scholarly journals Conventional versus the petrifilm method for the enumeration of different types of bacteria

1969 ◽  
Vol 73 (3) ◽  
pp. 183-187
Author(s):  
Fred Fernández-Coll ◽  
Luis Silva-Negrón
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Plate Count ◽  
Bacterial Populations ◽  
E Coli ◽  
Different Types ◽  
Plate Counts ◽  
Conventional Plate ◽  
Aerobic Plate Count

Performance of Petrifilm VRB and SM plates to enumerate different types of bacterial populations was evaluated. A total of 100 Petrifilms and 100 regular Petri plates were tested with each of 3 different bacterial populations in 4 experiments. The Petrifilm system was superior to the conventional pour plate methods, or at least not statistically different, in enumerating Escherichia coli (coliform) and a mixture of E. coli, Staphylococcus aureus and Serratia marcescens (total aerobic plate count). The Petrifilm method was superior to conventional plate counts in enumerating Pseudomonas aeruginosa (psychrotrophic plate count), when both incubations were at 21°-22° C for 96 h. If sustained in further experimentation, this last observation would mean that the Petrifilm SM system could be successfully used to detect bacterial populations in addition to those for which the system was originally intended.

Survey of the Bacterial Populations of Bologna Products1,2

1978 ◽  
Vol 41 (9) ◽  
pp. 692-695 ◽  
Author(s):  
JOHN T. FRUIN ◽  
JAMES F. FOSTER ◽  
JAMES L. FOWLER
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Foodborne Pathogens ◽  
High Volume ◽  
Plate Count ◽  
Retail Market ◽  
Bacterial Populations ◽  
Retail Markets ◽  
Aerobic Plate Count

Bologna products most frequently are stored and consumed as refrigerated products. Thus bacteria that survive processing or those that contaminate the product subsequent to processing are not destroyed. Ten types of presliced, vacuum-packaged bologna products were purchased from a high-volume retail market and analyzed for total aerobic plate count (APC) and common foodborne pathogens. No Salmonella were isolated. Less than 1% of the 419 samples analyzed contained either Clostridium perfringens or Escherichia coli, Staphylococcus aureus was isolated from 4% of the samples, but only one sample contained more than 1000/g. Just over 5% of the samples contained coliform organisms. The manufacturer appeared to play an important role in bacterial quality of the finished items. An APC < 5 × 106/g is a realistic criterion for bologna products at the time of delivery to retail markets.

Comparison of Brands of Media for Isolating Bacteria from Poultry, Beef and Shrimp

1984 ◽  
Vol 47 (5) ◽  
pp. 394-397 ◽  
Author(s):  
H. S. LILLARD ◽  
N. A. COX ◽  
J. S. BAILEY ◽  
J. E. THOMSON
Keyword(s):  
Escherichia Coli ◽  
Practical Significance ◽  
Plate Count ◽  
E Coli ◽  
Plate Counts ◽  
Aerobic Plate Count ◽  
Raw Shrimp

Five brands of media (BBL, Difco, Gibco, Oxoid and Scott) were evaluated for enumerating microorganisms by the aerobic plate count and by Enterobacteriaceae, Escherichia coli, and coliform counts, and for determining Salmonella incidence. Microbiological evaluations were done on raw chickens, raw beef and raw shrimp, except that Salmonella incidence was not determined on shrimp samples. There were statistically significant differences in total plate counts (with chicken, beef and shrimp), Enterobacteriaceae counts (with shrimp) coliforms (with chicken) and E. coli counts (with chicken) by the five brands of media, but these differences were too small to be of practical significance. It was concluded that no differences of practical significance were found among the five brands of media.

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]

Bacterial Contamination of Ready-to-Eat Foods and Fresh Products in Retail Shops and Food Factories

1999 ◽  
Vol 62 (6) ◽  
pp. 644-649 ◽  
Author(s):  
KEN-ICHI KANEKO ◽  
HIDEKI HAYASHIDANI ◽  
YOSHIMITSU OHTOMO ◽  
JUNKO KOSUGE ◽  
MASAHIKO KATO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacterial Contamination ◽  
Plate Count ◽  
E Coli ◽  
Cooked Rice ◽  
Two Samples ◽  
Cooked Food ◽  
Aerobic Plate Count ◽  
Fresh Products

Raw vegetables cut for salad, cooked salad, cooked rice, boiled noodles, bean curd, and cooked Japanese foods were purchased in 27 retail shops in Tokyo. Intact vegetables before being processed and ready-to-eat fresh salad products were obtained from two food factories located in the suburbs of Tokyo. Two hundred thirty-eight retail samples, 137 samples of intact vegetables, and 159 samples of fresh products were examined for aerobic plate count (APC), coliforms, Escherichia coli, Listeria spp., Staphylococcus aureus, and Bacillus cereus. The APC of retail foods were 2.1 to 5.7 log CFU/g, and the range for the coliforms was 0.1 to 2.3 log CFU/g. The APC and coliform values showed that the raw vegetables cut for salad were the most heavily contaminated among the six kinds of ready-to-eat foods examined. Although L. monocytogenes was not detected, two samples of raw vegetables and five kinds of cooked foods yielded Listeria spp. S. aureus was detected in one sample of Japanese cooked food. The APC of the intact vegetables were 2.9 to 7.3 log CFU/g upon arrival and 2.2 to 7.2 log CFU/g after 3 days storage at 10°C. The APC of the fresh products were 3.4 to 7.6 log CFU/g upon arrival and 4.7 to 8.7 log CFU/g after 3 days storage at 10°C. The isolation rates for coliforms were 6.1 to 50% for intact vegetables and 50 to 66.7% for fresh products. E. coli was detected only in the fresh products. B. cereus was isolated from 20.1% (17 of 81) of the intact vegetables and 9.2% (8 of 87) of the fresh products.

An Evaluation of Sampling Methods for the Detection of Escherichia coli and Salmonella on Turkey Carcasses

2005 ◽  
Vol 68 (1) ◽  
pp. 34-39 ◽  
Author(s):  
J. M. McEVOY ◽  
C. W. NDE ◽  
J. S. SHERWOOD ◽  
C. M. LOGUE
Keyword(s):  
Escherichia Coli ◽  
Breast Tissue ◽  
Sampling Methods ◽  
Skin Tissue ◽  
Plate Count ◽  
Microbiological Analysis ◽  
Bacterial Counts ◽  
E Coli ◽  
Plate Counts ◽  
Aerobic Plate Count

The efficacy of rinse, excision, and swab methods for the microbiological analysis of prechill turkey carcasses was investigated. Aerobic plate counts from a 50-cm2 area of the breast sampled by excision and by swabbing were compared. Escherichia coli and Salmonella recoveries were determined from turkeys sampled by a carcass rinse (CR), a modified rinse with the carcass supported in a swing (MCR), a two-site swab of 50 cm2 at the back and thigh (2S), a one-site swab of 50 cm2 beneath the wing (1S), a whole-carcass swab of the inner and outer carcass surface (WS), and excision of 25 g of neck skin tissue (NE). The effect of diluent volume (25, 50, and 100 ml) on E. coli counts from swab samples was also assessed. The aerobic plate count from breast tissue sampled by excision was greater than that by swabbing (P < 0.05). E. coli recoveries by the MCR method were similar to those by CR. E. coli counts from 1S and WS samples were higher when swabs were stomached in 50 rather than 25 ml of diluent (P < 0.05). For swabs stomached in 50 ml of diluent, E. coli recoveries by the MCR, 2S, 1S, and WS methods were similar. For swabs stomached in 50 ml of diluent, Salmonella recoveries by the WS and MCR methods were higher than those by the 2S and 1S methods. Excision was more effective than swabbing for obtaining total bacterial counts from reduced turkey carcass areas. Whole-carcass sampling by rinsing or swabbing is necessary for optimum Salmonella recovery. Sampling a reduced area of the carcass is sufficient for E. coli analysis.

scholarly journals Antibacterial Activity and Mechanism of Action of the Silver Ion in Staphylococcus aureus and Escherichia coli

2008 ◽  
Vol 74 (7) ◽  
pp. 2171-2178 ◽  
Author(s):  
Woo Kyung Jung ◽  
Hye Cheong Koo ◽  
Ki Woo Kim ◽  
Sook Shin ◽  
So Hyun Kim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Mechanism Of Action ◽  
Antibacterial Effect ◽  
Silver Ion ◽  
Plate Count ◽  
E Coli ◽  
Count Method ◽  
Plate Count Method ◽  
Conventional Plate

ABSTRACT The antibacterial effect and mechanism of action of a silver ion solution that was electrically generated were investigated for Staphylococcus aureus and Escherichia coli by analyzing the growth, morphology, and ultrastructure of the bacterial cells following treatment with the silver ion solution. Bacteria were exposed to the silver ion solution for various lengths of time, and the antibacterial effect of the solution was tested using the conventional plate count method and flow cytometric (FC) analysis. Reductions of more than 5 log10 CFU/ml of both S. aureus and E. coli bacteria were confirmed after 90 min of treatment with the silver ion solution. Significant reduction of S. aureus and E. coli cells was also observed by FC analysis; however, the reduction rate determined by FC analysis was less than that determined by the conventional plate count method. These differences may be attributed to the presence of bacteria in an active but nonculturable (ABNC) state after treatment with the silver ion solution. Transmission electron microscopy showed considerable changes in the bacterial cell membranes upon silver ion treatment, which might be the cause or consequence of cell death. In conclusion, the results of the present study suggest that silver ions may cause S. aureus and E. coli bacteria to reach an ABNC state and eventually die.

scholarly journals Nanokitosan Efektif Menekan Jumlah Bakteri Gram Negatif dan Gram Positif Penyebab Endometritis pada Sapi Friesian Holstein secara In Vitro

2021 ◽  
Vol 22 (2) ◽  
pp. 198-206
Author(s):  
Edelina Sinaga ◽  
Ni Wayan Kurniani Karja ◽  
Andriani Andriani ◽  
Amrozi Amrozi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Plate Count ◽  
Bacillus Sp ◽  
E Coli ◽  
Total Plate Count

Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi bakteri penyebab endometritis pada sapi Frisian Holstein (FH) serta menganalisis efektivitas nanokitosan secara in vitro terhadap bakteri penyebab endometritis. Sampel dikoleksi dari enam ekor sapi FH yang mengalami endometritis subklinis setelah dilakukan pemeriksaan dengan ultrasonografi/USG, kemudian dilakukan perhitungan jumlah koloni, isolasi dan identifikasi bakteri. Nanokitosan diukur kadar proteinnya dan dibuat menjadi pH netral dengan konsentrasi 0,5%, 1% dan 2% untuk digunakan pada tahap uji tantang dengan bakteri endometritis yang ditemukan. Hasil penelitian menunjukkan total plate count (TPC) pada cairan endometrium sapi FH paling tinggi terdapat pada sapi perah FH nomor 626 sebanyak 4,7 ± 0,6 Log sel/ mL dan terendah terdapat pada nomor 532 sebanyak 3,3 ± 0,8 Log sel/mL. Beberapa bakteri Gram negatif yang ditemukan pada penelitian ini yaitu Escherichia coli, Pseudomonas aeruginosa, dan Klebsiella sp. Bakteri Gram positif yang ditemukan adalah Staphylococcus aureus, Bacillus sp. dan S. pyogenes. Ujitantang nanokitosan pada bakteri E. coli dengan konsentrasi 1% dan 2% menunjukkan hasil yang tidak siginifikan jika dibandingkan dengan kontrol positif (P>0,05). Nanokitosan dengan semua konsentrasi mampu menurunkan jumlah bakteri Klebsiella sp. dan P. aeruginosa serta pada bakteri Bacillus sp. secara signifikan jika dibandingkan dengan kontrol negatif (P<0,05). Uji tantang nanokitosan 0,5% dan 2% mampu menurunkan jumlah koloni S. aureus tetapi tidak dapat menurunkan jumlah koloni S. pyogenes. Dapat disimpulkan bahwa pemberian nanokitosan sebagai antibakteri mampu menurunkan jumlah koloni bakteri Gram negatif (E. coli, Klebsiella sp. dan P. aeruginosa) dan Gram positif (Bacillus sp dan S. aureus).

scholarly journals Fabrication of a Novel AgBr/Ag2MoO4@InVO4 Composite with Excellent Visible Light Photocatalytic Property for Antibacterial Use

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1541
Author(s):  
Jie Zhang ◽  
Jia Wang ◽  
Qingjun Zhu ◽  
Binbin Zhang ◽  
Huihui Xu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Degradation Rate ◽  
Photocatalytic Property ◽  
Photocatalytic Reaction ◽  
Composite Photocatalyst ◽  
E Coli ◽  
Radical Trapping ◽  
Visible Light Photocatalytic

A novel AgBr/Ag2MoO4@InVO4 composite photocatalyst with different heterojunction structures was successfully constructed by compounding InVO4 with Ag2MoO4 and AgBr. According to the degradation, antibacterial and free radical trapping data, the photocatalytic antibacterial and antifouling activities of AgBr/Ag2MoO4@InVO4 composite were evaluated, and the corresponding photocatalytic reaction mechanism was proposed. Adding AgBr/Ag2MoO4@InVO4 composite, the degradation rate of ciprofloxacin (CIP) achieved 95.5% within 120 min. At the same time, the antibacterial rates of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) achieved 99.99%. The AgBr/Ag2MoO4@InVO4 composite photocatalyst showed promising usage in photocatalytic antibacterial and purification areas.

Microbial Quality of Hoummos (Chickpea Dip) Commercially Produced in Jordan

1994 ◽  
Vol 57 (5) ◽  
pp. 431-435 ◽  
Author(s):  
MOHAMMED I. YAMANI ◽  
BASIM A. AL-DABABSEH
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Low Ph ◽  
Plate Count ◽  
Microbial Quality ◽  
Aerobic Plate Count ◽  
And Staphylococcus Aureus ◽  
Reference Samples ◽  
Hygienic Conditions

Sixty samples of fresh hoummos (chickpea dip) from 15 restaurants were examined in winter and summer to find out numbers and types of microorganisms present. Five reference samples, produced by the investigators under hygienic conditions, were examined for comparison. The microbial load of commercial hoummos was high, and spherical lactic acid bacteria (LAB) belonging to Lactococcus, Enterococcus and Leuconostoc were the predominant microorganisms. The means of the aerobic plate count (APC) and the counts of LAB and coliforms (1.9 × 108, 1.6 × 108 and 2.9 × 105/g, respectively) in summer samples were significantly higher (p &lt; 0.05) than the averages of the same counts in winter samples (2.7 × 107, 1.6 × 107 and 2.2 × 103/g). The average summer and winter yeast counts were 4.2 × 104 and 1.5 × 104g, respectively. In reference samples of hoummos, APC and LAB counts were &lt; 103/g, while the coliform and yeast counts were &lt; 10/g and 102/g, respectively, indicating lack of hygienic practices during the production of commercial hoummos. Salmonella was not detected in any sample, and Escherichia coli and Staphylococcus aureus counts of all samples were &lt; 10/g. The relatively low pH of hoummos (the average pH of all samples was 5.1) and the rapid growth of LAB, possibly accompanied by production of inhibitory substances, may explain the predominance of these bacteria, and could have contributed to the absence of the pathogens examined.

scholarly journals Estudio fitoquímico y actividad antimicrobiana de plantas medicinales empleadas para el control de infecciones urinarias

2021 ◽  
Vol 16 (1) ◽  
pp. 43-56
Author(s):  
Lida Vanessa Hernández Moreno ◽  
Ludy Cristina Pabón Baquero ◽  
Patricia Hernández-Rodríguez
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Zingiber Officinale ◽  
Taraxacum Officinale ◽  
Portulaca Oleracea ◽  
Uncaria Tomentosa ◽  
E Coli ◽  
Anthoxanthum Odoratum ◽  
Parietaria Officinalis

Las enfermedades infecciosas han sido un desafío para la humanidad. A pesar de los avances en la ciencia, aún muchas infecciones no tienen tratamientos efectivos o los microorganismos han generado resistencia a los antibióticos, de manera que las plantas medicinales son una alternativa de tratamiento y reducción de la resistencia. El objetivo de este estudio fue realizar un análisis fitoquímico preliminar y evaluar la actividad antimicrobiana de doce extractos etanólicos deplantas empleadas en la medicina tradicional colombiana como control de infecciones urinarias (IU). Las especies Anthoxanthum odoratum (grama), Urera caracasana (ortigón), Equisetum bogotenses (cola de caballo), Parietaria officinalis (parietaria), Achyrocline bogotensis (vira vira), Kohleria hirsuta (caracola), Taraxacum officinale (diente de león), Sedum praealtum (siempre viva), Portulaca oleracea (verdolaga), Petroselinum sativum (perejil), Zingiber officinale (jengibre) y Uncaria tomentosa (uña de gato) fueron adquiridas en la plaza de mercado Soacha (Cundinamarca) y sometidas a maceración con etanol a temperatura ambiente. La actividad antimicrobiana se evaluó por difusión en agar, microdilución en placa y bioautografía frente a Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923) y Pseudomonas aeruginosa (ATCC 9027). Se determino que S. aureus y P. aeruginosa presentaron inhibición frente a cinco extractos en los tres métodos realizados, mientras que E. coli no fue inhibida por ningún extracto. Se estableció mediante bioautografía con reveladores específicos que los esteroides y/o triterpenoides, fenoles y flavonoides son los posibles metabolitos responsables de la actividad. Este tipo de investigaciones propicia estudios orientados al aislamiento de principios activos con utilidad en la elaboración de medicamentos para tratar IU.

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