ABSTRACT
Several studies have been conducted in recent years to elucidate the structure, function and significance of AcrB, MarA, SoxS and RamA in Salmonella enterica. In this study, the relative quantification of acrB, soxS, marA and ramA genes expression was evaluated in 14 strains of S. enterica, with or without accompanying mutations in the quinolone resistance-determining regions of the gyrA gene, that were exposed to ciprofloxacin during the exponential growth phase. The presence of ciprofloxacin during the log phase of bacterial growth activated the genes marA, soxS, ramA and acrB in all S. enterica strains analyzed in this study. The highest expression levels for acrB were observed in strains with gyrA mutation, and marA showed the highest expression in the strains without mutation. Considering only the strains with ciprofloxacin minimum inhibitory concentration values < 0.125 [1]g/mL (sensitive to ciprofloxacin), the most expressed gene in the strains both with and without mutations was acrB. In the strains with ciprofloxacin minimum inhibitory concentration values > 0.125 [1]g/mL (low susceptibility), with and without mutations in gyrA, the most expressed gene was marA. In this study, we observed that strains resistant to nalidixic acid may express genes associated with the efflux pump and the expression of the AcrAB-TolC pump genes seems to occur independently of mutations in gyrA.
Subject(s)
Humans , Bacterial Proteins/genetics , Drug Resistance, Bacterial/genetics , Mutation/genetics , Salmonella enterica/drug effects , Salmonella enterica/genetics , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Ciprofloxacin/pharmacology , Gene Expression Regulation, Bacterial , Genes, Bacterial/genetics , Microbial Sensitivity Tests , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , RNA, Bacterial/genetics , Trans-Activators/genetics , Trans-Activators/metabolismABSTRACT
Mutations into codons Aspartate-87 (62 percent) and Serine-83 (38 percent) in QRDR of gyrA were identified in 105 Salmonella strains resistant to nalidixic acid (94 epidemic and 11 of poultry origin). The results show a high incidence of mutations associated to quinolone resistance but suggest association with others mechanisms of resistance.
Subject(s)
Animals , Chick Embryo , Anti-Bacterial Agents/analysis , Base Sequence , Codon/genetics , Drug Resistance, Microbial , Fluoroquinolones/analysis , In Vitro Techniques , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Poultry , Quinolones/analysis , Salmonella/isolation & purification , Methods , MethodsABSTRACT
O objetivo deste trabalho foi avaliar o padrão higiênico-sanitário de alimentos comercializados na Regiãode Londrina cadastrados no Ministério da Saúde, porém, dispensados de registro, conforme a RDC nº.23 da Agência Nacional de Vigilância Sanitária (ANVISA). Os alimentos foram escolhidos de acordo comas sugestões da Vigilância Sanitária de Londrina, PR, que levou em consideração o risco epidemiológico.Os padrões microbiológicos foram avaliados conforme a RDC nº. 12 da ANVISA. Contagens de E. colie S. aureus acima do permitido foram observadas respectivamente em 11 (18,3%) e 13 (21,6%) dos 60alimentos analisados. Os demais resultados microbiológicos estavam dentro do estabelecido pela RDCnº. 12. Ficou clara a necessidade de maior fiscalização do processamento e armazenagem de váriosalimentos analisados, em especial, sorvetes, massas recheadas, pães de queijo, lasanha, doces comcreme e salgados recheados. Esses resultados serão encaminhados às Vigilâncias Regional e Municipalalertando sobre a real potencialidade desses alimentos veicularem doenças e na intenção de abrir umadiscussão sobre a liberação ou não de registro desses alimentos junto ao Ministério da Saúde. Alémdisso, os resultados obtidos confirmam que a análise microbiológica do produto final é um instrumentoessencial de validação e verificação das Boas Práticas de Fabricação (BPF) e da Análise de Perigos ePontos Críticos de Controle (APPCC).
The aim of this study was to analyze the sanitary quality of foods commercialized in Londrina, Paraná that are exempt of Brazilian Health Ministry registration procedures, according to Resolution n°. 23 from the National Sanitary Administration Agency (ANVISA). The food categories analyzed were chosenaccording to ANVISA, Londrina, PR which took the epidemiological risk in account. Microbiologicalstandards were evaluated according to ANVISA Resolution n°. 12. Escherichia coli and coagulase positive Staphylococcus counts were above standards in 11 (18.3%) and 13 (21.6%) of food samples analyzed, respectively. The others microbiological results were in conformity to ANVISA Resolution n°.12. These results indicate inadequate sanitary conditions during food processing especially for ice-cream, stuffed pasta, "pães de queijo", lasanha, cream felled pastries, and "salgado recheado". The results could help the State and Local Sanitary Administration Agencies to evaluate the potentiality of these foods cause food-borne diseases and the adequacy of their liberation from Brazilian Health Ministry registration procedures. The results also show that microbiological analysis of the final product is a valuable validation and verification procedure for the GMP and HACCP system.