AIM: In the current study, for further validation, we initiated a comprehensive epidemiological study to identify the dominant NDV genotype(s) circulating within the country. Collection of samples was executed between October 2017 and February 2018 from 108 commercial broiler farms which reported clinical signs of respiratory disease in their broilers.
RESULT: We report that 38 of the farms (> 35%) tested positive for NDV. The complete F gene sequences of seven of the isolates are shown as representative sequences in this study. According to the phylogenetic tree constructed, the recent broiler farm isolates clustered into the newly designated cluster VII(L) together with the older Iranian backyard poultry isolates in our previous work. All the sequences shared the same virulence-associated F cleavage site of 112RRQKR↓F117.
CONCLUSION: Our phylogenetic analysis suggested that the NDV subgenotype VII(L) may have been derived from subgenotype VIId, and contrary to popular belief, subgenotype VIId may not be the dominant subgenotype in Iran. Tracking of the subgenotype on BLAST suggested that the NDV subgenotype VII(L), although previously unidentified, may have been circulating in this region as an endemic virus for at least a decade. Other NDV genotypes, however, have also been reported in Iran in recent years. Hence, ongoing study is aimed at determining the exact dominant NDV genotypes and subgenotypes in the country. This will be crucial in effective mitigation of outbreaks in Iranian broiler farms.
METHOD: Endolysin and VAPGH genes were cloned and expressed in L. lactis NZ9000 after fusion with the SPK1 signal peptide for secretion. The recombinant proteins were expressed and purified, then analyzed for antimicrobial activity using plate assay and turbidity reduction assay. In addition, the spent media of the recombinant lactococcal culture was analyzed for its ability to inhibit the growth of the S. aureus PS 88.
RESULTS: Extracellular recombinant endolysin (Endo88) and VAPGH (VAH88) was successfully expressed and secreted from L. lactis which was able to inhibit S. aureus PS 88, as shown by halozone formation on plate assays as well as inhibition of growth in the turbidity reduction assay. Moreover, it was observed that the spent media from L. lactis NZ9000 expressing Endo88 and VAH88 reduced the viability of PS 88 by up to 3.5-log reduction with Endo88 being more efficacious than VAH88. In addition, Endo88 was able to lyse all MRSA strains tested and Staphylococcus epidermidis but not the other bacteria while VAH88 could only lyse S. aureus PS 88.
CONCLUSION: Recombinant L. lactisNZ9000 expressing phage 88 endolysin may be potentially developed into a new antimicrobial agent for the treatment of MDRSA infection.
METHODS:: This meta-narrative review was performed by searching PubMed using the following search terms: (molecular diagnosis) AND (antimicrobial resistance) AND (methicillin-resistant Staphylococcus aureus). Studies using molecular diagnostic techniques for the detection of MRSA were included, while non-English language, duplicates and non-article studies were excluded. After reviewing the libraries and a further manual search, 20 studies were included in this article. RAMESES publication standard for narrative reviews was used for this synthesis.
RESULTS:: A total of 20 full papers were reviewed and appraised in this synthesis, consisting of PCR technique (n = 7), deoxyribonucleic acid (DNA) Microarray (n = 1), DNA sequencing (n = 2), Xpert MRSA/SA BC assay (n = 2), matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) (n = 2), MLST (n = 4), SCCmec typing (n = 1) and GENECUBE (n = 1).
DISCUSSION:: Different diagnostic methods used to diagnose MRSA have been studied in this review. This study concludes that PCR has been extensively used due to its higher sensitivity and cost-effectiveness in the past five years
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.