广西凡纳滨对虾源副溶血弧菌耐药性和耐药基因的检测

Detection of Antibiotics Resistance and Resistance Genes in Vibrio parahaemolyticus from Litopenaeus vannamei of Guangxi

【目的】检测广西沿海地区凡纳滨对虾源副溶血弧菌的耐药性及部分相关耐药基因的携带状况,为凡纳滨对虾疾病防控以及副溶血弧菌耐药机制的深入研究提供基础数据。【方法】采用K-B纸片扩散法检测30株分离自广西钦州市、防城港市和北海市的副溶血弧菌对12种常见抗生素的耐药性,以PCR方法检测氨基糖苷类耐药基因ant(3")-I、磺胺类耐药基因Sul1、四环素类耐药基因tet(A)和β-内酰胺类耐药基因TEM在副溶血弧菌中的携带状况,通过SPSS软件进行菌株耐药表型和耐药基因的相关性分析。【结果】30株副溶血弧菌对试验药物的敏感率以氟苯尼考最高(96. 7%),其次是链霉素(90. 0%);耐药率以磺胺二甲嘧啶和青霉素G最高(均为96. 7%)。优势耐药谱型是SDM/SMD/PG/AMP和SMD/PG/AMP。PCR检测结果,ant(3")-I、Sul1、tet(A)、TEM基因的检出率分别为6. 7%、43. 3%、0. 0%和13. 3%。受试菌株共包含ant(3")-I-Sul1+tet(A)-TEM-、ant(3")-I-Sul1-tet(A)-TEM-、ant(3")-I-Sul1-tet(A)-TEM+、ant(3")-I+Sul1-tet(A)-TEM-和ant(3")-I-Sul1+tet(A)-TEM+5种耐药基因型,其中优势耐药基因型是ant(3")-I-Sul1+tet(A)-TEM-和ant(3")-I-Sul1-tet(A)-TEM-,各占40. 0%。相关性分析结果,氨基糖苷类、磺胺类、四环素类、β-内酰胺类抗生素耐药表型与对应耐药基因之间均未发现存在显著相关性。【结论】30株广西沿海凡纳滨对虾源副溶血弧菌对氟苯尼考最敏感,对磺胺二甲嘧啶和青霉素G耐药性最强;受试菌株共包含5种耐药基因型,优势耐药基因型是ant(3")-I-Sul1+tet(A)-TEM-和ant(3")-I-Sul1-tet(A)-TEM-。菌株的4类抗生素耐药基因与耐药表型之间均未发现存在显著相关性。

[ Objective ] In order to provide basic data for disease control of L. vannamei and for further researching the antibiot- ics resistance mechanism of K parahaemolyticus, the antibiot- ics resistance and file carying status of related resistance genes were detected in Vibrio parahaemolyticus isolated fi＇om Litope- naeus vannamei in coastal areas of Guangxi. [ Method ] The re-sistances of 30 strains of K parahaemolyticus isolated from Qinzhou, Fangchenggang and Beihai cities of Guangxi, against 12 conunon anti- biotics were determined by K-B disc diffusion test. The carrying statuses of ant（3＂）-1 （aminoglycoside resistance gene）, Sull （sulfanila- mide resistance gene）, tet（A） （tetracycline resistance gene） and TEM （^-lactam gene） in V. parahaemolyticus were detected by PCR method. Correlation between the antibiotics resistances of strains and the related resistance genes was analyzed by the software SPSS. [ Resuit] For the sensitivity rates of the tested antibiotics in the 30 strains of V. parahaemolyticus, florfenicol was the most sensitive antibiotic （96.7 % ）, streptomycin was the second （90.0 % ）. Sulfadimidine and penicillin G were the most resistant antibiotics and the resistant rates were both 96.7 %. The dominant antibiotic resistance phenotypes were SDM/SMD/PG/AMP and SMD/PG/AMP. PCR results showed that the detection rates of gene ant（3＂）-1, Sull, tet（A） and TEM are 6.7 %, 43.3 %, 0.0 % and 13.3 %, respectively. In the tested strains, there were 5 antibiotic resistance genotypes containing ant（ 3 ＂ ）-I Sull ＋ tet（ A ） TEM , ant（ 3 ＂ ）-I Sull tet（ A ） TEM , ant （3＂）-1 Sull tet（A） TEM＋, ant（3＂）-I＋ Sull tet（A） TEM and ant（3＂）-I Sull＋ tet（A） TEM＋, among which ant（3＂）-I Sull ＋ tet（A） TEM and ant（3＂）-I Sull tet（A） TEM are the dominant genotypes, each accounting for 40.0 %. Correlation analysis results showed that no significant correlation is detected between the resistance phenotype of aminoglycoside, sulfanilamide, tetracycline and β-1actam, with the relevant resistance genes, respectively. [ Conclusion ] For the 30 strains of V. parahaemolyticus isolated from L. van- namei, florfenicol was the most sensitive antibiotic, whereas sulfadimidine and penicillin G were the most resistant ones. There were 5 anti- biotic resistance genotypes and the dominant genotypes were ant （3 ＂ ） -1 Sull ＋ tet （ A ） TEM and ant （3 ＂ ） -1 Sull tet （ A ） TEM . No significant correlation was detected between the four antibiotics resistances and the related resistance genes.