Revista de patogénesis microbiana

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tickborne
nairovirus of the Bunyaviridae family, causing severe
illness with high mortality rates in humans. Here, we
demonstrate that CCHFV nucleocapsid protein (CCHFV-NP)
augments mRNA translation. CCHFV-NP binds to the viral
mRNA 5' untranslated region (UTR) with high affinity. It
facilitates the translation of reporter mRNA both in vivo and in
vitro with the assistance of the viral mRNA 5' UTR. CCHFVNP
equally favors the translation of both capped and
uncapped mRNAs, demonstrating the independence of this
translation strategy on the 5' cap. Unlike the canonical host
translation machinery, inhibition of eIF4F complex, an
amalgam of three initiation factors, eIF4A, eIF4G, and eIF4E,
by the chemical inhibitor 4E1RCat did not impact the CCHFVNP-
mediated translation mechanism. However, the proteolytic
degradation of eIF4G alone by the human Rhinovirus 2A
protease abrogated this translation strategy. Our results
demonstrate that eIF4F complex formation is not required but
eIF4G plays a critical role in this translation mechanism. Our
results suggest that CCHFV has adopted a unique translation
mechanism to facilitate the translation of viral mRNAs in the
host cell cytoplasm where cellular transcripts are competing
or the same translation apparatus.

Sharing security threat information is a challenge for
governments and their agencies. Especially in biotechnology
and microbiology, the agencies do not know how to classify or
to disclose collected information on potential bio-threats.
There is vague border between man-made and natural
biological threats. An example is the several month delays of
the publication of research on the transmissibility of H5N1
avian influenza virus in the leading scientific journal science
by researchers of the Erasmus Medical Centre in Rotterdam,
Netherlands. The publication was delayed in 2012 by several
months due to the fact that various organizations first wanted
to investigate whether the details could be misused by
malicious individuals. In the study, the researchers show that
only a small number of mutations were necessary to change
the H5N1 virus so that it can spread through the respiratory
system between mammals. This implies that the risk of a
H5N1 pandemic cannot be ruled out. On the other hand, this
information can be used to develop new therapies and/or
vaccines for influenza. It also gives insight into the disease
mechanism, which helps in the prevention. The same
arguments are valid for therapeutic antibodies, like the
antibodies, which are developed to treat anthrax. They have
an extreme high affinity for the lethal factors of the bacterium
and stop the disease, but the same antibodies could be
misused to select the most pathogenic strains.

New formulations are needed to improve the efficacy of
influenza vaccines. Lack of efficient delivery systems for
transporting antigenic molecules to the cytosol of antigen
presenting cells presents a major obstacle for antigen uptake
by immune cells. To this end, influenza Whole Inactivated
Virus (WIV) vaccines were formulated with chitosan
nanoparticles and CpG oligonucleotide as a biodegradable
delivery system and a Th1-specific adjuvant, respectively.
Inactivated Influenza virus vaccine with CpG and Chitosan
was injected intradermally to female Balb/C mice. Injections
were single dose in high and a reduced valium. 30 days after
injection, cell proliferation assay (MTT), IFN-gamma and IL-4
Elispot assays were carried out. Sera samples were collected
21 days after immunization to measure IgG1 and IgG2a
levels. In addition, the mice challenged with mouse adopted
virus, were monitored for weight loss. The results of analyzing
the stimulation of cellular and humoral immune systems and
weighting the mice show a significant stimulation of both
humoral and cellular immunities; also, weight gain and a
decrease in mortality in the mice receiving both dosages of
inactivated influenza virus vaccines with CpG and Chitosan
coating were observed. This finding demonstrated that CpGchitosan
low-dose vaccine was less costly than high-dose and
helps in production of more vaccine despite the limited
production required virus. Based on our results, it can be
concluded that formulation of inactivated Influenza virus with
CpG and its delivery by Chitosan as low-dose in return of
high-dose with the same results as balanced between cellular
and humeral immune responses can make enormous saving
in manufacturing vaccine.

The shortage of drugs active against methicillin-resistant Staphylococcus aureus (MRSA) is a growing clinical problem. In vitro studies indicate that the phenothiazine thioridazine (TZ) might enhance the activity of the β-lactam antibiotic dicloxacillin (DCX) to a level where MRSA is killed, but positive in vivo studies have yet to be performed. We have introduced Caenorhabditis elegans infected by MRSA as an in vivo model to test the effect of TZ as a helper drug in combination with DCX. Because TZ is an anthelmintic, initial experiments were carried out to define the thresholds of toxicity, determined by larval development, and induction of stress-response markers. No measurable stress effects were observed at the concentrations below 64 mg/L TZ. Of seven tested MRSA strains the most pathogenic strain (ATCC 33591) was chosen for treatment analysis. Full-grown C. elegans were exposed to the test strain for three days and subsequently treated with 8 mg/L DCX and 8 mg/L TZ for two days. This resulted in a 14-fold reduction in the intestinal MRSA load as compared with untreated controls. Each drug alone resulted in a two to threefold reduction in MRSA load. In conclusion, we have proved C. elegans as a simple model for testing synergy between TZ and DCX against MRSA. Moreover, we have shown that TZ enhances the activity of DCX in a simple in vivo host model as C. elegans leading to a decrease of bacterial load of MRSA in the nematode gut and intestine.

Soft rot Enterobacteriaceae, including Pectobacterium and
Dickeya, affect a number of plants including vegetables and
fruits, causing high economic loses for producers. There is
currently no treatment for soft rot Enterobacteriaceae in field
conditions, and control is largely based on the use of sanitary
growing practices. The increasing number of epidemics in
recent years caused by Pectobacterium and Dickeya in
Europe indicate a need for the formulation of commercially
available and effective biocontrol measures to counteract soft
rot pathogens. Highly specific bacterial viruses –
bacteriophages – have been investigated by a number of
researchers as a biocontrol tool to treat bacterial diseases. In
this study, bacteriophages isolated from vegetable processing
water have been characterized using transmission electron
microscopy (TEM), molecular biology methods, and tested for
antimicrobial and lytic activity. Bacteriophages efficacious
against soft rot Enterobacteriaceae in potato have been
formulated into a phage-based ‘cocktail’, which has been
assessed through bioassays and field trials. It has been
shown that the phage ‘cocktail’ decreased soft rot symptoms
and increased yields in vivo.