This review covers a historical view and etiology of oedematous skin disease which affects buffalo in Egypt, the microbiology of Corynebacterium pseudotuberculosis causing the disease: its virulence; clinical signs; mechanism of pathogenesis; histopathology; mode of transmission; immunological aspects; treatment and control. It is concluded that C. pseudotuberculosis serotype II is the main cause of OSD and exotoxin phospholipase D and its lipid contents of the cell wall are the major causes of pathogenesis. After declaring the role of Hippobosca equina in transmission of the causative agent among buffaloes, control of OSD is now available.

The aim of this study was to evaluate the Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) as a tool for molecular typing of C. pseudotuberculosis isolates from eight different hosts in twelve countries. Ninety-nine C. pseudotuberculosis field strains, one type strain (ATCC 19410T) and one vaccine strain (1002) were fingerprinted using the ERIC-1R and ERIC-2 primers, and the ERIC-1R+ERIC-2 primer pair. Twenty-nine different genotypes were generated by ERIC 1-PCR, 28 by ERIC 2-PCR and 35 by ERIC 1+2-PCR. The discriminatory index calculated for ERIC 1, ERIC 2, and ERIC 1+2-PCR was 0.89, 0.86, and 0.92, respectively. Epidemiological concordance was established for all ERIC-PCR assays. ERIC 1+2-PCR was defined as the best method based on suitability of the amplification patterns and discriminatory index. Minimal spanning tree for ERIC 1+2-PCR revealed three major clonal complexes and clustering around nitrate-positive (biovar Equi) and nitrate-negative (biovar Ovis) strains. Therefore, ERIC 1+2-PCR proved to be the best technique evaluated in this study for genotyping C. pseudotuberculosis strains, due to its usefulness for molecular epidemiology investigations.

Hyperimmune sera against four strains of Corynebacterium pseudotuberculosis isolated from different animals (sheep, goat, buffalo and cattle) were obtained by inoculating rabbits with strains in different forms (live, dead plus live or dead). Immunization with live or dead bac teria followed by live strains gave similar results with regard to antibody titres and number of precipitin lines. Typing 21 strains of C. pseudotuberculosis by specific precipitin reac tions in agar gel was performed by using antigens extracted with sodium deoxycholate. The authors concluded that they were divisible into two serotypes, I and II. The nitrate reduction test and animal pathogenicity tests (by inocu lating guinea-pigs subcutaneously) demonstrated additional differences between the two types. Type I was nitrate negative, and produced local and general absces ses in guinea-pigs, with a prolonged course (15 days) ending fatally. It included all the strains originating from sheep and goats, but only 3 of 5 cattle strains. Type II comprised all 7 isolates from buffaloes and 2 of the cattle strains. All strains were nitrate positive and did not produce abscesses in guinea-pigs, but they caused tissue necrosis at the site of inoculation, with a rapid course (not more than five days) ending in death.

TB remains a challenging disease to control worldwide. Nanoparticles have been used as drug carriers to deliver high concentrations of antibiotics directly to the site of infection, reducing the duration of treatment along with any side effects of off-target toxicities after systemic exposure to the antibiotics. Herein we have developed a drug delivery platform where gold nanorods (AuNRs) are conjugated to rifampicin (RF), which is released after uptake into macrophage cells (RAW264.7). Due to the nature of the macrophage cells, the nanoparticles are actively internalized into macrophages and release RF after uptake, under the safety frame of the host cells (macrophage). AuNRs without RF conjugation exhibit obvious antimicrobial activity. Therefore, AuNRs could be a promising antimycobacterial agent and an effective delivery vehicle for the antituberculosis drug Rifampicin for use in tuberculosis therapy.

Plasmonic photothermal therapy (PPTT) is a cancer therapy in which gold nanorods are injected at the site of a tumor before near-infrared light is transiently applied to the tumor causing localized cell death. Previously, PPTT studies have been carried out on xenograft mice models. Herein, we report a study showing the feasibility of PPTT as applied to natural tumors in the mammary glands of dogs and cats, which more realistically represent their human equivalents at the molecular level. We optimized a regime of three low PPTT doses at 2-week intervals that ablated tumors mainly via apoptosis in 13 natural mammary gland tumors from seven animals. Histopathology, X-ray, blood profiles, and comprehensive examinations were used for both the diagnosis and the evaluation of tumor statuses before and after treatment. Histopathology results showed an obvious reduction in the cancer grade shortly after the first treatment and a complete regression after the third treatment. Blood tests showed no obvious change in liver and kidney functions. Similarly, X-ray diffraction showed no metastasis after 1 year of treatment. In conclusion, our study suggests the feasibility of applying the gold nanorods-PPTT on natural tumors in dogs and cats without any relapse or toxicity effects after 1 year of treatment.

No abstract

Corynebacterium pseudotuberculosis is a Gram-positive, pleomorphic, facultative intracellular pathogen that causes Oedematous Skin Disease (OSD) in buffalo. To better understand the pathogenic mechanisms of OSD, we performed a comparative genomic analysis of 11 strains of C. pseudotuberculosis isolated from different buffalo found to be infected in Egypt during an outbreak that occurred in 2008. Sixteen previously described pathogenicity islands (PiCp) were present in all of the new buffalo strains, but one of them, PiCp12, had an insertion that contained both a corynephage and a diphtheria toxin gene, both of which may play a role in the adaptation of C. pseudotuberculosis to this new host. Synteny analysis showed variations in the site of insertion of the corynephage during the same outbreak. A gene functional comparison showed the presence of a nitrate reductase operon that included genes involved in molybdenum cofactor biosynthesis, which is necessary for a positive nitrate reductase phenotype and is a possible adaptation for intracellular survival. Genomes from the buffalo strains also had fusions in minor pilin genes in the spaA and spaD gene cluster (spaCX and spaYEF), which could suggest either an adaptation to this particular host, or mutation events in the immediate ancestor before this particular epidemic. A phylogenomic analysis confirmed a clear separation between the Ovis and Equi biovars, but also showed what appears to be a clustering by host species within the Equi strains.

For localized tumors, gold nanorod (AuNR)-assisted plasmonic photothermal therapy (PPTT) is a potentially effective alternative to traditional surgery, in which AuNRs absorb near-infrared light and convert it to heat in order to kill cancer cells. However, for large tumors (volume ≥ 20 cm3), an uneven distribution of AuNRs might cause inhomogeneity of the heat distribution inside the tumor. Surgery is frequently recommended for removing large tumors, but it is associated with a high risk of cancer recurrence and metastasis. Here, we applied PPTT before surgery, which showed improved treatment for large tumors. We divided the animals (eight cats/dogs) into two groups: Group I (control), where three cases were solely treated with surgery, laser, or AuNRs alone, resulting in recurrence and metastasis; and Group II, where animals were treated with PPTT before surgery. In Group II, four out of the five cases had tumor regression without any recurrence or metastasis. Interestingly, we observed that applying PPTT before surgery displayed reduced bleeding during tumor removal, supported by histopathology that showed altered blood vessels. In conclusion, our study showed that applying AuNR-assisted PPTT (AuNRs-PPTT) before surgery could significantly affect blood vessels inside the tumor, leading to a decreased amount of bleeding during surgery, which can potentially decrease the risk of metastasis and blood loss during surgery.