SUMMARYIn order to elucidate the ecological role of bacteriophages in the human intestine, we analysed the numbers of coliphages and of coliphage strains present in faecal samples collected from healthy individuals and from patients with certain intestinal diseases. The isolated phages were grouped according to their serological properties. The samples with low phage titres, observed in both healthy subjects and patients, contained mainly temperate phages (many were related to ~b80 and 2), and those with higher titres, observed in patients, contained virulent phages. From successive surveys of coliphages and their host, Escherichia coli, in faecal samples of each subject, it was concluded that temperate phages are maintained in the human intestine through spontaneous induction of lysogenic bacteria. Qualitative and quantitative differences existed between phages isolated from faecal samples from healthy subjects and from patients. Simultaneous changes in the distribution patterns of coliphages and of the clinical symptoms were observed in a continuous survey of a leukaemic patient in a protective environmental ward.
Recently, a number of cases of human infections due to Yersinia enterocolitica have been reported in many countries, and much attention has been given to the organism as one of the important etiologic agents of enteritis, appendicitis, septicemia, arthritis and others (12). In most of the sporadic cases or outbreaks, however, the source and the route of the infection remained unknown, since ecology of the organism has not yet been understood clearly.The authors studied previously the distribution of Y. enterocolitica in healthy humans, livestock, foodstaff and the natural environment (14,15). Through these investigations, it was found that Y. enterocolitica was isolated from swine and rats at a high rate, and over 70% of the isolates were of the same serovars as those from human cases. These findings suggested the importance of swine as one of the infective sources for humans.In the present survey, distribution of Y. enterocolitica in dogs and cats, which have close relations to humans as pet animals, was investigated to obtain more extensive ecological informations of the organism. These animals were also examined for the presence of Y. pseudotuberculosis. A total of 704 stray or unwanted adult dogs and 373 unwanted adult cats obtained from the Tokyo Metropolitan Dog Pound Office were submitted to the survey. The dogs were examined between October 1974 and September 1976, and the cats between June 1975 and September 1976.Autopsies were made immediately after the sacrifice, and about 1 g each of the ileo-cecal contents, rectal contents and mesenteric lymph node was sampled. The content to be tested was suspended into 5 ml of sterile saline, and the mesentric lymph node was homogenized with 10 ml of sterile saline. A loopful of each specimen thus prepared was directly plated on both SS and MacConkey agar plates, and incubated at 25 C for 48 hr. Enrichment cultures were also made by inoculating 1 ml of each specimen into 20 ml of 1/15 M phosphate buffer solution (pH 7.6), and incubated at 4 C for 21 days. After the cold enrichment, a loopful of each culture was spread on the agar plates, and incubated at 25 C for 48 hr. Suspicious colonies grown on the agar plates were identified by the method described previously (14). The biovars of Y. enterocolitica were determined according to the scheme and method described by Wauters (11) .Summarized results are shown in Table 1. Y. enterocolitica was isolated from 42 643
A pathogenic Entamoeba histolytica-like variant (JSK2004 strain) with genetic variations and a novel isoenzyme pattern isolated from a De Brazza's guenon in a Tokyo zoo in Japan has previously been documented. In this study, a multiplex polymerase chain reaction (PCR) assay that could distinguish the JSK2004-type E. histolytica-like variant (JSK04-Eh-V) from E. histolytica and Entamoeba dispar using three newly designed primer sets for amplifying each specific DNA fragment from their small-subunit ribosomal RNA genes was developed and established. Forty-seven primates (11 species) from the zoo were surveyed by multiplex PCR to assess the prevalence of JSK04-Eh-V infection, which was recognized in six individuals of four species, including an Abyssinian colobus monkey, a De Brazza's guenon (including the individual from whom JSK2004 was isolated), a white-faced saki, and a Geoffroy's spider monkey. In addition, the autopsied individuals of an Abyssinian colobus and Geoffroy's spider monkey that died of amoebic liver abscess were also evaluated. DNA samples were also analyzed for specific genotypes based on the nucleotide sequencing of two protein-coding (chitinase and serine-rich E. histolytica protein) genes and the protein-noncoding locus 1-2 that was used for fingerprinting of the E. histolytica strain. These studies indicated that the E. histolytica-like variant infection in this zoo was caused by the same type (i.e., JSK04-Eh-V). An axenic culture medium (yeast extract-iron-maltose-dihydroxyacetone-serum) was developed based on the yeast extract-iron-gluconic acid-dihydroxyacetone-serum medium, which is designed for axenic culture of E. dispar. This new medium could be used for axenically culturing E. histolytica, JSK04-Eh-V, and E. dispar in a single medium.
Biopsy specimens of human gastric mucosa of patients with gastric complaints and subjected to endoscopic examination were cultured microaerobically, and Campylobacter pyloridis was detected in 46 out of 80 cases (57.5%). The organism was found in 13 out of 22 patients with gastritis, 11 out of 16 with gastric ulcer scar, 7 out of 16 with gastric ulcer, 3 out of 9 with gastric polyp, 4 out of 5 with gastric carcinoma, 2 out of 2 with esophagus carcinoma, and 6 out of 9 with other gastric diseases. The isolates were identified as C. pyloridis, demonstrating its characteristic features such as positive for oxidase and catalase, negative for reduction of nitrite and nitrate, positive for urease, no growth at 25 C, growth at 37 C, not tolerant to 1% glycine, and resistant to nalidixic acid. Positive alkaline phosphatase activity was considered as an additional feature characteristic for the strains of C. pyloridis. The major cellular fatty acids were tetradecanoic acid and 19-carbon-cyclopropane acid. This pattern is unique among Campylobacter species. The survival of the organism for a longer period than 60 min at pH 2.5 indicates its significant resistance to acidic environment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.