Critical points and potential pitfalls of outbreak of IMP-1-producing carbapenem-resistant Pseudomonas aeruginosa among kidney transplant recipients: a case-control study

Background Carbapenem-resistant Pseudomonas aeruginosa (CRPA) infection after kidney transplantation (KT) is associated with high mortality. Methods We analysed an outbreak of infection/colonization with IMP-1-producing CRPA on a KT ward, conducting a case-control study. Cases were identified through routine surveillance culture and real-time polymerase chain reaction (PCR) for carbapenemase performed directly from rectal swab samples. Controls were randomly selected from patients hospitalized on the same ward during the same period, at a ratio of 3:1. Strain clonality was analysed through pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing was performed for additional strain characterization. Results CRPA was identified in 37 patients, in 51.4% through surveillance cultures and in 49.6% through clinical cultures. The median persistence of culture positivity was 42.5 days. Thirteen patients (35.1%) presented a total of 15 infections, of which 7 (46.7%) were in the urinary tract, among those, 30-day mortality rate was 46.2%. PFGE analysis showed that all of the strains shared the same pulsotype. Multilocus sequence typing analysis identified the sequence type as ST446. Risk factors for CRPA acquisition were hospital stay > 10 days, re-transplantation, urological surgical re-intervention after KT, use of carbapenem or ciprofloxacin in the last three months and low median lymphocyte count in the last three months. Conclusions KT recipients remain colonised by CRPA for long periods and could be a source of nosocomial outbreaks. In addition, a high proportion of such patients develop infection. During an outbreak, urine culture should be added to the screening protocol for KT recipients.

Molecular phylogeny of penaeid shrimps inferred from two mitochondrial markers

Penaeid shrimps are an important resource in crustacean fisheries, representing more than the half of the gross production of shrimp worldwide. In the present study, we used a sample of wide-ranging diversity (41 shrimp species) and two mitochondrial markers (758 bp) to clarify the evolutionary relationships among Penaeidae genera. Three different methodologies of tree reconstruction were employed in the study: maximum likelihood, neighbor joining and Bayesian analysis. Our results suggest that the old Penaeus genus is monophyletic and that the inclusion of the Solenocera genus within the Penaeidae family remains uncertain. With respect to Metapenaeopsis monophyly, species of this genus appeared clustered, but with a nonsignificant bootstrap value. These results elucidate some features of the unclear evolution of Penaeidae and may contribute to the taxonomic characterization of this family.

Possible modulatory role of non-activated lymphocytes on insulin secretion

In order to study the probable physiological role of non-activated lymphocytes on islet B-cells, we incubated and perfused rat pancreatic islets in the presence of low (2.8 mM) and high (l6.7 mM) glucose concentrations after pre-exposure for 60 min to rat lymphocytes or to substances secreted by lymphocytes. Insulin secretion and 86Rb+, 45Ca2+ and [3H]-phosphoinositide metabolite fluxes were lower compared to controls when islets were pre-exposed to lymphocytes but were not different when islets were pre-exposed to substances secreted by lymphocytes. These alterations in isotope flux suggest that, when lymphocytes and islets are in contact, closure of potassium channels and a paradoxical effect of glucose load on insulin release occur in the presence of low glucose concentrations. The alterations observed are probably due to a swift and direct action of lymphocyte secretion perhaps induced by a direct contact of islet cells.

Regulatory mechanisms of blood lactate production during exercise in man

During cycloergometric exercise at progressively increasing loads, blood lactate concentration increased about 12-fold. Pyruvate concentration decreased initially(for loads of 50-75 W), increased with loads of 75 to 125 W and then decreased again until the end of exercise. the malate concentration increased abruptly between 50 and 75 W, followed by a slow decline; citrate increased about nine-fold as the exercise load was increased to 125 W and then fell sharply. Thus, the production of lactate during low-intensity exercise seems to occur by the "mass-action effect" caused by enhanced glycolysis, whereas with moderate loads the glycolysis rate is very much reduced and most of the lactate production seems to involve the action of the malate-aspartate shuttle. For high-intensity exercise, both mechanisms appear to participate in lactate production

Factores que justifican el control del tuberculoso no confirmado / Factors justifying the control of non-confirmed patients

Cuando se encuentran imágenes radiológicas con baciloscopía negativa, éstas deben ser estudiadas minuciosamente porque constituyen una información epidemiológica de afección pulmonar pero no de enfermedad tuberculosa. Imágenes precoces y antiguas son denominaciones de tiempo; mínima, moderada y avanzada indican extensión; cavitarias, nodulares y fibrosas se basan en la Anatomía patológica, ayudada con la broncoscopía de fibra óptica. La agravación sintomatológica ó radiológica puede constituir una alerta, pero no un criterio de fracaso. Muy buenos resultados de tratamiento antituberculosos se han dado en paciente a quienes se les aplica sistemáticamente y no cuando se lo hace en forma selectiva, esperando la agravación de los síntomas clínicos, radiológicos ó bacteriológicos, reduciéndose del 74% a un 2% las recaídas en pacientes estudiados durante cinco años de seguimiento