Expanded spectrum ß-lactamase producing Escherichia coli isolated from chickens with colibacillosis in Egypt.

Throughout the world, expanded spectrum ß-lactamases (ESBL) are increasing among clinical isolates of Enterobacteriaceae, both in humans and animals. Unfortunately, there is a paucity of data on ESBL or Ampicillin class C ß-lactamase (AmpC) in Egypt, although antimicrobial consumption is high in this developing country. This study aims to characterize the resistance mechanisms to expanded spectrum cephalosporins among resistant veterinary Escherichia coli isolates in Egypt. We investigated 50 clinical multi-resistant E. coli strains isolated from 20 chicken farms for production of ESBL or AmpC. Antibiotic susceptibility was tested by Clinical and Laboratory Standards Institute (CLSI) disk diffusion and ESBL confirmatory tests. PCR and sequencing were performed to screen for plasmid mediated ESBL genes and genes encoding AmpC ß-lactamases. All the isolates were phylogentically classified, investigated for harboring class 1 integrons, and genotyped by amplified fragment length polymorphism (AFLP). Three strains showed ESBL and 6 strains AmpC phenotypic patterns, respectively, with confirmed ESBL genes of blaTEM-57, blaSHV-12, blaCTX-M-14, and blaCMY-2 for AmpC producing strains. All ESBL strains belonged to phylogroup D with different clones isolated from different flocks, while most of the AmpC strains belonged to phylogroup B1 (4/6) and were assigned to the same genotype distributed in 2 different farms. Class 1 integrons were disseminated in 60% of all tested strains and in 100% of ESBL and AmpC strains. These results highlight the antimicrobial resistance problem in Egypt, caused in all probability by unwise use of antimicrobials in animal husbandry. The results call for a nationwide surveillance program to monitor antimicrobial resistance.

Study of the effect of using mini-transitional implants as temporary abutments in implant overdenture cases.

In an attempt to improve patient satisfaction during the healing period after placement of implants, mini-transitional implants (MTIs) have been advocated to allow immediate use of temporary dentures and to prevent transmucosal loads over the definitive implants. Twelve edentulous patients received two screw implants each in the predetermined mandibular canine region. At the time of surgery, six patients had two MTIs placed medially to the permanent ones. The flap was repositioned allowing transmucosal penetration of MTIs. Patients left the operating room wearing their relined lower dentures. The results indicated that MTIs integrated sufficiently in bone, giving successful immediate support for the transitional prosthesis and allowing proper mucosal healing. Two of these transitional implants showed mobility three months after phase I surgery. After loading the final implants, patients who had MTI-supported dentures showed bone loss that was not significantly different from the control group.