Istituto Zooprofilattico Sperimentale della Sardegna "G. Pegreffi", Via Vienna 2, 07100, Sassari, Italy.
Ospedale "San Francesco", 08100, Nuoro, Italy.
BMC Vet Res. 2022 Jun 2;18(1):212. doi: 10.1186/s12917-022-03257-w.
In a collaboration between animal and human health care professionals, we assessed the genetic characteristics shared by non-aureus staphylococci (NAS) infecting humans and dairy ewes to investigate their relatedness in a region concentrating half of the total National sheep stock. We examined by PCR 125 ovine and 70 human NAS for biofilm production, pyrogenic toxins, adhesins, autolysins genes, and accessory gene regulator (agr) locus. The microtiter plate assay (MPA) was used for the phenotypic screening of biofilm production. Ovine NAS included S. epidermidis, S. chromogenes, S. haemolyticus, S. simulans, S. caprae, S. warneri, S. saprophyticus, S. intermedius, and S. muscae. Human NAS included S. haemolyticus, S. epidermidis, S. hominis, S. lugdunensis, S. capitis, S. warneri, S. xylosus, S. pasteuri, and S. saprophyticus subsp. bovis.
Phenotypically, 41 (32.8%) ovine and 24 (34.3%) human isolates were characterized as biofilm producers. Of the ovine isolates, 12 were classified as biofilm-producing while the remaining 29 as weak biofilm-producing. All 24 human isolates were considered weak biofilm-producing. Few S. epidermidis isolates harbored the icaA/D genes coding for the polysaccharide intercellular adhesin (PIA), while the bhp, aap, and embp genes coding biofilm accumulation proteins were present in both non-producing and biofilm-producing isolates. Fifty-nine sheep NAS (all S. epidermidis, 1 S. chromogenes, and 1 S. haemolyticus) and 27 human NAS (all S. epidermidis and 1 S. warneri) were positive for the agr locus: agr-3se (57.8%) followed by agr-1se (36.8%) predominated in sheep, while agr-1se (65.4%), followed by agr-2se (34.6%) predominated in humans. Concerning virulence genes, 40, 39.2, 47.2%, 52.8, 80 and 43.2% of the sheep isolates carried atlE, aae, sdrF, sdrG, eno and epbS respectively, against 37.1, 42.8, 32.8, 60, 100 and 100% of human isolates. Enterotoxins and tsst were not detected.
Considerable variation in biofilm formation ability was observed among NAS isolates from ovine and human samples. S. epidermidis was the best biofilm producer with the highest prevalence of adhesin-encoding genes.
在动物和人类医疗保健专业人员的合作下，我们评估了感染人类和奶牛羊的非金黄色葡萄球菌（NAS）之间共享的遗传特征，以调查它们在集中了全国一半绵羊总存栏量的地区的相关性。我们通过 PCR 检测了 125 株绵羊 NAS 和 70 株人 NAS 的生物膜生成、热原毒素、黏附素、自溶素基因和辅助基因调节（agr）基因座。微量滴定板检测（MPA）用于生物膜生成的表型筛选。绵羊 NAS 包括表皮葡萄球菌、变绿气球菌、溶血葡萄球菌、解糖葡萄球菌、山羊葡萄球菌、沃纳葡萄球菌、腐生葡萄球菌、中间葡萄球菌和摩氏葡萄球菌。人类 NAS 包括溶血葡萄球菌、表皮葡萄球菌、人葡萄球菌、路邓葡萄球菌、头状葡萄球菌、沃纳葡萄球菌、木糖葡萄球菌、巴斯德葡萄球菌和牛亚种葡萄球菌。
表型上，41 株（32.8%）绵羊和 24 株（34.3%）人分离株被鉴定为生物膜生成菌。在绵羊分离株中，12 株被分类为生物膜生成菌，其余 29 株为弱生物膜生成菌。所有 24 株人分离株均被认为是弱生物膜生成菌。很少有表皮葡萄球菌分离株携带编码细胞间多糖黏附素（PIA）的 icaA/D 基因，而编码生物膜积累蛋白的 bhp、aap 和 embp 基因存在于非生物膜生成和生物膜生成分离株中。59 株绵羊 NAS（均为表皮葡萄球菌、1 株变绿气球菌和 1 株溶血葡萄球菌）和 27 株人 NAS（均为表皮葡萄球菌和 1 株沃纳葡萄球菌）agr 基因座呈阳性：agr-3se（57.8%）为主，其次是 agr-1se（36.8%）在绵羊中占主导地位，而 agr-1se（65.4%）为主，其次是 agr-2se（34.6%）在人类中占主导地位。关于毒力基因，40、39.2、47.2%、52.8、80 和 43.2%的绵羊分离株分别携带 atlE、aae、sdrF、sdrG、eno 和 epbS，而人类分离株分别携带 37.1、42.8、32.8、60、100 和 100%的分离株。未检测到肠毒素和 tsst。
从绵羊和人样本中分离的 NAS 分离株的生物膜形成能力存在相当大的差异。表皮葡萄球菌是最好的生物膜生成菌，具有最高的黏附素编码基因流行率。
