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At least 19 recordsLinked to original sources
PubMedDate not supplied

[Atypical bacterial forms in septicemia. (L-forms). Preliminary report].

This paper refers to the presence of atypical bacterial forms in the blood culture of 40 children who evolved with septicemia. Bacterial growth appeared in 18 (45%) patients in ordinary cultures. With hypertonic culture media 26 (65%) patients showed positive results. In 13 cases the reverted bacteria coincided with those isolated in ordinary culture media. In 12 patients (30%) whose cultures in normal media were negative, abnormal atypical bacterial forms were identified. Gram-negative bacteria predominated and Staphylococcus epidermidis was observed to develop with a certain frequency.

Child↗
PubMed1978

Abnormal forms of Trichomonas vaginalis.

Abnormal forms of Trichomonas vaginalis have been demonstrated by both conventional and scanning electron microscopy after inoculation of media with clinical material from cases of trichomonal vaginitis. Twenty-six cases of vaginitis have been studied; 10 of them showed the abnormal forms of trichomonads after growth in a modification of the medium described by Bushby and Copp (1955), while 16 showed only normal forms.

Atypical Bacterial Forms↗
PubMed1975

Persistence and isolation of L cycle forms of Erysipelothrix rhusiopathiae in experimental infection.

In experimental infection of rats induced with teh S-form of Erysipelothrix rhusiopathiae the pathogen was found to persist for a long time (up to fifteen months according to the author's personal observations). Under the effect of the specific and unspecific defense of the animal's organism the causative agent suffered a number of morphologic changes. In the course of the first days of infection the R-form was isolated, and thirty days later up to the fifteenth month forms of the L cycle were recovered from the parenchymal organs, blood, and joints. An electron microscopic study was carried out on the structure of the isolated L-forms. The long-term persistence of the agent in its different morphologic forms may well account for the chronic course of the infection in rats.

Animals↗
PubMed1980

Filterable cell-associated cryptic bacterial forms in immunologic renal diseases.

Blood and urine derived from patients with certain types of nephritis contain filterable (0.22 mu.) bacterial forms, which heretofore have not been considered as possible etiologic agents in those diseases. Furthermore, these cryptic bacterial forms are overlooked by conventional culture techniques. It is hypothesized that the organisms and/or host-cell-variant-bacterial antigen complexes could be the initiators of immunopathologic events in various types of immunologic renal diseases.

Atypical Bacterial Forms↗
PubMed1976

Aberrant bacterial forms from various ocular sites.

Patients may harbor cell-wall-deficient organisms or other aberrant bacterial forms (ABFs) in their eyes. In this survey of 400 cultures, we found the incidence of ABFs isolated from various ocular sites to be 13.2%. The rate of isolation of these forms from the eyes of patients with suspected bacterial infection differed greatly from that for noninfected eyes. We will describe the microbiological techniques employed and will present our analysis of the data obtained.

Aqueous Humor↗
PubMedDate not supplied

[Influence of aeration and phosphorus concentration in the medium on growth of S-, R- and M-forms of Mycobacterium lacticolum in mixed cultures].

S, R and M forms of Mycobacterium lacticolum were compared. The cells of the R form had the highest requirement in aeration and phosphorus, whereas the cells of the M form, the lowest requirement. The content of oxygen in the medium and the concentration of phosphorus almost did not affect the viriability of these forms. On a medium containing n-hexadecane, the cells of the R form possessed selective advantages under favourable growth conditions, i.e. when the content of oxygen and phosphorus in the medium was high, whereas the cells of the M form had selective advantages under unfavourable conditions of growth when it decelerated as a result of a low concentration of oxygen and phosphorus in the medium. These correlations changed on a medium containing carbohydrates.

Atypical Bacterial Forms↗
PubMed1979

Bacterial variants in urinary casts and renal epithelial cells.

Casts with numerous and unusually large granules were seen in the urine of a child with renal Fanconi's syndrome. When the urine sediment was sealed under a coverslip for several days, many granules changed to filamentous bacterial variants that segmented and, finally, appeared as streptococcal-like forms. When the patient's blood was cultured by a special method, bacterial variants grew consistently, and frequently reverted to parent coccal forms, although conventional cultures were negative. Variants from blood cultures had the same morphology and staining properties as granules in casts and in cystic structures found within hypertrophied renal pelvic epithelial cells. Cryptic parasitization with bacterial variants probably occurs in many nephropathies. Variants are known to produce toxins and immunogens, which could lead to mesangial and basement membrane deposits as well as to occlusive reactions in the renal microcirculation.

Atypical Bacterial Forms↗
PubMed1997

Identification of atypical strains of Staphylococcus epidermidis by use of molecular tools.

Four atypical coagulase-negative staphylococcal (CNS) isolates from clinical sources were compared with Staphylococcus epidermidis strains by ribotyping. The ribotypes of the four strains shared close rDNA restriction profiles with those of the S. epidermidis strains used. The DNA sequence encoding 16S rRNA demonstrated 99.9% homology with S. epidermidis. S1 nuclease experiments showed that these atypical strains formed a homogeneous genomic group. DNA-DNA homologies between the S. epidermidis type strain CCM 2124 and the four CNS isolates ranged from 70 to 89%. The guanine-plus-cytosine content of the deoxyribonucleic acid of the four strains ranged from 31 to 32 mol%.

Amino Acids↗
PubMedDate not supplied

Cell wall-deficient bacteria as a cause of infections: a review of the clinical significance.

Cell wall-deficient bacteria (CWDB) are pleomorphic bacterial forms. These atypical organisms may occur naturally or they can be induced in the laboratory. Their presence has been known about for over a century, but a definite link to clinical disease outcomes has not been demonstrated. A number of case reports and laboratory studies suggest some disease associations, however. Considerable controversy surrounds the true relevance of CWDB to disease; there is a widespread belief that they may represent a response by the walled organism to adverse extracellular conditions like antibiotic pressure. This review looks at studies published between 1934 and 2003, which were identified by Dialog DataStar using the key words 'cell wall deficient bacteria and clinical significance and infections' and by further scanning the reference list at the end of the papers retrieved. We conclude that the evidence for the clinical significance of CWDB in disease is not compelling.

Bacterial Infections↗
PubMed1991

Characterization of the morphologic conversion of Helicobacter pylori from bacillary to coccoid forms.

Growth studies of Helicobacter pylori were performed involving analysis of the bacterium and its microenvironment, to lend insight into the factors responsible for the morphologic conversion phenomenon. H. pylori converted from bacillary to coccoid forms in broth culture after incubation for 5 days under microaerobic conditions with agitation. This morphologic conversion was paralleled by a dramatic decrease in colony-forming units per milliliter (CFU/ml) and a significant endogenous increase in the pH of the broth culture. In addition, removal of broth cultures from microaerobic conditions after 3 days of incubation resulted in a rapid increase in culture pH, a morphologic conversion, and a concomitant decrease of CFU/ml. These observations suggest an inhibitory effect of basic pH, endogenously produced, on the growth of H. pylori in vitro. Experiments designed to identify the reason for the endogenous increase in culture pH demonstrated that the urease enzyme of H. pylori is not primarily responsible for this phenomenon. Rather, H. pylori appears to produce a deaminase enzyme that is likely responsible for the generation of ammonia, which results in the increase in culture pH, the morphologic conversion, and the loss of culturability observed in vitro. Also indicated is the need for a buffering component (for example, bicarbonate) to maintain pH conditions favorable to the growth of H. pylori.

Atypical Bacterial Forms↗
PubMed1976

Mycobacterium fortuitum mastoiditis.

Improved techniques of bacteriologic identification have led to increasing recognition of the clinical significance of the atypical or anomymous mycobacteria. Mycobacterium fortuitum, included in group IV of Runyon's classification because of its characteristic rapid growth, is widespread in nature as a saprophyte. Its facultative pathogenicity has received increasing attention in the literature recently with reports of a number of isolated infections, epidemics, and deaths. We report a case of mastoiditis due to M fortuitum and discuss the pathogenesis and treatment. This is the first known report of the organism causing otolaryngologic disease.

Atypical Bacterial Forms↗
PubMed2006

Viral and atypical bacterial infections in the outpatient pediatric cystic fibrosis clinic.

BACKGROUND: Respiratory viral and atypical bacterial infections are associated with pulmonary exacerbations and hospitalisations in cystic fibrosis patients. We wanted to study the impact of such infections on children attending the outpatient clinic. METHODS: Seventy-five children were followed for 12 months at regular clinic visits. Routine sputum/laryngeal aspirations were tested with PCR for 7 respiratory viruses. Antibodies against C. pneumoniae, M. pneumoniae and B. pertussis were measured every 3-4 months. FEV-1, FEF(25-75) and specific airway resistance, "viral" symptoms and bacterial culture were recorded. RESULTS: Ninety-seven viral and 21 atypical bacterial infections were found. FEV-1 was significantly reduced during viral infection (-12.5%, p=0.048), with the exception of rhinovirus infection. A small change in FEV-1 (-3%) was seen during atypical bacterial infection (p=0.039). Viral and atypical bacterial infections caused no change in type and frequency of bacterial culture. Positive predictive value of "viral symptoms" was low (0.64%). Eight patients received "unnecessary" antibiotics because of viral symptoms. CONCLUSIONS: Some viral infections and atypical bacterial infections affect FEV-1 acutely. Viral infections did not precipitate bacterial infection or change of colonisation. Clinical symptoms failed to diagnose viral infection accurately. Routine surveillance for virus or atypical bacteria seems not to be justified in this patient category.

Adolescent↗
PubMedDate not supplied

Appropriateness of laboratory tests: requests for atypical pneumonia serology in a teaching hospital.

The cost of providing medical care is ever-increasing but the resources available are at best static. Major savings can be made by reducing inappropriate investigations. Using serological testing for organisms causing atypical pneumonia as an example, we examined the appropriateness of requests and also physicians' understanding of the test. Of 119 patients tested, only 3 had titres indicative of acute infection. Most patients were tested within 2 days of hospital admission, before receipt of results excluding more likely diagnoses. Forty-five patients had no current or recent respiratory symptoms, in whom infection was highly unlikely. Titres were most often requested by the least experienced members of the clinical team. Of 70 patients with an acute illness in whom a definitive diagnosis, bacteriological or otherwise, was not made, in only 9 was a convalescent specimen sent for follow-up titres. Most requests for serology for organisms causing atypical pneumonia were inappropriate. Furthermore, in the majority of cases the test was incorrectly used.

Adolescent↗