Population structure of Escherichia coli causing bacteraemia in the UK and Ireland between 2001 and 2010.

OBJECTIVES: Escherichia coli is the most common agent of bacteraemia, bacterial gastroenteritis and urinary tract infections (UTIs). Lineages causing UTIs and gastrointestinal disease are well defined, but less is known about those causing bacteraemia. We therefore investigated the population structure of E. coli from bacteraemia in the UK and Ireland between 2001 and 2010. METHODS: E. coli isolates (n = 2166) were submitted to the BSAC Bacteraemia Surveillance Programme from 18 UK and Irish centres from 2001 to 2010. Genotypes were analysed by MLST using the Achtman scheme; MICs, blaCTX-M group and patient demographics were previously determined in the BSAC surveillance. RESULTS: Four hundred and forty-eight STs were identified, but five of these, and their associated clonal complexes (CCs), accounted for 58.4% (1264 of 2166) of isolates: CC73 was the most common (20.7%), followed by CC131 (13.9%), CC95 (11.3%), CC69 (6.9%) and CC12 (5.5%). All these, except CC69 (group D), belong to phylogenetic group B2. CC131 isolates were much more often MDR than other STs were: they rose from 2.9% of isolates in 2001 to 20.5%-20.7% in 2007-08 and then declined to 14.3% in 2010. Resistance rates to cephalosporins, aminoglycosides and fluoroquinolones remained below 10% in other major CCs throughout. CONCLUSIONS: The five most prevalent bacteraemia STs have all been associated previously with UTIs. They dominated in all years, but their proportions fluctuated, most notably for ST131, a globally disseminated high-risk clone that is often MDR.

Epidemiology of Escherichia coli bacteraemia in England: results of an enhanced sentinel surveillance programme.

BACKGROUND: Escherichia coli causes more than one-third of the bacteraemia cases in England each year, and the incidence of these infections is increasing. AIM: To determine the underlying risk factors associated with E. coli bacteraemia. METHODS: A three-month enhanced sentinel surveillance study involving 35 National Health Service hospitals was undertaken in the winter of 2012/13 to collect risk factor information and further details on the underlying source of infection to augment data already collected by the English national surveillance programme. Antimicrobial susceptibility results for E. coli isolated from blood and urine were also collected. FINDINGS: A total of 1731 cases of E. coli bacteraemia were included. The urogenital tract was the most frequently reported source of infection (51.2% of cases) with previous treatment for a urinary tract infection being the largest independent effect associated with this infection source. Half of all patients had previous healthcare exposure in the month prior to the bacteraemia with antimicrobial therapy and urinary catheterization being reported in one-third and one-fifth of these patients, respectively. Previous healthcare exposure was associated with a higher proportion of antibiotic non-susceptibility in the blood culture isolates (P=0.001). CONCLUSION: Analysis of risk factors suggests the potential benefit of community- and hospital-related interventions, especially the better use of urinary catheters and improved antibiotic management of urinary tract infections. As part of the latter strategy, antibiotic resistance profiles need to be closely monitored to ensure that treatment guidelines are up to date to limit inappropriate empiric therapy.

Thirty day all-cause mortality in patients with Escherichia coli bacteraemia in England.

Escherichia coli is the commonest cause of bacteraemia in England, with an incidence of 50.7 cases per 100 000 population in 2011. We undertook a large national study to estimate and identify risk factors for 30-day all-cause mortality in E. coli bacteraemia patients. Records for patients with E. coli bacteraemia reported to the English national mandatory surveillance system between 1 July 2011 and 30 June 2012 were linked to death registrations to determine 30-day all-cause mortality. A multivariable regression model was used to identify factors associated with 30-day all-cause mortality. There were 5220 deaths in 28 616 E. coli bacteraemia patients, a mortality rate of 18.2% (95% CI 17.8-18.7%). Three-quarters of deaths occurred within 14 days of specimen collection. Factors independently associated with increased mortality were: age < 1 year or > 44 years; an underlying respiratory or unknown infection focus; ciprofloxacin non-susceptibility; hospital-onset infection or not being admitted; and bacteraemia occurring in the winter. Female gender and a urogenital focus were associated with a reduction in mortality. This is the first national study of mortality among E. coli bacteraemia patients in England. Interventions to reduce mortality need to be multifaceted and include both primary and secondary healthcare providers. Greater awareness of the risk factors for and symptoms of E. coli bacteraemia may prompt earlier diagnosis and treatment. Changes in antimicrobial resistance patterns need to be monitored for their potential impact on infection and mortality.

Urinary electrolytes, body weight, and blood pressure. Pooled cross-sectional results among four groups of adolescent females.

Results of blood pressures (BP) and urinary electrolyte excretion studies are reported among several groups of adolescent and young adult females, both black and white, who were initially examined in high school and restudied at home 3--4 years later. Pooling of the data from the several cross-sectional studies (n = 662) revealed a weak but statistically significant positive correlation systolic blood pressure (SBP) and the urinary sodium (Na) excretion rate. Three of four correlations between SBP and potassium (K) were of an inverse nature. Although not statistically significant in their own right, when coupled with the Na/K excretion ratio, which was significantly associated with SBP, a moderating role for K is suggested. The urinary Na, K, and creatinine (Cr) excretion rates were highly intercorrelated and were correlated with weight. As measured by R2 in a stepwise regression analysis, weight contributed approximately 3% to the BP variance, and the urinary electrolytes accounted for approximately 2% of the SBP variance. Statistically significant partial correlation coefficients between SBP and Na, and Na/K, remained after adjusting for body weight.

Differential effect of salt loading on sodium and lithium excretion in Dahl salt-resistant and -sensitive rats.

Fractional excretion of lithium, as a marker for proximal sodium reabsorption, was determined in normotensive Dahl S rats (susceptible to NaCl hypertension) and Dahl R rats (resistant to NaCl hypertension) before and following an acute sodium load. Baseline mean arterial pressures, inulin clearances, sodium excretion rates, and fractional lithium clearances were not different between the R and S rats. Following the salt loading and despite similar mean arterial pressures and degree of volume expansion, the glomerular filtration rate, urinary flow rates, and absolute sodium excretion rates were greater in R than S rats. The fractional excretion of lithium was also greater in R than S rats. These data demonstrate that, at equal mean arterial pressures, Dahl S rats have a reduced capacity for sodium excretion, and that this defect is present prior to the development of hypertension. Furthermore, the observation that these animals also have a lower fractional lithium excretion during volume expansion suggests that salt loading reduces proximal tubule reabsorption to a lesser extent in Dahl S than R rats. These data suggest that the subnormal sodium and water excretion observed after sodium loading in S rats may be partially due to an abnormality in proximal tubule sodium handling.

Epidermotropic metastatic malignant melanoma simulating melanoma in situ. A report of 10 examples from two patients.

Epidermotropic metastatic malignant melanoma (EMMM) is a well-recognized entity that can simulate primary malignant melanoma, and in the past reports of numerous (> or = 100) such lesions were misconstrued as multiple primary lesions. We present the cases of two patients who had not only numerous epidermotropic metastases that simulated primary melanomas but also 10 lesions that mimicked melanoma in situ. After removal of a primary malignant melanoma, the two patients developed 35 and 22 epidermotropic metastases over a 4-year period before dying with brain and pulmonary metastases, respectively. In these patients, 29 and 22 of the skin lesions were excised, respectively. All had epidermotropic metastases, of which seven and three showed pagetoid melanocytes in a pagetoid pattern exclusively within the epidermis and epithelial structures of adnexa, an "epidermal only" (in situ) pattern. Other lesions showed a continuum of dermal involvement, from the more conventional description of EMMM with the extent of dermal involvement > or = epidermal (n = 2) to epidermal involvement > dermal disease (n = 36). This histologic spectrum of dermal versus epidermal involvement in conjunction with the extremely small size (2.8 mm average histologic diameter), symmetry, large number, and time course of development argues strongly that these lesions represent metastases rather than multiple primary melanomas. The lesions illustrate the diagnostic dilemma posed by EMMM that simulates primary melanoma and further exhibits an "epidermal only" (melanoma in situ) pattern.

Partial purification and characterization of a murine glioma-associated antigen defined by syngeneic rat monoclonal antibodies.

A glioma-associated antigen was previously identified on an avian sarcoma virus-induced F-344 rat astrocytoma cell line S69-c15 by four rat monoclonal antibodies (7G4, 9F1, 10E3 and 10E7) produced after syngeneic immunization. Earlier data suggested all four antibodies reacted with a polypeptide-associated epitope. We report here that the antigen activity was detected in the supernatant of tumor homogenates and could pass through a 1000 Da molecular weight cut-off dialysis membrane, as determined by antibody binding inhibition in a cell surface radioimmunoassay. When the dialysate was fractionated by Bio-Gel P-2 chromatography, antibody inhibiting activity eluted in the range of 300-600 Da. A highly purified material was further isolated by ion exchange high pressure liquid chromatography. Parallel purification product from an antigen-negative cell line failed to demonstrate antibody inhibiting activity. We conclude that greater than 400-fold purification enrichment of antigen can be achieved. We postulate that the partially purified antigenic determinant is a glioma-associated determinant of highly restricted expression and is presented in hapten-carrier form by the glioma cells.

The problem of non-compliance in long-term antihypertensive therapy.

Of 1,593 subjects admitted to the Australian National Blood Pressure Study 1 to 2 years ago, a substantial number (391 or 24.5%) ceased attending, in 85% of cases voluntarily. Withdrawal rates were very high in the first 4 months, settling to 5% per annum by the second year. Extrapolation to clinical practice is hazardous but contibutory factors elicited by questionnaire suggest certain management strategies: maximisation of efforts to enlist subject co-operation at the onset of treatment; management of treatment by family doctor or health centre with appointments flexible in time and infrequent in number; minimisation of doctors' ambivalence about treatment effectiveness and the withholding of information from the subject. It is inevitable that a proportion of subjects will reject long-term drug treatment. This adds further weight to the need for research on alternatives such as low salt diets.

Blood pressure and length of stay in Australia of Italian immigrants in the Australian National Blood Pressure Study.

Data obtained from 10,975 Australian-born and 1,717 Italian-born subjects aged 30-69 years in one centre of the Australian National Blood Pressure Study revealed that the Italians had lower systolic and diastolic blood pressures compared with Australians of the same age and sex. The Italians' blood pressures rose in successive age groups and at the same rate as in the Australians. After the effect of age was eliminated, the duration of residence of the Italians in Australia had a small but significant association with their blood pressures, possibly indicating exposure to blood pressure-elevating environmental factors in Australia.

Systolic blood pressure as an independent predictor of mortality in the Hypertension Detection and Follow-up Program.

The Hypertension Detection and Follow-up Program (HDFP) findings demonstrate the predictive value of baseline systolic blood pressure (SBP) and of pulse pressure (PB) in five-year mortality from all causes. Grouping participants into four SBP strata revealed an approximately two-fold increase in age-adjusted mortality rate from SBP stratum I to SBP stratum IV. This effect remained after the contributions of other risk factors were controlled by multivariate analysis. In contrast, baseline diastolic blood pressure (DBP) had little demonstrable effect on mortality in this particular population. The predictive power of pulse pressure was similar to that of SBP. The group mean SBP of every stratum fell progressively during the trial, the change being of greater magnitude in the stepped care (SC) group than in the referred care (RC) group. Also, the reduction in all-cause mortality associated with SC treatment was observed at all levels of baseline SBP. An analysis using life table regression with SBP as a time-dependent variable showed that the postrandomization reduction in SBP was a significant factor in reducing mortality. Similarly, reduced DBP was also contributory. Prospective studies are required to answer definitively the question of the efficacy of treatment of systolic hypertension. Nevertheless, the present analysis of the HDFP data, despite design limitations, supports the advisability of reducing elevated systolic blood pressure.

The impact in the UK of the Central and Eastern European HIV epidemics.

Despite increasing migration, the impact of HIV epidemics from Central and Eastern Europe (C&EE) on the UK HIV epidemic remains small. C&EE-born adults comprised 1.2% of adults newly diagnosed with HIV in the UK between 2000 and 2007. Most C&EE-born women probably acquired their infection heterosexually in C&EE. In contrast, 59% of C&EE-born men reported sex with men, half of whom probably acquired their infection in the UK. Previously undiagnosed HIV prevalence in C&EE-born sexual-health-clinic attendees was low (2007, 0.5%) as was overall HIV prevalence in C&EE-born women giving birth in England (2007, <0.1%). The high proportion of men who have sex with men (MSM) suggests under-reporting of this group in C&EE HIV statistics and/or migration of MSM to the UK. In addition to reducing HIV transmission in injecting drug users, preventative efforts aimed at C&EE-born MSM both within their country of origin and the UK are required.

Gompertzian mortality originates in the winding-down of the mitotic clock.

UNLABELLED: Gompertz' age-related exponential increase in mortality rate and the obdurately flat mortality trajectory of Drosophila are paradoxical notions for metazoan aging theory. A multiclonal model of Gompertzian organisms provides a resolution by assuming that (a) conception initiates a stochastic process producing a train of replications of fixed length (the Hayflick limit); (b) unique stem cells arise early on to generate multiple vital clones; (c) life continues until one such clone critically depletes its replicative potential. Lifespan is thus governed by the time it takes to reach the terminal branches of the mitotic tree. Although these times are not independent, asymptotic independence can be justified. This clears the way for asymptotic extreme-value theory to guarantee: (1) a non-increasing failure rate, under unlimited replicability; (2) an exponentially increasing failure rate, under limited replicability. However, to obtain an exact fit to the human force-of-mortality function also requires the inclusion of the phenomenon of mitotic deceleration (implemented with a lognormal model of replication). CONCLUSION: the sine qua non of Gompertzian mortality is cellular aging, expressed through these two mitotic phenomena. Conversely, those metazoa with unlimited cellular replicability, by staving off clonal failure would succumb only to catastrophic, age-independent events, yielding a constant mortality rate, the signature of a mitotic clock that does not run down.

The need to treat mild hypertension. Misinterpretation of results from the Australian trial.

Despite the clear-cut result of the Australian Therapeutic Trial in Mild Hypertension, which demonstrated prospectively the benefit of treatment of diastolic blood pressure in the range of 95 to 109 mm Hg, a retrospective analysis that classified subjects by the average diastolic pressure level attained during the trial purported to show an absence of treatment benefit at lower average diastolic pressures and a negative treatment effect at higher levels. However, the method of classification by average attained diastolic pressure introduced substantial selection bias, invalidating the retrospective analysis and rendering as spurious both the deleterious treatment effect and its lack of efficacy at lower diastolic levels.

The Australian National Blood Pressure Study: a test of the effectiveness of antihypertensive therapy on the incidence of ischaemic heart disease.

Although hypertension is an acknowledged risk factor in ischaemic heart disease (IHD) the question remains whether antihypertensive therapy is necessarily beneficial. A priori, because coronary atherosclerosis is probably irreversible, the time for effective intervention would seem to be well before the development of clinical manifestations. The Australian National Blood Pressure Study, a long term clinical trial of the treatment of mild hypertension, is in principle better suited than previous trials to answer the question because the trial population selected (4000 subjects aged 30-69) contains substantial proportions of younger age groups (26% below 45) and of females (37%) and none had manifest IHD at entry. Sensitivity to the emergence of IHD in the trial population is increased by including as diagnostic indices angina and ischaemic ECG changes, using suitably objective methods, as well as myocardial infarction and sudden death. Thus morbidity and mortality from IHD which currently accounts for 71% of trial end points (cf 19% for stroke) will effectively determine the outcome of the trial. The occurrence of a substantial proportion of subjects withdrawn from randomised treatment will mean that the question will be answered necessarily in two ways: firstly in respect of those subjects remaining on their assigned treatments and secondly in terms of all subjects initially assigned one treatment or other irrespective of the subsequent need to change treatment on ethical grounds or of the degree of compliance.

Thin-layer chromatography for detection of peptide cleavage or integrity during reactions of the Z-alanylglycines with aniline or phenylhydrazine under papain catalysis.

Z-l-Ala-gly and Z-dl-ala-gly can yield anilides and phenylhydrazides through peptide cleavage or peptide integrity during papain-catalyzed reactions with aniline (NH2Ph) or phenylhydrazine (NH2NHPh). Since Z-d-ala-gly yielded only uncleaved Z-d-ala-gly-NHPh or Z-d-ala-gly-NHNHPh, these were used as standards in thinlayer chromatography (TLC) for detecting integrity. Known Z-l-ala-NHPh and Z-l-ala-NHNHPh were the standards for cleavage. Depending on the time of incubation, cleaved or unsplit products, or both, were readily detected. The solvent systems that were used for TLC were also effectively employed for separations of reasonable amounts of mixtures of cleaved and uncleaved products through thick-layer chromatography on Chrom AR. This was followed by isolation of the separated components.

epsilon-(gamma-Glutamyl)lysine cross-links in human stratum corneum.

epsilon-(gamma-Glutamyl)lysine has been found in human stratum corneum in the fraction containing the alpha helical fibrous proteins (keratins) and other high molecular weight proteins. The S-carboxymethylated fractions were enzymatically digested with pronase, carboxypeptidase A and B, leucine aminopeptidase and prolidase, and epsilon-(gamma-glutamyl)lysine isolated from digests by gel filtration and cation ion exchange chromatography. Acid hydrolysis of the purified epsilon-(gamma-glutamyl)lysine yielded equimolar amounts of lysine and glutamic acid, and end group analysis of the peptide by dansylation (application of 5-dimethylaminonaphthalene-1-sulfonyl) confirmed the isomer assignment to be epsilon-(gamma-glutamyl)lysine. About 9 nmol of the peptide per mg of protein were found in the fraction by isotope dilution after the enzymatic digestion. These results suggest that proteins in stratum corneum may be covalently cross-linked through epsilon-(gamma-glutamyl)lysine bonds.