Synergistic effects of sulbactam in multi-drug-resistant Acinetobacter baumannii

Abstract Acinetobacter baumannii is a frequently isolated etiologic agent of nosocomial infections, especially in intensive care units. With the increase in multi-drug resistance of A. baumannii isolates, finding appropriate treatment alternatives for infections caused by these bacteria has become more difficult, and available alternate treatments include the use of older antibiotics such as colistin or a combination of antibiotics. The current study aimed to evaluate the in vitro efficacy of various antibiotic combinations against multi-drug resistant A. baumannii strains. Thirty multi-drug and carbapenem resistant A. baumannii strains isolated at the Ankara Training and Research Hospital between June 2011 and June 2012 were used in the study. Antibiotic susceptibility tests and species-level identification were performed using conventional methods and the VITEK 2 system. The effects of meropenem, ciprofloxacin, amikacin, tigecycline, and colistin alone and in combination with sulbactam against the isolates were studied using Etest (bioMérieux) in Mueller-Hinton agar medium. Fractional inhibitory concentration index (FIC) was used to determine the efficacy of the various combinations. While all combinations showed a predominant indifferent effect, a synergistic effect was also observed in 4 of the 5 combinations. Synergy was demonstrated in 43% of the isolates with the meropenem-sulbactam combination, in 27% of the isolates with tigecycline-sulbactam, and in 17% of the isolates with colistin-sulbactam and amikacin-sulbactam. No synergy was detected with the sulbactam-ciprofloxacin combination and antagonism was detected only in the sulbactam-colistin combination (6.66% of the isolates). Antibiotic combinations can be used as an alternative treatment approach in multi-drug resistant A. baumannii infections.

16S Ribosomal RNA Identification of Prevotella nigrescens from a Case of Cellulitis

No abstract available.

Comparison of in vitro activities of ceftazidime, piperacillin-tazobactam, and cefoperazone-sulbactam, and the implication on empirical therapy in patients with cancer.

Background: Infection is a common cause of morbidity and mortality in cancer patients. In most of these cases empirical treatment is provided because the focus of infection is not identified. Empiric antibiotics provided to these patients are based on isolates, sensitivity, and on guidelines. Here we have compared three antibiotics recommended as empirical treatment by the Infectious Disease Society of America (IDSA). Aims: To compare the three antibiotic sensitivities for gram negative isolates at our institute. Objective: To choose the optimal antibiotic as the empirical treatment for cancer patients developing infections. Materials and Methods: We collected the data on isolates and antibiotic sensitivity patterns of isolates for ceftazidime, piperacillin + tazobactum, and cefoperazone from the medical oncology department. We subsequently compared the sensitivity of these three antibiotics. Statistical Methods: The isolates were mapped using the WHONET 5.4 software. The analysis was conducted using SPSS 15.0 for Windows. McNemar Chi-square test was used to compare the sensitivity percentages between any two antibiotics. The agreement between the antibiotic and the gold standard was calculated using the Kappa statistic. Two tailed p values were reported. Results: The results showed that there was a difference among sensitivities for these antibiotics. It appears that the sensitivity of ceftazidime was inferior to the two other antibiotics. Also cefoperazone has better sensitivity as compared to piperacillin + tazobactum. Conclusion: In spite of these three antibiotics being recommended by IDSA our data suggest that it should not be followed blindly and local sensitivity data is important for formulating institutional guidelines for using antibiotics.

Comparative in vitro activity of beta-lactam/beta-lactamase inhibitor combinations against gram negative bacteria.

BACKGROUND & OBJECTIVE: Currently, the use of beta-lactamase inhibitors in combination with beta-lactam antibiotics represents an effective measure to combat a specific resistance mechanism of beta-lactamase producing organisms. Knowledge about the susceptibility profile of bacteria to different combination agents available is essential to guide appropriate treatment of severe infections in hospitalized patients. The present study compares the in vitro activity of three commercially available beta-lactam/beta-lactamase inhibitor combinations (piperacillin/tazobactam, cefoperazone/sulbactam, ticarcillin/clavulanic acid) against beta-lactamase producing gram negative bacteria in a tertiary care hospital in north India. METHODS: A total of 9004 consecutively isolated extended spectrum beta-lactamase (ESBL) producing gram negative bacteria isolated from various clinical samples from patients admitted to the All India Institute of Medical Sciences, New Delhi, from September 2003 to August 2004 were included in the study. These isolates were screened for ESBL production by the inhibitor based test recommended by the National Committee for Clinical Laboratory Standards (NCCLS). Antibiotic susceptibility testing was carried out by disc diffusion method as per NCCLS guidelines. RESULTS: Of the 9004 isolates tested, 3232 (35.89%) were sensitive and 568 (6.31%) were resistant to all three combination agents, and rest 5204 (57.80%) were resistant to at least one of the combinations. Susceptibility to piperacillin/tazobactam, cefoperazone/sulbactam, and ticarcillin/clavulanic acid was 81.37, 76.06 and 45.48 per cent respectively. Piperacillin/tazobactam exhibited significantly (P<0.05) greater antimicrobial activity against Pseudomonas spp., Escherichia coli and Klebsiella spp. compared to cefoperazone/sulbactam. INTERPRETATION & CONCLUSION: Overall piperacillin/tazobactam was observed to be the best combination agent followed by cefoperazone/sulbactam in our setting. This difference in activities of these combination agents needs to be evaluated further by ascertaining their efficacy in clinical studies.

Comparative susceptibilities of Escherichia coli to ceftriaxone alone and in combination with sulbactam

The study was conducted to observe the effect of ceftriaxone alone and in combination with sulbactam against Escherichia coli. Forty Isolates of -lactamase producing Escherichia coli were collected in the microbiology laboratory Khyber Medical College, Peshawar. These were cultured and their sensitivity tests were done both with and without adding sulbactam in ceftriaxone using specially prepared antibiotic disks. NCCL zone diameter criteria was used. The disks containing the combination of ceftriaxone and sulbactam produced larger zones of inhibitions than those containing only ceftriaxone. This showed that the bacteria which had become resistant to ceftriaxone can once again become sensitive to ceftriaxone, if the inhibitor sulbactam is added

In vitro activity of cefoperazone-sulbactam: Singapore experience.

In vitro activity of commonly used antimicrobial agents against consecutively isolated 521 strains of Gram negative bacilli causing serious infections in the National University Hospital, Singapore were tested in parallel with cefoperazone-sulbactam combination. With the combination complete resistance of 2% and intermediate resistance of 5% were noted among the 521 strains tested. Resistance to imipenem was low (5%) but resistance against other antimicrobial agents varied from 12% (amikacin) to 80% (ampicillin). In vitro data demonstrated a possible future role for cefoperazone-sulbactam in the treatment of sepsis caused by Gram negative bacilli in our hospital.

Eficacia y seguridad de sulbactam-ampicilina: unasyn; en el tratamiento de algunas infecciones pediátricas / Efficacy and security of sulbactam-ampicyllin: unasyn; in the treatment of some pediatric infection

Se trataron 30 pacientes pediátricos con sulbactam-ampicilina (UNASYN) vía intravenosa durante siete días. Los diagnósticos clínicos fueron bronconeumonía, celulitis, septicemia y pielonefritis. La respuesta clínica fue catalogada como excelente en 93% de los pacientes, y esto se correlacionó perfectamente con la actividad in vitro de la droga usando el método cuantitativo de dilución en agar (CIM)