Defining Species-Specific Immunodominant B Cell Epitopes for Molecular Serology of Chlamydia Species

Urgently needed species-specific enzyme-linked immunosorbent assays (ELISAs) for the detection of antibodies against Chlamydia spp. have been elusive due to high cross-reactivity of chlamydial antigens. To identify Chlamydia species-specific B cell epitopes for such assays, we ranked the potential epitopes of immunodominant chlamydial proteins that are polymorphic among all Chlamydia species. High-scoring peptides were synthesized with N-terminal biotin, followed by a serine-glycine-serine-glycine spacer, immobilized onto streptavidin-coated microtiter plates, and tested with mono-specific mouse hyperimmune sera against each Chlamydia species in chemiluminescent ELISAs. For each of nine Chlamydia species, three to nine dominant polymorphic B cell epitope regions were identified on OmpA, CT618, PmpD, IncA, CT529, CT442, IncG, Omp2, TarP, and IncE proteins. Peptides corresponding to 16- to 40-amino-acid species-specific sequences of these epitopes reacted highly and with absolute specificity with homologous, but not heterologous, Chlamydia monospecies-specific sera. Host-independent reactivity of such epitopes was confirmed by testing of six C. pecorum-specific peptides from five proteins with C. pecorum-reactive sera from cattle, the natural host of C. pecorum. The probability of cross-reactivity of peptide antigens from closely related chlamydial species or strains correlated with percent sequence identity and declined to zero at <50% sequence identity. Thus, phylograms of B cell epitope regions predict the specificity of peptide antigens for rational use in the genus-, species-, or serovar-specific molecular serology of Chlamydia spp. We anticipate that these peptide antigens will improve chlamydial serology by providing easily accessible assays to nonspecialist laboratories. Our approach also lends itself to the identification of relevant epitopes of other microbial pathogens.     

湿润烧伤膏治疗Wagner1～2级糖尿病足疗效观察

目的对比观察湿润烧伤膏治疗糖尿病足的临床疗效。方法将2012年7月—2017年6月松江区岳阳街道社区卫生服务中心与上海览海康复医院收治的37例Wagner1～2级糖尿病足患者按照随机数表法随机分为观察组(20例)与对照组(17例),其中观察组患者在调节血糖、抗感染等全身综合治疗的基础上,局部创面采用湿润烧伤膏换药治疗;对照组患者在调节血糖、抗感染等全身综合治疗的基础上,局部创面采用碘伏常规消毒治疗。对比观察两组患者在治疗第7、14、21、28天时的创面愈合率,创面愈合时间及治疗28 d后的临床疗效。结果治疗第7天时,两组患者创面愈合率对比采用t检验,t=1. 604,P=0. 118,P 0. 05,差异无统计学意义;治疗第14、21、28天时,两组患者创面愈合率对比采用t检验,t=5. 117、7. 196及5. 060,P均=0. 000,P均0. 01,差异具有统计学意义;治疗28 d后,观察组患者的治疗总有效率为95. 0%,对照组患者的治疗总有效率为70. 6%,两组对比采用2行×4列表资料的卡方检验,χ2=8. 156,P=0. 043,P 0. 05,差异具有统计学意义;最终两组患者创面均完全愈合,其中观察组患者的创面愈合时间为(39. 8±7. 6) d,对照组患者的创面愈合时间为(52. 4±6. 5) d,两组对比采用t检验,t=5. 366,P=0. 000,P 0. 01,差异具有统计学意义。结论湿润烧伤膏治疗Wagner1～2级糖尿病足,可有效促进创面愈合,缩短创面愈合时间,提高创面愈合率,可作为Wagner1～2级糖尿病足的首选治疗方法。