Bacterial flora in bottled uncarbonated mineral drinking water

A quantitative study of bacterial populations in mineral water was carried out. Samples were stored at 6 and 20 °C, and the colony counts were determined on tryptone agar plates incubated at 22 and 37 °C. Samples were collected from the spring source in sterile glass flasks and from the bottling factory in conventional plastic and glass containers. In both cases, the initial population (101–102 cfu/mL water) increased to 105–106 cfu/mL after 3 days storage as determined from plate counts incubated at 22 °C. The levels reached by this population were similar to those of samples of mineral water obtained at the market stage. Results from plate counts incubated at 37 °C showed that populations in samples collected at the bottling factory reached 102–103 cfu/mL. No growth was observed in water collected from spring source. Bacterial multiplication was not stopped even when water was stored at 6 °C. Caulobacter was the genus found most frequently in both types of samples, followed by Sphaerotilus-Leptothrix. Acinetobacter calcoaceticus and Pseudomonas fluorescens were frequently found in only two springs, and Pseudomonas putida, Arthrobacter, Aeromonas hydrophila, and Corynebacterium were isolated less frequently. Janthinobacterium was recovered only once from a single spring. A giant bacterium closely resembling Hyphomicrobium and a budding one similar to Pasteuria were recovered from all samples of a single spring and from some of the commercial samples.

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Note. Effect of trisodium phosphate on mesophilic and psychrotrophic bacterial flora attached to the skin of chicken carcasses during refrigerated storage Nota. Efecto del fosfato trisódico en los microorganismos mesófilos y psicrotrofos presentes en la piel de canales de pollo durante su almacenamiento en refrigeración

Food Science and Technology International ◽

10.1177/108201320000600410 ◽

2000 ◽

Vol 6 (4) ◽

pp. 345-350 ◽

Cited By ~ 8

Author(s):

R. Capita ◽

C. Alonso-Calleja ◽

M.T. García Arias ◽

B. Moreno ◽

M.C. García-Fernández

Keyword(s):

Tap Water ◽

Bacterial Flora ◽

Trisodium Phosphate ◽

Refrigerated Storage ◽

Water Control ◽

Bacterial Populations ◽

Ph Values ◽

Popula Tions ◽

Chicken Skin ◽

Plate Counts

The potential for using trisodium phosphate (TSP) to reduce mesophilic and psychrotrophic popula tions on the skin of chicken carcasses was explored. Skin samples were immersed in sterile tap water (control) or an 8%, 10% or 12% solution of TSP at 20 °C for 15 min. Surface pH values and mesophilic and psychrotrophic plate counts were determined after 0, 1, 3 and 5 days of storage at 2° C. After washing, bacterial populations were significantly smaller in the samples treated with TSP than in the controls. The concentration of the TSP solution was a significant factor in reducing the populations of the bacteria on chicken skin. Before storage, the reduction in the presence of bacteria achieved in treated samples with respect to controls ranged between 0.95 log10 cycles and 1.78 log10 cycles in the case of mesophilic microorganisms, and 0.92 log10 cycles and 1.94 log10 cycles in the case of psychrotrophic strains. These differences between the concentrations of bacteria in samples immersed in water and those treated with TSP increased over time, ranging from 2.35 log 10 cycles to 3.08 log10 cycles (mesophilic microorganisms), and from 2.79 log10 cycles to 4.09 log10 cycles (psychrotrophic microorganisms) on day 5 of storage. The pH of the skin remained more or less constant throughout the study period, ranging between 8 and 9 in skin treated with TSP, depending on the concentration, while it was two units lower in the control samples.

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Alterations in total bacteria, iodonitrophenyltetrazolium (INT)-positive bacteria, and heterotrophic plate counts of bottled mineral water

Canadian Journal of Microbiology ◽

10.1139/m94-012 ◽

1994 ◽

Vol 40 (1) ◽

pp. 72-77 ◽

Cited By ~ 23

Author(s):

Ana-Cristina Ferreira ◽

Paula Vasconcellos Morais ◽

Milton S. da Costa

Keyword(s):

Ethidium Bromide ◽

Mineral Water ◽

Mineral Waters ◽

Culturable Bacteria ◽

Bacterial Populations ◽

Prolonged Incubation ◽

Plate Counts ◽

Heterotrophic Plate Counts ◽

Total Bacteria ◽

Bottled Mineral Water

The quantitative variation in the microflora in bottled mineral waters stored in polyvinyl chloride bottles was studied immediately after bottling and after 7 days storage, over 9 months. The microflora was determined by combining total counts using ethidium bromide, and the number of iodonitrophenyltetrazolium (INT)-positive cells determined with heterotrophic plate counts on R2A for prolonged incubation periods at 22 and 37 °C. Immediately after bottling of mineral water A, the total counts with ethidium bromide varied between 70.0 and 495.0 bacteria/mL. The number of INT-positive bacteria varied between 14.0 and 40.0% counts. The heterotrophic plate counts were higher at 22 °C than at 37 °C and varied between 1.1 and 13.2% and between 0.7 and 9.3% of the total counts, respectively. After 7 days storage, total bacterial counts increased by 1000 times, indicating multiplication of bacteria that were present in low numbers immediately after bottling. The percentage of INT-positive bacteria remained between 2.6 and 39.0% of the total counts but the number of culturable bacteria was higher than the number of INT-positive cells. Similar counts were found in other mineral waters (B, C, and D), but the numbers of INT-positive cells in two of them (B and D) were higher than the heterotrophic plate counts at 22 °C. These results show the presence in the aquifer and (or) bottling system of a flora that is neither INT-positive nor culturable and reinforce previous results that still mineral waters have a large bacterial population after storage.Key words: mineral water, bacterial populations, ethidium bromide, INT, HPC.

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Stochasticity in Colonial Growth Dynamics of Individual Bacterial Cells

Applied and Environmental Microbiology ◽

10.1128/aem.03629-12 ◽

2013 ◽

Vol 79 (7) ◽

pp. 2294-2301 ◽

Cited By ~ 64

Author(s):

Konstantinos P. Koutsoumanis ◽

Alexandra Lianou

Keyword(s):

Kinetic Parameters ◽

Single Cells ◽

Growth Curves ◽

Growth Dynamics ◽

Time Lapse ◽

Initial Population ◽

Bacterial Cells ◽

Stochastic Growth ◽

Bacterial Populations ◽

Content Type

ABSTRACTConventional bacterial growth studies rely on large bacterial populations without considering the individual cells. Individual cells, however, can exhibit marked behavioral heterogeneity. Here, we present experimental observations on the colonial growth of 220 individual cells ofSalmonella entericaserotype Typhimurium using time-lapse microscopy videos. We found a highly heterogeneous behavior. Some cells did not grow, showing filamentation or lysis before division. Cells that were able to grow and form microcolonies showed highly diverse growth dynamics. The quality of the videos allowed for counting the cells over time and estimating the kinetic parameters lag time (λ) and maximum specific growth rate (μmax) for each microcolony originating from a single cell. To interpret the observations, the variability of the kinetic parameters was characterized using appropriate probability distributions and introduced to a stochastic model that allows for taking into account heterogeneity using Monte Carlo simulation. The model provides stochastic growth curves demonstrating that growth of single cells or small microbial populations is a pool of events each one of which has its own probability to occur. Simulations of the model illustrated how the apparent variability in population growth gradually decreases with increasing initial population size (N0). For bacterial populations withN0of >100 cells, the variability is almost eliminated and the system seems to behave deterministically, even though the underlying law is stochastic. We also used the model to demonstrate the effect of the presence and extent of a nongrowing population fraction on the stochastic growth of bacterial populations.

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Isolation of Aeromonas hydrophila from Bottled Waters and Domestic Water Supplies in Saudi Arabia

Journal of Food Protection ◽

10.4315/0362-028x-49.6.471 ◽

1986 ◽

Vol 49 (6) ◽

pp. 471-476 ◽

Cited By ~ 23

Author(s):

PETER J. SLADE ◽

MOHAMMED A. FALAH ◽

AHMED M. R. AI-GHADY

Keyword(s):

Saudi Arabia ◽

Aeromonas Hydrophila ◽

Mineral Water ◽

False Negative ◽

Domestic Water ◽

Selective Method ◽

Arginine Dihydrolase ◽

Presumptive Identification ◽

High Degree ◽

Bottled Mineral Water

A total of 139 replicate samples of water were tested for Aeromonas hydrophila and coliforms. These consisted of 95 replicates from bottled mineral water, 13 replicates from flower petal infusions and 31 samples of domestic municipality supplies. Of these, 59 (43%) were positive for A. hydrophila, 15 (11%) were positive for coliforms and 11 (8%) positive for both A. hydrophila and coliforms. Most of the isolates of A. hydrophila came from various batches of one brand of bottled mineral water, none of which contained coliforms. The organism was isolated more frequently from newer samples, particularly those bottled for 59 d or less. Samples of treated water from one municipality were free from coliforms and A. hydrophila. Chlorinated water from another town was free from coliforms, but some samples contained A. hydrophila. In unchlorinated water from a third municipal source, there was a high degree of correlation between incidence of A. hydrophila and presence of coliforms. A selective method, using media without antibiotics, for isolation of A. hydrophila was used. A novel medium for the presumptive identification of A. hydrophila, gelatin arginine dihydrolase (GAD) medium, was assessed, with confirmation of suspected isolates using the API 20E system. Of 109 isolates from two selective agars identified with the organism on API strips, 18 (16.5%) were falsely gelatinase negative in GAD medium, of which 9 (8.3%) also gave false-negative arginine dihydrolase reactions. Of those presumptively identified as A. hydrophila in GAD, 4/95 isolates (4.2% false-positives) were not confirmed.

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Evaluation of Minerals Content of Drinking Water in Malaysia

The Scientific World JOURNAL ◽

10.1100/2012/403574 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 22

Author(s):

Azrina Azlan ◽

Hock Eng Khoo ◽

Mohd Aizat Idris ◽

Amin Ismail ◽

Muhammad Rizal Razman

Keyword(s):

Drinking Water ◽

Water Samples ◽

Mineral Water ◽

Tap Water ◽

Fluoride Concentration ◽

Daily Intake ◽

Peninsular Malaysia ◽

Mineral Water Sample ◽

Geographical Locations ◽

Iron And Manganese

The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water.

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Determination of Viable Bacterial Populations in Raw Milk within 20 Minutes by Using a Direct Epifluorescent Filter Technique

Journal of Food Protection ◽

10.4315/0362-028x-60.7.874 ◽

1997 ◽

Vol 60 (7) ◽

pp. 874-876 ◽

Cited By ~ 5

Author(s):

CLAUDE P. CHAMPAGNE ◽

NANCY J. GARDNER ◽

JULIE FONTAINE ◽

JACQUES RICHARD

Keyword(s):

Raw Milk ◽

Plate Count ◽

Bacterial Populations ◽

Filter Technique ◽

Milk Samples ◽

Standard Plate ◽

Plate Counts ◽

Direct Epifluorescent Filter Technique ◽

Triton X

The results from a shortened procedure for the direct epifluorescent filter technique (DEFT) determination of viable bacterial populations in raw milk were compared to standard plate counts. Shortening the prefiltration trypsin-Triton X-100 incubation period from 10 to 3 min enabled the completion of the analysis within 20 min. The short DEFT method results had a correlation coefficient (r) of 0.81 with plate counts. With respect to precision, the average difference between values of duplicate plate count analyses was 0.16 log units; that of the short DEFT was 0.14 log units. The slopes of the regressions equations were less than 1, indicating that a direct correlation is not achieved. Short DEFT values were 0.17 log units higher than those of plate counts on milk samples containing less than 10,000 CFU/ml. For milk samples containing counts over 10,000 CFU/ml, short DEFT values averaged only 0.05 log units above plate count readings. Daily preparation of the stain appears unnecessary since acridine orange solutions stored for up to 2 days at 4°C did not produce results significantly (P > 0.05) different from those obtained with fresh solutions. The short DEFT method has potential for the assessment of the bacteriological quality of raw milk in tanker deliveries.

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Survival of Campylobacter jejuni in Modified Atmosphere Packaged Turkey Roll

Journal of Food Protection ◽

10.4315/0362-028x-54.3.194 ◽

1991 ◽

Vol 54 (3) ◽

pp. 194-199 ◽

Cited By ~ 25

Author(s):

RANDALL K. PHEBUS ◽

FRANCES A. DRAUGHON ◽

JOHN R. MOUNT

Keyword(s):

Lactic Acid ◽

Campylobacter Jejuni ◽

Co2 Concentration ◽

Initial Population ◽

Modified Atmosphere ◽

Bacterial Populations ◽

Direct Plating ◽

Low Co2 ◽

Co2 Levels ◽

Storage Temperatures

Survival of Campylobacter jejuni, inoculated into turkey roll slices and stored under seven different atmospheric mixtures, was determined. Turkey roll samples were stored at 4°C for 18 d and at 21°C for 48 h. The effects of various atmospheric mixtures on aerobic, psychrotrophic, and lactic acid bacterial populations were also determined throughout storage. Campylobacter jejuni was inactivated under all atmospheric gas mixtures tested throughout storage. Increasing CO2 concentration inside the package from 0% to 100% CO2 resulted in a lower rate of inactivation of C. jejuni at both storage temperatures. Increases in CO2 concentrations provided greater inhibition of aerobic and psychrotrophic populations as compared to low CO2 levels. The effect of CO2 on survival of C. jejuni and growth rate of aerobic, psychrotrophic, and lactic acid bacteria was more pronounced at 4°C. Campylobacters were isolated from inoculated turkey roll held under all atmospheres by enrichment procedures on the 18th day and 48th hour of storage at 4 and 21°C, respectively, with an initial population of log 6.0 Campylobacter s/g. However, no Campylobacters were isolated by 18 d of storage at 4°C by direct plating.

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Effect of Delayed Heading on Some Quality Attributes of Penaeus Shrimp1

Journal of Food Protection ◽

10.4315/0362-028x-42.5.407 ◽

1979 ◽

Vol 42 (5) ◽

pp. 407-409 ◽

Cited By ~ 4

Author(s):

R. J. ALVAREZ ◽

J. A. KOBURGER

Keyword(s):

Panel Data ◽

Storage Period ◽

Plate Count ◽

Sensory Panel ◽

Bacterial Populations ◽

Standard Plate Count ◽

Plate Count Agar ◽

Pseudomonas Species ◽

Standard Plate ◽

Plate Counts

To determine the effect of delayed heading on shrimp quality, shrimp were stored on ice with and without heads for 10 days. Some shrimp were delay-headed after 5 days and returned to ice for the remainder of the storage period. Microbiological studies were conducted at 0, 5 and 10 days of storage. Total aerobic plate counts were done using Standard Plate Count agar with an added 0.5% NaCl. Incubation was at 20 C for 5 days. Analyses indicated similar counts on shrimp tails stored with or without heads and those delayed-headed. Counts ranged from 2.4 × 106 bacteria/gram at 0 day to 1.6 × 109 bacteria/gram on the 10th day. Identification of the flora present revealed that the same major groups of organisms predominated on shrimp tails subjected to the different storage treatments and the head did not alter development of the usual flora. Flavobacterium, Pseudomonas, Planococcus, Moraxella and the Vibrio/Aeromonas group were the major genera encountered. A shift in bacterial populations was observed during storage. Flavobacterium species predominated during the first 5 days of storage; however, after the fifth day Pseudomonas species predominated. Sensory panel data revealed no differences in acceptability between shrimp tails stored with or without heads and those delay-headed.

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