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Molecular diagnostics of Sarcocystis spp. infections

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Protozoa of the genus Sarcocystis (phylum Apicomplexa, family Sarcocystidae) is one of the most common parasites affecting animals. Interspecies diagnostic of Sarcocystis genus was based on electron microscopy for many years. Because of absence of visible differences between species with reachable magnifications, light microscopy is useless. In many cases serological diagnostic method have lack of sensitivity. A variety of molecular methods have been developed and used to detect and identify Sarcocystis spp. and to assess the genetic diversity among this protozoan from different population/hosts. Nowadays, molecular diagnostic is the common, time/cost effective method used all over the world to interspecies differentiation.
The genus Scopulariopsis contains over 30 species of mitosporic moulds, which although usually saprophytic may also act as opportunistic pathogens in humans. They have mainly been associated with onychomycosis, and only sporadically reported as a cause of deep tissue infections or systemic disease. Identification of Scopulariopsis species still largely relies on phenotype-based methods. There is a need for a molecular diagnostic approach, that would allow to reliably discriminate between different Scopulariopsis species. The aim of this study was to apply sequence analysis of partial 28S rRNA gene for species identification of Scopulariopsis clinical isolates. Although the method employed did reveal some genetic polymorphism among Scopulariopsis isolates tested, it was not enough for species delineation. For this to be achieved, other genetic loci, within and beyond the rDNA operon, need to be investigated.
Thrips from the genus Frankliniella (Thysanoptera, Thripidae) are phytophagous on crops and wild plants. Some of them cause slight economic damage, however, others including F. occidentalis and F. intonsa are responsible for considerable losses in crop production. Moreover, they constitute a double threat for host plants by not only feeding on them but also vectoring viruses, some of which are on the quarantined list of the European Plant Protection Organization. The rapid detection and differentiation between more and less harmful Frankliniella species is, therefore, important in order to combat the pests at the time of their appearance. In this study, we have undertaken to develop a method of detecting F. occidentalis, F. intonsa, F. pallida, and F. tenuicornis. The protocol is based on PCR amplification of ITS1 rDNA fragments of these insects using universal primers pair giving products of slightly distinct length for studied insects. Restriction enzymes digestion which is easy to interpret, allows for visible differentiation of all these Frankliniella species. The method was shown to be species-specific and sensitive. Even single specimens in either the larvae or adult stage could be distinguished.
We have reported a bacterial infection in a dog with progressive dysplasia of the hips. Orthopedic surgery was performed. Seven weeks prior to the surgery, the patient was bitten by another dog. The postimplantation wound exuded for four days after the surgery. Microbiological analysis performed by standard identification techniques showed the presence of Staphylococcus intermedins, but an additional molecular analysis indicated S. pseudintermedius. This was followed by an evaluation of antibiotic susceptibility of the strain which showed cefoxitin, ciprofloxacin, clindamycin, trimethoprim/sulfamethoxazole, doksycycline, erythromycin, and gentamicin resistance. Minimal inhibitory concentration (MIC) values for selected antibiotics were reported. Resistance for cefoxitin indicates that methicillin resistant S. pseudintermedius (MRSP) strains were present in individual macroorganisms, but they can expand and persist the colonization of other hosts.
Ditylenchus is a serious pathogen occurring worldwide which causes huge losses in agricultural crop production. The quarantine Ditylenchus dipsaci is one of the most devastating species of this genus. A proper identification by this species is crucial because of significant morphological similarity to non-quarantine Ditylenchus species. There are several diagnostic methods recommended by EPPO. However, because of considerable genetic variability within discussed species not all of them are suitable for each population. In our work some of molecular detection protocols for identtification of Polish D. dipsaci populations were tested. The most useful among proposed EPPO methods were chosen for identification of Polish population of this species. Moreover, the new specific PCR protocol was described. This method can be used both for identification of Polish population of D. dipsaci and on the basis of the amplified rDNA region the genetic correlation and phylogenetic studies can be performed.
Spores of many fungal pathogens are dispersed by wind. Detection of these airborne inocula is important in forecasting both the onset and the risk of epiphytotics. Species-specific primers targeted at the internal transcribed spacer (ITS) region of Leptosphaeria maculans and L. biglobosa - the causal organisms of phoma stem canker and stem lesions of Brassica spp., including oilseed rape - were used to detect DNA extracted from particles deposited on tapes obtained from a spore trap operated in Rarwino (northwest Poland) from September to November in 2004 and 2006. The quantities of DNA assessed by traditional end-point PCR and quantitative real-time PCR were compared to microscopic counts of airborne ascospores. Results of this study showed that fluctuations in timing of ascospore release corresponded to the dynamics of combined concentrations of DNA from L. maculans and L. biglobosa, with significant positive correlations between ascospore number and DNA yield. Thus the utilization of PCR-based molecular diagnostic techniques enabled the detection, identification, and accurate quantification of airborne inoculum at the species level. Moreover, real-time PCR was more sensitive than traditional PCR, especially in years with low ascospore numbers.
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Q fever - selected issues

45%
Q fever is an infectious disease of humans and animals caused by Gram-negative coccobacillus Coxiella burnetii, belonging to the Legionellales order, Coxiellaceae family. The presented study compares selected features of the bacteria genome, including chromosome and plasmids QpH1, QpRS, QpDG and QpDV. The pathomechanism of infection – starting from internalization of the bacteria to its release from infected cell are thoroughly described. The drugs of choice for the treatment of acute Q fever are tetracyclines, macrolides and quinolones. Some other antimicrobials are also active against C. burnetii, namely, telitromycines and tigecyclines (glicylcycline). Q-VAX vaccine induces strong and long-term immunity in humans. Coxevac vaccine for goat and sheep can reduce the number of infections and abortions, as well as decrease the environmental transmission of the pathogen. Using the microarrays technique, about 50 proteins has been identified which could be used in the future for the production of vaccine against Q fever. The routine method of C. burnetii culture is proliferation within cell lines; however, an artificial culture medium has recently been developed. The growth of bacteria in a reduced oxygen (2.5%) atmosphere was obtained after just 6 days. In serology, using the IF method as positive titers, the IgM antibody level >1:64 and IgG antibody level >1:256 (against II phase antigens) has been considered. In molecular diagnostics of C. burnetii infection, the most frequently used method is PCR and its modifications; namely, nested PCR and real time PCR which detect target sequences, such as htpAB and IS1111, chromosome genes (com1), genes specific for different types of plasmids and transposase genes. Although Q fever was diagnosed in Poland in 1956, the data about the occurrence of the disease are incomplete. Comprehensive studies on the current status of Q fever in Poland, with special focus on pathogen reservoirs and vectors, the sources of infection and molecular characteristics of bacteria should be conducted.
The identification concerned 71 isolates obtained from potato tubers which were identified on the basis of morphological features as Fusarium sambucinum, and 46 isolates from wheat, barley rye, triticale and potato. Which were identified as F. culmorum. Molecular analyses using SCARPCR revealed incorrect identification of 5 isolates obtained from potato: two were earlier identified as F. sambucinum and 3 as F. culmorum. This indicates the fact that F. culmorum and F. sambucinum occurring on potato can be mistaken while using a traditional microscopic identification. The research confirmed the usefulness of species-specific primers in diagnostics of plant pathogens. It was stated that for obtaining fully reliable results, it is advisable to use, besides a microscopic method, a molecular analysis.
Plant parasitic nematodes feed and develop on many economically important crop species causing high losses amounting to many billions dollars every year throughout the world. This negative balance make them the second most damaging group of pathogen/pests after fungi. Additionally, some of them are viral vectors that is contributing to their higher extent of harm caused. Nevertheless, plant nematology is underrepresented in terms of staff in comparison to other fields focusing on plant pests and pathogens. Development in biotechnology however, caused also the development in plant nematology providing tools for characterization or identification of nematode species. New modern diagnostics approaches are continuously described on the basis of genome analysis. Also in Plant Protection Institute – National Research Institute several studies are conducted that concentrate on populations variability of economically important nematode species, diagnostics, and plant-nematode interactions. Another aspect of interest involving biotechnologists is characterization of host reaction to plant-parasitic nematode infection and description of genes participating in production of resistance against those pests. The use and generation of resistant cultivars is a powerful tool in reducing the spread of some quarantine nematodes. Since nematodes are very difficult to destroy, their reduction is a major challenge for plant protection. The use of biotechnology along with other alternative approaches may help to achieve this goal.
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