A Rare i (I-negative) Phenotype Blood Found in Japanese Families

ABSTRACT Yersinia pestis has been historically divided into three biovars: antiqua, mediaevalis, and orientalis. On the basis of this study, strains from Microtus-related plague foci are proposed to constitute a new biovar, microtus. Based on the ability to ferment glycerol and arabinose and to reduce nitrate, Y. pestis strains can be assigned to one of four biovars: antiqua (glycerol positive, arabinose positive, and nitrate positive), mediaevalis (glycerol positive, arabinose positive, and nitrate negative), orientalis (glycerol negative, arabinose positive, and nitrate positive), and microtus (glycerol positive, arabinose negative, and nitrate negative). A 93-bp in-frame deletion in glpD gene results in the glycerol-negative characteristic of biovar orientalis strains. Two kinds of point mutations in the napA gene may cause the nitrate reduction-negative characteristic in biovars mediaevalis and microtus, respectively. A 122-bp frameshift deletion in the araC gene may lead to the arabinose-negative phenotype of biovar microtus strains. Biovar microtus strains have a unique genomic profile of gene loss and pseudogene distribution, which most likely accounts for the human attenuation of this new biovar. Focused, hypothesis-based investigations on these specific genes will help delineate the determinants that enable this deadly pathogen to be virulent to humans and give insight into the evolution of Y. pestis and plague pathogenesis. Moreover, there may be the implications for development of biovar microtus strains as a potential vaccine.

Download Full-text

Gelatinase-Associated Phenotypes and Genotypes Among Clinical Isolates of Enterococcus faecalis in Poland

Polish Journal of Microbiology ◽

10.33073/pjm-2011-041 ◽

2011 ◽

Vol 60 (4) ◽

pp. 287-292 ◽

Cited By ~ 9

Author(s):

JANUSZ STRZELECKI ◽

WALERIA HRYNIEWICZ ◽

EWA SADOWY

Keyword(s):

Gene Expression ◽

Enterococcus Faecalis ◽

Clonal Complex ◽

Nosocomial Pathogen ◽

Gelatinase Activity ◽

Sensing System ◽

Quorum Sensing System ◽

Invasive Infections ◽

Genetic Events ◽

Negative Phenotype

Enterococcus faecalis is an important nosocomial pathogen causing serious invasive infections. One of the virulence factors of this pathogen, gelatinase GelE, is a protease whose gene expression is regulated by the Fsr quorum sensing system. In this study, we used a well-characterized collection of 153 clinical E. faecalis isolates to investigate the distribution of genes involved in gelatinase expression. Although 140 isolates (91% of the group) harbored the gelE gene, only 81 isolates (53%) produced active gelatinase. The gelatinase-negative phenotype was found in several unrelated clones, and appeared to be caused by various genetic events. Isolates of the hospital-adapted clonal complex 2 (CC2) and of CC40 were uniformly gelatinase-positive, while all the CC87 isolates contained the 23.9 kb deletion encompassing most of the fsr locus and were gelatinase-negative. No significant differences among isolates of different clinical origin and gelatinase activity or presence of the fsr genes were found with the exception of isolates from cerebrospinal fluid, which were more often gelatinase-positive than colonizing isolates.

Download Full-text

Antiangiogenic therapy for breast cancer with triple negative phenotype

Modern Oncology ◽

10.26442/18151434.2021.1.200763 ◽

2021 ◽

Vol 23 (1) ◽

pp. 88-92

Author(s):

Inna P. Ganshina ◽

Kristina A. Ivanova ◽

Olga O. Gordeeva ◽

Aleksandr V. Arkhipov ◽

Liudmila G. Zhukova

Keyword(s):

Breast Cancer ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Malignant Tumors ◽

Antiangiogenic Therapy ◽

Treatment Strategies ◽

Her 2 ◽

Triple Negative Phenotype ◽

The Impact ◽

Negative Phenotype

Triple-negative breast cancer is 1024% of all cases of breast cancer and is characterized by the absence of estrogen, progesterone, and HER-2 receptors in the tumor. The therapy of this illness is a difficult clinical case. In contrast to hormone-positive and HER-2-positive phenotypes, in which we successfully use targeted drugs (antiestrogens and anti-HER-2 drugs), for triple-negative breast cancer we have not had such targets for a long time. Thus, despite the impressive results of immunotherapy of triple-negative breast cancer, there remains a fairly large group of patients with negative PD-L1 status, for whom it is necessary to develop other treatment strategies. One of the approaches in the treatment of malignant tumors includes not the impact on tumor cells, but the process of angiogenesis. Antiangiogenic drugs have positively proven themselves in the treatment of a large number of malignant tumors but are underestimated for breast cancer (including triple-negative phenotype). The use of bevacizumab in combinations with cytostatic drugs in breast cancer therapy (including triple-negative breast cancer) has been studied in a large number of clinical trials but was undeservedly forgotten in some countries due to the revoked FDA registration. This review presents the role of bevacizumab in the treatment of patients with triple-negative breast cancer and suggests the conditions when the administration of this drug is justified and leads to better results.

Download Full-text

Development of cytotoxic chemotherapy in metastatic breast cancer with a triple-negative phenotype

Modern Oncology ◽

10.26442/1815-1434_2016.2.34-38 ◽

2016 ◽

Vol 18 (2) ◽

pp. 34-38

Author(s):

E.V. Karabina ◽

◽

L.G. Zhukova ◽

Keyword(s):

Breast Cancer ◽

Metastatic Breast Cancer ◽

Triple Negative ◽

Metastatic Breast ◽

Cytotoxic Chemotherapy ◽

Triple Negative Phenotype ◽

Negative Phenotype

Download Full-text

Tumor immunotherapy by converting tumor cells to MHC class II?positive, Ii protein?negative phenotype

Cancer Immunology Immunotherapy ◽

10.1007/s00262-003-0404-9 ◽

2003 ◽

Vol 52 (10) ◽

pp. 592-598 ◽

Cited By ~ 15

Author(s):

Xueqing Lu ◽

Nikoletta L. Kallinteris ◽

Jizhi Li ◽

Shuzhen Wu ◽

Yu Li ◽

...

Keyword(s):

Tumor Cells ◽

Mhc Class Ii ◽

Tumor Immunotherapy ◽

Class Ii ◽

Negative Phenotype

Download Full-text

Transcriptional activity of icaADBC is not correlated to the degree of biofilm formation in clinical ica-positive Staphylococcus epidermidis strains

Biofilms ◽

10.1017/s1479050504001218 ◽

2004 ◽

Vol 1 (2) ◽

pp. 101-106 ◽

Cited By ~ 5

Author(s):

S. Dobinsky ◽

H. Rohde ◽

J. K.-M. Knobloch ◽

M. A. Horstkotte ◽

D. Mack

Keyword(s):

Sequence Analysis ◽

Growth Phase ◽

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Promoter Region ◽

Transcriptional Activity ◽

Exponential Growth Phase ◽

Polysaccharide Intercellular Adhesin ◽

Different Strains ◽

Negative Phenotype

Biofilm-formation in Staphylococcus epidermidis depends on the expression of the icaADBC operon encoding the enzymes required for the synthesis of polysaccharide intercellular adhesin (PIA). Different S. epidermidis strains vary widely in the degree of PIA and biofilm that they produce. In 11 clinical S. epidermidis strains we analyzed the biofilm-forming capacity in relation to the amount of ica expressed in static biofilm cultures. In mid-exponential growth phase no correlation could be detected between the level of ica transcription and the biofilm-forming phenotype. When the different strains were grown under conditions leading to a biofilm-negative phenotype, ica-expression was highly upregulated. Sequence analysis demonstrated that the observed differences were not due to major mutations in the ica promoter region but apparently to other strain-specific regulators.

Download Full-text