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PloS One 2024Fourier transform infrared (FTIR) spectroscopy is a biophysical technique used for non-destructive biochemical profiling of biological samples. It can provide...
Fourier transform infrared (FTIR) spectroscopy is a biophysical technique used for non-destructive biochemical profiling of biological samples. It can provide comprehensive information about the total cellular biochemical profile of microbial cells. In this study, FTIR spectroscopy was used to perform biochemical characterization of twenty-nine bacterial strains isolated from the Antarctic meltwater ponds. The bacteria were grown on two forms of brain heart infusion (BHI) medium: agar at six different temperatures (4, 10, 18, 25, 30, and 37°C) and on broth at 18°C. Multivariate data analysis approaches such as principal component analysis (PCA) and correlation analysis were used to study the difference in biochemical profiles induced by the cultivation conditions. The observed results indicated a strong correlation between FTIR spectra and the phylogenetic relationships among the studied bacteria. The most accurate taxonomy-aligned clustering was achieved with bacteria cultivated on agar. Cultivation on two forms of BHI medium provided biochemically different bacterial biomass. The impact of temperature on the total cellular biochemical profile of the studied bacteria was species-specific, however, similarly for all bacteria, lipid spectral region was the least affected while polysaccharide region was the most affected by different temperatures. The biggest temperature-triggered changes of the cell chemistry were detected for bacteria with a wide temperature tolerance such Pseudomonas lundensis strains and Acinetobacter lwoffii BIM B-1558.
Topics: Antarctic Regions; Spectroscopy, Fourier Transform Infrared; Bacteria; Ponds; Phylogeny; Temperature; Water Microbiology; Principal Component Analysis
PubMed: 38885224
DOI: 10.1371/journal.pone.0303298 -
Indian Journal of Pathology &... Jun 2024Helicobacter pylori (H. pylori) colonization affects the gastric microbiome, causing gastrointestinal (GI) diseases. Modern sequencing technology provides insights into...
BACKGROUND/AIM
Helicobacter pylori (H. pylori) colonization affects the gastric microbiome, causing gastrointestinal (GI) diseases. Modern sequencing technology provides insights into GI microbe interaction with H. pylori and their metabolic pathways in causing GI diseases. We aim to compare the gastric microbiota alteration due to H. pylori infection in patients suffering from GI diseases.
MATERIALS AND METHODS
Genomic DNA were isolated from gastric antrum tissue from 37 H.pylori-infected patients diagnosed with GERD, duodenal ulcers, and gastritis. We conducted the genomic library preparation and sequencing of the amplified product using 16S rRNA NGS analysis. Using microbiome analyst tool diversity analysis, random forest analysis and ANOVA were conducted to find out the comparison of microbial abundance. We have also conducted functional pathway prediction analysis using PICRUSt.
RESULTS
Metagenomic analysis shows high bacterial diversity in H. pylori-positive gastritis patients. Streptococcus infantis and Neisseria subflava were significantly higher in duodenal ulcer (DU) and gastritis groups. Acinetobacter lwoffii and Helicobacter pullorum were significantly high in the gastritis group only. The functional metabolic pathway analyses revealed that gastroesophageal reflux disease (GERD) samples were significantly enriched with the energy metabolism and xenobiotic biodegradation and metabolism pathways, whereas fructose-1,6-bisphosphatase III was found less in gastritis and DU groups.
CONCLUSION
There is a difference in microbiota composition in different disease outcomes. We found positive association between microbial diversity and H. pylori in gastritis group only, whereas negative association was found in DU and GERD groups. The functional metabolic pathway analysis revealed significant differences in various disease outcomes.
PubMed: 38847202
DOI: 10.4103/ijpm.ijpm_1015_23 -
BMC Veterinary Research May 2024Acinetobacter lwoffii (A.lwoffii) is a serious zoonotic pathogen that has been identified as a cause of infections such as meningitis, bacteremia and pneumonia. In...
BACKGROUND
Acinetobacter lwoffii (A.lwoffii) is a serious zoonotic pathogen that has been identified as a cause of infections such as meningitis, bacteremia and pneumonia. In recent years, the infection rate and detection rate of A.lwoffii is increasing, especially in the breeding industry. Due to the presence of biofilms, it is difficult to eradicate and has become a potential super drug-resistant bacteria. Therefore, eradication of preformed biofilm is an alternative therapeutic action to control A.lwoffii infection. The present study aimed to clarify that baicalin could eradicate A.lwoffii biofilm in dairy cows, and to explore the mechanism of baicalin eradicating A.lwoffii.
RESULTS
The results showed that compared to the control group, the 4 MIC of baicalin significantly eradicated the preformed biofilm, and the effect was stable at this concentration, the number of viable bacteria in the biofilm was decreased by 0.67 LogCFU/mL. The total fluorescence intensity of biofilm bacteria decreased significantly, with a reduction rate of 67.0%. There were 833 differentially expressed genes (367 up-regulated and 466 down-regulated), whose functions mainly focused on oxidative phosphorylation, biofilm regulation system and trehalose synthesis. Molecular docking analysis predicted 11 groups of target proteins that were well combined with baicalin, and the content of trehalose decreased significantly after the biofilm of A.lwoffii was treated with baicalin.
CONCLUSIONS
The present study evaluated the antibiofilm potential of baicalin against A.lwoffii. Baicalin revealed strong antibiofilm potential against A.lwoffii. Baicalin induced biofilm eradication may be related to oxidative phosphorylation and TCSs. Moreover, the decrease of trehalose content may be related to biofilm eradication.
Topics: Biofilms; Animals; Flavonoids; Acinetobacter; Cattle; Milk; Anti-Bacterial Agents; Microbial Sensitivity Tests; Molecular Docking Simulation; Female; Acinetobacter Infections
PubMed: 38764041
DOI: 10.1186/s12917-024-04015-w -
Biomedical and Environmental Sciences :... Mar 2024The purpose of this study was to investigate the bacterial communities of biting midges and ticks collected from three sites in the Poyang Lake area, namely, Qunlu...
OBJECTIVE
The purpose of this study was to investigate the bacterial communities of biting midges and ticks collected from three sites in the Poyang Lake area, namely, Qunlu Practice Base, Peach Blossom Garden, and Huangtong Animal Husbandry, and whether vectors carry any bacterial pathogens that may cause diseases to humans, to provide scientific basis for prospective pathogen discovery and disease prevention and control.
METHODS
Using a metataxonomics approach in concert with full-length 16S rRNA gene sequencing and operational phylogenetic unit (OPU) analysis, we characterized the species-level microbial community structure of two important vector species, biting midges and ticks, including 33 arthropod samples comprising 3,885 individuals, collected around Poyang Lake.
RESULTS
A total of 662 OPUs were classified in biting midges, including 195 known species and 373 potentially new species, and 618 OPUs were classified in ticks, including 217 known species and 326 potentially new species. Surprisingly, OPUs with potentially pathogenicity were detected in both arthropod vectors, with 66 known species of biting midges reported to carry potential pathogens, including and , compared to 50 in ticks, such as and . We found that was the most dominant group in both midges and ticks. Furthermore, the outcomes demonstrated that the microbiota of midges and ticks tend to be governed by a few highly abundant bacteria. sp7 was predominant in biting midges, while sp1 was enriched in ticks. Meanwhile, spp., which may be essential for the survival of Neumann, were detected in all tick samples. The identification of dominant species and pathogens of biting midges and ticks in this study serves to broaden our knowledge associated to microbes of arthropod vectors.
CONCLUSION
Biting midges and ticks carry large numbers of known and potentially novel bacteria, and carry a wide range of potentially pathogenic bacteria, which may pose a risk of infection to humans and animals. The microbial communities of midges and ticks tend to be dominated by a few highly abundant bacteria.
Topics: Animals; Humans; Ticks; Ceratopogonidae; Phylogeny; RNA, Ribosomal, 16S; Prospective Studies; Microbiota; Coxiella
PubMed: 38582991
DOI: 10.3967/bes2024.030 -
MSphere May 2024The two species that account for most cases of -associated bacteremia in the United Kingdom are , often a commensal but also an emerging pathogen, and , a well-known...
UNLABELLED
The two species that account for most cases of -associated bacteremia in the United Kingdom are , often a commensal but also an emerging pathogen, and , a well-known antibiotic-resistant species. While these species both cause similar types of human infection and occupy the same niche, (unlike ) has thus far remained susceptible to antibiotics. Comparatively little is known about the biology of , and this is the largest study on it conducted to date, providing valuable insights into its behaviour and potential threat to human health. This study aimed to explain the antibiotic susceptibility, virulence, and fundamental biological differences between these two species. The relative susceptibility of was explained as it encoded fewer antibiotic resistance and efflux pump genes than (9 and 30, respectively). While both species had markers of horizontal gene transfer, encoded more DNA defense systems and harbored a far more restricted range of plasmids. Furthermore, displayed a reduced ability to select for antibiotic resistance mutations, form biofilm, and infect both and in models of infection. This study suggests that the emerging pathogen has remained susceptible to antibiotics because mechanisms exist to make it highly selective about the DNA it acquires, and we hypothesize that the fact that it only harbors a single RND system restricts the ability to select for resistance mutations. This provides valuable insights into how development of resistance can be constrained in Gram-negative bacteria.
IMPORTANCE
is often a harmless commensal but is also an emerging pathogen and is the most common cause of -derived bloodstream infections in England and Wales. In contrast to the well-studied and often highly drug-resistant , has remained susceptible to antibiotics. This study explains why this organism has not evolved resistance to antibiotics. These new insights are important to understand why and how some species develop antibiotic resistance, while others do not, and could inform future novel treatment strategies.
Topics: Acinetobacter; Virulence; Acinetobacter Infections; Anti-Bacterial Agents; Biofilms; Microbial Sensitivity Tests; Animals; Humans; Drug Resistance, Bacterial; Acinetobacter baumannii; Mice; Gene Transfer, Horizontal; United Kingdom; Female; Plasmids
PubMed: 38578105
DOI: 10.1128/msphere.00109-24 -
The Journal of Hospital Infection Apr 2024Carbapenem-resistant Acinetobacter baumannii is a common pathogen associated with healthcare-acquired infections, and robust infection prevention and control protocols...
BACKGROUND
Carbapenem-resistant Acinetobacter baumannii is a common pathogen associated with healthcare-acquired infections, and robust infection prevention and control protocols exist in human healthcare settings. In contrast, infection prevention and control (IPC) standards are limited in veterinary medicine, necessitating further investigation.
AIM
Examine the possible transmission of carbapenem-resistant Acinetobacter spp. in a veterinary practice where a cat was diagnosed with an OXA-23-producing A. baumannii ST2 strain.
METHODS
Environmental samples together with nasal and hand swabs from the veterinary personnel were collected. All swabs were screened for the presence of extended-spectrum-β-lactamase- and carbapenemase-producing Enterobacterales, meticillin-resistant staphylococcus and multi-drug-resistant Acinetobacter spp. Whole-genome sequencing was performed for carbapenemase-producing strains.
RESULTS
Of the veterinary staff, 60% carried meticillin-resistant Staphylococcus epidermidis. Environmental evaluation showed that 40% (N=6/15) of the surfaces analysed by contact plates and 40% (N=8/20) by swabs failed the hygiene criteria. Assessment of the surfaces revealed contamination with five OXA-23-producing Acinetobacter spp. strains: an OXA-23-producing Acinetobacter schindleri on the weight scale in the waiting room; and four OXA-23-producing Acinetobacter lwoffii strains, on different surfaces of the treatment room. The bla gene was located on the same plasmid-carrying Tn2008 across the different Acinetobacter spp. strains. These plasmids closely resemble a previously described OXA-23-encoding plasmid from a human Portuguese nosocomial Acinetobacter pittii isolate. Distinctly, the OXA-23-producing A. baumannii ST2 clinical strain had the resistant gene located on Tn2006, possibly inserted on the chromosome.
CONCLUSION
The detection of an OXA-23-producing A. baumannii ST2 veterinary clinical strain is of concern for companion animal health and infection, prevention and control. This study established the dynamic of transmission of the plasmid-mediated bla gene on critical surfaces of a small animal veterinary practice. The genetic resemblance to a plasmid found in human nosocomial settings suggests a potential One Health link.
Topics: Animals; Humans; Interleukin-1 Receptor-Like 1 Protein; Methicillin; Methicillin-Resistant Staphylococcus aureus; One Health; Acinetobacter Infections; Microbial Sensitivity Tests; Bacterial Proteins; beta-Lactamases; Acinetobacter baumannii; Carbapenems; Cross Infection; Anti-Bacterial Agents
PubMed: 38365067
DOI: 10.1016/j.jhin.2024.02.001 -
Animals : An Open Access Journal From... Jan 2024Antimicrobials are extensively utilized in dairy farms to prevent and control diseases in cattle. However, their use contributes to the emergence of...
Antimicrobials are extensively utilized in dairy farms to prevent and control diseases in cattle. However, their use contributes to the emergence of antimicrobial-resistant bacteria (ARB) and antimicrobial-resistant genes (ARG), and these can be transmitted to the environment. Regular monitoring of antimicrobial resistance (AMR) is crucial for implementing effective mitigation strategies. This research aimed to assess the environmental microbial species present on dairy farms in Shandong Province and characterize the antimicrobial resistance profiles of the isolates. Five dairy farms located in Shandong Province were selected, representing the prevalent large-scale farming patterns in the area. Sampling took place from April to June 2022, with a total of 223 isolates collected from various environmental locations within each farm (bedding, sports field, and milking parlor). Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) was employed to identify the species of the clinical isolates. The main pathogens isolated were (5.38%, = 12), (4.93%, = 11), and (4.03%, = 9). Among the bacterial isolates, resistance to lincomycin was highest at 91%, and 88% were resistant to sulfadiazine. Antimicrobial resistance genes were detected in only a small proportion of the isolates, the most common of which was . These findings highlight the necessity for careful evaluation of antimicrobial usage in maintaining their effectiveness in human medicine. Understanding the microbial species present and their antimicrobial resistance profiles aids in focusing efforts toward sustainable antimicrobial use and safeguarding human health.
PubMed: 38200891
DOI: 10.3390/ani14010160 -
Antimicrobial Stewardship & Healthcare... 2023To describe antimicrobial therapy used for multidrug-resistant (MDR) bacteremia in Veterans and impacts on mortality.
OBJECTIVE
To describe antimicrobial therapy used for multidrug-resistant (MDR) bacteremia in Veterans and impacts on mortality.
METHODS
This was a retrospective cohort study of hospitalized Veterans Affairs patients from 2012 to 2018 with a positive MDR blood culture who received antimicrobial treatment 2 days prior to through 5 days after the culture date. Only the first culture per patient was used. The association between treatment and patient characteristics was assessed using bivariate analyses. Multivariable logistic regression models examined the relationship between antibiotic regimen and in-hospital, 30-day, and 1-year mortality. Generalized linear models were used to assess cost outcomes.
RESULTS
MDR was identified in 184 patients. Most cultures identified were , 3% were and 7% were other Penicillins-β-lactamase inhibitor combinations (51.1%) and carbapenems (51.6%)-were the most prescribed antibiotics. In unadjusted analysis, extended spectrum cephalosporins and penicillins-β-lactamase inhibitor combinations-were associated with a decreased odds of 30-day mortality but were insignificant after adjustment (adjusted odds ratio (aOR) = 0.47, 95% CI, 0.21-1.05, aOR = 0.75, 95% CI, 0.37-1.53). There was no association between combination therapy vs monotherapy and 30-day mortality (aOR = 1.55, 95% CI, 0.72-3.32).
CONCLUSION
In hospitalized Veterans with MDR ., none of the treatments were shown to be associated with in-hospital, 30-day, and 1-year mortality. Combination therapy was not associated with decreased mortality for MDR bacteremia.
PubMed: 38156232
DOI: 10.1017/ash.2023.500 -
Frontiers in Immunology 2023is a widespread Gram-negative pathogen involved in a variety of gastrointestinal diseases, including gastritis, ulceration, mucosa-associated lymphoid tissue (MALT)...
is a widespread Gram-negative pathogen involved in a variety of gastrointestinal diseases, including gastritis, ulceration, mucosa-associated lymphoid tissue (MALT) lymphoma and gastric cancer. Immune responses aimed at eradication of often prove futile, and paradoxically play a crucial role in the degeneration of epithelial integrity and disease progression. We have previously shown that infection of primary human monocytes increases their potential to respond to subsequent bacterial stimuli - a process that may be involved in the generation of exaggerated, yet ineffective immune responses directed against the pathogen. In this study, we show that -induced monocyte priming is not a common feature of Gram-negative bacteria, as induces tolerance to subsequent lipopolysaccharide (LPS) challenge. Although the increased reactivity of infected monocytes seems to be specific to , it appears to be independent of its virulence factors Cag pathogenicity island (CagPAI), cytotoxin associated gene A (CagA), vacuolating toxin A (VacA) and γ-glutamyl transferase (γ-GT). Utilizing whole-cell proteomics complemented with biochemical signaling studies, we show that infection of monocytes induces a unique proteomic signature compared to other pro-inflammatory priming stimuli, namely LPS and the pathobiont . Contrary to these tolerance-inducing stimuli, priming leads to accumulation of NF-кB proteins, including p65/RelA, and thus to the acquisition of a monocyte phenotype more responsive to subsequent LPS challenge. The plasticity of pro-inflammatory responses based on abundance and availability of intracellular signaling molecules may be a heretofore underappreciated form of regulating innate immune memory as well as a novel facet of the pathobiology induced by .
Topics: Humans; NF-kappa B; Bacterial Proteins; Helicobacter pylori; Trained Immunity; Lipopolysaccharides; Proteomics
PubMed: 38053995
DOI: 10.3389/fimmu.2023.1290833 -
International Journal of Molecular... Nov 2023Microorganism-based methods have been widely applied for the treatment of phenol-polluted environments. The previously isolated NL1 strain could completely degrade 0.5...
Microorganism-based methods have been widely applied for the treatment of phenol-polluted environments. The previously isolated NL1 strain could completely degrade 0.5 g/L phenol within 12 h, but not higher concentrations of phenol. In this study, we developed an evolutionary strain NL115, through adaptive laboratory evolution, which possessed improved degradation ability and was able to degrade 1.5 g/L phenol within 12 h. Compared with that of the starting strain NL1, the concentration of degradable phenol by the developed strain increased three-fold; its phenol tolerance was also enhanced. Furthermore, comparative genomics showed that sense mutations mainly occurred in genes encoding alkyl hydroperoxide reductase, phenol hydroxylase, 30S ribosomal protein, and mercury resistance operon. Comparative transcriptomics between NL115 and NL1 revealed the enrichment of direct degradation, stress resistance, and vital activity processes among the metabolic responses of adapted to phenol stress. Among these, all the upregulated genes (logfold-change > 5) encoded peroxidases. A phenotypic comparison of NL1 and NL115 found that the adapted strain NL115 exhibited strengthened antioxidant capacity. Furthermore, the increased enzymatic activities of phenol hydroxylase and alkyl hydroperoxide reductase in NL115 validated their response to phenol. Overall, this study provides insight into the mechanism of efficient phenol degradation through adaptive microbial evolution and can help to drive improvements in phenol bioremediation.
Topics: Transcriptome; Phenols; Phenol; Biodegradation, Environmental; Genomics; Peroxiredoxins
PubMed: 38003719
DOI: 10.3390/ijms242216529