Survival of Selected Indicator and Pathogenic Bacteria in Refrigerated Pizzas

1987 ◽  
Vol 50 (10) ◽  
pp. 859-861 ◽  
Author(s):  
JAMES S. DICKSON

This study was conducted to determine the shelf life of previously frozen pizzas stored at refrigeration temperatures. Pizzas were prepared using meat inoculated with Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium. The pizzas were frozen, then stored at 3 and 10°C. Samples were analyzed every 2 d for 14 d. Sensory analysis was conducted every day for 8 d using uninoculated product. There was a significant (P<0.05) increase in the population of E. coli between 8 and 10 d at 10°C. There were no significant (P>0.05) differences in the populations of S. typhimurium or S. aureus with either time or temperature. The sensory shelf life of the pizzas was approximately 5 d at 10°C and 6 d at 3°C. The pizzas were unacceptable after 7 d at either temperature.

2018 ◽  
Vol 19 (0) ◽  
Author(s):  
Priscila Alves Dias ◽  
Daiani Teixeira Silva ◽  
Cláudio Dias Timm

Resumo Kefir é o produto da fermentação do leite pelos grãos de kefir. Esses grãos contêm uma mistura simbiótica de bactérias e leveduras imersas em uma matriz composta de polissacarídeos e proteínas. Muitos benefícios à saúde humana têm sido atribuídos ao kefir, incluindo atividade antimicrobiana contra bactérias Gram positivas e Gram negativas. A atividade antimicrobiana de 60 microrganismos isolados de grãos de kefir, frente à Escherichia coli O157:H7, Salmonella enterica subsp. enterica sorotipos Typhimurium e Enteritidis, Staphylococcus aureus e Listeria monocytogenes, foi estudada através do teste do antagonismo. A ação antimicrobiana dos sobrenadantes das bactérias ácido-lácticas que apresentaram atividade no teste do antagonismo foi testada. O experimento foi repetido usando sobrenadantes com pH neutralizado. Salmonella Typhimurium e Enteritidis sobreviveram por 24 horas no kefir em fermentação. E. coli O157:H7, S. aureus e L. monocytogenes foram recuperados até 72 horas após o início da fermentação. Todos os isolados apresentaram atividade antimicrobiana contra pelo menos um dos patógenos usados no teste do antagonismo. Sobrenadantes de 25 isolados apresentaram atividade inibitória e três mantiveram essa atividade com pH neutralizado. As bactérias patogênicas estudadas sobreviveram por tempo superior àquele normalmente utilizado para a fermentação do kefir artesanal, o que caracteriza perigo em potencial para o consumidor quando a matéria-prima não apresentar segurança sanitária. Lactobacillus isolados de grãos de kefir apresentam atividade antimicrobiana contra cepas de E. coli O157:H7, Salmonella sorotipos Typhimurium e Enteritidis, S. aureus e L. monocytogenes além daquela exercida pela diminuição do pH.


Author(s):  
Bing Han ◽  
Xiaoyu Han ◽  
Mengmeng Ren ◽  
Yilin You ◽  
Jicheng Zhan ◽  
...  

Diseases caused by harmful microorganisms pose a serious threat to human health. Safe and environment-friendly disinfectants are, therefore, essential in preventing and controlling such pathogens. This study aimed to investigate the antimicrobial activity and mechanism of a novel hydrogen peroxide and silver (H 2 O 2 -Ag + ) complex (HSC) in combatting Staphylococcus aureus ATCC 29213, Escherichia coli O157:H7 NCTC 12900 and Salmonella typhimurium SL 1344. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against S. aureus were found to be 0.014 % H 2 O 2 -3.125 mg/L Ag + , while 0.028 % H 2 O 2 -6.25 mg/L Ag + for both E. coli and S. typhimurium . Results of the growth curve assay and time-kill trial suggest that the HSC could inhibit the growth of the tested bacteria, as 99.9 % of viable cells were killed following treatment at the 1 MIC for 3 h. Compared with Oxytech D10 disinfectant (0.25 % H 2 O 2 -5 mg/L Ag + ), the HSC exhibited better antibacterial efficacy at a lower concentration (0.045 % H 2 O 2 -10 mg/L Ag + ). The mechanism of antibacterial action of HSC was found including the disruption of the bacterial cell membrane, followed by entry into the bacteria cell to reduce intracellular adenosine triphosphate (ATP) concentration, and inhibit the activity of antioxidases, superoxide dismutase (SOD) and catalase (CAT). The enhanced bactericidal effect of hydrogen peroxide combined with silver indicates a potential for its application in environmental disinfection, particularly in the food industry.


2021 ◽  
Vol 31 (4) ◽  
pp. 2
Author(s):  
IDSAP Peramiarti

Diarrhea is defecation with a frequency more often than usual (three times or more) a day (10 mL/kg/day) with a soft or liquid consistency, even in the form of water alone. Pathogenic bacteria, such as Escherichia coli, Salmonella typhimurium, and Shigella sp., play a role in many cases, to which antibiotics are prescribed as the first-line therapy. However, since antibiotic resistance cases are often found, preventive therapies are needed, such as consuming yogurt, which is produced through a fermentation process by lactic acid bacteria (LAB). This research aimed to determine the activity of lactic acid bacteria (Liactobacillus bulgaricus and Streptococcus thermophilus) in yogurt in inhibiting the growth of the pathogenic bacteria E. coli, S. typhimurium, and Shigella sp. The research applied in vitro with the liquid dilution test method and the true experimental design research method with post-test-only and control group design. The design was used to see the inhibitory effect of yogurt LAB on the growth of E. coli, S. typhimurium, and Shigell sp. to compare the effect of several different yogurt concentrations, namely 20%, 40%, 60%, and 80%. The results of the Least Significance Different analysis showed that there was a significant difference between yogurt with a concentration of 0% and that with various concentrations in inhibiting the growth of E. coli, S. typhimurium, and Shigella sp. with a p-value of &lt;0.05. Whereas, there was no significant difference in the various concentrations of yogurt in inhibiting the growth of the three kinds of bacteria with a p-value of &gt; 0.05.<p class="Default" align="center"> </p>


1979 ◽  
Vol 42 (6) ◽  
pp. 464-469 ◽  
Author(s):  
M. E. STILES ◽  
L.-K. NG

Ham and chopped ham from two manufacturers were contaminated with five enteropathogens: Bacillus cereus, Clostridium perfringens, Escherichia coli, Salmonella typhimurium and Staphylococcus aureus, at time of slicing and vacuum-packaging, to simulate contamination by manufacturer. Subsequent treatment of the samples, representing sound and undesirable retail handling and consumer use conditions, indicated marked differences in the fate of the pathogens between these products and within product type between the two manufacturers. Greatest differences were observed between the chopped ham products. All pathogens, except C. perfringens, grew actively in fresh ham and chopped ham with abusive holding at 30 and 21 C. After storage at 4 or 10 C for 30 days, B. cereus and C. perfringens were no longer detected, even after subsequent holding at 30 or 21 C for 24 h. E. coli survival and growth was variable, S. typhimurium survived well and grew under some conditions and S. aureus was generally inhibited at high levels of competition.


2004 ◽  
Vol 67 (5) ◽  
pp. 1014-1016 ◽  
Author(s):  
M. J. CHO ◽  
R. W. BUESCHER ◽  
M. JOHNSON ◽  
M. JANES

The effects of (E,Z)-2,6-nonadienal (NDE) and (E)-2-nonenal (NE) on Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium were investigated. A suspension of each organism of 6 to 9 log CFU/ml was incubated for 1 h at 37° C in brain heart infusion solution that contained 0 to 500 or 1,000 ppm of NDE or NE. Depending on concentration, exposure to either NDE or NE caused a reduction in CFU of each organism. Treatment with 250 and 500 ppm NDE completely eliminated viable B. cereus and Salmonella Typhimurium cells, respectively. L. monocytogenes was the most resistant to NDE, showing only about a 2-log reduction from exposure to 500 ppm for 1 h. Conversely, this concentration of NDE caused a 5.8-log reduction in E. coli O157:H7 cells. NE was also effective in inactivating organisms listed above. A higher concentration of NE, 1,000 ppm, was required to kill E. coli O157:H7, L. monocytogenes, or Salmonella Typhimurium compared with NDE. In conclusion, both NDE and NE demonstrated an apparent bactericidal activity against these pathogens.


2000 ◽  
Vol 57 (3) ◽  
pp. 389-394 ◽  
Author(s):  
Marta Helena Filet Spoto ◽  
Cláudio Rosa Gallo ◽  
André Ricardo Alcarde ◽  
Maria Sílvia do Amaral Gurgel ◽  
Lucimara Blumer ◽  
...  

This work evaluated the effect of gamma radiation on reducting the population of Staphylococcus aureus, Escherichia coli and Salmonella typhimurium in ground chicken breast stored under refrigeration. The experiment included a control and 4 doses of gamma radiation (2.0, 4.0, 6.0 and 8.0 kGy) along with 5 periods of storage under refrigeration (1, 7, 14, 21 and 28 days). Samples of ground chicken breast were inoculated with Staphylococcus aureus (ATCC 14458), Escherichia coli (ATCC 11105) and Salmonella typhimurium (ATCC 0626), irradiated at temperatures between 4 and 8°C and stored under refrigeration (5°C) for 28 days. The increased radiation dose and period of storage under refrigeration caused a reduction of Staphylococcus aureus, Escherichia coli and Salmonella typhimurium populations in the ground chicken breast. Mean radiation D values determined for Staphylococcus aureus and Escherichia coli were 0.41 and 0.72 kGy, respectively. Gamma irradiation was an effective treatment for chicken meat conservation because the radiation dose of 6.0 kGy kept the ground chicken breast within the microbiological limits established by the Brazilian legislation, for up to 28 days under refrigeration.


2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Michele Sumampouw

Abstract: The aim of this study is to investigate the antibacterial effect of endophytic fungi originated from the root of mangrove Rhizophora stylosa growing on Mangrove Plantation Area around DAS Simpang 5 Jl. Piere Tendean Manado. The method of this research was using combination of PDA and NA media. Two species of endophytic fungi were extracted from the root of R. stylosa, black mycelium fungi as isolate A and brown mycelium fungi as isolate B. The activities of both isolates were tested against pathogenic bacteria Staphylococcus aureus and Escherichia coli. The result showed the same inhibition zone of isolate A and B to S. aureus, while, isolate A showed bigger the inhibition zone in comparison to isolate B against E. coli. As a conclusion, the endophytic fungi taken from the root of R. stylosa have antibacterial activity toward S. aureus and E. coli. Keywords: endophytic fungi, Rhizophora stylosa, antibacterial, Staphylococcus aureus, Escherichia coli.   Abstrak: Penelitian ini bertujuan untuk melihat adanya efek antibakteri dari jamur endofit yang diambil dari akar bakau Rhizophora stylosa yang ditanam di sekitar Perairan Daerah Aliran Sungai Simpang Lima Jl. Piere Tendean Manado. Metode penelitian dilakukan dengan menggunakan kombinasi media Potato Dextrose Agar (PDA) dan Nutrient Agar (NA). Dari akar bakau R. stylosa diperoleh dua  jenis jamur endofit yaitu isolat A dengan karateristik miselium jamur berwarna hitam dan isolat B yang dengan karakteristik miselium berwarna coklat. Kedua isolat ini selanjutnya diujikan aktivitasnya terhadap bakteri Staphylococcus aureus dan Escherichia coli. Hasil penelitian menunjukkan isolat A dan B memberikan  zona hambat yang sama terhadap bakteri Staphylococcus aureus dan pada bakteri Escherichia coli isolat A menunjukkan diameter zona hambat yang lebih besar dibandingkan isolat B. Kesimpulan, Jamur endofit yang diisolasi dari akar bakau R. Stylosa memiliki efek antibakteri terhadap pertumbuhan bakteri S. aureus dan E. coli. Kata kunci: jamur endofit, Rhizophopra stylosa, antibakteri, Staphylococcus aureus, Escherichia coli.


PHARMACON ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 834
Author(s):  
Eunike Pelealu ◽  
Defny S. Wewengkang ◽  
Surya Sumantri Abdullah

ABSTRACTSponges are one of the biota components that make up coral reefs which are quite widely distributed. The metabolite content in the sponge can ward off and inhibit the pathogenic bacteria that interfere with it. This study aims to determine the activity of inhibiting bacterial growth from the extract and fraction of Leucetta chagosensis sponge against the growth of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. The samples were extracted using the maceration method with 95% ethanol solvent and then fractionated using 3 solvents with different polarity levels, namely methanol, n-hexane and chloroform. Activity test using the disk diffusion agar method of Kirby and Bauer. Only the MeOH fraction was able to inhibit the growth of E. coli bacteria with an average inhibition zone of 6.88 mm. Whereas for S.aureus bacteria extracts and all fractions showed activity to inhibit bacterial growth with an average inhibition zone of EtOH (6.61 mm), CHCI3 (6.68 mm), n-hexane (7.83 mm) and MeOH (8.00 mm), respectively. All activities that are shown are categorized as weak (weak).Keywords: Antibacterial, Leucetta chagosensis, Staphylococcus aureus, Escherichia coli ABSTRAKSpons merupakan salah satu komponen biota penyusun terumbu karang yang penyebarannya cukup luas. Kandungan metabolit yang ada di dalam spons dapat menangkal dan menghambat bakteri patogen pengganggunya.  Penelitian ini bertujuan untuk melihat aktivitas menghambat pertumbuhan bakteri dari ekstrak dan fraksi spons Leucetta chagosensis. terhadap pertumbuhan bakteri Gram positif Staphylococcus aureus dan Gram negatif Escherichia coli. Sampel di ekstraksi menggunakan metode maserasi dengan pelarut etanol 95% lalu di fraksinasi dengan menggunakan 3 pelarut dengan tingkat kepolaran yang berbeda yaitu metanol, n-heksan dan kloroform. Uji aktivitas menggunakan metode disk diffusion agar Kirby dan Bauer.  Hanya fraksi MeOH yang mampu menghambat pertumbuhan bakteri E.coli dengan zona hambat rata-rata 6,88 mm. Sedangkan terhadap bakteri S.aureus ekstrak dan semua fraksi menunjukan aktifitas menghambat pertumbuhan bakteri dengan rata-rata zona hambat masing-masing EtOH (6,61 mm), CHCl3 (6,68 mm), n-Heksan (7,83 mm), dan MeOH (8,00 mm). Semua aktivitas yang ditunjukan dikategorikan lemah (weak).Kata kunci : Antibakteri, Leucetta chagosensis, Staphylococcus aureus,  Escherichia coli


2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Alce Magani ◽  
Trina Tallei ◽  
Beivy Kolondam

Uji Antibakteri Nanopartikel Kitosan terhadap Pertumbuhan Bakteri Staphylococcus aureus dan Escherichia coli.(Antibacterial Test of Chitosan Nanoparticles against Staphylococcus Aureus and Escherichia coli) Alce K. Magani*, Trina E. Tallei, Beivy J. KolondamProgram Studi Biologi, FMIPA Universitas Sam Ratulangi, Manado 95115*Email korespondensi: [email protected] (Article History: Received 30-12-2019; Revised 15-01-2020; Accepted 23-01-2020) Abstrak Antibakteri merupakan zat yang dapat menghambat pertumbuhan bakteri dan dapat membunuh bakteri penyebab infeksi. Staphylococcus aureus dan Escherichia coli merupakan bakteri Gram positif dan Gram negatif yang dapat menimbulkan infeksi atau penyakit dalam tubuh. Penelitian ini bertujuan untuk menguji aktivitas bakteri patogen dengan memakai nanopartikel kitosan sebagai antibakteri yang dibuat dalam empat konsentrasi (0,5%, 1%, 1,5% dan 2%) serta penggunaan kontrol asam asetat 1%, ciprofloxacin dan air steril sebagai pembanding. Metode penelitian yang digunakan yaitu metode gelasi ionik untuk pembuatan nanopartikel kitosan dan difusi agar untuk pengujian antibakteri. Data dianalisis dengan One Way Anova yang dilanjutkan dengan metode BNT (Beda Nyata Terkecil). Hasil penelitian diperoleh penghambatan pertumbuhan bakteri S. aureus dan E. coli tertinggi pada konsentrasi 0,5%, dengan diameter zona hambat hari pertama sampai hari ketiga 12,31 mm, 9,98 mm, dan 20,46 mm pada S. aureus dan 15,88 mm, 18,71 mm, dan 20,43 mm pada E. coli, kategori kuat, dan bersifat bakteriostatik dan penghambatan terendah pada konsentrasi 2% dengan diameter zona hambat pada S. aureus yaitu 5,56 mm, 5,50 mm, dan 5,40 mm, dan pada E. coli yaitu 5,93 mm, 9,64 mm, dan 12,58 mm, kategori sedang, dan bersifat bakteriostatik. Kata kunci: Kitosan, nanopartikel kitosan, aktivitas antibakteri.  Abstract Antibacteria is a substance that can inhibit the growth of bacteria and able to kill bacteria that cause infections. Staphylococcus aureus and Escherichia coli are Gram positive and Gram negative bacteria that able to cause infections or diseases. This study aimed to examine the activity of pathogenic bacteria by using chitosan nanoparticles as antibacterial. The treatments were made in four concentrations (0.5%, 1%, 1.5% and 2%) and, for comparison, there were also acetic acid control, ciprofloxacin and sterile water. The research method used is the ionic gelation method for the manufacture of chitosan nanoparticles and agar diffusion for antibacterial testing. Data were analyzed with One Way Anova followed by LSD (Least Significant Difference) method. The results showed the highest inhibition of growth of S. aureus and E. coli bacteria at a concentration of 0.5%, with a diameter of inhibition zones of the first day to the third day of 12.31 mm, 9.98 mm, and 20.46 mm in S. aureus and 15,88 mm, 18,71 mm, and 20,43 mm in E. coli, the strong category, and are bacteriostatic and the lowest inhibition was at 2% concentration with inhibition zone diameters in S. aureus namely 5.568 mm, 5.50 mm, and 5, 40 mm, and in E. coli, 5.93 mm, 9.63 mm and 12.58 mm, the medium category and bacteriostatic.Key words: Chitosan, nanoparticles chitosan, antibacterial activity.


2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Alce K Magani ◽  
Trina E Tallei ◽  
Beivy J Kolondam

Uji Antibakteri Nanopartikel Kitosan terhadap Pertumbuhan Bakteri Staphylococcus aureus dan Escherichia coli.(Antibacterial Test of Chitosan Nanoparticles against Staphylococcus aureus and Escherichia coli) Alce K. Magani*, Trina E. Tallei, Beivy J. KolondamProgram Studi Biologi, FMIPA Universitas Sam Ratulangi, Manado 95115*Email korespondensi: [email protected] (Article History: Received 30-12-2019; Revised 15-01-2020; Accepted 23-01-2020) Abstrak Antibakteri merupakan zat yang dapat menghambat pertumbuhan bakteri dan dapat membunuh bakteri penyebab infeksi. Staphylococcus aureus dan Escherichia coli merupakan bakteri Gram positif dan Gram negatif yang dapat menimbulkan infeksi atau penyakit dalam tubuh. Penelitian ini bertujuan untuk menguji aktivitas bakteri patogen dengan memakai nanopartikel kitosan sebagai antibakteri yang dibuat dalam empat konsentrasi (0,5%, 1%, 1,5% dan 2%) serta penggunaan kontrol asam asetat 1%, ciprofloxacin dan air steril sebagai pembanding. Metode penelitian yang digunakan yaitu metode gelasi ionik untuk pembuatan nanopartikel kitosan dan difusi agar untuk pengujian antibakteri. Data dianalisis dengan One Way Anova yang dilanjutkan dengan metode BNT (Beda Nyata Terkecil). Hasil penelitian diperoleh penghambatan pertumbuhan bakteri S. aureus dan E. coli tertinggi pada konsentrasi 0,5%, dengan diameter zona hambat hari pertama sampai hari ketiga 12,31 mm, 9,98 mm, dan 20,46 mm pada S. aureus dan 15,88 mm, 18,71 mm, dan 20,43 mm pada E. coli, kategori kuat, dan bersifat bakteriostatik dan penghambatan terendah pada konsentrasi 2% dengan diameter zona hambat pada S. aureus yaitu 5,56 mm, 5,50 mm, dan 5,40 mm, dan pada E. coli yaitu 5,93 mm, 9,64 mm, dan 12,58 mm, kategori sedang, dan bersifat bakteriostatik. Kata kunci: Kitosan, nanopartikel kitosan, aktivitas antibakteri.  Abstract Antibacteria is a substance that can inhibit the growth of bacteria and able to kill bacteria that cause infections. Staphylococcus aureus and Escherichia coli are Gram positive and Gram negative bacteria that able to cause infections or diseases. This study aimed to examine the activity of pathogenic bacteria by using chitosan nanoparticles as antibacterial. The treatments were made in four concentrations (0.5%, 1%, 1.5% and 2%) and, for comparison, there were also acetic acid control, ciprofloxacin and sterile water. The research method used is the ionic gelation method for the manufacture of chitosan nanoparticles and agar diffusion for antibacterial testing. Data were analyzed with One Way Anova followed by LSD (Least Significant Difference) method. The results showed the highest inhibition of growth of S. aureus and E. coli bacteria at a concentration of 0.5%, with a diameter of inhibition zones of the first day to the third day of 12.31 mm, 9.98 mm, and 20.46 mm in S. aureus and 15,88 mm, 18,71 mm, and 20,43 mm in E. coli, the strong category, and are bacteriostatic and the lowest inhibition was at 2% concentration with inhibition zone diameters in S. aureus namely 5.568 mm, 5.50 mm, and 5, 40 mm, and in E. coli, 5.93 mm, 9.63 mm and 12.58 mm, the medium category and bacteriostatic.Key words: Chitosan, nanoparticles chitosan, antibacterial activity.


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