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PubMed2006

A function of polar flagellum and anisotropic growth in Vibrio alginolyticus early-phase colonies.

We continuously observed growth of Vibrio alginolyticus early-phase colonies on agar plates by phase-contrast microscopy. Two mutants defective in motility on solid surfaces were used in this study: one (YM4) can swim in liquid environments using its polar flagellum, and the other (NMB198) cannot swim because it lacks any flagella. We found that isolated colonies of YM4 were generally more circular than those of NMB198. This observation suggests that YM4 cells moved slightly within a colony by the function of their polar flagella. For clustered colonies, where the distance between the colonies was short (<50 microm), the colonies of YM4 grew rapidly along the line between them, but they grew slowly in the lateral directions. Some colonies of NMB198 grew toward neighboring colonies. These observations indicate colony-to-colony interaction.

Adaptation, Physiological↗
PubMed1975

A comparison of DNA from free living and endosymbiotic Rhizobium leguminosarum (strain PRE).

1. Bacteroids of Rhizobium leguminosarum (strain PRE) purified from root nodules of Pisum sativum (var. 'Rondo') by the standard procedure of differential centrifugation contained considerable contamination of mitochondrial material. This could be removed by incubation of the bacteroid preparation with 1 M KCl/1% deoxycholate. 2. The DNA content of bacteroid cells of R. leguminosarum was found to have increased about three fold in comparison with the DNA content of free living R. leguminosarum bacteria. 3. No significant difference in DNA composition of free living R. leguminosarum bacteria and bacteroids could be detected by CsCl equilibrium centrifugation, RNA - DNA hybridization and DNA - DNA reassociation studies.

Atypical Bacterial Forms↗
PubMed1991

Escherichia coli CS31A fimbriae: molecular cloning, expression and homology with the K88 determinant.

CS31A is a plasmid-encoded K88-related fimbrial antigen. A Sau3AI library was constructed from p31A, a 180 kb CS31A encoding plasmid, in the pSUP202 vector. Bacterial recombinant clones expressing CS31A were isolated. A 8.5 kb EcoRI-HinIII DNA fragment from one of them was subcloned in pBR322 and pHSG575 vectors, leading to pAG315 and pEH524 recombinant plasmids respectively. Escherichia coli harboring pAG315 or pEH524 expressed CS31A fimbrial antigens on their cell surface. Analysis of these plasmids in minicells showed that at least seven mature polypeptides were encoded by the EcoRI-HindIII DNA fragment, with apparent molecular masses of 76,000, 54,000, 30,000, 29,000, 28,000, 15,500 and 13,500 daltons respectively. The genetic organization of the CS31A gene cluster was determined and showed to be similar to that of the K88 operon. The nucleotide sequence homology between CS31A and K88 determinants was investigated by Southern blot hybridization at high stringency. This indicated that extensive nucleotide sequence homology exists throughout both gene clusters except for the subunit structural genes.

Alanine↗
PubMed2006

[Simultaneous detection by multiplex PCR of atypical bacterial pathogens involved in infections of respiratory tract. Is it useful for the microbiological diagnosis of respiratory infections].

The aim was to evaluate the "strategical place" of the new commercial test Chlamylege (Argene-Biosoft-France) which allows the simultaneous detection in respiratory samples of Chlamydophila pneumoniae, Mycoplasma pneumoniae and most Legionella species using a PCR multiplex. 41 patients with an atypical pneumonia were included, all standard procedures of diagnosis were done and in addition the chamylege test. A pathogen was identified in 12 patients, an other microorganisms than the 3 targeted by our study was found in 8 patients. 4 positive PCR were obtained, 3 with M. pneumoniae and 1 with Legionella pneumophila 1. That means that for 29 patients no aetiology was found. Among them 23 clearly improved under antibiotic treatment. Though that PCR multiplex is an attractive test, easy to perform, sensitive, specific and convenient, we need further studies to approach the place of this PCR test in the diagnosis of multifaceted atypical pneumonia. We also need to know if the cost associated with the microbiological diagnosis (culture, serology, immunofluorescence, urinary antigen test, PCR...) for atypical pneumonia worth value? An algorithm as to be drawn to determine the value of intensive microbiological investigation. An other point to discuss, may be this kind of rapid and multiplex PCR technique could lead to spare the use of some antibiotics.

Atypical Bacterial Forms↗
PubMed1999

Atypical pathogens in community-acquired pneumonia.

The atypical pathogens are an important and significant cause of CAP. The clinical and radiologic manifestations of CAP caused by these pathogens are modulated by the immunologic and physiologic status of the host, and therefore are not pathogen-specific. The range of frequencies found in various studies for the atypical pathogens among the causes of CAP is broad. These frequencies are affected by very important factors that should be recognized. In a significant percentage of patients, an atypical pathogen can be identified together with an additional cause. The significance of multiple causes has not been clarified sufficiently. The principal diagnostic techniques in use today for the causative diagnosis of CAP are serologic tests. Different serologic methods have been used in various studies and diagnostic criteria are not standardized. In the future it is likely that diagnostic testing will be based on the PCR technique on serum samples. The effectiveness and importance of antimicrobial therapy in some patients with atypical pathogen CAP are unclear. The accepted therapy today for atypical pathogen CAP, which is based on erythromycin, will probably be changed in the near future in favor of the new generations of fluoroquinolone or the new macrolide preparations.

Adult↗
PubMed2005

[Antibiotherapy in children with atypical bacterial infections].

Atypical bacteria responsible for infections in children are mainly Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila. Atypical pneumonia is a frequent disease in children. Until recently, the outcome was thought to be rather benign and antibiotherapy to have only a minor impact on the prognosis. Recent studies have demonstrated that M. pneumoniae and C. pneumoniae were involved in a variety of infections, including acute upper airway disease, otitis and pharyngitis under five. Antibiotherapy was proven able to decrease the rate of complications and recurrence, notably episodes of wheezing and exacerbations of asthma. Atypical bacteria infections may be severe in immunocompromised children and children with underlying disease such as sickle cell anaemia. Whenever bacteriological documentation is lacking, one of the critical issues in choosing an antibiotic is to consider its activity against Streptococcus pneumoniae, especially in lower respiratory tract infections. The main available molecules are reviewed and discussed, with a special emphasis on ketolides, a newer family of molecules active on both atypical bacteria and S. pneumoniae.

Anti-Bacterial Agents↗
PubMed1991

Toxin production by atypical strains of Vibrio cholerae E1 Tor under different cultural conditions.

It was observed that at 37 degrees C under in vitro conditions, aerobic culture filtrates of a few strains of Vibrio cholerae biotype El Tor isolated from diarrhoeal cases produced a minute amount of toxin which failed to elicit a positive ileal loop reaction like toxigenic strains. Thus, these strains showed an atypical behaviour in their toxin producing ability. At 25 degrees C and 30 degrees C under aerobic cultural conditions enhanced toxin production was noticed in toxigenic strains, but these temperatures did not affect the toxigenicity of the atypical strains. The atypical Vibrio cholerae El Tor strains exhibited enhanced toxin production only at 37 degrees C under anaerobic conditions and the amount of toxin produced was akin to those of the toxigenic strains. In comparison to aerobic conditions, growth was observed to be comparatively lower under anaerobiosis both in the toxigenic and atpyical V. cholerae strains. Moreover, in contrast to the toxigenic strains, the toxin did not remain membrane-bound in these atypical strains at 37 degrees C and aerobic cultural conditions.

Aerobiosis↗
PubMed2002

Alpha-proteobacteria cultivated from marine sponges display branching rod morphology.

Most isolates recovered from marine environments are Gram-negative proteobacteria, even with the use of various media and media additions to enhance recoverability. Cultivation studies with two genera of deep-water sponges yielded nine isolates that demonstrated bulbous branching rod morphology, which is usually associated with microorganisms staining Gram-positive. Gram reactions indicated that the isolates were Gram-negative, which was confirmed by partial 16S rDNA sequencing. All nine isolates were shown to be alpha-proteobacteria most closely related to other alpha-proteobacteria isolated from various sponges.

Alphaproteobacteria↗
PubMed1984

Acute conjunctivitis caused by an atypical chlamydial strain: Chlamydia IOL 207.

A case of acute conjunctivitis in man caused by Chlamydia IOL 207 is described. Chlamydiae were isolated from the eye, and rising titres of type-specific antibodies to C. IOL 207, in serum and tears demonstrated an aetiological role for this agent. C. IOL 207 is an atypical chlamydial strain which serological studies suggest is widespread in some communities.

Acute Disease↗
PubMed1985

Listeria monocytogenes endocarditis.

A fatal case of endocarditis due to Listeria monocytogenes is reported. Case reports of endocarditis due to this organism are rare but indicate a higher mortality than with many other causes of bacterial endocarditis. The size of the problem may be underestimated because the organism has a "diphtheroid' appearance and may be incorrectly dismissed as a contaminant.

Aged↗
PubMed1976

Atypical mycoplasmas from sheep in Great Britain and Australia identified as Mycoplasma ovipneumoniae.

Representative strains of "lacy-colony" mycoplasmas isolated from sheep in Great Britain and Victoria (Australia) were classified as M ovipneumoniae following comparison with strain Y98 of this species. The taxonomic description of M ovipneumoniae is extended and Y98 is proposed as the type strain. A brief description is given of the isolation of M ovipneumoniae from sheep in East Anglia.

Animals↗
PubMed2006

Multiplexed serology in atypical bacterial pneumonia.

Atypical pneumonia is a term applied to lower respiratory tract infections that are not characterized by signs and symptoms of lobar consolidation. This article will discuss the epidemiology, clinical manifestations, and laboratory diagnoses of Mycoplasma pneumoniae, Chlamydia sp., Legionella sp., Francisella tularensis, and Coxiella burnetii, which are the agents most commonly associated with atypical pneumonia. Because many of these pathogens are intracellular, diagnosis depends upon serological confirmation. The current serological tests used to identify these agents in the etiologic diagnosis of atypical pneumonia are described. Recently, however, it has become possible to make a diagnosis directly in these cases using DNA or protein microarrays. Here, we describe the development of a new, automated technique for simultaneous testing and detection of several pathogens using a multiplexed serology test. This should prove to be a valuable tool for the rapid determination of patient status, allowing effective and efficient postexposure prophylaxis and treatment.

Atypical Bacterial Forms↗
PubMed1975

Tuberculin and histoplasmin sensitivity in six solomon islands populations.

Skin testing with antigens from Histoplasma capsulatum, Mycobacterium tuberculosis (PPD-S), and atypical mycobacteria (PPD-B, PPD-G, PPD-Y, and PPD-platy) was carried out among six population groups in the Solomon Islands between 1968 and 1972. There was no positive reaction to histoplasmin among any of the groups, suggesting that histoplasmosis is not endemic in the Solomon Islands. There were significant numbers of tuberculin reactors among each group. Largest mean reactions to PPD-S were present among the Lau and Ulawa, in whom reactions to PPD-S were larger than those to any other antigen tested. Thus significant infection with M. tuberculosis appears to occur in these populations. This was corroborated by radiologic survey. Among the Lau, large reactions to PPD-G and PPD-Y were also elicited, raising the possibility of multiple infection. Among the Aita, Baegu, Nagovisi, and Ontong Java, PPD-G elicited the largest reactions. PPD-G produced the second largest reactions among the Lau and Ulawa. PPD-S elicited the largest or second largest reaction among 4 of the 6 groups. A notable exception was the Aita, in whom PPD-S elicited the smallest mean reaction. The Aita also had the lowest prevalence of radiologic findings consistent with tuberculosis. These observations suggest that M. tuberculosis has been introduced into the Solomon Islands from outside sources, a hypothesis which may explain the variability in prevalence of tuberculosis-like disease demonstrated by chest film among the six groups. Genetic differences may also play a role in this variability. The study also demonstrated a high prevalence of "baseline" sensitivity to the atypical mycobacteria among the Solomon Islanders. This sensitivity may confer some immunity to infection with M; tuberculosis, but this protection is far from complete.

Adolescent↗
PubMed1975

Runyon group III atypical mycobacteria as a cause of tuberculosis in a rhesus monkey.

Bilateral draining fistulas which communicated with the cheek pouches were noted in the threat region of an adult femal Macaca mulatta receiving isoniazid for tuberculosis prophylaxis. Necrospy findings included enlargedregional lymph nodes and ulceration of cheek pouch mucous membranes. Acid-fast bacilli were demonstrated in tissue section. Cultures of the regional lymph nodes and cheek pouch mucous membrane yielded Runyon Group III mycobacteria. Intrapalpebral tuberculin tests with homologous mycobacterial antigen (Battery strain PPD) and Kochs Old Tuberculin were performed in an unsuccessful attempt to identify additional infected monkeys. This case is considered significant because of the unusual manifestation of mycobacterial disease and its occurrence in an animal receiving isoniazid at levels considered sufficient for the prevention of tuberculosis.

Animals↗