Ahmed Shahana, Hansen Claus, Dahlkilde Ane Laursen, Herrero-Fresno Ana, Pedersen Ken Steen, Nielsen Jens Peter, Olsen John Elmerdahl
Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark.
Danish Agriculture & Food Council, SEGES Pig Research Centre, 1609 Copenhagen V, Denmark.
Antibiotics (Basel). 2021 Apr 20;10(4):465. doi: 10.3390/antibiotics10040465.
The treatment of diarrhea in the postweaning period is a common reason for the use of antimicrobials in pig production, and is the single most important causative agent for this condition. Colistin has recently been classified as a critically important antimicrobial for human health, as it is a last-resort drug against certain multi-drug-resistant Gram-negative bacteria. Therefore, the use of colistin has been significantly reduced in some countries, including Denmark. Despite this, the drug is still commonly used to treat diarrhea in pigs in many countries, and there is a need to understand the risks associated with this practice. We performed a prospective cohort study to investigate the effect of colistin treatment on the changes in the average minimum inhibitory concentration (MIC) in commensal in a pig herd where no colistin-resistant bacteria were detectable before treatment. One group of pigs was batch treated with colistin after the clinical observation of diarrhea, one group was batch treated with colistin approximately 10 days before the expected onset of diarrhea, and a control group was not treated with colistin but provided with nonantimicrobial antidiarrheal feed supplement. Treatment with colistin in the dose and time combinations used did not result in a significant increase in the average colistin MIC values in Moreover, no strains showed a MIC above the breakpoint of >2 mg/L against colistin. Co-selection of resistance to other antimicrobials was not observed.
断奶期腹泻的治疗是养猪生产中使用抗菌药物的常见原因，也是导致这种情况的最重要单一病因。黏菌素最近被列为对人类健康至关重要的抗菌药物，因为它是对抗某些多重耐药革兰氏阴性菌的最后手段药物。因此，在包括丹麦在内的一些国家，黏菌素的使用已大幅减少。尽管如此，在许多国家，该药物仍常用于治疗猪腹泻，因此有必要了解这种做法相关的风险。我们进行了一项前瞻性队列研究，以调查黏菌素治疗对一个猪群中肠道共生菌平均最低抑菌浓度（MIC）变化的影响，该猪群在治疗前未检测到耐黏菌素细菌。一组猪在出现腹泻临床症状后分批用黏菌素治疗，一组在预计腹泻发作前约10天分批用黏菌素治疗，对照组未用黏菌素治疗，但提供不含抗菌药物的止泻饲料添加剂。在所使用的剂量和时间组合下，黏菌素治疗并未导致肠道共生菌平均黏菌素MIC值显著增加。此外，没有分离株对黏菌素的MIC高于>2mg/L的折点。未观察到对其他抗菌药物耐药性的共同选择。
