scholarly journals Congenital Dyserythropoietic Anemia Type 1: A New Variant Pathogenic CDAN1 Mutation

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4551-4551 ◽  
Author(s):  
Jenny McDaniel ◽  
Stuart Cramer
Keyword(s):  
Bone Marrow ◽  
Amino Acid ◽  
Amino Acid Substitution ◽  
Sequence Variant ◽  
Type I ◽  
Red Cell ◽  
Female Fetus ◽  
Congenital Dyserythropoietic Anemia ◽  
Bone Marrow Evaluation ◽  
New Variant

Abstract Introduction: Congenital dyserythropoietic anemia (CDA) is a rare autosomal recessive condition that results in dyserythropoiesis and iron overload. Bone marrow evaluation in these patients demonstrates distinctive abnormalities in red cell precursors including multinucleated erythroblasts and chromatin bridges. Dysmorphisms such as distal limb abnormalities, skin pigmentation defects, vertebral malformations, and short stature may also be present. Mutations in the CDAN1/codanin-1 gene underlie the majority of CDA type I cases. We describe a previously unreported pathogenic variant. Case report: The female fetus of a gravida 2 para 1 woman was noted to have hepatomegaly, cardiomegaly, and elevated middle cerebral artery velocity concerning for severe intrauterine anemia at approximately 20 weeks gestation. The parents had one previous pregnancy that resulted in a stillborn male infant with hydrops fetalis and club foot. Given concern for anemia with this pregnancy, percutaneous umbilical cord blood sampling was performed demonstrating a fetal hematocrit of 9%. This severe fetal anemia was initially thought to be secondary to ABO incompatibility as mother was O- with a positive antibody screen and infant was A+. The fetus required four intrauterine transfusions and was delivered at 34 weeks 6 days via cesarean section due to history of previous cesarean. Exam revealed a phenotypically normal female with APGARs of 9/9 and a birth weight of 2130 grams. Following delivery the infant had serial blood counts performed over a 6-week period, which noted a steady decrease in her hematocrit to 16%. A transfusion was given, and a bone marrow evaluation revealed a cellular marrow with red cell hyperplasia and dyserythropoiesis. Next generation sequencing through PreventionGenetics was performed revealing a novel CDAN1 alteration. Results: The patient was found to be heterozygous for two mutations in trans in the CDAN1 gene: c.2072dupT and c.2093A>T. Discussion: We present a patient with severe fetal and infant transfusion dependent anemia who has two novel CDAN1 gene variants not previously described. The sequence variant c.2072dupT is predicted to result in a frameshift and premature protein termination and is expected to be pathogenic. The second variant c.2093A>T is predicted to result in an amino acid substitution (p.Glu698Val). Another amino acid substitution (p.Glu698Lys) was previously reported as pathogenic in an individual with congenital dyserythropoietic anemia. Based upon the clinical picture, morphologic characteristics, and genetic findings, we have concluded that this presentation is consistent with a diagnosis of CDA type I. Through the utilization of improved diagnostic techniques we continue to gain knowledge regarding the molecular underpinnings of CDA type I. Disclosures No relevant conflicts of interest to declare.

Congenital Dyserythropoietic Anemia Type II: Excessive Endoplasmic Reticulum in Erythroid Cells and Mitochondrial Inclusions of Hepatic Cells

1971 ◽  
Vol 29 ◽  
pp. 294-295
Author(s):  
George Hug ◽  
K. Y. Wong ◽  
Beatrice Lampkin
Keyword(s):  
Bone Marrow ◽  
Human Serum ◽  
Present Report ◽  
Initial Study ◽  
Red Cells ◽  
Type I ◽  
Red Cell ◽  
Type Ii ◽  
Erythroid Cells ◽  
Congenital Dyserythropoietic Anemia

Congenital dyserythropoietic anemia (CDA) as described in 1966 was characterized by (i) erythroblastic multinuclearity and (ii) lysis of the patient's red cells in acidified compatible normal human serum. This condition has since been labeled CDA Type II to distinguish it from a similar entity, CDA Type I, with erythroblastic multinuclearity but without red cell lysis in acidified human serum. According to this classification, our initial study of bone marrow ultrastructure in CDA concerned a girl with Type II. Her bone marrow contained erythroid cells with excessive cytoplasmic membranes and multiple nuclei. The present report illustrates this observation. The patient was a 12 year old white girl with congenital anemia and benign recurrent jaundice. Hemolysis was not present since Cr51 red cell survival time was normal. Bone marrow aspirates (Figure 1, 2 and 4) circulating red cells (Figure 3) and hepatic biopsy specimens were examined. The markers indicate 0.5 microns and N designates nucleus. The myeloid series was normal. Figure 1 shows a representative polychromatophilic normoblast.

Immunogenetic Characterization of Primary Immune Thrombocytopenia (ITP) in Adults: Preliminary Results of the Unit Study.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2192-2192
Author(s):  
Francesco Zaia ◽  
Elena Boggio ◽  
Davide Rossi ◽  
Eleonora Toffoletti ◽  
Giuseppe Cappellano ◽  
...  
Keyword(s):  
T Cells ◽  
Amino Acid ◽  
T Cell ◽  
Amino Acid Substitution ◽  
Cell Expansion ◽  
Clinical Presentation ◽  
Function Analysis ◽  
Similar Distribution ◽  
Type I ◽  
T Cell Expansion

Abstract Abstract 2192 Background. In adults, ITP displays variable clinical presentation and different response to steroid, Rituximab, and other immune suppressive agents. The pathophysiological differences underlying these different behaviours are mostly unknown and a better knowledge of this biological heterogeneity might help identifying more targeted and rationale treatments for this disease. Purpose. To identify immunogenetic features distinguishing ITP patients from control and different subsets of ITP patients based on clinical presentation and responsiveness to steroid or Rituximab. Several biological analyses were based on the model of autoimmune lymphoprolipherative syndrome (ALPS), a pediatric disease due to genetic defects decreasing function of the Fas death receptor involved in shutting off the immune response and cytotoxic cell function. ALPS displays polyclonal lymphoproliferation, peripheral blood (PB) expansion of TCRαβ+ T-cells double negative for CD4 and CD8 (DN T-cells) and autoimmune manifestations frequently including thrombocytopenia. ALPS is mostly due to deleterious mutations of the Fas gene, but the +1239A>C single nucleotide polymorphism (SNP) of the osteopontin gene (OPN) and several variations of the perforin gene (PRF1) can act as disease modifier. Moreover, defective Fas function and these OPN and PRF1 variations are also displayed by subsets of patients with multiple sclerosis, type-I diabetes mellitus, systemic lupus erythematosus, progressive sclerosis, and chronic inflammatory demyelinating polyneuropathy. Patients and Methods. Adult patients with ITP and matched controls were selected for the analyses and stratified in different clinical subsets according to the disease severity and responsiveness to therapy (asymptomatic, steroid or Rituximab sensitive vs. steroid or Rituximab refractory). Analyses included evaluation of Fas-mediated apoptosis in T cell cultures; proportions of DN-T cells in PB; typing of the +1239A>C SNP of OPN and sequencing of PRF1. All patients were also investigated for TCR monoclonality, whereas BCR monoclonality was analysed in Rituximab-untreated patients only. Results. Analysis of Fas function and DN T-cell expansion was assessed in 100 ITP patients and showed that they displayed higher frequency of defective Fas function than the controls (17/100 vs. 5/100; P<0.05). Expansion of DN T-cells was detected in 2/17 (12%) patients displaying defective Fas function and 3/83 (4%) of those with normal Fas function. Analysis of PRF1 and OPN was performed in 64 patients. Sequencing of PRF1 detected three patients carrying two rare variations; two carried the N252S amino acid substitution (previously described in ALPS) and one the novel R385W amino acid substitution. The overall frequency of these rare variations was higher in the patients than in the controls (4.7% vs. 0.8%, P<0.05). By contrast, the OPN +1239A>C SNP displayed a similar distribution in the patients and the controls. TCR monoclonality was assessed in 76 patients and was detected in 4 of them (5%). BCR monoclonality was assessed in 17 patients in PB and bone marrow and it was always absent. No statistical differences of these parameters were detected comparing patients refractory vs. sensitive to either Rituximab or steroid treatments. However, a trend was found for DN T-cell expansion that tended to be more frequent in Rituximab resistant vs. sensitive patients (0/13 vs. 4/20, P=0.13). Conclusions. These preliminary analyses detected some differences between ITP patients and controls suggesting that defects involved in ALPS development may play a role in adult ITP too. Increasing the patient number is needed to confirm these data and, possibly, to detect differences between clinical subgroups. Disclosures: Off Label Use: Rituximab in ITP.

scholarly journals Congenital Dyserythropoietic Anemia Type I Due to Biallelic CDAN1 mutations: Report from the Congenital Dyserythropoietic Anemia Registry (CDAR)

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3521-3521
Author(s):  
Omar Niss ◽  
Robert B. Lorsbach ◽  
David K. Buchbinder ◽  
Satheesh Chonat ◽  
Morgan L. McLemore ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Pulmonary Hypertension ◽  
Neonatal Jaundice ◽  
Macrocytic Anemia ◽  
Advisory Board ◽  
Type I ◽  
Severe Anemia ◽  
Congenital Dyserythropoietic Anemia ◽  
Hematological Manifestations

Congenital dyserythropoietic anemias (CDA) are rare hereditary diseases of abnormal erythropoiesis. The CDA Registry of North America (CDAR) (NCT02964494) was opened in 2016 to investigate the natural history and molecular biology of CDA. CDA type I (CDA-I) is a recessive form of CDA characterized by macrocytic anemia, hemolysis with inadequate reticulocytosis, and iron overload. The bone marrow shows binucleated erythroblasts with chromatin bridges by light microscopy and spongy heterochromatin in erythroblasts by electron microscopy. The phenotypic heterogeneity in presentation and course of CDA-I is remarkable. Most CDA-I cases are caused by biallelic mutations in CDAN1or C15orf41, and 10-20% do not have an identifiable mutation. Non-hematological features, especially skeletal features, were historically reported in 10-20% of patients (Wickramasinghe, 1998). Due to the rarity of CDA-I and its clinical overlap with several disorders, the diagnosis is often missed or delayed by up to 17 yrs (median) (Roy, 2019). We describe in this study the characteristics and clinical course of CDA-I patients due to CDAN1 mutations enrolled in CDAR. Patients with a phenotypic diagnosis of CDA and their family members were enrolled in CDAR. Clinical and demographic data were gathered from participants at study entry and updated periodically thereafter. Participants elect to give blood, bone marrow, and DNA samples to the biorepository associated with CDAR. Participants with a phenotypic diagnosis of CDA-I and confirmed mutations in CDAN1 were included in this study. Six participants had a diagnosis of CDA-I due to biallelic CDAN1 mutations, comprising 18% (6/33) of affected CDAR participants. CDAN1 mutations were found in 75% of cases diagnosed phenotypically as CDA-I. All six participants presented early in life with a variable degree of non-immune hemolysis, and the diagnosis was confirmed within a median of 2 years from presentation. The characteristics of participants are summarized in table 1. Two had family history of stillbirth or fetal demise in older siblings due to hydrops fetalis. One participant presented prenatally with fetal anemia and started intrauterine transfusions at 24 weeks of gestation; 2 presented with severe anemia and signs of hydrops, pulmonary hypertension, transaminitis, severe hyperbilirubinemia, and thrombocytopenia at birth; and 3 presented with neonatal jaundice and moderate anemia. All participants required blood transfusions in the neonatal period. Three had spontaneous improvement and did not require transfusions after the first year of life. One remained transfusion-dependent at last follow up at the age of 4 yrs. One became transfusion-independent after starting interferon-alpha at 1 yr of age and did not need further transfusions even after discontinuation at 3 yrs of age. One had splenectomy at 11 y.o because he was misdiagnosed to have a membrane disorder but presented in adulthood with hemolytic anemia and pulmonary hypertension and was diagnosed at that time with CDA-I by genetic sequencing. All participants had one or more non-hematological manifestations, including hypertrophic skin folds, onychocryptosis, curved toenails, syndactyly, café-au-lait spots, macrocephaly, spinal fusion, scoliosis, and short stature. One participant suffered a thalamic stroke in the postnatal period, 2 had transient neonatal pulmonary hypertension in the setting of severe anemia, and one had pulmonary hypertension post-splenectomy in adulthood. Ferritin was high in all participants at last follow up, and 4 received chelation therapy. In summary, mutations in CDAN1 are the most common identified mutations in CDAR. CDA-I causes early-onset macrocytic anemia, which may present prenatally, with variable severity of hemolysis ranging from hydrops to mild neonatal jaundice and anemia. Non-hematological manifestations, mainly skeletal, nail and skin abnormalities are more common in CDA-I than previously reported, and their presence in infants with unexplained anemia should raise suspicion for the diagnosis. The availability of molecular testing has significantly accelerated the diagnosis. Management of patients with CDA-I requires multidisciplinary approach from an early age to improve outcome. Collaboration between clinicians, scientists, patients, and families is needed to advance the understanding and treatment of this rare disease. Disclosures Chonat: Alexion: Other: advisory board; Agios Pharmaceuticals, Inc.: Other: advisory board. Kalfa:Agios: Other: local PI of clinical research trial; FORMA: Other: sponsored research agreement.

scholarly journals Codanin-1 Binds to Key Erythroid Genes and Its Knockdown Coupled with Ectopic Mutant Expression Recapitulates the Congenital Dyserythropoietic Anemia Type I (CDA I) Phenotype

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 360-360
Author(s):  
Linette Bosques ◽  
Caroline Tang ◽  
Diane Krause ◽  
Sherman M. Weissman ◽  
Patrick G Gallagher ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bone Marrow ◽  
Binding Sites ◽  
Erythroid Differentiation ◽  
Type I ◽  
Loss Of Function ◽  
Hemoglobin Content ◽  
Congenital Dyserythropoietic Anemia ◽  
Dna Binding Sites ◽  
Control Shrna

Abstract Congenital dyserythropoietic anemia type I (CDA I) is an autosomal recessive disorder marked by specific morphological abnormalities of erythroblasts in the bone marrow, resulting in ineffective erythropoiesis and anemia. CDA I principally affects the erythroid lineage, while other non-erythroid hematopoietic lineages are unaffected. Light microscopy of bone marrow shows erythroid hyperplasia and binucleated erythroblasts connected by internuclear bridges. Electron microscopy of bone marrow demonstrates erythroblasts with spongy heterochromatin and invagination of the nuclear membrane. The gene responsible for causing CDA I, CDAN1, encodes for a ubiquitous protein, codanin-1, with unknown function. The goal of our study is to understand how codanin-1 regulates erythropoiesis and how codanin-1 defects result in CDA I. To determine codanin-1 expression pattern during erythroid differentiation, we analyzed codanin-1 RNA and protein levels in erythroid primary cells and cell lines. RNA-seq conducted in erythroid-induced human primary CD34+ cells revealed codanin-1 RNA expression is maintained in erythroid lineage. Similarly, immunoblotting shows codanin-1 protein is expressed at high levels in human erythroleukemia cell line stimulated down the erythroid lineage. Codanin-1 has been identified as a chromatin-binding protein. Thus, we conducted ChIP-seq analysis to determine the location of DNA binding sites for codanin-1 in K562 cells. The ChIP-seq results identified 2534 binding sites for codanin-1. Interestingly, many of these sites belong to key erythroid genes. Furthermore, 28% of these DNA binding sites overlap with GATA-1 bound sites. Because putative loss of function mutations in CDAN1 result in CDA I, we studied the effects of codanin-1 gene silencing on erythroid differentiation. shRNA-mediated knockdown reduced codanin-1 mRNA by 50% and protein expression levels by 90%. To assess the effects of codanin-1 perturbation on erythroid differentiation, hemoglobin synthesis was quantified using Drabkin’s reagent in which the absorbance measured at 540 nm is proportional to hemoglobin content in the sample. Erythroid-induced knockdown cells displayed decreased hemoglobin content when compared to non-targeting control shRNA (0.20 versus 0.48, measured in 3 separate experiments; p<0.01). In order to assess binuclearity of the knockdown cells, we stained cytospin slides with Wright Giemsa to assess nuclear morphology. Codanin-1 knockdown cells showed increased binuclearity when compared to control shRNA cells (6% versus 1%, measured in 3 separate experiments; p<0.01). Furthermore, we quantified changes in gene expression induced by codanin-1 gene silencing. Quantitative PCR showed that knockdown of codanin-1 decreased expression of key erythroid genes. To establish a robust CDA I cell system, the first well-characterized CDAN1 mutation (R1042W) was studied because codanin-1 deletion mutants are embryonic lethal in mice and do not occur in humans. Endogenous codanin-1 knockdown cells were transduced with mutant or wild type codanin-1 and induced down the erythroid lineage. Because CDA I is characterized by abnormal heterochromatin appearance, we conducted electron microscopy studies to examine the ultrastructural features. Studies show that knockdown of endogenous codanin-1 coupled with ectopic expression of mutant codanin-1 results in recapitulation of the CDA I phenotype in the K562 cell line model. Because CDA I is almost exclusively restricted to the erythroid lineage, understanding its pathophysiology has the potential to identify critical pathways in erythropoiesis. Here we show that the full phenotype of CDA I is recapitulated upon not only the loss of function of the codanin-1 protein but also on the expression of the mutant form of codanin-1. Our analysis demonstrates that codanin-1 binds to important erythroid loci, suggesting that codanin-1 affects the expression of erythroid genes. Further work will focus on studying codanin-1 function in human primary erythroid cells and in animal models. Disclosures No relevant conflicts of interest to declare.

scholarly journals Hemoglobin Köln in a Black: Preand PostSplenectomy Red Cell Survival (DF32P and 51Cr) and the Pathogenesis of Hemoglobin Instability

Blood ◽  
1973 ◽  
Vol 42 (5) ◽  
pp. 771-781 ◽  
Author(s):  
Paul R. Pedersen ◽  
Paul R. McCurdy ◽  
R. N. Wrightstone ◽  
J. B. Wilson ◽  
L. L. Smith ◽  
...  
Keyword(s):  
Platelet Count ◽  
Amino Acid ◽  
Life Span ◽  
Cell Survival ◽  
Amino Acid Substitution ◽  
Black Male ◽  
Red Cell ◽  
Dimer Formation ◽  
Cell Life ◽  
Red Cell Survival

Abstract A 17-yr-old black male with hemolysis and pigmenturia but no anemia was found to have hemoglobin Köln (α2β298 val→met [FG5]). Splenectomy was done because of complicating thrombocytopenia. Thrombokinetic studies with 51Cr tagged platelets suggested hypersplenism, and after surgery the platelet count returned to normal. The red cell t ½ 51Cr was more than doubled, but the red cell life span (DF32P) was more modestly improved (30.6 → 47.2 days). The "elution" of 51Cr from the red cells presplenectomy was 5.6%/day, whereas after surgery it was normal (1.9%/day), accounting for the disparity between the survival methods. Study of the isolated cyanferri derivative of hemoglobin Köln by ultracentrifugation at various salt concentrations and various pH’s indicated an increased tendency to dimer formation under conditions where normal hemoglobin is a tetramer. This results from the site and type of amino acid substitution and accounts in part for its instability.

scholarly journals Evaluation of a new variant in the aggrecan gene potentially associated with chondrodysplastic dwarfism in Miniature horses

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Danilo Giorgi Abranches de Andrade ◽  
Roberta Martins Basso ◽  
Angelo José Magro ◽  
Renée Laufer-Amorim ◽  
Alexandre Secorun Borges ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Amino Acid ◽  
Amino Acid Substitution ◽  
Autosomal Recessive ◽  
Autosomal Recessive Disorder ◽  
Dwarf Phenotype ◽  
Horse Genome ◽  
Complex Interactions ◽  
New Variant ◽  
Exon 11

Abstract Chondrodysplastic dwarfism in Miniature horses is an autosomal recessive disorder previously associated with four mutations (D1, D2, D3*, and D4) in the aggrecan (ACAN) gene. The aim of this study was to identify additional variants in the candidate ACAN gene associated with chondrodysplastic dwarfism in Miniature horses. Fifteen dwarf Miniature horses were found to possess only one of the dwarfism-causing variants, and two possessed none of the variants. The ACAN exons (EquCab3.0) of seven dwarf Miniature horses were sequenced. A missense SNP in coding exon 11 (g.95271115A > T, c.6465A > T—RefSeq XM_005602799.2), which resulted in the amino acid substitution p.Leu2155Phe (RefSeq XP_005602856.2), was initially associated with the dwarf phenotype. The variant was tested and found present in 14 dwarf foals as well as one parent of each, and both parents of a dwarf possessing two copies. Genetic testing of 347 phenotypically normal Miniature horses demonstrated that none had more than one of the dwarf alleles or c.6465A > T. However, a study of large breeds revealed the presence of c.6465A > T, which was present in homozygosis in two Mangalarga Marchador horses. We suggest that c.6465A > T as a marker of disequilibrium or complex interactions in the Miniature horse genome could contribute to the associated dwarfism.

Amino acid substitution R384P in aldosterone synthase causes corticosterone methyloxidase type I deficiency.

1995 ◽  
Vol 80 (2) ◽  
pp. 424-429
Author(s):  
S Geley ◽  
K Jöhrer ◽  
M Peter ◽  
K Denner ◽  
R Bernhardt ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Type I ◽  
Aldosterone Synthase

A Novel Missense Mutation in the Gene for Lipoprotein Lipase Resulting in a Highly Conservative Amino Acid Substitution (Asp180→Glu) Causes Familial Chylomicronemia (Type I Hyperlipoproteinemia)

Genomics ◽  
1993 ◽  
Vol 18 (2) ◽  
pp. 392-396 ◽  
Author(s):  
Sabine Haubenwallner ◽  
Gerd Hörl ◽  
Neil S. Shachter ◽  
Elio Presta ◽  
Susan K. Fried ◽  
...  
Keyword(s):  
Amino Acid ◽  
Missense Mutation ◽  
Lipoprotein Lipase ◽  
Amino Acid Substitution ◽  
Type I

scholarly journals Analysis of the ARTIC version 3 and version 4 SARS-CoV-2 primers and their impact on the detection of the G142D amino acid substitution in the spike protein

2021 ◽  
Author(s):  
James Davis ◽  
Scott Wesley Long ◽  
Paul Christensen ◽  
Randall J Olsen ◽  
Robert Olson ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Drop Out ◽  
Spike Protein ◽  
Clinical Samples ◽  
New Variant ◽  
Common Resource ◽  
Improved Performance ◽  
Primer Sets ◽  
Public Repositories

The ARTIC Network provides a common resource of PCR primer sequences and recommendations for amplifying SARS-CoV-2 genomes. The initial tiling strategy was developed with the reference genome Wuhan-01, and subsequent iterations have addressed areas of low amplification and sequence drop out. Recently, a new version (V4) was released, based on new variant genome sequences, in response to the realization that some V3 primers were located in regions with key mutations. Herein, we compare the performance of the ARTIC V3 and V4 primer sets with a matched set of 663 SARS-CoV-2 clinical samples sequenced with an Illumina NovaSeq 6000 instrument. We observe general improvements in sequencing depth and quality, and improved resolution of the SNP causing the D950N variation in the spike protein. Importantly, we also find nearly universal presence of spike protein substitution G142D in Delta-lineage samples. Due to the prior release and widespread use of the ARTIC V3 primers during the initial surge of the Delta variant, it is likely that the G142D amino acid substitution is substantially underrepresented among early Delta variant genomes deposited in public repositories. In addition to the improved performance of the ARTIC V4 primer set, this study also illustrates the importance of the primer scheme in downstream analyses.

scholarly journals New Variant of CTX-M-Type Extended-Spectrum β-Lactamases, CTX-M-71, with a Gly238Cys Substitution in a Klebsiella pneumoniae Isolate from Bulgaria

2009 ◽  
Vol 53 (10) ◽  
pp. 4518-4521 ◽  
Author(s):  
Ines Schneider ◽  
Anne Marie Queenan ◽  
Rumyana Markovska ◽  
Boyka Markova ◽  
Emma Keuleyan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Amino Acid Substitution ◽  
Hydrolytic Activity ◽  
Extended Spectrum ◽  
New Variant

ABSTRACT A single K lebsiella pneumoniae strain isolated in a Bulgarian hospital was found to produce CTX-M-71, a new CTX-M variant characterized by one amino acid substitution from glycine to cysteine at position 238 in comparison to CTX-M-15. This exchange decreased the hydrolytic activity of the β-lactamase for cefotaxime, ceftazidime, and cefepime.

Sign in / Sign up

Export Citation Format

Share Document