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Surgical Infections Nov 2021(HPI) is a rare and underreported pathogen. causes respiratory, soft tissue, and central nervous system (CNS) infections, and endocarditis. Little data on HPI... (Review)
Review
(HPI) is a rare and underreported pathogen. causes respiratory, soft tissue, and central nervous system (CNS) infections, and endocarditis. Little data on HPI surgical infections are available, especially for intra-abdominal infections (IAI). isolates were recovered from patients treated at a rural hospital during a two-year period. Isolation and identification of the pathogen was done according to standard guidelines. A literature review with regard to HPI IAI was done. A total of 273 HPI isolates were analyzed, 15 patients had double isolates; HPI was commonly part of a mixed infection. Respiratory tract infections accounted for 64.8%, ear-nose-throat (ENT)/eye infections for 17.9%, genital/urologic infections for 3%, blood stream infections for 1% of cases and 13.2% of HPI isolates involved surgical infections. Thirty-four patients (36 isolates) had HPI surgical infections including 28 skin/soft tissue infections, two bone infections, two perirectal abscesses, one infected hemodialysis catheter, and three IAIs including perforated appendicitis, perforated diverticulitis, and a pelvic abscess 10 days after laparoscopic appendectomy. All three IAIs were mixed infections and successfully managed with percutaneous drainage and antibiotic therapy. More than 90% of HPI isolates in our hospital tested negative for β-lactamase production. A literature review revealed 32 reported cases of HPI IAI including biliary infections (12), peritonitis (9), liver abscess (7), and IA abscess (4) with the majority being monomicrobial; treatment included antibiotic agents and surgery/intervention in most cases. Outcomes were generally favorable. Our study confirms data from the literature that HPI is capable of causing a variety of severe surgical infections. More research with regard to this pathogen is warranted.
Topics: Appendectomy; Haemophilus Infections; Haemophilus parainfluenzae; Humans; Liver Abscess; Respiratory Tract Infections
PubMed: 33970041
DOI: 10.1089/sur.2020.172 -
Journal of Visualized Experiments : JoVE Jun 2021Haemophilus influenzae (Hi) is a prevalent bacterium found in a range of respiratory conditions. A variety of different assays/techniques may be used to assess the...
Haemophilus influenzae (Hi) is a prevalent bacterium found in a range of respiratory conditions. A variety of different assays/techniques may be used to assess the respiratory immune/inflammatory response to this bacterium. Flow cytometry and confocal microscopy are fluorescence-based technologies that allow detailed characterization of biological responses. Different forms of Hi antigen can be used, including cell wall components, killed/inactivated preparations, and live bacteria. Hi is a fastidious bacterium that requires enriched media but is generally easy to grow in standard laboratory settings. Tissue samples for stimulation with Hi may be obtained from peripheral blood, bronchoscopy, or resected lung (e.g., in patients undergoing surgery for the treatment of lung cancer). Macrophage and neutrophil function may be comprehensively assessed using flow cytometry with a variety of parameters measured, including phagocytosis, reactive oxygen species, and intracellular cytokine production. Lymphocyte function (e.g., T cell and NK cell function) may be specifically assessed using flow cytometry, principally for intracellular cytokine production. Hi infection is a potent inducer of extracellular trap production, both by neutrophils (NETs) and macrophages (METs). Confocal microscopy is arguably the most optimal way to assess NET and MET expression, which may also be used to assess protease activity. Lung immunity to Haemophilus influenzae can be assessed using flow cytometry and confocal microscopy.
Topics: Extracellular Traps; Haemophilus Infections; Haemophilus influenzae; Humans; Neutrophils; Phagocytosis
PubMed: 34279491
DOI: 10.3791/62572 -
Journal of Biological Regulators and... 2020The aim of this study was to verify the sterilizing effectiveness of the laser in the treatment of the periodontal pockets in vivo, with the recording of clinicians'... (Review)
Review
The aim of this study was to verify the sterilizing effectiveness of the laser in the treatment of the periodontal pockets in vivo, with the recording of clinicians' parameters and microbiological analysis, and in vitro with particular attention to the presence of specific bacterial stocks. During our study, in particular, it has been used the diodes laser. In order to estimate the effectiveness of the treatment of the periodontal pockets with laser, it has been examined the microbial content of the pockets carrying out withdrawals of the sulcular material before, immediately after and twenty minutes from the radiation. The microbiological results of the studies assert that, although substantial qualitative discrepancies between the several colonies of pathogen do not exist, quantitative differences are taken place with respect to the lessening of number and dimension of the present colonie.
Topics: Aggregatibacter actinomycetemcomitans; Humans; Lasers, Semiconductor; Periodontal Pocket; Porphyromonas gingivalis
PubMed: 32618171
DOI: No ID Found -
Microbiology Spectrum Feb 2022Actinobacillus pleuropneumoniae causes porcine pleuropneumonia, an important disease in the pig industry. Accurate and sensitive diagnostics such as DNA-based...
Actinobacillus pleuropneumoniae causes porcine pleuropneumonia, an important disease in the pig industry. Accurate and sensitive diagnostics such as DNA-based diagnostics are essential for preventing or responding to an outbreak. The specificity of DNA-based diagnostics depends on species-specific markers. Previously, an insertion element was found within an A. pleuropneumoniae-specific gene commonly used for A. pleuropneumoniae detection, prompting the need for additional species-specific markers. Herein, 12 marker candidates highly conserved (99 - 100% identity) among 34 A. pleuropneumoniae genomes (covering 13 serovars) were identified to be A. pleuropneumoniae-specific , as these sequences are distinct from 30 genomes of 13 other and problematic [] species and more than 1700 genomes of other bacteria in the family. Five marker candidates are within the gene, a known A. pleuropneumoniae-specific gene, validating our marker discovery method. Seven other A. pleuropneumoniae-specific marker candidates within the , , , , and genes were validated by polymerase chain reaction (PCR) to be specific to 129 isolates of A. pleuropneumoniae (covering all 19 serovars), but not to four closely related species, four [] species, or seven other bacterial species. This is the first study to identify A. pleuropneumoniae-specific markers through genome mining. Seven novel A. pleuropneumoniae-specific DNA markers were identified by a combination of and molecular methods and can serve as additional or alternative targets for A. pleuropneumoniae diagnostics, potentially leading to better control of the disease. Species-specific markers are crucial for infectious disease diagnostics. Mutations within a marker sequence can lead to false-negative results, inappropriate treatment, and economic loss. The availability of several species-specific markers is therefore desirable. In this study, 12 DNA markers specific to A. pleuropneumoniae, a pig pathogen, were simultaneously identified. Five marker candidates are within a known A. pleuropneumoniae-specific gene. Seven novel markers can be used as additional targets in DNA-based diagnostics, which in turn can expedite disease diagnosis, assist farm management, and lead to better animal health and food security. The marker discovery strategy outlined herein requires less time, effort, and cost, and results in more markers compared with conventional methods. Identification of species-specific markers of other pathogens and corresponding infectious disease diagnostics are possible, conceivably improving health care and the economy.
Topics: Actinobacillus pleuropneumoniae; Animals; Bacterial Proteins; Genetic Markers; Genome, Bacterial; Pathology, Molecular; Pleuropneumonia; Polymerase Chain Reaction; Swine; Swine Diseases
PubMed: 34985298
DOI: 10.1128/spectrum.01311-21 -
Critical Reviews in Microbiology Mar 2021is the most common cause of bacterial infection in the lungs of chronic obstructive pulmonary disease (COPD) patients and contributes to episodes of acute exacerbation... (Review)
Review
is the most common cause of bacterial infection in the lungs of chronic obstructive pulmonary disease (COPD) patients and contributes to episodes of acute exacerbation which are associated with increased hospitalization and mortality. Due to the ability of to adhere to host epithelial cells, initial colonization of the lower airways can progress to a persistent infection and biofilm formation. This is characterized by changes in bacterial behaviour such as reduced cellular metabolism and the production of an obstructive extracellular matrix (ECM). Herein we discuss the multiple mechanisms by which contributes to the pathogenesis of COPD. In particular, mechanisms that facilitate bacterial adherence to host airway epithelial cells, biofilm formation, and microbial persistence through immune system evasion and antibiotic tolerance will be discussed.
Topics: Animals; Bacterial Adhesion; Haemophilus Infections; Haemophilus influenzae; Humans; Lung; Pulmonary Disease, Chronic Obstructive
PubMed: 33455514
DOI: 10.1080/1040841X.2020.1863330 -
Microbial Genomics Feb 2022is a Gram-negative, rod-shaped bacterium of the family causing pig pleuropneumonia associated with great economic losses worldwide. Nineteen serotypes with distinctive...
is a Gram-negative, rod-shaped bacterium of the family causing pig pleuropneumonia associated with great economic losses worldwide. Nineteen serotypes with distinctive lipopolysaccharide (LPS) and capsular (CPS) compositions have been described so far, yet complete circular genomes are publicly available only for the reference strains of serotypes 1, 4 and 5b, and for field strains of serotypes 1, 3, 7 and 8. We aimed to complete this picture by sequencing the reference strains of 17 different serotypes with the MinION sequencer (Oxford Nanopore Technologies, ONT) and on an Illumina HiSeq (Illumina) platform. We also included two field isolates of serotypes 2 and 3 that were PacBio- and MinION-sequenced, respectively. Genome assemblies were performed following two different strategies, i.e. PacBio- or ONT-only assemblies polished with Illumina reads or a hybrid assembly by directly combining ONT and Illumina reads. Both methods proved successful in obtaining accurate circular genomes with comparable qualities. blast-based genome comparisons and core-genome phylogeny based on core genes, SNP typing and multi-locus sequence typing (cgMLST) of the 26 circular genomes indicated well-conserved genomes across the 18 different serotypes, differing mainly in phage insertions, and CPS, LPS and RTX-toxin clusters, which, consistently, encode serotype-specific antigens. We also identified small antibiotic resistance plasmids, and complete subtype I-F and subtype II-C CRISPR-Cas systems. Of note, highly similar clusters encoding all those serotype-specific traits were also found in other pathogenic and commensal species. Taken together with the presence of transposable elements surrounding these loci, we speculate a dynamic intra- and interspecies exchange of such virulence-related factors by horizontal gene transfer. In conclusion, our comprehensive genomics analysis provides useful information for diagnostic test and vaccine development, but also for whole-genome-based epidemiological studies, as well as for the surveillance of the evolution of antibiotic resistance and virulence genes in .
Topics: Actinobacillus pleuropneumoniae; Animals; Genomics; Lipopolysaccharides; Multilocus Sequence Typing; Serogroup; Swine
PubMed: 35196217
DOI: 10.1099/mgen.0.000776 -
Veterinary Microbiology Aug 2023Amongst the bacterial pathogens associated with the bovine respiratory disease syndrome (BRD) in cattle are Mannheimia haemolytica and Mycoplasma bovis. The interaction...
Amongst the bacterial pathogens associated with the bovine respiratory disease syndrome (BRD) in cattle are Mannheimia haemolytica and Mycoplasma bovis. The interaction between these two pathogens has not been investigated before; thus, there are gaps in the knowledge of why and how a previous infection with M. haemolytica allows the development of M. bovis-related lesions. We hypothesized that upon M. haemolytica infection, inflammatory products are produced in the lung and that these inflammatory products stimulate M. bovis to produce proteases and lipases that degrade lipids and proteins important for lung function. In this work, we identified several M. bovis proteases and lipases whose expression was modulated by M. haemolytica products in vitro. We performed co-infection animal challenges to develop a model to test vaccine protection. A prior exposure to BHV-1 followed by infection with M. bovis and M. haemolytica resulted in severe pathology and the BHV-1 infection was abandoned. When M. bovis and M. haemolytica were introduced into the lungs by bronchoscopy, we found that M. haemolytica resulted in worsening of the respiratory disease caused by M. bovis. We performed a proof-of-concept trial where animals were immunized with the M. bovis proteins identified in this study and challenged with both pathogens. Despite detecting significant humoral immune responses to the antigens, the experimental vaccine failed to protect against M. bovis disease.
Topics: Animals; Cattle; Bacteria; Cattle Diseases; Mannheimia haemolytica; Mycoplasma bovis; Respiratory Tract Diseases; Proof of Concept Study
PubMed: 37276814
DOI: 10.1016/j.vetmic.2023.109793 -
Veterinary Microbiology Aug 2021Bovine respiratory disease (BRD) is caused by a mixture of viruses and opportunistic bacteria belonging to Pasteurellaceae and Mycoplasma bovis. However, these organisms...
Bovine respiratory disease (BRD) is caused by a mixture of viruses and opportunistic bacteria belonging to Pasteurellaceae and Mycoplasma bovis. However, these organisms are also commonly isolated from healthy calves. This study aimed to determine whether the organisms are present in higher numbers in calves sick with acute BRD than in clinically healthy calves, and further to genetically characterize bacteria of the family Pasteurellaceae to understand whether particular types are associated with disease. Forty-six clinically healthy and 46 calves with BRD were sampled by broncheoalveolar lavage (BAL) method in 11 herds geographically spread over Denmark to determine presence and quantity of microorganisms by culture and quantitative real time qPCR. Isolates of Pasteurellaceae were tested for antibiotic resistance and were whole genome sequenced to determine genotypes. Histophilus somni was in particular positively associated with BRD, suggesting particular importance of this organism as likely aetiology of BRD. In addition, quantification of bacteria revealed that higher counts of H. somni as well as of M. haemolytica was also a good indicator of the disease. Pasteurellaceae isolates were susceptible to the commonly used antibiotics in treatment of BRD, and genotypes were shared between isolates from clinically healthy and sick calves.
Topics: Animals; Anti-Bacterial Agents; Bacteria; Bovine Respiratory Disease Complex; Bronchoalveolar Lavage Fluid; Cattle; Cattle Diseases; Mannheimia haemolytica; Pasteurellaceae; Respiratory Tract Diseases
PubMed: 34090248
DOI: 10.1016/j.vetmic.2021.109135 -
Veterinary Microbiology Jul 2021Actinobacillus pleuropneumoniae is a Gram-negative bacterium causing porcine pleuropneumonia and severe economic losses in the global swine industry. The toxic trace...
Actinobacillus pleuropneumoniae is a Gram-negative bacterium causing porcine pleuropneumonia and severe economic losses in the global swine industry. The toxic trace element copper is required for many physiological and pathological processes in organisms. However, CopA, one of the most well-characterized P-type ATPases contributing to copper resistance, has not been characterized in A. pleuropneumoniae. We used quantitative PCR analysis to examine expression of the copA gene in A. pleuropneumoniae and investigated sequence conservation among serotypes and other Gram-negative bacteria. Growth characteristics were determined using growth curve analyses and spot dilution assays of the wild-type strain and a △copA mutant. We also used flame atomic absorption spectrophotometry to determine intracellular copper content and examined the virulence of the △copA mutant in a mouse model. The copA expression was induced by copper, and its nucleotide sequence was highly conserved among different serotypes of A. pleuropneumoniae. The amino acid sequence of CopA shared high identity with CopA sequences reported from several Gram-negative bacteria. Furthermore, the △copA mutant exhibited impaired growth and had higher intracellular copper content compared with the wild-type strain when supplemented with copper. The mouse model revealed that CopA had no influence on the virulence of A. pleuropneumoniae. In conclusion, these results demonstrated that CopA is required for resistance of A. pleuropneumoniae to copper and protects A. pleuropneumoniae against copper toxicity via copper efflux.
Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Bacterial Proteins; Computational Biology; Copper; Gene Expression Regulation, Bacterial; Mice; Mice, Inbred BALB C; Up-Regulation; Virulence
PubMed: 34052743
DOI: 10.1016/j.vetmic.2021.109122 -
Molecular Oral Microbiology Apr 2021Periodontitis is an irreversible, chronic inflammatory disease where inflammophilic pathogenic microbial communities accumulate in the gingival crevice. Neutrophils are... (Review)
Review
Periodontitis is an irreversible, chronic inflammatory disease where inflammophilic pathogenic microbial communities accumulate in the gingival crevice. Neutrophils are a major component of the innate host response against bacterial challenge, and under homeostatic conditions, their microbicidal functions typically protect the host against periodontitis. However, a number of periodontal pathogens developed survival strategies to evade neutrophil microbicidal functions while promoting inflammation, which provides a source of nutrients for bacterial growth. Research on periodontal pathogens has largely focused on a few established species: Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis. However, advances in culture-independent techniques have facilitated the identification of new bacterial species in periodontal lesions, such as the two Gram-positive anaerobes, Filifactor alocis and Peptoanaerobacter stomatis, whose characterization of pathogenic potential has not been fully described. Additionally, there is not a full understanding of the pathogenic mechanisms used against neutrophils by organisms that are abundant in periodontal lesions. This presents a substantial barrier to the development of new approaches to prevent or ameliorate the disease. In this review, we first summarize the neutrophil functions affected by the established periodontal pathogens listed above, denoting unknown areas that still merit a closer look. Then, we review the literature on neutrophil functions and the emerging periodontal pathogens, F. alocis and P. stomatis, comparing the effects of the emerging microbes to that of established pathogens, and speculate on the contribution of these putative pathogens to the progression of periodontal disease.
Topics: Aggregatibacter actinomycetemcomitans; Clostridiales; Humans; Inflammation; Neutrophils; Porphyromonas gingivalis; Treponema denticola
PubMed: 33128827
DOI: 10.1111/omi.12321