Decimo Marilù, Silvetti Tiziana, Brasca Milena
Inst. of Sciences of Food Production, National Research Council of Italy, Via Celoria 2, 20133, Milan, Italy.
J Food Sci. 2016 Apr;81(4):M944-51. doi: 10.1111/1750-3841.13250. Epub 2016 Feb 22.
Bacterial resistance to antibiotics is a major global health problem and resistance of Pseudomonadaceae and Enterobacteriaceae is a serious concern. We investigated the prevalence of drug-resistance in a total of 80 psychrotrophic strains from bulk milk belonging to Pseudomonas genus (n. 63) and Enterobacteriaceae group (n. 17). All the strains were tested against 16 antibiotics. Pseudomonas were further investigated for their sensitivity against 12 additional antibiotics. Pseudomonas showed a high susceptibility toward fluoroquinolones, aminoglycosides, and piperacillin and, to a lesser extent, to imipenem, ceftazidime, cefepime. Thirty-five out of 63 Pseudomonas strains were susceptible to meropenem, while among antibiotics for which recommended breakpoints are not yet available, 55% of Pseudomonas strains had no inhibition halo in presence of nitrofurantoin, highlighting a resistance toward this drug. The results obtained in this study indicate a high efficiency of fluoroquinolones, chloramphenicol (94%), and kanamycin (76%) for Enterobacteriaceae while a high prevalence of resistant strains was found to ampicillin (13/17). Serratia marcescens is highly susceptible to fluoroquinolones, chloramphenicol, and kanamycin. Moreover, mupirocin seems to be the new antibiotic with the less efficacy for Enterobacteriaceae, with 41% of strains without halo, pointing out an important resistance. Further knowledge on resistance to known and new antibiotics among Pseudomonas species and Enterobacteriaceae of milk origin was acquired.
细菌对抗生素的耐药性是一个重大的全球健康问题，假单胞菌科和肠杆菌科的耐药性令人严重担忧。我们调查了来自原料奶的总共80株嗜冷菌株的耐药性，这些菌株属于假单胞菌属（63株）和肠杆菌科组（17株）。所有菌株都针对16种抗生素进行了测试。对假单胞菌进一步测试了它们对另外12种抗生素的敏感性。假单胞菌对氟喹诺酮类、氨基糖苷类和哌拉西林表现出高度敏感性，对亚胺培南、头孢他啶、头孢吡肟的敏感性稍低。63株假单胞菌中有35株对美罗培南敏感，而在尚无推荐断点的抗生素中，55%的假单胞菌菌株在有呋喃妥因存在时没有抑菌圈，这突出表明对该药物存在耐药性。本研究获得的结果表明，氟喹诺酮类、氯霉素（94%）和卡那霉素（76%）对肠杆菌科有高效，而氨苄西林耐药菌株的发生率很高（13/17）。粘质沙雷氏菌对氟喹诺酮类、氯霉素和卡那霉素高度敏感。此外，莫匹罗星似乎是对肠杆菌科疗效最差的新型抗生素，41%的菌株没有抑菌圈，这表明存在重要的耐药性。我们获得了关于源自牛奶的假单胞菌属物种和肠杆菌科对已知和新型抗生素耐药性的进一步知识。
