Purification and characterization of bacteriocins-like inhibitory substances from food isolated Enterococcus faecalis OS13 with activity against nosocomial enterococci.

Nosocomial infections caused by enterococci are an ongoing global threat. Thus, finding therapeutic agents for the treatment of such infections are crucial. Some Enterococcus faecalis strains are able to produce antimicrobial peptides called bacteriocins. We analyzed 65 E. faecalis isolates from 43 food samples and 22 clinical samples in Egypt for 17 common bacteriocin-encoding genes of Enterococcus spp. These genes were absent in 11 isolates that showed antimicrobial activity putatively due to bacteriocins (three from food, including isolate OS13, and eight from clinical isolates). The food-isolated E. faecalis OS13 produced bacteriocin-like inhibitory substances (BLIS) named enterocin OS13, which comprised two peptides (enterocin OS13α OS13ß) that inhibited the growth of antibiotic-resistant nosocomial E. faecalis and E. faecium isolates. The molecular weights of enterocin OS13α and OS13ß were determined as 8079 Da and 7859 Da, respectively, and both were heat-labile. Enterocin OS13α was sensitive to proteinase K, while enterocin OS13ß was resistant. Characterization of E. faecalis OS13 isolate revealed that it belonged to sequence type 116. It was non-hemolytic, bile salt hydrolase-negative, gelatinase-positive, and sensitive to ampicillin, penicillin, vancomycin, erythromycin, kanamycin, and gentamicin. In conclusion, BLIS as enterocin OS13α and OS13ß represent antimicrobial agents with activities against antibiotic-resistant enterococcal isolates.

Surgical treatment of thoracic and lumbar tuberculosis by anterior interbody fusion and posterior instrumentation.

OBJECTIVE: To evaluate the efficacy and clinical outcome of simultaneous or sequential anterior and posterior surgical approaches in the management of spinal tuberculosis in the form of anterior extirpation of the tuberculous lesion, strut bone grafting of the defect produced and posterior instrumentation for spinal fixation. SUBJECTS AND METHODS: Twenty-two patients who had tuberculosis of the thoracic and lumbar spine with moderate to severe localized kyphosis and variable degrees of neurological deficits were treated at Al Razi Hospital (Kuwait) in the period from 1998 to 2000 by anterior debridement and autogenous strut bone grafting with simultaneous or staged posterior spinal fixation using either USS or SOCON spinal instrumentation. Appropriate antituberculosis treatment was given to all patients for 9-12 months. The postoperative follow-up period was 18 months. RESULTS: Of the 22 cases the average of preoperative kyphosis was 42 degrees. The average of immediate postoperative correction was 27 degrees. At the last follow-up the average correction was 24 degrees and the loss of correction did not exceed 3 degrees. Average fusion times were 5 months for one-segment fusions and 8 months for two-segment fusions. There was no recurrence of the disease in any of the cases. CONCLUSION: Posterior instrumental stabilization and anterior interbody fusion were found to be effective in arresting the disease, correcting kyphotic deformity and maintaining correction until solid spinal fusion.