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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 -
Colloids and Surfaces. B, Biointerfaces Jun 2024Antibiotic resistance has become an urgent threat to health care in recent years. The use of drug delivery systems provides advantages over conventional administration...
Toxin-triggered liposomes for the controlled release of antibiotics to treat infections associated with the gram-negative bacterium, Aggregatibacter actinomycetemcomitans.
Antibiotic resistance has become an urgent threat to health care in recent years. The use of drug delivery systems provides advantages over conventional administration of antibiotics and can slow the development of antibiotic resistance. In the current study, we developed a toxin-triggered liposomal antibiotic delivery system, in which the drug release is enabled by the leukotoxin (LtxA) produced by the Gram-negative pathogen, Aggregatibacter actinomycetemcomitans. LtxA has previously been shown to mediate membrane disruption by promoting a lipid phase change in nonlamellar lipids, such as 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-methyl (N-methyl-DOPE). In addition, LtxA has been observed to bind strongly and nearly irreversibly to membranes containing large amounts of cholesterol. Here, we designed a liposomal delivery system composed of N-methyl-DOPE and cholesterol to take advantage of these interactions. Specifically, we hypothesized that liposomes composed of N-methyl-DOPE and cholesterol, encapsulating antibiotics, would be sensitive to LtxA, enabling controlled antibiotic release. We observed that liposomes composed of N-methyl-DOPE were sensitive to the presence of low concentrations of LtxA, and cholesterol increased the extent and kinetics of content release. The liposomes were stable under various storage conditions for at least 7 days. Finally, we showed that antibiotic release occurs selectively in the presence of an LtxA-producing strain of A. actinomycetemcomitans but not in the presence of a non-LtxA-expressing strain. Together, these results demonstrate that the designed liposomal vehicle enables toxin-triggered delivery of antibiotics to LtxA-producing strains of A. actinomycetemcomitans.
Topics: Liposomes; Anti-Bacterial Agents; Aggregatibacter actinomycetemcomitans; Delayed-Action Preparations; Drug Liberation; Cholesterol; Microbial Sensitivity Tests; Exotoxins; Phosphatidylethanolamines; Drug Delivery Systems
PubMed: 38555763
DOI: 10.1016/j.colsurfb.2024.113870 -
Clinical Microbiology and Infection :... Jul 2024To investigate the prevalence of ampicillin resistance in Haemophilus influenzae and the diagnostic accuracy of the EUCAST recommended disc diffusion method to detect... (Comparative Study)
Comparative Study
Ampicillin susceptibility testing of Haemophilus influenzae in the routine clinical laboratory by the EUCAST methodology compared to broth microdilution and the presence of ftsI gene mutations.
OBJECTIVES
To investigate the prevalence of ampicillin resistance in Haemophilus influenzae and the diagnostic accuracy of the EUCAST recommended disc diffusion method to detect the increasingly prevalent ampicillin resistance due to the presence of PBP3 alterations based on mutations in the ftsI gene.
METHODS
During a 6-month period all consecutive non-duplicate H. influenzae isolates were prospectively collected and stored. MICs of ampicillin were determined by broth microdilution (BMD). PCR was performed to detect mutations in the ftsI gene. Results of routine disc diffusion susceptibility testing, including the penicillin screening test in accordance with the current EUCAST methodology, as well as additional Etest results, were compared to the BMD as the reference method.
RESULTS
In 102 isolates, the prevalence of ampicillin resistance was 28% (29/102) by BMD. There was a good correlation between MICs of ampicillin and the presence of a β-lactamase and/or an ftsI gene mutation. The prevalence of ampicillin resistance was overestimated using the EUCAST method (33% (34/102)) and underestimated when an additional Etest was used (24% (24/102)) (not significant). The sensitivity and specificity of the EUCAST methodology for the detection of ampicillin resistance were 97% ((28/29); 95% CI, 82-100%) and 92% ((67/73); 95% CI, 83-97%), respectively.
CONCLUSIONS
The prevalence of ampicillin resistance was 28%, as determined by BMD. Although the overall diagnostic accuracy of the EUCAST ampicillin disc diffusion was high, misclassification of ampicillin susceptibility may still occur.
Topics: Humans; Haemophilus influenzae; Ampicillin; Microbial Sensitivity Tests; Anti-Bacterial Agents; Mutation; Ampicillin Resistance; Haemophilus Infections; Prospective Studies; Male; Middle Aged; Female; Aged; Adult; Child, Preschool; Infant; Child; Aged, 80 and over; Adolescent; Young Adult; Disk Diffusion Antimicrobial Tests; Penicillin-Binding Proteins; Prevalence
PubMed: 38554928
DOI: 10.1016/j.cmi.2024.03.026 -
Applied and Environmental Microbiology Apr 2024is a zoonotic conditional pathogen that infects multiple livestock species, causing substantial economic losses in the animal husbandry industry. An efficient...
is a zoonotic conditional pathogen that infects multiple livestock species, causing substantial economic losses in the animal husbandry industry. An efficient markerless method for gene manipulation may facilitate the investigations of gene function and pathogenesis of . Herein, a temperature-sensitive shuttle vector was constructed using as a selection marker, and markerless , , and mutants of were subsequently constructed through blue-white colony screening. The screening efficiency of markerless deletion strains was improved by the system, and the method could be used for multiple gene deletions. However, the mutant was unavailable via this method. Therefore, we constructed a m screening system based on mutated phenylalanine tRNA synthetase as a counterselection marker to achieve deletion mutant. The transformed strain was sensitive to 20 mM -chloro-phenylalanine, demonstrating the feasibility of m as a counter-selective marker. The m system was used for markerless deletions of , , and as well as that could not be screened by the system. A comparison of screening efficiencies of the system showed that the m counterselection system was more efficient than the system and broadly applicable for mutant screening. The methods developed herein may provide valuable tools for genetic manipulation of .IMPORTANCE is a highly contagious zoonotic pathogen. An understanding of its underlying pathogenic mechanisms is of considerable importance and requires efficient species-specific genetic tools. Herein, we propose a screening system for mutants using or m screening markers. We evaluated the efficiencies of both systems, which were used to achieve markerless deletion of multiple genes. The results of this study support the use of or m as counterselection markers to improve counterselection efficiency in . This study provides an effective genetic tool for investigations of the virulence gene functions and pathogenic mechanisms of .
Topics: Animals; Pasteurella multocida; Lac Operon; Genetic Vectors; Phenylalanine
PubMed: 38547470
DOI: 10.1128/aem.02043-23 -
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 -
Microbial Pathogenesis May 2024With the widespread introduction of the Hib conjugate vaccine, Nontypeable Haemophilus influenzae (NTHi) has emerged as the predominant strain globally. NTHi presents a...
With the widespread introduction of the Hib conjugate vaccine, Nontypeable Haemophilus influenzae (NTHi) has emerged as the predominant strain globally. NTHi presents a significant challenge as a causative agent of chronic clinical infections due to its high rates of drug resistance and biofilm formation. While current research on NTHi biofilms in children has primarily focused on upper respiratory diseases, investigations into lower respiratory sources remain limited. In this study, we collected 54 clinical strains of lower respiratory tract origin from children. Molecular information and drug resistance features were obtained through whole gene sequencing and the disk diffusion method, respectively. Additionally, an in vitro biofilm model was established. All clinical strains were identified as NTHi and demonstrated the ability to form biofilms in vitro. Based on scanning electron microscopy and crystal violet staining, the strains were categorized into weak and strong biofilm-forming groups. We explored the correlation between biofilm formation ability and drug resistance patterns, as well as clinical characteristics. Stronger biofilm formation was associated with a longer cough duration and a higher proportion of abnormal lung imaging findings. Frequent intake of β-lactam antibiotics might be associated with strong biofilm formation. While a complementary relationship between biofilm-forming capacity and drug resistance may exist, further comprehensive studies are warranted. This study confirms the in vitro biofilm formation of clinical NTHi strains and establishes correlations with clinical characteristics, offering valuable insights for combating NTHi infections.
Topics: Biofilms; Humans; Haemophilus Infections; Haemophilus influenzae; Anti-Bacterial Agents; Child, Preschool; Female; Male; Child; Infant; Microbial Sensitivity Tests; Respiratory Tract Infections; Microscopy, Electron, Scanning; Drug Resistance, Bacterial; Respiratory System
PubMed: 38537762
DOI: 10.1016/j.micpath.2024.106632