Microorganisms Isolated from Stored Meat in India, with Potential Antimicrobial Activity against Food Pathogens

2019 ◽  
Vol 20 (5) ◽  
pp. 401-409 ◽  
Author(s):  
Gokila Thangavel ◽  
Subramaniyan Thiruvengadam

Background:World Health Organization has estimated that 1 in 10 people fall ill and 4, 20, 000 die every year from eating contaminated food. Food pathogens like Escherichia, Salmonella, Staphylococcus and Listeria pose a serious threat to human health.Objective:The objective was to isolate microbes from meat stored at refrigerated conditions and evaluate the antimicrobial activity of the cell-free supernatant against food pathogens.Methods:Chicken and Pork samples were procured and stored at refrigerated conditions (4-7ºC) for 2 weeks. The samples were plated on to Nutrient agar (NA) and De Man, Rogosa and Sharpe (MRS) agar for isolation of aerobic and lactic acid bacteria. Cell-free supernatants of the isolates were screened for antimicrobial activity against Escherichia coli, Salmonella typhimurium, Listeria monocytogenes and Staphylococcus aureus by microtiter plate assay. The 5 most - effective strains were screened for hemolytic activity and identified by 16s rRNA sequencing.Results:A total of 110 strains were isolated, out of which the top 5 most - effective strains were all from MRS agar. They showed 88-90% inhibition against E. coli and S. typhimurium, whereas 60 to 70 % against S. aureus and L. monocytogenes. These strains were found to be non - hemolytic and were identified as Leuconostoc spp. namely, L. mesenteroides subsp. mesenteroides J18, CP003101; L. mesenteroides LM2; L. mesenteroides ATCC 8293, CP000414; L. gelidum subsp. gasicomitatum LM G 18811 and L. mesenteroides; LM2, AY675249.Conclusion:Leuconostoc are known to be effective in controlling foodborne pathogens and therefore, these strains have the potential for application in food and human.

2021 ◽  
Author(s):  
◽  
Joshua J Carter

AbstractThe World Health Organization goal of universal drug susceptibility testing for patients with tuberculosis is most likely to be achieved through molecular diagnostics; however, to date these have focused largely on first-line drugs, and always on predicting binary susceptibilities. Here, we used whole genome sequencing and a quantitative microtiter plate assay to relate genomic mutations to minimum inhibitory concentration in 15,211 Mycobacterium tuberculosis patient isolates from 27 countries across five continents.This work identifies 449 unique MIC-elevating genetic determinants across thirteen drugs, as well as 91 mutations resulting in hypersensitivity for eleven drugs. Our results provide a guide for further implementation of personalized medicine for the treatment of tuberculosis using genetics-based diagnostics and can serve as a training set for novel approaches to predict drug resistance.


2021 ◽  
Vol 5 ◽  
Author(s):  
Constanza Díaz-Gavidia ◽  
Francisca P. Álvarez ◽  
Jose M. Munita ◽  
Sandra Cortés ◽  
Andrea I. Moreno-Switt

Antimicrobial resistance is one of the most important public health concerns—it causes 700,000 deaths annually according to the World Health Organization (WHO). Enterobacterales such as E. coli and Klebsiella pneumoniae, have become resistant to many relevant antimicrobials including carbapenems and extended spectrum cephalosporins. These clinically relevant resistant Enterobacterales (CRRE) members are now globally distributed in the environment including different food types (meats, produce, dairy). Unlike known foodborne pathogens, CRRE are not usually part of most food surveillance systems. However, numerous reports of CRRE highlight the importance of these bacteria in food and have been shown to contribute to the overall crisis of antimicrobial resistance. This is especially important in the context of carriage of these pathogens by immuno-compromised individuals. CRRE infections upon consumption of contaminated food could colonize the human gastrointestinal tract and eventually be a source of systemic infections such as urinary tract infections or septicemia. While different aspects need to be considered to elucidate this, whole genome sequencing along with metadata could be used to understand genomic relationships of CRRE obtained from foods and humans, including isolates from clinical infections. Once robust scientific data is available on the role of CRRE in food, countries could move forward to better survey and control CRRE in food.


Foods ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 206 ◽  
Author(s):  
Juliane Dao ◽  
Kathrin Stenchly ◽  
Oumar Traoré ◽  
Philip Amoah ◽  
Andreas Buerkert

Vegetable production in urban gardens of Ouagadougou contributes to food security, but water for irrigation is often of low quality. This is particularly acute if irrigation water is taken from wastewater polluted channels. This study aimed at (i) verifying to what degree irrigation water quality is correlated with contamination of lettuce with Escherichia coli, total coliforms, and Salmonella spp., and (ii) assessing effects of post-harvest handling on pathogen development during the trade chain. We tested pathogen removal efficiency on lettuce by applying post-harvest washing. Irrigation water of production areas in Ouagadougou (n = 10) showed a mean E. coli load of 2.1 × 105 CFU 100 mL−1. In 60% of the cases, irrigation water did not meet the standards of the World Health Organization (WHO) for safe irrigation water, and in 30% of the cases, irrigation water was contaminated with Salmonella spp. Loads of total coliforms on lettuce leaves ranged from 2.9 × 103 CFU g−1 to 1.3 × 106 CFU g−1, while E. coli averaged 1.1 × 102 CFU g−1. Results on post-harvest handling revealed that microbial loads increased along the trade chain. Overall, half of all lettuce samples (n = 60) were tested positively for Salmonella spp. The experiment showed that appropriate post-harvest handling could prevent the increase of total coliforms.


2014 ◽  
Vol 13 (2) ◽  
pp. 446-458 ◽  
Author(s):  
Florentina Zurita ◽  
Alejandra Carreón-Álvarez

Three pilot-scale two-stage hybrid constructed wetlands were evaluated in order to compare their efficiency for total coliforms (TCol) and Escherichia coli removal and to analyze their performances in two 1-year periods of experimentation. System I consisted of a horizontal flow (HF) constructed wetland (CW) followed by a stabilization pond. System II was also configured with a HF CW as a first stage which was then followed by a vertical flow (VF) CW as a second stage. System III was configured with a VF CW followed by a HF CW. In the first year of evaluation, the HF–VF system was the most effective for TCol removal (p < 0.05) and achieved a reduction of 2.2 log units. With regard to E. coli removal, the HF–VF and VF–HF systems were the most effective (p < 0.05) with average reductions of 3.2 and 3.8 log units, respectively. In the second year, the most effective were those with a VF component for both TCol and E. coli which underwent average reductions of 2.34–2.44 and 3.44–3.74 log units, respectively. The reduction achieved in E. coli densities, in both years, satisfy the World Health Organization guidelines that require a 3–4 log unit pathogen reduction in wastewater treatment systems.


Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 14 ◽  
Author(s):  
Angélique Rousseau ◽  
Stéphanie La Carbona ◽  
Aurélien Dumètre ◽  
Lucy J. Robertson ◽  
Gilles Gargala ◽  
...  

Giardia duodenalis, Cryptosporidium spp. and Toxoplasma gondii are protozoan parasites that have been highlighted as emerging foodborne pathogens by the Food and Agriculture Organization of the United Nations and the World Health Organization. According to the European Food Safety Authority, 4786 foodborne and waterborne outbreaks were reported in Europe in 2016, of which 0.4% were attributed to parasites including Cryptosporidium, Giardia and Trichinella. Until 2016, no standardized methods were available to detect Giardia, Cryptosporidium and Toxoplasma (oo)cysts in food. Therefore, no regulation exists regarding these biohazards. Nevertheless, considering their low infective dose, ingestion of foodstuffs contaminated by low quantities of these three parasites can lead to human infection. To evaluate the risk of protozoan parasites in food, efforts must be made towards exposure assessment to estimate the contamination along the food chain, from raw products to consumers. This requires determining: (i) the occurrence of infective protozoan (oo)cysts in foods, and (ii) the efficacy of control measures to eliminate this contamination. In order to conduct such assessments, methods for identification of viable (i.e. live) and infective parasites are required. This review describes the methods currently available to evaluate infectivity and viability of G. duodenalis cysts, Cryptosporidium spp. and T. gondii oocysts, and their potential for application in exposure assessment to determine the presence of the infective protozoa and/or to characterize the efficacy of control measures. Advantages and limits of each method are highlighted and an analytical strategy is proposed to assess exposure to these protozoa.


2014 ◽  
Vol 70 (1) ◽  
pp. 108-113 ◽  
Author(s):  
N. D. Miranda ◽  
E. L. Oliveira ◽  
G. H. R. Silva

The purpose of this research was to study the disinfection of sanitary effluent from constructed wetlands, evaluating the oxidation of organic matter, the formation of formaldehyde, as well as the efficiency of total coliforms and Escherichia coli inactivation. A constant flow of ozone was applied to the batch system in 5 and 10 mg.O3 L−1 doses with contact times of 5 and 10 min. This study revealed that the average values of formaldehyde formation ranged between 259.00 and 379.00 μg L−1, which means that the values are within World Health Organization recommended values. The total coliforms and E. coli showed complete inactivation in almost all tests. The dose of ozone 5 mg.O3 L−1 and contact time of 5 min were sufficient for a significant reduction of the concentration levels of pathogens in constructed wetlands effluent with similar characteristics, thus allowing for its agricultural reuse.


2019 ◽  
Author(s):  
Jenny Yijian Huang

AbstractBackgroundAccording to the World Health Organization, nearly 15% of all hospitalized patients worldwide acquire nosocomial infections. A particular area of concern for bacterial build up in hospitals is sink drains. The moist, microbiologically active environment of drains promotes the formation of biofilms that are difficult to target with standard chemical disinfectants. Bacteriophages, however, show potential to be used as disinfecting agents in hospital drains. Not only do bacteriophages increase in titer as they infect, spreading to hard-to-reach surfaces, phages have been shown to degrade the extracellular matrix of biofilms and gain access to underlying bacteria. This research explores the potential of bacteriophages to eradicate biofilms in an environment modeling a sink drain by comparing the efficacy, range, and durability of bacteriophage to a chemical disinfectant.MethodsE. coli biofilms were grown in M9 minimal media placed in sink P-traps assigned one of three treatments: chemical disinfectant, bacteriophage, or deionized water (control). Biofilms were quantified at five time points -- 1, 12, 24, 36, and 48 hours -- using the crystal violet assay.ResultsBoth chemical disinfectant and bacteriophage significantly decreased the optical densities of biofilms (p < 0.001***). P-traps treated with bacteriophages showed more uniform destruction of biofilm across P-trap compared to chemical disinfectant (p < 0.01**). A trend may suggest that over time bacteriophage became more effective at reducing biofilm than chemical disinfectant.ConclusionThis work highlights the potential of bacteriophage as an alternative to conventional chemical disinfectants for biofilm control in settings such as hospital drains.ImportanceNosocomial infections prolong hospital stay, costing the U.S. healthcare system $5-10 billion annually. An increasing number of reports demonstrate that sink drains -- reservoirs for multidrug resistant bacteria -- may be a source of hospital-related outbreaks. Recent studies have elucidated the mechanism of dispersal of bacteria from contaminated sinks to patients, but limited data are available identifying disinfecting methods for hospital drains. Not only did this study demonstrate that bacteriophages could reduce biofilms on sink drains just as effectively as a commercial disinfectant, it showed that phages tended to spread more thoroughly across P-traps and may work for longer. With hand-washing an imperative activity for disease prevention, hospital sinks should remain clean. This work explores an alternative disinfecting method for hospital sink drains.


2020 ◽  
Author(s):  
Sara Abdollahi ◽  
Mohammad Hossein Morowvat ◽  
Amir Savardashtaki ◽  
Cambyz Irajie ◽  
Sohrab Najafipour ◽  
...  

Abstract Escherichia coli is one of the most preferred host microorganisms for the production of recombinant proteins due to its well-characterized genome, availability of various expression vectors and host strains. Choosing a proper host strain for the overproduction of a desired recombinant protein is very important because of the diversity of genetically modified expression strains. This study attempted to evaluate the five host strains including BL21 (DE3), Rosetta (DE3), DH5α, XL1-BLUE and SHuffle in terms of arginine deiminase (ADI) production and enzyme activity. Arginine deiminase (ADI) was chosen a bacterial enzyme which degrades L-arginine. It is effective in treatment of some types of human cancers like melanoma and hepatocellular carcinoma (HCC) which are arginine-auxotrophic. Five mentioned E. coli strains were cultivated. The pET-3a was used as the expression vector. The competent E. coli cells were obtained through CaCl 2 method. It was then transformed with the construct of pET3a-ADI using heat shock strategy. The ADI production levels were examined by 10% SDS-PAGE analysis. The ability of host strains for expression of the requested recombinant protein was compared. The enzymatic activity of the obtained recombinant ADI from each studied strain was assessed by a colorimetric 96-well microtiter plate assay. All the five strains exhibited a significant band at 46 kDa. BL21 (DE3) produced the highest amount of ADI protein followed by Rosetta (DE3). The following activity assay showed that ADI from BL21 (DE3) and Rosetta (DE3) had the most activity. There are some genetic and metabolic differences among the various E. coli strains, leading to differences in the amount of recombinant protein production. The results of this study can be used for the efficacy evaluation of the five studied strains for the production of similar pharmaceutical enzymes. The strains also could be analyzed in terms of proteomics.


Author(s):  
Yebpella G.G ◽  
Magomya A.M ◽  
Hikon B.N ◽  
Joshua Y ◽  
Gani J

Heavy metals accumulation in biological system are by inhalation of contaminated air, intake of contaminated food or drinking water has been considered to be an ecological menace to man and other organisms. This study was carried out to ascertain the pollution status of Cr, Pb, Zn, Cu and Cd in sediment of Akata Lake, Katsina- Ala Benue State, Nigeria. Sediment samples were collected, digested using 30% H2O2 followed by 0.5M HCl and the metal concentrations were determined with Varian AA240 Atomic absorption spectrophotometer equipped with Zeeman’s background correction (Varian, New Jersey, USA). The mean level of the heavy metals, Pb, Zn, Cu, Cd and Cr are 31.05, 2.72, 19.22 and 0.88 mg/kg while the concentration of Cr was below the detection limit of the instrument. The values obtained were compared with the established soil and sediment standard by World Health Organization (WHO). The contamination factors value for Zn, Cu and Cd are <1 while that of Pb is >1, hence it shows that the sediment is polluted by lead. The pollution load index (PLI) and Geo-accumulation index (Igeo) levels for Cr, Zn, Cu, Cd heavy metals in sample A - E were less than 1 except for Pb which is >1, this show that, the sediment were polluted with Pb.


Author(s):  
Okere J. Kelechi ◽  
Azorji J. Nnawuike ◽  
Iheagwam S. Kelechi ◽  
Emeka J. Emmanuel ◽  
Nzenwa P. Odinaka

Water pollution is a global problem. The study was carried out to assess the microbial constituents in water and sediment of Rivers Otamiri and Nworie during dry and rainy seasons (March and September, 2020) with comparison to WHO benchmark for drinking water .Samples were randomly collected at six (6) sampling points and analyzed using routine microbiological protocols.  The results revealed detectable amount of microbial activates in surface water of both rivers during the dry and rainy season. During the rainy season, a THB bioload average of 2.02x104 and 5.1x104CFU/mL for Nworie and Otamiri river respectively were measured. For the TCC, the average was 9.8x103 and 2.5x104 CFU/mL, while in the dry period there was corresponding reduction in the bioload value for both rivers. THB average value for Nworie river was 1.34x104 CFU/mL, with corresponding 3.5x104 values for Otamiri river, while in same inclination, TCC measured 6.1x103 and 1.8x104 CFU/mL. There were noteworthy variations in the values for the two rivers as well as in the two seasons. TBC value for Otamiri measured about 1.5 folds than the value for Nworie. In same trend, TCC value for Nworie measured about 39%. All values measured were above WHO permissible limit for drinking water. The biochemical and cultural features of the isolated microorganism in water showed the presence of E. coli identified in the entire stations (100%), Salmonella and faecal coliform occurred 83.3% each, while Vibrio and Shigella were detected in 4 of the 6 stations. The mean total bacterial count, total coliform count and total E. coli, were not in conformity with World Health Organization (WHO) Standard for drinking water and thus constitute a threat to the River; these were attributed to indiscriminate waste dumps around the rivers. The study underscores the need for adequate waste management system to forestall outbreak of pathogenic diseases in the area.


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