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.
Microbial surfactants are amphiphilic surface-active substances aid to reduce surface and interfacial tensions by accumulating between two fluid phases. They can be generically classified as low or ...high molecular weight biosurfactants based on their molecular weight, whilst overall chemical makeup determines whether they are neutral or anionic molecules. They demonstrate a variety of fundamental characteristics, including the lowering of surface tension, emulsification, adsorption, micelle formation, etc. Microbial genera like
Bacillus
spp.,
Pseudomonas
spp
., Candida
spp., and
Pseudozyma
spp. are studied extensively for their production. The type of biosurfactant produced is reliant on the substrate utilized and the pathway pursued by the generating microorganisms. Some advantages of biosurfactants over synthetic surfactants comprise biodegradability, low toxicity, bioavailability, specificity of action, structural diversity, and effectiveness in harsh environments. Biosurfactants are physiologically crucial molecules for producing microorganisms which help the cells to grasp substrates in adverse conditions and also have antimicrobial, anti-adhesive, and antioxidant properties. Biosurfactants are in high demand as a potential product in industries like petroleum, cosmetics, detergents, agriculture, medicine, and food due to their beneficial properties. Biosurfactants are the significant natural biodegradable substances employed to replace the chemical surfactants on a global scale in order to make a cleaner and more sustainable environment.
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.
We recently identified a novel plasmid-mediated resistance-nodulation-division (RND)-type efflux pump gene cluster,
, in
that conferred resistance to multiple antimicrobials, including tigecycline. ...While homologs of
were found encoded in many other bacterial species in GenBank, their functions and transfer mechanisms remain unknown. This study identified another mobile gene cluster,
, co-occurring on both a plasmid (pHNNC189-2) and the chromosome of a clinical
isolate, strain NC189, producing KPC-2, NDM-1, and RmtC.
shares high similarity at the nucleotide level with
, with 98.02%, 96.75%, and 99.93% identities to
,
, and
, respectively. Phylogenetic analysis revealed that
may have originated from the chromosome of a
species. The expression of
in an
strain resulted in an 8-fold increase in the tigecycline MIC and decreased susceptibility to other antimicrobials. Genetic context analyses demonstrated that
, together with the adjacent hypothetical site-specific integrase genes, was possibly captured and mobilized by a XerD-like tyrosine recombinase system, forming a putative transposition unit (
-like-
-like-
Δ
-
-like-
-like-
IS
Δ
), which was inserted into
like genes in both the NC189 plasmid pHNNC189-2 and the chromosome. Since
and
could confer multidrug resistance, the spread of these gene clusters, associated with the new recombinase system, calls for more attention.
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.
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