[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.

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.

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.