MDMA (ecstasy) use is associated with reduced BOLD signal change during semantic recognition in abstinent human polydrug users: a preliminary fMRI study.

3,4-methylenedioxymethamphetamine (MDMA) users have impaired verbal memory, and voxel-based morphometry has shown decreased grey matter in Brodmann area (BA) 18, 21 and 45. Because these regions play a role in verbal memory, we hypothesized that MDMA users would show altered brain activation in these areas during performance of a functional magnetic resonance imaging (fMRI) task that probed semantic verbal memory. Polysubstance users enriched for MDMA exposure participated in a semantic memory encoding and recognition fMRI task that activated left BA 9, 18, 21/22 and 45. Primary outcomes were percent blood oxygen level-dependent signal change in left BA 9, 18, 21/22 and 45, accuracy and response time. During semantic recognition, lifetime MDMA use was associated with decreased activation in left BA 9, 18 and 21/22 but not 45. This was partly influenced by contributions from cannabis and cocaine use. MDMA exposure was not associated with accuracy or response time during the semantic recognition task. During semantic recognition, MDMA exposure was associated with reduced regional brain activation in regions mediating verbal memory. These findings partially overlap with previous structural evidence for reduced grey matter in MDMA users and may, in part, explain the consistent verbal memory impairments observed in other studies of MDMA users.

Patient retention and attrition on antiretroviral treatment at district level in rural Malawi.

We report on rates of patient retention and attrition in the context of scaling-up antiretroviral treatment (ART) within a district hospital and its primary health centres in rural Malawi. 'Retention' was defined as being alive and on ART or transferred out, whereas 'attrition' was defined as died, lost to follow-up or stopped treatment. A total of 4074 patients were followed-up for 1803 person-years: 2904 were at the hospital and 1170 at health centres. Approximately 85% of patients were retained in care, both at hospital and health centres, with a retention rate per 100 person-years of 185 and 211, respectively [adjusted hazard ratio (HR) 1.18, 95% CI 1.10-1.28, P=0.001). Attrition rates per 100 person-years were similar: 33 and 36, respectively (adjusted HR 1.17, 95% CI 0.97-1.4, P=0.1). At health centres the incidence of loss to follow-up was significantly lower than at the hospital (adjusted HR 0.24, P<0.001, risk reduction 77%), but the rate of reported deaths was higher at health centres (adjusted HR 2.2, 95% CI 1.76-2.72, P<0.001). As Malawi continues to extend the coverage (and equity) of ART, including in rural areas, attention is needed to reduce losses to follow-up at hospital level and reduce mortality at primary care level.

Extended-spectrum beta-lactamase-producing Serratia marcescens outbreak in a Bulgarian hospital.

We describe a nosocomial outbreak of extended-spectrum beta-lactamase (ESBL)-producing Serratia marcescens in a Bulgarian university hospital affecting nine patients on four wards. Phenotypic and genotypic (plasmid profile, randomly amplified polymorphic DNA analysis and amplified ribosomal DNA restriction analysis) analysis of the isolates indicated a single clone. The epidemic strain was resistant to oxyimino beta-lactams, aztreonam, aminoglycosides, tetracycline and chloramphenicol. It produced CTX-M-3 ESBL as demonstrated by isoelectric focusing, CTX-M PCR-RFLP and gene sequencing. The isolate was also found in the environment and from a nurse's hands, suggesting transmission by staff handling. The outbreak was controlled by patient isolation and intensified hand washing. This is the first report from Bulgaria describing a hospital outbreak caused by CTX-M-3 ESBL-producing S. marcescens.

Nosocomial bloodstream infections with Burkholderia stabilis.

Burkholderia stabilis was grown from blood cultures of seven patients presenting with signs and symptoms of septicaemia in the intensive care unit at Mersin University Hospital, Mersin, Turkey between July and October 2002. Four patients had one B. stabilis-positive blood culture, two patients had two, and one patient had four. Isolates from six of seven patients had the same resistotype and random amplified polymorphic DNA analysis type. Despite treatment with ciprofloxacin and imipenem, to which the strains were susceptible, all patients died one to eight days after isolation of B. stabilis from their blood. B. stabilis should be regarded as an opportunistic pathogen that may cause nosocomial bloodstream infections.

Extended-spectrum beta-lactamase (ESBL) CTX-M-15-producing Escherichia coli and Klebsiella pneumoniae in Sofia, Bulgaria.

During a survey of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in Bulgaria in 2001-2002, three isolates from Sofia (two Escherichia coli, one Klebsiella pneumoniae) showed cefotaxime MICs that were decreased in the presence of clavulanate and were 2-8-fold higher than those of ceftazidime. Resistance was transferred to a sensitive recipient strain of E. coli. Both wild-type and transconjugant strains produced a cefotaxime-hydrolysing beta-lactamase of pI 8.8. Sequencing of the PCR product obtained with oligonucleotide primers binding outside the coding region identified this beta-lactamase as CTX-M-15. To our knowledge, this is the first report of CTX-M-15 in Bulgaria.

Sequential genotyping of Pseudomonas aeruginosa from upper and lower airways of cystic fibrosis patients.

A controversy exists concerning the adequate specimen to characterise colonisation of cystic fibrosis (CF) airways by Pseudomonas aeruginosa. Oropharyngeal, sputum and bronchoalveolar lavage samples were evaluated from 38 stable CF patients for the detection of P. aeruginosa, genetically different isolates within the same host and longitudinal variations in the genotype during repeated examinations. Bacterial isolates were typed by pulsed-field gel electrophoresis of deoxyribonucleic acid macrorestriction fragments. Sensitivity, negative and positive predictive values and specificity to detect P. aeruginosa were 35.7, 73.5, 83.3 and 96.2% for oropharyngeal cultures in nonexpectorating patients and 91.7, 94.1, 100 and 100% for sputum cultures from expectorating patients, respectively. Genotypes of Pseudomonas isolates recovered from oropharyngeal swabs and sputum differed to the strains recovered by bronchoscopy in 55% and 40%, respectively. In 62% longitudinal variations in the genotype occurred. One-half of these alterations were detectable by bronchoscopy only. In conclusion, sputum samples were of equal value as specimens from bronchoalveolar lavage to detect Pseudomonas aeruginosa colonisation. Cultures from the oropharynx are not suitable for characterising bacterial conditions in the cystic fibrosis lung. Different genotypes within the same host and longitudinal genetic alterations are common and may be detectable in the bronchoalveolar lavage fluid exclusively.

Epidemiological analysis of the spread of pathogens from a urological ward using genotypic, phenotypic and clinical parameters.

Surveillance studies using molecular typing methods help clinicians assess the rate of potential spread of pathogens. The rate of cross transmission of uropathogens among patients on a urological ward was investigated. Urine samples were collected from 144 patients with urinary catheters and a significant bacteriuria. In a subgroup of 54 of these patients, cultures from a rectal swab were also made. Typing by PFGE, RAPD or bacteriocins showed that 41% of uropathogens were related and represented by 38 typing patterns. Endogenous infection was present in 30% and exogenous infection in 38% of isolates. Altogether, there was a high rate of clonal relationship amongst uropathogens in our urological ward and we conclude that hygienic means and measures are far from being optimal.

A novel type of AmpC beta-lactamase, ACC-1, produced by a Klebsiella pneumoniae strain causing nosocomial pneumonia.

A Klebsiella pneumoniae strain resistant to oxyimino cephalosporins was cultured from respiratory secretions of a patient suffering from nosocomial pneumonia in Kiel, Germany, in 1997. The isolate harbors a bla resistance gene located on a transmissible plasmid. An Escherichia coli transconjugant produces a beta-lactamase with an isoelectric point of 7.7 and a resistance phenotype characteristic of an AmpC (class 1) beta-lactamase except for low MICs of cephamycins. The bla gene was cloned and sequenced. It encodes a protein of 386 amino acids with the active site serine of the S-X-X-K motif at position 64, as is characteristic for class C beta-lactamases. Multiple alignment of the deduced amino acid sequence with 21 other AmpC beta-lactamases demonstrates only very distant homology, reaching at maximum 52.3% identity for the chromosomal AmpC beta-lactamase of Serratia marcescens SR50. The beta-lactamase of K. pneumoniae KUS represents a new type of AmpC-class enzyme, for which we propose the designation ACC-1 (Ambler class C-1).

Pharmacodynamics of levofloxacin and ofloxacin against Streptococcus pneumoniae.

The aim of this study was to compare the bactericidal efficacy of levofloxacin and ofloxacin against Streptococcus pneumoniae at different dosage regimens for both agents. An in-vitro pharmacodynamic model was used. Levofloxacin kinetics of 500 mg, administered od or bd, were compared with ofloxacin kinetics of 400 mg od or bd. Killing by 3 log10 (99.9%) was achieved up to an MIC of 0.5 mg/L (500 mg od) or 1 mg/L (500 mg bd). For levofloxacin killing of S. pneumoniae was unimpaired in mixed cultures with Haemophilus influenzae. For ofloxacin, killing by 2 log10 was achieved up to an MIC of 0.5 mg/L for 400 mg od and up to an MIC of 1 mg/L for 400 mg bd. Killing by 3 log10 was not achievable by 400 mg od, but was achieved up to an MIC of 0.5 mg/L for 400 mg bd. Killing of S. pneumoniae with identical MICs of levofloxacin was not influenced by their susceptibility to penicillin G. These data, together with the two-fold higher activity of levofloxacin in comparison with ofloxacin, indicate good therapeutic perspectives for levofloxacin over ofloxacin in the treatment of S. pneumoniae infections.

Discrimination of Burkholderia multivorans and Burkholderia vietnamiensis from Burkholderia cepacia genomovars I, III, and IV by PCR.

We present a PCR procedure for identification of Burkholderia cepacia, Burkholderia multivorans, and Burkholderia vietnamiensis. 16S and 23S ribosomal DNAs (rDNAs) of B. multivorans and B. vietnamiensis were sequenced and aligned with published sequences for definition of species-specific 18-mer oligonucleotide primers. Specific antisense 16S rDNA primers (for B. cepacia, 5'-AGC ACT CCC RCC TCT CAG-3'; for B. multivorans, 5'-AGC ACT CCC GAA TCT CTT-3') and 23S rDNA primers (for B. vietnamiensis, 5'-TCC TAC CAT GCG TGC AA-3') were paired with a general sense primer of 16S rDNAs (5'-AGR GTT YGA TYM TGG CTC AG-3') or with a sense primer of 23S rDNA (5'-CCT TTG GGT CAT CCT GGA-3'). PCR with these primers under optimized conditions is appropriate to specifically and rapidly identify B. multivorans, B. vietnamiensis, and B. cepacia (genomovars I, III, and IV are not discriminated). In comparison with the polyphasic taxonomic analyses presently necessary for species and genomovar identification within the B. cepacia complex, our procedure is more rapid and easier to perform and may contribute to clarifying the clinical significance of individual members of the complex in cystic fibrosis.

[Imipenem resistance in Pseudomonas aeruginosa]. / Imipenem-Resistenz bei Pseudomonas aeruginosa.

In 1997 in western Austria, 9.9% of Pseudomonas aeruginosa strains from patients of general practitioners were resistant to imipenem as well as 18.2% of the isolates from hospitals and 20.2% of the strains at a university teaching hospital. Within the hospital the imipenem resistance varied from 9.9% among out-patients to 28.7% in isolates from intensive care units. In medical/surgical words, up to 15.1% of P. aeruginosa strains were resistant to imipenem. The incidence of imipenem-resistant P. aeruginosa strains correlates to the use of carbapenems. In June 1997, 10 consecutive isolates from 8 patients were obtained and typed using restriction fragment length polymorphism analysis (RFLP) and Pyocin typing. All 10 isolates were resistant to meropenem as well as to imipenem. The finding (by RFLP and Pyocin typing) of individual bacterial types in each isolate strongly contradicts the spread of infection by cross infection. However, all patients were proven to have been treated with imipenem during the 3 months prior to testing. In 1997, 13,880 g of imipenem were used at the university hospital in Innsbruck. The use of carbapenems appears to be the main cause for the increased incidence of imipenem-resistant P. aeruginosa strains.

[Frequency and antibiotic susceptibility of oxacillin resistant Staphylococcus aureus in a teaching hospital]. / Häufigkeit und Antibiotikaempfindlichkeit von Oxacillin-resistenten Staphylococcus aureus-Stämmen in einem Lehrkranhaus.

From October 1993 till October 1994, 115 oxacillin resistant Staphylococus aureus strains were isolated in the laboratory of a teaching hospital. This was 2.4% of all of the Staphylococcus aureus strains. The bacteria were isolated from 30 patients, 7 medical personnel and in the environment of the infected patients. Most of the isolates were cultured from blood cultures, wound swabs and drains. If the referring hospitals has been informed about the MRSA status of the patients, several transmissions could have been prevented. In 10 infected patients, the MRSA strains were isolated from the nose, throat and hands. The isolates were also found on the hands of several personnel and in the patients environment, suggesting that the strains had been widely spread. The MRSA strains predominated in the medical and surgical intensive care units and in 2 general surgical wards. They were only found sporadically in other departments (Ophthalmology, Gynaecology, Paediatrics and Urology). MRSA-strains were more resistant to imipenem, ofloxacin, gentamicin, trimethoprim-sulfamethoxazole, tetracycline, erythromycin and clindamycin as oxacillin-sensitive Straphylococcus aureus strains. Genotyping (Restriction-Fragment-Length-Polymorphism) revealed six different strain patterns. The same RFLP types were mainly found on different wards. We conclude that various clones of MRSA may have emerged independently within one hospital and that their spread between wards was remarkably limited. Subsequent intensive hygiene measures have been successful in reducing the number of new isolates.

Molecular procedure for rapid detection of Burkholderia mallei and Burkholderia pseudomallei.

A PCR procedure for the discrimination of Burkholderia mallei and Burkholderia pseudomallei was developed. It is based on the nucleotide difference T 2143 C (T versus C at position 2143) between B. mallei and B. pseudomallei detected in the 23S rDNA sequences. In comparison with conventional methods the procedure allows more rapid identification at reduced risk for infection of laboratory personnel.

Discrimination of Burkholderia gladioli from other Burkholderia species detectable in cystic fibrosis patients by PCR.

A procedure for molecular identification of Burkholderia gladioli is described. Specific 16S and 23S rRNA gene signature sequences were defined as primers for PCR. The method allows rapid and specific discrimination of B. gladioli from related species (B. cepacia, B. multivorans, B. vietnamiensis, B. mallei, B. pseudomallei, Ralstonia pickettii, and R. eutropha) and should contribute to the clarification of its role as a human pathogen, e.g., in cystic fibrosis.

Cefotaxime-resistant Enterobacteriaceae isolates from a hospital in Warsaw, Poland: identification of a new CTX-M-3 cefotaxime-hydrolyzing beta-lactamase that is closely related to the CTX-M-1/MEN-1 enzyme.

A group of cefotaxime-resistant Citrobacter freundii and Escherichia coli isolates were collected by a clinical laboratory in a hospital in Warsaw, Poland, in July 1996. Detailed analysis has shown that all of these produced a beta-lactamase (pI, 8.4) belonging to the CTX-M family, one of the minor extended-spectrum beta-lactamase families with a strong cefotaxime-hydrolyzing activity. Sequencing has revealed that C. freundii isolates produced a new CTX-M-3 enzyme which is very closely related to the CTX-M-1/MEN-1 beta-lactamase, sporadically identified in Europe over a period of 6 years. Amino acid sequences of these two beta-lactamases differ at four positions: Val77Ala, Asp114Asn, Ser140Ala, and Asn288Asp (the first amino acid of each pair refers to CTX-M-1/MEN-1 and second refers to CTX-M-3). The partial sequence of the E. coli CTX-M gene was identical to the corresponding region of bla(CTX-M-3), but a transconjugant of the E. coli isolate expressed higher levels of resistance to beta-lactams than did C. freundii transconjugants. These resistance differences correlated with differences in plasmid DNA restriction patterns. Our results suggest that CTX-M genes have been spread among different species of the family Enterobacteriaceae in the hospital and that the CTX-M-3-expressing C. freundii strain causing routine urinary tract infections has been maintained for a relatively long time in the hospital environment.