Colistin Selection of the Mcr-1 Gene in Broiler Chicken Intestinal Microbiota

Colistin has a long story of safe use in animals for the treatment and prevention of certain bacterial diseases. Nevertheless, the first description of the mcr-1 gene showed that colistin resistance can spread by horizontal gene transfer and changed the landscape. This study aimed to assess the effect of colistin administration on the dispersion of resistance in the microbiota of day-old broiler chicks and how the presence of mcr-1 genes influences the spread of colistin resistance determinants. In this study, 100 one-day-old chicks were divided into four groups of 25 animals (G1, G2, G3, and G4). Animals from G3/G4 were challenged with mcr-1-carrying Salmonella (day 7), while colistin (600 mg/L) was administered daily to G2/G4 animals through drinking water (from day 8 to day 15). Two quantitative PCR assays were performed to compare the amount of Salmonella and mcr-1 that were present in the caecal samples. We observed that levels of mcr-1 were higher in G3/G4 animals, especially G4, due to the spread of mcr-1-carrying Salmonella. On day 21, Salmonella levels decreased in G4, reaching similar values as those for G3, but mcr-1 levels remained significantly higher, suggesting that colistin may accelerate the spreading process when mcr-1-carrying bacteria reach the gut

Co-occurrence of colistin-resistance genes mcr-1 and mcr-3 among multidrug-resistant Escherichia coli isolated from cattle, Spain, September 2015

Los genes de resistencia a colistina mcr-3 y mcr-1 se detectaron en un aislado de Escherichia coli de heces de ganado en un matadero español en 2015. Las secuencias de ambos genes se hibridaron a la misma banda de plásmidos de aproximadamente 250 kb, aunque la resistencia a la colistina no fue movilizable . El aislado producía betalactamasas de espectro extendido y pertenecía al serotipo O9: H10 y al tipo de secuencia ST533. Aquí informamos un gen mcr-3 detectado en Europa después de informes anteriores de Asia y los Estados Unidos.Colistin resistance genes mcr-3 and mcr-1 have been detected in an Escherichia coli isolate from cattle faeces in a Spanish slaughterhouse in 2015. The sequences of both genes hybridised to same plasmid band of ca 250 kb, although colistin resistance was non-mobilisable. The isolate was producing extended-spectrum beta-lactamases and belonged to serotype O9:H10 and sequence type ST533. Here we report an mcr-3 gene detected in Europe following earlier reports from Asia and the United States.• Ministerio de Economía, Industria y Competitividad. Proyecto AGL2016- 74882-C3 • Ministerio de Agricultura y Pesca (España) y Comunidad Autónoma de Comunidad Autónoma de Madrid. Ayuda S2013 / ABI-2747 • Junta de Extremadura y Fondo Europeo de Desarrollo Regional. Ayuda GR15075 e IB16073 • Fundación para la Ciencia y la Tecnología (Portugal). Ayudas UID / MAR / 04292/2013 • Fundación Tatiana de Guzmán El Bueno (España). Beca doctoral para María del Rocío Iglesias Parro • Instituto Nacional de Agricultura y Alimentación. Investigación y Tecnología (INIA). Beca doctoral para María del Rocío Iglesias Parro • Ministerio de Economía, Industria y Competitividad. Beca FPI2014-020, para Narciso Martín QuijadapeerReviewe

Identification and characterization of colistin resistant bacteria from food-producing animals in Spain. Assessment of its persistence and possible dissemination

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Veterinaria, leída el 02/10/2023La colistina es un polipéptido catiónico en desuso como antibiótico desde la década de los setenta debido a su toxicidad, pero que fue reintroducido en medicina humana para tratar infecciones causadas por bacterias Gram negativas multirresistentes, siendo categorizado como antimicrobiano de "último recurso". En medicina veterinaria la colistina se ha utilizado desde su descubrimiento para el tratamiento de infecciones en animales, especialmente las diarreas post-destete causada por E. coli en lechones y terneros o para el tratamiento de colibacilosis en aves.Inicialmente, la resistencia a colistina parecía estar ligada exclusivamente a mutaciones en los genes de sistemas de doble componente pmrA/B y phoP/Q, localizados en el cromosoma bacteriano. Sin embargo, en 2015 se describió por primera vez un gen de resistencia a colistina que se denominó mcr-1 y que estaba localizado en un plásmido. Dado que la colistina era una de las pocas alternativas disponibles para el tratamiento de infecciones por bacterias Gram negativas multirresistentes y que la dispersión de este gen plasmídico podría aumentar exponencialmente debido a fenómenos de transferencia horizontal, la Agencia Europea del Medicamento (European Medicines Agency, EMA) recomendó en 2016 reducir el uso de colistina en animales...Colistin is a cationic polypeptide whose use as antibiotic was withdrawn since the 1970s because of its toxicity, but was reintroduced later in human medicine to treat infections caused by multi-resistant Gram-negative bacteria, being categorised as a "last resort antimicrobial". Colistin has been used in veterinary medicine since its discovery for the treatment of infections in animals, especially post-weaning diarrhoea caused by E. coli in piglets and calves and colibacillosis in poultry.Traditionally, colistin was linked exclusively to chromosome mutations in the two-component systems genes pmrA/B and phoP/Q. However, in 2015, a colistin resistance gene, called mcr-1, was described for the first time on a plasmid. Since colistin was one of the few alternatives available for the treatment of multidrug-resistant Gram negative bacteria infections and the spread of this plasmid gene could increase exponentially due to horizontal transfer, the European Medicines Agency (EMA) recommended in 2016 a reduction in the use of colistin in animals...Fac. de VeterinariaTRUEunpu

Carbapenemase-Producing Elizabethkingia Meningoseptica from Healthy Pigs Associated with Colistin Use in Spain

Carbapenems are considered last-resort antimicrobials, especially for treating infections involving multidrug-resistant Gram-negative bacteria. In recent years, extended-spectrum β-lactamase (ESBL) and carbapenemase-producing Gram-negative bacteria have become widespread in hospitals, community settings, and the environment, reducing the range of effective therapeutic alternatives. The use of colistin to treat infection caused by these multi-drug bacteria may favour the selection and persistence of carbapenem-resistant bacteria. In this study, it is described, for the first time to our knowledge, a carbapenemase-producing isolate of Elizabethkingia meningoseptica from healthy pigs in Spain. The isolate we report was recovered during a study to detect colistin-resistant bacteria from faecal samples of healthy food-production animals using a chromogenic selective medium. Unexpectedly, we found an isolate of Elizabethkingia meningoseptica with high Minimum Inhibitory Concentration (MIC) values for several antibiotics tested. Molecular analysis did not show any mcr family genes related with colistin resistance, but two carbapenemase genes, blaB-12_1 and blaGOB-17_1, were detected. This finding in healthy animals could suggest that colistin may favour the selection and persistence of carbapenem-resistant bacteria

Reduction of Salmonella Typhimurium Cecal Colonisation and Improvement of Intestinal Health in Broilers Supplemented with Fermented Defatted ‘Alperujo’, an Olive Oil By-Product

Salmonella spp. contaminates egg and poultry meat leading to foodborne infections in humans. The emergence of antimicrobial-resistant strains has limited the use of antimicrobials. We aimed to determine the effects of the food supplement, fermented defatted ‘alperujo’ (FDA), a modified olive oil by-product, on Salmonella Typhimurium colonisation in broilers. One hundred and twenty 1-day-old broilers were divided into four experimental groups—two control groups and two treated groups, and challenged with S. Typhimurium at day 7 or 21. On days 7, 14, 21, 28, 35, and 42 of life, duodenum and cecum tissue samples were collected for histopathological and histomorphometric studies. Additionally, cecum content was collected for Salmonella spp. detection by culture and qPCR, and for metagenomic analysis. Our results showed a significant reduction of Salmonella spp. in the cecum of 42-day-old broilers, suggesting that fermented defatted ‘alperujo’ limits Salmonella Typhimurium colonization in that cecum and may contribute to diminishing the risk of carcass contamination at the time of slaughter. The improvement of the mucosal integrity, observed histologically and morphometrically, may contribute to enhancing intestinal health and to limiting Salmonella spp. colonisation in the host, mitigating production losses. These results could provide evidence that FDA would contribute to prophylactic and therapeutic measures to reduce salmonellosis prevalence in poultry farms