Growth and Production of Enterotoxins A and D by Staphylococcus aureus in Salad Bar Ingredients and Clam Chowder

1991 ◽  
Vol 54 (11) ◽  
pp. 844-847 ◽  
Author(s):  
HASSAN GOURAMA ◽  
W. Y. J. TSAI ◽  
L. B. BULLERMAN
Keyword(s):  
Staphylococcus Aureus ◽  
Brain Heart Infusion ◽  
Brain Heart Infusion Broth ◽  
Plate Count ◽  
Green Pepper ◽  
Blue Cheese ◽  
Salad Dressing ◽  
Cell Counts ◽  
Elisa Technique ◽  
Number Of Cells

Growth and production of enterotoxins A and D (SEA, SED) by two strains of Staphylococcus aureus were determined in salad bar ingredients and clam chowder. Salad bar ingredients included lettuce, canned black olives, canned green olives, tomato, green pepper, blue cheese salad dressing, blue cheese crumbles, celery, and croutons. Total S. aureus were determined by plate count on Baird-Parker agar. Enterotoxins were quantified by using an ELISA technique. S. aureus did not survive in salad dressing, with pH 4.3. With the exception of olives and blue cheese, S. aureus survived on all ingredients for more than 12 h. After 24 h, the total number of cells decreased on most of the ingredients. S. aureus grew well on green pepper during the first 24 h, reaching 105 CFU/g, but no enterotoxins were detected. S. aureus also increased in moist and dry plain croutons, but there was no detectable production of enterotoxins. S. aureus growth was excellent in clam chowder with cell counts exceeding 108 CFU/g after 12 h at 42°C. Production of SEA and SED began shortly after 3 h. Maximal levels of SEA and SED were 0.29 and 1.6 ng/g, respectively, after 12 h. In brain heart infusion broth, the production of SEA and SED reached 21.9 and 36.3 ng/ml, respectively, after 24 h at 37°C.

Analysis of Native Microflora and Selection of Strains Antagonistic to Human Pathogens on Fresh Produce†

2001 ◽  
Vol 64 (8) ◽  
pp. 1110-1115 ◽  
Author(s):  
CHING-HSING LIAO ◽  
WILLIAM F. FETT
Keyword(s):  
Fresh Produce ◽  
Brain Heart Infusion ◽  
Erwinia Carotovora ◽  
Plate Count ◽  
Human Pathogens ◽  
Green Pepper ◽  
Significant Difference ◽  
Bell Peppers ◽  
Native Microflora ◽  
Baby Carrots

The native microflora of three types of produce (green bell peppers, Romaine lettuce, and prepeeled baby carrots) and two types of sprouting seeds (alfalfa and clover) were investigated. Aerobic plate count (APC) for each produce or seed type as determined on Pseudomonas agar F (PAF) with incubation at 28°C was in the range of 4 to 7 log CFU per g of tissue or seed. There was no significant difference (P ≥ 0.05) in APC when the determinations were made with three agar media including PAF, brain heart infusion agar, and plate count agar. However, the APC as determined from plates that were incubated at 28°C was significantly (P ≤ 0.05) higher than with incubation at 37°C. Fluorescent pseudomonads accounted for 23 to 73% of APC and 6 to 18% of APC recovered from carrots, pepper, and lettuce were pectolytic. Forty-eight strains of pectolytic bacteria were randomly isolated and identified, respectively, as members of the genera of Pseudomonas, Erwinia, Bacillus, Xanthomonas, or Flavobacterium. Lactic acid bacteria and/or yeast were consistently isolated from baby carrots, lettuce, and sprouting seeds (alfalfa or clover) but not from green bell peppers. Approximately 120 strains of indigenous microflora were tested for their ability to inhibit the growth of Salmonella Chester, Listeria monocytogenes, Escherichia coli, or Erwinia carotovora subsp. carotovora on PAF. Six isolates capable of inhibiting the growth of at least one pathogen were isolated and identified, respectively, as Bacillus spp. (three strains), Pseudomonas aeruginosa (one strain), Pseudomonas fluorescens (strain A3), and yeast (strain D1). When green pepper disks were inoculated with strains A3 and D1, the growth of Salmonella Chester and L. monocytogenes on the disks was reduced by 1 and 2 logs, respectively, over a period of 3 days. Application of strains A3 and D1 as potential biopreservatives for enhancing the quality and safety of fresh produce is discussed.

Antibacterial Effect of Water-Soluble Tea Extracts on Foodborne Pathogens in Laboratory Medium and in a Food Model†

2004 ◽  
Vol 67 (11) ◽  
pp. 2608-2612 ◽  
Author(s):  
S. KIM ◽  
C. RUENGWILYSUP ◽  
D. Y. C. FUNG
Keyword(s):  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Brain Heart Infusion ◽  
Ground Beef ◽  
Viable Cell ◽  
Water Soluble ◽  
Brain Heart Infusion Broth ◽  
Cell Counts ◽  
Jasmine Tea ◽  
Food Model

The microbial inhibition of foodborne pathogens was determined in brain heart infusion broth with 10% (wt/vol) water-soluble extracts of green, jasmine, black, dungglre, and oolong tea against Escherichia coli O157:H7, Salmonella enterica serovar Enteritidis, Listeria monocytogenes, and Staphylococcus aureus. The mixed culture (approximately 6.0 log CFU/ml), which was composed of the four pathogens, was inoculated into brain heart infusion broth with and without tea extracts. After incubation at 35°C for 0, 1, 3, and 5 days, proper dilution of each sample was spiral plated on each selective agar. Viable cell counts were performed after incubation at 35°C for 24 to 36 h. Green, jasmine, and black tea exhibited an approximately 5.0-log suppression of S. aureus compared with the control from days 1 to 5. Green and jasmine tea also suppressed the growth of L. monocytogenes by approximately 3.0 log CFU/ml on day 5. In contrast, no tea extracts inactivated E. coli O157:H7 and Salmonella Enteritidis. Based on the result in liquid medium, green and jasmine teas of 0.1% (vol/wt) were individually evaluated for their antimicrobial activity against L. monocytogenes and S. aureus in a food model (ground beef) stored at 7°C for 0, 1, 3, 5, and 7 days. Viable cell counts of total bacteria, L. monocytogenes, and S. aureus in ground beef were not significantly different among green and jasmine tea and the control.

scholarly journals An inhibitor of Staphylococcus aureus exfoliative toxin

2001 ◽  
Vol 7 (1-2) ◽  
pp. 121-127
Author(s):  
A. A. Al Sulami ◽  
K. K. Al Rubiay ◽  
A. M. Affat
Keyword(s):  
Staphylococcus Aureus ◽  
Culture Filtrate ◽  
Brain Heart Infusion ◽  
Brain Heart Infusion Broth ◽  
Aureus Strain ◽  
Staphylococcal Scalded Skin Syndrome ◽  
Exfoliative Toxin

We describe here an inhibitor of Staphylococcus aureus exfoliative toxin. The toxin was extracted from an S. aureus strain isolated from a case of staphylococcus scalded skin syndrome. The activity of the toxin was compared in tryptic soy broth and brain heart infusion broth. Both supported growth of S. aureus but the culture filtrate of brain heart infusion broth lacked exfoliative toxin activity. Furthermore it appeared to contain a substance that neutralized the action of exfoliative toxin. This suggests the possibility of a treatment for staphylococcal scalded skin syndrome and bullous impetigo.

Antimicrobial Effect of Butylated Hydroxyanisole and Butylated Hydroxytoluene on Staphylococcus aureus1

1980 ◽  
Vol 43 (1) ◽  
pp. 4-6 ◽  
Author(s):  
M. AYAZ ◽  
L. O. LUEDECKE ◽  
A. L. BRANEN
Keyword(s):  
Staphylococcus Aureus ◽  
Brain Heart Infusion ◽  
Antimicrobial Effect ◽  
Complete Inhibition ◽  
Butylated Hydroxytoluene ◽  
Brain Heart Infusion Broth ◽  
Aureus Strain ◽  
Butylated Hydroxyanisole

The antimicrobial effect of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) on three enterotoxigenic strains of Staphylococcus aureus in Brain Heart Infusion broth (BHI) was evaluated by turbidity measurements. Also, the interaction of these compounds with pH and NaCl on growth of S. aureus strain 100 was measured. Inhibition of S. aureus growth increased with an increase in the concentration of BHA and/or BHT. Complete inhibition of S. aureus growth occurred in BHI with 1.12 μmole of BHA/ml or 0.70 μmole of BHT/ml as well as with a combination of 0.25 μmole of both BHT and BHA/ml. Inhibition of S. aureus growth by BHA or BHT was substantial at pH 7.0 and with 2% NaCl. When 0.84 μmole or greater of BHA/ml and 0.47 μmole or greater of BHT/ml were added to BHL, growth of S. aureus 100 was inhibited to the extent that enterotoxin A could not be detected after 24 h of incubation.

Effect of Organic Acids and Temperature on Survival of Shigella flexneri in Broth at pH 4†,‡

2002 ◽  
Vol 65 (9) ◽  
pp. 1417-1421 ◽  
Author(s):  
LAURA L. ZAIKA
Keyword(s):  
Organic Acids ◽  
Tartaric Acid ◽  
Storage Temperature ◽  
Shigella Flexneri ◽  
Brain Heart Infusion ◽  
Brain Heart Infusion Broth ◽  
Ion Concentration ◽  
Plate Count ◽  
Control Medium ◽  
Hydrogen Ion Concentration

The survival of bacterial pathogens in acidified foods depends not only on the hydrogen ion concentration, but also on the type of acid and the storage temperature. Shigella flexneri is a foodborne pathogen that is acid tolerant. The survival of S. flexneri 5348 in brain heart infusion broth supplemented with 0.04 M acetic, citric, lactic, malic, or tartaric acid and adjusted to pH 4 with HCl or NaOH was studied. The control medium was brain heart infusion broth adjusted to pH 4 with HCl. Stationary-phase cells were inoculated into media at initial populations of 6 to 7 log10 CFU/ml and incubated at 4, 19, 28, and 37°C. A two-phase linear inactivation model was applied to plate count data to derive lag times (tL) and slopes of the curves, from which D-values and time required for a 4-log10 decrease in population (T4D) were calculated. In all cases, survival increased with decreasing temperature. For each acid, tL, the D-value, and T4D increased with decreasing temperature. All acids inhibited S. flexneri to some extent but to differing degrees as follows: lactic acid, acetic acid > citric acid, malic acid, tartaric acid > HCl. The T4D values for the control medium and for media containing acetic, citric, lactic, malic, and tartaric acids were 64, 47, 50, 34, 58, and 52 h, respectively, at 37°C and 2,607, 1,498, 1,905, 1,346, 1,726, and 2,134 h, respectively, at 4°C. The results of this study indicate that organic acids may aid in the inactivation of Shigella. However, these data also suggest that foods stored at or below room temperature containing low levels (<1%) of acids could cause illness if contaminated with Shigella.

Growth, Injury, and Survival Potential of Yersinia enterocolitica. Listeria monocytogenes, and Staphylococcus aureus in Brine Chiller Conditions†

1997 ◽  
Vol 60 (11) ◽  
pp. 1334-1340 ◽  
Author(s):  
ARTHUR J. MILLER ◽  
JEFFREY E. CALL ◽  
B. SHAWN EBLEN
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Yersinia Enterocolitica ◽  
Brain Heart Infusion ◽  
Brain Heart Infusion Broth ◽  
Processed Foods ◽  
Survival Potential ◽  
And Staphylococcus Aureus ◽  
Significant Injury

A model brine system was used to evaluate growth, injury, and survival potential of Yersinia enterocolitica. Listeria monocytogenes, and Staphylococcus aureus. Each strain was incubated for up to 30 days at −12 to 28°C in brain heart infusion broth containing 0.5 to 20% NaCl. Samples were enumerated on a dual agar plating system to assess growth and injury. Y. enterocolitica grew at −2°C in 0.5% brine and at 5°C in 5% NaCl. L. monocytogenes grew at 5°C in 5% NaCl and at 12°C in 9% NaCl. S. aureus grew at 12°C in 5% NaCl. Significant injury was observed for two of the pathogens, but not for L. monocytogenes. Bacteriostatic or lethal conditions were maintained for the three organisms at −2°C and 9% NaCl. While lethal NaCl and temperature combinations were defined for Y. enterocolitica and S. aureus. L. monocytogenes survived for 30 days at −12°C in 20% NaCl. This study provides safety criteria and recommendations for use in the operation of recycle brine systems for cooling processed foods.

A Rapid Microbiological Method for Enumeration of Pseudomonas fluorescens from Broiler Chicken Carcasses

1997 ◽  
Vol 60 (4) ◽  
pp. 385-390 ◽  
Author(s):  
SCOTT M. RUSSELL
Keyword(s):  
Pseudomonas Fluorescens ◽  
Broiler Chicken ◽  
Brain Heart Infusion ◽  
Brain Heart Infusion Broth ◽  
Animal Origin ◽  
Plate Count ◽  
Isolation And Identification ◽  
Plate Count Agar ◽  
Spoilage Bacteria ◽  
Time Required

A method to selectively enumerate Pseudomonas fluorescens from fresh chicken carcasses in less than 24 h using capacitance microbiology was developed. Capacitance assays were conducted on whole-carcass rinses at 25°C using brain heart infusion broth (BHI) containing 25 μg of Irgasan per ml to obtain a detection time. The capacitance samples were spread plated on plate count agar for isolation and identification. From plates with the highest dilution, from each carcass, 4 colonies were randomly selected and identified. Seven species of bacteria including Pseudomonas fluorescens were responsible for capacitance detection times. Various antibiotics and chemicals were added to basal media or brain heart infusion broth with Irgasan and were evaluated to select for the growth of P. fluorescens. BHI broth containing 4 μg of nitrofurantoin, 120 μg of carbenicillin, and 25 μg of Irgasan, all per ml, was found to be optimal and was termed Pseudomonas fluorescens selective additive (PSA) (patent pending). In a second study, 12 carcasses were collected in each of three replicate trials. For each trial, 2 carcasses were sampled immediately and 2 were sampled after storage at 3°C on days 3, 6, 9, 12, and 15. The BHI-PSA broth was found to be excellent for enumeration of P. fluorescens from broiler chicken carcass rinses in assays using capacitance microbiology at 25°C. The time required to enumerate P. fluorescens for all samples (day 0 to 15) was <22.4 h. This method is rapid and would be a useful tool for determining the number of spoilage bacteria on fresh chicken and thus may possibly be used to predict the potential shelf life of fresh chicken and other foods of animal origin.

Effect of Sodium Nitrite on Growth of Shigella flexneri

1991 ◽  
Vol 54 (6) ◽  
pp. 424-428 ◽  
Author(s):  
LAURA L. ZAIKA ◽  
ANNA H. KIM ◽  
LOUISE FORD
Keyword(s):  
Exponential Growth ◽  
Shigella Flexneri ◽  
Salt Content ◽  
Brain Heart Infusion ◽  
Growth Curves ◽  
Inhibitory Effect ◽  
Plate Count ◽  
Generation Times ◽  
High Salt Content ◽  
Lag Times

A partial factorial design study of the effect of NaNO2 (0, 100, 200, 1000 ppm) in combination with NaCl (0.5, 2.5, 4.0%), pH (7.5, 6.5, 5.5), and temperature (37, 28, 19°C) on growth of Shigella flexneri is reported. Experiments were done aerobically in brain-heart infusion medium, using an inoculum of 1 × 103 CFU/ml. Growth curves were fitted from plate count data by the Gompertz equation; exponential growth rates, lag times, generation times, and maximum populations were derived for all variable combinations. In the absence of nitrite, the organism grew well under all test conditions at 37 and 28°C but did not grow at 19°C at pH 5.5 nor at pH 7.5 with 4% NaCl. Nitrite did not affect growth in media of pH 7.5 at 37 and 28°C. At pH 6.5 growth was inhibited by 1000 ppm NaNO2. The organism failed to grow at 19°C at all nitrite levels in the presence of 2.5 or 4.0% NaCl. The inhibitory effect of nitrite was much greater in media of pH 5.5 and increased with increasing salt levels. More inhibition was apparent at 28 than at 37°C. While lack of growth was used as a paradigm of the effect of nitrite on S. flexneri, nitrite also increased the lag and generation times and decreased the exponential growth rate. Results indicated that NaNO2 in combinations with low temperature, low pH, and high salt content can effectively inhibit the growth of S. flexneri.

THE EFFECT OF "COMPETASE" ON DNA UPTAKE IN PROVOKED TRANSFORMATION OF A STREPTOCOCCUS

1965 ◽  
Vol 11 (5) ◽  
pp. 823-827 ◽  
Author(s):  
R. Pakula ◽  
A. H. W. Hauschild
Keyword(s):  
Deoxyribonucleic Acid ◽  
Brain Heart Infusion ◽  
Streptomycin Resistance ◽  
Brain Heart Infusion Broth ◽  
Dna Uptake ◽  
Retarding Effect ◽  
Competence Factor ◽  
Effect On Growth

The competence-provoking factor produced by the highly transformable group H streptococcus, strain Challis, was used to provoke efficient transformability in the poorly transformable group H streptococcus, strain Wicky. Transformations to streptomycin resistance were carried out with C14-labelled DNA which was extracted from bacteria fed with thymidine-2-C14.When cultures of strain Wicky were grown in Difco brain–heart infusion broth, supplemented with serum, and treated with competence factor and deoxyribonucleic acid, 25 to 40% of viable units were transformed while no transformation occurred without the factor. At the same time, the incorporation of C14 into cells treated with competence factor was higher than incorporation of C14 into untreated cells.Crude preparations of the competence factor had a retarding effect on growth of the streptococcus, irrespective of whether DNA was added.

scholarly journals Screening for Intermediately Vancomycin-Susceptible and Vancomycin-Heteroresistant Staphylococcus aureus by Use of Vancomycin-Supplemented Brain Heart Infusion Agar Biplates: Defining Growth Interpretation Criteria Based on Gold Standard Confirmation

2015 ◽  
Vol 53 (11) ◽  
pp. 3543-3546 ◽  
Author(s):  
Riad Khatib ◽  
Kathleen Riederer ◽  
Mamta Sharma ◽  
Stephen Shemes ◽  
Sugantha P. Iyer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gold Standard ◽  
Population Analysis ◽  
Area Under The Curve ◽  
Brain Heart Infusion ◽  
Roc Curves ◽  
Clinical Samples ◽  
Content Type ◽  
Interpretation Criteria ◽  
Profile Area

BHI agars supplemented with vancomycin 4 (BHI-V4) and 3 (BHI-V3) mg/liter have been proposed for screening vancomycin intermediately susceptibleStaphylococcus aureus(VISA) and heteroresistant (hVISA) phenotypes, respectively, but growth interpretation criteria have not been established. We reviewed the growth results (CFU) during population analysis profile-area under the curve (PAP-AUC) of consecutive methicillin-resistantStaphylococcus aureus(MRSA) blood isolates, which were saved intermittently between 1996 and 2012. CFU counts on BHI-V4 and BHI-V3 plates were stratified according to PAP-AUC interpretive criteria: <0.90 (susceptible [S-MRSA]), 0.90 to 1.3 (hVISA), and >1.3 (VISA). CFU cutoffs that best predict VISA and hVISA were determined with the use of receiver operating characteristic (ROC) curves. Mu3, Mu50, and methicillin-susceptibleS. aureus(MSSA) controls were included. We also prospectively evaluated manufacturer-made BHI-V3/BHI-V4 biplates for screening of 2010-2012 isolates. The PAP-AUC of 616 clinical samples was consistent with S-MRSA, hVISA, and VISA in 550 (89.3%), 48 (7.8%), and 18 (2.9%) instances, respectively. For VISA screening on BHI-V4, a cutoff of 2 CFU/droplet provided 100% sensitivity and 97.7% specificity. To distinguish VISA from hVISA, a cutoff of 16 CFU provided 83.3% sensitivity and 94.7% specificity; the specificity was lowered to 89.5% with a 12-CFU cutoff. For detecting hVISA/VISA on BHI-V3, a 2-CFU/droplet cutoff provided 98.5% sensitivity and 93.8% specificity. These results suggest that 2-CFU/droplet cutoffs on BHI-V4 and BHI-V3 best approximate VISA and hVISA gold standard confirmation, respectively, with minimal overlap in samples with borderline PAP-AUC. Simultaneous screening for VISA/hVISA on manufacturer-made BHI-V4/BHI-V3 biplates is easy to standardize and may reduce the requirement for PAP-AUC confirmation.

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