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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 -
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 -
Veterinary Medicine and Science May 2024Companion animals, including dogs and cats, are frequently identified as sources of Pasteurella multocida, a bacterium that can be transmitted to humans and cause...
BACKGROUND
Companion animals, including dogs and cats, are frequently identified as sources of Pasteurella multocida, a bacterium that can be transmitted to humans and cause infections.
OBJECTIVES
This survey defines the prevalence, antibiotic sensitivity, capsular types, lipopolysaccharide (LPS) types and virulence factors of P. multocida isolated from cats.
METHODS
A total of 100 specimens from various cat breeds were collected. P. multocida was characterized using both biochemical tests and PCR. Genotypes of isolates were determined using capsular and LPS typing methods. Additionally, virulotyping was performed by detecting the presence of 12 virulence-associated genes. Disk diffusion was used to determine the antibiotic sensitivity of the isolates.
RESULTS
The prevalence of P. multocida in cats was 29%. Among the isolates, the majority were capsular type A (96.5%) and type D (3.4%), with a predominant presence of type A. Twenty-six of the isolates (89.66%) belonged to LPS genotype L6, whereas three isolates (10.3%) belonged to genotype L3. Among the 12 virulence genes examined, sodC, oma87, ptfA, nanB and ompH showed remarkable prevalence (100%). The toxA gene was detected in four isolates (13.8%). Variations were observed in other virulence genes. The nanH gene was present in 93.1% of the isolates, whereas the pfhA gene was detected in 58.6% of the isolates. The exbD-tonB, hgbB, sodA and hgbA genes showed prevalence rates of 96.5%, 96.5%, 96.5% and 82.8%, respectively. Additionally, particular capsule and LPS types were associated with specific virulence genes. Specifically, the toxA and pfhA genes were found to be more prevalent in isolates with capsular type A and LPS genotype L6. Most isolates were resistant to ampicillin, clindamycin, lincomycin, streptomycin and penicillin.
CONCLUSIONS
According to this epidemiological and molecular data, P. multocida from cats possess several virulence-associated genes and are resistant to antimicrobial medicines commonly used in humans and animals. Thus, it is crucial to consider the public health concerns of P. multocida in humans.
Topics: Cats; Animals; Humans; Dogs; Pasteurella multocida; Pasteurella Infections; Anti-Bacterial Agents; Lipopolysaccharides; Cat Diseases; Dog Diseases
PubMed: 38519838
DOI: 10.1002/vms3.1424 -
Scientific Reports Mar 2024Haemorrhagic septicaemia (HS) is an economically important disease affecting cattle and buffaloes and the livelihoods of small-holder farmers that depend upon them. The...
Haemorrhagic septicaemia (HS) is an economically important disease affecting cattle and buffaloes and the livelihoods of small-holder farmers that depend upon them. The disease is caused by Gram-negative bacterium, Pasteurella multocida, and is considered to be endemic in many states of India with more than 25,000 outbreaks in the past three decades. Currently, there is no national policy for control of HS in India. In this study, we analysed thirty year (1987-2016) monthly data on HS outbreaks using different statistical and mathematical methods to identify spatial variability and temporal patterns (seasonality, periodicity). There was zonal variation in the trend and seasonality of HS outbreaks. Overall, South zone reported maximum proportion of the outbreaks (70.2%), followed by East zone (7.2%), Central zone (6.4%), North zone (5.6%), West zone (5.5%) and North-East zone (4.9%). Annual state level analysis indicated that the reporting of HS outbreaks started at different years independently and there was no apparent transmission between the states. The results of the current study are useful for the policy makers to design national control programme on HS in India and implement state specific strategies. Further, our study and strategies could aid in implementation of similar approaches in HS endemic tropical countries around the world.
Topics: Animals; Cattle; Hemorrhagic Septicemia; Pasteurella multocida; Buffaloes; Disease Outbreaks; India; Cattle Diseases
PubMed: 38514747
DOI: 10.1038/s41598-024-56213-z -
The Journal of Contemporary Dental... Feb 2024The study aims is to evaluate the antibacterial effect of vitamin D3 against the , in chronic periodontitis patients.
AIM
The study aims is to evaluate the antibacterial effect of vitamin D3 against the , in chronic periodontitis patients.
MATERIALS AND METHODS
The study comprised 98 participants with chronic periodontitis. All clinical parameters including plaque index (PI), gingival bleeding index (GBI), probing pocket depth (PPD), clinical attachment level (CAL), and a microbiological assay of were assessed at the baseline. All study participants who underwent scaling and root planning were divided into two groups, A and B, each with 49 patients and only group B patients were advised to take vitamin D supplementation of 60,000 IU granules, once daily for 2 months. All the patients of both the groups were recalled at the end of 2nd month and all the clinical and microbiological parameters were reassessed.
RESULTS
After two months, there was a reduction in all the clinical markers in both groups, but the group B patients showed more improvement following non-surgical treatment vitamin D intake. There was also a statistical reduction in and following administration of vitamin D in group B patients compared to group A.
CONCLUSION
These discoveries proposed that vitamin D has a superb antimicrobial impact against red complex periodontal microbes and might be considered a promising compound in the counteraction of periodontal disease.
CLINICAL SIGNIFICANCE
Vitamin D is considered to possess anti-inflammatory and antimicrobial activity, which may help to delay the progression of periodontitis. So, vitamin D3 can be used as a potential supplement that could be employed to stop the advancement of periodontal disease. How to cite this article: Govindharajulu R, Syed NK, Sukumaran B, . Assessment of the Antibacterial Effect of Vitamin D3 against Red Complex Periodontal Pathogens: A Microbiological Assay. J Contemp Dent Pract 2024;25(2):114-117.
Topics: Humans; Chronic Periodontitis; Cholecalciferol; Periodontal Pocket; Porphyromonas gingivalis; Anti-Bacterial Agents; Periodontal Attachment Loss; Aggregatibacter actinomycetemcomitans
PubMed: 38514407
DOI: 10.5005/jp-journals-10024-3642 -
Molecular Oral Microbiology Mar 2024Considered the second largest and most diverse microbiome after the gut, the human oral ecosystem is complex with diverse and niche-specific microorganisms. Although...
BACKGROUND
Considered the second largest and most diverse microbiome after the gut, the human oral ecosystem is complex with diverse and niche-specific microorganisms. Although evidence is growing for the importance of oral microbiome in supporting a healthy immune system and preventing local and systemic infections, the influence of craniomaxillofacial (CMF) trauma and routine reconstructive surgical treatments on community structure and function of oral resident microbes remains unknown. CMF injuries affect a large number of people, needing extensive rehabilitation with lasting morbidity and loss of human productivity. Treatment efficacy can be complicated by the overgrowth of opportunistic commensals or multidrug-resistant pathogens in the oral ecosystem due to weakened host immune function and reduced colonization resistance in a dysbiotic oral microbiome.
AIMS
To understand the dynamics of microbiota's community structure during CMF injury and subsequent treatments, we induced supra-alveolar mandibular defect in Hanford miniature swine (n = 3) and compared therapeutic approaches of immediate mandibullar reconstructive (IMR) versus delayed mandibullar reconstructive (DMR) surgeries.
METHODS
Using bacterial 16S ribosomal RNA gene marker sequencing, the composition and abundance of the bacterial community of the uninjured maxilla (control) and the injured left mandibula (lingual and buccal) treated by DMR were surveyed up to 70-day post-wounding. For the injured right mandibula receiving IMR treatment, the microbial composition and abundance were surveyed up to 14-day post-wounding. Moreover, we measured sera level of biochemical markers (e.g., osteocalcin) associated with bone regeneration and healing. Computed tomography was used to measure and compare mandibular bone characteristics such as trabecular thickness between sites receiving DMR and IMR therapeutic approaches until day 140, the end of study period.
RESULTS
Independent of IMR versus DMR therapy, we observed similar dysbiosis and shifts of the mucosal bacteria residents after CMF injury and/or following treatment. There was an enrichment of Fusobacterium, Porphyromonadaceae, and Bacteroidales accompanied by a decline in Pasteurellaceae, Moraxella, and Neisseria relative abundance in days allotted for healing. We also observed a decline in species richness and abundance driven by reduction in temporal instability and inter-animal heterogeneity on days 0 and 56, with day 0 corresponding to injury in DMR group and day 56 corresponding to delayed treatment for DMR or injury and immediate treatment for the IMR group. Analysis of bone healing features showed comparable bone-healing profiles for IMR vs. DMR therapeutic approach.
PubMed: 38511906
DOI: 10.1111/omi.12460 -
The Tokai Journal of Experimental and... Apr 2024We report a case of chronic infection with in the lower respiratory tract in a man with a cat. A 77-year-old man presented with recurrent hemoptysis accompanied by...
We report a case of chronic infection with in the lower respiratory tract in a man with a cat. A 77-year-old man presented with recurrent hemoptysis accompanied by bronchiectasis and an opacity in the left lung on chest computed tomography. Although the patient was seropositive for complex, repeated sputum cultures were negative for any specific pathogen. Three years later, he was referred to our hospital for hemoptysis with enhanced opacity in the lower lobe of the left lung. Culture of bronchial lavage fluid obtained via bronchoscopy was positive for . The patient was treated with amoxicillin-clavulanic acid for 14 days and was instructed to avoid close contact with his cat. His symptoms and chest imaging findings improved and have not recurred during more than 1 1/2 years of follow up. can cause chronic lower respiratory infections.
Topics: Male; Humans; Aged; Pasteurella multocida; Hemoptysis; Respiratory Tract Infections; Lung; Bronchitis
PubMed: 38509006
DOI: No ID Found -
Veterinary Microbiology May 2024The intensification of pig farming has posed significant challenges in managing and preventing sanitary problems, particularly diseases of the respiratory complex....
The intensification of pig farming has posed significant challenges in managing and preventing sanitary problems, particularly diseases of the respiratory complex. Monitoring at slaughter is an important control tool and cannot be overstated. Hence, this study aimed at characterizing both macroscopical and microscopical lesions and identifying the Actinobacillus pleuropneumoniae (APP), Mycoplasma hyopneumoniae (Mhyo), and Pasteurella multocida (PM) associated with pleurisy in swine. For this, a selected slaughterhouse in São Paulo State underwent a thorough examination of carcasses on the slaughter line, followed by lung sampling. The carcasses and lungs underwent macroscopical examination and were classified according to the score of pleurisy and lung samples were allocated into five groups, being: G0: score 0 - no lesions; G1: score 1; G2: score 2; G3: score 3; and G4: score 4. In total, 217 lung fragments were collected, for the histopathological evaluation and detection of the following respiratory pathogens: APP, Mhyo, and PM by qPCR. The results demonstrated that Mhyo and APP were the most prevalent etiological agents (single and co-identification) in lung samples, in different scores of pleurisies, while bronchopneumonia and bronchus-associated lymphoid tissue (BALT) hyperplasia lesions were the most frequent histopathological findings. Positive correlations were found between the quantification of APP DNA with 1) the score of pleurisy (R=0.254); 2) with the score of lung consolidation in all lung lobes (R=0.181 to R=0.329); and 3) with the score of lung consolidation in the entire lung (R=0.389). The study brings relevant information regarding the main bacterial pathogens associated with pleurisy in pigs and helps with understanding the relationship between the abovementioned pathogens and their impact on the respiratory health of pigs.
Topics: Swine; Animals; Swine Diseases; Brazil; Lung; Pleurisy; Lung Diseases; Pasteurella multocida
PubMed: 38502977
DOI: 10.1016/j.vetmic.2024.110039