Mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa

Bovine mastitis is considered one of the main causes of economic losses in dairy cows. Although it is caused by several etiological agents, in recent years\nthe prevalence of coagulase-negative staphylococci (CNS) has increased worldwide, being considered an emerging pathogen. Recent studies show th...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autor principal:	Srednik, Mariela Elizabeth
Otros Autores:	Gentilini, Elida Raquel
Formato:	Tesis doctoral acceptedVersion
Lenguaje:	Español
Publicado:	Facultad de Ciencias Veterinarias 2017
Materias:	Estafilococos coagulasa negativos Mastitis bovina Resistencia antimicrobiana Biofilm Coagulase negative staphylococci Bovine mastitis Antimicrobial resistance Vaca Mastitis Estudio molecular Fenotipo Biología Staphylococcus coagulasa negativa Ciencias Veterinarias
Acceso en línea:	http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=avaposgra&cl=CL1&d=HWA_6987 http://repositoriouba.sisbi.uba.ar/gsdl/collect/avaposgra/index/assoc/HWA_6987.dir/6987.PDF
Aporte de:	Repositorio Digital de la Universidad de Buenos Aires (UBA) de Universidad de Buenos Aires

id	I28-R145-HWA_6987
record_format	dspace
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-145
collection	Repositorio Digital de la Universidad de Buenos Aires (UBA)
language	Español
orig_language_str_mv	spa
topic	Estafilococos coagulasa negativos Mastitis bovina Resistencia antimicrobiana Biofilm Coagulase negative staphylococci Bovine mastitis Biofilm Antimicrobial resistance Vaca Mastitis Estudio molecular Fenotipo Biología Staphylococcus coagulasa negativa Ciencias Veterinarias
spellingShingle	Estafilococos coagulasa negativos Mastitis bovina Resistencia antimicrobiana Biofilm Coagulase negative staphylococci Bovine mastitis Biofilm Antimicrobial resistance Vaca Mastitis Estudio molecular Fenotipo Biología Staphylococcus coagulasa negativa Ciencias Veterinarias Srednik, Mariela Elizabeth Mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa
topic_facet	Estafilococos coagulasa negativos Mastitis bovina Resistencia antimicrobiana Biofilm Coagulase negative staphylococci Bovine mastitis Biofilm Antimicrobial resistance Vaca Mastitis Estudio molecular Fenotipo Biología Staphylococcus coagulasa negativa Ciencias Veterinarias
description	Bovine mastitis is considered one of the main causes of economic losses in dairy cows. Although it is caused by several etiological agents, in recent years\nthe prevalence of coagulase-negative staphylococci (CNS) has increased worldwide, being considered an emerging pathogen. Recent studies show that microorganisms among the CNS group have the ability to form biofilm and\nbecause of that, they could persist in the mammary gland. It is important to\nhighlight the implications to public health, since CNS are reservoirs of resistance genes. The objective of this study was to evaluate the antimicrobial susceptibility and the presence of resistance genes to antimicrobial agents\ncommonly used in bovine mastitis therapeutics. Furthermore, to evaluate biofilm formation, enzymatic treatments of biofilms formed by CNS, and the presence of virulence genes in CNS isolates from bovine mastitis from different dairy\nherds in Argentina. 138 CNS isolates were identified at the species level by\nrestriction fragment length polymorphism (RFLP) analysis of the gap gene. The most prevalent CNS species were staphylococcus chromogenes (n=59,\n42.8%), Staphylococcus epidermidis (n=19, 13.8%) and Staphylococcus\ndevriesei (n=12, 8.7%).\nGenes encoding resistance to ?-lactams (n=26; 28.8%) were detected among\nthe isolates: blaZ (n=28, 20.3%), mecA (n=4, 2.9%) and mecC (n=1, 0.7%).\nResistance to macrolides and lincosamides (n=14, 10.1%) was attributable \nermC (n=9, 6.5), ermB (n=6, 4.3), mphC (n=5, 6%) and mrsA (n=3, 2.2%),\nalone or in a combination of those genes.\n The majority (93.5%) of isolates was able to form biofilms. Among the biofilm-\npositive isolates, 37.2%, 11.6% and 51.2% were strong, moderate and weak\nbiofilm formers, respectively. The ability to form biofilms varied among CNS\nspecies. S. haemolyticus and S. devriesei isolates formed significantly more\nbiofilms than other species. Enzymatic treatment results suggest that proteins\nand eDNA play a larger role in the structural integrity of CNS biofilms. icaA\n(n=9, 6.5%), bap (n=5, 3.6%) and aap (n=5, 3.6%) were detected in a few\nisolates, while atlE (n=38, 27.5%), embP (n=35, 25,4%) and fbe (n=20, 14.4%) were detected in a considerable number of CNS. The eno gene (n=122, 88.4%) was present in the majority of isolates.\nThe results obtained show differences in the ability of biofilm formation among\nCNS species and there are intra-species variations. Although antimicrobial\nresistance to common antibiotics is low, it is important to highlight the presence of methicillin-resistant CNS carrying the mecA/C genes, important for the public health implications, since CNS are reservoirs of resistance genes. In this study,\nwe identified CNS species involved in mastitis and provide information about\npathogenicity and antimicrobial resistance, which is essential to design efficient strategies to control mastitis caused by CNS.\nFuture studies should be carried out to examine the association of biofilm\nformation with treatment failure and the occurrence of persistent intramammary\ninfections by different CNS species in cattle.
author2	Gentilini, Elida Raquel
author_facet	Gentilini, Elida Raquel Srednik, Mariela Elizabeth
format	Tesis doctoral Tesis doctoral acceptedVersion
author	Srednik, Mariela Elizabeth
author_sort	Srednik, Mariela Elizabeth
title	Mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa
title_short	Mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa
title_full	Mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa
title_fullStr	Mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa
title_full_unstemmed	Mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa
title_sort	mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa
publisher	Facultad de Ciencias Veterinarias
publishDate	2017
url	http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=avaposgra&cl=CL1&d=HWA_6987 http://repositoriouba.sisbi.uba.ar/gsdl/collect/avaposgra/index/assoc/HWA_6987.dir/6987.PDF
work_keys_str_mv	AT srednikmarielaelizabeth mastitisbovinaestudiosmolecularesfenotipicosybiologicosdeestafilococoscoagulasanegativa
_version_	1766017565668147200
spelling	I28-R145-HWA_69872023-04-24 Bovine mastitis is considered one of the main causes of economic losses in dairy cows. Although it is caused by several etiological agents, in recent years\nthe prevalence of coagulase-negative staphylococci (CNS) has increased worldwide, being considered an emerging pathogen. Recent studies show that microorganisms among the CNS group have the ability to form biofilm and\nbecause of that, they could persist in the mammary gland. It is important to\nhighlight the implications to public health, since CNS are reservoirs of resistance genes. The objective of this study was to evaluate the antimicrobial susceptibility and the presence of resistance genes to antimicrobial agents\ncommonly used in bovine mastitis therapeutics. Furthermore, to evaluate biofilm formation, enzymatic treatments of biofilms formed by CNS, and the presence of virulence genes in CNS isolates from bovine mastitis from different dairy\nherds in Argentina. 138 CNS isolates were identified at the species level by\nrestriction fragment length polymorphism (RFLP) analysis of the gap gene. The most prevalent CNS species were staphylococcus chromogenes (n=59,\n42.8%), Staphylococcus epidermidis (n=19, 13.8%) and Staphylococcus\ndevriesei (n=12, 8.7%).\nGenes encoding resistance to ?-lactams (n=26; 28.8%) were detected among\nthe isolates: blaZ (n=28, 20.3%), mecA (n=4, 2.9%) and mecC (n=1, 0.7%).\nResistance to macrolides and lincosamides (n=14, 10.1%) was attributable \nermC (n=9, 6.5), ermB (n=6, 4.3), mphC (n=5, 6%) and mrsA (n=3, 2.2%),\nalone or in a combination of those genes.\n The majority (93.5%) of isolates was able to form biofilms. Among the biofilm-\npositive isolates, 37.2%, 11.6% and 51.2% were strong, moderate and weak\nbiofilm formers, respectively. The ability to form biofilms varied among CNS\nspecies. S. haemolyticus and S. devriesei isolates formed significantly more\nbiofilms than other species. Enzymatic treatment results suggest that proteins\nand eDNA play a larger role in the structural integrity of CNS biofilms. icaA\n(n=9, 6.5%), bap (n=5, 3.6%) and aap (n=5, 3.6%) were detected in a few\nisolates, while atlE (n=38, 27.5%), embP (n=35, 25,4%) and fbe (n=20, 14.4%) were detected in a considerable number of CNS. The eno gene (n=122, 88.4%) was present in the majority of isolates.\nThe results obtained show differences in the ability of biofilm formation among\nCNS species and there are intra-species variations. Although antimicrobial\nresistance to common antibiotics is low, it is important to highlight the presence of methicillin-resistant CNS carrying the mecA/C genes, important for the public health implications, since CNS are reservoirs of resistance genes. In this study,\nwe identified CNS species involved in mastitis and provide information about\npathogenicity and antimicrobial resistance, which is essential to design efficient strategies to control mastitis caused by CNS.\nFuture studies should be carried out to examine the association of biofilm\nformation with treatment failure and the occurrence of persistent intramammary\ninfections by different CNS species in cattle. Fil: Srednik, Mariela E. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Buenos Aires, Argentina Facultad de Ciencias Veterinarias Gentilini, Elida Raquel Srednik, Mariela Elizabeth 2017-05-07 La mastitis bovina es considerada una de las principales causas de pérdidas económicas en el sector lechero. Si bien es causada por numerosos agentes microbianos, en los últimos años la frecuencia de aislamientos de estafilococos coagulasa-negativos (ECN) se ha incrementado undialmente,\nconsiderándose un patógeno emergente. Estudios recientes demuestran que\ndeterminadas especies que integran el grupo de los ECN presentan la habilidad\npara formar biofilm y así podrían persistir en la glándula mamaria. Además, es importante destacar las implicancias en salud pública, por ser los ECN\nreservorios de genes de resistencia a antimicrobianos y por la posibilidad de transferencia de resistencia. El objetivo de este estudio fue identificar las especies de ECN, determinar la susceptibilidad y portación de genes de\nresistencia a antibióticos de uso habitual en la terapéutica antimastítica.\nAdemás, detectar formación de biofilm, su dispersión enzimática, y la portación\nde genes de virulencia, en especies de ECN aislados de mastitis bovina de\ndiferentes tambos de Argentina. Por el análisis del polimorfismo en la longitud\nde fragmentos de restricción (RFLP) del gen gap, se identificaron 138\naislamientos a nivel de especie. Los resultados arrojaron que, las especies de ECN más prevalentes resultaron: Staphylococcus chromogenes (n=59, 42,8%),Staphylococcus epidermidis (n=19, 13,8%) y Staphylococcus devriesei (n=12,\n8,7%).\n?Mastitis Bovina: Estudios Moleculares y Fenotípicos de Estafilococos Coagulasa Negativos? En distintas especies fueron detectados genes responsables de la resistencia a ?-lactámicos (n=26; 18,8%), como el gen blaZ (n=28; 20,3%), mecA (n=4; 2,9%) y mecC (n=1; 0,7%). Con respecto a la resistencia a macrólidos y\nlincosamidas (n=14; 10,1%) fue atribuible a los genes ermC (n=9; 6,5%), ermB\n(n=6; 4,3%), mphC (n=5; 3,6%) y msrA (n=3; 2,2%), estando solos o en\ncombinaciones.\nLa mayoría (93,5%) de los aislamientos analizados presentaron habilidad para\nformar biofilm. De este total, el 37,2%, 11,6% y 51,2% resultaron fuertes,\nmoderados y débiles formadores de biofilm, respectivamente. La capacidad de formación de biofilm mostró variaciones en las distintas especies.\nStaphylococcus haemolyticus y S. devriesei resultaron los mayores productores de biofilm. Los resultados de los tratamientos enzimáticos sugieren que las\nproteínas y el ADN extracelular desempeñarían un papel más importante en la matriz del biofilm de los ECN. Los genes asociados a biofilm se detectaron sólo en algunos aislamientos,\nsiendo para icaA (n=9; 6,5%), bap (n=5; 3,6%) y aap (n=5; 3,5%), mientras que los genes atlE (n=38; 27,5%), embP (n=35; 25,4%) y fbe (n=20; 14,4%) se detectaron en mayor cantidad de aislamientos, y el gen eno (n=122; 88,4%) en casi todas las especies. Los resultados obtenidos demuestran que la\nresistencia de los ECN frente a los antibióticos de uso habitual en las mastitis,\nen general es baja comparada con otros países. Es importante que se encontraron aislamientos meticilino-resistentes portadores de los genes\nmecA/C, por las implicancias que esto tiene en salud pública, al ser los ECN reservorios de genes de resistencia. Además, se observó que los ECN son\n?Mastitis Bovina: Estudios Moleculares y Fenotípicos de Estafilococos Coagulasa Negativos? productores de biofilm y, que existen diferencias en la capacidad de formación en las distintas especies y además variaciones intraespecies.\nEste estudio aporta información sobre las distintas especies de ECN\ninvolucradas en mastitis bovina, factores de patogenicidad y datos sobre\nfrecuencia, emergencia y mecanismos de resistencia antimicrobiana,\npermitiendo al profesional diseñar estrategias eficaces para el control de las\nmastitis bovina.\nEstudios futuros deberían llevarse a cabo para examinar la asociación de la\nformación de biofilm con el fracaso de los tratamientos y la aparición de infecciones intramamarias persistentes por las distintas especies de ECN en bovinos application/pdf Estafilococos coagulasa negativos Mastitis bovina Resistencia antimicrobiana Biofilm Coagulase negative staphylococci Bovine mastitis Biofilm Antimicrobial resistance spa Universidad de Buenos Aires. Facultad de Ciencias Veterinarias info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-ncnd/2.5/ar/ Vaca Mastitis Estudio molecular Fenotipo Biología Staphylococcus coagulasa negativa Ciencias Veterinarias Mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa info:eu-repo/semantics/doctoralThesis info:ar-repo/semantics/tesis doctoral info:eu-repo/semantics/acceptedVersion http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=avaposgra&cl=CL1&d=HWA_6987 http://repositoriouba.sisbi.uba.ar/gsdl/collect/avaposgra/index/assoc/HWA_6987.dir/6987.PDF

Mastitis bovina : estudios moleculares, fenotípicos y biológicos de estafilococos coagulasa negativa

Ejemplares similares