Castaño-Arriba Ana, González-Machado Camino, Igrejas Gilberto, Poeta Patrícia, Alonso-Calleja Carlos, Capita Rosa
Institute of Food Science and Technology, University of León, E-24071 León, Spain.
Department of Food Hygiene and Technology, Veterinary Faculty, University of León, E-24071 León, Spain.
Pathogens. 2020 Dec 3;9(12):1021. doi: 10.3390/pathogens9121021.
This study investigated the resistance to antibiotics and the capacity to form a biofilm of 200 isolates of enterococci isolated from raw preparations of beef (51 strains), pork (47), chicken (50), and turkey (52) acquired in north-western Spain. Fifteen antimicrobials of clinical importance were tested by the disc diffusion method. The average number of resistances per strain was 4.48 ± 1.59. If resistant strains were taken together with those showing reduced susceptibility, the total number of resistances per strain was 6.97 ± 2.02. Two isolates (1.0% of strains) were resistant to a single antibiotic, twenty-two isolates (11.0%) presented resistance to two, one strain (0.5%) was resistant to three, and 175 isolates (87.5%) showed a multiple drug-resistant phenotype (MDR; defined as no susceptibility to at least one agent from each of three or more antimicrobial categories). The prevalence of resistance varied between 0.5% (gentamicin) and 100% (kanamycin). All strains produced biofilm on polystyrene microwell plates, determined using crystal violet assay. Isolates were classified as having a weak (51 strains; average optical density at 580 nanometers -OD- = 0.206 ± 0.033), moderate (78 strains; average OD = 0.374 ± 0.068), or strong (71 strains; average OD = 1.167 ± 0.621) ability to produce biofilm ( < 0.05). Isolates from beef preparations produced the most substantial ( < 0.05) biofilms. The results of this study indicate that meat and poultry preparations are major reservoirs of antibiotic-resistant enterococcal strains capable of forming a biofilm. In order for food-borne infections to be prevented, the importance of careful handling of these foodstuffs during preparation, avoiding cross-contamination, and ensuring thorough cooking, is stressed.
本研究调查了从西班牙西北部采购的牛肉（51株）、猪肉（47株）、鸡肉（50株）和火鸡肉（52株）的生制品中分离出的200株肠球菌的抗生素耐药性及形成生物膜的能力。采用纸片扩散法检测了15种具有临床重要性的抗菌药物。每株菌的平均耐药数为4.48±1.59。若将耐药菌株与敏感性降低的菌株合并计算，每株菌的总耐药数为6.97±2.02。有2株菌（占菌株总数的1.0%）对单一抗生素耐药，22株菌（11.0%）对两种抗生素耐药，1株菌（0.5%）对三种抗生素耐药，175株菌（87.5%）呈现多重耐药表型（MDR；定义为对三种或更多抗菌类别中的至少一种药物不敏感）。耐药率在0.5%（庆大霉素）至100%（卡那霉素）之间变化。所有菌株在聚苯乙烯微孔板上均产生生物膜，采用结晶紫测定法进行测定。分离株被分类为具有弱（51株；580纳米处平均光密度 -OD- = 0.206±0.033）、中（78株；平均OD = 0.374±0.068）或强（71株；平均OD = 1.167±0.621）生物膜形成能力（P<0.05）。牛肉制品中的分离株产生的生物膜最显著（P<0.05）。本研究结果表明，肉类和禽类制品是能够形成生物膜的抗生素耐药肠球菌菌株的主要储存库。为预防食源性感染，强调了在制备过程中小心处理这些食品、避免交叉污染以及确保彻底烹饪的重要性。
