RESUMEN
Human metapneumovirus, a paramyxovirus discovered in 2001, is a major cause of lower respiratory infection in adults and children worldwide. There are no licensed vaccines or drugs for human metapneumovirus. We developed a fluorescent, cell-based medium-throughput screening assay for human metapneumovirus that captures inhibitors of all stages of the viral lifecycle except budding of progeny virus particles from the cell membrane. We optimized and validated the assay and performed a successful medium-throughput screening. A number of hits were identified, several of which were confirmed to inhibit viral replication in secondary assays. This assay offers potential to discover new antivirals for human metapneumovirus and related respiratory viruses. Compounds discovered using the medium-throughput screening may also provide useful probes of viral biology.
Asunto(s)
Antivirales/farmacología , Descubrimiento de Drogas , Evaluación Preclínica de Medicamentos/métodos , Metapneumovirus/efectos de los fármacos , Animales , Antivirales/aislamiento & purificación , Línea Celular , Humanos , Metapneumovirus/patogenicidad , Metapneumovirus/fisiología , Pruebas de Sensibilidad Microbiana , Infecciones del Sistema Respiratorio/microbiología , Pase Seriado , Replicación Viral/efectos de los fármacosRESUMEN
BACKGROUND: Human metapneumovirus (HMPV) is a pneumovirus known to cause respiratory disease in children. It was identified as a pathogen in 2001 and its healthcare burden and associated costs are not fully understood. OBJECTIVES: This study aimed to assess the clinical characteristics of children with HMPV infection admitted to paediatric intensive care units (PICUs) across the United Kingdom (UK) over a nine-year period and to estimate the associated costs of care. STUDY DESIGN: Data were collected from the UK paediatric intensive care audit network (PICANet) and costs calculated using the National Health Service (NHS) reference costing scheme. RESULTS: There were 114 admissions in which HMPV was detected. The number of admissions associated with a code of HMPV rose steadily over the study period (three in 2006 to 28 in 2014) and showed significant seasonal variability, with the peak season being from November to May. Children required varying levels of intensive care support from minimal to complex support including invasive ventilation, inotropes, renal replacement therapy and extracorporeal membrane oxygenation (ECMO). HMPV was associated with five deaths during the study period. The associated costs of PICU admissions were estimated to be between £2,256,823 and £3,997,823 over the study period, with estimated annual costs rising over the study period due to increasing HMPV admissions. CONCLUSIONS: HMPV is associated with a significant healthcare burden and associated cost of care in PICUs in the UK.
Asunto(s)
Hospitalización/estadística & datos numéricos , Unidades de Cuidado Intensivo Pediátrico/estadística & datos numéricos , Infecciones por Paramyxoviridae/epidemiología , Adolescente , Niño , Preescolar , Costo de Enfermedad , Femenino , Hospitalización/economía , Humanos , Lactante , Recién Nacido , Unidades de Cuidado Intensivo Pediátrico/economía , Masculino , Metapneumovirus/patogenicidad , Programas Nacionales de Salud/estadística & datos numéricos , Infecciones por Paramyxoviridae/economía , Infecciones por Paramyxoviridae/mortalidad , Estudios Retrospectivos , Estaciones del Año , Reino Unido/epidemiologíaRESUMEN
INTRODUCTION: Human metapneumovirus (hMPV) has become one of the major pathogens causing acute respiratory infections (ARI) mainly affecting young children, immunocompromised patients, and the elderly. Currently there are no licensed vaccines against this virus. Areas covered: Since the discovery of hMPV in 2001, many groups have focused on developing vaccines against this pathogen. This review presents the outcomes and perspectives derived from preclinical studies performed in cell cultures and animals as well as the only candidate that has reached evaluation in a clinical trial. Limitations of the current vaccine candidates are discussed and perspectives for the development of plant-based vaccines are analyzed. Expert commentary: Several hMPV vaccine candidates are under development with the potential to progress into clinical trials. In parallel, the molecular farming field offers new opportunities to generate innovative vaccines that will offer several advantages in the fight against hMPV.
Asunto(s)
Metapneumovirus/inmunología , Infecciones por Paramyxoviridae/prevención & control , Vacunas Virales/inmunología , Vacunas Virales/aislamiento & purificación , Animales , Ensayos Clínicos como Asunto , Modelos Animales de Enfermedad , Descubrimiento de Drogas/tendencias , Evaluación Preclínica de Medicamentos , Humanos , Modelos Biológicos , Infecciones por Paramyxoviridae/inmunologíaRESUMEN
Se presenta el caso de un varón prematuro y con cardiopatía congénita de 4 meses de edad que presentaba unas bronquiolitis y conjuntivitis causadas por CI Metapneumovirus humano. El virus se detectó tanto en el aspirado nasofaríngeo como en la secreción conjuntival. Debido a la rareza de esta entidad, se revisa la literatura correspondiente a esta entidad (AU)
A premature male with congenital heart disease and 4 months of age had a bronchiolitis and conjunctivitis caused by human metapneumovirus. The virus was detected in both the nasopharyrngeal aspirate as coniunctival secretion. Because of the rarity of this entity we reviewed scientific literature (AU)
Asunto(s)
Humanos , Masculino , Lactante , Conjuntivitis Viral/complicaciones , Conjuntivitis Viral/diagnóstico , Conjuntivitis Viral/etiología , Conjuntivitis/complicaciones , Conjuntivitis/virología , Metapneumovirus , Metapneumovirus/inmunología , Metapneumovirus/aislamiento & purificación , Combinación Amoxicilina-Clavulanato de Potasio/uso terapéutico , Enfermedades del Prematuro/diagnóstico , Bronquiolitis/complicaciones , Bronquiolitis/diagnóstico , Bronquiolitis/terapia , Hospitalización/estadística & datos numéricos , Hospitalización/tendencias , Tiempo de Internación/tendenciasRESUMEN
BACKGROUND AND OBJECTIVE: Postoperative pain treatment in mastectomy remains a major challenge despite the multimodal approach. The aim of this study was to investigate the analgesic effect of intravenous lidocaine in patients undergoing mastectomy, as well as the postoperative consumption of opioids. METHODS: After approval by the Human Research Ethics Committee of the Instituto de Medicina Integral Prof. Fernando Figueira in Recife, Pernambuco, a randomized, blind, controlled trial was conducted with intravenous lidocaine at a dose of 3 mg/kg infused over 1 h in 45 women undergoing mastectomy under general anesthesia. One patient from placebo group was. RESULTS: Groups were similar in age, body mass index, type of surgery, and postoperative need for opioids. Two of 22 patients in lidocaine group and three of 22 patients in placebo group requested opioid (p = 0.50). Pain on awakening was identified in 4/22 of lidocaine group and 5/22 of placebo group (p = 0.50); in the post-anesthetic recovery room in 14/22 and 12/22 (p = 0.37) of lidocaine and placebo groups, respectively. Pain evaluation 24 h after surgery showed that 2/22 and 3/22 patients (p = 0.50) of lidocaine and placebo groups, respectively, complained of pain. CONCLUSION: Intravenous lidocaine at a dose of 3 mg/kg administered over a period of an hour during mastectomy did not promote additional analgesia compared to placebo in the first 24 h, and has not decreased opioid consumption. However, a beneficial effect of intravenous lidocaine in selected and/or other therapeutic regimens patients cannot be ruled out. .
JUSTIFICATIVA E OBJETIVO: O tratamento da dor pós-operatória em mastectomia continua sendo um grande desafio apesar da abordagem multimodal. O objetivo deste estudo foi investigar o efeito analgésico da lidocaína intravenosa em pacientes submetidas a mastectomia, como também, o consumo de opioide pós-operatório. MÉTODOS: Após aprovação pelo comitê de ética e pesquisa em seres humanos do Instituto de Medicina Integral Prof. Fernando Figueira em Recife - Pernambuco foi realizado ensaio clínico aleatório encoberto placebo controlado com lidocaína intravenosa na dose de 3 mg/kg infundida em uma hora, em 45 mulheres submetidas a mastectomia sob anestesia geral. Excluída uma paciente do grupo placebo. RESULTADOS: Os grupos foram semelhantes quanto à idade, índice de massa corpórea, tipo de intervenção cirúrgica e necessidade de opioide no pós-operatório. Solicitaram opioide 2/22 pacientes nos grupos da lidocaína e 3/22 placebo (p = 0,50). Identificada a dor ao despertar em 4/22 no grupo lidocaína e 5/22 (p = 0,50) no grupo placebo; na sala de recuperação pós-anestésica em 14/22 e 12/22 (p = 0,37) nos grupos lidocaína e placebo respectivamente. Ao avaliar a dor 24 horas após o procedimento cirúrgico 3/22 e 2/22 (p = 0,50) das pacientes relataram dor em ambos os grupos respectivamente. CONCLUSÃO: A lidocaína intravenosa na dose de 3mg/kg administrada em um período de uma hora no transoperatório de mastectomia não promoveu analgesia adicional em relação ao grupo placebo nas primeiras 24 horas e não diminuiu o consumo de opioide. Contudo, um efeito benéfico da lidocaína intravenosa em pacientes selecionadas e/ou em outros regimes terapêuticos não pode ser descartado. .
JUSTIFICACIÓN Y OBJETIVO: El tratamiento del dolor postoperatorio en la mastectomía continúa siendo un gran reto a pesar del abordaje multimodal. El objetivo de este estudio fue investigar el efecto analgésico de la lidocaína intravenosa en pacientes sometidas a mastectomía, así como el consumo postoperatorio de opiáceos. MÉTODOS: Después de la aprobación por el Comité de Ética e Investigación en seres humanos del Instituto de Medicina Integral Prof. Fernando Figueira, en Recife, Pernambuco, se realizó un ensayo clínico aleatorizado, encubierto, placebo controlado con lidocaína intravenosa en una dosis de 3 mg/kg infundida en una hora, en 45 mujeres sometidas a mastectomía bajo anestesia general. Una paciente del grupo placebo fue excluida. RESULTADOS: Los grupos fueron similares en cuanto a la edad, índice de masa corporal, tipo de intervención quirúrgica y necesidad de opiáceos en el postoperatorio. Solicitaron opiáceos 2/22 pacientes en los grupos de la lidocaína y 3/22 placebo (p = 0,50). Fue identificado el dolor al despertar en 4/22 en el grupo lidocaína y 5/22 (p = 0,50) en el grupo placebo; en la sala de recuperación postanestésica en 14/22 y 12/22 (p = 0,37) en los grupos lidocaína y placebo, respectivamente. Al calcular el dolor 24 h después del procedimiento quirúrgico 3/22 y 2/22 (p = 0,50) de las pacientes relataron dolor en ambos grupos respectivamente. CONCLUSIÓN: La lidocaína intravenosa en una dosis de 3 mg/kg administrada en un período de una hora en el transoperatorio de mastectomía no generó analgesia adicional con relación al grupo placebo en las primeras 24 h y no disminuyó el consumo de opiáceos. Sin embargo, no puede ser descartado un efecto beneficioso de la lidocaína intravenosa en pacientes seleccionadas y/o en otros regímenes terapéuticos. .
Asunto(s)
Humanos , Metapneumovirus/genética , Transcripción Genética , Proteínas Virales/química , Secuencia de Aminoácidos , Adenosina Monofosfato/metabolismo , Cristalografía por Rayos X , ADN , Ácido Edético/farmacología , Simulación de Dinámica Molecular , Datos de Secuencia Molecular , Unión Proteica , Conformación Proteica , Multimerización de Proteína , Estabilidad Proteica , Subunidades de Proteína/química , ARN Viral/metabolismo , ARN Viral/ultraestructura , Dispersión del Ángulo Pequeño , Soluciones , Solventes , Proteínas Virales/metabolismo , Proteínas Virales/ultraestructura , Dedos de ZincRESUMEN
Human metapneumovirus (hMPV) is a major cause of respiratory tract infections in children, elderly and immunocompromised hosts, for which no vaccine or treatment are currently available. Oxidative stress and inflammatory responses represent important pathogenic mechanism(s) of hMPV infection. Here, we explored the potential protective role of dietary antioxidants in hMPV infection. Treatment of airway epithelial cells with resveratrol and quercetin during hMPV infection significantly reduced cellular oxidative damage, inflammatory mediator secretion and viral replication, without affecting viral gene transcription and protein synthesis, indicating that inhibition of viral replication occurred at the level of viral assembly and/or release. Modulation of proinflammatory mediator expression occurred through the inhibition of transcription factor nuclear factor (NF)-κB and interferon regulatory factor (IRF)-3 binding to their cognate site of endogenous gene promoters. Our results indicate the use of dietary antioxidants as an effective treatment approach for modulating hMPV induced lung oxidative damage and inflammation.
Asunto(s)
Antioxidantes/farmacología , Suplementos Dietéticos/análisis , Metapneumovirus/efectos de los fármacos , Infecciones por Paramyxoviridae/virología , Línea Celular , Citocinas/genética , Citocinas/inmunología , Humanos , Metapneumovirus/genética , Metapneumovirus/fisiología , Estrés Oxidativo/efectos de los fármacos , Infecciones por Paramyxoviridae/tratamiento farmacológico , Infecciones por Paramyxoviridae/inmunología , Infecciones por Paramyxoviridae/metabolismo , Quercetina/farmacología , Resveratrol , Estilbenos/farmacología , Replicación Viral/efectos de los fármacosRESUMEN
CONTEXT: Medicinal plants are well known for their use in traditional folk medicine as treatments for many diseases including infectious diseases. OBJECTIVE: Six Brazilian medicinal plant species were subjected to an antiviral screening bioassay to investigate and evaluate their biological activities against five viruses: bovine herpesvirus type 5 (BHV-5), avian metapneumovirus (aMPV), murine hepatitis virus type 3, porcine parvovirus and bovine respiratory syncytial virus. MATERIALS AND METHODS: The antiviral activity was determined by a titration technique that depends on the ability of plant extract dilutions (25 or 2.5 µg/mL) to inhibit the viral induced cytopathic effect and the extracts' inhibition percentage (IP). RESULTS: Two medicinal plant species showed potential antiviral activity. The Aniba rosaeodora Ducke (Lauraceae) extract had the best results, with 90% inhibition of viral growth at 2.5 µg/mL when the extract was added during the replication period of the aMPV infection cycle. The Maytenus ilicifolia (Schrad.) Planch. (Celastraceae) extracts at a concentration of 2.5 µg/mL exhibited antiviral activity during the attachment phase of BHV-5 (IP = 100%). DISCUSSION AND CONCLUSION: The biomonitored fractionation of the active extracts from M. ilicifolia and A. rosaeodora could be a potential tool for identifying their active compounds and determining the exact mechanism of action.
Asunto(s)
Antivirales/farmacología , Extractos Vegetales/farmacología , Plantas Medicinales/química , Enfermedades de los Animales/tratamiento farmacológico , Enfermedades de los Animales/virología , Animales , Antivirales/administración & dosificación , Antivirales/aislamiento & purificación , Brasil , Bovinos , Relación Dosis-Respuesta a Droga , Herpesvirus Bovino 5/efectos de los fármacos , Lauraceae/química , Maytenus/química , Medicina Tradicional , Metapneumovirus/efectos de los fármacos , Ratones , Extractos Vegetales/administración & dosificación , Porcinos , Replicación Viral/efectos de los fármacosRESUMEN
Drinking-water treatment with enrofloxacin is widely used to cure respiratory infections in turkeys. The current treatment regimen advises a 5-day treatment at 10 mg/kg body weight. Since enrofloxacin exerts a concentration-dependent activity it might be useful to provide the total treatment dose of 50 mg/kg total dose in a single-day treatment regimen. We therefore assessed whether single-day treatment regimens with 50 mg/kg body weight were clinically equivalent to the advised multiple-day treatment regimen with 10 mg/kg body weight for 5 days. For this purpose, five groups of 16 turkeys, 22 days old, were experimentally inoculated with avian metapneumovirus (APV) and Ornithobacterium rhinotracheale and subsequently treated in the drinking water with enrofloxacin, using either a single-day treatment regimen at 50 mg/kg body weight during a 5-h, 10-h or 20-h period or a standard 5-day treatment regimen at 10 mg/kg body weight/ day for 20 h. Although initially all dosage regimens cleared O. rhinotracheale from the trachea, 4 days after onset of treatment O. rhinotracheale bacteria were re-excreted in the single-day regimens but without worsening of the clinical symptoms. The 5-day treatment with 10 mg enrofloxacin/kg in turkeys provided the best results for the treatment of an O. rhinotracheale infection in turkeys by shortening the course and reducing the severity of clinical disease and by eliminating O. rhinotracheale from the respiratory tract without re-emergence. None of the used treatment regimens promoted the selection of bacterial clones with reduced susceptibility or resistance.
Asunto(s)
Infecciones por Flavobacteriaceae/veterinaria , Fluoroquinolonas/administración & dosificación , Metapneumovirus/patogenicidad , Ornithobacterium , Infecciones por Paramyxoviridae/veterinaria , Enfermedades de las Aves de Corral/terapia , Administración Oral , Animales , Protocolos Clínicos , Farmacorresistencia Bacteriana/efectos de los fármacos , Enrofloxacina , Infecciones por Flavobacteriaceae/terapia , Infecciones por Flavobacteriaceae/virología , Ornithobacterium/patogenicidad , Infecciones por Paramyxoviridae/terapia , Infecciones por Paramyxoviridae/virología , Enfermedades de las Aves de Corral/virología , Tráquea/patología , Resultado del Tratamiento , PavosRESUMEN
A dose titration and reduced duration medication study were performed to evaluate the current enrofloxacin treatment schedule in growing turkeys experimentally infected with avian metapneumovirus and Ornithobacterium rhinotracheale. Experimental groups of 17 four-week-old turkeys were first infected with avian metapneumovirus and 3 d later with O. rhinotracheale. Enrofloxacin treatment in the drinking water was started 24 h after O. rhinotracheale inoculation. In the dose titration study, enrofloxacin doses of 5, 10, and 20 mg/kg of BW were administered for 5 successive days. In the reduced duration medication study, the following enrofloxacin regimens were compared: 25 mg/kg of BW per day on d 0 and 2; 15 mg/kg of BW per day on d 0, 2, and 4; and 10 mg/kg of BW for 5 successive days. In both studies, all enrofloxacin treatments were equally efficacious (i.e., equally capable of shortening the course of clinical disease), eliminating O. rhinotracheale from the respiratory tract and reducing gross lesions. Ornithobacterium rhinotracheale bacteria were not recovered from any of the birds on enrofloxacin-supplemented media, indicating that none of the used treatment regimens promoted the selection of bacterial clones with reduced susceptibility or resistance to this antimicrobial agent. In conclusion, none of the alternative enrofloxacin treatment regimens yielded better results than the current prescribed treatment (i.e., 10 mg/kg of BW for 5 successive days) of O. rhinotracheale infections in turkeys. However, the reduced duration of application would offer a less time-consuming and equally effective alternative.
Asunto(s)
Infecciones por Flavobacteriaceae/veterinaria , Fluoroquinolonas/administración & dosificación , Fluoroquinolonas/farmacología , Infecciones por Paramyxoviridae/veterinaria , Enfermedades de las Aves de Corral/tratamiento farmacológico , Pavos , Animales , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Enrofloxacina , Infecciones por Flavobacteriaceae/tratamiento farmacológico , Metapneumovirus , Ornithobacterium , Infecciones por Paramyxoviridae/tratamiento farmacológicoRESUMEN
Field evidences have suggested that a natural extract, containing tannins, could be effective against poultry enteric viral infections. Moreover previous studies have shown that vegetable tannins can have antiviral activity against human viruses. Based on this knowledge three different Chestnut (Castanea spp.) wood extracts and one Quebracho (Schinopsis spp.) wood extract, all containing tannins and currently used in the animal feed industry, were tested for in vitro antiviral activity against avian reovirus (ARV) and avian metapneumovirus (AMPV). The MTT assay was used to evaluate the 50% cytotoxic compounds concentration (CC(50)) on Vero cells. The antiviral properties were tested before and after the adsorption of the viruses to Vero cells. Antiviral activities were expressed as IC(50) (concentration required to inhibit 50% of viral cytopathic effect). CC(50)s of tested compounds were > 200 microg/ml. All compounds had an extracellular antiviral effect against both ARV and AMPV with IC(50) values ranging from 25 to 66 microg/ml. Quebracho extract had also evident intracellular anti-ARV activity (IC(50) 24 microg/ml). These preliminary results suggest that the examined vegetable extracts might be good candidates in the control of some avian virus infections. Nevertheless further in vivo experiments are required to confirm these findings.
Asunto(s)
Anacardiaceae/química , Hippocastanaceae/química , Metapneumovirus/efectos de los fármacos , Orthoreovirus Aviar/efectos de los fármacos , Extractos Vegetales/farmacología , Madera/química , Animales , Antivirales/química , Antivirales/farmacología , Chlorocebus aethiops , Extractos Vegetales/química , Células VeroRESUMEN
BACKGROUND: Acute respiratory infections (ARI) cause significant childhood mortality. Nutritional homeostasis, particularly micronutrient levels, is important in modulating response to infection. More information is required regarding micronutrient levels in ARI viral infections, especially newly identified viruses such as human metapneumovirus (HMPV). AIM: To describe zinc, copper, selenium and vitamins A and E concentrations in children with respiratory syncytial virus (RSV) and/or HMPV in relation to levels of C-reactive protein (CRP). METHODS: The presence of RSV/HMPV in nasopharyngeal aspirates (NPA) was identified in 246 children using RTPCR. Zinc, copper, selenium and vitamins A and E concentrations were measured using inductive coupled plasma mass spectrometry and high performance liquid chromatography. RESULTS: 183 children had RSV, 39 had HMPV and 24 were co-infected. Zinc concentrations were lower in children with HMPV than in children with RSV or RSV/HMPV co-infection. Copper concentrations were lower in children with RSV than in children with RSV/HMPV or HMPV and zinc/copper ratios were lower in children with HMPV/RSV or RSV than in children with HMPV alone. Retinol and a alpha-tocopherol were lower in children with RSV than in children with HMPV. Most children had low selenium concentrations. Children with RSV and raised CRP (>5 mg/L) had higher copper and lower zinc/copper ratios than those with low CRP (< or =5 mg/L). Children with HMPV and raised CRP had higher copper and lower zinc concentrations than children with low CRP. Children with RSV/HMPV and raised CRP had higher copper concentrations. Children with RSV/HMPV and raised CRP had higher a alpha-tocopherol concentrations. CONCLUSION: The profiles of micronutrients differ in children with RSV and HMPV and are confounded by CRP. These results may guide strategies for micronutrient supplementation in ARI.
Asunto(s)
Metapneumovirus , Micronutrientes/sangre , Infecciones por Paramyxoviridae/sangre , Infecciones por Virus Sincitial Respiratorio/sangre , Proteína C-Reactiva/análisis , Cobre/sangre , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estudios Prospectivos , Selenio/sangre , Vitamina A/sangre , Vitamina E/sangre , Yemen , Zinc/sangreRESUMEN
OBJECTIVES: To determine the frequency and types of respiratory viruses circulating in Boston long-term care facilities (LTCFs) during a 3-year period. DESIGN: Observational. SETTING: Thirty-three Boston-area LTCFs over a 3-year period. PARTICIPANTS: Residents of long-term care who had previously participated in a trial of vitamin E supplementation and had paired serum samples available for viral analysis. MEASUREMENTS: Viral antibody titers to eight respiratory viruses (influenza A and B, respiratory syncytial virus (RSV), parainfluenza virus serotype three (PIV-3), PIV-2, human metapneumovirus (hMPV), and coronaviruses 229E and OC43) were measured using enzyme immunoassay at baseline and 53 weeks. Infection was defined as a more than quadrupling of viral titers. Clinical data on respiratory illnesses were collected throughout the study period. RESULTS: A total of 617 persons were enrolled in the trial. Of these, 382 (62%) had sera available for viral analysis. A total of 204 viral infections were documented in 157 subjects. Serological responses to all eight viruses were documented, with hMPV (12.8%) and coronavirus 229E (10.5%) being the most common and PIV-2 (2.4%) the least common. The occurrence of bronchitis (P=.007), pneumonia (P=.02), and any lower respiratory tract infection (P=.002) was significantly associated with having a viral diagnosis. CONCLUSION: A wide range of respiratory viruses cocirculates in LTCFs and contributes to respiratory illness morbidity in these populations.
Asunto(s)
Anticuerpos Antivirales/sangre , Casas de Salud , Infecciones del Sistema Respiratorio/virología , Virus/aislamiento & purificación , Anciano , Anciano de 80 o más Años , Boston/epidemiología , Femenino , Humanos , Técnicas para Inmunoenzimas , Cuidados a Largo Plazo , Masculino , Metapneumovirus/inmunología , Metapneumovirus/aislamiento & purificación , Metapneumovirus/patogenicidad , Infecciones por Paramyxoviridae/epidemiología , Infecciones del Sistema Respiratorio/epidemiología , Virus/patogenicidadRESUMEN
Experimental groups of 15 susceptible 3-week-old turkeys were inoculated oculonasally with avian metapneumovirus (APV) subtype A and susceptible Escherichia coli O2:K1 and Ornithobacterium rhinotracheale (ORT) bacteria, with a 3 days interval between viral and bacterial inoculation and approximately 8h between the two bacterial inoculations. The aims of the present study were to assess the efficacy of drinking-water administration of enrofloxacin for 3 and 5 days, amoxicillin for 5 days and florfenicol for 5 days for the treatment of the resulting respiratory disease, based on clinical and bacteriological examinations. Antimicrobial treatment started 1 day after dual bacterial inoculation. After infection, the birds were examined and scored for clinical signs daily, weighed at different times, and their tracheae swabbed daily. Five birds were euthanised and examined for macroscopic lesions at necropsy at 5 days post-bacterial inoculation (dpbi) and the remainder at 15dpbi. Samples of the turbinates, trachea, lungs, sinuses, air sacs, heart, pericardium and liver were collected for bacteriological examination. Recovery from respiratory disease caused by an APV/E. coli/ORT triple infection in 3-week-old turkey poults was overall most successful after enrofloxacin treatment, irrespective of treatment duration, followed by florfenicol treatment. Compared with the untreated group, clinical signs as well as ORT and E. coli multiplication in the respiratory tract were significantly reduced by both enrofloxacin treatments and the florfenicol treatment, with the enrofloxacin treatments showing significantly better reductions than the florfenicol treatment. Five-day treatment with amoxicillin, compared with the untreated group, did not cause a significant reduction in any of the aforementioned parameters.
Asunto(s)
Antibacterianos/uso terapéutico , Infecciones por Escherichia coli/veterinaria , Infecciones por Paramyxoviridae/veterinaria , Enfermedades de las Aves de Corral/tratamiento farmacológico , Enfermedades de las Aves de Corral/microbiología , Enfermedades Respiratorias/veterinaria , Pavos , Amoxicilina/uso terapéutico , Animales , Área Bajo la Curva , Peso Corporal/efectos de los fármacos , Enrofloxacina , Escherichia coli/crecimiento & desarrollo , Infecciones por Escherichia coli/complicaciones , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Infecciones por Flavobacteriaceae/complicaciones , Infecciones por Flavobacteriaceae/tratamiento farmacológico , Infecciones por Flavobacteriaceae/microbiología , Infecciones por Flavobacteriaceae/veterinaria , Fluoroquinolonas/uso terapéutico , Metapneumovirus/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana/veterinaria , Ornithobacterium/crecimiento & desarrollo , Infecciones por Paramyxoviridae/complicaciones , Infecciones por Paramyxoviridae/tratamiento farmacológico , Infecciones por Paramyxoviridae/virología , Enfermedades de las Aves de Corral/virología , Enfermedades Respiratorias/tratamiento farmacológico , Enfermedades Respiratorias/microbiología , Enfermedades Respiratorias/virología , Organismos Libres de Patógenos Específicos , Tianfenicol/análogos & derivados , Tianfenicol/uso terapéutico , Tráquea/microbiología , Tráquea/virologíaRESUMEN
The clinical efficacy of drinking-water administration of enrofloxacin for 3 and 5 days, amoxicillin for 5 days and florfenicol for 5 days for the treatment of respiratory disease induced by an experimental Ornithobacterium rhinotracheale infection in turkeys pre-infected with avian pneumovirus (APV) was assessed based on clinical, bacteriological and histopathological examinations. Experimental groups of 15 susceptible 3-week-old turkeys were each inoculated oculonasally with APV subtype A and 3 days later with susceptible O. rhinotracheale bacteria. Antimicrobial treatment started 1 day after O. rhinotracheale inoculation. After infection, the birds were examined and scored for clinical signs, swabbed daily and weighed at different times. Five birds were euthanized and examined for macroscopic lesions at necropsy at 5 days post bacterial inoculation, and the remainder at 15 days post bacterial inoculation. Samples of the turbinates, trachea, lungs, air sacs, heart and pericardium were collected for bacteriological and/or histological examination. Recovery from respiratory disease caused by an APV/O. rhinotracheale dual infection was most successful after enrofloxacin treatment, irrespective of treatment duration, followed by florfenicol. Amoxicillin treatment was not efficacious. Clinical signs and the number of O. rhinotracheale organisms re-isolated from the trachea and the different respiratory organs were significantly reduced by enrofloxacin treatment for 3 and 5 days. O. rhinotracheale bacteria were not re-isolated from the tracheas of the birds treated with enrofloxacin except for one bird in the 5-day group, as early as 1 day after medication onset. In the group treated with enrofloxacin for 5 days, O. rhinotracheale organisms with a higher minimal inhibitory concentration value (x8) were isolated starting 2 days following treatment onset, initially from a single turkey and subsequently from the other animals.
Asunto(s)
Antibacterianos/uso terapéutico , Infecciones por Flavobacteriaceae/veterinaria , Metapneumovirus/fisiología , Ornithobacterium , Infecciones por Paramyxoviridae/veterinaria , Enfermedades de las Aves de Corral/tratamiento farmacológico , Amoxicilina/uso terapéutico , Animales , Enrofloxacina , Infecciones por Flavobacteriaceae/complicaciones , Infecciones por Flavobacteriaceae/tratamiento farmacológico , Infecciones por Flavobacteriaceae/microbiología , Fluoroquinolonas/uso terapéutico , Infecciones por Paramyxoviridae/complicaciones , Enfermedades de las Aves de Corral/microbiología , Organismos Libres de Patógenos Específicos , Tianfenicol/análogos & derivados , Tianfenicol/uso terapéutico , PavosRESUMEN
The ability of the avian pathogen Mycoplasma gallisepticum to persist despite fluoroquinolone treatment was investigated in chickens. Groups of specific pathogen free chickens were experimentally infected with M. gallisepticum and treated with enrofloxacin at increasing concentrations up to the therapeutic dose. When M. gallisepticum could no longer be re-isolated from chickens, birds were stressed by inoculation of infectious bronchitis virus or avian pneumovirus. Although M. gallisepticum could not be cultured from tracheal swabs collected on several consecutive sampling days after the end of the enrofloxacin treatments, the infection was not eradicated. Viral infections reactivated the mycoplasma infection. Mycoplasmas were isolated from tracheal rings cultured for several days, suggesting that M. gallisepticum persisted in the trachea despite the enrofloxacin treatment. The minimal inhibitory concentration (MIC) of enrofloxacin for most of the re-isolated mycoplasmas was the same as that of the strain with which the birds were inoculated. Furthermore, no mutation could be detected in the fluoroquinolone target genes. These results suggest that M. gallisepticum can persist in chickens without development of resistance despite several treatments with enrofloxacin.