Hosseini Sareh Sadat, Niakan Mohammad, Saderi Horieh, Motallebi Mitra, Taherikalani Morovat, Asadollahi Khairollah, Emaneini Mohammad
Department of Microbiology, School of Medicine, Shahed University, Tehran, Iran.
Molecular Microbiology Research Center, School of Medicine, Shahed University, Tehran, Iran.
Iran J Microbiol. 2016 Jun;8(3):161-167.
Macrolide, lincosamide and streptogramin type B (MLSB) antibiotics are important in the treatment of infections and existence of isolates with ability to resist against MLSB antibiotics is worrisome.
In this cross sectional study, 101 isolates were collected from patients of five selected hospitals in Tehran over a period of five months. Disk diffusion tests and differentiation between constitutive and inducible resistances were carried out by D-test. The presence of and genes were detected using PCR or multiplex PCR.
Out of 101 isolates, 58 (57.4%) were methicillin resistant and 57 (56.4%) expressed resistance to erythromycin. The prevalence of constitutive MLSB (cMLSB), inducible MLSB (iMLSB) and MS (Negative) phenotype in all erythromycin resistant isolates were 71.9, 26.3 and 1.7%, respectively. Out of all the erythromycin resistant isolates, 57.8% harbored both and genes which possessed constitutive resistance. 8.7% of the isolates contained gene alone which possessed inducible resistance with D phenotype and 5.2% of isolates just contained gene which had inducible resistance with D phenotype. gene was detected in 3.5% of the erythromycin resistant isolates with constitutive resistance. None of the genes were detected among MS phenotypes.
In this study, most of isolates carried both and genes and there was a significant relationship ( value ≤ 0.05) between different resistance phenotypes and genes.
大环内酯类、林可酰胺类及B型链阳菌素（MLSB）抗生素在感染治疗中很重要，而存在对MLSB抗生素具有耐药能力的分离株令人担忧。
在这项横断面研究中，在五个月的时间里从德黑兰五家选定医院的患者中收集了101株分离株。采用纸片扩散法进行药敏试验，并通过D试验区分组成型和诱导型耐药。使用PCR或多重PCR检测 erm和 mef基因的存在情况。
在101株分离株中，58株（57.4%）对甲氧西林耐药，57株（56.4%）对红霉素耐药。在所有红霉素耐药分离株中，组成型MLSB（cMLSB）、诱导型MLSB（iMLSB）和MS（阴性）表型的患病率分别为71.9%、26.3%和1.7%。在所有红霉素耐药分离株中，57.8%同时携带erm和mef基因，具有组成型耐药。8.7%的分离株仅含有erm基因，具有D表型诱导型耐药，5.2%的分离株仅含有mef基因，具有D表型诱导型耐药。在3.5%具有组成型耐药的红霉素耐药分离株中检测到 erm基因。在MS表型中未检测到任何基因。
在本研究中，大多数分离株同时携带erm和mef基因，不同耐药表型与 erm和 mef基因之间存在显著关系（P值≤0.05）。
