Antibiotic susceptibility, antibacterial activity and characterisation of Enterococcus faecium strains isolated from breast milk

Abstract

Enterococci, which have useful biotechnological applications, produce bacteriocins, including those that exert anti-Listerial activity. The present study aimed to determine the antibiotic susceptibility patterns and antimicrobial activity of Enterococcus faecium strains isolated from human breast milk. The strains were identified using carbohydrate fermentation tests and ribotyping. Subsequently, the antibacterial activity of the isolates was investigated, and the quantities of lactic acid and hydrogen peroxide produced, and the proteolytic activity of E. faecium, were determined. In addition, biofilm formation by E. faecium strains was assessed. E. faecium strains exhibited antimicrobial activity against food-borne and clinical bacterial isolates. Furthermore, following 24 h incubation, the tested strains exhibited resistance to a pH range of 2.0–9.5 and tolerance of bile acid, lysozyme activity and phenol. Supernatants of the E. faecium TM13, TM15, TM17 and TM18 strains were shown to be effective against Listeria monocytogenes, and were also resistant to heat. Further studies are required in order to determine whether certain strains of E. faecium may be used for the development of novel antibacterial agents.

Characterization of Potential Probiotic Activity of Lactic Acid Bacteria Isolated from Camel Colostrum by Biochemical and Molecular Methods

“…In this study, the isolated LAB were screened for potential probiotic activities. Te results of acidity tolerance revealed that all the 60 isolates are tolerant to diferent pH concentrations (2, 3, 4, 5, 6, 7, 8, 9, and 10) as expected for probiotics to have the ability to survive within the varied pH of the intestinal tract, and these results were in agreement with the previous studies which proved that some Enterococcus species can survive in the pH range between 2.0 and 9.5 [29]. Other studies proved that Enterococcus faecium can survive at low pH (1.5 and 3) with the survival rate % between 43 ± 3.0 and 79 ± 4.5 [30], and according to Sanhueza et al [31], some strains of Lactobacillus salivarius can survive for 24 h at pH 2.6.…”

Unveiling the Antibiotic Susceptibility and Antimicrobial Potential of Bacteria from Human Breast Milk of Pakistani Women: An Exploratory Study

“…MB618 which exhibited resistance to 7, 6, and 5 of the antibiotics used in this study, respectively. This trend was observed by Kıvanç et al [ 56 ] and Reis et al [ 57 ] who reported multiple drug resistance in Enterococcus faecium isolated from human breast milk to ciprofloxacin, ampicillin, gentamicin, penicillin, and vancomycin. Antimicrobial resistance is a complex problem that could be accredited to numerous kinds of mode of transmission and selection pressures [ 58 ].…”

Exploring the Therapeutic Potenital of the Leaderless Enterocins K1 and EJ97 in the Treatment of Vancomycin-Resistant Enterococcal Infection

“…This opportunistic pathogen, although somewhat less virulent than E. faecalis , is more frequent in vancomycin resistance than E. faecalis and therefore becoming a major threat to public health ( Comerlato et al, 2013 ; Kristich et al, 2014 ). E. faecalis is well-known for its lysozyme resistance, and although not well characterised there are some reports of lysozyme resistant E. faecium strains ( Le Jeune et al, 2010 ; Kivanc et al, 2016 ). The eep -mutants of E. faecium in the present study showed an 8x reduction in lysozyme tolerance compared to the wild type strains.…”