Species identification by MALDI-TOF MS and gap PCR–RFLP of non-aureus Staphylococcus, Mammaliicoccus, and Streptococcus spp. associated with sheep and goat mastitis

Abstract

Staphylococci and streptococci are common causes of intramammary infection in small ruminants, and reliable species identification is crucial for understanding epidemiology and impact on animal health and welfare. We applied MALDI-TOF MS and gap PCR–RFLP to 204 non-aureus staphylococci (NAS) and mammaliicocci (NASM) and to 57 streptococci isolated from the milk of sheep and goats with mastitis. The top identified NAS was Staphylococcus epidermidis (28.9%) followed by Staph. chromogenes (27.9%), haemolyticus (15.7%), caprae, and simulans (6.4% each), according to both methods (agreement rate, AR, 100%). By MALDI-TOF MS, 13.2% were Staph. microti (2.9%), xylosus (2.0%), equorum, petrasii and warneri (1.5% each), Staph. sciuri (now Mammaliicoccus sciuri, 1.0%), arlettae, capitis, cohnii, lentus (now M. lentus), pseudintermedius, succinus (0.5% each), and 3 isolates (1.5%) were not identified. PCR–RFLP showed 100% AR for Staph. equorum, warneri, arlettae, capitis, and pseudintermedius, 50% for Staph. xylosus, and 0% for the remaining NASM. The top identified streptococcus was Streptococcus uberis (89.5%), followed by Strep. dysgalactiae and parauberis (3.5% each) and by Strep. gallolyticus (1.8%) according to both methods (AR 100%). Only one isolate was identified as a different species by MALDI-TOF MS and PCR–RFLP. In conclusion, MALDI-TOF MS and PCR–RFLP showed a high level of agreement in the identification of the most prevalent NAS and streptococci causing small ruminant mastitis. Therefore, gap PCR–RFLP can represent a good identification alternative when MALDI-TOF MS is not available. Nevertheless, some issues remain for Staph. haemolyticus, minor NAS species including Staph. microti, and species of the novel genus Mammaliicoccus.

An Insight into Goat Cheese: The Tales of Artisanal and Industrial Gidotyri Microbiota

“…Str. parauberis is associated with small ruminant mastitis and has been identified as a minor component of cheeses produced with their milk [ 38 , 58 , 59 ]. Other mastitis-causing pathogens can be found in cheese via contaminated milk [ 60 , 61 , 62 , 63 ].…”

Candida Genus Maximum Incidence in Boar Semen Even after Preservation, Is It Not a Risk for AI though?

“…genera in preserved boar semen, we used only the classic and Miniapi methods. According to studies in the literature [ 34 ], the Conventional Identification (CI)-MiniApi method compared to MALDI-TOF [ 35 , 36 ] or MT-MS is slower and less faithful but generates the same results. According to Sendid B. et al (2013), concordance between the two techniques is excellent for the medically important species (98–100%), including the identification of closely-related species ( Candida genus).…”

Non-aureus staphylococci and mammaliicocci as a cause of mastitis in domestic ruminants: current knowledge, advances, biomedical applications, and future perspectives – a systematic review

“…Non- aureus staphylococci (NAS) are abundant in dairy cows’ teat apices that are recovered from bovine fecal samples, and their differences in ecology, epidemiology, effect on udder health, and virulence or protective traits have been reported among other species within this group (De Visscher et al 2016 ; Vanderhaeghen et al 2015 ; Wuytack et al 2020a , b ). Several studies have reported that S. chromogenes, S. epidermidis, S. xylosus , S. vitulinus , S. simulans , and M. sciuri are the main NASM species isolated from the tips and skin of the animal’s teats increasing the probability to develop an intramammary infection during lactation, whereas in milk samples, S. chromogenes , S. xylosus , S. haemolyticus are most prevalent (Koop et al 2012 ; Rosa et al 2022 ; Ruiz-Romero et al 2020 ; Traversari et al 2019 ). Overall, more NASM isolates are identified in used bedding than in unused bedding (Adkins et al 2022 ).…”