VanA-Type MRSA (VRSA) Emerged in Surface Waters

Due to the widespread occurrence of mecA-encoded methicillin resistance in Staphylococcus aureus (MRSA), treatment of staphylococcal infections is shifted to glycopeptide antibiotics like vancomycin and teicoplanin. The selective pressure of glycopeptides has eventually led to the emergence of staphylococci with increased resistance. Of great concern is vanA-encoded high level vancomycin and teicoplanin resistance in MRSA (VRSA). Therefore, this study aimed at investigating the occurrence of VRSA in surface waters. Out of 290, two staphylococcal isolates identified as MRSA Al11, Ba01, and one as MRS Co11 through 16S rRNA sequencing, also displayed high level resistance towards vancomycin and teicoplanin. These staphylococcal isolates were found to harbor vanA gene with sequence similarities of 99 %-100 % to the vanA gene extracted from vancomycin- and teicoplanin-resistant enterococcal (VRE) surface water isolates of Enterococcus faecalis Cr07, E07, Pb06 and E. faecium E330. High level glycopeptide resistance rendering protein encoded by the vanA gene, d-alanine-d-lactate ligase found in VRE, was also shown to be present in all vanA-type staphylococcal isolates through western blot. Current study elucidated that surface waters provide high potential for enterococcal vanA gene being transferred to MRSA, so called VRSA, and require special scientific consideration.


Untreated HWWs Emerged as Hotpots for ARGs
Kayali, Osman; İçgen, Bülent (Springer Science and Business Media LLC, 2020-03-01)
Hospital wastewaters (HWWs) are reported to be hotspots for antibiotics and antibiotic-resistant bacteria. However, limited information involves the impact of these effluents on dissemination of antibiotic-resistance genes (ARGs). In this study, therefore, seasonally collected HWWs were monitored for overall bacterial load and seven ARGs aadA, tetA, cmlA, sul1, qnrS, ermB and bla CTX-M by using quantitative polymerase chain reaction method. Overall bacterial 16S rRNA copy number was found to be the lowest i...
vanA-targeted oligonucleotide DNA probe designed to monitor vancomycin- and teicoplanin-resistant bacteria in surface waters
Nakipoğlu, Mustafa; İçgen, Bülent (2016-10-01)
The glycopeptide antibiotics teicoplanin and vancomycin are common to treat severe Gram-positive bacterial infections. The gene vanA confers high-level resistance to these antibiotics, and these phenomena have been shown to be transferable. Release of vancomycin-and teicoplanin-resistant bacteria to surface waters is, therefore, of particular concern since they might proliferate and spread in different environments. Monitoring of the fate of vanA gene in these waters provides information on the exposure and...
ARINC, E; Adalı, Orhan; ISCAN, M; Güray, Nülüfer Tülün (Springer Science and Business Media LLC, 1991-01-01)
Treatment of rabbits with benzene (880 mg/kg/day), s.c. for 3 consecutive days, caused 3.8- and 5.7-fold increases in aniline 4-hydroxylation rates of liver and kidney microsomes, respectively. Benzene treatment markedly enhanced hydroxylation rates of p-nitrophenol by liver and kidney by 7.2- and 4.2-fold, respectively. Both of these enzymes are associated with cytochrome P-450 LM3a. In contrast, the activity of benzphetamine N-demethylase, associated with P-450 LM2, was not altered significantly in eit...
Real-Time PCR Investigation of the Dynamic Expression of Three "RNA Processing and Modification" Genes of Phanerochaete chrysosporium Exposed to Lead
Tekın, Elif; İçgen, Bülent; Özcengiz, Gülay (Springer Science and Business Media LLC, 2013-01-01)
The expression of three ribosome binding proteins namely; polyadenylate-binding protein, splicing factor RNPS1 and ATP-dependent RNA helicase of Phanerochaete chrysosporium exposed to lead were analyzed by real-time PCR. The mRNA level of splicing factor RNPS1 showed 2.7 (p < 0.05), 2.6 (p < 0.05) and 4.9-fold (p < 0.001) increase when the cells were exposed to 25, 50 and 100 mu M lead, respectively. 50 and 100 mu M lead exposure resulted in almost 2-fold (p < 0.01and p < 0.05, respectively) increase in the...
Cellular uptake, genotoxicity and cytotoxicity of cobalt ferrite magnetic nanoparticles in human breast cells
Asik, Elif; Akpinar, Yeliz; Güray, Nülüfer Tülün; Iscan, Mesude; ÇAKMAK DEMİRCİGİL, GONCA; Volkan, Mürvet (Oxford University Press (OUP), 2016-01-01)
Magnetic nanoparticles (MNPs) have been increasingly used for many years as MRI agents and for gene delivery and hyperthermia therapy, although there have been conflicting results on their safety. In this study, cobalt ferrite magnetic nanoparticles (CoFe-MNPs) were prepared by the co-precipitation method and their surfaces were modified with silica by the sol-gel method. The particle and hydrodynamic sizes, morphology and crystal structure of the bare and silica-coated CoFe-MNPs were evaluated by transmiss...
Citation Formats
B. İçgen, “VanA-Type MRSA (VRSA) Emerged in Surface Waters,” BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, pp. 359–366, 2016, Accessed: 00, 2020. [Online]. Available: