Successful treatment of recurrent subclinical mastitis in cows caused by enrofloxacin resistant bacteria by means of the sequential intramammary infusion of enrofloxacin HCl-2H₂O and ceftiofur HCl: a clinical trial

Abstract

Background Recurrent subclinical mastitis (RScM) due to resistant bacteria has low clinical and bacteriological cure rates, often requiring the culling of cows. The sequential intra-mammary administration of enrofloxacin hydrochloride-dihydrate (enro-C) followed by ceftiofur HCl may be useful for treating these cases. Objectives This study assessed the bacteriological and clinical cure-efficacies of the sequentially intramammary administration of enro-C, followed by ceftiofur HCl to treat RScM in Holstein/Friesian cows. Methods This trial was conducted in a herd with a high prevalence of RScM, and 20 Holstein/Friesian cows were included: 45% suffering subclinical mastitis and 38.9% of the mammary quarters affected. Twenty-nine bacterial isolates in vitro resistant to enro-C were obtained (coagulase-negative Staphylococcus spp, 55.2%; Staphylococcus aureus , 27.6%; Escherichia coli , 6.9%; Streptococcus uberis , 6.9%; Corynebacterium bovis , 3.4%). Polymerase chain reaction-isolated the following genes linked to enro-C resistance: chromosomal ( gyrA ) and plasmid ( aac(6')-lb-cr ). The treatments were as follows: twice-daily intramammary infusions of enro-C (300 mg/10 mL) for 5 days. Cows clinically considered treatment failures were also treated with intramammary ceftiofur (125 mg/10 mL, twice daily for 5 days. The clinical and bacteriological cure rates were carried out when completing each treatment phase and at 14 and 21 days, aided by a California mastitis test, somatic cell count, and failure to identify the initially causative bacteria. Results Enro-C achieved 65% clinical and bacteriological cure rates, and 100% cure rates were obtained after the rescue treatment with ceftiofur HCl. Conclusions Outstanding clinical and bacteriological cure rates in cows affected by RScM were achieved with the consecutive intramammary infusions of enro-C, followed by ceftiofur HCl.

Enrofloxacin—The Ruthless Killer of Eukaryotic Cells or the Last Hope in the Fight against Bacterial Infections?

“…The antibiotic (in the form of hydrochloride dihydrate) was administered twice daily for 5 days via intramammary infusions (infusions into the udder) at a dose of 300 mg. The authors showed that 65% of cattle treated with enrofloxacin recovered, while the additional introduction of ceftiofur-HCl led to a 100% recovery [ 68 ].…”

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): antimicrobial‐resistant Staphylococcus aureus in cattle and horses

“…Most of the substances are typically used intramammary, some can also be administered systemically. Fluoroquinolones can also be applied systemically for treatment of S. aureus mastitis (Alfonseca‐Silva et al., 2021 ).…”

“…In general, SEB is considered in literature as a potent biological weapon with incapacitating effects (Ahanotu et al, 2006;Bhaskar and Sant, 2020). It is one out of 25 currently characterised staphylococcal enterotoxins and has its toxic effect from its ability to function as a superantigen, toxins able to evoke an immune response of large proportions, commonly resulting in food poisoning and flulike symptoms that can lead to multi-organ failure and death (Bhaskar and Sant, 2020).…”

“…Formulations of the compounds can be varying, with an important effect on efficacy (Barkema et al, 2006;Alfonseca-Silva et al, 2021).…”

Intramammary preparation of enrofloxacin hydrochloride-dihydrate for bovine mastitis (biofilm-forming Staphylococcus aureus)

“…It has a pH of 6.5 in suspension at 30 mg/mL and achieves high concentrations in mammary tissue. Enro-C has shown high success in treating uncomplicated cases of mastitis [ 10 11 12 ] and recurrent chronic cases caused by bacteria resistant to fluoroquinolones [ 13 ].…”