Abstract:
Bacterial keratitis is a common and serious condition that often leads to vision impairment and potential loss of the eye if not treated promptly and adequately. Topical blood products are often used concurrently with topical antibiotics, helping to mitigate corneal \'melt\' from proteases released on the ocular surface. However, blood products are rich in albumin and could affect the efficacy of antibiotics due to drug-protein binding. In this study, serum and plasma samples were harvested from 10 healthy dogs and 10 healthy horses, obtaining fresh and frozen (1 month at -20°C) aliquots for in vitro experiments. Albumin levels were quantified using species-specific ELISA kits. Thirty bacteria (10 Staphylococcus pseudintermedius, 10 Streptococcus canis, 10 Pseudomonas aeruginosa), isolated from canine patients with infectious keratitis, were each tested with blank plates as well as commercial susceptibility plates (Sensititre™ JOEYE2) to assess the minimal inhibitory concentration (MIC) of 17 different antibiotics in the absence (control) or presence of eight test groups: serum or plasma (fresh or frozen) from canines or equines. Albumin concentrations ranged from 13.8-14.6 mg/mL and 25.9-26.5 mg/mL in canine and equine blood products, respectively. A direct antimicrobial effect was observed mostly with equine vs. canine blood products (specifically serum and to a lesser degree plasma), and mostly for Staphylococcus pseudintermedius isolates. MICs generally increased in the presence of blood products (up to 10.8-fold), although MICs also decreased (down to 0.25-fold) for selected antibiotics and ocular pathogens. Median (range) fold changes in MICs were significantly greater (p = 0.004) with the canine blood products [2 (0.67-8.1)] than the equine blood products [2 (0.5-5)]. In practice, clinicians should consider equine over canine blood products (lesser impact on antimicrobial susceptibility), serum over plasma (greater antimicrobial effects), and administering the blood product ≥15 min following the last antibiotic eyedrop to minimize the amount of albumin-antibiotic binding in tear film.
摘要:
细菌性角膜炎是一种常见且严重的疾病,如果不及时和充分治疗,通常会导致视力障碍和潜在的眼睛损失。外用血液制品通常与外用抗生素同时使用,有助于减轻眼表释放的蛋白酶的角膜融化。然而,血液制品含有丰富的白蛋白,由于药物-蛋白结合,可能会影响抗生素的疗效。在这项研究中,从10只健康的狗和10只健康的马收集血清和血浆样本,获得新鲜和冷冻(在-20°C下1个月)的等分试样用于体外实验。使用物种特异性ELISA试剂盒定量白蛋白水平。30个细菌(10个假中间葡萄球菌,10犬链球菌,10铜绿假单胞菌),从患有传染性角膜炎的犬患者中分离出来,分别用空白板和商业药敏板(Sensivitre™JOEYE2)测试,以评估在不存在(对照)或存在八个测试组的情况下17种不同抗生素的最小抑制浓度(MIC):来自犬或马的血清或血浆(新鲜或冷冻)。犬和马血液制品中的白蛋白浓度范围为13.8-14.6mg/mL和25.9-26.5mg/mL,分别。马与马之间主要观察到直接的抗菌作用。犬血液制品(特别是血清和较低程度的血浆),主要是假中间葡萄球菌。在有血液制品的情况下,中等收入国家通常会增加(高达10.8倍),尽管选定的抗生素和眼部病原体的MIC也下降了(降至0.25倍)。犬血液制品[2(0.67-8.1)]的MIC的中位数(范围)倍数变化明显大于(p=0.004)马血液制品[2(0.5-5)]。在实践中,临床医生应该考虑马而不是犬科血液制品(对抗菌药物敏感性的影响较小),血清高于血浆(更大的抗菌作用),并在最后一次抗生素滴眼液后≥15分钟施用血液制品,以最大程度地减少泪膜中白蛋白-抗生素的结合量。