Analysis Of The Antibiotic Resistance And Detection Of AmpC Enzyme Of Pseudomonas Aeruginosa From Clinical Specimens

Pseudomonas aeruginosa, an important opportunistic pathogen, widely exists in soil and water. It is also found throughout the hospital environment in moist reservoirs, and sometimes colonizes humans. Pseudomonas aeruginosa is frequently present in small numbers in the normal intestinal flora and on the skin of humans. Pseudomonas aeruginosa is pathogenic only when introduced into areas devoid of normal defenses, eg, when mucous membranes and skin are disrupted by direct tissue damage, also when intravenous or urinary catheters are used; or when neutropenia is present, as in cancer chemotherapy. Pseudomonas aeruginosa and other pseudomonads are resistant to many antimicrobial agents and therefore become dominant and important when more susceptible bacteria of the normal flora are suppressed. Moreover, susceptible organisms can become resistant during therapy by inducing the formation of antibiotic-inactivating enzymes or the mutation of the genes coding the outer membrane pore proteins or through the transfer of plasmid-mediated resistance from a resistant organism to a susceptible one. In this study, the colonial morphology combined with the results of selected rapid biochemical tests is sufficient for the preliminary identification of these isolates. Antibiotic susceptibility patterns were carried out, and a plasmid-mediated resistance to ampenicilin from a strain of Pseudomonas aeruginosa was identified. ObjectiveTo investigate the resistance of Pseudomonas aeruginosa to 12 antimicrobial agents and the mechanism of its resistance. Methods1. 98 strains of Pseudomonas aeruginosa were identified by the colonial morphology combined with the results of selected rapid biochemical tests.2. Antibiotic susceptibility patterns of these bacteria were analyzed.3. Aplasmid plasmid-mediated resistance to ampenicilin was identified by electrophoresis.4. AmpC enzyme produced by Pseudomonas aeruginosa was investigated.Results1. 98 strains of P seudomonas aeruginosa were isolated.2. The resistance rates of Pseudomonas aeruginosa to penicillin, ampecillin, amocillin, cefetadin, ceftriaxone were altus respectively.3. R plasmid (5.4kb) presented in a strain of Pseudomonas aeruginosa is associated with ampencillin.4. AmpC enzyme producing strain is up 57.1% among these isolates.Conclusion1. Pseudomonas aeruginosa is primarily a nosocomial pathogen, and can cause a variety of infectious disease.2. Pseudomonas aeruginosa is resistant to many antibiotics. The susceptibility patterns of Pseudomonas aeruginosa vary geographically, and susceptibility tests should be done as an adjunct to selection of antimicrobial therapy.3. R plasmid and AmpC enzyme play an important role in resistance to antibiotics.4. The test for AmpC enzyme-producing bacteria should be improved further to guarantee the accuracy.