RESUMEN
Tylosin, an antibiotic with a long history in treating respiratory bacterial infections, has unknown effects on the gut microbiota of healthy and infected pigs. The study aimed to investigate the effect of a therapeutic dose of tylosin on swine gut microbiota and explored the relationship between this effect and tylosin pharmacokinetics (PK). We also assessed whether changes in gut microbiota after tylosin administration differ between healthy animals (n = 7) and animals intranasally co-infected (n = 7) with Actinobacillus pleuropneumoniae and Pasteurella multocida. Both groups were intramuscularly administered with tylosin (20 mg/kg). The 16S rRNA gene analyses revealed a significantly lower species richness and diversity, after tylosin treatment, in the infected than the healthy pigs, with infected pigs having lower levels of Bacteroidetes and Firmicutes and higher levels of Proteobacteria. Greater tylosin exposure (greater area under curve (AUC) and maximum plasma concentration (Cmax), and slower elimination (longer terminal half-life, T1/2) were observed in healthy than infected pigs. Relative abundance of Lactobacillus, Oscillibacter, Prevotella, and Sporobacter was positively and significantly correlated with AUC and Cmax, whereas the abundance of Acinetobacter, Alishewanella, and Pseudomonas was positively and significantly correlated with T1/2 and mean residence time (MRT) of tylosin. Our findings, for the first time, demonstrated significant changes in swine gut microbiota after a single therapeutic dose of tylosin was administered, whereas the effect of these changes on tylosin PK was not evident.
Asunto(s)
Antibacterianos , Microbioma Gastrointestinal , Tilosina , Animales , Tilosina/farmacocinética , Tilosina/administración & dosificación , Microbioma Gastrointestinal/efectos de los fármacos , Porcinos , Antibacterianos/farmacocinética , Antibacterianos/farmacología , Enfermedades de los Porcinos/microbiología , Enfermedades de los Porcinos/tratamiento farmacológico , ARN Ribosómico 16S/genética , Pasteurella multocida/efectos de los fármacos , Actinobacillus pleuropneumoniae/efectos de los fármacosRESUMEN
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/genéticaRESUMEN
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
BACKGROUND: Actinobacillus pleuropneumoniae is a serious pathogen in pigs. The abundant application of antibiotics has resulted in the gradual emergence of drugresistant bacteria, which has seriously affected treatment of disease. To aid measures to prevent the emergence and spread of drug-resistant bacteria, herein, the kill rate and mutant selection window (MSW) of danofloxacin (DAN) against A. pleuropneumoniae were evaluated. METHODS: For the kill rate study, the minimum inhibitory concentration (MIC) was tested using the micro dilution broth method and time-killing curves of DAN against A. pleuropneumoniae grown in tryptic soy broth (TSB) at a series drug concentrations (from 0 to 64 MIC) were constructed. The relationships between the kill rate and drug concentrations were analyzed using a Sigmoid Emax model during different time periods. For the MSW study, the MIC99 (the lowest concentration that inhibited the growth of the bacteria by ≥ 99%) and mutant prevention concentration (MPC) of DAN against A. pleuropneumoniae were measured using the agar plate method. Then, a peristaltic pump infection model was established to simulate the dynamic changes of DAN concentrations in pig lungs. The changes in number and sensitivity of A. pleuropneumoniae were measured. The relationships between pharmacokinetic/pharmacodynamic parameters and the antibacterial effect were analyzed using the Sigmoid Emax model. RESULTS: In kill rate study, the MIC of DAN against A. pleuropneumoniae was 0.016 µg/mL. According to the kill rate, DAN exhibited concentration-dependent antibacterial activity against A. pleuropneumoniae. A bactericidal effect was observed when the DAN concentration reached 4-8 MIC. The kill rate increased constantly with the increase in DAN concentration, with a maximum value of 3.23 Log10 colony forming units (CFU)/mL/h during the 0-1 h period. When the drug concentration was in the middle part of the MSW, drugresistant bacteria might be induced. Therefore, the dosage should be avoided to produce a mean value of AUC24h/MIC99 (between 31.29 and 62.59 h. The values of AUC24h/MIC99 to achieve bacteriostatic, bactericidal, and eradication effects were 9.46, 25.14, and > 62.59 h, respectively. CONCLUSION: These kill rate and MSW results will provide valuable guidance for the use of DAN to treat A. pleuropneumoniae infections.
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Infecciones por Actinobacillus , Actinobacillus pleuropneumoniae , Antibacterianos , Fluoroquinolonas , Pruebas de Sensibilidad Microbiana , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/genética , Antibacterianos/farmacología , Fluoroquinolonas/farmacología , Animales , Infecciones por Actinobacillus/veterinaria , Infecciones por Actinobacillus/tratamiento farmacológico , Porcinos , Farmacorresistencia Bacteriana , Enfermedades de los Porcinos/tratamiento farmacológico , Enfermedades de los Porcinos/microbiología , MutaciónRESUMEN
Actinobacillus pleuropneumoniae (APP) causes porcine pleuropneumonia (PCP), which is clinically characterized by acute hemorrhagic, necrotizing pneumonia, and chronic fibrinous pneumonia. Although many measures have been taken to prevent the disease, prevention and control of the disease are becoming increasingly difficult due to the abundance of APP sera, weak vaccine cross-protection, and increasing antibiotic resistance in APP. Therefore, there is an urgent need to develop novel drugs against APP infection to prevent the spread of APP. Naringin (NAR) has been reported to have an excellent therapeutic effect on pulmonary diseases, but its therapeutic effect on lung injury caused by APP is not apparent. Our research has shown that NAR was able to alleviate APP-induced weight loss and quantity of food taken and reduce the number of WBCs and NEs in peripheral blood in mice; pathological tissue sections showed that NAR was able to prevent and control APP-induced pathological lung injury effectively; based on the establishment of an in vivo/in vitro model of APP inflammation, it was found that NAR was able to play an anti-inflammatory role through inhibiting the MAPK/NF-κB signaling pathway and exerting anti-inflammatory effects; additionally, NAR activating the Nrf2 signalling pathway, increasing the secretion of antioxidant enzymes Nqo1, CAT, and SOD1, inhibiting the secretion of oxidative damage factors NOS2 and COX2, and enhancing the antioxidant stress ability, thus playing an antioxidant role. In summary, NAR can relieve severe lung injury caused by APP by reducing excessive inflammatory response and improving antioxidant capacity.
Asunto(s)
Infecciones por Actinobacillus , Actinobacillus pleuropneumoniae , Lesión Pulmonar Aguda , Flavanonas , Proteína 1 Asociada A ECH Tipo Kelch , Factor 2 Relacionado con NF-E2 , FN-kappa B , Animales , Ratones , Infecciones por Actinobacillus/veterinaria , Infecciones por Actinobacillus/tratamiento farmacológico , Actinobacillus pleuropneumoniae/efectos de los fármacos , Lesión Pulmonar Aguda/tratamiento farmacológico , Lesión Pulmonar Aguda/prevención & control , Flavanonas/uso terapéutico , Flavanonas/farmacología , Hemo-Oxigenasa 1 , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Proteínas de la Membrana , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
Background. Actinobacillus pleuropneumoniae, a member of the Pasteurellaceae family, is known for its highly infectious nature and is the primary causative agent of infectious pleuropneumonia in pigs. This disease poses a considerable threat to the global pig industry and leads to substantial economic losses due to reduced productivity, increased mortality rates, and the need for extensive veterinary care and treatment. Due to the emergence of multi-drug-resistant strains, Chinese herbal medicine is considered one of the best alternatives to antibiotics due to its unique mechanism of action and other properties. As a type of Chinese herbal medicine, Rhein has the advantages of a wide antibacterial spectrum and is less likely to develop drug resistance, which can perfectly solve the limitations of current antibacterial treatments.Methods. The killing effect of Rhein on A. pleuropneumoniae was detected by fluorescence quantification of differential expression changes of key genes, and scanning electron microscopy was used to observe the changes in A. pleuropneumoniae status after Rhein treatment. Establishing a mouse model to observe the treatment of Rhein after A. pleuropneumoniae infection.Results. Here, in this study, we found that Rhein had a good killing effect on A. pleuropneumoniae and that the MIC was 25 µg ml-1. After 3 h of action, Rhein (4×MIC) completely kills A. pleuropneumoniae and Rhein has good stability. In addition, the treatment with Rhein (1×MIC) significantly reduced the formation of bacterial biofilms. Therapeutic evaluation in a murine model showed that Rhein protects mice from A. pleuropneumoniae and relieves lung inflammation. Quantitative RT-PCR (Quantitative reverse transcription polymerase chain reaction is a molecular biology technique that combines both reverse transcription and polymerase chain reaction methods to quantitatively detect the amount of a specific RNA molecule) results showed that Rhein treatment significantly downregulated the expression of the IL-18 (Interleukin refers to a class of cytokines produced by white blood cells), TNF-α, p65 and p38 genes. Along with the downregulation of genes such as IL-18, it means that Rhein has an inhibitory effect on the expression of these genes, thereby reducing the activation of inflammatory cells and the production of inflammatory mediators. This helps reduce inflammation and protects tissue from further damage.Conclusions. This study reports the activity of Rhein against A. pleuropneumoniae and its mechanism, and reveals the ability of Rhein to treat A. pleuropneumoniae infection in mice, laying the foundation for the development of new drugs for bacterial infections.
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Infecciones por Actinobacillus , Actinobacillus pleuropneumoniae , Antraquinonas , Antibacterianos , Animales , Antraquinonas/farmacología , Antraquinonas/uso terapéutico , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/genética , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Ratones , Infecciones por Actinobacillus/tratamiento farmacológico , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/veterinaria , Porcinos , Modelos Animales de Enfermedad , Femenino , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/uso terapéutico , Pulmón/microbiología , Pulmón/patología , Enfermedades de los Porcinos/tratamiento farmacológico , Enfermedades de los Porcinos/microbiologíaRESUMEN
Actinobacillus pleuropneumoniae infection causes a high mortality rate in porcine animals. Antimicrobial resistance poses global threats to public health. The current study aimed to determine the antimicrobial susceptibilities and probe the resistome of A. pleuropneumoniae in Taiwan. Herein, 133 isolates were retrospectively collected; upon initial screening, 38 samples were subjected to next-generation sequencing (NGS). Over the period 2017-2022, the lowest frequencies of resistant isolates were found for ceftiofur, cephalexin, cephalothin, and enrofloxacin, while the highest frequencies of resistant isolates were found for oxytetracycline, streptomycin, doxycycline, ampicillin, amoxicillin, kanamycin, and florfenicol. Furthermore, most isolates (71.4%) showed multiple drug resistance. NGS-based resistome analysis revealed aminoglycoside- and tetracycline-related genes at the highest prevalence, followed by genes related to beta-lactam, sulfamethoxazole, florphenicol, and macrolide. A plasmid replicon (repUS47) and insertion sequences (IS10R and ISVAp11) were identified in resistant isolates. Notably, the multiple resistance roles of the insertion sequence IS10R were widely proposed in human medicine; however, this is the first time IS10R has been reported in veterinary medicine. Concordance analysis revealed a high consistency of phenotypic and genotypic susceptibility to florphenicol, tilmicosin, doxycycline, and oxytetracycline. The current study reports the antimicrobial characterization of A. pleuropneumoniae for the first time in Taiwan using NGS.
Asunto(s)
Infecciones por Actinobacillus , Actinobacillus pleuropneumoniae , Antibacterianos , Secuenciación de Nucleótidos de Alto Rendimiento , Pruebas de Sensibilidad Microbiana , Enfermedades de los Porcinos , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/genética , Taiwán/epidemiología , Antibacterianos/farmacología , Animales , Enfermedades de los Porcinos/microbiología , Enfermedades de los Porcinos/epidemiología , Porcinos , Infecciones por Actinobacillus/veterinaria , Infecciones por Actinobacillus/microbiología , Estudios Retrospectivos , Farmacorresistencia Bacteriana Múltiple/genética , Farmacorresistencia Bacteriana/genéticaRESUMEN
Actinobacillus pleuropneumoniae is a pathogen that infects pigs and poses a serious threat to the pig industry. The emergence of quinolone-resistant strains of A.pleuropneumoniae further limits the choice of treatment. However, the mechanisms behind quinolone resistance in A.pleuropneumoniae remain unclear. The genomes of a ciprofloxacin-resistant strain, A. pleuropneumoniae SC1810 and its isogenic drug-sensitive counterpart were sequenced and analyzed using various bioinformatics tools, revealing 559 differentially expressed genes. The biological membrane, plasmid-mediated quinolone resistance genes and quinolone resistance-determining region were detected. Upregulated expression of efflux pump genes led to ciprofloxacin resistance. The expression of two porins, OmpP2B and LamB, was significantly downregulated in the mutant. Three nonsynonymous mutations in the mutant strain disrupted the water-metal ion bridge, subsequently reducing the affinity of the quinolone-enzyme complex for metal ions and leading to cross-resistance to multiple quinolones. The mechanism of quinolone resistance in A. pleuropneumoniae may involve inhibition of expression of the outer membrane protein genes ompP2B and lamB to decrease drug influx, overexpression of AcrB in the efflux pump to enhance its drug-pumping ability, and mutation in the quinolone resistance-determining region to weaken the binding of the remaining drugs. These findings will provide new potential targets for treatment.
Asunto(s)
Quinolonas/farmacología , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/genética , Biopelículas/efectos de los fármacos , Porinas/metabolismo , Transcriptoma/genéticaRESUMEN
Actinobacillus pleuropneumoniae is a Gram-negative bacterium causing porcine pleuropneumonia and severe economic losses in the global swine industry. The toxic trace element copper is required for many physiological and pathological processes in organisms. However, CopA, one of the most well-characterized P-type ATPases contributing to copper resistance, has not been characterized in A. pleuropneumoniae. We used quantitative PCR analysis to examine expression of the copA gene in A. pleuropneumoniae and investigated sequence conservation among serotypes and other Gram-negative bacteria. Growth characteristics were determined using growth curve analyses and spot dilution assays of the wild-type strain and a â³copA mutant. We also used flame atomic absorption spectrophotometry to determine intracellular copper content and examined the virulence of the â³copA mutant in a mouse model. The copA expression was induced by copper, and its nucleotide sequence was highly conserved among different serotypes of A. pleuropneumoniae. The amino acid sequence of CopA shared high identity with CopA sequences reported from several Gram-negative bacteria. Furthermore, the â³copA mutant exhibited impaired growth and had higher intracellular copper content compared with the wild-type strain when supplemented with copper. The mouse model revealed that CopA had no influence on the virulence of A. pleuropneumoniae. In conclusion, these results demonstrated that CopA is required for resistance of A. pleuropneumoniae to copper and protects A. pleuropneumoniae against copper toxicity via copper efflux.
Asunto(s)
Infecciones por Actinobacillus/microbiología , Actinobacillus pleuropneumoniae/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Cobre/farmacología , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Actinobacillus pleuropneumoniae/genética , Actinobacillus pleuropneumoniae/metabolismo , Actinobacillus pleuropneumoniae/patogenicidad , Animales , Proteínas Bacterianas/genética , Biología Computacional , Ratones , Ratones Endogámicos BALB C , Regulación hacia Arriba/efectos de los fármacos , VirulenciaRESUMEN
Actinobacillus pleuropneumoniae, the etiological agent of porcine pleuropneumonia, is increasingly resistant to antibiotics. However, little is known about the mechanisms of antibiotic resistance in this pathogen. In this study, we experimentally evolved the reference strain of both A. pleuropneumoniae serovar 1 and serovar 7, the most prevalent serovars worldwide, to quinolone resistance by sequential exposure to subinhibitory concentrations of ciprofloxacin. The adaptive ciprofloxacin-resistant mutants of A. pleuropneumoniae serovar 1 and serovar 7 had a minimum inhibitory concentration (MIC) increment from 0.004 to 1 or 2 µg/mL, respectively. Adaptation to ciprofloxacin was shown to confer quinolone resistance with a 32- to 512-fold increase (serovars 1 and 7, respectively) as well as cross-resistance to ampicillin with an increased MIC by 16,384- and 64-fold (serovars 1 and 7, respectively). The genetic analysis of quinolone resistance-determining region mutations showed that substitutions occurred in gyrA (S83A) and parC (D84N) of serovar 1, and gyrA (D87N) of serovar 7. The ciprofloxacin-resistant mutants showed significantly reduced bacterial fitness. The mutants also showed changes in efflux ability and biofilm formation. Notably, the transcription and secretion levels of Apx toxins were dramatically reduced in ciprofloxacin-resistant mutants compared with their wild-type strains. Altogether, these results demonstrated marked phenotypic changes in ciprofloxacin-resistant mutants of A. pleuropneumoniae. The results stress the need for further studies on the impact of both the genotypic and phenotypic characteristics of A. pleuropneumoniae following exposure to subinhibitory concentrations of antibiotics.
Asunto(s)
Actinobacillus pleuropneumoniae/efectos de los fármacos , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Ciprofloxacina/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Actinobacillus pleuropneumoniae/genética , Animales , Antibacterianos/administración & dosificación , Ciprofloxacina/administración & dosificación , Relación Dosis-Respuesta a Droga , Farmacorresistencia Bacteriana Múltiple/genética , Genes Bacterianos/efectos de los fármacos , Genotipo , Pruebas de Sensibilidad Microbiana , Fenotipo , Reacción en Cadena de la Polimerasa , Quinolonas/administración & dosificación , Quinolonas/farmacología , Serogrupo , Porcinos , Enfermedades de los Porcinos/microbiologíaRESUMEN
The pharmacokinetics of gamithromycin were evaluated in 26 male castrated and female crossbred swine administered gamithromycin 15% w/v (Zactran®, Boehringer Ingelheim) intravenously at 6 mg/kg bodyweight or intramuscularly at 3, 6 or 12 mg/kg bodyweight. Blood samples were collected up to Day 10 to establish the plasma profile of gamithromycin, bioavailability and dose proportionality. When administered by intramuscular injection at 6 mg/kg BWT, pharmacokinetic parameters were as follows: area under the curve until last quantifiable plasma concentration, 5.13 ± 0.957 µg*hours/ml; maximum plasma concentration, 960 ± 153 ng/ml at 5 to 15 min; terminal half-life of 94.1 ± 20.4 hr. Absolute bioavailability was 92.2%. Increase in systemic exposure was proportional to the gamithromycin dose level over the range 3-12 mg/kg BWT. No gender-related statistically significant difference in exposure was observed. For clinical evaluation of Zactran® against swine respiratory disease, 305 pigs from six commercial farms in three countries in Europe with signs associated with Actinobacillus pleuropneumoniae and/or Haemophilus parasuis and/or Pasteurella multocida and/or Bordetella bronchiseptica were used. At each site, animals were treated once in a 1:1 ratio with a single intramuscular dose of Zactran® (6 mg gamithromycin/kg bodyweight) or Zuprevo® (4% w/v tildipirosin at 4 mg/kg bodyweight; MSD Animal Health) at the recommended dose respectively. Animals were observed and scored daily for 10 consecutive days for signs of swine respiratory disease (depression, respiration and rectal temperature), and animals presenting signs of clinical swine respiratory disease (Depression Score 3 and/or Respiratory Score 3 associated with Rectal Temperature > 40.0°C) were removed from the study and considered as treatment failure. Animals which remained in the study were individually assessed for 'treatment success' or 'treatment failure' (Depression Score ≥ 1 and Rectal Temperature > 40.0°C or Respiratory Score ≥ 1 and Rectal Temperature > 40.0°C). Using a non-inferiority hypothesis test (non-inferiority margin = 0.10), the proportion of treatment successes in the Zactran® group (97%) was equivalent to or better than that in the Zuprevo® group (93%).
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Antibacterianos/farmacocinética , Macrólidos/farmacocinética , Infecciones del Sistema Respiratorio/veterinaria , Enfermedades de los Porcinos/tratamiento farmacológico , Infecciones por Actinobacillus/tratamiento farmacológico , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/efectos de los fármacos , Animales , Infecciones por Bordetella/tratamiento farmacológico , Infecciones por Bordetella/microbiología , Infecciones por Bordetella/veterinaria , Bordetella bronchiseptica/efectos de los fármacos , Femenino , Infecciones por Haemophilus/tratamiento farmacológico , Infecciones por Haemophilus/microbiología , Infecciones por Haemophilus/veterinaria , Haemophilus parasuis/efectos de los fármacos , Masculino , Infecciones por Pasteurella/tratamiento farmacológico , Infecciones por Pasteurella/microbiología , Infecciones por Pasteurella/veterinaria , Pasteurella multocida/efectos de los fármacos , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Infecciones del Sistema Respiratorio/microbiología , Sus scrofa , Porcinos , Enfermedades de los Porcinos/microbiologíaRESUMEN
BACKGROUND: Actinobacillus pleuropneumoniae formerly known as Haemophilus pleuropneumoniae, can cause pleuropneumoniae in pigs, which lead to significant mortality. Ceftiofur was the first cephalosporin antibiotic used in animals, which was effective against gram-negative and gram-positive bacterium. This study aimed to formulate a rational dosage strategy and review the preceding recommended dosage based on PK/PD modeling and Establish Clinical breakpoint of ceftiofur against Actinobacillus pleuropneumoniae based on the pharmacodynamic-pharmacokinetic cutoff. RESULTS: The epidemiologic cutoff value was 0.125 µg/mL. The results of the pharmacodynamic study showed that the MICs of BW39 were 0.5 µg/mL and 1 µg/mL in vitro and ex-vivo, respectively. The minimal bactericidal concentrations (MBCs) under in vitro and ex vivo conditions were both 1 µg/mL. The time-killing profiles of ceftiofur against BW39 were time-dependent with a partly concentration-dependent pattern. Based on the inhibitory sigmoid Emax model, the AUC24 h/MIC values for the bacteriostatic, bactericidal, and elimination effects in serum were 45.73, 63.83, and 69.04 h for healthy pigs separately. According to the Monte Carlo simulation, the COPD was calculated as 2 µg/mL, and the optimized dosage regimen of ceftiofur against Actinobacillus pleuropneumoniae to achieve bacteriostatic, bactericidal, and elimination effects over 24 h was 2.13, 2.97, and 3.42 mg/kg for the 50% target attainment rate (TAR) and 2.47, 3.21, and 3.70 mg/kg for the 90% TAR respectively. CONCLUSIONS: In conclusion, we reveal the EOFF and PK/PD cutoff values of ceftiofur against A. pleuropneumoniae in piglets. However, with the paucity of clinical data for ceftiofur to establish a clinical cutoff against A. pleuropneumoniae, the PK/PD cutoff value of 2 µg/mL will be recommended as surrogate. According to the PK/PD data and the MIC distribution in China, the single bactericidal dose was 3.21 mg/kg for the 90% target, which would be more able to cure Actinobacillus pleuropneumoniae and avoid the emergence of resistance for clinical ceftiofur use in piglet.
Asunto(s)
Infecciones por Actinobacillus/tratamiento farmacológico , Actinobacillus pleuropneumoniae/efectos de los fármacos , Antibacterianos/farmacología , Cefalosporinas/farmacología , Animales , Antibacterianos/administración & dosificación , Antibacterianos/farmacocinética , Cefalosporinas/administración & dosificación , Cefalosporinas/farmacocinética , Masculino , Pruebas de Sensibilidad Microbiana/veterinaria , Sus scrofa , Porcinos , Enfermedades de los Porcinos/tratamiento farmacológicoRESUMEN
BACKGROUND: Penicillin is important for treatment of pigs, but data on its absorption and disposition in pigs are sparse. This is reflected by the variation in recommended dosages in the literature. Inadequate dosage may lead to treatment failure and selection of resistant bacteria. To optimize treatment regimens, plasma exposure to benzylpenicillin for two sustained release formulations of procaine benzylpenicillin for intramuscular administration was studied in growing pigs by means of tandem mass spectrometry (UPLC-MS/MS). One formulation was an aqueous suspension, Ethacilin® vet (ETH), and the other an oily suspension, Ultrapen vet (UPA). Benzylpenicillin exposure after intravenous administration of potassium benzylpenicillin was also explored. Exposure profiles were first studied after single administrations of the approved dosages in healthy pigs and then after repeated administration of different dosages in pigs inoculated intranasally with an Actinobacillus pleuropneumoniae serotype 2 strain. RESULTS: After intravenous administration of benzylpenicillin (n = 6), maximum plasma concentration (Cmax), 1860-9318 µg/L, was observed after 15 min. At four h, plasma concentrations decreased to 15-76 µg/L. After intramuscular administration of ETH (n = 6) Cmax, 1000-4270 µg/L, was observed within one h (tmax) in 5 pigs but at four h in one pig. Cmax for UPA (n = 6), 910-3220 µg/L, was observed within one h in three pigs, but at four or 24 h in three pigs. For both ETH and UPA, the terminal phase was characterized by slow decline compared with intravenous administration. Repeated administration of different dosages of ETH and UPA in pigs inoculated with A. pleuropneumoniae (n = 54) showed that the approved dose for UPA (30 mg/kg, qd) but not for ETH (20 mg/kg, qd) gave adequate plasma exposure for bacteria with a penicillin MIC of 500 µg/L. However, more frequent dosing of ETH (bid) or increased dosage gave an adequate exposure. CONCLUSIONS: The approved dosage of ETH provided insufficient plasma exposure for adequate therapy of infections caused by A. pleuropneumoniae or other bacteria with a penicillin MIC of 500 µg/L. More frequent ETH dosing (bid) or an increased dosage would improve exposure. The approved dosage of UPA however provided adequate exposure.
Asunto(s)
Antibacterianos/farmacocinética , Penicilina G/farmacocinética , Sus scrofa/metabolismo , Infecciones por Actinobacillus/tratamiento farmacológico , Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/fisiología , Animales , Relación Dosis-Respuesta a Droga , Femenino , Inyecciones Intramusculares/veterinaria , MasculinoRESUMEN
Actinobacillus pleuropneumoniae is the causative agent of highly contagious and fatal respiratory infections, causing substantial economic losses to the global pig industry. Due to increased antibiotic resistance, there is an urgent need to find new antibiotic alternatives for treating A. pleuropneumoniae infections. MPX is obtained from wasp venom and has a killing effect on various bacteria. This study found that MPX had a good killing effect on A. pleuropneumoniae and that the minimum inhibitory concentration (MIC) was 16 µg/mL. The bacterial density of A. pleuropneumoniae decreased 1000 times after MPX (1 × MIC) treatment for 1 h, and the antibacterial activity was not affected by pH or temperature. Fluorescence microscopy showed that MPX (1 × MIC) destroyed the bacterial cell membrane after treatment for 0.5 h, increasing membrane permeability and releasing bacterial proteins and Ca2+, Na+ and other cations. In addition, MPX (1 × MIC) treatment significantly reduced the formation of bacterial biofilms. Quantitative RT-PCR results showed that MPX treatment significantly upregulated the expression of the PurC virulence gene and downregulated that of ApxI, ApxII, and Apa1. In addition, the Sap A gene was found to play an important role in the tolerance of A. pleuropneumoniae to antimicrobial peptides. Therapeutic evaluation in a murine model showed that MPX protects mice from a lethal dose of A. pleuropneumoniae and relieves lung inflammation. This study reports the use of MPX to treat A. pleuropneumonia infections, laying the foundation for the development of new drugs for bacterial infections.
Asunto(s)
Infecciones por Actinobacillus/tratamiento farmacológico , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/patogenicidad , Péptidos Catiónicos Antimicrobianos/farmacología , Animales , Proteínas Bacterianas/genética , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Membrana Celular/efectos de los fármacos , Femenino , Pulmón/efectos de los fármacos , Pulmón/microbiología , Ratones , Pruebas de Sensibilidad Microbiana , Péptido Sintasas/genética , Porcinos , Enfermedades de los Porcinos/microbiología , Virulencia/efectos de los fármacosRESUMEN
Most outbreaks of disease due to infection with Actinobacillus (A.) pleuropneumoniae are caused by pigs already pre-colonised in tonsillar tissue, where the pathogen is protected from exposure to antibiotic substances administered for treatment. As it has been shown recently under experimental conditions, A. pleuropneumoniae displays host tissue-specific metabolic adaptation. In this study, pairs of A. pleuropneumoniae field isolates were recovered from lung as well as from tonsillar and nasal tissue from 20 pigs suffering from acute clinical signs of pleuropneumonia and showing characteristic pathological lung alterations. Metabolic adaptation to the porcine lower and upper respiratory tract of 32 A. pleuropneumoniae serotype 2 field isolates was examined using Fourier transform infrared (FTIR) spectroscopy as a high resolution metabolic fingerprinting method. All strains showed metabolic adaptations to organ tissue reflected by hierarchical cluster analysis of FTIR spectra similar to those previously observed under experimental conditions. Notably, differences in antimicrobial resistance patterns and minimal inhibitory concentrations of isolates from different tissues in the same animal, but not in biofilm production capability in a microtiter plate assay were found. Overall, biofilm formation was observed for 71 % of the isolates, confirming that A. pleuropneumoniae field isolates are generally able to form biofilms, although rather in a serotype-specific than in an organ-specific manner. A. pleuropneumoniae serotype 6 isolates formed significantly more biofilm than the other serotypes. Furthermore, biofilm production was negatively correlated to the lung lesion scores and tonsillar isolates tended to be more susceptible to antimicrobial substances with high bioavailability than lung isolates.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/metabolismo , Adaptación Fisiológica , Biopelículas/crecimiento & desarrollo , Pleuroneumonía/veterinaria , Neumonía Bacteriana/veterinaria , Enfermedades Respiratorias/veterinaria , Infecciones por Actinobacillus/microbiología , Actinobacillus pleuropneumoniae/efectos de los fármacos , Actinobacillus pleuropneumoniae/crecimiento & desarrollo , Animales , Antibacterianos/farmacología , Bronquios/microbiología , Pulmón/microbiología , Pulmón/patología , Pruebas de Sensibilidad Microbiana , Tonsila Palatina/microbiología , Pleuroneumonía/microbiología , Neumonía Bacteriana/microbiología , Enfermedades Respiratorias/microbiología , Porcinos/microbiología , Enfermedades de los Porcinos/microbiologíaRESUMEN
BACKGROUND: Porcine infectious pleuropneumonia caused by Actinobacillus pleuropneumoniae (App) is one of the most serious infectious diseases in pigs and has brought huge economic losses to the world pig industry. The aim of this trial was to evaluate the effect of enteric-coated tilmicosin granule in the treatment and control of artificial infection of App. METHODS: Sixty Duroc and Yorkshire crossbred pigs (50 of which were artificially infected) were divided into six groups: BCG (Blank control group), ICG (Infection-only control group), HDG (High-dose enteric-coated tilmicosin granules), MDG (Medium-dose enteric-coated tilmicosin granules), LDG (Low-dose enteric-coated tilmicosin granules) and TPG (Tilmicosin premix drug control group). The cure rate, mortality, clinical respiratory score, body temperature score, weight gain, lung score and so on were recorded. RESULTS: The cure rate of HDG and MDG was as high as 90%, the mortality was 10%, and the clinical signs recovered quickly. CONCLUSION: The results showed that enteric-coated tilmicosin granules had obvious therapeutic effect on artificial infection, which could reduce the damage caused by the disease and reduce the mortality.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/efectos de los fármacos , Antibacterianos/farmacología , Enfermedades de los Porcinos/tratamiento farmacológico , Tilosina/análogos & derivados , Infecciones por Actinobacillus/tratamiento farmacológico , Infecciones por Actinobacillus/microbiología , Animales , Antibacterianos/administración & dosificación , Femenino , Masculino , Sus scrofa , Porcinos , Enfermedades de los Porcinos/microbiología , Comprimidos Recubiertos , Tilosina/administración & dosificación , Tilosina/farmacologíaRESUMEN
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
Aim: To compare the pharmacokinetic profiles of tilmicosin, administered orally at a single dose of 20â mg/kg bodyweight, in healthy pigs and in pigs experimentally infected with Actinobacillus pleuropneumoniae. Methods: Twelve healthy crossbred pigs, aged approximately 8 weeks, were randomly assigned to uninfected and infected groups, with six pigs per group. Pigs in the infected group were inoculated intranasally with a bacterial suspension of A. pleuropneumoniae containing approximately 108 cfu. Each pig received a single oral dose of 20â mg/kg bodyweight of tilmicosin, given 3-4 hours after inoculation in infected pigs. Blood samples were collected before drug administration and up to 48 hours after tilmicosin administration. Concentrations of tilmicosin in plasma samples were determined by HPLC. Throughout the experimental period pigs were observed for signs of inappetence and clinical abnormalities. After sampling was complete pigs were subject to euthanasia and samples collected for gross and histopathology as well as microbiology. Results: Infected pigs showed signs of bradykinesia, nasal discharge dyspnoea, and coughing 1 hours after inoculation and A. pleuropneumoniae was cultured from the lungs of all infected pigs postmortem. Comparing pharmacokinetic parameters in uninfected and infected pigs, the maximum plasma concentration of tilmicosin was higher in uninfected pigs (1.17 (SD 0.17) vs. 0.96 (SD 0.17) µg/mL), the time to reach maximum concentration was shorter (1.53 (SD 0.23) vs. 2.40 (SD 0.37) hours), and the half-life of the absorption phase and half-life of the elimination phase were both shorter (0.66 (SD 0.08) vs. 1.00 (SD 0.27) hours) and (12.93 (SD 0.96) vs. 16.53 (SD 0.55) hours), respectively. The apparent volume of distribution was smaller in uninfected than infected pigs (1.91 (SD 0.22) vs. 2.16 (SD 0.21) L/kg). The relative bioavailability of tilmicosin in infected relative to uninfected pigs was 108.6 (SD 9.71)%. Conclusions and clinical relevance: The results of this study indicate that A. pleuropneumoniae infection significantly changed certain pharmacokinetic parameters of tilmicosin in pigs. In infected pigs tilmicosin exhibited a longer drug persistence and a better extent of absorption. These results indicate that it is necessary to monitor and adjust the dose of tilmicosin administration during the presence of pleuropneumonia. It is expected that this can optimise clinical efficacy and help avoid the development of resistance.
Asunto(s)
Infecciones por Actinobacillus/veterinaria , Actinobacillus pleuropneumoniae/efectos de los fármacos , Antibacterianos/farmacocinética , Enfermedades de los Porcinos/tratamiento farmacológico , Tilosina/análogos & derivados , Infecciones por Actinobacillus/tratamiento farmacológico , Animales , Antibacterianos/sangre , Autopsia/veterinaria , China , Cromatografía Líquida de Alta Presión/veterinaria , Modelos Animales de Enfermedad , Femenino , Semivida , Pulmón/microbiología , Masculino , Distribución Aleatoria , Porcinos , Enfermedades de los Porcinos/microbiología , Tilosina/sangre , Tilosina/farmacocinéticaRESUMEN
The purpose of this study was to compare the pharmacokinetics and relative bioavailability of tilmicosin enteric granules and premix after oral administration at a dose of 40 mg/kg in pigs. Three kinds of different respiratory pathogens were selected for determination of minimal inhibitory concentration (MIC) to tilmicosin. Eight healthy pigs were assigned to a two-period, randomized crossover design. A modified rapid, sensitive HPLC method was used for determining the concentrations of tilmicosin in plasma. Pharmacokinetic parameters were calculated by using WinNonlin 5.2 software. The MIC90 of tilmicosin against Haemophilus parasuis, Actinbacillus pleuropneumoniae, and Pasteurella multocida were all 8 µg/ml. These results indicated that these common pig respiratory bacteria are sensitive to tilmicosin. The main parameters of time to reach maximum plasma concentration (Tmax ), elimination half-life (t1/2ß ), mean residence time (MRT), and apparent volume of distribution (VF ) were 2.03 ± 0.37 hr, 29.31 ± 5.56 hr, 25.22 ± 2.57 hr, 4.06 ± 1.04 L/kg, and 3.05 ± 0.08 hr, 17.06 ± 1.77 hr, 15.55 ± 1.37 hr, 2.95 ± 0.62 L/kg after the orally administrated tilmicosin enteric granules and premix. The relative bioavailability of tilmicosin enteric granules to premix was 114.97 ± 7.19%, according to the AUC0-t values. These results demonstrated that tilmicosin enteric granules produced faster tilmicosin absorption, slower elimination, larger tissue distribution, and higher bioavailability compared to the tilmicosin premix. The present study results manifest that tilmicosin enteric granules can be used as a therapeutic alternative to premix in clinical treatment.
Asunto(s)
Antibacterianos/farmacocinética , Tilosina/análogos & derivados , Actinobacillus pleuropneumoniae/efectos de los fármacos , Administración Oral , Animales , Antibacterianos/administración & dosificación , Antibacterianos/sangre , Antibacterianos/farmacología , Cromatografía Líquida de Alta Presión/veterinaria , Estudios Cruzados , Haemophilus parasuis/efectos de los fármacos , Semivida , Masculino , Pruebas de Sensibilidad Microbiana/veterinaria , Pasteurella multocida/efectos de los fármacos , Distribución Aleatoria , Porcinos , Tilosina/administración & dosificación , Tilosina/sangre , Tilosina/farmacocinética , Tilosina/farmacologíaRESUMEN
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.