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Background Addition of vitamin E to polyethylene is theorized to reduce the potential for oxidative wear in acetabular components. This paper presents a multicenter prospective cohort study that reports on outcomes from use of a Vitamin E–infused highly cross-linked polyethylene acetabular cup. Methods Patients were recruited across nine medical institutions. Clinical outcome measures recorded were the Harris Hip Score, visual analogue score for pain and satisfaction. Evidence of implant loosening or osteolysis was collected radiologically. Cup survival and reasons for revision in relevant cases were also recorded. Data collection was undertaken preoperatively, at 6-12 weeks, 6 months, 1 year, 2 years, and 5 years. A total of 675 patients were recruited, with 450 cases available at final review. Data regarding cup survival was available to 8 years and 9 months postoperatively. Results Improvements in both the Harris Hip Score and visual analogue score for pain and satisfaction were recorded at all time points, with these being maintained through the length of follow-up. In total, 89% of cups were implanted within the Lewinnek safe zone. A lucent line was identified in one case, with no evidence of acetabular osteolysis observed throughout the follow-up period. Cup survival was 98.9% at 8 years and 9 months. No revisions for aseptic loosening were observed. Conclusions The use of a vitamin E–infused polyethylene acetabular cup demonstrates reassuring patient-reported outcomes, radiological measures, and cup survival at medium to long-term follow-up.

Background Aseptic loosening and periprosthetic osteolysis are frequent complications in total hip arthroplasty requiring revision surgery. Highly crosslinked polyethylene (HXLPE) implants have improved wear resistance, permitting larger femoral heads. However, such implants may experience surface cracking, mechanical failure, and oxidative damage. Vitamin E-infused HXLPE (VEPE) implants were therefore developed to reduce oxidation without compromising mechanical strength. We addressed the following questions: (1) Does femoral head size affect the midterm annual polyethylene wear rates of VEPE acetabular cups? (2) Does femoral head size affect the midterm migration rates of VEPE acetabular cups? (3) Are clinical outcomes affected by femoral head size? Hypothesis Annual wear rate, migration rate, and clinical outcomes of VEPE acetabular cups are independent of femoral head size. Patients and methods This was a prospective, multicenter, observational study of patients that underwent total hip arthroplasty. Hips were grouped according to the size of femoral head implanted (28 mm, 32 mm, and 36 mm). We determined annual wear rate and migration rate of VEPE acetabular cups using the Einzel-Bild-Rontgen-Analyse software. Clinically, we assessed the Harris Hip Score and visual analog score for pain and satisfaction. Results We followed 253 patients (267 hips) for a mean of 55.0 ± 20.6 months in the 28 mm, 46.2 ± 21.4 months in the 32 mm, and 43.8 ± 22.6 months in the 36 mm group. The annual wear rate was 0.025 mm per year from 1 year to the last follow-up and remained similar between the groups (p > 0.05). Also, mean two-dimensional migration rates did not exceed 0.05 mm from 2 years to the last follow-up and remained similar between the groups (p = 0.355). Finally, clinical outcomes also did not differ between the groups (p > 0.05). Two patients required revision surgery. Discussion Femoral head size did not influence midterm annual wear rate, migration rate, and clinical outcomes of VEPE acetabular cups. Furthermore, wear and cup migration rates were below the reported values leading to osteolysis and aseptic loosening. Nevertheless, studies with extended follow-up periods will be necessary to confirm these results in the long term. Level of evidence IV.

To harness the work already done by the community frailty team in establishing advanced care plans for frail care home residents. Identifying patients with these plans at the front door to ensure clinical teams can be best placed to deliver care which is tailored to patients’ own wishes. East Sussex Healthcare NHS Trust has a large elderly …

Background Aseptic loosening and periprosthetic osteolysis are frequent complications in total hip arthroplasty requiring revision surgery. Highly cross-linked polyethylene (HXLPE) implants have improved wear resistance, permitting larger femoral heads. However, such implants may experience surface cracking, mechanical failure, and oxidative damage. Vitamin E-infused HXLPE (VEPE) implants were therefore developed to reduce oxidation without compromising mechanical strength. We addressed the following questions: (1) Does femoral head size affect the midterm annual polyethylene wear rates of VEPE acetabular cups? (2) Does femoral head size affect the midterm migration rates of VEPE acetabular cups? (3) Are clinical outcomes affected by femoral head size? Hypothesis Annual wear rate, migration rate, and clinical outcomes of VEPE acetabular cups are independent of femoral head size. Patients and methods This was a prospective, multicentre, observational study of patients that underwent total hip arthroplasty. Hips were grouped according to the size of femoral head implanted (28 mm, 32 mm, and 36 mm). We determined annual wear rate and migration rate of VEPE acetabular cups using the Einzel-Bild-Rontgen-Analyse software. Clinically, we assessed the Harris Hip Score and visual analog score for pain and satisfaction. Results We followed 253 patients (267 hips) for a mean of 55.0 ± 20.6 months in the 28 mm, 46.2 ± 21.4 months in the 32 mm, and 43.8 ± 22.6 months in the 36 mm group. The annual wear rate was 0.025 mm per year from 1 year to the last follow-up and remained similar between the groups (p > 0.05). Also, mean two-dimensional migration rates did not exceed 0.05 mm from 2 years to the last follow-up and remained similar between the groups (p = 0.355). Finally, clinical outcomes also did not differ between the groups (p > 0.05). Two patients required revision surgery. Discussion Femoral head size did not influence midterm annual wear rate, migration rate, and clinical outcomes of VEPE acetabular cups. Furthermore, wear and cup migration rates were below the reported values leading to osteolysis and aseptic loosening. Nevertheless, studies with extended follow-up periods will be necessary to confirm these results in the long term. Level of evidence IV.

Introduction To report a series of patients with osteoid osteoma treated by radiofrequency ablation in whom no complications or recurrences occurred. Methods Over a 13-year period, 32 consecutive patients with osteoid osteoma were treated by radiofrequency ablation in an Australasian teaching centre. Results All patients had resolution of symptoms with no complication or recurrence. Conclusions This series is further evidence for the use of radiofrequency ablation as the primary treatment for osteoid osteoma.

Introduction: In the developed world,Clostridium difficile infection (CDI) is the mostimportant cause of nosocomial infectiousdiarrhea. In addition to providingepidemiological data and helping to indicatethat a local outbreak may be occurring,laboratory tests are used to augment clinicaldecisions on individual patients. Very rarely dodiagnostic tests provide results at the point of decision making; in the intervening periodbetween requesting investigations on a patientwith suspected CDI and return of the laboratoryresult, decisions must be made regardingpatient isolation and treatment.Methods: A 22-month, real-world feasibilitystudy was conducted in patients with clinicallysignificant diarrhea, in a London Hospitalbetween March 2011 and January 2013, inthree older persons’ wards and two intensivecare units (ICUs) to determine acceptability,ease of use, change in turnaround time andclinical utility of a rapid, polymerase chainreaction (PCR)-based point-of-care test (POCT)(Cepheid GeneXpert, Sunnyvale, California,USA) for diagnosis of Clostridium difficile. Nursesin the older persons’ ward and laboratorytechnicians in the ICU were trained toperform the test. Residual samples were sent tothe centralized laboratory for parallel testingusing a two-step algorithm.Results: A total of 335 samples were tested usingthe POCT with a median turnaround time of1.85 h compared with 18 h for the centralizedlaboratory test. Overall agreement withcentralized laboratory testing was 98.1%.Discrepant samples were more frequent on elderly wards than ICU. Overall 20/335 (6%)processing errors were encountered and werehighest in the first few months of the study.Significantly more processing errors occurred onthe older persons’ wards 13/102 (12.7%) than onICU 7/271 (2.6%). Older persons’ patients whohad POCT were significantly less likely to have atest requested for bacterial stool culture (3.1% vs.10.9% p = 0.044). This difference was notobserved in the ICU patients. No otherdifferences in ancillary test requesting,mortality or length of stay were observed.Conclusions: The majority of users reportedthat the POCT was easy to perform and was anacceptable part of their job. POCT using thissystem is feasible and acceptable to nursing staffand technicians working within these twohospital-based settings.

We describe the identification and control of an outbreak of gentamicin resistant, meticillin susceptible Staphylococcus aureus (GR-MSSA) on a 36-bed neonatal unit (NNU) in London. Control measures included admission and weekly screening for GR-MSSA, cohorting affected babies, environmental and staff screening, hydrogen peroxide vapour (HPV) for terminal disinfection of cohort rooms, and reinforcement of hand hygiene. Seventeen babies were affected by the outbreak strain over ten months; seven were infected and ten were asymptomatic carriers. The outbreak strain was gentamicin resistant and all isolates were indistinguishable by pulsed-field gel electrophoresis. The outbreak strains spread rapidly and were associated with a high rate of bacteraemia (35% of 17 affected patients had bacteraemia vs. 10% of 284 patients with MSSA prior to the outbreak, p=0.007). None of 113 staff members tested were colonised with GR-MSSA. GR-MSSA was recovered from 11.5% of 87 environmental surfaces in cohort rooms, 7.1% of 28 communal surfaces and 4.1% of 74 surfaces after conventional terminal disinfection. None of 64 surfaces sampled after HPV decontamination yielded GR-MSSA. Recovery of GR-MSSA from two high level sites suggested that the organism could have been transmitted via air. Occasional breakdown in hand hygiene compliance and contaminated environmental surfaces probably contributed to transmission.

Summary Background Meticillin-resistant Staphylococcus aureus (MRSA) is frequently endemic in healthcare settings and may be transmitted by person-to-person spread. Asymptomatic MRSA carriers are potential, unsuspected sources for transmission and some of them may be identified by admission screening. Aim To assess whether rapid point-of-care screening (POCS) for MRSA at hospital admission may be associated with a reduction in MRSA acquisition rates when compared with slower laboratory-based methods. Methods A cluster-randomized cross-over trial was conducted in four admission wards of an acute London tertiary care hospital. Polymerase chain reaction-based POCS screening was compared with conventional culture screening. Patients were screened on ward admission and discharge, and the MRSA acquisition rate on the admission wards was calculated as the primary outcome measure. Results In all, 10,017 patients were included; 4978 in the control arm, 5039 in the POCS arm. The MRSA carriage rate on admission was 1.7%. POCS reduced the median reporting time from 40.4 to 3.7 h (P

Summary Background There is debate over the optimal policy for detecting meticillin-resistant Staphylococcus aureus (MRSA) colonization at hospital admission. The emergence of community-associated (CA)-MRSA may compromise targeted screening strategies based on risk factors for healthcare-associated (HA)-MRSA. Aim To determine the prevalence of MRSA colonization at admission, and the genotype and molecular epidemiology of the strains involved. Methods A 12-month observational study was performed at a 1200-bed London tertiary referral hospital from 1 April 2008 to 1 March 2009. All available MRSA isolates were genotyped by spa and staphylococcal cassette chromosome mec (SCC mec ) typing. Findings The overall MRSA colonization rate was 2.0% of 28,892 admissions (range 6.6% in critical care to 0.8% in obstetrics/gynaecology/neonatology). The overall frequency of previously unknown carriage of MRSA on admission was 1.4%. Most colonizing strains were epidemic HA-MRSA-15 and -16. However, heterogeneous CA strains accounted for 18% of recovered isolates, including 37.5% of MRSA from accident and emergency and 23.1% of MRSA from surgery. The CA-MRSA strain types had significantly different epidemiological associations from the HA-MRSA strains, so risk factors used for the identification of HA-MRSA may not detect CA-MRSA reliably. Conclusion The low rate of HA-MRSA in the UK increases the relative proportion due to CA-MRSA, for which conventional risk-factor-based screening strategies may be less effective. Cost–benefit analyses of universal MRSA admission screening will need to take account of this new epidemiology.

A novel molecular assay for Clostridium difficile was developed using Linear-After-The-Exponential polymerase chain reaction (LATE-PCR). Single-stranded DNA products generated by LATE-PCR were detected and distinguished by hybridization to fluorescent mismatch-tolerant probes, as the temperature was lowered after amplification in 5 ° C intervals between 65 °C and 25 °C. Single-tube multiplex reactions for tcdA , tcdB , tcdC , and cdtB (binary toxin) sequences were initially optimized using synthetic targets and were subsequently done using genomic DNA; each target was detected and characterized by hybridization to one or more probes of a different fluorescent color. In the case of tcdC , three probes, each labeled with a Quasar fluorophore, hybridize to different locations with known mutations, including the deletion at nucleotide 117 in ribotype 027 strains and the premature stop codon mutation at nucleotide 184 in ribotype 078 strains, each of which is associated with hypervirulent infections. These and other tcdC mutations were distinguished from the reference sequence, as well as from each other by changes in the fluorescent contour generated from the combined Quasar-labeled probes. Specific variations in tcdA and tcdB were also identified in the multiplex assay, including those that identified strains lacking toxin A production. This single closed-tube assay generates substantially more information about virulent C. difficile than currently available commercial assays and could be further expanded to provide strain typing.

Infection control for hospital pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) often takes the form of a package of interventions, including the use of patient isolation and decolonization treatment. Such interventions, though widely used, have generated controversy because of their significant resource implications and the lack of robust evidence with regard to their effectiveness at reducing transmission. The aim of this study was to estimate the effectiveness of isolation and decolonization measures in reducing MRSA transmission in hospital general wards. Prospectively collected MRSA surveillance data from 10 general wards at Guy's and St. Thomas' hospitals, London, United Kingdom, in 2006-2007 were used, comprising 14,035 patient episodes. Data were analyzed with a Markov chain Monte Carlo algorithm to model transmission dynamics. The combined effect of isolation and decolonization was estimated to reduce transmission by 64% (95% confidence interval: 37, 79). Undetected MRSA-positive patients were estimated to be the source of 75% (95% confidence interval: 67, 86) of total transmission events. Isolation measures combined with decolonization treatment were strongly associated with a reduction in MRSA transmission in hospital general wards. These findings provide support for active methods of MRSA control, but further research is needed to determine the relative importance of isolation and decolonization in preventing transmission.

Spores of Clostridium difficile may play a significant role in transmission of disease within the healthcare environment and are resistant to a variety of detergents and cleaning fluids. A range of environmental cleaning agents has recently become available, many of which claim to be sporicidal. We investigated the effect of changing to a chlorine dioxide-based cleaning regimen on C. difficile environmental contamination and patient infection rates. The prevalence of environmental contamination was unaffected with a rate of 8% (9/120) before and 8% (17/212) following the change. Rates of patient infection were also unchanged during these periods.

Summary Background Litigation costs resulting from clinical negligence claims involving healthcare-associated infections are a significant but underappreciated cost to healthcare organizations. In England these claims are handled on behalf of the National Health Service (NHS) organizations by the NHS Litigation Authority (NHSLA). The total number of claims and the amounts awarded have increased significantly in recent years. Aim To determine whether the recent significant reductions in meticillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) and Clostridium difficile infections in England have had an effect on the number and value of NHSLA claims relating to these infections. Methods Data obtained from the NHSLA relating to claims mentioning C. difficile or MRSA from 2003 to 2010 were correlated with mandatory surveillance data from the Health Protection Agency for these infections. Findings The rate of NHSLA claims for MRSA has decreased in line with reductions in BSI for this infection (0.007 per BSI between 2003/4–2006/7 to 0.0017 per BSI between 2007/8 and 2010/11), but there was no significant change in claims relating to C. difficile infection. Overall the amounts awarded for successful claims have decreased significantly from a total of £76,846 for the period 1997/8–2006/7 to £24,821 for the period 2007/8–2010/11. Conclusions The number of litigation claims involving MRSA has recently decreased significantly in line with surveillance data. There was no observed effect on claims involving C. difficile . The amounts awarded for successful claims for both infections have also fallen, although the reasons for this are not clear.

Community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) was first noticed as a cause of infection in community-based individuals without healthcare contact. As the global epidemic of CA-MRSA has continued, CA-MRSA strain types have begun to emerge as a cause of healthcare-associated infections (HAIs) and hospital outbreaks have occurred worldwide. In areas where CA-MRSA clones have become established with high prevalence, for example USA300 (ST8-IV) in the USA, CA-MRSA are beginning to supplant or overtake traditional healthcare-associated MRSA strains as causes of HAI. The emergence of CA-MRSA as a cause of HAI puts a wider group of hospitalised patients, healthcare workers and their community contacts potentially at risk of MRSA infection. It also exposes CA-MRSA strains to the selective pressure of antibiotic use in hospitals, potentially resulting in increased antibiotic resistance, challenges traditional definitions of CA-MRSA and hampers control efforts due to the constant re-introduction of MRSA from an emerging community reservoir. There is thus an urgent need to clarify the definitions, prevalence and epidemiology of CA-MRSA and to develop systems for the identification and control of these organisms in the community, in hospitals and other healthcare facilities, and at the community-hospital interface.

Summary Recent studies have shown poor performance of commonly used toxin enzyme immunoassays (EIAs) for laboratory testing for Clostridium difficile infection (CDI). In 2009–2010, the UK Health Protection Agency and the European Society of Clinical Microbiology and Infectious Diseases stated that toxin EIA testing alone is suboptimal, and recommended a two-step testing protocol (i.e. screening with one method and confirming the results with another method). All acute English National Health Service trusts were surveyed to determine their testing methods and positivity rates using freedom of information requests. Replies were received from 168 of 170 trusts (99% response rate). Seventy percent of trusts were using a toxin EIA as a standalone testing method, with positive predictive values (PPVs) as low as 20% in some cases. The mean positivity rate decreased from 6.45% in 2008 to 4.47% in 2009, which will have a negative effect on the PPVs of these tests. The UK Department of Health publishes CDI rates as a measure of quality of care and good infection control practice. However, this may not provide valid comparisons because of the wide disparity between testing methods. The present study demonstrates wide variation in testing practices for CDI in England, and laboratories should reconsider their current testing strategies.

Studies in the 1970s and 1980s suggested that environmental surface contamination played a negligible role in the endemic transmission of healthcare-associated infections. However, recent studies have demonstrated that several major nosocomial pathogens are shed by patients and contaminate hospital surfaces at concentrations sufficient for transmission, survive for extended periods, persist despite attempts to disinfect or remove them, and can be transferred to the hands of healthcare workers. Evidence is accumulating that contaminated surfaces make an important contribution to the epidemic and endemic transmission ofClostridium difficile,vancomycin-resistant enterococci, methicillin-resistantStaphylococcus aureus, Acinetobacter baumannii, Pseudomonas aeruginosa,and norovirus and that improved environmental decontamination contributes to the control of outbreaks. Efforts to improve environmental hygiene should include enhancing the efficacy of cleaning and disinfection and reducing the shedding of pathogens. Further high-quality studies are needed to clarify the role played by surfaces in nosocomial transmission and to determine the effectiveness of different interventions in reducing associated infection rates.

We investigated the prevalence and role of efflux pump activity and possible drug influx resistance in ciprofloxacin susceptibility amongst 26 distinct clinical isolates of Klebsiella pneumoniae of varying ciprofloxacin susceptibilities and known quinolone resistance-determining region (QRDR) genotypes. Cellular [(14)C]ciprofloxacin accumulation patterns and the amount of cell-associated [(14)C]ciprofloxacin of mid-logarithmic phase cells were determined before and after challenging with the efflux pump inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP). Most isolates (24/26), and all with ciprofloxacin minimum inhibitory concentrations (MICs)1 µg/ml, had efflux activity that could extrude up to 90% of cell-associated [(14)C]ciprofloxacin; none had significant influx resistance. In isolates with no QRDR mutations, efflux alone reduced ciprofloxacin susceptibility. In isolates with QRDR mutations, the efflux activity varied: in one isolate with no efflux activity, the most common fluoroquinolone resistance-causing QRDR mutation did not bring about clinically significant ciprofloxacin resistance; isolates with multiple mutations had high MICs and, usually, high levels of efflux activity. Fluoroquinolone efflux activity is much more common in clinical isolates of K. pneumoniae than previously reported and it can contribute to decreased ciprofloxacin susceptibility.

Current diagnosis of Clostridium difficile infection (CDI) relies upon detection of toxins A/B in stool by enzyme immunoassay [EIA(A/B)]. This strategy is unsatisfactory because it has a low sensitivity resulting in significant false negatives. We investigated the performance of a two-step algorithm for diagnosis of CDI using detection of glutamate dehydrogenase (GDH). GDH-positive samples were tested for C. difficile toxin B gene (tcdB) by polymerase chain reaction (PCR). The performance of the two-step protocol was compared with toxin detection by the Meridian Premier EIA kit in 500 consecutive stool samples from patients with suspected CDI. The reference standard among samples that were positive by either EIA(A/B) or GDH testing was culture cytotoxin neutralisation (culture/CTN). Thirty-six (7%) of 500 samples were identified as true positives by culture/CTN. EIA(A/B) identified 14 of the positive specimens with 22 false negatives and two false positives. The two-step protocol identified 34 of the positive samples with two false positives and two false negatives. EIA(A/B) had a sensitivity of 39%, specificity of 99%, positive predictive value of 88% and negative predictive value of 95%. The two-step algorithm performed better, with corresponding values of 94%, 99%, 94% and 99% respectively. Screening for GDH before confirmation of positives by PCR is cheaper than screening all specimens by PCR and is an effective method for routine use. Current EIA(A/B) tests for CDI are of inadequate sensitivity and should be replaced; however, this may result in apparent changes in CDI rates that would need to be explained in national surveillance statistics.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) often produce Panton–Valentine leukocin (PVL), which is encoded by two co-transcribed genes located on lysogenized bacteriophages. Six PVL-encoding temperate phages have been described and single nucleotide polymorphisms (SNPs) in the PVL genes have been reported. In the present study, 22 PVL-positive CA-MRSA isolates were chosen to reflect the diversity of multilocus sequence type (MLST) clonal complexes (CC) identified in our hospital. Isolates were characterized by antimicrobial resistance profile, staphylococcal cassette chromosome mec (SCCmec) and spa type, pulsed-field gel electrophoresis profile and MLST. Primers were designed to sequence the lukSF-PV genes. PVL-encoding phages were characterized using a PCR-based assay. SNPs were identified at seven locations in the lukSF-PV genes, which varied with S. aureus MLST lineage. One SNP was nonsynonymous. All CC80 and some CC1 isolates carried FSa2mw; CC8, CC88 and CC154 isolates harboured PVL-encoding elongated head-type phages; and some CC59 isolates harboured a FSa2958-like phage. Novel or variant phages were present in CC5 and some CC1 and CC59 isolates. The PVL gene sequence and the PVL-encoding phage varied with lineage. Further work is required to determine whether PVL sequence and/or phage variations result in biological differences.

The clinical utility of real-time PCR screening assays for methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) colonization is constrained by the predictive values of their results: as MRSA prevalence falls, the assay's positive predictive value (PPV) drops, and a rising proportion of positive PCR assays will not be confirmed by culture. We provide a quantitative analysis of universal PCR screening of critical care and emergency surgical patients using the BD GeneOhm MRSA PCR system, involving 3,294 assays over six months. A total of 248 PCR assays (7.7%) were positive; however, 88 failed to be confirmed by culture, giving a PPV of 65%. Multivariate analysis was performed to compare PCR-positive culture-positive (P+C+) and PCR-positive culture-negative (P+C−) assays. P+C− results were positively associated with a history of methicillin-sensitive Staphylococcus aureus infection or colonization (odds ratio [OR], 3.15; 95% confidence interval [CI], 1.32 to 7.54) and high PCR thresholds of signal intensity, indicative of a low concentration of target DNA (OR, 1.19 per cycle; 95% CI, 1.11 to 1.26). P+C− results were negatively associated with a history of MRSA infection or colonization (OR, 0.19; 95% CI, 0.09 to 0.42) and male sex (OR, 0.40; 95% CI, 0.20 to 0.81). P+C+ patients were significantly more likely to have subsequent positive MRSA culture assays and microbiological evidence of clinical MRSA infection. The risk of subsequent MRSA infection in P+C− patients was not significantly different from that in case-matched PCR-negative controls. We conclude that, given the low PPV and poor correlation between a PCR-positive assay and the clinical outcome, it would be prudent to await culture confirmation before altering infection control measures on the basis of a positive PCR result.

OBJECTIVE To analyse the results of positive urine cultures over a 5-year period in a large hospital and urology department (amongst both inpatients and outpatients), assess the prevalence of different organisms and the resistance profiles of a range of antibiotics, and thus provide information on which organisms are likely to cause urosepsis. METHODS The use of antibiotics should be based on knowledge of which pathogens are present and what resistance patterns are emerging, particularly relevant in surgical disciplines like urology, as antibiotics are now routinely administered peri-operatively, whereby evidence-based prescription is preferable to generic guidelines. We therefore examined almost 25 000 positive urine cultures in our hospital over a 5-year period, and focused on the infections encountered amongst urology patients during this time. RESULTS A significant proportion of inpatient urinary infection (40%) is caused by Gram-positive bacteria such as Streptococcus faecalis, underlining the need for including Gram-positive cover during urological prophylaxis. The commonest pathogen remains Escherichia coli among both inpatients and outpatients. The ineffectiveness of common antibiotics such as ciprofloxacin and trimethoprim was identified, as was the increase in gentamicin resistance. CONCLUSION We propose using an aminoglycoside with a penicillin for high-risk cases (e.g. endoscopic stone surgery) while low-risk cases (e.g. flexible cystoscopy with no risk factors) might be managed without such prophylaxis. Pathogenic patterns and resistance rates should be monitored regularly.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is increasingly common in the USA, but rare in the UK. We compared CA-MRSA from the UK and USA to examine differences in the molecular epidemiology. We investigated patients presenting with MRSA in the first 72 h of hospital admission or in out-patient settings in a UK and a US hospital from January 2004 to March 2006. Fluoroquinolone susceptibility was used as a screening marker to select presumptive CA-MRSA. One hundred and eighteen and 49 such strains were identified, representing a prevalence of 0.1 and 0.2 isolates per 1,000 patient days in the UK and US respectively. Panton-Valentine leukocidin (PVL)-positive ST8-IVa (USA300)-type strains predominated among 43 surviving US isolates, whereas PVL-negative ST1-IVa predominated among 71 surviving UK isolates. There are striking differences between the molecular epidemiology of CA-MRSA in UK and US hospitals, which may have implications for control.

Despite increasing antimicrobial resistance and multiple drug resistance in clinical isolates of both Gram-positive and Gram-negative bacteria, there are few novel antimicrobial agents in development. The few new agents that have been recently licensed have tended to have narrow spectra of activity, focused on Gram-positive pathogens, especially methicillin-resistant Staphylococcus aureus (MRSA). This situation is rightly causing concern among clinicians and public health authorities worldwide. This article reviews available data on three new antibacterials currently in development. The cephalosporin ceftobiprole is active against MRSA, Enterococcus faecalis and penicillin-resistant Streptococcus pneumoniae, but otherwise has a spectrum of activity similar to that of other recent cephalosporins. In a clinical trial, ceftobiprole was non-inferior to vancomycin for the treatment of MRSA-associated complicated skin and skin structure infections (cSSSIs). Doripenem, a new carbapenem, has some activity against MRSA, but otherwise has an anti-Gram-positive spectrum of activity similar to that of imipenem and an anti-Gram-negative spectrum similar to that of meropenem. In a clinical trial, it was non-inferior to meropenem for the treatment of complicated intra-abdominal infections. Iclaprim is a dihydrofolate reductase inhibitor with greatly enhanced activity, as compared with trimethoprim, against a range of Gram-positive and Gram-negative pathogens. The limited literature concerning this agent has concentrated on its potential role in the treatment of infections with Gram-positive bacteria. A clinical trial has demonstrated the non-inferiority of iclaprim, as compared with linezolid, in the treatment of cSSSIs, including those associated with MRSA.

A commercial rapid polymerase chain reaction methicillin-resistant Staphylococcus aureus (MRSA) screening method (IDI-MRSA) is validated for the use with nasal swabs transported in liquid Stuart's medium. We investigated the use of IDI-MRSA for screening for MRSA in pooled nose, axilla, and groin swabs and in single swabs from skin puncture sites, wounds, throat, rectum, and groin using swabs transported in Amies medium without charcoal. We performed the IDI-MRSA test on swabs that had been used for routine MRSA broth culture and which were selected to be about 50% MRSA positive. We compared the IDI-MRSA result with the MRSA culture result. With 201 pooled sets, the sensitivity of IDI-MRSA was 85% and the specificity 95%. With 32 single screening swabs, sensitivity was 94% and specificity 80%. The method is not compromised by swab transport in Amies medium if an additional heating step is used. We had a low rate of initial inhibition (1.3%), which may have been due to the extra heating step used to liquefy gel from the Amies medium. Thus, in this study IDI-MRSA gives similar results to culture with pooled or single swabs from multiple screening sites.

Over the last decade, methicillin-resistant Staphylococcus aureus (MRSA) strains have emerged as serious pathogens. These strains are often multiresistant to several antibiotic classes and are a major cause of serious hospital- and now community-acquired infections and associated morbidity and mortality. As a result of increasing antimicrobial resistance, glycopeptides, such as vancomycin, are widely used as first-line therapy for serious MRSA infections. However, the emergence of glycopeptide tolerance and resistance has complicated treatment and there remains a clinical need for new antibiotics with suitable pharmacokinetic properties with activity against MRSA and other gram-positive pathogens. Infections caused by MRSA and other bacteria usually respond as well to bacteriostatic agents as to bactericidal ones. Nevertheless, there is evidence that rapid bacterial killing has potential clinical advantages over bacteriostatic therapy in certain infections. Daptomycin, the first of the cyclic lipopeptides, shows rapid bactericidal activity against S. aureus, including strains tolerant or resistant to other agents. This review outlines the methods by which bactericidal and bacteriostatic properties are defined and tested, discusses the potential importance of bactericidal therapy in MRSA and other infections and examines the potential role of daptomycin in treatment.

Purpose of review An overview of best evidence-based current practice in the use of prophylactic antibiotics in elective oncological head and neck surgery is presented. Recent findings Patients undergoing head and neck oncological surgery are at great risk of developing complications following surgery. The incidence of wound infection has been reported to be as high as 87%, often with devastating effects. Prophylactic antibiotics have helped to reduce significantly the risk of infection; however, clinicians managing these patients should also have a thorough understanding of the risk factors leading to postoperative infections and should apply the most basic surgical principles at all times, to minimize infection rates. Summary Prophylactic antibiotics usage in clean-contaminated major oncological head and neck surgery is mandatory to reduce the risk of infection. In clean major oncological head and neck surgery their use is also advisable but there is no evidence that in clean surgery for benign disease it offers any advantage. Short antibiotic regimes of four doses per 24 h are as effective as prolonged courses regardless of the complexity of the procedure. A combination of antibiotic agents covering aerobic, anaerobic and Gram-negative bacteria is superior to single agents. High-risk patients should be also given short regimes, as there is no evidence that prolonged courses are of more benefit in these patients. Methicillin-resistant Staphylococcus aureus infection can have devastating consequences for patients undergoing major head and neck surgery. Protocols of prevention and treatment should be in place in all institutions treating patients with head and neck cancer. Close collaboration between surgical, microbiology and infection-control teams is essential.

Summary 1.From September 2003, acute National Health Service trusts in England have been required by the Department of Health to undertake mandatory surveillance of bacteraemias caused by glycopeptide-resistant enterococci (GRE). 2.In total, 4855 enterococcal bacteraemias (including 256 reports of ‘Group D streptococci') were reported through the voluntary reporting system to the Communicable Disease Surveillance Centre (CDSC) in England and Wales in 2002, and 8.9% of the reports that contained information on vancomycin susceptibility indicated that the isolate was resistant to vancomycin. Most hospitals reported fewer than five GRE bacteraemias per year to the CDSC, with only 13 hospitals reporting more than five episodes per year, although there is undoubtedly an element of under-reporting. 3.This Working Group was established to review the methods used to identify and test the susceptibility of enterococci to glycopeptides, and to make recommendations on the reporting of GRE bacteraemias, as there were indications that current methods would not provide a suitable basis for this surveillance. 4.A review of methods was undertaken, including a national questionnaire on methods, approaches to testing and risk factors for GRE bacteraemia. This, together with data from routine laboratory reports and special surveys, revealed the following. –A significant proportion of enterococci are not identified to species level. –There are problems with identification of enterococci. Commercially available kits do not identify some enterococcal species reliably. –Not all laboratories test vancomycin susceptibility of enterococci from bacteraemia. This does not allow a robust assessment of GRE bacteraemia rates because the prevalence of glycopeptide resistance will be underestimated if laboratories test teicoplanin alone or no glycopeptides against enterococci. –There are technical difficulties in detecting non-VanA resistance in enterococci and this will also contribute to under-reporting of glycopeptide resistance. 5.Clinically significant GRE infection is associated with a worse prognosis than infection with susceptible strains, but this factor has not been clearly separated from the possible influence of co-morbidities and antibiotic usage. 6.GRE bacteraemia occurs mainly on specialist units, particularly transplantation, renal, haematological malignancy and intensive care units. Hospitals with such units will inevitably have a higher risk of featuring prominently in surveillance studies. Hence, meaningful denominators for surveillance of GRE bacteraemia are required. Recommendations for GRE bacteraemia surveillance 1.As the mandatory surveillance of glycopeptide-resistant enterococci (GRE) bacteraemias has already started, this report recommends a phased approach to some of the developments, such as using meaningful denominators for the bacteraemia rates. 2.Rates of GRE bacteraemias in trusts should not be used as a performance indicator because the numbers are too small for valid analysis in this way. 3.GRE bacteraemias as a proportion of all clinically significant bacteraemias in the trust should be measured as an indicator of changing trends. 4.Since most GRE are likely to be associated with specialist units, reports of GRE bacteraemia should indicate the specialty in which the patient acquired the infection. 5.Data on clinical activity in the special units where patients acquired GRE bacteraemias should be obtained from trusts with more than five GRE bacteraemias in a year. 6.The significance of blood cultures containing GRE should be assessed clinically. If the bacteraemia that includes GRE is deemed to be clinically significant (according to the case definitions for bacteraemia), whether mono- or polymicrobial, it should be reported as a GRE bacteraemia. 7.Enterococci from blood cultures should be identified to species level to provide data on resistance rates in different species. 8.Biochemical identification should be augmented by antimicrobial susceptibility patterns. The identification is suspect if Enterococcus faecalis appears to be ampicillin resistant and/or quinupristin/dalfopristin susceptible, or if Enterococcus faecium appears to be ampicillin susceptible and/or quinupristin/dalfopristin resistant. The identification and susceptibility of such isolates should be checked and, if confirmed, the isolate should be sent to a reference laboratory for further investigation. 9.Enterococci from blood cultures should be tested for susceptibility to vancomycin. Teicoplanin is not an acceptable alternative to vancomycin for these purposes. 10.Standardized methods should be used for glycopeptide susceptibility testing of enterococci, and the technical requirements of the methods must be adhered to. 11.The situation should be reviewed after a year and the methodology should be amended as appropriate. Recommendations for further research 1.A group should be established to explore methods of data collection for global and individual risk factors for GRE bacteraemia. 2.Further studies on the performance of commercial identification kits with a range of enterococcal species are necessary. 3.Further studies to improve the reliability of susceptibility testing methods for detection of GRE are necessary.

The increase since the mid 1980s in glycopepetide resistant enterococci (GRE) raised concerns about the limited options for antimicrobial therapy, the implications for ever-increasing numbers of immunocompromised hospitalised patients, and fuelled fears, now realised, for the transfer of glycopeptide resistance to more pathogenic bacteria, such as Staphylococcus aureus. These issues underlined the need for guidelines for the emergence and control of GRE in the hospital setting. This Hospital Infection Society (HIS) and Infection Control Nurses Association (ICNA) working party report reviews the literature relating to GRE prevention and control. It provides guidance on microbiological investigation, treatment and management, including antimicrobial prescribing and infection control measures. Evidence identified to support recommendations has been categorized. A risk assessment approach is recommended and areas for research and development identified.

In this study, errors in the English writing of students in the College of World Englishes at Chukyo University, Japan are examined to determine if there is a level of acceptance among teachers. If there is, are these errors becoming part of an accepted, standardized Japanese English? Results show there is little acceptance of third person “-s”, article and plural errors in student writing, but there is a measured degree of the acceptance of errors with regards to sentence combining and sentence fragments, omission of subject, generalizing or obscuring of subjects, and omission of expected superlatives.

Due to increasing methicillin-resistant Staphylococcus aureus (MRSA) infection in cardiothoracic patients at St Thomas' Hospital, an enhanced infection control programme was introduced in September 2000. It was based on UK national guidelines on the control of MRSA and targeted additional identified risk factors for surgical site infection (SSI). It included recognition of the problem by senior staff and their taking responsibility for it; intensive support, education and advice from the infection control team; improved ward and theatre hygiene; pre-admission, admission and weekly MRSA screening; isolation and clearance treatment; nursing care pathways for MRSA colonized patients; and teicoplanin plus gentamicin surgical prophylaxis. The effectiveness of the programme was assessed by retrospective analysis of computerized patient data for the 16 months before and after the introduction of the programme. There was no significant change in the number of operations or the proportion of patients admitted with MRSA, although nine patients were cleared of carriage before admission. However, there were significant falls in the proportion of patients acquiring MRSA on the ward [38/1036 to 14/921, P=0.003, RR 2.4 (95%CI 1.32-4.42)] and in the rate of bloodstream MRSA infections [12/1075 to 2/956, P=0.014, RR 5.34 (95%CI 1.20-23.78)]. Sternal and leg wound infections both halved (from 28/1075 to 13/956 and 16/1075 to 7/956, respectively) but this did not reach statistical significance. These results demonstrate that an enhanced, targeted infection control programme based on the UK national guidelines, SSI prevention guidelines and local risk assessment can reduce the incidence of nosocomial MRSA acquisition and invasive infection in cardiothoracic patients in the face of continuing endemic risk.

Background: Acromegalic patients have slow colonic transit, increased rates of deoxycholic acid formation, and an increased prevalence of cholesterol gall stones, especially during long term octreotide treatment. However, the effects of this prolonged large bowel transit time on the numbers of faecal anaerobes and the activities of the enzyme systems which biotransform conjugated cholic acid into unconjugated deoxycholic acid (cholylglycine hydrolase and 7α-dehydroxylase) are unknown. Methods: Therefore, in 10 non-acromegalic controls, 11 acromegalic patients not treated with octreotide, and 11 acromegalics on long term (8–48 months) octreotide (100–200 μg three times daily subcutaneously), we measured large bowel transit time and, in freshly voided faeces, the activities of the two bile acid metabolising enzymes, and related the results to the proportion of deoxycholic acid in fasting serum. Moreover, in patients with acromegaly, we measured quantitative bacteriology in faeces. Results: Mean large bowel transit time in acromegalics not treated with octreotide (35 (SEM 6.5) hours) was 66% longer than that in non-acromegalic controls (21 (3.1) hours; NS) and became further prolonged during octreotide treatment (48 (6.6) hours; p

Objectives: To investigate the changes in resistance frequencies of common Gram-negative bacteria in a London teaching hospital. Methods: Antimicrobial susceptibilities were analysed for the 6 years 1995-2000. Gentamicin-resistant isolates from 1995 and 2000 were typed by a repetitive element sequence-based PCR (Rep-PCR) method. Results: Resistance rates for all agents and all organisms were higher in isolates from inpatients than in those from outpatients or general practice. For most agents and most species there was a trend for a highly significant linear increase in resistance over the study period, and there was significant cross-resistance between different agents. Increases in resistance were especially marked in Klebsiella, Enterobacter and Acinetobacter spp., organisms that tend to cause outbreaks of hospital cross-infection. For example, the increases in gentamicin resistance in isolates from inpatients was from 2.9% to 23.5% for Klebsiella spp., from 0.3% to 20.8% for Enterobacter spp. and from 10.1% to 42.2% for Acinetobacter spp. There was much less increase in acquired resistance in Escherichia coli and Pseudomonas aeruginosa, organisms that tend to cause endogenous infections, with gentamicin resistance in isolates from inpatients increasing from 0.4% to 3.2% for E. coli and decreasing from 4.6% to 3.6% for P. aeruginosa. Rep-PCR typing showed consid- erable diversity amongst gentamicin-resistant isolates of E. coli and P. aeruginosa, but dominance by a limited number of presumably epidemic types of gentamicin-resistant isolates of the other species. Conclusions: Multiple antibiotic resistance has increased dramatically in some hospital isolates, and appears to be associated with hospital cross-infection.

Several factors influence the in vitro susceptibility of microbes to disinfectants. We evaluated the impact of various suspending media on the susceptibility of meticillin-resistant Staphylococcus aureus (MRSA) to hydrogen peroxide vapour (HPV) decontamination. From a6 log(10) inoculum, relative susceptibility was 10% bovine serum albumin (BSA)TSB3% BSAsaline0.3% BSA = water. MRSA was not recovered after60 min exposure to HPV for all suspensions. These findings indicate that the suspending medium has an effect on the in vitro susceptibility of MRSA to HPV, which may have implications in the case of suboptimal cleaning.

Clinical trials have shown that linezolid (600 mg twice daily in adults) is safe and generally well tolerated for up to 28 days. Drug-related adverse events, which are typically mild to moderate in intensity and of limited duration, include diarrhoea, nausea and headache in adults, and diar- rhoea, loose stools and vomiting in children. Clostridium difficile-related complications with linezolid are uncommon. Linezolid is a weak, reversible monoamine oxidase inhibitor: foods containing high concentrations of tyramine should be avoided, and linezolid should be used with caution in patients taking adrenergic or serotonergic agents or in those with uncontrolled hypertension. In the majority of patients, linezolid has minimal adverse effects on blood chem- istry or haematology. There have been case reports of reversible thrombocytopenia, anaemia and neutropenia associated with linezolid therapy. In Phase III studies, 2.4% of patients treated with linezolid and 1.5% of patients treated with comparator drugs developed reversible thrombo- cytopenia (P = 0.066), but there was no evidence of an increased risk of agranulocytosis, aplastic anaemia or other irreversible blood dyscrasias. Reduced platelet counts were associ- ated with linezolid treatment for ≥2 weeks; complete blood counts should be monitored weekly in patients receiving linezolid for more than 14 days and treatment should be discontinued if there is evidence of myelosuppression.

Since the mid-1980s the number of cases of TB notified within the U.K. has continued to rise although the contribution of HIV to this rise remains unclear. A 12-month prospective cohort study was conducted at chest and HIV clinics in four hospitals in Lambeth, Southwark and Lewisham (LSL), an area of South London, to determine the proportion of patients with culture-proven TB infected with HIV. Secondary aims were to determine the proportion of patients with TB and undiagnosed HIV at first presentation to chest clinics, to determine the proportion of patients presenting with TB as an AIDS defining illness (ADI) and to identify risk factors for co-infection with TB and HIV. In chest clinics, demographic data and left-over blood from patients aged 16 or over with culture-proven TB was collected, anonymised and HIV tested. In HIV clinics, demographic data on patients with TB already known to be HIV seropositive were also obtained. Twenty-one patients (13%, 95% CI—8–19%) of 159 with culture-proven TB were infected with HIV. Four (3%) of 133 patients at first presentation to chest clinics had undiagnosed HIV; two were subsequently diagnosed. Of the 21 patients with TB and HIV, nine (43%) presented with TB as an ADI. Patients with TB and HIV were significantly more likely to be aged between 35 and 55 years compared to HIV seronegative patients [12/21 (57%) vs. 38/138 (28%), P =0.006]. None of the patients from the Indian Subcontinent were HIV seropositive [0/21 vs. 25/138 (18%), P =0.047]. At the present time, universal HIV testing of patients with culture-proven TB in chest clinics within the U.K. is unlikely to significantly reduce the number of patients with undiagnosed HIV.

Objective: A recently proposed guideline from the NCCLS recommends that results only from the first isolate of a species per patient be used in calculation of percentage susceptibilities to antimicrobial agents. Because this is apparently based on the comparison of various calculation methods for results for oxacillin against a fairly small number of isolates of Staphylococcus aureus, we have applied these methods to a wider range of antibiotic/organism combinations. Methods: Antibiotic susceptibility results from our hospital laboratory database were analysed. Rates of antimicrobial susceptibility were calculated using the various criteria proposed by the NCCLS, including exclusion of results from duplicate isolates and surveillance specimens from the calculations. Results and conclusion: Analysis of results for methicillin against S. aureus, gentamicin against Klebsiella spp., vancomycin against enterococci (all in-patient specimens), and amoxicillin and cefuroxime against Escherichia coli (general practice specimens) confirm that, if duplicates and surveillance specimens are excluded, results obtained with the various patient- and episode- based methods for the calculation of percentage susceptibility are very similar. Because of its simplicity and unambiguity, we agree with the suggestion of the NCCLS group that results for the 'first isolate of a given species per patient per analysis period, irrespective of body site, antimicrobial susceptibility profile or other phenotypic characteristics' should be used in the calculation of susceptibility frequencies.

A compact laser-produced plasma X-ray source that radiates 1 nm X-rays with an average power of 24 W in 2π steradians is presented. The X-ray conversion efficiency is 9% of the laser power delivered on target. The 300 W laser power is generated by a compact diode-pumped, solid-state Nd:YAG laser system. The X-ray source was used to demonstrate X-ray lithography of 75 nm lines. The X-ray source is optimized for integration with an X-ray stepper to provide a complete X-ray lithography exposure tool for the manufacture of high-speed GaAs devices.

To investigate the effect of screening specimens and different criteria for exclusion of duplicate isolates when surveillance of antimicrobial resistances is performed.Trends in resistance were analysed for recent isolates of selected organisms from Guy's and St Thomas' Hospitals with the use of various criteria for the exclusion of duplicates, including time since the last isolate and antibiogram pattern, and the effect of excluding screening specimens.There was a significant difference of about 8% in the apparent frequency of methicillin resistance in Staphylococcus aureus in inpatients if the time limit for duplicates was set at 5 rather than 30 days; it was about 10% if a 5 day limit was compared with a 365 day limit. There was also a significant difference, of 6-10%, in apparent resistance frequencies if isolates from screening specimens were excluded. Apparent gentamicin resistance rates in Klebsiella spp. varied between 11% and 28%, and the number of apparent patient isolates of gentamicinresistant organisms varied by up to 35%, depending on the duplicate exclusion criteria chosen. Effects were smaller, though still significant, for vancomycin resistance in Enterococcus spp. There was little effect for amoxicillin or cefuroxime resistance in Escherichia coli isolates from general practitioners, where the proportion of duplicates was small.Improved surveillance of antibiotic resistance is needed. However, care needs to be taken in setting the criteria for classifying isolates as duplicates and in comparing results where these criteria may be different or unknown.

Cementless isoelastic “all-poly” pressfit cups exist with an experience of some decades in clinical application for total hip replacement (THR). There are some good study and register data showing a good clinical outcome and a good long-time survival rate. Besides these good clinical databases, a newer generation of similar implants made of vitamin E-enriched HXLPE was recently introduced into clinical practice. This chapter is to report on the clinical observation of cementless isoelastic pressfit cups for total hip replacement (THR) manufactured with vitamin E-blended HXLPE. From a number of 890 cases (780 patients), a 2-year follow-up is available for 440 cases. All cases demonstrated a good improvement with clinical and functional outcome. Radiological observations detected in a few cases so-called radiolucent lines, but most of them disappear during follow-up. There is no correlation of detected radiolucent lines and migration.

Studies in the 1970s and 1980s suggested that environmental surface contamination had a negligible role in the endemic transmission of healthcare-associated infections. However, recent studies demonstrate that several major nosocomial pathogens are shed by patients and contaminate hospital surfaces at concentrations sufficient for transmission, survive for extended periods, persist despite attempts to disinfect or remove them and can be transferred to the hands of healthcare workers. Evidence is accumulating that contaminated surfaces make an important contribution to the epidemic and endemic transmission of C. difficile, vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, Pseudomonas aeruginosa and norovirus and that improved environmental decontamination contributes to the control of outbreaks. Efforts to improve environmental hygiene should include enhancing the efficacy of cleaning and disinfection and reducing the shedding of pathogens. Further high quality studies are needed to clarify the role of surfaces in nosocomial transmission and determine the effectiveness of different interventions in reducing associated infection rates.

Conventional disinfection methods are limited by reliance on the operator to ensure appropriate selection, formulation, distribution and contact time of the agent. ‘No-touch’ automated room disinfection (NTD) systems remove or reduce reliance on operators and so they have the potential to improve the efficacy of terminal disinfection. The most commonly used systems are hydrogen peroxide vapour (H2O2 vapour), aerosolised hydrogen peroxide (aHP) and ultraviolet (UV) radiation. These systems have important differences in their active agent, delivery mechanism, efficacy, process time and ease of use. The choice of NTD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation and cost constraints.

BACKGROUND—Deoxycholic acid (DCA), implicated in the pathogenesis of gall stones and colorectal cancer, is mainly formed by bacterial deconjugation (cholylglycine hydrolase (CGH)) and 7α-dehydroxylation (7α-dehydroxylase (7α-DH)) of conjugated cholic acid (CA) in the caecum/proximal colon. Despite this, most previous studies of CGH and 7α-DH have been in faeces rather than in caecal contents. In bacteria, CA increases 7α-DH activity by substrate-enzyme induction but little is known about CA concentrations or CA/7α-DH induction in the human colon. AIMS AND METHODS—Therefore, in fresh "faeces", and in caecal aspirates obtained during colonoscopy from 20 patients, we: (i) compared the activities of CGH and 7α-DH, (ii) measured 7α-DH in patients with "low" and "high" percentages of DCA in fasting serum (less than and greater than the median), (iii) studied CA concentrations in the right and left halves of the colon, and examined the relationships between (iv) 7α-DH activity and CA concentration in caecal samples (evidence of substrate-enzyme induction), and (v) 7α-DH and per cent DCA in serum. RESULTS—Although mean CGH activity in the proximal colon (18.3 (SEM 4.40) ×10−2 U/mg protein) was comparable with that in "faeces" (16.0 (4.10) ×10− 2 U/mg protein) , mean 7α-DH in the caecum (8.54 (1.08) ×10-4 U/mg protein) was higher (p

Two aminoglycoside-resistant strains of Klebsiella pneumoniae caused an outbreak on the neonatal unit at St Thomas' Hospital. One, which affected 18 patients, was capsular type K18 and resistant to newer cephalosporins by the production of the extended-spectrum β-lactamase SHV-2; the other, which colonized four patients, was capsular non-typeable and did not produce extended-spectrum β-lactamase. Both strains were probably brought into the unit by carrier patients; the probable carrier of the non-typeable strain was transferred from another hospital but was negative on a single admission screen; the probable carrier of the K18 strain was not screened on admission because he had been born at St Thomas', but his mother had been transferred from another hospital. Despite intensive efforts to control the outbreak by standard methods of hand washing, screening, patient isolation and environmental cleaning, a total of 22 neonates on the unit eventually became colonized or infected. One of three patients with bacteraemia died. A small proportion of samples of expressed breast milk, electronic thermometers and oxygen saturation probes were contaminated by the K18 strain and may have contributed to some of the cross-infection, but this did not explain the extent of the outbreak. The outbreak was controlled only by opening a temporary ward for colonized neonates and another for newly born babies, which allowed the closure and cleaning of the main neonatal unit. Multiply antibiotic resistant klebsiellas may be highly epidemic and cause serious, difficult-to-control outbreaks on neonatal units. All patients, regardless of their admission history, should be screened on admission for carriage of multiply resistant enterobacteria by a sensitive method, and units should have plans for temporary ward closure should outbreaks occur.

The Osmetech Microbial Analyzer (OMA) is an automated headspace analyzer fitted with a novel detector system consisting of an array of polymer sensors, each of which responds to different volatile organic compounds. The system can be used for screening clinical urine specimens for significant bacteriuria by sampling urine headspace and subjecting the output of the multiple-detector response to principal component analysis. The OMA readily distinguished artificially infected urine samples from sterile controls. The OMA was then used to analyze 534 unselected clinical urine specimens, of which 21.5% had significant bacteriuria (containing >10 5 CFU of bacteria/ml). The sensitivity and specificity of the OMA compared with conventional culture were 83.5 and 87.6%, respectively. The OMA is a promising automated system for the rapid routine screening of urine specimens, and further clinical trials are in progress.

Near instantaneous detection of pathogens from clinical material, combined with simultaneous prediction of their antimicrobial resistance profiles, would revolutionize the impact of microbiology on the management of infection. Array-based assays allow a range of characteristics to be rapidly and simultaneously determined. At present these systems have found their primary role as research tools for the monitoring of mRNA expression in the form of DNA microarrays or 'chips'. As fabrication costs reduce and validated targeted arrays are developed, it is inevitable they will be used for more routine applications. Microfluidics offers the exciting possibility of combining purification, amplification and detection in a single disposable device; microarrays are particularly suitable for use within these systems. Arrays will become an important tool for clinical diagnostics.

Over a two-month period, two distinct types of Pseudomonas aeruginosa resistant to ceftazidime and azlocillin were isolated from bronchial specimens of ITU patients who had been previously bronchoscoped. The source of the outbreak was probably a faulty contaminated bronchoscope washer-disinfector which had been purchased a year earlier but not properly maintained. This paper describes the outbreak, the identification and elimination of the source, and the steps taken to prevent recurrence. Several automated, closed washer-disinfectors had been bought by the hospital in response to health and safety concerns about glutaraldehyde disinfection toxicity, but the operation and maintenance of these machines had not been supervised. Several other washer-disinfectors were also found to be faulty. The potential hazards of automated endoscope washer-disinfectors and the importance of controlled professional maintenance, servicing and training is discussed.

Background & Aims: Many patients with cholesterol gallbladder stones (GBS) have a high percentage of deoxycholic acid (DCA) in gallbladder bile (all of which are in the conjugated form), probably as a result of prolonged large bowel transit times (LBTT). However, whether the prolonged LBTT increases DCA formation, solubilization, or absorption (or all 3) is not known. Methods: In 40 subjects (20 with GBS; age range, 24–74 years), we measured LBTT using radiopaque markers, and intestinal luminal pH by radiotelemetry. We also measured quantitative anaerobic bacteriology and the activities of 2 bile acid–metabolizing enzymes in fresh cecal aspirates obtained during clinically indicated unprepared colonoscopy, and related these results to the percentage of DCA in fasting serum measured by gas chromatography–mass spectrometry. Results: Compared with controls, GBS patients had longer LBTT (mean 23.1 ± SEM 2.8 h vs. 36.5 ± 3.3 h; P 9 vs. 5.9 ± 1.5 × 10 9 cfu/mL) and Gram-positive (9.5 ± 3.1 × 10 8 vs. 18.0 ± 4.1 × 10 8 cfu/mL; P −4 U/mg protein) in the cecal aspirates. They also had higher intracolonic pH values ( P P Conclusions: Slow colonic transit (more time), increased Gram-positive anaerobes (more bacteria), and greater 7α-DH activity (more enzyme) favor enhanced DCA formation; transit-induced increases in distal colonic luminal pH favor enhanced DCA solubilization/bioavailability; and increases in LBTT (more time) again favor DCA absorption. GASTROENTEROLOGY 2000;119:806-815

A review of 43 patients with soft-tissue tumours identified from a tumour registry showed a 23% rate of incorrect initial diagnosis by ultrasound imaging. Seven patients, five with malignant tumours, suffered a delay in diagnosis (ranging up to 6 months) as a result. The most common error was to mistake a solid tumour for a haematoma. Caution is recommended in the interpretation of ultrasound of soft-tissue masses, particularly with regard to the erroneous diagnosis of haematoma.

Tea tree oil has recently emerged as an effective topical antimicrobial agent active against a wide range of organisms. Tea tree oil may have a clinical application in both the hospital and community, especially for clearance of methicillin-resistant Staphylococcus aureus (MRSA) carriage or as a hand disinfectant to prevent cross-infection with Gram-positive and Gramnegative epidemic organisms. Our study, based on the time-kill approach, determined the kill rate of tea tree oil against several multidrug-resistant organisms, including MRSA, glycopeptide-resistant enterococci, aminoglycoside-resistant klebsiellae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, and also against sensitive microorganisms. The study was performed with two chemically different tea tree oils. One was a standard oil and the other was Clone 88 extracted from a specially bred tree, which has been selected and bred for increased activity and decreased skin irritation. Our results confirm that the cloned oil had increased antimicrobial activity when compared with the standard oil. Most results indicated that the susceptibility pattern and Gram reaction of the organism did not influence the kill rate. A rapid killing time (less than 60 min) was achieved with both tea tree oils with most isolates, but MRSA was killed more slowly than other organisms.