Occurrence And Source Of Antibiotic Resistance Genes In Arctic And Antarctic

The emergence and spread of antibiotic resistance is seriously threatening global public health and economic development,and the globalization of antibiotic resistance pollution has begun to appear.Studies have found that clinically,antibiotic resistance will further migrate,transform and spread among environmental flora,eventually leading to environmental microorganisms becoming a natural repository of various antibiotic resistance genes?ARGs?.ARGs in the environment have a unique"relay"process of replication and transmission of genetic pollutants.At the same time,they can migrate and spread to remote areas using the air,ocean currents,birds,and other animal migration as carriers for traditional chemical pollutants.However,the main sources of ARGs in the polar environment and the global transmission mechanism have not been reported.Compared with other regions,the polar region is one of the regions with the most significant and sensitive responses to global climate and environmental changes,and has a special environment and less interference from human activities.Therefore,it is an ideal region for tracking the environmental ecological behavior and geochemical processes of ARGs.This article studies the occurrence levels,distribution characteristics,and sources of ARGs in polar environments in order to clarify the transmission process of ARGs under the influence of global climate change.By detecting the occurrence of sulfonamide and quinolone resistance genes in the Fildes Peninsula in Antarctica,it was found that antibiotic resistance contamination was prevalent in the multi-environment media in the Fildes Peninsula in Antarctica,sulfonamine-resistance genes were generally detected,and the detection rate of sul1 in each medium was up to 100%.The absolute abundance of sulfonamine and quinolone resistance genes in soil was 8.91×10¹?1.58×10³ copies/g,the absolute abundance of ARGs in sediments was 1.03×10²?7.95×10² copies/g,and the absolute abundance of ARGs in animal feces was 5.45×10²?1.81×10³ copies/g.This study also analyzed the relationship between relative abundance of int I1 and sulfonamide resistance gene sul1,and found that the relative abundance of sulfonamide resistance gene had a positive correlation with int I1.The abundance of ARGs in the Fildes Peninsula is much lower than that in the lower latitudes than in the regions frequently affected by human activity.Based on a survey of the Yellow River Station in 2018,soil samples,soilsediments,and animal dung such as Barnacle Geese,and Svalbard reindeer samples were collected and analyzed for the abundance levels of ARGs.A total of 172 genes?including 162 ARGs,7 transposase genes,2 type 1 integron genes and 16S r RNA genes?were detected,indicating that ARGs were widely found in the Ny-Alesund region.The three main types in the samples were multidrug resistance,?-lactam and MLSB resistance genes.The total abundance of all ARGs was 3.45×10²?5.29×10⁶ copies/g in soil,2.77×10²?4.63×10⁶ copies/g in sediments,2.57×10²?6.93×10⁶ copies/g in deer dung and 1.72×10²?3.15×10⁷ copies/g in bird fece.Efflux pump and inactivation of antibiotics are the most important mechanisms of ARGs,followed by cell protective mechanisms.Aac C4,amp C-06,bac A-02,bla _ROB,cml A1-02,mtr D-03,van HB and yid Y/mdt L-02 were strongly correlated with transposons,int I1 and MGEs,suggesting that these genes may be acquired resistance genes.The co-occurrence of MGEs and ARGs was analyzed by network analysis,and it was found that acr A,yce E/mdt G,yid Y/mdt L-02 and bla _PAO were the central genes of the four modules,which could be used as indicators for the co-occurrence of ARGs among the modules.Tracing to the source of ARGs,it was found that ARGs in the Ny-Alesund may be the result of a combination of human activities,animal migration and atmospheric circulation.