RESUMEN
Gallibacterium anatis is a member of the Pasteurellaceae family and is an opportunistic pathogen that causes gallibacteriosis in chickens. Stress plays a relevant role in promoting the development of pathogenicity in G. anatis. Epinephrine (E) and norepinephrine (NE) are relevant to stress; however, their effects on G. anatis have not been elucidated. In this work, we evaluated the effects of E and NE on the growth, biofilm formation, expression of adhesins, and proteases of two G. anatis strains, namely, the hemolytic 12656-12 and the nonhemolytic F149T biovars. E (10 µM/mL) and NE (30 and 50 µM/mL) increased the growth of G. anatis 12656-12 by 20 % and 25 %, respectively. E did not affect the growth of F149T, whereas 40 µM/mL NE decreased bacterial growth by 25 %. E and NE at a dose of 30-50 µM/mL upregulated five fibrinogen adhesins in the 12565-12 strain, whereas no effect was observed in the F149T strain. NE increased proteolytic activity in both strains, whereas E diminished proteolytic activity in the 12656-12 strain. E and NE reduced biofilm formation (30 %) and increased Congo red binding (15 %) in both strains. QseBC is the E and NE two-component detection system most common in bacteria. The qseC gene, which is the E and NE receptor in bacteria, was identified in the genomic DNA of the 12565-12 and F149TG. anatis strains via PCR amplification. Our results suggest that QseC can detect host changes in E and NE concentrations and that catecholamines can modulate the expression of several virulence factors in G. anatis.
Asunto(s)
Biopelículas , Pollos , Epinefrina , Regulación Bacteriana de la Expresión Génica , Norepinefrina , Pasteurellaceae , Factores de Virulencia , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Norepinefrina/farmacología , Norepinefrina/metabolismo , Epinefrina/farmacología , Biopelículas/crecimiento & desarrollo , Biopelículas/efectos de los fármacos , Pasteurellaceae/genética , Pasteurellaceae/patogenicidad , Pasteurellaceae/efectos de los fármacos , Pasteurellaceae/metabolismo , Animales , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Adhesinas Bacterianas/genética , Adhesinas Bacterianas/metabolismo , Péptido Hidrolasas/metabolismo , Péptido Hidrolasas/genética , Enfermedades de las Aves de Corral/microbiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Infecciones por Pasteurellaceae/microbiología , Infecciones por Pasteurellaceae/veterinariaRESUMEN
The purpose of this report is to provide information about the different presentations of cardiac and extra-cardiac histophilosis and, to assess the antimicrobial (ATM) susceptibility of Histophilus somni isolated from these cardiac lesions to different ATM agents commonly used for treating bovine bacterial respiratory pathogens. Eight feedlot calves, which died after suffering from food rejection, apathy, hyperthermia, cough and nasal mucous discharge, and lack of response to ATM therapy, were studied. Cardiac lesions observed at necropsy included valvular/mural endocarditis, myocardial infarction, and necrotizing myocarditis, miliar non-suppurative myocarditis, myocardic necrotic sequestrum, and/or pericarditis. Histopathological, bacteriological and molecular studies confirmed the presence of a fastidious microorganism in the affected organs. H. somni showed no resistance to most ATM tested (ceftiofur, gamithromycin, enrofloxacin, florfenicol, tilmicosin). The results obtained in this study confirmed that H. somni was the main cause of the subacute cardiac lesions associated with hyperthermia, apathy and respiratory signs observed in cattle examined in this research. These presentations must be considered by veterinary practitioners in order to establish a rational therapeutic.
Asunto(s)
Enfermedades de los Bovinos , Miocarditis , Infecciones por Pasteurellaceae , Pasteurellaceae , Bovinos , Animales , Enfermedades de los Bovinos/microbiología , Infecciones por Pasteurellaceae/veterinaria , Infecciones por Pasteurellaceae/microbiología , Miocarditis/microbiología , Miocarditis/veterinaria , MuerteRESUMEN
This is the first extensive report on the identification and characterization of Avibacterium paragallinarum (AVP) isolates obtained from outbreaks of infectious coryza (IC) in IC-vaccinated layer flocks from Sonora State in Mexico. Isolates obtained from IC outbreaks during the years 2007, 2014, 2015, 2017, and 2019 were identified by conventional PCR test and 16S rRNA gene analysis, serotyped by Page serotyping and genotyped by the recently described partial sequence analysis of the HPG2 region. Furthermore, antimicrobial susceptibility profiles were determined by a recently improved minimal inhibitory concentration (MIC) test. The conventional PCR test and the 16S rRNA analyses confirmed the isolates as AVP. Serotyping results showed the involvement of isolates belonging to serotypes A, B, and C in the IC outbreaks. Genotyping of the HPG2 region revealed the presence of sequence type (ST)1, ST4, and ST11, of which the latter has also been identified in Europe. The MIC susceptibility test showed that all tested isolates were susceptible for the majority of tested antimicrobials, including erythromycin and tetracycline, which are important antibiotics for the treatment of IC. The IC situation in Sonora State, Mexico, is complex because of the presence of serotypes A, B, and C. This finding emphasizes the importance of biosecurity in combination with the application of the most optimal vaccination programs in the control of IC in Sonora State, Mexico.
Nota de investigaciónAnálisis de secuencias de la región HPG2 y susceptibilidad antimicrobiana de aislamientos de Avibacterium paragallinarum obtenidos de brotes de coriza infecciosa en aves de postura comerciales en el estado de Sonora, México. Este es el primer informe extenso sobre la identificación y caracterización de aislamientos de Avibacterium paragallinarum (AVP) obtenidos de brotes de coriza infecciosa (IC) de parvadas de ponedoras vacunadas con coriza infecciosa en el estado de Sonora en México. Los aislamientos obtenidos de los brotes de coriza infecciosa durante los años 2007, 2014, 2015, 2017 y 2019 se identificaron mediante una prueba de PCR convencional y el análisis del gene de ARNr 16S, se serotipificaron mediante el método de Page y se genotipificaron mediante el análisis parcial de secuencias descrito recientemente de la región HPG2. Además, se determinaron los perfiles de susceptibilidad a los antimicrobianos mediante la prueba de concentración mínima inhibitoria (MIC) que ha sido mejorada recientemente. La prueba de PCR convencional y los análisis de secuencias del gene ARNr 16S confirmaron que los aislados eran A. paragallinarum. Los resultados de la serotipificación mostraron la participación de aislamientos pertenecientes a los serotipos A, B y C en los brotes de coriza infecciosa. La genotipificación de la región HPG2 reveló la presencia de secuencias del tipo (ST) 1, ST4 y ST11, de los cuales este último también ha sido identificada en Europa. La prueba de susceptibilidad por concentración mínima inhibitoria mostró que todos los aislados analizados eran susceptibles a la mayoría de los antimicrobianos analizados, incluida la eritromicina y la tetraciclina, que son antibióticos importantes para el tratamiento contra la coriza infecciosa. La situación de coriza infecciosa en el estado de Sonora, México, es compleja por la presencia de los serotipos A, B y C. Este hallazgo enfatiza la importancia de la bioseguridad en combinación con la aplicación de los programas de vacunación óptimos en el control de la coriza infecciosa en el estado de Sonora, México.
Asunto(s)
Pollos , Farmacorresistencia Bacteriana , Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae/aislamiento & purificación , Enfermedades de las Aves de Corral , Proteínas Virales/análisis , Animales , Femenino , México , Pruebas de Sensibilidad Microbiana/veterinaria , Pasteurellaceae/efectos de los fármacos , Pasteurellaceae/genética , Infecciones por Pasteurellaceae/diagnóstico , Infecciones por Pasteurellaceae/microbiología , Enfermedades de las Aves de Corral/diagnóstico , Enfermedades de las Aves de Corral/microbiologíaRESUMEN
We investigated deaths in a group of feedlot steers in Argentina. The main findings in 3 steers autopsied were pulmonary congestion and edema, necrotizing myocarditis, pericarditis, suppurative leptomeningitis, and bronchopneumonia. Histophilus somni was detected by bacterial culture and immunohistochemistry in the hearts of the 3 animals. Partial sequences of the 16S rRNA gene of a H. somni isolate had 99% similarity with other H. somni sequences in GenBank. Most reports of H. somni septicemia in cattle originate from North America and western Europe. There is scant information about cardiac histophilosis in South America. A survey of diagnostic laboratory personnel in 7 South American countries documented various forms of bovine histophilosis in Argentina, Brazil, Uruguay, and Venezuela.
Asunto(s)
Enfermedades de los Bovinos/diagnóstico , Meningitis/veterinaria , Miocarditis/veterinaria , Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae/aislamiento & purificación , Animales , Argentina , Brasil , Bovinos , Enfermedades de los Bovinos/microbiología , Masculino , Meningitis/diagnóstico , Meningitis/microbiología , Miocarditis/diagnóstico , Miocarditis/microbiología , Pasteurellaceae/clasificación , Infecciones por Pasteurellaceae/diagnóstico , Infecciones por Pasteurellaceae/microbiología , ARN Bacteriano/análisis , ARN Ribosómico 16S/análisis , Uruguay , VenezuelaRESUMEN
Gallibacterium anatis, a member of the Pasteurellaceae family, leads to decrease in egg-production, animal welfare and increase in mortality. This study aimed to diagnose G. Anatis, which caused economic losses in laying hens by using conventional and molecular techniques. In this study, G. anatis was examined from a total of 200 dead chicken tissues (heart, liver, lung, spleen and trachea) in laying hen farms that observed a decrease in egg production with respiratory system infection. Conventional methods based on colony morphology, sugar fermentation tests and hemolytic properties and molecular conformation using 16S rRNA-23S rRNA specific primers were performed to identify G. anatis. G. anatis was isolated in 20 (10%) of the examined samples and isolates were confirmed by conventional PCR. A total of 11 (2.2%) positivity was obtained as isolates were the result of PCR performed on tissues and organs directly. As a result, the presence of G. anatis was detected for the first time in Turkey by this study. It was thought that G. anatis may have a role in egg production losses due to respiratory tract infection in poultry and this situation may be a guide for poultry clinicians and microbiologists.
Asunto(s)
Animales , Pollos/microbiología , Infecciones por Pasteurellaceae/diagnóstico , Infecciones por Pasteurellaceae/veterinaria , Reacción en Cadena de la Polimerasa/veterinariaRESUMEN
Gallibacterium anatis, a member of the Pasteurellaceae family, leads to decrease in egg-production, animal welfare and increase in mortality. This study aimed to diagnose G. Anatis, which caused economic losses in laying hens by using conventional and molecular techniques. In this study, G. anatis was examined from a total of 200 dead chicken tissues (heart, liver, lung, spleen and trachea) in laying hen farms that observed a decrease in egg production with respiratory system infection. Conventional methods based on colony morphology, sugar fermentation tests and hemolytic properties and molecular conformation using 16S rRNA-23S rRNA specific primers were performed to identify G. anatis. G. anatis was isolated in 20 (10%) of the examined samples and isolates were confirmed by conventional PCR. A total of 11 (2.2%) positivity was obtained as isolates were the result of PCR performed on tissues and organs directly. As a result, the presence of G. anatis was detected for the first time in Turkey by this study. It was thought that G. anatis may have a role in egg production losses due to respiratory tract infection in poultry and this situation may be a guide for poultry clinicians and microbiologists.(AU)
Asunto(s)
Animales , Pollos/microbiología , Infecciones por Pasteurellaceae/diagnóstico , Infecciones por Pasteurellaceae/veterinaria , Reacción en Cadena de la Polimerasa/veterinariaRESUMEN
Abstract Histophilus somni is a Gram-negative bacterium that is associated with a disease complex (termed histophilosis) that can produce several clinical syndromes predominantly in cattle, but also in sheep. Histophilosis is well described in North America, Canada, and in some European countries. In Brazil, histophilosis has been described in cattle with respiratory, reproductive, and systemic disease, with only one case described in sheep. This report describes the occurrence of Histophilus somni-associated disease in sheep from Southern Brazil. Eight sheep with different clinical manifestations from five farms were investigated by a combination of pathological and molecular diagnostic methods to identify additional cases of histophilosis in sheep from Brazil. The principal pathological lesions were thrombotic meningoencephalitis, fibrinous bronchopneumonia, pulmonary abscesses, and necrotizing myocarditis. The main clinical syndromes associated with H. somni were thrombotic meningoencephalitis (n = 4), septicemia (n = 4), bronchopneumonia (n = 4), and myocarditis (n = 3). H. somni DNA was amplified from multiple tissues of all sheep with clinical syndromes of histophilosis; sequencing confirmed the PCR results. Further, PCR assays to detect Pasteurella multocida and Mannheimia haemolytica were negative. These findings confirmed the participation of H. somni in the clinical syndromes investigated during this study, and adds to the previous report of histophilosis in sheep from Brazil.
Asunto(s)
Animales , Enfermedades de las Ovejas/microbiología , Infecciones por Pasteurellaceae/veterinaria , Mannheimia haemolytica/aislamiento & purificación , Brasil , Ovinos , Reacción en Cadena de la Polimerasa , Infecciones por Pasteurellaceae/microbiología , Mannheimia haemolytica/genéticaRESUMEN
Histophilus somni is a Gram-negative bacterium that is associated with a disease complex (termed histophilosis) that can produce several clinical syndromes predominantly in cattle, but also in sheep. Histophilosis is well described in North America, Canada, and in some European countries. In Brazil, histophilosis has been described in cattle with respiratory, reproductive, and systemic disease, with only one case described in sheep. This report describes the occurrence of Histophilus somni-associated disease in sheep from Southern Brazil. Eight sheep with different clinical manifestations from five farms were investigated by a combination of pathological and molecular diagnostic methods to identify additional cases of histophilosis in sheep from Brazil. The principal pathological lesions were thrombotic meningoencephalitis, fibrinous bronchopneumonia, pulmonary abscesses, and necrotizing myocarditis. The main clinical syndromes associated with H. somni were thrombotic meningoencephalitis (n=4), septicemia (n=4), bronchopneumonia (n=4), and myocarditis (n=3). H. somni DNA was amplified from multiple tissues of all sheep with clinical syndromes of histophilosis; sequencing confirmed the PCR results. Further, PCR assays to detect Pasteurella multocida and Mannheimia haemolytica were negative. These findings confirmed the participation of H. somni in the clinical syndromes investigated during this study, and adds to the previous report of histophilosis in sheep from Brazil.
Asunto(s)
Mannheimia haemolytica/aislamiento & purificación , Infecciones por Pasteurellaceae/veterinaria , Enfermedades de las Ovejas/microbiología , Animales , Brasil , Mannheimia haemolytica/genética , Infecciones por Pasteurellaceae/microbiología , Reacción en Cadena de la Polimerasa , OvinosRESUMEN
Gallibacterium, which is a bacterial pathogen in chickens, can form biofilms. Amyloid proteins present in biofilms bind Congo red dye. The aim of this study was to characterize the cell-surface amyloid-like protein expressed in biofilms formed by Gallibacterium strains and determine the relationship between this protein and curli, which is an amyloid protein that is commonly expressed by members of the Enterobacteriaceae family. The presence of amyloid-like proteins in outer membrane protein samples from three strains of G. anatis and one strain of Gallibacterium genomospecies 2 was evaluated. A protein identified as elongation factor-Tu (EF-Tu) by mass spectrometric analysis and in silico analysis was obtained from the G. anatis strain F149T. This protein bound Congo red dye, cross-reacted with anti-curli polyclonal serum, exhibited polymerizing properties and was present in biofilms. This protein also reacted with pooled serum from chickens that were experimentally infected with G. anatis, indicating the in vivo immunogenicity of this protein. The recombinant EF-Tu purified protein, which was prepared from G. anatis 12656-12, polymerizes under in vitro conditions, forms filaments and interacts with fibronectin and fibrinogen, all of which suggest that this protein functions as an adhesin. In summary, EF-Tu from G. anatis presents amyloid characteristics, is present in biofilms and could be relevant for the pathogenesis of G. anatis.
Asunto(s)
Proteínas Amiloidogénicas/metabolismo , Adhesión Bacteriana , Biopelículas , Pasteurellaceae/metabolismo , Factor Tu de Elongación Peptídica/metabolismo , Proteínas Amiloidogénicas/química , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Pollos/microbiología , Simulación por Computador , Rojo Congo/metabolismo , Infecciones por Pasteurellaceae/microbiología , Infecciones por Pasteurellaceae/veterinaria , Factor Tu de Elongación Peptídica/análisis , Factor Tu de Elongación Peptídica/química , Factor Tu de Elongación Peptídica/inmunología , Enfermedades de las Aves de Corral/microbiología , Unión Proteica , Dominios Proteicos , Factores de VirulenciaRESUMEN
The ß-nicotinamide adenine dinucleotide (NAD) requirement has been considered to be essential for the isolation of the causal agent of infectious coryza, Avibacterium paragallinarum. Nevertheless, NAD-independent reports from South Africa and Mexico dismissed this paradigm. It is now accepted that both NAD-dependent and NAD-independent agents are able to cause infectious coryza and thus belong to the species A. paragallinarum. Here, we report for the first time in Peru a NAD-independent isolate from broiler chickens with typical signs of infectious coryza that have received a trivalent inactivated vaccine against infectious coryza. The isolate was identified based on its morphology, biochemical and serologic tests, and PCR results. Partial 16S rRNA gene sequence analysis confirmed the isolate as A. paragallinarum. There have been no cases of NAD-independent A. paragallinarum isolates reported in South America. Increasing reports around the world highlight not only the need to reconsider the in vitro nutritional requirements of this species for its correct isolation but also the cross-protection conferred by commercial infectious coryza vaccines against NAD-independent isolates.
Asunto(s)
Pollos , NAD/metabolismo , Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae , Enfermedades de las Aves de Corral/microbiología , Enfermedades Respiratorias/veterinaria , Animales , Infecciones por Pasteurellaceae/epidemiología , Infecciones por Pasteurellaceae/microbiología , Perú/epidemiología , Enfermedades de las Aves de Corral/epidemiología , Enfermedades Respiratorias/epidemiología , Enfermedades Respiratorias/microbiologíaRESUMEN
BACKGROUND: Mannheimia haemolytica is an important etiological agent in bovine respiratory disease. OBJECTIVES: Explore risk factors for recovery of susceptible and resistant M. haemolytica in feedlot cattle and explore associations with health outcomes. ANIMALS: Cattle (n = 5,498) from 4 feedlots sampled at arrival and later in feeding period. METHODS: Susceptibility of M. haemolytica isolates tested for 21 antimicrobials. Records of antimicrobial use and health events analyzed using multivariable regression. RESULTS: M. haemolytica recovered from 29% of cattle (1,596/5,498), 13.1% at arrival (95% CI, 12.3-14.1%), and 19.8% at second sampling (95% CI, 18.7-20.9%). Nearly half of study cattle received antimicrobial drugs (AMDs) parenterally, mostly as metaphylactic treatment at arrival. Individual parenteral AMD exposures were associated with decreased recovery of M. haemolytica (OR, 0.2; 95% CI, 0.02-1.2), whereas exposure in penmates was associated with increased recovery (OR, 1.5; 95% CI, 1.05-2.2). Most isolates were pan-susceptible (87.8%; 95% CI, 87.0-89.4%). AMD exposures were not associated with resistance to any single drug. Multiply-resistant isolates were rare (5.9%; 95% CI, 5.1-6.9%), but AMD exposures in pen mates were associated with increased odds of recovering multiply-resistant M. haemolytica (OR, 23.9; 95% CI, 8.4-68.3). Cattle positive for M. haemolytica on arrival were more likely to become ill within 10 days (OR, 1.7; 95% CI, 1.1-2.4). CONCLUSIONS AND CLINICAL IMPORTANCE: Resistance generally was rare in M. haemolytica. Antimicrobial drug exposures in penmates increased the risk of isolating susceptible and multiply-resistant M. haemolytica, a finding that could be explained by contagious spread.
Asunto(s)
Enfermedades de los Bovinos/microbiología , Mannheimia haemolytica/efectos de los fármacos , Infecciones por Pasteurellaceae/veterinaria , Animales , Antibacterianos/administración & dosificación , Antibacterianos/uso terapéutico , Bovinos , Enfermedades de los Bovinos/tratamiento farmacológico , Farmacorresistencia Bacteriana Múltiple , Análisis Multivariante , Infecciones por Pasteurellaceae/tratamiento farmacológico , Infecciones por Pasteurellaceae/microbiología , Factores de Riesgo , Estaciones del AñoRESUMEN
Two separate bird trials were performed to establish a reliable route of infection for Gallibacterium anatis in chickens, comparing intranasal (i.n.) and intravenous (i.v.) applications. Additionally, three mutually divergent isolates from three geographical locations, as shown by MALDI-TOF-MS and partial rpoB gene sequence analysis, were compared. In the first trial, birds were infected with one of the selected isolates by the i.v. or i.n. route. Subsequently, birds were killed 3, 12 and 24 h post infection following i.v. infection while at 3, 7 and 10 days post infection (dpi) in the case of i.n. infection along with birds of the control group. As a result, i.n. infection showed prominent and consistent bacterial tissue distribution in different organs persisting until 10 dpi, which was a striking contrast to the i.v. infection route. Likewise, histopathology revealed mild to severe tracheal lesions following i.n. infection. The second trial was set up to confirm both the achieved results and the robustness of i.n. infection but with an extended observation period, until 28 dpi In agreement with the preceding trial, identical results for bacteriological and histopathological examinations were obtained with persistency of bacteria until 28 dpi Comparing the three different isolates from Mexico, China and Austria, the Mexican isolate showed a somewhat higher pathogenicity than the other strains. Consequently, pathogenesis of G. anatis strains was studied in chickens elucidating i.n. infection as the most reliable route characterized by a long-lasting bacteraemia, targeting the respiratory and reproductive tract.
Asunto(s)
Pollos , Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae/patogenicidad , Enfermedades de las Aves de Corral/microbiología , Infecciones del Sistema Genital/veterinaria , Infecciones del Sistema Respiratorio/veterinaria , Administración Intranasal , Administración Intravenosa , Animales , Austria , Proteínas Bacterianas/genética , Secuencia de Bases , China , Cartilla de ADN/genética , México , Datos de Secuencia Molecular , Pasteurellaceae/genética , Análisis de Secuencia de ADN/veterinaria , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/veterinaria , Factores de TiempoRESUMEN
Histophilus somni is an economically important pathogen of cattle and other ruminants and is considered one of the key components of the bovine respiratory disease (BRD) complex, the leading cause of economic loss in the livestock industry. BRD is a multifactorial syndrome, in which a triad of agents, including bacteria, viruses, and predisposing factors or "stressors," combines to induce disease. Although vaccines against H. somni have been used for many decades, traditional bacterins have failed to demonstrate effective protection in vaccinated animals. Hence, the BRD complex continues to produce strong adverse effects on the health and well-being of stock and feeder cattle. The generation of recombinant proteins may facilitate the development of more effective vaccines against H. somni, which could confer better protection against BRD. In the present study, primers were designed to amplify, clone, express, and purify two recombinant lipoproteins from H. somni, p31 (Plp4) and p40 (LppB), which are structural proteins of the outer bacterial membrane. The results presented here demonstrate, to our knowledge for the first time, that when formulated, an experimental vaccine enriched with these two recombinant lipoproteins generates high antibody titers in rabbits and sheep and exerts a protective effect in mice against septicemia induced by H. somni bacterial challenge.
Asunto(s)
Proteínas de la Membrana Bacteriana Externa/inmunología , Vacunas Bacterianas/inmunología , Lipoproteínas/inmunología , Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae/inmunología , Sepsis/veterinaria , Animales , Anticuerpos Antibacterianos/sangre , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas de la Membrana Bacteriana Externa/aislamiento & purificación , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/genética , Bovinos , Clonación Molecular , Modelos Animales de Enfermedad , Expresión Génica , Lipoproteínas/genética , Lipoproteínas/aislamiento & purificación , Ratones , Infecciones por Pasteurellaceae/inmunología , Infecciones por Pasteurellaceae/prevención & control , Reacción en Cadena de la Polimerasa , Conejos , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificación , Sepsis/inmunología , Sepsis/prevención & control , Ovinos , Análisis de Supervivencia , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunologíaRESUMEN
Bovine respiratory disease (BRD) complex is a major cause of economic losses for the cattle backgrounding and feedlot industries. Mannheimia haemolytica is considered the most important pathogen associated with this disease. Vaccines against M. haemolytica have been prepared and used for many decades, but traditional bacterins have failed to demonstrate effective protection and their use has often exacerbated disease in vaccinated animals. Thus, the BRD complex continues to exert a strong adverse effect on the health and wellbeing of stocker and feeder cattle. Therefore, generation of recombinant proteins has been helpful in formulating enhanced vaccines against M. haemolytica, which could confer better protection against BRD. In the present study, we formulated a vaccine preparation enriched with recombinant small fragments of leukotoxin A (LKTA) and outer-membrane lipoprotein (PlpE) proteins, and demonstrated its ability to generate high antibody titers in rabbits and sheep, which protected against M. haemolytica bacterial challenge in mice.
Asunto(s)
Proteínas de la Membrana Bacteriana Externa/inmunología , Proteínas Bacterianas/inmunología , Vacunas Bacterianas/inmunología , Proteínas Hemolisinas/inmunología , Lipoproteínas/inmunología , Mannheimia haemolytica/inmunología , Infecciones por Pasteurellaceae/veterinaria , Animales , Anticuerpos Antibacterianos , Proteínas de la Membrana Bacteriana Externa/química , Proteínas Bacterianas/química , Clonación Molecular , Ensayo de Inmunoadsorción Enzimática/veterinaria , Proteínas Hemolisinas/química , Lipoproteínas/química , Ratones , Ratones Endogámicos BALB C , Infecciones por Pasteurellaceae/prevención & control , Conejos , Proteínas Recombinantes , OvinosRESUMEN
In order to evaluate the protection conferred by an experimental inactivated vaccine against infectious coryza, three challenge trials were undertaken using 112 1-day-old broilers. The vaccine "Hepa Inmuno NC" included bacterial antigens of Avibacterium paragallinarum (serogroups A, B, variant B, and C) as well as antigens of Newcastle virus and hepatitis virus. Fifty-six broiler chicks were vaccinated at the first day of life at the hatchery while another 56 chicks were left unvaccinated. Three infection trials were conducted simultaneously using each of the three serogroups A, B, or C of Av. paragallinarum. In each trial, 17 vaccinated and 17 unvaccinated broilers were used. Challenge was performed at day 31 of life by injection, into the left infraorbital sinus, of approximately 1 x 10(5) colony forming units of the corresponding Av. paragallinarum strain. Clinical signs were recorded on day 2 postchallenge. All broilers were euthanatized and both infraorbital sinuses were bacteriologically examined for the presence of Av. paragallinarum on day 5 postchallenge. In comparison with the unvaccinated broilers, the vaccine significantly reduced the number of broilers with clinical signs after challenge with serogroup B, and significantly fewer vaccinated broilers were positive for the presence of Av. paragallinarum after challenge with serogroup C. On the other hand, no significant protection was observed when broilers were challenged with Av. paragallinarum from serogroup A. Despite the high infection rates in vaccinated chicks after an experimental infection with Av. paragallinarum, it was possible to reduce colonization of Av. paragallinarum (serogroup B) and clinical signs (serogroup C) in broiler chicks by vaccination at the first day of life. Further cross-protection trials should be done, including other Av. paragallinarum strains in the vaccine, especially those from serogroup A.
Asunto(s)
Vacunas Bacterianas/inmunología , Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae/clasificación , Enfermedades de las Aves de Corral/prevención & control , Animales , Pollos , Infecciones por Pasteurellaceae/prevención & control , Organismos Libres de Patógenos EspecíficosRESUMEN
The present investigation was undertaken to identify and characterize the tetracycline resistance determinant in 22 Gallibacterium anatis strains for which no determinant was identified using primers specific for tet(A, B, C, D, E, G, H, K, L, M, O). A recent study found tet(B) to be the most prevalent tetracycline resistance determinant in a larger collection of G. anatis field strains from Mexico and Denmark. However, in 41% of the tetracycline resistant strains no determinant could be assigned. Here we demonstrate that tet(31) is a common determinant in G. anatis originating from chickens from very different production systems and localities. In addition, tet(31) was identified in strains isolated over a 30-year period. This is the first report on tet(31) since its original identification in Aeromonas salmonicida.
Asunto(s)
Pasteurellaceae/efectos de los fármacos , Pasteurellaceae/genética , Resistencia a la Tetraciclina/genética , Animales , Antibacterianos/farmacología , Pollos/microbiología , Dinamarca , Genes Bacterianos , México , Infecciones por Pasteurellaceae/microbiología , Infecciones por Pasteurellaceae/veterinaria , Enfermedades de las Aves de Corral/microbiología , Tetraciclina/farmacologíaRESUMEN
Background: Bronchopneumonia caused by Mannheimia haemolytica affects sheep of all ages worldwide and may be devastating especially in young animals undergone recent stress (i.e. transportation, weaning, mixing with animals from different farms. It is a common cause of morbidity and mortality in lambs and kids, especially in those that have not received adequate colostrum or in which passive colostral immunity is waning. Yearly herd losses costing millions of dollars have led to research focused on theurapeutic trials and vaccine production because of various strains isolated demonstrating the continuing economic importance of Mannheimia haemolytica infection. A field trial was performed under commercial sheep farm located in Western Turkey, Aydin in an attempt to investigate the efficacy of an injectable formulation of florfenicol against naturally occuring Mannheimia haemolytica. Materials, Methods & Results: A total of 27 Sakiz breed lambs at the age of 3660 days old, of both sexes, with naturally occuring M. haemolytica infection were included in the present study. Prior to allocation into groups, a detailed clinical examination carried out in all the lambs, revealed a variety of abnormal findings: coughing, presence of nasal and ophthalmic discharge increased respiratory rate and rectal temperature and abnormal sounds at lung auscultation. A total of 27 samples taken from transtracheal aspiration bronchoalveolar fluid in the Sakiz breed lambs were taken into sterile containers in an attemp to perf orm isolation and identification of Mannheimia haemolytica . The antibiotic susceptibility tests for Mannheimia haemolytica strains isolated from transtracheal aspiration bronchoalveolar fluid were carried out by disc diffusion as described previously. [...](AU)
Asunto(s)
Animales , Mannheimia haemolytica/patogenicidad , Infecciones por Pasteurellaceae/veterinaria , Antibacterianos/administración & dosificación , Ovinos/fisiologíaRESUMEN
Background: Bronchopneumonia caused by Mannheimia haemolytica affects sheep of all ages worldwide and may be devastating especially in young animals undergone recent stress (i.e. transportation, weaning, mixing with animals from different farms. It is a common cause of morbidity and mortality in lambs and kids, especially in those that have not received adequate colostrum or in which passive colostral immunity is waning. Yearly herd losses costing millions of dollars have led to research focused on theurapeutic trials and vaccine production because of various strains isolated demonstrating the continuing economic importance of Mannheimia haemolytica infection. A field trial was performed under commercial sheep farm located in Western Turkey, Aydin in an attempt to investigate the efficacy of an injectable formulation of florfenicol against naturally occuring Mannheimia haemolytica. Materials, Methods & Results: A total of 27 Sakiz breed lambs at the age of 3660 days old, of both sexes, with naturally occuring M. haemolytica infection were included in the present study. Prior to allocation into groups, a detailed clinical examination carried out in all the lambs, revealed a variety of abnormal findings: coughing, presence of nasal and ophthalmic discharge increased respiratory rate and rectal temperature and abnormal sounds at lung auscultation. A total of 27 samples taken from transtracheal aspiration bronchoalveolar fluid in the Sakiz breed lambs were taken into sterile containers in an attemp to perf orm isolation and identification of Mannheimia haemolytica . The antibiotic susceptibility tests for Mannheimia haemolytica strains isolated from transtracheal aspiration bronchoalveolar fluid were carried out by disc diffusion as described previously. [...]
Asunto(s)
Animales , Antibacterianos/administración & dosificación , Infecciones por Pasteurellaceae/veterinaria , Mannheimia haemolytica/patogenicidad , Ovinos/fisiologíaRESUMEN
This study appears to represent the first serotyping study of 24 isolates of Avibacterium paragallinarum obtained from different regions of Peru during 1998-2008. All isolates were characterized as beta-nicotinamide adenine dinucleotide dependent. According to the Page scheme, modified by Blackall, it was found that eight isolates were classified as serogroup A, seven isolates as serogroup B, and five isolates as serogroup C, while four isolates could not be serotyped. Further serotyping, following the same scheme but using rabbit antiserum raised against Argentinean strains of the three serogroups, allowed allocation of these four unclassified isolates to serogroup B. These results suggest that some of the Peruvian B isolates appear to be similar to the previously described variant B isolates from Argentina. Therefore, inactivated vaccines used in Peru should include the three recognized serogroups (A, B, and C), with the addition of at least one of these variant B isolates. Cross-protection trials are needed to compare the protection conferred by vaccines containing traditional B serovar strains to the protection by experimental vaccines containing variant B serovar isolates from Peru.
Asunto(s)
Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae/clasificación , Enfermedades de las Aves de Corral/microbiología , Serotipificación , Animales , Pollos , Pruebas de Inhibición de Hemaglutinación , Pruebas de Hemaglutinación , Infecciones por Pasteurellaceae/epidemiología , Infecciones por Pasteurellaceae/microbiología , Perú/epidemiología , Enfermedades de las Aves de Corral/epidemiología , ConejosRESUMEN
Mannheimia spp. strains obtained from bovine nasal exudates of either clinically healthy or clinically affected by respiratory tract disease animals were isolated and characterised to estimate the prevalence of isolated serotypes in dairy farms in Mexico, by means of a trans-sectional descriptive study. Strains were isolated and typified through biochemical and immunological tests. chi(2) or Fisher statistical tests were applied, as well as odds ratio calculation and logistic regression analysis to evaluate the association and effect of some variables on Mannheimia spp. isolation. The apparent prevalence rates of Mannheimia haemolytica was significantly higher in diseased bovines (OR = 1.94; p < 0.05), as well as in bovines younger than 1 year of age (OR = 23.98; p < 0.05), and in bovines not vaccinated against bovine pasteurellosis (OR = 1.52; p < 0.05). Age was the variable that remained in the logistic regression model. Serotype A1 showed the highest prevalence, even when most isolates were not-typable. Bovines younger than one year of age and those with disease were the groups with the highest frequency of M. haemolytica and Mannheimia glucosida isolates.