| Objective:1.To survey the distribution,species composition and seasonal fluctuation of flies at five types of habitats in Zhongshan;compare the trapping efficiency of animal bait and plant bait for diverse fly species.2.To understand the bacterial status of common fly species in Zhongshan,and to compare the differences in the bacteria carried by common flies in different habitats and seasons,and provide scientific evidence for controlling fly and fly-borne diseases.Methods:1.The density surveillance of flies was conducted using trap cages twice per month from October 2017 to October 2018,surveillance site covered 5 different habitat types,including the park,the periphery of the restaurant,the residential area,the hospital and the market.Two trap cages were placed side by side at each monitoring point,using animal bait and plant baitfor trapping respectively,and the captured flies were brought back to lab for statistics and classification.2.Sarcophagidae were selected in the park in Jan,Apr,Jul,Oct2019,respectively.Flies are random samples,and each sample was selected in three each month.Then the bacteria carried by them were collected.The bacterial DNA was extracted by magnetic bead extraction instrument,and the extracted DNA was amplified by PCR.Finally,the PCR products were sent to huada sequencing company for high-throughput sequencing.3.In October 2018,Synthesiomyia nudiseta and Hemipyrellia ligurriens were selected in the above five habitats respectively.Three for each fly in each habitat,as a duplicate sample.The bacteria was collected in vitro and in vitro.Then the bacterial DNA was extracted by magnetic bead extraction instrument,and the extracted DNA was amplified by PCR,and the PCR products were sent to huada sequencing company for high-throughput sequencing.4.Chrysomya megacephala,S.nudiseta,H.ligurriens were selected in the park in Jan,Apr,Jul,Oct2019,respectively.Three for each fly in each month,as a duplicate sample.Then the bacteria carried by them were collected.The bacterial DNA was extracted by magnetic bead extraction instrument,and the extracted DNA was amplified by PCR.Finally,the PCR products were sent to huada sequencing company for high-throughput sequencing.Results:1.Analysis of fly density monitoring results: a total of 6128 flies were captured,classified into 39 species belonging to 23 genera of 5 families,the dominant fly species is C.megacephala,followed by A.rufifacies and H.ligurriens,respectively accounting for 51.30%,20.01% and 9.92%.In the five types of habitats,the highest population diversity appeared in the park and the lowest in the market.The seasonal fluctuation of the density of flies showed a three-peak curve,the highest peak,the second peak and the smallest peak appeared in late May,early March and early September respectively.The number and species of flies in animal bait are all more than that in plant bait.2.Analysis of the bacteria carried by sarcophagidae based on next-generation sequencing: a total of 405162 high quality reads were obtained,and the number of OTUs was 331,which were classified into 8 phylums,19 classes,36 orders,76 families,126 genera,and 79 species.Among the 79 species,5 pathogenic bacteria and 13 opportunistic pathogens were included.After grouping the samples by quarter,it was found that the species composition and diversity of sarcophagidae were different in different quarters,and the species of bacteria carried by sarcophagidae were abundant in the second and third quarters.3.Analysis of the bacteria carried by S.nudiseta and H.ligurriens in different habitats and in vivo and in vitro based on next-generation sequencing: a total of 1195082 high quality reads were obtained,and the number of OTUs was 551,which were classified into 16 phylums,34 classes,55 orders,92 families,193 genera,and 106 species.Among the 106 species,10 pathogenic bacteria and 13 opportunistic pathogens were included.After grouping the samples by habitat,it was found that bacteria carried by flies were more abundant in the residential area,followed by the park,and the hospital was the least.After grouping the samples by in vitro and in vivo,it was found that bacteria in vitro were more abundant than in vivo.4.Analysis of the bacteria carried by C.megacephala,S.nudisetaand H.ligurriens in different quarter based on next-generation sequencing: a total of 1934999 high quality reads were obtained,and the number of OTUs was 881,which were classified into 19 phylums,35 classes,55 orders,114 families,217 genera,and 135 species.Among the 135 species,8 pathogenic bacteria and 14 opportunistic pathogens were included.After grouping the samples by quarter,it is found that the species of bacteria in the second and third quarters are rich.After grouping the samples by fly species,the species of bacteria carried by S.nudiseta was the most,followed by H.ligurriens,and C.megacephala were the least.Conclusion:1.The dominant species of flies in Zhongshan are C.megacephala,A.rufifacies and H.ligurriens.Parks are important areas that should be surveilled.The trapping effect of animal bait is obviously better than that of plant bait,and it is a suitable bait for routine monitoring of flies.2.The analysis of bacteria carried by flies based on next-generation sequencing technology shows that the species and quantity of carried by flies are very rich,and they can carry a variety of pathogenic bacteria or opportunistic pathogens.Therefore,the prevention and control of flies should be strengthened to prevent the occurrence of fly-borne diseases.3.According to the analysis of different groups of flies,it is found that the bacteria carried by flies have differences in different fly species,different habitats,different quarters,and in vivo and in vitro. |
PDF Full Text Request