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PubMed1965

APPLICATION OF FLUORESCENT-ANTIBODY PROCEDURES TO THE STUDY OF PATHOGENIC DEMATIACEOUS FUNGI.II. SEROLOGICAL RELATIONSHIPS OF THE GENUS FONSECAEA.

Gordon, Morris A. (New York State Department of Health, Albany), and Yousef Al-Doory. Application of fluorescent-antibody procedures to the study of pathogenic dematiaceous fungi. II. Serological relationships of the genus Fonsecaea. J. Bacteriol. 89:551-556. 1965.-The staining spectra of fluorescein-labeled antiglobulins to Fonsecaea compactum, F. dermatitidis, and F. pedrosoi were determined with respect to 71 strains of morphologically related and 21 miscellaneous molds (including so-called "black yeasts"). All three conjugates showed considerable reaction with saprophytic Cladosporium spp. F. dermatitidis appeared to be most closely related serologically to the genus Cladosporium; F. compactum conjugate was fairly specific; and the few non-specific reactions of diluted F. pedrosoi reagent were almost unexceptionally with species of Fonsecaea and Cladosporium. Most strains of F. pedrosoi were unstained by F. compactum conjugate, and there was very little relationship shown between either of these species and Phialophora verrucosa. Conjugates of two strains of P. verrucosa failed to react with any of the three species of Fonsecaea. The possible significance of these results for classification of the "black yeasts" and other dematiaceous molds is discussed.

Ascomycota↗
PubMedDate not supplied

[Aeromonas spp. isolated from human feces. Species and pathogenicity factors].

The role of Aeromonas genus as a primary intestinal pathogen is still a matter of controversy. We have studied the isolation of Aeromonas spp. from human stools samples, looking for the production of pathogenic factors and its relationship with different species. From a total of 471 strains isolated, 241 were A. caviae, 127 A. sobria, 89 A. hydrophila and 14 non-typable strains. The pathogenic factors production was studied in a bacteria-free filtrate from a 18 hours trypticase-soy broth culture. Enterotoxin production was assessed by suckling-mice test, cytotoxin production by using Hela cells monolayer and hemolysin production by double dilution from the filtrate, plated in microdilution plates, against rabbit red-blood cells. Enterotoxin production test was positive for A. sobria, A. hydrophila and A. caviae in 81.1%, 62.9% and 7.0% of strains respectively. Cytotoxin production was also positive for these species in 96.6%, 76.4% and 4.1%, and hemolysin production was positive in 95.3%, 70.7% and 2.4% of the strains respectively.

Aeromonas↗
PubMed2005

Characterisation of the early events in atypical tomato root colonisation by a biocontrol agent, Pythium oligandrum.

The specific oomycete-plant relationship established between a biological agent, Pythium oligandrum, and tomato (Lycopersicon esculentum Mill.) plants was examined over the first 48 h after inoculation of tomato roots with the antagonist. One of the most significant effects was the quick colonisation of cortical and vascular root areas by P. oligandrum (until 9 h post-inoculation); it was similar to invasions by the major pathogens of Pythium genus, and much faster than those by Pythium-minor pathogens. Despite the multiplication of hyphae in the root areas, fungal colonisation was associated with neither host wall disruption nor host cell alterations. The colonising hyphae looked healthy till the ninth hour after inoculation, then, they progressively became highly vacuolated. Cytological observations showed that, over the first 14 h of experiment, oomycete invasion was accompanied with rare host-induced defence reactions. Biochemical analysis evidenced an accumulation of phenolic compounds starting 3 h after inoculation. The 14th hour corresponded to the beginning of rishitin (phytoalexin) synthesis. Accumulation of biochemical host defence compounds was concomitant with early signs of hyphae alterations. During the next 34 h several host reactions were regularly amplified as evidenced by the plugging of invaded host cells with heterogeneous osmiophilic or high electron-dense (ED) materials. Fungal cell decay was accompanied with the formation of oogonia in the cortex, vascular parenchyma and xylem vessels. All these early events suggest a peculiar relationship established between P. oligandrum and the plant.

Cell Wall↗
PubMed2001

A brief survey of free-living amebae in Thailand and Hamamatsu District, Japan.

The aim of this study was to determine the presence of free-living amebae in aquatic habitats of human environments in Thailand and Hamamatsu district, Japan. Genus identification was based on the morphology of cyst and trophozoite forms and a flagellation test for genus Naegleria. The pathogenic potential was tested in mice by nasal instillation for genus Naegleria and Acanthameba. In 14 provinces of Thailand, amebae were isolated in 43 from 95 water samples and 67 from 120 soil swabs. Amebae of 49 isolates from waters were identified as Acanthameba (36.7%), Naegleria (28.6%), Hartmannella (20.4%), Vahlkampfia (12.2%) and Vannella (2%). Soil samples have significantly higher levels of Acanthameba and Hartmannella (p<0.05) but lower for Naegleria (p<0.05) and 7 unidentified amebae were found. In Hamamatsu district, Japan, 62 amebae of the same genera were isolated from 47 of 95 water samples. There were significantly higher levels of Acanthameba (22.6%) (p<0.05) but lower for Naegleria (4.8%) (p<0.05) than those of Thailand which each of them caused death in mice. Three unidentified amebae were isolated. This finding serves as additional evidence for the presence of free-living amebae under natural and the difference in distribution between tropic and subtropic areas.

Acanthamoeba↗
PubMed1993

Morphological and genomic characterization of two reoviruses (P and W2) pathogenic for marine crustaceans; do they constitute a novel genus of the Reoviridae family?

P and W2 viruses are pathogenic in two crustaceans of the Mediterranean Sea, Macropipus depurator and Carcinus mediterraneus, respectively. Investigation of virus, virus density and genome structure leads us to propose their classification in a genus similar to aquareovirus of the Reoviridae family. They differ from aquareoviruses by the number of dsRNA segments forming the genome (12 instead of 11), their electrophoretic pattern in PAGE (1/5/6 instead of 3/3/5), and the absence of virus replication in fish cell lines.

Animals↗
PubMed1995

Plasmodium: genus-conserved primers for species identification and quantitation.

Stable RNAs have regions of primary sequence that are nearly identical in every member of the Plasmodium genus and not found in the host or in other common pathogens. Several "genus-conserved" sequences, which flank hypervariable regions, were identified within the small subunit ribosomal RNA of Plasmodium species. Primers based on these conserved sequences permit amplification of species- or possibly even strain-specific sequences from samples of unknown composition. As an example of this approach, sequences from the four human malaria species were successfully recovered from Giemsa-stained blood smears, including two different sequences for Plasmodium ovale (of 91.5% similarity). This type of information is useful for epidemiological and phylogenetic analysis of any malaria species. We show that amplification of rRNA-derived sequences behaves in a competitive fashion during the cycles of polymerase amplification and therefore target sequences from Plasmodium species are amplified in proportion to their abundance in the sample. There are several implications of this finding. (1) The proportion of different products resulting from amplification from samples with mixed infections is closely related to the proportion of infecting species. (2) Direct quantitation of parasite nucleic acids within a sample can be derived when known amounts of competitor RNA are added to the RT/PCR reaction. (3) Amplification of rRNA sequences, using genus-specific primers, allows one to monitor the development of the parasite in the mosquito.

Animals↗
PubMed1997

Bartonella spp. as emerging human pathogens.

Members of the genus Bartonella (formerly Rochalimaea) were virtually unknown to modern-day clinicians and microbiologists until they were associated with opportunistic infections in AIDS patients about 6 years ago. Since that time, Bartonella species have been associated with cat scratch disease, bacillary angiomatosis, and a variety of other disease syndromes. Clinical presentation of infection with Bartonella ranges from a relatively mild lymphadenopathy with few other symptoms, seen in cat scratch disease, to life-threatening systemic disease in the immunocompromised patient. In some individuals, infection manifests as lesions that exhibit proliferation of endothelial cells and neovascularization, a pathogenic process unique to this genus of bacteria. As the spectrum of disease attributed to Bartonella is further defined, the need for reliable laboratory methods to diagnose infections caused by these unique organisms also increases. A brief summary of the clinical presentations associated with Bartonella infections is presented, and the current status of laboratory diagnosis and identification of these organisms is reviewed.

Animals↗
PubMed1999

Rats of the genus Rattus are reservoir hosts for pathogenic Bartonella species: an Old World origin for a New World disease?

Bartonella species were isolated from the blood of 63 of 325 Rattus norvegicus and 11 of 92 Rattus rattus from 13 sites in the United States and Portugal. Infection in both Rattus species ranged from 0% (e.g., 0/87) to approximately 60% (e.g., 35/62). A 337-bp fragment of the citrate synthase (gltA) gene amplified by polymerase chain reaction was sequenced from all 74 isolates. Isolates from R. norvegicus were most similar to Bartonella elizabethae, isolated previously from a patient with endocarditis (93%-100% sequence similarity), followed by Bartonella grahamii and other Bartonella species isolated from Old World rodents (Clethrionomys species, Mus musculus, and Rattus species). These data suggest that Rattus species are a reservoir host for pathogenic Bartonella species and are consistent with a hypothesized Old World origin for Bartonella species recovered from Rattus species introduced into the Americas.

Animals↗
PubMed1975

Virulence of genus Staphylococcus. III. Studies on the pathogenicity to mice.

Six representative strains of staphylococci were selected on the basis of DNase activity and inoculated into the mice to study the correlation of the presence of this enzyme to the virulence of the staphylococci. Two strains of staphylococci among them produced DNase but not the free coagulase, and one of these two strains had an obvious virulence against the mice. The results of experiments suggest that there are at least certain strains which may be designated as Staphylococcus aureus among these DNase-producing staphylococci producing no free coagulase. This is an additional evidence that this enzyme activity should be adopted as a criterion to distinguish from the other S. aureus which has lost the free coagulase activity. In this sense, the staphylococci producing neither free coagulase nor DNase are after all Staphylococcus epidermidis, regardless of their ability to ferment mannitol or not.

Animals↗
PubMed1993

[Mobile species of the genus Aeromonas: difficulties of identification and pathogenicity].

Sixty-two Aeromonas strains (39 of clinical and 23 of environmental origin) were identified. The suicide phenomenon and autoagglutination were studied. Identification is based on esculin hydrolysis; fermentation of arabinose salicin, sucrose and mannitol; gas production from glucose, indole and beta hemolysis; Voges-Proskauer and decarboxylation reactions; and finally resistance to cephalothin (30 micrograms) and colistin (4 micrograms/ml). Thirty-four per cent of A hydrophila, 33% A caviae, 28% A veronii subspecies sobria, 3% A jandaei, 2% A veronii subspecies veronii were accurately identified. Also, several new species were identified such as A trota, A enteropelogenes, A schubertii, A ichthiosmia, according to the more recently proposed taxa. This identification scheme could enhance our knowledge concerning virulence factors, pathogenicity and environmental distribution.

Aeromonas↗