Microbiological investigations of rainwater and graywater collected for toilet flushing

2002 ◽  
Vol 46 (6-7) ◽  
pp. 311-316 ◽  
Author(s):  
H.-J. Albrechtsen
Keyword(s):  
Campylobacter Jejuni ◽  
Microbiological Quality ◽  
Plate Count ◽  
Microbial Water Quality ◽  
E Coli ◽  
Plate Count Agar ◽  
Hand Wash ◽  
Plate Counts ◽  
Heterotrophic Plate Counts ◽  
Micro Organisms

Seven Danish rainwater systems were investigated with respect to the microbial water quality. The general microbiological quality (total numbers of bacteria (AODC)), and heterotrophic plate counts on R2A and Plate Count Agar in the toilets supplied with rainwater were approximately the same as in the reference toilets supplied with drinking water. However, in 12 of the 27 analysed samples one or more pathogens were observed (Aeromonas sp., Pseudomonas aeruginosa, Legionella non-pneumophila, Campylobacter jejuni, Mycobacterium avium, and Cryptosporidium sp.). These pathogens were not found in any of the reference toilets (32 toilets). This means that the use of rainwater introduced new, potentially pathogenic micro-organisms into the households which would normally not occur in toilets supplied with water from waterworks. Furthermore, four graywater systems were investigated where water from the shower and hand wash basin was reused. The graywater systems gave more problems in terms of bad smell and substantially higher numbers of E. coli and Enterococcus in some toilet bowls supplied with graywater.

Destruction de Microbacterium lacticum, Escherichia coli et Staphylococcus aureus au cours du séchage du lait par atomisation. I. Dénombrement sélectif des bactéries survivantes

1977 ◽  
Vol 23 (6) ◽  
pp. 716-720
Author(s):  
A. Chopin ◽  
G. Mocquot ◽  
Y. Le Graet
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Spray Drying ◽  
Skim Milk ◽  
Resistant Mutant ◽  
Plate Count ◽  
Mannitol Salt Agar ◽  
E Coli ◽  
Plate Count Agar ◽  
Plate Counts

In this paper a method which allows the measure of microbial death rate during spray-drying by means of a streptomycin-resistant mutant that can be grown on a streptomycin-containing agar is described. Plate counts of Microbacterium lacticum, Escherichia coli, and Staphylococcus aureus recovered from skim milk powders were done on plate count agar in the presence and absence of streptomycin and on various selective media. The powders were produced from evaporated milk previously inoculated with those organisms.Our results showed that the proposed method allows the recovery of 78% of M. lacticum, 61% of E. coli, and 100% of S. aureus that survived spray-drying. Recoveries of surviving E. coli on violet bile agar and brilliant green bile 2% were 34% and 29% respectively. Baird-Parker and mannitol salt agar media allow the recovery of all surviving S. aureus, thus showing that S. aureus cells did not lose their ability to grow in media containing 7.5% NaCl. Our results show that physiological injury of the cells during spray-drying differs from injury due to heating only. [Traduit par le journal]

Enumeration of the contaminating bacterial microbiota in unfermented pasteurized milks enriched with probiotic bacteria

2009 ◽  
Vol 55 (4) ◽  
pp. 410-418 ◽  
Author(s):  
C. P. Champagne ◽  
Y. Raymond ◽  
J. Gonthier ◽  
P. Audet
Keyword(s):  
Lactobacillus Rhamnosus ◽  
Microbiological Quality ◽  
Probiotic Bacteria ◽  
Plate Count ◽  
Plate Count Agar ◽  
Bacterial Microbiota ◽  
Standard Plate ◽  
Plate Counts ◽  
Probiotic Lactobacilli ◽  
De Man

Pasteurized and unfermented milks supplemented with probiotic bacteria are appearing on the market. It then becomes a challenge to ascertain the undesirable contamination microbiota in the presence of a largely superior population of probiotic bacteria. A method to enumerate the contaminating microbial microbiota in such probiotic-enriched milks was developed. The probiotic cultures, Lactobacillus rhamnosus Lb-Immuni-T™ and Bifidobacterium animalis subsp. lactis BB-12®, were added to a pasteurized unfermented milk to reach a minimum of 1 billion CFU per 250 mL portion, as ascertained by plating on de Man – Rogosa – Sharpe (MRS) agar in anaerobic conditions. No growth of B. animalis subsp. lactis BB-12 was noted on plate count agar (PCA) or Petrifilm™ plates, and the presence of this culture did not affect standard plate counts (SPC) of contaminating bacteria. However, L. rhamnosus formed colonies on PCA and Petrifilm™ plates. Attempts were thus made to inhibit the growth of the probiotic lactobacilli in PCA. The addition of 2% sodium phosphate (SP) or 5% glycerophosphate (GP) inhibited the growth of the lactobacilli in broths, but pin-point colonies of L. rhamnosus Lb-Immuni-T nevertheless appeared on PCA supplemented with phosphates. SPC could be obtained on PCA + 2% SP by only counting the large colonies, but this resulted in a significant (4.4 fold) underestimation of SPC values. On Petrifilm™ AC, at dilutions 0 to 2, all colonies were considered as being contaminants, while at dilutions 3 and 4, only large colonies were counted for SPC determinations. There was a direct correlation (R2 = 0.99) between SPC values with Petrifilm™ in uninoculated milks and those obtained on probiotic-enriched milks. The high correlation obtained over the 102 to 106 CFU/mL range of SPC values show that this Petrifilm™ method is appropriate to evaluate the microbiological quality of pasteurized milks enriched with L. rhamnosus Lb-Immuni-T and B. animalis subsp. lactis BB-12.

Comparative quantification of Campylobacter jejuni from environmental samples using traditional and molecular biological techniques

2009 ◽  
Vol 55 (6) ◽  
pp. 633-641 ◽  
Author(s):  
Michael J. Rothrock ◽  
Kimberly L. Cook ◽  
Carl H. Bolster
Keyword(s):  
Campylobacter Jejuni ◽  
Environmental Samples ◽  
Limit Of Detection ◽  
Plate Count ◽  
E Coli ◽  
Common Causes ◽  
Plate Counts ◽  
Selective Plate ◽  
Potential Risks ◽  
Cell Concentrations

Campylobacter jejuni is one of the most common causes of gastroenteritis in the world. Given the potential risks to human, animal, and environmental health, the development and optimization of methods to quantify this important pathogen in environmental samples is essential. Two of the most commonly used methods for quantifying C. jejuni are selective plate counting and quantitative real-time PCR (qPCR). Unfortunately, little comparative research has been performed to evaluate the accuracy of these methods for quantification of C. jejuni in aqueous and solid matricies. In this study, the limit of detection and the level of resolution obtained using these 2 methods was evaluated for C. jejuni and compared with that of the common indicator organism Escherichia coli . The use of selective plate count media for quantification of C. jejuni resulted in a 0.7–1.2 log underestimation of cell concentrations, compared with qPCR in both water and column leachate samples, whereas E. coli concentrations were found to be similar with either technique. For C. jejuni, only the qPCR assay accurately measured 2-fold changes in cell concentrations in water samples, whereas concentrations of E. coli were accurately measured regardless of method. Based on these data, qPCR assays were found to be more accurate than selective plate counts for quantification of C. jejuni from environmental samples.

Impact of Raw Materials and Processing Techniques on The Microbiological Quality of Egyptian Domiati Cheese

2020 ◽  
Keyword(s):  
Raw Materials ◽  
Microbiological Quality ◽  
Raw Milk ◽  
Plate Count ◽  
E Coli ◽  
Fresh Cheese ◽  
Processing Techniques ◽  
The Impact ◽  
Total Yeast

Domiati cheese is the most popular brand of cheese ripened in brine in the Middle East in terms of consumed quantities. This study was performed to investigate the impact of the microbiological quality of the used raw materials, the applied traditional processing techniques and ripening period on the quality and safety of the produced cheese. Three hundred random composite samples were collected from three factories at Fayoum Governorate, Egypt. Collected samples represent twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker hands; cheese molds and utensils; tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, Salmonellae and Listeria monocytogenes (L. monocytogenes). The mean value of SPC, coliforms, S. aureus and total yeast & mould counts ranged from (79×102 CFU/m3 for air to 13×108 CFU/g for fresh cheese), (7×102 MPN/ cm2 for tank swabs to 80×106 MPN/ml for raw milk), (9×102 CFU/g for salt to 69×106 CFU/g for fresh cheese) and (2×102 CFU/cm2 for hand swabs to 60×104 CFU/g for fresh cheese), respectively. Whereas, E. coli, Salmonella and L. monocytogenes failed to be detected in all examined samples. There were significant differences in all determined microbiological parameters (p ≤0.05) between fresh and ripened cheese which may be attributed to different adverse conditions such as water activity, pH, salt content and temperature carried out to improve the quality of the product.

The Microbiological Quality of Honey as Determined by Aerobic Colony Counts

1993 ◽  
Vol 56 (4) ◽  
pp. 336-337 ◽  
Author(s):  
JOSEP SERRA BONVEHI ◽  
ROSSEND ESCOLÁ JORDÁ
Keyword(s):  
Membrane Filter ◽  
Microbiological Quality ◽  
Plate Count ◽  
Filter Method ◽  
Filter Methods ◽  
Plate Counts ◽  
Multifloral Honey ◽  
Plate Count Method ◽  
Membrane Filter Method

The number of mesophilic aerobic colonies was determined in 72 samples of mono- and multifloral honey from various sources by the plate count and the membrane filter methods. The presence of motile colonies made the plate counts unreliable. The microorganism producing these colonies was identified as Bacillus alvei. Colony counts could only be carried out in 27 of the samples when using the plate count method, while with the membrane filter method the number of colonies was counted in all the samples.

Effectiveness of Trimming and/or Washing on Microbiological Quality of Beef Carcasses

1995 ◽  
Vol 58 (10) ◽  
pp. 1114-1117 ◽  
Author(s):  
R. K. PRASAI ◽  
R. K PHEBUS ◽  
C. M. GARCIA ZEPEDA ◽  
C. L. KASTNER ◽  
A. E. BOYLE ◽  
...  
Keyword(s):  
Control Point ◽  
Microbiological Quality ◽  
Effective Control ◽  
E Coli ◽  
Beef Carcasses ◽  
Colony Forming Units ◽  
Plate Counts ◽  
Commercial Processing ◽  
Being Moved

Beef carcass sides (n = 48) were selected randomly on three different days in a commercial processing facility and microbiologically analyzed before being moved to the cooler. Four types of samples were obtained per side from the inside round area: no trim and no wash (NTNW); trim, but no wash (TNW); trim and wash (TW), and no trim but wash (NTW). A flame-sterilized knife, forceps, and scalpel were used for each trimming treatment and sampling. Significant differences (P < 0.05) were observed in mean aerobic plate counts (APCs) between treatments. The greatest reduction in APC (log10 colony forming units [CFU] per cm2) was observed in TNW samples followed by TW and NTW, with the corresponding mean APC reductions relative to NTNW being 3.0, 0.9, and 0.3, respectively, indicating that trimming can be an effective control point in reducing bacterial contamination in the slaughter process. Although TNW samples, had the lowest counts, samples from the same location after wash (TW) had counts 2 log cycles higher than TNW samples. These results indicate that washing spreads contamination to adjacent carcass sites. However, washing of carcasses was effective in lowering microbial populations relative to the NTNW treatment. Escherichia coli and coliform counts in all samples were low (0.03 to 0.4 log10 CFU/cm2); however, the mean E. coli or coliform count in NTNW samples was higher (P < 0.05) than those in the rest of the treatments.

Comparison of the Petrifilm™ Yeast and Mold Culture Film Method to Conventional Methods for Enumerating Yeasts and Molds in Foods

1991 ◽  
Vol 54 (6) ◽  
pp. 443-447 ◽  
Author(s):  
L. R. BEUCHAT ◽  
B. V. NAIL ◽  
R.E. BRACKETT ◽  
T. L. FOX
Keyword(s):  
Correlation Coefficients ◽  
Food Group ◽  
Black Pepper ◽  
Plate Count ◽  
Food Groups ◽  
Plate Count Agar ◽  
Plate Counts ◽  
Yeasts And Molds ◽  
Potential Food ◽  
Film Method

Petrifilm™ Yeast and Mold (YM) plates were compared to acidified potato dextrose agar (APDA) and chloramphenicol-supplemented plate count agar (CPCA) for its suitability to enumerate yeasts and molds in 13 groups of food products. These products consisted of beans (dry and frozen, green), corn meal, flour (wheat), fruit (apple), a meat/vegetable entree (chicken pot pie), a precooked meat (beef), milk (dehydrated, nonfat), nuts (pecans), pasta, potatoes (dehydrated), precooked sausage, and a spice (black pepper). Correlation coefficients of Petrifilm™ YM plates versus APDA and CPCA pour plates for recovering total yeasts and molds from a composite of the thirteen test foods were, respectively, 0.961 and 0.974. Individually, Petrifilm™ YM plate counts were equivalent or higher than APDA and CPCA for some food groups and lower for other food groups. Because food particle interference can make enumeration of yeast and mold colonies on Petrifilm™ YM plates difficult for some food groups, potential food interference will need to be evaluated for each food group tested.

Microbiological Evaluation of Shrimp (Pandalus borealis) Processing

1978 ◽  
Vol 41 (1) ◽  
pp. 40-43 ◽  
Author(s):  
STEPHEN C. RIDLEY ◽  
BOHDAN M. SLABY J
Keyword(s):  
Salt Water ◽  
Bacterial Load ◽  
Microbiological Quality ◽  
Plate Count ◽  
Water Medium ◽  
Pandalus Borealis ◽  
Plate Count Agar ◽  
Cooking Process ◽  
Processing Plants ◽  
Aerobic Plate Count

Line samples from three different shrimp processing plants (brine-cooked shell-on, hand-peeled raw, and machine-peeled cooked) in Maine were examined for microbiological quality. Aerobic plate count (APC) of freshly caught shrimp (Pandalus borealis) was found to be about 530/g (Plate Count Agar at 35 C) while salt-requiring (SR) organisms were at significantly higher concentration (1.11 ×105/g; Salt Water Medium at 21 C). Some increase in psychrotrophic-mesophilic flora of shrimp delivered to the plant was observed. Cooking in-plant or on board the boat drastically reduced the SR flora, which was subsequently observed to increase after culling and inspection in the brine-cooked shell-on process. No such significant fluctuation due to processing was detected in APC. Shrimp sampled from steel barrels before a hand-peeled raw operation exhibited relatively high APC (7.2 × 104/g) and SR microflora (2.78 × 106/g). Heading and hand-peeling reduced the APC and SR bacterial loads by 71 and 95%, respectively. Subsequent processing and holding at room temperature resulted in a product with an APC and SR load of about 4 × 104/g. Similarly, high APC (1.66 × 105/g) and SR bacterial loads (1.84 × 105/g) were detected in samples obtained from a storage hopper of the machine-peeled cooking process. Although significant reduction in bacterial load was detected on line samples of this process (fluming, preheating, and cooking), the total bacterial load reached about 4 × 104/g before the canning step. Low levels of contamination with coliform and/or coagulase-positive staphylococci were detected in the three processes studied.

scholarly journals Taking Screenshots of the Invisible: A Study on Bacterial Contamination of Mobile Phones from University Students of Healthcare Professions in Rome, Italy

2020 ◽  
Vol 8 (7) ◽  
pp. 1075 ◽  
Author(s):  
Domenico Cicciarella Modica ◽  
Massimo Maurici ◽  
Gian Loreto D’Alò ◽  
Cinzia Mozzetti ◽  
Alessandra Messina ◽  
...  
Keyword(s):  
Mobile Phones ◽  
Staphylococcus Epidermidis ◽  
Univariate Analysis ◽  
Clinical Settings ◽  
Linear Regression Models ◽  
Biochemical Tests ◽  
E Coli ◽  
Plate Counts ◽  
Healthcare Professions ◽  
Heterotrophic Plate Counts

Mobile phones (MPs) are commonly used both in the personal and professional life. We assessed microbiological contamination of MPs from 108 students in healthcare professions (HPs), in relation to their demographic characteristics and MPs handling habits, collected by means of a questionnaire. Cultural and biochemical tests were performed, and statistical analyses were carried out. Staphylococci were present in 85% of MPs, Enterococci in 37%, Coliforms in 6.5%; E. coli was never detected. Staphylococcus epidermidis was the most frequently isolated staphylococcal species (72% of MPs), followed by S. capitis (14%), S. saprophyticus, S. warneri, S. xylosus (6%), and by S. aureus (4%). Heterotrophic Plate Counts (HPC) at 37 °C, ranged from 0 to 1.2 × 104 CFU/dm2 (mean = 362 CFU/dm2). In univariate analysis, the male gender only was significantly associated with higher HPCs and enterococcal contamination. Multiple linear regression models explained only 17% and 16% of the HPC 37 °C and staphylococcal load variability, respectively. Developing specific guidelines for a hygienic use of MPs in clinical settings, for preventing cross-infection risks, is advisable, as well as introducing specific training programs to HP students. MPs decontamination procedures could also be implemented in the community.

A National Survey of the Microbiological Quality of Retail Raw Meats in Australia

2008 ◽  
Vol 71 (6) ◽  
pp. 1232-1236 ◽  
Author(s):  
DAVID PHILLIPS ◽  
DAVID JORDAN ◽  
STEPHEN MORRIS ◽  
IAN JENSON ◽  
JOHN SUMNER
Keyword(s):  
Salmonella Typhimurium ◽  
National Survey ◽  
Microbiological Quality ◽  
Ground Beef ◽  
Plate Count ◽  
E Coli ◽  
Phage Types ◽  
The Mean ◽  
Aerobic Plate Count ◽  
Coagulase Positive Staphylococci

A national survey of the microbiology of meat (ground beef and diced lamb) at the retail level in Australia was undertaken. For ground beef samples (n = 360), the mean aerobic plate count (APC) was 5.79 log CFU/g, and Escherichia coli was detected in 17.8% of samples; the mean population for these positive samples was 1.49 log CFU/g. Enterobacteriaceae were detected in 96.9% of samples (mean for positive samples, 3.01 log CFU/g), and coagulase-positive staphylococci were detected in 28.1% of samples (mean for positive samples, 2.18 log CFU/g). For diced lamb samples (n = 360), the mean APC was 5.71 log CFU/g, and E. coli was detected in 16.7% of samples (mean for positive samples, 1.67 log CFU/g). Enterobacteriaceae were detected in 91.1% of samples (mean for positive samples, 2.85 log CFU/g), and coagulase-positive staphylococci were detected in 22.5% of samples (mean for positive samples, 2.34 log CFU/g). Salmonella was recovered from 4 (1.1%) of the 360 ground beef samples (isolates were Salmonella Typhimurium phage types), and E. coli O157 was recovered from 1 (0.3%) of 357 samples; Campylobacter and Clostridium perfringens were not recovered from any of the 91 and 94 samples tested, respectively. Salmonella was recovered from 2 (0.6%) of the 360 diced lamb samples (serovars were Salmonella Infantis and Salmonella Typhimurium), Campylobacter was recovered from 1 (1.1%) of 95 samples, and C. perfringens was recovered from 1 (1.1%) of 92 samples.

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