Detection of virulence genes and investigation of the immunogenicity of outer membrane proteins of Salmonella enterica

Salmonella enterica is one of the most important food-borne pathogens, causing a variety of diseases in humansand animals. This study aimed to detect the virulence genes in 33 S. enterica strains isolated from patients andto investigate the immunogenicity of the outer membrane proteins (OMPs) of S. enterica serovar Typhimurium.The aggregative fimbriae (agfA) gene was detected in all S. enterica isolates except one strain, SalmonellaParatyphi C strain SA7. In addition, 81.8% of the isolates harbored the sefC gene (fimbrial protein). However,all of the tested S. enterica isolates possessed the fimA, hilA, invA, stn, and misL virulence genes, regardless ofserovar. The predominant OMPs of S. enterica Typhimurium SA3 identified by 12% sodium dodecyl sulfatePolyacrylamide Gel Electrophoresis (PAGE) were used as eliciting antigens in the experimental mice. Theresults of the protection studies indicated that the selected OMPs conferred varying degrees of protection.However, the highest protection was observed using the 38-kDa OMP, which provided 100% protection tomice challenged with 50× LD50 of Salmonella Typhimurium SA3 and 75% protection to mice subjected toan even higher bacterial challenge of 100× LD50. The humoral response in mice caused by the 38-kDa OMPwas confirmed using an immunodiffusion assay. This 38-kDa OMP is a promising candidate for the vaccinedevelopment against S. enterica Typhimurium. Further research on the protein structure was recommended.

Clonal diversity and antimicrobial resistance of Enterococcus faecalis isolated from endodontic infections

Background Enterococcus faecalis is considered to be one of most prevalent species in the oral cavity, particularly in endodontic infections. The aim of the present study was to investigate the prevalence of E. faecalis in dental root canals, clonal diversity by restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD-PCR) analysis, and the antibiotic susceptibility of E. faecalis isolates. Results Among the bacterial strains isolated from dental root canal specimens (n = 82), E. faecalis was determined to have the highest prevalence followed by Streptococcus viridians, Leuconostoc mesenteroides, Staphylococcus aureus, Streptococcus mitis, and Pediococcus pentosaceus. Cluster analysis of RAPD-PCR and RFLP patterns of the E. faecalis isolates discriminated five and six different genotypes, respectively. Among the tested strains, 43%, 52% and 5% were susceptible, intermediate resistant, and resistant to erythromycin, respectively. In addition, one strain (E-12) was intermediate resistant to linezolid, and one isolate (E-16) was resistant to tetracycline. Interestingly, many of the intermediate resistant/resistant strains were grouped in clusters 5 and 6, according RAPD and to RFLP, respectively. Conclusions E. faecalis demonstrated the highest prevalence in the tested dental root canal specimens collected from Saudi patients and were grouped into five to six different genotypes. Different levels of antimicrobial susceptibility were observed in the tested E. faecalis strains, which clearly indicated that although bacterial strains may be similar, point mutations can result in extreme susceptibility or resistance to various antibiotics. This phenomenon is a cause for concern for clinicians in the treatment of dental infections caused by E. faecalis.

Investigation of the biosynthetic origin of the diterpenes in gorgonian Pseudopterogorgia acerosa

The main goal of this work was to investigate the biosynthetic origin of diterpenes in gorgorian Pseudopterogorgia acerosa and to investigate the possibility of diterpenes production by the coral associated bacteria. Live coral Pseudopterogorgia acerosa was treated with different antibiotics, specific for different bacterial groups. The treated coral homogenate was prepared and assayed for conversion of radiolabeled terpenes precursor geranyl genranyl diphosphate [3H-GGPP] into radiolabled diterpenes. Mixed bacterial cultures were started from different coral tissues. Cell free extract were prepared from the isolated mixed culture and assayed for radiolabeled diterpenes biosynthesis. Production of diterpenes by the mixed bacterial cultures was investigated using LC-MS analysis. Investigation of the effect of different antibiotics on live coral demonstrated that the biosynthetic capability of diterpenes by the coral homogenate, from 3H-GGPP, was reduced by the effect of antibiotics mixture which suggested bacterial origin of this diterpene in P. acerosa. Furthermore, coral treated with nalidixic acid [gram negative bacterial inhibitor] resulted in about three fold increase of the biosynthesis of the radiolabled diterpes by the coral homogenate which suggested that the diterpenes producer may be gram positive bacteria. The cell free extract of mixed bacterial cultures isolated from the coral tissues was able to convert the radiolabled diterpenes precursor, 3H-GGPP, into pseudopterolide. Furthermore, mixed bacterial culture, isolated from the coral, showed low level production of diterpenes using diluted marine broth medium The results provided strong evidences that the diterpenes biosynthesis in P. acerosa is due to bacterial symbionts rather than the coral tissues

Effect of muscular exercise on some serum biochemical constituents in camels

Six mature healthy trained male one-humped camels of Bahttcharry breed aged from 8 to 10 years were exposed to muscular exercise, in form of running for 30 minutes. Blood samples were collected separately from each animal before and after running and sera were separated. Serum level of urea, creatinine, total proteins, albumins, cholesterol, triglycerides, total and direct bilirubin, AST, ALT as well as AP activities were determined. The results of the present investigation revealed that muscular exercise in camel induced significant increase in serum levels of urea, creatinine, total proteins, albumins triglycerides, total and direct bilirubin, AST, as well as AP activities

Effect of virginiamycin on some physiological characters in Fayoumi pullets

A total of 350 female Fayoumi pullets 7 weeks of age was fed 20 and 30 ppm of virginiamycin during the growth and laying period, respectively, to study the effect of virginiamycin on growth rate, weight gain, development of the reproductive organs, thyroid gland weight age of sexual maturity and egg production. Virginiamycin significantly increased the growth rate and weight gain as well as it increased the development of reproductive organs; while it did not affect the development of thyroid gland. The experimental group reached the age of sexual maturity one day earlier than control group. Virginiamycin significantly increases egg production, egg weight and egg quality