RESUMEN

ST11-KL47 is a hypervirulent carbapenem-resistant Klebsiella pneumoniae (CRKP) that is highly prevalent in China and poses a major public health risk. To investigate the evolutionary dynamics of virulence genes in this subclone, we analysed 78 sequenced isolates obtained from a long-term study across 29 centres from 17 cities in China. Virulence genes were located in large hybrid pNDM-Mar-like plasmids (length: ∼266 kilobases) rather than in classical pK2044-like plasmids. These hybrid plasmids, derived from the fusion of pK2044 and pNDM-Mar plasmids mediated by insertion sequence (IS) elements (such as ISKpn28 and IS26), integrated virulence gene fragments into the chromosome. Analysis of 217 sequences containing the special IncFIB (pNDM-Mar) replicon using public databases indicated that these plasmids typically contained T4SS-related and multiple antimicrobial resistance genes, were present in 24 countries, and were found in humans, animals, and the environment. Notably, the chromosomal integration of virulence genes was observed in strains across five countries across two continents. In vivo and in vitro models showed that the large hybrid plasmid increased the host fitness cost while increasing virulence. Conversely, virulence genes transferred to chromosomes resulted in increased fitness and lower virulence. In conclusion, virulence genes in the plasmids of ST11-KL47 CRKP are evolving, driven by adaptive negative selection, to enable vertical chromosomal inheritance along with conferring a survival advantage and low pathogenicity.

Asunto(s)

Enterobacteriaceae Resistentes a los Carbapenémicos , Evolución Molecular , Infecciones por Klebsiella , Klebsiella pneumoniae , Plásmidos , Factores de Virulencia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/patogenicidad , Plásmidos/genética , Humanos , Infecciones por Klebsiella/microbiología , Infecciones por Klebsiella/epidemiología , China , Factores de Virulencia/genética , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Enterobacteriaceae Resistentes a los Carbapenémicos/patogenicidad , Animales , Virulencia/genética , Antibacterianos/farmacología , Carbapenémicos/farmacología

RESUMEN

INTRODUCTION: Neonatal diabetes is a rare disease with incidence estimated at 1 in 300,000 to 1 in 400,000 live births. Walcott-Rallison syndrome has been identified as the most common cause of permanent neonatal diabetes in consanguineous families caused by mutations in eukaryotic translation initiation factor 2-α kinase 3 (EIF2AK3), characterized by permanent neonatal diabetes associated with liver dysfunction, multiple epiphyseal dysplasia, and developmental delay. We herein report 3 cases of genetically proven Wolcott-Rallison syndrome with variable phenotype presentation. CASE SERIES: All cases presented with high glucose levels and were treated with insulin. EIF2AK3 homozygous mutation was identified in all 3 on genetic analysis. Initial screening testing for associated comorbidities was normal, including X-ray examination, which did not show any signs of epiphyseal dysplasia in all cases. Case 2 and case 3 were both lost to follow-up and were later found to have expired at the ages of 18 months and 2 years, respectively, due to liver failure associated with intercurrent respiratory illness in hospitals in their native towns. Case one is now 2 years old on regular follow-up in paediatric Endocrine and neurology clinics and doing well so far. CONCLUSIONS: Morbidity, as well as mortality, is high among children with WRS neonatal diabetes. It is crucial to screen for gene mutation in patients with diabetes diagnosed before 6 months. Close therapeutic monitoring is recommended in WRS because of the risk of acute episodes of hypoglycaemia and ketoacidosis.

Asunto(s)

Diabetes Mellitus Tipo 1 , Diabetes Mellitus , Insulinas , Osteocondrodisplasias , Diabetes Mellitus/etiología , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/genética , Epífisis/anomalías , Glucosa , Humanos , Mutación , Osteocondrodisplasias/complicaciones , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/genética , Factor 2 Procariótico de Iniciación/genética

RESUMEN

AIMS: Neonatal diabetes mellitus (NDM) is a rare disease where diabetes presents during the first six months of life. There are two types of this disorder: permanent neonatal diabetes (PNDM) and transient neonatal diabetes mellitus (TNDM). PNDM occurs due to mutations in genes involved in either beta-cell survival, insulin regulation, and secretion. This study aims to define the genetic aetiology and clinical phenotypes of PNDM in a large Egyptian cohort from a single centre. METHODS: Patients with PNDM who were diagnosed, treated, or referred for follow-up between January 2002 and January 2021 were identified and clinically phenotyped. All patients were tested for mutations in EIF2AK3, KCNJ11, ABCC8, INS, FOXP3, GATA4, GATA6, GCK, GLIS3, HNF1B, IER3IP1, PDX1, PTF1A, NEUROD1, NEUROG3, NKX2-2, RFX6, SLC2A2, SLC19A2, STAT3, WFS1, ZFP57 using targeted next-generation sequencing (NGS) panel. INSR gene mutation was tested in one patient who showed clinical features of insulin resistance. RESULTS: Twenty-nine patients from twenty-six families were diagnosed with PNDM. Pathogenic variants were identified in 17/29 patients (59%). EIF2AK3, INS, and KATP channel mutations were the commonest causes with frequency of 17%, 17%, and 14%, respectively. Patients with ABBC8 and KCNJ11 mutations were successfully shifted to sulfonylureas (SU). Paired data of glycosylated haemoglobin before and after SU transfer showed improved glycaemic control; 9.6% versus 7.1%, P = 0.041. CONCLUSIONS: PNDM is a heterogenous disease with variable genotypes and clinical phenotypes among Egyptian patients. EIF2AK3, INS, ABCC8, and KCNJ11 mutations were the commonest causes of PNDM in the study cohort. All patients with KATP channel mutations were effectively treated with glyburide, reflecting the fact that genetic testing for patients with NDM is not only important for diagnosis but also for treatment plan and prognosis.

Asunto(s)

Diabetes Mellitus , Diabetes Mellitus/epidemiología , Diabetes Mellitus/genética , Pruebas Genéticas , Proteína Homeobox Nkx-2.2 , Proteínas de Homeodominio , Humanos , Lactante , Insulina/genética , Proteínas de Transporte de Membrana , Mutación , Proteínas Nucleares , Fenotipo , Factores de Transcripción

RESUMEN

BACKGROUND: Neonatal diabetes mellitus (NDM) is a rare condition that occurs within the first six months of life. Permanent NDM (PNDM) is caused by mutations in specific genes that are known for their expression at early and/or late stages of pancreatic beta- cell development, and are either involved in beta-cell survival, insulin processing, regulation, and release. The native population in Qatar continues to practice consanguineous marriages that lead to a high level of homozygosity. To our knowledge, there is no previous report on the genomics of NDM among the Qatari population. The aims of the current study are to identify patients with NDM diagnosed between 2001 and 2016, and examine their clinical and genetic characteristics. METHODS: To calculate the incidence of PNDM, all patients with PNDM diagnosed between 2001 and 2016 were compared to the total number of live births over the 16-year-period. Whole Genome Sequencing (WGS) was used to investigate the genetic etiology in the PNDM cohort. RESULTS: PNDM was diagnosed in nine (n = 9) patients with an estimated incidence rate of 1:22,938 live births among the indigenous Qatari. Seven different mutations in six genes (PTF1A, GCK, SLC2A2, EIF2AK3, INS, and HNF1B) were identified. In the majority of cases, the genetic etiology was part of a previously identified autosomal recessive disorder. Two novel de novo mutations were identified in INS and HNF1B. CONCLUSION: Qatar has the second highest reported incidence of PNDM worldwide. A majority of PNDM cases present as rare familial autosomal recessive disorders. Pancreas associated transcription factor 1a (PTF1A) enhancer deletions are the most common cause of PNDM in Qatar, with only a few previous cases reported in the literature.

Asunto(s)

Diabetes Mellitus/diagnóstico , Glucemia/análisis , Diabetes Mellitus/epidemiología , Diabetes Mellitus/genética , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/genética , Elementos de Facilitación Genéticos , Epífisis/anomalías , Síndrome de Fanconi/diagnóstico , Síndrome de Fanconi/genética , Femenino , Eliminación de Gen , Quinasas del Centro Germinal/genética , Transportador de Glucosa de Tipo 2/genética , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/genética , Linaje , Fenotipo , Qatar , Factores de Transcripción/genética , Secuenciación Completa del Genoma

RESUMEN

PURPOSE OF REVIEW: MODY6 due to mutations in the gene NEUROD1 is very rare, and details on its clinical manifestation and pathogenesis are scarce. In this review, we have summarized all reported cases of MODY6 diagnosed by genetic testing, and examined their clinical features in detail. RECENT FINDINGS: MODY6 is a low penetrant MODY, suggesting that development of the disease is affected by genetic modifying factors, environmental factors, and/or the effects of interactions of genetic and environmental factors, as is the case with MODY5. Furthermore, while patients with MODY6 can usually achieve good glycemic control without insulin, when undiagnosed they are prone to become ketotic with chronic hyperglycemia, and microangiopathy can progress. MODY6 may also cause neurological abnormalities such as intellectual disability. MODY6 should be diagnosed early and definitively by genetic testing, so that the correct treatment can be started as soon as possible to prevent chronic hyperglycemia.

Asunto(s)

Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Diabetes Mellitus Tipo 2/genética , Proteínas del Tejido Nervioso/genética , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/química , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/fisiología , Enfermedad Crónica , Diabetes Mellitus Tipo 2/diagnóstico , Pruebas Genéticas , Humanos , Hiperglucemia/genética , Hiperglucemia/prevención & control , Recién Nacido , Ratones , Mutación , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/fisiología

RESUMEN

PURPOSE OF REVIEW: The goal of this review is to provide updates on congenital (neonatal) diabetes from 2011 to present, with an emphasis on publications from 2015 to present. RECENT FINDINGS: There has been continued worldwide progress in uncovering the genetic causes of diabetes presenting within the first year of life, including the recognition of nine new causes since 2011. Management has continued to be refined based on underlying molecular cause, and longer-term experience has provided better understanding of the effectiveness, safety, and sustainability of treatment. Associated conditions have been further clarified, such as neurodevelopmental delays and pancreatic insufficiency, including a better appreciation for how these "secondary" conditions impact quality of life for patients and their families. While continued research is essential to understand all forms of congenital diabetes, these cases remain a compelling example of personalized genetic medicine.

Asunto(s)

Diabetes Mellitus/congénito , Diabetes Mellitus/genética , Pruebas Genéticas/métodos , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/economía , Impresión Genómica , Humanos , Insulina/genética , Mutación/genética , Calidad de Vida

RESUMEN

Small RNAs (sRNAs) play significant roles in regulating gene expression post-transcriptionally in response to environmental changes in bacteria. In this work, we identified and characterized six novel sRNAs from an emerging multidrug-resistance (MDR) plasmid pNDM-HK, a New Delhi metallo-ß-lactamase 1 gene (blaNDM-1)-carrying IncL/M plasmid that has caused worldwide threat in recent years. These sRNAs are located at different regions of pNDM-HK, such as replication, stability, and variable regions. Moreover, one of the plasmid-encoded sRNAs (NDM-sR3) functions in an Hfq-dependent manner and possibly plays roles in the fitness of pNDM-HK carrying bacteria. In addition, we attempted to construct the phylogenetic tree based on these novel sRNAs and surprisingly, the sRNA-phylogenetic tree provided significant information about the evolutionary pathway of pNDM-HK, including possible gene acquisition and insertion from relevant plasmids. Moreover, the sRNA-phylogenetic tree can specifically cluster the IncM2 type and distinguish it from other IncL/M subtypes. In summary, this is the first study to systematically identify and characterize sRNAs from clinically-isolated MDR plasmids. We believe that these newly found sRNAs could lead to further understanding and new directions to study the evolution and dissemination of the clinically MDR bacterial plasmids.

RESUMEN

A carbapenemase-producing Enterobacter cloacae hhy03 with a blaNDM-1 and blaSHV-12-coharboring plasmid was isolated from a sputum specimen of a patient. This is the third nucleotide sequence report of blaNDM-1-harboring plasmid from Enterobacter cloacae that have caused lethal infections in China, indicating the spread of NDM-1 by IncX3 plasmid between Enterobacteriaceae.

Asunto(s)

Enterobacter cloacae/efectos de los fármacos , Enterobacter cloacae/genética , Infecciones por Enterobacteriaceae/microbiología , Plásmidos/genética , beta-Lactamasas/genética , Anciano , Antibacterianos/farmacología , Proteínas Bacterianas/genética , China , Enterobacter cloacae/enzimología , Humanos , Lactante , Klebsiella pneumoniae/genética , Masculino , Pruebas de Sensibilidad Microbiana , Esputo/microbiología , Resistencia betalactámica/genética

RESUMEN

Monogenic diabetes is a rare genetic type of diabetes caused by pancreatic ß-cells dysfunction. All subtypes of monogenic diabetes are recognized in the pediatric population. They include maturity onset diabetes of the young, permanent neonatal diabetes mellitus and rare syndromic forms of diabetes. An early and proper diagnosis allows to implement an optimal treatment, leads to improved metabolic control and amelioration of related disabilities as well as increases the quality of life of the patients.

Asunto(s)

Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus/genética , Adulto , Síndrome de Alstrom/diagnóstico , Síndrome de Alstrom/genética , Síndrome de Bardet-Biedl/diagnóstico , Síndrome de Bardet-Biedl/genética , Diabetes Mellitus/diagnóstico , Diabetes Mellitus Tipo 2/diagnóstico , Glucoquinasa/antagonistas & inhibidores , Humanos , Células Secretoras de Insulina/citología , Mutación , Polonia , Calidad de Vida , Reino Unido , Síndrome de Wolfram/diagnóstico , Síndrome de Wolfram/genética

RESUMEN

Objective To investigate the relationship between the resistance of the Klebsiella pneumoni-ae and the Klebsiella pneumoniae plasmid pNDM-LJ carrying blaNDM-1 by high-throughput DNA sequencing. Methods High-throughput DNA sequencing was carried out by the Illumina Miseq platform , and sequencing data were assembled by Edena software. Contigs were annotated by the RAST server and analyzed by the BLAST server. Results The plasmid pNDM-LJ was 54-kb in size with a GC content of 49%. The plasmid encoded 52 putative functional genes and belonged to the IncX3 group in incompatible classifications. Analysis of the plasmid sequence revealed high similarity with other IncX3 plasmids. The blaNDM-1 gene was located in a complicated gene environment possibly constructed by several transposition events. The 5′ and 3′ ends of the blaNDM-1 gene were adjacent to the ISAba125 and IS 26 respectively , forming a 10.8-kb transposon-like structure. Conclusion The plasmid pNDM-LJ carried the blaNDM-1 gene being resistant to carbapenems and played a possibly impor-tant role in transmission of blaNDM-1 in China.

RESUMEN

BACKGROUND: Permanent neonatal diabetes mellitus (PNDM) is a rare disorder, characterized by uncontrolled hyperglycemia diagnosed during the first 6 months of life. In general, PNDM has a genetic origin and most frequently it results from heterozygous mutations in KCNJ11, INS and ABCC8 genes. Homozygous or compound heterozygous inactivating mutations in GCK gene as cause of PNDM are rare. In contrast, heterozygosis for GCK inactivating mutations is frequent and results in the maturity-onset diabetes of young (MODY), manifested by a mild fasting hyperglycemia usually detected later in life. Therefore, as an autosomal recessive disorder, GCK-PNDM should be considered in families with history of glucose intolerance or MODY in first relatives, especially when consanguinity is suspected. RESULTS: Here we describe two patients born from non-consanguineous parents within a family. They presented low birth weight with persistent hyperglycemia during the first month of life. Molecular analyses for KCNJ11, INS, ABCC8 did not show any mutation. GCK gene sequencing, however, revealed that both patients were compound heterozygous for two missense combined in a novel GCK-PNDM genotype. The p.Asn254His and p.Arg447Gly mutations had been inherited from their mothers and fathers, respectively, as their mothers are sisters and their fathers are brothers. Parents had been later diagnosed as having GCK-MODY. CONCLUSIONS: Mutations' in silico analysis was carried out to elucidate the role of the amino acid changes on the enzyme structure. Both p.Asn254His and p.Arg447Gly mutations appeared to be quite damaging. This is the first report of GCK-PNDM in a Brazilian family.

RESUMEN

A carbapenem resistant Salmonella enterica serovar Senftenberg isolate BCH 2406 was isolated from a diarrheal child attending an outpatient unit of B.C. Roy Hospital in Kolkata, India. This isolate was positive for the bla NDM-1 in the PCR assay, which was confirmed by amplicon sequencing. Except for tetracycline, this isolate was resistant to all the tested antimicrobials. The bla NDM-1 was found to be located on a 146.13-kb mega plasmid pNDM-SAL, which could be conjugally transferred into Escherichia coli and other enteric pathogens such as Vibrio cholerae O1 Ogawa and Shigella flexneri 2a. However, the expression of ß-lactam resistance is not the same in different bacteria. The whole genome sequence of pNDM-SAL was determined and compared with other pNDM plasmids available in public domain. This plasmid is an IncA/C incompatibility type composed of 155 predicted coding sequences and shares homology with plasmids of E. coli pNDM-1_Dok01, Klebsiella pNDM-KN, and Citrobacter pNDM-CIT. In pNDM-SAL, gene cluster containing bla NDM-1 was located between IS26 and IS4321 elements. Between the IS26 element and the bla NDM-1, a truncated ISAba125 insertion sequence was identified. Downstream of the bla NDM-1, other genes, such as ble MBL, trpF, tat, and an ISCR1 element with class 1 integron containing aac(6')-Ib were detected. Another ß-lactacamase gene, bla CMY -4 was found to be inserted in IS1 element within the type IV conjugative transfer loci of the plasmid. This gene cluster had blc and sugE downstream of the bla CMY -4. From our findings, it appears that the strain S. Senftenberg could have acquired the NDM plasmid from the other members of Enterobacteriaceae. Transfer of NDM plasmids poses a danger in the management of infectious diseases.

RESUMEN

OBJECTIVE: This study describes the clinical and genetic evaluation of permanent neonatal diabetes due to Wolcott-Rallison syndrome (WRS) in south Indian consanguineous families. We aimed to evaluate the genetic basis of the disease in eight children with WRS from five South Indian families. PATIENTS AND METHODS: We studied eight children who presented with permanent neonatal diabetes from five South Indian families. Follow up clinical evaluation revealed features (like liver disease, skeletal dysplasia, and thyroid dysfunction) suggestive of WRS. All the coding exons along with splice sites of KCNJ11, ABCC8, INS, GCK and EIF2AK3 genes were sequenced in all the probands. RESULTS: Two novel homozygous mutations (Trp658Ser, c.3150+1G>T) and one known homozygous mutation (Arg1065*, c.3193C>T) in EIF2AK3 gene were identified in children with WRS. Mutation Arg1065*was identified in four children. CONCLUSIONS: Our results in these families show that the mutations in homozygous state are likely to be causative. We suggest the screening for EIF2AK3 gene mutations as WRS is now recognized as the most frequent cause of neonatal diabetes in children with consanguineous parents. As the mode of inheritance is recessive, screening for genetic mutations becomes important to aid in risk prediction and clinical management.

Asunto(s)

Diabetes Mellitus Tipo 1/genética , Epífisis/anomalías , Mutación , Osteocondrodisplasias/genética , eIF-2 Quinasa/genética , Sustitución de Aminoácidos , Hipotiroidismo Congénito/etiología , Hipotiroidismo Congénito/fisiopatología , Consanguinidad , Diabetes Mellitus Tipo 1/mortalidad , Diabetes Mellitus Tipo 1/fisiopatología , Epífisis/fisiopatología , Femenino , Estudios de Seguimiento , Estudios de Asociación Genética , Insuficiencia Hepática/etiología , Insuficiencia Hepática/fisiopatología , Homocigoto , Humanos , India , Lactante , Recién Nacido , Masculino , Osteocondrodisplasias/mortalidad , Osteocondrodisplasias/fisiopatología , Linaje , Mutación Puntual , Insuficiencia Renal Crónica/etiología , Insuficiencia Renal Crónica/fisiopatología , Índice de Severidad de la Enfermedad