Miniature PCR based portable bioaerosol monitor development.

AIMS: A portable bioaerosol monitor is greatly demanded technology in many areas including air quality control, occupational exposure assessment and health risk evaluation, environmental studies and, especially, in defence and bio-terrorism applications. Our recent groundwork allowed us to formulate the concept of a portable bioaerosol monitor, which needs to be light, user friendly, reliable and capable of detecting airborne pathogens within 1-1·5 h on the spot. METHODS AND RESULTS: Conceptually, the event of a bioaerosol concentration burst is determined by triggers to commence the representative air sampling with sequential real-time polymerase chain reaction (PCR) confirmation of the targeted micro-organism present in the air. To minimize reagent consumption and idle running of the technology, an event of a bioaerosol burst is confirmed by three parameters: aerosol particle size, concentration and composition. Only particle sizes above 200 nm attract interest in the bioaerosol. Only an elevated aerosol concentration above the threshold (background aerosol concentration) is a signal to commence the analytical procedure. The combination of our previously developed personal bioaerosol sampler, aerosol particle counter based trigger and portable real-time PCR device formed the basis of the bioaerosol monitoring technology. The portable real-time PCR device was advanced to provide internally controlled detection, significantly reducing false-positive alarms. CONCLUSIONS: The technique is capable of detecting selected airborne micro-organisms on the spot within 30-80 min, depending on the genome organization of the particular strain. SIGNIFICANCE AND IMPACT OF THE STUDY: Due to recent outbreaks of infectious airborne diseases and the continuing threat of intentionally released bioaerosol attacks, investigations into the possibility of the early and reliable detection of pathogenic micro-organisms in the air is becoming increasingly important. The proposed technology consisting of a bioaerosol sampler, technology trigger and PCR device is capable of detecting selected airborne micro-organisms on the spot within a short time period.

Surface plasmon resonance-based bacterial aerosol detection.

AIMS: In the area of bioaerosol research, rapid methods for precise detection attracted much interest over last decades. One of such technologies operating in nearly real-time mode without any specific labelling is known as surface plasmon resonance (SPR). Recently, we validated a SPR protocol in conjunction with our earlier developed personal bioaerosol sampler for rapid detection of airborne viruses. Considering that the biological interaction between targeted micro-organism and corresponding antibody is strongly related to sizes of targeted micro-organisms, this research is vital validating suitability of SPR technique for bacterial aerosol detection, as characteristic size of bacteria is 2-3 orders of magnitude larger than sizes of common viruses. The combination of SPR with portable air sampling instrumentation could lead to the development of portable bioaerosol monitor. METHODS AND RESULTS: This study is focussed on the SPR technology application for direct detection of common environmental bacterial strain-Escherichia coli. The detection limit of developed SPR techniques based on utilization of a planar gold sensor chip functionalized with polyclonal antibody via NeutrAvidin junction for sensing of bacterial cells was found to be 1·5 × 10(3)  CFU ml(-1) , which corresponds to the limit of detection in the air to be 2·19 × 10(4)  CFU l(-1) for 1 min of sampling time. CONCLUSIONS: The technology was found fully suitable for rapid and reliable detection of large size bacterial aerosols. Low magnitude of the limit of detection looks very promising for sensitive detection of highly pathogenic airborne bacteria in the ambient air. SIGNIFICANCE AND IMPACT OF THE STUDY: The suggested technology based on a simple model organism is one of the first attempts to develop a real-time monitor for reliable detection of airborne bacteria. The outcomes would be of strong interest of professionals involved in monitoring and/or control of pathogenic airborne bacteria, including Legionella, Mycobacterium tuberculosis and Bacillus anthracis.

Surface plasmon resonance-based real-time bioaerosol detection.

AIMS: Rapid and precise bioaerosol detection in different environments has become an important research and technological issue over last decades. Previously, we employed a real-time PCR protocol in conjunction with personal bioaerosol sampler for rapid detection of airborne viruses. The approach has been proved to be specific and sensitive. However, a period of time required for entire procedure was in manner of hours. Some new developments are required to decrease the detection time down to real-time protocols. METHODS AND RESULTS: Presently, a surface plasmon resonance (SPR)-based immunosensor that coupled with a specific antigen-antibody reaction could offer sensitive, specific, rapid and label-free detection. This study describes the possibility of combining the personal sampler with SPR technology for qualitative and extremely rapid detection of airborne micro-organisms. Common viral surrogate MS2 bacteriophage, frequently used in bioaerosol studies, was employed as a model organism. The results of the sensor functionalizing procedure with monoclonal anti-MS2 antibody and optimization of the chip performance are presented. The SPR-based detection of the airborne virus was found to be very fast; the viral presence was detected in less than 2 min, and the entire procedure (sampling and analysis) was undertaken in 6 min, which could be considered as real-time detection for this type of measurements. CONCLUSIONS: The combination of SPR with the personal sampler targeted towards bioaerosol detection was proven to be feasible. The SPR sensor was found to be highly stable and suitable for multiple utilizations without significant decrease in response. The suggested approach opens new possibilities for the development of portable and rapid (almost real time) bioaerosol monitors. SIGNIFICANCE AND IMPACT OF THE STUDY: This technology is the first in the world real-time bioaerosol monitor. This outcome would be of strong interest to individuals representing public health, biosecurity, defence forces, environmental sciences and many others.

[Molecular genetic characteristics of the newcastle disease virus velogenic strains isolated in Russia, Ukraine, Kazakhstan, and Kirghizia].

The F gene fragment of 79 Newcastle disease virus (NDV) strains isolated from domestic and synanthropic birds in Kazakhstan, Kirghizia, Ukraine, and Russia in 1993 to 2007 was comparatively analyzed. Phylogenetic analysis of test isolates and reference NDV strains obtained from the GenBank was carried out by polymerase chain reaction with subsequent sequencing and comparative analysis of 154-bp nucleotide sequences in the main functional region of the F gene. All newly characterized isolates belong to three NDV genotype VII subgroups: VIIa, VIIb, VIId. The results show it necessary to monitor of NDV strains isolated in the CIS countries since the spread of NDV among migratory and synanthropic birds (pigeons, crows, and jackdaws) poses a serious threat to commercial poultry industry.

[Interpretation of the epizootic outbreak among wild and domestic birds in the south of the European part of Russia in December 2007].

The paper presents the results of interpreting the epizootic outbreak etiologically associated with high-virulent influenza virus A/H5N1 among domestic and wild birds in the Zernogradsky and Tselinsky districts of the Rostov Region. Epizooty was characterized by a high infection rate in the synanthropic birds of a ground-based complex. RT-PCT revealed influenza virus A/H5 in 60% of pigeons and crows and in around 20% of starlings, and in 10% of tree sparrows. Fifteen viral strains from chickens (Gallus gallus domesticus), Indian ducks (Cairina moschata), rooks (Corvus frugilegus), rock pigeons (Columba livia), tree sparrows (Passer montanus), common starlings (Sturnus vulgaris), and great white herons (Egretta alba) were isolated and deposited in the State Collection of Viruses of the Russian Federation. Full-sized genomes of 5 strains were sequenced and deposited in the international database GenBank. The isolated strains belong to the Quinhai-Siberian (2.2) genotype, an Iranian-Northern Caucasian subgroup, they are phylogenetically closest to the strain A/chicken/Moscow/2/2007 (inducing epizooty among poultry in the near-Moscow Region in February 2007) and have 13 unique amino acid replacements as the consensus of the Quinhai-Siberian genotypes in the proteins PB2, PA, HA, NP, NA, and M2, by preserving thereby 4 unique replacements first describes for the strain A/chicken/Moscow/2/2007. The findings are indicative of a different mechanism that is responsible for bringing the virus into the northeastern part of the Azov Sea area in September 2007 (during the fall migration of wild birds) and in December 2007 in the south-western Rostov Region where a human factor cannot be excluded. Mass infection of synanthropic birds endangers the further spread of epizooty, including that in the central regions of the Russian Federation in spring after near migrants return after wintering.

[Molecular genetic characteristics of the strain A/chicken/Moscow/2/2007 (H5N1) strain from a epizootic focus of highly pathogenic influenza A among agricultural birds in the neear-Moscow region (February 2007)].

Among agricultural birds in the near-Moscow Region (February 2007), local epizootics caused by the highly pathogenic avian influenza A/H5N1 virus seem to be of unintended manual origin. Such a situation may be considered to be model when the source of inoculation is elucidated in cases of potentially possible acts of bioterrorism. Molecular genetic analysis of isolated A/chicken/Moscow/2/2007 strain established its genetic similarity with the highly pathogenic strains detected in the Black-and-Caspian Sea region in 2006. At the same time, comparison of nucleotide sequences of the strain A/chicken/Moscow/2/2007 with the strains of Qinghai-Siberian genotype (CSG) for which the sequences of full-sized genomes are known in the international databases revealed a significant distinction of the near-Moscow strain from the earlier known analogues. The uniqueness of the primary structure of the PB1 gene is shown. The paper discusses the functional value of amino acid substitutions in the proteins of the strain A/chicken/Moscow/2/2007 and in other variants of CSG of the subtype H5N1.