Alonso-Hernando Alicia, Capita Rosa, Prieto Miguel, Alonso-Calleja Carlos
Area de Nutrición y Bromatología, Escuela Superior y Técnica de Ingeniería Agraria, Avenida de Astorga, s/n, 24400, Ponferrada, Spain.
J Microbiol. 2009 Apr;47(2):142-6. doi: 10.1007/s12275-008-0237-5. Epub 2009 May 2.
Information on the potential for acquired reduced susceptibility of bacteria to poultry decontaminants occurring is lacking. Minimal Inhibitory Concentrations (MICs) were established for assessing the initial susceptibility and the adaptative and cross-adaptative responses of four bacterial strains (Listeria monocytogenes serovar l/2a, L. monocytogenes serovar 4b, Salmonella enterica serotype Typhimurium, and S. enterica serotype Enteritidis) to four poultry decontaminants (trisodium phosphate, acidified sodium chlorite -ASC-, citric acid, and peroxyacetic acid). The initial susceptibility was observed to differ among species (all decontaminants) and between Salmonella strains (ASC). These inter- and intra-specific variations highlight (1) the need for strict monitoring of decontaminant concentrations to inactivate all target pathogens of concern, and (2) the importance of selecting adequate test strains in decontamination studies. MICs of ASC (0.17+/-0.02 to 0.21+/-0.02 mg/ml) were higher than the U.S. authorized concentration when applied as a pre-chiller or chiller solution (0.05 to 0.15 mg/ml). Progressively increasing decontaminant concentrations resulted in reduced susceptibility of strains. The highest increase in MIC was 1.88 to 2.71-fold (ASC). All decontaminants were shown to cause cross-adaptation of strains between both related and unrelated compounds, the highest increase in MIC being 1.82-fold (ASC). Our results suggest that the in-use concentrations of ASC could, in certain conditions, be ineffective against Listeria and Salmonella strains. The adaptative and cross-adaptative responses of strains tested to poultry decontaminants are of minor concern. However, the observations being presented here are based on in vitro studies, and further research into practical applications are needed in order to confirm these findings.
目前缺乏关于细菌对家禽去污剂获得性敏感性降低可能性的信息。确定了最低抑菌浓度（MIC），以评估四种细菌菌株（单核细胞增生李斯特菌血清型1/2a、单核细胞增生李斯特菌血清型4b、肠炎沙门氏菌鼠伤寒血清型和肠炎沙门氏菌肠炎血清型）对四种家禽去污剂（磷酸三钠、酸化亚氯酸钠-ASC-、柠檬酸和过氧乙酸）的初始敏感性以及适应性和交叉适应性反应。观察到初始敏感性在不同物种（所有去污剂）之间以及沙门氏菌菌株之间（ASC）存在差异。这些种间和种内差异突出了（1）严格监测去污剂浓度以灭活所有相关目标病原体的必要性，以及（2）在去污研究中选择合适测试菌株的重要性。当用作预冷却器或冷却器溶液时，ASC的MIC（0.17±0.02至0.21±0.02毫克/毫升）高于美国授权浓度（0.05至0.15毫克/毫升）。逐渐增加去污剂浓度导致菌株敏感性降低。MIC的最高增加倍数为1.88至2.71倍（ASC）。所有去污剂均显示会导致菌株在相关和不相关化合物之间产生交叉适应性，MIC的最高增加倍数为1.82倍（ASC）。我们的结果表明，在某些情况下，ASC的使用浓度可能对李斯特菌和沙门氏菌菌株无效。测试菌株对家禽去污剂的适应性和交叉适应性反应不太受关注。然而，此处呈现的观察结果基于体外研究，需要进一步开展实际应用研究以证实这些发现。
