Uterine infections, well known to be one of the most common causes of reduced fertility in mares [1], are caused by several opportunistic pathogens [2]. Antibiotic resistance has increased globally and bacterial prevalence as well as antimicrobial susceptibility patterns can change over time and among equine populations [3]. Therefore, this study was aimed at providing an update on bacterial species isolated from equine uteri and analyzing variations of antibiotic sensitivity over eight years (2010-2017). A retrospective study was conducted selecting 4445 uterine swabs collected from mares in the course of routine breeding examination or reproductive tract disorder. Subsequently to bacterial culture, the agar diffusion test was performed and interpreted according to the CLSI guidelines. Additionally, the results of prevalence and trends of susceptibility were processed and analyzed over time. Aerobic bacteria were isolated from 3245/4445 (73%) samples. The most frequently isolated microorganisms were Escherichia coli (892/3245, 20.1%) and Streptococcus equi zooepidemicus (791/3245, 17.8%). Antimicrobial susceptibility patterns of E. coli, S. equi zooepidemicus, Pseudomonas spp. and other bacteria belonging to Enterobacteriaceae family changed over the years. Overall, E. coli showed a slight reduction of sensitivity to gentamicin and amikacin, while quinolones maintained durable efficacy over the time. Ampicillin was the most active molecule against S. equi zooepidemicus but recently thiamphenicol and rifampicin increased their efficacy against this bacterium. The present epidemiological study demonstrated that the prevalence of uterine pathogens differs from previous studies [4-6]. Such a difference could be due to geographical area and antecedent antibiotic management of equine populations. However, quinolones and aminoglycosides appear to still be the first therapeutic choice for uterine infections. To conclude, antimicrobial susceptibility monitoring programs are essential to guarantee an effective antimicrobial treatment over time and consequently to enhance the reproductive performance.
ANTIMICROBIAL SUSCEPTIBILITY OF COMMON BACTERIA ISOLATED FROM EQUINE UTERI: VARIATION OF EFFICACY OVER TIME
Lorenzo Pisello
;Elisa Rampacci;Valentina Stefanetti;Francesca Beccati;Mauro Coletti;Fabrizio Passamonti
2018
Abstract
Uterine infections, well known to be one of the most common causes of reduced fertility in mares [1], are caused by several opportunistic pathogens [2]. Antibiotic resistance has increased globally and bacterial prevalence as well as antimicrobial susceptibility patterns can change over time and among equine populations [3]. Therefore, this study was aimed at providing an update on bacterial species isolated from equine uteri and analyzing variations of antibiotic sensitivity over eight years (2010-2017). A retrospective study was conducted selecting 4445 uterine swabs collected from mares in the course of routine breeding examination or reproductive tract disorder. Subsequently to bacterial culture, the agar diffusion test was performed and interpreted according to the CLSI guidelines. Additionally, the results of prevalence and trends of susceptibility were processed and analyzed over time. Aerobic bacteria were isolated from 3245/4445 (73%) samples. The most frequently isolated microorganisms were Escherichia coli (892/3245, 20.1%) and Streptococcus equi zooepidemicus (791/3245, 17.8%). Antimicrobial susceptibility patterns of E. coli, S. equi zooepidemicus, Pseudomonas spp. and other bacteria belonging to Enterobacteriaceae family changed over the years. Overall, E. coli showed a slight reduction of sensitivity to gentamicin and amikacin, while quinolones maintained durable efficacy over the time. Ampicillin was the most active molecule against S. equi zooepidemicus but recently thiamphenicol and rifampicin increased their efficacy against this bacterium. The present epidemiological study demonstrated that the prevalence of uterine pathogens differs from previous studies [4-6]. Such a difference could be due to geographical area and antecedent antibiotic management of equine populations. However, quinolones and aminoglycosides appear to still be the first therapeutic choice for uterine infections. To conclude, antimicrobial susceptibility monitoring programs are essential to guarantee an effective antimicrobial treatment over time and consequently to enhance the reproductive performance.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
