[Salmonella gastroenteritis in children]. / Gastrenterite a Salmonella em idade pediátrica.

INTRODUCTION: The gastroenteritis (GE) by Salmonella is an important cause of disease in childhood. In Portugal an average of 456 cases per year are notified, 82% of which before the age of fifteen. AIM OF THE STUDY: Clinical and laboratorial characterization of the pediatric population with GE by Salmonella admitted in a level two hospital. MATERIAL AND METHODS: Retrospective study of patients admitted in the Emergency Room between 2005 and 2009 with Salmonella isolation in coproculture. RESULTS: In 8195 admissions by GE, 218 (2.66%) cases of Salmonella GE were identified. The most frequently isolated serotypes were S. enteritidis (49.1%) and S. typhimurium (29.8%). The studied population was mostly rural (83%) with median of age of 36 months. It was registered a predominance of S. enteritidis (63.6%, p < 0.01) above 36 months and of S. typhimurium under this age (75.3%, p < 0.01). As for the annual distribution, 166 (76%) cases occurred between May and October. It was noticed an association between S. enteritidis and the summer (52.3%, p < 0.01), and between S. typhimurium and the spring (35.4%, p < 0.01). Among the food items potentially involved in the infection, eggs and non-potable water were the most mentioned. A number of 182 (83.5%) children were hospitalized, of which one with septic shock and another with secondary bacteraemia, both with good clinical evolution. CONCLUSION: The authors observed the high prevalence of Salmonella GE within the context of a rural population, as well as a high admission rate. It is to detach the potential association between the serotypes and specific food items, the prevalence in the hottest seasons of the year and its distribution by age groups.

Modified Pseudomonas agar: new differential medium for the detection/enumeration of Pseudomonas aeruginosa in mineral water.

Pseudomonas aeruginosa has been implicated as a foodborne and waterborne pathogen and is now considered a primary infectious agent. In the present study, the survival of P. aeruginosa inoculated in mineral water was evaluated by drop counts on Pseudomonas Agar Base (PAB), PAB with CN supplement X107, PAB with cetrimide, PAB with nalidixic acid, and these media with added FeSO(4). Initial counts, before starvation, were the same in all media tested. Following this period, P. aeruginosa became sensitive to PAB with added cetrimide. The addition of FeSO(4) did not improve the recovery of stressed P. aeruginosa but gave colonies a typical dark brown colour being easily differentiated from other species that can grow at 42 degrees C. The modified Pseudomonas agar medium was also tested with several P. aeruginosa strains, other species of Pseudomonas, and other genera. Only P. aeruginosa strains (pyocyanin positive) produced the typical colonies. Our results demonstrate that Pseudomonas agar with ferrous sulphate, used for the differentiation of P. aeruginosa colonies, and nalidixic acid, used as an inhibitor of Gram-positive bacteria, might be a useful medium for the detection of injured P. aeruginosa in mineral water.