Potential virulence of Klebsiella sp. isolates from enteral diets

We aimed to evaluate the potential virulence of Klebsiellaisolates from enteral diets in hospitals, to support nosocomial infection control measures, especially among critical-care patients. Phenotypic determination of virulence factors, such as capsular expression on the external membrane, production of aerobactin siderophore, synthesis of capsular polysaccharide, hemolytic and phospholipase activity, and resistance to antibiotics, which are used therapeutically, were investigated in strains ofKlebsiella pneumoniae and K. oxytoca. Modular industrialized enteral diets (30 samples) as used in two public hospitals were analyzed, and Klebsiella isolates were obtained from six (20%) of them. The hypermucoviscous phenotype was observed in one of the K. pneumoniae isolates (6.7%). Capsular serotypes K1 to K6 were present, namely K5 and K4. Under the conditions of this study, no aerobactin production, hemolytic activity or lecithinase activity was observed in the isolates. All isolates were resistant to amoxicillin and ampicillin and sensitive to cefetamet, imipenem, chloramphenicol, gentamicin and sulfamethoxazole-trimethoprim. Most K. pneumoniae isolates (6/7, 85.7%) from hospital B presented with a higher frequency of resistance to the antibiotics tested in this study, and multiple resistance to at least four antibiotics (3/8; 37.5%) compared with isolates from Hospital A. The variations observed in the antibiotic resistance profiles allowed us to classify theKlebsiella isolates as eight antibiotypes. No production of broad-spectrum β-lactamases was observed among the isolates. Our data favor the hypothesis that Klebsiella isolates from enteral diets are potential pathogens for nosocomial infections.

Nutrição enteral artesanal, semiartesanal e industrializada em unidades hospitalares do Rio Grande do Sul: inquérito telefônico / Hospital-prepared, semi-industrialized and industrialized enteral nutrition in hospitals in Rio Grande do Sul: telephone survey

Introdução: estimativas apontam frequente utilização de formulações de nutrição enteral (NE) produzidas nas próprias unidades hospitalares (UHs) brasileiras por razões econômicas, culturais e logísticas. Objetivo: caracterizar o tipo de formulação de nutrição enteral utilizado, estabelecendo associações com o cadastramento das UHs para terapia nutricional enteral e com a equipe multidisciplinar de terapia nutricional. Métodos: foi realizado estudo transversal com UHs do Rio Grande do Sul (RS). Participaram do estudo UHs que utilizam terapia nutricional enteral para adultos internados, inseridas no Cadastro Nacional de Estabelecimentos de Saúde do Ministério da Saúde, como hospitais gerais, especializados, unidades mistas, pronto socorro geral, especializado e hospitais dia.Resultados: de um universo de 419 UHs do RS, foram incluídas 375 neste estudo. Considerando as perdas, recusas e a exclusão das UHs que não faziam uso de nutrição enteral, foram obtidos dados de 278 UHs de 220 municípios, por meio de entrevista telefônica com o profissional responsável pela terapia nutricional enteral. Das instituições participantes, 29,5% (82) relataram possuir equipes multidisciplinares de terapia nutricional enteral, sendo que, destas, 74,4% (61) possuíam equipe completa, 61,2% (170) utilizavam sistema aberto de infusão e 65,7% (182) usavam fórmula industrializada. Foi observada associação entre UHs cadastradas com o uso de fórmulas industrializadas, equipe multidisciplinar de terapia nutricional enteral completa, bomba de infusão (qui-quadrado; p < 0,001) e sistema fechado (qui-quadrado; p < 0,002), em contraposição às UHs não cadastradas. Conclusão: UHs cadastradas apresentam maiores conformidades quanto às recomendações do Ministério da Saúde.

Background: estimates indicate an increasing use of enteral formulas prepared in hospital kitchens in Brazil for economic, cultural and logistical reasons. Aim: to characterize the type of enteral nutrition used in hospitals, establishing an association with the hospital’s license for enteral nutrition therapy (ENT) and the multidisciplinary team of nutrition therapy (MTNT). Methods: this cross-sectional study was conducted in hospital units (HUs) located in the State of Rio Grande Sul, Brazil. HUs that used ENT for adult inpatients and were registered in the National Registry of Health Care Institutions of the Brazilian Ministry of Health, such as general and specialized hospitals, mixed units, general and specialized emergency departments, and day hospitals, participated in the study. Results: of a total of 419 HUs selected in the state, 375 were included in the study. Considering loss, refusal and exclusion of HUs that did not use enteral diets, we collected data from 278 HUs of 220 municipalities by telephone interview with the professional responsible for ENT. Of the participating institutions, 29.5% (82) reported having MTNTs, and of these, 74.4% (61) had a full team, 61.2% (170) used an open infusion system, and 65.7% (182) used industrially manufactured formulas. There was an association of registered HUs with use of industrially manufactured formulas, full MTNT, infusion pump (chi-square; p < 0.001), and closed systems (chi-square; p < 0.002), in contrast to non-registered HUs. Conclusion: Registered HUs show higher compliance with the recommendations of the Brazilian Ministry of Health.Conclusion: Further studies should be performed to confirm these findings.

Validation of a predictive model describing growth of Salmonella in enteral feeds / Validação de um modelo preditivo para descrever o crescimento de Salmonella em dietas enterais

The growth of Salmonella enterica subs. enterica sorovar Typhimurium at 25ºC was monitored in industrialized and hospital formulated enteral feeds and the results were used to validate the mathematical model of Salmonella growth presented by the Pathogen Modeling Program (PMP) 7.0 (USDA-USA). The generation time of Salmonella in enteral feeds ranged from 21 to 34.8 min and, the maximum growth rate (µmax) varied from 1.28 to 1.95 h-1, resulting in a population increase from 5 to 6 log10 cycles within 14 to 24 h incubation. Growth was faster in the hospital formulated feed containing vegetables and eggs. The growth kinetic's parameters as lag phase; µmax and maximum population density (MPD) were similar to those predicted by the PMP 7.0, with exception of lag phase in enteral diet at pH 6.3. The results of this study validated the PMP 7.0 model for describe Salmonella growth in enteral feeds and demonstrates the appropriateness of use such model to determine the pathogen behavior in a wide range of storage conditions in this food.

O crescimento de Salmonella enterica subs. enterica sorovar Typhimurium a 25ºC foi determinado em dietas enterais industrializadas e formuladas em hospital e os resultados obtidos foram usados para validar um modelo matemático de crescimento de Salmonella apresentado no Programa de Modelagem de Patógenos (PMP), versão 7,0 (USDA-EUA). O tempo de geração de Salmonella em dietas enterais variou de 21 a 34,8 min e a velocidade específica máxima de crescimento (µmax) foi de 1,28 a 1,95 h-1, resultando em aumento de 5 a 6 ciclos logarítimos em um período de 14 a 24 h de incubação. O crescimento foi mais rápido na dieta formulada em hospital contendo vegetais e ovos. Os parâmetros cinéticos como fase lag, µmax e densidade populacional máxima (MDP) foram similares aqueles previstos no PMP 7.0, com exceção da fase lag em dietas enteral com pH 6,3. Os resultados deste estudo validaram o modelo do PMP 7,0 para descrever o crescimento de Salmonella em dietas enterais e demonstraram a propriedade desse modelo para determinar o comportamento do patógeno em uma variedade de condições nesse tipo de alimento.