonably well against disease but not infection, although viral shedding may be reduced. Genetically engineered vaccines have also been developed, both for FeHV-1 and as vector vaccines for other pathogens, but none is as yet marketed.
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Affiliation(s)
- Rosalind Gaskell
- Department of Veterinary Pathology, Faculty of Veterinary Science, University of Liverpool, Leahurst, Chester High Road, Neston, S. Wirral, CH64 7TE, United Kingdom.
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Ledbetter EC, Riis RC, Kern TJ, Haley NJ, Schatzberg SJ. Corneal ulceration associated with naturally occurring canine herpesvirus-1 infection in two adult dogs. J Am Vet Med Assoc 2006; 229:376-84. [PMID: 16881829 DOI: 10.2460/javma.229.3.376] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
CASE DESCRIPTION An 8-year-old Labrador Retriever with diabetes mellitus in which bilateral phacoemulsification had been performed 3 weeks earlier was evaluated for acute onset of blepharospasm, and a 7-year-old Miniature Schnauzer with chronic immune-mediated thrombocytopenia was reevaluated for keratoconjunctivitis sicca that had been diagnosed 4 weeks earlier. CLINICAL FINDINGS Dendritic corneal ulcerations were detected in both dogs. Canine herpesvirus-1 (CHV-1) was isolated from corneal swab specimens obtained during the initial evaluation of each dog and during recheck examinations performed until the ulcerations were healed. Canine herpesvirus-1 serum neutralization titers were detected in both dogs. Results of virus isolation from oropharyngeal and genital swab specimens were negative for both dogs. The isolated viruses were identified as CHV-1 via immunofluorescence, transmission electron microscopy, PCR assay, and gene sequencing. Negative controls for PCR assay and virus isolation included conjunctival swab specimens from 50 dogs without extraocular disease and corneal swab specimens from 50 dogs with corneal ulcers, respectively. TREATMENT AND OUTCOME Lesions resolved in both dogs after topical administration of idoxuridine or trifluridine and discontinuation of topically administered immunosuppressive medications. CLINICAL RELEVANCE To the authors' knowledge, this is the first report of corneal ulcerations associated with naturally occurring CHV-1 infection and may represent local ocular recrudescence of latent CHV-1 infection. The viruses isolated were identified as CHV-1, and the morphology, antigenicity, and genotype were similar to those for CHV-1 isolates obtained from a puppy that died from systemic CHV-1 infection.
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Affiliation(s)
- Eric C Ledbetter
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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Affiliation(s)
- Paul B Bloom
- Allergy and Dermatology Clinic for Animals, 31205 Five Mile Road, Livonia, MI 48158, USA.
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Stiles J, Townsend WM, Rogers QR, Krohne SG. Effect of oral administration of L-lysine on conjunctivitis caused by feline herpesvirus in cats. Am J Vet Res 2005; 63:99-103. [PMID: 16206789 DOI: 10.2460/ajvr.2002.63.99] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether oral administration of L-lysine to cats would lessen the severity of conjunctivitis caused by feline herpesvirus (FHV-1). ANIMALS 8 healthy young adult cats. PROCEDURE Cats received oral administration of lysine monohydrochloride (500 mg, q 12 h) or placebo (lactose) beginning 6 hours prior to inoculation of virus. The left conjunctival sac received a 50-microl suspension of FHV-1 grown in cell culture (1.8 X 10(8) tissue culture infective dose50) on day 1. Cats were evaluated and scores given for clinical signs each day for 21 days. Samples for virus isolation were collected from the eye and throat every third day. Plasma lysine and arginine concentrations were measured prior to the study and on days 3, 14, and 22. RESULTS Cats that received lysine had less severe conjunctivitis than cats that received placebo. Virus isolation results did not differ between the groups. Plasma lysine concentration was significantly higher in cats that received lysine, compared with control cats, whereas plasma arginine concentrations did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE Oral administration of 500 mg of lysine to cats was well tolerated and resulted in less severe manifestations of conjunctivitis caused by FHV-1, compared with cats that received placebo. Oral administration of lysine may be helpful in early treatment for FHV-1 infection by lessening the severity of disease.
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Affiliation(s)
- Jean Stiles
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
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Abstract
Feline herpesvirus type 1 (FHV-1) infection, but not necessarily chronic or recurrent disease, is common throughout domestic cat populations worldwide. Knowledge of a few essential virological facts permits practitioners to provide appropriate advice to owners of individual pet cats infected with this virus and to assist in the management of shelters and other multicat households in which the virus is enzootic. This article discusses pathogenesis, diagnostic techniques, and clinical signs considered characteristic of infection with FHV-1. Treatment options are considered under the broad categories of supportive care, antiviral agents, and adjunctive therapies.
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Affiliation(s)
- David J Maggs
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA.
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Fascetti AJ, Maggs DJ, Kanchuk ML, Clarke HE, Rogers QR. Excess dietary lysine does not cause lysine-arginine antagonism in adult cats. J Nutr 2004; 134:2042S-2045S. [PMID: 15284398 DOI: 10.1093/jn/134.8.2042s] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Andrea J Fascetti
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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Maggs DJ, Clarke HE. In vitro efficacy of ganciclovir, cidofovir, penciclovir, foscarnet, idoxuridine, and acyclovir against feline herpesvirus type-1. Am J Vet Res 2004; 65:399-403. [PMID: 15077679 DOI: 10.2460/ajvr.2004.65.399] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To establish the in vitro efficacy of 4 novel drugs (ie, ganciclovir, cidofovir, penciclovir, and foscarnet) against feline herpesvirus type-1 (FHV-1) and compare their antiviral efficacy with that of acyclovir and idoxuridine. SAMPLE POPULATION Cultured Crandell-Reese feline kidney (CRFK) cells and FHV-1 strain 727 PROCEDURE For each drug, antiviral effect was estimated by use of conventional plaque-reduction assays, and inhibitory concentration 50 (IC50; drug concentration at which plaque numbers were reduced by 50% relative to the number of plaques for nontreated control wells) was calculated. To determine whether observed antiviral effects were related to alterations in the number or viability of CRFK cells, cytotoxicity assays were performed at 1, 2, and 10 times the median IC50 for each antiviral drug. RESULTS Median IC50 for each drug was as follows: ganciclovir, 5.2 microM; cidofovir, 11.0 microM; penciclovir, 13.9 microM; foscarnet, 232.9 microM; idoxuridine, 4.3 microM; and acyclovir, 57.9 microM. Obvious changes in morphologic characteristics, confluence, or viability of CRFK cells were not observed at concentrations up to and including 2 times the IC50 for each drug. CONCLUSIONS AND CLINICAL RELEVANCE In vitro efficacy of idoxuridine and ganciclovir against FHV-1 was approximately equivalent and about twice that of cidofovir and penciclovir. Foscarnet appeared to be comparatively ineffective. Given the reasonable clinical efficacy of idoxuridine in cats infected with FHV-1, clinical trials of ganciclovir, cidofovir, and penciclovir or their prodrug forms appear to be warranted.
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Affiliation(s)
- David J Maggs
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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Abstract
Ophthalmic manifestations of viral disease are commonly encountered in veterinary practice. Although the number of antiviral agents is rapidly increasing, the efficacy of many of these drugs against animal viral pathogens may not be known. Furthermore, some of these newer medications may, in fact. be toxic to animal patients. Continued research on the efficacy of these medications in treating viral diseases of veterinary importance is warranted.A thorough review of the ever-growing body of literature is imperative before instituting any new or unknown antiviral therapy. At this time, feline HSV-1 infections remain the most well understood of the ocular viral infections that veterinary practitioners may be called on to treat. Ironically, the number of antiviral agents proven to be effective in naturally occurring clinical cases of FHV-I remains quite limited. With new medications being investigated, this paucity of information on efficacious antiviral therapeutic agents will hopefully improve.
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Affiliation(s)
- Laurence E Galle
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Clydesdale Hall, 379 East Campus Drive, Columbia, MO 65211, USA.
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Beaumont SL, Maggs DJ, Clarke HE. Effects of bovine lactoferrin on in vitro replication of feline herpesvirus. Vet Ophthalmol 2003; 6:245-50. [PMID: 12950656 DOI: 10.1046/j.1463-5224.2003.00301.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the effects of bovine lactoferrin on in vitro replication of feline herpes virus (FHV-1) and to determine at what points during viral replication these effects occur. SAMPLE POPULATION Cultured Crandell-Reese feline kidney (CRFK) cells and FHV-1 strain 727. PROCEDURE Five concentrations of bovine lactoferrin (0.5, 1, 2, 5, and 10 mg/mL) were added at one or more of three time points during conventional plaque reduction assays: (a) uninfected CRFK cells were incubated in lactoferrin-containing medium for 30 min prior to viral adsorption; (b) virus was suspended in lactoferrin-containing medium prior to and during adsorption, or (c) CRFK cells were incubated with lactoferrin-containing medium for 48 h following viral adsorption. Plaques were counted and antiviral effect expressed as percent inhibition relative to control medium that contained no lactoferrin. RESULTS Exposure of CRFK cells to lactoferrin prior to or during viral adsorption inhibited FHV-1 replication by 87-96% (mean: 91%). Application of lactoferrin following viral adsorption had no appreciable effect on FHV-1 replication. No additive or synergistic effects were noted when lactoferrin was added at multiple steps. These effects were similar at all concentrations of lactoferrin tested. Cytotoxic effects of lactoferrin on CRFK cells were not observed at any concentration tested. CONCLUSIONS AND CLINICAL RELEVANCE Bovine lactoferrin has a notable inhibitory effect on the in vitro replication of FHV-1 prior to and during, but not following viral adsorption. These findings strongly suggest that lactoferrin inhibits FHV-1 adsorption to the cell surface and/or penetration of the virus into the cell. Clinical effects of topical lactoferrin in acute or recrudescent herpetic episodes in cats warrant investigation.
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Affiliation(s)
- Stephanie L Beaumont
- Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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Maggs DJ, Nasisse MP, Kass PH. Efficacy of oral supplementation with L-lysine in cats latently infected with feline herpesvirus. Am J Vet Res 2003; 64:37-42. [PMID: 12518876 DOI: 10.2460/ajvr.2003.64.37] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To examine the effects of orally administered L-lysine on clinical signs of feline herpesvirus type 1 (FHV-1) infection and ocular shedding of FHV-1 in latently infected cats. ANIMALS 14 young adult, FHV-1-naive cats. PROCEDURE Five months after primary conjunctival inoculation with FHV-1, cats were rehoused and assigned to receive 400 mg of L-lysine in food once daily for 30 days or food only. On day 15, all cats received methylprednisolone to induce viral reactivation. Clinical signs of infection were graded, and viral shedding was assessed by a polymerase chain reaction assay throughout our study. Peak and trough plasma amino acid concentrations were assessed on day 30. RESULTS Fewer cats and eyes were affected by conjunctivitis, and onset of clinical signs of infection was delayed on average by 7 days in cats receiving L-lysine, compared with cats in the control group; however, significant differences between groups were not demonstrated. Significantly fewer viral shedding episodes were identified in the treatment group cats, compared with the control group cats, after rehousing but not following corticosteroid-induced viral reactivation. Mean plasma L-lysine concentration was significantly increased at 3 hours but not at 24 hours after L-lysine administration. Plasma arginine concentration was not significantly altered. CONCLUSIONS AND CLINICAL RELEVANCE Once daily oral administration of 400 mg of L-lysine to cats latently infected with FHV-1 was associated with reduced viral shedding following changes in housing and husbandry but not following corticosteroid administration. This dose caused a significant but short-term increase in plasma L-lysine concentration without altering plasma arginine concentration or inducing adverse clinical effects.
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Affiliation(s)
- David J Maggs
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
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