Ivermectin treatment failure on four Irish dairy farms

Abstract

We report on the use of the faecal egg count reduction test to evaluate the performance of ivermectin in treating gastrointestinal nematode infections in first grazing season (FGS) calves on four dairy farms in Co. Kilkenny, Ireland. On each farm, FGS calves were injected subcutaneously with ivermectin in accordance with their live weight (day 0). Calves were individually faecal sampled on both day 0 and day 14. Faecal egg counts were determined using the Mini-FLOTAC technique. Composite faecal cultures for each farm were performed on each sampling occasion. The faecal egg count reductions (mode) ranged from 17.3–80.2% with the lower 95% confidence limit ranging from 3.1–72.3% on the four farms, respectively. Ivermectin-resistant nematodes were detected on all farms, with evidence of Ostertagia resistance on one farm. This study highlights the urgent need for Irish producers to reappraise their parasite control practices. Electronic supplementary material The online version of this article (10.1186/s13620-019-0142-8) contains supplementary material, which is available to authorized users.

Anthelmintic resistance among gastrointestinal nematodes of cattle on dairy calf to beef farms in Ireland

“…Therefore, these farms may not be truly representative of all dairy calf to beef farmers in Ireland. Notwithstanding this, other studies have confirmed that IVM resistance is common on cattle farms in Ireland, albeit few farms have been previously tested [19,20]. Prior to this study, testing for AR had only occurred on one farm although some farmers reported that they perceived IVM had become less effective.…”

“…There are over 92,000 farms in Ireland, of which over 54,000 are classed as cattle rearing and fattening enterprises, which includes both dairy calf to beef and suckler beef production [26]. Despite the importance of this sector to the agricultural industry in Ireland, and the industry's reliance on a grass-based production system, there is a distinct lack of information on the prevalence of AR among GIN of cattle in Ireland, although resistance to IVM has been reported [19,20]. This study provides clear evidence for resistance to all commonly available anthelmintic classes among GIN of cattle in Ireland, including resistance to IVM in Ostertagia spp.…”

“…on each of them and resistant Ostertagia spp. on one farm [20]. Therefore, there is a need to quantify the extent of AR on cattle farms in Ireland.…”

Comparison of FECPAKG2, a modified Mini-FLOTAC technique and combined sedimentation and flotation for the coproscopic examination of helminth eggs in horses

“…egg is found [ 11 , 22 , 57 ]. In contrast, for a faecal egg count reduction test (FECRT) to identify drug-resistant nematode populations, a sensitive and precise quantitative method is required, and the Mini-FLOTAC method has been repeatedly shown to perform very well in FECRT studies [ 63 – 65 ], including studies on horses [ 32 , 66 – 68 ]. Reasons to consider when choosing a test based on convenience include access to the laboratories that offer tests and acceptable turnaround times for results.…”

Atomic Force Microscopy (AFM) As a Surface Mapping Tool in Microorganisms Resistant Toward Antimicrobials: A Mini-Review

“…The emergence of widespread antimicrobial resistance (AMR) exhibited now by many commonly encountered pathogens including bacteria (e.g., Gram-positive: Staphylococcus aureus , Streptococcus pyogenes , Mycobacterium tuberculosis , and Clostridium difficile ; and Gram-negative: Escherichia coli , Klebsiella pneumoniae , Salmonella typhi , Pseudomonas aeruginosa , and Neisseria gonorroheae ), viruses (e.g., hepatitis B and C, herpes, and influenza), and fungi (e.g., Candida albicans , Aspergillus fumigatus , and Cryptococcus neoformans ) against a range of popular antimicrobials, such as β-lactam antibiotics, macrolides, tetracyclines, aminoglycosides, fluoroquinolones, antihelminthics, and antifungals ( Singer et al., 2016 ; Naylor et al., 2018 ; Hofer, 2019 ; Laws et al., 2019 ), in both human and veterinary medicine, such as the resistance noted against ivermectin in animal husbandry ( O’Shaughnessy et al., 2019 ), is a major challenge today. Indiscriminate use of antibiotics due to their widespread availability and over-the-counter sales, often without prescription and in conjunction with poor sanitation, inadequate water purification, and wastewater management, as often occurs in developing countries, is posited to be a prime contributing factor to the surge of multidrug-resistant (MDR) strains, including methicillin-resistant Staphylococcus aureus (MRSA, Okwu et al., 2019 ) and vancomycin-resistant Enterococcus (VRE; Cetinkaya et al., 2000 )—collectively termed as the superbugs ( Davies and Davies, 2010 ; Khan and Khan, 2016 ).…”