摘要
目的检测Ⅰ类、Ⅱ类和Ⅳ类整合子及Ⅰ类整合子携带的耐药基因盒在霍乱弧菌临床菌株中的分布,分析整合子对细菌耐药性的影响。方法纸片扩散法行药物敏感试验,PCR法检测50株临床菌株Ⅰ类、Ⅱ类和Ⅳ类整合酶基因(intⅠ)阳性菌株,并对intⅠ1阳性菌株整合的耐药基因行序列分析。结果全部菌株至少对一种抗生素耐药。3株Ⅰ类整合酶基因阳性菌株的耐药基因盒PCR扩增得到1009 bp的产物。序列分析表明,1009 bp序列与已知的aadA 1c 100%同源,为对壮观霉素、链霉素产生耐药的基因盒;未检测到Ⅱ类整合子阳性菌株;50株临床菌株均含有第Ⅳ类整合酶基因,2株菌株第Ⅳ整合酶基因扩增得到2200bp产物,序列分析表明,在第Ⅳ类整合酶基因序列中含有一个插入片段IS1359转座酶基因。结论第1类整合子存在于孟加拉国的临床致病弧菌中,第Ⅳ类整合子在霍乱弧菌临床菌株中分布广泛,整合子在细菌耐药中发挥作用。
Objective To examine the distribution of class 1, 2 and 4 integrons and resistance gene cassette in class 1 integron in clinical strains of Vibrio cholerae （V. cholerae）, and clarify its influence on the bacterial drug-resistance. Methods Susceptibility to antimicrobial agents was tested by the disk agar diffusion method. The presence of integrase gene（int Ⅰ ） in class 1, 2 and 4 integrons in 50 clinically isolated strains were examined using polymerase chain reaction（PCR）. Drug-resistance related genes of int Ⅰ positive strains were analyzed by sequencing. Results All the isolates were resistant to at least one of the antibiotics tested. One 1 009 bp product was found in three integrase gene positive strains by amplifying the region of antibiotics resistance genes using PCR. Sequencing data revealed that the 1 009 bp product had 100% homology to known aadA lc encoding resistance to streptomycin and spectinomycin, No strain was positive for class 2 integron. All V. cholerae strains were positive for the int Ⅰ 4 gene by PCR and colony hybridization test. Amplification of the int Ⅰ 4 gene by PCR yielded a 2 200 bp fragment from two strains, Sequence analysis of this amplicon revealed an insertion of a transposase gene IS1359 in the middle of the int Ⅰ 4 gene. Conclusions Class Ⅰ is present in some clinical strains of V. cholerae isolated in Bangladesh, and class 4 integron is ubiquitously distributed among V. cholerae strains, showing integrons influence the development of antibiotic resistance.
出处
《中华传染病杂志》
CAS
CSCD
北大核心
2007年第8期454-457,共4页
Chinese Journal of Infectious Diseases
