[Investigation of Group A Rotavirus G10, G12 Genotypes Emerging in Patients with Acute Gastroenteritis in a Tertiary Care Hospital]. / Hastanemize Basvuran Akut Gastroenteritli Hastalarda Yeni Görülmeye Baslayan A Grubu Rotavirüs G10, G12 Genotiplerinin Arastirilmasi.

Rotaviruses are the most common cause of viral gastroenteritis with the highest mortality and morbidity rates in children aged 0-5 years. The aim of this study was to determine the frequency of rotavirus infection in patients whose stool samples were sent to microbiology laboratory to investigate the etiology of diarrhea, to investigate the rotavirus genotypes that are common in our region and G10, G12 genotypes that have recently become common in the world. Fecal samples of 476 patients aged between 0-92 years who applied between November 2016 and February 2018 were studied via immunochromatographic rapid test and enzyme-linked immunosorbent assay (ELISA) methods. ELISA positive samples were studied by nested reverse transcriptase chain reaction (RT-PCR) and genotyped by agarose gel electrophoresis. Rotavirus was found positive in 18.3% and 17% of stool samples by immunochromatographic test and ELISA, respectively. All ELISA positive samples were also detected as positive by RT-PCR. 18.5% of female patients and 15.7% of male patients were found to be positive and rotavirus positivity was not statistically significant between genders. The frequency of rotavirus in different age groups was 23.5% (6-12 years), 17.3% (13-24 months) and 16% (25-36 months). It was determined that rotavirus cases were most common in the spring. G1, G2, G3, G4, G9, G10, and G12 were detected in 37%, 7.4%, 16.1%, 6.2%, 9.9%, 2.5%, 26% of the samples, respectively. G12 was the most common genotype after G1. The most common G and P genotype combination was G1P[8] (17.2%). This was followed by G12P[8] (11.11%) and G3P[8] (11.11%). P[8] (53%) was found to be the dominant P genotype. In this study, it was observed that rotavirus, which is the cause of childhood diarrhea, can also be encountered in advanced ages and even new genotypes that infect humans worldwide may also be the causative agents. Therefore, we concluded that it is important to investigate new genotypes such as G10 and G12 in molecular epidemiological studies.

[Characterization of Klebsiella pneumoniae strains exposed to subinhibitory concentrations of chlorhexidine]. / Düsük düzeyde Klorhekzidin ile karsilastirilmis Klebsiella pneumoniae izolatlarinin karakterizasyonu.

Chlorhexidine, a topical antiseptic, acts as a cationic biguanide altering the osmotic transport of the bacterial cell wall that has been used throughout the world to prevent healthcare-associated infections for decades. The routine application of chlorhexidine can result in decreased susceptibility of bacteria over time. The aim of this study was to develop Klebsiella pneumoniae strains after exposure to chlorhexidine and characterize these adapted strains in terms of their virulence ability both by in vivo and in vitro methods. Two clinical strains of K.pneumoniae were included in the study. One strain was completely susceptible and the other was resistant to certain antibiotics. Susceptible strain was subjected in the exposure assay as parent/wild strain. Exposure was performed by increasing chlorhexidine concentrations in agar plates. Chlorhexidine concentrations were gradually decreased reaching a final concentration of 0.12 mg/L after five weeks. Chlorhexidine-adapted viable colonies were selected and isolated. Minimal inhibitor concentrations of chlorhexidine, sodium hypochloride, benzalkonium chloride and triclosan for K.pneumoniae strains were determined using broth microdilution method. Reverse transcription-polymerase chain reaction analysis were performed for efflux pumps named cepA, kdeA and acrKp expressions. Fluorimetric efflux assay by using Rhodamine 6G was performed. Galleria mellonella killing assay and in vitro virulence determinants such as esculin hydrolysis, biofilm production, lecithinase, DNase activity, hemolytic activity, lipase production, mucoviscocity, casein hydrolysis and complement-mediated serum killing were evaluated. K.pneumoniae strains exposed to chlorhexidine did not show any antibiotic resistance. MICs for chlorhexidine, sodium hypochloride, and benzalkonium chloride were increased in the adapted strain. Efflux pumps of cepA and kdeA were over-expressed in the chlorhexidine adapted strain. Rhodamine 6G assay showed an increased efflux in the adapted strain. G.mellonella killing assay showed median virulence score. All strains, were esculin positive, while biofilm production, lecithinase, DNase, hemolytic activity, lipase production, mucoviscocity, casein hydrolysis were all negative. The susceptible parent/wild strain was susceptible to the complement-mediated serum killing, while the chlorhexidine adapted strain showed intermediate susceptibility. Chlorhexidine adapted strains of K.pneumoniae showed increased efflux pump expression, enhanced G.mellonella killing and raised resistance to serum killing. No difference was determined for other determinants. Minimal correlation was found between chlorhexidine resistance and virulence in K.pneumoniae.