ABSTRACT
Apex predators are exposed to antimicrobial compounds and resistant microbes, which accumulate at different trophic levels of the related ecosystems. The study aimed to characterize the presence and the antimicrobial resistance patterns of fecal Escherichia coli isolated from cloacal swab samples obtained from wild-living American crocodiles (Crocodylus acutus) (n = 53). Sampling was conducted within the distinctive context of a freshwater-intensive aquaculture farm in Costa Rica, where incoming crocodiles are temporarily held in captivity before release. Phenotypic antimicrobial susceptibility profiles were determined in all isolates, while resistant isolates were subjected to whole-genome sequencing and bioinformatics analyses. In total, 24 samples contained tetracycline-resistant E. coli (45.3%). Isolates carried either tet(A), tet(B), or tet(C) genes. Furthermore, genes conferring resistance to ß-lactams, aminoglycosides, fosfomycin, sulfonamides, phenicol, quinolones, trimethoprim, and colistin were detected in single isolates, with seven of them carrying these genes on plasmids. Genome sequencing further revealed that sequence types, prevalence of antibiotic resistance carriage, and antibiotic resistance profiles differed between the individuals liberated within the next 24 h after their capture in the ponds and those liberated from enclosures after longer abodes. The overall presence of tetracycline-resistant E. coli, coupled with potential interactions with various anthropogenic factors before arriving at the facilities, hinders clear conclusions on the sources of antimicrobial resistance for the studied individuals. These aspects hold significant implications for both the aquaculture farm's biosecurity and the planning of environmental monitoring programs using such specimens. Considering human-crocodile conflicts from the One Health perspective, the occurrence of antimicrobial resistance underscores the importance of systematical surveillance of antibiotic resistance development in American crocodiles.
ABSTRACT
Recientes investigaciones han relacionado la microbiota intestinal con la salud humana en múltiples aspectos. La evolución de los estilos de vida ha determinado un cambio en la composición de las bacterias intestinales, así como la implicación que la comunidad de estas ejerce sobre la salud. Actualmente, se conoce que la mayoría de las bacterias presentes en el sistema gastrointestinal pertenecen principalmente a los fila Firmicutes y Bacterioidetes, aunque también se encuentran otros grupos tales como proteobacterias y actinobacterias. A medida que se avanza en el tracto gastrointestinal predominan algunos géneros de bacterias. Los efectos de la microbiota pueden ser directos e indirectos, además, dependen de muchos factores tales como la edad de la persona, el grupo etario, la genética del individuo, la dieta y el estilo de vida. Durante los últimos años, la accesibilidad a tecnologías de secuenciación ha permitido tener un acercamiento más estrecho a la microbiota intestinal. Esto, sumado a herramientas bioinformáticas, ha permitido establecer relaciones microbiales entre la cantidad y estructura poblacional y las manifestaciones clínicas en el ser humano. Algunas de las afecciones estudiadas y que tienen relación con la microbiota intestinal son: la obesidad, la diabetes, el cáncer, las enfermedades relacionadas con el cerebro, las enfermedades cardiovasculares y las enfermedades gastrointestinales. De acuerdo con lo mencionado, se hizo una recopilación de información de carácter científico en cuanto a estudios relevantes que describen la relación microbiota-salud humana y casos donde se observa compromiso del organismo, al mismo tiempo que se describen opciones terapéuticas propuestas y un abordaje de perspectivas futuras.
Recent research has linked gut microbiota to human health in multiple ways. The evolution of lifestyles has determined a change in the composition of intestinal bacteria, as well as the implications that they exert on health. Currently, it is known that most of the bacteria present in the gastrointestinal sector belong mainly to the phylum Firmicutes and Bacterioidetes, although there are also other groups such as proteobacteria and actinobacteria. As it progresses through the gastrointestinal tract, some genera of bacteria and species predominate. The effects of the microbiota can be direct and indirect, and also depend on many factors such as the age of the person, the age group, the individual's genetics, diet, and lifestyle. In recent years, accessibility to sequencing technologies has allowed for a closer approach to the intestinal microbiota. This, added to bioinformatic tools has allowed establishing microbial relationships in terms of quantity and population structure with clinical manifestations in humans. Some of the pathologies studied that are related to intestinal microbiota are obesity, diabetes, cancer, brain-related diseases, cardiovascular diseases, and gastrointestinal diseases. A compilation of scientific information is made regarding relevant studies that describe the microbiota-human health relationship, cases where the organism is affected, as well as proposed therapeutic options and an approach to future perspectives