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Applied Microbiology and Biotechnology Jun 2024Direct ammonia oxidation (Dirammox) might be of great significance to advance the innovation of biological nitrogen removal process in wastewater treatment systems....
Direct ammonia oxidation (Dirammox) might be of great significance to advance the innovation of biological nitrogen removal process in wastewater treatment systems. However, it remains unknown whether Dirammox bacteria can be selectively enriched in activated sludge. In this study, a lab-scale bioreactor was established and operated for 2 months to treat synthetic wastewater with hydroxylamine as a selection pressure. Three Dirammox strains (Alcaligenes aquatilis SDU_AA1, Alcaligenes aquatilis SDU_AA2, and Alcaligenes sp. SDU_A2) were isolated from the activated sludge, and their capability to perform Dirammox process was confirmed. Although these three Dirammox bacteria were undetectable in the seed sludge (0%), their relative abundances rapidly increased after a month of operation, reaching 12.65%, 0.69%, and 0.69% for SDU_A2, SDU_AA1, and SDU_AA2, respectively. Among them, the most dominant Dirammox (SDU_A2) exhibited higher nitrogen removal rate (32.35%) than the other two strains (13.57% of SDU_AA1 and 14.52% of SDU_AA2). Comparative genomic analysis demonstrated that the most dominant Dirammox bacterium (SDU_A2) possesses fewer complete metabolic modules compared to the other two less abundant Alcaligenes strains. Our findings expanded the understanding of the application of Dirammox bacteria as key functional microorganisms in a novel biological nitrogen and carbon removal process if they could be well stabilized. KEY POINTS: • Dirammox-dominated microbial community was enriched in activated sludge bioreactor. • The addition of hydroxylamine played a role in Dirammox enrichment. • Three Dirammox bacterial strains, including one novel species, were isolated.
Topics: Wastewater; Bioreactors; Nitrogen; Alcaligenes; Oxidation-Reduction; Sewage; Ammonia; Water Purification; Hydroxylamine; Phylogeny; RNA, Ribosomal, 16S; Bacteria; Microbiota
PubMed: 38904674
DOI: 10.1007/s00253-024-13214-2 -
Annals of Clinical Microbiology and... Jun 2024Achromobacter spp. are opportunistic pathogens, mostly infecting immunocompromised patients and patients with cystic fibrosis (CF) and considered as difficult-to-treat...
BACKGROUND
Achromobacter spp. are opportunistic pathogens, mostly infecting immunocompromised patients and patients with cystic fibrosis (CF) and considered as difficult-to-treat pathogens due to both intrinsic resistance and the possibility of acquired antimicrobial resistance. Species identification remains challenging leading to imprecise descriptions of resistance in each taxon. Cefiderocol is a broad-spectrum siderophore cephalosporin increasingly used in the management of Achromobacter infections for which susceptibility data remain scarce. We aimed to describe the susceptibility to cefiderocol of a collection of Achromobacter strains encompassing different species and isolation sources from CF or non-CF (NCF) patients.
METHODS
We studied 230 Achromobacter strains (67 from CF, 163 from NCF patients) identified by nrdA gene-based analysis, with available susceptibility data for piperacillin-tazobactam, meropenem and trimethoprim-sulfamethoxazole. Minimal inhibitory concentrations (MICs) of cefiderocol were determined using the broth microdilution reference method according to EUCAST guidelines.
RESULTS
Strains belonged to 15 species. A. xylosoxidans represented the main species (71.3%). MICs ranged from ≤ 0.015 to 16 mg/L with MIC of ≤ 0.015/0.5 mg/L overall and 0.125/2 mg/L against 27 (11.7%) meropenem-non-susceptible strains. Cefiderocol MICs were not related to CF/NCF origin or species although A. xylosoxidans MICs were statistically lower than those of other species considered as a whole. Considering the EUCAST non-species related breakpoint (2 mg/L), 228 strains (99.1%) were susceptible to cefiderocol. The two cefiderocol-resistant strains (A. xylosoxidans from CF patients) represented 3.7% of meropenem-non-susceptible strains and 12.5% of MDR strains.
CONCLUSIONS
Cefiderocol exhibited excellent in vitro activity against a large collection of accurately identified Achromobacter strains, irrespective of species and origin.
Topics: Microbial Sensitivity Tests; Humans; Achromobacter; Anti-Bacterial Agents; Cephalosporins; Cefiderocol; Cystic Fibrosis; Gram-Negative Bacterial Infections
PubMed: 38886694
DOI: 10.1186/s12941-024-00709-z -
Frontiers in Oncology 2024This study employs a two-sample bidirectional Mendelian randomization (MR) approach to systematically evaluate the causal relationship between gut microbiota and oral...
UNLABELLED
This study employs a two-sample bidirectional Mendelian randomization (MR) approach to systematically evaluate the causal relationship between gut microbiota and oral cavity cancer (OCC).
OBJECTIVE
To address the challenge in establishing the causal relationship between gut microbiota and OCC, we applied a systematic MR analysis.
METHODS
Utilizing GWAS data from the MiBioGen consortium (18,340 individuals) and UK Biobank (n = 264,137), we selected instrumental variables and employed MR-Egger, weighted median, IVW, and weighted mode analyses. Heterogeneity and pleiotropy were assessed using Cochran's Q test and MR-Egger intercept test.
RESULTS
Our findings indicate, at the order level, (OR = 0.9990, 95% CI = 0.9980-1.0000, = ), (OR = 1.0009, 95% CI = 1.0001-1.0018, = ), and (OR = 0.9979, 95% CI = 0.9962-0.9995, = ) exhibit causality on OCC in the Weighted median, IVW, and MR-Egger analyses, respectively. At the family level, (OR = 1.0012, 95% CI = 1.0004-1.0019, = ) and (OR = 0.9970, 95% CI = 0.9948-0.9992, = ) show causality on OCC in IVW and MR-Egger analyses. At the genus level, (IVW, OR = 0.9987, 95% CI = 0.9980-0.9995, = ; MR-Egger, OR = 0.9978, 95% CI = 0.9962-0.9995, = ), (IVW, OR = 1.0008, 95% CI = 1.0001-1.0015, = ), (IVW, OR = 0.9995, 95% CI = 0.9990-1.0000, = ), group (IVW, OR = 1.0005, 95% CI = 1.0000-1.0009, = ), and (IVW, OR = 0.9994, 95% CI = 0.9989-0.9999, = ) are implicated in causing OCC in related analyses.
CONCLUSION
Our study identifies order, family, genus, and group as causally increasing OCC risk. In contrast, order, order, family, genus, genus, and genus are causally associated with a decreased OCC risk. However, further investigations are essential to delineate an optimal gut microbiota composition and unravel the underlying mechanisms of specific bacterial taxa in OCC pathophysiology.
PubMed: 38884080
DOI: 10.3389/fonc.2024.1389678 -
Euro Surveillance : Bulletin Europeen... Jun 2024We describe a pertussis outbreak in the Vallès region of Catalonia, from September 2023 to April 2024. Incidence was high in children aged 10-14 years compared with...
We describe a pertussis outbreak in the Vallès region of Catalonia, from September 2023 to April 2024. Incidence was high in children aged 10-14 years compared with previous outbreaks. Limited impact in newborns could be explained by the high vaccination coverage during pregnancy and at 11 months of age in 2022, at 85% and 94.1 %, respectively. A third booster vaccine dose during preadolescence should be considered and vaccination coverage in pregnant women be improved to control future outbreaks.
Topics: Humans; Whooping Cough; Spain; Female; Adolescent; Child; Incidence; Disease Outbreaks; Infant; Pertussis Vaccine; Pregnancy; Child, Preschool; Male; Infant, Newborn; Vaccination; Adult; Vaccination Coverage; Immunization, Secondary; Young Adult; Bordetella pertussis; Age Distribution; Population Surveillance
PubMed: 38873794
DOI: 10.2807/1560-7917.ES.2024.29.24.2400332 -
Science Advances Jun 2024Heterotrophic nitrifiers continue to be a hiatus in our understanding of the nitrogen cycle. Despite their discovery over 50 years ago, the physiology and environmental...
Heterotrophic nitrifiers continue to be a hiatus in our understanding of the nitrogen cycle. Despite their discovery over 50 years ago, the physiology and environmental role of this enigmatic group remain elusive. The current theory is that heterotrophic nitrifiers are capable of converting ammonia to hydroxylamine, nitrite, nitric oxide, nitrous oxide, and dinitrogen gas via the subsequent actions of nitrification and denitrification. In addition, it was recently suggested that dinitrogen gas may be formed directly from ammonium. Here, we combine complementary high-resolution gas profiles, N isotope labeling studies, and transcriptomics data to show that hydroxylamine is the major product of nitrification in . We demonstrated that denitrification and direct ammonium oxidation to dinitrogen gas did not occur under the conditions tested. Our results indicate that is capable of hydroxylamine production from an organic intermediate. These results fundamentally change our understanding of heterotrophic nitrification and have important implications for its biotechnological application.
Topics: Alcaligenes faecalis; Nitrification; Hydroxylamine; Heterotrophic Processes; Ammonium Compounds; Nitrites; Oxidation-Reduction
PubMed: 38848370
DOI: 10.1126/sciadv.adl3587 -
Euro Surveillance : Bulletin Europeen... Jun 2024Since January 2024, Italy experiences a pertussis outbreak, primarily affecting neonates and unvaccinated infants at high risk of severe complications and mortality; 11...
Since January 2024, Italy experiences a pertussis outbreak, primarily affecting neonates and unvaccinated infants at high risk of severe complications and mortality; 11 major paediatric centres noted 108 hospitalisations and three deaths by 10 May. The outbreak reflects increased circulation of and non-adherence to immunisation recommendations during pregnancy. Public health interventions, including maternal immunisation, vaccination of infants as early as possible and post-exposure prophylaxis, are critical for reducing the burden of pertussis and preventing further mortality.
Topics: Humans; Whooping Cough; Italy; Disease Outbreaks; Infant, Newborn; Infant; Female; Vaccination; Pertussis Vaccine; Bordetella pertussis; Male; Pregnancy; Hospitalization
PubMed: 38847118
DOI: 10.2807/1560-7917.ES.2024.29.23.2400301 -
The American Journal of Case Reports Jun 2024BACKGROUND Peritoneal dialysis (PD) serves as a critical renal replacement therapy for individuals with end-stage renal disease (ESRD), leveraging the peritoneum for... (Review)
Review
BACKGROUND Peritoneal dialysis (PD) serves as a critical renal replacement therapy for individuals with end-stage renal disease (ESRD), leveraging the peritoneum for fluid and substance exchange. Despite its effectiveness, PD is marred by complications such as peritonitis, which significantly impacts patient outcomes. The novelty of our report lies in the presentation of a rare case of PD-associated peritonitis caused by 2 unusual pathogens, emphasizing the importance of rigorous infection control measures. CASE REPORT We report on an 80-year-old African-American female patient with ESRD undergoing PD, who was admitted twice within 8 months for non-recurring episodes of peritonitis. These episodes were attributed to the rare pathogens Achromobacter denitrificans/xylosoxidans and Carbapenem-resistant Acinetobacter baumannii. Despite presenting with similar symptoms during each episode, such as abdominal pain and turbid dialysis effluent, the presence of these uncommon bacteria highlights the intricate challenges in managing infections associated with PD. The treatment strategy encompassed targeted antibiotic therapy, determined through susceptibility testing. Notably, the decision to remove the PD catheter followed extensive patient education, ensuring the patient comprehended the rationale behind this approach. This crucial step, along with the subsequent shift to hemodialysis, was pivotal in resolving the infection, illustrating the importance of patient involvement in the management of complex PD-related infections. CONCLUSIONS This case underscores the complexities of managing PD-associated peritonitis, particularly with uncommon and resistant bacteria. It emphasizes the importance of rigorous infection control measures, the need to consider atypical pathogens, and the critical role of patient involvement in treatment decisions. Our insights advocate for a more informed approach to handling such infections, aiming to reduce morbidity and improve patient outcomes. The examination of the literature on recurrent peritonitis and treatment strategies provides key perspectives for navigating these challenging cases effectively.
Topics: Humans; Peritonitis; Female; Aged, 80 and over; Peritoneal Dialysis; Kidney Failure, Chronic; Acinetobacter baumannii; Achromobacter denitrificans; Anti-Bacterial Agents; Gram-Negative Bacterial Infections; Acinetobacter Infections; Practice Guidelines as Topic
PubMed: 38831580
DOI: 10.12659/AJCR.943953 -
Journal of Hazardous Materials Jul 2024Spent mushroom substrate (SMS) holds valuable microbiota that can be useful in remediating polluted soils with hydrocarbons. However, the microorganisms behind the...
Spent mushroom substrate (SMS) holds valuable microbiota that can be useful in remediating polluted soils with hydrocarbons. However, the microorganisms behind the bioremediation process remain uncertain. In this work, a bioremediation assay of total petroleum hydrocarbons (TPHs) polluted soil by SMS application was performed to elucidate the microorganisms and consortia involved in biodegradation by a metabarcoding analysis. Untreated polluted soil was compared to seven bioremediation treatments by adding SMS of Agaricus bisporus, Pleurotus eryngii, Pleurotus ostreatus, and combinations. Soil microbial activity, TPH biodegradation, taxonomic classification, and predictive functional analysis were evaluated in the microbiopiles at 60 days. Different metagenomics approaches were performed to understand the impact of each SMS on native soil microbiota and TPHs biodegradation. All SMSs enhanced the degradation of aliphatic and aromatic hydrocarbons, being A. bisporus the most effective, promoting an efficient consortium constituted by the bacterial families Alcanivoraceae, Alcaligenaceae, and Dietziaceae along with the fungal genera Scedosporium and Aspergillus. The predictive 16 S rRNA gene study partially explained the decontamination efficacy by observing changes in the taxonomic structure of bacteria and fungi, and changes in the potential profiles of estimated degradative genes across the different treatments. This work provides new insights into TPHs bioremediation.
Topics: Biodegradation, Environmental; Soil Pollutants; Hydrocarbons; Soil Microbiology; Petroleum; Bacteria; Agaricus; Fungi; Pleurotus; Agaricales; RNA, Ribosomal, 16S
PubMed: 38776816
DOI: 10.1016/j.jhazmat.2024.134650 -
PloS One 2024Swine atrophic rhinitis is a disease caused by Pasteurella multocida and Bordetella bronchiseptica that affects pigs. Inactivated vaccines containing the toxins produced...
Swine atrophic rhinitis is a disease caused by Pasteurella multocida and Bordetella bronchiseptica that affects pigs. Inactivated vaccines containing the toxins produced by Pasteurella multocida and Bordetella bronchiseptica have been widely used for the prevention of swine atrophic rhinitis. The efficacy of a vaccine is correlated with the amount of antigen present; however, the protective toxin of P. multocida bound to aluminum hydroxide, which is used as an adjuvant, can hinder the monitoring of the antigen concentration in the vaccine. This study assessed the applicability of a dot immunoassay as an antigen quantification method using monoclonal antibodies. This quantification method was able to detect the antigen with high specificity and sensitivity even when the antigen was bound to the adjuvant, and its application to vaccine products revealed a correlation between the amount of antigen present in the vaccine and the neutralizing antibody titers induced in pigs. The antigen quantification method presented in this study is a simple and sensitive assay capable of quantifying the amount of antigen present in a vaccine that can be used as an alternative quality control measure.
Topics: Animals; Pasteurella multocida; Swine; Rhinitis, Atrophic; Bacterial Vaccines; Aluminum Hydroxide; Adjuvants, Immunologic; Antigens, Bacterial; Swine Diseases; Bordetella bronchiseptica; Antibodies, Bacterial; Pasteurella Infections; Antibodies, Neutralizing
PubMed: 38768145
DOI: 10.1371/journal.pone.0301688 -
PloS One 2024The resurgence of pertussis has occurred around the world. However, the epidemiological profiles of pertussis cannot be well understood by current diseases surveillance....
PURPOSE
The resurgence of pertussis has occurred around the world. However, the epidemiological profiles of pertussis cannot be well understood by current diseases surveillance. This study was designed to understand the seroepidemiological characteristics of pertussis infection in the general population of Huzhou City, evaluate the prevalence infection of pertussis in the population, and offer insights to inform adjustments in pertussis prevention and control strategies.
METHODS
From September to October 2023, a cross-sectional serosurvey was conducted in Huzhou City, involving 1015 permanent residents. Serum samples were collected from the study subjects, and pertussis toxin IgG antibodies (Anti-PT-IgG) were quantitatively measured using enzyme-linked immunosorbent assay (ELISA). The analysis included the geometric mean concentration (GMC) of Anti-PT-IgG, rates of GMC≥40IU/mL, ≥100IU/mL, and <5IU/mL. Stratified comparisons were made based on age, vaccination history, and human categories.
RESULTS
Among the 1015 surveyed individuals, the geometric mean concentration (GMC) of Anti-PT-IgG was 10.52 (95% CI: 9.96-11.11) IU/mL, with a recent infection rate of 1.58%, a serum positivity rate of 11.43%, and a proportion with <5IU/mL of 40.49%. Among 357 children with clear vaccination history, susceptibility decreased with an increasing number of vaccine doses (Z = -6.793, P < 0.001). The concentration of Anti-PT-IgG exhibited a significant post-vaccination decline over time (Z = -5.143, P < 0.001). In women of childbearing age, the GMC of Anti-PT-IgG was 7.71 (95% CI: 6.90-8.62) IU/mL, with no significant difference in susceptibility among different age groups (χ2 = 0.545, P = 0.909). The annual pertussis infection rate in individuals aged ≥3 years was 9321 (95%CI: 3336-16039) per 100,000, with peak infection rates in the 20-29, 40-49, and 5-9 age groups at 34363 (95%CI: 6327-66918) per 100,000, 22307.72 (95%CI: 1380-47442) per 100,000, and 18020(95%CI: 1093-37266) per 100,000, respectively.
CONCLUSIONS
In 2023, the actual pertussis infection rate in the population of Huzhou City was relatively high. Vaccine-induced antibodies exhibit a rapid decay, and the estimated serum infection rate increases rapidly from post-school age, peaking in the 20-29 age group. It is recommended to enhance pertussis monitoring in adolescents and adults and refine vaccine immunization strategies.
Topics: Humans; Whooping Cough; Female; Cross-Sectional Studies; Adult; Male; China; Seroepidemiologic Studies; Child; Middle Aged; Adolescent; Child, Preschool; Young Adult; Infant; Immunoglobulin G; Antibodies, Bacterial; Aged; Pertussis Toxin; Prevalence; Pertussis Vaccine; Vaccination; Bordetella pertussis
PubMed: 38768133
DOI: 10.1371/journal.pone.0303508