Browsing by Subject "Minimum inhibitory concentration"
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- PublicationOpen AccessImportance and antimicrobial resistance of Mycoplasma bovis in clinical respiratory disease in feedlot calves(MDPI, 2021-05-20) García Galán, Ana; Gómez Martín, Ángel; Ortega, Joaquín; Rodríguez, Francisco; García Muñoz, Ángel; Fé Rodríguez, David Christian de la; Seva Alcaraz, Juan; Anatomía y Anatomía Patológica ComparadasBovine respiratory disease (BRD) is an important viral and/or bacterial disease that mainly affects feedlot calves. The involvement of Mycoplasma bovis in BRD can lead to chronic pneumonia poorly responsive to antimicrobial treatment. Caseonecrotic bronchopneumonia is a pulmonary lesion typically associated with M. bovis. In Spain, M. bovis is widely distributed in the feedlots and circulating isolates are resistant to most antimicrobials in vitro. However, the role of this species in clinical respiratory disease of feedlot calves remains unknown. Furthermore, available data are relative to a fixed panel of antimicrobials commonly used to treat BRD, but not to the specific set of antimicrobials that have been used for treating each animal. This study examined 23 feedlot calves raised in southeast Spain (2016–2019) with clinical signs of respiratory disease unresponsive to treatment. The presence of M. bovis was investigated through bacteriology (culture and subsequent PCR), histopathology and immunohistochemistry. The pathogen was found in 86.9% (20/23) of the calves, mainly in the lungs (78.26%; 18/23). Immunohistochemistry revealed M. bovis antigens in 73.9% (17/23) of the calves in which caseonecrotic bronchopneumonia was the most frequent lesion (16/17). Minimum inhibitory concentration assays confirmed the resistance of a selection of 12 isolates to most of the antimicrobials specifically used for treating the animals in vivo. These results stress the importance of M. bovis in the BRD affecting feedlot calves in Spain.
- PublicationOpen AccessImportance and Antimicrobial Resistance of Mycoplasma bovis in Clinical Respiratory Disease in Feedlot Calves(MDPI, 2021-05-20) García Galán, Ana; Gómez Martín, Ángel; Ortega, Joaquín; Rodríguez, Francisco; García Muñoz, Angel; Fé Rodríguez, Christian de la; Seva Alcaraz, Juan; Sanidad AnimalBovine respiratory disease (BRD) is an important viral and/or bacterial disease that mainly affects feedlot calves. The involvement of Mycoplasma bovis in BRD can lead to chronic pneumonia poorly responsive to antimicrobial treatment. Caseonecrotic bronchopneumonia is a pulmonary lesion typically associated with M. bovis. In Spain, M. bovis is widely distributed in the feedlots and circulating isolates are resistant to most antimicrobials in vitro. However, the role of this species in clinical respiratory disease of feedlot calves remains unknown. Furthermore, available data are relative to a fixed panel of antimicrobials commonly used to treat BRD, but not to the specific set of antimicrobials that have been used for treating each animal. This study examined 23 feedlot calves raised in southeast Spain (2016–2019) with clinical signs of respiratory disease unresponsive to treatment. The presence of M. bovis was investigated through bacteriology (culture and subsequent PCR), histopathology and immunohistochemistry. The pathogen was found in 86.9% (20/23) of the calves, mainly in the lungs (78.26%; 18/23). Immunohistochemistry revealed M. bovis antigens in 73.9% (17/23) of the calves in which caseonecrotic bronchopneumonia was the most frequent lesion (16/17). Minimum inhibitory concentration assays confirmed the resistance of a selection of 12 isolates to most of the antimicrobials specifically used for treating the animals in vivo. These results stress the importance of M. bovis in the BRD affecting feedlot calves in Spain
- PublicationOpen AccessMycoplasma bovis in Spanish Cattle Herds: Two Groups of Multiresistant Isolates Predominate, with One Remaining Susceptible to Fluoroquinolones(MDPI, 2020-07-07) Nouvel, Laurent-Xavier; Baranowski, Eric; Gómez-Martín, Ángel; Sánchez López, Antonio; Citti, Christine; de la Fe Rodríguez, Christian; García-Galán Pérez, Ana; Sanidad AnimalMycoplasma bovis is an important bovine pathogen causing pneumonia, mastitis, and arthritis and is responsible for major economic losses worldwide. In the absence of an efficient vaccine, control of M. bovis infections mainly relies on antimicrobial treatments, but resistance is reported in an increasing number of countries. To address the situation in Spain, M. bovis was searched in 436 samples collected from beef and dairy cattle (2016–2019) and 28% were positive. Single-locus typing using polC sequences further revealed that two subtypes ST2 and ST3, circulate in Spain both in beef and dairy cattle, regardless of the regions or the clinical signs. Monitoring of ST2 and ST3 isolates minimum inhibitory concentration (MIC) to a panel of antimicrobials revealed one major difference when using fluoroquinolones (FQL): ST2 is more susceptible than ST3. Accordingly, whole-genome sequencing (WGS) further identified mutations in the gyrA and parC regions, encoding quinolone resistance-determining regions (QRDR) only in ST3 isolates. This situation shows the capacity of ST3 to accumulate mutations in QRDR and might reflect the selective pressure imposed by the extensive use of these antimicrobials. MIC values and detection of mutations by WGS also showed that most Spanish isolates are resistant to macrolides, lincosamides, and tetracyclines. Valnemulin was the only one effective, at least in vitro, against both STs.
- PublicationOpen AccessPenetration of levofloxacin into the anterior chamber (aqueous humour) of the human eye after intravenous administration(Springer Verlag, 2007-01-11) García-Vázquez, Elisa; Mensa, J.; Sarasa, M.; López, Y.; Couchard, P. D.; Soy, D.; Fontenla, J. R.; MedicinaIn the study presented here, levofloxacin con centrations in serum samples and the aqueous humour (AH) of 16 patients undergoing cataract extraction were measured in order to determine the penetration characteristics of levofloxacin into the AH of the non-inflamed human eye. Cataract removal was performed at various times (from 90 to 270 min) after the end of a 30-min intravenous infusion of 500 mg of levofloxacin. Serum samples were obtained 1 h after the end of levofloxacin administration (C max ); AH and a second serum sample were taken simultaneously during the operation, and the concentrations of levofloxacin in AH (C AH ) and serum (C S) were determined using a rapid high-performance liquid chromatography assay. The mean Cmax was 6.07 μg/ml (range 3.75–9.53 μg/ml, SD 1.83). The mean CAH at the first hour following levofloxacin administration was 1.37 μg/ml (range 1.17–1.6 μg/ml, SD 0.22) and the mean ratio (R=CAH /C S ) was 0.26 (range 0.24–0.3, SD 0.02). The mean CAH at 125–270 min following levofloxacin administration was 1.39 μg/ml (range 0.82–1.98 μg/ml, SD 0.33) and the mean R was 0.3 (range 0.15–0.53, SD 0.11). Of 16 patients, 15 had a CAH of >1 μg/ml 1 h after levofloxacin administration. In conclusion, 1 h after administration of 500 mg of levofloxacin, the levels obtained were higher than the MIC at which 90% of methicillin-susceptible Staphylococcus aureus and certain gram-negative bacteria strains are inhibited.
- PublicationRestrictedResistance patterns to C and D antibiotic categories for veterinary use of Campylobacter spp., Escherichia coli and Enterococcus spp. commensal isolates from laying hen farms in Spain during 2018(Elsevier, 2021-01) Rivera Gomis, Jorge; Marín Carrillo, Pedro; Otal, Julio; Galecio Naranjo, Juan Sebastian; Martínez Conesa, Cristina; Cubero Pablo, María José; FarmacologíaAntimicrobial Resistance (AMR) is a global threat for human and animal health. Few studies have been carried out on laying hens. The aim of this work was to evaluate the antimicrobial susceptibility of commensal Campylobacter spp., E. coli, and Enterococcus spp. isolates in Spanish laying hens in 2018. Samples were collected from 39 laying hen farms. The microorganisms of interest were isolated and confirmed by PCR. The Minimum Inhibitory Concentration (MIC) to antimicrobials of C and D categories were determined. 195 E. coli, 195 Enterococcus spp. and 25 Campylobacter spp. isolates were obtained. E. coli isolates showed high resistance to D category antimicrobials (sulfamethoxazole 76.41 %, tetracycline 62.05 %, trimethoprim 50.77 %, ampicillin 30.77 %) and lower resistance to C category (azithromycin 30.26 %, gentamicin 12.31 %, chloramphenicol 4.62 %). A 10.26 % of E. coli isolates were susceptible to all antimicrobials tested, Multi Drug Resistance (MDR) to 3 antimicrobial families was found in 23.08 % of the isolates and 13.85 % were MDR to 4 families, being Erythromycin-Sulfamethoxazole-Tetracycline the most common resistance profile (10.77 %). Enterococcus spp. showed very high resistance to D category tetracycline (78.47 %) and C category erythromycin (76.42 %). The 11.79 % of Enterococcus spp. isolates were susceptible to all antimicrobials and 53.33 % were resistant to 2 families, being Erythromycin-Tetracycline the most common AMR profile (51.79 %). Regarding Campylobacter spp., resistance to tetracycline (48 %) was higher than resistance to C category antimicrobials (erythromycin 28 %, streptomycin 24 %, gentamicin 16 %). There was a 52 % sensitivity to all tested antimicrobials and 24 % showed MDR to aminoglycosides, macrolides and tetracyclines (Gentamicin-Streptomycin-Erythromycin-Tetracycline MDR profile). Novel data on AMR in laying hen commensal isolates in Spain was provided. High resistance to several antimicrobials was found, especially to key drugs for the treatment of zoonosis, which represents a public health risk. Better surveillance and careful regulation of antimicrobial use is required in laying hen production.