Suliman Muath, Bishr Amr S, Tohamy Sally T K, Mabrouk Samar S, Ismail Nasser S M, Samy Abdallah M, Aboshanab Khaled M
Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, P.O. Box 61413, 9088, Abha, Saudi Arabia.
Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, 11566, Egypt.
BMC Infect Dis. 2025 Sep 16;25(1):1107. doi: 10.1186/s12879-025-11433-0.
Macrolide-resistant and methicillin-resistant Staphylococcus aureus, particularly those exhibiting pristinamycin resistance, impose significant medical health consequences with limited therapeutic options. This study is designed to determine their prevalence in a major tertiary care hospital in Egypt, antimicrobial susceptibility and evaluate various pristinamycin (PST)-antibiotic combinations.
Standard procedures were employed for isolation, identification, antimicrobial susceptibility, and molecular analysis of key macrolide- and methicillin-resistant genes. Phenotypic relatedness and antibiotic combinations of pristinamycin with other antimicrobial agents were done using the heatmap analysis and checkerboard assay.
Out of 154 positive cultures of S. aureus were collected from different types of skin infections. The lowest resistance was shown for linezolid (5.2%), followed by vancomycin (9.1%), teicoplanin (9.1%), chloramphenicol (12.3%), and doxycycline (14.9%). The MDR isolates (43%, n = 67) showed diverse phenotypic relatedness. They showed multiple antibiotic resistance (MAR) index range from 0.31-1.0, exhibiting 100% non-susceptibility to cefoxitin (MRSA), erythromycin, and clarithromycin known as macrolide resistant S. aureus (McRSA), followed by 80%, 74.6%, and 46.2% for clindamycin, azithromycin, and PST, respectively. All the MDR isolates gave positive nuc, mecA and confirmed MRSA. The ermC, ermA, and msrA, genes were detected in 49.25%, 26.8%, and 23.8% of the MDR isolates, respectively. The PST-doxycycline and PST-levofloxacin combinations were mostly synergistic in 82.13% and 70.14%, while PST-linezolid showed mostly additive effects in 67% of the MDR S. aureus isolates.
This study highlights the high prevalence of MRSA isolates recovered from various skin infections. Linezolid, vancomycin, teicoplanin, pristinamycin, chloramphenicol, and doxycycline remain effective therapeutic options. Macrolide and methicillin resistance are increasingly developing among S. aureus clinical isolates. The pristinamycin combination with doxycycline or levofloxacin was mostly synergistic and recommended for clinical evaluation.
对大环内酯类耐药且对甲氧西林耐药的金黄色葡萄球菌，尤其是那些表现出对普那霉素耐药的菌株，会带来严重的健康后果，且治疗选择有限。本研究旨在确定它们在埃及一家大型三级护理医院中的流行情况、抗菌药敏性，并评估各种普那霉素（PST）-抗生素组合。
采用标准程序对关键的大环内酯类和甲氧西林耐药基因进行分离、鉴定、抗菌药敏性及分子分析。使用热图分析和棋盘稀释法进行普那霉素与其他抗菌药物的表型相关性及抗生素组合研究。
从不同类型的皮肤感染中收集了154份金黄色葡萄球菌阳性培养物。对利奈唑胺的耐药率最低（5.2%），其次是万古霉素（9.1%）、替考拉宁（9.1%）、氯霉素（12.3%）和多西环素（14.9%）。多重耐药菌株（43%，n = 67）表现出多样的表型相关性。它们的多重抗生素耐药（MAR）指数范围为0.31 - 1.0，对头孢西丁（耐甲氧西林金黄色葡萄球菌，MRSA）、红霉素和克拉霉素（即大环内酯类耐药金黄色葡萄球菌，McRSA）的不敏感率达100%，其次对克林霉素、阿奇霉素和PST的不敏感率分别为80%、74.6%和46.2%。所有多重耐药菌株的nuc、mecA基因检测均为阳性，确诊为MRSA。ermC、ermA和msrA基因在多重耐药菌株中的检出率分别为49.25%、26.8%和23.8%。PST - 多西环素和PST - 左氧氟沙星组合在82.13%和70.14%的多重耐药金黄色葡萄球菌菌株中大多表现为协同作用，而PST - 利奈唑胺在67%的多重耐药金黄色葡萄球菌菌株中大多表现为相加作用。
本研究突出了从各种皮肤感染中分离出的MRSA菌株的高流行率。利奈唑胺、万古霉素、替考拉宁、普那霉素、氯霉素和多西环素仍是有效的治疗选择。金黄色葡萄球菌临床分离株中对大环内酯类和甲氧西林的耐药性正在日益增加。普那霉素与多西环素或左氧氟沙星的组合大多具有协同作用，推荐进行临床评估。
