Souza F N, Piepers S, Della Libera A M M P, Heinemann M B, Cerqueira M M O P, De Vliegher S
M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium; Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte 31270-010, Brazil.
M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium.
J Dairy Sci. 2016 Apr;99(4):2867-2874. doi: 10.3168/jds.2015-10230. Epub 2016 Jan 29.
Bacteria adherence seems to be an essential first stage for the internalization of bacteria into the cytoplasm of the host cell, which is considered an important virulence strategy enabling bacteria to occupy a microenvironment separated from host defense mechanisms. Thus, this study aimed to explore the difference in the capacity of 4 bovine-associated staphylococci species or strains to adhere to and internalize into bovine mammary epithelial cells (MEC). Three different isolates of coagulase-negative staphylococci (CNS) were used: one strain of Staphylococcus fleurettii isolated from sawdust and considered an environmental opportunistic bacterium, and 2 dissimilar Staphylococcus chromogenes isolates, one cultured from a heifer's teat apex (Staph. chromogenes TA) and the other originating from a chronic intramammary infection (Staph. chromogenes IM). Also, one well-characterized strain of Staphylococcus aureus (Newbould 305) was used for comparison with a major mastitis pathogen. The CNS species and strains adhered to and internalized into MEC slower than did Staph. aureus. Still, we observed high variation in adhesion and internalization capacity among the different CNS, with Staph. chromogenes IM showing a greater ability to adhere to and internalize into MEC than the 2 CNS strains isolated from extramammary habitats. In conclusion, the 3 well-characterized bovine-associated CNS species and strains originating from distinct habitats showed clear differences in their capacity to adhere to and internalize into MEC. The observed differences might be related to their diversity in ecology and epidemiological behavior.
细菌黏附似乎是细菌内化进入宿主细胞胞质的关键第一步，这被认为是一种重要的毒力策略，使细菌能够占据与宿主防御机制相分离的微环境。因此，本研究旨在探讨4种牛源葡萄球菌物种或菌株黏附并内化进入牛乳腺上皮细胞（MEC）的能力差异。使用了3种不同的凝固酶阴性葡萄球菌（CNS）分离株：1株从锯末中分离出的弗勒里葡萄球菌，被认为是一种环境机会致病菌，以及2株不同的产色葡萄球菌分离株，1株从小母牛乳头顶端培养而来（产色葡萄球菌TA），另一株源自慢性乳房内感染（产色葡萄球菌IM）。此外，还使用了1株特征明确的金黄色葡萄球菌（纽博尔德305）与一种主要的乳腺炎病原体进行比较。CNS物种和菌株黏附并内化进入MEC的速度比金黄色葡萄球菌慢。不过，我们观察到不同CNS之间在黏附及内化能力上存在很大差异，产色葡萄球菌IM比从乳房外栖息地分离出的2株CNS菌株表现出更强的黏附并内化进入MEC的能力。总之，这3种特征明确的源自不同栖息地的牛源CNS物种和菌株在黏附并内化进入MEC的能力上存在明显差异。观察到的差异可能与其生态和流行病学行为的多样性有关。
