Sallam Hussien H, Ramadan Asmaa A, Attia Nancy M, ElBaradei Amira, Shawky Sherine M, El-Kholy Mohammed A
Department of Microbiology, Medical Research Institute, Alexandria University, Alexandria, Egypt.
Department of Microbiology and Biotechnology, Clinical and Biological Sciences Division, College of Pharmacy, Arab Academy for Science, Technology and Maritime Transport (AASTMT), Alexandria, Egypt.
Int J Microbiol. 2025 May 19;2025:4558662. doi: 10.1155/ijm/4558662. eCollection 2025.
Ceftaroline is a fifth-generation cephalosporin that was recently introduced into the Egyptian market for the treatment of methicillin-resistant (MRSA) infections. However, limited data are available regarding the susceptibility of MRSA isolates in Egypt to this antibacterial agent. This study aimed to determine the susceptibility of MRSA strains recovered from different clinical samples to ceftaroline and to investigate the prevalence of the A and C resistance genes. A total of 412 MRSA isolates were selected from 520 () samples. Identification and antibiotic susceptibility testing were performed using the VITEK-2 compact system. Molecular identification of the gene, encoding nuclease enzyme, a species-specific marker for , and the A and C genes associated with methicillin resistance was performed using the polymerase chain reaction (PCR) technique. Moreover, the activity of ceftaroline was explored using the disc diffusion method, and its minimum inhibitory concentration (MIC) was determined according to the Clinical Laboratory Standards Institute (CLSI) criteria. Staphylococcal Protein A () typing was carried out for ceftaroline nonsusceptible strains as determined by MIC. Most isolates were recovered from skin and soft tissue infections. Of the 412 clinical isolates, 407 (98.7%) were susceptible to ceftaroline, with an MIC of ≤ 1 mg/L, while five isolates (1.3%) showed a susceptible dose-dependent (SDD) profile with MIC values of 2-4 g/mL. No isolates were resistant to ceftaroline. All isolates carried the gene, 94% harbored , while was undetected. Of the five SDD isolates, three were identified as type t037, corresponding to ST-239, ST-240, or ST-241 by multilocus sequence type (MLST), whereas the two remaining isolates were untypeable. From various clinical samples, ceftaroline demonstrated excellent activity against MRSA strains, positioning it as a promising therapeutic option for managing MRSA infections in Egypt.
头孢洛林是一种第五代头孢菌素，最近被引入埃及市场用于治疗耐甲氧西林金黄色葡萄球菌（MRSA）感染。然而，关于埃及MRSA分离株对这种抗菌药物的敏感性数据有限。本研究旨在确定从不同临床样本中分离出的MRSA菌株对头孢洛林的敏感性，并调查A和C耐药基因的流行情况。从520个（）样本中总共选择了412株MRSA分离株。使用VITEK-2紧凑型系统进行鉴定和抗生素敏感性测试。使用聚合酶链反应（PCR）技术对编码核酸酶的基因（一种金黄色葡萄球菌特异性标志物）以及与耐甲氧西林相关的A和C基因进行分子鉴定。此外，使用纸片扩散法探索头孢洛林的活性，并根据临床实验室标准协会（CLSI）标准确定其最低抑菌浓度（MIC）。对通过MIC确定的头孢洛林不敏感菌株进行葡萄球菌蛋白A（）分型。大多数分离株来自皮肤和软组织感染。在412株临床分离株中，407株（98.7%）对头孢洛林敏感，MIC≤1mg/L，而5株（1.3%）表现出剂量依赖性敏感（SDD）特征，MIC值为2 - 4μg/mL。没有分离株对头孢洛林耐药。所有分离株都携带基因，94%携带，而未检测到。在5株SDD分离株中，3株被鉴定为t037型，通过多位点序列分型（MLST）对应于ST-239、ST-240或ST-241，而其余2株分离株无法分型。从各种临床样本来看，头孢洛林对MRSA菌株显示出优异的活性，使其成为埃及管理MRSA感染的一种有前景的治疗选择。
