Large triglyceride-rich lipoproteins from fasting patients with type 2 diabetes activate platelets.

AIMS: Type 2 diabetes (T2D) patients present with risk factors for atherothrombosis such as fasting hypertriglyceridaemia and platelet hyperactivity. Our study objective was to determine the effect of large triglyceride-rich lipoproteins (TGRL) from fasting T2D patients on platelet aggregation and, if any, to identify the signaling pathway involved. METHODS: Large TGRL were isolated from the plasma of 25 T2D patients by ultracentrifugation (density < 1.000 g/mL). Platelets were isolated from healthy blood donors (HBD) and suspended in buffer, then preincubated in the presence or absence of TGRL and stimulated with either collagen or thrombin. Platelet aggregation and the arachidonic acid (AA) signaling pathway were studied. RESULTS: Fasting T2D large TGRL were mostly of hepatic origin (apoB100/apoB48 ratio: 42 ± 7) and rich in triglycerides (TG/total apoB ratio: 4.2 ± 0.5), and able to potentiate agonist-stimulated platelet aggregation (collagen: +68%, P < 0.05; thrombin: +771%, P < 0.05). It should also be mentioned that TGRL from the plasma of HBD (n = 7) had no effect on platelet aggregation. In addition, T2D large TGRL increased thromboxane B2 (TxB2) concentration in platelets stimulated with either collagen (+34%, P < 0.05) or thrombin (+37%, P < 0.05) compared with platelets stimulated with either of these agonists without TGRL. Phosphorylation of p38 MAPK and cytosolic phospholipase A2 (cPLA2) was enhanced after incubation of platelets with T2D TGRL and thrombin (+87% and +32%, respectively, P < 0.05) compared with platelets incubated with thrombin only. CONCLUSION: Large TGRL from fasting T2D patients may play a role in the development of atherothrombosis by increasing platelet aggregation and activating the platelet AA signaling pathway.

The effects of topical antibiotics on eradication and acquisition of third-generation cephalosporin and carbapenem-resistant Gram-negative bacteria in ICU patients; a post hoc analysis from a multicentre cluster-randomized trial.

OBJECTIVES: The aim was to quantify the effects of selective digestive tract decontamination (SDD) consisting of a mouth paste and gastro-enteral suspension, selective oropharyngeal decontamination with a mouth paste (SOD) and 1-2% chlorhexidine (CHX) mouthwash on eradication and acquisition of carriage of third-generation cephalosporin-resistant Enterobacterales (3GCR-E) and carbapenem-resistant Gram-negative bacteria (CR-GNB) in Intensive Care Unit (ICU) patients. METHODS: This was a nested cohort study within a cluster-randomized cross-over trial in six European countries and 13 ICUs with 8665 patients. Eradication and acquisition during ICU stay of 3GCR-E and CR-GNB were investigated separately in the rectum and respiratory tract for the three interventions and compared with standard care (SC) using Cox-regression competing events analyses. RESULTS: Adjusted cause specific hazard ratios (CSHR) for eradication of rectal carriage for SDD were 1.76 (95% CI 1.31-2.36) for 3GCR-E and 3.17 (95% CI 1.60-6.29) for CR-GNB compared with SC. For the respiratory tract, adjusted CSHR for eradication of 3GCR-E were 1.47 (0.98-2.20) for SDD and 1.38 (0.92-2.06) for SOD compared with SC, and for eradication of CR-GNB these were 0.77 (0.41- 1.45) for SDD and 0.81 (0.44-1.51) for SOD, compared with SC. Adjusted CSHRs for acquisition of rectal carriage during SDD (compared with SC) were 0.51 (0.40-0.64) for 3GCR-E and of 0.56 (0.40-0.78) for CR-GNB. Adjusted CSHRs for acquiring respiratory tract carriage with 3GCR-E compared with SC were 0.38 (0.28-0.50) for SDD and 0.55 (0.42-0.71) for SOD, and for CR-GNB 0.46 (0.33-0.64) during SDD and 0.60 (0.44-0.81) during SOD, respectively. SOD was not associated with eradication or acquisition of 3GCR-E and CR-GNB in the rectum. CONCLUSIONS: Among mechanically ventilated ICU patients, SDD was associated with more eradication and less acquisition of 3GCR-E and CR-GNB in the rectum than SC. SDD and SOD were associated with less acquisition of both 3GCR-E and CR-GNB than SC in the respiratory tract.

Hospitalisations with infections related to antimicrobial-resistant bacteria from the French nationwide hospital discharge database, 2016.

Massive use of antibiotics has led to increased bacterial resistance to these drugs, making infections more difficult to treat. Few studies have assessed the overall antimicrobial resistance (AMR) burden, and there is a paucity of comprehensive data to inform health policies. This study aims to assess the overall annual incident number of hospitalised patients with AMR infection in France, using the National Hospital Discharge database. All incident hospitalisations with acute infections in 2016 were extracted. Infections which could be linked with an infecting microorganism were first analysed. Then, an extrapolation of bacterial species and resistance status was performed, according to age class, gender and infection site to estimate the total number of AMR cases. Resistant bacteria caused 139 105 (95% CI 127 920-150 289) infections, resulting in a 12.3% (95% CI 11.3-13.2) resistance rate. ESBL-producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus were the most common resistant bacteria (>50%), causing respectively 49 692 (95% CI 47 223-52 142) and 19 493 (95% CI 15 237-23 747) infections. Although assumptions are needed to provide national estimates, information from PMSI is comprehensive, covering all acute bacterial infections and a wide variety of microorganisms.

Metabolic effects in mice of cream processing: Direct ultra-high-temperature process lowers high-fat-induced adipose tissue inflammation.

Although UHT heat treatment is being optimized to improve the stability and functional properties of dairy products, its metabolic effects remain scarcely known. As such, we studied the effect of the type of UHT process on lipid metabolism, intestinal barrier, and inflammation in mice. Nine-week-old male C57Bl/6J mice were fed a diet composed of nonlipidic powder mixed with different UHT dairy creams (final: 13% milkfat) for 1 or 4 wk. All creams contained 0.02% of thickener (carrageenan) and were treated via either (1) classical indirect heating process (Th), (2) indirect process at higher temperature (Th+), or (3) direct process by steam injection (ThD). Plasma, epididymal adipose tissue (EAT), and intestine were analyzed. Multivariate principal component analyses were used to identify differential effects of processes. Th+ differed by a globally higher liver damage score compared with that of the other creams. After 4 wk, the duodenal expression of lipid absorption genes fatty acid binding protein 4 (Fatp4) and microsomal triglycerides transfer protein (Mttp) was lower in the Th+ versus Th group. Expression in the colon of tight junction protein zonula occludens 1 (Zo1) and of some endoplasmic reticulum stress markers was lower in both Th+ and ThD versus the Th group. In EAT, ThD had lower gene expression of several inflammatory markers after 4 wk. Some differential effects may be related to heat-induced physicochemical changes of creams. The type of cream UHT process differentially affected metabolic parameters in mice after a 4-wk fat-rich diet, partly due to cream structure. Altogether, direct steam injection process induced the lowest early markers of high-fat-induced metabolic inflammation in EAT.

Metabolic effects in mice of cream formulation: Addition of both thickener and emulsifier does not alter lipid metabolism but modulates mucus cells and intestinal endoplasmic reticulum stress.

Additives stabilize or improve the organoleptic or functional properties (or both) of many dairy products including whipping cream. Their influence on the metabolic effect of dairy cream is scarcely known. We tested the hypothesis that added emulsifier (lactic acid esters of mono- and diglycerides; MAG/DAG), thickener (carrageenan, CGN), or both, could modify the metabolic effect, notably in the intestine and liver. Nine-week-old male C57Bl/6J mice were fed UHT cream (indirect treatment) mixed with nonlipidic powder (final: 13% milkfat) for 1 or 4 wk. We compared creams (1) without additive (Ctl), (2) with thickener (Th), 0.02% of κ-CGN, and (3) with both thickener and emulsifier, 0.1% of MAG/DAG esters (Th/Em). We analyzed plasma parameters, intestine, and liver. Fasting glycemia, insulinemia, triglyceridemia, nonesterified fatty acids, body weight gain, and liver weight did not differ among groups. After 1 wk, Th/Em had higher expression in the duodenum of some of the genes involved in (1) intestinal lipid absorption and (2) tight junction proteins versus Ctl and Th. After 4 wk, mucus cell number in the small intestine was higher in Th/Em versus Ctl and Th. Genes involved in endoplasmic reticulum (ER) stress in the duodenum were more expressed in Th/Em after 1 wk. After 4 wk, in the colon, a higher expression of ER stress genes was observed for Th versus Th/Em and Ctl. Liver damage score was not altered by additives. Adding both CGN (0.02%) and MAG/DAG esters (0.1%) in dairy cream did not result in deleterious outcomes in mice after 4 wk regarding lipid metabolism, intestinal permeability, and liver disorders. The longer term effect of intestinal ER stress modulation deserves further investigation.

Neuroendocrine and inflammatory responses to DHEA administration in young healthy women.

DHEA is reported to have beneficial effects for the elderly and for several pathologies because of its behavioral and anti-inflammatory properties. However, these properties have never been investigated in a young healthy population. The purpose of this double-blind, randomized study was therefore to investigate the effects of short-term DHEA administration (100 mg/day/4 weeks) on neuroendocrine (i.e., beta-endorphin and prolactin) and inflammatory (i.e., interleukin-6 and TNF-alpha) parameters in 10 young healthy female volunteers with regular sports practice. In parallel, the stress state was assessed with the Profile of Mood States (POMS) questionnaire. DHEA administration did not alter prolactin, interleukin-6 or TNF-alpha, and no significant change in tension, depression, anger, vigor, fatigue or confusion was noted. However, beta-endorphin levels increased significantly (p < 0.05) with the DHEA treatment. The results of this investigation indicate that short-term DHEA administration improves neuroendocrine modulation but does not affect the inflammatory status or psychological state in recreationally trained female athletes. Further studies are needed to determine the exact mechanisms and the responses of these parameters to DHEA administration at higher dosages and/or for longer durations, especially in response to physical/psychological stress.

Implementation of AICAR analysis by GC-C-IRMS for anti-doping purposes.

AICAR (5-aminoimidazole-4-carboxamide-1-ß-D-ribofuranoside), is a naturally occurring substance which is part to the World Anti-Doping Agency (WADA) Prohibited List. It is claimed to improve physical performance when administered as a supplement. As for other endogenous compounds such as steroids, the gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) analysis remains an efficient tool to differentiate endogenous substances from exogenous ones. A protocol was described in the literature for the analysis of AICAR by GC-C-IRMS. The aim of the present study was to implement this protocol in our laboratory and to propose solutions to avoid the difficulties encountered. The first point discussed in this study is the derivatization step. Due to the structure of the AICAR molecule, conventional derivatization for GC-C-IRMS such as acetylation could not be applied and silylation was preferred. The improvement of the derivatives stability was achieved thanks to several derivatization conditions tested. This adjustment led to a reproducible derivatization pattern with the 3-TMS form as major derivative product. The second point discussed in this study is the diminution of extracts' background noise. Indeed, the implementation of the published protocol was not easy due to high performance liquid chromatography (HPLC) problems encountered when concentrated urine was injected into our system. Also, too many interferences in the endogenous reference compound fractions were observed. The addition of both a wash step before the HPLC purification and a HPLC purification step for the endogenous reference compound (ERC) fraction allowed us to increase the robustness of the method. This study presents the modified protocol compared to the original protocol as well as the evaluation of the whole method performances. Copyright © 2017 John Wiley & Sons, Ltd.

Healthcare workers' knowledge and perceptions of the risks associated with emerging extensively drug-resistant bacteria.

OBJECTIVE: Guidelines have been issued in 2010 to prevent the spread of emerging extensively resistant bacteria (eXDR), but their implementation is difficult. We aimed to evaluate healthcare workers' (HCW) knowledge and their risk perception to identify barriers to the implementation of guidelines. METHODS: Semi-structured interviews were conducted at a University Hospital, where case patients are regularly admitted. The interviews focused on HCW's knowledge, risk perception, and challenges met. The evaluation of HCW's knowledge and contagiousness and perception of severity of eXDR carriage were analyzed statistically. Risk perception and opinion about guidelines were analyzed by qualitative description. RESULTS: One hundred and twenty-one HCWs were interviewed. The category of HCW, having searched for information on resistant bacteria, and having taken care of case patients were associated with better knowledge. The HCW category, age, type of unit, seniority, and having taken care of case patients were associated with risk perceptions. Qualitative analysis identified 61 themes. HCWs were extremely concerned by the spread of bacteria within the hospital. The main challenges identified were organizational and communication issues. CONCLUSION: HCWs reported a lack of knowledge and a lack of resources to implement guidelines. Strategies to improve guidelines implementation must be based on a better availability of resources, better communication, and new educational methods.

Report on an anti-doping operation in Guadeloupe: High number of positive cases and inferences about doping habits.

Anti-doping controls in non-major events are relatively infrequent and athletes that compete only in these events are less likely to be controlled. The French Anti-Doping Agency carried out an anti-doping operation during a regional cycling competition in Guadeloupe. The urine and serum samples were analysed by the French anti-doping laboratory. Out of 42 athletes, 7 were positive for one or more substances prohibited by the World Anti-Doping Agency. Four serum samples contained continuous erythropoietin receptor activator (CERA) and one a recombinant erythropoietin. However, no traces were found in the corresponding urines. One of the athletes positive for CERA was also positive for growth hormone (GH), identified using the GH isoform test. The same serum was negative with the GH biomarkers test, probably because of the brief interval between injection and control (less than a day). The stimulants heptaminol and dimethylbutylamine, as well as the glucocorticoid prednisone and its metabolite prednisolone, were also found. Strikingly, 16.6% of the controlled athletes were using one or more prohibited drugs. These findings indicate that doping is widespread in athletes competing regionally and that CERA is still a popular drug for endurance sports. They underline the need for more controls, particularly blood sampling during non-major competitions. Copyright © 2017 John Wiley & Sons, Ltd.

Estimating the morbidity and mortality associated with infections due to multidrug-resistant bacteria (MDRB), France, 2012.

BACKGROUND: A study based on 2007 data estimated that 386,000 infections due to multidrug-resistant bacteria (MDRB) occurred in Europe that year and 25,000 patients died from these infections. Our objective was to estimate the morbidity and mortality associated with these infections in France. METHODS: The MDRB considered were methicillin-resistant Staphylococcus aureus (MRSA), glycopeptide-resistant enterococci, third-generation cephalosporin-resistant (3GC-R) Escherichia coli and Klebsiella pneumoniae, carbapenem-resistant Klebsiella pneumoniae, Acinetobacter spp. and Pseudomonas aeruginosa (CR P. aeruginosa). The number of invasive infections (infections with bacteria isolated from blood or cerebrospinal fluid) due to MDRB, as reported by France to EARS-Net in 2012, was corrected for the coverage of our surveillance network and extrapolated to other body sites using ratios from the French healthcare-associated infections point prevalence survey and the literature. Mortality associated with MDRB infection was estimated using proportions from the literature. Methods and parameters were reviewed by a panel of experts. RESULTS: We estimate that 158,000 (127,000 to 245,000) infections due to MDRB occurred in 2012 in France (incidence: 1.48 to 2.85 per 1000 hospital days), including 16,000 invasive infections. MRSA, 3GC-R E. coli and K. pneumoniae were responsible for 120,000 (90,000 to 172,000) infections, i.e., 75% of the total. An estimated 12,500 (11,500 to 17,500) deaths were associated with these infections, including 2,700 associated with invasive infections. MRSA, 3GC-R E. coli and CR P. aeruginosa accounted for 88% of these deaths. CONCLUSION: These first estimates confirm that MRSA, 3GC-R Escherichia coli and Klebsiella pneumoniae account for the largest portion of the morbidity and mortality of infections due to MDRB in France. These results are not directly comparable with the European study because the methodology used differs in many respects. The differences identified between our study and previous studies underline the need to define a standardised protocol for international assessments of the morbidity and mortality of antibiotic resistance. Estimating morbidity and mortality will facilitate communication and awareness in order to reinforce adherence and support of healthcare professionals and policy-makers to MDRB prevention programs.

First nosocomial outbreak of vanA-type vancomycin-resistant Enterococcus raffinosus in France.

BACKGROUND: Vancomycin-resistant Enterococcus raffinosus has rarely been associated with nosocomial infection and outbreaks. AIM: To report the successful control of a nosocomial outbreak of vanA-type vancomycin-resistant E. raffinosus in a surgical intensive care unit. METHODS: The investigation of the outbreak is reported with control measures taken. Molecular typing of vancomycin-resistant E. raffinosus isolates was performed by repetitive sequence-based polymerase chain reaction (PCR). FINDINGS: Between September and October 2014, vancomycin-resistant E. raffinosus isolates were isolated from four patients. The index patient had been hospitalized previously in Portugal, and was not found to be colonized by vancomycin-resistant enterococci on screening cultures obtained at admission. However, vancomycin-resistant E. raffinosus was isolated from a bile sample 19 days after hospital admission. All four isolates were resistant to both vancomycin and teicoplanin due to the presence of the vanA gene, while remaining susceptible to daptomycin and linezolid. Repetitive sequence-based PCR confirmed the spread of a single vanA-positive E. raffinosus clone. Infection control measures including direct PCR screening on rectal specimens, contact precautions, and cohorting of patients and personnel led to successful control of the outbreak. CONCLUSION: This is the first reported outbreak of vanA-type vancomycin-resistant E. raffinosus in France in both clinical and screening specimens among hospitalized patients. The inability of routine selective screening media to detect the vancomycin-resistant E. raffinosus in the index case likely contributed to the outbreak.

Detection by LC-MS/MS of HIF stabilizer FG-4592 used as a new doping agent: Investigation on a positive case.

Stabilizing the labile factor HIF (hypoxia inducible factor) for therapeutic use has led to the development of various molecules by pharmaceutical companies. These HIF stabilizers show promising erythropoiesis stimulating capacities and are of great interest for patients with chronical kidney disease and anemia. Amongst them FG-4592 from FibroGen is now under phase 3 of clinical studies. While this drug is still under investigation, a parallel market already allows to buy this product, which could be tempting for some athletes willing to increase their performances. To avoid such a use for doping purpose, WADA has listed HIF stabilizers and FG-4592 in particular as prohibited substances since 2011 and some anti-doping laboratories have developed a technique of identification of FG-4592 in urine. Here, we described the first case ever identified by an anti-doping laboratory of an athlete using FG-4592. Detection and confirmation in urinary samples was performed by LC-MS/MS. In addition, potential indirect markers erythropoietin (EPO) and hematological parameters followed in the Athlete Biological Passport (ABP) were analyzed during and after the period of use but showed no profound alterations. Only ABPS (abnormal blood profile score) reached (but did not exceed) the upper limit proposed by the ABP adaptive model just after the period of use of FG-4592. Altogether this case sends a warning for anti-doping laboratories which now must strengthen surveillance on HIF stabilizers and develop sensitive methods of detection for this new class of drugs.

Dietary calcium impairs tomato lycopene bioavailability in healthy humans.

Lycopene (LYC) bioavailability is relatively low and highly variable, because of the influence of several factors. Recent in vitro data have suggested that dietary Ca can impair LYC micellarisation, but there is no evidence whether this can lead to decreased LYC absorption efficiency in humans. Our objective was to assess whether a nutritional dose of Ca impairs dietary LYC bioavailability and to study the mechanism(s) involved. First, in a randomised, two-way cross-over study, ten healthy adults consumed either a test meal that provided 19-mg (all-E)-LYC from tomato paste or the same meal plus 500-mg calcium carbonate as a supplement. Plasma LYC concentration was measured at regular time intervals over 7 h postprandially. In a second approach, an in vitro digestion model was used to assess the effect of increasing Ca doses on LYC micellarisation and on the size and zeta potential of the mixed micelles produced during digestion of a complex food matrix. LYC bioavailability was diminished by 83 % following the addition of Ca in the test meal. In vitro, Ca affected neither LYC micellarisation nor mixed micelle size but it decreased the absolute value of their charge by 39 %. In conclusion, a nutritional dose of Ca can impair dietary LYC bioavailability in healthy humans. This inhibition could be due to the fact that Ca diminishes the electrical charge of micelles. These results call for a thorough assessment of the effects of Ca, or other divalent minerals, on the bioavailability of other carotenoids and lipophilic micronutrients.

KPC-Like Carbapenemase-Producing Enterobacteriaceae Colonizing Patients in Europe and Israel.

In a 2008-2011 survey, 17,945 patients in 18 hospital units in Europe and Israel were screened for carriage of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae, resulting in identification of 124 positive patients. The isolates were dominated by Klebsiella pneumoniae sequence type 258 (ST258) KPC-2 and ST512 KPC-3, mainly from Greece and Italy, respectively, whereas Israeli isolates were of diverse species, clones, and KPC variants. Various blaKPC platforms were observed, among which IncFIIK-FIBK plasmids with blaKPC-2/-3 genes in the Tn4401a transposon prevailed.

Inhaled nitric oxide for acute chest syndrome in adult sickle cell patients: a randomized controlled study.

PURPOSE: Previous clinical trials suggested that inhaled nitric oxide (iNO) could have beneficial effects in sickle cell disease (SCD) patients with acute chest syndrome (ACS). METHODS: To determine whether iNO reduces treatment failure rate in adult patients with ACS, we conducted a prospective, double-blind, randomized, placebo-controlled clinical trial. iNO (80 ppm, N = 50) gas or inhaled nitrogen placebo (N = 50) was delivered for 3 days. The primary end point was the number of patients with treatment failure at day 3, defined as any one of the following: (1) death from any cause, (2) need for endotracheal intubation, (3) decrease of PaO2/FiO2 ≥ 15 mmHg between days 1 and 3, (4) augmented therapy defined as new transfusion or phlebotomy. RESULTS: The two groups did not differ in age, gender, genotype, or baseline characteristics and biological parameters. iNO was well tolerated, although a transient decrease in nitric oxide concentration was mandated in one patient. There was no significant difference in the primary end point between the iNO and placebo groups [23 (46 %) and 29 (58 %); odds ratio (OR), 0.8; 95 % CI, 0.54-1.16; p = 0.23]. A post hoc analysis of the 45 patients with hypoxemia showed that those in the iNO group were less likely to experience treatment failure at day 3 [7 (33.3 %) vs 18 (72 %); OR = 0.19; 95 % CI, 0.06-0.68; p = 0.009]. CONCLUSIONS: iNO did not reduce the rate of treatment failure in adult SCD patients with mild to moderate ACS. Future trials should target more severely ill ACS patients with hypoxemia. CLINICAL TRIAL REGISTRATION: NCT00748423.

COPD patients with ventilator-associated pneumonia: implications for management.

Data on the occurrence and outcome of patients with chronic obstructive pulmonary disease (COPD) and ventilator-associated pneumonia (VAP) are quite limited. The aim of this study was to determine if COPD intensive care unit (ICU) patients have a higher rate of VAP development, different microbiological aetiology or have worse outcomes than other patients without VAP. A secondary analysis of a large prospective, observational study conducted in 27 European ICUs was carried out. Trauma patients were excluded. Of 2082 intubated patients included in the study, 397 (19.1%) had COPD; 79 (19.9%) patients with COPD and 332 (19.7%) patients without COPD developed VAP. ICU mortality increased by 17% (p < 0.05) when COPD patients developed VAP, remaining an independent predictor of mortality [odds ratio (OR) 2.28; 95% confidence interval (CI) 1.35-3.87]. The development of VAP in COPD patients was associated with a median increase of 12 days in the duration of mechanical ventilation and >13 days in ICU stay (p < 0.05). Pseudomonas aeruginosa was more common in VAP when COPD was present (29.1% vs. 18.7%, p = 0.04) and was the most frequent isolate in COPD patients with early-onset VAP, with a frequency 2.5 times higher than in patients without early-onset VAP (33.3% vs. 13.3%, p = 0.03). COPD patients are not more predisposed to VAP than other ICU patients, but if COPD patients develop VAP, they have a worse outcome. Antibiotic coverage for non-fermenters needs to be included in the empiric therapy of all COPD patients, even in early-onset VAP.

Phylogenetic lineages, clones and ß-lactamases in an international collection of Klebsiella oxytoca isolates non-susceptible to expanded-spectrum cephalosporins.

OBJECTIVES: The objective of this study was to examine Klebsiella oxytoca clonal and phylogenetic diversity, based on an international collection of carriage isolates non-susceptible to expanded-spectrum cephalosporins (ESCs). METHODS: The study material comprised 68 rectal carriage K. oxytoca isolates non-susceptible to ESCs recovered in 2008-11 from patients in 14 hospitals across Europe and Israel. ESC resistance was tested phenotypically; genes encoding ESBLs, AmpC cephalosporinases and carbapenemases were amplified and sequenced. The isolates were typed by PFGE and MLST, followed by sequencing of blaOXY genes. RESULTS: MLST and PFGE distinguished 34 STs and 47 pulsotypes among the isolates, respectively. Six STs were split into several pulsotypes each. Five STs were more prevalent (n = 2-9) and occurred in several countries each, including ST2, ST9 and ST141, which belong to a growing international clonal complex (CC), CC2. Four phylogenetic lineages were distinguished, each with another type of chromosomal OXY-type ß-lactamase. Three of these, with OXY-1/-5, OXY-2 types and OXY-4, corresponded to previously described phylogroups KoI, KoII and KoIV, respectively. A single isolate from Israel represented a distinct lineage with a newly defined OXY-7 type. The phylogroups showed interesting differences in mechanisms of ESC resistance; KoI strains rarely overexpressed the OXY enzymes but commonly produced ESBLs, whereas KoII strains often were OXY hyperproducers and carried ESBLs much less frequently. AmpCs (DHA-1) and carbapenemases (VIM-1) occurred sporadically. CONCLUSIONS: The study confirmed the high genetic diversity of the collection of K. oxytoca ESC-non-susceptible isolates, composed of phylogroups with distinct types of OXY-type ß-lactamases, and revealed some STs of broad geographical distribution.