Emergence of NDM-1-producing Klebsiella pneumoniae in Greece: evidence of a widespread clonal outbreak.

OBJECTIVES: NDM-producing Enterobacteriaceae clinical isolates remain uncommon in the European region. We describe the emergence and broad dissemination of one successful NDM-1-producing Klebsiella pneumoniae clone in Greek hospitals. METHODS: During a 4 year survey (January 2013-December 2016), 480 single-patient carbapenem non-susceptible K. pneumoniae isolates, phenotypically MBL positive, were consecutively recovered in eight Greek hospitals from different locations and subjected to further investigation. Antimicrobial susceptibility testing, combined-disc test, identification of resistance genes by PCR and sequencing, molecular fingerprinting by PFGE, plasmid profiling, replicon typing, conjugation experiments and MLST were performed. RESULTS: Molecular analysis confirmed the presence of the blaNDM-1 gene in 341 (71%) K. pneumoniae isolates. A substantially increasing trend of NDM-1-producing K. pneumoniae was noticed during the survey (R2 = 0.9724). Most blaNDM-1-carrying isolates contained blaCTX-M-15, blaOXA-1, blaOXA-2 and blaTEM-1 genes. PFGE analysis clustered NDM-1 producers into five distinct clonal types, with five distinct STs related to each PFGE clone. The predominant ST11 PFGE clonal type was detected in all eight participating hospitals, despite adherence to the national infection control programme; it was identical to that observed in the original NDM-1 outbreak in Greece in 2011, as well as in a less-extensive NDM-1 outbreak in Bulgaria in 2015. The remaining four ST clonal types (ST15, ST70, ST258 and ST1883) were sporadically detected. blaNDM-1 was located in IncFII-type plasmids in all five clonal types. CONCLUSIONS: This study gives evidence of possibly the largest NDM-1-producing K. pneumoniae outbreak in Europe; it may also reinforce the hypothesis of an NDM-1 clone circulating in the Balkans.

Inflammatory bowel disease exacerbation associated with Epstein-Barr virus infection.

BACKGROUND: Epstein-Barr virus infection is associated with inflammatory bowel disease, but its role as a pathogenetic or exacerbating factor remains unclear. OBJECTIVE: The aim of this study was to evaluate the association between Epstein-Barr virus infection and inflammatory bowel disease, particularly in regard to exacerbation of disease activity. DESIGN: This was a nonrandomized crosssectional study in subgroups of patients with inflammatory bowel disease compared with a control group with noninflammatory disease. SETTINGS AND PATIENTS: Participants were patients treated for ulcerative colitis or Crohn's disease and individuals undergoing evaluation for noninflammatory disease recruited from 2 urban adult gastrointestinal referral centers in Greece. MAIN OUTCOME MEASURES: Diagnosis of inflammatory bowel disease was based on standard clinical and endoscopic criteria. Demographic and clinical characteristics of all participants were recorded. Whole blood samples and fresh tissue samples from biopsy of intestinal sites were obtained from each participant. The presence of Epstein-Barr virus was determined by amplifying the LMP1 gene of the virus in blood and intestinal tissue samples. RESULTS: The study comprised 94 patients with inflammatory bowel disease (63 with ulcerative colitis and 31 with Crohn's disease) and 45 controls with noninflammatory disease. Of the 94 patients, 67 (71.3%) had disease exacerbation and 27 (28.7%) were in remission. The prevalence of Epstein-Barr virus genome was significantly higher in patients than in controls for intestinal tissue (44 patients, 46.8% vs 6 controls, 13.3%; p = 0.001), but not for whole blood (24 patients, 25.5% vs 9 controls, 20%; p = 0.3). The viral genome was found significantly more frequently in intestinal samples from patients with disease exacerbation compared with patients in remission (38 patients with exacerbation, 56.7% vs 6 patients in remission, 22.2%; p = 0.001), but no significant difference was found for whole blood (18 patients with exacerbation, 26.8% vs 6 patients in remission, 22.2%; p = 0.79). Neither disease exacerbation nor the presence of virus genome was related to demographic or clinical characteristics. LIMITATIONS: The exact location of Epstein-Barr virus in the intestinal tissues could not be specified because morphological data by immunohistochemistry or in situ hybridization were not available. CONCLUSIONS: Although causality could not be determined, the significantly higher prevalence of Epstein-Barr virus in intestinal tissue from patients with inflammatory bowel disease compared with controls and in patients with exacerbation compared with patients in remission suggests a potential viral involvement in the severity of inflammatory bowel disease. These findings merit further investigation in view of a potential for usefulness of antiviral therapy against Epstein-Barr virus infection in patients with exacerbation of inflammatory bowel disease.

High prevalence of clonally related ST182 NDM-1-producing Enterobacter cloacae complex clinical isolates in Greece.

NDM-type metallo-ß-lactamase (MBL)-producing Enterobacterales remain uncommon in the European region, especially among species other than Klebsiella pneumoniae and Escherichia coli. The aim of this study was to describe epidemiological and molecular characteristics of a widespread NDM-1-producing Enterobacter cloacae complex outbreak in Greece. Over a 6-year period (March 2016-March 2022), a retrospective study was conducted in a tertiary care Greek hospital. Ninety single-patient carbapenem-non-susceptible E. cloacae complex clinical isolates were recovered consecutively. The isolates were subjected to further investigation, including antimicrobial susceptibility testing and combined disc tests for carbapenemase production, polymerase chain reaction and sequencing for resistance genes, molecular fingerprinting by pulsed-field gel electrophoresis (PFGE), plasmid profiling, replicon typing, conjugation experiments, genotyping by multi-locus sequence typing (MLST), whole-genome sequencing and phylogenetic analysis. Phenotypic and molecular testing confirmed the presence of blaNDM-1 in 47 (52.2%) of the E. cloacae complex isolates. MLST analysis clustered all but four of the NDM-1 producers into a single MLST sequence type (ST182), whereas single isolates belonged to different sequence types (ST190, ST269, ST443 and ST743). PFGE analysis revealed that ST182 isolates were clustered into a single clonal type, with three subtypes, which differed from the clonal types detected among the remaining carbapenem non-susceptible E. cloacae complex isolates identified during the study period. All ST182 blaNDM-1-carrying isolates also harboured the blaACT-16 AmpC gene, while the blaESBL, blaOXA-1 and blaTEM-1 genes were detected in most cases. In all clonal isolates, the blaNDM-1 gene was located on an IncA/C-type plasmid, and flanked upstream by an ISAba125 element and downstream by bleMBL. Conjugation experiments failed to produce carbapenem-resistant transconjugants, indicating a low dynamic for horizontal gene transfer. Application of enforced infection control measures led to the absence of new NDM-positive cases for periods of time during the survey. This study represents the largest clonal outbreak of NDM-producing E. cloacae complex in Europe.

Temporal relationship of myocarditis and pericarditis following COVID-19 vaccination: A pragmatic approach.

BACKGROUND: Complications following COVID-19 vaccination, particularly with mRNA vaccines, rarely include myocarditis and pericarditis. This work principally aimed at defining a realistic temporal relationship between vaccination and myocarditis/pericarditis development. METHODS: All relevant cases reported from week 52/2020 through week 41/2021 in the VAERS database were retrieved and analyzed for licensed vaccines. These included BNT162b2, mRNA-1273, and AD26.COV2·S. Incidence rates were calculated using the corresponding administered vaccine doses as denominators. Additionally, analyzed parameters included demographics, dose series, hospitalization length and outcome. RESULTS: Overall, 2016 myocarditis and 1380 pericarditis cases, (4.96/106 and 3.40/106 administered vaccine doses, respectively), were recorded. Most myocarditis cases occurred following BNT162b2 (5.60/106 doses) in males <30 years. Pericarditis affected predominantly males <40, both sexes >40 years, and was most common post AD26.COV2·S (4.78/106 doses). Hospitalization was required for 40.3% and 27.2% of myocarditis and pericarditis cases, respectively. A bimodal pattern was found for both myocarditis and pericarditis, with two peaks that coincided temporally, but were reversed in intensity. The first peak was recorded 1-3 days post-vaccination and was more pronounced in myocarditis, while the second was recorded 15-30 days post-vaccination and was more intense in pericarditis. CONCLUSIONS: Myocarditis/pericarditis after COVID-19 vaccination is rare and depicts a bimodal pattern.

Containment of an outbreak of KPC-3-producing Klebsiella pneumoniae in Italy.

From March 2009 to May 2009, 24 carbapenem-resistant Klebsiella pneumoniae isolates were recovered from 16 patients hospitalized in an Italian intensive care unit (ICU). All isolates contained KPC-3 carbapenemase and belonged to a single pulsed-field gel electrophoresis (PFGE) clone of multilocus sequence type 258 (designated as ST258). A multimodal infection control program was put into effect, and the spread of the KPC-3-producing K. pneumoniae clone was ultimately controlled without closing the ICU to new admissions. Reinforced infection control measures and strict monitoring of the staff adherence were necessary for the control of the outbreak.

Recurrent healthcare-associated community-onset infections due to Klebsiella pneumoniae producing VIM-1 metallo-beta-lactamase.

OBJECTIVES: To investigate the extrahospital dissemination of carbapenem-resistant Klebsiella pneumoniae isolates and the mechanisms of acquired resistance. METHODS: Patients who were referred to the outpatient department of Serres General Hospital with community-onset infections due to carbapenem-resistant K. pneumoniae isolates during August 2007-October 2008 were included in the study. The selected isolates were tested by determination of agar dilution MICs, phenotypic carbapenemase testing and PFGE. PCR and sequencing analyses were employed for identification of bla genes and mapping of the integron carrying the metallo-ß-lactamase (MBL) gene. The location of the MBL allele was investigated by mating experiments, plasmid analysis and PCR assays. RESULTS: Twenty-four carbapenem-resistant K. pneumoniae isolates causing urinary tract infections were recovered from 12 outpatients. Six of the patients presented with recurrent infections within a period of 1-6 months after the initial extrahospital isolation. All patients reported prior hospitalization within the preceding 4 months, whilst two were infected by carbapenem-resistant K. pneumoniae isolates during their previous hospitalization. Imipenem, meropenem and ertapenem MICs ranged from 8 to 64 mg/L, 4 to 32 mg/L and 8 to 128 mg/L, respectively. All studied isolates as well as those obtained from prior hospitalization belonged to a single PFGE clone. They harboured a plasmid-mediated bla(VIM-1) gene in an integron structure that has been previously described among K. pneumoniae isolates causing hospital-acquired infections in Greece. CONCLUSIONS: This is the first study to document the dissemination of an MBL-producing K. pneumoniae strain in the community. The successful strain caused recurrent community-onset infections and was most likely acquired during patients' previous hospitalization.

Adenovirus genome in the placenta: association with histological chorioamnionitis and preterm birth.

Adenovirus is isolated frequently from the amniotic fluid and has been implicated in severe neonatal infections. A case control study was carried out to examine the association of detection of adenovirus in placentas with preterm birth and histological chorioamnionitis. Placentas from preterm and full term deliveries were collected prospectively. Preterm cases were divided into three subgroups according to the gestational age. PCR was carried out on placental tissues for the detection of adenovirus genome. Placentas were evaluated histologically for the presence of chorioamnionitis. Chi-square and odds ratios (OR) were used to determine if detection of adenovirus is associated with preterm birth and histological evidence of inflammation. Seventy-one preterm and 122 full term placentas were studied. Adenovirus genome was detected in 29 (40.8%) of preterm cases and in 25 (20.5%) of the full term controls (OR = 2.6; 95% CI, 1.4-5.1; P = 0.002). Detection of adenovirus in preterm placentas was significantly higher compared to full term particularly in the lower gestational age. Detection of adenovirus in placenta followed the seasonal variation of adenovirus infections. Thirty-seven preterm and 21 full term placentas were also selected for paraffin inclusion and histological examination. Chorioamnionitis was present more frequently in preterm adenovirus-positive placentas compared to preterm adenovirus-negative placentas (75% vs. 36%; P = 0.026) as well as compared to term adenovirus-positive placentas (75% vs. 19%; P = 0.003). This study demonstrates that adenovirus infection of the placenta is associated strongly with histological chorioamnionitis and preterm birth.

SARS-CoV-2 transmission, the ambiguous role of children and considerations for the reopening of schools in the fall.

Tweetable abstract The reopening of schools in the fall entails risks given the controversies in pediatric COVID-19 pathogenesis and the ambiguous role of children in transmission.

Large dissemination of VIM-2-metallo-{beta}-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-beta-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.

Detection of cytomegalovirus, parvovirus B19 and herpes simplex viruses in cases of intrauterine fetal death: association with pathological findings.

There are previous indications that transplacental transmission of cytomegalovirus (CMV), parvovirus B19 (PB19) and herpes simplex virus types 1 and 2 (HSV-1/2) cause fetal infections, which may lead to fetal death. In a prospective case-control study we examined the incidence of these viruses in intrauterine fetal death and their association with fetal and placenta pathological findings. Molecular assays were performed on placenta tissue extracts of 62 fetal deaths and 35 controls for the detection of CMV, PB19 and HSV-1/2 genomes. Formalin-fixed, paraffin-embedded liver, spleen and placenta tissues of fetal death cases were evaluated histologically. Thirty-four percent of placental specimens taken from intrauterine fetal deaths were positive for any of the three viruses (16%, 13%, and 5% positive for CMV, PB19, and HSV-1/2, respectively), whereas only 6% of those taken from full term newborns were positive (P = 0.0017). No dual infection was observed. This difference was also observed when fetal deaths with a gestational age <20 weeks or a gestational age >20 weeks were compared with the controls (P = 0.025 and P = 0.0012, respectively). Intrauterine death and the control groups differed in the detection rate of CMV DNA (16% and 3%, respectively; P = 0.047), which was more pronounced in a gestational age >20 weeks (P = 0.03). Examination of the pathological findings among the PCR-positive and PCR-negative fetal deaths revealed that hydrops fetalis and chronic villitis were more common among the former group (P = 0.0003 and P = 0.0005, respectively). In conclusion, an association was detected between viral infection and fetal death, which was more pronounced in the advanced gestational age. Fetal hydrops and chronic villitis were evidently associated with viral DNA detection in cases of intrauterine death.

Efflux system overexpression and decreased OprD contribute to the carbapenem heterogeneity in Pseudomonas aeruginosa.

Pseudomonas aeruginosa strains exhibiting a heterogeneous mode of growth against carbapenems have been described recently. This study investigated the underlying molecular mechanisms in four genetically unrelated P. aeruginosa clinical isolates that were previously characterized by population analyses as heterogeneously resistant against carbapenems. Mutant subpopulations of all four isolates had at least fourfold higher minimum inhibitory concentrations than those of native cells for imipenem and meropenem. The heterogeneous subpopulations, when compared with the respective native ones, had significantly increased transcription levels of the mexB and mexY genes (P<0.05), whereas transcription levels of the mexE gene remained unchanged. They also exhibited significantly decreased expression of the oprD gene (P<0.05) and decreased intensity of the protein band of the porin OprD. Upregulation of efflux systems, in part, and the decrease of OprD contribute to the heterogeneous growth against carbapenems in our P. aeruginosa clinical isolates.

Enterovirus-associated hemophagocytic syndrome in children with malignancy: report of three cases and review of the literature.

Enteroviruses can cause severe manifestations in children with malignancy. Infection-associated hemophagocytic syndrome (IAHS) due to enterovirus is a rare entity in children. Patients with malignancy and IAHS due to enterovirus were retrospectively evaluated at the University of Athens' Hematology-Oncology pediatric unit within a 6-year period (2000-2006). IAHS occurred in three cases among 56 patients with documented enteroviral infection. The diagnosis of IAHS was confirmed by bone marrow aspiration and biopsy. Nested reverse transcriptase-polymerase chain reaction (RT-PCR), sequencing of the amplified alleles, and immunohistochemistry were performed to document the presence of enterovirus. The type of enterovirus was specified by indirect immunofluorescence assay. At the early phase of the disease, patients presented mild, non-specific viral symptoms, persistent unexplained fever, and pancytopenia. At the late phase, patients had more severe manifestations, such as persistent high fever, diarrhea, weight loss, hepatosplenomegaly, and hepatic dysfunction. The therapeutic approach consisted of supportive care, administration of immunoglobulin (400 mg/kg or 2 g/kg), and pleconaril. All patients had fatal outcome; two patients succumbed to multiorgan failure (MOF), while one patient succumbed to ventricular fibrillation. IAHS usually has fulminant course and leads to severe and life-threatening complications, such as liver failure and MOF. IAHS should always be included in the differential diagnosis of viral syndrome or unexplained fever. The therapeutic approach for IAHS should be administered as early as possible, before the progression to irreversible tissue damage. Early therapeutic intervention involving high doses of immunoglobulin might be beneficial for the patient's outcome.

NDM-1 Hazard in the Balkan States: Evidence of the First Outbreak of NDM-1-Producing Klebsiella pneumoniae in Bulgaria.

New Delhi MBL (NDM) carbapenemase-producing Klebsiella pneumoniae has become one of the most concerning multidrug-resistant pathogens. The Balkan counties are considered a reservoir for the spread of such strains based on several reports documenting NDM infections after hospitalization in this region. Nevertheless, NDM-producing K. pneumoniae have been only occasionally documented from Balkans. The current study documents the first polyclonal outbreak caused by NDM-1-producing K. pneumoniae in Bulgaria. From July 2015 to April 2016, all 25 single-patient carbapenem-nonsusceptible K. pneumoniae isolates were collected. Phenotypic and molecular screening revealed that 17 produced NDM-1 carbapenemase. All NDM-1 producers harbored blaCTX-M-15, blaCMY-4, blaTEM-1, and blaOXA-2; five also harbored blaOXA-1. In all cases, blaNDM-1 was flanked upstream by ISAba125 element and downstream by bleMBL. Pulsed-field gel electrophoresis (PFGE) clustered NDM-1-positive isolates into four distinct clonal types, A to D. MLST assigned isolates of the dominant clonal type A (n = 14) to sequence type (ST) 11, while isolates of clonal types B, C, and D to ST16, ST15, and ST391, respectively. Of interest, ST11 isolates belonged to the same PFGE type as those of the recently described NDM-1 ST11 clonal outbreak in Greece. Traveling abroad or overseas hospitalization was not reported in any case, suggesting most likely intra- and interhospital dissemination. The study presents the first polyclonal outbreak of NDM-producing K. pneumoniae in the Balkans and underlines the need for larger epidemiological studies in the region to illustrate commonalities in the transmission of NDM clones and possible sources in the community.

Emergence of carbapenem-resistant Enterobacter cloacae carrying VIM-4 metallo-beta-lactamase and SHV-2a extended-spectrum beta-lactamase in a conjugative plasmid.

Enterobacter cloacae strains are still infrequently resistant to carbapenems. A carbapenem-resistant clinical isolate of E. cloacae producing a plasmid-mediated metallo-beta-lactamase (MBL), VIM-4, was recovered from a Greek hospitalized patient. The bla(VIM-4) gene was located in the variable array of a class 1 integron structure repeatedly detected among bla(VIM-1)-bearing Gram-negative pathogens in Greece. The isolate possessed also on the same conjugative plasmid an extended-spectrum beta-lactamase (ESBL), SHV-2a, which contributed to the beta-lactam-resistant phenotype. This is the first report showing co-transfer of an ESBL with a VIM-type MBL. It suggests also that different VIM-type gene cassettes have been incorporated in a common integron structure, which seems indigenous of Gram-negative pathogens in our region.

Characterization of clinical isolates of Pseudomonas aeruginosa heterogeneously resistant to carbapenems.

Fourteen apparently carbapenem-susceptible Pseudomonas aeruginosa clinical isolates that exhibited colonies within the inhibition zone around carbapenem discs were analysed. MICs of carbapenems were determined and the isolates were genotyped by PFGE. Population analysis, one-step selection of carbapenem-resistant mutants and growth curves of progenitors and carbapenem-resistant subpopulations were performed. Agar dilution MICs of imipenem and meropenem ranged from 0.5 to 4 mg l(-1) and from 0.25 to 2 mg l(-1), respectively. Population analysis confirmed subpopulations that grew in concentrations of up to 18 mg l(-1) and 12 mg l(-1) of imipenem and meropenem, respectively, at frequencies ranging from 6.9 x 10(-5) to 1.1 x 10(-7), suggesting that they might not be detected by standard agar dilution MIC testing. The minority subpopulations exhibited MICs for imipenem ranging from 10 to 20 mg l(-1) and for meropenem from 4 to 14 mg l(-1). The one-step 8 mg l(-1) selection of imipenem-resistant mutants test showed growth in all isolates at frequencies ranging from 3.8 x 10(-4) to 5.1 x 10(-7). Growth curves revealed a prolonged lag phase and a short exponential phase for the heterogeneous subpopulations compared with their respective native subpopulations. These findings may be indicative that the use of carbapenems can lead to selection of P. aeruginosa resistant subpopulations that subsequently cause infections and result in treatment failure.

Frequent detection of cytomegalovirus in the intestine of patients with inflammatory bowel disease.

BACKGROUND: Although a growing number of reports have described inflammatory bowel disease (IBD) complicated with cytomegalovirus (CMV) infection, there are limited molecular studies that investigate CMV genome in intestinal sections of patients with IBD. METHODS: A cross-sectional prospective study was conducted between September 2000 and June 2003 in a cohort of 85 patients diagnosed with IBD (58 with ulcerative colitis and 27 with Crohn's disease) in two adult gastrointestinal referral centers in Athens, Greece. Prevalence of CMV infection was estimated by pathologic studies in intestinal sections and by molecular assays in blood and intestinal tissue samples and compared with a control group of 42 individuals with noninflammatory disease. RESULTS: Immunohistochemical staining showed CMV antigen in 10 IBD patients (7 with ulcerative colitis; 9 with severe disease), whereas CMV antigen was not detected in any of the controls. CMV genome in both the intestinal tissue and blood was found by polymerase chain reaction in 23 (27.1%) of the total IBD patients, in 18 (31.0%) of those with ulcerative colitis, and in 5 (18.5%) of those with Crohn's disease. In addition, five (5.9%) IBD patients (2 with ulcerative colitis and 3 with Crohn's disease) had detectable CMV genome in their intestinal samples but not in their blood. In the control group, five (11.9%) individuals had detectable CMV genome in their blood, but only one (2.2%) in his intestine. CONCLUSION: Patients with ulcerative colitis had more often detectable CMV genome in their blood as well as in their intestinal tissue samples as compared with controls (P = 0.022 and P < 0.0001, respectively). However, patients with Crohn's disease had more often detectable CMV genome only in their intestinal tissue samples as compared with controls (P = 0.001). Detection of CMV genome in blood or intestinal tissue was significantly associated with short duration of IBD (P = 0.0088 and 0.04, respectively) but not with age, sex, severity of the disease, activity at colonoscopy, pancolitis, administration of a specific treatment, and surgery. In this cross-sectional prospective study, detection of CMV genome or antigen in the intestine was commonly associated with IBD.

Prevalence of infection by HTLV-I/II among pregnant women and high-risk groups in the Peloponnese peninsula, Greece.

Although screening for human T-cell lymphotropic virus types I and II (HTLV-I/II) antibodies in volunteer blood donors has been systematic in Greece since 1995, the epidemiology and the determinants of HTLV-I/II infection are not well defined among population groups. During 1997-2005, the prevalence of HTLV-I/II infection was investigated in a sample of 2016 pregnant women, 102 multitransfused haematologic and oncologic patients, 93 thalassaemic patients and 57 intravenous drug users originating from four geographic areas of Pelopennese peninsula, Greece. One recipient of HTLV-I infected blood and the relatives of a woman died from adult T-cell leukaemia/lymphoma (ATTL) related to HTLV-I have also been tested. The subjects were initially screened by an enzyme immunoassay whereas Western blot, INNO-LIA HTLV, polymerase chain reaction and nucleotide sequencing confirmed the infection. One thalassaemic patient had proved HTLV-I infection giving an overall prevalence of 11 per 1000. In the recipient of the infected blood and in two of the five relatives of the woman died from ATTL, HTLV-I infection was also detected. In none of the pregnant women, multitransfused patients and intravenous drug users HTLV-I/II infection was confirmed. These data suggest that HTLV-I is present in Greece among populations at high-risk. However, they would not support the need for HTLV-I/II antenatal screening in Greece.

Current perspectives on tigecycline resistance in Enterobacteriaceae: susceptibility testing issues and mechanisms of resistance.

During the past decades, rates of multidrug-resistant (MDR) and carbapenem-resistant (CR) Enterobacteriaceae clinical isolates, mainly Klebsiella spp., Escherichia coli, Enterobacter spp., Proteus spp. and Serratia marcescens, have increased, considerably restricting effective antimicrobial treatments. Tigecycline, the first member of the glycylcyclines, has been approved by the US Food and Drug Administration (FDA) for the treatment of complicated skin and soft-tissue, complicated intra-abdominal and community-acquired bacterial respiratory infections and is increasingly administered against MDR Enterobacteriaceae. Although resistance has gradually appeared, tigecycline still remains relatively active among Enterobacteriaceae, with resistance rates largely <10% in most wide-scale surveillance studies. Tigecycline resistance has been reported in some studies to be elevated among extended-spectrum ß-lactamase (ESBL)-producing, MDR, extensively drug-resistant and CR isolates. Broth microdilution (BMD) is the reference method for tigecycline susceptibility testing, but disagreements have been reported between the methods applied for routine tigecycline susceptibility testing. Therefore, confirmation of daily tigecycline susceptibility testing with BMD appears important in order to avoid misclassification of isolates. Various mechanisms have been reported to confer tigecycline resistance, with RND-type transporters, mainly the AcrAB efflux pump, playing an important role. Other pumps and various control pathways are also implicated in tigecycline resistance. Overall, tigecycline is a potent therapeutic option for enterobacterial infections. Accurate detection of tigecycline susceptibility status and surveillance of resistant organisms in the hospital environment is necessary in order to optimise its use and to preserve tigecycline in our therapeutic arsenal.

Bronchiectasis exacerbations: The role of atypical bacteria, respiratory syncytial virus and pulmonary function tests.

BACKGROUND: Aside from the known role of common bacteria, there is a paucity of data regarding the possible role of atypical bacteria and viruses in exacerbations of non-cystic fibrosis bronchiectasis. OBJECTIVE: To explore the possible role of atypical bacteria (namely, Mycoplasma pneumoniae and Chlamydophila pneumoniae) and respiratory syncytial virus (RSV) as causative agents of bronchiectasis exacerbations. METHODS: A cohort of 33 patients was studied over a two-year period (one year follow-up for each patient). Polymerase chain reaction for the detection of M pneumoniae, C pneumoniae and RSV in bronchoalveolar lavage samples were performed during all visits. Antibody titres (immunoglobulin [Ig]M and IgG) against the aforementioned pathogens were also measured. In addition, cultures for common bacteria and mycobacteria were performed from the bronchoalveolar lavage samples. RESULTS: Fifteen patients experienced a total of 19 exacerbations during the study period. Although RSV was detected by polymerase chain reaction during stable visits in four patients, it was never detected during an exacerbation. M pneumoniae and C pneumoniae were never detected at stable visits or during exacerbations. IgM antibody titres for these three pathogens were negative in all patient visits. CONCLUSIONS: Atypical pathogens and RSV did not appear to be causative agents of bronchiectasis exacerbations.

Oseltamivir-resistant influenza A(H1N1) 2009 virus in Greece during the post-pandemic 2010-2011 season.

Information on the drug susceptibility of influenza epidemic strains is important for antiviral resistance monitoring. In Greece, the 2009-2010 pandemic waves were very mild and seroprevalence rates remained low after this influenza season, resulting in exclusive detection of the pandemic strain during the 2010-2011 influenza season. In the present study during the post-pandemic 2010-2011 season, 50 consecutive influenza A(H1N1) 2009 virus-positive samples from patients hospitalised in Greek hospitals were analysed for resistance to the neuraminidase inhibitor oseltamivir. All patients were hospitalised with severe influenza complications and had previously received oseltamivir. Influenza A(H1N1) 2009 virus detection and testing for oseltamivir resistance were performed with real-time PCR amplification assays. The H275Y substitution associated with resistance to oseltamivir was identified in two immunocompetent patients who received oseltamivir treatment for 3 days and 5 days, respectively. In both cases, patients were discharged in good condition despite development of resistance to antiviral treatment.