Browsing by Subject "Staphylococcus aureus"

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    Cephalosporin susceptibility of Staphylococcus aureus strains isolated from commercial rabbit and goat farms in Spain
    (Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', 2022-12-31) Badillo Puerta, Elena; Escudero, Elisa; Galecio, Juan Sebastian; Marín, Pedro; Farmacología
    Antimicrobial drug resistance is an important problem that challenges veterinary clinicians to provide effective treatments without further spreading this resistance to other animals and people. The most commonly used pharmacodynamic parameter to define potency of antimicrobial drugs is minimum inhibitory concentration (MIC). The aim of this study was to evaluate the antibiotic susceptibility of thirty-six strains of Staphylococcus aureus isolated from dairy goats with mastitis and rabbits with chronic staphylococcosis. Four cephalosporins were tested: cephalexin, cephalotin, cefonicid and ceftiofur. MIC tests were performed according to the microdilution broth method. The calculated values of sensitivity in goats and rabbits were 66.67% and 72.22% for cephalexin, 72.22 % and 94.44% for cefonicid, 77.78% and 94.44% for cephalotin and 77.78% and 100% for ceftiofur, respectively. For all antibiotics, MIC90 of S. aureus from rabbits were lower than MIC90 from goats. These data suggest that more antibiotics are used in goat milk production than in rabbit farming. According to MIC values obtained in this study, ceftiofur and cephalotin may be the best option for treating S. aureus infections in lactating goats. For rabbits, ceftiofur showed lowest MIC values, but cephalosporins can produce fatal diarrhoea in this species, therefore additional studies are needed to evaluate the effects of repeated ceftiofur administration on microflora of rabbits before recommending the use of this antibiotic in this species.
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    Estudio comparativo de pacientes con bacteriemia por Staphylococcus aureus sensible a la meticilina frente a S. aureus resistente a la meticilina: epidemiología y factores pronósticos
    (Elsevier, 2007-05) García-Vázquez, Elisa; Gómez, Joaquín; Baños, Ramón; Canteras, Manuel; Ruiz, Joaquín; Baños, Víctor; Herrero, José Antonio; Valdés, Mariano; Medicina
    RESUMEN: Fundamento y Objetivo : Hay controversia sobre la influencia de la resistencia a la meticilina en el pronóstico de los pacientes con bacteriemia por Staphylococcus aureus. En este trabajo, analizamos los patrones clínicos y los factores pronósticos que se relacionan con el desarrollo de complicaciones y la mortalidad en pacientes con bacteriemia por S. aureus y valoramos la influencia de la resistencia a la meticilina (S. aureus sensible a la meticlina [SASM] frente a S. aureus resistente a la meticilina [SARM]). Pacientes y Método: Estudio prospectivo y comparativo de 213 pacientes con bacteriemia por S. aureus. Resultados : Del total de pacientes con bacteriemia, 131 (61,5%) correspondían a SASM y 82 (38,5%) a SAMR. Se asociaron a SARM la adquisición nosocomial de la infección, la presencia de una enfermedad de base rápidamente fatal y ciertos factores predisponentes (diabetes mellitus, utilización de catéteres vasculares, estancia previa en unidades de cuidados intensivos y uso previo de antibióticos). Los pacientes con bacteriemia por SARM presentaron mayor gravedad clínica y desarrollaron complicaciones con más frecuencia que los pacientes con bacteriemia por SASM. La mortalidad de los casos con bacteriemia por SARM fue del 42,6%, mientras que en la de SASM fue del 16% (p < 0,05). En el análisis multivariado, del total de casos de bacteriemia por S. aureus, las variables que se asociaron a un fracaso terapéutico mayor fueron la gravedad de la enfermedad de base, una situación clínica inicial crítica-mala y el tratamiento empírico no adecuado; la resistencia a la meticilina no se asoció a más mortalidad. Conclusiones : En los pacientes con bacteriemia por S. aureus, la resistencia a la meticilina no se asocia a una mayor mortalidad cuando se hace un análisis ajustado por otros factores clínicos/pronósticos. La gravedad de la enfermedad de base, la situación clínica inicial crítica-mala y el tratamiento empírico no adecuado son los factores pronósticos relacionados con el fracaso terapéutico en los pacientes con bacteriemia por S. aureus.
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    Galvanic current dosage and bacterial concentration are determinants of the bactericidal effect of percutaneous needle electrolysis: an in vitro study
    (Springer Nature, 2021-09) García Vidal, José Antonio; Salinas Lorente, Jesús; Escolar-Reina, Pilar; Cuello, Francisco; Berná Mestre, Juan de Dios; López-Nicolás, Manuel; Valera-Garrido, Fermín; Medina Mirapeix, Francesc; Ortega Hernández, Nieves; Sanidad Animal
    Percutaneous needle electrolysis (PNE) is a physiotherapy technique that has been shown to be effective in different pathologies such as tendinopathies or mammary fistula. For many years, theoretical bactericidal and germicidal effects have been attributed to this type of galvanic currents, partly explained by the changes in pH that it generates. However, these effects have not yet been demonstrated. The aim of this study was to evaluate the bactericidal effect and the changes in pH caused by PNE. S. aureus were prepared in two different solutions (TSB and saline solution) and in different concentrations (from 9 to 6 Log10 CFU/mL). Bacteria were treated with three experimental PNE doses to assess bacterial death levels and the changes caused to the pH of the medium. The viable cell count showed that all experimental PNE doses had a bactericidal efect against a high concentration (9 Log10 CFU/mL) of S. aureus in saline solution (p < 0.001). Furthermore, we found that when the concentration of bacteria decreased, a lower dose of galvanic current generated the same effect as a higher dose. Changes in pH were registered only in experiments performed with saline solution. PNE had a bactericidal effect against S. aureus and the level of this effect was mainly modulated by the solution, the bacterial concentration and the dose. Changes affecting pH were modulated by the type of solution and there was no relationship between this and bacterial death.
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    Role of cytokines in host defense against Staphylococcus aureus skin infection
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Wu, Guosheng; Zhu, Banghui; Hong, Xudong; Luo, Pengfei; Xia, Zhaofan
    Wound infection caused by Staphylococcus aureus (S. aureus) is a critical clinical problem due to long hospitalization times, significant morbidity and mortality, as well as considerable medical resource consumption. With the emergence of methicillinresistant S. aureus (MRSA) strains, current antibiotic treatments are becoming ineffective in combatting S. aureus infection. Thus, a novel therapeutic strategy is required. Recent studies discovered that several cytokines in the infected wound area play protective roles against S. aureus infection. This review summarizes recent discoveries regarding the role of cytokines-mediated responses in host defense against S. aureus skin infection, and discusses their implications for future immunotherapy and vaccine development.
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    Synergistic antimicrobial effect of photodynamic therapy and chitosan on the titanium-adherent biofilms of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa: An in vitro study
    (Wiley, 2022) Camacho Alonso, Fabio; Salinas, Jesús; Sánchez Siles, Mariano; Pato Mourelo, Jesús; Cotrina Veizaga, Brian Davis; Ortega Hernández, Nieves; Dermatología, Estomatología, Radiología y Medicina Física; Sanidad Animal
    Background: To date, no studies on the combined use of photodynamic therapy (PDT) and chitosan against peri-implantitis have been published. The aim of this study was to evaluate the possible synergistic antimicrobial effect of PDT and chitosan on the titanium-adherent biofilms of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Methods: A total of 60 titanium discs were included in this study. The discs were randomized into three bacterial contaminations (n = 20 discs per bacterium). After being cultured (incubated for 48 hours) they were randomized again into four different disinfection modalities (n = 5 discs per treatment): control (without treatment), PDT, chitosan 3 mg/mL, and PDT + chitosan 3 mg/mL. After the treatments, the colony forming units (CFU) were measured to determine antimicrobial effects, and field emission scanning electron microscopy (FESEM) was used to study cell morphology and titanium adherence. Results: For all the evaluated bacteria and all the variables studied the order from highest to lowest antimicrobial effectiveness was: PDT + chitosan 3 mg/mL > chitosan 3 mg/mL > PDT > control. Although, all disinfection methods were significantly effective when compared to control, the combined treatment of PDT + chitosan 3 mg/mL had the greatest antimicrobial effect against the three studied bacteria. Conclusions: The combination of PDT and chitosan has a synergistic antimicrobial effect against the bacteria S. aureus, E. coli, and P. aeruginosa, all closely related to peri-implantitis. However, further in vivo studies are needed because this study provides data based on an in vitro scenario that might not be extrapolated to patients with peri-implantitis.