scholarly journals Mastitis bovina causada por Staphylococcus coagulasa negativos

2014 ◽  
Author(s):  
◽  
César C. Bonetto
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Agalactiae ◽  
Sobre Todo

El presente Trabajo de Tesis se desprende como una línea de investigación del grupo de la UNRC dedicado al estudio de la problemática de la mastitis bovina tanto en aspectos básicos como aplicados con estudios genéticos, epidemiológicos y de virulencia de los principales microorganismos involucrados en la mastitis bovina. Staphylococccus coagulasa negativo (SCN) es un grupo bacteriano formado por varias especies que por lo general eran considerados flora oportunista de la piel y agentes patógenos menores de mastitis bovina sobre todo en comparación con los principales agentes patógenos tales como Staphylococcus aureus y Streptococcus agalactiae, e incluso con frecuencia ignorados en el marco del control de la mastitis. En estos últimos años están emergiendo como potenciales bacterias responsables de infecciones intramamarias (IIM) en las explotaciones lecheras modernas, siendo frecuentemente los más aislados. Existen claras evidencias, principalmente en casos subclínicos, como también mastitis clínicas leves y subclínica de larga duración que ocasionan una reducción en la producción de leche además de un daño en los tejidos secretores. Por lo tanto, este trabajo de tesis intenta dilucidar algunos aspectos relacionados con la metodología de diagnóstico fenotípica y genotípica, los factores de virulencia que contribuyen a la patogenicidad, persistencia de las infecciones, y a la susceptibilidad de los distintos antimicrobianos, como así también los genes asociados a la formación de biofilm y los relacionados con los antibióticos β-lactámicos. En resumen, esta tesis intenta profundizar el conocimiento del rol de los SCN dentro de las IIM, en especial la significancia clínica de cada especie, contribuyendo al desarrollo de estrategias de control y prevención de la mastitis por SCN.

scholarly journals Rapid Detection of Mycoplasma bovis, Staphylococcus aureus and Streptococcus agalactiae in Cattle Bulk Tank Milk in Cyprus and Relations with Somatic Cell Counts

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 841
Author(s):  
Maria Liapi ◽  
George Botsaris ◽  
Costas Arsenoglou ◽  
Nikolas Markantonis ◽  
Christodoulos Michael ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Somatic Cell ◽  
Real Time ◽  
Streptococcus Agalactiae ◽  
Mycoplasma Bovis ◽  
Bulk Tank Milk ◽  
Somatic Cell Counts ◽  
Milk Samples ◽  
Cell Counts ◽  
Bulk Tank

One hundred and seventy-seven (177) bulk tank milk samples were analyzed with a commercially available real-time polymerase chain reaction kit and 11 (6.21%), 41 (23.16%), and 58 (32.77%) tested positive for Mycoplasma bovis, Staphylococcus aureus, and Streptococcus agalactiae, respectively. Statistical analysis revealed a significant relationship between the presence of S. aureus and S. agalactiae. Enumeration of somatic cells was performed in the same samples by flow cytometry. The somatic cell counts were found higher in S. aureus and S. agalactiae positive samples. No association was found between M. bovis presence and somatic cells counts. Low internal assay control Ct values were found to be related with high somatic cell counts. Noticeably, this is the first report for the presence of M. bovis in Cyprus. Therefore, its presence was confirmed by bulk tank milk culture, conventional PCR, and next generation sequencing. Furthermore, M. bovis was typed with multilocus sequencing typing and was allocated to sequence type 29 (ST 29). Real-time PCR in bulk tank milk samples is a useful tool to detect mammary infections, especially for neglected pathogens such as M. bovis.

scholarly journals Possibility of application of dodicin hydrochloride in prevention of mastitis in cows

2006 ◽  
Vol 60 (3-4) ◽  
pp. 207-221
Author(s):  
Svetlana Joksovic ◽  
Vitomir Cupic ◽  
Vera Katic
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Streptococcus Agalactiae ◽  
Control Group ◽  
Main Approach ◽  
Laboratory Conditions ◽  
Streptococcus Uberis ◽  
Holstein Friesian ◽  
Experimental Group ◽  
Outer Environment

The main approach to curbing mastitis is to prevent the entry of microorganisms from the outer environment into the mammary gland, which is achieved by the use of papilla disinfection following every time of milking. The objective of this work was to examine the antimicrobial activity of the disinfectant dodicin hydrochloride, in fact the preparation that contains this disinfectant (DESU? M), against bacteria, the most frequent causes of mastitis in cows. The efficacy of modified DESU? Mwas examined under laboratory conditions using the quantitative test against the following microorganisms: Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae and Streptococcus uberis, under the conditions in the field. The udders of an experimental group of 20 cows of the Holstein-Friesian breed were immersed in a solution of the modified preparation DESU ? M following every time of milking over a period of three months. In the second group of 10 cows of the Holstein-Friesian breed, marked as the control group, no disinfection was applied following the milkings. The preparation DESU? Mexhibited satisfactory antimicrobial efficacy against the most frequent causes (Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae and Streptococcus uberis) of mastitis in cows under laboratory conditions. With the application of the preparation DESU? M, following every time of milking over a period of three months, the number of somatic cells was reduced by almost one half in comparison with their number at the start of the experiment. No residue of the modified preparation DESU ? M were found in any sample of milk from the experimental group of cows.

Absence of Bacterial Adherence in the Establishment of Experimental Mastitis in Mice

1978 ◽  
Vol 15 (6) ◽  
pp. 770-775 ◽  
Author(s):  
J. C. Anderson
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Mammary Gland ◽  
Significant Role ◽  
Streptococcus Agalactiae ◽  
Staphylococcus Epidermidis ◽  
Alveolar Epithelium ◽  
Bacterial Adherence ◽  
E Coli ◽  
Suckling Mice

The possibility of adherence of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli or Streptococcus agalactiae to the epithelium of the mammary gland was investigated by inoculating them into this gland of mice. S. aureus, S. epidermidis and E. coli did not adhere to alveolar epithelium in suckling or non-suckling mice. S. agalactiae adhered to alveolar epithelium in non-suckling mice but adhesion was not sufficiently strong to withstand suckling. Bacterial adherence probably does not play a significant role in the establishment of mastitis by these organisms.

scholarly journals Characterization of Staphylococci and Streptococci Isolated from Milk of Bovides with Mastitis in Egypt

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 381
Author(s):  
Wedad Ahmed ◽  
Heinrich Neubauer ◽  
Herbert Tomaso ◽  
Fatma Ibrahim El Hofy ◽  
Stefan Monecke ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Microarray Analysis ◽  
Streptococcus Agalactiae ◽  
Nile Delta ◽  
Meca Gene ◽  
Resistance Rate ◽  
Coagulase Negative Staphylococci ◽  
Flight Mass Spectrometry ◽  
Streptococcus Gallolyticus ◽  
Broth Microdilution Method

The aim of this study was to characterize staphylococci and streptococci in milk from Egyptian bovides. In total, 50 milk samples were collected from localities in the Nile Delta region of Egypt. Isolates were cultivated, identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and antibiotic susceptibility testing was performed by the broth microdilution method. PCR amplifications were carried out, targeting resistance-associated genes. Thirty-eight Staphylococcus isolates and six Streptococcus isolates could be cultivated. Staphylococcus aureus isolates revealed a high resistance rate to penicillin, ampicillin, clindamycin, and erythromycin. The mecA gene defining methicillin-resistant Staphylococcus aureus, erm(C) and aac-aphD genes was found in 87.5% of each. Coagulase-negative staphylococci showed a high prevalence of mecA, blaZ and tetK genes. Other resistance-associated genes were found. All Streptococcus dysgalactiae isolates carried blaZ, erm(A), erm(B), erm(C) and lnuA genes, while Streptococcus suis harbored erm(C), aphA-3, tetL and tetM genes, additionally. In Streptococcus gallolyticus, most of these genes were found. The Streptococcus agalactiae isolate harbored blaZ, erm(B), erm(C), lnuA, tetK, tetL and tetM genes. Streptococcus agalactiae isolate was analyzed by DNA microarray analysis. It was determined as sequence type 14, belonging to clonal complex 19 and represented capsule type VI. Pilus and cell wall protein genes, pavA, cadD and emrB/qacA genes were identified by microarray analysis.

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