[Genotypes of rhinoviruses in children and adults patients with acute respiratory tract infections].Mikrobiyol Bul. 2017 Oct; 51(4):350-360.MB
Rhinovirus (RV) is one of the most frequent causative agent of acute respiratory tract infections in the world. The virus may cause a mild cold, as well as more serious clinical symptoms in patients with immune system deficiency or comorbidities. Rhinoviruses have been identified by molecular methods under three types: RV-A, RV-B and RV-C. In most of the cases, it was reported that RV-A and RV-C were related with lower respiratory tract infections and asthma exacerbations, while RV-B was rarely reported in lower respiratory tract infections. The main objective of this study was to investigate RV species by sequence analysis in nasopharyngeal samples in pediatric and adult patients who were admitted to hospital with acute respiratory tract infections and to establish the relationship between species and age, gender and clinical diagnosis of the patients. Secondly, it was planned to emphasize the efficiency of the sequence analysis method in the determination of RV species. One hundred twenty seven patients (children and adults) who were followed up with acute respiratory tract infections in our university hospital were evaluated between January 2014 and January 2016. Viral loads were determined by quantitative real-time PCR in RV positive patients detected by a commercial kit in nasopharyngeal swab specimens. Thirty-one samples whose viral loads could not be determined were excluded from the study. The remaining 96 samples (50 children and 46 adults) were retested by conventional PCR using the target of VP4/VP2 gene region. A total of 65 samples (32 adults and 33 children) with the bands (549 bp) corresponding to the VP4/VP2 gene regions after the conventional PCR were analyzed by DNA sequencing. A phylogenetic tree was constructed using the neighbour-joining method. After sequence analysis it was determined that 28 (43.07%) were RV-A, 7 (10.76%) were RV-B and 28 (43.07%) were RV-C; and moreover one of each enterovirus (EV) species EV-D68 (1.53%) and EV-C (1.53%) were detected. The distribution of the species in adults was: 15 (48.3%) RV-A, 5 (16.1%) RV-B and 11 (35.4%) RV-C. The distribution of the species in children was 13 (40.6%) RV-A, 2 (6.3%) RV-B and 17 (53.1%) RV-C. RV-A is more frequent in adults, while RV-C is more frequent among children. It has been observed that RV-C infection is detected in children with bronchiolitis, while RV-A infection is detected in adults with pneumonia. There was no statistically significant difference between RV species and clinical diagnosis, age and gender in both of the age groups (p> 0.05). In conclusion, this is the first study that reports the frequency of RV species in children and adult patients with acute respiratory tract infections; the frequency of RV-A and RV-C species were found to be similar but higher than RV-B species in all age groups. RV-C and RV-A was the highest species seen in children and adult patients, respectively. There is a need for further research to identify the types of RV circulating in the community and the prevalence of infections caused by the species.