Report of a new meq gene size: The first study on genetic characterisation of Marek's disease viruses circulating in Iranian commercial layer and backyard chicken.

1. In recent months, several outbreaks with clinical signs of MDV-1 were reported in Iranian parent and laying hen farms, in addition to backyard chickens. Several meq gene sequences from these outbreaks were amplified and molecularly characterised.2. The meq protein sequences revealed three different sizes, namely the standard 339 aa, a shorter form of 338 aa lacking a proline residue at position 191, and a very short (vs) size of 265 aa. Based on sequence and size, the 265 aa meq has never been reported from international research groups before. The protein has only one PPPP repeat motif suggesting it belongs to a highly virulent strain.3. The standard meq sequences showed 100% BLAST identity to the vv+ isolate Polen5. However, the 338 aa form clustered to the clade usually reported from North America.4. This is the first report on genetic analysis of MDV-1 from Iran, but further study is required to obtain a better picture of the diversity and prevalence of different MDV-1 strains circulating in the country's farms, backyard poultry and other bird species.

Association of antimicrobial resistance and gut microbiota composition in human and non-human primates at an urban ecotourism site.

BACKGROUND: The rise of nature-based ecotourism in the past decade has introduced unprecedented challenges in managing the increasing interaction between humans and animals. The potential transmission of antibiotic resistant microbes between humans and non-human primate populations is a concern due to their genetic similarity. Malaysia is well known for hotspots of wildlife diversity where non-human primates like monkeys and orangutans have become popular tourist attractions. In this study, we assessed the prevalence of antimicrobial resistant Staphylococcus aureus, Enterococcus species, and other Enterobacteriaceae in the faeces of human (HS) and two non-human primates (NHP) in Malaysia, the Long-tailed macaque (Macaca fascicularis, MF) and Silvered leaf monkey (Trachypithecus cristatus, TC). In addition, the faecal bacterial composition was profiled to evaluate the potential association between antibiotic resistant profiles and composition of gut microbiota. RESULTS: We tested the isolated bacteria using a selection of antibiotics. The results showed that both the number of antibiotic resistant strains and resistance level were higher in humans than NHPs. Overall, the composition of gut microbiome and pattern of antibiotic resistance showed that there was higher similarity between MF and TC, the two NHPs, than with HS. In addition, samples with higher levels of antibiotic resistance showed lower bacterial richness. Homo sapiens had the lowest bacterial diversity and yet it had higher abundance of Bacteroides. In contrast, NHPs displayed higher bacterial richness and greater prevalence of Firmicutes such as Ruminococceae and Oscillospira. CONCLUSION: Higher antibiotic susceptibility in NHPs is likely related to low direct exposure to antibiotics. The lack of resistance may also suggest limited antimicrobial resistance transmission between humans and NHP. Nonetheless, continued monitoring over a long period will help mitigate the risk of anthropozoonosis and zooanthroponosis.

Membrane disruption and anti-quorum sensing effects of synergistic interaction between Lavandula angustifolia (lavender oil) in combination with antibiotic against plasmid-conferred multi-drug-resistant Escherichia coli.

AIM: The aim of this study was to investigate the mode of action of the lavender essential oil (LV) on antimicrobial activity against multi-drug-resistant Escherichia coli J53 R1 when used singly and in combination with piperacillin. METHOD AND RESULTS: In the time-kill analysis, a complete killing of bacteria was observed based on colony counts within 4 h when LV was combined with piperacillin during exposure at determined FIC concentrations. Analysis of the membrane permeabilizing effects of LV on treated cultures through their stability against sodium dodecyl sulphate revealed that the LV played a role in disrupting the bacterial cell membrane. The finding is further supported by scanning electron microscopy analysis and zeta potential measurement. In addition, reduction in light production expression of E. coli [pSB1075] by the LV showed the presence of potential quorum sensing (QS) inhibitors. CONCLUSIONS: These results indicated that the LV has the potential to reverse bacterial resistance to piperacillin in E. coli J53 R1. It may operate via two mechanisms: alteration of outer membrane permeability and inhibition of bacterial QS. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings offer a novel approach to develop a new option of phytopharmaceuticals against multi-drug-resistant E. coli.

Surface display of respiratory syncytial virus glycoproteins in Lactococcus lactis NZ9000.

AIMS: A system for displaying heterologous respiratory syncytial virus (RSV) glycoproteins on the surface of Lactococcus lactis NZ9000 was developed. METHODS AND RESULTS: Fusion of the USP45 signal peptide and the cA (C terminus of the peptidoglycan-binding) domains of AcmA, a major autolysin from L. lactis, to the N- and C-terminal of the target proteins, respectively, was carried out. The target protein was the major immunogenic domain of either the F (40.17-kDa) or G (11.49-kDa) glycoprotein domains of the RSV. Whole-cell ELISA readings obtained after 24 h of induction showed an increase in protein expression as the cA domain repeats increased, for the G glycoprotein of RSV. On the other hand, the F glycoprotein indicated decreasing expression levels as the number of cA domain repeats increased. The difference in the expression levels of the F and G domains may be attributed to the different sizes of the antigenic domains. CONCLUSIONS: The size and properties of the target proteins are vital in determining the amount of antigenic domains being displayed on the surface of live cells. SIGNIFICANCE AND IMPACT OF THE STUDY: The system demonstrated here can aid in the utilization of the generally regarded as safe (GRAS) bacteria L. lactis, as a vaccine delivery vehicle to surface display the antigenic proteins of RSV.

Glycosylation is not necessary for recognition of the fusion glycoprotein domain of the human respiratory syncytial virus by a polyclonal antibody.

Human respiratory syncytial virus (HRSV) is a leading pathogen causing lower respiratory tract infections in infants and young children worldwide. In line with the development of an effective vaccine against HRSV, a domain of the fusion (F) glycoprotein of HRSV was produced and its immunogenicity and antigenic properties, namely the effect of deficient glycosylation was examined. A His-tagged recombinant F (rF) protein was expressed in Escherichia coli, solubilized with 8 mol/l urea, purified by the Ni-NTA affinity chromatography and used for the raising of a polyclonal antibody in rabbits. The non-glycosylated rF protein proved to be a strong immunogen that induced a polyclonal antibody that was able to recognize also the glycosylated F1 subunit of native HRSV. The other way around, a polyclonal antibody prepared against the native HRSV was able to react with the rF protein. These results indicated that glycosylation was not necessary for the F domain aa 212-574 in order to be recognized by the specific polyclonal antibody.