Developmental expression of B cell molecules in equine lymphoid tissues
VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY
Authors: Prieto, J. M. B.; Tallmadge, R. L.; Felippe, M. J. B.
Abstract
Identification and classification of B cell subpopulations has been shown to be challenging and inconsistent among different species. Our study tested aspects of ontogeny, phenotype, tissue distribution, and function of equine CD5(hi) B cells, which represented a greater proportion of B cells early in development and in the peritoneal cavity. CD5(hi) and CD5(l0) B cells differentially expressed B cell markers (CD2, CD21, IgM) measured using flow cytometry, but similar mRNA expression of signature genes (DGKA, FGL2, PAX5, IGHM, IL10) measured using quantitative RT-PCR. Sequencing lambda light chain segments revealed that CD5(hi) B cells generated diverse immunoglobulin repertoires, and more frequently bound to fluorescence-labeled phosphorylcholine. This study shows developmental characteristics and tissue distribution of a newly described subpopulation of B cells in the horse. (C) 2016 Elsevier B.V. All rights reserved.
Co-Occurrence of the mcr-1.1 and mcr-3.7 Genes in a Multidrug-Resistant Escherichia coli Isolate from China
INFECTION AND DRUG RESISTANCE
Authors: Du, Chongtao; Feng, Yuyang; Wang, Guizhen; Zhang, Zhiyuan; Hu, Huimin; Yu, Yu; Liu, Jiayang; Qiu, Lihao; Liu, Hongtao; Guo, Zhimin; Huang, Jing; Qiu, Jiazhang
Abstract
Objective: A colistin-resistant Escherichia coli strain isolated from dog feces was characterized in this study. Methods and Results: A multiplex PCR assay was used to detect the presence of colistinresistant mcr genes; it was found that E. coli QDFD216 co-harbored the mcr-1 and mcr-3 genes. Whole-genome sequencing and further bioinformatics analysis revealed that E. coli QDFD216 belonged to serotype O176:H11, fimH1311 type and ST132. The resistance genes bla(CTX-M-14), mdfA, dfrA3, acrA, acrB, tolc, and sul3 were present in the chromosome. The mcr-1.1 and mcr-3.7 genes were located in two plasmids of different incompatibility groups. mcr-1.1 was carried by a IncX4-type plasmid within an typical IS26-parA-mcr-1.1-pap2 cassette, while mcr-3.7 was encoded by an IncP1-type plasmid with a genetic structure of TnAs2-mcr-3.7-dgkA-IS26. No additional antibiotic resistance genes were carried by either plasmid. Conclusion: This is the first report of an E. coli isolate co-harboring a mcr-1.1-carrying IncX4 plasmid and a mcr-3.7-carrying IncP1 plasmid. The evolution and mechanism of mcr gene co-existence need further study to assess its impact on public health.