Investigation of an Escherichia coli O145 outbreak in a child day-care centre - extensive sampling and characterization of eae- and stx1-positive E. coli yields epidemiological and socioeconomic insight

<p>Abstract</p> <p>Background</p> <p>On October 29^th2009 the health authorities in the city of Trondheim, Norway were alerted about a case of Shiga toxin-positive <it>E. coli </it>(STEC) O145 in a child with bloody diarrhoea attending a day-care centre. Symptomatic children in this day-care centre were sampled, thereby identifying three more cases. This initiated an outbreak investigation.</p> <p>Methods</p> <p>A case was defined as a child attending the day-care centre, in whom <it>eae- </it>and <it>stx</it>₁- but not <it>stx</it>₂-positive <it>E. coli </it>O145:H28 was diagnosed from a faecal sample, with multilocus variable number of tandem repeat analysis (MLVA) profile identical to the index isolate. All 61 children, a staff of 14 in the day-care centre, and 74 close contacts submitted faecal samples. Staff and parents were interviewed about cases' exposure to foods and animals. Faecal samples from 31 ewes from a sheep herd to which the children were exposed were analyzed for <it>E. coli </it>O145.</p> <p>Results</p> <p>Sixteen cases were identified, from which nine presented diarrhoea but not haemolytic uremic syndrome (HUS). The attack rate was 0.26, and varied between age groups (0.13-0.40) and between the three day-care centre departments (0.20-0.50), and was significantly higher amongst the youngest children. Median duration of shedding was 20 days (0-71 days). Children were excluded from the day-care centre during shedding, requiring parents to take compassionate leave, estimated to be a minimum total of 406 days for all cases. Atypical enteropathogenic <it>E. coli </it>(aEPEC) were detected among 14 children other than cases. These isolates were genotypically different from the outbreak strain. Children in the day-care centre were exposed to faecal pollution from a sheep herd, but <it>E. coli </it>O145 was not detected in the sheep.</p> <p>Conclusions</p> <p>We report an outbreak of <it>stx</it>₁- and <it>eae-</it>positive STEC O145:H28 infection with mild symptoms among children in a day-care centre. Extensive sampling showed occurrence of the outbreak strain as well as other STEC and aEPEC strains in the outbreak population. MLVA-typing of the STEC-isolates strongly indicates a common source of infection. The study describes epidemiological aspects and socioeconomic consequences of a non-O157 STEC outbreak, which are less commonly reported than O157 outbreaks.</p

Review of juxtaglomerular cell tumor with focus on pathobiological aspect

Juxtaglomerular cell tumor (JGCT) generally affects adolescents and young adults. The patients experience symptoms related to hypertension and hypokalemia due to renin-secretion by the tumor. Grossly, the tumor is well circumscribed with fibrous capsule and the cut surface shows yellow or gray-tan color with frequent hemorrhage. Histologically, the tumor is composed of monotonous polygonal cells with entrapped normal tubules. Immunohistochemically, tumor cells exhibit a positive reactivity for renin, vimentin and CD34. Ultrastructurally, neoplastic cells contain rhomboid-shaped renin protogranules. Genetically, losses of chromosomes 9 and 11 were frequently observed. Clinically, the majority of tumors showed a benign course, but rare tumors with vascular invasion or metastasis were reported. JGCT is a curable cause of hypertensive disease if it is discovered early and surgically removed, but may cause a fatal outcome usually by a cerebrovascular attack or may cause fetal demise in pregnancy. Additionally, pathologists and urologists need to recognize that this neoplasm in most cases pursues a benign course, but aggressive forms may develop in some cases

Infant High-Grade Gliomas Comprise Multiple Subgroups Characterized by Novel Targetable Gene Fusions and Favorable Outcomes.

Infant high-grade gliomas appear clinically distinct from their counterparts in older children, indicating that histopathologic grading may not accurately reflect the biology of these tumors. We have collected 241 cases under 4 years of age, and carried out histologic review, methylation profiling, and custom panel, genome, or exome sequencing. After excluding tumors representing other established entities or subgroups, we identified 130 cases to be part of an "intrinsic" spectrum of disease specific to the infant population. These included those with targetable MAPK alterations, and a large proportion of remaining cases harboring gene fusions targeting ALK (n = 31), NTRK1/2/3 (n = 21), ROS1 (n = 9), and MET (n = 4) as their driving alterations, with evidence of efficacy of targeted agents in the clinic. These data strongly support the concept that infant gliomas require a change in diagnostic practice and management. SIGNIFICANCE: Infant high-grade gliomas in the cerebral hemispheres comprise novel subgroups, with a prevalence of ALK, NTRK1/2/3, ROS1, or MET gene fusions. Kinase fusion-positive tumors have better outcome and respond to targeted therapy clinically. Other subgroups have poor outcome, with fusion-negative cases possibly representing an epigenetically driven pluripotent stem cell phenotype.See related commentary by Szulzewsky and Cimino, p. 904.This article is highlighted in the In This Issue feature, p. 890

High frequency of hybrid Escherichia coli strains with combined Intestinal Pathogenic Escherichia coli (IPEC) and Extraintestinal Pathogenic Escherichia coli (ExPEC) virulence factors isolated from human faecal samples

Abstract Background Classification of pathogenic Escherichia coli (E. coli) has traditionally relied on detecting specific virulence associated genes (VAGs) or combinations thereof. For E. coli isolated from faecal samples, the presence of specific genes associated with different intestinal pathogenic pathovars will determine their classification and further course of action. However, the E. coli genome is not a static entity, and hybrid strains are emerging that cross the pathovar definitions. Hybrid strains may show gene contents previously associated with several distinct pathovars making the correct diagnostic classification difficult. We extended the analysis of routinely submitted faecal isolates to include known virulence associated genes that are usually not examined in faecal isolates to detect the frequency of possible hybrid strains. Methods From September 2012 to February 2013, 168 faecal isolates of E. coli routinely submitted to the Norwegian Institute of Public Health (NIPH) from clinical microbiological laboratories throughout Norway were analysed for 33 VAGs using multiplex-PCR, including factors associated with extraintestinal pathogenic E. coli (ExPEC) strains. The strains were further typed by Multiple Locus Variable-Number Tandem-Repeat Analysis (MLVA), and the phylogenetic grouping was determined. One isolate from the study was selected for whole genome sequencing (WGS) with a combination of Oxford Nanopore’s MinION and Illumina’s MiSeq. Results The analysis showed a surprisingly high number of strains carrying ExPEC associated VAGs and strains carrying a combination of both intestinal pathogenic E. coli (IPEC) and ExPEC VAGs. In particular, 93.5% (101/108) of isolates classified as belonging to an IPEC pathovar additionally carried ExPEC VAGs. WGS analysis of a selected hybrid strain revealed that it could, with present classification criteria, be classified as belonging to all of the Enteropathogenic Escherichia coli (EPEC), Uropathogenic Escherichia coli (UPEC), Neonatal meningitis Escherichia coli (NMEC) and Avian pathogenic Escherichia coli (APEC) pathovars. Conclusion Hybrid ExPEC/IPEC E. coli strains were found at a very high frequency in faecal samples and were in fact the predominant species present. A sequenced hybrid isolate was confirmed to be a cross-pathovar strain possessing recognised hallmarks of several pathovars, and a genome heavily influenced by horizontal gene transfer

Comparative genomics of clinical hybrid Escherichia coli strains in Norway

The global rise of hybrid Escherichia coli (E. coli) is a major public health concern, as enhanced virulence from multiple pathotypes complicates the traditional E. coli classification system and challenges clinical diagnostics. Hybrid strains are particularly concerning as they can infect both intestinal and extraintestinal sites, complicating treatment and increasing the risk of severe disease. This study analyzed virulence-associated genes (VAGs) in 13 E. coli isolates from fecal samples of patients with symptoms of gastrointestinal (GI) infection in Norwegian hospitals and clinics. Whole genome sequencing (WGS) was conducted using Oxford Nanopore’s MinION and Illumina’s MiSeq platforms. Eleven strains harbored molecular diagnostic markers of atypical enteropathogenic E. coli (aEPEC), enteroinvasive E. coli (EIEC), Shiga toxin-producing E. coli (STEC), enterotoxigenic E. coli (ETEC), or typical enteropathogenic E. coli (tEPEC). Two of those isolates were identified as triple intestinal hybrids with molecular diagnostic markers for aEPEC, EIEC, and STEC. Notably, two isolates lacked any IPEC-specific molecular diagnostic markers, yet were suspected of causing the patient’s GI infection. Furthermore, genes associated with extraintestinal pathogenic E. coli (ExPEC)—including adhesins, toxins, protectins, siderophores, iron acquisition systems, and invasins—were identified in all the isolates. Thus, most of the isolates were classified as hybrid aEPEC/ExPEC, STEC/ExPEC, tEPEC/ExPEC, or aEPEC/EIEC/STEC/ExPEC. These findings emphasize the genomic plasticity of E. coli and highlight the need to revise the classification system for enteric pathogens

Plasma fibrinolysis, inflammatory markers, and postthrombotic syndrome: preliminary findings from the Kids-DOTT Biobank

Abstract Plasma levels of markers of coagulation and inflammation have been identified as prognostic factors for adult postthrombotic syndrome (PTS). We aimed to determine whether plasma fibrinolytic capacity and cytokine levels during the first 3 months after provoked deep venous thrombosis (DVT) are associated with risk of PTS in young patients. We analyzed plasma biospecimens (6 weeks and 3 months after provoked DVT) and clinical data from a National Heart, Lung, and Blood Institute–sponsored multinational trial of anticoagulation for provoked venous thromboembolism in patients younger than age 21 years (Kids-DOTT). Patients with a provoked extremity DVT who had plasma samples available at both 6-week and 3-month post-DVT time points and PTS assessment at 1 year were included. We measured plasma fibrinolytic capacity using the Clot Formation and Lysis (CloFAL) assay and plasma cytokine levels by multiplex immunoassay. Logistic regression analyses evaluated prognostic associations with PTS. Seventy-nine patients were included (median age, 12.8 years; range, 0.04-20.8 years). PTS developed in 34%. Complete veno-occlusion at 6 weeks after diagnosis of DVT (odds ratio [OR], 3.12; 95% confidence interval [CI], 0.81-11.94; P = .097), low fibrinolytic capacity in plasma at 3 months post-DVT (OR, 2.71; 95% CI, 0.92-7.97; P = .07), and elevated serum amyloid A at 3 months post-DVT (OR, 2.85; 95% CI, 0.98-8.34; P = .055) were identified as putative prognostic factors for development of PTS. In multivariable logistic regression analysis, these factors did not retain a statistically significant independent association with PTS, but these preliminary results warrant further investigation in an independent data set to definitively evaluate these findings and identify additional potential prognostic factors for the development of PTS after a provoked DVT in young patients.</jats:p