Presence of Class I and Class II Integrons in Methicilin Resistant Staphylococci and Their Relations with Antibiotic Resistance: A Preliminary Study from Turkey

Background: Emergence of antibiotic resistance is a major public health concern. It is known that antibiotic resistance is transferred by different ways. Integrons as one of these mechanisims cause to spread antibiotic resistance in Gram negative bacteria but also it is shown to be effective for transferring genes in Gram positive bacteria. In the present study we aimed to examine the prevalence of class I and class II integrons in MRSA and MRCNS strains isolated from patients and to determine the relationship between antibiotic resistance and the presence of integrons. Methods: Sixty four MRSA and 62 MRCNS strains were included in this study. Antibiotic susceptibility testings were performed. Genomic and plasmid DNAs were extracted and Polymerase Chain Reaction (PCR) was used for the detection of the intI and intII genes. The PCR products were visualised in 1.5 % agarose gel electrophoresis. Pearson chi-square test and Fisher’s exact test were used for comparing categorical variables. Results: Among 126 staphylococci 11 (8.7% - 4 MRSA and 7 MRCNS) were shown to carry class I integron; whereas 7 MRCNS (5.5%) were class II positive. Both of class I and class II integrons were detected to possess in four MRSA (3.2%). There was no statistically significant relation between presence of integrons and resistance to each of antibiotics (p>0.05). Conclusion & Recommendation: In the present study we did not find any significant relation between resistance rates and the presence of integrons but we suggest that these results showed an important data about the extended distributions of integrons not only among Gram negative bacteria but also in staphylococci.Keywords: MRSA, MRCNS, class I integron, class II integron, anbiotic resistanceDOI: 10.7176/JHMN/75-0

IN VITRO SUSCEPTIBILITY OF ENTEROCOCCUS STRAINS TO HIGH LEVEL AMINOGLYCOSIDES AND HEAVY METALS

The widespread use of antimicrobial agents in the hospitals and environmental contamination with heavy metals are increasingly related to resistance progression in microorganisms. The aim of this study was to investigate the resistance of enterococci to high level aminoglycosides and some heavy metals [lead (Pb(+2)), cadmium (Cd(+2)), mercury (Hg(+2)), arsenic (As(+5))]. A total of 39 Enterococcus strains, isolated from stool and rectal swabs of hospitalized patients were included to the study. Twenty of the strains were resistant to glycopeptides (11 were resistant to vancomycin + teicoplanin and 9 were resistant to only vancomycin). Disk diffusion method was performed to determine the high level resistance to aminoglycosides (gentamicin 120 mu g and streptomycin 300 mu g), and agar dilution method was used to detect the sensitivities of the strains against different concentrations (0.005-20 mM begin_of_the_skype_highlighting 005-20 mM ÜCRETSİZ end_of_the_skype_highlighting) of heavy metals. Since there is no specified minimum inhibitory concentration (MIC) breakpoints for heavy metals, resistance criteria described in previous studies were used. Accordingly, enterococci which exhibited MIC >= 1 mM for lead and cadmium, MIC >= 0.1 mM for mercury, and MIC >= 10 mM for arsenic were accepted as resistant. High level aminoglycoside (HLAG) resistance rates were found as 91% (10/11) for vancomycin (V) + teicoplanin (T) resistant and 42% (8/19) for glycopeptide susceptible strains. While all of the isolates were resistant to lead (100%), arsenic (2.6%) and mercury (2.6%) resistance was detected in one isolate for each metal. No cadmium resistance has been detected. In our study, enterococci have exhibited seven different resistance profiles (10 strains were resistant to V + T + HLAG + Pb; 1 was resistant to V + T + Pb; 1 was resistant to V + As + Pb; 1 was resistant to HLAG + Hg + Pb; 8 were resistant to V + Pb; 7 were resistant to HLAG + Pb; 11 were only resistant to Pb). Resistance to antibiotics (aminoglycosides and/or vancomycin and/or teicoplanin) and heavy metals (lead and arsenic and/or mercury) were detected concurrently in 28 (%71.8) of the strains. It was considered remarkable that all of the isolates were resistant to lead and there was no difference between antibiotic-resistant and-susceptible strains in terms of lead resistance. In conclusion, further investigations are needed to reveal the extreme lead resistance and the relations between antibiotic and heavy metal resistances in clinical enterococcus strains. Keywords Author Keywords:Enterococcus; glycopeptide; high level aminoglycoside; heavy metal; susceptibility KeyWords Plus:ANTIBIOTIC-RESISTANCE; STAPHYLOCOCCUS; PLASMID; GENE

Virulence Genes and Antibiotic Susceptibilities of Uropathogenic E. coli Strains

Background: The aim of this study is to detect the presence of and possible relation between virulence genes and antibiotic resistance in E. coli strains isolated from patients with acute, uncomplicated urinary tract infections (UTI)