Browsing by Subject "Contagious agalactia"

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    23S rRNA and L22 ribosomal protein are involved in the acquisition of macrolide and lincosamide resistance in Mycoplasma capricolum subsp. capricolum
    (Elsevier, ) Prats-van der Ham, Miranda; Tatay-Dualde, Juan; Gómez-Martín, Angel; Corrales, Juan Carlos; Contreras de Vera, Antonio; Sánchez López, Antonio; de la Fe, Christian; Sanidad Animal
    Mycoplasma capricolum subsp. capricolum (Mcc) is one of the causative agents of contagious agalactia, and antimicrobial treatment is the most commonly applied measure to treat outbreaks of this disease. Macrolides and lincosamides bind specifically to nucleotides at domains II and V of the 23S rRNA gene. Furthermore, rplD and rplV genes encode ribosomal proteins L4 and L22, which are also implicated in the macrolide binding site. The aim of this work was to study the relationship between these genes and the acquisition of macrolide and lincosamide resistance in Mcc. For this purpose, in vitro selected resistant mutants and field isolates were studied. This study demonstrates the appearance of DNA point mutations at the 23S rRNA encoding genes (A2058G, A2059G and A2062C) and rplV gene (Ala89Asp) in association to high minimum inhibitory concentration values. Hence, it proves the importance of 23S rRNA domain V and ribosomal protein L22 as molecular mechanisms responsible for the acquisition of macrolide and lincosamide resistance in both field isolates and in vitro selected mutants. Furthermore, these mutations enable us to provide an interpretative breakpoint of antimicrobial resistance for Mcc at MIC 0.8 µg/ml.
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    Antibacterial potential of commercial and wild lactic acid bacteria strains isolated from ovine and caprine raw milk against Mycoplasma agalactiae
    (Frontiers Media, 2023-06-22) Toquet, Marion; Bataller, Esther; Gomis Almendro, Jesús; Sánchez López, Antonio; Toledo-Perona, Raquel; de la Fe Rodríguez, Christian; Corrales Romero, Juan Carlos; Gómez-Martin, Ángel; Sanidad Animal
    Introduction: The complexity of fighting contagious agalactia (CA) has raised the necessity of alternative antimicrobial therapies, such as probiotics. Lactic acid bacteria (LAB) are present in the mammary gland of small ruminants and their antimicrobial effect have been previously described against species like Mycoplasma bovis but never against Mycoplasma agalactiae (Ma). This in vitro study aims to evaluate the antimicrobial activity against Ma of ovine and caprine LAB strains and a human commercial probiotic (L2) of Lactobacillus spp. Methods: A total of 63 possible LAB strains were isolated from nine ovine and caprine farms in Spain, three isolates (33B, 248D, and 120B) from the 63 strains were selected, based on their capacity to grow in a specific medium in vitro, for an in vitro experiment to assess their antimicrobial activity against Ma in Ultra High Temperature (UHT) processed goat milk (GM). A women commercial vaginal probiotic was also included in the study. The inoculum of L2 was prepared at a concentration of 3.24 × 108  CFU/mL and the average concentration of the inoculum of the wild LAB varied from 7.9 × 107 to 8.4 × 108  CFU/mL. Results: The commercial probiotic L2 significantly reduced the concentration of Ma to 0.000 log CFU/mL (p < 0.001), strain 33B reduced it from 7.185 to 1.279 log CFU/mL (p < 0.001), and 120B from 6.825 to 6.466 log CFU/mL (p < 0.05). Strain 248D presented a bacteriostatic effect in GM. Moreover, the three wild strains and the commercial probiotic produced a significative reduction of the pH (p < 0.001). Discussion: This is the first in vivo report of the antimicrobial potential of LAB strains against Ma and its interaction. Our results support possible future alternative strategies to antibiotic therapy, previously not contemplated, to fight CA in small ruminants. Further studies are necessary to elucidate the action mechanisms through which these LAB are able to inhibit Ma and to assess the safety of using these strains in possible in vivo studies.
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    Comparison of commercial enzyme-linked immunosorbent assays for diagnosis of contagious agalactia caused by Mycoplasma agalactiae
    (Sciendo, 2022-03-10) Sánchez López, Antonio; Contreras de Vera, Antonio; Sánchez-Corral, María L.; Martínez-Nista, Carmen; Collado, Soledad; Sáez, José L.; Minguez, Olga; de la Fe Rodríguez, Christian; Sanidad Animal
    Introduction: Contagious agalactia (CA) is a disease affecting small ruminants with worldwide distribution and caused by several mycoplasmas, especially M. agalactiae. The main option for systematic diagnosis under monitoring control programmes is the enzyme-linked immunosorbent assay (ELISA) test. Material and Methods: This study was designed to appraise the performance of two commercial indirect ELISA tests using M. agalactiae p48 protein and one using total protein, for antibody detection in small ruminants after natural infection with different M. agalactiae strains. We carried out the test evaluation using sera of confirmed M. agalactiae-positive goats with clinical signs. In addition, test agreement was assessed by kappa between the three commercial ELISA tests. Results: All three ELISA tests showed high validity scores (Youden’s J: 72.9–84%). The sensitivity values for the P48 protein-based tests were 76.9% and 84.6%, and was 79% for the total protein-based test. The specificity of all tests was 100%. In addition, between the total protein-based ELISA test and the other two ELISA tests based on the P48 protein, the agreement was substantial (kappa: 0.762–0.763) and the agreement between the latter two tests was almost perfect (kappa: 0.93). Conclusion: The validity parameters for all tests allowed their application for diagnostic purposes in lactating goats excreting M. agalactiae in milk and presenting clinical signs.
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    Particularidades etiológicas y epidemiológicas de la agalaxia contagiosa ovina: similitudes y diferencias con el caprino
    (Murcia: Servicio de Publicaciones de la Universidad de Murcia, 2013) Prats-van der Ham, M.; Gómez-Martín, A.; Tatay-Dualde, J.; Paterna, A.; Amores Iniesta, Joaquín; Corrales Romero, Juan Carlos; Contreras de Vera, Antonio; Sánchez, A.; De la Fe Rodríguez, Christian; Sanidad Animal
    Este trabajo describe las diferencias existentes en la presentación de la agalaxia contagiosa, síndrome infectocontagioso causado por varias especies del genero Mycoplasma spp., en el ganado ovino y caprino. Las particularidades etiológicas y epidemiológicas de la infección crónica en la cabra, y la ausencia de datos similares en el ovino, evidencian la necesidad de realizar nuevos trabajos que determinen si las diferencias observadas en referencia a la presencia de portadores auriculares en los rebaños o la participación de los sementales en la difusión de la enfermedad son fruto de la escasez de trabajos científicos o por el contrario, establecen verdaderas diferencias sobre las que desarrollar estrategias dirigidas de control en función de la especie de rumiante afectada.
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    PK/PD analysis of marbofloxacin by Monte Carlo Simulation against Mycoplasma agalactie in plasma and milk of lactating goats after IV, SC and SC-long acting formulations administration
    (MDPI, 2021-04-12) Fernández-Varón, Emilio; García Romero, Edgar; Serrano-Rodriguez, Juan M.; Cárceles Rodríguez, Carlos; García-Galán Pérez, Ana; Cárceles-García, Carlos; Fernández, Rocío; Muñoz, Cristina; Fé Rodríguez, David Christian de la; Farmacología; Facultad de Veterinaria
    Contagious agalactia is a mycoplasmosis affecting small ruminants that have become an important issue in many countries. However, PK/PD studies of antibiotics to treat this problem in lactating goats affected by Mycoplasma (M.) agalactiae, the main CA-causing mycoplasma are almost non-existent. The aims of this study were to evaluate the plasma and milk disposition of marbofloxacin in lactating goats after intravenous (IV), subcutaneous (SC) and subcutaneous poloxamer P407 formulations with and without carboxy-methylcellulose (SC-P407-CMC and SC-P407) administration. Marbofloxacin concentrations were analysed by the High Performance Liquid Chromatography (HPLC) method. Minimum inhibitory concentrations (MIC) of M. agalactiae field isolates from mastitic goat’s milk were used to calculate surrogate markers of efficacy. Terminal half-lives of marbofloxacin after IV, SC, SC-P407 and SC-P407-CMC administration were 7.12, 6.57, 13.92 and 12.19 h in plasma, and the half-lives of elimination of marbofloxacin in milk were 7.22, 7.16, 9.30 and 7.74 h after IV, SC, SC-P407 and SC-P407-CMC administration, respectively. Marbofloxacin penetration from the blood into the milk was extensive, with Area Under the Curve (AUCmilk/AUCplasma) ratios ranged 1.04–1.23, and maximum concentrations (Cmax-milk/Cmax-plasma) ratios ranged 0.72–1.20. The PK/PD surrogate markers of efficacy fAUC24/MIC and the Monte Carlo simulation show that marbofloxacin ratio (fAUC24/MIC > 125) using a 90% of target attainment rate (TAR) need a dose regimen between 8.4 mg/kg (SC) and 11.57 mg/kg (P407CMC) and should be adequate to treat contagious agalactia in lactating goats.
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    Sensitivity of two methods to detect Mycoplasma agalactiae in goat milk
    (BioMed Central, 2015) Tatay-Dualde, Juan; Prats- Van der Ham, Miranda; Gómez-Martín, Angel; Paterna, Ana; Corrales, Juan Carlos; Sánchez, Antonio; Fe, Christian de la; Amores, Joaquín; Amores, Joaquín; Sanidad Animal
    Background: Laboratory diagnostic techniques able to detect Mycoplasma agalactiae are essential in contagious agalactia in dairy goats. This study was designed: 1) to determine the detection limits of PCR and culture in goat milk samples, 2) to examine the effects of experimental conditions including the DNA extraction method, PCR technique and storage conditions (fresh versus frozen stored milk samples) on these methods and 3), to establish agreement between PCR and culture techniques using milk samples from goats with mastitis in commercial dairy herds. The study was conducted both on artificially inoculated and field samples. Results: Our findings indicate that culture is able to detect M. agalactiae in goat milk at lower concentrations than PCR. Qualitative detection of M.agalactiae by culture and PCR was not affected by sample freezing, though the DNA extraction method used significantly affected the results of the different PCR protocols. When clinical samples were used, both techniques showed good agreement. Conclusions: The results from this study indicate that both culture and PCR are able to detect M. agalactiae in clinical goat mastitis samples. However, in bulk tank milk samples with presumably lower M. agalactiae concentrations, culture is recommended within the first 24 h of sample collection due to its lower limit of detection. To improve the diagnostic sensitivity of PCR in milk samples, there is a need to increase the efficiency of extracting DNA from milk samples using protocols including a previous step of enzymatic digestion.
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    The moderate drift towards less tetracycline-susceptible isolates of contagious agalactia causative agents might result from different molecular mechanisms.
    (2018) Prats-van der, Ham M; Tatay-Dualde, J; Ambroset, C; De la Fe, C.; Tardy, F.; Sanidad Animal
    Contagious agalactia is a mycoplasmosis that affects small ruminants, is associated with loss of milk production and high morbidity rates, and is highly deleterious to dairy industries. The etiological agents are four mycoplasma (sub)species, of which the relative importance depends on the countries and the animal host. Tetracyclines are non 23 expensive, broad-spectrum antimicrobials and are often used to control mastitis in dairy herds. However, the in vitro efficiency of tetracyclines against each of the etiological agents of contagious agalactia has been poorly assessed. The aims of this study were i) to compare the tetracycline susceptibilities of various field isolates, belonging to different mycoplasma (sub)species and subtypes, collected over the years from different clinical contexts in France or Spain, and ii) to investigate the molecular mechanisms behind the decreased susceptibility of some isolates to tetracyclines. The Minimum Inhibitory Concentrations (MICs) of tetracyclines were determined in vitro on a set of 120 isolates. Statistical analyses were run to define the significance of any observed differences in MICs distribution. As mutations in the genes encoding the ttracycline targets (rrs loci) are most often associated with increased tetracycline MICs in animal mycoplasmas, these genes were sequenced. The loss of susceptibility to tetracyclines after year 2010 is not significant and recent MICs are higher in M. agalactiae, especially isolates from ovine mastitis cases, than in other etiological agents of contagious agalactia. The observed increases in MICs were not always associated with mutations in the rrs alleles which suggests the existence of other resistance mechanisms yet to be deciphere