RESUMEN
Background. Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) has been linked to outbreaks of foodborne gastroenteritis disease, and the emergence of antimicrobial-resistant clones. In Colombia, laboratory surveillance of Salmonella spp. between 1997-2018 revealed that S. Typhimurium was the most ubiquitous serovar (27.6â% of all Salmonella isolates), with increasing levels of resistance to several families of antibiotics.Hypothesis. Resistant isolates of S. Typhimurium recovered from human clinical, food and swine samples carry class 1 integrons that are linked to antimicrobial resistance genes.Aim. Identify class 1 integrons, and investigate their association with other mobile genetic elements, and their relationship to the antimicrobial resistance of Colombian S. Typhimurium isolates.Methods. In this study, 442 isolates of S. Typhimurium were analysed, of which 237 were obtained from blood culture, 151 from other clinical sources, 4 from non-clinical sources and 50 from swine samples. Class 1 integrons and plasmid incompatibility groups were analysed by PCR and whole-genome sequencing (WGS), and regions flanking integrons were identified by WGS. The phylogenetic relationship was established by multilocus sequence typing (MLST) and single-nucleotide polymorphism (SNP) distances for 30 clinical isolates.Results . Overall, 39â% (153/392) of the human clinical isolates and 22â% (11/50) of the swine S. Typhimurium isolates carried complete class 1 integrons. Twelve types of gene cassette arrays were identified, including dfr7-aac-bla OXA-2 (Int1-Col1), which was the most common one in human clinical isolates (75.2â%, 115/153). Human clinical and swine isolates that carried class 1 integrons were resistant to up to five and up to three antimicrobial families, respectively. The Int1-Col1 integron was most prevalent in stool isolates and was associated with Tn21. The most common plasmid incompatibility group was IncA/C.Conclusions. The widespread presence of the IntI1-Col1 integron in Colombia since 1997 was striking. A possible relationship between integrons, source and mobile elements that favour the spread of antimicrobial resistance determinants in Colombian S. Typhimurium was identified.
Asunto(s)
Salmonelosis Animal , Salmonella enterica , Porcinos , Animales , Humanos , Salmonella typhimurium/genética , Integrones/genética , Colombia/epidemiología , Tipificación de Secuencias Multilocus , Filogenia , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Pruebas de Sensibilidad Microbiana , Salmonella enterica/genéticaRESUMEN
En Colombia, el cáncer colorectal es reconocido como un importante problema de salud pública, con una tendencia general al incremento en ambos géneros; se ubica entre los cinco primeros lugares en relación con la mortalidad. Teniendo en cuenta los diagnósticos histopatológicos reunidos entre enero de 2000 y diciembre de 2007, se realizó un análisis descriptivo retrospectivo en 191 pacientes tolimenses con tumores colorrectales tipo adenocarcinoma; estos fueron seleccionados en cinco centros de patología de la ciudad de Ibagué, mediante pruebas descriptivas básicas empleando el método porcentual. Los datos más sobresalientes corresponden a la edad al momento del diagnóstico (promedio mayor de 60 años), localización en el recto (34,6%) y en el colon izquierdo (28,3%) y aumento de los adenomas tubulovelloso y velloso.
In Colombia, colorectal cancer is recognized as a major public health problem. Its general tendency is occur more frequently among both genders. It now ranks among the top five in terms of mortality. Using histopathological diagnoses collected from pathology laboratories in Ibagué, Tolima between January 2000 and December 2007, we conducted a retrospective analysis of 191 patients who had colorectal adenocarcinoma. The most important findings are that the average age of diagnosis was over 60 years, most common tumor locations were in the rectum (34.6%) and in the left colon (283%), and the greatest numbers of tumors were tubulovillous adenoma, or villous adenoma. Most of cases were tubular.