Molecular technique identifies the pathogen responsible for culture negative infective endocarditis.

A case of culture negative endocarditis complicated by immune complex glomerulonephritis and severe aortic regurgitation necessitated aortic valve replacement. Empirical treatment with penicillin and gentamicin according to UK guidelines was started. The pathogen, Streptococcus sanguis, was later identified by polymerase chain reaction amplification and sequencing of bacterial 16S ribosomal RNA. This molecular technique is likely to be of increasing importance in determining the aetiology of culture negative infective endocarditis, thus providing essential treatment and epidemiological information.

Effectiveness of electrochemically activated water as an irrigant in an infected tooth model.

AIM: To test the effectiveness of electrochemically activated aqueous solutions in the debridement of Enterococcus faecalis biofilms in root canals of extracted teeth. METHODOLOGY: Extracted, human, single-rooted teeth (198) assembled into 11 sets (n = 18) with matching anatomical characteristics were randomly assigned to eight experimental groups. After decoronation, the root canals were prepared to a standard size. Enterococcus faecalis biofilms were grown in the root canals of autoclaved, individually mounted teeth over 48 h. Electrolysed saline collected as anolyte at the anode and catholyte at the cathode were the test agents. The four ultrasonication and four without ultrasonication irrigant groups included: neutral anolyte (NA) (pH 6.5), acidic anolyte (AA) (pH 3.0), catholyte (C) (pH 11.5) and C alternated with neutral anolyte (C/NA). Phosphate-buffered saline (PBS) with and without ultrasonication formed negative and NaOCl (3%) positive control groups. After irrigation, root canal samples were serially diluted, cultured and enumerated. The data were analysed as ratios of residual colony-forming units (CFUs) in PBS versus the test irrigants and using multivariate regression. RESULTS: The NA and NA (ultrasonicated, U), C/NA and AA (U) groups had significantly (alpha = 0.05) less and C (U) and C/NA (U) significantly (alpha = 0.05) more bacteria (CFUs mL(-1)) compared with their respective PBS controls. Ultrasonicated C/NA had significantly (alpha = 0.05) higher CFU counts than the nonultrasonicated solution. Other comparisons between ultrasonic and nonultrasonic groups were not significant. Of the nonultrasonicated groups, C/NA and NA were most effective, whilst of the ultrasonicated groups, AA and NA were most effective. None of these was as effective as 3% NaOCl. CONCLUSIONS: All but two groups (AA and C) were significantly different from their PBS controls. There was a significant difference between the C/NA groups with and without ultrasonication but not between other combinations. NA (U) and AA (U) were the most effective test solutions but NaOCl (3%) gave by far the highest bacterial kills.

Emergence of vancomycin-resistant Enterococcus faecium at a tertiary care hospital in Karachi, Pakistan.

Vancomycin-resistant enterococcus (VRE) has not been reported previously in Pakistan. This is the first report where in vancomycin-resistant Enterococcus faecium was isolated from the clinical specimens of six patients admitted to the intensive care unit (ICU) and neonatal intensive care unit (NICU) of the Aga Khan University Hospital, Karachi. To identify the extent of the outbreak, rectal swabs were obtained from all the patients admitted to the ICU and NICU at that time. A total of 10 strains of vancomycin-resistant Enterococcus faecium were isolated. All the strains showed high-level resistance to both glycopeptides (vancomycin and teicoplanin) with a vancomycin minimum inhibitory concentration greater than 256 mg/L. All isolates had the vanA gene detected by polymerase chain reaction. The contour-clamped homogeneous electric field (CHEF) pattern demonstrated that all but one of the isolates were of a single clone, suggesting that they were derived from common source. Use of vancomycin and prolonged hospitalization were common features in all cases investigated.

The epidemiology of glycopeptide-resistant enterococci on a haematology unit--analysis by pulsed-field gel electrophoresis.

As part of an interventional study to determine glycopeptide-resistant enterococci (GRE) acquisition on a three-ward haematology unit, rectal swabs were taken weekly from 293 patients recruited to the study between June 1995 and December 1996. The GRE isolates obtained from the first positive rectal swab from 120 colonized patients, the isolates from 7 patients with clinical infection and 43 isolates obtained from the ward environment were compared by pulsed-field gel electrophoresis (PFGE). Sixty-three of 120 patients were colonized by one of strains A-H, while 49 were colonized by unique strains. The first 18 weeks were associated with the highest prevalence of GRE by rectal swab, with a single strain A responsible for 52% of acquisitions on ward 2, 22% on ward 3 and 36% on ward 4. Other smaller ward associated clusters were evident. Environmental sampling of ward 2 during this time showed that all but 2 of 30 isolates were indistinguishable from strain A. As the GRE prevalence fell, rectal swab and environmental isolates became more heterogeneous, and strain A disappeared after week 55. GRE prevalence rose again in the final 15 weeks of the study, and a new predominant strain B emerged on ward 2 responsible for 50% of new acquisitions. In the seven patients with clinical infection with GRE, the clinical isolates were compared with the contemporaneous rectal swab isolate, and were found to be the same in only two cases. An analysis of five long-term carriers colonized for a median of 19 weeks (range 11-34) showed colonization with at least two and in one case six distinct strains, raising the question of how many strains may be colonizing a patient at any one time, and suggesting that multiple colonies should be analysed. These data suggest that cross-infection was an important factor in the spread of GRE when the colonization rate was high.

Loss of vision: a manifestation of TURP syndrome. A case report.

We report a case of transient blindness, part of a TURP syndrome, in a 65 year old man undergoing TUR of the prostate under centro-neuron block. Irrigating fluid consisted of 1.5% glycine. As a result, serum levels of glycine increased to 12,470 mols.l-1 (N176-332 mumols.l-1). We attribute this loss of vision to glycine toxicity.

HELLP syndrome: undiagnosed in a case of impending rupture of uterus. A case report.

A 31-year-old women, 34 weeks gestation with intrauterine fetal death, and transverse lie with impending rupture of the uterus due to obstructed labor, was scheduled for urgent cesarean section. On preoperative anesthetic assessment, she was diagnosed to have HELLP syndrome based on clinical findings (subsequently confirmed by laboratory results). She was anesthetized taking the necessary precautions. Her intra and postoperative course is described. The case demonstrates how the anesthetist is often confronted by undiagnosed HELLP syndrome for urgent cesarean section and has limited time for investigations. He should depend on his clinical acumen to diagnose and treat appropriately for a favorable maternal outcome.

Measurement of the deformation of isolated chondrocytes in agarose subjected to cyclic compression.

Mechanically induced cell deformation is one of a number of possible mechanotransduction pathways by which chondrocytes sense and respond to changes in their mechanical environment. The present study describes a system for measuring the deformation of isolated chondrocytes in agarose during both static and cyclic compression. A test rig mounted on the stage of an inverted microscope was used to apply precise levels of compressive strain to individual cell-agarose constructs bathed in culture medium. Images of the cells were recorded using a CCD video camera attached to the microscope. Cell deformation was quantified in terms of a deformation index (X/Y) representing the ratio of cell diameters measured parallel (X) and perpendicular (Y) to the axis of compression. Cyclic compression between 0 and 15% strain, at 0.3 Hz, resulted in cyclic deformation of the cells at the same frequency. However, during the unstrained phase the cells did not fully recover to their initially spherical morphology (X/Y = 1.0). During the strained phase, the level of deformation (X/Y = 0.59) was initially similar to that observed during static 15% strain. However, this level of cell deformation reduced over a 20 min period of cyclic compression (X/Y = 0.72), although during static compression the cell deformation remained constant. This system may be used to examine cellular events under a range of dynamic mechanical stimuli.

46,XY,i(21q) identified by maternal serum screening.

Maternal serum screening for the detection of fetal Down syndrome has become widespread. Prenatal detection of fetal Down syndrome has important implications not only for management of the current pregnancy, but also for recurrence risk counseling for future pregnancies. We report a case of fetal Down syndrome due to an isochromosome 21q detected after maternal serum screening using alpha-fetoprotein and human chorionic gonadotropin indicated an increased risk for fetal Down syndrome in a 19-year-old pregnant woman. This confirms that maternal serum screening can detect fetal Down syndrome due to rare chromosome rearrangements and illustrates the importance of cytogenetic studies for provision of appropriate genetic counseling.

A pointing sign for localization in early pneumonia.

In a study of the first 48 hours of 500 consecutive cases of early pneumonia mostly complicating the influenzal syndrome in Benin City, Nigeria, radiological examination which shows opacities in 12--18 hours confirmed accurate localization in 50 per cent of cases localized by physical examination alone, and in 90 per cent of cases cross-checked by the pointing sign--asking the patient to cough hard and point to the side where pain is clearly felt.