ANTIMICROBIAL SENSITIVITY OF GRAM-NEGATIVE BACTERIA WITH BETA LACTAM /BETA LACTAMASE INHIBITOR COMBINATION OF DRUGS IN COMPARISON TO OTHER ANTIBIOTICS IN TERTIARY CARE CENTER.

Corresponding Author:
Dr. R. Sasireha,
Assistant Professor,
Department of Microbiology,
Government Sivagangai Medical College,
Sivagangai, Tamilnadu, India.
E-mail: rammddo@yahoo.co.in

ABSTRACT

BACKGROUND

Objectives of the study were- 1. isolation and speciation of Gram-negative bacteria from urine, pus sample, wound swab, blood, tissue, BAL and other body fluids. 2. To identify bacteria most commonly isolated in ICU and Non-ICU Samples. 3. To compare sensitivity and resistant patterns of beta lactam and beta lactamase inhibitor combination of drugs, carbapenem, and aminoglycosides in various Gram-negative bacterial isolates.

Bacterial isolates are compared with MIC testing (E test) for Cefepime Tazobactam (CPT) and disc diffusion method.

MATERIALS AND METHODS

Gram negative bacterial pathogens from various clinical samples (urine, blood, broncho-alveolar lavage [BAL], other body fluids (bile, endometrial secretions), pus, wound swab, sputum and vaginal swab) were included in this study. The Isolates were identified with a battery of standard biochemical tests. Cefepime/tazobactam (CPT) (30/10 μg HiMedia, Mumbai) against various bacterial isolates and their susceptibility were compared with other β-lactam/β-lactamase inhibitor combinations like piperacillin/ tazobactam (PTZ), cefoperazone/sulbactam (CFS), carbapenems [imipenem (IMP), meropenem (MRP) and Amikacin]. MIC determination paper strip which is coated with Cefepime/Tazobactam on a single paper strip in a concentration gradient capable of showing MICs in the range of 0.016 mcg/ml to 256 mcg/ml, on testing against the test organism.

RESULTS

A total of 130 isolates from patients attending the tertiary care teaching hospital were included in the study. Most common age groups of isolation of Gram-negative bacilli was 40-60 yrs. and above 60 yrs. Out of 130 isolates isolated, 68 isolates were from male patients and 53 isolates were from female patients, 7 isolates were from male children and 2 isolates were from female children. Out of 130 isolates isolated, most common area of isolation of Gram-negative bacilli were from Inpatient (IP) from various wards, Out Patient (OP) and ICU. Out of 130 isolates isolated, most common samples were from urine, blood, pus and wound swab. Out of 130 samples isolated, 43% were from Escherichia coli, 24% were from Klebsiella pneumoniae, 18% were from Pseudomonas aeruginosa, 5% were from Enterobacter species and 3% were from Proteus species. Among 43% E. coli isolates, the sensitivity pattern towards, Cefepime Tazobactam was 90%, Cefepime - 32%, Piperacillin Tazobactam -75%, Cefoperazone sulbactam -71%, Carbapenem– 91%, and Amikacin- 92%. Klebsiella Pneumoniae (24%) showed susceptibility of 42% on Cefepime Tazobactam, Cefepime-16%, Piperacillin Tazobactam -48%, Cefoperazone sulbactam -46%, Carbapenem-55%, and Amikacin 55%. Pseudomonas aeruginosa (18%) showed highest susceptibility of 87% Sensitivity to Cefepime Tazobactam, Cefepime, Carbapenem and Amikacin followed by 70% Sensitivity to Piperacillin Tazobactam and Cefoperazone sulbactam. Proteus spp. showed 100 % susceptibility to Cefepime Tazobactam, Cefoperazone sulbactam, Carbapenem and Amikacin followed by 80% sensitivity to Cefepime, Piperacillin Tazobactam. Citrobacter spp. showed highest percentage of 100% susceptibility to Cefepime Tazobactam, Cefepime followed by 75% sensitivity to CFS, PIT, Carbapenem and Amikacin. Acinetobacter spp. Showed 50% sensitivity to Carbapenem and Amikacin respectively. E. Coli showed 68% resistant to Cefepime. Klebsiella showed resistant to 58%-Cefepime Tazobactam, 84%-, Cefepime, 52%-Piperacillin Tazobactam and 54% Cefoperazone sulbactam. Acinetobacter showed 100% resistant to Cefepime Tazobactam, Cefepime, Piperacillin Tazobactam and Cefoperazone sulbactam. Out of 130 Samples, Cefepime Tazobactam showed highest sensitivity to E. Coli, Enterobacter, Pseudomonas, Proteus, Serratia and Citrobacter. It showed resistant to Klebsiella and Acinetobacter.

CONCLUSION

This study showed a high level of antibiotic resistance among Gram-negative bacilli, particularly E. coli, K. pneumoniae and Acinetobacter spp. to the third generation cephalosporins. Cefepime Tazobactam is highly sensitive than Cefoperazone Sulbactam, Ceftazidime Sulbactam and Piperacillin Tazobactam. Cefepime, Tazobactam can be used to limit the Carbapenem usage in hospitals. E test and Antibiotic disc diffusion test showed equally sensitivity and resistant patterns.

KEY WORDS

Cefepime Tazobactam, Gram Negative Bacteria, E Test.