Photoelectron Spectroscopy of Ions: Study of the Auger Decay of the 4d→nf (n=4,5) Resonances in Xe

We have studied, for the first time by electron spectroscopy, the Auger decay of the 4d→nf (n=4,5) resonances in Xe^{5+} ion. By detecting in coincidence the Auger electrons with the resulting Xe^{6+} ions, we unravel the contribution of the different final ionic states to the total cross section measured by ion spectroscopy. A strong intensity of 5s5p satellite lines has been observed, up to 4 times stronger than the 5s^{2} main lines. This unexpected behavior is confirmed by multiconfiguration Dirac-Fock calculations. This technique provides the most stringent test for theoretical models and allows us to disentangle the contribution of ions in the ground and metastable states in the target beam.

New type F lineage-related Tn1546 and a vanA/vanB type vancomycin-resistant Enterococcus faecium isolated from patients in Dammam, Saudi Arabia during 2006-2007.

Knowledge regarding vancomycin-resistant enterococci (VRE) from Middle Eastern countries is scarce. We therefore investigated the antimicrobial resistance profiles and genetic relationships of VRE Enterococcus faecium isolates obtained from patients attending the King Fahad Specialist Hospital, Dammam, during 2006-2007. The predominant VRE comprised 20 vanB, five vanA and one vanA/vanB type isolates, which tended to fall into two genetic clusters that were identifiable phenotypically by their susceptibility to tetracycline. Multi-locus sequence typing of a random selection of isolates showed that they were part of clonal cluster 17, showing the importance of this genotype in nosocomial VRE infections in Saudi Arabia. Further analysis showed that four of the vanA genotype isolates possessed a new type F Tn1546 transposon, associated with IS1216V and IS1251. Finally, E. faecium vanA/B isolates are rarely reported in the clinical setting including in Saudi Arabia.

Interaction of Escherichia coli heat-stable enterotoxin (STa) with its putative receptor on the intestinal tract of newborn kids.

The elaboration of heat stable enterotoxin (STa) is an important step in the pathogenesis of enterotoxigenic Escherichia coli (ETEC), which causes severe diarrhea in newborn animals. In this study, the distribution of the STa-specific receptors on enterocytes and brush border membrane vesicles (BBMVs) prepared from the anterior jejunum, posterior jejunum, ileum and colon of newborn kids was investigated. The density of STa-receptors on enterocytes and BBMVs was higher in the posterior jejunum than that in other segments of the kids' intestines. Additionally, the affinity of the posterior jejunum STa-receptors was higher than the affinity of receptors present on the epithelium of other intestinal segments. Our findings suggest that the posterior jejunum is a major target for STa within the intestinal tract of newborn kids.

High-energy x-ray diffractometer for nondestructive strain depth profile measurement.

We describe a lab-based high-energy x-ray diffraction system and a new approach to nondestructively measuring strain profiles in polycrystalline samples. This technique utilizes the tungsten K(α1) characteristic radiation from a standard industrial x-ray tube. We introduce a simulation model that is used to determine strain values from data collected with this system. Examples of depth profiling are shown for shot peened aluminum and titanium samples. Profiles to 1 mm depth in aluminum and 300 µm depth in titanium with a depth resolution of 20 µm are presented.

In vitro activity of tigecycline against Acinetobacter baumannii isolates from a teaching hospital in Malaysia.

The In vitro susceptibility of clinical and environmental isolates of Acinetobacter baumannii to tigecycline and other antibiotics was determined by disk diffusion method. The E-test was used to determine the minimum inhibitory concentration (MIC). The growth curves of tigecycline treated environmental and clinical strains were established. Fifty-seven percent and 75% of the clinical and environmental isolates were MDR strains, respectively. Ninety-five percent of the clinical isolates were susceptible to tigecycline and 5% showed intermediate resistance with MIC ranging between 0.032 and 3 mg/l. Tigecycline susceptible and intermediate resistance among the environmental isolates were 40% and 60%, respectively, with a significantly lower MIC range of 0.5-4 mg/l. The bacterial growth curves demonstrated the higher ability of the environmental strains to tolerate the antibiotic effects than the clinical strains. The relatively high resistance profile among the environmental isolate suggests an insidious emergence of tigecycline resistance amongst A. baumannii. Strict infection control procedures are imperative to prevent the dissemination of tigecycline-resistant A. baumannii strains in the hospital environment.

Evaluation of the BD GeneOhm MRSA and VanR Assays as a Rapid Screening Tool for Detection of Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci in a Tertiary Hospital in Saudi Arabia.

Objectives. The aim of this study was to evaluate the diagnostic performance of BD GeneOhm VanR Assay, a rapid PCR test that detects the presence of vanA and/or vanB genes and the performance of BDGeneOhm MRSA Assay which detects the staphylococcal cassette chromosomemec (SCCmec cassette) carrying the mecA gene and Staphylococcus aureus specific sequence located within the orfX gene. Methods. 300 duplicate rectal swabs collected consecutively were analyzed for the presence of VRE by culture and BD PCR. 2267 duplicate swabs were collected (728 nasal and 1539 groin swabs) and analyzed for the presence of MRSA by culture method and BD PCR. Results. Compared to culture, the BD GeneOhm VanR Assay showed a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 100%, 91.1%, 23.5%, and 100%, respectively. The BD GeneOhm MRSA Assay revealed sensitivity, specificity, PPV, and NPV of 97.2%, 99.4%, 89.7%, and 99.9%, respectively, for nasal swabs. For groin swabs, it was 100%, 98.7%, 61.5% and 100%, respectively. Conclusion. The BD GeneOhm vanR Assay is a good screening test for rapid exclusion of VRE carriers in hospitals. The BD GeneOhm MRSA Assay represents a reliable screening test. The true strength of the BD GeneOhm Assay for MRSA and VRE is its exceptionally high NPV making the test an ideal tool for rapid exclusion of MRSA and VRE carriers in hospitals. As a consequence, this would dramatically shorten the patient isolation time.

Pulmonary botryomycosis in a patient with down syndrome.

Pulmonary botryomycosis is a rare chronic, pyogranulomatous infection affecting the lung parenchyma. We describe here the clinical and histopathological findings of pulmonary botryomycosis reported for the first time in a Down syndrome female who required prolonged intensive care. This case has other different unique aspects. It is the first case to present with empyema, the second case involving the right lower lobe and the first case managed by decortication.