Transfer of Salmonella montevideo onto the Interior Surfaces of Tomatoes by Cutting†

1997 ◽  
Vol 60 (7) ◽  
pp. 858-862 ◽  
Author(s):  
CHIA-MIN LIN ◽  
CHENG-I WEI
Keyword(s):  
Recovery Rate ◽  
Enrichment Method ◽  
Direct Plating ◽  
Inoculum Dose ◽  
Scar Region ◽  
Plating Method ◽  
Safety Operation ◽  
The Relationship ◽  
Cut Surface ◽  
Broth Enrichment

Salmonella contamination of precut watermelon, tomatoes, and cantaloupes was responsible for several outbreaks of salmonellosis. To better understand the relationship between bacterial doses and their transfer onto cut surfaces by using a knife, rifampicin-resistant Salmonella montevideo at 7, 70, 700, or 7,000 CFU in Butterfield's buffer (BPB) or tryptic soy broth (TSB) was added to the stem scars of tomatoes. Tomatoes were cut from the stem scar to blossom end using a sterilized knife. After stem scars were aseptically removed, cut surfaces were placed on tryptic soy agar-rifampicin (TSA-RIF) plates or processed by a broth enrichment method to determine if S. montevideo had been transferred to the cut surface. S. montevideo was recovered in a dose-related fashion using both methods. A higher recovery rate was obtained with bacterial inocula in TSB than in BPB, and also with broth enrichment rather than the direct plating method. The distribution of the transferred S. montevideo on the cut surface of contaminated and noncontaminated tomatoes with a knife was related to the inoculum dose added to the stem scars. S. montevideo colonies were found to cluster at the stem scar region with the lower inoculum dose. However, when a higher inoculum dose was used, the colonies spread from the stem scar region to the center and bottom of cut tomatoes, or they were transferred to another uninoculated tomato by the contaminated knife. Therefore, the safety operation criteria recommended by FDA to wash fruits before cutting, to use clean and sanitized utensils and surfaces when preparing cut fruits, and to store the cut fruits below 7°C should be followed in preparing tomato slices to minimize salmonellosis outbreaks caused by this product.

scholarly journals Recovery of Salmonella by Using Selenite Brilliant Green Sulfa Enrichment Broth

1999 ◽  
Vol 37 (12) ◽  
pp. 4120-4123 ◽  
Author(s):  
Chiao-tang Chang ◽  
Chung-Yee Yuo ◽  
Hui-Ching Shen ◽  
A-Mai Li ◽  
Chao-yu Chen ◽  
...  
Keyword(s):  
Recovery Rate ◽  
Sodium Selenite ◽  
Brilliant Green ◽  
Isolation Rate ◽  
Enrichment Method ◽  
Enrichment Broth ◽  
Direct Plating ◽  
Gram Negative ◽  
Plating Method ◽  
Optimal Incubation

The efficacy and sensitivity of selenite brilliant green sulfa enrichment (SBG) broth for the isolation of Salmonella from fecal specimens were evaluated by using both clinical and artificially infected (artificial) fecal specimens. An examination of 1,588 clinical fecal specimens found Salmonella in 296 specimens, including 89 cases detected by the direct-plating xylose-lysine-desoxycholate method and an additional 207 cases detected after enrichment with SBG broth. Therefore, the recovery ofSalmonella with SBG broth is increased 3.3-fold over that by the direct-plating method alone. Furthermore, the isolation rate ofSalmonella is higher when using SBG broth than when using gram-negative (GN) broth or GN broth supplemented with sodium selenite. To determine the sensitivity for the recovery ofSalmonella, artificial specimens containing various amounts of Salmonella were prepared and analyzed. The results indicated that the sensitivity is also higher with SBG broth than with GN broth. Moreover, the optimal incubation period for SBG broth can be extended to 24 h. In conclusion, the SBG enrichment method provides a higher recovery rate of Salmonella from fecal specimens.

scholarly journals Comparison of Culture-Based Methods for Identification of Colonization with Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus in the Context of Cocolonization

2016 ◽  
Vol 54 (7) ◽  
pp. 1907-1911 ◽  
Author(s):  
Meghan F. Davis ◽  
Baofeng Hu ◽  
Karen C. Carroll ◽  
Warren B. Bilker ◽  
Pam Tolomeo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Screening Methods ◽  
Enrichment Method ◽  
Direct Plating ◽  
Methicillin Resistant ◽  
Content Type ◽  
Broth Enrichment

Two screening methods to detect staphylococcal colonization in humans were compared. Direct plating to CHROMagar (BD Diagnostics) was compared to a broth preenrichment followed by plating to Baird-Parker agar. The broth-enrichment method was comparable to CHROMagar for methicillin-resistantStaphylococcus aureas(MRSA) detection, but the enrichment method was optimum for recovery of coagulase-positiveStaphylococcusspp.

scholarly journals Comparison of Fecal Coliform Agar and Violet Red Bile Lactose Agar for Fecal Coliform Enumeration in Foods

2002 ◽  
Vol 68 (4) ◽  
pp. 1631-1638 ◽  
Author(s):  
A. Leclercq ◽  
C. Wanegue ◽  
P. Baylac
Keyword(s):  
Escherichia Coli ◽  
Fecal Coliform ◽  
Food Samples ◽  
Fecal Coliforms ◽  
Predictive Values ◽  
Direct Plating ◽  
Hafnia Alvei ◽  
E Coli ◽  
Plating Method ◽  
Mashed Potatoes

ABSTRACT A 24-h direct plating method for fecal coliform enumeration with a resuscitation step (preincubation for 2 h at 37 ± 1°C and transfer to 44 ± 1°C for 22 h) using fecal coliform agar (FCA) was compared with the 24-h standardized violet red bile lactose agar (VRBL) method. FCA and VRBL have equivalent specificities and sensitivities, except for lactose-positive non-fecal coliforms such as Hafnia alvei, which could form typical colonies on FCA and VRBL. Recovery of cold-stressed Escherichia coli in mashed potatoes on FCA was about 1 log unit lower than that with VRBL. When the FCA method was compared with standard VRBL for enumeration of fecal coliforms, based on counting carried out on 170 different food samples, results were not significantly different (P > 0.05). Based on 203 typical identified colonies selected as found on VRBL and FCA, the latter medium appears to allow the enumeration of more true fecal coliforms and has higher performance in certain ways (specificity, sensitivity, and negative and positive predictive values) than VRBL. Most colonies clearly identified on both media were E. coli and H. alvei, a non-fecal coliform. Therefore, the replacement of fecal coliform enumeration by E. coli enumeration to estimate food sanitary quality should be recommended.

scholarly journals Comparing the Yield of Staphylococcus aureus Recovery with Static versus Agitated Broth Incubation

2018 ◽  
Vol 2018 ◽  
pp. 1-3
Author(s):  
Carol E. Muenks ◽  
Patrick G. Hogan ◽  
Carey-Ann D. Burnham ◽  
Stephanie A. Fritz
Keyword(s):  
Staphylococcus Aureus ◽  
Enrichment Culture ◽  
Culture Method ◽  
Ambient Air ◽  
Built Environments ◽  
Culture Methods ◽  
Semiquantitative Assessment ◽  
Direct Plating ◽  
Static Conditions ◽  
Broth Enrichment

Given the lack of standardization of methodologies for microbial recovery from built environments, we sought to compare the yield of Staphylococcus aureus with a broth enrichment method when incubated in agitated versus static conditions. Five unique strains of S. aureus at five different concentrations were cultured to compare direct plating, agitated broth enrichment, and static broth enrichment culture methods. All samples were incubated at 35° in ambient air. The lowest concentration recovered across three replicates and five strains did not differ between culture methods (Fisher’s exact test, p=0.50); notably, recovery of S. aureus was equivalent between static and agitated broth incubation. When broth enrichment was used (both static and agitated), the burden of S. aureus growth was higher (by semiquantitative assessment of 4-quadrant streaking) compared to the direct plating culture method. Optimizing strategies for microbial recovery is essential, particularly in areas of lower biomass, given the paucity of research concerning microbial communities of built environments. The results of this study, in conjunction with other experiments investigating microbiomes of built environments, can help inform protocols for standardizing culturing methods within built environments.

scholarly journals To study the relationship of parity and laterality with different ovarian lesions

2021 ◽  
Vol 6 (2) ◽  
pp. 135-137
Author(s):  
Dupinder Kaur ◽  
Pooja Agarwal
Keyword(s):  
Observational Study ◽  
Outer Surface ◽  
Neoplastic Lesions ◽  
Relationship Of ◽  
The Relationship ◽  
Cut Surface ◽  
Gross Examination ◽  
Solid Area

The present study is based on histomorphological evaluation in 107 cases of Ovarian neoplastic and non-neoplastic lesions received. The gross specimens received were fixed in 10 percent formalin for 24 hours. Gross examination was done carefully examining the outer surface and on-cut surface of ovary, looking for any cyst with its content and type of fluid filled inside, any solid area, papillary projections and growth. Observational study.Among 69 non neoplastic lesions, right sided cases found in 34 (49.4%), and left sided lesion found in 22 cases (31.8%). 13 cases (18.8%) of non neoplastic lesions are observed to be bilateral. Like non neoplastic lesions, neoplastic lesions are also found more common on right side (55%) than left (35%), while bilaterality is found in 10% of the cases. The results of present study are comparable to other series of studies regarding occurrence with respect to age, bilaterality, gross features and microscopy. Both non neoplastic and neoplastic lesions were more common in right side. 18% of non neoplastic and 11% of neoplastic lesions were found to be bilateral.

Evaluation of a lysis direct plating method for pediatric blood cultures.

1985 ◽  
Vol 21 (6) ◽  
pp. 955-958 ◽  
Author(s):  
D F Welch ◽  
R K Scribner ◽  
D Hensel
Keyword(s):  
Blood Cultures ◽  
Direct Plating ◽  
Plating Method

Activities of Trovafloxacin Compared with Those of Other Fluoroquinolones against Purified Topoisomerases and gyrA and grlA Mutants ofStaphylococcus aureus

1999 ◽  
Vol 43 (8) ◽  
pp. 1845-1855 ◽  
Author(s):  
Thomas D. Gootz ◽  
Richard P. Zaniewski ◽  
Suzanne L. Haskell ◽  
Frank S. Kaczmarek ◽  
Alison E. Maurice
Keyword(s):  
Dna Cleavage ◽  
Dna Gyrase ◽  
The Other ◽  
Second Step ◽  
Ofstaphylococcus Aureus ◽  
Topoisomerase Iv ◽  
Direct Plating ◽  
Clinical Strains ◽  
Plating Method ◽  
Susceptibility Breakpoint

ABSTRACT Frequencies of mutation to resistance with trovafloxacin and four other quinolones were determined with quinolone-susceptibleStaphylococcus aureus RN4220 by a direct plating method. First-step mutants were selected less frequently with trovafloxacin (1.1 × 10−10 at 2 to 4× the MIC) than with levofloxacin or ciprofloxacin (3.0 × 10−7 to 3.0 × 10−8 at 2 to 4× the MIC). Mutants with a change in GrlA (Ser80→Phe or Tyr) were most commonly selected with trovafloxacin, ciprofloxacin, levofloxacin, or pefloxacin. First-step mutants were difficult to select with sparfloxacin; however, second-step mutants with mutations in gyrA were easily selected when a preexisting mutation in grlA was present. Against 29 S. aureus clinical isolates with known mutations in gyrA and/or grlA, trovafloxacin was the most active quinolone tested (MIC at which 50% of isolates are inhibited [MIC50] and MIC90, 1 and 4 μg/ml, respectively); in comparison, MIC50s and MIC90s were 32 and 128, 16 and 32, 8 and 32, and 128 and 256 μg/ml for ciprofloxacin, sparfloxacin, levofloxacin, and pefloxacin, respectively. Strains with a mutation in grlA only were generally susceptible to all of the quinolones tested. For mutants with changes in both grlA and gyrA MICs were higher and were generally above the susceptibility breakpoint for ciprofloxacin, sparfloxacin, levofloxacin, and pefloxacin. Addition of reserpine (20 μg/ml) lowered the MICs only of ciprofloxacin fourfold or more for 18 of 29 clinical strains. Topoisomerase IV and DNA gyrase genes were cloned from S. aureus RN4220 and from two mutants with changes in GrlA (Ser80→Phe and Glu84→Lys). The enzymes were overexpressed in Escherichia coli GI724, purified, and used in DNA catalytic and cleavage assays that measured the relative potency of each quinolone. Trovafloxacin was at least five times more potent than ciprofloxacin, sparfloxacin, levofloxacin, or pefloxacin in stimulating topoisomerase IV-mediated DNA cleavage. While all of the quinolones were less potent in cleavage assays with the altered topoisomerase IV, trovafloxacin retained its greater potency relative to those of the other quinolones tested. The greater intrinsic potency of trovafloxacin against the lethal topoisomerase IV target in S. aureus contributes to its improved potency against clinical strains of S. aureus that are resistant to other quinolones.

scholarly journals Comparison of Petrifilm Staph Express Count System with the Bacteriological Analytical Manual Direct-Plating Method for Enumeration of Staphylococcus aureus in Artificially Contaminated Hard Cheese

2008 ◽  
Vol 91 (5) ◽  
pp. 1138-1141 ◽  
Author(s):  
Willis M Fedio ◽  
Chitra N Wendakoon ◽  
Ruben Zapata ◽  
Christina Carrillo ◽  
Paul Browning
Keyword(s):  
Staphylococcus Aureus ◽  
Multivariate Analysis ◽  
Rapid Method ◽  
Analysis Of Variance ◽  
Plate Count ◽  
Direct Plating ◽  
Plating Method ◽  
Plate Count Method ◽  
The U.S ◽  
Hard Cheese

Abstract The 3M Petrifilm Staph Express Count System was compared with the U.S. Food and Drug Administration's Bacteriological Analytical Manual (BAM) direct-plate count method for the enumeration of Staphylococcus aureus in 6 types of artificially contaminated hard cheese (Asiago, Cheddar, Gruyre, Parmesan, Romano, and Swiss). Five different samples of each cheese type were inoculated with S. aureus (ATCC 25923) to achieve low, medium, and high inoculum levels. S. aureus was enumerated by the Petrifilm and BAM methods, and the results were compared. Multivariate analysis of variance revealed no significant differences (P <0.05) between the 2 methods. The Petrifilm method compared favorably with the BAM procedure. The rapid method was more convenient to use, considerably faster, and less expensive to perform than the BAM method.

Isolation and Enumeration of Staphylococcus aureus: Review and Recommendations for Revision of AOAC Method

1971 ◽  
Vol 54 (3) ◽  
pp. 732-735
Author(s):  
E F Baer
Keyword(s):  
Staphylococcus Aureus ◽  
Present Method ◽  
Collaborative Study ◽  
Direct Plating ◽  
Alternative Method ◽  
Plating Method ◽  
Aoac Method ◽  
Aoac Official

Abstract The genesis of the present AOAC official first action method for isolation and enumeration of Staphylococcus is reviewed and information is supplied to support recommendations for revision of the method. It is recommended that the present method be revised by deleting instructions for preparation and use of Vogel and Johnson agar and substituting instructions for preparation and use of Baird-Parker medium. It is also recommended that a direct plating method be provided as an alternative method and that the required collaborative study of the alternative method be conducted. The recommendations have been accepted by the Association.

Parameters Design of Discontinuous Dot Indenter in Fine Blanking Process with Different Thickness Workpiece

2016 ◽  
Vol 716 ◽  
pp. 762-769 ◽  
Author(s):  
Fei Zhou ◽  
Hua Jie Mao ◽  
Yan Xiong Liu ◽  
Lin Hua
Keyword(s):  
Orthogonal Experiment ◽  
Machining Accuracy ◽  
Surface Zone ◽  
Fine Blanking ◽  
Element Simulation ◽  
The Cost ◽  
Blanking Process ◽  
The Relationship ◽  
Cut Surface ◽  
Different Thickness

This paper proposes a new blankholder to fine blanking process. V-ring indenter has been widely applied in fine blanking to produce clean cut parts, however, it is difficult to be manufactured, the machining accuracy of which is hard to ensure and the cost is very high. In this approach, the fine blanking process combined with discontinuous dot indenter was put forward and the parameters design for workpiece with different thickness was studied with the finite element simulation and the orthogonal experiment methods. The larger burnished surface zone can be obtained by optimizing discontinuous dot indenter parameters. In addition, the relationship between the discontinuous dot indenter parameters and the workpiece thickness was got from data processing. Finally, applying this relationship to fine blank workpiece with different thickness, nearly full clean cut surface part was obtained.

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