scholarly journals Effect of citric acid at different pH on the survival of Escherichia coli

2021 ◽  
Vol 14 (1) ◽  
pp. 79-84
Author(s):  
A. Mahe ◽  
B. Sabiu ◽  
A.A. Adam ◽  
U.Z. Abdullahi,
Keyword(s):  
Citric Acid ◽  
Biochemical Tests ◽  
Food Material ◽  
Food Preservatives ◽  
E Coli ◽  
Significant Difference ◽  
Polymerase Chain ◽  
The Difference ◽  
Ph Level ◽  
Negative Controls

Microorganisms are included among the major spoilers of food, they achieve this by using the nutrients present in food material. Susceptibility of microorganisms to the most currently used preservatives has been decreasing. Organic acids have been considered as valuable food preservatives. This study aimed to isolate, identify and determine the effect of citric acid at different pH levels on the survival of E. coli. The E. coli was isolated and a pure culture was obtained after series of sub-ulturing on Eosine Methylene Blue agar. The biochemical tests known as IMViC were performed to confirm the presence of the organism. The organism was also identified using polymerase chain reaction (PCR) in which the DNA was extracted, amplified and viewed by gel electrophoresis. The organism was then inoculated in nutrient broth containing citric acid at pH levels of 3.0, 4.5 and 6.0 in different test tubes. Negative controls were included. Results were analyzed using one way ANOVA to compare the means obtained. Results obtained was positive for indole and methyl red tests but negative for VogesProskauer and citrate tests which confirmed the organism. After 24 hours of inoculation, the results of spectrophotometry showed that at pH level of 3.0, the absorbance was lower than the results obtained at pH level of 4.5 and 6.0. This is an indication of higher reduction in the count of the organism at pH of 3.0. There was significant difference between the control and the test groups (p<0.05) but the difference obtained between the test groups were not significant (p>0.05). Results from this study showed that citric acid could not eliminate the whole organism but was effective in inhibiting the growth of the organism dependent on pH level. This indicates that a pH dependent citric acid can be used as a good preservative.

scholarly journals Prevalence ofPlasmodium falciparumParasitaemia and Its Correlation with Haematological Parameters among HIV-Positive Individuals in Nigeria

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Olusola Ojurongbe ◽  
Oluwatoyin Adeola Oyeniran ◽  
Oyebode Armstrong Terry Alli ◽  
Sunday Samuel Taiwo ◽  
Taiwo Adetola Ojurongbe ◽  
...  
Keyword(s):  
Haemoglobin Concentration ◽  
Malaria Parasitaemia ◽  
Cd4 Cell Count ◽  
Significant Difference ◽  
Parasite Detection ◽  
Important Health ◽  
The Mean ◽  
Polymerase Chain ◽  
The Difference ◽  
Cd4 Cell

Malaria and HIV are the two most important health challenges of our time. Haematologic abnormalities are features inPlasmodium falciparuminfection, and anaemia is a well-known outcome. The prevalence and haematological impact ofP. falciparumparasitaemia were determined among HIV-infected individuals in Nigeria. Parasite detection was carried out using microscopy and Polymerase Chain Reaction (PCR). Haemoglobin concentration was determined using an automated machine while CD4+ T-cells count was analyzed using flow cytometer. Thirty-seven (18.5%) out of the 200 HIV individuals enrolled had malaria parasites detected in their blood. All the positive cases were detected by PCR while only 20 (10%) were detected by thick blood microscopy. The mean haemoglobin concentration and packed cell volume (PCV) of HIV individuals with malaria parasitaemia were lower compared to those without malaria parasitaemia but the difference was not statistically significant. Also no significant difference was observed in malaria positivity in respect to sex and mean CD4+ cell count. The study highlights the effects ofP. falciparumparasitaemia on the haematologic and immune components of HIV individuals.

scholarly journals Relationship of Sanitation Parameters with Microbial Diversity and Load in Raw Meat from the Outlets of the Metropolitan City Biratnagar, Nepal

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Sanjay Mahato
Keyword(s):  
Bacterial Contamination ◽  
Fungal Contamination ◽  
Raw Meat ◽  
E Coli ◽  
Significant Difference ◽  
The Difference ◽  
Meat Samples ◽  
Relationship Of ◽  
Operating Methods ◽  
Microbiological Procedures

The main aim of this study is to assess the microbial load of raw meat from outlets of Biratnagar and its relationship with several sanitation parameters. Samples were taken from meat outlets, and required microbiological procedures were followed as per guidelines. Approximately 63.6% of microbes were present in meat with poor sanitation while 36.4% were present in meat with good sanitation. Fungal contamination in poorly kept mutton was one and half times greater than chicken/mutton of good sanitation. Fungi such asPenicillium(21.3%),Mucor(16.3%),Aspergillus(15%), andTrichosporon(13.8%) were most predominant. 73.8% of meat samples containedStaphylococcusspp., 61.3% containedE. coli,48.8% ofPseudomonasspp., and 37.5% samples containedSalmonellaspp. Outlets selling both types of meat showed no significant difference in microbial types. Mean of TVC of meat is 8.2 log CFU/g. Mean TVC of mutton (7.6 log CFU/g) is lower than mean TVC of chicken/meat (8.5 log CFU/g) and differed significantly. Tiled outlets showed comparatively lower bacterial contamination than cemented outlets which was statistically significant (t = −3.16,p=0.002). With the difference among microbial type and few sanitation parameters being statistically significant, it can be suggested that outlets should be tiled (p=0.002), showcased (p=0.001), and the meat-handling employee must wear washed apron (p=0.013). Proper cleaning of water supply and use area (p≤0.001) and drainage (p=0.048) maintain a good meat sanitation (p≤0.001) which reduces microbial contamination significantly. To diminish microbiological load on meat sold in the Biratnagar city, standard operating methods should be practiced.

scholarly journals The interaction of Gram negative bacteria and S. mansoni in mice with experimental Schistosomiasis

1980 ◽  
Vol 75 (1-2) ◽  
pp. 161-172 ◽  
Author(s):  
Heonir Rocha ◽  
Vanete S. Oliveira ◽  
Moema Magnavita G. de Oliveira
Keyword(s):  
Portal System ◽  
Saline Control ◽  
Control Group ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Sterile Saline ◽  
E Coli ◽  
Significant Difference ◽  
The Difference ◽  
Gram Negative Organisms

Animals (122 mice) were infected each with eighty cercariae of S. mansoni and subsequently challenged intravenously eight weeks later with the following gram-negative organisms. S. typhi, E. coli, Klebsiella-enterobacter species, Proteus mirabilis and Pseudomonas aeruginosa. Enumeration of bacteria in the liver, spleen and blood and S. mansoni from the portal sistem was performed from one to four weeks later in infected animals. A significant difference between infection produced by S. typhi and other gram negative organisms was observed: S. typhi persisted longer in the spleen and liver and could be recovered from S. mansoni worms up to three weeks following bacterial infection. Other gram negative bacteria disappeared from S. mansoni worms after two weeks of initial challenge. Additional animals (51 mice) infected with S. mansoni were given S. typhi, E. coli or sterile saline. After two weeks, animals were sacrificed and the recovery rate of worms from the portal system, and the mesenteric and hepatic oogram were determined. in animals infected with E. coli a significant decrease in the number of worms was observed compared to the saline control group; thirty worms were recovered in the control group compared to two worms in e. coli infected animals. In addition, the patterns of oviposition was significantly different in these latter animals suggesting complete inhibition of this process. Following S. typhi infection the difference in recovery of worms and pattern of oviposition was minimal. These findings suggest a difference in the interaction of various gram negative bacteria and S. mansoni and are consistent with the clinical observation of prolonged salmonella bacteremia in patients with schistosomiasis.

scholarly journals Detection of Enterococcus faecalis in Necrotic Teeth Root Canals by Culture and Polymerase Chain Reaction Methods

2007 ◽  
Vol 01 (04) ◽  
pp. 216-221 ◽  
Author(s):  
Dilsah COGULU ◽  
Atac UZEL ◽  
Ozant ONCAG ◽  
Semiha d AKSOY ◽  
Cemal ERONAT
Keyword(s):  
Polymerase Chain Reaction ◽  
Enterococcus Faecalis ◽  
Permanent Teeth ◽  
Deciduous Teeth ◽  
Chain Reaction ◽  
Test Species ◽  
Root Canals ◽  
Significant Difference ◽  
Polymerase Chain ◽  
The Difference

ABSTRACTObjectives: The aim of this study was to investigate the presence of Enterococcus faecalis in endodontic infections in both deciduous and permanent teeth by culture and polymerase chain reaction (PCR) methods.Methods: A total of 145 children aged 5-13 years old were involved in this study. The presence of E. faecalis in necrotic deciduous and permanent teeth root canals was studied using culture and polymerase chain reaction methods.Results: Among 145 molar teeth, 57% (n=83) presented necrotic asymptomatic pulp tissues and were included in this study. Culture and PCR methods detected the test species in 18 and 22 of 83 teeth involved, respectively. E. faecalis was cultured from 8 (18%) of 45 necrotic deciduous teeth and from 10 (26%) of 38 necrotic permanent teeth. PCR detection identified the target species in 10 (22%) and 12 (32%) of necrotic deciduous and permanent teeth respectively. Statistically significant difference in the presence of E. faecalis in deciduous and permanent teeth was found by culture and PCR methods (P=0.03 and 0.02, respectively). The difference in the presence of E. faecalis between two different methods was not statistically significant (P>.05).Conclusions: The results of the present study confirm that both culture and PCR methods are sensitive to detect E. faecalis in root canals. (Eur J Dent 2007;1:216-221)

scholarly journals Survival of Enterococcus faecalis in Mouse Peritoneal Macrophages

1999 ◽  
Vol 67 (5) ◽  
pp. 2160-2165 ◽  
Author(s):  
Claudia R. Gentry-Weeks ◽  
RoxAnn Karkhoff-Schweizer ◽  
Andreas Pikis ◽  
Monica Estay ◽  
Jerry M. Keith
Keyword(s):  
Enterococcus Faecalis ◽  
Brain Heart Infusion ◽  
Extended Period ◽  
Peritoneal Macrophages ◽  
Bacterial Cells ◽  
Infection Period ◽  
E Coli ◽  
Significant Difference ◽  
The Difference ◽  
Mouse Peritoneal Macrophages

ABSTRACT Enterococcus faecalis was tested for the ability to persist in mouse peritoneal macrophages in two separate studies. In the first study, the intracellular survival of serum-passaged E. faecalis 418 and two isogenic mutants [cytolytic strain FA2-2(pAM714) and non-cytolytic strain FA2-2(pAM771)] was compared with that of Escherichia coli DH5α by infecting BALB/c mice intraperitoneally and then monitoring the survival of the bacteria within lavaged peritoneal macrophages over a 72-h period. All E. faecalis isolates were serum passaged to enhance the production of cytolysin. E. faecalis 418, FA2-2(pAM714), and FA2-2(pAM771) survived at a significantly higher level (P = 0.0001) than did E. coli DH5α at 24, 48, and 72 h. Internalized E. faecalis 418, FA2-2(pAM714), and FA2-2(pAM771) decreased 10-, 55-, and 31-fold, respectively, over the 72-h infection period, while internalizedE. coli DH5α decreased 20,542-fold. The difference in the rate of survival of E. faecalis strains and E. coli DH5α was most prominent between 6 and 48 h postinfection (P = 0.0001); however, no significant difference in killing was observed between 48 and 72 h postinfection. In the second study, additional E. faecalisstrains from clinical sources, including DS16C2, MGH-2, OG1X, and the cytolytic strain FA2-2(pAM714), were compared with the nonpathogenic gram-positive bacterium, Lactococcus lactis K1, for the ability to survive in mouse peritoneal macrophages. In these experiments, the E. faecalis strains and L. lactis K1 were grown in brain heart infusion (BHI) broth to ensure that there were equal quantities of injected bacteria. E. faecalis FA2-2(pAM714), DS16C2, MGH-2, and OG1X survived significantly better (P < 0.0001) than did L. lactis K1 at each time point. L. lactis K1 was rapidly destroyed by the macrophages, and by 24 h postinfection, viable L. lactis could not be recovered. E. faecalis FA2-2(pAM714), DS16C2, MGH-2, and OG1X declined at an equivalent rate over the 72-h infection period, and there was no significant difference in survival or rate of decline among the strains. E. faecalis FA2-2(pAM714), MGH-2, DS16C2, and OG1X exhibited an overall decrease of 25-, 55-, 186-, and 129-fold respectively, between 6 and 72 h postinfection. The overall reduction by 1.3 to 2.27 log units is slightly higher than that seen for serum-passaged E. faecalis strains and may be attributable to the higher level of uptake of serum-passaged E. faecalis than of E. faecalis grown in BHI broth. Electron microscopy of infected macrophages revealed that E. faecalis 418 was present within an intact phagocytic vacuole at 6 h postinfection but that by 24 h the infected macrophages were disorganized, the vacuolar membrane was degraded, and the bacterial cells had entered the cytoplasm. Macrophage destruction occurred by 48 h, and the bacteria were released. In conclusion, the results of these experiments indicate that E. faecaliscan persist for an extended period in mouse peritoneal macrophages.

scholarly journals The Association between Helicobacter Pylori and Laryngopharyngeal Reflux in Laryngeal Pathologies

2012 ◽  
Vol 91 (3) ◽  
pp. E6-E9 ◽  
Author(s):  
Engin Çekin ◽  
Mustafa Ozyurt ◽  
Evren Erkul ◽  
Koray Ergunay ◽  
Hakan Cincik ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Laryngopharyngeal Reflux ◽  
Endoscopic Examination ◽  
Reflux Symptom Index ◽  
Symptom Index ◽  
Significant Difference ◽  
Laryngeal Lesions ◽  
Polymerase Chain ◽  
The Difference ◽  
H Pylori

We conducted a study to determine the presence or absence of Helicobacter pylori and laryngopharyngeal reflux (LPR) in 43 previously untreated patients who had presented with a laryngeal lesion. Our aim was to determine if there was any association among H pylori, LPR, and laryngeal lesions. H pylori status was determined by real-time polymerase chain reaction (PCR) assays of biopsy tissue obtained during direct laryngoscopy. The presence or absence of LPR was determined on the basis of patients’ reflux symptom index (RSI) and reflux finding score (RFS), which were based on their questionnaire responses and findings on endoscopic examination of the larynx, respectively. Patients with an RSI of 14 or more and/or an RFS of 8 or more were considered to have LPR. H pylori was present in 24 patients (55.8%) and absent in 19 (44.2%)—not a statistically significant difference. The prevalence of LPR was higher than the prevalence of H pylori; it was present in 30 patients (69.8%) and absent in 13 (30.2%). The difference was statistically significant (p = 0.01). We found no association between H pylori status and LPR status. Additionally, we analyzed two subgroups based on whether their lesions were benign or malignant/premalignant and found a significant relationship between LPR positivity and the presence of malignant/premalignant laryngeal lesions (p = 0.03). We found no association between H pylori status and either of the two subgroup categories.

Risk factors for antimicrobial resistance in Escherichia coli isolates from poultry in Haryana

2019 ◽  
Author(s):  
S. Kumar ◽  
R. Gupta
Keyword(s):  
Risk Factors ◽  
Bacterial Strains ◽  
Chain Reaction ◽  
Phylogenetic Groups ◽  
Class 1 Integron ◽  
E Coli ◽  
Economic Significance ◽  
Significant Difference ◽  
Class 1 ◽  
Polymerase Chain

Colibacillosis is a disease of severe economic significance to all poultry producers worldwide, characterized by a diverse array of lesions. Due to enormous exploitation of antibiotics in broilers, an increased number of resistant bacterial strains have developed in recent years. 106 E. coli strains were collected from broilers suffering from colibacillosis. The resistance to different classes of antimicrobials was determined. The presence of integrons was determined by Polymerase Chain Reaction (PCR). All the statistical analyses were carried out using STATA™. All the isolates were multidrug resistance (MDR), i.e. resistant to at least one agent in three or more antimicrobial categories. 37 (34.90%) isolates were found positive for Class 1 integrons. There was significant difference in carriage of integrons in different phylogentic groups, p=0.001, however, there was no difference among different serotypes for carriage of integrons. Significant difference was observed for resistance towards co-trimoxazole (p=0.002), piperacillin (p=0.034) and ciprofloxacin (p=0.046) in Class 1 integron carrying isolates and Class 1 integron negative isolates. Significant difference was observed for resistance towards ceftriaxone (p=0.004) and cefotaxime (p=0.027) in relation to phylogenetic groups. Also, significant difference was observed among different serotypes for resistance towards co-trimoxazole (p=0.001), gentamicin (p=0.005) and kanamycin (p=0.041).

An Improved Rapid Technique for Isolation of Escherichia coli O157:H7 from Foods

1995 ◽  
Vol 58 (1) ◽  
pp. 7-12 ◽  
Author(s):  
STEPHEN D. WEAGANT ◽  
JAMES L. BRYANT ◽  
KAREN G. JINNEMAN
Keyword(s):  
Escherichia Coli ◽  
Comparative Method ◽  
Immunomagnetic Separation ◽  
Latex Agglutination ◽  
Escherichia Coli O157 ◽  
Biochemical Tests ◽  
Isolation Technique ◽  
Selective Enrichment ◽  
E Coli ◽  
Polymerase Chain

A newly revised enrichment and agar-plating system was tested for selectivity and sensitivity in recovery of unstressed and cold-stressed Escherichia coli O157:H7 from foods. Various foods inoculated with known levels of enterohemorrhagic E. coli O157:H7 (EHEC) were tested by enrichment for 6 h at 37°C in modified tryptic soy broth (mTSB) base supplemented with vancomycin, cefsulodin and cefixime, referred to as EHEC enrichment broth (EEB). Subsequently, portions were spread-plated on sorbitol–MacConkey agar supplemented with tellurite and cefixime (TCSMAC). Further selective enrichment was also examined using immunomagnetic separation (IMS) from the EEB prior to spread-plating on TCSMAC agar. These methods were compared to a procedure of enrichment in mTSB (supplemented with novobiocin) at 37°C for 24 h followed by spread-plating of decimal dilutions on hemorrhagic colitis 4–methylumbelliferyl–B–D–glucuronide (HC–MUG) agar. The new enrichment isolation technique was found to be sensitive at a level of one EHEC organism per 10 g of food in four food types. This represents an approximate l00-fold to 1,000-fold enhancement in sensitivity over the comparative method for foods with high levels of competitive microflora. These enrichment-isolation protocols also were compared in analysis of naturally contaminated raw or undercooked ground beef samples implicated in foodborne illness. EEB-TCSMAC with and without IMS were combined with rapid biochemical tests, and with O157 latex agglutination and confirmation of toxin genes by polymerase chain reaction (PCR) to provide a completed test within 30 h of initiating testing. The new system was successful in 15 of 17 samples, where only 6 of 17 were found positive by the comparative technique.

scholarly journals Isolation and characterization E. coli O157:H7 from meat &cheese and detection of Stx1, Stx2, hlyA, eaeA by using multiplex PCR

2011 ◽  
Vol 5 (2) ◽  
pp. 15-24
Author(s):  
Shatha T. Ahmed ◽  
Amina N. Jasim ◽  
Ayad M. Ali
Keyword(s):  
Escherichia Coli ◽  
Diagnostic System ◽  
Latex Agglutination ◽  
Diagnostic Methods ◽  
Bacterial Isolates ◽  
Biochemical Tests ◽  
E Coli ◽  
Isolation And Characterization ◽  
Minced Beef ◽  
Polymerase Chain

total of 189 samples were collected from 74 raw uncooked minced beef meat, 115 local white cheeses from 3 different areas in Baghdad. All samples were surveyed and examined for the presence of the Escherichia coli O157:H7 and differentiate it from other Non -Sorbitol Fermenting Escherichia coli (NSF E. coli). The Bacterial isolates were identified by using morphological diagnostic methods; Samples were cultured on liquid enrichment medium, incubated at 41.5Cº for 6 hrs, and then cultured on Cefixime Tellurite -Sorbitol MacConkey Agar (CT- SMAC). 66 non-sorbitol fermenting bacterial isolates were obtained of which 13 were identified as Escherichia coli from (6 meat and 7 cheese samples). By using traditional biochemical tests and Api20E diagnostic system without differentiation between serotype O157:H7 and other NSF E. coli isolates. Four specific biochemical tests (Cellobiose fermentation, β-Glocuronidase production, KCN and Enterohemolysin production) were done to differentiate serotype O157 differentiation from other NSF bacteria. Only 2 isolates belonging to the serotype O157 were obtained of which one isolate from meat and other isolate from cheese. Latex agglutination test for O157 and H7 showed that the 5 isolates gave positive results with both kits. The Bacterial isolates were identified by using Multiplex Polymerase Chain Reaction (MPCR) technology for the presence or absence of 4 genes (Stx1, Stx2, hlyA and eaeA) that encode for main virulence factors to diagnose E. coli O157:H7 isolated from various sources by using specific primers in mPCR. The result showed that gene content variety in two E. coli O157:H7 isolates, 1 from meat contain all 4 genes and other isolate from cheese contains 2 genes: Stx1 and hlyA .

scholarly journals PENGARUH WAKTU POLISHING DAN ASAM SITRAT TERHADAP MICROLEAKAGE PADA TUMPATAN RESIN KOMPOSIT NANOFILLER AKTIVASI LIGHT EMITING DIODE - In Vitro

2015 ◽  
Vol 1 (1) ◽  
pp. 11
Author(s):  
Dhurohmah . ◽  
Rochman Mujayanto ◽  
Siti Chumaeroh
Keyword(s):  
Citric Acid ◽  
Composite Resin ◽  
Distilled Water ◽  
Test Results ◽  
Class V ◽  
Group I ◽  
Significant Difference ◽  
Composite Resin Restoration ◽  
The Difference

Background: The objective of this research is to investigate influence of polishing time and citric acid on microleakage in nanofiller composite resin restoration (Z350XT,3M). Method: The research was conducted on a class V restoration amount sample 24 on bovine teeth. The first group restoration was polished immediately after curing then was soaked in distilled water. The second group was polished immediately after curing and then was soaked in citric acid.The third group was polished after 24 hours of curing and then was soaked in distilled water. The fourth group was polished after 24 hours of curing then was soaked in citric acid. Samples were immersed for 7 days and then were soaked in methylene blue for 1 day and were split longitudinally and were observed using microskopstereo and were measured using calipers. Result: Data were analized by Kruskal-wallis with the result of p > 0,05, there is a significant difference in group I, II, III, and IV. Mann- Whitney test results the difference between the data. Conclusion: The conclution is there were significant differences between the groups which immersed with citric acid of distilled water and there is no significant difference between groups which polished immediately and polished 24 hours later.

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