23 results on '"Legakis NJ"'
Search Results
2. Evaluation of molecular typing methods in characterizing a European collection of epidemic methicillin-resistant Staphylococcus aureus strains: the HARMONY collection.
- Author
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Cookson BD, Robinson DA, Monk AB, Murchan S, Deplano A, de Ryck R, Struelens MJ, Scheel C, Fussing V, Salmenlinna S, Vuopio-Varkila J, Cuny C, Witte W, Tassios PT, Legakis NJ, van Leeuwen W, van Belkum A, Vindel A, Garaizar J, Haeggman S, Olsson-Liljequist B, Ransjo U, Muller-Premru M, Hryniewicz W, Rossney A, O'Connell B, Short BD, Thomas J, O'Hanlon S, and Enright MC
- Subjects
- Amino Acid Sequence, Anti-Bacterial Agents pharmacology, Electrophoresis, Gel, Pulsed-Field, Europe epidemiology, Humans, Microbial Sensitivity Tests, Molecular Sequence Data, Population Surveillance, Sequence Analysis, DNA, Staphylococcal Infections microbiology, Staphylococcal Protein A genetics, Staphylococcus aureus drug effects, Bacterial Typing Techniques, Disease Outbreaks, Methicillin Resistance genetics, Staphylococcal Infections epidemiology, Staphylococcus aureus classification, Staphylococcus aureus genetics
- Abstract
We analyzed a representative sample of methicillin-resistant Staphylococcus aureus (MRSA) from 11 European countries (referred to as the HARMONY collection) using three molecular typing methods used within the HARMONY group to examine their usefulness for large, multicenter MRSA surveillance networks that use these different laboratory methodologies. MRSA isolates were collected based on their prevalence in each center and their genetic diversity, assessed by pulsed-field gel electrophoresis (PFGE). PFGE groupings (< or = 3 bands difference between patterns) were compared to those made by sequencing of the variable repeats in the protein A gene spa and clonal designations based on multilocus sequence typing (MLST), combined with PCR analysis of the staphylococcal chromosome cassette containing the mec genes involved in methicillin resistance (SCCmec). A high level of discrimination was achieved using each of the three methodologies, with discriminatory indices between 89.5% and 91.9% with overlapping 95% confidence intervals. There was also a high level of concordance of groupings made using each method. MLST/SCCmec typing distinguished 10 groups containing at least two isolates, and these correspond to the majority of nosocomial MRSA clones described in the literature. PFGE and spa typing resolved 34 and 31 subtypes, respectively, within these 10 MRSA clones, with each subtype differing only slightly from the most common pattern using each method. The HARMONY group has found that the methods used in this study differ in their availability and affordability to European centers involved in MRSA surveillance. Here, we demonstrate that the integration of such technologies is achievable, although common protocols (such as we have developed for PFGE) may also be important, as is the use of centralized Internet sites to facilitate data analysis. PFGE and spa-typing data from analysis of MRSA isolates from the many centers that have access to the relevant equipment can be compared to reference patterns/sequences, and clonal designations can be made. In the majority of cases, these will correspond to those made by the (more expensive) method of choice-MLST/SCCmec typing-and these alternative methods can therefore be used as frontline typing systems for multicenter surveillance of MRSA.
- Published
- 2007
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3. Repeated occurrence of diverse extended-spectrum beta-lactamases in minor serotypes of food-borne Salmonella enterica subsp. enterica.
- Author
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Politi L, Tassios PT, Lambiri M, Kansouzidou A, Pasiotou M, Vatopoulos AC, Mellou K, Legakis NJ, and Tzouvelekis LS
- Subjects
- Aged, Animals, Child, Preschool, Drug Resistance, Multiple, Bacterial genetics, Female, Greece, Humans, Infant, Plasmids genetics, Salmonella Infections microbiology, Salmonella Infections, Animal microbiology, Salmonella enterica drug effects, Salmonella enterica enzymology, Salmonella enterica genetics, Serotyping, beta-Lactamases genetics, Gastroenteritis microbiology, Poultry Products microbiology, Salmonella enterica classification, beta-Lactamases metabolism
- Abstract
Screening of Greek nontyphoid salmonellae from 2000 to 2002 yielded three extended-spectrum beta-lactamase (ESBL)-producing human isolates. Salmonella enterica serotype Brandenburg harbored a multiresistant SHV-5 gene-carrying plasmid. S. enterica serotype Blockley and S. enterica serotype Hadar harbored a TEM-52 gene-carrying plasmid. An S. enterica serotype Virchow strain producing plasmid-mediated CTX-M-32 was isolated twice from poultry end products. All ESBL plasmids were self-transferable and carried by clones currently common in Greece.
- Published
- 2005
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4. Chryseobacterium indologenes non-catheter-related bacteremia in a patient with a solid tumor.
- Author
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Christakis GB, Perlorentzou SP, Chalkiopoulou I, Athanasiou A, and Legakis NJ
- Subjects
- Anti-Bacterial Agents therapeutic use, Carcinoma, Squamous Cell secondary, Drug Therapy, Combination therapeutic use, Flavobacteriaceae Infections drug therapy, Humans, Male, Middle Aged, Nose Neoplasms pathology, Penicillanic Acid analogs & derivatives, Penicillanic Acid therapeutic use, Piperacillin therapeutic use, Piperacillin, Tazobactam Drug Combination, Bacteremia microbiology, Carcinoma, Squamous Cell complications, Chryseobacterium isolation & purification, Flavobacteriaceae Infections microbiology, Lymphatic Metastasis, Nose Neoplasms complications
- Abstract
A case of non-catheter-related bacteremia caused by Chryseobacterium indologenes in a nonneutropenic man with a solid tumor is described. The patient was successfully treated with piperacillin-tazobactam.
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- 2005
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5. Discrepancies and interpretation problems in susceptibility testing of VIM-1-producing Klebsiella pneumoniae isolates.
- Author
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Giakkoupi P, Tzouvelekis LS, Daikos GL, Miriagou V, Petrikkos G, Legakis NJ, and Vatopoulos AC
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- Drug Resistance, Bacterial, Humans, Klebsiella pneumoniae enzymology, Meropenem, Microbial Sensitivity Tests methods, Quality Control, Reproducibility of Results, beta-Lactams pharmacology, Anti-Bacterial Agents pharmacology, Imipenem pharmacology, Klebsiella pneumoniae drug effects, Thienamycins pharmacology, beta-Lactamases metabolism
- Abstract
Susceptibilities to beta-lactam antibiotics of five VIM-1-producing Klebsiella pneumoniae isolates were determined by broth microdilution, Etest, disk diffusion, and the automated systems Vitek 2, Phoenix, and MicroScan. Significant discrepancies were observed in the determination of susceptibility to imipenem and meropenem. Interpretation problems by the automated systems were also noted.
- Published
- 2005
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6. VIM-1 Metallo-beta-lactamase-producing Klebsiella pneumoniae strains in Greek hospitals.
- Author
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Giakkoupi P, Xanthaki A, Kanelopoulou M, Vlahaki A, Miriagou V, Kontou S, Papafraggas E, Malamou-Lada H, Tzouvelekis LS, Legakis NJ, and Vatopoulos AC
- Subjects
- Base Sequence, DNA Primers, Electrophoresis, Gel, Pulsed-Field, Greece, Hospitals, Humans, Intensive Care Units, Klebsiella pneumoniae genetics, Klebsiella pneumoniae isolation & purification, Polymerase Chain Reaction methods, Restriction Mapping, Cross Infection microbiology, Klebsiella Infections diagnosis, Klebsiella pneumoniae enzymology, beta-Lactamases genetics
- Abstract
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.
- Published
- 2003
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7. Spread of integron-associated VIM-type metallo-beta-lactamase genes among imipenem-nonsusceptible Pseudomonas aeruginosa strains in Greek hospitals.
- Author
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Giakkoupi P, Petrikkos G, Tzouvelekis LS, Tsonas S, Legakis NJ, and Vatopoulos AC
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- DNA, Bacterial analysis, Greece, Hospitals, Humans, Imipenem pharmacology, Microbial Sensitivity Tests, Molecular Sequence Data, Pseudomonas aeruginosa drug effects, Random Amplified Polymorphic DNA Technique, Integrons genetics, Pseudomonas aeruginosa genetics, beta-Lactamases genetics
- Abstract
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.
- Published
- 2003
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8. Performance of methods for detection of extended-spectrum beta-lactamases applied to clinical enterobacterial strains producing IBC-type beta-lactamases.
- Author
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Lebessi E, Stamos G, Foustoukou M, Vourli S, Legakis NJ, and Tzouvelekis LS
- Subjects
- Ceftazidime pharmacology, Clavulanic Acid pharmacology, Drug Combinations, Enterobacteriaceae enzymology, Humans, Microbial Sensitivity Tests, beta-Lactamases metabolism, Drug Resistance, Bacterial, Enterobacteriaceae drug effects, beta-Lactamases analysis, beta-Lactams pharmacology
- Published
- 2003
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9. Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in a neonatal intensive care unit in the high-prevalence area of Athens, Greece.
- Author
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Lebessi E, Dellagrammaticas H, Tassios PT, Tzouvelekis LS, Ioannidou S, Foustoukou M, and Legakis NJ
- Subjects
- Electrophoresis, Gel, Pulsed-Field, Greece, Humans, Infant, Newborn, Intensive Care Units, Neonatal, Klebsiella pneumoniae classification, Klebsiella pneumoniae enzymology, Klebsiella pneumoniae isolation & purification, beta-Lactamases biosynthesis
- Abstract
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.
- Published
- 2002
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10. Serum is the preferred clinical specimen for diagnosis of human brucellosis by PCR.
- Author
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Zerva L, Bourantas K, Mitka S, Kansouzidou A, and Legakis NJ
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- Adult, Aged, Brucella abortus genetics, Brucellosis microbiology, Humans, Middle Aged, Sensitivity and Specificity, Blood microbiology, Brucella abortus isolation & purification, Brucellosis diagnosis, DNA, Bacterial blood, Polymerase Chain Reaction methods
- Abstract
Human brucellosis poses a significant public health problem in many developing countries and requires fast and accurate diagnosis. A PCR assay amplifying part of the 31-kDa Brucella abortus antigenic protein gene sequence was developed and applied to whole-blood and serum samples from 31 brucellosis patients and 45 healthy individuals. All patients except one had detectable Brucella DNA in either whole blood or serum (combined sensitivity, 97%), but the assay sensitivity was higher with serum samples (94%) than with whole-blood samples (61%). The assay specificity was excellent (100%). A confirmatory PCR assay targeting another Brucella gene region (omp-2) was also developed but lacked sensitivity. Serum is the optimal specimen for the diagnosis of brucellosis by PCR, a choice that leads to assay simplification and shortens turnaround time.
- Published
- 2001
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11. Multicenter evaluation of epidemiological typing of methicillin-resistant Staphylococcus aureus strains by repetitive-element PCR analysis. The European Study Group on Epidemiological Markers of the ESCMID.
- Author
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Deplano A, Schuermans A, Van Eldere J, Witte W, Meugnier H, Etienne J, Grundmann H, Jonas D, Noordhoek GT, Dijkstra J, van Belkum A, van Leeuwen W, Tassios PT, Legakis NJ, van der Zee A, Bergmans A, Blanc DS, Tenover FC, Cookson BC, O'Neil G, and Struelens MJ
- Subjects
- Bacterial Typing Techniques, DNA, Ribosomal genetics, Electrophoresis, Gel, Pulsed-Field methods, Europe, Humans, Phylogeny, Polymerase Chain Reaction methods, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 23S genetics, Software, Staphylococcal Infections transmission, Staphylococcus aureus drug effects, Staphylococcus aureus genetics, Methicillin Resistance, Staphylococcal Infections epidemiology, Staphylococcus aureus classification
- Abstract
Rapid and efficient epidemiologic typing systems would be useful to monitor transmission of methicillin-resistant Staphylococcus aureus (MRSA) at both local and interregional levels. To evaluate the intralaboratory performance and interlaboratory reproducibility of three recently developed repeat-element PCR (rep-PCR) methods for the typing of MRSA, 50 MRSA strains characterized by pulsed-field gel electrophoresis (PFGE) (SmaI) analysis and epidemiological data were blindly typed by inter-IS256, 16S-23S ribosomal DNA (rDNA), and MP3 PCR in 12 laboratories in eight countries using standard reagents and protocols. Performance of typing was defined by reproducibility (R), discriminatory power (D), and agreement with PFGE analysis. Interlaboratory reproducibility of pattern and type classification was assessed visually and using gel analysis software. Each typing method showed a different performance level in each center. In the center performing best with each method, inter-IS256 PCR typing achieved R = 100% and D = 100%; 16S-23S rDNA PCR, R = 100% and D = 82%; and MP3 PCR, R = 80% and D = 83%. Concordance between rep-PCR type and PFGE type ranged by center: 70 to 90% for inter-IS256 PCR, 44 to 57% for 16S-23S rDNA PCR, and 53 to 54% for MP3 PCR analysis. In conclusion, the performance of inter-IS256 PCR typing was similar to that of PFGE analysis in some but not all centers, whereas other rep-PCR protocols showed lower discrimination and intralaboratory reproducibility. None of these assays, however, was sufficiently reproducible for interlaboratory exchange of data.
- Published
- 2000
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12. Multiple clones within multidrug-resistant Salmonella enterica serotype Typhimurium phage type DT104. The Greek Nontyphoidal Salmonella Study Group.
- Author
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Markogiannakis A, Tassios PT, Lambiri M, Ward LR, Kourea-Kremastinou J, Legakis NJ, and Vatopoulos AC
- Subjects
- Animals, Anti-Bacterial Agents pharmacology, Chickens, Columbidae, Drug Resistance, Microbial, Electrophoresis, Gel, Pulsed-Field methods, Greece, Humans, Microbial Sensitivity Tests, Phenotype, Phylogeny, Polymerase Chain Reaction methods, Salmonella enterica genetics, Salmonella enterica isolation & purification, Serotyping methods, Sewage microbiology, Swine, Bacteriophage Typing methods, Drug Resistance, Multiple, Meat microbiology, Salmonella enterica classification
- Abstract
Six distinct clones were present among Greek multidrug-resistant Salmonella enterica serotype Typhimurium phage type DT104, since isolates belonging to resistance phenotypes including the ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) core could be distinguished with respect to their pulsed-field gel electrophoresis patterns, int1 integron structures, and presence or absence of antibiotic resistance genes ant(3'')-Ia, pse-1, and tem-1.
- Published
- 2000
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13. Spread of a Salmonella typhimurium clone resistant to expanded-spectrum cephalosporins in three European countries.
- Author
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Tassios PT, Gazouli M, Tzelepi E, Milch H, Kozlova N, Sidorenko S, Legakis NJ, and Tzouvelekis LS
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- DNA, Bacterial genetics, DNA, Bacterial isolation & purification, Electrophoresis, Gel, Pulsed-Field, Gastroenteritis microbiology, Greece, Humans, Hungary, Russia, Salmonella Infections microbiology, Salmonella typhimurium genetics, Salmonella typhimurium isolation & purification, Cephalosporin Resistance, Salmonella typhimurium drug effects
- Abstract
Twelve Salmonella typhimurium strains resistant to broad-spectrum cephalosporins were isolated from cases of gastroenteritis during 1996 to 1998 in Russia, Hungary, and Greece. Resistance was due to the production of CTX-M-type extended-spectrum beta-lactamases encoded by similar 12-kb plasmids. By pulsed-field gel electrophoresis, all strains shared the same chromosomal type. These data suggest that an S. typhimurium clone resistant to broad-spectrum cephalosporins is present in at least three European countries.
- Published
- 1999
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14. Emergence of multidrug resistance in ubiquitous and dominant Pseudomonas aeruginosa serogroup O:11. The Greek Pseudomonas Aeruginosa Study Group.
- Author
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Tassios PT, Gennimata V, Maniatis AN, Fock C, and Legakis NJ
- Subjects
- DNA Fingerprinting, DNA, Bacterial analysis, Drug Resistance, Microbial, Drug Resistance, Multiple, Pseudomonas aeruginosa classification, Serotyping, Pseudomonas aeruginosa drug effects
- Abstract
The serotypes of 88 nonreplicate nosocomial Pseudomonas aeruginosa isolates from 11 Greek hospitals were studied in relation to their antibiotic susceptibilities. Rates of resistance to beta-lactams, aminoglycosides, and quinolones ranged from 31 to 65%, except for those to ceftazidime (15%) and imipenem (21%). Four serotypes were dominant: O:12 (25% of isolates), O:1 (17%), O:11 (16%), and O:6 (10%). Multidrug resistance rates in the major serogroups O:12 (91%) and O:11 (79%) were higher than those in serogroups O:1 (40%) and O:6 (43%). Further typing with respect to pulsed-field gel electrophoresis patterns following XbaI digestion of genomic DNA discriminated the isolates into 74 types. Pulsed-field gel electrophoresis revealed that the ubiquitous O:12 group was genetically homogeneous, since 95% of strains belonged to two clusters of genotypic similarity, while the O:11 strains, present in 8 of the 11 hospitals, were distributed among five such clusters. Therefore, apart from the already reported O:12 multidrug-resistant European clone, an O:11 population, characterized by a serotype known to be dominant in the environment and the hospital in several parts of the world, but previously not associated with multidrug resistance to antibiotics, has progressed to a multidrug-resistant state.
- Published
- 1998
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15. Sporadic emergence of Klebsiella pneumoniae strains resistant to cefepime and cefpirome in Greek hospitals.
- Author
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Tzouvelekis LS, Tzelepi E, Prinarakis E, Gazouli M, Katrahoura A, Giakkoupi P, Paniara O, and Legakis NJ
- Subjects
- Cefepime, Drug Resistance, Microbial, Humans, Microbial Sensitivity Tests, Cefpirome, Cephalosporins pharmacology, Klebsiella pneumoniae drug effects
- Abstract
The sporadic emergence of Klebsiella pneumoniae strains resistant to cefepime and cefpirome was observed in Greek hospitals during 1996. Examination of six epidemiologically distinct strains and clones selected in vitro provided indications that resistance is due to the cooperation of decreased outer membrane permeability and hydrolysis of the cephalosporins by SHV-5 beta-lactamase, which was produced in large amounts.
- Published
- 1998
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16. Characterization to species level of Mycobacterium avium complex strains from human immunodeficiency virus-positive and -negative patients.
- Author
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Kyriakopoulos AM, Tassios PT, Matsiota-Bernard P, Marinis E, Tsaousidou S, and Legakis NJ
- Subjects
- AIDS-Related Opportunistic Infections classification, AIDS-Related Opportunistic Infections epidemiology, Adult, Child, DNA Primers, Gastric Mucosa microbiology, Greece, HIV Seronegativity, Humans, Incidence, Lymph Nodes microbiology, Lymph Nodes pathology, Mycobacterium avium Complex isolation & purification, Mycobacterium avium-intracellulare Infection epidemiology, Mycobacterium avium-intracellulare Infection pathology, Polymerase Chain Reaction methods, Sputum microbiology, Therapeutic Irrigation, AIDS-Related Opportunistic Infections microbiology, Mycobacterium avium Complex classification, Mycobacterium avium-intracellulare Infection microbiology
- Abstract
Forty human clinical Mycobacterium avium-M. intracellulare complex strains isolated in Greece were characterized to the species level by PCR with three sets of primers specific for one or both species. M. avium predominated in both human immunodeficiency virus-positive and -negative patients, but the frequency of M. intracellulare isolation appeared to be higher in the latter.
- Published
- 1997
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17. Molecular epidemiology of antibiotic resistance of Salmonella enteritidis during a 7-year period in Greece.
- Author
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Tassios PT, Markogiannakis A, Vatopoulos AC, Katsanikou E, Velonakis EN, Kourea-Kremastinou J, and Legakis NJ
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- Ampicillin pharmacology, Animals, Drug Resistance, Microbial genetics, Food Microbiology, Greece epidemiology, Humans, Microbial Sensitivity Tests, Molecular Epidemiology, Penicillins pharmacology, R Factors analysis, Restriction Mapping, Salmonella Infections microbiology, Salmonella enteritidis genetics, Ampicillin Resistance genetics, Salmonella Infections epidemiology, Salmonella enteritidis drug effects
- Abstract
A significant increase in the frequency of isolation of Salmonella enteritidis has been observed during recent years in Greece, parallelled by an increasing rate of resistance of this organism to antibiotics. A substantial proportion of ampicillin- and doxycycline-resistant isolates exhibited cross-resistance to drugs of other classes, such as sulfonamides and streptomycin. Isolates of human origin were overall less resistant than those of animal or food-feed origin. Indeed, strains associated with animal infections were characterized by the highest rates of resistance to several antibiotics. These phenotypic data were correlated with genotypic information concerning two distinct populations: isolates from all sources that were resistant only to ampicillin, the drug toward which resistance rates were highest, and a control group of sensitive isolates. Ampicillin resistance was due to a 34-MDa conjugative plasmid. DNA fingerprinting by macrorestriction of genomic DNA revealed two types, A and B, common to both ampicillin-resistant and -sensitive strains, with 80 to 90% of strains being of type A. However, a third type, C, was specific for the sensitive population, representing 17% of those strains. Therefore, although the majority of resistant isolates were genetically related to sensitive ones, there existed a susceptible clone which had not acquired any resistance traits.
- Published
- 1997
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18. Rapid discrimination of Mycobacterium avium strains from AIDS patients by randomly amplified polymorphic DNA analysis.
- Author
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Matsiota-Bernard P, Waser S, Tassios PT, Kyriakopoulos A, and Legakis NJ
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- Bone Marrow microbiology, DNA Primers, DNA, Bacterial analysis, DNA, Bacterial blood, Humans, Mycobacterium avium Complex genetics, Mycobacterium avium Complex isolation & purification, Sputum microbiology, AIDS-Related Opportunistic Infections microbiology, Bacterial Typing Techniques, Mycobacterium avium Complex classification, Mycobacterium avium-intracellulare Infection microbiology, Random Amplified Polymorphic DNA Technique
- Abstract
A randomly amplified polymorphic DNA (RAPD) analysis was performed for the molecular typing of Mycobacterium avium strains. This method was applied to epidemiologically unrelated M. avium strains isolated from the blood of 10 different AIDS patients and to strains that were considered epidemiologically related, as they had been isolated from the same patient but from different body locations (4 patients, 10 strains). Three oligonucleotide primers among the six tested were found to generate RAPD profiles with DNA from all M. avium strains and to successfully type them. This method for the typing of M. avium strains is rapid and easy to perform.
- Published
- 1997
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19. Antibiotic resistance of clinical isolates of Streptococcus pneumoniae in Greece.
- Author
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Kanavaki S, Karabela S, Marinis E, and Legakis NJ
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- Chloramphenicol pharmacology, Community-Acquired Infections microbiology, Drug Resistance, Microbial, Erythromycin pharmacology, Greece, Humans, Streptococcus pneumoniae isolation & purification, Penicillin Resistance, Pneumonia, Pneumococcal microbiology, Streptococcus pneumoniae drug effects, Tetracycline Resistance
- Abstract
The antibiotic susceptibilities of 1,002 Streptococcus pneumoniae clinical isolates from patients with community-acquired pneumonia were determined over an 18-month period. Resistance rates were 14% for penicillin, 20% for erythromycin, 26% for tetracycline, and 1% for chloramphenicol. Resistance to non-beta-lactam antibiotics was associated with penicillin resistance at statistically levels.
- Published
- 1994
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20. Molecular epidemiology of ampicillin-resistant clinical isolates of Salmonella enteritidis.
- Author
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Vatopoulos AC, Mainas E, Balis E, Threlfall EJ, Kanelopoulou M, Kalapothalki V, Malamou-Lada H, and Legakis NJ
- Subjects
- Ampicillin Resistance genetics, Bacterial Typing Techniques, Child, Greece epidemiology, Humans, R Factors, Salmonella Food Poisoning microbiology, Salmonella Phages classification, Salmonella enteritidis classification, Salmonella enteritidis isolation & purification, Seroepidemiologic Studies, Serotyping, Salmonella Food Poisoning epidemiology, Salmonella enteritidis drug effects
- Abstract
During the last 6 years in Greece, there has been a significant increase in the number of ampicillin-resistant Salmonella clinical isolates reported. In this study 23 ampicillin-resistant Salmonella strains, consecutively isolated from patients with epidemiologically unrelated cases of food poisoning, were investigated. By serotyping and phage typing, 21 of these strains were identified as Salmonella enteritidis phage type 6a, 1 was identified as Salmonella typhimurium, and 1 was identified as Salmonella saintpaul. By plasmid pattern analysis, the 21 S. enteritidis strains were further differentiated into five groups. Group I consisted of 5 strains (carrying two plasmids of ca. 38 and 34 MDa), group II consisted of 10 strains (three plasmids of ca. 38, 34, and 2.5 MDa), group III consisted of 3 strains (four plasmids of ca. 38, 34, 15, and 2.5 MDa), group IV consisted of 1 strain (five plasmids of ca. 100, 38, 34, 24, and 15 MDa), and group V consisted of 2 strains (three plasmids of ca. 100, 38, and 24 MDa). Ampicillin resistance was easily transferred to Escherichia coli and was associated with the transfer of the 34-MDa plasmid, classified in the N incompatibility group for all strains of groups I to IV, and with the transfer of the 100-MDa plasmid for the group V strains. EcoRI restriction endonuclease digestions showed an extensive homology among the 34-MDa conjugative R plasmids. Hybridizations of the EcoRI restriction fragments of the 34-MDa plasmids with a TEM-type probe revealed the locus of the beta-lactamase gene to be situated on a ca. 6.6-MDa fragment, common in all plasmids. These results indicate that ampicillin resistance in Greece is due to the spread of a limited number of clones of S. enteritidis phage type 6A, carrying related 34-MDa R plasmids. Work is in progress to obtain a better understanding of ampicillin resistance in S. enteritidis.
- Published
- 1994
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21. Thin-layer chromatographic technique for rapid detection of bacterial phospholipases.
- Author
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Legakis NJ and Papavassiliou J
- Subjects
- Bacillus cereus enzymology, Bacillus subtilis enzymology, Citrobacter enzymology, Egg Yolk, Enterobacter enzymology, Escherichia coli enzymology, Fatty Acids, Nonesterified biosynthesis, Female, Hydrolysis, Phosphatidylcholines metabolism, Phospholipases metabolism, Proteus enzymology, Pseudomonas aeruginosa enzymology, Serratia marcescens enzymology, Species Specificity, Bacteria enzymology, Chromatography, Thin Layer methods, Phospholipases analysis
- Abstract
Silica gel thin-layer chromatography was employed to detect lecithinase activity induced from bacterial resting cell preparations induced from bacterial resting cell preparations incubated at 37 C for 4 h in the presence of purified egg yolk lecithin. Bacillus subtilis, Bacillus cereus, Serratia marcescens, and Pseudomonas aeruginosa hydrolyzed lecithin with the formation of free fatty acids as the sole lipid-soluble product. In none of the Escherichia coli and Citrobacter freundii strains tested could lecithinase activity be detected. Four among eight strains of Enterobacter aerogenes and one among 12 strains of Proteus tested produced negligible amounts of free fatty acid.
- Published
- 1975
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22. Selective medium for growth of Proteus.
- Author
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Xilinas ME, Papavassiliou JT, and Legakis NJ
- Subjects
- Agar, Bile Acids and Salts, Cell Count, Citrates, Escherichia coli isolation & purification, Evaluation Studies as Topic, Feces microbiology, Humans, Lithium, Proteus isolation & purification, Species Specificity, Thiosulfates, Urine microbiology, Culture Media, Proteus growth & development
- Abstract
A medium containing heart infusion agar supplemented with bile salts, lithium chloride, sodium thiosulfate, and sodium citrate was developed for the selective growth of Proteus.
- Published
- 1975
- Full Text
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23. Serotypes of Pseudomonas aeruginosa in clinical specimens in relation to antibiotic susceptibility.
- Author
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Legakis NJ, Aliferopoulou M, Papavassiliou J, and Papapetropoulou M
- Subjects
- Carbenicillin pharmacology, Humans, Microbial Sensitivity Tests, Pseudomonas aeruginosa drug effects, Pseudomonas aeruginosa enzymology, Serotyping, beta-Galactosidase analysis, Anti-Bacterial Agents pharmacology, Pseudomonas aeruginosa classification
- Abstract
Ninety-eight hospital strains of Pseudomonas aeruginosa isolated from six different hospitals in Athens were serotyped by a slide agglutination test with unabsorbed commercial antisera. Serotypes O6, O11, O12, and "pool E" strains (strains that agglutinated only in pool E, which contained antisera against O2, O5, O15, and O16 antigens, but did not agglutinate in the individual antisera) predominated, accounting for more than 62% of all isolates tested. In respect to serotypes, (i) there was no apparent correlation with hospital of origin, (ii) most strains of serotypes O6 and O11 were sensitive to gentamicin and carbenicillin (iii) most strains of pool E were from urine and were resistant to these drugs, (iv) all 9 strains of serotype O12 tested were resistant to carbenicillin and all 5 strains tested hydrolyzed this drug, and (v) 24 of 25 strains of pool E were resistant to carbenicillin but only 2 of 17 strains hydrolyzed it.
- Published
- 1982
- Full Text
- View/download PDF
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