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Dio-Sensimedia: a novel culture medium for rapid detection of extended spectrum beta-lactamases.

Cagatay AA, Kocagoz T, Eraksoy H - BMC Infect. Dis. (2003)

Bottom Line: Of 40 ESBL-producing E. coli isolates, 38 (95%) were ESBL-positive by the DDST on MH agar, and 37 (92.5%), on DSM-ES agar.The average incubation period required for ESBL detection by the DDST on DSM-ES agar was 4 hours.Since the DDST results were available within 4 hours when DSM-ES agar was used, the use of this media may significantly lower the length of hospital stay, the total cost for patient care and even the mortality rate by facilitating early treatment against ESBL-producing organisms.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Infectious Diseases and Clinical Microbiology, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey. atayon@yahoo.com

ABSTRACT

Background: Resistance to contemporary broad-spectrum beta-lactams, mediated by extended-spectrum beta-lactamases (ESBL), is an increasing problem worldwide. Many of the emerging antimicrobial resistance problems of this decade have been characterized by difficulty in the recognition of resistance in the laboratory, particularly by rapid susceptibility test methods. The plasmid-encoded ESBL represent such a resistance phenomenon that is difficult to recognize. We compared Dio-Sensimedia-ES (DSM-ES; Diomed, Istanbul, Turkey) and Mueller-Hinton (MH) agar in the double-disk synergy test (DDST) as a novel rapid system for detecting ESBL directly from bacterial culture.

Methods: Sixty ESBL-producing Klebsiella pneumoniae isolates cultured from blood (30), endotracheal aspirates (20), urine (5) and pus (5), as well as 40 Escherichia coli isolates cultured from endotracheal aspirates (15), urine (10), blood (8) and pus (7) were studied. Isolates positive for ESBL by the combined disk tests were tested with the DDST using MH and DSM-ES agar to detect ESBL-mediated resistance in K. pneumoniae and E. coli. DSM-ES agar was also used to determine the susceptibility of Enterobacteriaceae and staphylococci.

Results: Among 60 ESBL-producing K. pneumoniae isolates, 59 (98.3%) were identified as ESBL-positive by the DDST using MH, and 58 (96.6%), using DSM-ES agar. Of 40 ESBL-producing E. coli isolates, 38 (95%) were ESBL-positive by the DDST on MH agar, and 37 (92.5%), on DSM-ES agar. The average incubation period required for ESBL detection by the DDST on DSM-ES agar was 4 hours.

Conclusions: Since the DDST results were available within 4 hours when DSM-ES agar was used, the use of this media may significantly lower the length of hospital stay, the total cost for patient care and even the mortality rate by facilitating early treatment against ESBL-producing organisms.

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Detection of ESBL production by the double disk test on DSM-ES agar. Disks: centre, amoxycillin+clavulanate 20 + 10 μg; right, cefepime 30 μg; left, ceftriaxone 30 μg; top, ceftazidime 30 μg; bottom, aztreonam 30 μg.
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Figure 2: Detection of ESBL production by the double disk test on DSM-ES agar. Disks: centre, amoxycillin+clavulanate 20 + 10 μg; right, cefepime 30 μg; left, ceftriaxone 30 μg; top, ceftazidime 30 μg; bottom, aztreonam 30 μg.

Mentions: The detection of ESBL-mediated resistance by the DDST was performed according to a published protocol [11,12]. Bacterial suspensions were prepared from overnight cultures of clinical isolates to produce a turbidity of a 0.5 McFarland standard. These suspensions were then spread on the surface of MH and DSM-ES agar plates as in the Kirby-Bauer disk diffusion technique. Antibiotic susceptibility disks containing amoxicillin (20 μg) plus clavulanate (10 μg) were placed on the centre of Petri dishes containing the two different media. Ceftazidime (30 μg), ceftriaxone (30 μg), cefpodoxime (10 μg), aztreonam (30 μg), cefotaxime (30 μg) disks were placed 25–30 mm apart circularly around the co-amoxiclav disk. The MH agar plates were incubated for 24 hours at 35°C. DSM-ES agar that is originally red, changed its color to yellow as bacterial culture grew (Fig. 1). DSM-ES agar plates were incubated at 35°C until red inhibition zones became apparent. Red inhibition zones around disks containing antibacterials were visually observed and measured. When the disk containing co-amoxiclav extended to any of the other antibiotic disk inhibition zones, ESBL production was inferred [11,12] (Fig. 2).


Dio-Sensimedia: a novel culture medium for rapid detection of extended spectrum beta-lactamases.

Cagatay AA, Kocagoz T, Eraksoy H - BMC Infect. Dis. (2003)

Detection of ESBL production by the double disk test on DSM-ES agar. Disks: centre, amoxycillin+clavulanate 20 + 10 μg; right, cefepime 30 μg; left, ceftriaxone 30 μg; top, ceftazidime 30 μg; bottom, aztreonam 30 μg.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC222987&req=5

Figure 2: Detection of ESBL production by the double disk test on DSM-ES agar. Disks: centre, amoxycillin+clavulanate 20 + 10 μg; right, cefepime 30 μg; left, ceftriaxone 30 μg; top, ceftazidime 30 μg; bottom, aztreonam 30 μg.
Mentions: The detection of ESBL-mediated resistance by the DDST was performed according to a published protocol [11,12]. Bacterial suspensions were prepared from overnight cultures of clinical isolates to produce a turbidity of a 0.5 McFarland standard. These suspensions were then spread on the surface of MH and DSM-ES agar plates as in the Kirby-Bauer disk diffusion technique. Antibiotic susceptibility disks containing amoxicillin (20 μg) plus clavulanate (10 μg) were placed on the centre of Petri dishes containing the two different media. Ceftazidime (30 μg), ceftriaxone (30 μg), cefpodoxime (10 μg), aztreonam (30 μg), cefotaxime (30 μg) disks were placed 25–30 mm apart circularly around the co-amoxiclav disk. The MH agar plates were incubated for 24 hours at 35°C. DSM-ES agar that is originally red, changed its color to yellow as bacterial culture grew (Fig. 1). DSM-ES agar plates were incubated at 35°C until red inhibition zones became apparent. Red inhibition zones around disks containing antibacterials were visually observed and measured. When the disk containing co-amoxiclav extended to any of the other antibiotic disk inhibition zones, ESBL production was inferred [11,12] (Fig. 2).

Bottom Line: Of 40 ESBL-producing E. coli isolates, 38 (95%) were ESBL-positive by the DDST on MH agar, and 37 (92.5%), on DSM-ES agar.The average incubation period required for ESBL detection by the DDST on DSM-ES agar was 4 hours.Since the DDST results were available within 4 hours when DSM-ES agar was used, the use of this media may significantly lower the length of hospital stay, the total cost for patient care and even the mortality rate by facilitating early treatment against ESBL-producing organisms.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Infectious Diseases and Clinical Microbiology, Istanbul University, Istanbul Faculty of Medicine, Capa, Istanbul, Turkey. atayon@yahoo.com

ABSTRACT

Background: Resistance to contemporary broad-spectrum beta-lactams, mediated by extended-spectrum beta-lactamases (ESBL), is an increasing problem worldwide. Many of the emerging antimicrobial resistance problems of this decade have been characterized by difficulty in the recognition of resistance in the laboratory, particularly by rapid susceptibility test methods. The plasmid-encoded ESBL represent such a resistance phenomenon that is difficult to recognize. We compared Dio-Sensimedia-ES (DSM-ES; Diomed, Istanbul, Turkey) and Mueller-Hinton (MH) agar in the double-disk synergy test (DDST) as a novel rapid system for detecting ESBL directly from bacterial culture.

Methods: Sixty ESBL-producing Klebsiella pneumoniae isolates cultured from blood (30), endotracheal aspirates (20), urine (5) and pus (5), as well as 40 Escherichia coli isolates cultured from endotracheal aspirates (15), urine (10), blood (8) and pus (7) were studied. Isolates positive for ESBL by the combined disk tests were tested with the DDST using MH and DSM-ES agar to detect ESBL-mediated resistance in K. pneumoniae and E. coli. DSM-ES agar was also used to determine the susceptibility of Enterobacteriaceae and staphylococci.

Results: Among 60 ESBL-producing K. pneumoniae isolates, 59 (98.3%) were identified as ESBL-positive by the DDST using MH, and 58 (96.6%), using DSM-ES agar. Of 40 ESBL-producing E. coli isolates, 38 (95%) were ESBL-positive by the DDST on MH agar, and 37 (92.5%), on DSM-ES agar. The average incubation period required for ESBL detection by the DDST on DSM-ES agar was 4 hours.

Conclusions: Since the DDST results were available within 4 hours when DSM-ES agar was used, the use of this media may significantly lower the length of hospital stay, the total cost for patient care and even the mortality rate by facilitating early treatment against ESBL-producing organisms.

Show MeSH
Related in: MedlinePlus