scholarly journals Comparison of BCYE and BMPA media on recovery rate of Legionella pneumophila

2020 ◽  
Vol 11 (1) ◽  
pp. 32-37
Author(s):  
Lucky Moehario ◽  
Enty Tjoa ◽  
Mutiara J. Taslim ◽  
Yohanna Angelina
Keyword(s):  
Yeast Extract ◽  
Legionella Pneumophila ◽  
Recovery Rate ◽  
Culture Method ◽  
Colony Growth ◽  
Selective Medium ◽  
Plate Count ◽  
Surveillance Program ◽  
Specific Medium ◽  
Routine Surveillance

Latar belakang: Legionella pneumophila (L. pneumophila) telah banyak diketahui sebagai penyebab legionellosis; habitat nya di berbagai sumber air, lingkungan lembab dan hangat. Metode kultur menggunakan media spesifik masih menjadi baku emas untuk identifikasi L. pneumophila. Penelitian ini bertujuan membandingkan recovery rate L. pneumophila ATCC®33823 pada medium spesifik BCYE, dan medium selektif BMPA. Metode: Dilakukan dilusi serial pada suspensi 0,5 McFarland L. pneumophila ATCC®33823; 100 ul dari tiap tingkat dilusi diinokulasi pada medium Buffered Charcoal Yeast Extract (BCYE) dan medium BMPA (medium BCYE yang ditambahkan suplemen BMPA-α), secara duplo. Konsentrasi suspensi dihitung menggunakan metode Angka Lempeng Total (ALT) dari Standar Nasional Indonesia No. 01-2332.3-2006. Persentase recovery rate dihitung dan dianalisis secara statistik menggunakan SPSS versi 23,0. Hasil: Jumlah koloni L. pneumophila yang tumbuh pada medium BMPA jauh lebih tinggi daripada yang tumbuh di medium BCYE; konsentrasi tertinggi yang diperoleh adalah pada medium BMPA sebesar 1,45 x 107 CFU/ml. Persentase recovery rate pada medium BMPA adalah 96,67%, dan 60,67% pada medium BCYE. Kesimpulan: Recovery rate medium BMPA untuk pertumbuhan koloni L. pneumophila ATCC®33823 jauh lebih tinggi daripada media BCYE, karena itu medium BMPA dapat direkomendasikan untuk kultivasi L. pneumophila, khususnya pada program surveilans berbagai sumber air dengan biaya lebih terjangkau. Kata kunci: Legionella pneumophila, medium spesifik, BCYE , BMPA, recovery rate   Abstract Background: Legionella pneumophila (L. pneumophila) has been known as the etiology of legionellosis; they live in aquatic environment, warm and moist. Culture method using specific medium remains as the gold standard in the identification of L. pneumophila. This study aimed to compare the recovery rate of L. pneumophila ATCC® 33823 on the specific medium BCYE for the cultivation of Legionella, and BMPA, the selective medium. Methods: Suspension of L. pneumophila ATCC® 33823 of 0.5 McFarland was diluted to 10 fold serial dilution; 100 ul of each dilution was inoculated on Buffered Charcoal Yeast Extract (BCYE) medium, and BMPA (BCYE supplemented with BMPA-α) in duplicate manner. The concentration was calculated using Total Plate Count standard as of Indonesian Nasional Standard number 01-2332.3-2006. The percentage of recovery rate was calculated, and the statistical analysis was performed using SPSS version 23.0.   Results: Numbers of colonies of L. pneumophila grew on BMPA was much higher than on BCYE medium; the highest concentration was yielded on BMPA medium i.e. 1.45x107 CFU/ml. The recovery rates were 96.67% and 60.67% on BMPA medium and BCYE subsequently. Conclusion: The recovery rate of the BMPA medium on the colony growth of L. pneumophila ATCC®33823 was markedly higher than the BCYE, therefore BMPA medium can be suggested to be used in the cultivation of L. pneumophila especially in the routine surveillance program for water sources with less cost. Keywords: Legionella pneumophila, specific medium, BCYE , BMPA, recovery rate

scholarly journals Is a Proactive Approach to Controlling Legionella in the Environment Justified?

2021 ◽  
Vol 59 (3) ◽  
Author(s):  
Daniela Glažar Ivče ◽  
Dobrica Rončević ◽  
Marina Šantić ◽  
Arijana Cenov ◽  
Dijana Tomić Linšak ◽  
...  
Keyword(s):  
Drinking Water ◽  
Legionella Pneumophila ◽  
Cold Water ◽  
Aged Care ◽  
Water Systems ◽  
Hot Water ◽  
Plate Count ◽  
Surveillance Program ◽  
Adequate Treatment ◽  
Proactive Approach

Research background. Legionella are Gram-negative bacteria that are ubiquitous in the natural environment. Contaminated water in manmade water systems is a potential source of transmission of Legionnaires’ disease (LD). The aim of this study was to explore the prevalence of Legionella pneumophila (L. pneumophila) in the drinking water distribution system (DWDS) of Primorje-Gorski Kotar County (PGK County), Croatia, for the period 2013-2019, coupled with the incidence of LD. A number of L. pneumophila-positive samples (>100 CFU/L), serogroup distribution, and the degree of contamination of specific facilities (health & aged care, tourism, sports) were assessed. Based on the results obtained, the reasoning for the implementation of a mandatory Legionella environmental surveillance program was assessed. Experimental approach. Sample testing for Legionella was carried out according to ISO 1173. A Heterotrophic Plate Count (HPC) and P. aeruginosa were analysed along with the basic physico-chemical indicators of drinking water quality. The research period was divided into two parts, namely, the 2013-2018 period (before implementation of the prevention program, after the outbreak of LD), and year 2019 (proactive approach, no LD cases recorded). Results and conclusion. During the 7-year observation period in PGK County, an increase in the number of samples tested for Legionella was found. An increase in Legionella-positive samples (particularly pronounced during the warmer part of the year) was recorded, along with a growing trend in the number of reported LD cases. In addition to hot water systems, the risk of Legionella colonization also applies to cold water systems. Health & aged care facilities appear to be at highest risk. In addition to the higher proportion of positive samples and a higher degree of microbiological load at these facilities, the highest proportion of L. pneumophila SGs 2-14 was identified. Due to the diagnostic limitations of the applied tests, the number of LD cases is underdiagnosed. Novelty and scientific contribution. The introduction of a mandatory preventive approach to monitoring Legionella in DWDS water samples, along with the definition of national criteria for the interpretation of results, will create the preconditions for diagnosis and adequate treatment of larger numbers of LD cases.

scholarly journals Occurrence of Legionella in showers at recreational facilities

2017 ◽  
Vol 15 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Patrizia De Filippis ◽  
Cinzia Mozzetti ◽  
Massimo Amicosante ◽  
Gian Loreto D'Alò ◽  
Alessandra Messina ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Distribution Systems ◽  
Water Distribution ◽  
Culture Method ◽  
Plate Count ◽  
Recreational Facilities ◽  
Hygiene Practices ◽  
Serotype 1 ◽  
Polymerase Chain ◽  
Good Hygiene

Critical environments, including water systems in recreational settings, represent an important source of Legionella pneumophila infection in humans. In order to assess the potential risk for legionellosis, we analyzed Legionella contamination of water distribution systems in 36 recreational facilities equipped with swimming pools. One hundred and sixty water samples were analyzed from shower heads or taps located in locker rooms or in bathrooms. By culture method and polymerase chain reaction, 41/160 samples were positive for Legionella from 12/36 recreational centers. Hotels (57.1%) and sports centers (41.2%) were the most contaminated. L. pneumophila serotypes 2–14 (25/41) were more frequently found than serotype 1 (10/41). Samples at temperature ≥30 °C were more frequently positive than samples at temperature <30 °C (n = 39 vs n = 2, p < 0.00001). The presence of L. pneumophila was investigated by comparison with heterotrophic plate count (HPC), an indicator of water quality. The presence of L. pneumophila was associated more frequently with high and intermediate HPC load at 37 °C, therefore should be considered a potential source when HPC at 37 °C is >10 CFU/mL. Maintenance, good hygiene practices, interventions on the hydraulic system and regular controls must be implemented to minimize exposure to L. pneumophila infection risk.

scholarly journals Performance of Legiolert Test vs. ISO 11731 to Confirm Legionella pneumophila Contamination in Potable Water Samples

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 690 ◽  
Author(s):  
Maria Scaturro ◽  
Matteo Buffoni ◽  
Antonietta Girolamo ◽  
Sandra Cristino ◽  
Luna Girolamini ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Legionella Pneumophila ◽  
Water Samples ◽  
Gold Standard ◽  
Liquid Culture ◽  
Potable Water ◽  
Culture Method ◽  
Alternative Methods ◽  
Significant Difference

Detection and enumeration of Legionella in water samples is of great importance for risk assessment analysis. The plate culture method is the gold standard, but has received several well-known criticisms, which have induced researchers to develop alternative methods. The purpose of this study was to compare Legionella counts obtained by the analysis of potable water samples through the plate culture method and through the IDEXX liquid culture Legiolert method. Legionella plate culture, according to ISO 11731:1998, was performed using 1 L of water. Legiolert was performed using both the 10 mL and 100 mL Legiolert protocols. Overall, 123 potable water samples were analyzed. Thirty-seven (30%) of them, positive for L. pneumophila, serogroups 1 or 2–14 by plate culture, were used for comparison with the Legiolert results. The Legiolert 10 mL test detected 34 positive samples (27.6%) and the Legiolert 100 mL test detected 37 positive samples, 27.6% and 30% respectively, out of the total samples analyzed. No significant difference was found between either the Legiolert 10 mL and Legiolert 100 mL vs. the plate culture (p = 0.9 and p = 0.3, respectively) or between the Legiolert 10 mL and Legiolert 100 mL tests (p = 0.83). This study confirms the reliability of the IDEXX Legiolert test for Legionella pneumophila detection and enumeration, as already shown in similar studies. Like the plate culture method, the Legiolert assay is also suitable for obtaining isolates for typing purposes, relevant for epidemiological investigations.

scholarly journals A selective medium for the isolation of the acinetobacter genus bacteria

1980 ◽  
Vol 75 (3-4) ◽  
pp. 11-21 ◽  
Author(s):  
Altair A. Zebral
Keyword(s):  
Yeast Extract ◽  
Crystal Violet ◽  
Sodium Citrate ◽  
Agar Medium ◽  
Selective Medium ◽  
Phenol Red ◽  
Gram Positive ◽  
Gram Negative ◽  
Fermentative Activity

A selective and differencial medium was developed for the isolation of Acinetobacter genus bacteria. This Acinobacter Agar Medium (p.H + 7.4) contains in grams per litre: thiotone, 10; yeast extract, 3; naC1, 5; saccharose, 10; mannitol, 10; sodium citrate, 0.5; sodium desoxycholate, 0.1; crystal violet, 0.00025; phenol red, 0.04 and agar-agar 15. This medium has the advantage of inhibiting the growth of cocci and Gram-positive bacilli, by the use of sodium citrate and sodium desoxycholate associated with the crystal violet; and of differentiating the Gram-negative bacilli from the Enterobacteriaceae, through the fermentative activity upon the saccharose and/or mannitol, contrasting with the complete inactivity of the Acinetobacter genus bacteria over those substances.

Impedance Measurements in Raw Milk as an Alternative to the Standard Plate Count1

1982 ◽  
Vol 45 (1) ◽  
pp. 4-7 ◽  
Author(s):  
S. GNAN ◽  
L. O. LUEDECKE
Keyword(s):  
Yeast Extract ◽  
Geometric Mean ◽  
Raw Milk ◽  
Plate Count ◽  
Impedance Method ◽  
Microbial Count ◽  
Specific Detection ◽  
Standard Plate Count ◽  
Milk Samples ◽  
Standard Plate

Electrical impedance, using the Bactometer 32, was evaluated as an alternative method to the Standard Plate Count (SPC) to determine the initial microbial count of raw milk samples. The raw milk samples were obtained from farm bulk tanks on commercial dairy farms. Analyses were started within 24–36 h after collection. The impedance method was used to evaluate the samples as raw milk, raw milk plus yeast extract, raw milk given preliminary incubation (18 h at 13 C) or raw milk given preliminary incubation plus yeast extract. The yeast extract (1% final concentration) was added after the milk was placed in the module wells. The geometric mean SPC of each of these four groups was 4.51, 4.37, 4.96 and 5.14, and the corresponding mean detection times with Bactometer 32 were 10.13, 8.80, 8.28 and 6.11 h, respectively. The correlation coefficient of detection time to SPC was −0.77, −0.88, −0.78 and −0.79, respectively, for the four sample groups. When specific detection cut-off times (approximately 7 h) were selected and a maximum SPC of 100,000 CFU/ml was selected, 85.2%, 97.2%, 81.0% and 83.6%ofthe samples in the above four groups were correctly classified.

Study on the Detection of Total Colony in Medical and Health Environment Based on ATP Bioluminescence

2018 ◽  
Vol 24 (2) ◽  
Author(s):  
Zhe Li
Keyword(s):  
Culture Method ◽  
Pass Rate ◽  
Plate Count ◽  
Count Method ◽  
Atp Bioluminescence ◽  
Bioluminescence Assay ◽  
Plate Count Method ◽  
The Difference ◽  
Atp Bioluminescence Assay ◽  
Bioluminescence Method

In this paper, the application of ATP fluorescence in the detection of colonies in the health environment of hospitals was studied. Firstly, the principle of ATP bioluminescence method was described. Then, ATP bioluminescence and plate count method were used to test the density of the surface of the objects in selected area, taking the time points 2 hours after disinfection as the time nodes. The results showed that the difference between the qualified rate of ATP bioluminescence assay and the plate count method was statistically significant {P<0.01}. Therefore, ATP bioluminescence method was highly correlated with bacterial culture method. The correlation coefficient of pass rate of the two methods was 0.782, which indicated that there was a positive correlation between the two test results. Besides, the detection results showed that ATP bioluminescence method had higher sensitivity than plate counting method. Therefore, ATP bioluminescence method was more suitable for the rapid detection of the colony of hospital health environment, and helps the hospital to better manage its environmental hygiene conditions. 

NATURE AND GROWTH RESPONSE OF THE MICROFLORA OF PASTEURIZED, PACKAGED MILK1

1967 ◽  
Vol 30 (7) ◽  
pp. 213-218 ◽  
Author(s):  
R. B. Maxcy
Keyword(s):  
Quality Control ◽  
Bacterial Growth ◽  
Growth Response ◽  
Selective Medium ◽  
Plate Count ◽  
Alkyl Aryl Sulfonate ◽  
Alkyl Aryl ◽  
Standard Methods ◽  
Plate Count Agar ◽  
Subsequent Storage

Summary The microflora of freshly pasteurized, packaged milk is heterogeneous, and the numbers are generally low. While it is commonly assumed all bacteria are included in assays of numbers with plate count agar and standard methods, under normal conditions few are able to grow and contribute significantly to spoilage. Post-pasteurization contamination, which contributes insignificantly to the total count on freshly pasteurized, packaged milk, contributes most of the bacteria that are capable of growth to cause spoilage during subsequent storage. Though there is a delay after pasteurization before significant bacterial growth takes place, the same group of bacteria is responsible at either 5 C or 32 C. The growth response of these bacteria was measured with a selective medium of nutrient agar containing alkyl aryl sulfonate. Data obtained by the use of the selective medium indicated a potentially useful approach to quality control.

INHIBITION OF GROWTH OF AIRBORNE COLIFORMS AND OTHER BACTERIA ON SELECTIVE MEDIA1

1972 ◽  
Vol 35 (3) ◽  
pp. 156-162 ◽  
Author(s):  
Attila K. Stersky ◽  
T. I. Hedrick
Keyword(s):  
Methylene Blue ◽  
Skim Milk ◽  
Enterobacter Aerogenes ◽  
Colony Growth ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Pseudomonas Fragi ◽  
Selective Media ◽  
Standard Plate Count ◽  
Plate Count Agar

Coliforms when sampled from air were inhibited or restricted in growth on regular selective media. For trials, growth on Standard Plate Count Agar ( SPC) was used as 100%. The percentage of colony growth of Escherchia coli and Enterobacter aerogenes on modified selective media or with SPC were respectively as follows: violet red bile/violet red bile (VRB/VRB) (overlay on base) &lt;4, 15; desoxycholate/desoxyeholate (DES/DES) &lt; 1, 17; tergitol/tergitol (TER/TER) 23,49; eosine methylene blue/eosine methylene blue (EMB/EMB) 122, 86; endo/endo (END/END) 40, 104; MacConkey/MacConkey (MAC/MAC) &lt;2, 10; SPC/VRB &lt;2, 22; SPC/DES &lt;2, 23; VRB/SPC 54, 60; TER/SPC 72, 119; EMB/SPC 97, 119; END/SPC 95, 90; 1 VRB: 1 SPC, as overlay and base 14, 50. Recovery percentages of Pseudomonas aeruginosa and Pseudomonas fragi on modified selective media were greater than those of the coliform bacteria. Fewer Serratia marcescens colonies grew on DES or SPC/DES and more grew on the other modified selective media than did coliform colonies. Growth of airborne Salmonella newbrumwick ranged from &lt;1% on SS agar to 118% on MAC/SPC. Aerosolization of coliforms with skim milk compared to distilled water resulted in growth of more colonies on selective media. Desoxycholate, Bile Salts No. 3, Tergitol No. 7, and crystal violet in the media definitely limited growth of airborne coliforms.

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