Amplification of the multidrug resistance gene pfmdr1 in Plasmodium falciparum has arisen as multiple independent events

1991 ◽  
Vol 11 (10) ◽  
pp. 5244-5250
Author(s):  
T Triglia ◽  
S J Foote ◽  
D J Kemp ◽  
A F Cowman
Keyword(s):  
Polymerase Chain Reaction ◽  
Plasmodium Falciparum ◽  
Multidrug Resistance ◽  
Tumor Cells ◽  
Yeast Artificial Chromosome ◽  
Chloroquine Resistance ◽  
Chain Reaction ◽  
Pfmdr1 Gene ◽  
Independent Events ◽  
Polymerase Chain

The multidrug resistance (MDR) phenotype in mammalian tumor cells can involve amplification of mdr genes that results in overexpression of the protein product termed P-glycoprotein. Chloroquine resistance (CQR) in Plasmodium falciparum has similarities with the MDR phenotype in tumor cells, and some isolates of P. falciparum have amplified levels of the pfmdr1 gene. To investigate the nature and origin of pfmdr1 amplicons, we have cloned large regions of a 110-kb amplicon from the CQR cloned isolate B8 by using the yeast artificial chromosome system. We have identified and sequenced the breakpoints of the amplicon by a novel method employing inverted polymerase chain reaction that is applicable to analysis of any large-scale repeat. We show that the five copies of the amplicon in this isolate are in a head to tail configuration. A string of 30 A's flank the breakpoints on each side of the amplified segment, suggesting a mechanism for the origin of the tandem amplification. Polymerase chain reaction analysis with oligonucleotides that cross the B8 breakpoint has shown in 26 independent CQR isolates, 16 of which contain amplified copies of pfmdr1, that amplification of the pfmdr1 gene in P. falciparum has arisen as multiple independent events. These results suggest that this region of the genome is under strong selective pressure.

scholarly journals Amplification of the multidrug resistance gene pfmdr1 in Plasmodium falciparum has arisen as multiple independent events.

1991 ◽  
Vol 11 (10) ◽  
pp. 5244-5250 ◽  
Author(s):  
T Triglia ◽  
S J Foote ◽  
D J Kemp ◽  
A F Cowman
Keyword(s):  
Polymerase Chain Reaction ◽  
Plasmodium Falciparum ◽  
Multidrug Resistance ◽  
Tumor Cells ◽  
Yeast Artificial Chromosome ◽  
Chloroquine Resistance ◽  
Chain Reaction ◽  
Pfmdr1 Gene ◽  
Independent Events ◽  
Polymerase Chain

The multidrug resistance (MDR) phenotype in mammalian tumor cells can involve amplification of mdr genes that results in overexpression of the protein product termed P-glycoprotein. Chloroquine resistance (CQR) in Plasmodium falciparum has similarities with the MDR phenotype in tumor cells, and some isolates of P. falciparum have amplified levels of the pfmdr1 gene. To investigate the nature and origin of pfmdr1 amplicons, we have cloned large regions of a 110-kb amplicon from the CQR cloned isolate B8 by using the yeast artificial chromosome system. We have identified and sequenced the breakpoints of the amplicon by a novel method employing inverted polymerase chain reaction that is applicable to analysis of any large-scale repeat. We show that the five copies of the amplicon in this isolate are in a head to tail configuration. A string of 30 A's flank the breakpoints on each side of the amplified segment, suggesting a mechanism for the origin of the tandem amplification. Polymerase chain reaction analysis with oligonucleotides that cross the B8 breakpoint has shown in 26 independent CQR isolates, 16 of which contain amplified copies of pfmdr1, that amplification of the pfmdr1 gene in P. falciparum has arisen as multiple independent events. These results suggest that this region of the genome is under strong selective pressure.

scholarly journals Missed Plasmodium falciparum and Plasmodium vivax Mixed Infections in Ethiopia Threaten Malaria Elimination

2021 ◽  
Author(s):  
Colleen M. Leonard ◽  
Hussein Mohammed ◽  
Mekonnen Tadesse ◽  
Jessica N. McCaffery ◽  
Doug Nace ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Plasmodium Falciparum ◽  
Lactate Dehydrogenase ◽  
Plasmodium Vivax ◽  
Therapeutic Efficacy ◽  
Dried Blood Spots ◽  
Mixed Infections ◽  
Efficacy Study ◽  
Chain Reaction ◽  
Polymerase Chain

Plasmodium falciparum and Plasmodium vivax are co-endemic in Ethiopia. This study investigated whether mixed infections were missed by microscopy from a 2017 therapeutic efficacy study at two health facilities in Ethiopia. All patients (N = 304) were initially classified as having single-species P. falciparum (n = 148 samples) or P. vivax infections (n = 156). Dried blood spots were tested for Plasmodium antigens by bead-based multiplex assay for pan-Plasmodium aldolase, pan-Plasmodium lactate dehydrogenase, P. vivax lactate dehydrogenase, and histidine-rich protein 2. Of 304 blood samples, 13 (4.3%) contained both P. falciparum and P. vivax antigens and were analyzed by polymerase chain reaction for species-specific DNA. Of these 13 samples, five were confirmed by polymerase chain reaction for P. falciparum/P. vivax co-infection. One sample, initially classified as P. vivax by microscopy, was found to only have Plasmodium ovale DNA. Plasmodium falciparum/P. vivax mixed infections can be missed by microscopy even in the context of a therapeutic efficacy study with multiple trained readers.

HRP2/3 mutation in recrudescent Plasmodium falciparum malaria case acquired in Ethiopia

2020 ◽  
Author(s):  
Shiraz Gefen-Halevi ◽  
Valentin Belinson ◽  
Uri Manor ◽  
Zeala Gazit ◽  
Gill Smollan ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Plasmodium Falciparum ◽  
Lactate Dehydrogenase ◽  
Falciparum Malaria ◽  
Malaria Case ◽  
Rapid Detection ◽  
Plasmodium Falciparum Malaria ◽  
Malaria Prophylaxis ◽  
Chain Reaction ◽  
Polymerase Chain

A 65-year-old Israeli working in Welkait, Ethiopia, not using malaria prophylaxis, developed fever. Malaria rapid detection test was consistent with non-falciparum malaria (plasmodium lactate dehydrogenase+/histidine-rich protein− [LDH+/HRP−]) but microscopy showed typical Plasmodium falciparum. HRP2/3 were negative by polymerase chain reaction. The patient suffered two recrudescence episodes following artemether–lumefantrine and atovaquone–proguanil treatments, and responded to mefloquine treatment.

Specific detection of carcinoembryonic antigen-expressing tumor cells in bone marrow aspirates by polymerase chain reaction.

1994 ◽  
Vol 12 (4) ◽  
pp. 725-729 ◽  
Author(s):  
M Gerhard ◽  
H Juhl ◽  
H Kalthoff ◽  
H W Schreiber ◽  
C Wagener ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Bone Marrow ◽  
Polymerase Chain Reaction ◽  
Tumor Cells ◽  
Normal Bone Marrow ◽  
Specific Detection ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Normal Bone ◽  
Polymerase Chain

PURPOSE To establish a sensitive assay for the specific detection of carcinoembryonic antigen (CEA)-expressing tumor cells in the bone marrow of patients with colorectal cancer and other CEA-positive carcinomas. PATIENTS AND METHODS A CEA-specific nested reverse transcriptase (RT) polymerase chain reaction (PCR) assay was developed and optimized using limiting dilutions of a CEA-positive cancer cell line mixed with normal bone marrow cell specimens. The optimized test was then used to examine bone marrow samples obtained from 15 patients with abdominal carcinomas (colorectal, n = 10; pancreatic, n = 3; gastric, n = 2) and six patients with breast cancer. Specificity was assessed by examination of 56 negative controls (malignant hematologic disease, n = 28; nonmalignant disease conditions, n = 5; healthy bone marrow donors, n = 8; normal peripheral-blood samples, n = 15). For 11 patients with abdominal carcinomas, immunostaining evaluations were performed using an anti-CEA and an anticytokeratin antibody, and the results compared with the nested PCR assay. RESULTS In the sensitivity calibration system, single CEA-expressing tumor cells were detected in 2 to 5 x 10(7) normal bone marrow cells. All 56 control samples failed to amplify. This demonstrates that mRNAs coding for highly homologous CEA-related antigens expressed by various lineages of blood cells do not interfere. Bone marrow samples from 10 of 15 patients with abdominal cancers and four of six breast cancer patients scored positive, indicating micrometastatic bone disease. Four of 11 samples from the gastrointestinal cancer patients were found to be positive by the PCR method, but were negative with the immunocytology method. CONCLUSION Since approximately 30% of the colorectal carcinoma patients that score negative in immunocytology staining of bone marrow samples have been reported to relapse, earlier diagnosis of the presence of malignant cells is needed. Our result that samples scoring positive in the described CEA-specific PCR test remained negative by two immunostaining methods suggests a higher sensitivity. We conclude that PCR amplification of CEA mRNA may lead to an earlier diagnosis of micrometastatic bone disease in patients with CEA-expressing carcinomas.

Sign in / Sign up

Export Citation Format

Share Document