Lection Jennine, Van Syoc Emily, Miles Asha, Hamilton Julia, Martinez Marcela, Bas Santiago, Silverman Justin, Barragan Adrian, Ganda Erika
Intergraduate Degree Program in Integrative and Biomedical Physiology, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, United States.
Department of Animal Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, PA, United States.
Front Vet Sci. 2024 Dec 16;11:1478288. doi: 10.3389/fvets.2024.1478288. eCollection 2024.
Clinical metritis (CM) has significant costs to dairy producers. Current treatment strategy involves systemic antibiotics; however, there is increasing concern about judicious antibiotic use. The study objective was to evaluate the effects of a non-antibiotic treatment vs. systemic antibiotic therapy on the vaginal discharge microbiome of dairy cows diagnosed with CM at 7 ± 3 DIM (days in milk). We hypothesize that both treatment methods will have a similar impact on the reproductive microbiome due to broad-spectrum bactericidal activity; therefore, there will not be significant differences amongst the microbiota after the completion of therapy.
Cows from a central Pennsylvania dairy were screened for CM at 7 ± 3 days DIM using a Metricheck™ device ( = 351). Cows with red-brown watery discharge were diagnosed with CM and eligible for enrollment. Eligible cows ( = 77) were blocked by parity and randomly allocated to one of two treatments starting on the day of diagnosis: (1) Intrauterine dextrose (DEX, = 38): 1 l of an intrauterine 50% dextrose solution for 3 days, and (2) Systemic ceftiofur (CONV, = 39): two injections of ceftiofur (6.6 mg/Kg of BW; Excede, Zoetis Inc.) 72 h apart. Cows were evaluated for clinical cure rate at 7 ± 3 and 14 ± 3 days post-diagnosis. Vaginal discharge samples were collected using the Metricheck™ at enrollment day [study day (sd) 0, pre-treatment], sd 7, and sd 14 for a subset of enrolled cows (DEX = 13, CONV = 14). Vaginal discharge samples were analyzed with 16S rRNA sequencing to evaluate changes in the microbiome between treatments.
After treatment, there were only minor differences within the microbiome between the two treatments indicating the potential suitability of dextrose as an antibiotic-alternative treatment. Alpha diversity did not differ (Welch's -test) between the treatments at any of the time points. Beta diversity based on PERMANOVA analysis did differ between treatments at sd 0 ( = 0.014) and again at sd 14 ( = 0.028), but not at sd 7 ( = 0.261).
While 16S rRNA analysis does not provide information on bacterial viability, the relative similarity of the microbiome between the two groups immediately following treatment might suggest that intrauterine dextrose could be utilized as an alternative treatment for CM.
临床型子宫炎（CM）给奶牛养殖户带来了巨大成本。目前的治疗策略包括使用全身抗生素；然而，人们越来越关注抗生素的合理使用。本研究的目的是评估非抗生素治疗与全身抗生素治疗对在产犊后7±3天被诊断为CM的奶牛阴道分泌物微生物群的影响。我们假设，由于广谱杀菌活性，两种治疗方法对生殖微生物群的影响相似；因此，治疗结束后微生物群之间不会有显著差异。
使用Metricheck™设备在产犊后7±3天对宾夕法尼亚州中部一家奶牛场的奶牛进行CM筛查（n = 351）。阴道分泌物为红棕色水样的奶牛被诊断为CM并符合入组条件。符合条件的奶牛（n = 77）按胎次进行分组，并在诊断当天随机分配到两种治疗方法之一：（1）子宫内注射葡萄糖（DEX，n = 38）：1升50%的子宫内葡萄糖溶液，连续注射3天；（2）全身注射头孢噻呋（CONV，n = 39）：两次注射头孢噻呋（6.6毫克/千克体重；Excede，硕腾公司），间隔72小时。在诊断后7±3天和14±3天对奶牛的临床治愈率进行评估。对于一部分入组奶牛（DEX = 13，CONV = 14），在入组当天[研究日（sd）0，治疗前]、sd 7和sd 14使用Metricheck™收集阴道分泌物样本。对阴道分泌物样本进行16S rRNA测序分析，以评估不同治疗方法之间微生物群的变化。
治疗后，两种治疗方法之间的微生物群仅有微小差异，这表明葡萄糖作为抗生素替代治疗具有潜在的适用性。在任何时间点，两种治疗方法之间的α多样性均无差异（Welch t检验）。基于PERMANOVA分析的β多样性在sd 0时治疗组之间存在差异（P = 0.014），在sd 14时再次出现差异（P = 0.028），但在sd 7时无差异（P = 0.261）。
虽然16S rRNA分析不能提供细菌活力的信息，但治疗后两组微生物群的相对相似性可能表明子宫内注射葡萄糖可作为CM的替代治疗方法。
