Ishii H, Fukuyasu T, Iyobe S, Hashimoto H
Laboratory of Drug Resistance in Bacteria, School of Medicine, Gunma University, Japan.
Am J Vet Res. 1993 May;54(5):701-8.
The genetic basis of drug-resistant strains of Actinobacillus pleuropneumoniae in Japan was studied. The A pleuropneumoniae strains AV277 and AV281 that belong to serotype 2 were resistant to streptomycin (SM) and sulfonamide (SA). Both strains had an 8.1-kilobase (kb) SM-SA plasmid that was previously classified in the H1 group. The AV177 (serotype 1) strain was resistant to SM, SA, ampicillin, and kanamycin (KM), but did not have any plasmids. The AV319 and AV324 (serotype 1) strains were resistant to SM, SA, tetracycline (TC), and chloramphenicol (CP). The AV318 (serotype 12) strain was resistant to SM, SA, TC, minocycline, and CP. These 3 strains (AV319, AV324, and AV318) had a 4.3-kb SM-SA plasmid and a 5.2-kb CP plasmid. The 4.3-kb plasmid was classified in the H2 group. The AV263 (serotype 1) strain was resistant to SM, SA, KM, TC, and CP. It had a 5.2-kb CP plasmid and a 6.6-kb SM-SA-KM plasmid. Both plasmids did not replicate stably in Escherichia coli strains. The former 5.2-kb plasmid was mobilized in E coli strains by plasmid RP4, which belonged to incompatibility P with broad host range, but the latter 6.6-kb plasmid was not so mobilized. Three 5.2-kb CP plasmids isolated from strains AV319, AV324, and AV318, had the same restriction endonuclease pattern after digestion with Ava I and EcoRI. They coexisted with H1 group plasmids in the incompatibility test, and coexisted also with H2 group plasmids of the original A pleuropneumoniae strains. Results indicated that the 5.2-kb CP plasmids could be classified in a new incompatibility group, H3. In this study, 4 types of plasmids were isolated, but no plasmids encoded TC and minocycline resistance.
对日本胸膜肺炎放线杆菌耐药菌株的遗传基础进行了研究。属于血清型2的胸膜肺炎放线杆菌菌株AV277和AV281对链霉素（SM）和磺胺类药物（SA）耐药。这两种菌株都有一个8.1千碱基（kb）的SM - SA质粒，该质粒先前被归类于H1组。AV177（血清型1）菌株对SM、SA、氨苄青霉素和卡那霉素（KM）耐药，但没有任何质粒。AV319和AV324（血清型1）菌株对SM、SA、四环素（TC）和氯霉素（CP）耐药。AV318（血清型12）菌株对SM、SA、TC、米诺环素和CP耐药。这3种菌株（AV319、AV324和AV318）有一个4.3 kb的SM - SA质粒和一个5.2 kb的CP质粒。4.3 kb的质粒被归类于H2组。AV263（血清型1）菌株对SM、SA、KM、TC和CP耐药。它有一个5.2 kb的CP质粒和一个6.6 kb的SM - SA - KM质粒。这两种质粒在大肠杆菌菌株中都不能稳定复制。前一个5.2 kb的质粒可通过属于广泛宿主范围不相容性P的质粒RP4在大肠杆菌菌株中转移，但后一个6.6 kb的质粒则不能如此转移。从菌株AV319、AV324和AV318中分离出的3个5.2 kb的CP质粒，在用Ava I和EcoRI消化后具有相同的限制性内切酶图谱。它们在不相容性试验中与H1组质粒共存，也与原始胸膜肺炎放线杆菌菌株的H2组质粒共存。结果表明，5.2 kb的CP质粒可归类于一个新的不相容性组，H3。在本研究中，分离出了4种类型的质粒，但没有质粒编码对TC和米诺环素的耐药性。
