RESUMO
The compositional stability of the complex Gouda cheese starter culture Ur is thought to be influenced by diversity in phage resistance of highly related strains that co-exist together with bacteriophages. To analyze the role of bacteriophages in maintaining culture diversity at the level of genetic lineages, simple blends of Lactococcus lactis strains were made and subsequently propagated for 152 generations in the absence and presence of selected bacteriophages. We first screened 102 single-colony isolates (strains) from the complex cheese starter for resistance to bacteriophages isolated from this starter. The collection of isolates represents all lactococcal genetic lineages present in the culture. Large differences were found in bacteriophage resistance among strains belonging to the same genetic lineage and among strains from different lineages. The blends of strains were designed such that 3 genetic lineages were represented by strains with different levels of phage resistance. The relative abundance of the lineages in blends with phages was not stable throughout propagation, leading to continuous changes in composition up to 152 generations. The individual resistance of strains to phage predation was confirmed as one of the factors influencing starter culture diversity. Furthermore, loss of proteolytic activity of initially proteolytic strains was found. Reconstituted blends with only 4 strains with a variable degree of phage resistance showed complex behavior during prolonged propagation.
Assuntos
Bacteriófagos/fisiologia , Queijo/microbiologia , Microbiologia de Alimentos , Lactococcus lactis/fisiologia , Lactococcus lactis/virologia , Queijo/virologia , Manipulação de Alimentos , Lactococcus lactis/genéticaRESUMO
Identification of work-related allergy, particularly work-related asthma, in a (nationwide) medical surveillance programme among bakery workers requires an effective and efficient strategy. Bakers at high risk of having work-related allergy were indentified by use of a questionnaire-based prediction model for work-related sensitisation. The questionnaire was applied among 5,325 participating bakers. Sequential diagnostic investigations were performed only in those with an elevated risk. Performance of the model was evaluated in 674 randomly selected bakers who participated in the medical surveillance programme and the validation study. Clinical investigations were evaluated in the first 73 bakers referred at high risk. Overall 90% of bakers at risk of having asthma could be identified. Individuals at low risk showed 0.3-3.8% work-related respiratory symptoms, medication use or absenteeism. Predicting flour sensitisation by a simple questionnaire and score chart seems more effective at detecting work-related allergy than serology testing followed by clinical investigation in all immunoglobulin E class II-positive individuals. This prediction based stratification procedure appeared effective in detecting work-related allergy among bakers and can accurately be used for periodic examination, especially in small enterprises where delivery of adequate care is difficult. This approach may contribute to cost reduction.
Assuntos
Asma/imunologia , Farinha , Hipersensibilidade Imediata/imunologia , Doenças Profissionais/diagnóstico , Alérgenos/imunologia , Asma/etiologia , Indústria Alimentícia , Hipersensibilidade Imediata/etiologia , Exposição Ocupacional , Saúde Ocupacional , Risco , Inquéritos e Questionários , TrabalhoRESUMO
Associations have been observed between exposure to isocyanates, consisting mainly of oligomers, and respiratory symptoms and isocyanate specific sensitisation in spray painters. The aim of the present study was to assess associations between isocyanate exposure and more objective respiratory effect measures such as bronchial hyperresponsiveness (BHR), baseline spirometry and exhaled nitric oxide (eNO) in a subset of spray painters. Methacholine challenge and eNO measurements were performed in 229 workers. Questionnaires and blood samples were obtained. Specific immunoglobulin (Ig)E and IgG to hexamethylene di-isocyanate were assessed in serum using various assays. Personal exposure was estimated by combining personal task-based inhalatory exposure measurements and time-activity information. Workers with higher isocyanate exposure were more often hyperresponsive (prevalence ratio comparing the 75th versus 25th percentile of exposure 1.8). In addition, significant exposure-related decreased forced expiratory volume in one second (FEV(1)), FEV(1)/forced vital capacity ratio and flow-volume parameters independent of BHR were found. BHR was more prevalent among sensitised workers. This was statistically significant for only IgG-ImmunoCAP (Phadia, Uppsala, Sweden) positive workers. eNO was not associated with exposure although slightly elevated eNO levels in specific IgG positive subjects were found. The current study provides evidence that exposure to isocyanate oligomers is related to asthma with bronchial hyperresponsiveness as a hallmark, but also shows independent chronic obstructive respiratory effects resulting from isocyanate exposure.
Assuntos
Aerossóis/efeitos adversos , Hiper-Reatividade Brônquica/etiologia , Isocianatos/efeitos adversos , Exposição Ocupacional , Pintura/efeitos adversos , Adulto , Hiper-Reatividade Brônquica/induzido quimicamente , Testes de Provocação Brônquica , Expiração , Feminino , Humanos , Pulmão/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Fenótipo , Espirometria/métodosRESUMO
Asbestosis in the Netherlands is a rare work-related form of pulmonary fibrosis caused by long-term, intensive exposure to asbestos. It can have a great impact on patients' quality of life and life expectancy even 20-30 years after initial exposure. The Dutch Institute of Asbestos Victims (IAS) mediates between the victims and their employers or former employers about payment of compensation. Liability procedures against a previous employer are long and stressful. Since 1 April 2014 it has, therefore, been possible to receive financial aid from the state. The IAS and the Netherlands Asbestosis Panel determine who is eligible for this. In this article we look in detail at the conditions for, and the process of, application for this financial aid. Since the introduction of this arrangement, more than 250 asbestosis victims have applied for aid; so far, 65 applicants have met the required conditions.