Cefiderocol is a novel cephalosporin–siderophore conjugate antibiotic that holds promise to thwart infections caused by multi-drug-resistant gram-negative bacilli. Its antibacterial activity against ...normally susceptible species is not affected by most β-lactamases, including metallo-β-lactamases. Due to the siderophore-mediated entry into the cell, the activity of cefiderocol is less affected by porin loss or active efflux resistance than many other β-lactam antibiotics. The aim of this study was to assess in vitro susceptibility to the cefiderocol of carbapenemase-producing gram-negative bacilli from clinical samples of hospitalized patients.
We analyzed 102 clinical strains of carbapenemase-producing Enterobacterales and non-fermentives from hospital centers in Łódź, Poland. Antimicrobial susceptibility to cefiderocol was tested by the minimum inhibitory concentration test strips and disc diffusion methods.
The obtained results turned out to be ambiguous, and the area of technical uncertainty made their interpretation very difficult.
The cost of therapy with this antibiotic, and difficulties in interpreting the drug susceptibility are the limitations to the use of cefiderocol. Intensive work should be carried out to finally standardize an easily accessible and reliable method for the determination of susceptibility to cefiderocol.
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•Nanoemulsified clove essential oil (NCEO)-fish gelatin (FG) was prepared.•NCEO-FG inhibited the growth of Pseudomonas spp. on fillets.•NCEO-FG effectively delayed the deterioration ...of tilapia fillets.•NCEO-FG disturbed metabolisms of Pseudomonas spp.•Pseudomonas spp. developed a defense system within 24 h.
Fish products suffer Pseudomonas-causing spoilage quickly during refrigeration storage, which could be solved by applying edible coating derived from nanoemulsified clove essential oils and fish gelatin (NCEO-FG). This study aimed to evaluate the effects and mechanism of NCEO-FG in preserving tilapia (Oreochromis niloticus) fillets that were inoculated with Pseudomonas spp. (Pseudomonas sp. strain ABa3, P. psychrophila strain ABe3, and P. fragi strain BBa3). NCEO caused remarkable leakage of proteins (198.5–252.8 μg/L) and nucleic acids (0.30–0.34 of OD260). After being incorporated into FG, NCEO-FG effectively delayed the deterioration of tilapia fillets because it significantly reduced the surviving bacteria populations (0.78 – 1.80 log CFU/g reductions) and inhibited the proteolysis and oxidation during cold storage. Further, the metabolic responses of NCEO-FG coated Pseudomonas spp. were revealed using NMR spectroscopy: the reducing levels of metabolites (e.g., pyruvate, amino acids, and betaine) suggested that the NCEO-FG disturbed energy and amino acid metabolisms of bacteria cells. However, the levels of metabolites (e.g., amino acids and osmoprotectants) were upregulated after 3 h and then back to normal concentration after 24 h, which indicated a defense system was built in bacterial cells to tolerate NCEO-FG. In short, this study confirmed that NCEO-FG could control the Pseudomonas-causing spoilage in fish fillets via elucidating the metabolisms.
This work aimed to focus on the antibacterial properties of garlic nanoemulsion on some multidrug resistance (MDR) strains of Pseudomonas aeruginosaisolated from broiler farms and hatcheries in ...Sharkia and Ismailia governorates, Egypt. Pseudomonas spp. was isolated in 21.3% of collected samples. It was isolated from younger broilers 1-10 days with an incidence rate of 22% (11/50), older broilers 16% (8/50), dead embryo in shell 31.4% (11/35), and from hatcheries was 13.3% (2/15). There was a variable range of antibiotic resistance ranging from 66.7-100% against the isolated strains of P. aeruginosa. Tetracycline and sulfamethoxazole-trimethoprim achieved the highest resistance rates, while penicillin and gentamycin were of a lower rate. However, norfloxacin, ciprofloxacin, and colistin were the most sensitive antibiotics against examined MDR P. aeruginosa.16SrDNA gene was found in ten P. aeruginosa isolates. Theseisolates were found to be virulent as oprL gene was detected in all isolates 100%. In addition, tetA(A),blaTEM,arr, and mexRantibiotic resistance genes were shown positive 100% in all MDR P. aeruginosa isolates. Minimum Inhibitory Concentration (MIC) values showed that garlic nanoemulsion (GN) was effective against examined P. aeruginosa at different concentrations. GN had 29.61% sulfur compounds of active components with 0.52 ug/ml of IC50 and 40.94 nm size with polydispersity index: 0.165 using dynamic light scattering had a 19.6± 5.11mV. In conclusion, the application of garlic nanoemulsion is an excellent alternative candidate to antibiotics for treatment because it significantly reduced the gene expression levels of MDR P. aeruginosa in broiler farms.
Introdução: Pseudomonas sp é um patógeno oportunista que está associado a diversos casos de Infecções Relacionadas à Assistência à Saúde (IRAS). A produção de enzimas carbapenamases incluíndo a ...coprodução destas enzimas por estes patógenos se tornou uma preocupação em saúde pública, principalmente após a pandemia da COVID-19, uma vez que os carbapenêmicos estão entre os antimicrobianos de último recurso para o tratamento de infecções multirresistentes e novos antimicrobianos, como ceftazidima-avibactam, dependem do tipo de carbapenemase envolvido. Objetivo: Avaliar a prevalência dos genes de enzimas carbapenemases mais prevalentes em 208 isolados de Pseudomonas sp não sensíveis ao meropenem, no período de julho de 2022 a junho 2023 no Hospital de Clínicas de Porto Alegre. Métodos: A identificação bacteriana foi realizada pela técnica de MALDI TOF pelo Vitek MS, Biomerieux. O teste de suscetibilidade aos antimicrobianos foi realizado pelo método de disco-difusão conforme o BrCAST, 2022. A Reação em Cadeia da Polimerase (PCR) convencional para a identificação do gene blaSPM e o teste de RT-qPCR por High-Resolution Melt (HRM) para a detectação de seis diferentes tipos genéticos de carbapenemases blaKPC, blaNDM, blaGES, blaOXA-48, blaIMP e blaVIM foram realizados. Resultados: Um total de 52,9% dos isolados de Pseudomonas spp. meropenem resistentes não apresentou nenhum dos genes pesquisados; 37,0% apresentaram o gene blaNDM; 3,4% apresentaram o gene blaVIM, 1,4% apresentaram o gene blaIMP e 1,0% apresentaram o gene blaSPM; 1,9% apresentaram concomitantemente os genes blaIMP e blaVIM; 0,5% apresentaram os genes blaVIM e blaSPM; e 0,5% apresentaram os genes blaNDM e blaGES. Conclusão: Mais da metade dos isolados de Pseudomonas spp. não apresentaram produção das carbapenemases pesquisadas, podendo haver outros mecanismos de resistência aos carbapenêmicos que não foram pesquisados. A enzima mais prevalente foi a blaNDM sendo detectada em mais de um terço dos isolados, excluindo a possibilidade de tratamento com ceftazidima-avibactam. Portanto, evidencia-se a importância em pesquisar a produção de carbapenemases em Pseudomonas spp. tanto para o sucesso do tratamento como para o conhecimento da epidemiologia local.
Heavier fraction hydrocarbons (C15-C36) formed in soil after biotic and abiotic weatherings of engine oil are the continuing constraints in the bioremediation strategy, and their bioavailability ...remains a poorly quantified regulatory factor. In a microcosm study, we used two strains of Pseudomonas, P. putida TPHK-1 and P. aeruginosa TPHK-4, in strategies of bioremediation, viz., natural attenuation, biostimulation and bioaugmentation, for removal of weathered total petroleum hydrocarbons (TPHs) in soil contaminated long-term with high concentrations of engine oil (39,000–41,000 mg TPHs kg−1 soil). Both the bacterial strains exhibited a great potential in remediating weathered hydrocarbons of engine oil. Addition of inorganic fertilizers (NPK), at recommended levels for bioremediation, resulted in significant inhibition in biostimulation/enhanced natural attenuation as well as bioaugmentation. The data on dehydrogenase activity clearly confirmed those of bioremediation strategies used, indicating that this enzyme assay could serve as an indicator of bioremediation potential of oil-contaminated soil. Extraction of TPHs from engine oil-contaminated soil with hydroxypropyl-β-cyclodextrin (HPCD), but not 1-butanol, was found reliable in predicting the bioavailability of weathered hydrocarbons. Also, 454 pyrosequencing data were in accordance with those of bioremediation strategies used in the present microcosm study, suggesting the possible use of pyrosequencing in designing approaches for bioremediation.
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•Weathered TPHs in engine oil-contaminated soil were bioaugmented by Pseudomonas spp.•Combination of biostimulation and bioaugmentation inhibited bioremediation of weathered TPHs.•Soil dehydrogenase activity is in conformity with bioremediation of weathered TPHs.•Soil extraction with cyclodextrin is suitable for assessing bioavailability of weathered TPHs.•Pyrosequencing data clearly corroborate the results of weathered TPHs bioremediation.
The aim of this study was to investigate the ability of Pseudomonas spp. strains isolated from milk, dairy products and dairy plants, to produce blue pigment in situ, to form biofilm onto polystyrene ...surfaces and to perform different types of motility. Molecular identification revealed that, out of 72 Pseudomonas spp. isolates, P. fluorescens was the most common species (50 isolates) followed by P. putida (9), P. koreensis (4), P. brenneri (4), P. aeruginosa (2), P. granadensis (2) and P. veronii (1).
The evaluation of blue colour production showed that the pigment was produced at 10 °C but not at 30 °C; in addition this character was strain- and species-dependent, with only 16 P. fluorescens strains showing blue pigment production. Most of the studied strains produced biofilm although with some differences related to the strains and the incubation temperatures. Within the most abundant isolated species (P. fluorescens), about 46%, 34% and 26% of the strains were able to swim, swarm and twitch, respectively. The observed relationship between biofilm formation and blue pigment production in P. fluorescens strains was statistically significant.
Since these characteristics may contribute to the persistence of microorganisms in food processing environments and therefore to the contamination of food products, our results may help to focus on the control of the strains involved in the blue discolouration of dairy products.
•Pseudomonas fluorescens was the most common species among 72 isolates from dairy products and plants.•Only 16 P. fluorescens strains produced blue pigment at 10 °C.•Biofilm production was strain-dependent, with differences related also to incubation conditions.•Great part of the strong biofilm producers were also blue pigment producers.
The rhizosphere was defined over 100 years ago as the zone around the root where microorganisms and processes important for plant growth and health are located. Recent studies show that the diversity ...of microorganisms associated with the root system is enormous. This rhizosphere microbiome extends the functional repertoire of the plant beyond imagination. The rhizosphere microbiome of Arabidopsis thaliana is currently being studied for the obvious reason that it allows the use of the extensive toolbox that comes with this model plant. Deciphering plant traits that drive selection and activities of the microbiome is now a major challenge in which Arabidopsis will undoubtedly be a major research object. Here we review recent microbiome studies and discuss future research directions and applicability of the generated knowledge.
The quality of raw milk is important in determining the quality of manufactured dairy products. In recent years, the amalgamation of small dairy manufacturing plants into large mega sites has ...resulted in longer storage of milk during transportation and storage, particularly during peak milk flow in a seasonal dairy industry. The aim of this research is to determine the influence of this extended storage on psychrotrophic enzyme-producing bacteria even if the cold chain is maintained. In this study, the numbers and types of psychrotrophs in raw milk with and without refrigerated enrichment (5 days at 7 °C) were compared to understand the effect of extended refrigeration on the changes in raw milk microbial ecology. Two-hundred and six isolates from both fresh and enriched raw milk were identified by MALDI-TOF MS and assessed for proteolytic and lypolytic activity at 7 °C and the heat stability of these enzymes (72 °C, 15 s) was measured. This is the first report to compare the raw milk microbiota before and after extended refrigeration at both genus and species levels. This study also characterized these bacterial isolates, some of which have never been reported in milk, for their potential to spoil dairy products.
•Extended refrigeration can shift the microbial diversity of raw milk.•Five Pseudomonas species producing heat stable protease and lipase found for the first time in milk.•MALDI-TOF MS and agar diffusion assays rapidly identifies protease and lipase producing bacteria.
The world potato is facing major economic losses due to disease pressure and environmental concerns regarding pesticides use. This work aims at addressing these two issues by isolating indigenous ...bacteria that can be integrated into pest management strategies. More than 2,800 strains of
-like and
-like were isolated from several soils and substrates associated with potato agro-systems in Belgium. Screenings for antagonistic activities against the potato pathogens
(BCCM-MUCL 5492),
(ATCC 15713),
(CRA-W10022) and
(BCCM-MUCL 51929) were performed, allowing the selection of 52
spp. and eight
spp. displaying growth inhibition of at least 50% under
conditions, particularly against
. All 60 bacterial isolates were identified based on 16S rRNA gene sequencing and further characterized for the production of potential bio-active secondary metabolites. The antagonistic activities displayed by the selected strains indicated that versatile metabolites can be produced by the strains. For instance, the detection of genes involved bacilysin biosynthesis was correlated with the strong antagonism of
strains toward
, whereas the production of both bio-surfactants and siderophores might explain the high antagonistic activities against late blight. Greenhouse assays with potato plants were performed with the most effective strains (seven
spp. and four
spp.) in order to evaluate their
antagonistic effect against
. Based on these results, four strains (
17A-B3,
30B-B6,
43R-P1 and
44R-P8) were retained for further evaluation of their protection index against
in a pilot field trial. Interestingly,
30B-B6 was shown to significantly decrease late blight severity throughout the crop season. Overall, this study showed that antagonistic indigenous soil bacteria can offer an alternative to the indiscriminate use of pesticide in potato agro-systems.
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