Tetracycline-resistant bacteria and ribosomal protection protein genes in soils from selected agricultural fields and livestock farms

Abstract

Antibiotic resistance in soil environment has eminently been compared and studied between agricultural and pristine soils, and the role of concentrated animal feeding operations has markedly been recognized as one of the major sources of antibiotic resistance. This study described the tetracycline resistance in small-scale farms in pursuit of presenting its possible role and contribution to the persistence of antibiotic resistance in the environment. Results of the study would render additional information on the occurrence of the ribosomal protection protein (RPP) tet genes among the isolated bacteria from the selected agricultural soils. Four tetracycline resistance and RPP genes were determined in two different agricultural soil settings. Both the culture and molecular method were used to determine and measure tetracycline resistance in soils from arable land and animal house. Results revealed a significantly higher number of culturable antibiotic-resistant bacteria in animal houses than arable lands which was suggestive of higher antibiotic resistance in areas where there was direct administration of the antibiotics. However, quantification of the gene copy numbers in the agricultural soils indicated a different result. Higher gene copy number of tetO was determined in one animal house (IAH-3), while the two other tet genes tetQ and tetW were found to be higher in arable lands. Of the total 110 bacterial isolates, tetW gene was frequently detected, while tetO gene was absent in any of the culturable bacterial isolates. Principal component analysis of occurrence and gene copy number of RPP tet genes tetO, tetQ, and tetW also revealed highest abundance of RPP tet genes in the manure and arable soils. Another important highlight of this study was the similarity of the RPP tet genes detected in the isolated bacteria from the agricultural soils to the identified RPP tet genes among pathogenic bacteria. Some of the tetracycline-resistant bacterial isolates were also multidrug resistant as it displayed resistance to tetracycline, erythromycin, and streptomycin using disk diffusion testing.

Short-Term Impact of Oxytetracycline Administration on the Fecal Microbiome, Resistome and Virulome of Grazing Cattle

“…The most prevalent RPP genes found in this study (tetO, tetQ and tetW) are potentially transferred between bacteria as they are associated with mobile genetic elements such as plasmids, conjugative transposons, and integrons [ 45 , 47 ]. Quantification of the burden, mechanisms of resistance, and localization in bacterial genomes of tet genes in farm animals can be used as a baseline to evaluate the variation of the AMR level over time and to establish associations of the use of antibiotics in animal production systems and spread of AMR [ 48 , 49 ].…”

“…Knowledge about co-resistance can contribute to target intervention strategies to reduce unintended enrichment and the spread of emerging genes conferring resistance to critically important antibiotic agents. It is also essential to determine which critical ARGs should be including for monitoring during surveillance [ 49 , 59 ].…”

Bacterias cultivables resistentes a oxitetraciclina durante el proceso de vermicompostaje de excretas bovinas

“…Utilizamos 10µg/ml de oxitetraciclina para seleccionar bacterias resistentes ambientales. Esta concentración es superior a la concentración mínima inhibitoria (CMI) para bacterias susceptibles, pero menor a la CMI para bacterias resistentes patógenas humanas, considerando que los microorganismos de origen ambiental están expuestos a concentraciones mucho menores que bacterias de origen clínico y que también generan resistencia en el entorno natural (Popowska et al, 2012;Sandegren, 2014;Nogrado et al, 2021).…”

The host-specific resistome in environmental feces of Eurasian otters (Lutra lutra) and leopard cats (Prionailurus bengalensis) revealed by metagenomic sequencing

“…5 b). The tetW gene, first identified in rumen bacteria isolated from bovine and sheep [ 45 ], has a wide host range and spreads widely in environments, e.g., animal farms [ 46 ]. One hypothesis why tetW was abundant in the feces of leopard cats may be due to dietary differences from Eurasian otters.…”