Short communication: In vitro antimicrobial susceptibility of Mycoplasma agalactiae strains isolated from dairy goats

Abstract

This study examined the susceptibility to several antimicrobials of 28 isolates of Mycoplasma agalactiae obtained from goats in a region (southeastern Spain) where contagious agalactia is endemic. For each isolate, the minimum inhibitory concentration (MIC) against 12 antimicrobials of the quinolone, macrolide, aminoglycoside, and tetracycline families was determined. The antimicrobials with the lowest MIC were enrofloxacin, ciprofloxacin, tylosin, and doxycycline, all with MIC90 (concentration at which growth of 90% of the isolates is inhibited) <1 µg/mL. Norfloxacin (a quinolone) showed a wide MIC range (0.1-12.8 µg/mL), suggesting a resistance mechanism toward this antimicrobial that was not elicited by enrofloxacin or ciprofloxacin (the other quinolones tested). Erythromycin showed the highest MIC90 such that its use against Mycoplasma agalactiae is not recommended. Finally, Mycoplasma agalactiae isolates obtained from goat herds with clinical symptoms of contagious agalactia featured higher MIC90 and MIC50 (concentration at which growth of 50% of the isolates is inhibited) values for many of the antimicrobials compared with isolates from asymptomatic animals. The relationship between the extensive use of antimicrobials in herds with clinical contagious agalactia and variations in MIC requires further study.

Antimicrobial susceptibility and multilocus sequence typing of Mycoplasma capricolum subsp. capricolum

“…Moreover, their MIC 50 and MIC 90 values showed that these antimicrobials are not effective against this pathogen. These results are in agreement with those described in previous studies performed on other mycoplasma species [8, 10, 11, 33]. Hence, our work supports the previously proposed hypothesis about an intrinsic resistance of the mycoplasmas of the M .…”

“…We evaluated the effect of 18 antimicrobials: spectinomycin (Sigma-Aldrich, USA), kanamycin (Sigma-Aldrich, USA), gentamycin (Sigma-Aldrich, USA), neomycin (Sigma-Aldrich, USA) and streptomycin (Sigma-Aldrich, USA) in a range from 128 μg/ml to 16 μg/ml; ciprofloxacin (Fluka, USA), enrofloxacin (Fluka, USA), marbofloxacin (Tokyo Chemical Industry, Japan), danofloxacin (Fluka, USA), moxifloxacin (Cayman Chemical Company, USA), norfloxacin (Sigma-Aldrich, USA), doxycycline (Sigma-Aldrich, USA), tylosin (Fluka, USA) and tilmicosin (Molekula, UK), which were studied in a range from 12.8 μg/ml to 0.006 μg/ml; and erythromycin (Fluka, USA), spiramycin (Sigma-Aldrich, USA), clindamycin (Cayman Chemical Company, USA) and lincomycin (Sigma-Aldrich, USA), which were evaluated in a range from 12.8 μg/ml to 0.8 μg/ml. The concentration range of these antimicrobials was selected considering data published in previous studies [8–10]. Different concentrations of antimicrobials were obtained by serial two-fold dilutions from the highest to the lowest concentration.…”

Diversity and variation in antimicrobial susceptibility patterns over time in Mycoplasma agalactiae isolates collected from sheep and goats in France

“…; Paterna et al . ). Furthermore, half of the isolates had been collected from asymptomatic infections, which suggests that the circulation of these strains with increased MICs within flocks is extensive.…”

“…; Paterna et al . ). No data are available as yet concerning the susceptibility of M. agalactiae isolates in France.…”

Milk hygiene in small ruminants: A review

“…have been, however, increasingly documented. Indeed, the ewe and goat field isolates were mostly resistant to erythromycin, indicating that this macrolide would not be a suitable choice for therapy (Antunes et al, 2008;de Garnica et al, 2013c;Paterna et al, 2013). In addition, in a recent published study carried out over the last 25 years in M. agalactiae isolates collected from sheep and goats in France, this species showed increased minimum inhibitory concentrations over time for several antimicrobials used against CA (Poumarat et al, 2016).…”