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.
Milk spoilage is caused by the presence of proteolytic enzymes produced by
spp. during storage at low temperatures. The aim of this study was to identify
spp. in raw milk and investigate their ...associated proteolytic properties at low temperatures. Raw milk samples (
= 87) were collected from 87 bulk tanks in Shaanxi Province in China.
spp. were identified using
specific 16S, universal
sequencing, and
B gene sequencing. The proteolytic properties of
spp. were examined using milk agar, quantitative trinitrobenzenesulfonic acid assay, and by the presence of alkaline metallopeptidase gene (
X). A total 143 isolates from all 87 samples were confirmed as
, and were identified as belonging to 14
species. Of these, 40 (28.0%) isolates revealed proteolysis on milk agar at 2°C, 74 (51.8%) at 4°C, 104 (72.7%) at 7°C, and 102 (71.3%) at 10°C. However, proteolytic activity of 45 (31.5%) isolates exceeded 2 μmol of glycine equivalents per mL at 7°C, followed by 43 (30.1%) at 10°C, 18 (12.6%) at 4°C, and 7 (4.9%) at 2°C. The results reveal proteolytic activity of
spp. present in milk and their spoilage potential at different temperatures.
Plant-associated microbes play an important role in plant growth and development. While the introduction of beneficial microbes into the soil could improve plant production in low-input agricultural ...systems, real-world applications are still held back by poor survival and activity of the probiotic microbes. In this study, we used a biodiversity-ecosystem functioning (BEF) framework to specifically test how Pseudomonas community richness shapes the bacterial inoculant survival and functioning in terms of plant growth. To this end, we manipulated the richness of a probiotic Pseudomonas spp. bacterial community inoculant (1, 2, 4 or 8 strains per community) and compared diversity and strain identity effects on plant biomass production and nutrient assimilation in vivo with tomato. We found that increasing the richness of the bacterial inoculant enhanced the survival and abundance of Pseudomonas communities leading to higher accumulation of plant biomass and more efficient assimilation of nutrients into the plant tissue. Diversity effects were clearly stronger than the Pseudomonas strain identity effects and diversity-mediated plant growth promotion could be linked with increased production of plant hormones, siderophores and solubilization of phosphorus in vitro. Together these results suggest that multi-strain microbial inoculants can promote plant growth more reliably and effectively compared to single-strain inoculants.
•Multi-strain inoculants improve plant growth better than single-strain inoculants.•Richness effects were clearly stronger than the Pseudomonas strains identity effects.•Multi-strain inoculants enhance inoculants' abundance in the rhizosphere.•Plant growth linked with plant hormones, siderophores and phosphorus solubilization.
Normal bile is sterile. Studies have shown that cholangitis after liver transplantation (LT) was associated with a relatively poor prognosis. It remains unclear whether the bacteriobilia or ...fungibilia impact the patient outcomes in LT recipients, especially with donation after circulatory death (DCD) allografts, which was correlated with a higher risk of allograft failure.
This retrospective study included 139 LT recipients of DCD grafts from 2019 to 2021. All patients were divided into two groups according to the presence or absence of bacteriobilia or fungibilia. The prevalence and microbial spectrum of postoperative bacteriobilia or fungibilia and its possible association with outcomes, especially hospital stay were analyzed.
Totally 135 and 171 organisms were isolated at weeks 1 and 2, respectively. Among all patients included in this analysis, 83 (59.7%) developed bacteriobilia or fungibilia within 2 weeks post-transplantation. The occurrence of bacteriobilia or fungibilia (β = 7.43, 95% CI: 0.02 to 14.82, P = 0.049), particularly the detection of Pseudomonas (β = 18.84, 95% CI: 6.51 to 31.07, P = 0.003) within 2 weeks post-transplantation was associated with a longer hospital stay. However, it did not affect the graft and patient survival.
The occurrence of bacteriobilia or fungibilia, particularly Pseudomonas within 2 weeks post-transplantation, could influence the recovery of liver function and was associated with prolonged hospital stay but not the graft and patient survival.
Psychrotrophic bacteria in raw milk are most well known for their spoilage potential and the economic losses they cause to the dairy industry. Food-related psychrotrophic bacteria are increasingly ...reported to have antibiotic resistance features. The aim of this study was to evaluate the resistance patterns of
Pseudomonas
spp. isolated from bulk-tank milk. In total, we investigated the antibiotic susceptibility profiles of 86
Pseudomonas
spp. isolates from raw milk. All strains were tested against 15 antimicrobial agents.
Pseudomonas
isolates were most highly resistant to imipenem (95.3%), followed by trimethoprim-sulfamethoxazole (69.8%), aztreonam (60.5%), chloramphenicol (45.3%), and meropenem (27.9%). Their multiple antibiotic resistance (MAR) index values ranged from 0.0 to 0.8. Whole-genome sequencing revealed the presence of intrinsic resistance determinants, such as BcI,
amp
C-09,
bla
CTX-M,
opr
D,
sul
1,
dfr
E,
cat
A1,
cat
B3,
cat
I,
flo
R, and
cml
V. Moreover, resistance-nodulation-cell division (RND) and ATP-binding cassette (ABC) antibiotic efflux pumps were also found. This study provides further knowledge of the antibiotic resistance patterns of
Pseudomonas
spp. in milk, which may advance our understanding of resistance in
Pseudomonas
and suggests that antibiotic resistance of
Pseudomonas
spp. in raw milk should be a concern.
Pseudomonas aeruginosa healthcare outbreaks can be time consuming and difficult to investigate. Guidance does not specify which typing technique is most practical for decision-making.
To explore the ...usefulness of whole-genome sequencing (WGS) in the investigation of a P. aeruginosa outbreak, describing how it compares with pulsed-field gel electrophoresis (PFGE) and variable number tandem repeat (VNTR) analysis.
Six patient isolates and six environmental samples from an intensive care unit (ICU) positive for P. aeruginosa over two years underwent VNTR, PFGE and WGS.
VNTR and PFGE were required to fully determine the potential source of infection and rule out others. WGS results unambiguously distinguished linked isolates, giving greater assurance of the transmission route between wash-hand basin water and two patients, supporting the control measures employed.
WGS provided detailed information without the need for further typing. When allied to epidemiological information, WGS can be used to understand outbreak situations rapidly and with certainty. Implementation of WGS in real-time would be a major advance in day-to-day practice. It could become a standard of care as it becomes more widespread due to its reproducibility and lower costs.
Pharmaceutical effluents primarily enter aquatic environments through the discharge of treated and untreated wastewater from various sources, including hospitals, pharmaceutical manufacturing ...facilities, and households. Microbes sourced from pharmaceutical effluents such as
spp. pose a significant public health concern because of their high levels of resistance to multiple drugs and extreme multidrug resistance. Therefore, the present study was conducted for the isolation, identification, and molecular characterization of selected isolates from pharmaceutical effluents and also determined their antibiotic sensitivity patterns. From June 2016 to March 2017, a study was conducted on four well-known pharmaceutical companies specializing in antibiotic production in Dhaka and Gazipur. Four wastewater samples were collected from various origins and then brought to the Bacteriology laboratory for microbiological examination. Twelve pure isolates were obtained and characterized through cultural and biochemical tests while molecular identification of
spp. was performed using the 16S rRNA gene sequence. Twelve commercially available antibiotics were used for antibiotic sensitivity tests using Kirby-Bauer disk diffusion methods. We isolated the most predominant isolates,
(41.67%), followed by
spp. (33.33%) and
spp. (25%) respectively. Among 12 antibiotics, ciprofloxacin is 100% sensitive against
while the remaining 11 antibiotics are 100% resistant.
spp. showed 100% resistance to all antibiotics while 50% sensitive to vancomycin and 100% to chloramphenicol, respectively.
spp. was 100% resistant to all antibiotics. Our research suggested that
is the reservoir of antibiotic resistance genes and spreads disease to humans from the environment. The findings of this study, i.e., the isolation, identification, and characterization of antibiotic-resistant bacteria from pharmaceutical effluent have highlighted, comprehended, and mitigated the dissemination of antibiotic resistance and opportunistic bacteria.
Here, Pseudomonas spp. molecularly imprinted polymer-based surface plasmon resonance (MIP-based SPR) sensor has been prepared to perform quantitative analysis of Pseudomonas spp simultaneously. The ...polymeric nanofilm is imprinted on the SPR sensor surface with the microcontact printing method. Nanofilm was characterized with contact angle Non-Imprinted Polymer (NIP) and MIP SPR chips were found at 68.7° and 79.5°, respectively), ellipsometer measurement (the thickness of MIP and NIP nanofilm determined 150.4 ± 1.5 nm and 72.4 ± 1.2 nm values, respectively) and SEM analysis. The different Pseudomonas spp. were prepared at a concentration range of <inline-formula> <tex-math notation="LaTeX">1 \times 10^{2} </tex-math></inline-formula>-<inline-formula> <tex-math notation="LaTeX">1\,\,\times10 </tex-math></inline-formula> 4 CFU/mL and passed through the SPR system. The total detection time for all steps was reported in 150 seconds for microorganism detection, which is very short compared to the cultural method (2 days). The detection of limit value was calculated <inline-formula> <tex-math notation="LaTeX">0.5\,\,\times10 </tex-math></inline-formula> 2 CFU/mL. Selectivity of Pseudomonas spp. nanofilm based SPR sensors % <inline-formula> <tex-math notation="LaTeX">\boldsymbol {\Delta } \text{R} </tex-math></inline-formula> value was determined 8.3 for MIP and 0.25 for NIP. The relative selectivity coefficients (<inline-formula> <tex-math notation="LaTeX">\text{k}^\prime </tex-math></inline-formula>) of MIP nanofilm based SPR sensor for Staphylococcus aureus , Salmonella paratyphi and Escherichia coli were reported 25.82, 31.69 and 31.24 times, respectively. According to the data obtained in this study, the prepared Pseudomonas spp, suppressed surface plasmon resonance sensor, can be used as an alternative to the current cultural method and effective suppression quality, selectivity, and affinity.
Sixty-six putative Pseudomonas strains isolated from different food matrices (ready-to-eat vegetables, meat, milk and dairy products) were examined for their phenotypic features and enzymatic ...spoilage activities. Their genotype was studied by BOX-PCR, Pseudomonas specific 16S PCR, aprX and housekeeping genes sequencing (16S rRNA gene, gyrB and rpoB). The majority of the isolates are very versatile as shown by their wide ranges in growth temperature (4–45 °C), pigment production and production of enzymes. The BOX-PCR clustering showed a high genetic diversity among the isolates and phylogenetic analysis of the rpoB gene allowed a first putative identification at the species level. Thirteen isolates were provisionally classified as Pseudomonas gessardii-like, but probably belong to a yet unknown Pseudomonas species in the Pseudomonas fluorescens group.
Protease-activity was qualitatively and quantitatively verified. A large variation in proteolytic activity measured in UHT-milk was observed amongst the protease positive isolates. Several isolates provisionally classified as P. gessardii-like showed the highest activities. An aprX gene based phylogenetic dendrogram showed five different groups and two sub-groups, for which a correlation with the matrix of origin could be demonstrated. An insertion of 15 bp was observed in the aprX gene sequences of isolates of mainly dairy origin.
•A large diversity of Pseudomonas species was found over the different food matrices.•All isolates were able to produce enzymes and/or pigments that can affect foods.•A perfect match was found between proteolytic activity and presence of aprX gene.
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