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The dynamics of the composition and antibiotic resistance of the fecal coliform bacteria (FCB) in a typical wastewater treatment plant (WWTP) were investigated concerning the seasonal changes. Results showed that WWTP could remove the FCB concentration by 3â¼5 logs within the effluent of 104â¼105 CFU/L, but the antibiotic resistant rate of FCB species increased significantly after WWTP. The dominant FCB changed from Escherichia coli in the influent (â¼73.0%) to Klebsiella pneumoniae in the effluent (â¼53.3%) after WWTP, where the Escherichia coli was removed the most, while Klebsiella pneumoniae was the most persistent. The secondary tank removed the most of FCB (by 3â¼4 logs) compared to other processes, but increased all the concerned antibiotic resistant rate. The potential super bugs of FCB community showing resistance to all the target antibiotics were selected in the biological treatment unit of WWTP. The FCB showed the highest multiple antibiotic resistance (92.9%) in total which even increased to 100% in the effluent. Klebsiella has the highest antibiotic resistant rate in FCB, with a multiple antibiotic resistance rate of 98.4%. These indicated that the Klebsiella pneumoniae not just Escherichia coli should be specially emphasized after WWTP concerning the health risk associated with FCB community.
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Escherichia coli , Heces , Eliminación de Residuos Líquidos , Aguas Residuales , Aguas Residuales/microbiología , Eliminación de Residuos Líquidos/métodos , Heces/microbiología , Escherichia coli/efectos de los fármacos , Antibacterianos/farmacología , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/aislamiento & purificación , Farmacorresistencia Bacteriana , Microbiología del Agua , Klebsiella pneumoniae/efectos de los fármacosRESUMEN
This study focused on the removal of the total coliforms, fecal coliforms and four target antibiotics in the dissolved ozone flotation (DOF) thickening sludge process. Additionally, the thickened effluent chromaticity and its effect on thickened sludge hydrolysis process were investigated. Ozonation in the DOF process could inactivate coliforms by oxidizing cellular components and destroying genetic material, as well as altering the chemical structure of antibiotics, leading to the degradation of antibiotics. At an O3 dosage of 16 mg/g TS, the concentration of total coliforms and fecal coliforms decreased by 2.2 log and 2.4 log, corresponding to an overall removal rate of 99.4 % and 99.7 %, respectively. The total degradation rate of four target antibiotics (tetracycline (TC), oxytetracycline (OTC), norfloxacin (NOR), ofloxacin (OFL)) were 66.5 %, 68.8 %, 53.3 % and 57.5 %, respectively. The chromaticity removal rate of the thickened effluent reached 95 %. Analysis of fluorescence spectra indicated alterations in the fluorescence properties of dissolved organic matter, resulting in a decrease in fluorescence intensity by ozonation. The thickened sludge had higher hydrolysis rates, resulting in a greater production of volatile fatty acids (VFAs). This was mainly attributed to the increased amount of soluble protein and carbohydrate in the substrate after DOF treatment, which was more conducive for the rapid conversion of hydrolysis into VFAs during the initial stage. These results provided new ideas for upgrading and transforming the thickening process of wastewater treatment plants (WWTPs).
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Antibacterianos , Ozono , Ozono/química , Aguas del Alcantarillado/química , Tetraciclina , BacteriasRESUMEN
Shredded cabbage treated with either tap water or electrolyzed water was stored in an active modified atmosphere packaging (MAP) of 10% CO2 for 5 d at 10â, 7 d at 5â, and 8 d at 1â to evaluate the occurrence and viability of sublethally injured coliform bacteria. The CO2 and O2 concentrations in the packages approached an equilibrium of 10% CO2 and 10% O2 during storage at all temperatures tested. Coliforms in shredded cabbage increased during storage at all three temperatures, with the increase being greater at 10â. Sublethal injury at 65% to 69% for the coliforms was detected only on cabbage samples treated with electrolyzed water and stored at 5â for 4 and 7 d. Enterobacter cloacae was one of the injured species of coliform bacteria in shredded cabbage. Shredded cabbage was inoculated with chlorine-injured Escherichia coli O157:H7 and stored at 5â for 6 d in an active MAP of 10% CO2. Counts of E. coli O157:H7 remained almost constant during storage, and injured E. coli O157:H7 ranging from 50% to 70% were found on shredded cabbage throughout the storage period. These results indicate that sublethally injured indicator and pathogenic bacteria would be found on fresh-cut cabbage in the realistic MAP storage at 5â.
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Brassica , Brassica/microbiología , Dióxido de Carbono/farmacología , Microbiología de Alimentos , Recuento de Colonia Microbiana , Escherichia coli , Embalaje de Alimentos/métodos , AguaRESUMEN
Microbial water quality is routinely examined using the fecal indicator bacteria Escherichia coli, coliform bacteria and enterococci. Several practical cases in German drinking water distribution systems indicated invertebrates such as insects or gastropods as a source for the microbiological deterioration. Therefore, we examined three genera of Gastropoda (Arion, Helix and Cepaea) for the presence of fecal indictor bacteria in excreta using standard methods. Enterococci and coliform bacteria were detected in high concentrations (mean values of 1.5 × 106 and 6.3 × 106 per gram feces, respectively). E. coli was also detected, still specification revealed that what was assigned by standard ISO-methods to be E. coli was indeed a novel species of Buttiauxella, exhibiting ß-D-glucuronidase activity, thus, explaining the false-positive results. Microbiome analyses confirmed the cultural results. Enterobacteriaceae were dominant in the samples, yet only very few sequences could be assigned to Escherichia. Our study suggests, that enterococci and coliform bacteria are an integral component in the gastropod microbiome, whereas E. coli might be derived from other sources with gastropods being a vector. The results further indicate, that the current concept of fecal indicator bacteria needs to be extended, as not only humans and homeothermic animals could be a source for fecal indictor bacteria, but also gastropods need to be taken into consideration.
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Agua Potable , Escherichia coli , Animales , Humanos , Microbiología del Agua , Bacterias , Enterobacteriaceae , Enterococcus , Heces/microbiología , Monitoreo del AmbienteRESUMEN
Food safety has emerged as a major global issue. Detecting foodborne pathogenic microorganisms and controlling them is vital to guard against foodborne diseases caused by microorganisms. However, the current detection methods need to meet the demand for real-time detection on the spot after a simple operation. Considering unresolved challenges, we developed an Intelligent Modular Fluorescent Photoelectric Microbe (IMFP) system containing a special detection reagent. This IMFP system can automatically monitor microbial growth in which the photoelectric detection, temperature control, fluorescent probe, and bioinformatics screen are integrated into one platform and employed to detect pathogenic microorganisms. Moreover, a specific culture medium was also developed, which matched the system platform for Coliform bacteria and Salmonella typhi. The developed IMFP system could attain a limit of detection (LOD) of about 1 CFU/mL for both bacteria, while the selectivity could reach 99%. In addition, the IMFP system was applied to detect 256 bacterial samples simultaneously. This platform reflects the high-throughput needs of fields for microbial identification and related requirements, such as the development of pathogenic microbial diagnostic reagents, antibacterial sterilization performance tests, and microbial growth kinetics. The IMFP system also confirmed the other merits, such as high sensitivity, high-throughput, and operation simplicity compared to conventional methods, and it has a high potential as a tool for application in the health and food security fields.
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Contaminación de Alimentos , Inocuidad de los Alimentos , Contaminación de Alimentos/análisis , Límite de Detección , Medios de Cultivo , Bacterias , Colorantes Fluorescentes , Microbiología de AlimentosRESUMEN
For the first time, microcystin-producing cyanobacteria have been detected in Khubsugul, which is ancient, pristine and one of the world's largest lakes. The microcystin synthetase genes belonged to the genera Nostoc, Microcystis and possibly Snowella spp. No microcystins were found in the water of the lake. Using the HPLC-HRMS/TOF, five microcystin congeners were identified in biofilms from stony substrates sampled in the coastal zone. The concentration of microcystins in biofilms was low: 41.95 µg g-1 d. wt. by ELISA and 55.8 µg g-1 d. wt. using HPLC. The taxonomic composition of planktonic and benthic cyanobacterial communities was determined by means of microscopy and high-throughput sequencing of 16S rDNA amplicons. Nostocales cyanobacteria dominated benthos of Lake Khubsugul and Synechococcales-plankton. The abundance of cyanobacteria was low both in plankton and benthos; there was no mass development of cyanobacteria. Hydrochemical and microbiological analyses showed that the water in the lake was clean; the number of faecal microorganisms was significantly below the acceptable guideline values. Hydrochemical and hydrophysical parameters, and the concentration of chlorophyll a, were low and within the range of values recorded in the 1970s to 1990s, and corresponded to the oligotrophic state of the lake. There were no signs of anthropogenic eutrophication of the lake and no conditions for the cyanobacterial blooms.
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Cianobacterias , Microcystis , Lagos/microbiología , Plancton/genética , Calidad del Agua , Mongolia , Clorofila A , Monitoreo del Ambiente , Microcystis/genéticaRESUMEN
(1) Background: Water is necessary for the preparation of some medicines found in pharmacies where the local water source does not meet the required purity. This study aimed to investigate the presence of coliform contamination in water used for drug reconstitution in community pharmacies in Jordan. (2) Methods: Two water samples from 50 randomly selected community pharmacies representing all Jordanian governorates were filtered and then cultured in plate count agars to determine total microbial count, and in m-Endo Agar Les and Eosin Methylene Blue (EMB) agar to cultivate Escherichia coli (E. coli). The presence of E. coli was further characterized with gram stains, biochemical tests, and Polymerase chain reaction (PCR). Antibiotic susceptibility of isolated E. coli was tested against a variety of standard antibiotics. (3) Results: Community pharmacies used droppers filled with water from coolers (62%), bottled water (20%), boiled tap water (16%) and tap water (2%). The majority of the sampled water contained coliform bacteria (88%), and E. coli was isolated from 26% of all samples. Statistical analysis showed no significant difference in the percentage of contaminated water samples based on its source location. Nonetheless, the results showed a tendency for higher proportions of contamination in droppers filled from boiled tap water (37.5%; SE: 17.1), followed by water from water coolers (25.8%; SE: 7.9), and then from bottled water (20%; SE: 12.7). All of the isolated E. coli were sensitive to gentamycin, ciprofloxacin and levofloxacin. The susceptibility of the isolates to ceftazidime, doxycycline, tetracycline, azithromycin and amoxicillin/clavulanic acid were 92%, 61%, 46%, 23% and 15%, respectively. (4) Conclusions: This study confirms the widespread presence of multidrug-resistant bacteria in water intended for reconstituting drugs in local pharmacies. These findings expose an alarming situation that needs special attention by the acting pharmacists and competent authorities. Higher levels of personal hygiene in the pharmacies coupled with regular inspection of water quality may reduce the risk of microbial contamination in compounded products, especially multidrug-resistant strains of E. coli and other index microorganisms.
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Access to safe drinking water in rural Bangladesh remains a perpetual challenge. Most households are exposed to either arsenic or faecal bacteria in their primary source of drinking water, usually a tubewell. Improving tubewell cleaning and maintenance practices might reduce exposure to faecal contamination at a potentially low cost, but whether current cleaning and maintenance practices are effective remains uncertain, as does the extent to which best practice approaches might improve water quality. We used a randomized experiment to evaluate how effectively three approaches to cleaning a tubewell improved water quality, measured by total coliforms and E. coli. The three approaches comprise the caretaker's usual standard of care and two best-practice approaches. One best-practice approach, disinfecting the well with a weak chlorine solution, consistently improved water quality. However, when caretakers cleaned the wells themselves, they followed few of the steps involved in the best-practice approaches, and water quality declined rather than improved, although the estimated declines are not consistently statistically significant. The results suggest that, while improvements to cleaning and maintenance practices might help reduce exposure to faecal contamination in drinking water in rural Bangladesh, achieving widespread adoption of more effective practices would require significant behavioural change.
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Arsénico , Agua Potable , Escherichia coli , Calidad del Agua , Pozos de Agua , Arsénico/análisis , Bangladesh , Abastecimiento de AguaRESUMEN
Background microorganism growth on Chromogenic Coliform Agar (CCA) can be challenging. For this reason, a new alternative method with a Cefsulodin/Vancomycin (CV)-supplemented CCA should be developed in this study. CCA supplemented with CV was validated according to ÖNORM EN ISO 16140-4:2021 using water from natural sources in Styria, Austria. Results show that the alternative method using the supplemented CCA has similar values in relation to sensitivity (82.2%), specificity (98.6%) and higher selectivity (59%) compared to the reference method. Repeatability and reproducibility were acceptable for the alternative method and showed similar results with the reference method. The alternative method shows a very low false positive rate and a low false negative rate paired with good performance regarding the inclusion study. The exclusion study shows the advantage of our method by suppressing background microorganisms and facilitating the process of enumeration of Escherichia coli and other coliform bacteria on CCA plates. Aeromonas hydrophila and Pseudomonas aeruginosa growth was inhibited using the supplement. To conclude, the coliform CV selective supplement combined with CCA is an appropriate tool for coliform bacteria detection in water samples.
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BACKGROUND: To evaluate the drinking water quality in the popular trekking area of Solu-Khumbu Mt. Everest region as a possible source for the high incidence of diarrhea. MATERIAL AND METHODS: Drinking water samples (n = 80) were collected from whatever primary source the locals/tourists used at altitudes 2,608 to 5,180m; and where possible, also from inside households. Samples were analyzed for fecal contamination using the DelAgua Dual Incubator at 37 °C and 44 °C to detect the total and thermotolerant coliform bacteria. The pH, temperature, turbidity, smell, and taste were also registered. RESULTS: No thermotolerant bacteria were found but a significant number of specimens contained many colony forming units (CFU) of total coliform bacteria. Household specimens were more often contaminated compared to the water from the primary source. CONCLUSION: Data indicate a significant secondary contamination when water was handled and stored in unhygienic containers. Health education programs on water hygiene, sanitation, and the safe handling and storage of water needs improvement. It is strongly recommended that drinking water is disinfected using filter systems, UV-light dispensers or halogens (e.g. chlorine), or a combination of two methods. Although cooking is a common disinfection method here, fuel is scarce. Water was generally safer when collected directly from the primary source in a clean container than from a lodge.
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Agua Potable , Abastecimiento de Agua , Nepal , Saneamiento , Calidad del Agua , Microbiología del AguaRESUMEN
Raw foodstuffs have been marked as a healthier alternative in the context of nutrient content and are becoming more popular with consumers. Thermally untreated foods may represent a microbiological risk connected with the possible presence of antimicrobial resistance. The aim of this study was to prove that popular raw food beverages such as smoothies and raw milk may be a source of antibiotic-resistant coliform bacteria and resistant genes. The majority of antibiotic-resistant isolates (110) were identified as Enterobacter spp., Escherichia coli, and species of Klebsiella spp., predominantly ß-lactam and chloramphenicol resistant. Multidrug resistance has been registered in one-third of resistants. Overproduction of efflux pumps was clarified in 8 different bacteria. The majority of resistant isolates were strong biofilm producers. Antibiotic resistance gene blaOXA was detected in 25% of isolates, especially in E. coli. Resistance genes blaTEM and blaSHV were detected in 19% and 14%, respectively. This is the first study to point out that popular raw drinks such as smoothies or raw milk, besides their nutrient benefits, could represent a reservoir of antibiotic-resistant bacteria as well as antibiotic resistance genes. According to this, raw drinks could contribute to the dissemination of antibiotic resistance in the human gastrointestinal tract and environment.
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BACKGROUND: Hand drying is one of the most important factors affect hand hygiene. This study was conducted to investigate the effect of hand dryers used in the restrooms located on the food court floors in shopping malls in Turkey on hand hygiene. METHODS: Hands were washed for at least 20 seconds by following hygienic hand washing procedures of the World Health Organization. Swab samples were taken from the wet hands after hand washing, then from the dry hands, which were dried under the hand dryers and from the air blowing part of the hand dryers. Samples were cultured on agar plates that were directly exposed to the air-blowing part of the hand dryers. RESULTS: It was found that total coliform bacteria were 0.000 colony-forming unit (CFU)/petri in wet and dried hand, 3.437 CFU/petri in blown air and 5.250 CFU/petri in swab samples. Staphylococcus aureus was found to be 0.125, 64.125, 26.375, and 388.750 CFU/petri, respectively. Total bacteria count was found to be 0.687, 48.750, 35.625, and 595.000 CFU/petri, respectively. S. aureus and the total bacterial load were higher in the blower outlet of the hand dryers than washed hand, blown air and dried hand (P < .05). The bacteria count in the unfiltered hand dryers was higher than that in the filtered hand dryers (P < .05). CONCLUSIONS: Using hand dryers would negatively affect hand hygiene even if hands were washed following hygienic hand washing procedures.
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Higiene de las Manos , Agar , Recuento de Colonia Microbiana , Mano/microbiología , Desinfección de las Manos/métodos , Humanos , Staphylococcus aureusRESUMEN
Freshwater mussels are among the most endangered groups of fauna anywhere in world. The indiscriminate use of antibiotics has led to the emergence of resistant strains. These antibiotic-resistant bacteria play a key role in increasing the risk allied with the use of surface water and in spread of resistance genes. Two endangered freshwater mussel species, Margaritifera margaritifera and Potomida littoralis, were sampled at 4 sampling sites along a 50 km stretch of River Tua. Water samples were taken at same sites. Of the total of 135 isolates, 64.44% (39.26% from water and 25.19% from mussels) were coliform bacteria. Site T1, with the lowest concentration of coliform bacteria, and site T2 were the only ones where M. margaritifera was found. No E. coli isolates were found in this species and the pattern between water and mussels was similar. P. littoralis, which was present at T3/T4 sites, is the one that faces the highest concentration of bacterial toxins, which are found in treated wastewater effluents and around population centers. Sites T3/T4 have the isolates (water and mussels) with the highest resistance pattern, mainly to ß-lactams. Water and P. littoralis isolates (T3/T4) showed resistance to penicillins and their combination with clavulanic acid, and to cephalosporins, precisely to a fourth generation of cephalosporin antibiotics. The analysis provides important information on the risk to water systems, as well as the need to investigate possible management measures. It is suggested that future studies on the health status of freshwater bivalves should incorporate measures to indicate bacteriological water quality.
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Bivalvos , Animales , Bacterias , Agua Dulce , Ríos , Alimentos MarinosRESUMEN
In a large South American Reservoir (750 km2, limit between Uruguay and Argentina), we characterized the environmental risk posed by cyanobacteria proxies (abundance, toxin concentration, chlorophyll-a) and Escherichia coli abundances, integrating field (six sites, summers 2011-2015) and satellite (750 km2, summers 2011-2017) monitoring. We further assessed how well field cyanobacteria quantitative proxies (abundance, toxin concentration, chlorophyll-a and scum formation) used to build a local risk communication system for recreational (bathing) use of waters named "cyano-traffic-light", ongoing since 2011, reflected its outcome. Cyanobacteria abundance in the field ranged from moderate (>20,000 to <100,000 cells mL-1) to high-risk (>100,000 cells mL-1), and its abundance was positively related to toxin (microcystin) concentration. Mean microcystin concentrations was within the low (≤2 µg L-1, 50% sites) or moderate (>2 < 10 µg L-1, 50% sites) risk categories. On rare occasions, toxin concentration posed a high-risk for human health. E. coli abundance was within the high-risk category (>126 CFU 100 mL-1) for human health, mostly in the northern part of the reservoir. Cyanobacteria proxies (abundance and toxins) and E. coli abundance were, however, unrelated. The predictive model showed that, out of the four cyanobacteria proxies used to construct the cyano-traffic-light only cyanobacteria abundance (p < 0.05) explained the outcome of the reports, yet with low explanatory power (41%). The satellite monitoring allowed delimiting the extent and magnitude of the environmental risk posed by cyanobacteria at landscape scale (highest risk in the meander parts of the Argentinean side of the reservoir) and producing risk maps that can be used by water management agencies. Based upon our results we propose including E. coli abundances and satellite derived cyanobacteria abundances in the building of the cyano-traffic-light, among other modifications.
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Cianobacterias , Escherichia coli , Argentina , Monitoreo del Ambiente/métodos , Humanos , Microcistinas/análisis , UruguayRESUMEN
Curcumin is a polyphenolic compound present in turmeric with extensive uses in cooking foods and biomedical applications. However, due to its hydrophobic nature, it is poorly soluble in water and its bioavailability is very low on oral administration in organisms. In this study, we investigated the dietary curcumin nanospheres in a weaned piglet model based on the growth, serum biochemistry, proteomics, fecal coliform bacteria, and malodors in the feces of piglets. A total of 135 weaned piglets (Duroc × [Yorkshire × Landrace]) with an average initial body weight of 7.0 ± 1.0 kg (28 ± 1 days of age) were randomly distributed in 9 pens (15 pigs in each pen) fed the dietary curcumin nanospheres (CN) at 0 (control), 0.5 (T1), and 1.0 mL (T2) CN/kg of diet in triplicates for 21 days. At the end of the feeding trial, the results showed piglets fed 1.0 mL CN/kg diet had significantly higher growth performance and feed utilization than control diet (without CN). However, there were no significant differences in growth and feed utilization between piglets fed T1 and T2 diets. Serum glucose, gamma-glutamyl transferase, total bilirubin, amylase, and lipase contents were unaffected in piglets fed the experimental diets. Interestingly, piglets fed T1 and T2 diets showed significantly lower total cholesterol levels than control diet. In serum proteomics, a total of 103 differentially expressed proteins (DEPs) were identified in the piglets fed control, T1, and T2 diets, of which 14 DEPs were upregulated and 4 DEPs were downregulated. Fecal coliform bacteria and ammonia gas were significantly reduced in piglets fed T1 and T2 diets. Overall, the results indicated dietary supplementation of CN could enhance the growth, feed utilization, and immunity-and reduce fecal pathogenic bacteria as well as ammonia gas emissions-in weaned piglets.
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The aim of the present study was to evaluate the microbiological quality of rainbow trout meat treated with essential oils (EOs from Citrus limon and Cinnamomum camphora) at concentrations of 0.5% and 1.0% in combination with vacuum packaging during storage. The composition of the EOs were analyzed by gas chromatography coupled with mass spectrometry, and total viable counts (TVCs), coliform bacteria (CB), and lactic acid bacteria (LAB) were determined on the zeroth, first, third, fifth, and seventh days of storage at 4 °C. Individual species of isolated microorganisms were identified using a MALDI-TOF MS Biotyper. The results show that the major components of the EOs were linalool (98.1%) in C. camphora and α-limonene in C. limon. The highest number of TVCs and CB were 4.49 log CFU/g and 2.65 log CFU/g in aerobically packed samples at the seventh day. The lowest TVCs were those of samples treated with 1% C. camphora EO. For CB the most effective treatment was 1% lemon EO. LAB were only detected in a few samples, and were never present in aerobically packed samples; the highest number of LAB was 1.39 log CFU/g in samples treated with 1% lemon EO at day seven. The most commonly isolated coliform bacteria were Hafnia alvei, Serratia fonticola, Serratia proteamaculans, Pantoea agglomerans, and Yersinia ruckeri. Lactobacillus sakei, Staphylococcus hominis, and Carnobacterium maltaromaticum were the most frequently isolated bacteria from lactic acid bacteria. In conclusion, C. camphora EO at a concentration of 1% showed the highest antimicrobial activity.
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This study was conducted to evaluate the quality of water in selected dams in Albaha region, Kingdom of Saudi Arabia. Water samples from eight dams were subjected to physical, chemical, and bacteriological assessment using standardized procedures of conductivity, total dissolved solids, ions, acidity & alkalinity, and EC blue 100® coliform detection. About three fourth (75%) of dams' water samples exceeded the permissible levels of pH, total dissolved solids, turbidity, Mn and NO3 set by Saudi standards. Average levels of total dissolved solids, Fe, Mn, SO4, NO3, and NO2 were 3065.00, 0.10, 0.89, 68.25, 17.91 and 0.016â¯mg/L, respectively. However, the average pH of water samples was 7.95⯱â¯0.66 which still within the accepted range set by national and global standards. Moreover, total dissolved solids also exceeded regular standards of Food and Agriculture Organization for irrigation water quality. Coliform bacteria were detected in 37.5% of dams without any significant spatial differences between dams and sites as groups. Correlations were found between pH & NO3, SO4 & NO3, coliform bacteria & turbidity, coliform bacteria & NO2 levels. Increased concentrations of assessed parameters in dams may be attributed to agricultural activities as well as animal and human wastes deposited into dams via rainfalls and flash floods. Proper treatment of dams needs to be taken into account before consumption and irrigation.
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Beef can easily be contaminated with bacteria during the meat production chain. In this work, we studied the contamination levels of mesophilic aerobic bacteria (MAB) and thermotolerant coliform bacteria (TCB) on raw beef surfaces from small shops in Helsinki, Finland and meat markets in Benin City, Nigeria. We also investigated the prevalence of Salmonella, Campylobacter, Yersinia, Shiga toxin-producing Escherichia coli (STEC), Listeria, and cephalosporin-resistant E. coli (CREC). In total, one hundred unpacked raw beef samples from Finland and Nigeria were collected in 2019. The median MAB and TCB counts were significantly (P < 0.001) higher on beef from Nigeria than from Finland. The median MAB and TCB counts in Nigeria were 7.5 and 4.0 log10 cfu/cm2, respectively, and 6.5 and 2.8 log10 cfu/cm2 in Finland, respectively. Most (94%) Nigerian samples were unacceptable according to limits set by the EU. Beef samples from meat markets in Benin City were significantly (P < 0.05) more frequently contaminated with Salmonella, STEC, and CREC than beef samples from small shops in Helsinki. Salmonella, STEC, and CREC were isolated from 30, 36, and 96% of Nigerian samples, respectively, and from <2, 12, and 2% of Finnish samples, respectively. Our study demonstrates a significant difference between the bacterial contaminations of raw beef in Nigeria and Finland, along with a possible misuse of cephalosporins in animal husbandry in Nigeria.
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Bacterias/aislamiento & purificación , Contaminación de Alimentos/análisis , Carne/microbiología , Animales , Bacterias/clasificación , Bacterias/genética , Bacterias/crecimiento & desarrollo , Bovinos , Finlandia , Microbiología de Alimentos , NigeriaRESUMEN
A simple and rapid polymerase chain reaction (PCR)-based lateral flow assay (LFA) was developed for multiplex detection of hygiene indicator bacteria. Specifically, new PCR primers were designed for accurately detecting Escherichia coli, coliform bacteria, and total bacteria, and the results obtained as a colorimetric signal (generated by the accumulation of gold nanoparticles at distinct test zones on flow strips) could be identified by the naked eye in <10 min after the completion of PCR. The proposed LFA system did not exhibit any cross-reactivities with 8 distinct bacterial strains and can detect down to 1 colony forming unit (CFU)/mL. Furthermore, three species of cultured bacteria (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa) inoculated onto sterilized ham were successfully analyzed using the LFA system, which demonstrated that this system shows sufficient sensitivity and specificity for food hygiene monitoring. The speed and simplicity of this LFA make it suitable for use in the food industry as part of routine screening analysis.
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Bacterias/clasificación , Bacterias/aislamiento & purificación , ADN Bacteriano/química , Microbiología de Alimentos , Cartilla de ADN , Oro , Nanopartículas del Metal/química , Tiras Reactivas , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Pollution of riverine ecosystems through the multidimensional impact of human footprints around the world poses a serious challenge. Research studies that communicate potential repercussions of landscape structure metrics on snowmelt riverine water quality particularly, in climatically fragile Himalayan watersheds are very scarce. Though, worldwide, grasping the influence of land-use practices on water quality (WQ) has received renewed attention yet, the relevance of spatial scale linked to landscape pattern is still elusive due to its heterogenic nature across diverse geomorphic regions. In this work, therefore, we tried to capture the insights on landscape-aquascape interface by juxtapositioning the impacts of landscape structure pattern on snowmelt stream WQ of the whole Jhelum River Basin (JRB) under three varying spatial scales viz., watershed scale, riparian corridor (1000 m wide) and reach buffer (500 m wide). The percentage of landscape pattern composition and configuration metrics in the JRB were computed in GIS utilizing Landsat-8 OLI/TIRS satellite image having 30 m resolution. To better explicate the influence of land-use metrics on riverine WQ with space and time, we used Redundancy analysis (RDA) and multilinear regression (MLR) modeling. MLR selected land-use structure metrics revealed the varied response of WQ parameters to multi-scale factors except for total faecal coliform bacteria (TC) which showed perpetual presence. The reach-scale explained slightly better (76%) variations in WQ than riparian (75%) and watershed (70%) scales. Likewise, across seasonal scale, autumn (75%), winter (83%), and summer (77%) captured the most WQ variation at catchment, riparian, and reach scales respectively. We observed impairing WQ linkages with agriculture, built-up and barren rocky areas across watersheds, besides, pastures in riparian buffer areas, and fragmentation of landscape patches at the reach scale. Due to little appearance of spatial scale differences, a multi scale perspective landscape planning is emphasized to ensure future sustainability of Kashmir Himalayan water resources.