Agaricus biosporus is a mushroom known for its use for nutritional and medicinal purposes. This study tested whether silver nanoparticles (AgNPs) synthesized from phenolic compounds extracted from ...this mushroom have an efficient antimicrobial impact against pathogenic bacteria and yeast isolated from urine, sputum, and vaginal swabs. Different methods were employed in the characterization of AgNPs. The microorganisms of isolated bacteria and yeast were identified according to morphological features, results of biochemical tests, and the VITEK 2 compact system. The susceptibility to antibiotics was determined by the disk method. The bacteria and yeast resisted all antibiotics employed in this research. But the AgNPs had good antimicrobial activity against pathogenic bacteria and yeast. The highest inhibition zone of AgNPs against Pseudomonas aeruginosa in a 100 mg/mL concentration was 30 mm, while the minimal inhibition zone of AgNPs was 12 mm against Escherichia coli at the same concentration. The antibacterial effect of the synthesized AgNPs was concentration-dependent against Gram-positive and Gram-negative bacteria. With respect to the effect on yeast growth, there was a clear inhibitory effect of the synthesized AgNPs at 100 mg/mL, when the largest zone of inhibition was found against Candida glabrata (29 mm), and the minimal inhibition zone was found against C. guillermondi and C. albican (23 mm). Similarly, the AgNPs synergized with antibiotics were used against pathogenic bacterial and yeast isolates because when antibiotics and AgNPs were combined, the inhibition zones were larger compared to those of the antibiotics alone.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Mleko surowe, które nie zostało poddane obróbce termicznej, może być ważnym źródłem drobnoustrojów chorobotwórczych przenoszonych drogą pokarmową, głównie takich jak: patogenne szczepy Escherichia ...coli, bakterie z rodzaju Salmonella, niektóre paciorkowce kałowe czy Listeria monocytogenes. Najgroźniejszym z patogenów związanych z surowym mlekiem jest E. coli VTEC, która wytwarza werocytotoksyny – zwłaszcza szczep O157:H7. Enterococcus spp. jest jednym z czynników zapalenia wymienia u krów i dlatego często występuje w surowym mleku, co może stanowić zagrożenie dla konsumentów. Spożywanie mleka surowego jest dobrym wyborem, pod warunkiem, że mamy gwarancję wysokiego poziomu higienicznego jego pozyskiwania.
Free-living amoebae (FLA) are ubiquitous protozoa commonly found in water. FLA are well-established hosts for amoeba-resistant bacteria, most of which are pathogenic, and offer them shelter from ...adverse environmental conditions or water treatments. Since there is very little knowledge about the complete bacterial microbiome of FLA, in this work the bacterial microbiome of FLA isolated from wastewater both after secondary and tertiary treatments was studied by amplicon-based sequencing. FLA were detected in 87.5% and 50.0% of wastewater samples taken after secondary and tertiary disinfection treatments, respectively. The most abundant bacterial phyla were Proteobacteria, Planctomycetes, Bacteroidetes and Firmicutes, which represented 83.77% of the total bacterial FLA microbiome. The most abundant class of bacteria was Gammaproteobacteria, which contains an important number of relevant pathogenic bacteria. The bacteria of public health concern Aeromonas, Arcobacter, Campylobacter, Helicobacter, Klebsiella, Legionella, Mycobacterium, Pseudomonas and Salmonella were detected as part of the FLA microbiome. Although different microbial communities were identified in each sample, there is no correlation between the microbiome of FLA and the extent of wastewater treatment. To our knowledge, this is the first work in which the bacterial microbiome of FLA isolated from wastewater is studied. Obtained results indicate that FLA are hosts of potentially pathogenic bacteria in treated wastewater used for irrigation, which may pose a public health threat.
•Potentially pathogenic bacteria remain within FLA after wastewater treatments.•Bacterial microbiome of FLA does not correlate with wastewater treatment.•Treated wastewater containing FLA used for irrigation may pose a public health threat.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract Potable water supply and sanitization in rural areas in developing countries are still inadequate. The main risk associated with unsafe drinking water is the infection with pathogenic ...microorganisms. Objective: In this study, we investigate the bacterial diversity and the potentially pathogenic bacteria in water samples from diffe rent points of distribution in three rural villages from the Andean region of Colombia. Methods: Illumina libraries for water samples were prepared and sequenced using 300 bp paired-end MiSeq protocol, the bioinformatic analyses were performed with Mothur pipeline and the phyloseq package in Rstudio. Results: The mi crobial community composition showed statistically significant differences according to the village and the sample origin. Alpha, Beta, and Gammaproteobacteria were the dominant class detected in all water samples. The most relevant pathogenic genera detected in the surface were Legionella, Mycobacterium, Yersinia, Burkholderia, and Rickettsia. In the tap water samples, potential pathogens like Streptococcus, Staphylococcus, Corynebacterium, Nocardia, and Escherichia/Shige lla were detected.
A variety of bivalve mollusks (phylum Mollusca, class Bivalvia) constitute a prominent commodity in fisheries and aquacultures, but are also crucial in order to preserve our ecosystem's complexity ...and function. Bivalve mollusks, such as clams, mussels, oysters and scallops, are relevant bred species, and their global farming maintains a high incremental annual growth rate, representing a considerable proportion of the overall fishery activities. Bivalve mollusks are filter feeders; therefore by filtering a great quantity of water, they may bioaccumulate in their tissues a high number of microorganisms that can be considered infectious for humans and higher vertebrates. Moreover, since some pathogens are also able to infect bivalve mollusks, they are a threat for the entire mollusk farming industry. In consideration of the leading role in aquaculture and the growing financial importance of bivalve farming, much interest has been recently devoted to investigate the pathogenesis of infectious diseases of these mollusks in order to be prepared for public health emergencies and to avoid dreadful income losses. Several bacterial and viral pathogens will be described herein. Despite the minor complexity of the organization of the immune system of bivalves, compared to mammalian immune systems, a precise description of the different mechanisms that induce its activation and functioning is still missing. In the present review, a substantial consideration will be devoted in outlining the immune responses of bivalves and their repertoire of immune cells. Finally, we will focus on the description of antimicrobial peptides that have been identified and characterized in bivalve mollusks. Their structural and antimicrobial features are also of great interest for the biotechnology sector as antimicrobial templates to combat the increasing antibiotic-resistance of different pathogenic bacteria that plague the human population all over the world.
Global food systems can benefit significantly from continuous monitoring of microbial food safety, a task for which tedious operations, destructive sampling, and the inability to monitor multiple ...pathogens remain challenging. This study reports significant improvements to a paper chromogenic array sensor - machine learning (PCA-ML) methodology sensing concentrations of volatile organic compounds (VOCs) emitted on a species-specific basis by pathogens by streamlining dye selection, sensor fabrication, database construction, and machine learning and validation. This approach enables noncontact, time-dependent, simultaneous monitoring of multiple pathogens (Listeria monocytogenes, Salmonella, and E. coli O157:H7) at levels as low as 1 log CFU/g with over 90% accuracy. The report provides theoretical and practical frameworks demonstrating that chromogenic response, including limits of detection, depends on time integrals of VOC concentrations. The paper also discusses the potential for implementing PCA-ML in the food supply chain for different food matrices and pathogens, with species- and strain-specific identification.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The microbiomes on the surface of unclean removable prostheses are complex and yet largely underexplored using metagenomic sequencing technology.
To characterize the microbiome of removable ...prostheses with different levels of cleanliness using Type IIB Restriction-site Associated DNA for Microbiome (2bRAD-M) sequencing and compare the Microbial Index of Pathogenic Bacteria (MIP) between clean and unclean prostheses.
Ninety-seven removable prostheses were classified into 'clean' and 'unclean' groups. All prosthesis plaque samples underwent 2bRAD metagenomic sequencing to characterize the species-resolved microbial composition. MIPs for clean and unclean prostheses were calculated based on the sum of the relative abundance of pathogenic bacteria in a microbiome using a reference database that contains opportunistic pathogenic bacteria and disease-associated information.
Beta diversity analyses based on Jaccard qualitative and Bray-Curtis quantitative distance matrices identified significant differences between the two groups (
< 0.05). There was a significant enrichment of many pathogenic bacteria in the unclean prosthesis group. The MIP for unclean prostheses (0.47 ± 0.25) was significantly higher than for clean prostheses (0.37 ± 0.29),
= 0.029.
The microbial community of plaque samples from 'unclean' prostheses demonstrated compositional differences compared with 'clean' prostheses. In addition, the pathogenic microbiome in the 'unclean' versus 'clean' group differed.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The new European regulation on minimum quality requirements (MQR) for water reuse (EU, 2020/741) was launched in May 2020 and describes the directives for the use of reclaimed water for agricultural ...irrigation. This Regulation will be directly applicable in all Member States from 26 June 2023. Since its publication in 2020, concerns have raised about potential non-compliance situations in water reuse systems. The present study represents a case study where three different water reuse systems have been monitored to establish their compliance with the MQR. Each water reuse system includes a wastewater treatment plant (WWTP), a distribution/storage system and an end-user point, where water is used for irrigation of leafy greens. The selected water reuse systems allowed us to compare the efficacy of water treatments implemented in two WWTPs as well as the impact of three different irrigation systems (drip, furrow and overhead irrigation). The presence and concentration of indicator microorganisms (Escherichia coli and C. perfringens spores) as well as pathogenic bacteria (Shiga toxin-producing, E. coli (STEC), E. coli O157:H7, and Salmonella spp.) were monitored in different sampling points (influent and effluent of the WWTPs, water reservoirs located at the distribution system and the end-user point at the irrigation system as well as in the leafy greens during their growing cycle. Average levels of E. coli (0.73 ± 1.20 log cfu E. coli/100 mL) obtained at the point where the WWTP operator delivers reclaimed water to the next actor in the chain, defined in the European regulation as the ‘point of compliance’, were within the established MQR (<1 log cfu/100 mL) (EU, 2020/741). On the other hand, average levels of E. coli at the end-user point (1.0 ± 1.2 log cfu/100 mL) were below the recommended threshold (2 log cfu E. coli/100 mL) for irrigation water based on the guidance document on microbiological risks in fresh fruits and vegetables at primary production (EC, 2017/C_163/01). However, several outlier points were observed among the samples taken at the irrigation point, which were linked to a specific cross-contamination event within the distribution/storage system. Regarding pathogenic bacteria, water samples from the influent of the WWTPs showed a 100% prevalence, while only 5% of the effluent samples were positive for any of the monitored pathogenic bacteria. Obtained results indicate that reclaimed water produced in the selected water reuse system is suitable to be used as irrigation water. However, efforts are necessary not only in the establishment of advance disinfection treatments but also in the maintenance of the distribution/storage systems.
•Reclaimed water generated in the two WWTPs complied with new EU legislation.•Cross-contamination occurred during distribution and storage.•Only 5% of effluents and 1% of WWTP reservoirs were positive for pathogenic bacteria.•E. coli was a good indicator for the presence of foodborne pathogens.•Reclaimed water at the growing field was safe for irrigation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Nanopore sequencing is extremely promising for the high-throughput detection of pathogenic bacteria in natural water; these bacteria may be transmitted to humans and cause waterborne infectious ...diseases. However, the concentration of pathogenic bacteria in natural water is too low to be detected directly by nanopore sequencing. Herein, we developed a mica filter to enrich over 85% of bacteria from > 10 L of natural water in 100 min, which led to a 102-fold improvement in the assay limits of the MinION sequencer for assessing pathogenic bacteria. Correspondingly, the sequencing time of S. Typhi detection at a concentration as low as 105 CFU/L was reduced from traditional 48 h to 3 h. The bacterial adsorption followed pseudo-first-order kinetics and the successful adsorption of bacteria to the mica filter was confirmed by scanning electron microscopy and Fourier infrared spectroscopy et al. The mica filter remained applicable to a range of water samples whose quality parameters were within the EPA standard limits for freshwater water. The mica filter is thus an effective tool for the sensitive and rapid monitoring of pathogenic bacteria by nanopore sequencing, which can provide timely alerts for waterborne transmission events.
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•A mica filter was developed to monitor pathogenic bacteria by nanopore sequencing.•It could recover over 85% of bacteria from 10 L of natural water.•It enhanced the detection limits of pathogenic bacteria in water by 102-fold.•It reduced the detection time of pathogenic bacteria in water remarkably.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In nature, plants are always under the threat of pests and diseases. Pathogenic bacteria are one of the major pathogen types to cause diseases in diverse plants, resulting in negative effects on ...plant growth and crop yield. Chemical bactericides and antibiotics have been used as major approaches for controlling bacterial plant diseases in the field or greenhouse. However, the appearance of resistant bacteria to common antibiotics and bactericides as well as their potential negative effects on environment and human health demands bacteriologists to develop alternative control agents. Bacteriophages, the viruses that can infect and kill only target bacteria very specifically, have been demonstrated as potential agents, which may have no negative effects on environment and human health. Many bacteriophages have been isolated against diverse plant-pathogenic bacteria, and many studies have shown to efficiently manage the disease development in both controlled and open conditions such as greenhouse and field. Moreover, the specificity of bacteriophages to certain bacterial species has been applied to develop detection tools for the diagnosis of plant-pathogenic bacteria. In this paper, we summarize the promising results from greenhouse or field experiments with bacteriophages to manage diseases caused by plant-pathogenic bacteria. In addition, we summarize the usage of bacteriophages for the specific detection of plant-pathogenic bacteria.
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