Time to intestinal clearance of carbapenemase-producing Enterobacterales in hospital patients: a longitudinal retrospective observational cohort study.

BACKGROUND: Intestinal clearance of carbapenemase-producing Enterobacterales (CPE-IC) is a cornerstone to discontinue isolation precautions for CPE patients in hospitals. This study aimed to evaluate the time to spontaneous CPE-IC and identify its potential associated risk factors. METHODS: This retrospective cohort study was carried out between January 2018 and September 2020 on all patients in a 3200-bed teaching referral hospital with confirmed CPE intestinal carriage. CPE-IC was defined as at least three consecutive CPE-negative rectal swab cultures without a subsequent positive result. A survival analysis was performed to determine the median time to CPE-IC. A multivariate Cox model was implemented to explore the factors associated with CPE-IC. RESULTS: A total of 110 patients were positives for CPE, of whom 27 (24.5%) achieved CPE-IC. Median time to CPE-IC was 698 days. Univariate analysis showed that female sex (P=0.046), multiple CPE-species in index cultures (P=0.005), Escherichia coli or Klebsiella spp. (P=0.001 and P=0.028, respectively) were significantly associated with the time to CPE-IC. Multivariate analysis highlighted that identification of E. coli carbapenemase-producing or CPEs harbouring ESBL genes in index culture extended the median time to CPE-IC, respectively (adjusted hazard ratio (aHR) = 0.13 (95% confidence interval: 0.04-0.45]; P=0.001 and aHR = 0.34 (95% confidence interval: 0.12-0.90); P=0.031). CONCLUSION: Intestinal decolonization of CPE can take several months to years to occur. Carbapenemase-producing E. coli are likely to play a key role in delaying intestinal decolonization, probably through horizontal gene transfer between species. Therefore, discontinuation of isolation precautions in CPE-patients should be considered with caution.

[French recommendations on control measures to reduce the infectious risk in immunocompromised patients]. / Quelles mesures pour maîtriser le risque infectieux chez les patients immunodéprimés ? Recommandations formalisées d'experts.

The increase use of immunosuppressive treatments in patients with solid cancer and/or inflammatory diseases requires revisiting our practices for the prevention of infectious risk in the care setting. A review of the literature by a multidisciplinary working group at the beginning of 2014 wished to answer the following 4 questions to improve healthcare immunocompromised patients: (I) How can we define immunocompromised patients with high, intermediate and low infectious risk, (II) which air treatment should be recommended for this specific population? (III) What additional precautions should be recommended for immunocompromised patients at risk for infection? (IV) Which global environmental control should be recommended? Based on data from the literature and using the GRADE method, we propose 15 recommendations that could help to reduce the risk of infection in these exposed populations.

[Detection of extended-spectrum ß-lactamase-producing Enterobacteriaceae in rectal swabs with the Mastdiscs™ ID AmpC ßLSE detection set]. / Dépistage du portage digestif des entérobactéries productrices de ß-lactamase à spectre étendu par ensemencement direct des écouvillons rectaux à l'aide de la méthode Mastdiscs™ ID AmpC ßLSE.

OBJECTIVES: The double-disk synergy test was compared to the Mastdiscs™ ID AmpC and ESßL method for detection of ESßL production in rectal swab. METHODS: Two hundred and forty-nine rectal swabs were directly inoculated onto Mueller-Hinton plates and analyzed according to both methods. RESULTS: A total of 41 (16%) and 208 (84%) were positive and negative for ESßL, respectively. Twelve (29%) and 20 (49%) of the 41 rectal swabs positive for ESßL were detected after 24h of incubation with the double-disk synergy test and the Mastdiscs™ method, respectively (P=0.013). One hundred fifty-eight (76%) et 183 (88%) of the 208 rectal swabs were detected negative for ESßL after 24h of incubation with the double-disk synergy test and the Mastdiscs™ method, respectively (P<0.001). Finally, 79 (32%) and 46 (18%) rectal swabs respectively inoculated according to the double-disk synergy test and the Mastdiscs™ method were inconclusive after 24h of incubation. The better performance of the Mastdiscs™ method was due to an easier detection of cephalosporinase producing bacteria. CONCLUSIONS: The Mastdiscs™ method is a simple phenotypic method that detects more easily ESßL and non-ESßL producing bacteria in rectal swab.

[Update of clinical findings in cobalamin deficiency: personal data and review of the literature]. / Manifestations hématologiques de la carence en vitamine B12: données personnelles et revue de la littérature.

PURPOSE: During last decades, several progresses have been made in the diagnosis of cobalamin (vitamin B12) deficiency. Routine used of cobalamin standardized assays have potentially modified the frequency and the type of hematologic abnormalities. CURRENT KNOWLEDGE AND KEY POINTS: Current studies on cobalamin deficiency, including more precise definitions and the description of new etiologies of cobalamin deficiency in adults, as the food-cobalamin malabsorption syndrome, show that hematological abnormalities are generally incomplete compared to historical descriptions of megaloblastic anemia. Nevertheless, they include severe manifestations in 10% of the patients: pancytopenia, severe anemia (hemoglobin < 6 g/dl) or hemolytic anemia and pseudo thrombotic microangiopathy related to cobalamin deficiency. These studies also show the efficacy of new treatment modalities including oral cobalamin administration. PROSPECTS AND PROJECTS: Future studies will confirm these data with the routine use of the new cobalamin assay: holotranscobalamin and validate the usefulness of oral cobalamin therapy.

Effect of different stabilized preparations of peracetic acid on biofilm.

The effect of three stabilized peracetic acid (PAA) preparations (Bioxal M), with or without surfactants, on an Escherichia coli biofilm model was studied. The biofilm was prepared in glass tubes, and was evaluated indirectly using spectrophotometry. The ability of the products to fix or remove the biofilm was determined by their detergent activity (DA). None of the preparations tested fixed the biofilm. The effect of Bioxal M-1 on the biofilm was equivalent to the control (sterile water). Bioxal M-2 and Bioxal M-3 displayed slightly positive DAs. Non-ionic surfactant improved the DA of the products. Regardless of disinfectant activity, PAA agents display different DAs depending on their formulation. This criterion could be used to select the weakest biofilm-fixing agents. Users should therefore be concerned about the efficiency of the cleaning stage of medical devices. When choosing PAA products, non-fixing ability should be considered in addition to antimicrobial activity.

[Risk factors for nosocomial Clostridium difficile diarrhoea in an infectious and tropical diseases department]. / Facteurs de risque de diarrhée nosocomiale à Clostridium difficile dans un service de maladies infectieuses et tropicales.

FOREWORD: Clostridium difficile associated diarrhea (CDAD) accounts for 25% of all cases of diarrhea occurring in hospital. Infectious diseases departments are considered as presenting with an important risk of CDAD because of the large quantity of antibiotics used. OBJECTIVES AND METHOD: The authors made a prospective study in the first 6 months of 2001, in order to identify the risk factors of CDAD in their department. One hundred and fifty-two patients hospitalized for at least 6 days were included in this study. The studied factors were: age, mean number of days of hospitalization (MDH), antibiotic therapy, WHO scale of reduced mobility of patients, recent hospitalization (less than 3 months before). RESULTS: MDH was 36 (IC95%: 23-48). Beta-lactam antibiotics were found as significant risk factors, as reported in the literature. However, age and a recent hospitalization were not related to the CDAD as described in the literature. A reduced mobility of patients was identified as a significant risk factor for developing a CDAD in our department.

Effect of peracetic acid and aldehyde disinfectants on biofilm.

The effects of two aldehyde (Cidex, Endosporine) and four peracetic acid (PAA) (Nu Cidex, Anioxyde 1000, Hydraseptic, Peralkan) disinfectants on an Escherichia coli biofilm model were studied. The biofilm was prepared in glass tubes, and evaluated indirectly using a colourimetric method. The ability of the disinfectants to fix or remove the biofilm from tubes was determined by their detergent activity (DA). The two aldehyde derivatives and two of the PAA (Nu Cidex, Anioxyde 1000) agents fixed the biofilm. However, the effects of Hydraseptic and Peralkan were equivalent to the control (sterile water). Regardless of their disinfectant activity, PAA agents display different DAs that could be used to select the weakest biofilm-fixing agents. Users should be concerned about the efficiency of the cleaning stage of medical devices, and when choosing a PAA product, non-fixing ability should be considered in addition to antimicrobial activity.

[Update of pernicious anemia. A retrospective study of 49 cases]. / Données actuelles sur la maladie de Biermer. A propos d'une étude rétrospective de 49 observations.

PURPOSE: The aim of this study was to describe the present clinical characteristics of the pernicious anemia (PA). METHOD: It is a retrospective (1996-2002) multicenter (five departments of internal medicine) study of 49 patients presenting an established cobalamin deficiency related to PA. RESULTS: The median age of the patients was 74 years (25-93), the female/male ratio 2:9. Several autoimmune disorders were noted in 35% of the patients. Various clinical manifestations, mainly neurological, cutaneous and thrombotic, were found in 65.4% of the patients, at least one hematological abnormalities in 100%. Average serum vitamin B12 and homocystein levels were with 73 pg/ml (20-1960) and 42.9 micromol/l (7, 8-124). Anti-intrinsic factor or anti-parietal gastric cells antibodies were found in 87.5% and 62% of the patients (at least one antibody, in 96%) abnormal Schilling's test results in 86%. All the followed patients were successful treated with intramuscular (n = 27) or oral crystalline cyanocobalamin (n = 5). CONCLUSIONS: PA was associated with several autoimmune disorders; PA may be responsible of various clinical manifestations or biological abnormalities; and oral crystalline cyanocobalamin treatment may be successful.

[Is there a link between the food-cobalamin malabsorption and the pernicious anemia?]. / Existe-t-il un lien entre les non-dissociations de la vitamine B12 et la maladie de Biermer?

BACKGROUND: A relation between food-cobalamin malabsorption and pernicious anemia has been suggested, particularly in the event of food-cobalamin malabsorption related to hypochlorhydric atrophic gastritis. STUDY DESIGN: This work describes three cases of well-documented cobalamin deficiency related to food-cobalamin malabsorption in three women aged 56, 82 and 68 Years who had atrophic gastritis (not associated with Helicobacter pylori infection) and later developed authentic pernicious anemia. CONCLUSIONS: This work illustrates the potential relation between these two disorders responsible for cobalamin deficiency.

Effectiveness of detergent-disinfecting agents on Escherichia coli 54127 biofilm.

Detergent-disinfecting agents (dD) are used daily for cleaning reused medical devices. We have devised a simple method to test dD detergent activity (DA) using an E. coli 54127 biofilm prepared in haemolysis glass tubes, which are cleaned with test dD, according to supplier's recommendations. Crystal violet 0.05% is used to colour the residual biofilm after dD (or tap water control) application. The biofilm quantification was made indirectly by measuring the absorbance of crystal violet at 585 nm. A measure of the detergent effectiveness called DA was calculated as the percentage reduction of colour from a tap water control. Fifteen products including enzymatic and non-enzymatic dDs were evaluated. Most enzymatic dDs gave a high DA, as did some non-enzymatic products. Thus, the view that enzymatic dDs are more effective than non-enzymatic dDs, put forward by some manufacturers, should be regarded with caution. The DA determination should help infection control teams choose, within the wide range of products available on the market, the most effective dD based on both its detergent and disinfecting activity.

[Vitamin B12 in the adult: of metabolism and deficiencies]. / Vitamine B12 chez l'adulte: du métabolisme aux carences.

PURPOSE: Update on cobalamin deficiencies in adults. CURRENT KNOWLEDGE AND KEY POINTS: More precise definitions establish real cobalamin deficiency and determine epidemiological features. Current data on cobalamin metabolism suggest the concept of non-dissociation of vitamin B12 from its carrier proteins (NDB12), a generalization of the food-cobalamin malabsorption concept. The new features of cobalamin deficiency include neurological, gynecological and vascular manifestations. Current treatment modalities include nasal and oral administration of cobalamin. PROSPECTS AND PROJECTS: Validate the concept of NDB12 and the usefulness of oral cobalamin therapy, establish the relevance of the new clinical manifestations.

Fusion of the human gene for the polyubiquitination coeffector UEV1 with Kua, a newly identified gene.

UEV proteins are enzymatically inactive variants of the E2 ubiquitin-conjugating enzymes that regulate noncanonical elongation of ubiquitin chains. In Saccharomyces cerevisiae, UEV is part of the RAD6-mediated error-free DNA repair pathway. In mammalian cells, UEV proteins can modulate c-FOS transcription and the G2-M transition of the cell cycle. Here we show that the UEV genes from phylogenetically distant organisms present a remarkable conservation in their exon-intron structure. We also show that the human UEV1 gene is fused with the previously unknown gene Kua. In Caenorhabditis elegans and Drosophila melanogaster, Kua and UEV are in separated loci, and are expressed as independent transcripts and proteins. In humans, Kua and UEV1 are adjacent genes, expressed either as separate transcripts encoding independent Kua and UEV1 proteins, or as a hybrid Kua-UEV transcript, encoding a two-domain protein. Kua proteins represent a novel class of conserved proteins with juxtamembrane histidine-rich motifs. Experiments with epitope-tagged proteins show that UEV1A is a nuclear protein, whereas both Kua and Kua-UEV localize to cytoplasmic structures, indicating that the Kua domain determines the cytoplasmic localization of Kua-UEV. Therefore, the addition of a Kua domain to UEV in the fused Kua-UEV protein confers new biological properties to this regulator of variant polyubiquitination.

Protein kinase C-alpha activity inversely modulates invasion and growth of intestinal cells.

The phorbol ester phorbol 12-myristate 13-acetate induces remarkable phenotypic changes in intestinal HT-29 M6 cells; these changes consist of loss of homotypic adhesion and inactivation of E-cadherin. In parallel, cell growth is retarded. We have transfected HT-29 M6 cells with an activated form of the conventional protein kinase Calpha (cPK-Calpha). Expression of this isoform induced the acquisition of a scattered phenotype, similar to that adopted by cells after addition of phorbol 12-myristate 13-acetate, with very low cell-to-cell aggregation and undetectable levels of functional E-cadherin. These cell clones were highly motile and rapidly invaded embryonic chick heart fragments. Furthermore, cells expressing activated-cPK-Calpha showed decreased proliferation in comparison to control clones. We have also studied how these two apparently antagonistic changes affect the tumorigenic ability of HT-29 M6 cells. When the different cell clones were xenografted into athymic mice, the effect on cell growth seemed to predominate. Expression of activated-cPK-Calpha significantly reduced the size of the tumors; the cells with the highest level of expression did not even form subcutaneous tumors. Besides their smaller size, the morphology of these tumors was clearly different from those originated by HT-29 M6 cells, and they could be defined as infiltrative on anatomo-pathological basis. These results indicate that cPK-Calpha controls both cell-to-cell adhesion and proliferation of intestinal cells.

Role of UEV-1, an inactive variant of the E2 ubiquitin-conjugating enzymes, in in vitro differentiation and cell cycle behavior of HT-29-M6 intestinal mucosecretory cells.

By means of differential RNA display, we have isolated a cDNA corresponding to transcripts that are down-regulated upon differentiation of the goblet cell-like HT-29-M6 human colon carcinoma cell line. These transcripts encode proteins originally identified as CROC-1 on the basis of their capacity to activate transcription of c-fos. We show that these proteins are similar in sequence, and in predicted secondary and tertiary structure, to the ubiquitin-conjugating enzymes, also known as E2. Despite the similarities, these proteins lack a critical cysteine residue essential for the catalytic activity of E2 enzymes and, in vitro, they do not conjugate or transfer ubiquitin to protein substrates. These proteins constitute a distinct subfamily within the E2 protein family and are highly conserved in phylogeny from yeasts to mammals. Therefore, we have designated them UEV (ubiquitin-conjugating E2 enzyme variant) proteins, defined as proteins similar in sequence and structure to the E2 ubiquitin-conjugating enzymes but lacking their enzymatic activity (HW/GDB-approved gene symbol, UBE2V). At least two human genes code for UEV proteins, and one of them, located on chromosome 20q13.2, is expressed as at least four isoforms, generated by alternative splicing. All human cell types analyzed expressed at least one of these isoforms. Constitutive expression of exogenous human UEV in HT-29-M6 cells inhibited their capacity to differentiate upon confluence and caused both the entry of a larger proportion of cells in the division cycle and an accumulation in G2-M. This was accompanied with a profound inhibition of the mitotic kinase, cdk1. These results suggest that UEV proteins are involved in the control of differentiation and could exert their effects by altering cell cycle distribution.