Evaluation of wide broad spectrum antibiotic resistance of E. coliand Klebsiella pneumonia

The Study of E.coli and Klebsiella resistance to wide spectrum antibiotics and molecular evaluation of resistance in these bacteria were examined. Treatment with wide spectrum antibiotics against bacteria can lead to resistance. The antimicrobial resistance can be seen in two types: 1) chromosomal alterations which could result in changes in structure of receptors of specific drugs. Most of this mutation can cause the absence of a penicillin binding proteins (pbps) and 2) is plasmid resistance. Plasmid genes can usually produce enzymes which result in destruction of antibiotics. An example is extended spectrum B-lactamase (ESBLs) which causes résistance to the third generation of cephalosporin, monobactams and new penicillin. ESBL plasmids are derived from TEM-1, TEM-2 and SHV-2. It has been recognized that because of point mutations in these plasmids, there are about 90 types of TEM and 25 types of SHV. The reason for the formation of point mutations within the ESBL plasmids is due to high consumption of broad spectrum antibiotics. In a cross-sectional study, 218 specimens from patients were collected and after identification of bacteria, the percentage of ESBLs among the isolates was calculated. For this purpose combined disk method and double disk method are used. Then TEM and SHV plasmids from 23 specimens of E.coli and Klebsiella were examined using plasmid extraction kit and PCR. The result of this study showed; the antibiotic resistance in 10% of E.coli was chromosomal and 50% were plasmids. The remaining isolates were sensitive. In Klebsiella, 12.8% of resistance was chromosomal and 62% were due to plasmids and remaining isolates were sensitive. The results from PCR showed; in E. coli 52.8% of the isolates were TEM positive and 84.6% were SHV positive and 69.2% were positive for both TEM and SHV. For Klebsiella 80% were TEM positive and 80% were SHV and 60% were positive for both TEM and SHV. The rate of ESBLs in Iran is higher than the results in similar studies in other countries. This could be because of the overuse of third generation of cephalosporin. For the purpose of having proper treatment using antibiotics, medical education and laboratory detection of ESBLs could be effective to choose choice antibiotics.