Genotypic and phenotypic characterization of a Salmonella Typhimurium strain resistant to pulsed electric fields

Pulsed Electric Fields (PEF) technology is regarded as one of the most interesting alternatives to current food preservation methods, due to its capability to inactivate vegetative microorganisms while leaving the product's organoleptic and nutritional properties mostly unchanged. However, many aspects regarding the mechanisms of bacterial inactivation by PEF are still not fully understood. The aim of this study was to obtain further insight into the mechanisms responsible for the increased resistance to PEF of a Salmonella Typhimurium SL1344 variant (SL1344-RS, Sagarzazu et al., 2013), and to quantify the impact that the acquisition of PEF resistance has on other aspects of S. enterica physiology, such as growth fitness, biofilm formation ability, virulence and antibiotic resistance. WGS, RNAseq and qRT-PCR assays indicated that the increased PEF resistance of the SL1344-RS variant is due to a higher RpoS activity caused by a mutation in the hnr gene. This increased RpoS activity also results in higher resistance to multiple stresses (acidic, osmotic, oxidative, ethanol and UV-C, but not to heat and HHP), decreased growth rate in M9-Gluconate (but not in TSB-YE or LB-DPY), increased ability to adhere to Caco-2 cells (but no significant change in invasiveness) and enhanced antibiotic resistance (to six out of eight agents). This study significantly contributes to the understanding of the mechanisms of the development of stress resistance in Salmonellae and underscores the crucial role played by RpoS in this process. Further studies are needed to determine whether this PEF-resistant variant would represent a higher, equal or lower associated hazard than the parental strain.

Effects of a High-Intensity Exercise Program on Weight Regain and Cardio-metabolic Profile after 3 Years of Bariatric Surgery: A Randomized Trial

Weight regain is one of the most common problems in the long-term after bariatric surgery. It is unknown if high-intensity exercise programs applied in late phases of post-surgical follow-up could counteract this trend. After a 3-year follow-up, 21 patients underwent sleeve gastrectomy were randomized into an exercise group (EG, n = 11), that performed a 5-month supervised exercise program, and a control group (CG, n = 10), that followed the usual care. Body composition, cardiorespiratory fitness, glycaemia and blood cholesterol were evaluated before and after the intervention. Finally, the EG repeated the evaluations 2 months after the end of the exercise program. Both groups reached their maximum weight loss at the first year after surgery and showed significant weight regain by the end of the follow-up. After the exercise program, the EG showed reductions in fat mass (-2.5 ± 2.6  kg, P < 0.05), glycaemia (-13.4 ± 8.7  mg·dL-1, P < 0.01) and blood cholesterol (-24.6 ± 29.1  mg·dL-1, P < 0.05), whereas the CG during the same period showed increases in weight (1.5 ± 1.3  kg, P < 0.05) and fat mass (1.8 ± 0.9, P < 0.01). Two months after the end of the program, EG had increases in weight (1.1 ± 1.2  kg, P < 0.05), fat mass (2.6 ± 2.2  kg, P < 0.01), glycaemia (8.2 ± 11.6  mg·dL-1, P < 0.05) and blood cholesterol (20.0 ± 22.1  mg·dL-1, P < 0.05), when compared with the values after the exercise program. Therefore, in the medium-term after sleeve gastrectomy exercise may contribute to prevent weight regain and to reduce fat mass, glycaemia, and blood cholesterol.

Factors associated with severity in invasive community-acquired Staphylococcus aureus infections in children: a prospective European multicentre study

Staphylococcus aureus is the main pathogen responsible for bone and joint infections worldwide and is also capable of causing pneumonia and other invasive severe diseases. Panton-Valentine leukocidin (PVL) and methicillin-resistant S. aureus (MRSA) have been studied as factors related with severity in these infections. The aims of this study were to describe invasive community-acquired S. aureus (CA-SA) infections and to analyse factors related to severity of disease. Paediatric patients (aged 0-16 years) who had a CA-SA invasive infection were prospectively recruited from 13 centres in 7 European countries. Demographic, clinical and microbiological data were collected. Severe infection was defined as invasive infection leading to death or admission to intensive care due to haemodynamic instability or respiratory failure. A total of 152 children (88 boys) were included. The median age was 7.2 years (interquartile range, 1.3-11.9). Twenty-six (17%) of the 152 patients had a severe infection, including 3 deaths (2%). Prevalence of PVL-positive CA-SA infections was 18.6%, and 7.8% of the isolates were MRSA. The multivariate analysis identified pneumonia (adjusted odds ratio (aOR) 13.39 (95% confidence interval (CI) 4.11-43.56); p 0.008), leukopenia at admission (<3000/mm(3)) (aOR 18.3 (95% CI 1.3-259.9); p 0.03) and PVL-positive infections (aOR 4.69 (95% CI 1.39-15.81); p 0.01) as the only factors independently associated with severe outcome. There were no differences in MRSA prevalence between severe and nonsevere cases (aOR 4.30 (95% CI 0.68- 28.95); p 0.13). Our results show that in European children, PVL is associated with more severe infections, regardless of methicillin resistance.

[Effectiveness of antiretroviral therapy in HIV-1 infected children. A cross-sectional study]

INTRODUCTION

There are few cross-sectional studies describing the current situation of HIV-1-infected children. Such studies would be useful to determine patients' clinical and immunologic and virologic status, currently prescribed therapies and their associated toxicity.

OBJECTIVES

To perform a descriptive analysis of the clinical, immunological and virological status of HIV-1-infected children followed-up in the pediatric unit of a tertiary hospital and describe the current antiretroviral therapies used to treat them.

MATERIAL AND METHODS

A cross-sectional study was performed. Data were collected from all HIV-1-infected children followed-up until January 2002 in a large pediatric referral hospital (Hospital 12 de Octubre in Madrid). Clinical evaluation and laboratory investigations were scheduled to be performed every 3 months. The most recent CD4 and plasma viral loads were evaluated. Viral loads were considered undetectable when there were less than 300 copies/ml at the last evaluation.

RESULTS

Sixty-six HIV-1-infected children who were followed-up to January 2002 were analyzed. All the children acquired the infection through vertical transmission except one, in whom the mode of transmission was unknown. The median age was 111 months (18-216). Twenty children were category C. The median CD4 cell count was 953 cells/mm3 (276-3137), 28 % +/- 8 (12.42). One child was receiving no therapy, four were on combination therapy with two nucleoside reverse transcriptase inhibitors (NRTI) and 61 were receiving highly active anti-retroviral therapy (HAART). Twenty-seven children (44 %) were receiving the first HAART regimen, 23 the second, and 11 had already been switched more than twice. Overall, 37 of the 61 patients receiving HAART had an undetectable plasma viral load.

CONCLUSIONS

Most children in our study had gone through several antiretroviral regimens, although not all children were being treated with HAART. Fifty-six percent of the patients with HAART had an undetectable plasma viral load. However, new complications associated with this therapy have begun to appear.

Isolated cervical lymphadenopathy as unique manifestation of Brucellosis

We report the case of a 42-y-old male with an isolated cervical lymphadenopathy due to Brucella melitensis. The diagnosis was established by isolation of B. melitensis in a lymphatic specimen obtained by fine-needle aspiration and confirmed by serological test results showing high levels of Brucella agglutinins. Mycobacteria-specific cultures were negative. Treatment with streptomycin and doxycycline resulted in complete healing. Exceptionally, and only if the epidemiologic context supports it, brucellosis should be considered in the differential diagnosis of lymphadenopathy.

Multimedia telehomecare system using standard TV set

Nowadays, there are a very large number of patients that need specific health support at home. The deployment of broadband communication networks is making feasible the provision of home care services with a proper quality of service. This paper presents a telehomecare multimedia platform that runs over integrated services digital network and internet protocol using videoconferencing standards H.320 and H.323, and standard TV set for patient interaction. This platform allows online remote monitoring: ECG, heart sound, blood pressure. Usability, affordability, and interoperability were considered for the design and development of its hardware and software components. A first evaluation of technical and usability aspects were carried forward with 52 patients of a private clinic and 10 students in the University. Results show a high rate (mean = 4.33, standard deviation--SD = 1.63 in a five-points Likert scale) in the global perception of users on the quality of images, voice, and feeling of virtual presence.

User satisfaction with home telecare based on broadband communication

Home telecare services based on broadband communication were established in five locations in Europe. Two different types of telecare unit were developed: one based on a PC or set-top box containing a videoconferencing codec and another on off-the-shelf videoconferencing units. The participants in the project were 13 medical staff, 135 patients and 88 people informally caring for the patients. Questionnaires were used to evaluate user satisfaction with eight telecare services. Almost all participants rated the usability of the system as good or excellent. A total of 105 telecare sessions were scored by the medical staff. Overall, the quality of audio and video communication was judged satisfactory. For the patients and carers, the perceived quality of communication was also satisfactory and did not vary significantly between sites. The medical staff were reasonably satisfied with how the service supported them in their work. Except for the item about being able to support patients in a critical situation, medical staff agreed that an improved quality of health services was offered through telecare. All participants agreed that personal information was treated confidentially and that there was little risk in using the telecare services. The medical staff trusted the assessments they could make remotely while using the telecare system. Although the findings cannot be generalized due to the small number of telecare sessions and the relatively short duration of the experiment, the results encourage further research.

Impact of a broadband interactive televisit/teleconsultation service for residential and working environments

The availability of health care attention at the point of need is one of the key benefits of telemedicine. Home environment and working place are the two scenarios selected in this article to evaluate the impact of a televisit and teleconsultation service. 31 users from four different medical and patient groups participated in this study supported by European Commission ATTRACT project. The experiences, carried out in Madrid and Valencia Spanish sites, benefited from interactive broadband access networks to provide cost-effective telecare services. Key areas analyzed encompass systems usability, clinical outcomes, patients quality of care and infoethic issues. Services advantages were verified and compared both from patients and medical staff points of view. Main benefits pointed out refer to displacement reduction, better communication doctor/patient, provision of comfort or friendliness, more precise therapy follow-up and increases in patients sense of well being.