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Frontiers in Microbiology 2021The increasing occurrence of multidrug-resistant (MDR) extended-spectrum β-lactamase- (ESBL) and/or AmpC β-lactamase- (AmpC) producing Enterobacterales in irrigation...
The increasing occurrence of multidrug-resistant (MDR) extended-spectrum β-lactamase- (ESBL) and/or AmpC β-lactamase- (AmpC) producing Enterobacterales in irrigation water and associated irrigated fresh produce represents risks related to the environment, food safety, and public health. In South Africa, information about the presence of ESBL/AmpC-producing Enterobacterales from non-clinical sources is limited, particularly in the water-plant-food interface. This study aimed to characterize 19 selected MDR ESBL/AmpC-producing (=3), (=5), (=10), and (=1) isolates from spinach and associated irrigation water samples from two commercial spinach production systems within South Africa, using whole genome sequencing (WGS). Antibiotic resistance genes potentially encoding resistance to eight different classes were present, with being the dominant ESBL encoding gene and -types being the dominant AmpC encoding gene detected. A greater number of resistance genes across more antibiotic classes were seen in all the strains, compared to the other genera tested. From one farm, -positive strains of the same sequence type 985 (ST 985) were present in spinach at harvest and retail samples after processing, suggesting successful persistence of these MDR strains. In addition, ESBL-producing ST15, an emerging high-risk clone causing nosocomical outbreaks worldwide, was isolated from irrigation water. Known resistance plasmid replicon types of Enterobacterales including IncFIB, IncFIA, IncFII, IncB/O, and IncHI1B were observed in all strains following analysis with PlasmidFinder. However, was the only β-lactamase resistance gene associated with plasmids (IncFII and IncFIB) in (=4) strains. In one and five strains, integron In191 was observed. Relevant similarities to human pathogens were predicted with PathogenFinder for all 19 strains, with a confidence of 0.635-0.721 in , 0.852-0.931 in , 0.796-0.899 in , and 0.939 in the strain. The presence of MDR ESBL/AmpC-producing , , , and with similarities to human pathogens in the agricultural production systems reflects environmental and food contamination mediated by anthropogenic activities, contributing to the spread of antibiotic resistance genes.
PubMed: 34659162
DOI: 10.3389/fmicb.2021.734649 -
Antibiotics (Basel, Switzerland) Nov 2023The study examines the antibiotic resistance of metal-tolerant bacteria isolated from the wastewater treatment plant of a large city to six antibiotics belonging to the...
The study examines the antibiotic resistance of metal-tolerant bacteria isolated from the wastewater treatment plant of a large city to six antibiotics belonging to the β-lactam antibiotics, aminoglycosides and amphenicols. Resistance of bacteria from sewage sludge multitolerant to heavy metals to 18 antibiotics of the β-lactam antibiotics, tetracyclines, aminoglycosides, diaminopyrimidines, amphenicols and ansamycins was studied also. Out of 10, the metal-tolerant microorganisms isolated from wastewater treatment facilities only the strain (tolerant to 3 mM Cu) from the sludge of a secondary settling tank did not show resistance to the studied antibiotics at the concentrations considered. Resistance to the maximum amount of antibiotics was typical for strains SS0-1, isolated from fresh sewage sludge and resistant to 5 mmol Cu and 3 mmol Pb, or SS0-5, also isolated from fresh sludge and resistant to 3 mmol Zn and Cu. It is possible that bacterial resistance to antibiotics develops not only as a result of the use of antibiotics themselves, but also as a result of environmental pollution with heavy metals, and vice versa.
PubMed: 38136714
DOI: 10.3390/antibiotics12121678 -
Animals : An Open Access Journal From... Nov 2021The aim of the present study was to evaluate the microbiological quality of rainbow trout meat treated with essential oils (EOs from and ) at concentrations of 0.5% and...
The aim of the present study was to evaluate the microbiological quality of rainbow trout meat treated with essential oils (EOs from and ) 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 and α-limonene in . 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% 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 , , , , and , , and were the most frequently isolated bacteria from lactic acid bacteria. In conclusion, EO at a concentration of 1% showed the highest antimicrobial activity.
PubMed: 34827877
DOI: 10.3390/ani11113145 -
The Journal of Animal Ecology May 2015Despite growing interest in ecological consequences of parasitism in food webs, relatively little is known about effects of parasites on long-term population dynamics of...
Despite growing interest in ecological consequences of parasitism in food webs, relatively little is known about effects of parasites on long-term population dynamics of non-host species or about whether such effects are density or trait mediated. We studied a tri-trophic food chain comprised of (i) a bacterial basal resource (Serratia fonticola), (ii) an intermediate consumer (Paramecium caudatum), (iii) a top predator (Didinium nasutum) and (iv) a parasite of the intermediate consumer (Holospora undulata). A fully factorial experimental manipulation of predator and parasite presence/absence was combined with analyses of population dynamics, modelling and analyses of host (Paramecium) morphology and behaviour. Predation and parasitism each reduced the abundance of the intermediate consumer (Paramecium), and parasitism indirectly reduced the abundance of the basal resource (Serratia). However, in combination, predation and parasitism had non-additive effects on the abundance of the intermediate consumer, as well as on that of the basal resource. In both cases, the negative effect of parasitism seemed to be effaced by predation. Infection of the intermediate consumer reduced predator abundance. Modelling and additional experimentation revealed that this was most likely due to parasite reduction of intermediate host abundance (a density-mediated effect), as opposed to changes in predator functional or numerical response. Parasitism altered morphological and behavioural traits, by reducing host cell length and increasing the swimming speed of cells with moderate parasite loads. Additional tests showed no significant difference in Didinium feeding rate on infected and uninfected hosts, suggesting that the combination of these modifications does not affect host vulnerability to predation. However, estimated rates of encounter with Serratia based on these modifications were higher for infected Paramecium than for uninfected Paramecium. A mixture of density-mediated and trait-mediated indirect effects of parasitism on non-host species creates rich and complex possibilities for effects of parasites in food webs that should be included in assessments of possible impacts of parasite eradication or introduction.
Topics: Animals; Behavior, Animal; Ciliophora; Food Chain; Holosporaceae; Host-Pathogen Interactions; Paramecium caudatum; Population Dynamics; Predatory Behavior; Serratia
PubMed: 25382389
DOI: 10.1111/1365-2656.12317 -
Pharmaceuticals (Basel, Switzerland) Jun 2021Antibiotic resistance is a major health problem worldwide, causing more deaths than diabetes and cancer. The dissemination of vertical and horizontal antibiotic...
Antibiotic resistance is a major health problem worldwide, causing more deaths than diabetes and cancer. The dissemination of vertical and horizontal antibiotic resistance genes has been conducted for a selection of pan-resistant bacteria. Here, we test if the aerobic and anaerobic bacteria from human feces samples in health conditions are carriers of beta-lactamases genes. The samples were cultured in a brain-heart infusion medium and subcultured in blood agar in aerobic and anaerobic conditions for 24 h at 37 °C. The grown colonies were identified by their biochemical profiles. The DNA was extracted and purified by bacterial lysis using thermal shock and were used in the endpoint PCR and next generation sequencing to identify beta-lactamase genes expression (OXA, VIM, SHV, TEM, IMP, ROB, KPC, CMY, DHA, P, CFX, LAP, and BIL). The aerobic bacterias Aeromonas hydrophila, Citrobacter freundii, Proteus mirabilis, Providencia rettgeri, Serratia fonticola, Serratia liquefaciens, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Pantoea agglomerans, Enterococcus faecalis, and Enterobacter cloacae, the anaerobic bacteria: Capnocytophaga species, Bacteroides distasonis, Bifidobacterium adolescentis, Bacteroides ovatus, Bacteroides fragilis, Eubacterium species, Eubacterium aerofaciens, Peptostreptococcus anaerobius, Fusobacterium species, Bacteroides species, and Bacteroides vulgatus were isolated and identified. The results showed 49 strains resistant to beta-lactam with the expression of blaSHV (10.2%), blaTEM (100%), blaKPC (10.2%), blaCYM (14.3%), blaP (2%), blaCFX (8.2%), and blaBIL (6.1%). These data support the idea that the human enteric microbiota constitutes an important reservoir of genes for resistance to beta-lactamases and that such genes could be transferred to pathogenic bacteria.
PubMed: 34204872
DOI: 10.3390/ph14060533 -
Frontiers in Microbiology 2023The involvement of non-human-to-human transmission of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE) remains elusive. Foodstuffs may serve as...
BACKGROUND
The involvement of non-human-to-human transmission of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE) remains elusive. Foodstuffs may serve as reservoirs for ESBL-PE and contribute to their spread.
AIM
We aimed to systematically investigate the presence and spatiotemporal distribution of ESBL-PE in diverse unprocessed foodstuffs of different origin purchased in a central European city.
METHODS
Chicken and green (herbs, salad, sprouts, vegetables) samples were collected monthly for two consecutive years, from June 2017 to June 2019, from large supermarket chains and small local food retailers, representing all ten postcode areas of the City of Basel (Switzerland), and the kitchen of the University Hospital Basel (Basel, Switzerland). After enrichment, presumptive ESBL-PE were isolated by selective culture methods and identified by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. ESBL production was confirmed by phenotypic testing.
RESULTS
Among 947 food samples, 14.8% were positive for ESBL-PE isolate/s belonging to eight different ESBL-producing bacterial species. and were predominant across samples (9 and 2%, respectively). Higher ESBL-PE prevalence was observed in chicken (25.9%) than in green (3.8%) samples ( < 0.001). Among greens, ESBL-PE were most frequently isolated from sprouts (15.2%). High ESBL-PE species diversity was observed among chicken samples, with as predominant (17.6%). ESBL-producing was detected among different greens. Yet, ESBL-producing was predominant in sprouts (12.1%). In total, 20.5% of samples from organic farming and 14.2% of samples from conventionally raised animals harbored an ESBL-producing isolate. Detection of ESBL-PE across samples differed between organic and non-organic when stratified by food source ( < 0.001), particularly among greens (12.5% organic, 2.4% conventional). High proportion of organic chicken samples was positive for ESBL- (33.3%), while the detection of several species characterized the conventional chicken samples. No significant differences in ESBL-PE frequences were detected between national (13.4%) and international samples (8.0%) ( = 0.122). Instead, differences were observed between regions of food production and countries ( < 0.001). No significant differences were found when comparing the proportion of ESBL-PE positive samples across districts, shop sizes and the hospital kitchen. The percentage of ESBL-PE positive samples did not differ monthly across the two-year sampling period ( = 0.107).
CONCLUSION
Our findings indicate moderate dissemination of ESBL-PE in foodstuffs, especially between chicken products and sprouts. Chicken meat represents a source for several ESBL-producing Enterobacterales, especially , while greens are more prone to carry ESBL- and . We disclose the importance of food type, food production system and production origin when assessing the risk of contamination with different ESBL-PE species.
PubMed: 38075908
DOI: 10.3389/fmicb.2023.1295037 -
Stress Biology Jan 2024Worldwide wastewater treatment plants generate enormous amounts of sewage sludge, and their further disposal depends on the treatment technologies applied and...
Worldwide wastewater treatment plants generate enormous amounts of sewage sludge, and their further disposal depends on the treatment technologies applied and spontaneously occurring microbiological processes. From different ages urban sewage sludge, 12 strains of bacteria with simultaneous tolerance to two or more trace elements: Co, Ni, Cu, Zn, Cd and Pb at concentration of 3-5 mmol were isolated and identified by PCR of target genes and Sanger sequencing methods. The isloated metal(loids) tolerant strains belong to the species, i.e., Serratia fonticola, Rhodococcus qingshengii, Pseudomonas fragi, Pseudomonas extremaustralis, Pseudomonas cedrina, Stenotrophomonas maltophilia, Serratia liquefaciens and Citrobacter freundii. The ecological features of the isolated strains were studied. The optimal growth temperatures for most strains was 15-30°C at pH range of 5-9, although some strains grew at 7°C (Pseudomonas fragi SS0-4, Serratia fonticola SS0-9 and Serratia fonticola SS12-11). Satisfactory growth of two strains (Serratia fonticola SS0-1and Citrobacter freundii SS60-12) was noted in an acidic medium at pH 4. Most of the strains grew in the NaCl concentration range of 1-5%. The isolated bacteria resistant to high concentrations of trace elements can be used for the effective mineralization of sewage sludge and for the decontamination of wastewater.
PubMed: 38273092
DOI: 10.1007/s44154-023-00144-8 -
Impact of operational conditions on drinking water biofilm dynamics and coliform invasion potential.Applied and Environmental Microbiology May 2024Biofilms within drinking water distribution systems serve as a habitat for drinking water microorganisms. However, biofilms can negatively impact drinking water quality...
UNLABELLED
Biofilms within drinking water distribution systems serve as a habitat for drinking water microorganisms. However, biofilms can negatively impact drinking water quality by causing water discoloration and deterioration and can be a reservoir for unwanted microorganisms. In this study, we investigated whether indicator organisms for drinking water quality, such as coliforms, can settle in mature drinking water biofilms. Therefore, a biofilm monitor consisting of glass rings was used to grow and sample drinking water biofilms. Two mature drinking water biofilms were characterized by flow cytometry, ATP measurements, confocal laser scanning microscopy, and 16S rRNA sequencing. Biofilms developed under treated chlorinated surface water supply exhibited lower cell densities in comparison with biofilms resulting from treated groundwater. Overall, the phenotypic as well as the genotypic characteristics were significantly different between both biofilms. In addition, the response of the biofilm microbiome and possible biofilm detachment after minor water quality changes were investigated. Limited changes in pH and free chlorine addition, to simulate operational changes that are relevant for practice, were evaluated. It was shown that both biofilms remained resilient. Finally, mature biofilms were prone to invasion of the coliform, . After spiking low concentrations (i.e., ±100 cells/100 mL) of the coliform to the corresponding bulk water samples, the coliforms were able to attach and get established within the mature biofilms. These outcomes emphasize the need for continued research on biofilm detachment and its implications for water contamination in distribution networks.
IMPORTANCE
The revelation that even low concentrations of coliforms can infiltrate into mature drinking water biofilms highlights a potential public health concern. Nowadays, the measurement of coliform bacteria is used as an indicator for fecal contamination and to control the effectiveness of disinfection processes and the cleanliness and integrity of distribution systems. In Flanders (Belgium), 533 out of 18,840 measurements exceeded the established norm for the coliform indicator parameter in 2021; however, the source of microbial contamination is mostly unknown. Here, we showed that mature biofilms, are susceptible to invasion of . These findings emphasize the importance of understanding and managing biofilms in drinking water distribution systems, not only for their potential to influence water quality, but also for their role in harboring and potentially disseminating pathogens. Further research into biofilm detachment, long-term responses to operational changes, and pathogen persistence within biofilms is crucial to inform strategies for safeguarding drinking water quality.
Topics: Biofilms; Drinking Water; Enterobacteriaceae; RNA, Ribosomal, 16S; Water Quality; Water Purification; Water Microbiology; Water Supply
PubMed: 38647288
DOI: 10.1128/aem.00042-24 -
Microorganisms Jan 2023Enterobacteriaceae represent one of the main families of Gram-negative bacilli responsible for serious urinary tract infections (UTIs). The present study aimed to define...
Enterobacteriaceae represent one of the main families of Gram-negative bacilli responsible for serious urinary tract infections (UTIs). The present study aimed to define the resistance profile and the virulence of Enterobacteriaceae strains isolated in urinary tract infections in Benin. A total of 390 urine samples were collected from patients with UTIs, and Enterobacteriaceae strains were isolated according to standard microbiology methods. The API 20E gallery was used for biochemical identification. All the isolated strains were subjected to antimicrobial susceptibility testing using the disc diffusion method. Extended-spectrum beta-lactamase (ESBL) production was investigated using a double-disc synergy test (DDST), and biofilm production was quantified using the microplate method. Multiplex PCR was used to detect uro-virulence genes, namely: PapG, IronB, Sfa, iucD, Hly, FocG, Sat, FyuA and Cnf, using commercially designed primers. More than 26% (103/390) of our samples were contaminated by Enterobacteriaceae strains at different levels. Thus, E. coli (31.07%, 32/103), Serratia marcescens (11.65%, 12/103), Klebsiella ornithinolytica (8.74%, 9/103), Serratia fonticola (7.77%, 8/103) and Enterobacter cloacae (6.80%, 7/103) were identified. Among the isolated strains, 39.81% (41/103) were biofilm-forming, while 5.83% (6/103) were ESBL-producing. Isolates were most resistant to erythromycin, cefixime, ceftriaxone and ampicillin (≥90%) followed by ciprofloxacin, gentamycin, doxycycline and levofloxacin (≥50%), and least resistant to imipenem (27.18%). In regard to virulence genes, Sfa was the most detected (28.15%), followed by IronB (22.23%), iucD (21.36%), Cnf (15.53%), PapG (9.71%), FocG (8.74%), Sat (6.79%), FyuA (5.82%) and Hyl (2.91%). These data may help improve the diagnosis of uropathogenic strains of Enterobacteriaceae, but also in designing effective strategies and measures for the prevention and management of severe, recurrent, or complicated urinary tract infections in Benin.
PubMed: 36677505
DOI: 10.3390/microorganisms11010213 -
Frontiers in Microbiology 2021Mosquitoes have evolved an effective innate immune system. The mosquito gut accommodates various microbes, which play a crucial role in shaping the mosquito immune...
Mosquitoes have evolved an effective innate immune system. The mosquito gut accommodates various microbes, which play a crucial role in shaping the mosquito immune system during evolution. The resident bacteria in the gut microbiota play an essential role in priming basal immunity. In this study, we show that antibacterial immunity in can be enhanced by priming via a sugar meal supplemented with bacteria. S1 and sp. Ag1 are gut bacteria in mosquitoes. The intrathoracic injection of the two bacteria can result in an acute hemocoelic infection in the naïve mosquitoes with mortality of ∼40% at 24 h post-infection. However, the or primed mosquitoes showed a better 24 h survival upon the bacterial challenge. The priming confers the protection with a certain degree of specificity, the primed mosquitoes had a better survival upon the but not challenge, and the primed mosquitoes had a better survival upon the but not challenge. To understand the priming-mediated immune enhancement, the transcriptomes were characterized in the mosquitoes of priming as well as priming plus challenges. The RNA-seq was conducted to profile 10 transcriptomes including three samples of priming conditions (native microbiota, priming, and priming), six samples of priming plus challenges with the two bacteria, and one sample of injury control. The three priming regimes resulted in distinctive transcriptomic profiles with about 60% of genes affected by both bacteria. Upon challenges, different primed mosquitoes displayed different transcriptomic patterns in response to different bacteria. When a primed cohort was challenged with a heterogenous bacterium, more responsive genes were observed than when challenged with a homogenous bacterium. As expected, many canonical immune genes were responsive to the priming and challenge, but much more non-immune genes with various functions were also responsive in the contexts, which implies that the prior priming triggers a delicately coordinated systemic regulation that results in an enhanced immunity against the subsequent challenge. Besides the participation of typical immune pathways, the transcriptome data suggest the involvement of lysosome and metabolism in the context. Overall, this study demonstrated a trained immunity via priming with bacteria in diet.
PubMed: 33995307
DOI: 10.3389/fmicb.2021.649213