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Frontiers in Cellular and Infection... 2024The Gram-positive bacterium, is an oral pathogen, and approximately 50% of known strains encode a recently identified repeat-in-toxin (RTX) protein, FtxA. By assessing...
The Gram-positive bacterium, is an oral pathogen, and approximately 50% of known strains encode a recently identified repeat-in-toxin (RTX) protein, FtxA. By assessing a longitudinal Ghanaian study population of adolescents (10-19 years of age; mean age 13.2 years), we recently discovered a possible correlation between deep periodontal pockets measured at the two-year follow-up, presence of the gene, and a high quantity of . To further understand the contribution of and FtxA in periodontal disease, we used qPCR in the present study to assess the carriage loads of and the prevalence of its gene in subgingival plaque specimens, sampled at baseline from the Ghanaian cohort (n=500). Comparing these results with the recorded clinical attachment loss (CAL) longitudinal progression data from the two-year follow up, we concluded that carriers of -positive typically exhibited higher loads of the bacterium. Moreover, high carriage loads of and concomitant presence of the gene were two factors that were both associated with an enhanced prevalence of CAL progression. Interestingly, CAL progression appeared to be further promoted upon the simultaneous presence of and the non-JP2 genotype of . Taken together, our present findings are consistent with the notion that and its gene promotes CAL during periodontal disease.
Topics: Adolescent; Humans; Aggregatibacter actinomycetemcomitans; Periodontal Attachment Loss; Ghana; Periodontal Diseases; Toxins, Biological; Clostridiales
PubMed: 38596650
DOI: 10.3389/fcimb.2024.1376358 -
Veterinary Research Apr 2024Actinobacillus pleuropneumoniae (APP) is a bacterium frequently associated with porcine pleuropneumonia. The acute form of the disease is highly contagious and often...
Actinobacillus pleuropneumoniae (APP) is a bacterium frequently associated with porcine pleuropneumonia. The acute form of the disease is highly contagious and often fatal, resulting in significant economic losses for pig farmers. Serotype diversity and antimicrobial resistance (AMR) of APP strains circulating in north Italian farms from 2015 to 2022 were evaluated retrospectively to investigate APP epidemiology in the area. A total of 572 strains isolated from outbreaks occurring in 337 different swine farms were analysed. The majority of isolates belonged to serotypes 9/11 (39.2%) and 2 (28.1%) and serotype diversity increased during the study period, up to nine different serotypes isolated in 2022. The most common resistances were against tetracycline (53% of isolates) and ampicillin (33%), followed by enrofloxacin, florfenicol and trimethoprim/sulfamethoxazole (23% each). Multidrug resistance (MDR) was common, with a third of isolates showing resistance to more than three antimicrobial classes. Resistance to the different classes and MDR varied significantly depending on the serotype. In particular, the widespread serotype 9/11 was strongly associated with florfenicol and enrofloxacin resistance and showed the highest proportion of MDR isolates. Serotype 5, although less common, showed instead a concerning proportion of trimethoprim/sulfamethoxazole resistance. Our results highlight how the typing of circulating serotypes and the analysis of their antimicrobial susceptibility profile are crucial to effectively manage APP infection and improve antimicrobial stewardship.
Topics: Swine; Animals; Serogroup; Actinobacillus pleuropneumoniae; Microbial Sensitivity Tests; Enrofloxacin; Farms; Retrospective Studies; Pleuropneumonia; Anti-Bacterial Agents; Sulfamethoxazole; Trimethoprim; Italy; Swine Diseases; Actinobacillus Infections; Serotyping; Thiamphenicol
PubMed: 38594744
DOI: 10.1186/s13567-024-01305-x -
Veterinary Research Apr 2024Pasteurella multocida is an important zoonotic respiratory pathogen capable of infecting a diverse range of hosts, including humans, farm animals, and wild animals....
Pasteurella multocida is an important zoonotic respiratory pathogen capable of infecting a diverse range of hosts, including humans, farm animals, and wild animals. However, the precise mechanisms by which P. multocida compromises the pulmonary integrity of mammals and subsequently induces systemic infection remain largely unexplored. In this study, based on mouse and rabbit models, we found that P. multocida causes not only lung damage but also bacteremia due to the loss of lung integrity. Furthermore, we demonstrated that bacteremia is an important aspect of P. multocida pathogenesis, as evidenced by the observed multiorgan damage and systemic inflammation, and ultimately found that this systemic infection leads to a cytokine storm that can be mitigated by IL-6-neutralizing antibodies. As a result, we divided the pathogenesis of P. multocida into two phases: the pulmonary infection phase and the systemic infection phase. Based on unbiased RNA-seq data, we discovered that P. multocida-induced apoptosis leads to the loss of pulmonary epithelial integrity. These findings have been validated in both TC-1 murine lung epithelial cells and the lungs of model mice. Conversely, the administration of Ac-DEVD-CHO, an apoptosis inhibitor, effectively restored pulmonary epithelial integrity, significantly mitigated lung damage, inhibited bacteremia, attenuated the cytokine storm, and reduced mortality in mouse models. At the molecular level, we demonstrated that the FAK-AKT-FOXO1 axis is involved in P. multocida-induced lung epithelial cell apoptosis in both cells and animals. Thus, our research provides crucial information with regard to the pathogenesis of P. multocida as well as potential treatment options for this and other respiratory bacterial diseases.
Topics: Humans; Animals; Rabbits; Mice; Pasteurella multocida; Pasteurella Infections; Proto-Oncogene Proteins c-akt; Cytokine Release Syndrome; Lung; Bacteremia; Apoptosis; Mammals; Forkhead Box Protein O1; Rodent Diseases
PubMed: 38589976
DOI: 10.1186/s13567-024-01298-7 -
BMC Veterinary Research Apr 2024Glaesserella parasuis, an important respiratory bacterial pathogen, causes Glässer's disease in piglets, with potential immunosuppression. We established a piglet...
Glaesserella parasuis, an important respiratory bacterial pathogen, causes Glässer's disease in piglets, with potential immunosuppression. We established a piglet infection model and explored the immunosuppression mechanism to improve our understanding of the host immune response to G. parasuis. Twenty piglets were randomly divided into two groups (n = 10). The infection group was intraperitoneally challenged with 2 × 10 CFU of G. parasuis in 2 mL TSB. The control group was intraperitoneally injected with equivalent TSB. After 72 h, the piglets were sacrificed, and spleen tissue was collected. PD-1/PD-L1 expression was determined. The splenocytes were isolated to detect CD3 T, CD3CD4 T, CD3CD8 T and CD3CD21cell differentiation. Via data-independent acquisition (DIA), we compared the proteomics of healthy and infected spleen tissues. Glaesserella parasuis modified CD3 T, CD3CD4 T, CD3CD8 T and CD3CD21 cell differentiation and PD-1/PD-L1 expression in the spleen. The infection group had 596 proteins with significant differences in expression, of which 301 were significantly upregulated and 295 downregulated. Differentially expressed proteins (DEPs) were mainly related to immune responses. This is the first study on PD-1/PD-L1 expression in the spleen associated with immunosuppression in a piglet model to explore the protein changes related to immune responses via DIA.
Topics: Animals; B7-H1 Antigen; Haemophilus Infections; Haemophilus parasuis; Immunosuppression Therapy; Phosphatidylinositol 3-Kinases; Programmed Cell Death 1 Receptor; Proto-Oncogene Proteins c-akt; Swine; Swine Diseases; TOR Serine-Threonine Kinases
PubMed: 38582846
DOI: 10.1186/s12917-024-03993-1 -
Vaccine Apr 2024This study investigated the immunogenicity and safety of a pentavalent vaccine Gobik (DPT-IPV-Haemophilus influenzae type b [Hib]) in healthy Japanese infants... (Randomized Controlled Trial)
Randomized Controlled Trial
Immunogenicity and safety of adsorbed diphtheria-purified pertussis-tetanus-inactivated polio (Sabin strain)-Haemophilus type b conjugate combined vaccine (DPT-IPV-Hib) in healthy Japanese Infants ≥ 2 and < 43 months of Age: A phase III, multicenter, active controlled, assessor-blinded,...
OBJECTIVE
This study investigated the immunogenicity and safety of a pentavalent vaccine Gobik (DPT-IPV-Haemophilus influenzae type b [Hib]) in healthy Japanese infants aged ≥ 2 and < 43 months using a concomitant vaccination with ActHIB® (Hib) and Tetrabik (DPT-IPV) as a comparator.
METHODS
This study was conducted as a phase 3, multicenter, active controlled, assessor-blinded, randomized, parallel-group study. Participants received a total of 4 subcutaneous doses (3 primary immunization doses and a booster dose) of either the experimental drug (DPT-IPV-Hib) or the active comparator (Hib + DPT-IPV). The primary endpoints were the anti-PRP antibody prevalence rate with ≥ 1 μg/mL, and the antibody prevalence rates against pertussis, diphtheria toxin, tetanus toxin, and attenuated poliovirus after the primary immunization.
RESULTS
In 267 randomized participants (133 in the DPT-IPV-Hib group and 134 in the Hib + DPT-IPV group), the antibody prevalence rates after the primary immunization in both groups were 100.0 % and 88.7 % for anti-PRP antibody with ≥ 1 μg/mL, 99.2 % and 98.5 % against diphtheria toxin, and 100.0 % and 99.2 % against tetanus toxin, respectively. The antibody prevalence rates against pertussis and attenuated poliovirus were 100.0 % in both groups. The non-inferiority of the DPT-IPV-Hib group to the Hib + DPT-IPV group was verified for all measured antibodies. In both groups, all the GMTs of antibodies after the primary immunization were higher than those before the first dose, and those after the booster dose were higher than those after the primary immunization. No safety issues were identified.
CONCLUSION
A single-agent Gobik, the first DPT-IPV-Hib pentavalent vaccine approved in Japan, was confirmed to simultaneously provide primary and booster immunizations against Hib infection, pertussis, diphtheria, tetanus, and poliomyelitis and to have a preventive effect and safety comparable to concomitant vaccination with Hib (ActHIB®) and DPT-IPV quadrivalent vaccine (Tetrabik).
Topics: Infant; Humans; Haemophilus influenzae type b; Japan; Tetanus; Diphtheria; Whooping Cough; Tetanus Toxin; Diphtheria Toxin; Poliovirus Vaccine, Inactivated; Immunization Schedule; Antibodies, Bacterial; Diphtheria-Tetanus-Pertussis Vaccine; Vaccines, Combined; Poliomyelitis; Vaccines, Conjugate; Haemophilus Vaccines
PubMed: 38582691
DOI: 10.1016/j.vaccine.2023.03.077 -
International Journal of Infectious... Jun 2024This study aimed to describe the microbial aetiology of community-acquired pneumonia (CAP) in adults admitted to a tertiary care hospital and assess the impact of...
OBJECTIVES
This study aimed to describe the microbial aetiology of community-acquired pneumonia (CAP) in adults admitted to a tertiary care hospital and assess the impact of syndromic polymerase chain reaction (PCR) panels on pathogen detection.
METHODS
Conducted at Haukeland University Hospital, Norway, from September 2020 to April 2023, this prospective study enrolled adults with suspected CAP. We analysed lower respiratory tract samples using both standard-of-care tests and the BIOFIRE® FILMARRAY® Pneumonia Plus Panel (FAP plus). The added value of FAP Plus in enhancing the detection of clinically relevant pathogens, alongside standard-of-care diagnostics, was assessed.
RESULTS
Of the 3238 patients screened, 640 met the inclusion criteria, with 384 confirmed to have CAP at discharge. In these patients, pathogens with proven or probable clinical significance were identified in 312 (81.3%) patients. Haemophilus influenzae was the most prevalent pathogen, found in 118 patients (30.7%), followed by SARS-CoV-2 in 74 (19.3%), and Streptococcus pneumoniae in 64 (16.7%). Respiratory viruses were detected in 186 (48.4%) patients. The use of FAP plus improved the pathogen detection rate from 62.8% with standard-of-care methods to 81.3%.
CONCLUSIONS
Pathogens were identified in 81% of CAP patients, with Haemophilus influenzae and respiratory viruses being the most frequently detected pathogens. The addition of the FAP plus panel, markedly improved pathogen detection rates compared to standard-of-care diagnostics alone.
Topics: Humans; Community-Acquired Infections; Prospective Studies; Male; Female; Middle Aged; Aged; Adult; Norway; Hospitalization; SARS-CoV-2; Molecular Diagnostic Techniques; Pneumonia; Aged, 80 and over; Streptococcus pneumoniae; Haemophilus influenzae; Polymerase Chain Reaction; COVID-19
PubMed: 38582145
DOI: 10.1016/j.ijid.2024.107019 -
BMC Veterinary Research Apr 2024Periodontitis is the most common oral disease in dogs, and its progression and severity are influenced by risk factors, such as age and body size. Recent studies have...
BACKGROUND
Periodontitis is the most common oral disease in dogs, and its progression and severity are influenced by risk factors, such as age and body size. Recent studies have assessed the canine oral microbiota in relation to different stages of periodontitis and niches within the oral cavity. However, knowledge of the bacterial composition at different ages and body sizes, especially in puppies, is limited. This study aimed to characterize the oral microbiota in the healthy gingiva of small breed puppies using next-generation sequencing. Additionally, we assessed the impact of dental care practices and the presence of retained deciduous teeth on the oral microbiota.
RESULTS
In this study, plaque samples were collected from the gingival margin of 20 small breed puppies (age, 6.9 ± 0.6 months). The plaque samples were subjected to next-generation sequencing targeting the V3-V4 region of the 16 S rRNA. The microbiota of the plaque samples was composed mostly of gram-negative bacteria, primarily Proteobacteria (54.12%), Bacteroidetes (28.79%), and Fusobacteria (5.11%). Moraxella sp. COT-017, Capnocytophaga cynodegmi COT-254, and Bergeyella zoohelcum COT-186 were abundant in the oral cavity of the puppies. In contrast, Neisseria animaloris were not detected. The high abundance of Pasteurellaceae suggests that this genus is characteristic of the oral microbiota in puppies. Dental care practices and the presence of retained deciduous teeth showed no effects on the oral microbiota.
CONCLUSIONS
In this study, many bacterial species previously reported to be detected in the normal oral cavity of adult dogs were also detected in 6-8-month-old small breed dogs. On the other hand, some bacterial species were not detected at all, while others were detected in high abundance. These data indicate that the oral microbiota of 6-8-month-old small breed dogs is in the process of maturating in to the adult microbiota and may also have characteristics of the small dog oral microbiota.
Topics: Dogs; Animals; RNA, Ribosomal, 16S; Gingiva; Periodontitis; Microbiota; Bacteria; Dog Diseases
PubMed: 38580990
DOI: 10.1186/s12917-024-03973-5 -
Applied Microbiology and Biotechnology Apr 2024The production of succinic acid from corn stover is a promising and sustainable route; however, during the pretreatment stage, byproducts such as organic acids,...
The production of succinic acid from corn stover is a promising and sustainable route; however, during the pretreatment stage, byproducts such as organic acids, furan-based compounds, and phenolic compounds generated from corn stover inhibit the microbial fermentation process. Selecting strains that are resistant to stress and utilizing nondetoxified corn stover hydrolysate as a feedstock for succinic acid production could be effective. In this study, A. succinogenes CICC11014 was selected as the original strain, and the stress-resistant strain A. succinogenes M4 was obtained by atmospheric and room temperature plasma (ARTP) mutagenesis and further screening. Compared to the original strain, A. succinogenes M4 exhibited a twofold increase in stress resistance and a 113% increase in succinic acid production when hydrolysate was used as the substrate. By conducting whole-genome resequencing of A. succinogenes M4 and comparing it with the original strain, four nonsynonymous gene mutations and two upstream regions with base losses were identified. KEY POINTS: • A high-stress-resistant strain A. succinogenes M4 was obtained by ARTP mutation • The production of succinic acid increased by 113% • The mutated genes of A. succinogenes M4 were detected and analyzed.
Topics: Zea mays; Succinic Acid; Actinobacillus; Plant Breeding; Fermentation; Mutation
PubMed: 38558151
DOI: 10.1007/s00253-024-13112-7 -
Characteristics of the Gut Microbiota in Regard to Atopic Dermatitis and Food Allergies of Children.Biomedicines Mar 2024The gut microbiota plays an important role in maintaining human health, as well as in the development of various pathologies, as indicated by a large amount of research....
The gut microbiota plays an important role in maintaining human health, as well as in the development of various pathologies, as indicated by a large amount of research. One of the manifestations of an imbalance in the gut microbiome composition is the appearance of various diseases or immune reactions, in particular, atopic dermatitis (AD) and/or food allergies (FA). In this research, using 16S NGS sequencing, it was found that the gut microbiome of children with food allergies and children with atopic dermatitis can be characterized as having higher inflammatory potential. Both groups exhibited an abundance of representatives from the and families, as well as a decrease in the relative number of representatives from the family compared to healthy participants. In the group of participants with food allergies, there was a decrease in the relative number of representatives and family enrichment in relatively healthy participants. In addition, when comparing this group with patients with atopic dermatitis, it was revealed that a number of representatives of such families as , and prevailed. This information confirms that AD and FA correlate with changes in the composition of the gut microbiota. Further research is needed to determine the cause-effect connections and the effect of compounds derived from the microbiota on the AD and FA development and progression, as well as to create new probiotic drugs to prevent and modulate immune responses, including at an early age.
PubMed: 38540166
DOI: 10.3390/biomedicines12030553 -
Toxins Mar 2024is a Gram-negative bacterium associated with localized aggressive periodontitis as well as some systemic diseases. The strains of most closely associated with disease...
is a Gram-negative bacterium associated with localized aggressive periodontitis as well as some systemic diseases. The strains of most closely associated with disease produce more of a secreted leukotoxin (LtxA) than isolates from healthy carriers, suggesting a key role for this toxin in disease progression. LtxA is released into the bacterial cytosol in a free form as well as in association with the surface of outer membrane vesicles (OMVs). We previously observed that the highly leukotoxic strain JP2 produces two populations of OMVs: a highly abundant population of small (<100 nm) OMVs and a less abundant population of large (>300 nm) OMVs. Here, we have developed a protocol to isolate the OMVs produced during each specific phase of growth and used this to demonstrate that small OMVs are produced throughout growth and lack LtxA, while large OMVs are produced only during the exponential phase and are enriched with LtxA. Our results indicate that surface-associated DNA drives the selective sorting of LtxA into large OMVs. This study provides valuable insights into the observed heterogeneity of vesicles and emphasizes the importance of understanding these variations in the context of bacterial pathogenesis.
Topics: Aggregatibacter actinomycetemcomitans; Toxins, Biological; Cytosol; Biological Transport; Cell Movement
PubMed: 38535804
DOI: 10.3390/toxins16030138