Reduced susceptibility in leptospiral strains of bovine origin might impair antibiotic therapy

Abstract

Leptospirosis is a worldwide zoonotic disease determined by pathogenic spirochetes of the genus Leptospira. The control of bovine leptospirosis involves several measures including antibiotic treatment of carriers. Despite its importance, few studies regarding antimicrobial susceptibility of strains from bovine origin have been conducted. The aim of this study was to determine the in vitro susceptibility of Leptospira strains obtained from cattle in Rio de Janeiro, Brazil, against the main antibiotics used in bovine veterinary practice. A total of 23 Leptospira spp. strains were investigated for minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) using broth macrodilution. At the species level, there were not differences in MIC susceptibility except for tetracycline (P < 0.05). Nevertheless, at the serogroup level, differences in MIC were observed among Sejroe strains, mainly for ceftiofur, doxycycline and in MBC for streptomycin (P < 0.05). One strain presented MBC values above maximum plasmatic concentration described for streptomycin and was classified as presenting reduced susceptibility. Efficacy of antimicrobial therapy on bovine leptospirosis could be compromised due to occurrence of infection by Leptospira strains presenting reduced susceptibility.

Bacteriostatic and Bactericidal Effect of Tigecycline on Leptospira spp.

“…The obtained results were consistent with other data available in literature, according to which tetracycline MIC values for Leptospira reference strains or isolates are, on average, between 0.25 and 6.25 µg/mL [ 29 , 30 , 31 , 32 , 33 , 34 ]. Considering that the results obtained for tetracycline were very similar to those reported in literature, it is correct to suppose that the results for MIC and MBC for tigecycline were also similar, not under- or overestimated.…”

Determination of minimum inhibitory and minimum bactericidal concentrations of Brazilian strains of Leptospira spp. for streptomycin sulphate

“…These results showed a wide variation in the susceptibility of the strains against streptomycin, not only regarding MIC, but also MBC. The obtained outcomes are consistent with the values observed in other studies such as Correia et al [1] and Liegeon et al [2], and could define all studied strains as sensitive to streptomycin. These findings validate the usage of streptomycin in field conditions, a fact that can be considered positive, since this is the most common antibiotic used for the treatment of leptospirosis in livestock, particularly ruminants.…”

“…In 2018, our group published a paper reporting on the reduced antimicrobial susceptibility of Leptospira strains of animal origin in this prestigious journal [1]. Meanwhile, new strains were characterised, enlarging the epidemiological profile of leptospirosis in our scenario.…”

“…The obtained outcomes are consistent with the values observed in other studies such as Correia et al . [1] and Liegeon et al . [2], and could define all studied strains as sensitive to streptomycin.…”

Biochemical parameters of blood in cows in latent course of leptospirosis

“…Leptospirosis is a worldwide zoonosis, with a wide range of hosts, including humans and animals, caused by Leptospira pathogenic spirochetes (Correia et al, 2018;Daud et al, 2018;Jaeger et al, 2018;Zarantonelli et al, 2018), which has a large number of serovars, similarity of which is essential for effective diagnosis (Arent et al, 2012;Mughini-Gras et al, 2013). The disease is common in most regions of the world, particularly in Latin America (Correia et al, 2018;Guedes et al, 2019), Oceania (Subharat et al, 2012;Dreyfus et al, 2018;Reichel et al, 2018), Southeast Asia (Chadsuthi et al, 2018;Shrestha et al, 2018).…”