Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Actinobacillus Infections”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1995

Infection (Actinobacillus pleuropneumoniae)-mediated suppression of oxidative hepatic drug metabolism and cytochrome P4503A mRNA levels in pigs.

The effect of Actinobacillus pleuropneumoniae infection, a well-characterized pig infection model, on both phase I (oxidative) and phase II (conjugative) microsomal enzyme activities was investigated in castrated male conventional pigs. A. pleuropneumoniae infection resulted after 24 hr in a significant suppression of 33% or more of all oxidative enzyme activities determined. After 40 hr, the activities were still suppressed, but did not differ from the results after 24 hr. On the contrary, all glucuronosyltransferase activities measured were not affected by A. pleuropneumoniae infection after both 24 and 40 hr. To elucidate further the mechanism of the suppression of oxidative enzyme activities, analysis of mRNA were conducted by dot-blot analysis using a human cytochrome P4503A4 cDNA probe. The results indicated that A. pleuropneumoniae infection suppressed oxidative enzyme activities. The reduction in cytochrome P4503A activity, specific for 6 beta-hydroxylation of testosterone is at a pretranslational level as measured by a decrease in the amount of mRNA.

Actinobacillus Infections↗
PubMed1995

Selective effects of a bacterial infection (Actinobacillus pleuropneumoniae) on the hepatic clearances of caffeine, antipyrine, paracetamol, and indocyanine green in the pig.

1. In order to investigate the effect of a bacterial acute phase response model on drug disposition in vivo, plasma clearances of antipyrine, caffeine, paracetamol and indocyanine green were investigated in the healthy and Actinobacillus pleuropneumoniae-infected pig. 2. Indocyanine green plasma and endogenous creatinine clearance were not changed during the infection, which indicates that hepatic blood flow and renal function were not significantly affected. 3. In the A. pleuropneumoniae-infected pig, plasma clearances of antipyrine and caffeine, both marker substrates for hepatic oxidative biotransformation, were decreased by 72 and 68% respectively. The clearance of paracetamol, a drug mainly glucuronidated in the pig, was reduced by 39%. 4. It is concluded that the most important change in drug elimination during an acute phase response induced by A. pleuropneumoniae is a suppression of oxidative hepatic biotransformation.

Acetaminophen↗
PubMed2006

Development of a DIVA subunit vaccine against Actinobacillus pleuropneumoniae infection.

Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia which leads to high economic losses in the swine industry worldwide. Vaccination against this pathogen is hampered by the occurrence of 15 serotypes, and commonly used whole cell bacterin vaccines are not sufficiently cross-serotype protective. In addition, for generating and maintaining specified pathogen-free herds it is desirable to use DIVA (differentiating infected from vaccinated animals) vaccines. Based on a detergent wash extraction of outer membrane associated proteins and secreted proteins we developed a DIVA vaccine using the immunogenic ApxII toxin which is present in 13 of the 15 A. pleuropneumoniae serotypes as the DIVA antigen. The apxIIA gene was deleted in one strain each of serotypes 1, 2, and 5 using a single-step transconjugation system, and equal parts of detergent washes from these strains served as the vaccine antigen. After intramuscular immunisation all pigs developed a strong humoral immune response to the vaccine antigen and showed no reactivity in an ApxIIA ELISA. Upon challenge all pigs were completely protected from clinical symptoms in trials with a homologous (serotype 2) as well as with a heterologous strain (serotype 9); in addition, colonisation of the challenge strain was clearly reduced but not abolished completely. As a result of the highly efficient protection, however, immunised pigs did not develop antibodies to the DIVA-antigen at levels detectable by ELISA but only by a more sensitive Western blotting approach, thereby demonstrating the challenge in developing appropriate marker vaccines for the livestock industry.

Actinobacillus Infections↗
PubMed2002

Rare Actinobacillus infection of the cavernous sinus causing painful ophthalmoplegia: case report.

OBJECTIVE AND IMPORTANCE: Actinobacillus actinomycetemcomitans is a gram-negative coccobacillus that is known to cause a wide array of clinical infections in debilitated patients, including periodontal disease, soft tissue abscess, pleural empyema, endocarditis, cerebral abscess, and meningitis. We report a rare A. actinomycetemcomitans cavernous sinus abscess that caused painful ophthalmoplegia in a healthy man. CLINICAL PRESENTATION: A 34-year-old man presented with a 3-month history of acute onset of left-sided retro-orbital pain that progressed to a complete left Cranial Nerve VI palsy and Cranial Nerve V1 and V2 hypesthesia. Magnetic resonance imaging revealed the presence of an enhancing lesion in the left cavernous sinus, which encased and narrowed the ipsilateral intracavernous segment of the internal carotid artery. Routine blood and cerebrospinal fluid analyses were normal. Tolosa-Hunt syndrome was suspected, and the patient was treated with high-dose corticosteroids. An open biopsy was performed after failed prolonged corticosteroid therapy. INTERVENTION: A left frontotemporal craniotomy and cavernous sinus exploration through an interdural approach were performed. A soft reddish mass was found in the cavernous sinus around Cranial Nerve V1 and V2. Multiple biopsies were obtained. Pathological analysis revealed a purulent infection containing multiple gram-negative coccobacilli. The patient's pain improved immediately, and cranial neuropathy resolved during the next several weeks. After cultures demonstrated growth of A. actinomycetemcomitans, a regimen of orally administered amoxicillin and metronidazole was initiated. Eight months after surgery, the patient was free of symptoms and a repeat magnetic resonance imaging scan was normal. CONCLUSION: We present a rare bacterial abscess of the cavernous sinus causing painful ophthalmoplegia. In patients who present with presumed Tolosa-Hunt syndrome and do not improve with prolonged high-dose corticosteroid therapy, an open biopsy is recommended to exclude a bacterial infection.

Actinobacillus Infections↗
PubMed1977

[Actinobacillus infections in swine (author's transl)].

Actinobacilli infections in pigs are relatively rare. Most cases were septicaemic in the first week of life. With increasing age manifestations after generalized infections were characteristic, such as arthritis, polyarthritis, endocarditis, nephritis, osteomyelitis and embolic pneumonia. Of 34 porcine strains 33 were identified as A. equuli and only one was identical with A. suis. The justification of retaining this species is discussed.

Actinobacillus Infections↗
PubMed1987

The presence of phage-infected Actinobacillus actinomycetemcomitans in localized juvenile periodontitis patients.

Electron microscopy revealed 2 different types of bacteriophages isolated from Actinobacillus actinomycetemcomitans colonizing exclusively diseased sites in 4 patients with localized juvenile periodontitis (LJP). All sites infected with phage were undergoing periodontal destruction, as judged from consecutive routine radiographs. The phages isolated had a wide host range as assessed from their ability to infect a series of reference strains of A. actinomycetemcomitans. A 5th patient harboured non-infected A. actinomycetemcomitans in a surgically treated site which had undergone no bone destruction during the last 12 months. The present findings suggested that the pathogenic potential of A. actinomycetemcomitans in LJP may increase due to phage infection.

Actinobacillus↗
PubMed1987

Association between bacteriophage-infected Actinobacillus actinomycetemcomitans and rapid periodontal destruction.

Actinobacillus actinomycetemcomitans was isolated from periodontal pockets in a patient suffering from prepubertal periodontitis. Electron microscopy revealed 3 different groups of bacteriophages in filtrates of subgingival plaque from all the active periodontal lesions. Phage infected A. actinomycetemcomitans in this patient was restricted to periodontal pockets which, according to standardized roentgenograms, had shown bone destruction during the past 12 months. A follow-up study of 7 months revealed that a "burned out" site which harbored noninfected A. actinomycetemcomitans, turned into an active site at the same time as the A. actinomycetemcomitans of that site became infected with the phages. These findings indicate a relationship between rapid prepubertal periodontal destruction and phage-infected A. actinomycetemcomitans.

Actinobacillus↗
PubMed1990

[Role of Actinobacillus actinomycetemcomitans in human infection].

Actinobacillus actinomycetemcomitans (AA), is a cocobacillus thin and small, non motile, uncapsulate and capnophilic. AA, is: one of the species encountered in the mouth's comensal flora being able to be isolated in gingival crevices culture and oral mucosa in a 20% of the healthy population. An important number of pathogenic factors make it well equipped, to protect itself from host's defense mechanisms, and to destroy the periodontal tissue. Between the most important we find lipopolisacarides and leucotoxines which promote tisular invasion and destructive qualities of this microorganism. Since 1912, there are numerous reports of infectious process associated to it, between which we find: endocarditis in native and prothesic valve, soft tissues abscess, pneumonia, brain's abscess, urethritis, vertebral osteomielitis, thyroid's abscess, pericarditis and periodontal juvenile illness, being this one in which its isolation is more frequent. In vitro, AA is very susceptible to tetracicline. This antibiotic reaches high concentrations in gingival crevices, has significant affinity to the alveolar bone and contributes to protect the collagen. These special feature make them the election drug in periodontal disease produced by this microorganism.

Actinobacillus↗
PubMed2002

Actinobacillus pleuropneumoniae: pathobiology and pathogenesis of infection.

Actinobacillus pleuropneumoniae causes porcine pleuropneumonia, a highly contagious disease for which there is no effective vaccine. This review considers how adhesins, iron-acquisition factors, capsule and lipopolysaccharide, RTX cytotoxins and other potential future vaccine components contribute to colonisation, to avoidance of host clearance mechanisms and to damage of host tissues.

Actinobacillus Infections↗
PubMed2001

Involvement of caspases in apoptotic cell death of murine macrophages infected with Actinobacillus actinomycetemcomitans.

Infection of murine macrophages in vitro with periodontopathic bacterium Actinobacillus actinomycetemcomitans induces apoptotic cell death. In this study, we investigated the involvement of caspases in apoptotic cell death of A. actinomycetemcomitans-infected macrophages. Two peptide inhibitors of caspases, benzyloxycarbonyl-Val-Ala-Asp (OMe)-fluoromethyl ketone (Z-VAD-FMK) and benzyloxycarbonyl-Asp-Glu-Val-Asp (OMe)-fluoromethyl ketone (Z-DEVD-FMK), inhibited apoptotic cell death of murine macrophage cell line J774.1 infected with A. actinomycetemcomitans. During the process of apoptosis, interleukin-1beta (IL-1beta) was detected in the culture supernatants of J774.1 cells. IL-1beta secretion was blocked by the caspase-1 inhibitor, Z-VAD-FMK, indicating that caspase-1 is involved in not only the induction of apoptosis but also the IL-1beta secretion from A. actinomycetemcomitans-infected J774.1 cells. Immunoblot analysis revealed that the infection of A. actinomycetemcomitans to J774.1 cells induced the cleavage of retinoblastoma protein (Rb), suggesting that caspase-3 was activated by A. actinomycetemcomitans infection. The cytosol from A. actinomycetemcomitans-infected J774.1 cells induced Rb proteolysis in vitro, which was inhibited by the caspase-3 inhibitor, Z-DEVD-FMK. Furthermore, caspase-3-like activity was markedly increased in J774.1 cells infected with A.actinomycetemcomitans between 12 h and 24 h, which was subsequently inhibited by the addition of caspase-3 inhibitor, Z-DEVD-FMK. These findings indicate that caspase-3 induces apoptosis in J774.1 cells infected with A. actinomycetemcomitans. Taken together, these results suggest that caspase-1 and caspase-3 are involved in the induction of apoptosis in A. actinomycetemcomitans-infected macrophages.

Aggregatibacter actinomycetemcomitans↗
PubMed2003

Identification of dimethyl sulfoxide reductase in Actinobacillus pleuropneumoniae and its role in infection.

Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, is capable of persisting in oxygen-deprived surroundings, namely, tonsils and sequestered necrotic lung tissue. Utilization of alternative terminal electron acceptors in the absence of oxygen is a common strategy in bacteria under anaerobic growth conditions. In an experiment aimed at identification of genes expressed in vivo, the putative catalytic subunit DmsA of anaerobic dimethyl sulfoxide reductase was identified in an A. pleuropneumoniae serotype 7 strain. The 90-kDa protein exhibits 85% identity to the putative DmsA protein of Haemophilus influenzae, and its expression was found to be upregulated under anaerobic conditions. Analysis of the unfinished A. pleuropneumoniae genome sequence revealed putative open reading frames (ORFs) encoding DmsB and DmsC proteins situated downstream of the dmsA ORF. In order to investigate the role of the A. pleuropneumoniae DmsA protein in virulence, an isogenic deletion mutant, A. pleuropneumoniae DeltadmsA, was constructed and examined in an aerosol infection model. A. pleuropneumoniae DeltadmsA was attenuated in acute disease, which suggests that genes involved in oxidative metabolism under anaerobic conditions might contribute significantly to A. pleuropneumoniae virulence.

Actinobacillus Infections↗
PubMedDate not supplied

Immunohistochemical detection and distribution of inducible nitric oxide synthase in pigs naturally infected with Actinobacillus pleuropneumoniae.

Inducible nitric oxide synthase (iNOS) protein was detected immunohistochemically in formalin-fixed, paraffin wax-embedded lung tissues from 10 natural cases of porcine pleuropneumonia. Positive cells typically exhibited a red reaction product without background staining. Labelling of iNOS protein was intense in "oat cells", the clustered leucocytes with streaming nuclear chromatin that are a characteristic histological feature of porcine pleuropneumonia. Macrophages and neutrophils within alveolar spaces but not within blood vessels consistently showed iNOS labelling, but such labelling was minimal in non-lesional lung of Actinobacillus pleuropneumoniae -infected pigs and in normal lung from control pigs. The results suggest that iNOS plays a role in pathophysiological processes during A. pleuropneumoniae infection.

Actinobacillus Infections↗
PubMed1999

Pulmonary lesions in guinea pigs experimentally infected with Actinobacillus pleuropneumoniae (A.p.) serovar 1.

Pathological studies were carried out on the lungs of guinea pigs intratracheally inoculated with 4.6 x 10(6-8) colony forming units (CFU)/head of Actinobacillus pleuropneumoniae serovar 1. All animals in the highest dose group died within 24 hr post inoculation (hpi) and showed pulmonary lesions being hemorrhagic in nature while all animals in the lowest dose group were killed as scheduled at 11 days post inoculation (dpi) and showed only hyperplasia of peribronchial lymphoid tissues. In the middle dose group, two died within 24 hpi, two died at 9 dpi, and the remaining one was killed at 11 dpi. Two guinea pigs which died at 9 dpi showed fibrinonecrotic pleuropneumonia which is the most characteristic acute pulmonary lesion in swine, and has not yet been reproduced in laboratory animals up to the present time. This suggests that guinea pigs may be a useful laboratory animal for studying the pathogenesis of Actinobacillus pleuropneumoniae infection in swine.

Actinobacillus Infections↗
PubMed1995

Inflammatory cytokine expression in swine experimentally infected with Actinobacillus pleuropneumoniae.

An Actinobacillus pleuropneumoniae infection model in swine was established to study the expression of inflammatory cytokines during acute respiratory disease. Lavage fluid, lavage cells consisting primarily of alveolar macrophages, and lung tissue were analyzed for the presence of various cytokines at 2, 4, 8, and 24 h following endotracheal inoculation of A. pleuropneumoniae. Interleukin-1 beta (IL-1) and IL-8 mRNA levels were elevated within 2 h in lavage cells of animals inoculated with A. pleuropneumonia but not in cells from controls treated with saline-bovine serum albumin, based on Northern (RNA blot) analysis. Tumor necrosis factor (TNF) mRNA was present at low levels in all animals, and the level was not increased at any time point. In situ hybridization was more sensitive than Northern blotting and revealed elevations of all three cytokines in lavage cells within 2 to 4 h of A. pleuropneumoniae inoculation. IL-6 was detected in lavage cells by in situ hybridization but not by Northern blotting. In lung tissue obtained 18 to 24 h after A. pleuropneumoniae instillation, all cytokine mRNAs, including that of IL-6, were detected by Northern blot analysis. The levels of bioactive IL-1 and IL-6 in lavage fluids increased approximately 1,000-fold following A. pleuropneumoniae inoculation, but TNF bioactivity was not detected. Morphological localization of cytokine mRNAs by in situ hybridization indicated markedly increased levels of TNF, IL-1, and IL-8 mRNAs at the periphery of focal lung lesions. These findings indicate that inflammatory cytokines, particularly IL-1 and IL-8, are associated with the development of pleuropneumonia and may contribute to disease severity.

Actinobacillus Infections↗
PubMedDate not supplied

Differential proteomic analysis reveals increased cathelicidin expression in porcine bronchoalveolar lavage fluid after an Actinobacillus pleuropneumoniae infection.

Accurate definition of respiratory health in pigs is an important problem for swine producers and veterinarians. In an approach to identify potential biomarkers, two-dimensional gel electrophoresis and mass spectrometry on bronchoalveolar lavage fluid (BALF)-derived proteins from pigs experimentally infected with Actinobacillus pleuropneumoniae were performed at different time points post infection. Mock-infected pigs were used as a control. It was shown that the antimicrobial peptides, prophenin-2 and PR-39, and the calcium-binding protein calgranulin C were reproducibly upregulated in BALF of pigs chronically infected with A. pleuropneumoniae. Concentrations of PR-39 were significantly (p<0.05) increased in BALF (median of 4.8 nM) but not in serum (median of 2.5 nM) on day 21 after infection. A Receiver Operating Characteristics (ROC) plot showed that PR-39 in BALF is an accurate and easily accessible marker to detect clinically healthy pigs convalescent from an experimental A. pleuropneumoniae infection. These results imply that PR-39 might have a potential as a general biomarker to determine porcine respiratory health.

Actinobacillus Infections↗