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N J Legakis

Publications and source records attributed to N J Legakis.

At least 37 records · Page 2Linked to original sources
PubMed2003

Infrequent detection of acquired metallo-beta-lactamases among carbapenem-resistant Pseudomonas isolates in a Greek hospital.

OBJECTIVE: To study the possible distribution of metallo-beta-lactamases among nosocomial Pseudomonas isolates in a Greek hospital with a recent high prevalence of carbapenem-resistant Pseudomonas isolates. METHODS: All carbapenem-resistant (imipenem- and/or meropenem-resistant) (MICs > 8 mg/L) Pseudomonas non-replicate isolates recovered from clinical infections in the Microbiology Laboratory of Saint Demetrios Hospital, Thessaloniki, Greece, from April 1998 to November 2000 were studied for the presence of metallo-beta-lactamases. They were tested by a disk diffusion test, PCR analysis, and nucleotide sequencing. DNA fingerprints were obtained by pulsed-field gel electrophoresis (PFGE) of XbaI-digested chromosomal DNA. RESULTS: In total, 24 carbapenem-resistant isolates (23 P. aeruginosa and one P. putida) were recovered. The serotypes observed among the P. aeruginosa isolates were, in order of decreasing frequency, O:11 (52%), O:3 and O:12 (17% each), and O:6 (13%). PFGE grouped 17 of the P. aeruginosa isolates into four clusters, each containing from two to seven isolates, while the remaining isolates exhibited unique genotypes. blaVIM-2 was detected in the P. putida isolate and a P. aeruginosa serotype O:3 isolate. The latter strain was genotypically distinct from other contemporaneous or older carbapenem-resistant P. aeruginosa Greek isolates. CONCLUSION: These findings suggest that, although the prevalence of metallo-beta-lactamases is low, the integron-associated blaVIM genes can spread to P. aeruginosa serotypes that have not been previously associated with carbapenem resistance in our region, as well as to other pseudomonal species.

Carbapenems↗
PubMed2003

A common clone of erythromycin-resistant Streptococcus pneumoniae in Greece and the UK.

OBJECTIVE: To investigate the possible genetic relationship among erythromycin-resistant Streptococcus pneumoniae strains isolated in Greece and the UK. METHODS: During 1995-97, 140 S. pneumoniae strains were isolated from clinical specimens submitted to the microbiology departments of the two main children's hospital in Athens. All erythromycin-resistant strains were further studied with respect to the presence of genes encoding for the two major mechanisms of macrolide resistance, their serotypes, and pulsed-field gel electrophoresis (PFGE) types, in comparison to a previously characterized UK erythromycin-resistant clone. RESULTS: Eleven of the 140 isolates (7.9%) were resistant to erythromycin; nine of these were susceptible to penicillin. Serotyping allocated seven, three and one isolates to serotypes 14, 19F and serogroup 6, respectively. The mefA gene was detected in seven isolates (five serotype 14 and two serotype 19F), ermB in two (one serotype 19F and the serogroup 6 isolate), whilst in the remaining two isolates no resistance gene could be detected by polymerase chain reaction (PCR). Pulsed-field gel electrophoresis of genomic DNA showed that five Greek serotype 14 isolates belonged to the same chromosomal type as the serotype 14 erythromycin-resistant UK clone. CONCLUSIONS: The present study showed that erythromycin resistance among the S. pneumoniae isolates was mostly owing to the efflux mechanism and suggested a possible clonal spread of serotype 14 erythromycin-resistant S. pneumoniae strains between Greece and the UK.

Child↗
PubMed2003

Spread of integron-associated VIM-type metallo-beta-lactamase genes among imipenem-nonsusceptible Pseudomonas aeruginosa strains in Greek hospitals.

Fifty-eight imipenem-nonsusceptible (MIC >or= 8 microg/ml) Pseudomonas aeruginosa strains isolated during May 2001 in 15 Greek hospitals were studied. Thirty-six isolates derived from nine hospitals carried VIM-type metallo-beta-lactamase genes, as found by PCR. In 34 isolates, bla(VIM) was associated with class 1 integrons of various sizes. DNA sequencing indicated the presence of bla(VIM-2) gene cassettes in a variety of integron structures. Random amplified polymorphic DNA typing suggested diversity of the bla(VIM)-positive strains. Synergy between 2-mercaptoacetic acid and imipenem indicated carbapenemase activity in 26 bla(VIM)-positive strains.

DNA, Bacterial↗
PubMed2003

VIM-1 Metallo-beta-lactamase-producing Klebsiella pneumoniae strains in Greek hospitals.

Seventeen Klebsiella pneumoniae clinical isolates carrying the bla(VIM-1) metallo-beta-lactamase gene were collected in the intensive care units of three hospitals in Athens, Greece, in 2002. They exhibited various carbapenem resistance levels (Etest MICs of imipenem ranged from 4 to 32 microg/ml). All isolates gave positive results by the imipenem-EDTA synergy Etest. The isolates were classified into four main types by pulsed-field gel electrophoresis; the majority of the isolates (5 and 10 isolates) belonged to two types. The bla(VIM-1) gene cassette was part of the variable region of a class 1 integron that also included aac6, dhfrI, and aadA. This structure was carried by transferable plasmids.

Base Sequence↗
PubMed2002

Evaluation of an anti-PBP 2a slide latex agglutination test in coagulase-negative staphylococci isolated in Greek hospitals.

Oxacillin resistance was examined in 258 coagulase-negative staphylococci from Greek hospitals. mecA DNA was detected in 168 isolates, which were also resistant to oxacillin by agar dilution and disk diffusion, according to the current NCCLS breakpoints. Both methods exhibited a relatively low specificity misclassifying 21 and 19 of the 90 mecA-negative isolates respectively as oxacillin resistant. In contrast, an anti-PBP 2a latex agglutination test, applied after induction by oxacillin, correctly classified 163 mecA-positive (sensitivity 97%) and 88 mecA-negative isolates (specificity 97.7%).

Bacterial Proteins↗
PubMed2002

Identification of Malassezia species from patient skin scales by PCR-RFLP.

OBJECTIVE: This study was aimed at the development of a DNA-based procedure directly applicable to pathological skin scales and at the assessment of its value in rapid laboratory confirmation and identification of each of the seven Malassezia species. These lipophilic basidiomycetous yeasts in predisposed individuals are involved in pityriasis versicolor, seborrheic dermatitis, blepharitis, folliculitis, atopic dermatitis and fungemia. Standard identification procedures to species level are available, but so far no system for direct detection and characterization of Malassezia species in clinical specimens is available. METHODS: Malassezia DNA was extracted from pathological skin scales by a modified hexadecyltrimethylammonium bromide (CTAB) method and amplified by single and nested polymerase chain reaction (PCR), assays using the general fungal ITS 1/4 and 3/4 primers for amplification of sequences from the Malassezia major ribosomal DNA complex. Restriction fragment length polymorphism (RFLP) analysis of PCR products was used in subsequent species identification. DNA extracted from culture-positive skin scales was also tested by PCR and the RFLP patterns obtained were analyzed. RESULTS: A total of 36 isolates were tested. Distinct pure culture and skin-scale ITS 3/4 HinfI and AluI restriction patterns differentially identified M. furfur, M. globosa, M. restricta, M. sympodialis, M. pachydermatis, M. obtusa and M. slooffiae. Malassezia DNA was extracted from pathological skin scales and RFLP identified solitary and multiple Malassezia species in the same specimen. Molecular identification was confirmed by cultures and biochemical tests. Concurrent detection and identification of Candida and Yarrowia species was also feasible from skin scales. CONCLUSION: The proposed method, described for the first time, could provide a sensitive and rapid detection and identification system for Malassezia species, which may be applied to epidemiological surveys and routine practice.

Animals↗
PubMed2002

CTX-m-3 beta-lactamase-producing Escherichia coli from Greece.

An Escherichia coli clinical strain resistant to all beta-lactams except carbapenems was isolated in a Greek hospital. Analysis of beta-lactamase content by isoelectric focusing, PCR assays specific for various bla genes, and DNA sequencing showed that the strain produced TEM-1, a Citrobacter freundii AmpC-related cephalosporinase, and CTX-M-3. The blaCTX.M-3 gene was carried by a 120-kb plasmid that was readily transferable to a susceptible E. coli host.

Citrobacter freundii↗
PubMed2002

Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in a neonatal intensive care unit in the high-prevalence area of Athens, Greece.

Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (EPKP) strains are frequently implicated in outbreaks in neonatal intensive care units (NICUs). During the period from 1997 to 1998, 21 infections and 23 colonizations with EPKP were recorded in the NICU of a children's hospital in Athens, Greece. Seventeen of the infected and 12 of the colonized neonates had been referred from other hospitals. The remaining infections and colonizations occurred during the current hospitalization. Pulsed-field gel electrophoresis typing showed that the latter cases were due to an outbreak strain that persisted in the unit, while the repeated introduction of EPKP carriers was mostly due to clonal outbreaks in two maternity hospitals.

Electrophoresis, Gel, Pulsed-Field↗
PubMed2001

Antibiotic resistance rates and macrolide resistance phenotypes of viridans group streptococci from the oropharynx of healthy Greek children.

A total of 200 isolates of viridans group streptococci isolated from the oropharynx of healthy Greek children were studied. Vancomycin, rifampicin, fluoroquinolones and dalfopristin/quinupristin were active against all tested isolates. High level resistance to gentamicin was not seen. Intermediate and high-level penicillin resistance was present in 28.5 and 14.5% isolates, respectively, with 41.3% of the latter group, being also resistant to cefotaxime. Resistance rates to other antimicrobials were as follows - erythromycin 38.5%, clarithromycin 33.5%, clindamycin 7.5% and tetracycline 23%. Penicillin resistance occurred more frequently in Streptococcus mitis isolates, while macrolide resistance was more frequent in S. oralis. MLSB resistance phenotype M was dominant (74%) among erythromycin resistant isolates, with phenotypes IR and CR being represented by 6 and 20% of isolates, respectively.

Adolescent↗
PubMed2001

Subtyping and antifungal susceptibilities of Candida spp. in the intensive care unit of a Greek general hospital.

This study identified the Candida spp., susceptibility to antifungal agents and the prevailing Candida albicans subtypes responsible for infections or colonization of 42 patients in the ICU over a 6-month period. Most isolates were C. albicans (66.1%) and Candida tropicalis (28.3%) all of which were susceptible in vitro to antifungal agents. Subtypes of the C. albicans isolates were identified by pulsed field gel electrophoresis Sfi I chromosomal digests. Two major C. albicans subtypes were identified, whereas subtype heterogeneity was found among strains of Candida glabrata and C. tropicalis. Sfi I PFGE restriction patterns were able to discriminate between sub-populations of C. albicans isolates, clustering them into distinct, epidemiologically congruous groups.

Antifungal Agents↗
PubMed2001

Oral pseudomembranous candidiasis, herpes simplex virus-1 infection, and oral mucositis in head and neck cancer patients receiving radiotherapy and granulocyte-macrophage colony-stimulating factor (GM-CSF) mouthwash.

Oral pseudomembranous candidiasis (OPC) was evaluated in 61 patients receiving head and neck radiotherapy (RT). Herpes simplex virus-1 (HSV-1) reactivation was also investigated in 14 patients. According to the agreed protocol, granulocyte-macrophage colony-stimulating factor (GM-CSF) mouthwash was administered in 46 patients with radiation-induced ulcers. Candidiasis was diagnosed in 31 patients. Candida albicans was the most frequent isolate. Multiple Candida species were isolated from the lesions of four patients. Concurrent candidiasis and radiation-induced ulcers were observed in 17 patients. Viral culture and the polymerase chain reaction disclosed the presence of HSV-1 in five patients. Twenty of the 46 patients, with initial mucositis grade II and grade III, completed RT with mucositis grade I, indicating a beneficial effect of GMCSF mouthwash, although further controlled studies are necessary to verify that. In conclusion, OPC was an important infection in patients undergoing radiotherapy. The role of HSV-1 in oral mucositis during head and neck radiotherapy needs additional study.

Adenocarcinoma↗
PubMed2001

Prospective use of RFLP analysis on amplified Cryptococcus neoformans URA5 gene sequences for rapid identification of varieties and serotypes in clinical samples.

Clinical isolates of Cryptococcus neoformans, whole blood, cerebrospinal fluid, bronchoalveolar lavage fluid from patients with positive cryptococcal antigen latex-agglutination test, and spiked clinical material from healthy individuals, were tested by polymerase chain reaction (PCR) with primers amplifying C. neoformans URA5 gene sequences. To test compatibility of different DNA extraction protocols with the PCR-restriction fragment length polymorphism (RFLP) assay, a commercial DNA extraction kit (XTRAX; Gull Laboratories, UT, USA) was used alongside with the hexadecyltrimethylammonium bromide (CTAB) method on spiked biological fluids. Both methods extracted DNA from spiked clinical samples containing C. neoformans (8 +/- 2 cells ml(-1)) and generated amplification products suitable for restriction enzyme analysis. Alu I digestion differentiated the two varieties of C. neoformans. Three distinct RFLP patterns were obtained upon restriction with MspI corresponding to serotypes A, AD and B, C and D. URA5 PCR followed by RFLP analysis, coupled with a sensitive in-house or commercially available DNA extraction method from clinical samples, could be successfully incorporated into rapid routine diagnostic strategies. It could also provide an expeditious tool for epidemiology-based population genetics studies.

Base Sequence↗
PubMed2001

First report of Cryptococcus neoformans var. gattii serotype B from Greece.

A plethora of cases of Cryptococcus neoformans infections have been recorded worldwide in immunocompromised individuals. The number of such cases showed a steady rise before 1981 and increased dramatically thereafter due to the AIDS epidemic. A similar pattern has been seen in Greece but, so far, infections appear to have been caused by C. neoformans var. neoformans. This paper describes for the first time two culture-proven C. n. var. gattii serotype B infections in Greece, one in an AIDS patient and one in a patient with systemic lupus erythematosus.

Acquired Immunodeficiency Syndrome↗