Short communication: Streptococcus species isolated from mastitis milk samples in Germany and their resistance to antimicrobial agents

Abstract

Mastitis is one of the most frequent infectious diseases in dairy cattle and is a reason for antimicrobial drug usage in dairy cows. The bacteria involved in bovine mastitis are mainly Streptococcus spp., Staphylococcus spp., and coliforms. The aim of this study was to determine antimicrobial resistance among Streptococcus spp. isolated from bovine mastitis milk. Antimicrobial resistance in Strep. uberis (n=227), Strep. dysgalactiae (n=49), and Strep. agalactiae (n=3) was determined for 9 antimicrobial agents using the broth microdilution method in accordance with Clinical and Laboratory Standards Institute recommendations. Of all Streptococcus spp., 13% were multidrug resistant. The rate of multidrug resistance was higher among Strep. uberis (15%) than among Strep. dysgalactiae (6%) and Strep. agalactiae (0%). Resistance to tetracycline was the most common, followed by resistance to erythromycin, pirlimycin, and gentamicin. Resistance rates were higher on farms with more than 80 cows compared with those with fewer than 20 cows. β-Lactams should remain the drugs of choice in the treatment of streptococcal mastitis. The slightly elevated minimum inhibitory concentrations determined for these antibiotics may indicate, however, the emergence of resistant streptococci. To identify such changes in susceptibility as early as possible, antimicrobial resistance in streptococci should be surveyed regularly.

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

“…In the present work, consistent with such investigations (GUÉRIN-FAUBLÉE et al, 2002;MINST et al, 2012;RATO et al, 2013), most isolates (96.6%) were susceptible to penicillin, indicating that this antibiotic is a viable option for the treatment of mastitis. In humans, penicillin is the recommended first-line treatment for S. agalactiae infections for all age groups, in addition to being administered prophylactically to pregnant women (BOLUKAOTO et al, 2015;VERANI et al, 2010).…”

“…According to Myllys et al (1994), antimicrobial resistance is an important factor in the introduction and dissemination of bacterial clones within a herd, with handling changes such as the implementation of systematic antibiotic treatment, stabling, and introduction of automatic milkers being closely associated, given their influence as selective forces on the pathogens responsible for mastitis.…”

Antimicrobial Activity of 1,3 Dihydroxy-2-Methylimidazolium Bis (Trifluoromethylsulfonyl) Imde and Selected Antibiotics Against <i>Streptococcus</i> Species Isolated from Groundwater in the Northwest Province, South Africa

“…In the present study, isolates from different sample sites differed in their antimicrobial resistance patterns and similar observations have been reported [40]. In some of these studies resistance to tetracycline was the most common, followed by resistance to erythromycin, pirlimycin, and gentamicin [39]. Moreover, Streptococcus species have been reported to marked susceptibility to β-lactam antibiotics [37] and this is contrary to our finding.…”

“…The antibiotic resistance patterns of Streptococcus species from food products and humans have been investigated [36,37,38,39]. In the present study large proportions (75.0% to 100%) of the isolates were most often resistant to penicillin G, vancomycin, and erythromycin.…”

Prevalence and Antimicrobial Resistance Assessment of Subclinical Mastitis in Milk Samples From Selected Dairy Farms

“…Milk also serves as an optimum medium for the propagation of various pathogenic and spoilage microorganisms (Minst et al, 2012;Gatti et al, 2013). These pathogens invade the mammary glands, develop and multiply, producing some toxic substances that results in inflammation, reduced milk production and altered milk quality, leading to a clinical condition known as mastitis (Oliver and Muranda, 2012;Rall et al, 2013).…”