RESUMEN
A swine production system had 3 sections located a few kilometers apart. Sections A and C contained several thousand sows and nursery and finishing pigs. Section B, located between the other 2 sections, was the smallest and had 6 finishing sites and 2 sow sites. The entire system was infected with porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae, and Actinobacillus pleuropneumoniae. Section B was depopulated, cleaned, disinfected, and repopulated with negative gilts. Despite extreme measures, recontamination occurred for each pathogen, with aerosol considered the most plausible contamination source.
Transmission suspectée d'agents pathogènes porcins par aérosol : un cas de terrainUn système de production porcine comportait 3 sections situées à quelques kilomètres l'une de l'autre. Les sections A et C contenaient plusieurs milliers de truies et de porcs en maternité et en finition. La section B, située entre les 2 autres sections, était la plus petite et comptait 6 sites de finition et 2 sites de truies. L'ensemble du système était infecté par le virus du syndrome reproducteur et respiratoire porcin, Mycoplasma hyopneumoniae et Actinobacillus pleuropneumoniae. La section B a été dépeuplée, nettoyée, désinfectée et repeuplée de cochettes négatives. Malgré des mesures extrêmes, une recontamination s'est produite pour chaque agent pathogène, les aérosols étant considérés comme la source de contamination la plus plausible.(Traduit par Dr Serge Messier).
Asunto(s)
Actinobacillus pleuropneumoniae , Aerosoles , Mycoplasma hyopneumoniae , Virus del Síndrome Respiratorio y Reproductivo Porcino , Enfermedades de los Porcinos , Animales , Porcinos , Enfermedades de los Porcinos/transmisión , Enfermedades de los Porcinos/microbiología , Enfermedades de los Porcinos/virología , Mycoplasma hyopneumoniae/aislamiento & purificación , Actinobacillus pleuropneumoniae/aislamiento & purificación , Virus del Síndrome Respiratorio y Reproductivo Porcino/aislamiento & purificación , Infecciones por Actinobacillus/veterinaria , Infecciones por Actinobacillus/transmisión , Infecciones por Actinobacillus/microbiología , Neumonía Porcina por Mycoplasma/transmisión , Femenino , Síndrome Respiratorio y de la Reproducción Porcina/transmisión , Crianza de Animales DomésticosRESUMEN
Actinobacillus pleuropneumoniae is responsible for porcine pleuropneumonia, a highly contagious lung infection. The control of this respiratory disease remains heavily reliant on antibiotics, with phenicols being one of the primary classes of antibiotics used in pig farming. In the present study, we describe three isolates (B2278, B2176 and B2177) of A. pleuropneumoniae resistant to florfenicol attributed to the presence of the floR gene, which were obtained from two pig farms in Italy. Florfenicol susceptibility tests indicated that B2176 exhibited an intermediate susceptibility profile, while B2177 and B2278 were resistant. All three isolates belonged to serovar 6 and tested positive for the presence of the floR gene. Whole genome sequencing analysis revealed that isolates B2176, B2177 and B2278 harbored genes encoding the toxins ApxII and ApxIII, characteristic of strains with moderate virulence. Moreover, phylogenetic analysis demonstrated that these isolates were closely related, with single nucleotide polymorphisms (SNPs) ranging from 8 to 19. The floR gene was located on a novel 5588â¯bp plasmid, designated as pAp-floR. BLASTN analysis showed that the pAp-floR plasmid had high nucleotide identity (99â¯%) and coverage (60â¯%) with the pMVSCS1 plasmid (5621â¯bp) from Mannheimia varigena MVSCS1 of porcine origin. Additionally, at least under laboratory conditions, pAp-floR was stably maintained even in the absence of direct selective pressure, suggesting that it does not impose a fitness cost. Our study underscores the necessity of monitoring the spread of florfenicol-resistant A. pleuropneumoniae isolates in the coming years.
Asunto(s)
Infecciones por Actinobacillus , Actinobacillus pleuropneumoniae , Antibacterianos , Farmacorresistencia Bacteriana , Enfermedades de los Porcinos , Tianfenicol , Animales , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/genética , Actinobacillus pleuropneumoniae/aislamiento & purificación , Actinobacillus pleuropneumoniae/clasificación , Tianfenicol/análogos & derivados , Tianfenicol/farmacología , Porcinos , Italia/epidemiología , Enfermedades de los Porcinos/microbiología , Antibacterianos/farmacología , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/veterinaria , Farmacorresistencia Bacteriana/genética , Filogenia , Pruebas de Sensibilidad Microbiana , Secuenciación Completa del Genoma , Granjas , Pleuroneumonía/microbiología , Pleuroneumonía/veterinaria , Plásmidos/genética , Proteínas Bacterianas/genética , Polimorfismo de Nucleótido Simple , Virulencia/genéticaAsunto(s)
Actinobacillus pleuropneumoniae , Serogrupo , Infecciones Estreptocócicas , Streptococcus suis , Enfermedades de los Porcinos , Animales , Enfermedades de los Porcinos/microbiología , Porcinos , Quebec/epidemiología , Streptococcus suis/aislamiento & purificación , Infecciones Estreptocócicas/veterinaria , Infecciones Estreptocócicas/microbiología , Actinobacillus pleuropneumoniae/aislamiento & purificación , Actinobacillus pleuropneumoniae/clasificación , Actinobacillus pleuropneumoniae/genética , Infecciones por Actinobacillus/veterinaria , Infecciones por Actinobacillus/microbiologíaRESUMEN
Actinobacillus pleuropneumoniae (APP) causes significant economic losses to the swine industry. Antibiotic treatment can be challenging due to its clinical urgency and the turnover of antimicrobial susceptibility results from the diagnostic laboratory. The aim of this study was to evaluate the vertical transmission of APP within integrated systems as a criterion for optimising antimicrobial treatment in the field, using whole genome sequencing (WGS). Additionally, the genetic variability of Spanish APP isolates has been assessed to decipher antimicrobial resistance (AMR) determinants, toxin presence, serotype, and phenotype/genotype concordance of AMR. A total of 169 isolates from clinical cases of porcine pleuropneumonia with known antimicrobial susceptibility profiles were sequenced. Additionally, 48 NCBI assemblies were included to perform a phylogenetic analysis. Phylogenetic analysis revealed high association between phylogenetic clusters, serotypes, and presence of toxins that are associated within vertically integrated systems by its epidemiological link. Concordance between presence of AMR determinants (genotype) vs in-vitro antimicrobial susceptibility pattern (phenotype) was acceptable for amoxicillin, florfenicol, oxytetracycline, and enrofloxacin using epidemiological cut-off values (ECOFFs), but low concordance was observed for doxycycline and trimethoprim-sulfamethoxazole (T/S). On the other hand, using CLSI clinical breakpoints (CBPs), concordance was acceptable for florfenicol and enrofloxacin and not evaluated for doxycycline, oxytetracycline, trimethoprim-sulfamethoxazole (T/S), and amoxicillin because no CBP are available for them. Finally, WGS has demonstrated the clonality between isolates that shared a common origin (grandmother's farm) and resistance phenotype, suggesting vertical transmission of this pathogen and supporting the use of the epidemiological approach as a good criterion to optimise the antimicrobial use.
Asunto(s)
Infecciones por Actinobacillus , Actinobacillus pleuropneumoniae , Antibacterianos , Pruebas de Sensibilidad Microbiana , Filogenia , Enfermedades de los Porcinos , Secuenciación Completa del Genoma , Actinobacillus pleuropneumoniae/genética , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/clasificación , Actinobacillus pleuropneumoniae/aislamiento & purificación , Porcinos , Animales , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/veterinaria , Infecciones por Actinobacillus/transmisión , Enfermedades de los Porcinos/microbiología , Enfermedades de los Porcinos/transmisión , Antibacterianos/farmacología , Pleuroneumonía/microbiología , Pleuroneumonía/veterinaria , Genotipo , Genoma Bacteriano , Farmacorresistencia Bacteriana/genética , España/epidemiologíaRESUMEN
Actinobacillus pleuropneumoniae causes porcine pleuropneumonia, an important disease in the pig industry. Accurate and sensitive diagnostics such as DNA-based diagnostics are essential for preventing or responding to an outbreak. The specificity of DNA-based diagnostics depends on species-specific markers. Previously, an insertion element was found within an A. pleuropneumoniae-specific gene commonly used for A. pleuropneumoniae detection, prompting the need for additional species-specific markers. Herein, 12 marker candidates highly conserved (99 - 100% identity) among 34 A. pleuropneumoniae genomes (covering 13 serovars) were identified to be A. pleuropneumoniae-specific in silico, as these sequences are distinct from 30 genomes of 13 other Actinobacillus and problematic [Actinobacillus] species and more than 1700 genomes of other bacteria in the Pasteurellaceae family. Five marker candidates are within the apxIVA gene, a known A. pleuropneumoniae-specific gene, validating our in silico marker discovery method. Seven other A. pleuropneumoniae-specific marker candidates within the eamA, nusG, sppA, xerD, ybbN, ycfL, and ychJ genes were validated by polymerase chain reaction (PCR) to be specific to 129 isolates of A. pleuropneumoniae (covering all 19 serovars), but not to four closely related Actinobacillus species, four [Actinobacillus] species, or seven other bacterial species. This is the first study to identify A. pleuropneumoniae-specific markers through genome mining. Seven novel A. pleuropneumoniae-specific DNA markers were identified by a combination of in silico and molecular methods and can serve as additional or alternative targets for A. pleuropneumoniae diagnostics, potentially leading to better control of the disease. IMPORTANCE Species-specific markers are crucial for infectious disease diagnostics. Mutations within a marker sequence can lead to false-negative results, inappropriate treatment, and economic loss. The availability of several species-specific markers is therefore desirable. In this study, 12 DNA markers specific to A. pleuropneumoniae, a pig pathogen, were simultaneously identified. Five marker candidates are within a known A. pleuropneumoniae-specific gene. Seven novel markers can be used as additional targets in DNA-based diagnostics, which in turn can expedite disease diagnosis, assist farm management, and lead to better animal health and food security. The marker discovery strategy outlined herein requires less time, effort, and cost, and results in more markers compared with conventional methods. Identification of species-specific markers of other pathogens and corresponding infectious disease diagnostics are possible, conceivably improving health care and the economy.
Asunto(s)
Actinobacillus pleuropneumoniae/genética , Actinobacillus pleuropneumoniae/aislamiento & purificación , Proteínas Bacterianas/genética , Patología Molecular/métodos , Pleuroneumonía/veterinaria , Reacción en Cadena de la Polimerasa/métodos , Enfermedades de los Porcinos/microbiología , Actinobacillus pleuropneumoniae/clasificación , Animales , Marcadores Genéticos , Genoma Bacteriano , Pleuroneumonía/diagnóstico , Pleuroneumonía/microbiología , Porcinos , Enfermedades de los Porcinos/diagnósticoRESUMEN
Glaesserella australis, a newly described bacterial species, has been isolated from pig lungs that displayed lesions very similar to those caused by Actinobacillus pleuropneumoniae, prompting the need for a validated diagnostic tool. In this work, we have altered a multiplex PCR used for the identification of cultures of G. australis, A. pleuropneumoniae and Pasteurella multocida to be more sensitive and then evaluated the use of the altered diagnostic tool on cultures and directly on tissues. The altered multiplex PCR was validated using 47 related species, both type/reference strains and field isolates. The sensitivity was assessed by serial dilutions and used a mixture of target bacteria in different concentrations. Further, 166 lung samples from 54 farms from four Australian States were used to validate the ability of the multiplex PCR to detect bacteria in lung swabs. The multiplex PCR was specific for the three target species. The assay could detect a minimum of 40 colony forming units (CFU) of G. australis, 786 CFU of A. pleuropneumoniae and 238 CFU of P. multocida. The multiplex PCR yielded more positives than coventional bacteriological examination. From a total of 166 lung samples, 51.9%, 51.9% and 5.6% of farms were PCR positive for P. multocida, A. pleuropneumoniae and G. australis, respectively. The results suggested that the new multiplex PCR was specific, sensitive and out performed traditional culture. The prevalence of G. australis was not very high, but it was the dominant pathogen in infected pigs.
Asunto(s)
Actinobacillus pleuropneumoniae/genética , Reacción en Cadena de la Polimerasa Multiplex/métodos , Pasteurella multocida/genética , Pasteurellaceae/genética , Infecciones por Actinobacillus/diagnóstico , Infecciones por Actinobacillus/epidemiología , Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/aislamiento & purificación , Animales , Pruebas Diagnósticas de Rutina , Granjas , Pulmón/microbiología , Infecciones por Pasteurella/diagnóstico , Infecciones por Pasteurella/epidemiología , Infecciones por Pasteurella/veterinaria , Pasteurella multocida/aislamiento & purificación , Pasteurellaceae/aislamiento & purificación , Infecciones por Pasteurellaceae/diagnóstico , Infecciones por Pasteurellaceae/epidemiología , Infecciones por Pasteurellaceae/veterinaria , Prevalencia , Sensibilidad y Especificidad , Células Madre , Porcinos , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/microbiologíaRESUMEN
Serotyping is the most common method to characterize field isolates of Actinobacillus (A.) pleuropneumoniae, the etiological agent of porcine pleuropneumonia. Based on serology, many farms seem to be infected and antibodies against a wide variety of serovars are detectable, but, so far it is unknown to what degree respective serovars contribute to outbreaks of clinical manifest disease. In this study, 213 German A. pleuropneumoniae field isolates retrieved for diagnostic purposes from outbreaks of porcine pleuropneumonia between 2010 and 2019 were genetically serotyped and analyzed regarding their apx-toxin gene profile using molecular methods. Serotyping revealed a prominent role of serovar 2 in clinical cases (64% of all isolates) and an increase in the detection of this serovar since 2010 in German isolates. Serovar 9/11 followed as the second most frequent serovar with about 15% of the isolates. Furthermore, very recently described serovars 16 (n = 2) and 18 (n = 8) were detected. Most isolates (93.4%) showed apx-profiles typical for the respective serovar. However, this does not hold true for isolates of serovar 18, as 75% (n = 6) of all isolates of this serovar deviated uniformly from the "typical" apx-gene profile of the reference strain 7311555. Notably, isolates from systemic lesions such as joints or meninges did not harbor the complete apxICABD operon which is considered typical for highly virulent strains. Furthermore, the extremely low occurrence (n = 1) of NAD independent (biovar II) isolates in German A. pleuropneumoniae was evident in our collection of clinical isolates.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/genética , Pleuroneumonía/veterinaria , Enfermedades de los Porcinos/microbiología , Infecciones por Actinobacillus/microbiología , Actinobacillus pleuropneumoniae/aislamiento & purificación , Animales , Genotipo , Técnicas de Genotipaje/veterinaria , Alemania , Pleuroneumonía/microbiología , Serogrupo , Serotipificación/veterinaria , Sus scrofa , PorcinosRESUMEN
ApxI exotoxin is an important virulence factor derived from Actinobacillus pleuropneumoniae that causes pleuropneumonia in swine. Here, we investigate the role of lymphocyte function-associated antigen 1 (LFA-1, CD11a/CD18), a member of the ß2 integrin family, and the involvement of the integrin signaling molecules focal adhesion kinase (FAK) and Akt in ApxI cytotoxicity. Using Western blot analysis, we found that ApxI downregulated the activity of FAK and Akt in porcine alveolar macrophages (AMs). Preincubation of porcine AMs with an antibody specific for porcine CD18 reduced ApxI-induced cytotoxicity as measured by a lactate dehydrogenase release assay and decreased ApxI-induced FAK and Akt attenuation, as shown by Western blot analysis. Pretreatment with the chemical compounds PMA and SC79, which activate FAK and Akt, respectively, failed to overcome the ApxI-induced attenuation of FAK and Akt and death of porcine AMs. Notably, the transfection experiments revealed that ectopic expression of porcine LFA-1 (pLFA-1) conferred susceptibility to ApxI in ApxI-insensitive cell lines, including human embryonic kidney 293T cells and FAK-deficient mouse embryonic fibroblasts (MEFs). Furthermore, ectopic expression of FAK significantly reduced ApxI cytotoxicity in pLFA-1-cotransfected FAK-deficient MEFs. These findings show for the first time that pLFA-1 renders cells susceptible to ApxI and ApxI-mediated attenuation of FAK activity via CD18, thereby contributing to subsequent cell death.
Asunto(s)
Infecciones por Actinobacillus/patología , Actinobacillus pleuropneumoniae/metabolismo , Proteínas Bacterianas/metabolismo , Quinasa 1 de Adhesión Focal/antagonistas & inhibidores , Proteínas Hemolisinas/metabolismo , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Enfermedades de los Porcinos/patología , Infecciones por Actinobacillus/metabolismo , Infecciones por Actinobacillus/microbiología , Actinobacillus pleuropneumoniae/aislamiento & purificación , Actinobacillus pleuropneumoniae/patogenicidad , Animales , Muerte Celular/fisiología , Células Cultivadas , Quinasa 1 de Adhesión Focal/metabolismo , Humanos , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patología , Ratones , Proteínas Proto-Oncogénicas c-akt/metabolismo , Porcinos , Enfermedades de los Porcinos/metabolismo , Enfermedades de los Porcinos/microbiologíaRESUMEN
BACKGROUND: Osteomyelitis is relatively frequent in young pigs and a few bacterial species have been postulated to be potential causative agents. Although Actinobacillus (A.) pleuropneumoniae has been sporadically described to cause osteomyelitis, typically, actinobacillosis is characterized by respiratory symptoms. Nevertheless, subclinical infections are a challenging problem in pig herds. To the authors' knowledge, this is the first case description that reports clinical, diagnostic imaging, pathological and histopathological findings of vertebral osteomyelitis in a pig and first describes A. pleuropneumoniae as the causative agent identified by advanced molecular methods. CASE PRESENTATION: An eight-week-old female weaner was presented with a non-ambulatory tetraparesis. The neurological signs were consistent with a lesion in the C6-T2 spinal cord segments. Imaging studies revealed a collapse of the seventh cervical vertebral body (C7) with a well demarcated extradural space-occupying mass ventrally within the vertebral canal severely compressing the spinal cord. Post-mortem examination identified an abscess and osteomyelitis of C7 and associated meningitis and neuritis with subsequent pathological fracture of C7 and compression of the spinal cord. In the microbiological analysis, A. pleuropneumoniae was identified using PCR and DNA sequence analysis. CONCLUSIONS: A. pleuropneumoniae can be responsible for chronic vertebral abscess formation with subsequent pathological fracture and spinal cord compression in pigs.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/aislamiento & purificación , Osteomielitis/veterinaria , Fracturas de la Columna Vertebral/veterinaria , Enfermedades de los Porcinos/microbiología , Absceso/microbiología , Absceso/veterinaria , Animales , Vértebras Cervicales/patología , Femenino , Osteomielitis/microbiología , Sus scrofa , PorcinosRESUMEN
Respiratory infections caused by Actinobacillus pleuropneumoniae have a large impact on commercial pig farms globally. As current vaccines have limited efficacy, animal care and air hygiene are critical for disease control. Here we used a Coriolis µ cyclonic air sampler and an A. pleuropneumoniae-specific apxIV gene qPCR assay to detect the organism. Air samples were collected into a liquid medium by the Coriolis µ sampler for A. pleuropneumoniae detection by plate culture and qPCR assay. The method was validated by comparing the Coriolis µ sampler and a plate impactor (Millipore Air-T) in a specially designed aerosolization chamber. Two commercial farms, housing pigs between 3 and 21 weeks of age, were tested. On one farm, A. pleuropneumoniae was detected in low numbers (1000 organisms/m3 air) by qPCR, but not by culture, from sheds containing 8, 12, 16, and 18 weeks-old pigs. To our knowledge this is the first successful detection of naturally aerosolised A. pleuropneumoniae in commercial farms with the Coriolis µ air sampler, potentially allowing the identification of sub-clinically infected populations of pigs in the field.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/aislamiento & purificación , Aerosoles/análisis , Microbiología del Aire , Granjas , Infecciones por Actinobacillus/diagnóstico , Infecciones por Actinobacillus/microbiología , Actinobacillus pleuropneumoniae/genética , Crianza de Animales Domésticos , Animales , Anticuerpos Antibacterianos/sangre , Australia , Femenino , Masculino , Pleuroneumonía/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa , Porcinos/microbiología , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/microbiologíaRESUMEN
Two Actinobacillus pleuropneumoniae isolates from clinical cases of porcine pleuropneumonia in Japan were positive in the capsular serovar 15-specific PCR assay, but nontypeable (NT) in the agar gel precipitation (AGP) test. Nucleotide sequence analysis of gene clusters involved in the biosynthesis of capsular polysaccharide (CPS) and lipopolysaccharide O-polysaccharide (O-PS) revealed that both clusters contained transposable element ISApl1 of A. pleuropneumoniae belonging to the IS30 family. Immunoblot analysis revealed that these 2 isolates could not produce O-PS. We conclude that the ISApl1 of A. pleuropneumoniae can interfere in the biosynthesis of both CPS and O-PS.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/fisiología , Elementos Transponibles de ADN , Pleuroneumonía/veterinaria , Polisacáridos/análisis , Enfermedades de los Porcinos/diagnóstico , Infecciones por Actinobacillus/diagnóstico , Infecciones por Actinobacillus/microbiología , Actinobacillus pleuropneumoniae/aislamiento & purificación , Animales , Genes Bacterianos , Immunoblotting/veterinaria , Familia de Multigenes , Pleuroneumonía/diagnóstico , Pleuroneumonía/microbiología , Reacción en Cadena de la Polimerasa/veterinaria , Porcinos , Enfermedades de los Porcinos/microbiologíaRESUMEN
Actinobacillus pleuropneumoniae is an important veterinary pathogen that causes porcine pleuropneumonia. Lipoproteins of bacterial pathogens play pleiotropic roles in the infection process. In addition, many bacterial lipoproteins are antigenic and immunoprotective. Therefore, characterization of lipoproteins is a promising strategy for identification of novel vaccine candidates or diagnostic markers. We cloned 58 lipoproteins from A. pleuropneumoniae JL03 (serovar 3) and expressed them in Escherichia coli. Five proteins with strong positive signals in western blotting analysis were used to immunize mice. These proteins elicited significant antibody responses, and three of them (APJL_0922, APJL_1380 and APJL_1976) generated efficient immunoprotection in mice against lethal heterologous challenge with A. pleuropneumoniae 4074 (serovar 1), both in the active and passive immunization assays. Then immunogenicity of these three lipoproteins (APJL_0922, APJL_1380 and APJL_1976) were further tested in pigs. Results showed that these proteins elicited considerable humoral immune responses and effective protective immunity against virulent A. pleuropneumoniae challenge. Our findings suggest that these three novel lipoproteins could be potential subunit vaccine candidates.
Asunto(s)
Infecciones por Actinobacillus/prevención & control , Actinobacillus pleuropneumoniae/inmunología , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Vacunas Bacterianas/administración & dosificación , Lipoproteínas/inmunología , Enfermedades de los Porcinos/prevención & control , Infecciones por Actinobacillus/inmunología , Infecciones por Actinobacillus/metabolismo , Infecciones por Actinobacillus/microbiología , Actinobacillus pleuropneumoniae/aislamiento & purificación , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Vacunas Bacterianas/inmunología , Genoma Bacteriano , Inmunidad Humoral/inmunología , Inmunización/métodos , Lipoproteínas/genética , Lipoproteínas/metabolismo , Ratones , Ratones Endogámicos BALB C , Porcinos , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/metabolismo , Enfermedades de los Porcinos/microbiologíaRESUMEN
An electrochemically activated solution (ECAS), generated by electrolysis of a dilute sodium chloride solution in a four-chamber electrolytic cell (Ecas4), was tested as a sanitising aerosol in eliminating bacteria from the environment of a weaning room vacated 24-48h earlier, at a continuous flow pig farm. An ultrasonic humidifier was used to fill the environment with a fog (droplets with diameters of 1-5 µm) containing 0.25 ppm of hypochlorous acid. The weaning room was fogged for 3 min at 30 min intervals during five hours of aerosol disinfection. An innovative sample treatment with propidium monoazide dye in conjunction with cyclonic air sampling was optimised and adapted for discerning live/dead bacteria in subsequent molecular quantification steps. Without fogging, total bacterial load ranged from 5.06 ± 0.04 to 5.75 ± 0.04 Log10 CFU/m3. After the first hour of fogging, a 78% total bacterial reduction was observed, which further increased to > 97% after the second hour, > 99.4% after the third and 99.8% after the fourth hour, finally resulting in a 99.99% reduction from the farm environment over five hours. Unlike the current formaldehyde spray disinfection protocol, which requires a long empty period because of its hazardous properties, this economically viable and environmentally friendly disinfection protocol may significantly lower downtime. Moreover, ECAS fogging can be easily adapted to a variety of applications, including the elimination of pathogens from livestock farm air environment for disease prevention, as well as decontamination after disease outbreaks.
Asunto(s)
Bacterias/efectos de los fármacos , Infecciones Bacterianas/prevención & control , Descontaminación/métodos , Desinfectantes/administración & dosificación , Granjas , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/aislamiento & purificación , Aerosoles , Microbiología del Aire , Animales , Bacterias/aislamiento & purificación , Infecciones Bacterianas/microbiología , Infecciones Bacterianas/veterinaria , Carga Bacteriana , Desinfectantes/química , Electrólisis , Fumigación/métodos , Humidificadores , Concentración de Iones de Hidrógeno , Ácido Hipocloroso/administración & dosificación , Ácido Hipocloroso/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Porcinos/microbiologíaRESUMEN
A study was conducted on 21 pig herds using one-site production system in the southeast region of Brazil to assess the relationships among serological results for primary pathogens involved in respiratory diseases (Actinobacillus pleuropneumoniae, App; Mycoplasma hyopneumoniae, Mhyo; and swine influenza virus, SIV), cough index, pneumonia index, pleuritis and herd characteristics. The prevalence of antibodies against Mhyo and SIV increased throughout the raising phases, with the highest prevalence in slaughtered pigs (> 40%), while pigs in 65% (14/21) of nurseries demonstrated marked seroprevalence of App that decreased until the day of slaughter. Pleuritis and pulmonary consolidations were recorded in 9.0 and 72.4%, respectively, of the 908 evaluated lungs. Histopathological analysis of the lung lesions revealed suppurative bronchopneumonia in almost half of the lungs (48.9%). Regression analyses were conducted to identify risk factors associated with the cough index; pleuritis; pulmonary consolidation; and App, Mhyo and SIV serological results. All-in-all-out management in nursery buildings reduced the seroprevalence of Mhyo in herds. App seroprevalence was associated with pleuritis, and the presence of cough episodes in growing pigs was associated with SIV seropositivity in nursery pigs.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Infecciones por Orthomyxoviridae/veterinaria , Pleuresia/veterinaria , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/microbiología , Infecciones por Actinobacillus/epidemiología , Infecciones por Actinobacillus/patología , Actinobacillus pleuropneumoniae/aislamiento & purificación , Crianza de Animales Domésticos , Animales , Anticuerpos Antibacterianos/sangre , Anticuerpos Antivirales/sangre , Brasil/epidemiología , Tos/microbiología , Tos/veterinaria , Estudios Transversales , Granjas , Modelos Logísticos , Pulmón/patología , Mycoplasma hyopneumoniae/aislamiento & purificación , Infecciones por Orthomyxoviridae/epidemiología , Pleuresia/epidemiología , Pleuresia/microbiología , Pleuresia/patología , Neumonía Porcina por Mycoplasma/epidemiología , Análisis de Regresión , Factores de Riesgo , Estudios Seroepidemiológicos , Porcinos , Enfermedades de los Porcinos/patología , Enfermedades de los Porcinos/prevención & controlRESUMEN
Actinobacillus pleuropneumoniae is the etiological agent of swine contagious pleuropneumoniae, which is distributed globally and associated with severe economic losses in the pig rearing industry. In this study, a real-time recombinase polymerase amplification assay (real-time RPA) based on the apxIVA gene was developed to rapid detect A. pleuropneumoniae. Real-time RPA was performed successfully in Genie III at the constant temperature of 39⯰C for 20â¯min. The developed assay was highly specific for A. pleuropneumoniae, and the sensitivity at 95% probability was 536â¯fg of A. pleuropneumoniae genomic DNA. The real-time RPA for A. pleuropneumoniae was further evaluated on the 112 clinical swine lung and tonsil samples, and 25 (22.3%), 27 (24.1%), and 12 (10.7%) samples were positive for A. pleuropneumoniae by the real-time RPA, real-time PCR and bacterial isolation, respectively. With a real-time PCR as the reference method, the real-time RPA showed a diagnostic specificity of 98.8%, a diagnostic sensitivity of 88.9%, a positive predicative value of 96.0%, a negative predictive value of 96.5%, and a kappa value of 0.900. The above data demonstrated the well potentiality and usefulness of the developed real-time RPA assay in the reliable detection of A. pleuropneumoniae, especially in resource limited settings.
Asunto(s)
Infecciones por Actinobacillus/diagnóstico , Actinobacillus pleuropneumoniae/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/veterinaria , Enfermedades de los Porcinos/virología , Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/genética , Animales , Proteínas Bacterianas/genética , Pulmón/microbiología , Tonsila Palatina/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Recombinasas/metabolismo , Sensibilidad y Especificidad , PorcinosRESUMEN
Six atypical Actinobacillus pleuropneumoniae serovar 15 strains were isolated from pneumonic lesions of naturally infected dead pigs from the same farm in Japan. Genetic analyses of apx genes revealed that the atypical isolates contained the toxin-associated genes apxIBD, apxIIICA, apxIIIBD, and apxIVA, but not apxIICA. Coinciding with the result of the atypical gene profile, analyses of toxin protein production revealed that these atypical isolates expressed only ApxIII but not ApxII. A mouse pathogenicity test showed that the atypical isolate tested seemed to be less virulent than the typical isolates. This is the first report describing the emergence of atypical A. pleuropneumoniae serovar 15, which does not produce ApxII due to the absence of apxIICA genes, in Japan.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/aislamiento & purificación , Proteínas Bacterianas/genética , Genes Bacterianos , Proteínas Hemolisinas/genética , Enfermedades de los Porcinos/microbiología , Infecciones por Actinobacillus/microbiología , Actinobacillus pleuropneumoniae/genética , Actinobacillus pleuropneumoniae/patogenicidad , Animales , Femenino , Eliminación de Gen , Japón , Ratones , Porcinos , Transcriptoma , Virulencia/genéticaRESUMEN
Actinobacillus pleuropneumoniae, Pasteurella multocida and Streptococcus suis are prevalent bacterial causes of swine infections. Morbidity, mortality and positively impacting the financial burden of infection occurs with appropriate antimicrobial therapy. Increasing antimicrobial resistance complicates drug therapy and resistance prevention is now a necessity to optimize therapy and prolong drug life. Mutant bacterial cells are said to arise spontaneously in bacterial densities of 107-109 or greater colony forming units/ml. Antibiotic drug concentration inhibiting growth of the least susceptible cell in these high density populations has been termed the mutant prevention concentration (MPC). In this study MPC and minimum inhibitory concentration (MIC) values of ceftiofur, enrofloxacin, florfenicol, tilmicosin and tulathromycin were determined against the swine pathogens A. pleuropneumoniae, P.multocida and S. suis. The following MIC90/MPC90 values (mg/L) for 67 A. pleuropneumoniae and 73 P. multocida strains respectively were as follows: A. pleuropneumoniae 0.031/0.5, ≤0.016/0.5, 0.5/2, 4/32, 2/32; P. multocida 0.004/0.25, 0.016/0.125, 0.5/0.5, 8/16, 0.5/1. For 33 S. suis strains, MIC90 values (mg/L) respectively were as follows: 1, 0.25, 4, ≥8 and ≥8. A total of 16 S. suis strains with MIC values of 0.063-0.5 mg/L to ceftiofur and 0.25-0.5 mg/L to enrofloxacin were tested by MPC; MPC values respectively were 0.5 and 1 mg/L respectively. MPC concentrations provide a dosing target which may serve to reduce amplification of bacterial subpopulations with reduced antimicrobial susceptibility. Drug potency based on MIC90 values was ceftiofur > enrofloxacin >florfenicol = tulathromycin > tilmicosin; based on MPC90 values was enrofloxacin > ceftiofur > tulathromycin > florfenicol ≥ tilmicosin.
Asunto(s)
Actinobacillus pleuropneumoniae/efectos de los fármacos , Antibacterianos/farmacología , Pasteurella multocida/efectos de los fármacos , Streptococcus suis/efectos de los fármacos , Enfermedades de los Porcinos/tratamiento farmacológico , Actinobacillus pleuropneumoniae/genética , Actinobacillus pleuropneumoniae/aislamiento & purificación , Crianza de Animales Domésticos , Animales , Antibacterianos/uso terapéutico , Cefalosporinas/farmacología , Cefalosporinas/uso terapéutico , Disacáridos/farmacología , Disacáridos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genética , Enrofloxacina/farmacología , Enrofloxacina/uso terapéutico , Compuestos Heterocíclicos/farmacología , Compuestos Heterocíclicos/uso terapéutico , Pruebas de Sensibilidad Microbiana , Pasteurella multocida/genética , Pasteurella multocida/aislamiento & purificación , Streptococcus suis/genética , Streptococcus suis/aislamiento & purificación , Porcinos , Enfermedades de los Porcinos/microbiología , Tianfenicol/análogos & derivados , Tianfenicol/farmacología , Tianfenicol/uso terapéutico , Tilosina/análogos & derivados , Tilosina/farmacología , Tilosina/uso terapéuticoRESUMEN
Actinobacillus (A.) pleuropneumoniae is normally considered strictly adapted to the respiratory tract of swine. Despite this, scattered case reports of arthritis, osteomyelitis, hepatitis, meningitis or nephritis exist, in which A. pleuropneumoniae remained the only detectable pathogen. Therefore, the aim of this study was to investigate whether spreading to other organs than the lungs is incidental or may occur more frequently. For this, organ samples (blood, liver, spleen, kidney, tarsal and carpal joints, meninges, pleural and pericardial fluids) from weaners (n = 47) infected experimentally with A. pleuropneumoniae serovar 7 by aerosol infection (infection dose: 10.9 × 103 cfu/animal) were examined by culture during the first week after infection. In addition, tissue samples of eight weaners were examined by histology and immunohistochemistry (IHC). A. pleuropneumoniae was isolated in all examined sample sites (86.7% pleural fluids, 73.3% pericardial fluids, 50.0% blood, 61.7% liver, 51.1% spleen, 55.3% kidney, 14.9% tarsal joints, 12.8% carpal joints, 27.7% meninges). These results were also obtained from animals with only mild clinical symptoms. IHC detection confirmed these findings in all locations except carpal joints. Histological examination revealed purulent hepatitis (n = 2), nephritis (n = 1) and beginning meningitis (n = 2). Isolation results were significantly correlated (p < 0.001) with the degree of lung colonization and, to a lower extent, with the severity of disease. Detection of A. pleuropneumoniae in peripheral tissues was significantly correlated to spleen colonization. In conclusion, multi-organ spreading of A. pleuropneumoniae serovar 7 strain AP 76 seems to occur more frequently during acute infection following effective lung colonization than previously thought.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/aislamiento & purificación , Enfermedades de los Porcinos/fisiopatología , Infecciones por Actinobacillus/fisiopatología , Infecciones por Actinobacillus/virología , Actinobacillus pleuropneumoniae/genética , Actinobacillus pleuropneumoniae/fisiología , Animales , Serogrupo , Porcinos , Enfermedades de los Porcinos/virología , DesteteRESUMEN
The aim of this study was to investigate isolates of Actinobacillus pleuropneumoniae previously designated serologically either as non-typable (NT) or as 'K2:07', which did not produce serovar-specific amplicons in PCR assays. We used whole genome sequencing to identify the capsule (CPS) loci of six previously designated biovar 1 NT and two biovar 1 'K2:O7' isolates of A. pleuropneumoniae from Denmark, as well as a recent biovar 2 NT isolate from Canada. All of the NT isolates have the same six-gene type I CPS locus, sharing common cpsABC genes with serovars 2, 3, 6, 7, 8, 9, 11 and 13. The two 'K2:O7' isolates contain a unique three-gene type II CPS locus, having a cpsA gene similar to that of serovars 1, 4, 12, 14 and 15. The previously NT isolates share the same O-antigen genes, found between erpA and rpsU, as serovars 3, 6, 8, and 15. Whereas the 'K2:O7' isolates, have the same O-antigen genes as serovar 7, which likely contributed to their previous mis-identification. All of the NT and 'K2:O7' isolates have only the genes required for production of ApxII (apxIICA structural genes, and apxIBD export genes). Rabbit polyclonal antisera raised against representative isolates with these new CPS loci demonstrated distinct reactivity compared to the 16 known serovars. The serological and genomic results indicate that the isolates constitute new serovars 17 (previously NT) and 18 (previously 'K2:O7'). Primers designed for amplification of specific serovar 17 and 18 sequences for molecular diagnostics will facilitate epidemiological tracking of these two new serovars of A. pleuropneumoniae.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/clasificación , Actinobacillus pleuropneumoniae/genética , Genotipo , Serogrupo , Infecciones por Actinobacillus/epidemiología , Actinobacillus pleuropneumoniae/inmunología , Actinobacillus pleuropneumoniae/aislamiento & purificación , Animales , Cápsulas Bacterianas/genética , Canadá/epidemiología , Cartilla de ADN/genética , ADN Bacteriano/genética , Dinamarca/epidemiología , Reacción en Cadena de la Polimerasa/métodos , Serotipificación , Porcinos , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/microbiología , Secuenciación Completa del GenomaRESUMEN
An atypical urease-negative mutant of Actinobacillus pleuropneumoniae serovar 2 was isolated in Japan. Nucleotide sequence analysis of the urease gene cluster revealed that the insertion of a short DNA sequence into the cbiM gene was responsible for the urease-negative activity of the mutant. Veterinary diagnostic laboratories should be watchful for the presence of aberrant urease-negative A. pleuropneumoniae isolates.