SEARCH · PubMed Health

Results for “Atypical Bacterial Forms”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 145 records · Page 8Linked to original sources

PubMed1985

[Clinical picture of bacterial pneumonias and their differential diagnosis].

Under the influence of antibiotic therapy, bacterial pneumonias have undergone a remarkable change in the last few decades. Individual forms of pneumonia can be distinguished morphologically by their localization, the way in which they spread, their limitations, and their course. Clinically, opportunistic bacterial infections predominate. Increasingly, secondary pneumonias are observed in poststenotic areas, areas of infarction, in hypostatic areas, after aspiration, and in previously damaged lobes. Radiologic criteria for differentiating from atypical pneumonias (viruses, mycoplasmas and chlamydia) are discussed.

Bacterial Infections↗

PubMed2002

Epileptic seizure: an atypical presentation in an adolescent boy with neurobrucellosis.

Brucellosis is an infectious disease with multisystemic involvement caused by the genus Brucella. Neurological complications, including meningitis, meningoencephalitis, myelitis-radiculoneuritis, brain abscess, epidural abscess and meningovascular syndromes, are rarely encountered. We present a patient with epileptic seizures and aggressive mood due to chronic neurobrucellosis of 2.5 y duration, which was misdiagnosed as bacterial meningitis and epilepsy. This form of presentation has not previously been reported in the English language literature. We conclude that the diagnosis of neurobrucellosis should be considered in patients presenting with recurrent or chronic meningitis syndromes with or without seizure from endemic areas for brucellosis.

Adolescent↗

PubMedDate not supplied

[The use of a polymerase chain reaction method for the diagnosis of Mycoplasma pneumonia].

The assay system for the diagnosis of Mycoplasma pneumoniae infections, based on polymerase chain reaction (PCR), has been developed. The sensitivity of the detection of M. pneumoniae DNA in analysis of different clinical samples has been established. The study has shown the possibility of using the newly developed assay system for the detection of M. pneumoniae in the material obtained from patients with atypical forms of pneumonia and from Mycoplasma carriers.

Adult↗

PubMedDate not supplied

[Primary varicella-zoster virus infection--current knowledge, diagnostic and therapeutic approaches].

INTRODUCTION: It is well known that varicella, a clinical entity of primary varicella-zoster virus infection, is most commonly a mild, benign disease of preschool and school children. However, in spite of progress in diagnostic approach and up-to-date treatment based on specific antiviral agents, many clinicians face cases of life-threatening varicella with uncertain course and prognosis, in adult and immunocompromised patients predominantly. ETIOPATHOGENESIS AND HISTOPATHOLOGY: Varicella-zoster virus (VZV) is a member of the Herpesviridae family. The portal of entry is nasopharyngeal mucosa, sometimes conjunctiva. VZV causes a generalized infection and has dermal tropism. Histopathological findings include degenerative changes of epithelial cells such as ballooning, multinucleated giant cells and eosinophilic intranuclear inclusions. CLINICAL FEATURES AND COMPLICATIONS: The evolution of varicella includes 3 stages of disease and is characterized by gradual onset, constitutional symptoms, signs of upper respiratory tract and polymorphous rash. According to the severity of clinical presentation, there is a number of mild forms and severe, even life-threatening forms of varicella. According to etiology, varicella complications are divided in viral and bacterial ones. Immunocompromised patients often develop serious, life-threatening forms of varicella. Especially the prognosis of visceral dissemination commonly followed by liver and brain involvement is dubious. The course of varicella in pregnancy may be severe because of changed immune response and more frequent appearance of complications in adults. The probability of vertical transmission of VZV is 25%. The early infection of embryo may lead to abortion. The symptomatic intrauterine infection appears in about 3% of all cases of varicella of pregnant women and is called a "congenital varicella syndrome". Vertical transmission of VZV in the late pregnancy may result in preterm delivery or perinatal varicella (varicella in the newborn). DIAGNOSIS: The diagnosis is made by history and physical examination. Atypical cases of varicella require laboratory confirmation of diagnosis including virus/viral antigen detection, virus isolation and identification or serological diagnosis (detection of specific anti-VZV antibodies in patient's sera). PREVENTION: Prevention of varicella includes active and passive immunization. Passive immunization is based on the use of varicella-immunoglobulin (VZIG). A live, attenuated vaccine was developed by Takahashi and colleagues in Japan. This vaccine is recommended, first of all, to seronegative immunodeficient children. Vaccine virus is sensitive to acyclovir and is not transmissible to non-vaccinated children. The duration of vaccine-induced immunity is at least 6-10 years in the majority of vaccinees. THERAPY: Hygiene is the most important principle in the management of varicella, particularly bathing and use of a stringent soaks to avoid secondary bacterial skin infection. The patient should be isolated in a well-ventilated room with regular change of bed, linen and light food should be provided. Indications for, acyclovir (and other antiviral agents) treatment are, individuals who have suffered from severe forms of varicella and those, belonging to the high-risk group of patients (adults, viral, complications, immunocompromised host).

Chickenpox↗

PubMed2000

Crohn disease arthropathy: antigens in synovial fluid share epitopes with strains of two species of viridans streptococci.

BACKGROUND: There is evidence to suggest that Crohn disease is caused by an immunologic response to an unknown intestinal luminal antigen, probably of bacterial origin. The reported demonstration of yersinia antigen in the synovial fluid of patients with yersinosis therefore prompted a search for bacterial antigens in the synovial fluid of patients with Crohn arthropathy. METHODS: Antisera were raised in rabbits to synovial fluids obtained from seven patients with Crohn arthropathy and from seven 'control' subjects with other forms of arthropathy. These antisera were used to probe sonicates of the bacteria cultured from the gastric juice of patients with gastric Crohn disease. RESULTS: The antisera made from the Crohn synovial fluids, but none of those made from the controls, reacted uniquely with antigens in sonicates of strains of two species of viridans streptococci (Streptococcus parasanguis and an atypical S. oralis) isolated from four of the five patients with gastric Crohn disease. CONCLUSIONS: These findings suggest that the arthropathy of Crohn disease and, possibly, the intestinal disease itself may involve an immunologically mediated inflammatory response to these antigens.

Animals↗

PubMed1994

Genotypic and phenotypic relatedness of 80 strains of Branhamella catarrhalis of worldwide origin.

80 clinical Branhamella catarrhalis strains of worldwide origin were examined for genotypic relatedness and phenotypic characteristics. Using a quantitative bacterial dot method for DNA-DNA hybridization the strains were found to form a homogeneous group with delta Tm-values ranging from 0.0-2.3 degrees C, In Minibact-N, an identification kit for oxidase positive, Gram-negative diplococci using eight phenotypic characteristics, all isolates were correctly identified and also demonstrated complete homogeneity except for beta-lactamase production. Type strains representing the genera Branhamella, Moraxella and Neisseria were also examined for comparison. B. catarrhalis strain NCTC 4103-known to be atypical-had a delta Tm-value of 5.7 degrees C and produced gamma-glutamylaminopeptidase, in contrast to all other B. catarrhalis strains. In GN MicroPlate, a kit which tests utilizable carbon sources, B. catarrhalis strains were found to be able to utilize up to 16 to 95 carbon sources.

Carbon↗

PubMed2005

Determinants of the streptococcal surface glycoprotein GspB that facilitate export by the accessory Sec system.

GspB is a large cell-surface glycoprotein expressed by Streptococcus gordonii M99 that mediates binding of this organism to human platelets. This adhesin is glycosylated in the cytoplasm, and is then transported to the cell surface via an accessory Sec system. To assess the structural features of GspB that are needed for export, we examined the effects of altering the carbohydrate moieties or the polypeptide backbone of GspB. Truncated, glycosylated variants of GspB were exported exclusively via the accessory Sec pathway. When glycosylation was abolished, the GspB variants were still exported by this pathway, but minor amounts could also be transported by the canonical Sec system. GspB variants with in-frame insertions or deletions in the N-terminus were not secreted, indicating that this domain is necessary for export. However, the N-terminus is not sufficient for the transport of heterologous proteins, because C-terminal fusion of passenger proteins to this domain hindered export. In contrast, fusion of GspB to a canonical signal peptide resulted in the efficient export of non-glycosylated forms of the fusion protein via the canonical Sec pathway, whereas glycosylated forms could not be exported. Thus, the carbohydrate moieties and the atypical signal sequence of GspB interfere with export via the canonical pathway, and direct GspB towards the accessory Sec system.

Adenosine Triphosphatases↗

PubMed1998

Physiology of carbohydrate to solvent conversion by clostridia.

The solvent-forming clostridia have attracted interest because of their ability to convert a range of carbohydrates to end-products such as acetone, butanol and ethanol. Polymeric substrates such as cellulose, hemicellulose and starch are degraded by extracellular enzymes. The majority of cellulolytic clostridia, typified by Clostridium thermocellum, produce a multi-enzyme cellulase complex in which the organization of components is critical for activity against the crystalline substrate. A variety of enzymes involved in degradation of hemicellulose and starch have been identified in different strains. The products of degradation, and other soluble substrates, are accumulated via membrane-bound transport systems which are generally poorly characterized. It is clear, however, that the phosphoenolpyruvate-dependent phosphotransferase system (PTS) plays a major role in solute uptake in several species. Accumulated substrates are converted by intracellular enzymes to end-products characteristic of the organism, with production of ATP to support growth. The metabolic pathways have been described, but understanding of mechanisms of regulation of metabolism is incomplete. Synthesis of extracellular enzymes and membrane-bound transport systems is commonly subject to catabolite repression in the presence of a readily metabolized source of carbon and energy. While many genes encoding cellulases, xylanases and amylases have been cloned and sequenced, little is known of control of their expression. Although the mechanism of catabolite repression in clostridia is not understood, some recent findings implicate a role for the PTS as in other low G-C Gram-positive bacteria. Emphasis has been placed on describing the mechanisms underlying the switch of C. acetobutylicum fermentations from acidogenic to solventogenic metabolism at the end of the growth phase. Factors involved include a lowered pH and accumulation of undissociated butyric acid, intracellular concentration of ATP and reduced pyridine nucleotides, nutrient limitation, and the interplay between pathways of carbon and electron flow. Genes encoding enzymes of solvent pathways have been cloned and sequenced, and their expression correlated with the pattern of end-product formation in fermentations. There is evidence that the initiation of solvent formation may be subject to control mechanisms similar to other stationary-phase phenomena, including sporulation. The application of recently developed techniques for genetic manipulation of the bacterium is improving understanding of the regulatory circuits, but a complete molecular description of the control of solvent formation remains elusive. Experimental manipulation of the pathways of electron flow in other species has been shown to influence the range and yield of fermentation end-products. Acid-forming clostridia can, under appropriate conditions, be induced to form atypical solvents as products. While the mechanisms of regulation of gene expression are not at all understood, the capacity to adapt in this way further illustrates the metabolic flexibility of clostridial strains.

Acetone↗

PubMed1981

Characterisation of an epidemic strain of Klebsiella and its variants by computer analysis.

An outbreak of hospital-acquired klebsiella infection was investigated by means of six different typing schemes. Interpretation of the information generated by these schemes proved difficult and allowed only tentative conclusions to be reached concerning the origin of some strains. Consequently, the results were subjected to computer analysis by means of a numerical taxonomic programme adapted for the purpose. A dendrogram was constructed giving the percentage similarity between strains. It established the source of four atypical strains and showed that three of them were derived from the original clone. This form of numerical epidemiological analysis could have useful applications in the investigation of hospital-acquired infection.

Anti-Bacterial Agents↗

PubMed1999

Properties of a cyclodextrin-specific, unusual porin from Klebsiella oxytoca.

The function of CymA, 1 of the 10 gene products involved in cyclodextrin uptake and metabolism by Klebsiella oxytoca, was characterized. CymA is essential for growth on cyclodextrins, but it can also complement the deficiency of a lamB (maltoporin) mutant of Escherichia coli for growth on linear maltodextrins, indicating that both cyclic and linear oligosaccharides are accepted as substrates. CymA was overproduced in E. coli and purified to apparent homogeneity. CymA is a component of the outer membrane, is processed from a signal peptide-containing precursor, and possesses a high content of antiparallel beta-sheet. Incorporation of CymA into lipid bilayers and conductance measurements revealed that it forms ion-permeable channels, which exhibit a substantial current noise. CymA-induced membrane conductance decreased considerably upon addition of alpha-cyclodextrin. Titration experiments allowed the calculation of a half-saturation constant, K(S), of 28 microM for its binding to CymA. CymA assembled in vitro to two-dimensionally crystalline tubular membranes, which, on electron microscopy, are characterized by a p1-related two-sided plane group. The crystallographic unit cell contains four monomeric CymA molecules showing a central pore. The lattice parameters are a = 16.1 nm, b = 3.8 nm, gamma = 93 degrees. CymA does not form trimeric complexes in lipid membranes and shows no tendency to trimerize in solution. CymA thus is an atypical porin with novel properties specialized to transfer cyclodextrins across the outer membrane.

Amino Acid Sequence↗

PubMed2006

[Severe community acquired pneumonia due to Staphylococcus aureus in children. About two cases].

The staphylococcal pneumonia is the prerogative of the infant but rare cases were observed in the childhood. We report the observation of two children aged respectively of six years and three years and a half having presented a particular form of severe staphylococcal pneumonia apart from any context of immunodepression. The identification of the particular strains producing toxins Like the Panton and Valentine leukocidin constitutes the first stage of the comprehension of this atypical form of pneumonia. Through these observations and with a review of literature we underline the specific clinical and biological aspects of this form.

Amikacin↗

PubMed2000

Atypical behaviour and survival of Streptococcus pyogenes L forms during intraperitoneal infection in rats.

Groups of rats were injected intraperitoneally with cell wall-deficient (L) forms of Streptococcus pyogenes, with their parental (S) forms, as well as with a combined inoculum of both forms (S+L). Peritoneal exudate samples were harvested on days 1, 3, 7, 15 and 30 after challenge and were investigated by microbiological, electron microscopic, cytometric and biochemical methods. Parental S forms were isolated from peritoneal exudate samples up to day 15 post infection, while L form cultures were isolated until the end of the examined interval. Electron microscopic examination revealed continuous adhesion of L forms on the macrophage surface as well as intracellular persistence inside them. It was demonstrated that the intraperitoneal inflammatory response to L form infection was higher than to the other infections and the monocyte-macrophage populations were predominant. The established atypical behaviour and long survival of S. pyogenes L forms in the rat's peritoneum could explain some of the mechanisms of the pathogens' persistence as well as the reasons for chronic streptococcal infections.

Animals↗

PubMed2002

HLA-B27--associated uveitis.

HLA-B27--associated acute anterior uveitis, a relatively common form of uveal inflammation, has a sufficiently characteristic presentation that the diagnosis is often suggested by clinical assessment, although testing for HLA-B27 status provides strong support for the diagnosis. This condition usually responds readily to topical corticosteroid therapy, and the prognosis is generally good. Atypical cases may be chronic, complicated by visually disabling complications or posterior eye involvement. Chronic or progressive forms of the disorder may require systemic immunosuppression. A diagnosis of HLA-B27--associated uveitis may bring an associated systemic condition to medical attention for the first time. Ongoing research promises to elucidate the intriguing relationship between the HLA-B27 molecule, gram-negative bacterial infection, and inflammatory disease.

Acute Disease↗

PubMedDate not supplied

Tuberculosis of the spine: CT and MR imaging features.

Tuberculosis (TB) remains endemic in most of the developing countries. However, a resurgence of tuberculosis has also been reported in the past decades in developed countries, not only in the lungs, but also in extrapulmonary sites, e.g. the vertebral column. Vertebral TB is most often found in the lower thoracic and upper lumbar regions. Diagnosis is often difficult; clinical findings are usually non-specific and radiologic features may mimic those of other bacterial, fungal, inflammatory and neoplastic diseases. However, recognition and understanding of the radiological findings may help in diagnosis. Two distinct patterns of vertebral tuberculosis may be seen: the classic finding of spondylodiscitis, characterized by destruction of two or more contiguous vertebrae and opposed end plates, disk infection, and commonly a paraspinal mass or collection. The second pattern, increasing in frequency, is a atypical form of spondylitis without disk involvement.The value of CT and MR imaging are discussed in the diagnostic workup of vertebral tuberculosis. A positive culture or histopathologic analysis of CT-guided needle aspiration or biopsy specimens is required in the absence of pulmonary manifestations of tuberculosis for definitive diagnosis and adequate treatment.

Adult↗

PubMed1985

[Characteristics of bacteria in the genus Proteus isolated from patients with sporadic and group intestinal diseases].

The biochemical and biological properties of 148 Proteus strains isolated from patients both in sporadic intestinal infections and in a case of group infection in children's hospital was studied. The study revealed that the etiological factor of the group infection was P. mirabilis belonging to rare serovar 48:2. Proteus organisms isolated in sporadic infections belonged to a great number of serovars. No relationship between the isolated serovar and the nosological form of the intestinal disease was established. Among the Proteus strains under study, 82 strains showed atypical biochemical properties in 1 test or more. No correlation between the clinical diagnosis and the occurrence of atypical strains was established.

Acute Disease↗

PubMed1993

Fibrous histiocytoid leprosy of the cornea.

We describe a 50-year-old man with a 10-year history of gradually enlarging limbal tumors and conjunctival injection. An excised limbal mass presented a diagnostic challenge histopathologically and was initially believed to be a fibrous histiocytoma. Special stains, however, revealed acid-fast organisms in the fibrous histiocytes, and the diagnosis was changed to corneal leproma. This case confirms the existence of fibrous histiocytoma-like lesions in leprosy, which in this form can be termed fibrous histiocytoid leprosy. Furthermore, it suggests the need for special stains to rule out infectious cause in lesions believed to be atypical fibrous histiocytomas.

Corneal Diseases↗

PubMed1984

[Infectious endocarditis. Current aspects of its epidemiology and occurrence].

In epidemiological terms the frequency of infectious endocarditis is constant. In contrast acute forms in males and old people are on the increase. Atypical cases are more frequent than in the past so that prompt diagnosis is often difficult. Aetiologically, mycete and gram-negative cases are increasingly common.

Adult↗

PubMed2001

The clinical spectrum of Bruton's agammaglobulinemia.

X-linked, or Bruton's, agammaglobulinemia (XLA) was described in 1952 as the congenital inability to form antibodies. Patients were typically infants or young children with recurrent, severe bacterial infections. Other, milder cases of hypogammaglobulinemia were considered "acquired," and often presented later in life. Since the discovery of the defective gene in XLA in 1993, it has been shown that a significant number of male patients with sporadic or acquired hypogammaglobulinemia actually have XLA. We present here a case of atypical XLA and discuss similar cases in the literature. We conclude that any male with hypogammaglobulinemia, regardless of age of presentation, might have XLA. Males with low B-cell numbers are particularly likely to have XLA and should have Bruton's tyrosine kinase levels assessed.

Adult↗