Phenotypic and Genotypic Identification of Vancomycin Resistant Enterococci from Different Sources

Abstract

Enterococci are reservoirs for transmission of the most clinically important antimicrobial resistances such as vancomycin resistance. Therefore, this work aimed to determine the occurrence of enterococci and their respective vancomycine resistance genes (vanA and vanB) from different sources. Two hundred and twenty-four samples from chickens, turkey, fish and human urine, as well as, two types of human food including milk (raw and milk from mastitic animals) and sausage were tested for isolation of Enterococcus species. The isolates were identified morphologically and biochemically using catalase test, sodium chloride tolerance and growth at pH 9.6 and 10-45˚C. The vancomycin resistance profile of the isolates was verified by both disc diffusion and agar dilution methods. The genotypic enterococcal identification at both genus and species levels and their vancomycine resistance genes were also ascertained using PCR amplification of the respective genes for 28 isolates. Enterococci isolation rate was 70% of the examined samples with a higher percentage of vancomycine resistance (53.5%) and the minimum inhibitory concentrations (MICs) ranged from 16 to 512 µg/mL. Molecular identification of 28 enterococcal isolates revealed the dominance of E. faecalis (42.8%) and clarified a higher proportion of vanA (78.5%) and vanB (67.8%) genes. In conclusion, administration of the antimicrobials mainly vancomycin may be considered as a pronounced stress factor in the veterinary and human practices. In addition, VRE can act as a reservoir for vancomycin resistance.

Molecular and Antibacterial Studies of Titanium Dioxide (TiO2) Aspergillus oryzae Nanoparticles on Multidrug-Resistance Bacteria

“…Shridhar and Dhanashree (2019) conducted a similar investigation found that 46.6% were identified as E. faecalis. In a study done by Attia et al, (2017) found that VRMDR E. faecalis revealed 53.5% of the isolates. In a different research, individuals in Iraq who had communityacquired pneumonia had a cumulative prevalence of K. pneumoniae of 31.9% (Raouf et al, 2022).…”

Investigation of vancomycin resistance genes in Enterococcus species isolated from bovine mastitis

“…As in many infections, the most important problem in the treatment of mastitis is the increasing problem of resistance to antibiotics, in addition to the presence of antibiotic residues in milk (BENIĆ et al, 2018;LAMARI et al, 2021;MIMOUNE et al, 2021). However, there is limited research on the antibiotic resistance profiles of strains isolated from bovine mastitis genotypically determined to be VRE (JUNG et al, 2007;ERBAS et al, 2016;ATTIA et al, 2017). JUNG et al (2007 stated that seven vanC1 gene positive E. gallinarum strains were resistant to vancomycin (14%), chloramphenicol (14%), ciprofloxacin (29%), erythromycin (14%) and tetracycline (42%).…”

“…JUNG et al (2007 stated that seven vanC1 gene positive E. gallinarum strains were resistant to vancomycin (14%), chloramphenicol (14%), ciprofloxacin (29%), erythromycin (14%) and tetracycline (42%). In a study conducted in Egypt, it was reported that resistance to at least two different antibiotics was detected in vanA and vanB gene positive VRE strains isolated from mastitic milk samples, and it was emphasized that the multiple antibiotic resistance profile in the strains was more common against ampicillin, ciprofloxacin, gentamicin and erythromycin (ATTIA et al, 2017). ERBAS et al (2016) from Turkey stated that one vanA gene positive E. faecalis strain isolated from bovine mastitis was also resistant to tetracycline and erythromycin.…”