[Clinical symptoms and signs in hamsters during experimental infection with the SARS-CoV-2 virus (Coronaviridae: Betacoronavirus)].

INTRODUCTION: At the beginning of December 2019, humanity has faced a new problem caused by coronavirus. In Hubei province of central China, epidemic events associated with severe primary viral pneumonia in humans began to develop. The isolated etiological agent was identified as a representative of Coronaviridae family. The global pandemic associated with the new coronavirus infection, acute respiratory syndrome type 2 (Severe acute respiratory syndrome 2, SARS-CoV-2), has become a challenge for humanity. OBJECTIVE: In our work, we assessed the replicative ability and pathogenesis of the SARS-CoV-2 virus in hamsters. MATERIALS AND METHODS: Syrian hamsters (n=16) randomly divided into two groups were used in experiment. The first group was infected intranasally with the SARS-CoV-2 virus, strain SARS-CoV-2/human/KAZ/KZ_Almaty/2020 deposited in GenBank under number MZ379258.1. The second group remained as a control group. Clinical manifestations of the disease in hamsters were observed within 14 days. Samples were collected on days 3, 5, 7, 9, 12, and 14 postinfection. The obtained samples were tested for viral isolation in cell culture, histological examination and analysis of viral RNA by RT-PCR. RESULTS: SARS-CoV-2 virus isolates showed efficient replication in the lungs of hamsters, causing pathological lung lesions in animals infected intranasally. Clinical manifestations of the disease in hamsters infected with this virus were characterized by a decrease in temperature and body weight, wetness and ruffled fur, and frequent stroking of the nasal planum. High virus titers were observed following the virus isolation in cell cultures from nasal, oral swabs and lungs of animals infected intranasally. Pathological autopsy demonstrated pathological changes in the lungs. Moreover, transmission by airborne droplets has been established when a healthy hamster was kept together with animals infected using the intranasal method. CONCLUSION: In conclusion, our study showed that the Syrian hamster model is a useful tool for studying the SARS-CoV-2 pathogenesis, as well as testing vaccine candidates against acute respiratory syndrome type 2.

Some metals inhibit the glutathione S-transferase from Van Lake fish gills.

Glutathione S-transferases (GSTs) are the superfamily of multifunctional detoxification isoenzymes and play important role cellular signaling. The present article focuses on the role of Cd2+ , Cu2+ , Zn2+ , and Ag+ in vitro inhibition of GST. For this purpose, GST was purified from Van Lake fish (Chalcalburnus tarichii Pallas) gills with 110.664 EU mg-1 specific activity and 79.6% yield using GSH-agarose affinity chromatographic method. The metal ions were tested at various concentrations on in vitro GST activity. IC50 values were found for Cd+2 , Cu+2 , Zn+2 , Ag+ as 450.32, 320.25, 1510.13, and 16.43 µM, respectively. Ki constants were calculated as 197.05 ± 105.23, 333.10 ± 152.76, 1670.21 ± 665.43, and 0.433 ± 0.251 µM, respectively. Ag+ showed better inhibitory effect compared with the other metal ions. The inhibition mechanisms of Cd2+ and Cu2+ were non-competitive, whereas Zn2+ and Ag+ were competitive. Co2+ , Cr2+ , Pb2+ , and Fe3+ had no inhibitory activity on GST.

Purification of glutathione S-transferase from Van Lake fish (Chalcalburnus tarichii Pallas) muscle and investigation of some metal ions effect on enzyme activity.

Glutathione S-transferases (GSTs) are an important enzyme family which play a critical role in detoxification system. In our study, GST was purified from muscle tissue of Chalcalburnus tarichii Pallas with 301.5-fold purification and 19.07% recovery by glutathione agarose affinity chromatography. The purity of enzyme was checked by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, showing a two band, because of having heterodimer structure. KM values were 1.59 and 0.53 mM for 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione (GSH), respectively. Vmax values for CDNB and GSH were also determined as 5.58 and 1.88 EU/mL, respectively. In addition, inhibition effects of Ag(+), Cu(2+), Cd(2+), Fe(3+), Pb(2+), Cr(2+), Co(2+) and Zn(2+) metal ions were investigated on the enzyme activity and IC50, Ki values were calculated for these metal ions.

The microbial colonisation of mobile phone used by healthcare staffs.

Mobile phones are dispensable accessories in social life and normally they are not cleaned properly. Therefore, they serve as a reservoir of bacteria and may cause nosocomial infections in hospitals. The purpose of this study was to investigate microbiological colonization of mobile phones used by healthcare staffs. The study was carried out collecting swab samples with Cary-Blair transport medium from mobile phones of attending healthcare staffs from different departments of three hospitals in March, 2008. All collected samples were inoculated in 5% sheep blood agar, eosin-methylene blue agar and Sabouraud Dextrose agar. Isolated bacteria were identified using by classic technique and Vitec2 (Biomerieux, France) full automated bacteria identification system. Growth was observed in 65 of collected 106 samples, corresponding to 61.3%. The most frequent bacteria were Staphylococcus epidermidis followed by Staphylococcus aureus, Bacillus sp., Corynebacterium sp. and Escherichia coli, respectively. In conclusion, bacteria were colonized on mobile phones frequently and mobile phones may become reservoir of microorganism for nosocomial infections.

Occupational lead exposure effect on liver functions and biochemical parameters.

The effect of occupational lead exposure on the liver function and on the blood biochemical parameters among the battery workers and the muffler repair workers was studied. The study included 22 battery and 38 muffler repair workers. Whole blood lead levels were determined by atomic absorption spectrophotometers. Total protein, albumin, globulin, cholesterol, triglyceride, total bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), gamma glutamyltransferase (GGT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) levels were determined in the serum by spectrophotometry. The blood lead levels of the battery workers, muffler repair workers, and the controls were found to be 36.83 +/- 8.13 microg/dL, 26.99 +/- 9.42 microg/dL, and 14.81 +/- 3.01 microg/dL, respectively. Blood lead levels of the workers were significantly higher than those of controls (p < 0.001). The lead level of the battery workers was also significantly higher than that of muffler repair workers (p < 0.001). Although, statisticly significant, higher blood lead levels are not related to toxicity for battery and muffler repair workers. Total protein, globulin, cholesterol, LDH, and ALP levels were within normal levels, however, they were slightly higher than the control levels. Increased LDH among the workers seems to be related rather to other causes than to the liver injury.

Investigation of diarrhea agents less than 5 years of age in summer in Gaziantep/Turkey.

Pathogens causing summer diarrhea examined to detect among children less than 5 years of age in Gaziantep. We conducted among 100 children with diarrhea during summer at the pediatric hospital of Gaziantep. In stool samples from children, Rotavirus with Rotatect kit (Dade Behring, Germany), Entamoeba spp. with direct microscopy and bacterial pathogens with cultural techniques investigated. Cystic form of Entamoeba spp. was determined in 61 (61%) and Rotavirus antigen in 25 positive samples (25%). A predominant bacterium was determined in total 87 stool samples (87%). Despite of only cystic form of Entamoeba spp. was determined in seven, only bacteria in 22 and only Rotavirus in one; two of them were determined in 67 out of stool samples. According to comparison with stool samples belong to various months we have found that, Rotavirus and E. coli are the most pathogenic agents in August more than June and July.