Spatial spread and emergence of reassortant H5 highly pathogenic avian influenza viruses in Iran.

Since 2005, H5Nx highly pathogenic avian influenza (HPAI) viruses of the Goose/Guangdong (Gs/GD) lineage have spread worldwide, affecting poultry and wild birds in Asia, Europe, Africa and North America. So far, the role of Western Asia and the Middle East in the diffusion dynamics of this virus has been poorly explored. In order to investigate the genetic diversity and the role of Iran in the transmission dynamics of the Gs/GD lineage, we sequenced the complete genome of twenty-eight H5Nx viruses which were circulating in the country between 2016 and 2018. We reported the first characterization of the HPAI H5N6 subtype of clade 2.3.4.4B in Iran and gave evidence of the high propensity of the Gs/GD H5 AIVs to reassort, describing six novel H5N8 genotypes of clade 2.3.4.4B, some of them likely generated in this area, and one H5N1 reassortant virus of clade 2.3.2.1c. Our spatial analyses demonstrated that the viruses resulted from different viral introductions from Asia and Europe and provided evidence of virus spread from Iran to the Middle East. Therefore, Iran may represent a hot-spot for virus introduction, dissemination and for the generation of new genetic variability. Increasing surveillance efforts in this high-risk area is of utmost importance for the early detection of novel emerging strains with zoonotic potential.

Molecular characterization and Functional Analysis of the PilQ380-706: a Novel Secretin Domain in Pseudomonas aeruginosa.

BACKGROUND: Type 4 pili (T4P) is an important virulence factor of Pseudomonas aeruginosa (P. aeruginosa). T4P pass the outer membrane through a large oligomeric channel made of a single PilQ protein that is most highly conserved at their C-termini. To develop a functional vaccine that can be used in clinical application, the secretin domain of the PilQ (PilQ380-706) was produced as a recombinant protein. METHODS: A 981 bp fragment of C-terminal of the pilQ secretin (pilQ1138-2118) from was designed into the prokaryotic expression vector pET28a. The presence of the pilQ1138-2118 gene in the recombinant construct (pET28a/pilQ) was assessed by double digestion and PCR. After transformation, expression of the recombinant PilQ was induced by addition of IPTG. The expressed recombinant protein was purified by a modified method using a HisTrap affinity column and finally confirmed by SDS-PAGE. The functional activities of the produced PilQ380-706 confirmed by Western blot analysis and twitching inhibition assay. RESULTS: The PCR and enzymatic digestion results showed the presence of the pilQ1138-2118 gene in the construct. The protein electrophoresis showed that the molecular weight of the recombinant PilQ380-706 is approximately 37 kDa. The Western blot analysis confirmed the specificity of specific IgG against the PilQ380-706 protein. The PilQ380-706 protein showed high biological activity in all of these standard assays. CONCLUSION: Since, the PilQ380-706 protein plays an important role in the biogenesis of pili; and thus, the primary establishment of P. aeruginosa; it seems that it can be used as a candidate vaccine or an adjuvant in the future studies.

Antibiotic Resistance Pattern and Distribution of pslA Gene Among Biofilm Producing Pseudomonas aeruginosa Isolated From Waste Water of a Burn Center.

BACKGROUND: Pseudomonas aeruginosa is considered as a major cause of hospital-acquired infections due to its high antibacterial resistance. Biofilm formation is a well-known pathogenic mechanism in P. aeruginosa infections, since sessile bacteria are protected in an extracellular matrix of exopolysaccharide. The expression of polysaccharide synthesis locus (pslA gene) can be important for biofilm formation by P. aeruginosa. OBJECTIVES: The purpose of this research was to evaluate the antibiotic resistance pattern and distribution of the pslA gene among biofilm-producing P. aeruginosa isolates obtained from waste water of Burn Centre in Guilan, Iran. MATERIALS AND METHODS: Fifty isolates of P. aeruginosa were obtained from waste water of a burn center. The P. aeruginosa isolates were identified using standard bacteriological procedures. Drug susceptibility test was performed by disk diffusion method for all the isolates against nine antimicrobial agents. Biofilm formation was measured by microtiter plate assay. Polymerase chain reaction (PCR) was used to identify the presence of the pslA gene among the isolates. RESULTS: Biofilm formation was observed in 70% of the P. aeruginosa isolates. The potential formation of biofilm was significantly associated with resistance to gentamicin, imipenem, tobramycin and piperacillin. In addition, the pslA gene only existed in biofilm-producing isolates with a frequency of 42.9% (n = 15). CONCLUSIONS: The findings of the present study well demonstrated that the P. aeruginosa biofilm-producing isolates were more resistant to the tested antibiotics. Furthermore, because of wide distribution, it seems that the pslA gene is associated with biofilm formation.

Serotype determination of adenoviruses in children with respiratory infection.

OBJECTIVE: To determine adenovirus serotypes among children with acute respiratory infection (ARI) in Khoozestan province, Iran during years 2010-2011. METHODS: One hundred sixty three nasopharyngeal swabs were collected from children between 1 and 15 y who were hospitalized for the acute respiratory infection. The viral DNA was extracted from the nasopharyngeal swabs and adenoviruses were detected by Nested PCR. Positive PCR samples were sequenced in order to confirm the adenovirus serotypes. RESULTS: Out of 163 samples, 30 (18.4 %) were positive for adenoviruses by nested PCR. Twenty two PCR products were sequenced and recognized as Ad5 and Ad2 serotypes including 19 (86.3 %) Ad5 and 3 (13.7 %) Ad2. CONCLUSIONS: This study reveals that adenoviruses with Ad5 predominance are important cause of respiratory tract infection in children.