qnr prevalence in ceftazidime-resistant Enterobacteriaceae isolates from the United States.

We screened 313 ceftazidime-resistant Enterobacteriaceae isolates obtained in the United States from 1999 to 2004 for all three known qnr genes. A qnr gene was present in 20% of Klebsiella pneumoniae isolates, 31% of Enterobacter sp. isolates, and 4% of Escherichia coli isolates. qnrA and qnrB occurred with equivalent frequencies and, except for qnrB in enterobacters, were stable over time. qnrS was absent.

Cognitive impairment and its association with homocysteine plasma levels in females with eating disorders - findings from the HEaD-study.

Higher plasma homocysteine levels have been found in females with anorexia nervosa. Furthermore, elevated homocysteine levels are associated with cognitive decline in dementia and healthy elderly people. Aim of this prospective study was to investigate a possible association between homocysteine serum levels and Clinically well known cognitive deficits in females with eating disorders. We found that moderately elevated plasma homocysteine levels were associated with normal short- and long-term verbal memory while normal plasma homocysteine levels were associated with poorer memory performance in 14 females with anorexia nervosa and 12 females with bulimia nervosa (logistic forward regression Wald chi(2)=8.566, OR=24.75, CI 2.89 - 212.23, P=0.003). These results indicate that under the special circumstances of eating disorders elevated homocysteine levels improve memory signaling possibly by facilitating long-term potentiation.

Broader distribution of plasmid-mediated quinolone resistance in the United States.

The plasmid-encoded quinolone resistance gene qnrA confers low-level quinolone resistance, facilitating selection of higher-level resistance. Epidemiologic surveys for qnrA were extended to isolates of Enterobacter spp. and to quinolone-susceptible Enterobacteriaceae. Two (10%) of 20 ceftazidime-resistant quinolone-susceptible Klebsiella pneumoniae strains carried the gene, as did 12 (17%) of 71 ceftazidime-resistant Enterobacter strains from across the United States. One of these Enterobacter isolates was quinolone susceptible. Thus, qnrA is present in quinolone-resistant and quinolone-susceptible Enterobacter and Klebsiella strains in the United States.

Homocysteine plasma levels are elevated in females with anorexia nervosa.

In the present pilot study significantly (T = 2.46, P = 0.018) higher levels of homocysteine were found in female anorectic patients (14.07, SD 7.3 micromol/l; n = 18) when compared with bulimic patients (10.25, SD 2.82; n = 27) or healthy controls (8.10, SD 1.79; n = 25). Since homocysteine can induce neuronal cell death leading to brain atrophy in different diseases and since it has been linked to depressive disorders these findings may have important implications for understanding common symptoms in patients suffering from anorexia.

Lipoprotein metabolism in patients with anorexia nervosa: a case-control study investigating the mechanisms leading to hypercholesterolaemia.

Hypercholesterolaemia is a common finding in patients with anorexia nervosa (AN). To investigate the type, frequency and pathophysiological mechanisms of changes in lipoprotein metabolism in AN we performed a cross-sectional study in fifty-eight female patients (mean age 24.2 years, BMI 15.3 (sd 1.5) kg/m(2)) and fifty-eight healthy age-matched controls (CO; BMI 22.2 (sd 1.7) kg/m(2)). Total cholesterol and LDL-cholesterol were higher in AN (5.5 (sd 1.3) v. 5.0 (sd 0.8) mmol/l, P=0.023; 3.6 (sd 1.1) v. 3.2 (sd 0.7) mmol/l, P=0.025 respectively). LDL particles were significantly more enriched in cholesterol and triacylglycerol in AN. In multiple regression analysis with LDL-cholesterol as the dependent and BMI, total body fat ( %), lathosterol:cholesterol ratio (endogenous cholesterol synthesis), 7alpha-hydroxy-4-cholesten-3-one (bile acid synthesis), non-esterified glycerol, free triiodothyronine and free thyroxine as independent variables, BMI was the only significant predictor in CO (R(2) 0.36, overall P=0.001). In AN the variability of LDL-cholesterol was significantly predicted by total body fat, free thyroxine, BMI, free triiodothyronine and non-esterified glycerol (R(2) 0.55, overall P<0.001). Subgroup analysis between restricting (AN-R) and binge-eating-purging patients (AN-B) indicated that in AN-R changes in lipoproteins, BMI and total body fat were more pronounced. AN-R patients had lower bile acid synthesis than AN-B (P=0.02). We conclude that elevated cholesterol concentrations in AN are generally due to an increase in LDL-cholesterol, which is mostly determined by the severe loss of body fat and the resulting changes in thyroid hormones, increased lipolysis and decreased endogenous cholesterol synthesis with resulting decrease in LDL removal. The clinical subtype of AN plays a major role in the mechanisms leading to hypercholesterolaemia.

Epidemiology of conjugative plasmid-mediated AmpC beta-lactamases in the United States.

A sample of 752 resistant Klebsiella pneumoniae, Klebsiella oxytoca, and Escherichia coli strains from 70 sites in 25 U.S. states and the District of Columbia was examined for transmissibility of resistance to ceftazidime and the nature of the plasmid-mediated beta-lactamase involved. Fifty-nine percent of the K. pneumoniae, 24% of the K. oxytoca, and 44% of the E. coli isolates transferred resistance to ceftazidime. Plasmids encoding AmpC-type beta-lactamase were found in 8.5% of the K. pneumoniae samples, 6.9% of the K. oxytoca samples, and 4% of the E. coli samples, at 20 of the 70 sites and in 10 of the 25 states. ACT-1 beta-lactamase was found at eight sites, four of which were near New York City, where the ACT-1 enzyme was first discovered; ACT-1 beta-lactamase was also found in Massachusetts, Pennsylvania, and Virginia. FOX-5 beta-lactamase was also found at eight sites, mainly in southeastern states but also in New York. Two E. coli strains produced CMY-2, and one K. pneumoniae strain produced DHA-1 beta-lactamase. Pulsed-field gel electrophoresis and plasmid analysis suggested that AmpC-mediated resistance spread both by strain and plasmid dissemination. All AmpC beta-lactamase-containing isolates were resistant to cefoxitin, but so were 11% of strains containing transmissible SHV- and TEM-type extended-spectrum beta-lactamases. A beta-lactamase inhibitor test was helpful in distinguishing the two types of resistance but was not definitive since 24% of clinical isolates producing AmpC beta-lactamase had a positive response to clavulanic acid. Coexistence of AmpC and extended-spectrum beta-lactamases was the main reason for these discrepancies. Plasmid-mediated AmpC-type enzymes are thus responsible for an appreciable fraction of resistance in clinical isolates of Klebsiella spp. and E. coli, are disseminated around the United States, and are not so easily distinguished from other enzymes that mediate resistance to oxyimino-beta-lactams.

Evolution of TEM-related extended-spectrum beta-lactamases in Korea.

TEM-52, differing from TEM-1 by having the substitutions Glu-104-->Lys, Met-182-->Thr, and Gly-238-->Ser, has previously been described as the most prevalent extended-spectrum beta-lactamase (ESBL) in Korea. In a further survey, we discovered the ESBLs TEM-15, which is like TEM-52 but lacks the substitution at residue 182, and TEM-88, which is like TEM-52 with an additional Gly-196-->Asp substitution. TEM-88 retained the activity of TEM-52 against moxalactam. Otherwise, the kinetic properties of the three ESBLs failed to show an advantage to this evolution.

Identification of CTX-M-14 extended-spectrum beta-lactamase in clinical isolates of Shigella sonnei, Escherichia coli, and Klebsiella pneumoniae in Korea.

CTX-M-14 beta-lactamase was identified in a stool isolate of Shigella sonnei and in blood isolates of Escherichia coli (one isolate) and Klebsiella pneumoniae (two isolates) from different parts of Korea. The amino acid sequence differed by one amino acid from CTX-M-9 (Ala-231--> Val) and was identical to that of beta-lactamases recently found in China and Japan.

Sequences of the NPS-1 and TLE-1 beta-lactamase genes.

The NPS-1 and TLE-1 beta-lactamase genes were cloned and sequenced. NPS-1 differed from LCR-1 beta-lactamase in 8 of 260 amino acids. TLE-1 differed from TEM-1 by a single Asp(115)-->Gly substitution and has been renamed TEM-90.

Dexamethasone suppression test using saliva cortisol measurement in bulimia nervosa.

The assessment of cortisol in saliva has been proven a valid and reliable reflection of the respective unbound hormone in blood. In the present study, a standard dexamethasone suppression test (DST) with measures of salivary cortisol levels was performed in bulimic women without depression (DSM-IV; N=48) and healthy controls (N=24) matched for age. Feedback sensitivity was assessed using the standard DST with pre- and post-measures of salivary cortisol. Subjects were divided into suppressors and nonsuppressors according to their post-DST levels. Bulimic suppressors and nonsuppressors were compared for their basal cortisol levels, body weight (body mass index, BMI), previous episodes of anorexia nervosa, and their results in psychometric tests. A total of 16 (33.3%) out of 48 women with bulimia nervosa (BN) failed to suppress in the DST. Basal salivary cortisol levels were elevated in bulimic nonsuppressors. Significant differences between suppressors and nonsuppressors were found for body weight and previous episodes of anorexia nervosa. The results are in accordance with recent findings. They support the hypothesized association between low body weight and DST nonsuppression. Using saliva cortisol in the standard DST could be advantageous for studying bulimic patients. Furthermore, the results show the importance of determining HPA reagibility when measuring cortisol in bulimic patients.

Characterization of the extended-spectrum beta-lactamase reference strain, Klebsiella pneumoniae K6 (ATCC 700603), which produces the novel enzyme SHV-18.

Klebsiella pneumoniae K6 (ATCC 700603), a clinical isolate, is resistant to ceftazidime and other oxyimino-beta-lactams. A consistent reduction in the MICs of oxyimino-beta-lactams by at least 3 twofold dilutions in the presence of clavulanic acid confirmed the utility of K. pneumoniae K6 as a quality control strain for extended-spectrum beta-lactamase (ESBL) detection. Isoelectric-focusing analysis of crude lysates of K6 demonstrated a single beta-lactamase with a pI of 7.8 and a substrate profile showing preferential hydrolysis of cefotaxime compared to ceftazidime. PCR analysis of total bacterial DNA from K6 identified the presence of a bla(SHV) gene. K6 contained two large plasmids with molecular sizes of approximately 160 and 80 kb. Hybridization of plasmid DNA with a bla(SHV)-specific probe indicated that a bla(SHV) gene was encoded on the 80-kb plasmid, which was shown to transfer resistance to ceftazidime in conjugal mating experiments with Escherichia coli HB101. DNA sequencing of this bla(SHV)-related gene revealed that it differs from bla(SHV-1) at nine nucleotides, five of which resulted in amino acid substitutions: Ile to Phe at position 8, Arg to Ser at position 43, Gly to Ala at position 238, and Glu to Lys at position 240. In addition to the production of this novel ESBL, designated SHV-18, analysis of the outer membrane proteins of K6 revealed the loss of the OmpK35 and OmpK37 porins.

Roles of beta-lactamases and porins in activities of carbapenems and cephalosporins against Klebsiella pneumoniae.

Two clinical isolates of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae were noted to be less susceptible than expected to imipenem. Both were missing outer membrane proteins that serve as channels for antibiotic entry. The role of beta-lactamase in resistance was investigated by eliminating the original ESBL and introducing plasmids encoding various ESBLs and AmpC beta-lactamase types, by studying the effect of an increased inoculum, and by evaluating interactions with beta-lactamase inhibitors. The contribution of porin deficiency was investigated by restoring a functional ompK36 gene on a plasmid. Plasmids encoding AmpC-type beta-lactamases provided resistance to imipenem (up to 64 microg/ml) and meropenem (up to 16 microg/ml) in strains deficient in porins. Carbapenem resistance showed little inoculum effect, was not affected by clavulanate but was blocked by BRL 42715, and was diminished if OmpK36 porin was restored. Plasmids encoding TEM- and SHV-type ESBLs conferred resistance to cefepime and cefpirome, as well as to earlier oxyimino-beta-lactams. This resistance was magnified with an increased inoculum, was blocked by clavulanate, and was also lowered by OmpK36 porin restoration. In addition, SHV-2 beta-lactamase had a small effect on carbapenem resistance (imipenem MIC, 4 microg/ml, increasing to 16 microg/ml with a higher inoculum) when porins were absent. In K. pneumoniae porin loss can thus augment resistance provided either by TEM- or SHV-type ESBLs or by plasmid-mediated AmpC enzymes to include the latest oxyimino-beta-lactams and carbapenems.

Sequence of the MIR-1 beta-lactamase gene.

The complete nucleotide sequence of the plasmid-mediated MIR-1 beta-lactamase gene confirms its relationship to chromosomally located ampC genes of Enterobacter cloacae. blaMIR-1 is not part of a typical gene cassette but does lie near an element that could be involved in its capture on a plasmid.

Quinolone resistance from a transferable plasmid.

BACKGROUND: Bacteria can mutate to acquire quinolone resistance by target alterations or diminished drug accumulation. Plasmid-mediated resistance to quinolones in clinical isolates has been claimed but not confirmed. We investigated whether a multiresistance plasmid could transfer resistance to quinolones between bacteria. METHODS: We transferred resistance between strains by conjugation. The resistance plasmid was visualised in different hosts by agarose-gel electrophoresis. We determined the frequency of spontaneous mutations to ciprofloxacin or nalidixic-acid resistance in Escherichia coli strains, with or without the quinolone resistance plasmid. FINDINGS: A multiresistance plasmid (pMG252) from a clinical isolate of Klebsiella pneumoniae was found to increase quinolone resistance to minimum inhibitory concentrations (MICs) as high as 32 microg/mL for ciprofloxacin when transferred to strains of K pneumoniae deficient in outer-membrane porins. Much lower resistance was seen when pMG252 was introduced into K pneumoniae or E coli strains with normal porins. The plasmid had a wide host range and expressed quinolone resistance in other enterobacteriaceae and in Pseudomonas aeruginosa. From a plasmid-containing E coli strain with ciprofloxacin MIC of 0.25 microg/mL and nalidixic-acid MIC of 32 microg/mL, quinolone-resistant mutants could be obtained at more than 100 times the frequency of a plasmid-free strain, reaching MICs for ciprofloxacin of 4 microg/mL and for nalidixic acid of 256 microg/mL. INTERPRETATION: Transferable resistance to fluoroquinines and nalidixic acid has been found in a clinical isolate of K pneumoniae on a broad host range plasmid. Although resistance was low in wild-type strains, higher levels of quinolone resistance arose readily by mutation. Such a plasmid can speed the development and spread of resistance to these valuable antimicrobial agents.

Thirty-month outcome in patients with anorexia or bulimia nervosa and concomitant obsessive-compulsive disorder.

OBJECTIVE: The present study examines whether concomitant obsessive-compulsive disorder (OCD) indicates a poorer prognosis for patients with anorexia or bulimia nervosa. METHOD: Seventy-five female inpatients who met DSM-IV criteria for anorexia or bulimia nervosa took part in the follow-up study; 29 of these patients met criteria for concomitant OCD. All patients were investigated twice: during inpatient treatment and at follow-up 30 months after discharge. A semistructured diagnostic interview was used as well as the Eating Disorder Inventory and the Hamburg Obsession-Compulsion Inventory--Short Form. RESULTS: At follow-up, 51% (N = 38) of the patients no longer fulfilled DSM-IV criteria for anorexia or bulimia nervosa, but this improvement was not significantly correlated with the earlier presence of concomitant OCD. Analysis of variance for repeated measures revealed significant improvement over time on six of the eight Eating Disorder Inventory subscales for all patients regardless of OCD presence. Furthermore, no significant group effects or group-by-time interactions were identified. Clinically significant change, as reflected by improvement in scores on the Eating Disorder Inventory, was seen somewhat more often in patients without concomitant OCD, but this trend was not statistically significant. The patients whose eating disorders were most improved at follow-up also showed the highest reduction of obsessions and compulsions. CONCLUSIONS: The results suggest that concomitant OCD does not indicate a significantly poorer prognosis for patients with anorexia or bulimia nervosa.

Comparative in vitro activities of carbapenem L-749,345 and other antimicrobials against multiresistant gram-negative clinical pathogens.

Carbapenems L-749,345 and imipenem had the lowest MICs at which 90% of isolates were inhibited (0.5 microg/ml) of 14 antimicrobial agents tested against 76 multiresistant gram-negative clinical isolates with TEM- or SHV-type extended-spectrum beta-lactamases and chromosomal or plasmid-determined AmpC beta-lactamases, but the MIC of L-749,345 for one isolate of Klebsiella pneumoniae was 16 microg/ml.

Tree rings, carbon dioxide, and climatic change.

Tree rings have been used in various applications to reconstruct past climates as well as to assess the effects of recent climatic and environmental change on tree growth. In this paper we briefly review two ways that tree rings provide information about climate change and CO2: (i) in determining whether recent warming during the period of instrumental observations is unusual relative to prior centuries to millennia, and thus might be related to increasing greenhouse gases; and (ii) in evaluating whether enhanced radial growth has taken place in recent decades that appears to be unexplained by climate and might instead be due to increasing atmospheric CO2 or other nutrient fertilization. It is found that a number of tree-ring studies from temperature-sensitive settings indicate unusual recent warming, although there are also exceptions at certain sites. The present tree-ring evidence for a possible CO2 fertilization effect under natural environmental conditions appears to be very limited.