Browsing by Author "Millan, Javier"

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    ESBL-Producing Escherichia coli Carrying CTX-M Genes Circulating among Livestock, Dogs, and Wild Mammals in Small-Scale Farms of Central Chile
    (2021) Benavides, Julio A.; Salgado-Caxito, Marilia; Opazo-Capurro, Andres; Gonzalez Munoz, Paulina; Pineiro, Ana; Otto Medina, Macarena; Rivas, Lina; Munita, Jose; Millan, Javier
    Antibiotic-resistant bacteria of critical importance for global health such as extended-spectrum beta-lactamases-producing (ESBL)-Escherichia coli have been detected in livestock, dogs, and wildlife worldwide. However, the dynamics of ESBL-E. coli between these animals remains poorly understood, particularly in small-scale farms of low and middle-income countries where contact between species can be frequent. We compared the prevalence of fecal carriage of ESBL-E. coli among 332 livestock (207 cows, 15 pigs, 60 horses, 40 sheep, 6 goats, 4 chickens), 82 dogs, and wildlife including 131 European rabbits, 30 rodents, and 12 Andean foxes sharing territory in peri-urban localities of central Chile. The prevalence was lower in livestock (3.0%) and wildlife (0.5%) compared to dogs (24%). Among 47 ESBL-E. coli isolates recovered, CTX-M-group 1 was the main ESBL genotype identified, followed by CTX-M-groups 2, 9, 8, and 25. ERIC-PCR showed no cluster of E. coli clones by either host species nor locality. To our knowledge, this is the first report of ESBL-E. coli among sheep, cattle, dogs, and rodents of Chile, confirming their fecal carriage among domestic and wild animals in small-scale farms. The high prevalence of ESBL-E. coli in dogs encourages further investigation on their role as potential reservoirs of this bacteria in agricultural settings.
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    Multiple clonal transmissions of clinically relevant extended-spectrum beta-lactamase-producing Escherichia coli among livestock, dogs, and wildlife in Chile
    (2023) Hayer, Juliette; Salgado-Caxito, Marilia; Opazo-Capurro, Andres; Munoz, Paulina Gonzalez; Millan, Javier; Pineiro, Ana; Munita, Jose M.; Rivas, Lina; Benavides, Julio A.
    Objectives: Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E. coli) are a main cause of human deaths associated with antimicrobial resistance (AMR). Despite hundreds of reports of the faecal carriage of ESBL-E. coli in domestic and wild animals, the dynamics of its circulation remains poorly understood.
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    SEROSURVEY FOR SELECTED PARASITIC AND BACTERIAL PATHOGENS IN DARWIN'S FOX (LYCALOPEX FULVIPES): NOT ONLY DOG DISEASES ARE A THREAT
    (2022) Hidalgo-Hermoso, Ezequiel; Cabello, Javier; Verasay, Juan; Moreira-Arce, Dario; Hidalgo, Marcos; Abalos, Pedro; Borie, Consuelo; Galarce, Nicolas; Napolitano, Constanza; Sacristan, Irene; Cevidanes, Aitor; Ramirez-Toloza, Galia; Farias, Ariel; Di Cataldo, Sophia; Lagos, Rocio; Millan, Javier
    The Darwin's fox (Lycalopex fulvipes) is one of the most endangered carnivores worldwide, with the risk of disease spillover from domestic dogs being a major conservation threat. However, lack of epidemiologic information about generalist, non-dog-transmission-dependent protozoal and bacterial pathogens may be a barrier for disease prevention and management. To determine the exposure of some of these agents in Darwin's fox populations, 54 serum samples were collected from 47 Darwin's foxes in Southern Chile during 2013-18 and assessed for the presence of antibodies against Brucella abortus, Brucella canis, Coxiella burnetii, pathogenic Leptospira (serovars Grippotyphosa, Pomona, Canicola, Hardjo, and Copehageni), Toxoplasma gondii, and Neospora caninum. The highest seroprevalence was detected for T. gondii (78%), followed by pathogenic Leptospira (14%). All the studied Leptospira serovars were confirmed in at least one animal. Two foxes seroconverted to Leptospira and one to T. gondii during the study period. No seroconversions were observed for the other pathogens. No risk factors, either intrinsic (sex, age) or extrinsic (season, year, and degree of landscape anthropization), were associated with the probability of being exposed to T. gondii. Our results indicate that T. gondii exposure is widespread in the Darwin's fox population, including in areas with minimal anthropization, and that T. gondii and pathogenic Leptospira might be neglected threats to the species. Further studies identifying the causes of morbidity and mortality in Darwin's fox are needed to determine if these or other pathogens are having individual or population-wide effects in this species.
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    Species delimitation and intraspecific diversification in recently diverged South American foxes
    (2024) Pizarro, Eduardo J.; Julio-Kalajzic, Bernardita; Sallaberry-Pincheira, Nicole; Munoz, Valentina; Gonzalez-Acuna, Daniel; Cabello, Javier; Acosta-Jamett, Gerardo; Bonacic, Cristian; Iriarte, Agustin; Rodriguez, Alejandro; Travaini, Alejandro; Cevidanes, Aitor; Brito, Jose Luis; Millan, Javier; Marin, Juan Carlos; Vianna, Juliana A.
    The divergence between the Andean fox (Lycalopex culpaeus) and the South American gray fox (L. griseus) represents a recent speciation event in South America. These taxa are partially sympatric and share biological, morphological, and ecological traits. Previous studies failed to recover reciprocal monophyly, suggesting the occurrence of introgression or incomplete lineage sorting (ILS). Here, we obtained mitochondrial and nuclear markers for 140 L. culpaeus and 134 L. griseus from the Southern Cone of South America to assess their inter and intraspecific divergence. We recovered reciprocal monophyly of L. culpaeus and L. griseus, with mild signatures of introgression or ILS. Therefore, taxonomic misidentification and the use of a limited number of markers may be the main reason behind the past debate about the delimitation of both species. Two main divergent clades were found in L. culpaeus with a phylogeographical boundary in the High Plateau of northeastern Chile. The southern clade along with three northern sub-clades corresponded to four morphological subspecies. Less genetic differentiation was found in L. griseus with a spatial population structure that does not support the occurrence of distinct subspecies. The results found in this study suggest the extant evolutionary significant units that need to be considered for biological conservation management of these species.
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    Widespread Infection with Hemotropic Mycoplasmas in Free-Ranging Dogs and Wild Foxes Across Six Bioclimatic Regions of Chile
    (MDPI, 2021) Di Cataldo, Sophia; Cevidanes, Aitor; Ulloa Contreras, Claudia; Sacristan, Irene; Penaloza Madrid, Diego; Vianna, Juliana; Gonzalez Acuna, Daniel; Sallaberry Pincheira, Nicole; Cabello, Javier; Napolitano, Constanza; Hidalgo Hermoso, Ezequiel; Acosta Jamett, Gerardo; Millan, Javier
    Blood samples of 626 rural dogs, 140 Andean foxes (Lycalopex culpaeus), and 83 South American grey foxes (L. griseus) from six bioregions of Chile spanning 3000 km were screened for Mycoplasma DNA by conventional PCR and sequencing. Risk factors of infection were inferred using Generalized Linear Mixed Models and genetic structure by network analyses. Overall, Mycoplasma haemocanis/Mycoplasma haemofelis (Mhc/Mhf) and Candidatus Mycoplasma haematoparvum (CMhp) observed prevalence was 23.8% and 12.8% in dogs, 20.1% and 7.2% in Andean foxes, and 26.5% and 8.4% in grey foxes, respectively. Both hemoplasmas were confirmed in all the bioregions, with higher prevalence in those where ticks from the Rhipicephalus sanguineus species group were absent. Candidatus M. haematominutum and a Mycoplasma sp. previously found in South American carnivores were detected in one fox each. Although the most prevalent Mhc/Mhf and CMhp sequence types were shared between dogs and foxes, network analysis revealed genetic structure of Mhc/Mhf between hosts in some regions. Male sex was associated with a higher risk of Mhc/Mhf and CMhp infection in dogs, and adult age with CMhp infection, suggesting that direct transmission is relevant. No risk factor was identified in foxes. Our study provides novel information about canine hemoplasmas with relevance in distribution, transmission routes, and cross-species transmission.