High-virulence Strain Research Articles

EPIDEMIOLOGY ASPECTS OF HOSPITAL-ACQUIRED INFECTION MORBIDITY IN HEALTH SURGERY HOSPITALS IN PRIMORSKY REGION

The problem of prophylaxis and treatment of the hospital-acquired infections caused remains actual and urgent and stubborn in modern medicine. Appearance of antimicrobial agents resistant and high virulent strains adapting also to desinfectants. Development of innovative hi-tech diagnostic methods and treatment at wide circulation of microorganisms with multiple antimicrobial agents resistance defines need of continuous improvement of epidemiological surveillance and microbiological monitoring of this group of infections. Aim of project: to carry out the epidemiological analysis of a case rate of hospital-acquired infections in Primorsky Krai and to determine the specific role of hospital-acquired infections which arose in surgical hospitals and units. Material and methods: In work there were used statistical forms, e.g. No. 2 «The information on infectious and parasitic diseases» in Primorsky Krai. A research method — the retrospective epidemiological analysis. Results of a research: In 2015 in Primorsky Krai there were registered 159 cases of hospitalacquired infections, the indicator of a case rate made 0.05 per 1000 treated patients. In comparison with 2014 the case rate decreased, rate of depression made — 28%. According to the statistical reporting the greatest number of cases of hospital-acquired infections was registered in obstetrical institutions — 60 cases (38% of all hospital-acquired infections), in children’s hospitals — 46 (29%) and in surgical hospitals and units — 33 (21%). Other hospital-acquired infections are registered in out-patient and polyclinic institutions and in institutions of a therapeutic profile. In structure of hospitalacquired infections in the territory of Primorsky Krai in 2015, as well as in previous years, acute intestinal infections dominated (35 cases — 22%) and it is purulent — septic infections at newborns (34 cases — 21%). Conclusions: In the territory of Primorsky Krai the hospital-acquired infections are often registered in obstetrical institutions, in children’s and surgical hospitals and units. The tendency to hospital-acquired infections morbidity growthin surgical hospitals and units, most likely, not owing to augmentation of cases of postoperative complications, and at the expense of other nosologies.

Limited Interactions between Streptococcus Suis and Haemophilus Parasuis in In Vitro Co-Infection Studies.

Streptococcus suis and Haemophilus parasuis are normal inhabitants of the porcine upper respiratory tract but are also among the most frequent causes of disease in weaned piglets worldwide, causing inflammatory diseases such as septicemia, meningitis and pneumonia. Using an in vitro model of infection with tracheal epithelial cells or primary alveolar macrophages (PAMs), it was possible to determine the interaction between S. suis serotype 2 and H. parasuis strains with different level of virulence. Within H. parasuis strains, the low-virulence F9 strain showed higher adhesion levels to respiratory epithelial cells and greater association levels to PAMs than the high-virulence Nagasaki strain. Accordingly, the low-virulence F9 strain induced, in general, higher levels of pro-inflammatory cytokines than the virulent Nagasaki strain from both cell types. In general, S. suis adhesion levels to respiratory epithelial cells were similar to H. parasuis Nagasaki strain. Yet, S. suis strains induced a significantly lower level of pro-inflammatory cytokine expression from epithelial cells and PAMs than those observed with both H. parasuis strains. Finally, this study has shown that, overall and under the conditions used in the present study, S. suis and H. parasuis have limited in vitro interactions between them and use probably different host receptors, regardless to their level of virulence.

Ultrastructural Patterns of Interactions between Murine Lung Macrophages and Yeast Cells of Cryptococcus neoformans Strains with Different Virulence

This article presents the ultrastructural patterns of interactions between the murine lung macrophages and cells of low- (RKPGY-881, -1165, -1178) and high-virulence (RKPGY-1090, -1095, -1106) strains of Cryptococcus neoformans at the seventh post-experimental day. It was found that if macrophages ingest living yeast cells, the latter can: 1) become completely free from polysaccharide capsules, after that their contents undergo lysis, and cell wall debris are extruded from the macrophage (first scenario); 2) become partly free from their capsules, destroy the phagosomal plasma membrane and induce destructive processes inside the macrophage causing their death (second scenario); or 3) not lose their capsules and localize inside macrophage in latent state (third scenario). Macrophages can also ingest senescent and dead C. neoformans cells surrounded by capsules that are lost at the ingesting and phagosome stages (fourth scenario). The study revealed the dependence of cell-mediated immunity on the stage of development of ingested C. neoformans yeast cells. Here we describe a new mechanism of capsular polysaccharide elimination of C. neoformans yeast cells by murine macrophages.

THE DIVERSITY OF THE PARASITIC SYSTEM IS THE BASE OF THE STABILITY OF THE FUNCTIONING OF NATURAL FOCUS OF THE INFECTION

This paper presents the authors’ opinion concerning such understudied issue of epizootology as the cause of the stability of the functioning of the natural focus of infection. The diversity of the biocenotic complex including main, secondary and casual carriers; numerous, small in number and rare vectors; strains with high virulence, low virulence and altered strains of the causative agent of infection, as well as population nonuniformity of biocenosis constituents contribute to the stability of the functioning of the natural focus in certain landscape-geographic conditions. The heterogeneity during the achievement of the abundance peak by various carrier and vector species also promotes to the stability. Universality of the principle of the proposition offered here for three- and two-component constituents of a natural focus of infection, as well as for infections caused by sapronotic pathogens, allows consider it as a biological law of the stable functioning of a natural focus of infection.

Differential cellular immune response of Galleria mellonella to Actinobacillus pleuropneumoniae.

In the present work, we have investigate the cellular immune response of Galleria mellonella larvae against three strains of the gram-negative bacterium Actinobacillus pleuropneumoniae: low-virulence (780), high-virulence (1022) and the serotype 8 reference strain (R8). Prohemocytes, plasmatocytes, granulocytes, oenocytoids and spherulocytes were distinguished according to their size and morphology, their molecular markers and dye-staining properties and their role in the immune response. Total hemocyte count, differential hemocyte count, lysosome activity, autophagic response, cell viability and caspase-3 activation were determined in circulating hemocytes of naive and infected larvae. The presence of the autophagosome protein LC3 A/B within the circulating hemocytes of G. mellonella was dependent on and related to the infecting A. pleuropneumoniae strain and duration of infection. Hemocytes treated with the high-virulence strain expressed higher levels of LC3 A/B, whereas treatment with the low-virulence strain induced lower expression levels of this protein in the cells. Moreover, our results showed that apoptosis in circulating hemocytes of G. mellonella larvae after exposure to virulent bacterial strains occurred simultaneously with excessive cell death response induced by stress and subsequent caspase-3 activation.

Susceptibility and Lethality of Western Equine Encephalitis Virus in Balb/c Mice When Infected by the Aerosol Route.

Western equine encephalitis virus (WEEV) naturally cycles between mosquitos and birds or rodents, with a case fatality rate of up to 15% in humans during epizootic outbreaks. There are no medical countermeasures to treat WEEV infection, and accidental aerosol exposure increases the case fatality rate up to 40%. Understanding the pathogenesis of infection is required to develop and assess medical countermeasures. This study describes the clinical and pathological findings of mice infected with WEEV by the aerosol route, and use as a model for WEEV infection in humans. Balb/c mice were infected by the aerosol route with a dose range of high-virulence WEEV strain Fleming to establish the median lethal dose (MLD). The disease course was acute, culminating in severe clinical signs, neuroinvasion, and dose-dependent mortality. Further groups of mice were exposed by the aerosol route, periodically sacrificed, and tissues excised for histopathological examination and virology. Viral titres peaked four days post-challenge in the brain and lungs, corresponding with severe bilateral lesions in rostroventral regions of the encephalon, especially in the olfactory bulb and piriform cortex. Recapitulation of the most serious clinical presentations of human WEEV disease in mice may prove a useful tool in the evaluation of medical countermeasures.

IL-27 limits neutrophil mediated pathology during pulmonary infection with Cryptococcus neoformans

Abstract Cryptococcus neoformans is a pathogenic encapsulated fungus and a leading cause of fatal meningitis in immunocompromised individuals. IL-27 is a recently identified cytokine affecting both innate and adaptive immunity. Both proinflammatory and inhibitory functions on T cells by IL-27 have been reported in different disease models. Nevertheless, the effect of IL-27 during Cryptococcus infection has never been studied. In current study, IL-27 receptor alpha knockout mice (IL27R KO) was infected with a high virulent cryptococcal strain. We found that mice deficient in IL-27 signaling have significantly increased fungal burden in the lung and shortened survival time. Surprisingly, infected IL-27R KO mice showed unchanged Th1 and Th17 cytokines but significantly reduced Th2 cytokines including IL-4, IL-5 and IL-13. The reduced Th2 response is unlikely to be a cause of increase fungal burden since Th2 was generally known as detrimental during Cryptococcus infection. We next studied the immune cell composition by flow cytometry, no difference in cell number was found for all cell types except neutrophil which is increased during infection indicating more inflammation. The increase of neutrophils is associated with increased chemokines KC and MIP-2. Cryptococcus infection causes sustained production of TNF alpha, we next found that IL-27 suppressed the chemokine release by immune cells as a response to TNF-alpha. Lastly, depletion of neutrophils improved the outcome in infected IL-27R KO mice proving that immune pathology mediated by neutrophils can be detrimental during Cryptococcus infection.

ITRAQ-based quantitative proteomic analysis reveals potential virulence factors of Erysipelothrix rhusiopathiae

Erysipelothrix rhusiopathiae is a ubiquitous pathogen that has caused considerable economic losses to pig farmers. However, the mechanisms of E. rhusiopathiae pathogenesis remain unclear. To identify new virulence-associated factors, the differentially abundant cell wall-associated proteins (CWPs) between high- and low-virulence strains were investigated through isobaric Tags for Relative and Absolute Quantitation (iTRAQ) combined with liquid chromatography-quadrupole mass spectrometry (LC-MS/MS). In total, 100 CWPs showed significant differences in abundance. Selected differences were verified by western blotting to support the iTRAQ data. Among the differential proteins, the proteins with higher abundance in the high-virulence strain were mostly ABC transporter proteins and adhesion proteins, and the proteins with lower abundance in the high-virulence strain were mainly stress-response proteins. The more abundant proteins in the high-virulence strain may be related to bacterial virulence. The iTRAQ results showed that the abundance of the sugar ABC transporter substrate-binding protein Sbp (No. 5) was higher by 1.73-fold. We further constructed an sbp-deletion mutant. Experiments in animal models showed that the sbp-deletion mutant caused decreased mortality. Together, our data indicated that transporter proteins and adhesion proteins may play important roles in E. rhusiopathiae virulence and confirmed that sbp contributed to the virulence of E. rhusiopathiae. Biological significanceTo our knowledge, this is the first proteomic analysis comparing differentially abundant CWPs between high- and low-virulence E. rhusiopathiae strains by iTRAQ. We generated comprehensive and accurate lists of E. rhusiopathiae CWPs proteomes and identified many differences at the protein level. Among the differential proteins with higher abundance in the high-virulence strain, sbp was verified to contribute to the virulence of E. rhusiopathiae through the construction of an sbp-deletion mutant. The differential proteins with higher abundance in the high-virulence strain identified in the present study should provide a foundation for future evaluation of virulence factors.

Comparative Genome Analyses of Vibrio anguillarum Strains Reveal a Link with Pathogenicity Traits.

Vibrio anguillarum is a marine bacterium that can cause vibriosis in many fish and shellfish species, leading to high mortalities and economic losses in aquaculture. Although putative virulence factors have been identified, the mechanism of pathogenesis of V.anguillarum is not fully understood. Here, we analyzed whole-genome sequences of a collection of V.anguillarum strains and compared them to virulence of the strains as determined in larval challenge assays. Previously identified virulence factors were globally distributed among the strains, with some genetic diversity. However, the pan-genome revealed that six out of nine high-virulence strains possessed a unique accessory genome that was attributed to pathogenic genomic islands, prophage-like elements, virulence factors, and a new set of gene clusters involved in biosynthesis, modification, and transport of polysaccharides. In contrast, V.anguillarum strains that were medium to nonvirulent had a high degree of genomic homogeneity. Finally, we found that a phylogeny based on the core genomes clustered the strains with moderate to no virulence, while six out of nine high-virulence strains represented phylogenetically separate clusters. Hence, we suggest a link between genotype and virulence characteristics of Vibrio anguillarum, which can be used to unravel the molecular evolution of V.anguillarum and can also be important from survey and diagnostic perspectives. IMPORTANCE Comparative genome analysis of strains of a pathogenic bacterial species can be a powerful tool to discover acquisition of mobile genetic elements related to virulence. Here, we compared 28 V.anguillarum strains that differed in virulence in fish larval models. By pan-genome analyses, we found that six of nine highly virulent strains had a unique core and accessory genome. In contrast, V.anguillarum strains that were medium to nonvirulent had low genomic diversity. Integration of genomic and phenotypic features provides insights into the evolution of V.anguillarum and can also be important for survey and diagnostic purposes.

Virulence and genotypes of white spot syndrome virus infecting Pacific white shrimp Litopenaeus vannamei in north-western Mexico.

White spot syndrome virus (WSSV) has caused substantial global economic impact on aquaculture, and it has been determined that strains can vary in virulence. In this study, the effect of viral load was evaluated by infecting Litopenaeus vannamei with 10-fold serial dilution of tissue infected with strain WSSV Mx-H, and the virulence of four WSSV strains from north-western Mexico was assessed along with their variable number of tandem repeat (VNTR) genotypes in ORF75, ORF94 and ORF125. The LD50 of the Mx-H strain was a dilution dose of 10-7.5 ; the mortality titre was 109.2 LD50 per gram. In shrimp injected with 102.5 to 106.5 LD50 , no significant virulence differences were evident. Using mortality data, the four WSSV strains grouped into three virulence levels. The Mx-F strain (intermediate virulence) and the Mx-C strain (high virulence) showed more genetic differences than those observed between the Mx-G (low-virulence) and Mx-H (high-virulence) strains, in ORF94 and ORF125. The application of high-viral-load inocula proved useful in determining the different virulence phenotypes of the WSSV strains from the Eastern Pacific.

Comparative genomic analysis of three white spot syndrome virus isolates of different virulence.

Three white spot syndrome virus (WSSV) isolates of different virulence were identified in our previous study, the high-virulent strain WSSV-CN01, the moderate-virulent strain WSSV-CN02 and the low-virulent strain WSSV-CN03. In this study, the genomes of these three WSSV isolates were sequenced, annotated and compared. The genome sizes for WSSV-CN01, WSSV-CN02, and WSSV-CN03 are 309,286, 294,261, and 284,148bp, bearing 177, 164, and 154 putative protein-coding genes, respectively. The genomic variations including insertions, deletions, and substitutions were investigated. Thirty four genes show >20% variation in their sequences in WSSV-CN02 or WSSV-CN03, in comparison with WSSV-CN01, including six envelope protein genes (wsv237/vp41A, wsv238/vp52A, wsv338/vp62, wsv339/vp39, wsv077/vp36A, and wsv242/vp41B), and two immediate-early genes (wsv108 and wsv178). The genomic variations among WSSV isolates of different virulence, especially those in the coding regions, certainly provide new insight into the understanding of the molecular basis of WSSV pathogenesis.

Suppressive subtractive hybridization reveals different gene expression between high and low virulence strains of Cladosporium cladosporioides

Cladosporium cladosporioides is a ubiquitous fungus, causing infections in plants, humans, and animals. Suppression subtractive hybridization (SSH) and quantitative real-time PCR (qRT-PCR) were used in this study to identify differences in gene expression between two C. cladosporioides strains, the highly virulent Z20 strain and the lowly virulent Zt strain. A total of 61 unigenes from the forward library and 42 from the reverse library were identified. Gene ontology (GO) analysis showed that these genes were involved in various biological processes, cellular components and molecular functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the unigenes in the forward library corresponded to 5 different pathways and the reverse library unigenes were involved in 3 different pathways. The qRT-PCR results indicated that expressions of APL1, GUD1, CSE1, SPBC3E7.04c and MFS were significantly different between Z20 and Zt strains, while genes encoding the senescence-associated proteins, pse1, nup107, mip1, pex2, icl1 and α/β hydrolase exhibited no significant differences between the two strains. In addition, we found that 5 unigenes encoding mip1, chk1, icl1, α/β hydrolase and β-glucosidase may be associated with pathogenicity. One unigene (MFS) may be related to the resistance to 14 α-demethylase inhibitor fungicides, and 5 unigenes (PEX2, NUP107, PSE1, APL1, and SPBC3E7.04c) may be related to either low spore yield or earlier aging of the Zt strain. Our study may help better understand the molecular mechanism of C. cladosporioides infection, and therefore improve the treatment and prevention of C. cladosporioides induced diseases.

P6022 Transcriptomic study of bovine macrophages infected in vitro with Streptococcus agalactiae

Mastitis is a costly disease in dairy cattle, impairing animal welfare and increasing the use of antibiotics. It is a multi-factorial disease, affected by the load and virulence of the infecting pathogen, the milking hygiene, and the immune status and genetics of the host. Streptococcus agalactiae has re-emerged as a potential threat to udder health in Norway, especially in large herds and herds using automatic milking systems. Some cows develop chronic subclinical mastitis with high somatic cell count (SCC). Such animals shed the bacteria and contribute to spreading the infection to other cows and herds. Hence, investigation of why these become chronically infected is important. Macrophages are critical effectors and regulators of inflammation serving as the first line of defense against invading pathogens. Intramammary infections will activate macrophages to produce proinflammatory cytokines required to kill intracellular pathogens, however the balance between pro- and antiinflammatory signals is crucial for immune regulation of inflammation and preventing chronic conditions. The objective of this study is to increase the understanding of the host genetics and immune response to Streptococcus agalactiae causing chronic subclinical mastitis in Norwegian Red (NRF) dairy herds. In genotyped cows we will examine the transcriptomic responses of macrophages infected with high and low virulent strains of Streptococcus agalactiae. Seven animals were selected for a pilot study of in vitro challenge of blood monocyte-derived macrophages with two strains of Streptococcus agalactiae differing in virulence. Transcript analyses of several selected cytokines and chemokines were performed by qPCR. Four thousand NRF cows is currently genotyped using a customized 55K bovine SNP-chip (a typing tool for 55 000 Single Nucleotide Polymorphism markers) and genomic breeding values (GEBVs) for SCC will be estimated to evaluate the contrasts between the groups. Based on this genotyping cows with long duration of high SCC (= chronically infected animals) and unfavorable GEBV for SCC, and cows with very low SCC (= control) and favorable GEBV for SCC will be selected for in vitro challenge of blood monocyte-derived macrophages with the two bacterial strains. For each selected individual transcriptome analyses, i.e., mRNA sequencing, will be performed to identify the macrophage response to the infections in challenged and control sets of cells. This will generate information on genes and splice variants involved in immune responses during the infection with high and low virulent strains of Streptococcus agalactiae.

Virulence of Erwinia amylovora, a prevalent apple pathogen: Outer membrane proteins and type III secreted effectors increase fitness and compromise plant defenses.

Until now, no data are available on the outer membrane (OM) proteome of Erwinia amylovora, a Gram-negative plant pathogen, causing fire blight in most of the members of the Rosaceae family. Since the OM forms the interface between the bacterial cell and its environment it is in direct contact with the host. Additionally, the type III secretion system, embedded in the OM, is a pathogenicity factor of E. amylovora. To assess the influence of the OM composition and the secretion behavior on virulence, a 2D-DIGE analysis and gene expression profiling were performed on a high and lower virulent strain, both in vitro and in planta. Proteome data showed an increase in flagellin for the lower virulent strain in vitro, whereas, in planta several interesting proteins were identified as being differently expressed between both the strains. Further, gene expression of nearly all type III secreted effectors was elevated for the higher virulent strain, both in vitro and in planta. As a first, we report that several characteristics of virulence can be assigned to the OM proteome. Moreover, we demonstrate that secreted proteins prove to be the important factors determining differences in virulence between the strains, otherwise regarded as homogeneous on a genome level.

A surveillance study on CRISPR/Cas molecular biomarker in Escherichia coli

A new method related to molecular biomarker with CRISPR/Cas (clustered regularly interspaced short palindromic repeats-cas) in Escherichia (E.) coli was developed and used for surveillance programs. CRISPR/Cas sequence that containing 135 strains with complete sequence and 203 strains with whole genome shotgun sequence of E. coli in GenBank by BLAST and 361 strains of E. coli (including 38 strains of E. coli O157∶H7) in laboratory were identified by PCR and analyzed with the CRISPR Finder. Spacers were compared with DANMAN and the phylogenetic trees of cas gene were constructed under Clustal Ⅹ and Mega 5.1. With new perspective, a descriptive method was developed targeting on the position of CRISPR/cas in E. coli. The CRISPR1 was detected in 77.04%, 100.00% and 75.62% and the CRISPR2 was detected in 74.81%, 100.00% and 92.24% and the CRISPR3 and CRISPR4 were detected in 11.85%, 0 and 1.39% for 135 strains with complete sequence, 203 strains with whole genome shotgun sequence and 361 strains in the laboratory, respectively. One strain downloaded in GenBank with whole genome sequencing and 2 strains in the our laboratory were identified that containing four CRISPR locus. The other E. coli strain was with insertion sequence in downstream of the non-cas CRISPR1. The unique CRISPR was found in 8 strains of O55∶H7, in 180 strains of O157∶H7, in 8 strains of O157∶HNM, in 40 strains of O104∶H4, in 4 strains of O145∶H28, in all the 699 E. coli strains. The phylogenetic tree could be divided into two groups-cas with type I-E or type I-F. CRISPR/Cas might be used as a valuable molecular biomarker in epidemiological surveillance studies to identify the high virulent strains or new strains of E. coli. Phage night be related to the missing or obtaining of spacers.

The effect of statins on the outcome of Clostridium difficile infection in hospitalized patients.

Several studies have shown an association between exposure to statins and favorable clinical outcomes for various types of infections. We aimed to assess the impact of statin use on mortality, disease severity and complications among hospitalized patients with Clostridium difficile infection (CDI). Data were analyzed from a retrospectively collected database of 499 patients diagnosed with CDI during 2009-2014. We compared infection outcomes between 178 statin (36 %) users and 321 (64 %) non-users. On multivariate analysis, we found that statin use did not have a significant impact on 30-day mortality (OR = 1.54; 95 % CI, 0.85-2.79; p = 0.15) or any significant effect on CDI severity and complication. Concomitant statin use has no significant impact on short-term mortality or effect on CDI severity and complications among hospitalized patients with CDI. However, patients in the statin group were older and had higher Charlson score compared with the non-statin group. Whether these factors affected a possible impact of statins on the disease course remains to be investigated. • Clostridium difficile is the most common cause of infectious nosocomial diarrhea among hospitalized adult patients in the developed countries. • There is an increasing morbidity and mortality of CDI patients due to the emergence of new strains of high virulence. • Recent studies demonstrated that prior statin use has protective and ameliorating effects on morbidity and mortality among CDI patients. • Our study showed that concomitant statin use has no significant impact on short-term mortality, CDI severity and its complications.

Comparative Genomics Analysis of Two Different Virulent Bovine Pasteurella multocida Isolates.

The Pasteurella multocida capsular type A isolates can cause pneumonia and bovine respiratory disease (BRD). In this study, comparative genomics analysis was carried out to identify the virulence genes in two different virulent P. multocida capsular type A isolates (high virulent PmCQ2 and low virulent PmCQ6). The draft genome sequence of PmCQ2 is 2.32 Mbp and contains 2,002 protein-coding genes, 9 insertion sequence (IS) elements, and 1 prophage region. The draft genome sequence of PmCQ6 is 2.29 Mbp and contains 1,970 protein-coding genes, 2 IS elements, and 3 prophage regions. The genome alignment analysis revealed that the genome similarity between PmCQ2 and PmCQ6 is 99% with high colinearity. To identify the candidate genes responsible for virulence, the PmCQ2 and PmCQ6 were compared together with that of the published genomes of high virulent Pm36950 and PmHN06 and avirulent Pm3480 and Pm70 (capsular type F). Five genes and two insertion sequences are identified in high virulent strains but not in low virulent or avirulent strains. These results indicated that these genes or insertion sequences might be responsible for the virulence of P. multocida, providing prospective candidates for further studies on the pathogenesis and the host-pathogen interactions of P. multocida.

Oral Bacteria and Bowel Diseases – Mini Review

Oral bacteria are considered to be associated with several systemic diseases. Recently, their association with inflammatory bowel disease (Crohn's disease and ulcerative colitis) and colorectal carcinoma has attracted much attention. In this mini-review, the association of oral bacteria with these diseases is briefly summarized. Fusobacterium nucleatum is known as a periodontopathic bacterium, and it is also associated with inflammatory bowel disease and colorectal carcinoma. Campylobacter concisus, which is found at the site of periodontitis, is associated with inflammatory bowel disease. Streptococcus mutans is a famous cariogenic bacterium, but a highlyvirulent strain of this bacterium is also associated with inflammatory bowel disease. In this way, both periodontopathic bacteria and cariogenic bacteria are associated with bowel diseases. Further epidemiological studies are necessary to reveal the cause and effect relationship between oral bacterial and bowel diseases.

Prediction of the next highly pathogenic avian influenza pandemic that can cause illness in humans.

BackgroundIn recent years, avian influenza viruses (AIVs) have seriously threatened human health. Questions such as: why do AIVs infect humans?, how quickly can an AIV become pandemic?, and which virus is the most dangerous? cannot be sufficiently answered using current bioinformatic studies.MethodSecondary structures and energies of representative 5′-untranslated region (UTR) of the HA gene were calculated. Then their secondary structures and energies were re-calculated after one or two nucleotide substitutions were introduced into the HA 5′-UTR. Phylogenetic trees on the basis of hemagglutinin (HA) and polymerase basic protein 2 (PB2) amino acid sequences and HA 5′-UTR nucleotide sequences were constructed. The connection between the energy and translation efficiency of 5′-UTR was confirmed by in vitro coupled transcription/translation assay.ResultsThe simplicity of the secondary structure of the 5′-UTR of the HA gene determines the overall virus replication rate and transmission potential. Point mutation assays show that the 5′-UTR sequences of the HA gene in the influenza subtypes H2N2, H3N2, and H7N9 have greater variation potentials than other virus subtypes.ConclusionSome high-virulent strains of avian influenza might emerge in the next two to three years. The H2N2 subtype, once disappeared in humans, may stage a comeback. The current outbreak of H7N9 may become pandemic and cause even more deaths, if one or two bases are substituted in the 5′-UTR sequence of the HA gene.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-015-0083-8) contains supplementary material, which is available to authorized users.

Pathological findings in sheep experimentally infected with parapoxvirus

We have investigated patho-morphologic findings in some parenchymal and immune organs of sheep infected with high virulent strain ‘’Stavropoliskii’’ of parapoxvirus by a common method (MNS 5451:2005). By means of the microscope were found desquamation of some epithelium of epidermis, eosinophil and lymphocyte infiltration and vacuolization in the derma, and also edema and hyperemia in lung alveoli. Germinal center of lymph nodes was reduced and the number of plasma cells was decreased.Mongolian Journal of Agricultural Sciences Vol.15(2) 2015; 66-70