PubMed Health⌕ Search

Biomedical subjects

A N Maniatis

Publications and source records attributed to A N Maniatis.

At least 19 recordsLinked to original sources
PubMed2006

Low genetic diversity of the intrinsic OXA-51-like class D carbapenemases among Acinetobacter baumannii clinical isolates in Greece.

This study examined the geographical distribution and diversity of the intrinsic OXA-51-like class D carbapenemases among Acinetobacter baumannii clones recovered in three major Greek regions from 2000 to 2005. The blaOXA-66 allele was exclusively detected among clonally distinct A. baumannii isolates recovered in the regions of Thessaloniki and Larissa. This sequence was also the most widespread among A. baumannii isolates in Athens, while less frequent were blaOXA-69 and blaOXA-65 alleles. These findings highlight the high prevalence of a specific blaOXA-51-like allele in Greece, possibly indicating that our A. baumannii clones might have originated from a common ancestor. However, the possibility that blaOXA-51-like variants, with blaOXA-66 predominating, are widely disseminated among several unrelated A. baumannii strains cannot be excluded.

Acinetobacter baumannii↗
PubMed2006

Evaluation of high-risk human papillomavirus types PCR detection in paired urine and cervical samples of women with abnormal cytology.

BACKGROUND: During the last decade, increasing efforts have focused on HPV detection in self-obtained samples, to increase the overall proportion of patients participating in cervical cancer screening procedures. OBJECTIVES: A clinical evaluation study of an optimized protocol for PCR detection of high-risk human papillomavirus (HPV) types in urine compared with cervical samples in consecutive women referred to the colposcopy clinic with abnormal cervical cytology. STUDY DESIGN: Paired urine and cervical specimens were collected from 100 consecutive women referred to the colposcopy clinic with abnormal cervical cytology and normal urine parameters. In-house and a commercial PCR method for the detection of HPV types 16 and 18, and a commercial multiplex PCR for HPV types 6, 11, 16, 18, and 33 were performed. All HPV cervix-positive/urine-negative paired urine samples were spiked with serial dilutions of cell lines infected with HPV 16 or 18 to test the sensitivity of HPV detection in these urine samples. RESULTS: In all but two cases HPV type 16 was detected. In cancer cases, the urine/cervix HPV detection sensitivity was 88.8%; in cases with high-grade lesions it was 76.5%; and in cases with low-grade lesions it was 45.5%. In all concordant cases the same HPV type was detected in both samples. The urine/cervix HPV detection sensitivity was higher when urine samples contained two or more epithelial cells per field in urine microscopy. HPV detection in 9 cervix-positive but urine-negative urine samples spiked with serial dilutions of HPV-positive cell lines showed that in these cases urine PCR inhibitors did not affect PCR amplification. CONCLUSIONS: A higher urine/cervix HPV detection sensitivity in cancer and high-grade lesions suggests that urine testing could be used to detect HPV mainly when these lesions are present.

Cell Line↗
PubMed2006

Evaluation of HPV 16 PCR detection in self- compared with clinician-collected samples in women referred for colposcopy.

OBJECTIVES: A clinical prospective evaluation study was conducted to evaluate PCR detection of high-risk human papillomavirus (HPV) type 16 in self-sampled vaginal compared with clinician-collected cervical specimens. METHODS: Paired vaginal and cervical specimens were collected from 137 consecutive women referred for colposcopy because of abnormal cervical cytology. In-house and a commercial PCR method for HPV type 16 were used. Self-sampled vaginal HPV 16 detection was compared to histology and physician-collected cervical specimens. RESULTS: Of the 137 patients, 98 had proven abnormal histology and were included in the analysis. Overall, using the cervix HPV detection as reference method, the self-sampled vaginal sample showed sensitivity 91.8%, specificity 96.1% and agreement kappa (kappa) 0.881. Using the histology as reference, all 11 cervical cancer cases were HPV-16-positive in both cervical and vaginal samples, and in 43 high-grade lesions, detection sensitivity in cervix was 72.1% (kappa 0.588) and vagina 67.4% (kappa 0.516). HPV 16 detection did not differ (P=0.27) between clinician-collected cervical and self-sampled vaginal specimens. CONCLUSIONS: The self-collected vaginal sample is highly concordant with the physician-collected cervical sample in HPV 16 detection.

Cervix Uteri↗
PubMed2006

Outbreak of multiple clones of imipenem-resistant Acinetobacter baumannii isolates expressing OXA-58 carbapenemase in an intensive care unit.

OBJECTIVES: To investigate the resistance mechanisms and the genetic relationship of imipenem-resistant Acinetobacter baumannii isolates recovered in the intensive care unit (ICU) of a tertiary care hospital. METHODS: Imipenem-resistant A. baumannii clinical and environmental isolates were collected in the ICU of the Red Cross General Hospital, Athens, Greece between March and October 2002. The isolates were tested by Etest MBL, PCR, RT-PCR and sequencing for carbapenemase-encoding genes, PFGE and synergy experiments using meropenem and the efflux pump inhibitor carbonyl cyanide chlorophenylhydrazone. RESULTS: During the study period, 15 clinical and two environmental imipenem-resistant (MIC 8 to >128 mg/L) A. baumannii isolates were recovered. PFGE showed six different clones that included both clinical and environmental isolates. All 17 isolates were negative by Etest MBL and PCR for genes bla(IMP), bla(VIM), bla(SPM), bla(OXA-23-like) and bla(OXA-24-like). Genes bla(OXA-51-like) and bla(OXA-58-like) were amplified from 15 and 14 isolates, respectively. Sequencing of bla(OXA-51-like) amplicons identified bla(OXA-66) (nine cases) and bla(OXA-69) (six cases), whereas bla(OXA-58-like) sequences were classical bla(OXA-58). Reverse transcriptase-PCR showed that bla(OXA-51-like) genes were expressed in 12 and bla(OXA-58) in 10 isolates; in these isolates, inhibition of OXA enzymes by 200 mM of NaCl reduced carbapenem MICs by up to 4-fold. Overexpression of proton-gradient dependent efflux pumps did not contribute to carbapenem resistance in any isolate. Similarly, although AmpC expression was demonstrated in eight isolates, inhibition of AmpC with cloxacillin did not reduce the MICs of carbapenems significantly. CONCLUSIONS: These findings indicate wide dissemination of OXA-58 carbapenemase, which contributes, at least partially, to the imipenem resistance of unrelated A. baumannii isolates in our ICU.

Acinetobacter Infections↗
PubMed2005

Spread of efflux pump-overexpressing, non-metallo-beta-lactamase-producing, meropenem-resistant but ceftazidime-susceptible Pseudomonas aeruginosa in a region with blaVIM endemicity.

OBJECTIVES: To investigate the resistance mechanisms of meropenem-resistant, ceftazidime-susceptible Pseudomonas aeruginosa isolates, in a clinical setting where VIM-2 or VIM-4 metallo-beta-lactamase (MBL)-producing pseudomonads are common. METHODS: During May to December 2003, 13 consecutive meropenem-resistant, ceftazidime-susceptible P. aeruginosa isolates were recovered from separate patients at the University Hospital of Larissa, Thessaly, Greece. The isolates were studied by Etest MBL, PCR for blaVIM, blaIMP and blaSPM genes and PFGE. Experiments were performed to detect synergy between meropenem or other antimicrobials and the efflux pump inhibitor carbonyl cyanide-m-chlorophenylhydrazone (CCCP). The isolates were also tested by PCR and RT-PCR for the expression of the genes mexB and mexY, which encode the efflux pumps MexAB-OprM and MexXY-OprM. RESULTS: Twelve of the isolates, belonging to six distinct PFGE types, gave negative results in the MBL Etest and lacked genes encoding MBLs but exhibited synergy between meropenem and CCCP, indicating that efflux pump activity contributed to the meropenem resistance. All 12 isolates were positive for mexB and 11 were also positive for mexY genes. RT-PCR showed that 10 and five isolates over-expressed mexB and mexY, respectively. One isolate was blaVIM-2-positive and did not show synergy with CCCP, or harbour mexB or mexY. CONCLUSIONS: In our hospital, where MBL-producing P. aeruginosa were previously prevalent, meropenem resistance due to the overexpression of efflux pumps has also now emerged. Early recognition of this resistance mechanism should allow the use of alternative beta-lactams, such as ceftazidime, which would be inactive even against phenotypically susceptible MBL producers.

Bacterial Outer Membrane Proteins↗
PubMed2005

The value of a single combined measurement of VEGF, glycodelin, progesterone, PAPP-A, HPL and LIF for differentiating between ectopic and abnormal intrauterine pregnancy.

BACKGROUND: To evaluate whether serum concentrations of the non-placental markers vascular endothelial growth factor (VEGF), glycodelin (GLY) and progesterone (P) and the novel placental markers pregnancy-associated plasmaprotein A (PAPP-A), human placental lactogen (HPL) and leukaemia inhibiting factor (LIF) differ in ectopic pregnancy (EP) when compared with abnormal intrauterine pregnancy (aIUP). METHODS: A prospective clinical study was conducted at the University Hospital of Larissa, Greece. The study included 50 patients admitted with failed pregnancy and suspected ectopic pregnancy that were treated with curettage or laparoscopy and classified as histologically confirmed EPs (n = 27) or histologically confirmed aIUPs (n = 21) (mean gestational age of 7.15 and 7.3 weeks, respectively). Two suspected EPs proved to be normal IUPs and were excluded. VEGF, GLY, P, beta-HCG, PAPP-A, HPL and LIF were measured by enxyme-linked immunosorbent assay (ELISA) methods in a single pre-operative blood sample. RESULTS: The median VEGF concentration was 227.2 pg/ml in the EP group versus 107.2 pg/ml in the aIUP group (P < 0.001), with a suggested threshold value of 174 pg/ml for their differential diagnosis. LIF, P, PAPP-A, HPL and GLY serum measurements did not differ significantly between EP and aIUP. CONCLUSION: VEGF serum levels might be a useful marker in differentiating between EPs and aIUPs.

Biomarkers↗
PubMed2004

Substantially increased faecal carriage of vancomycin-resistant enterococci in a tertiary Greek hospital after a 4 year time interval.

OBJECTIVES: In a tertiary Greek hospital with no documented vancomycin-resistant enterococci (VRE) infections, a cross-sectional study was conducted in order to determine the degree of VRE faecal carriage among adult patients hospitalized in high-risk units. METHODS: Specimens for the surveillance were collected from separate patients in two periods (January-May 1999 and January-May 2003); 258 specimens were submitted during the first period and 149 during the second period. RESULTS: Three patients (1.2%) were colonized with VRE during the first period, whereas 52 (34.9%) were colonized during the second period. Two VRE isolates of the first period were Enterococcus faecalis and one Enterococcus faecium, whereas those of the second period were E. faecium except for three E. faecalis and two Enterococcus gallinarum. All VRE isolates apart from the two E. gallinarum isolates were positive for the vanA gene. The 48 vancomycin-resistant E. faecium were classified into eight clonal types, one of those predominating with 29 isolates; the remaining included one to nine isolates. The five vancomycin-resistant E. faecalis formed four distinct clonal types. CONCLUSIONS: The study reports a substantially higher prevalence of VRE carriage when the surveillance was repeated after a 4 year time interval. Urgent infection control measures are needed to prevent emergence of VRE outbreaks in our hospital setting.

Bacterial Proteins↗
PubMed2004

Persistent colonization of nine cystic fibrosis patients with an Achromobacter (Alcaligenes) xylosoxidans clone.

The present study was conducted to investigate the increasing incidence of Achromobacter (previously Alcaligenes) xylosoxidans isolates being recovered from sputum samples of cystic fibrosis patients at a cystic fibrosis department for adults in Athens, Greece. During the 1-year study period, a total of 34 isolates were detected persistently in 9 of 71 cystic fibrosis patients. The isolates exhibited resistance to multiple antimicrobial agents. Isolates that were recovered repeatedly from each patient exhibited identical macrorestriction profiles with pulsed-field gel electrophoresis, indicating that the same strain persisted in the lungs of these patients. Isolates from five of the patients were genetically related, suggesting a common-source outbreak of Achromobacter xylosoxidans colonization or infection.

Adolescent↗
PubMed2003

Clonal dissemination of mupirocin-resistant staphylococci in Greek hospitals.

OBJECTIVES: To determine the rates of mupirocin resistance in staphylococci during a 4 year period (1999-2002) in Greece. MATERIALS: A total of 1200 Staphylococcus aureus and 2760 coagulase-negative staphylococci (CoNS), consecutively collected from four Greek hospitals located in different geographical areas, were tested for susceptibility to mupirocin using the Etest and a reference agar dilution method. RESULTS: Twenty-four S. aureus (2%) and 532 CoNS (19.2%) were found to be mupirocin-resistant during the study period. High-level mupirocin resistance was detected in 20 S. aureus (1.6%) and in 440 CoNS (15.9%), respectively. No variations in the rates of mupirocin-resistant S. aureus in relation to the year of collection were observed. In contrast, the rate of mupirocin-resistant CoNS increased dramatically from 9% in 1999, to 14% in 2000, 20% in 2001 and reached 33% in 2002. PFGE analysis revealed the presence of one main clone (A) among mupirocin-resistant S. aureus and two main clones (i and a) among Staphylococcus epidermidis isolates. CONCLUSIONS: In Greece, the rate of mupirocin-resistant S. aureus has remained low and steady since 1999. The high rate of mupirocin-resistant CoNS (33%) in 2002 was due mainly to clonal dissemination of epidemic hospital clones.

Anti-Bacterial Agents↗
PubMed2003

Hospital outbreak of multiple clones of Pseudomonas aeruginosa carrying the unrelated metallo-beta-lactamase gene variants blaVIM-2 and blaVIM-4.

OBJECTIVES: The possible contribution of metallo-beta-lactamases in the frequent detection of carbapenem-resistant Pseudomonas aeruginosa isolates in a tertiary Greek hospital in Central Greece was investigated. MATERIALS AND METHODS: All carbapenem-resistant (imipenem- and/or meropenem-resistant) P. aeruginosa isolates recovered from separate patients during a 1 year period in the Clinical Microbiology Laboratory at the University Hospital of Thessaly, Larissa, Greece, were studied for metallo-beta-lactamases. They were tested by Etest MBL, PCR analysis and nucleotide sequencing. DNA fingerprints were obtained by pulsed-field gel electrophoresis (PFGE) of XbaI-digested chromosomal DNA. RESULTS: A blaVIM gene was detected in 47 of the 53 (88.7%) carbapenem-resistant P. aeruginosa isolates. PFGE grouped the blaVIM-positive isolates in six unrelated genotypes; one type included two subtypes. Nucleotide sequencing of the PCR amplicons of a randomly selected isolate from each one of the seven subtypes, detected the variant sequences blaVIM-2 in four and blaVIM-4 in three cases, respectively. They were carried as single gene cassettes or along with an aminoglycoside resistance gene (aacA29a) in class 1 integrons. CONCLUSIONS: These findings suggest that different strains of P. aeruginosa carrying unrelated metallo-beta-lactamase gene variants predominate in our hospital environment.

Anti-Bacterial Agents↗
PubMed2003

Evaluation of a novel method based on PCR Restriction Fragment Length Polymorphism Analysis of the tuf gene for the identification of Staphylococcus species.

A novel method, based on PCR Restriction Fragment Length Polymorphism Analysis (PRA) of a part of the tuf gene (370 bp), was designed for the identification of 11 staphylococcal species, including the most common staphylococcal pathogens. A total of 258 clinical isolates were validated by this assay, and the results were in concordance with those obtained by the reference method of Kloos and Schleifer.

Algorithms↗
PubMed2003

Multicenter evaluation of the fully automated bactec MGIT 960 system and three molecular methods for the isolation and the identification of mycobacteria from clinical specimens.

A combination of Bactec MGIT 960 system, a PCR-based assay and a PCR-Restriction Analysis procedure (PRA) was assessed for the detection and identification of mycobacteria from clinical samples. The MGIT recovered 243 from 266 mycobacterial isolates. The PCR-based assay correctly identified all (234) Mycobacterium tuberculosis isolates, while 35 nontuberculous mycobacterial isolates were identified by PRA.

Automation↗