Baselga R, Albizu I, De La Cruz M, Del Cacho E, Barberan M, Amorena B
CSIC Department of Animal Production, (SIA-DGA), Zaragoza, Spain.
Infect Immun. 1993 Nov;61(11):4857-62. doi: 10.1128/iai.61.11.4857-4862.1993.
Two methods commonly used for slime detection in coagulase-negative staphylococci (tube biofilm formation and colony morphology in Congo red agar) were used to study 144 ruminant mastitis Staphylococcus aureus strains. Slime production was detected in 21 strains. A majority of cells (85%) in slime-producing (SP) strains and a minority of cells (5%) in non-slime-producing (NSP) strains showed a condensed exopolysaccharide matrix (slime) surrounding the bacterial cell wall, as revealed by electron microscopy and immunofluorescence. In vivo slime production was also detected immunohistochemically after experimental infection of the mammary gland in sheep. Upon repeated subcultures in Congo red agar, NSP variants were obtained from four ovine and four bovine SP strains at a frequency ranging from 0.5 x 10(-4) to 10(-4). Because SP variants could not be obtained from NSP strains within this range or at a higher frequency, they were obtained by the tube biofilm formation (requiring repeated subculturing of NSP strains in tryptic soy broth containing 2% glucose for subsequent recovery of colonies adherent to the walls of the culture tubes). In experimental challenge, the SP variant showed a significantly higher colonization capacity than did the NSP variant of the same strain used (P < 0.001). However, the NSP variant had a higher virulence than did the SP variant (P < 0.001). These results may help to explain the different roles of S. aureus slime production cell types (SP and NSP) coexisting in disease.
采用两种常用于检测凝固酶阴性葡萄球菌中黏液的方法（试管生物膜形成法和刚果红琼脂平板上的菌落形态法），对144株引起反刍动物乳腺炎的金黄色葡萄球菌菌株进行了研究。在21株菌株中检测到黏液产生。电子显微镜和免疫荧光显示，产黏液（SP）菌株中的大多数细胞（85%）和不产黏液（NSP）菌株中的少数细胞（5%）在细菌细胞壁周围呈现浓缩的胞外多糖基质（黏液）。在绵羊乳腺进行实验性感染后，还通过免疫组织化学检测到了体内黏液的产生。在刚果红琼脂平板上反复传代培养后，从4株绵羊和4株牛的SP菌株中获得了NSP变异株，频率范围为0.5×10⁻⁴至10⁻⁴。由于在此范围内或更高频率下无法从NSP菌株中获得SP变异株，因此通过试管生物膜形成法获得（需要将NSP菌株在含有2%葡萄糖的胰蛋白胨大豆肉汤中反复传代培养，随后回收附着在培养管壁上的菌落）。在实验性攻毒中，SP变异株的定植能力显著高于同一菌株的NSP变异株（P<0.001）。然而，NSP变异株的毒力高于SP变异株（P<0.001）。这些结果可能有助于解释疾病中共存的金黄色葡萄球菌产黏液细胞类型（SP和NSP）的不同作用。
