Adhikari R P, Shrestha S, Barakoti A, Amatya R
Department of Microbiology, Nepal Medical College and Teaching Hospital, Jorpati, Kathmandu, Nepal.
BMC Infect Dis. 2017 Jul 11;17(1):483. doi: 10.1186/s12879-017-2584-5.
Staphylococcus aureus, an important nosocomial pathogen, is frequently associated with infections in human. The management of the infections by it especially methicillin resistant ones is often difficult because methicillin resistant S. aureus is usually resistant to multiple antibiotics. Macrolide-lincosamide streptogramin B family of antibiotics is commonly used to treat such infections as an alternative to vancomycin.
This study was conducted over the period of one and half year from November 2013-April 2015 in Microbiology laboratory of Nepal Medical College and Teaching Hospital, Kathmandu, Nepal to find the incidence of different phenotypes of MLS resistance among S. aureus from clinical samples and their association with methicillin resistance. Two hundred seventy isolates of S. aureus were included in the study. Methicillin resistance was detected by cefoxitin disc diffusion method and inducible clindamycin resistance by erythromycin and clindamycin disc approximation test (D-test).
Of the 270 clinical isolates of S. aureus, 25.1% (68/270) were MRSA. Erythromycin and clindamycin resistance was seen in 54.4% (147/270) and 41.8% (113/270) isolates respectively. Resistance to erythromycin and clindamycin were higher in MRSA as compared to MSSA (erythromycin-resistance: 88.2% Vs 39.1% and clindamycin-resistance: 79.4% Vs 41.8%). The overall prevalence of MLS and MLS phenotype was 11.48% (31/270) and 29.25% (79/270) respectively. Both MLS and MLS phenotypes predominated in MRSA strains.
Detection rate of MRSA in our study shows the necessity to improve in healthcare practices and to formulate new policy for the control of MRSA infections. Clindamycin resistance in the form of MLS and MLS especially among MRSA emphasizes the need of D-test to be performed routinely in our set up while using clindamycin as an alternative choice to anti-staphylococcal antibiotics like vancomycin and linezolid in the treatment of staphylococcal infections.
金黄色葡萄球菌是一种重要的医院病原体，常与人的感染相关。由其引起的感染，尤其是耐甲氧西林的感染，治疗往往困难，因为耐甲氧西林金黄色葡萄球菌通常对多种抗生素耐药。大环内酯 - 林可酰胺 - 链阳菌素B类抗生素通常作为万古霉素的替代品用于治疗此类感染。
本研究于2013年11月至2015年4月在尼泊尔加德满都尼泊尔医学院和教学医院的微生物实验室进行，为期一年半，旨在确定临床样本中金黄色葡萄球菌不同表型的大环内酯 - 林可酰胺 - 链阳菌素耐药发生率及其与耐甲氧西林的关系。该研究纳入了270株金黄色葡萄球菌分离株。通过头孢西丁纸片扩散法检测耐甲氧西林情况，通过红霉素和克林霉素纸片贴靠试验（D试验）检测诱导型克林霉素耐药情况。
在270株临床分离的金黄色葡萄球菌中，25.1%（68/270）为耐甲氧西林金黄色葡萄球菌（MRSA）。红霉素和克林霉素耐药率分别为54.4%（147/270）和41.8%（113/270）。与甲氧西林敏感金黄色葡萄球菌（MSSA）相比，MRSA对红霉素和克林霉素的耐药率更高（红霉素耐药率：88.2%对39.1%；克林霉素耐药率：79.4%对41.8%）。大环内酯 - 林可酰胺 - 链阳菌素耐药（MLS）和大环内酯 - 林可酰胺 - 链阳菌素耐药表型的总体发生率分别为11.48%（31/270）和29.25%（79/270）。MLS和MLS表型在MRSA菌株中占主导地位。
我们研究中MRSA的检出率表明有必要改进医疗保健实践并制定控制MRSA感染的新政策。以MLS和MLS形式存在的克林霉素耐药，尤其是在MRSA中，强调了在我们的机构中，当使用克林霉素作为万古霉素和利奈唑胺等抗葡萄球菌抗生素治疗葡萄球菌感染的替代选择时，需要常规进行D试验。
