Thakur A, Singhal S, Prakash K
Department of Microbiology, Lady Hardinge Medical School, New Delhi, India.
J Med Microbiol. 1996 Dec;45(6):483-9. doi: 10.1099/00222615-45-6-483.
This study was designed to identify the predominant serotypes of group A streptococci (GAS) responsible for rheumatic fever (RF) and rheumatic heart disease (RHD) in India. RF and RHD sera were screened for antibodies to M proteins retrospectively against known rheumatogenic M types and M types isolated from patients with acute RF. All GAS strains isolated from four patients with acute RF in a short outbreak of RF, were identical - serum opacity factor (SOF) negative, T-pattern 3/13 B3264 and M-non-typable. Because of this, M protein was isolated from only one of these four M-non-typable strain (S-399). This was done by limited pepsin digestion and purification by ion-exchange chromatography on DEAE-Sephadex, followed by gel filtration. Purified M protein was found to be homologous on SDS-PAGE (mol.wt 20 kDa), immunogenic in rabbits and to retain its antigenic structure. This purified M protein from an M-non-typable strain (pep-MNT) was used as an antigen to screen RF and RHD sera retrospectively by ELISA for the prevalence of the M-non-typable GAS strain. The prevalence of the M-non-typable strain was compared with that of the known rheumatogenic M types. Results suggest that the M-non-typable strain could be a provisional new rheumatogenic M type in India and could be a candidate for a multivalent M-protein vaccine to control RF and RHD.
本研究旨在确定在印度导致风湿热（RF）和风湿性心脏病（RHD）的A组链球菌（GAS）的主要血清型。回顾性地针对已知致风湿性M型以及从急性RF患者中分离出的M型，对RF和RHD血清进行M蛋白抗体筛查。在一次短暂的RF暴发中，从4例急性RF患者中分离出的所有GAS菌株均相同——血清混浊因子（SOF）阴性，T型3/13 B3264且M型不可分型。因此，仅从这4株M型不可分型菌株中的1株（S - 399）分离出了M蛋白。这是通过有限的胃蛋白酶消化以及在DEAE - 葡聚糖凝胶上进行离子交换色谱纯化，随后进行凝胶过滤来完成的。纯化后的M蛋白在SDS - PAGE上显示为同源（分子量20 kDa），在兔体内具有免疫原性且保留其抗原结构。这种从M型不可分型菌株中纯化得到的M蛋白（pep - MNT）被用作抗原，通过ELISA回顾性地筛查RF和RHD血清中M型不可分型GAS菌株的流行情况。将M型不可分型菌株的流行情况与已知致风湿性M型的流行情况进行比较。结果表明，M型不可分型菌株可能是印度一种暂定的新型致风湿性M型，并且可能是用于控制RF和RHD的多价M蛋白疫苗的候选菌株。
