Antibacterial activities of coagulase-negative staphylococci from bovine teat apex skin and their inhibitory effect on mastitis-related pathogens

Abstract

Aims: To explore antibacterial activities of coagulase-negative staphylococci (CoNS) from teat apices of dairy cows towards mastitis-causing pathogens. Methods and Results: Of 254 CoNS, 38 displayed bacteriocin-like activity after a first screening. Seven of these strains displayed activity against at least one mastitis-related pathogen (Streptococcus uberis, Streptococcus dysgalactiae and Staphylococcus aureus). Staphylococcus chromogenes L217 displayed the strongest inhibitory effect, being active against all tested mastitis-related pathogens and most tested CoNS. Based on cation exchange and reversed-phase chromatography, in addition to N-terminal Edman degradation and PCR, the antibacterial peptide was identified as a nukacin-type bacteriocin and named nukacin L217. Although staphylococcal bacteriocins are generally found in the cell-free supernatants of liquid cultures, Staph. chromogenes L217 only led to detectable activity when grown on agar medium. Conclusions: Bacteriocin-like activities are not uncommon among CoNS from teat apices and may inhibit mastitis-causing pathogens, as found for nukacin L217 production by Staph. chromogenes L217. Significance and Impact of the Study: Nukacin L217 is the first identified bacteriocin of the species Staph. chromogenes and displays unusual production kinetics, that is, requiring surface growth of its producer. The fact that nukacins are produced by different CoNS species suggests a role in the teat skin ecosystem.

Short communication: Subtyping of Staphylococcus haemolyticus isolates from milk and corresponding teat apices to verify the potential teat-skin origin of intramammary infections in dairy cows

“…Apparent contradictions have been noticed regarding the effect on udder health of CNS at the species level. For instance, Staphylococcus chromogenes can be associated with clinical mastitis (Zadoks and Watts, 2009) but also exerts protective properties (De Vliegher et al, 2003;Braem et al, 2014). These inconsistencies could indicate strain dependence of the pathogenic versus protective potential of CNS.…”

Antimicrobial spectrum activity of bacteriocinogenic Staphylococcus strains isolated from goat and sheep milk

“…Many bacteriocins have been characterized so far, but to date the only bacteriocins approved for use as food additives are nisin and pediocin PA-1. Furthermore, bacteriocin-containing products that are commercially available to prevent mastitis are based on nisin (Wipe Out, ImmuCell, Portland, OR), lacticin 3147, or macedocin ST91KM (Kim et al, 2010;Braem et al, 2014). The ineffectiveness of nisin in some food matrices (e.g., meat) and the emergence of nisin-resistant bacteria would, however, compromise its efficacy as an antibacterial agent (de Souza Duarte et al, 2013).…”

Prevalence and Antimicrobial Resistance Profile of Staphylococcus Species in Chicken and Beef Raw Meat in Egypt

“…Although CPS, and especially S. aureus, are regarded as important pathogens in humans and animals, CNS should not be ignored in epidemiological investigations of foodborne outbreaks based on the presence of enterotoxin genes (Rall et al, 2010;Batista et al, 2013). In the last 20 years, however, the interest in CNS species has significantly increased in both human and veterinary medicine (Rogers et al, 2009;Braem et al, 2014). Information regarding the detailed prevalence of S. aureus and NSA isolates was insufficient in Egypt.…”