Concentrations Of Coliform Bacteria Research Articles

Importance of baseline assessments: monitoring of Brunei River's water quality

Abstract This study illustrated the changes, pollution status, and significant pollution causes for Brunei River, Brunei Darussalam. Eleven parameters (pH, temperature, oxidation–reduction potential (ORP), dissolved oxygen, biochemical oxygen demand, conductivity, total dissolved solids (TDS), salinity, turbidity, ammonia-nitrogen (NH3-N), and total coliform) were analyzed from eight monitoring sites in 1984, 2019, 2020, and 2021. Box plots were used for a comparative study between 1984 and 2019+ data, while hierarchical cluster analysis (HCA) and principal component analysis (PCA) tests were performed on data from recent years (2019+). The box plot analysis showed that pollution levels in 2019, 2020, and 2021 increased compared to 1984 values, especially for total coliform bacteria. The doubling of the coliform bacteria concentration in the river between 1984 and 2019+ is concerning because the Malaysia National Water Quality Standards (NWQS) guideline values for fishing have now been exceeded. HCA pointed out that upstream stations are more polluted than downstream. PCA of the 11 water quality datasets generated five factors with a total variance of 75.21% and identified anthropogenic activities, seawater intrusion, and hydrological processes as possible causes for Brunei River water quality degradation.

The Effects of Operating Variables on Efficancy of Water Disinfection by Sodium Hypochlorite Using Al-Wathba Wastewater

The aim of this investigation was to study the impact of various reaction parameters on wastewater taken from Al-Wathba water treatment plant on Tigris River in south of Baghdad, Iraq with sodium hypochlorite solution. The parameters studied were sodium hypochlorite dose, contact time, initial fecal coliform bacteria concentration, temperature, and pH. In a batch reactor, different concentrations of sodium hypochlorite solution were used to disinfect 1L of water. The amount of hypochlorite ions in disinfected water was measured using an Iodimetry test for different reaction times, whereas the Most Probable Number (MPN) test was used to determine the concentration of coliform bacteria. Total Plate Count (TPC) was utilized in this study to count the number of colonies of common bacteria. Reaction variables that were examined showed that the increase in temperature, pH, and reaction time caused the concentration of Coliform bacteria to decrease, which in turn caused an accumulation-related increase in OCl- concentration. The optimum values of temperature and reaction pH were determined to be 8 and 29o C respectively. The kinetics of the reaction was examined in this study, and the results showed that Selleck model's order of reaction is two, with rate constants of 1.3791x10-5, 3.0806x10-5, and 5.738x10-5 L/(mole min) at 20o, 29o, and 37o C, respectively.

Probiotic potential of Lactobacillus plantarum DMR14 for preserving and extending shelf life of fruits and fruit juice

The harmful effects of chemical preservatives are driving the need for natural ones. To meet this demand, probiotic lactic acid bacteria (LAB) were isolated from fermented oats in this study. The goals of this study were to separate and identify probiotic LAB from fermented oats, to determine how effective these LAB are at combating pathogenic microorganisms in vitro, and to investigate their preservative capacity by applying the bacterium's cell-free supernatant (CFS) to specific fruits and fruit juice. The isolated strain was identified as Lactobacillus plantarum DMR14 using morphological, biochemical, and molecular investigation. Antimicrobial, antibiofilm, anti-oxidant, pH tolerance, and antibiotic resistance assays were used to evaluate the strain's probiotic potential, showing that Lactobacillus plantarum DMR14 had the strongest antagonistic and anti-biofilm capacity against Shigella boydii. Furthermore, the bacteriocin-containing compounds, cell-free supernatant (CFS) of the LAB, were tested against three fruits and one fruit juice, with the cell-free supernatant (CFS) of the bacterium lengthening the shelf life of the fruits compared to the untreated ones. Furthermore, while the concentration of coliform bacteria decreased in the treated sugarcane juice, an increase in the concentration of lactic acid bacteria suggested that the strain may be used as a fruit preservative in food industries.

Identification Coliform Bacteria In Student Drinking Water In The Al-Mu'aawanah Boarding School, District Rajadesa, Ciamis District

Background & Objective: Drinking water is a very important human need. Drinking water that is suitable for consumption must meet established standards, among others, according to the Minister of Health of the Republic of Indonesia No.492/Menkes/IV/2010. This study aims to determine the presence or absence of coliform bacteria in the drinking water of students using the MPN method. Methods: This type of research is descriptive. The sampling was carried out at the Al-Mu'aawanah Islamic boarding school. The results showed that the samples of drinking water for male and female students for microbiological parameters showed that the samples were positive for coliform bacteria. The sample for female students was 22/100 mL, and the sample for male students was 2/100 mL. Based on Permenkes No.472/Menkes/IV/2010, the maximum total concentration of coliform bacteria is 0/100 mL, which means that it is not in accordance with the standards of Permenkes No.472/Menkes/IV/2010, and the growth of faecal coliform bacteria was found in EMB media in both samples. namely the metallic green Escherichia coli bacteria, which indicates that the sample does not meet the microbiological requirements of drinking water.

Utilization of Tryptophan-like Fluorescence as a Proxy for E. coli Contamination in a Mixed-Land-Use Karst Basin

Karst aquifers are susceptible to contamination by pathogenic microorganisms, such as those found in human and animal waste, because the surface and subsurface drainage are well integrated through dissolution features. Fecal contamination of water is commonly assessed by the concentration of thermotolerant coliform bacteria, especially E. coli. This method is time-consuming, taking ≥18 h between the start of incubation and subsequent enumeration, as well as the time required to collect and transport samples. We examined the utility of continuous monitoring of tryptophan-like fluorescence (TLF) as a real-time proxy for E. coli in a mixed-land-use karst basin in the Inner Bluegrass region of central Kentucky (USA). Two logging fluorometers were sequentially deployed at the outlet spring. During storm flow, TLF typically peaked after discharge, which suggests that TLF transport in the phreatic conduit is likely related to sediment transport. The ability of TLF and other parameters (48 h antecedent precipitation, turbidity, and air temperature) to predict E. coli concentrations was assessed using the Akaike information criterion (AIC) applied to linear regression models. Because both the models and baseline concentrations of TLF differed between fluorometers, TLF and instrument interaction were accounted for in the AIC. TLF was positively correlated with E. coli and, in conjunction with antecedent precipitation, was the best predictor of E. coli. However, a model that included air temperature and antecedent precipitation but not TLF predicted E. coli concentrations similarly well. Given the expense of the fluorometers and the performance of the alternate model, TLF may not be a cost-effective proxy for E. coli in this karst basin.

Analisis Kepadatan bakteri Coliform serta hubungannya dengan konsentrasi Nitrat dan Fosfat di Pantai wisata Hamadi, Kota Jayapura.

There are several kinds of tourist objects in Jayapura City, one of which is the Hamadi beach tourist attraction. Tourists on Hamadi beach increases anthropogenic activities which can cause the aesthetics of the waters to decrease. Physical and chemical pollution can increase biological pollution, namely the presence of pathogenic bacteria such as coliform bacteria. Tourist beach waters that have been contaminated with Coliform bacteria will have an impact on tourists. The conducted of this study was to determine the density of Coliform bacteria, Nitrate and Phosphate concentrations and the relationship between Coliform bacteria density and Nitrate and Phosphate concentrations. The method used in this study was a survey method with a quantitative descriptive approach, while the data collection technique used a purposive random sampling technique at 3 stations with 3 points at each station. Data analysis used includes analysis of Coliform bacteria density, analysis of water quality based on the quality standard of the relationship between coliform bacteria density and concentrations of nitrate and phosphate using Pearson correlation analysis. The results showed that the average density of bacteria at station I was found to be 494 colonies/100mL, station II was found to be 58 colonies/100mL and station III was found to be 35 colonies/100mL. Nitrate and Phosphate concentrations in the coastal waters of Hamadi tourism were at station I the concentration of nitrate 1.90 mg/L and phosphate 0.045/mg/L. The concentration of nitrate at Station II was 2.4 mg/L and phosphate, which was 0.41, exceeded the water quality standard (0.015). Nitrate and phosphate concentrations at Station III were 4.40 mg/L nitrate and 0.060/mg/L phosphate. Based on the Pearson correlation test, the relationship between the density of Coliform bacteria and the concentration of Nitrate and Phosphate in the waters of the Hamadi tourism beach was found to have an opposite or weak and moderate relationship.

Two-year monitoring of enterovirus and rotavirus A in recreational freshwater from an island region, Pará State, northern Brazil

Enteric viruses are major causes of waterborne diseases and are present in large quantities in the stools of infected individuals. Its viability in the environment lasts for months, favoring the contamination of water used for consumption and recreation. The study aimed to monitor monthly the circulation of enterovirus (EV) and group A rotavirus (RVA) in recreational freshwater from an island region used as a bathhouse in northern Brazil, from January 2012 to December 2013. The viral RNA was obtained using guanidine isothiocyanate/silica after viral concentration by adsorption-elution method. The molecular detection was carried out by semi (EV) and nested-PCR (RVA) and the amplicons were sequenced on automated sequencer. At least one of these viruses was detected on 40.4% (42/104) of the samples. RVA was the most frequent (n = 32; 30.8%) when compared to EV (n = 20; 19.2%). Co-circulation between both was identified in 9.6% (n = 10). The highest viral positivity was found in SP02 (46.1%). The highest viral positivity was observed during high tides (57.7%; 60/104). Most EV samples were characterized as coxsackievirus (CV) A5 (85.7%, 12/14) and others as Sabin 1 poliovirus (14.2%, 2/14). The RVA positive samples were genotyped as G2, G3, G9, G12, P[8], P[4], and P[6]. These viruses were detected in 35.6% (37/104) of the samples with an acceptable concentration of fecal coliform bacteria. These results demonstrate the contamination of surface water intended for recreation by enteric viruses of Public Health concern even when bacterial indicators are within the tolerated limit, a factor that confirms the need for public policies aimed the sewage treatment before its release into water bodies.

Genome Analysis of Enterobacter asburiae and Lelliottia spp. Proliferating in Oligotrophic Drinking Water Reservoirs and Lakes.

Surface waters are one of the main sources for drinking water production, and thus microbial contamination should be as minimal as possible. However, high concentrations of coliform bacteria were detected in reservoirs and lakes used for drinking water production during summer months due to autochthonous proliferation processes. Here, we present the genomic analyses of 17 strains of Enterobacter asburiae and Lelliottia spp. proliferating in reservoirs and lakes with special focus on the hygienic relevance, antibiotic resistance, and adaptations to the oligotrophic environments. The genomes contain neither genes for the type III secretion system nor cytotoxins or hemolysins, which are considered typical virulence factors. Examination of antibiotic resistance genes revealed mainly efflux pumps and β-lactamase class C (ampC) genes. Phenotypically, single isolates of Enterobacter asburiae showed resistance to fosfomycin and ceftazidime. The genome analyses further suggest adaptations to oligotrophic and changing environmental conditions in reservoirs and lakes, e.g., genes to cope with low nitrate and phosphate levels and the ability to utilize substances released by algae, like amino acids, chitin, alginate, rhamnose, and fucose. This leads to the hypothesis that the proliferation of the coliform bacteria could occur at the end of summer due to algae die-off. IMPORTANCE Certain strains of coliform bacteria have been shown to proliferate in the oligotrophic water of drinking water reservoirs and lakes, reaching values above 104 per 100 mL. Such high concentrations challenge drinking water treatment, and occasionally the respective coliform bacteria have been detected in the treated drinking water. Thus, the question of their hygienic relevance is of high importance for water suppliers and authorities. Our genomic analyses suggest that the strains are not hygienically relevant, as typical virulence factors are absent and antibiotic resistance genes in the genomes most likely are of natural origin. Furthermore, their presence in the water is not related to fecal contamination. The proliferation in reservoirs and lakes during stable summer stratification is an autochthonic process of certain E. asburiae and Lelliottia strains that are well adapted to the surrounding oligotrophic environment.

Milk Thistle (Silybum marianum), Marine Algae (Spirulina platensis) and Toxin Binder Powders in the Diets of Broiler Chickens Exposed to Aflatoxin-B1: Growth Performance, Humoral Immune Response and Cecal Microbiota

This research was performed to investigate the effects of milk thistle (MT), toxin binder (TB) and marine algae (Spirulina platensis; SP) on the performance, blood indices, humoral immunity and cecal microbiota of broiler chickens exposed to aflatoxin-B1 (AFB1). A total of 300 one-day-old male chicks were equally divided into five treatments, with six replicates with 10 birds per treatment. Dietary treatments included: (T1) a control diet (without any feed additive or AFB1); (T2) control diet + 0.6 mg AFB1/kg; (T3) T2 + 10 g/kg MT; (T4) T2 + 1 g/kg TB; and (T5) T2 + 10 g/kg SP. BWG and FI were found to be considerably reduced in broilers given AFB1-contaminated diets (p < 0.05). The FCR was negatively influenced in birds fed AFB1-contaminated diets (p < 0.05). MT, TB, and SP powders also reduced the deleterious effects of AFB1 on the growth of chickens (p < 0.05). In comparison with the control birds and the other treatments, broilers given AFB1-contaminated diets had a higher relative weight of abdominal fat (p < 0.05). The feeding of AFB1 resulted in a substantial rise in AST and ALT activity (p < 0.05). MT, TB, and SP powders significantly decreased blood AST and ALT activity in broilers (p < 0.05). The AFB1 and MT groups had the lowest skin thickness (p < 0.05) twenty-four hours after injection. The phytohemagglutinin injection results showed that the TB and SP were more efficient than the other additives in removing toxins from the feed sources (p < 0.05). The antibody titer against sheep red blood cells (SRBCs) was lower in the AFB1 group compared to the control group at 28 days of age (p < 0.05). When comparing AFB1-fed chicks to the control treatment, there was a significant (p < 0.05) concentration of cecal Coliform bacteria. When MT, TB, and SP powders were added to AFB1-contaminated diet, cecal Coliforms were decreased (p < 0.05). When fed AFB1-contaminated diets, it can be concluded that MT, TB, and SP are suitable for supporting growth performance, immunological function, and the serum biochemical parameters of broiler chickens.

Sludge dewaterability enhancement under low temperature condition with cold-tolerant Bdellovibrio sp. CLL13

The dewatering performance of waste activated sludge (WAS) is generally deteriorated under low temperature due to the increase of viscosity, which would exacerbate the difficulties in sludge treatment and disposal. In this study, the cold-tolerant Bdellovibrio sp. CLL13 was successfully screened for efficient sludge biolysis, and it dramatically improved the sludge dewaterability while no significant biolysis effects were observed for the mesophilic BALO strain at 12 °C. The reduction rates of the sludge capillary suction time (CST), the specific resistance of filtration (SRF), the sludge dry weight, and the fecal coliform bacteria concentration at the optimal reaction time of 14 h were 40.1 ± 0.2%, 69.6 ± 0.7%, 7.7 ± 0.4%, and 78.5 ± 0.4%, respectively, when the mixed liquid suspended solids (MLSS) content was between 10.8 and 29.6 g/L, the input dosage of CLL13 was 8.8 × 106 PFU/mL sludge, and the DO level was 1.2 mg/L. Meanwhile, the viscosity reduction rate, the relative hydrophobicity increasement rate, and the bound water reduction rate were 20.3 ± 1.2%, 6.9 ± 0.7%, and 29.4 ± 1.0%, respectively. The ratios of protein content to polysaccharides content in the extracellular polymeric substances (EPS) decreased significantly. In addition, the degradation of the macromolecular substances in EPS and the increase of the soluble chemical oxygen demand, the total nitrogen, the total phosphorus, and the lactate dehydrogenase levels were observed. Therefore, the cold-tolerant CLL13 induced the sludge biolysis and compromised the negative effects of low temperature on the sludge dewatering performance, which should be beneficial for the efficient WAS biolysis treatment application in the near future under low temperature.

Precipitation-Driven Anthropogenic Pollutant Fluctuations Within Standing Water Sources of the Edwards Aquifer Region, Texas

The objective of this study was to assess the contribution of urban runoff in pollutant delivery to standing water pools within the Edwards Aquifer region of Texas. Grab samples of water were collected weekly over 5 months at one urban pool, one undeveloped pool, and one control pond that received minimal runoff. Samples were tested for nitrates, total dissolved phosphorus, Escherichia coli, and other coliform bacteria. The urban site had higher nitrate, E. coli, and other coliform bacteria concentrations than the undeveloped site. Significant positive linear relationships between weekly antecedent rainfall and both nitrate and E. coli were found at the urban site but not the undeveloped site. Water quality parameters at the control site remained stable, suggesting increases in nitrate and E. coli at the urban site were caused by runoff. Using publicly available data, relationships between water quality and weekly antecedent discharge were tested at 24 additional sites varying in land use. Positive relationships for E. coli were found at several urban sites, supporting runoff as a contributor to bacterial loading. Relationships for nitrate were variable, but all additional sites had flowing water, suggesting a unique response of water quality to urban runoff at the sampled urban pool.

Multiresistant bacteria: Invisible enemies of freshwater mussels

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 β-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.

Seasonal dynamics in the number and composition of coliform bacteria in drinking water reservoirs

Worldwide, surface waters like lakes and reservoirs are one of the major sources for drinking water production, especially in regions with water scarcity. In recent years, increased numbers of coliform bacteria have been observed in these surface waters. In our monitoring study we analyzed two drinking water reservoirs (Klingenberg and Kleine Kinzig Reservoir) over a two-year period in 2018 and 2019. We detected high numbers of coliform bacteria up to 2.4 × 104 bacteria per 100 ml during summer months, representing an increase of four orders of magnitude compared to winter. Diversity decreased to one or two species that dominated the entire water body, namely Enterobacter asburiae and Lelliottia spp., depending on the reservoir. Interestingly, the same, very closely related strains have been found in several reservoirs from different regions. Fecal indicator bacteria Escherichia coli and enterococci could only be detected in low concentrations. Furthermore, fecal marker genes were not detected in the reservoir, indicating that high concentrations of coliform bacteria were not due to fecal contamination. Microbial community revealed Frankiales and Burkholderiales as dominant orders. Enterobacterales, however, only had a frequency of 0.04% within the microbial community, which is not significantly affected by the extreme change in coliform bacteria number. Redundancy analysis revealed water temperature, oxygen as well as nutrients and metals (phosphate, manganese) as factors affecting the dominant species. We conclude that this sudden increase of coliform bacteria is an autochthonic process that can be considered as a mass proliferation or “coliform bloom” within the reservoir. It is correlated to higher water temperatures in summer and is therefore expected to occur more frequently in the near future, challenging drinking water production.

Multiresistant Bacteria: Invisible Enemies of Freshwater Mussels

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 50km 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 β-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. We discuss the conservation status and risk to water systems and the need for research into possible management measures. It is suggested that future studies on the health status of freshwater bivalves should incorporate measures to indicate bacteriological water quality.

Development of Fluorescence In Situ Hybridization as a Rapid, Accurate Method for Detecting Coliforms in Water Samples.

Coliform bacteria are indicators of water quality; however, most detection methods for coliform bacteria are time-consuming and nonspecific. Here, we developed a fluorescence in situ hybridization (FISH) approach to detect four types of coliform bacteria, including Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, and Citrobacter freundii, simultaneously in water samples using specific probes for 16S rRNA. This FISH method was applied to detect coliform bacteria in simulated water and domestic wastewater samples and compared with traditional detection methods (e.g., plate counting, multiple-tube fermentation (MTF) technique, and membrane filter (MF) technique). Optimal FISH conditions for detecting the four types of coliforms were found to be fixation in 3% paraformaldehyde at 4 °C for 2 h and hybridization at 50 °C for 1.5 h. By comparing FISH with plate counting, MTF, MF, and a commercial detection kit, we found that FISH had the shortest detection time and highest accuracy for the identification of coliform bacteria in simulated water and domestic wastewater samples. Moreover, the developed method could simultaneously detect individual species and concentrations of coliform bacteria. Overall, our findings indicated that FISH could be used as a rapid, accurate biosensor system for simultaneously detecting four types of coliform bacteria to ensure water safety.

Total and faecal coliforms presence in cenotes of Cancun; Quintana Roo, Mexico

The large increase in population in Cancun, Mexico has increased domestic, agricultural and industrial activities, resulting in inadequate solid and liquid waste management that can affect underground aquifers. One of the factors which affects water quality is coliform bacteria. The present study focused on determining the presence of total and faecal coliforms in ten urban cenotes in Cancun. Sampling was carried out in the dry and rainy seasons of 2018. The Most Probable Number (MPN) technique was used to determine the concentration of coliform bacteria. The results from the analyses indicate that the ten cenotes are contaminated with total and faecal coliforms. Additionally, the concentration of coliforms increases during the rainy season. We conclude that all the cenotes are contaminated with faecal coliforms and suggest that more studies are necessary to determine the origin of this contamination and the impact on the ecosystem.

Stable nitrogen isotopes in octocorals as an indicator of water quality decline from the northwestern region of Cuba.

Eutrophication is one of the causes of the degradation of reefs worldwide. The aim of this research is to determine if sewage discharge reaches the fore reefs at northwest of Cuba using δ15N in tissues of the octocorals Eunicea flexuosa and Plexaura kuekenthali and the concentration of microbiological and physical-chemical variables. Thirteen reefs at 10-m depth were selected near river basins and far from the urban and industrial development of Havana City. Branch tips of both species were collected, the concentrations of nutrient and microorganisms in water samples were quantified, and horizontal visibility in the water (Vis) was determined. Overall, δ15N of E. flexuosa ranged from 1.5 to 6.3‰ and P. kuekenthali from 1.7 to 6.7‰. The tissue of both species was significantly enriched in 15N in reefs near polluted watersheds compared with reefs far from pollution by anthropogenic activities. The δ15N of both species showed a positive and significant correlation with the concentration of fecal and total coliform bacteria, heterotrophic bacteria, and NH4+ and a negative and significant correlation with the Vis. The δ15N of the two species and microbiological and physical-chemical variables evidenced water quality decline by sewage discharge that reached reefs near polluted watersheds.

Oral supplementation of the diet of growing rabbits with a newly developed mixture of herbal plants and spices enriched with special extracts and essential oils affects their productive performance and immune status

This study aimed to evaluate the effect of feeding a mixture of herbal plants and spices enriched with special extracts and essential oils (phytogenic additives mixture) on feed intake, feed utilisation, blood chemistry, slaughter characteristics and caecal bacteria profile in rabbits. Ninety weaned unsexed V-Line rabbits, weighing 668.7 ± 8.2 g and aged 30 ± 1 days, were randomly allocated to three groups of 30 rabbits each and fed a basal diet without additives (Control rabbits) or supplemented with 0.5 mL (LA) or 1 mL (HA) of the additives mixture per litre of drinking water. Additives did not affect feed intake; however, the LA rabbits showed greater (P<0.001) feed conversion ratio compared to the other treatments. The LA treatment increased (P<0.01) final body weight and average daily gain compared to the control and HA treatments. Both the LA and HA treatments decreased (P<0.05) blood cholesterol, triglycerides and low-density lipoproteins; however, the LA treatment increased (P<0.05) high-density lipoproteins and total antioxidant capacity but decreased malondialdehyde (P<0.05) relative to the control treatment. Treatments did not affect carcass characteristics. The LA treatment followed by HA treatment increased (P<0.001) beneficial Lactobacillus spp. bacteria and decreased the concentrations of coliform bacteria and E. coli compared with the control treatment. It is concluded that additives mixture enhanced feed conversion and daily gain and positively altered caecal bacteria profile, with better effects of the low dose of the phytogenic additives mixture compared with the high dose.

Pulsed electric field application reduces carbapenem- and colistin-resistant microbiota and blaKPC spread in urban wastewater

Wastewater flows from metropolitan areas, especially those with healthcare inputs, can serve as transport reservoirs for the dissemination of clinically-relevant antimicrobial resistant bacteria (ARB) such as carbapenem- (CR) and colistin-resistant (CoR) strains. Pulsed electric field (PEF) is an emerging wastewater management tool for reducing bacterial loads without generating environmentally harmful byproducts, but it's ability to reduce ARB and their genetic determinants is not well reported. We collected 86, 10-L raw wastewater influent samples from a large metropolitan wastewater treatment plant in Columbus, Ohio and subjected them to low (34 kV cm−1 for 67 μsec) and high (36 kV cm−1 for 89 μsec) PEF treatment. We quantified the PEF effectiveness by measuring concentrations of total coliform bacteria, CR and CoR bacteria, and the epidemic carbapenemase gene, blaKPC, before and after PEF treatment. Utilizing marginal linear regression models with generalized estimating equations, we observed that low and high PEF treatment resulted in a 1.94 (95% CI 2.06–1.81; P < 0.001) and 2.32 (95% CI 2.46–2.18; P < 0.001) log reduction of total coliform bacteria concentrations, respectively. Low and high PEF treatment produced similar log reductions between CR E. coli (2.01 (95% CI 2.15–1.86; P < 0.001); 2.14 (95% CI: 5.30–4.61; P < 0.001)) and CR Enterobacteriaceae concentrations (1.55 (95% CI 1.70–1.41; P < 0.001); 1.86 (95% CI 2.05–1.68; P < 0.001)), and resulted in a 1.15 log (95% CI 1.38–0.93, P < 0.001) and 1.28 log (95% CI 1.54–1.03, P < 0.001) reduction of absolute blaKPC concentrations. Log CoR E. coli concentrations were reduced by 2.47 (95% CI 2.78–2.15; P < 0.001) and 2.52 (95% CI 2.91–2.15; P < 0.001) and CoR Enterobacteriaceae by 2.24 (95% CI 2.52–1.95; P < 0.001) and 2.50 (95% CI 2.89–2.11; P < 0.001) following low and high PEF application. PEF can be applied for wastewater management as an independent treatment method, particularly at critical control points, such as an on-site management of wastewater from hospitals or other healthcare facilities, or in series with other conventional methods to reduce total bacterial loads and concentrations of clinically-relevant ARB.

Coliform Bacteria Concentration in Okpon River, Obubra Local Government Area, Cross River State, Nigeria.

Coliform Bacteria Concentration in Okpon River, Obubra Local Government Area, Cross River State, Nigeria.