Comparison of direct and standard antimicrobial disk susceptibility testing for bacteria isolated from blood

Mirrett, Stanley; Reller, L. Barth

doi:10.1128/jcm.10.4.482-487.1979

Cited by 41 publications

(23 citation statements)

References 21 publications

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“…Direct susceptibility testing of bacteria from positive blood culture bottles by agar disk diffusion is a relatively inexpensive procedure, not tied to bacterial identification, in contrast to direct testing with an automated system such as MicroScan. Agar disk diffusion has been the most widely studied technique of direct susceptibility testing and has the greatest correlation with standardized methods, according to most studies (9).…”

Section: Discussionmentioning

confidence: 99%

Direct Susceptibility Testing with Positive BacT/Alert Blood Cultures by Using MicroScan Overnight and Rapid Panels

et al. 1998

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Studies were conducted on a method of direct inoculation of MicroScan dried overnight and of rapid panels with positive aerobic blood cultures obtained from the BacT/Alert to determine antimicrobial susceptibilities. Inocula were limited to specimens that appeared unimicrobic on Gram stain. Results were compared to those obtained from panels inoculated following subculture. For 133 gram-negative bacilli, there were 94.7 and 93.5% categorical agreements between direct and standard methods for all drugs tested with overnight and rapid panels, respectively. For 104 gram-positive cocci, there were 93.2 and 93.1% categorical agreements for overnight and rapid panels, respectively. The major error (false resistance) rate for gram negatives was 1.4% for overnight versus 0.7% for rapid panels. The very major error (false susceptibility) rate was 2.7% for overnight versus 8.1% for rapid panels. The total error rates were 1.6% for overnight panels and 1.5% for rapid panels. The major error rates for gram-positive direct susceptibility tests were 2.6% for overnight and 2.5% for rapid panels. The very major error rates were 8.8 and 7.2% for overnight and rapid panels, respectively. Total error rates were 3.6% for overnight and rapid gram-positive panels. These findings suggest that susceptibility results obtained from directly inoculated gram-negative overnight panels have the greatest correlation to those obtained by standard methods. When discrepant results occur with direct-susceptibility testing, they are more likely to show false susceptibility than false resistance.

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Section: Discussionmentioning

confidence: 99%

Direct Susceptibility Testing with Positive BacT/Alert Blood Cultures by Using MicroScan Overnight and Rapid Panels

et al. 1998

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“…When bacterial cells grew to the late‐exponential phase as monitored by a colorimeter (Asahi Science) (OD 660 = 0.95), the turbidity was adjusted to match a 0.5 MacFarland turbidity standard using BHI. The diluted samples were inoculated onto the TH‐YE agar plates by swabbing over the entire surface in three directions . Every sterile disk (diameter, 6.5 mm; cut from thin chromatography paper) was saturated with 20 μL of 275 mM H 2 O 2 , and three disks were evenly placed on every inoculated plate.…”

Section: Methodsmentioning

confidence: 99%

Analysis of the roles of NrdR and DnaB fromStreptococcus pyogenesin response to host defense

Zhang

Okada

Isaka

et al. 2014

APMIS

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Toxic shock syndrome caused by Streptococcus pyogenes (S. pyogenes) is a re-emerging infectious disease. Many virulence-associated proteins play important roles in its pathogenesis and the production of these proteins is controlled by many regulatory factors. CovS is one of the most important two-component sensor proteins in S. pyogenes, and it has been analyzed extensively. Our recent analyses revealed the existence of a transposon between covS and nrdR in several strains, and we speculated that this insertion has some importance. Hence, we examined the significances of the NrdR stand-alone regulator and DnaB, which is encoded by the gene located immediately downstream of nrdR in S. pyogenes infection. We established an nrdR-only knockout strain, and both nrdR and partial dnaB knockout strain. These established knockout strains exhibited a deteriorated response to H2 O2 exposure. nrdR and partial dnaB knockout strain was more easily killed by human polynuclear blood cells, but the nrdR-only knockout strain had no significant difference compared to wild type in contrast to the combined knockout strain. In addition, the mouse infection model experiment illustrated that nrdR and partial dnaB knockout strain, but not the nrdR-only knockout strain, was less virulent compared with the parental strain. These results suggest that DnaB is involved in response to host defense.

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“…For detecting antimicrobial activity for each oil, the disk diffusion method was used; firstly, inoculating bacterial colony from mannitol salt agar and MacConkey agar into nutrient broth for 12 hours, pre-inoculated plates of Mueller Hinton agar by using pour plate method. 0.9 ml of nutrient broth allocated in the center of the plate then spread by L-shape, then 6 mm sterilized filter paper disks (Whatmann No.1) cut as a form of disk then the 4 impregnated disks were placed onto the surface of Mueller Hinton agar [42], the disks are saturated with oils by putting 0.7 ml of the oils on the disk, after absorption oils by filter paper, the plates were incubated for 24 hours at 37 °C. After incubation, susceptibility of bacteria was determined by measuring the zone of inhibition (ZOI) of bacterial growth in millimeters.…”

Section: Disk Diffusion Methodsmentioning

confidence: 99%

Antibacterial Effect of Fixed and Volatile Oils against Gram-positive and Gram-negative Bacteria

Salih

Abdullah

Ali

et al. 2019

KJAR

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Antibiotic resistance phenomena among pathogenic bacteria considered as a major health problem and associated with increased mortality or long-term hospitalization, which lead to open a new era by using plant and herbal extracts as an alternative source of various chemotherapeutic drugs, also to increase antibiotic efficiency by combining with plant extract for obtaining a powerful and broad spectrum action. The current investigation aims to investigate antibacterial actions of fixed oils of (Olea europaea L., Ricinus communis L. and Linum usitatissimum) and volatile oil of (Nigella sativa, Curcuma longa L and Zingiber officinale) against both Staphylococcus aureus strain (6734151) and Escherichia coli strain (5344572). This study conducted on antibacterial effect of six different extracted oils from medical herbs. The findings revealed that the oil extracts have different antibacterial activities with efficacy. Bacterial inhibition zone was detected by using disk diffusion method. Furthermore , volatile oil of N. sativa showed a great inhibitory action against resistant S. aureus, which was (27.7± 1.2 mm). The antimicrobial effects of other fixed and volatile oils against S. aureu, the inhibition zone was (10 ± 1.0 mm) for (Zingiber officinale), (9 ± 1.0 mm) for Ricinus communis L., (7.7 ± 0.6 mm) for Olea europea L., (7.3 ± 0.6 mm) for Linum usitatissimum and for Curcuma longa L. was (6.7 ± 0.6mm). Moreover, antimicrobial effect of N. sativa against E. coli was more active in comparison with other oils, while other oils showed a slight antibacterial effect. In conclusion, volatile oil of N. sativa reveals great antibacterial activities in comparison with other extracted oils.

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Comparison of direct and standard antimicrobial disk susceptibility testing for bacteria isolated from blood

Cited by 41 publications

References 21 publications

Direct Susceptibility Testing with Positive BacT/Alert Blood Cultures by Using MicroScan Overnight and Rapid Panels

Direct Susceptibility Testing with Positive BacT/Alert Blood Cultures by Using MicroScan Overnight and Rapid Panels

Analysis of the roles of NrdR and DnaB fromStreptococcus pyogenesin response to host defense

Antibacterial Effect of Fixed and Volatile Oils against Gram-positive and Gram-negative Bacteria

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