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Food Science and Biotechnology May 2023is a traditionally fermented cabbage, with a unique taste and beneficial properties, in northeast China. The taste and flavor of vary from region to region, owing to...
is a traditionally fermented cabbage, with a unique taste and beneficial properties, in northeast China. The taste and flavor of vary from region to region, owing to the differences in microorganisms. Illumina MiSeq sequencing was used to identify and quantify the microbial community composition of the broth and leaves of the naturally fermented collected from northeast China. The alpha and beta diversity of the samples from three areas in Heilongjiang province shown that the complexity of bacterial diversity of the three samples was C, A and B in turn. The widely existed in fermented , of these, , subsp. , subsp. , and were more abundant in the leaves than in fermentation broth. Other genera of lactic acid bacteria and , which have potential probiotic properties, were also present. However, some harmful bacteria such as and were also detected.
PubMed: 37041807
DOI: 10.1007/s10068-022-01221-w -
FEMS Microbiology Ecology Dec 2022Planktonic particle-associated bacteria comprise particle-attached and motile free-living cells. These groups were obtained by settlement in Imhoff cones. Dilution...
Planktonic particle-associated bacteria comprise particle-attached and motile free-living cells. These groups were obtained by settlement in Imhoff cones. Dilution plating on marine agar 2216 (ZoBell marine agar) and microscopic counts indicated a cultivability of 0.7% (0.4%-1.2%) of bacteria in coastal seawater collected at Helgoland Roads, North Sea. Particle-associated bacteria presented a minority population in seawater, but had a larger cultivability of 25% (0.9%-100%) for populations collected by settlement of particles and 5.7% (0.9%-24%) for populations collected by filtration. Partial 16S rRNA gene sequences indicated that 84% of the cultured taxa were either enriched in particle-associated microbiomes or only found in these microbiomes, including Sulfitobacter and other Rhodobacteraceae, Pseudoalteromonas, Psychromonas, Arcobacter and many Flavobacteriaceae. Illumina-based 16S rRNA V3V4 amplicon sequences of plate communities revealed that nearly all operational taxonomic units had a cultivated and described strain in close phylogenetic proximity. This suggested that decades of strain isolation from seawater on ZoBell marine agar had achieved a very good coverage of cultivable genera abundant in nature. The majority belonged to particle-associated bacteria, complementing observations that abundant free-living seawater bacteria often require cultivation conditions closer to their natural habitat like liquid cultivation in oligotrophic medium.
Topics: Agar; Phylogeny; RNA, Ribosomal, 16S; DNA, Bacterial; Sequence Analysis, DNA; Seawater; Flavobacteriaceae; Microbiota
PubMed: 36513318
DOI: 10.1093/femsec/fiac151 -
Gut Pathogens Dec 2021Members of the genus Arcobacter are considered as emerging zoonotic food and waterborne pathogens that cause gastroenteritis and bacteremia in humans. However, the...
Prevalence, antimicrobial susceptibility and virulence gene profiles of Arcobacter species isolated from human stool samples, foods of animal origin, ready-to-eat salad mixes and environmental water.
BACKGROUND
Members of the genus Arcobacter are considered as emerging zoonotic food and waterborne pathogens that cause gastroenteritis and bacteremia in humans. However, the potential risk that Arcobacter species pose to public health remains unassessed in various countries, including Baltic states. Therefore, the aim of this study was to determine the prevalence, antimicrobial susceptibility and presence of putative virulence genes of Arcobacter isolates recovered from humans, food products and environmental water in Lithuania.
RESULTS
A total of 1862 samples were collected and examined from 2018 to 2020 in the city of Kaunas. Overall, 11.2% (n = 208) of the samples were positive for the presence of Arcobacter spp. The highest prevalence was detected in chicken meat (36%), followed by environmental water (28.1%), raw cow milk (25%), ready-to-eat salad mixes (7.1%) and human stool (1.7%). A. butzleri was the most frequently isolated species (n = 192; 92.3%), followed by A. cryaerophilus (n = 16; 7.7%). Arcobacter spp. antimicrobial susceptibility testing revealed unimodally distributed aggregated minimal inhibitory concentrations (MICs) for gentamicin, tetracycline, ciprofloxacin, ampicillin and erythromycin. However, a bimodal distribution for azithromycin was found with 96.2% of determined MICs above the epidemiological cut-off value (ECOFF) defined for Campylobacter jejuni (0.25 µg/ml). Majority of the Arcobacter isolates (n = 187; 89.9%) showed high susceptibility to ciprofloxacin with MICs below or equal to the ECOFF value of 0.5 µg/ml. The putative virulence genes cadF (100%), ciaB (100%), cj1349 (99%), tlyA (99%), mviN (97.9%) and pldA (95.8%) were the predominant genes detected among A. butzleri isolates. In contrast, the mviN and ciaB genes were present in all, whereas cj1349 (12.5%), tlyA (25%) and hecA (12.5%) were only detected in few A. cryaerophilus isolates.
CONCLUSIONS
Our results demonstrate that food products and environmental water in Lithuania are frequently contaminated with Arcobacter spp. that carry multiple putative virulence genes. Furthermore, A. butzleri were isolated from 1.7% of inpatients. Fluoroquinolones and aminoglycosides were found to be more effective against Arcobacter in comparison to other antimicrobial agents. However, further studies are needed to determine the pathogenic mechanisms and factors that facilitate the spread of Arcobacter infections.
PubMed: 34930425
DOI: 10.1186/s13099-021-00472-y -
Microorganisms Apr 2024In contrast to "frank" pathogens, like , , and , that always have a probability of disease, "opportunistic" pathogens are organisms that cause an infectious disease in a... (Review)
Review
In contrast to "frank" pathogens, like , , and , that always have a probability of disease, "opportunistic" pathogens are organisms that cause an infectious disease in a host with a weakened immune system and rarely in a healthy host. Historically, drinking water treatment has focused on control of frank pathogens, particularly those from human or animal sources (like , , or ), but in recent years outbreaks from drinking water have increasingly been due to opportunistic pathogens. Characteristics of opportunistic pathogens that make them problematic for water treatment include: (1) they are normally present in aquatic environments, (2) they grow in biofilms that protect the bacteria from disinfectants, and (3) under appropriate conditions in drinking water systems (e.g., warm water, stagnation, low disinfectant levels, etc.), these bacteria can amplify to levels that can pose a public health risk. The three most common opportunistic pathogens in drinking water systems are , , and . This report focuses on these organisms to provide information on their public health risk, occurrence in drinking water systems, susceptibility to various disinfectants, and other operational practices (like flushing and cleaning of pipes and storage tanks). In addition, information is provided on a group of nine other opportunistic pathogens that are less commonly found in drinking water systems, including , , , , , , , and several free-living amoebae including and species of The public health risk for these microbes in drinking water is still unclear, but in most cases, efforts to manage , mycobacteria, and risks will also be effective for these other opportunistic pathogens. The approach to managing opportunistic pathogens in drinking water supplies focuses on controlling the growth of these organisms. Many of these microbes are normal inhabitants in biofilms in water, so the attention is less on eliminating these organisms from entering the system and more on managing their occurrence and concentrations in the pipe network. With anticipated warming trends associated with climate change, the factors that drive the growth of opportunistic pathogens in drinking water systems will likely increase. It is important, therefore, to evaluate treatment barriers and management activities for control of opportunistic pathogen risks. Controls for primary treatment, particularly for turbidity management and disinfection, should be reviewed to ensure adequacy for opportunistic pathogen control. However, the major focus for the utility's opportunistic pathogen risk reduction plan is the management of biological activity and biofilms in the distribution system. Factors that influence the growth of microbes (primarily in biofilms) in the distribution system include, temperature, disinfectant type and concentration, nutrient levels (measured as AOC or BDOC), stagnation, flushing of pipes and cleaning of storage tank sediments, and corrosion control. Pressure management and distribution system integrity are also important to the microbial quality of water but are related more to the intrusion of contaminants into the distribution system rather than directly related to microbial growth. Summarizing the identified risk from drinking water, the availability and quality of disinfection data for treatment, and guidelines or standards for control showed that adequate information is best available for management of . For , the risk for this organism has been clearly established from drinking water, cases have increased worldwide, and it is one of the most identified causes of drinking water outbreaks. Water management best practices (e.g., maintenance of a disinfectant residual throughout the distribution system, flushing and cleaning of sediments in pipelines and storage tanks, among others) have been shown to be effective for control of in water supplies. In addition, there are well documented management guidelines available for the control of the organism in drinking water distribution systems. By comparison, management of risks for from water are less clear than for . Treatment of is difficult due to its resistance to disinfection, the tendency to form clumps, and attachment to surfaces in biofilms. Additionally, there are no guidelines for management of in drinking water, and one risk assessment study suggested a low risk of infection. The role of tap water in the transmission of the other opportunistic pathogens is less clear and, in many cases, actions to manage (e.g., maintenance of a disinfectant residual, flushing, cleaning of storage tanks, etc.) will also be beneficial in helping to manage these organisms as well.
PubMed: 38792751
DOI: 10.3390/microorganisms12050916 -
Frontiers in Microbiology 2019The Campylobacterota, previously known as Epsilonproteobacteria, are a large group of Gram-negative mainly, spiral-shaped motile bacteria. Some members like the spp.... (Review)
Review
The Campylobacterota, previously known as Epsilonproteobacteria, are a large group of Gram-negative mainly, spiral-shaped motile bacteria. Some members like the spp. are free-living, while others such as spp. can only persist in strict association with a host organism as commensal or as pathogen. Species of this phylum colonize diverse habitats ranging from deep-sea thermal vents to the human stomach wall. Despite their divergent environments, they share common energy conservation mechanisms. The Campylobacterota have a large and remarkable repertoire of electron transport chain enzymes, given their small genomes. Although members of recognized families of transcriptional regulators are found in these genomes, sofar no orthologs known to be important for energy or redox metabolism such as ArcA, FNR or NarP are encoded in the genomes of the Campylobacterota. In this review, we discuss the strategies that members of Campylobacterota utilize to conserve energy and the corresponding regulatory mechanisms that regulate the branched electron transport chains in these bacteria.
PubMed: 31417516
DOI: 10.3389/fmicb.2019.01719 -
Water Research Mar 2021Plastic pollution in aquatic environments, particularly microplastics (<5 mm), is an emerging health threat. The buoyancy, hydrophobic hard surfaces, novel polymer...
Plastic pollution in aquatic environments, particularly microplastics (<5 mm), is an emerging health threat. The buoyancy, hydrophobic hard surfaces, novel polymer carbon sources and long-distance transport make microplastics a unique substrate for biofilms, potentially harbouring pathogens and enabling antimicrobial resistance (AMR) gene exchange. Microplastic concentrations, their polymer types and the associated microbial communities were determined in paired, contemporaneous samples from the Dutch portion of the river Rhine. Microplastics were collected through a cascade of 500/100/10 μm sieves; filtrates and surface water were also analysed. Microplastics were characterized with infrared spectroscopy. Microbial communities and selected virulence and AMR genes were determined with 16S rRNA-sequencing and qPCR. Average microplastic concentration was 213,147 particles/m; polyamide and polyvinylchloride were the most abundant polymers. Microbial composition on 100-500 μm samples differed significantly from surface water and 10-100 μm or smaller samples, with lower microbial diversity compared to surface water. An increasingly 'water-like' microbial community was observed as particles became smaller. Associations amongst specific microbial taxa, polymer types and particle sizes, as well as seasonal and methodological effects, were also observed. Known biofilm-forming and plastic-degrading taxa (e.g. Pseudomonas) and taxa harbouring potential pathogens (Pseudomonas, Acinetobacter, Arcobacter) were enriched in certain sample types, and other risk-conferring signatures like the sul1 and erm(B) AMR genes were almost ubiquitous. Results were generally compatible with the existence of taxon-selecting mechanisms and reduced microbial diversity in the biofilms of plastic substrates, varying over seasons, polymer types and particle sizes. This study provided updated field data and insights on microplastic pollution in a major riverine environment.
Topics: Environmental Monitoring; Microbiota; Microplastics; Netherlands; Plastics; RNA, Ribosomal, 16S; Water Pollutants, Chemical
PubMed: 33517045
DOI: 10.1016/j.watres.2021.116852 -
Journal of Food Protection Apr 2020Cloacal swabs were obtained from live ostriches reared on 30 different farms situated in South Africa (Oudtshoorn) during the period of June 2018 to July 2019 to...
ABSTRACT
Cloacal swabs were obtained from live ostriches reared on 30 different farms situated in South Africa (Oudtshoorn) during the period of June 2018 to July 2019 to determine the prevalence of Campylobacter and Arcobacter species. PCR (n = 168 pooled cloacal swabs), the Cape Town protocol (n = 836 cloacal swabs), International Organization for Standardization ISO 10272-1:2006 (n = 836 cloacal swabs), and a selective Arcobacter spp. method (n = 415 cloacal swabs) were used for detection. PCR determined an average prevalence of 24.63% for species belonging to the Campylobacteraceae family. The ISO 10272-1:2006 method determined a Campylobacter spp. prevalence level of 16.83%, while the Cape Town protocol could not detect Campylobacter spp. For Arcobacter spp., a prevalence of 18.80 and 39.14% was determined with the Cape Town protocol and the selective Arcobacter spp. method, respectively. Results showed that prevalence levels could be influenced by season, the source of water, and the presence of wild water birds. Higher prevalence levels for Campylobacter spp. (23.38%) and Arcobacter spp. (68%) were detected in ostriches sampled during spring and autumn, respectively. Higher prevalence levels for Campylobacter spp. (25.23%) and Arcobacter spp. (44.50%) were detected in ostriches reared on farms that made use of borehole water. Higher prevalence levels for Arcobacter spp. (44.38%) were seen in ostriches reared on farms with wild water birds. This research shows that ostriches from South Africa can be considered as potential carriers of species belonging to the Campylobacteraceae family.
Topics: Animals; Arcobacter; Bird Diseases; Campylobacter; Prevalence; South Africa; Struthioniformes
PubMed: 31855449
DOI: 10.4315/JFP-19-472 -
Water Research Apr 2020Antibiotic resistome is a raising concern around the world, especially considering treated wastewater for reclamation. A wastewater reclamation system (WWRS), composed...
Antibiotic resistome is a raising concern around the world, especially considering treated wastewater for reclamation. A wastewater reclamation system (WWRS), composed by a treatment system (TS) and a reclaimed system (RS) with supplementation from the treated effluent and considered as an integrated system of treatment and reclamation, was selected in this study. High-throughput qPCR (HT-qPCR) was applied to profile 283 antibiotic resistance genes (ARGs) and 12 mobile genetic elements (MGEs) in the WWRS. A total of 251 ARG and 12 MGE subtypes were detected in the WWRS. The TS exhibited good performance for the removal of ARGs with the number, relative and absolute abundances of ARGs largely decreased (99.07% removal efficiency) in the final effluent, which might be ascribed to biosolid sedimentation. Enhancement of biosolids removal contributed the lessening of ARGs. In the RS, high quality effluent significantly reduced the number and abundance of ARGs along the flow to downstream. MGEs were less reduced in the treated effluent than that of the influent (R = -0.16, p > 0.05), and exhibited close connections with ARGs. Arcobacter, Cloacibacterium, Cyanobacteria, Acinetobacter, Flavobacterium and Dechloromonas were the relatively abundant genera in the WWRS, and exhibited significantly correlations with ARGs. Microbial communities and MGEs contributed 65.64% to the changes of ARGs. These two factors may be the main drivers of ARG proliferation in the WWRS. Thus, attention should be paid to MGEs and those abundant genera when considering treated wastewater for reclamation.
Topics: Anti-Bacterial Agents; Drug Resistance, Microbial; Genes, Bacterial; Microbiota; Wastewater
PubMed: 32036288
DOI: 10.1016/j.watres.2020.115541 -
Fish & Shellfish Immunology Dec 2022Bacteria of the Arcobacter-like spp. represent emerging foodborne zoonotic pathogens in humans and animals. Their increasing presence in seafood, suggesting higher...
Bacteria of the Arcobacter-like spp. represent emerging foodborne zoonotic pathogens in humans and animals. Their increasing presence in seafood, suggesting higher occurrence in seawater due to marine pollution, is raising some environmental concern. Although Arcobacter is frequently detected in diseased oysters and stressed bivalve species, no data are available so far on its potential pathogenicity or interactions with the immune system of the bivalve host. In this work, responses to challenge with two strains of Malaciobacter marinus IRTA-19-131 and IRTA-19-132, R1 and R2), isolated from adult Crassostrea gigas during a mortality event in 2019 in Spain, were investigated in the mussel Mytilus galloprovincialis. In vivo experiments were performed in larvae (48 h post-fertilization), and in adult mussels at 24 h post-injection, in order to evaluate the pathogenicity for early developmental stages, and the hemolymph immune responses, respectively. Both R1 and R2 were moderately pathogenic to early larvae, with significant decreases in the development of normal D-veligers from 10 and 10 CFU/mL, respectively. In adults, both strains decreased hemocyte lysosomal membrane stability (LMS), and stimulated extracellular defense responses (ROS production and lysozyme activity). The interactions between mussel hemocytes and M. marinus were investigated in in vitro short-term experiments (30-90 min) using the R1 strain (10-10 CFU/mL). R1 decreased LMS and induced lysosomal enlargement, but not cell detachment or death, and stimulated extracellular ROS production and lysozyme release, confirming in vivo data. Moreover, lysosomal internalization and degradation of bacteria were observed, together with changes in levels of activated mTor and LC3, indicating phagocytic activity. Overall, the results indicate the activation of both extracellular and intracellular immune defenses against M. marinus R1. Accordingly, these responses resulted in a significant hemolymph bactericidal activity, with a large contribution of hemolymph serum. The results represent the first data on the potential pathogenicity of Arcobacter isolated from a shellfish mortality to bivalve larvae and adults, and on their interactions with the immune system of the host.
Topics: Humans; Animals; Mytilus; Muramidase; Arcobacter; Reactive Oxygen Species; Hemocytes; Bacteria
PubMed: 36154890
DOI: 10.1016/j.fsi.2022.09.048 -
Environmental Research Feb 2021Wastewaters serve as important hot spots for antimicrobial resistance and monitoring can be used to analyse the abundance and diversity of antimicrobial resistance genes...
Extended-spectrum beta-lactamase-producing Escherichia coli and antimicrobial resistance in municipal and hospital wastewaters in Czech Republic: Culture-based and metagenomic approaches.
Wastewaters serve as important hot spots for antimicrobial resistance and monitoring can be used to analyse the abundance and diversity of antimicrobial resistance genes at the level of large bacterial and human populations. In this study, whole genome sequencing of beta-lactamase-producing Escherichia coli and metagenomic analysis of whole-community DNA were used to characterize the occurrence of antimicrobial resistance in hospital, municipal and river waters in the city of Brno (Czech Republic). Cefotaxime-resistant E. coli were mainly extended-spectrum beta-lactamase (ESBL) producers (95.6%, n = 158), of which the majority carried bla (98.7%; n = 151) and were detected in all water samples except the outflow from hospital wastewater treatment plant. A wide phylogenetic diversity was observed among the sequenced E. coli (n = 78) based on the detection of 40 sequence types and single nucleotide polymorphisms (average number 34,666 ± 15,710) between strains. The metagenomic analysis revealed a high occurrence of bacterial genera with potentially pathogenic members, including Pseudomonas, Escherichia, Klebsiella, Aeromonas, Enterobacter and Arcobacter (relative abundance >50%) in untreated hospital and municipal wastewaters and predominance of environmental bacteria in treated and river waters. Genes encoding resistance to aminoglycosides, beta-lactams, quinolones and macrolides were frequently detected, however bla was not found in this dataset which may be affected by insufficient sequencing depth of the samples. The study pointed out municipal treated wastewater as a possible source of multi-drug resistant E. coli and antimicrobial resistance genes for surface waters. Moreover, the combination of two different approaches provided a more holistic view on antimicrobial resistance in water environments. The culture-based approach facilitated insight into the dynamics of ESBL-producing E. coli and the metagenomics shows abundance and diversity of bacteria and antimicrobial resistance genes vary across water sites.
Topics: Anti-Bacterial Agents; Czech Republic; Drug Resistance, Bacterial; Escherichia coli; Hospitals; Humans; Metagenomics; Phylogeny; Wastewater; beta-Lactamases
PubMed: 33232750
DOI: 10.1016/j.envres.2020.110487