ABSTRACT
Solanum whitefly, Aleurothrixus trachoides (Back). (Hemiptera: Aleyrodidae) was considered as a non-virusvector by European and Mediterranean Plant Protection Organization (EPPO) reports. However, in the presentstudy it was found to transmit Duranta leaf curl virus (DLCV) to tomato, bell pepper and potato. A. trachoidesinfested field samples of Duranta sp (100%) and tomato (20%) tested positive for begomovirus by PCR usingbegomovirus degenerate primers and primers specific to Tomato leaf curl New Delhi virus showing ampliconof 520 bp and 2.7 Kb respectively. The DNA samples of A. trachoides collected from virus positive durantaand tomato plants also tested positive for the virus. Virulent whiteflies from duranta could successfully transmitDLCV to bell pepper (26%) and tomato (13%) plants as confirmed by Rolling Circle Amplification. The rate ofvirus transmission by A. trachoides from DLCV inoculated tomato to bell pepper and tomato to potato was100% and tomato to tomato was 80%. The results suggest whitefly A. trachoides as the vector for DLCV and tothe best of our knowledge, this is the first report for A. trachoides as vector of begomovirus. These findingssuggest need for reconsideration of A. trachoides as a virus-vector. This will have great impact on solanaceousvegetable cultivation in India and other parts of the world.
ABSTRACT
Background & objectives: Intravenous device (IVD) associated nosocomial blood stream infections due to staphylococci are major cause of morbidity and mortality. The present study was carried out to assess the frequency of staphylococcal IVD associated infections in a paediatric ward of a tertiary case hospital. Prevalence of resistance to commonly used antimicrobials in hospital acquired staphylococcal isolates was also tested. Methods: Children admitted in paediatric wards with IVD for more than 48 h were enrolled. Blood, IVD tip at the time of removal, skin swab at the site of insertion of IVD and nasal swab were collected and cultured by standard protocol. All staphylococcal isolates from any source were analyzed for antimicrobial susceptibility by disk diffusion method. Genotyping matching of those staphylococcal isolates was done which were isolated from different sites of the same patient, but were phonotypically similar. Genotype of blood isolate was compared with genotype of isolate from nose/IVD/skin. Results: Staphylococcus aureus was the most frequent blood isolate (8.7%) followed by Candida (2.9%), coagulase negative staphylococci (CoNS 2.6%), Pseudomonas spp. (0.4%), Klebsiella spp. (0.3%) and Escherichia coli (0.1%). Isolation of microorganisms from blood was significantly higher in patients whose skin, IVD and nose were colonized by same microorganism (P<0.001). None of the staphylococcal isolate was found to be resistant to glycopeptides (vancomycin and teicoplanin). High penicillin and oxacillin resistance was present in both S. aureus (penicillin resistance; 76.8%, oxacillin resistance; 66.7%) and CoNS (penicillin resistance; 73.3%, oxacillin resistance; 60.0%). Among CoNS biotypes, S. haemolyticus was commonest blood isolate while S. epidermidis was commonest isolate from Skin/nose. Only 33.3 per cent of S. aureus blood stream infections and most of S. epidermidis and S. haemolyticus blood infections were IVD associated. Interpretation & conclusions: Staphylococci were the major causative agent of nosocomial blood stream infections. All episodes of septicaemia due to S. epidermidis and S. haemolyticus were IVD associated while only 1/3 of S. aureus septicaemia was IVD associated.