The potential role of protein disulfide isomerases (PDIs) during parasitic infections: a focus on Leishmania spp.

Leishmaniasis is a group of vector-borne diseases caused by intracellular protozoan parasites belonging to the genus Leishmania. Leishmania parasites can employ different and numerous sophisticated strategies, including modulating host proteins, cell signaling, and cell responses by parasite proteins, to change the infected host conditions to favor the parasite persistence and induce pathogenesis. In this sense, protein disulfide isomerases (PDIs) have been described as crucial proteins that can be modulated during leishmaniasis and affect the pathogenesis process. The effect of modulated PDIs can be investigated in both aspects, parasite PDIs and infected host cell PDIs, during infection. The information concerning PDIs is not sufficient in parasitology; however, this study aimed to provide data regarding the biological functions of such crucial proteins in parasites with a focus on Leishmania spp. and their relevant effects on the pathogenesis process. Although there are no clinical trial vaccines and therapeutic approaches, highlighting this information might be fruitful for the development of novel strategies based on PDIs for the management of parasitic diseases, especially leishmaniasis.

Phage JS02, a putative temperate phage, a novel biofilm-degrading agent for Staphylococcus aureus.

Staphylococcus aureus is a biofilm-producing organism that is frequently isolated from various environments worldwide. Because of the natural resistance of S. aureus biofilm to antibiotics, bacteriophages are considered as a promising alternative for its removal. The bacteriophage vB_SauS_JS02 was isolated from livestock wastewater and showed activity against multidrug-resistant S. aureus. The phage vB_SauS_JS02 exhibited a broad host range and possessed a large burst size (52 PFU/CFU) as well as moderate pH stability (4-11) and appropriate thermal tolerance (40-50°C). Electron microscopy and genome sequence revealed that vB_SauS_JS02 belonged to Triavirus genus in Siphoviridae family. Genetic analysis of the 46 kb sequence of vB_SauS_JS02 revealed 66 ORFs. The predicted protein products of the ORFs were clustered functionally into five groups as follows: replication/regulation, DNA packaging, structure/morphogenesis, lysis and lysogeny. Although the phage vB_SauS_JS02 was a temperate phage, it exhibited a higher inhibiting and degrading activity against planktonic cells (80~90% reduction), even to S. aureus biofilm (~68% reduction in biofilm formation). Moreover, the removal activity of the phage vB_SauS_JS02 against both planktonic cells and S. aureus biofilms was even better than that of the antibiotic (ceftazidime). In summary, the present study introduced the phage vB_SauS_JS02 as a potential biocontrol agent against biofilm-producing S. aureus after making it virulent. It may be applicable for phage therapy.

An in-vitro study on a novel six-phage cocktail against multi-drug resistant-ESBL Shigella in aquatic environment.

Shigella spp. are water-borne pathogens responsible for mild to severe cases bacilli dysentery all around the world known as Shigellosis. The progressively increasing of antibiotic resistance among Shigella calls for developing and establishing novel alternative therapeutic methods. The present study aimed to evaluate a novel phage cocktail of lytic phages against extended spectrum beta lactamase isolates of Shigella species in an aquatic environment. The phage cocktail containing six novel Shigella specific phages showed a broad host spectrum. The cocktail was very stable in aquatic environment. The cocktail resulted in about 99% decrease in the bacterial counts in the contaminated water by several species and strains of Shigella such as Shigella sonnei, Shigella flexneri and Shigella dysenteriae. Achieving such a high efficiency in this in-vitro study demonstrates a high potential for in-vivo and in-situ application of this phage cocktail as a bio-controlling agent against Shigella spp. contamination and infections.

Characterization of the outer membrane proteome of Francisella noatunensis subsp. orientalis.

AIMS: The aims of the current study were to characterize the outer membrane proteins (OMPs) of Francisella noatunensis subsp. orientalis (Fno) STIR-GUS-F2f7, and identify proteins recognized by sera from tilapia, Oreochromis niloticus, (L) that survived experimental challenge with Fno. METHODS AND RESULTS: The composition of the OMPs of a virulent strain of Fno (STIR-GUS-F2f7), isolated from diseased red Nile tilapia in the United Kingdom, was examined. The sarcosine-insoluble OMPs fraction was screened with tilapia hyperimmune sera by western blot analysis following separation of the proteins by 1D SDS-PAGE. Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was used to identify the various proteins present in the OMP profile. Two hundred and thirty-nine proteins were identified, of which 44 were found in the immunogenic band recognized by the tilapia hyperimmune serum. In silico analysis was performed to predict the function and location of the OMPs identified by MS. CONCLUSIONS: Using a powerful proteomic-based approach in conjugation with western immunoblotting, proteins comprising the outer membrane fraction of Fno STIR-GUS-F2f7 were identified, catalogued and screened for immune recognition by tilapia sera. SIGNIFICANCE AND IMPACT OF THE STUDY: The current study is the first report on the characterization of Fno-OMPs. The findings here provide preliminary data on bacterial surface proteins that exist in direct contact with the host's immune defences during infection and offer an insight into the pathogenesis of Fno.

The effect of breed-type and castration on bone growth and distribution in cattle.

Data from carcasses of 210 cattle (119 bulls and 91 steers) from 4 breed types, serially slaughtered from approximately 200-800 kg kg liveweight were used to test the hypothesis of similar gender dimorphism among breeds in relation to carcass bone growth and distribution. Relative to total bone weight, breed types tended to have similar growth rates for all bones other than the cervical vertebrae, ribs, tibia and fibula, and tarsus. Adjusted to the same total bone weight there were significant differences among breed types in bone weight distribution, but the differences were very small and probably of little economic importance. Castration stimulated growth of the lumbar vertebrae, hindlimb bones, patella and hindquarter bones but inhibited growth of the ribs, scapula, carpus, forelimb bone, and forequarter bone. At the same total bone weight, steers as compared to bulls showed a shift in bone weight distribution towards the hindquarter, pistol and long bones. There were small but significant breed x gender interactions in the distribution of some bones.

Genetic influences on growth and partition of fat between depots and its distribution in fowl carcasses.

Thirty-two Hubbard and 40 Egyptian Fayoumi (dual-purpose) chickens were slaughtered in series at 2-wk intervals between 2-8 wk and 2-10 wk of age, respectively. Genetic differences in the allometric fat growth equation constants were studied. Relative to total body fat (TBF), the breeds did not differ significantly in relative growth of non-carcass fat. The Fayoumi tended to lay down carcass fat at a faster rate than the Hubbard. As TBF increased, the proportion of non-carcass fat increased and that of carcass fat decreased in the Hubbard; these depots tended to grow at the same rate as TBF in the Fayoumi. The Hubbard had significantly higher relative rates of fat deposition in the thigh, drumstick, breast and lower rates of fat deposition in the wing and neck than the Fayoumi. As the Hubbard matured, their growth coefficients of carcass fat tended to decrease anteriorly from breast to neck and also from leg to wing. The specific growth rates in almost all parts of the Fayoumi did not differ significantly from that of the total carcass fat. The present study shows for the Hubbard, as compared to Fayoumi, distinct patterns of fat partitioning (higher non-carcass fat: carcass fat; higher intermuscular fat: subcutaneous fat) and distinct patterns of fat distribution (higher proportion of the total depot occurring in the prime cuts). The study also gives some indications of different fat deposition patterns in poultry as compared to ruminants (cattle and sheep).