European Journal of Molecular & Clinical Medicine

Background: Pseudomonas species is responsible for 10% of nosocomial infections particularly in patients with burns and in an ICU environment. The most frequent mechanism of resistance to carbapenem, the most widely used medication to treat Pseudomonas, is the synthesis of metallo-β-lactamases (MBL). Both microbiologists and clinicians need to know the incidence of MBL-producing Pseudomonas in their area in order to develop an infection control plan for hospitals. The current study aimed to identify the incidence of MBL among clinical isolates of Pseudomonas species in a tertiary care hospital.
Methods: The samples include blood, urine, pus, body fluids, and catheter tips.  The samples were cultivated on Blood agar, MacConkey's agar, and Thioglycolate broth, except for blood and urine samples. Brain Heart Infusion broth was used to culture blood. Blood and MacConkey's agar were used to culture urine. All culture plates were incubated overnight at 37°C. Identification of organisms was done by standard laboratory technique based on colony characteristics, Gram staining, and biochemical tests.
Results: All n=50 pseudomonas isolates were tested for antibiotic sensitivity testing by using the Kirby-Bauer disk diffusion method. Among the n=50 isolates n=45 isolates showed resistance to imipenem remaining n=5 isolates were intermediate sensitive. The highest sensitivity was noted to Polymyxin-B (100%) followed by Piperacillin+tazobactam (70%), Amikacin (50%), Cefoperazone+Sulbactam (36%), Gentamycin (28%), Netilmycin (26%), Cefotaxime (12%), Ciprofloxacin (10%) and Ceftazidime (2%). Pseudomonas aeruginosa isolates tested for metallo β-lactamases by using imipenem-EDTA combined disk method (CDT). N=18 (36%) isolates were shown positive results and the remaining n=32 (64%) isolates were shown negative results.
Conclusion: The development of MBL genes and their proliferation among bacterial pathogens are a topic of concern concerning the future of antimicrobial therapy since more and more MBL-producing Pseudomonas aeruginosa isolates are being identified as a major source of nosocomial infections. To conclude there are 36% of metallo beta-lactamase-producing pseudomonas aeruginosa prevalent in our area. Therefore, detection of these MBL-producing P. aeruginosa is crucial for the optimal treatment of critically ill patients and to prevent the spread of resistance.

Background: The broad spectrum ß-lactam antibiotics are commonly used empirically for the treatment of gram negative sepsis. But the emergence of ESBL producing organisms has posed a serious threat for their continuing use. Present study was undertaken to find out the magnitude of the problem of infections due to extended spectrum β-lactamase producing organisms.
Material and Methods: Present study was a descriptive & observational study, conducted in patients < 18 years age, all cultures showing a significant growth of ESBL producing organisms from any of the clinical specimens, as per CLSI guidelines.
Results: Infections by ESBL producing organisms were found more common in 13-18 years of age group (36.25%) & males (71.25%). K. pneumoniae has been found to be the most commonly isolated ESBL producing organism (56.25%) followed by E. coli (38.75%). ESBL producing organisms were most commonly grown in urine samples (51.25%) followed by pus culture (11.25%) and blood (10%). All were sensitive to tigecycline and colistin (100%). In the carbapenem group, sensitivity to imipenem was highest (93.75%) followed by ertapenem (66.25%), doripenem (65%) and meropenem (53.75%). Among the 45 isolates of ESBL K. pneumoniae, all were sensitive to tigecycline and colistin. Sensitivity to imipenem is 93.33% while that to meropenem, doripenem and ertapenem were 46.66%, 62.22% and 64.44% respectively. Out of the 31 isolates of ESBL producing E. coli, all were sensitive to tigecycline and colistin. Sensitivity to Imipenem was 96.77% while that to meropenem, doripenem and ertapenem were 64.71%, 70.96% and 70.96% respectively. Sensitivity to meropenem has gone down dramatically from 71.42% to 22.22%, which is significant.
Conclusion: A growing resistance in the ESBL producing organisms is noted which is very alarming. A limited number of drugs are available against these ESBL producing organisms and the drug of choice is carbapenem.