凝固酶阴性葡萄球菌(CoNS)是一组革兰氏阳性葡萄球菌,自然栖息在健康人的皮肤和粘膜中。CoNS相关感染的临床影响最近被认为是诊断和治疗选择的挑战。CoNS相关感染主要由细菌对抗生素的抗性和生物膜形成引起。由于抗生素仍然是最常用的治疗方法,这个问题将来可能会持续下去。本研究旨在研究从各种痤疮皮损中恢复的CoNS的抗性和毒力,并探讨其遗传基础。从患有痤疮和健康皮肤的参与者收集皮肤拭子样品。所有样品都经过常规培养以分离CoNS,MALDI-TOF确认,抗生素敏感性,和生物膜形成测试。从样品中回收共85株CoNS分离物,初步鉴定为表皮葡萄球菌。来自痤疮组(n=60)的分离株对青霉素的耐药率最高(73%),头孢西丁(63%),克林霉素(53.3%),和红霉素(48%),其次是左氧氟沙星(36.7%)和庆大霉素(31.7%)。对四环素的耐药率最低(28.3%),多西环素(11.7%),和米诺环素(8.3%)。从轻度分离的CoNS,中度痤疮和健康的分离株没有表现出强烈的生物膜形成,而痤疮组严重病例的分离株显示出强烈的生物膜形成(76.6%)。选择从严重痤疮患者中回收的四种广泛耐药和强生物膜形成的葡萄球菌分离株进行全基因组测序(WGS),他们的基因组使用生物信息学工具进行调查。三个测序的基因组被鉴定为表皮葡萄球菌;然而,分离株29AM被鉴定为沃氏葡萄球菌,这是一种新出现的病原体,通常与痤疮无关,MALDI-TOF未检测到。所有测序的菌株均具有多重耐药,并携带多个耐药基因,包括BlaZ,mecA,tet(K),erm(C),lnuA,vgaa,dfrc,fusB,fosBx1,norA,而vant,被发现位于质粒和染色体上。在存在参与粘附和生物膜形成的基因的情况下,在所有基因组中检测到毒力特征(icaA,icaB,icaC,sdrG,sdrH,atl,ebh,和ebp)。只有S.warneri分离株29AM含有免疫逃避基因(capB,capc,acpXL,andmanA),抗吞噬基因(cdsA),和其他独特的功能。由于其潜在的致病性和抗生素抗性,CoNS必须作为与痤疮感染相关的新兴病原体进行监测。据我们所知,这是第一份隔离报告,identify,并使用WGS和生物信息学分析将S.warneri与埃及患者的严重痤疮感染相关联。
Coagulase-negative staphylococci (
CoNS) are a group of gram-positive staphylococcal species that naturally inhabit the healthy human skin and mucosa. The clinical impact of
CoNS-associated infections has recently been regarded as a challenge for diagnosis and therapeutic options.
CoNS-associated infections are primarily caused by bacterial resistance to antibiotics and biofilm formation. As antibiotics are still the most used treatment, this problem will likely persist in the future. The present study aimed to investigate the resistance and virulence of
CoNS recovered from various acne lesions and explore their genetic basis. Skin swab samples were collected from participants with acne and healthy skin. All samples underwent conventional culture for the isolation of
CoNS, MALDI-TOF confirmation, antibiotic susceptibility, and biofilm formation testing. A total of 85 CoNS isolates were recovered from the samples and preliminarily identified as Staphylococcus epidermidis. Isolates from the acne group (n = 60) showed the highest rates of resistance to penicillin (73%), cefoxitin (63%), clindamycin (53.3%), and erythromycin (48%), followed by levofloxacin (36.7%) and gentamycin (31.7%). The lowest rates of resistance were observed against tetracycline (28.3%), doxycycline (11.7%), and minocycline (8.3%). CoNS isolated from mild, moderate acne and healthy isolates did not show strong biofilm formation, whereas the isolates from the severe cases of the acne group showed strong biofilm formation (76.6%). Four extensively drug-resistant and strong biofilm-forming staphylococcal isolates recovered from patients with severe acne were selected for whole-genome sequencing (WGS), and their genomes were investigated using bioinformatics tools. Three of the sequenced genomes were identified as S. epidermidis; however, isolate 29AM was identified as Staphylococcus warneri, which is a newly emerging pathogen that is not commonly associated with acne and was not detected by MALDI-TOF. All the sequenced strains were multidrug-resistant and carried multiple resistance genes, including blaZ, mecA, tet(K), erm(C), lnuA, vgaA, dfrC, fusB, fosBx1, norA, and vanT, which were found to be located on plasmids and chromosomes. Virulence features were detected in all genomes in the presence of genes involved in adherence and biofilm formation (icaA, icaB, icaC, sdrG, sdrH, atl, ebh, and ebp). Only the S. warneri isolate 29AM contained immune evasion genes (capB, capC, acpXL, and manA), an anti-phagocytosis gene (cdsA), and other unique features. As a result of their potential pathogenicity and antibiotic resistance, CoNS must be monitored as an emerging pathogen associated with acne infections. To the best of our knowledge, this is the first report to isolate, identify, and correlate S. warneri with severe acne infections among Egyptian patients using WGS and bioinformatic analysis.