Large Dissemination of VIM-2-Metallo-β-Lactamase-Producing Pseudomonas aeruginosa Strains Causing Health Care-Associated Community-Onset Infections

During a 3-year period (May 2005 to April 2008), a series of 45 outpatients presented with community-onset urinary tract infections due to carbapenem-resistant Pseudomonas aeruginosa isolates. Forty of them had a history of previous hospitalization or exposure to healthcare facilities, while the remaining five had not been previously admitted to our healthcare facilities or elsewhere within the preceding 12 months. In 18 outpatients, the carbapenem-resistant organisms caused recurrent community-onset urinary tract infections, while in three outpatients the organisms were also implicated in bacteremic episodes. All 45 single-patient P. aeruginosa isolates harbored the bla_VIM-2 metallo-β-lactamase (MBL) gene in a common class 1 integron structure. They belonged to one predominant pulsed-field gel electrophoresis type and three sporadically detected types; two of the sporadic clonal types were identified among outpatients without previous exposure to healthcare facilities, while the predominant clonal type was also identified to cause infections in hospitalized patients. This is the first study documenting that MBL-producing P. aeruginosa isolates cause community-onset infections that are related or not with exposure to healthcare facilities. Community-onset infections in our patients most likely resulted from the nosocomial acquisition of MBL producers, followed by a prolonged digestive carriage. The high rate of recurrent infections in the community underlies the difficulty of constraining infections caused by such microorganisms in the extrahospital setting.Pseudomonas aeruginosa is a clinically significant gram-negative rod-shaped bacterium that may be selected and propagated within the hospital environment. Antimicrobial resistance in this species is a problem of growing concern and limits our therapeutic alternatives. Carbapenems are commonly used as last-resort drugs for the treatment of infections caused by multidrug-resistant P. aeruginosa isolates. However, intensive use of carbapenems in the treatment of nosocomial P. aeruginosa infections has facilitated the emergence of mechanisms that confer resistance to carbapenems, such as diminished permeability, overexpression of the intrinsic efflux systems, and production of carbapenemases (21). Acquisition of class B metallo-β-lactamases (MBLs) constitutes a growing family of carbapenem-hydrolyzing β-lactamases among P. aeruginosa strains (26). These enzymes efficiently hydrolyze all β-lactam compounds except aztreonam, and in most cases their genes reside within class 1 integrons of various compositions of gene cassettes (18). They are frequently classified in the IMP and VIM types, while other types, such as AIM, GIM, and SPM, are found only sporadically in some geographic regions (26).MBL-producing P. aeruginosa bacteria are slowly but steadily increasing within hospitals, causing outbreaks and/or hyperendemic situations in several centers, mostly in the Far East and south of Europe (5, 9, 11, 15, 18). Studies have identified the risk factors for MBL acquisition (8, 14, 29) as well as the outcome of P. aeruginosa infections caused by MBL producers (12, 14). The increasing prevalence of nosocomial infections produced by MBL-possessing P. aeruginosa strains severely compromises the selection of appropriate treatments and is therefore associated with significant morbidity and mortality.In Greece, the proportion of MBL-producing P. aeruginosa strains has been rapidly increasing among hospital-acquired infections since the beginning of the last decade (24). Previous studies have shown that this epidemic occurrence is frequently due to the clonal spread of VIM-type MBLs but also due to horizontal transmission of these enzymes between unrelated clonal strains (17, 20). In several European countries, also the increase of MBL production in P. aeruginosa is due primarily to the spread of VIM-type MBLs, suggesting a large reservoir of the respective bla_VIM gene cassettes (5, 11, 15, 18). However, no previously published studies in Europe or elsewhere have described infections caused by MBL-producing P. aeruginosa strains among community patients with or without information on their association with healthcare facilities.In our clinical laboratory, we observed during May 2005 the emergence of imipenem- and meropenem-resistant P. aeruginosa isolates, which were recovered from urine samples of elderly patients in the community. This event prompted the present observational cohort survey in which we describe the emergence and spread of MBL-producing P. aeruginosa strains among patients attending our outpatient community department. The route of the MBL-producing P. aeruginosa acquisition in outpatients was also investigated.     

Metallo-��-Lactamase-Producing Pseudomonas spp. in Korea: High Prevalence of Isolates with VIM-2 Type and Emergence of Isolates with IMP-1 Type

Purpose

Two Korean nationwide studies showed that metallo-β-lactamases (MBLs)-producing-Pseudomonas spp. are not rare. The aim of this study was to assess the trends of MBL-producing isolates among imipenem-resistant isolates of Pseudomonas spp.

Materials and Methods

Imipenem-resistant clinical isolates were collected from 23 hospitals and one commercial laboratory participating in the KONSAR program in 2005. Polymerase chain reaction (PCR) was used to detect MBL genes.

Results

Alleles of MBL genes were detected in 10.8% of 415 Pseudomonas aeruginosa and 66.7% of 12 P. putida isolates from 18 of 24 hospitals/laboratory. Among the 14 IMP-1-like and 39 VIM-2-like MBLs, emergence of IMP-6 was detected for the first time.

Conclusion

Prevalence of MBL-producing P. aeruginosa has not significantly increased, but IMP-6 emerged in P. aeruginosa.     

Coproduction of KPC-18 and VIM-1 Carbapenemases by Enterobacter cloacae: Implications for Newer β-Lactam–β-Lactamase Inhibitor Combinations

Enterobacter cloacae strain G6809 with reduced susceptibility to carbapenems was identified from a patient in a long-term acute care hospital in Kentucky. G6809 belonged to sequence type (ST) 88 and carried two carbapenemase genes, bla_KPC-18 and bla_VIM-1. Whole-genome sequencing localized bla_KPC-18 to the chromosome and bla_VIM-1 to a 58-kb plasmid. The strain was highly resistant to ceftazidime-avibactam. Insidious coproduction of metallo-β-lactamase with KPC-type carbapenemase has implications for the use of next-generation β-lactam–β-lactamase inhibitor combinations.     

FGFR4 and TGF-β1 Expression in Hepatocellular Carcinoma: Correlation with Clinicopathological Features and Prognosis

Objective: To investigate the expression and correlation of transforming growth factor-β1 (TGF-β1) and fibroblast growth factor receptor 4 (FGFR4) in human hepatocellular carcinoma (HCC) and the relationship with clinicopathological features and prognosis.Materials and methods: The expression of TGF-β1 and FGFR4 in 126 HCC samples was detected immunohistochemically. Combined with clinical postoperative follow-up data, the expression of TGF-β1 and FGFR4 in HCC and the relationship with the prognosis of patients were analyzed by statistically.Results: The positive expression rate of TGF-β1 was 84.1% (106/126) in tumors, and that in peritumoral liver tissues was 64.3% (81/126); the positive expression rate of FGFR4 in tumors was 74.6% (94/126) and that in peritumoral liver tissues was 57.1% (72/126). The expression of TGF-β1 and FGFR4 in the carcinoma tissues was significantly higher than that in peritumoral liver tissues (p < 0.05). Intratumoral TGF-β1 and FGFR4 expression was associated with TNM stage (p < 0.05). TGF-β1 and FGFR4 expression levels didn''t significantly correlate with other clinicopathological parameters, including age, sex, tumor size, serum AFP level, tumor differentiation, lymph node metastasis, etc. (p > 0.05). TGF-β1 expression was positively correlated with FGFR4 expression (r = 0.595, p < 0.05). Patients with positive FGFR4 or TGF-β1 expression had shorter overall survival compared with negative expression (p < 0.05).Conclusions: The expression of TGF-β1 and FGFR4 could make synergy on the occurrence and progression of HCC, and may be used as prognosis indicators for HCC patients.     

Evaluation of Double-Disk Potentiation and Disk Potentiation Tests Using Dipicolinic Acid for Detection of Metallo-β-Lactamase-Producing Pseudomonas spp. and Acinetobacter spp

Accurate detection of metallo-β-lactamase (MBL)-producing Pseudomonas spp. and Acinetobacter spp. became very important with the increasing prevalence of carbapenem-nonsusceptible clinical isolates. The performance of phenotypic MBL detection methods may depend on the types of MBL and the characteristics of the isolates. A high false-positive rate is a problem with EDTA-based MBL detection methods. We evaluated the performance of double-disk potentiation tests (DDPTs) and disk potentiation tests (DPTs) with dipicolinic acid (DPA) using 44 isolates of Pseudomonas spp. and Acinetobacter spp. producing IMP-1-like, VIM-2-like, and SIM-1 type MBLs. Also, we characterized P. aeruginosa isolates with positive imipenem (IPM)-DPA DDPT, but negative meropenem (MEM)-DPA DDPT, and determined possibility of improving a DDPT by using MacConkey agar. Among five different DDPT methods, the IPM-DPA 250-μg method showed the highest sensitivity (97.7%) and specificity (100%). Among four DPT tests, the highest sensitivity (100%) was shown by the IPM-EDTA 1,900-μg disk method, but the specificity was very low (11.4%). Five of six P. aeruginosa isolates with false-negative DDPTs with MEM-DPA 250-μg disks carried bla(IMP-6,) and the high level resistance to MEM (MIC ≥ 512 μg/ml) was reduced by the presence of phenylalanine arginine β-naphtylamide. Improvement of DDPTs was observed when MacConkey agar was used instead of Mueller-Hinton agar. In conclusion, DPA is a better MBL inhibitor than EDTA for detection of Pseudomonas spp. and Acinetobacter spp. with IMP-1-like, VIM-2-like, and SIM-1-type MBLs. In DPA DDPTs, IPM disks perform better than MEM disks when the isolates are highly resistant to MEM due to the overexpression of efflux pumps.     

Carbapenem-resistant Enterobacter cloacae and the emergence of metallo-β-lactamase-producing strains in a third-level hospital (Santiago de Compostela, NW Spain)

The purpose of this paper was to investigate the occurrence of carbapenem-resistant Enterobacter cloacae in our institution, to detect the carbapenemase-associated resistance and to determine the genetic relatedness of the isolates. Species identification and antimicrobial susceptibility testing were performed using the Vitek 2 system and Etest. Multiplex polymerase chain reaction–enzyme linked immunosorbent assay (PCR-ELISA) was used for the detection of extended-spectrum β-lactamase (ESBL)-producers. The bla _IMP and bla _VIM genes were amplified by PCR and sequenced. The DiversiLab System was used for strain-typing. During the period 2006–2008, 12 different isolates of carbapenem-resistant E. cloacae (2.3 %) were recovered in our laboratory. Only two positive isolates for the bla _VIM gene were detected. The minimum inhibitory concentration (MIC) values were higher for all carbapenems in the group of non-metallo-β-lactamase (MBL)-producers. All isolates showed MIC values ≤2 against this tigecycline. The two bla _VIM-1-carrying isolates showed different genotypes. For non-MBL-producers, two clonally related clusters were observed. Different mechanisms can be associated with carbapenem-resistance in E. cloacae. MBL-producing strains are less prevalent than those with other mechanisms of resistance. The clonal relationship confirms the risk of spread of these organisms with the transfer of patients to different wards and the persistence of these clones over time or the ‘de novo’ acquisition of the resistance caused by the selective pressure exerted by antibiotics treatments.     

Clinical Isolates of Salmonella enterica Serovar Agona Producing NDM-1 Metallo-β-Lactamase: First Report from Pakistan

We report two cases of infantile diarrhea due to multidrug-resistant, NDM-1 metallo-β-lactamase-producing Salmonella enterica serovar Agona from Pakistan. This study alerts toward possible risk of NDM-1 transmission to enteric fever pathogens and encourages microbiologists to consider active screening of carbapenem resistance in nontyphoidal Salmonella isolates.     

Presentation of Interleukin-12/-23 Receptor β1 Deficiency with Various Clinical Symptoms of Salmonella Infections

Clinical disease caused by weakly pathogenic mycobacterial species, Mycobacterium bovis Bacille Calmette-Guérin (BCG) and non-tuberculous environmental mycobacteria (EM), which is known as Mendelian susceptibility to mycobacterial disease (MSMD), is a rare entity defined recently. Infections with the more virulent Mycobacterium species, M. tuberculosis, may have largely gone unnoticed in these patients due to early death. Mutations in five proteins (IFNγR1, IFNγR2, IL-12/IL-23Rβ1, IL-12/IL-23p40 and STAT1) have been found in MSMD. These patients are prone to surprisingly few other infectious diseases mainly to salmonellosis. Here we present three IL-12/IL-23Rβ1 deficient patients from three different families and with different genetic mutations, who presented exclusively with Salmonella infections. Bacteremia and lymph node involvement were common clinical expressions. Leukocytoclastic vasculitis developed in one of these patients. Two patients were not inoculated with BCG, the third patient did not develop BCG infection although BCG vaccine had been given twice at ages of 1 and 7 years. All three patients responded well to antibiotic treatment. In conclusion, patients with chronic, recurrent or complicated Salmonella infections should be screened for MSMD, particularly for IL-12/IL-23p40/IL-12R/-23Rβ1 deficiency. Conversely, in patients with genetic IL-12/-23Rβ1 deficiency a full evaluation for Salmonella infection is required. IL-12/IL-23p40/IL-12R/IL-23Rβ1 deficiency seem to be underdiagnosed in patients with salmonellosis, and since such patients need prolonged therapy, diagnosis is important.     

Response to Liposomal Doxorubicin and Clinical Outcome of HIV-1–Infected Patients with Kaposi’s Sarcoma Receiving Highly Active Antiretroviral Therapy

Abstract

Purpose: HIV-associated Kaposi’s sarcoma (KS) may not resolve despite highly active antiretroviral therapy (HAART). Moreover, the therapeutic goal has shifted from palliative care to long-term durable complete remission. The objective of the study was to assess the impact of liposomal doxorubicin in the treatment of HIV-associated KS in the HAART era. Method: In this prospective, noncomparative, multicenter study, patients with more than 10 cutaneous lesions or visceral disease were treated with 20 mg/m² of liposomal doxorubicin (Caelyx^®) every 3 weeks in addition to their antiretroviral therapy. In addition to tumor measurements and laboratory tests, human herpes virus 8 (HHV-8) polymerase chain reaction (PCR) in peripheral blood mononuclear cells (PBMC) was performed. Results: Out of 79 participants enrolled in the study, 47 (59%) had stage T₁ , 41 (52%) I₁ , and 32 (40%) S₁ . Nine individuals were not evaluable for response, 32 (40%) had complete response, 30 (38%) partial response, 5 (6%) stable disease, and 3 (4%) progression. Regression analysis did not find any statistically significant factor predicting response. HHV-8 PCR was positive in 37/53 (70%) patients with available PBMC samples, and HHV-8 viremia cleared in 14/27 (52%) without correlation with clinical response. Eleven (14%) participants experienced a relapse of KS, while at the last update of data, 49 (62%) remained stable. The only risk factor for recurrence identified was the follow-up time (odds ratio [OR] 1.21, 95% CI 1.07-1.36; p = .002). Conclusion: The response rate of AIDS-associated KS to liposomal doxorubicin administered with HAART was high, and most often the response was durable. HHV-8 viremia did not correlate well with clinical outcome.     

Clinical Characteristics and Outcome of Patients with Invasive Pneumococcal Disease, Puy-de-Dôme, France, 1994–1998

P =0.04) from 5.5 in 1994 to 9.3 cases per 10⁵ person-years in 1998. The highest incidences were for children <2 years of age (59.2 cases per 10⁵ person-years) and for adults ≥65 years (18 cases per 10⁵ person-years). Clinical diagnoses, available in 200 patients, included acute pneumonia (62%), meningitis (10%), sepsis without focus (20%), and others (8%). The most frequent chronic medical conditions of the patients included smoking, alcoholism, cardiovascular and pulmonary diseases, and malignancies. Thirty-one percent of the isolates were nonsusceptible to penicillin. Penicillin resistance (MIC≥0.1 mg/l) was more frequent (P=0.02) in cancer patients. The overall case-fatality rate was 21.5%. Risk factors for death were age, sex, and underlying diseases of the patients, along with the severity of illness. These population-based findings should convince clinicians to offer pneumococcal vaccine to patients at high risk for invasive pneumococcal disease, thereby increasing vaccination coverage levels in France.     

The effects of high dose interferon-β1a on plasma microparticles: Correlation with MRI parameters

Background

Autoimmunity to brain may play a pathogenic role in autism. In autoimmune disorders, the formation of antigen-antibody complexes triggers an inflammatory response by inducing the infiltration of neutrophils. Local administration of recombinant progranulin, which is an anti-inflammatory neurotrophic factor, potently inhibit neutrophilic inflammation in vivo, demonstrating that progranulin represents a crucial inflammation-suppressing mediator. We are the first to measure plasma progranulin levels in autism.

Methods

Plasma levels of progranulin were measured, by ELISA, in 40 autistic patients, aged between 3 and 12 years, and 40 healthy-matched children.

Results

Autistic children had significantly lower plasma progranulin levels, P = 0.001. Reduced plasma progranulin levels were found in 65% (26/40) of autistic children. On the other hand, there was a non significant difference between plasma progranulin levels of children with mild to moderate autism and patients with severe autism, P = 0.11.

Conclusions

Plasma progranulin levels were reduced in a subgroup of patients with autism. Progranulin insufficiency in some patients with autism may result in many years of reduced neutrotrophic support together with cumulative damage in association with dysregulated inflammation that may have a role in autism. However, these data should be treated with caution until further investigations are performed, with a larger subject population, to determine whether the decrease of plasma progranulin levels is a mere consequence of autism or has a pathogenic role in the disease. The role of progranulin therapy should also be studied in autism.     

Effect of Plasma Lipoproteins and Their Complexes with Polysaccharides on Interleukin-1β Concentration in Macrophages of Mice with HA-1 Ascitic Hepatoma

Experiments on cultured peritoneal macrophage from mice with HA-1 ascitic hepatoma showed that plasma lipoproteins present in the incubation medium decreased intracellular concentration of interleukin-1β. These changes were most pronounced for high-density lipoproteins (alone or in combination with cortisol). Bacterial and yeast polysaccharides had little effect on interleukin-1β concentration in macrophages. Addition of polysaccharides in combination with lipoproteins was followed by a 2-3-fold decrease in interleukin-1β concentration. A combination of polysaccharides and high-density lipoproteins had the strongest effect. These properties of plasma lipoproteins should be taken into account in the correction of macrophage function during tumor growth.     

Sulfated hyaluronan and chondroitin sulfate derivatives interact differently with human transforming growth factor-β1 (TGF-β1)

This study demonstrates that the modification of hyaluronan (hyaluronic acid; Hya) and chondroitin sulfate (CS) with sulfate groups leads to different binding affinities for recombinant human transforming growth factor-β1 (TGF-β1) for comparable average degrees of sulfation (DS). In general, Hya derivates showed higher binding strength than CS derivatives. In either case, a higher degree of sulfation leads to a stronger interaction. The high-sulfated hyaluronan sHya3 (average DS≈3) exhibited the tightest interaction with TGF-β1, as determined by surface plasmon resonance and enzyme-linked immunosorbent assay. The binding strength was significantly weakened by carboxymethylation. Unmodified Hya and low-sulfated, native CS showed weak or no binding affinity. The interaction characteristics of the different sulfated glycosaminoglycans are promising for incorporation into bioengineered coatings of biomaterials to modulate growth factor binding in medical applications.     

Blood Cytokines in Rats with Various Behavioral Characteristics during Emotional Stress and Treatment with Interleukin-1β

We studied the effect of acute emotional stress and exogenous IL-1β (5 μg/kg intraperitoneally) on the cytokine profile of blood serum in Wistar rats with various behavioral characteristics in the open-field test. Blood level of proinfl ammatory cytokine IL-1β decreased in behaviorally passive rats, but increased in active animals after simultaneous immobilization and electrocutaneous stimulation. These changes refl ect the opposite immune responses to a similar stress exposure in rats with different emotional reactivity. Poststress variations in the concentration of circulating IL-1β differed in rats receiving exogenous IL-1β. Blood cytokine concentration decreased in behaviorally active rats, but remained unchanged in passive animals that were exposed to immobilization and electrocutaneous stimulation after pretreatment with IL-1β. Emotional stress and injection of IL-1β had no effect on blood level of an anti-infl ammatory cytokine IL-4 in rats. Our results indicate that rats with various behavioral parameters are characterized by significant differences in the cytokine profile of blood serum under conditions of emotional stress and treatment with IL-1β. These data illustrate the specific functional features of immune mechanisms, which provide an individual resistance of rats to the same stress exposure.     

Type 2 diabetes–associated polymorphisms correlate with SIRT1 and TGF-β1 gene expression

The polymorphisms rs3758391 and rs1800470 located in SIRT1 and TGF-β1 have been associated with type 2 diabetes in different populations but its functional effect is not clear. In this study, we evaluated their effect on the expression of SIRT1 and TGF-β1 in peripheral blood as well as their participation in the formation of DNA–protein complexes in a pancreas-derived cell line. It has been described that SIRT1 and TGF-β1 participate in cell growth and regulation of production and secretion of insulin in the pancreas. Anthropometric and biochemical profiles of 127 adults were measured. Genotypes for rs3758391 and rs1800470 were determined using TaqMan assays. Expression analysis of SIRT1 and TGF-β1 were performed using real-time PCR. Gene expression of these genes increased 1.8 ± 0.6- and 1.3 ± 0.6-fold in patients carrying the TT genotype of rs3758391 and rs1800470 when compared to carriers of the CC genotype. Then, we tested whether these single-nucleotide polymorphisms (SNPs) (and rs932658, which is in linkage disequilibrium with rs3758391) are located in regulatory DNA-protein binding sites by electrophoretic mobility shift assays using nuclear extract from the pancreas-derived cell line BxPC-3. The electrophoretic mobility shift assay showed no binding of nuclear proteins to DNA. In conclusion, the genotypes of rs3758391 and rs1800470 are associated with modifications in the expression of the genes SIRT1 and TGF-β1, respectively, but none of the tested SNPs are located in regulatory DNA-protein binding sites.     

Jab1 expression is associated with TGF-β1 signaling in chronic rhinosinusitis and nasal polyposis

Jab1, which is a fifth component of COP9 signalosome, plays an essential role in cell growth and proliferation. Jab1 is also shown to regulate transforming growth factor-beta (TGF-β) signaling in carcinoma cells. The aim of the present study was to investigate the expression and the correlation of Jab1 and TGF-β1 in chronic rhinosinusitis and nasal polyposis. Here, we show the elevated expression of Jab1 and TGF-β1 in diseased mucosa without nasal polyps and a correlation between Jab1 and TGF-β1 expression. Forty-six samples (26 patients with nasal polyps, 10 patients with chronic rhinosinusitis and 10 control subjects) were included to this study. Immunohistochemistry and Western blotting were performed for the assessment of Jab1 and TGF-β1 localization and the expression of proteins. Double staining of both proteins showed that Jab1 and TGF-β1 were colocalized in the epithelium, inflammatory cells and the vascular endothelium of nasal mucosa. There was a significant increase in the expression of TGF-β1 and Jab1 in patients without nasal polyps and a significant decrease in patients with nasal polyps compared to controls. Moreover, correlation was detected between the expression of Jab1 and TGF-β1 in chronic rhinosinusitis and nasal polyposis. Our results demonstrate that chronic rhinosinusitis is characterized by elevated expression of Jab1 and TGF-β1 compared to nasal polyposis and Jab1 may play a vital role in the pathogenesis of both chronic rhinosinusitis and nasal polyposis.     

Four Main Virotypes among Extended-Spectrum-β-Lactamase-Producing Isolates of Escherichia coli O25b:H4-B2-ST131: Bacterial,Epidemiological, and Clinical Characteristics

A total of 1,021 extended-spectrum-β-lactamase-producing Escherichia coli (ESBLEC) isolates obtained in 2006 during a Spanish national survey conducted in 44 hospitals were analyzed for the presence of the O25b:H4-B2-ST131 (sequence type 131) clonal group. Overall, 195 (19%) O25b-ST131 isolates were detected, with prevalence rates ranging from 0% to 52% per hospital. Molecular characterization of 130 representative O25b-ST131 isolates showed that 96 (74%) were positive for CTX-M-15, 15 (12%) for CTX-M-14, 9 (7%) for SHV-12, 6 (5%) for CTX-M-9, 5 (4%) for CTX-M-32, and 1 (0.7%) each for CTX-M-3 and the new ESBL enzyme CTX-M-103. The 130 O25b-ST131 isolates exhibited relatively high virulence scores (mean, 14.4 virulence genes). Although the virulence profiles of the O25b-ST131 isolates were fairly homogeneous, they could be classified into four main virotypes based on the presence or absence of four distinctive virulence genes: virotypes A (22%) (afa {"type":"entrez-nucleotide","attrs":{"text":"FM955459","term_id":"218921801","term_text":"FM955459"}}FM955459 positive, iroN negative, ibeA negative, sat positive or negative), B (31%) (afa {"type":"entrez-nucleotide","attrs":{"text":"FM955459","term_id":"218921801","term_text":"FM955459"}}FM955459 negative, iroN positive, ibeA negative, sat positive or negative), C (32%) (afa {"type":"entrez-nucleotide","attrs":{"text":"FM955459","term_id":"218921801","term_text":"FM955459"}}FM955459 negative, iroN negative, ibeA negative, sat positive), and D (13%) (afa {"type":"entrez-nucleotide","attrs":{"text":"FM955459","term_id":"218921801","term_text":"FM955459"}}FM955459 negative, iroN positive or negative, ibeA positive, sat positive or negative). The four virotypes were also identified in other countries, with virotype C being overrepresented internationally. Correspondingly, an analysis of XbaI macrorestriction profiles revealed four major clusters, which were largely virotype specific. Certain epidemiological and clinical features corresponded with the virotype. Statistically significant virotype-specific associations included, for virotype B, older age and a lower frequency of infection (versus colonization), for virotype C, a higher frequency of infection, and for virotype D, younger age and community-acquired infections. In isolates of the O25b:H4-B2-ST131 clonal group, these findings uniquely define four main virotypes, which are internationally distributed, correspond with pulsed-field gel electrophoresis (PFGE) profiles, and exhibit distinctive clinical-epidemiological associations.