Abstract

The aim of the present investigation is to trace the epidemiological relatedness between different isolates of proteus sp. obtained from Dakahleia governorate as compared with similar sources from the adjacent Damietta governorate in Egypt. A total of 500 bacterial isolates were collected from human and animal sources including urine samples, sputum, wound, throat and ear swabs, endotracheal aspirate, breast swab, bile aspirate, blood samples, human and animal stools. From a total of 70 Proteus isolates, 62 were identified as Proteus mirabilis while eight as Proteus vulgaris. All Proteus mirabilis isolates were screened for susceptibility to ten different antimicrobials and were classified into 29 different patterns. Two resistant strains were found to belong to pattern No. 10 (isolates No. 11 and 19). A second pair of isolates namely No. 27&31 was classified into pattern No. 18. A third pair of (isolates No 30 and 16) was found to have great similarity to pattern No. 18 with a minor difference in resistance against one or two antibiotics. For a molecular characterization of the resistance determinants, 15 of the highly resistant Proteus mirabilis isolates were screened for the presence of different classes of integrons. Class 1 was the dominantly detected type that confers resistance to trimethoprim and aminoglycosides. One isolate was found to contain class 2. Similar integron components (dfrA15) could be proved among strains of different human sources (No. 11 & 19). Another similar type of intergon components (dfrA17) -(aadA5) was found in human isolates 31, 27, 30 & 16. In conclusion, three pairs of the studied isolates have been turned out to be epidemiologically related with the possibility of hospital infection and of strain transfer from one governorate to the other.

Key words: Proteus, integrons, resistance pattern, swarming.