Determination of SHV-2, SHV-5, SHV-12 and CTX-M-3 Extended-Spectrum Beta-Lactamases in Clinical Enterobacteriaceae Isolates: Scientific Letter

WOS: 000284798000037Extended spectrum beta-lactamases (ESBLs) are common in our country as well as in the world. However, data about the molecular types of these enzymes are lacking in Turkey. ESBLs were initially determined commonly as TEM and SHV derivatives, but in recent years CTX-M enzymes have become more dominant. The aim of the study was to investigate of CTX-M and PER genes in Enterobacteriaceae isolates which were positive for ESBL and carried TEM and/or SHV genes, and to determine DNA sequences of all enzymes. Presence of CTX-M and PER beta-lactamases was investigated with polymerase chain reaction (PCR) method in 28 strains obtained from the Microbiology Laboratory of Dokuz Eylul University Medical School. PCR-restriction fragment lenght polymorphism (PCR-RFLP) and DNA sequence analysis were performed on PCR positive strains. While CTX-M gene was determined in three strains using PCR, PER gene was determined in none of the strains. All CTX-M enzymes were found to belong to CTX-M-1 group according to RFLP analysis. As a result of both strands DNA sequence analysis, SHV-2 in four strains, SHV-5 in 14 strains, SHV-12 in 10 strains and CTX-M-3 in three strains were determined

Evaluation of the Relationship Between Microenvironment and Biofilm and Coagulase Responses of Staphylococcus aureus Strains Under the Effect of Gentamicin

The frequency of infections caused by Staphylococcus aureus strains and the rate of antibiotic resistance among these strains are gradually increasing. Accordingly, serious problems emerge in the treatment of community or hospital acquired S.aureus infections. This study was aimed to determine the role of MIC and sub-MIC concentrations of gentamicin on biofilm and coagulase forming effects of S.aureus in in vitro test systems and cell cultures. A standard S.aureus ATCC 25923 strain and two clinical S.aureus strains isolated from blood cultures (Cl and C2) were included in the study. Gentamicin MIC values of the strains were determined with microdilution method at the cation-adjusted Mueller Hinton broth according to CLSI standards. For each strain, MIC, 50% MIC and 25% MIC values of gentamicin were determined separately. At the determined MIC values, biofilm formations of strains were determined with crystal violet method spectrophotometrically. Also, coagulase activities of the strains were evaluated in glass tubes. Human origin epithelial cell cultures namely HEp-2 cell lines, were infected with the standard and clinical S.aureus strains (Multiplicity of infection: 50/1) and left for incubation for two hours. After all, MIC, 50% MIC and 25% MIC values of gentamicin, were added to infected cell lines and incubated for 18 hours. Cells were blown up with distilled water and then bacteria were collected. Biofilm formation and coagulase production of these bacteria were evaluated. When S.aureus ATCC 25923 strain and Cl strains' biofilm formation was evaluated before (in vitro) and after incubation in cell culture, no difference was observed. However in C2 strain, under the effect of MIC level gentamicin, biofilm formation was occurred after interaction with the cell. In the same way, when coagulase responses were evaluated, after interaction with the cell, coagulase production of C2 strain was inhibited. These results indicated that, phenotypic characteristics such as biofilm formation and coagulase production might change during the process of bacterial adaptation to microenvironment. Further advanced experimental modelling designed with different combinations of antibiotics and different cell lines may provide data about the causes and timing of these phenotypic changes and shed light on the development of new treatment policies

The life history of the non-native cyprinid fish Carassius gibelio (Bloch, 1782) from Demirkopru Reservoir in the Aegean Region in Turkey

Age, growth, reproduction, mortality, and length-weight relationships of 733 specimens of Carassius gibelio caught monthly using fishing nets of different mesh sizes (9 to 90 mm) in June 2015 - November 2016 from Demirkopru Reservoir, Aegean Region, were studied. Of the 689 fish specimens whose sex was determined, 475 were female and 214 were male. The total length and weight were determined to range between 10.7-39.6 cm and 12- 928 g, respectively. The length-weight relationships of females, males, and the entire population were described by the equations W=0.010xL(3.10), W=0.010xL(3.18), and W=0.010xL(3.12), respectively. The condition factor (CF) of the population did not vary by month and was generally in a similar value range. Gonadosomatic index (GSI) values reached the highest value in female individuals in March, while male individuals in February. The spawning period was determined to be from April to August when GSI values decreased, and the spent maturity stage female individuals were seen. According to the age identification using vertebrae, the population was in the age range of I - XIII. With 17%, the III age group had the highest ratio in all individuals. Growth parameters of the population were: L-infinity = 44.49 cm, K = 0.20 year(-1) and t(0) = -1.92 years for females; L-infinity = 38.32 cm, K = 0.25 year(-1) and t(0) = -2.14 years for males and L-infinity = 44.84 cm, K = 0.20 year(-1) and t(0) = -1.83 years for all population. The growth performance index (Phi') was calculated as 2.60, 2.56, and 2.60, for females, males, and all individuals, respectively. The natural mortality (M) rate was calculated to be 0.17 year(-1) for females and males. Total mortality (Z), fishing mortality, and (F) exploitation (E) rates were calculated to be 0.34, 0.17 year(-1), and 50% for females; 0.31, 0.14 year- 1, and 45% for males, respectively. As a result, the invasive Carassius gibelio was found to be best adapted to the environment in Demirkopru Reservoir, where it was first recorded in the 2011 fishing reports.Izmir Katip Celebi University Scientific Research Projects [2015-ODL-SUUF-0003]; TUBITAK [214O632]We thank Turhan Kebapcioglu and Yusuf Sen for their help in field and laboratory studies. The study was sponsored by Izmir Katip Celebi University Scientific Research Projects (2015-ODL-SUUF-0003 Numbered Project) and TUBITAK (214O632 Numbered Project). The authors also thank the journal editor and anonymous referees for their valuable comments and suggestions