ABSTRACT
BACKGROUND: Comprehensive understanding about the local antibiogram is an essential requirement for preparation of hospital or unit based antibiotic policy. Bacteremic isolates are the most useful ones for this purpose, representing invasive disease. OBJECTIVE: To analyze susceptibility pattern of bacteremic Gram‑negative isolates in our center, to various antibiotics, including beta lactam‑beta lactamase inhibitor (BL‑BLI) agents and carbapenem. MATERIALS AND METHODS: This is a retrospective study done in Apollo Specialty Hospital, a tertiary care oncology center in South India. The susceptibility of Escherichia coli, Klebsiella, Acinetobacter and Pseudomonas blood culture isolates, identified between January 2013 and June 2014 to various antibiotics were analyzed. RESULTS: A total of 231‑Gram‑negative bacteremic isolates were analyzed. ESBL rate among E. coli isolates was 82.7% (67 out of 81) and 74.3% (58 out of 78) in Klebsiella. Carbapenem (imipenem) susceptibility rate in E. coli was 76.5%, Klebsiella 58.9%, Acinetobacter 32% and Pseudomonas 77.2%. Colistin susceptibility in E. coli was 96.2%, Klebsiella 93.5%, Acinetobacter 92.8% and Pseudomonas 97.7%. Difference in the susceptibility of Enterobacteriaceae to BL‑BLI agents (especially cefepime‑tazobactam) and carbapenem were minimal. In nonfermenters, BL‑BLI susceptibility was better than that of carbapenem. CONCLUSION: Findings of the study make a strong argument for using BL‑BLI agents and sparing carbapenem to curtail the spiraling scenario of carbapenem resistance.
ABSTRACT
Background & objectives: Salmonella enterica serovars Typhi and Paratyphi are predominantly known to cause enteric fever. Multidrug resistance in S. Tphi and S. Paratyphi has emerged as a cause of concern. This study was done to evaluate status in antimicrobial susceptibility patterns of Salmonella enterica serovar Typhi (S. Typhi) and S. Paratyphi obtained from blood culture in a tertiary care hospital in south India. Methods: Blood isolates of Salmonella species over a two year period between May 2009 and June 2011 were studied. A total of 322 isolates of Salmonella species were tested for antimicrobial susceptibility by Kirby-Bauer disc diffusion method. The MIC of ciprofloxacin was obtained by E-test, and azithromycin MIC was confirmed by agar dilution method for a limited number of isolates. Results: Of the total of 322 isolates studied, 186 (57.8%) were S. Typhi, 134 (41.6%) were S. Paratyphi A, and two were S. Paratyphi B. Of these, 44(13.66%) were resistant to ciprofloxacin (MIC <0.50 μg/ml) and 296 (91.9%) were nalidixic acid resistant. Of these 296 nalidixic acid resistant isolates, 278 (94%) were susceptible to ciprofloxacin by MIC criteria (<0.5 μg/ml). Of the 262 isolates tested for azithromycin sensitivity, only 120 (46%) were susceptible, whereas 81 (31%) were resistant and 55 (21%) showed intermediate susceptibility. Of the isolates, 322 (90%) were susceptible to ampicillin and (95%) were susceptible to co-trimoxazole. However, all the isolates were susceptible to chloramphenicol and ceftriaxone. Interpretation & conclusions: Nalidixic acid resistance screening is not a reliable surrogate indicator of ciprofloxacin resistance. Ciprofloxacin MIC should to be routinely done. Azithromycin resistance appears to be emerging. However, isolates showed a high degree of susceptibility to ampicillin, co-trimoxazole and chloramphenicol. Thus, antibiotics like ampicillin and co-trimoxazole may once again be useful for the management of enteric fever in southern India.