Browsing by Subject "Antimicrobial susceptibility"

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    Antimicrobial Susceptibility of Isolated from Sheep with Fibrinous Pneumonia
    (Sciendo, 2023-07-01) Galecio, Juan Sebastián; Badillo, Elena; Escudero, Elisa; Corrales, Juan Carlos; Yuste Pérez, María Teresa; Marín, Pedro; Farmacología
    Ovine respiratory complex is a signifi cant cause of death in sheep fl ocks, where Pasteurella multocida is the most frequent microorganisms isolated from animals with pneumonia. There is an urgent need to refi ne the use of different antimicrobials to avoid the problem of antimicrobial resistance and optimize the control of this disease in ovine livestock. The fi rst step in approaching this problem is gaining an insight into the antimicrobial susceptibility of ovine pathogens. This study evaluated the in vitro activity of tildipirosin, gamithromycin, oxytetracycline, and danofl oxacin against Pasteurella multocida strains isolated from sheep with fi brinous pneumonia. The strains were incubated following Clinical and Laboratory Standards Institute (CLSI) standard conditions and also with a modifi ed method by 25% supplementation with sheep serum. Minimum inhibitory concentrations (MIC) were determined using the broth microdilution technique. The lowest MIC90 under standard conditions and by supplementation with sheep serum was obtained with tildipirosin. Sheep serum signifi cantly reduced tildipirosin, gamithromycin, and danofl oxacin MIC values for Pasteurella multocida strains. In brief, the potency of tildipirosine, gamithromycin, and danofl oxacin against Pasteurella multocida increases when sheep serum is added to the culture media.
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    Antimicrobial susceptibility of Rhodococcus equi strains isolated from foals in Chile
    (2023-06-22) Badillo Puerta, Elena; Zúñiga, María Paz; Abalos, Pedro; Valencia, Eduardo David; Marín, Pedro; Escudero, Elisa; Galecio, Juan Sebastián; Farmacología
    Rhodococcus equi is responsible for foal pneumonia worldwide, with a significant economic impact on the production and breeding of horses. In Chile, the first case was reported in 2000, and since then, its incidence has been increasing. Distinctive characteristics of R. equi as an intracellular pathogen in macrophages, emergence of virulence plasmids encoding surface lipoprotein antigens, and appearance of antibiotic resistance against macrolides and rifampicin have significantly complicated the treatment of R. equi pneumonia in foals. Therefore, in vitro susceptibility studies of first-line and newer antibiotics against R. equi are the first step to establishing effective treatments and optimizing new therapeutic options. The aim of the present study is to determine the susceptibility profile of fourteen strains of R. equi isolated from foals in Chile to several antibiotics of the macrolide group including azithromycin, amikacin, tildipirosin and gamithromycin as well as others such as rifampicin, doxycycline and ceftiofur. Identification of R. equi in collected isolates from foals in Chile has been performed by CAMP test and PCR based on detecting of the gene encoding the 16 S rRNA. The presence of genes encoding virulence plasmids was also determined using PCR. Results obtained have demonstrated presence of virulent R. equi strains in Chile. In vitro susceptibility pattern to different antibiotics has shown better results for doxycycline and rifampicin similar to previous studies performed. Current macrolides have been evaluated in order to consider alternative treatment options in a context of emerging resistance to classic macrolides and rifampicin, obtaining better results with gamithromycin (MIC range of 0.125 to 128 mg/ml) than with tildipirosin (MIC range of 16 to 128 mg/ml). An adequate diagnosis of bacterial susceptibility based on antibiograms is necessary to treat the Rhodococcus equi infection in foals.
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    Impact of pneumococcal vaccination in the nasopharyngeal carriage of streptococcus pneumoniae in healthy children of the Murcia Region in Spain
    (MDPI, 2020-12-28) Alfayate Miguélez, Santiago; Yagüe Guirao, Genoveva; Menasalvas Ruiz, Ana Isabel; Sánchez-Solís de Querol, Manuel; Domenech Lucas, Mirian; González Camacho, Fernando; Ortíz Romero, M. Mar; Espejo García, Pilar; Guerrero Gómez, Carmen; Iofrío de Arce, Antonio; Moreno Parrado, Laura; Sánchez Andrada, Rosa M.; Cascales Alcolea, Eva; Lorente García, Sebastián; Paredes Reyes, Pedro; Casquet Barceló, Ángela; López Yepes, M. Luisa; Vigueras Abellán, Juan José; Sanz Mateo, Gonzalo; Murcian Pneumococcal Study Group; Cirugía, Pediatría y Obstetricia y Ginecología; Facultad de Medicina
    Background: An epidemiological study of Streptococcus pneumoniae nasopharyngeal carriage in healthy children was carried out five years after the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13). Objectives: Study the impact of pediatric vaccination with PCV13, and other associated epidemiological factors on the status of nasopharyngeal carriage, the circulating pneumococcal serotypes, and the antibiotic susceptibility to more frequently used antibiotics. Methods: A multi-center study was carried out in Primary Health Care, which included 1821 healthy children aged 1 to 4 years old. All isolates were sent to the Spanish Pneumococcal Reference Laboratory for serotyping and antimicrobial susceptibility testing. Results: At least one dose of PCV13 had been received by 71.9% of children and carriage pneumococcal prevalence was 19.7%. The proportion of PCV13 serotypes was low (14.4%), with an observed predominance of non-vaccine serotypes, 23B, 11A, 10A, 35B/F, and 23A were the five most frequent. A high rate of resistance to penicillin, erythromycin, and trimethoprim sulfamethoxazole was found. Conclusions: A low proportion of PCV13 serotypes were detected, confirming the impact of pediatric vaccination for reducing the serotypes vaccine carriage. High resistance rates to clinically important antibiotics were observed.