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Robin A J Nicholas - One of the best experts on this subject based on the ideXlab platform.
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Mycoplasma Agalactiae: The Sole Cause of Classical Contagious Agalactia?
MDPI AG, 2021Co-Authors: Sergio Migliore, Robin A J Nicholas, Roberto Puleio, Guido R. LoriaAbstract:Contagious Agalactia (CA) is suspected when small ruminants show all or several of the following clinical signs: mastitis, arthritis, keratoconjunctivitis and occasionally abortion. It is confirmed following mycoplasma isolation or detection. The historical and major cause is Mycoplasma Agalactiae which was first isolated from sheep in 1923. Over the last thirty years, three other mycoplasmas (Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum and Mycoplasma putrefaciens) have been added to the etiology of CA because they can occasionally cause clinically similar outcomes though nearly always in goats. However, only M. Agalactiae is subject to animal disease regulations nationally and internationally. Consequently, it makes little sense to list mycoplasmas other than M. Agalactiae as causes of the OIE-listed CA when they are not officially reported by the veterinary authorities and unlikely to be so in the future. Indeed, encouraging countries just to report M. Agalactiae may bring about a better understanding of the importance of CA. In conclusion, we recommend that CA should only be diagnosed and confirmed when M. Agalactiae is detected either by isolation or molecular methods, and that the other three mycoplasmas be removed from the OIE Manual of Diagnostic Tests and Vaccines in Terrestrial Animals and associated sources.
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Effect of Mycoplasma Agalactiae mastitis on milk production and composition in Valle dell Belice dairy sheep
Italian Journal of Animal Science, 2019Co-Authors: Marco Tolone, Robin A J Nicholas, Roberto Puleio, Anna Maria Sutera, Silvio Borrello, Maria Luisa Scatassa, Serena Tumino, Baldassare Portolano, Guido Ruggero LoriaAbstract:Contagious Agalactia (CA), a disease caused by Mycoplasma Agalactiae and other pathogenic mycoplasmas, is a well-known multietiological syndrome affecting dairy breeds of sheep and goats in...
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can vaccines for contagious Agalactia reduce disease progression in infected animals a preliminary study
Veterinary Record Case Reports, 2018Co-Authors: Guido Ruggero Loria, Stefano Agnello, Roberto Puleio, Gavino Marogna, Robin A J NicholasAbstract:A flock of sheep in Central Sicily was affected by a severe outbreak of contagious Agalactia (CA) caused by Mycoplasma Agalactiae, affecting nearly 30% resulting in a large drop in milk production. Many ewes had warm and swollen udders that often became sclerotic and was accompanied by keratoconjunctivitis and arthritis in both adults and young. As antibiotic treatment appeared ineffective, the whole flock was given two doses of an inactivated vaccine against M Agalactiae two weeks apart. A small group was selected for close examination and additional tests. A fortnight after the last vaccination mycoplasma excretion fell in all but one of the selected ewes and was undetectable in all but two animals two weeks after that. In nearly all the selected ewes, there was an improvement in milk quality and udder condition. This work provided preliminary evidence for the continued use of CA vaccines to slow or prevent disease progression.
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Severe otitis and pneumonia in adult cattle with mixed infection of Mycoplasma bovis and Mycoplasma Agalactiae
Veterinary Record Case Reports, 2016Co-Authors: Salvatore Catania, Eliana Schiavon, Federica Gobbo, Robin A J NicholasAbstract:Respiratory disease and otitis were seen on a northern Italian farm in weaned bulls obtained from multiple sources. Mycoplasma bovis was consistently identified in nasal swabs, tonsil, ears, eyes and lung samples from affected animals. Unusually the closely related Mycoplasma Agalactiae , the main cause of contagious Agalactia (CA) in small ruminants, was also isolated. It was identified by molecular methods in bulls but only from eye, ear and brain samples. Outbreaks were reduced by retaining the bulls on their original farms for weaning, then moving them directly to the fattening areas on the farm. This prevented the spread of mycoplasma from infected to uninfected calves from different sources. As no small ruminants were within close proximity and the area is free of CA, it is possible that M Agalactiae may be more prevalent in cattle than previously thought.
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isolation molecular characterization and antimicrobial susceptibilities of isolates of mycoplasma Agalactiae from bulk tank milk in an endemic area of spain
Journal of Applied Microbiology, 2013Co-Authors: M L De Garnica, Ruben S. Rosales, C Gonzalo, Jesus Santos, Robin A J NicholasAbstract:Aim To isolate and characterize strains of Mycoplasma Agalactiae from bulk tank and silo ewes' milk. Methods and Results Thirteen mycoplasma isolates were obtained from samples of sheep milk taken from bulk tank and large silos and identified as Myc. Agalactiae by PCR-DGGE. The isolates were typed by pulsed field gel electrophoresis (PFGE), SDS-PAGE and immunoblot. The in vitro activity of 13 antimicrobials of veterinary interest was tested against these isolates. Results showed that the most effective compounds against Myc. Agalactiae in vitro were clindamycin, an antibiotic not previously described as a suitable contagious Agalactia (CA) treatment, with Minimum Inhibitory Concentration (MIC) values of <0·12 μg ml−1, and quinolones, with MIC values <0·12–0·5 μg ml−1, which are used as standard treatments against CA. Conclusions Based on the in vitro assay, clindamycin, quinolones, tylosin and tilmicosin would be appropriate antimicrobials for CA treatment. The isolates were mostly resistant to erythromycin, indicating that it would not be a suitable choice for therapy. The isolates showed common molecular and protein profiles by PFGE and SDS-PAGE, with minor differences observed by immunoblot analysis, suggesting a clonal relationship among them. Significance and impact of the Study This study demonstrated the importance of the appropriate selection of antimicrobials for treatment of CA.
A Contreras - One of the best experts on this subject based on the ideXlab platform.
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molecular resistance mechanisms of mycoplasma Agalactiae to macrolides and lincomycin
Veterinary Microbiology, 2017Co-Authors: Miranda Pratsvan Der Ham, Adrian Paterna, A Contreras, Juan Tataydualde, Antonio Sánchez, J C Corrales, Angel GomezmartinAbstract:The extensive use of antimicrobials for disease control has caused a remarkable decrease in antimicrobial susceptibility of different animal mycoplasma species, including Mycoplasma Agalactiae (M. Agalactiae), the main causative agent of contagious Agalactia. However, the molecular mechanisms behind M. Agalactiae resistance to macrolides and lincomycin have not yet been elucidated. The aim of the present study was to investigate the association between minimum inhibitory concentration (MIC) values of different antimicrobials and mutations in the 23S rRNA gene and ribosomal proteins L4 and L22, analysing both field isolates (n=50) and in vitro selected resistant mutants of M. Agalactiae. The obtained MIC results of the studied field isolates demonstrate an increasing development of tylosin resistance in this bacterium, in comparison to previous studies. Interestingly, predicted amino acid changes in L22 (Ser89Leu and Gln90Lys/His) were the first variations observed when MICs of M. Agalactiae started to increase (tylosin MIC ≥0.8μg/ml), whereas mutations at positions 2058 or 2059 of domain V of the 23S rRNA gene appeared from MIC values of 1.6μg/ml. These results were consistent in both field isolates and in vitro selected mutants of M. Agalactiae. Thus, although in other mycoplasma species resistance to macrolides and lincosamides had been mainly related to mutations in the 23S rRNA gene, this work demonstrates the role of alterations in ribosomal protein L22 in decreased susceptibility of M. Agalactiae. Moreover, these mutations can be used as molecular markers to set an interpretative breakpoint of antimicrobial resistance for M. Agalactiae.
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mutations in the quinolone resistance determining region conferring resistance to fluoroquinolones in mycoplasma Agalactiae
Veterinary Microbiology, 2017Co-Authors: Juan Tataydualde, Adrian Paterna, A Contreras, Antonio Sánchez, J C Corrales, Miranda Pratsvan Der Ham, Angel GomezmartinAbstract:M. Agalactiae is the main causative agent of contagious Agalactia, against which antimicrobial treatment is the main applied control measure. Quinolones are an effective group of antimicrobials inhibiting the growth of M. Agalactiae, but in the last years, various reports have demonstrated an increase of resistance in field isolates due to its massive use. Nevertheless, the molecular mechanisms involved in the acquisition of fluoroquinolones resistance in M. Agalactiae have not been elucidated yet. Therefore, the aim of this work was to analyze the presence of DNA variations that could be related to changes in fluoroquinolone susceptibility. For this purpose, three M. Agalactiae strains were selected to obtain in vitro resistant mutants against enrofloxacin, marbofloxacin and moxifloxacin and afterwards, partial sequences of their gyrA, gyrB, parC and parE genes were analyzed. In addition, a set of field isolates with different MIC values were also studied. Changes related to variations in fluoroquinolones susceptibility were found in gyrB, parC and parE. Specifically, gyrB genes were affected at the predicted amino acid position 424, four amino acid changes were detected in parC (positions 78, 79, 80 and 84) and two substitutions were reported in parE (amino acid positions 429 and 459). Mutations at predicted positions 424 of gyrB and 429 of parE are novel DNA changes which had not been previously described and, on the whole, parC was the first gene showing alterations when changes in susceptibility to fluoroquinolones occurred. Thus, this gene is the most suitable target for a rapid study of fluoroquinolone resistance in field isolates of M. Agalactiae.
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RESEARCH Open Access Sensitivity of two methods to detect
2016Co-Authors: A Contreras, Judith AmoresAbstract: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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anatomic location of mycoplasma mycoides subsp capri and mycoplasma Agalactiae in naturally infected goat male auricular carriers
Veterinary Microbiology, 2012Co-Authors: Angel Gomezmartin, Adrian Paterna, A Contreras, Antonio Sánchez, Judith Amores, A J Buendia, J C CorralesAbstract:This study sought to determine whether male goat auricular carriers of mycoplasmas known to cause contagious Agalactia could harbour these microorganisms at anatomical sites other than the ears. A microbiological study was conducted in 6 naturally infected bucks that had been diagnosed as chronic auricular asymptomatic carriers of Mycoplasma (M.) mycoides subsp. capri (Mmc) more than one year previously. To detect mycoplasmas, cultures and PCR were performed on 46 samples taken from each goat from the cardio-respiratory, digestive, nervous, lymph and genitourinary systems and several joints. Of a total of 274 samples analyzed, 28 were positive for mycoplasmas (10.1%): Mmc was detected in 17 (6.1%), Mycoplasma (M.) Agalactiae in 12 (4.3%) and both microorganisms were identified in one of the samples. In all 6 goats, mixed infection was observed despite none being auricular carriers of M. Agalactiae. Mycoplasma spp. were identified at 15 different sites; the most frequent sites being the joints (31.2%, 5 positive samples), lymph nodes (25%, 4 positive samples) and respiratory tract (25%, 4 positive samples). Positive results were also obtained in three brain tissue (18.7%), two cardiac tissue (12.5%) and one ileum, urethra, testicle and bulbourethral gland (6.25%) samples. The histopathological findings may suggest the presence of mild chronic conditions in some of the organs where the bacteria were found. Our findings reveal for the first time the capacity of Mmc and M. Agalactiae to colonize several other organ systems in chronically naturally infected auricular carriers, possibly representing an added risk factor for the spread of these microorganisms. In the case of M. Agalactiae, colonization seemed to be independent of the animal's auricular carrier state.
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surveillance of mycoplasma Agalactiae and mycoplasma mycoides subsp capri in dairy goat herds
Small Ruminant Research, 2012Co-Authors: Judith Amores, Antonio Sánchez, Angel Gomezmartin, J C Corrales, A ContrerasAbstract:Abstract This study was designed to monitor the presence of Mycoplasma Agalactiae and Mycoplasma mycoides subsp. capri (Mmc) in 66 dairy goat herds of a genetic improvement programme in a region of Spain where contagious Agalactia is endemic. Over a whole lactation period, 300 bulk tank milk and 381 milk samples from goats with clinical mastitis were subjected to polymerase chain reaction (PCR) to detect the two mycoplasma species. The presence of mycoplasmas (either species or both) was detected in 66.7% of the herds and M. Agalactiae was identified in 95.45% of these positives herds. In a given infected herd, mycoplasmas were not continuously detected over the whole study period. Our findings indicate that in an endemic area, M. Agalactiae and Mmc can be monitored through PCR analysis of mastitic milk and bulk tank milk (BTM) samples. Over a lactation period we recommend testing multiple BTM samples on a herd. No relationship was observed between the use of inactivated mycoplasma vaccines and the PCR detection of both mycoplasmas.
Florence Tardy - One of the best experts on this subject based on the ideXlab platform.
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the moderate drift towards less tetracycline susceptible isolates of contagious Agalactia causative agents might result from different molecular mechanisms
Veterinary Microbiology, 2018Co-Authors: Juan Tataydualde, Chloe Ambroset, Florence TardyAbstract:Abstract 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-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 tetracycline 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 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 deciphered.
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development of a multiplex real time pcr for contagious Agalactia diagnosis in small ruminants
Journal of Microbiological Methods, 2012Co-Authors: Claire A M Becker, F Poumarat, Fabien Ramos, Eric Sellal, Sandrine Moine, Florence TardyAbstract:Contagious Agalactia is an important disease worldwide that affects small ruminants. Clinical manifestations vary from mastitis, pneumonia, arthritis and keratoconjunctivitis to septicemia. Four mycoplasmal etiological agents have been identified: Mycoplasma (M.) Agalactiae, M. mycoides subsp. capri, M. capricolum subsp. capricolum and M. putrefaciens. The current procedure for direct diagnosis, recommended by the World Organization for Animal Health, involves the isolation of one or several causative agents from clinical specimens and further time-consuming identification steps. The present study reports the development of a new multiplex real-time PCR (including an internal positive control) that detects all four pathogens simultaneously and distinguishes M. Agalactiae from the others. First, intra- and inter-species polymorphisms of the two target house-keeping genes, namely polC and fusA, were analyzed to design primers and probes adapted to the diversity of currently circulating strains. The specificity and the sensitivity of the assay were then challenged and the limit of detection was found to be as low as 6 to 12 copies of the target genes. The assay requires further assessment on clinical specimens but its performances (notably low intra- and inter-assay variability) are already very promising for use in large-scale diagnosis and prophylactic surveys of contagious Agalactia.
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Emergence of Atypical Mycoplasma Agalactiae Strains Harboring a New Prophage and Associated with an Alpine Wild Ungulate Mortality Episode
Applied and Environmental Microbiology, 2012Co-Authors: Florence Tardy, Francois Thiaucourt, Eric Baranowski, Xavier Nouvel, Virginie Mick, Lucia Manso-silvan, Patricia Thébault, Marc Breton, Pascal Sirand-pugnet, Alain BlanchardAbstract:The bacterium Mycoplasma Agalactiae is responsible for contagious Agalactia (CA) in small domestic ruminants, a syndrome listed by the World Organization for Animal Health and responsible for severe damage to the dairy industry. Recently, we frequently isolated this pathogen from lung lesions of ibexes during a mortality episode in the French Alps. This situation was unusual in terms of host specificity and tissue tropism, raising the question of M. Agalactiae emergence in wildlife. To address this issue, the ibex isolates were characterized using a combination of approaches that included antigenic profiles, molecular typing, optical mapping, and whole-genome sequencing. Genome analyses showed the presence of a new, large prophage containing 35 coding sequences (CDS) that was detected in most but not all ibex strains and has a homolog in Mycoplasma conjunctivae, a species causing keratoconjunctivitis in wild ungulates. This and the presence in all strains of large integrated conjugative elements suggested highly dynamic genomes. Nevertheless, M. Agalactiae strains circulating in the ibex population were shown to be highly related, most likely originating from a single parental clone that has also spread to another wild ungulate species of the same geographical area, the chamois. These strains clearly differ from strains described in Europe so far, including those found nearby, before CA eradication a few years ago. While M. Agalactiae pathogenicity in ibexes remains unclear, our data showed the emergence of atypical strains in Alpine wild ungulates, raising the question of a role for the wild fauna as a potential reservoir of pathogenic mycoplasmas.
Judith Amores - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH Open Access Sensitivity of two methods to detect
2016Co-Authors: A Contreras, Judith AmoresAbstract: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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Sensitivity of two methods to detect Mycoplasma Agalactiae in goat milk.
Irish Veterinary Journal, 2015Co-Authors: Juan Tatay-dualde, Adrian Paterna, Ángel Gómez-martín, Antonio Contreras, Juan Carlos Corrales, A. Sánchez, Judith AmoresAbstract: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.
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Short communication: In vitro antimicrobial susceptibility of Mycoplasma Agalactiae strains isolated from dairy goats.
Journal of Dairy Science, 2013Co-Authors: Adrian Paterna, Ángel Gómez-martín, Antonio Contreras, Juan Carlos Corrales, A. Sánchez, Judith AmoresAbstract:Abstract This study examined the susceptibility to several antimicrobials of 28 isolates of Mycoplasma Agalactiae obtained from goats in a region (southeastern Spain) where contagious Agalactia is endemic. For each isolate, the minimum inhibitory concentration (MIC) against 12 antimicrobials of the quinolone, macrolide, aminoglycoside, and tetracycline families was determined. The antimicrobials with the lowest MIC were enrofloxacin, ciprofloxacin, tylosin, and doxycycline, all with MIC 90 (concentration at which growth of 90% of the isolates is inhibited) 90 such that its use against Mycoplasma Agalactiae is not recommended. Finally, Mycoplasma Agalactiae isolates obtained from goat herds with clinical symptoms of contagious Agalactia featured higher MIC 90 and MIC 50 (concentration at which growth of 50% of the isolates is inhibited) values for many of the antimicrobials compared with isolates from asymptomatic animals. The relationship between the extensive use of antimicrobials in herds with clinical contagious Agalactia and variations in MIC requires further study.
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anatomic location of mycoplasma mycoides subsp capri and mycoplasma Agalactiae in naturally infected goat male auricular carriers
Veterinary Microbiology, 2012Co-Authors: Angel Gomezmartin, Adrian Paterna, A Contreras, Antonio Sánchez, Judith Amores, A J Buendia, J C CorralesAbstract:This study sought to determine whether male goat auricular carriers of mycoplasmas known to cause contagious Agalactia could harbour these microorganisms at anatomical sites other than the ears. A microbiological study was conducted in 6 naturally infected bucks that had been diagnosed as chronic auricular asymptomatic carriers of Mycoplasma (M.) mycoides subsp. capri (Mmc) more than one year previously. To detect mycoplasmas, cultures and PCR were performed on 46 samples taken from each goat from the cardio-respiratory, digestive, nervous, lymph and genitourinary systems and several joints. Of a total of 274 samples analyzed, 28 were positive for mycoplasmas (10.1%): Mmc was detected in 17 (6.1%), Mycoplasma (M.) Agalactiae in 12 (4.3%) and both microorganisms were identified in one of the samples. In all 6 goats, mixed infection was observed despite none being auricular carriers of M. Agalactiae. Mycoplasma spp. were identified at 15 different sites; the most frequent sites being the joints (31.2%, 5 positive samples), lymph nodes (25%, 4 positive samples) and respiratory tract (25%, 4 positive samples). Positive results were also obtained in three brain tissue (18.7%), two cardiac tissue (12.5%) and one ileum, urethra, testicle and bulbourethral gland (6.25%) samples. The histopathological findings may suggest the presence of mild chronic conditions in some of the organs where the bacteria were found. Our findings reveal for the first time the capacity of Mmc and M. Agalactiae to colonize several other organ systems in chronically naturally infected auricular carriers, possibly representing an added risk factor for the spread of these microorganisms. In the case of M. Agalactiae, colonization seemed to be independent of the animal's auricular carrier state.
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surveillance of mycoplasma Agalactiae and mycoplasma mycoides subsp capri in dairy goat herds
Small Ruminant Research, 2012Co-Authors: Judith Amores, Antonio Sánchez, Angel Gomezmartin, J C Corrales, A ContrerasAbstract:Abstract This study was designed to monitor the presence of Mycoplasma Agalactiae and Mycoplasma mycoides subsp. capri (Mmc) in 66 dairy goat herds of a genetic improvement programme in a region of Spain where contagious Agalactia is endemic. Over a whole lactation period, 300 bulk tank milk and 381 milk samples from goats with clinical mastitis were subjected to polymerase chain reaction (PCR) to detect the two mycoplasma species. The presence of mycoplasmas (either species or both) was detected in 66.7% of the herds and M. Agalactiae was identified in 95.45% of these positives herds. In a given infected herd, mycoplasmas were not continuously detected over the whole study period. Our findings indicate that in an endemic area, M. Agalactiae and Mmc can be monitored through PCR analysis of mastitic milk and bulk tank milk (BTM) samples. Over a lactation period we recommend testing multiple BTM samples on a herd. No relationship was observed between the use of inactivated mycoplasma vaccines and the PCR detection of both mycoplasmas.
J C Corrales - One of the best experts on this subject based on the ideXlab platform.
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molecular resistance mechanisms of mycoplasma Agalactiae to macrolides and lincomycin
Veterinary Microbiology, 2017Co-Authors: Miranda Pratsvan Der Ham, Adrian Paterna, A Contreras, Juan Tataydualde, Antonio Sánchez, J C Corrales, Angel GomezmartinAbstract:The extensive use of antimicrobials for disease control has caused a remarkable decrease in antimicrobial susceptibility of different animal mycoplasma species, including Mycoplasma Agalactiae (M. Agalactiae), the main causative agent of contagious Agalactia. However, the molecular mechanisms behind M. Agalactiae resistance to macrolides and lincomycin have not yet been elucidated. The aim of the present study was to investigate the association between minimum inhibitory concentration (MIC) values of different antimicrobials and mutations in the 23S rRNA gene and ribosomal proteins L4 and L22, analysing both field isolates (n=50) and in vitro selected resistant mutants of M. Agalactiae. The obtained MIC results of the studied field isolates demonstrate an increasing development of tylosin resistance in this bacterium, in comparison to previous studies. Interestingly, predicted amino acid changes in L22 (Ser89Leu and Gln90Lys/His) were the first variations observed when MICs of M. Agalactiae started to increase (tylosin MIC ≥0.8μg/ml), whereas mutations at positions 2058 or 2059 of domain V of the 23S rRNA gene appeared from MIC values of 1.6μg/ml. These results were consistent in both field isolates and in vitro selected mutants of M. Agalactiae. Thus, although in other mycoplasma species resistance to macrolides and lincosamides had been mainly related to mutations in the 23S rRNA gene, this work demonstrates the role of alterations in ribosomal protein L22 in decreased susceptibility of M. Agalactiae. Moreover, these mutations can be used as molecular markers to set an interpretative breakpoint of antimicrobial resistance for M. Agalactiae.
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mutations in the quinolone resistance determining region conferring resistance to fluoroquinolones in mycoplasma Agalactiae
Veterinary Microbiology, 2017Co-Authors: Juan Tataydualde, Adrian Paterna, A Contreras, Antonio Sánchez, J C Corrales, Miranda Pratsvan Der Ham, Angel GomezmartinAbstract:M. Agalactiae is the main causative agent of contagious Agalactia, against which antimicrobial treatment is the main applied control measure. Quinolones are an effective group of antimicrobials inhibiting the growth of M. Agalactiae, but in the last years, various reports have demonstrated an increase of resistance in field isolates due to its massive use. Nevertheless, the molecular mechanisms involved in the acquisition of fluoroquinolones resistance in M. Agalactiae have not been elucidated yet. Therefore, the aim of this work was to analyze the presence of DNA variations that could be related to changes in fluoroquinolone susceptibility. For this purpose, three M. Agalactiae strains were selected to obtain in vitro resistant mutants against enrofloxacin, marbofloxacin and moxifloxacin and afterwards, partial sequences of their gyrA, gyrB, parC and parE genes were analyzed. In addition, a set of field isolates with different MIC values were also studied. Changes related to variations in fluoroquinolones susceptibility were found in gyrB, parC and parE. Specifically, gyrB genes were affected at the predicted amino acid position 424, four amino acid changes were detected in parC (positions 78, 79, 80 and 84) and two substitutions were reported in parE (amino acid positions 429 and 459). Mutations at predicted positions 424 of gyrB and 429 of parE are novel DNA changes which had not been previously described and, on the whole, parC was the first gene showing alterations when changes in susceptibility to fluoroquinolones occurred. Thus, this gene is the most suitable target for a rapid study of fluoroquinolone resistance in field isolates of M. Agalactiae.
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anatomic location of mycoplasma mycoides subsp capri and mycoplasma Agalactiae in naturally infected goat male auricular carriers
Veterinary Microbiology, 2012Co-Authors: Angel Gomezmartin, Adrian Paterna, A Contreras, Antonio Sánchez, Judith Amores, A J Buendia, J C CorralesAbstract:This study sought to determine whether male goat auricular carriers of mycoplasmas known to cause contagious Agalactia could harbour these microorganisms at anatomical sites other than the ears. A microbiological study was conducted in 6 naturally infected bucks that had been diagnosed as chronic auricular asymptomatic carriers of Mycoplasma (M.) mycoides subsp. capri (Mmc) more than one year previously. To detect mycoplasmas, cultures and PCR were performed on 46 samples taken from each goat from the cardio-respiratory, digestive, nervous, lymph and genitourinary systems and several joints. Of a total of 274 samples analyzed, 28 were positive for mycoplasmas (10.1%): Mmc was detected in 17 (6.1%), Mycoplasma (M.) Agalactiae in 12 (4.3%) and both microorganisms were identified in one of the samples. In all 6 goats, mixed infection was observed despite none being auricular carriers of M. Agalactiae. Mycoplasma spp. were identified at 15 different sites; the most frequent sites being the joints (31.2%, 5 positive samples), lymph nodes (25%, 4 positive samples) and respiratory tract (25%, 4 positive samples). Positive results were also obtained in three brain tissue (18.7%), two cardiac tissue (12.5%) and one ileum, urethra, testicle and bulbourethral gland (6.25%) samples. The histopathological findings may suggest the presence of mild chronic conditions in some of the organs where the bacteria were found. Our findings reveal for the first time the capacity of Mmc and M. Agalactiae to colonize several other organ systems in chronically naturally infected auricular carriers, possibly representing an added risk factor for the spread of these microorganisms. In the case of M. Agalactiae, colonization seemed to be independent of the animal's auricular carrier state.
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surveillance of mycoplasma Agalactiae and mycoplasma mycoides subsp capri in dairy goat herds
Small Ruminant Research, 2012Co-Authors: Judith Amores, Antonio Sánchez, Angel Gomezmartin, J C Corrales, A ContrerasAbstract:Abstract This study was designed to monitor the presence of Mycoplasma Agalactiae and Mycoplasma mycoides subsp. capri (Mmc) in 66 dairy goat herds of a genetic improvement programme in a region of Spain where contagious Agalactia is endemic. Over a whole lactation period, 300 bulk tank milk and 381 milk samples from goats with clinical mastitis were subjected to polymerase chain reaction (PCR) to detect the two mycoplasma species. The presence of mycoplasmas (either species or both) was detected in 66.7% of the herds and M. Agalactiae was identified in 95.45% of these positives herds. In a given infected herd, mycoplasmas were not continuously detected over the whole study period. Our findings indicate that in an endemic area, M. Agalactiae and Mmc can be monitored through PCR analysis of mastitic milk and bulk tank milk (BTM) samples. Over a lactation period we recommend testing multiple BTM samples on a herd. No relationship was observed between the use of inactivated mycoplasma vaccines and the PCR detection of both mycoplasmas.
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comparison of culture and pcr to detect mycoplasma Agalactiae and mycoplasma mycoides subsp capri in ear swabs taken from goats
Veterinary Microbiology, 2010Co-Authors: Judith Amores, Angel Gomez Martin, Antonio Sánchez, J C Corrales, A ContrerasAbstract:This study was designed to evaluate the validity of PCR for the direct detection of Mycoplasma (M.) Agalactiae and Mycoplasma mycoides subsp. capri (Mmc), as the two species most frequently causing contagious Agalactia (CA) in goats. The PCR method was compared with the traditional culture technique to determine which method was most efficient at identifying all auricular carriers present in herds. The samples analyzed were 307 ear swabs taken from goats reared in a CA endemic area. We assessed the validity of each technique to detect each species and agreement between both methods. For each species, the result was taken as true-positive when at least one of the two tests was positive. Of the swabs tested, 246 were scored positive by PCR (235 and 11 for Mmc and M. Agalactiae, respectively) and 117 showed a positive culture result (113 for Mmc and 4 for M. Agalactiae). 133 of the PCR-positive samples (124 and 9 for Mmc and M. Agalactiae, respectively) yielded negative culture results and 4 culture-positive samples tested negative using PCR (2 for each species). Sensitivity and negative predictive values for PCR were 84.62 and 99.32 (for M. Agalactiae) and 99.16 and 97.22% (for Mmc) respectively, and for culture were 30.77 and 97.03 (for M. Agalactiae) and 47.08 and 36.08% (for Mmc), respectively. PCR proved to be a rapid and sensitive method for the detection of mycoplasmas in the external ear of asymptomatic carriers. Tools such as this are needed to adopt efficient control measures against CA.