Serratia marcescens in the neonatal intensive care unit: A cluster investigation using molecular methods.

BACKGROUND: Serratia marcescens (S. marcescens) is associated with nosocomial infections with significant morbidity and mortality in the neonatal intensive care units (NICU). We describe the control of a multi-clonal S. marcescens infections outbreak in our tertiary-level NICU and the application of molecular typing using repetitive element palindromic PCR (rep-PCR) and next generation sequencing (NGS) in the investigation. METHODS: Outbreak investigation was performed where clinical, spatial and epidemiologic links were established. Screening of all infants in the NICU and the environment was performed. Rep-PCR and NGS methods were used to identify potential environmental sources of infections and clustering among cases. RESULTS: Eleven cases were detected during the outbreak period: mean gestational age 27 weeks (range: 24-32), predominantly male (82%), mean age of infection 24 days (range: 6-51). Six infants were treated for conjunctivitis and one for bacteraemia. Identification of colonized infant via a point prevalence survey and cohorting of all infected/colonized patients were implemented. We performed environmental swabbing of surfaces, water outlets, chlorhexidine hand wash solutions and hand hygiene hand rubs. Both rep-PCR and NGS classified the 11 case isolates into 5 types. No point source was identified except for a single positive environmental isolate from a sink which was clonally distinct from the cases. CONCLUSION: Identification and cohorting of infected/colonized patient was important in the control of S. marcescens outbreak in the NICU. The utility of rep-PCR was comparable to NGS in providing molecular information to develop S. marcescens outbreak control strategies.

A Hydrothermal-Sedimentary Context for the Origin of Life.

Critical to the origin of life are the ingredients of life, of course, but also the physical and chemical conditions in which prebiotic chemical reactions can take place. These factors place constraints on the types of Hadean environment in which life could have emerged. Many locations, ranging from hydrothermal vents and pumice rafts, through volcanic-hosted splash pools to continental springs and rivers, have been proposed for the emergence of life on Earth, each with respective advantages and certain disadvantages. However, there is another, hitherto unrecognized environment that, on the Hadean Earth (4.5-4.0 Ga), would have been more important than any other in terms of spatial and temporal scale: the sedimentary layer between oceanic crust and seawater. Using as an example sediments from the 3.5-3.33 Ga Barberton Greenstone Belt, South Africa, analogous at least on a local scale to those of the Hadean eon, we document constant permeation of the porous, carbonaceous, and reactive sedimentary layer by hydrothermal fluids emanating from the crust. This partially UV-protected, subaqueous sedimentary environment, characterized by physical and chemical gradients, represented a widespread system of miniature chemical reactors in which the production and complexification of prebiotic molecules could have led to the origin of life. Key Words: Origin of life-Hadean environment-Mineral surface reactions-Hydrothermal fluids-Archean volcanic sediments. Astrobiology 18, 259-293.

A Case Report: Organs From a Donor With Highly Virulent Zoonotic Outbreak Strain of Streptococcus agalactiae Serotype III, Multilocus Sequence Type 283 Infective Endocarditis Did Not Result in Transmission With Adequate Prophylactic Antibiotic Cover.

In 2015, an outbreak involving a highly virulent zoonotic outbreak strain of Streptococcus agalactiae serotype III, multilocus sequence type 283 occurred in Singapore with increased neurologic complications, septic arthritis, and spinal infections in healthier patients. We report a case of a successful dual kidney transplant from a deceased donor with infective endocarditis and disseminated infection with the same strain of S agalactiae and we review the current literature.

Glutamate and GABA in lateral hypothalamic mechanisms controlling food intake.

By the 1990s a convergence of evidence had accumulated to suggest that neurons within the lateral hypothalamus (LH) play important roles in the stimulation of feeding behavior. However, there was little direct evidence demonstrating that neurotransmitters in the LH could, like electrical stimulation, elicit feeding in satiated animals. The present paper is a brief review in honor of Bartley Hoebel's scientific contributions, emphasizing the evidence from my lab that the excitatory neurotransmitter glutamate and the inhibitory neurotransmitter gamma aminobutyric acid (GABA) in the LH mediate feeding stimulation and feeding inhibition respectively. Specifically, we summarize evidence that LH injection of glutamate, or agonists of its N-methyl-D-aspartate (NMDA) and non-NMDA receptors, elicits feeding in satiated rats, that NMDA receptor antagonists block the eating elicited by NMDA and, more importantly, that NMDA blockade suppresses natural feeding and can reduce body weight. Conversely, GABA(A) agonists injected into the LH suppress feeding and can also reduce body weight, while GABA(A) receptor antagonists actually elicit eating when injected into the LH of satiated rats. It is suggested that natural feeding may reflect the moment-to-moment balance in the activity of glutamate and GABA within the LH.

Impact of patterns of proteinuria on renal allograft function and survival: a prospective cohort study.

BACKGROUND: Proteinuria is an important complication in renal transplant recipients. The aim of this prospective study was to evaluate the long-term impact of transplant proteinuria patterns on allograft function and survival. METHODS: We analyzed urinary protein of a cohort of 83 renal transplants with proteinuria ≥0.5 g/d by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and radial immunogel diffusion assay. After initial stratification and analysis, the cohort was followed up for 16 yr. The graft outcome and survival were analyzed using Cox regression model to determine their association with different patterns of initial transplant proteinuria. RESULTS: Group with predominantly glomerular (middle- and high-molecular-weight with or without low-molecular-weight) proteinuria (61%) had higher serum creatinine (p < 0.001) than the group with predominantly tubular (low-molecular-weight) proteinuria (39%). The incidences of chronic graft dysfunction and graft loss had increased in the glomerular proteinuria group (p < 0.001, hazard ratio 3.6, 95% confidence interval 1.7-7.5 and p < 0.001, hazard ratio 4.9, 95% confidence interval 1.9-12.1, respectively). Patient death did not differ (p = 0.434, hazard ratio 1.5, 95% confidence interval 0.5-4.5). CONCLUSION: Proteinuria in renal transplants can be differentiated into glomerular and tubular types based on molecular weight. Glomerular proteinuria is associated with significant increase in graft dysfunction and graft loss.

Binding assays of inhibitors towards selected V-ATPase domains.

The macrolide antibiotic bafilomycin and the related synthetic compound SB 242784 are potent inhibitors of the vacuolar H+ -ATPases (V-ATPase). It is currently believed that the site of action of these inhibitors is located on the membrane bound c-subunits of V-ATPases. To address the identification of the critical inhibitors binding domain, their specific binding to a synthetic peptide corresponding to the putative 4th transmembrane segment of the c-subunit was investigated using fluorescence resonance energy transfer (FRET), and for this purpose a specific formalism was derived. Another peptide of the corresponding domain of the c' isoform, was checked for binding of bafilomycin, since it is not clear if V-ATPase inhibition can also be achieved by interaction of the inhibitor with the c'-subunit. It was concluded that bafilomycin binds to the selected peptides, whereas SB 242784 was unable to interact, and in addition for bafilomycin, its interaction with the peptides either corresponding to the c- or the c'-subunit isoforms is identical. Since the observed interactions are however much weaker as compared to the very efficient binding of both bafilomycin and SB 242784 to the whole protein, it can be concluded that assembly of all V-ATPase transmembrane segments is required for an efficient interaction.

Interaction of the indole class of vacuolar H(+)-ATPase inhibitors with lipid bilayers.

The selective inhibitor of osteoclastic V-ATPase (2Z,4E)-5-(5,6-dichloro-2-indolyl)-2-methoxy-N-(1,2,2,6,6-pentamethylpiperidin-4-yl)-2,4-pentadienamide (SB 242784), member of the indole class of V-ATPase inhibitors, is expected to target the membrane-bound domain of the enzyme. A structural study of the interaction of this inhibitor with the lipidic environment is an essential step in the understanding of the mechanism of inhibition. In this work, a comprehensive study of the relevant features of this interaction was performed. Inhibitor partition coefficients to lipid vesicles as well as its transverse location, orientation (order parameters), and dynamics while bound to bilayers were determined through photophysical techniques, taking advantage of the intrinsic fluorescence of the molecule. To better evaluate the functionally relevant features of SB 242784, a second inhibitor, INH-1, from the same class and having a reduced activity was also examined. It is shown that regarding membrane interaction their properties remain very similar for both molecules, suggesting that the differences in inhibition efficiencies are solely a consequence of the molecular recognition processes within the inhibition site in the V-ATPase.

Spectrum of severe infections in an Asian renal transplant population.

UNLABELLED: Infections in renal transplant recipients (RTX) account for 26% of hospitalization days annually and 40% of overall mortalities. A retrospective study of infections requiring hospitalization occurring among 725 Asian RTX in 2002 was performed. RESULTS: Serious infections requiring at least one hospitalization occurred in 9.2% of RTX (n = 67). Multiple pathogens affected 28.4% of patients, resulting in 118 infectious episodes during 93 hospitalizations. Mean age of affected patients was 48 years and female to male ratio was 2:1. Forty-one (61.2%) had impaired renal function (serum creatinine >141 mumol/L). Mean duration of hospitalization per patient was 17 days and the in-patient mortality rate was 17.9% eighty-one (87%) hospitalizations were for late infections (>6 months posttransplant). Cyclosporine (CsA) with prednisolone with or without azathioprine was the immunosuppressant in 62.7% (n = 42) of RTX but proportionally, infections were more frequent among RTX on other more potent immunosuppressants (n = 21; 7.4% CsA-based vs. 19.3%, potent, P < .05). Bacterial, viral, fungal, and Pneumocystis carinii infections comprised 64.4%, 20.3%, 5.9%, and 4.2% respectively. Urinary tract infection, pneumonia, and bacterial septicemia (35.52%, 31.6%, and 11.8%, respectively) were the major presentations. E. coli, cytomegalovirus (CMV), and Candida were the most common pathogens. Notably, 13 out of 18 (72.2%) viral CMV infections were co- infections, occurring together with bacterial infections. CONCLUSIONS: Late infections with the use of potent immunosuppressives and concurrent CMV reactivation are a major cause of morbidity. Longer antibacterial prophylaxis and closer monitoring for CMV infections may help reduce morbidity.

Post firing visualisation of fingerprint on spent cartridge cases.

A considerable range of techniques is available to visualise latent fingerprints on smooth surfaces. Published methods and those developed or modified in the authors' laboratory have been evaluated for spent cartridge cases. The most suitable were found to be vacuum cyanoacrylate (with fluorescent staining) and selenious acid treatments. Both were used to investigate the post firing recovery of finger-marks on spent cartridge cases from the ammunition and weapon systems encountered in terrorist casework in Northern Ireland. Only certain revolvers and the SLR rifle yielded identifiable ridge detail. These results are borne out by casework experience.

The detection of aerosol propellants in body fluids and tissue by gas chromatography-mass spectrometry.

The increased incidence of aerosol abuse in recent years has led to the development of a method for the detection of halogenated hydrocarbons in body fluids and tissue compatible with other routine methods. The use of the method in two background studies and a case investigation is described.