Multilocus sequence typing for characterization of methicillin-resistant and methicillin-susceptible clones of Staphylococcus aureus

A multilocus sequence typing (MLST) scheme has been developed for Staphylococcus aureus. The sequences of internal fragments of seven housekeeping genes were obtained for 155 S. aureus isolates from patients with community-acquired and hospital-acquired invasive disease in the Oxford, United Kingdom, area. Fifty-three different allelic profiles were identified, and 17 of these were represented by at least two isolates. The MLST scheme was highly discriminatory and was validated by showing that pairs of isolates with the same allelic profile produced very similar SmaI restriction fragment patterns by pulsed-field gel electrophoresis. All 22 isolates with the most prevalent allelic profile were methicillin-resistant S. aureus (MRSA) isolates and had allelic profiles identical to that of a reference strain of the epidemic MRSA clone 16 (EMRSA-16). Four MRSA isolates that were identical in allelic profile to the other major epidemic MRSA clone prevalent in British hospitals (clone EMRSA-15) were also identified. The majority of isolates (81%) were methicillin-susceptible S. aureus (MSSA) isolates, and seven MSSA clones included five or more isolates. Three of the MSSA clones included at least five isolates from patients with community-acquired invasive disease and may represent virulent clones with an increased ability to cause disease in otherwise healthy individuals. The most prevalent MSSA clone (17 isolates) was very closely related to EMRSA-16, and the success of the latter clone at causing disease in hospitals may be due to its emergence from a virulent MSSA clone that was already a major cause of invasive disease in both the community and hospital settings. MLST provides an unambiguous method for assigning MRSA and MSSA isolates to known clones or assigning them as novel clones via the Internet.

Nasal carriage in Vietnamese children of Streptococcus pneumoniae resistant to multiple antimicrobial agents

Resistance to antimicrobial agents in Streptococcus pneumoniae is increasing rapidly in many Asian countries. There is little recent information concerning resistance levels in Vietnam. A prospective study of pneumococcal carriage in 911 urban and rural Vietnamese children, of whom 44% were nasal carriers, was performed. Carriage was more common in children <5 years old than in those >/=5 years old (192 of 389 [49.4%] versus 212 of 522 [40.6%]; P, 0.01). A total of 136 of 399 isolates (34%) had intermediate susceptibility to penicillin (MIC, 0.1 to 1 mg/liter), and 76 of 399 isolates (19%) showed resistance (MIC, >1.0 mg/liter). A total of 54 of 399 isolates (13%) had intermediate susceptibility to ceftriaxone, and 3 of 399 isolates (1%) were resistant. Penicillin resistance was 21.7 (95% confidence interval, 7.0 to 67.6) times more common in urban than in rural children (35 versus 2%; P, <0.001). More than 40% of isolates from urban children were also resistant to erythromycin, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline. Penicillin resistance was independently associated with an urban location when the age of the child was controlled for. Multidrug resistance (resistance to three or more antimicrobial agent groups) was present in 32% of isolates overall but in 39% of isolates with intermediate susceptibility to penicillin and 86% of isolates with penicillin resistance. The predominant serotypes of the S. pneumoniae isolates were 19, 23, 14, 6, and 18. Almost half of the penicillin-resistant isolates serotyped were serotype 23, and these isolates were often multidrug resistant. This study suggests that resistance to penicillin and other antimicrobial agents is common in carriage isolates of S. pneumoniae from children in Vietnam.

Synchronous bilateral carcinoma of the breasts occurring in a young woman with a history of Langerhans' cell histiocytosis in infancy

We report the case history of a 28-year-old woman who developed synchronous bilateral carcinoma of the breasts, having been diagnosed with multisystem Langerhans' cell histiocytosis in infancy. She had been treated with vinblastine and corticosteroids for 3 years and made a full recovery without late sequelae. We review the association of Langerhans' cell histiocytosis and its treatment with subsequent malignancy, with particular reference to carcinoma of the breast, and discuss the possible causes.

The 1.8 A crystal structure and active-site architecture of beta-ketoacyl-acyl carrier protein synthase III (FabH) from escherichia coli

BACKGROUND

beta-Ketoacyl-acyl carrier protein synthase III (FabH) initiates elongation in type II fatty acid synthase systems found in bacteria and plants. FabH is a ubiquitous component of the type II system and is positioned ideally in the pathway to control the production of fatty acids. The elucidation of the structure of FabH is important for the understanding of its regulation by feedback inhibition and its interaction with drugs. Although the structures of two related condensing enzymes are known, the roles of the active-site residues have not been experimentally tested.

RESULTS

The 1.8 A crystal structure of FabH was determined using a 12-site selenium multiwavelength anomalous dispersion experiment. The active site (Cys112, His244 and Asn274) is formed by the convergence of two alpha helices and is accessed via a narrow hydrophobic tunnel. Hydrogen-bonding networks that include two tightly bound water molecules fix the positions of His244 and Asn274, which are critical for the decarboxylation and condensation reactions. Surprisingly, the His244-->Ala mutation does not affect the transacylation reaction suggesting that His244 has only a minor influence on the nucleophilicity of Cys112.

CONCLUSIONS

The histidine and asparagine active-site residues are both required for the decarboxylation step in the condensation reaction. The nucleophilicity of the active-site cysteine is enhanced by the alpha-helix dipole effect, and an oxyanion hole promotes the formation of the tetrahedral transition state.

'Sausage toe': a reliable sign of underlying osteomyelitis

AIMS

To follow-up patients with a 'sausage' deformity of the toe associated with local neuropathic ulceration to confirm the diagnosis of underlying osteomyelitis. This was based on our observation that some diabetic patients with suspected pedal osteomyelitis with a local neuropathic ulcer have a 'sausage' deformity of a toe.

METHODS

Over a period of 2 years, 14 patients with foot ulcers, who were observed to have the 'sausage' deformity of a toe in the diabetic foot clinic were followed up and investigated.

RESULTS

Underlying osteomyelitis was confirmed in six on the very first X-ray examination. A further seven had osteomyelitis diagnosed on bone scanning. Both the X-ray and the bone scan were equivocal in one patient, whose ulcer only healed after an 8-week course of antibiotics. Antibiotic therapy was successful in 11 patients and three patients required amputation of the affected toe. Following successful treatment, there was full resolution of the 'sausage toe' in the majority.

CONCLUSIONS

The appearance of a 'sausage toe' should alert the physician of the possibility of underlying osteomyelitis in diabetic foot, so that prompt treatment can be commenced with antibiotics.

Quality of diagnostic services for cancer: a comparison of open access and conventional outpatient clinics

OBJECTIVE AND STUDY DESIGN

To assess quality of a quick and early diagnosis route (QED) by determining effectiveness and cost-effectiveness of five clinics compared with three conventional outpatient clinics. Prospective economic evaluation. Six-month cohort of all referrals (November 1996-April 1997).

SUBJECTS

All referrals for suspected cancers of: upper gastro-intestinal tract; urinary tract, prostate and testis; skin.

EFFECTIVENESS

Median days saved between GP referral and date of: diagnostic appointment; consultant decision; intervention.

RESULTS

GP referral to diagnostic appointment: QED was effective (median days) for all clinics. Diagnostic appointment to consultant decision: QED was effective for testicular and haematuria clinics. Consultant decision to intervention: QED was effective for haematuria, testicular and melanoma clinics.

COST-EFFECTIVENESS

Extra (incremental) NHS cost per patient diagnosed.

RESULTS

Less than 5 Pounds per day saved between GP referral and diagnostic appointment for: endoscopy; haematuria; prostate; testicular; melanoma. Less than 3 Pounds per day saved between GP referral and consultant decision for: testicular; haematuria. Less than 3 Pounds per day saved between GP referral and intervention for: endoscopy; haematuria; testicular; melanoma.

CONCLUSION

A "quick and early" diagnostic route provides a higher quality service through improved effectiveness and cost-effectiveness compared to conventional outpatients.

Survey of British Columbia cardiologists' and emergency physicians' practice of using nonstandard ECG leads (V4R to V6R and V7 to V9) in the diagnosis and treatment of acute myocardial infarction

BACKGROUND

There is evidence that the addition of nonstandard electrocardiographic (ECG) leads results in significant increases in sensitivity for the diagnosis of acute myocardial infarction compared with the standard 12-lead ECG.

OBJECTIVE

To examine how cardiologists and emergency physicians in British Columbia use nonstandard ECG leads (V4R to V6R and V7 to V9) in the diagnosis and treatment of acute myocardial infarction.

DESIGN

A list of fax numbers of all cardiologists and emergency physicians in British Columbia was obtained and questionnaires were then transmitted.

MAIN RESULTS

More than 75% of cardiologists and emergency physicians correctly identified the diagnostic criteria for acute right ventricular and posterior myocardial infarction. More than 70% of surveyed physicians reported that they would use the 18-lead ECG regularly if they could gain an increased sensitivity for the diagnosis of acute myocardial infarction. However, fewer than 20% of all surveyed physicians reported regular use of the 18-lead ECG. Furthermore, the survey determined that the majority of physicians would alter their choice of thrombolytic if they could diagnose right ventricular infarction complicating an inferior infarction. Finally, most physicians reported that they would treat an isolated posterior wall myocardial infarction with a thrombolytic.

CONCLUSIONS

This study suggests most cardiologists and emergency physicians in British Columbia are aware of 18-lead ECG diagnostic criteria for acute right ventricular and posterior wall myocardial infarction. Furthermore, these physicians would be willing to use this tool if it were to increase diagnostic sensitivity for acute myocardial infarction. Despite these findings, only the minority of surveyed physicians use this tool regularly.

Teaching in practice

This article describes an action research project designed to develop a teaching programme which would enable students to bridge the theory-practice gap they experienced while on placement in a gynaecology unit.

Skills competency in nurse education: nurse managers' perceptions of diploma level preparation

This paper reports on part of a national study conducted between 1994 and 1996, the overall aim of which was to examine the 'fitness for purpose' of the Project 2000 nursing education reforms. The study used multiple methods of data collection, including an individual and group interview study of nurse managers (n = 132) and a national survey of Project 2000 diplomates and traditionally prepared registered nurses (n = 5417). Findings in relation to the managers' expectations and experiences of diplomates are presented. This includes views on the level of skills achievement and skills acquisition of diploma level education. The qualities of the diplomates are discussed and this includes those areas where the skills of the diplomates are felt to achieve what is required of the role. Also included is an exploration of those skills which the managers felt fell short of expectations. Managers raised the long-standing concerns of clinical skills and competencies and discussed these in relation to the changing health care environment and the relative roles of other health care workers. The conclusions highlight the need to identify what could be seen as the 'core skills' required of a registered nurse and the need to explore the environment in which the diplomate takes up first appointment.

Is normal pregnancy atherogenic?

Serum cholesterol, triacylglycerols and low-density lipoprotein (LDL) subfractions were determined in 120 primagravid women during normal gestation (40 in each trimester) and in 20 non-pregnant age-matched controls. LDL subfractions were determined by PAGE, and an LDL score was calculated. The higher the score, the smaller the subfractions. The objective of the study was to determine the effects of the hyperlipidaemia, high oestrogen concentrations and insulin resistance known to exist in normal pregnancy on LDL subfraction formation. Pregnant women had an increased mean serum cholesterol concentration [5.78 (S.D. 1.09) mmol/l] in the first trimester compared with the non-pregnant controls [5.11 (0.77) mmol/l; P<0.01]. The serum cholesterol concentration increased progressively throughout gestation to a mean of 8.14 (1.39) mmol/l in the third trimester (P<0.001 compared with the second trimester). Triacylglycerol concentrations in the first trimester were similar to those of controls, and there was a non-significant increase by the second trimester to 1.32 (0.44) mmol/l. However, by the third trimester the mean triacylglycerol concentration had doubled [2.58 (0.98) mmol/l; P<0.001 compared with the first and second trimester]. During gestation the LDL score increased dramatically, from 1.17 (0.39) during the first trimester to 2.01 (0.37) in the second trimester (P<0.001) to 2.73 (0.48) in the third trimester (P<0.001 compared with the second trimester). Thus an atherogenic lipid profile develops during normal gestation. The significance of these changes remains unclear, but thay may have important implications for mother and foetus.

[Meningeal hemangiopericytoma with liver metastasis]

Hemangiopericytomas are mesenchymal tumors and account for about 1% of all CNS tumors. Aggressive growth, tendency to local recurrence and relatively frequent metastases are the clinical features of these tumors. Histological characteristics are marked cellularity, vascularity and a dense net of reticular fibers. This case presents a patient with a local recurrence of a right temporal, atypical meningioma that had been operated on and irradiated elsewhere. After embolization large parts of the tumor were removed palliatively. Histological aspects of the resected tumor were consistent with a diagnosis of an atypical meningioma. Not until hepatic metastases from this tumor were found was the diagnosis re-examined and corrected to a malignant meningeal hemangiopericytoma. Surgical resection of primary tumor with frequent controls and, if needed, postoperative radiation therapy is the treatment of choice. Furthermore metastasizing atypical meningiomas should be examined critically to determine if a hemangiopericytoma is present.

Measuring outcome in community-based rehabilitation services for people who have suffered traumatic brain injury: the Community Outcome Scale

OBJECTIVE

To develop a way of measuring long-term outcomes after traumatic brain injury (TBI) that takes account of individual circumstances.

DESIGN

Reports by head-injured people and their families about problems and coping strategies were elicited via semi-structured interviews. Specially designed computer software was used to record problems and strengths and to measure their impact for the individual on four handicap dimensions.

SETTING

Interviews took place in the respondents' homes.

SUBJECTS

Between 1992 and 1997 the services at 10 rehabilitation centres in England were evaluated. Subjects were men and women aged between 16 and 65 who had suffered TBI and who had been referred for treatment to one of the centres under study.

INTERVENTIONS

Head-injured people and their families were interviewed three months, 18 months and in some cases 36 months after recruitment.

MAIN OUTCOME MEASURES

The Hospital Anxiety and Depression Scale (HAD) and the Functional Independence/Assessment Measure (FIM/FAM) were used to validate relevant dimensions of the new scale.

RESULTS

A measure of long-term outcome was developed and called the Community Outcome Scale. Relevant dimensions of the scale showed significant correlation with the HAD and with items of the FIM/FAM.

CONCLUSION

The scale captures information which no other instrument does, and merits further validation.

A site for CD4 binding in the beta 1 domain of the MHC class II protein HLA-DR1

Using a lymphocyte binding assay, we have previously demonstrated that the CD4 protein can mediate cell adhesion by direct interaction with MHC class II molecules. In this report, we have used this assay to test whether synthetic peptides, corresponding to DR beta sequences, could inhibit CD4-class II adhesion. A peptide derived from sequences within the beta1 domain (DR beta 41-55), as well as two peptides derived from sequences within the beta 2 domain (DR beta 121-135 and DR beta 141-155), were shown to inhibit CD4-class II adhesion. Inasmuch as a site for CD4 binding in the beta 2 domain had been previously documented, these studies were designed to investigate the role of the beta 1 domain as an additional site of interaction with CD4. Sixteen site-specific mutations were engineered within the beta1 domain of DR beta 1*0101. Several mutations were shown to disrupt CD4-dependent T cell activation. Based on these results, we propose a model for the molecular interaction of CD4 with MHC class II proteins in which both the beta 1 and beta 2 domains of class II interact with the two amino-terminal Ig-like domains of CD4.