The First Isolation of Arthroderma benhamiae in Japan

A clinical isolate of Trichophyton mentagrophytes from rabbit was examined by polymerase chain reaction (PCR) analysis and a mating experiment. The species-specific primers designed from the nucleotide sequences of the chitin synthase 1 (CHS1) gene in the teleomorph of Arthroderma benhamiae amplified a fragment from genomic DNA samples of A. benhamiae and the clinical isolate but not from those of A. simii and A. vanbreuseghemii. On the other hand, the species-specific primers of A. simii and A. vanbreuseghemii did not amplify any fragment from the genomic DNA of the clinical isolates. When the isolate was respectively crossed with (+) or (-) tester strains of A. benhamiae, A. simii and A. vanbreuseghemii, ascospores were produced in the crossing with the A. benhamiae (+) strain. Therefore, the isolate was identified to be A. benhamiae (-), confirming the result of molecular analysis. This is the first report on the isolation of A. benhamiae in Japan.     

Trichophyton simii infections in chickens,dogs and man in India

The clinical, mycological and epidemiological aspects of naturally occurringTrichophyton simii infections in chickens, dogs and man are described. Nineteen strains ofT. simii, were isolated (16 from chickens, 2 from dogs and one from man). None of 16 soil samples from these localities were positive forT. simii, although two soil samples yieldedMicrosporon gypseum.     

Molecular Analysis of Chitin Synthase 1 (CHS1) Gene Sequences of Trichophyton mentagrophytes Complex and T. rubrum

Nucleotide sequences of chitin synthase 1 (CHS1) gene of dermatophytes, Arthroderma benhamiae, A. simii, A. vanbreuseghemii, Trichophyton mentagrophytes var. interdigitale (T. interdigitale), and T. rubrum were analyzed for their phylogenetic relationship. About 620-bp genomic DNA fragments of the CHS1 gene were amplified from these dermatophytes by polymerase chain reaction (PCR) and sequenced. The CHS1 nucleotide sequences of these five dermatophytes showed more than 90% similarity between the species. The phylogenetic analysis of their sequences revealed that A. benhamiae, A. simii, A. vanbreuseghemii, and T. rubrum were genetically distinct from one another, but T. interdigitale was genetically very close to A. vanbreuseghemii. On the other hand, a specific restriction endonuclease site of HinfI was present in the CHS1 gene fragment of T. rubrum but not in those of A. benhamiae, A. simii, A. vanbreuseghemii and T. interdigitale. The molecular analysis of CHS1 genes will provide useful information for the identification of these Trichophyton species and the understanding of their evolution. Received: 6 March 1998 / Accepted: 4 May 1998     

Aflatrem,the tremorgenic mycotoxin from aspergillus flavus

Résumé La croissance et la conidiogenèse des souches ( + ) IMI 101 693 et (–) 101 695 de Trichophyton simii sont comparées à diverses températures (de 20 à 40 °C), à des pH variés (entre 4 et 9) et en fonction de la concentration en glucose (20 à 100 g/l) ou d'autres substrats glucidiques (10 g/l). Bien que pour les deux souches le développement soit optimal entre 25 et 33 °C, à pH 6 ou 6, 5 et en présence de 10 g de glucose par litre de milieu nutritif, la souche (–) croît toujours plus lentement que la souche (+); la conidiogenèse est bloquée par le saccharose dans la souche (–), par le lactose dans la souche (+).

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Summary Growth and conidiogenesis of the (+) IMI 101 693 and (–) IMI 101 695 strains of Trichophyton simii were compared at several temperatures (20 to 40 °C) and various pH (pH 4 to 9) and were correlated with the concentration of glucose (20 to 100 g/l) or other glucidic substrates (10 g/l). Although the development of both strains was optimal between 25 to 33 °C at pH 6 and with 10 g/l of glucose, the (–) strain always growed less than the (+) strain. Conidiogenesis was inhibited by sucrose in the (–) strain and by lactose in the (+) strain.

     

Tinea capitis an endemic disease in Madras

A study ofTinea capitis in Outpatient Clinic, Skin Department, Government General Hospital, Madras during a three year period from November, 1973 to October, 1976, has shown a gradual increase in incidence of 3.56%, 5.09 % and 6.25 % respectively. Findings suggest thatTinea capitis is endemic in South India. Male children were more commonly affected than female children and the age groups chiefly affected were between 5 and 10 years. A considerable number of adults were also affected. The disease showed no correlation to environmental temperature, humidity and rainfall but was correlated to all types of mycoses and total incidence of mycoses.Among 357 isolates,Trichophyton violaceum was the commonest in 264 (73.94%) andT. tonsurans was the next common in 47 (13.16%). The other agents wereT. rubrum in 30 (8.4%),T. mentagrophytes in 11 (3.08%) andT. simii in 5 (1.4%). Noninflammatory lesions were more common than inflammatory lesions and both were produced byT. violaceum andT. tonsurans, suggesting strain differences in pathogenesis. Treatment with oral griseofulvin was satisfactory in all but had to be discontinued in 4 patients due to side effects.     

Aero-biological significance of Keratinophilic fungi in Kanpur

Summary Airborne fungal infestation and its significance in biology and disease spread is well documented. Kanpur is an industrialized and agricultural area supporting highly polluted environment. Aerobiology. of the area is hitherto unexplored, moreso, with special reference to airborne Keratinophilic fungi. Such fungal organisms are known to cause degradation of keratinous substrates. Present endeavour was undertaken to screen and survey Keratinophilic fungi from local air dust.Tricophyton simii andChrysosporium indicum, two keratinophilous forms, were observed repeatedly during various calendar months. Findings emphasize the importance of these fungi in spread and control of diseases of nails, hair, horns and hoofs of cattle or human beings.     

Studies in the differentiation between Microsporum ferrugineum Ota and Trichophyton soudanense Joyeux

A study, conducted with 20 isolates of Microsporum ferrugineum and 12 isolates of Trichophyton soudanense, revealed that some of the discrepancies in the literature regarding their characteristics and differentiation were due to methodology, strain variation and the use of an insufficient number of isolates. We found all isolates of T. soudanense to be urease negative and gelatinase positive (usually by the first week); to produce brown to black colonies on Lowenstein-Jensen medium; to rapidly decompose casein and more slowly tyrosine; to grow well or better at 37°C as compared to room temperature; to produce reflexive branching on cornmeal Tween agar and abundant microconidia on casero medium and to exhibit no sexual reaction with either mating type of Arthroderma simii. All but one isolate demonstrated restricted growth on lactose agar and only three isolates perforated hair.In contrast, we found 18 of 20 isolates of M. ferrugineum to be urease positive in urea broth (most isolates were negative on urea agar); all produced light-colored colonies on Lowenstein-Jensen medium; spreading colonies on lactose agar and failed to perforate hair in vitro or to produce reflexive branching. Most isolates manifested poorer to no growth at 37°C compared to room temperature and all but one failed to decompose casein and tyrosine. A few strains produced macroconidia and/ or microconidia on casero medium and some reacted sexually with A. simii (a) or (–) mating type. Gelatin hydrolysis was variable.We suggest the following key tests to differentiate M. ferrugineum from T. soudanense: urease activity in urea broth; colony color on Lowenstein-Jensen medium; growth on lactose agar; growth at 37° C compared to room temperature; presence of reflexive branching on cornmeal Tween agar.     

Incidence of keratinophilic fungi from selected soils of Kerala state (India)

One hundred and fifty-eight soil samples were collected from various areas of four districts of Kerala and screened for prevalence of keratinophilic fungi and related dermatophytes. From the positive samples (60.75%), a total of eight genera with 15 species were isolated viz., Arthroderma simii (0.63%), Chrysosporium indicum (20.25%), C. keratinophilum (6.96%), C. lobatum (1.26%), C. pannicola (1.26%), C. tropicum (5.06%), Chrysosporium state of Arthroderma cuniculi (1.26%), Chrysosporium state of Ctenomyces serratus (2.53%), Gymnascella hyalinospora (1.26%), Malbranchea aurantiaca (0.63%) M. fulva (1.26%), Microsporum gypseum complex (12.65%), Pseudogymnoascus roseus (1.26%), Trichophyton mentragrophytes (1.26%), and T. terrestre (3.16%).This revised version was published online in October 2005 with corrections to the Cover Date.     

Trichophyton simii infection in man and animals

Nine human infections due toT. simii comprising of tinea corporis (6), tinea cruris (2) and tinea capitis (1) have been reported. Human cases were having lesions typically of zoophilic contracted infections. Lesions in dogs were on nose and upper lip and were circular. All the strains showed typical and identical macro and microscopie morphology. Three isolates studied by Stockdale were negative (2) and positive (1) strains. One studied here was negative. Possible epidemiology is discussed.     

Characterization of an extracellular keratinase of Trichophyton simii and its role in keratin degradation

The ability of Trichophyton simii HN 50, isolated from the Ghana Bird Sanctuary, Bharatpur, India, to produce extracellular keratinase was studied. Enzyme was produced on a keratin salt broth medium at pH7 and a temperature of 28 ± 1 °C. Enzyme secretion was best at 15 days of incubation. Asparagine and keratin were repressive to enzyme yield in comparison to gelatin. No relationship was observed between enzyme release and biomass. Exogenous sugars suppressed keratinase production in descending order as follows: glucose > mannose > maltose > arabinose > fructose. The enzyme showed ability to degrade all of the 3 keratin substrates. Buffalow skin was best degraded in the absence of glucose while chicken feathers were the least degraded in its presence.This revised version was published online in October 2005 with corrections to the Cover Date.     

Isolation of Dermatophytes and Related Species from Domestic Fowl (Gallus gallus domesticus)

We investigated 793 bird combs [645 chickens and 148 fighting cocks (Shamo)] to determine the prevalence of dermatophytes and their related fungal species. The targeted fungal species were recovered from 195 of the 793 examined birds (24.6 %). Prevalence ratios were compared in temperate (the mainland) and subtropical (Nansei Islands) areas, genders, strains, breeding scale (individual and farm), and housing system (in cage and free ranging). The frequency of the fungal species in the mainland, males, fighting cocks, breeding scale by individual nursing, and free-range housing system exhibited significantly higher positive ratios than that in the other groups. A total of 224 dermatophytes and related species were isolated, including 101 Arthroderma (Ar.) multifidum, 83 Aphanoascus (Ap.) terreus, five Uncinocarpus queenslandicus, two U. reesii, two Ap. pinarensis, one Amauroascus kuehnii, one Ar. simii, one Gymnoascus petalosporus, one Microsporum gallinae, and 28 Chrysosporium-like (Chrysosporium spp.) isolates, which were identified using internal transcribed spacer regions of ribosomal RNA gene sequences. The predominant fungal species in the mainland was Ap. terreus and that in the Nansei Islands was Ar. multifidum. Pathogenic fungal species to humans and animals were limited to M. gallinae and Ar. simii, which corresponded to 0.025 % of the isolates in this study.     

Construction of a trivalent candidate vaccine against Shigella species with DNA recombination

In this work asd gene of Shigella flexneri 2a strain T32 was replaced by Vibrio cholerae toxin B subunit (ctxB) gene with DNA recombination in vivo and in vitro. The resulting derivative of T32, designed as FWL01, could stably express CtxB, but its growth in LB medium depended on the presence of diaminopimelic acid (DAP). Then form I plasmid of Shigella sonnei strain S7 was labeled with strain T32 asd gene and mobilized into FWL01. Thus a trivalent candidate oral vaccine strain, designed as FSW01, was constructed. In this candidate strain, a balanced-lethal system was constituted between the host strain and the form I plasmid expressing S. sonnei O antigen. Therefore the candidate strain can express stably not only its own O antigen but also CtxB and O antigen of S. sonnei in the absence of any antibiotic. Experiments showed that FSW01 did not invade HeLa cells or cause keratoconjunctivitis in guinea pigs. However, rabbits immunized FSW01 can elicit significant immune responses. In mice and rhesus monkey models, vaccinated animals were protected against the challenges of wild S. flexneri 2a strain 2457T and S. sonnei strain S9.     

Comparison of invasion of fibroblasts and macrophages by high- and low-virulence Leptospira strains: colonization of the host-cell nucleus and induction of necrosis by the virulent strain

The infection cycle of low- and high-virulence strains of Leptospira interrogans was compared in fibroblasts and macrophages. L. interrogans serovar Lai strain Lai was used as a representative high-virulence strain, while L. interrogans serovars Pomona strain Luo was used as a low-virulence strain. L. biflexa serovar Patoc strain Patoc I, a nonparasitic strain of Leptospira, was used as a control. Both the high- and low-virulence strains could adhere to fibroblasts and macrophages using one or both ends of the spirochete, which was followed by phagocytosis of both strains. Both strains adhered more strongly to macrophages than fibroblasts. However, the high-virulence strain could invade the host-cell nucleus, while the low-virulence strain remained in phagosomes. The L. biflexa strain neither adhered to nor invaded either cell type. Both of the L. interrogans strains also induced cell death (mostly necrosis) of macrophages, whether or not the spirochetes were viable, suggesting that leptospiral virulence is unrelated to macrophage death. However, the high-virulence strain induced mainly necrosis in fibroblasts, while the low-virulence strain induced more apoptosis. Thus, the main feature distinguishing the two L. interrogans strains is the ability of the high-virulence strain to invade the host-cell nucleus and induce pro-inflammatory necrosis in fibroblasts.     

Pirimiphos-methyl resistance in two stored product mites, Acarus siro and Acarus farris, as detected by impregnated paper bioassay and esterase activity assays

The response to pirimiphos-methyl, in one strain of Acarus farris and two strains of Acarus siro, was assessed using an impregnated filter paper bioassay and by the selection of adults following exposure to pirimiphos-methyl. It was concluded that one of the strains of A. siro was resistant to pirimiphos-methyl and that a major resistance mechanism was involved. The second strain of A. siro gave a response similar to that of a laboratory strain unexposed to organophosphates and was considered to be susceptible. The A. farris strain responded to selection at the ED50 but not at the ED99, and it was concluded that a minor resistance mechanism is present in this strain. Assays of esterase activity were used to attempt to identify the biochemical mechanisms involved in the resistance detected by the bioassays. The A. farris and susceptible A. siro strains showed similar levels of esterase activity but the esterase activity of the resistant A. siro strain was significantly greater. An increase in esterase activity followed selection of both the A. farris strain and the resistant A. siro strain. An acetylcholinesterase assay showed no significant difference between the susceptible and pirimiphos-methyl selected strains of A. siro. The results suggest that esterases are involved in the resistance to pirimiphos-methyl found in A. siro and A. farris but that in A. siro, at least, other mechanisms may also be present.     

Effect of Rifampicin and Uracil Depletion on Bacteriophage ϕX174 DNA Synthesis in an E. coli dnaHts Mutant

The fluorescent antibody technique was used to trace an inoculated Nocardia erythropolis strain which was capable of rapidly degrading phthalate esters in soil column and activated sludge systems. The reaction of antibody to Nocardia erythropolis S-1 was highly strain specific, i. e., only one of twelve other strain of N. erythropolis was stained with this fluorescent antibody. All other species of Nocardia and other genera of bacteria and a strain of Candida were not stained. Using this technique it was demonstrated that N. erythropolis S-1 inoculated into activated sludge and soil column systems was successfully distinguished from many other microorganisms in mixed culture systems, and the distribution of this strain was appreciated.     

The involvement of DNA polymerase I in the postreplication repair of ultraviolet radiation-induced damage in Escherichia coli K-12.

Summary A deficiency in DNA polymerase I increased the ultraviolet (UV) radiation sensitivity of a uvrA strain of Escherichia coli K-12 when plated on minimal growth medium. The slope of the survival curve for the uvrA polA strain was 2.0-times greater than that for the uvrA strain. The fluence-dependent yield of unrepaired deoxyribonucleic acid (DNA) parental-strand breaks following UV irradiation and incubation in minimal growth medium was similar in both strains. However, the fluence-dependent yield of unrepaired DNA daughter-strand gaps observed following UV irradiation was 1.8-fold greater in the uvrA polA strain than in the uvrA strain. These results suggest that DNA polymerase I is involved in the filling of at least some daughter-strand gaps during postreplication repair. Also, the uvrA polA strain was sensitized by a post-UV treatment with chloramphenicol (CAP) to a similar extent as was the uvrA strain, indicating that DNA polymerase I is not involved in the CAP-inhibitable pathway of postreplication repair.     

Studies on Streptomycetes

Investigation was made on the mycological properties of a strain No. 45449 isolated from a sample of soil collected in Fukuchiyama. Since the antibiotics produced by the strain resembled hydroxymycin and paromomycin, the strain was compared with the hydroxymycin and paromomycin-producing strains, S. paucisporogenes and S. rimosus forma paromomycinus, and as a result the strain No. 45449 was found to be different from the latter two strains. Among known strains, S. flavogriseus resembles the present strain, but they are different morphologically and in the kind of the antibiotics they produce. Thus, as the strain No. 45449 was found to be a new strain, it was named S. pulveraceus nov. sp. The antibiotics produced by the present strain are physiologically basic substances active against Gram-positive and negative bacteria and acid fast bacteria, and they are considered to belong to the neomycin-kanamycin group.     

Efficiency of insecticidal crystal protein production in a Bacillus thuringiensis mutant with derepressed expression of the terminal oxidase aa 3 during sporulation

A Bacillus thuringiensis respiratory mutant (AB1 strain) that shows premature sporulation and insecticidal crystal protein (ICP) production was isolated. The mutant strain harbours the cryIC and cryID insecticidal genes and could be important for the production of ICP highly toxic to Spodoptera sp. The mutant was selected by its increased capacity to oxidize. N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD). In this strain, cytochrome aa ₃ expression is not repressed during the sporulation phase, in contrast with the wild-type strain. The growth, spore production, dissolved O₂, O₂ consumption, CO₂ evolution rate and ICP production were recorded as a function of time. The AB1 mutant strain has a similar growth yield to the wild-type strain, but begins sporulation at least 4 h earlier. The AB1 strain consumes 74.5% more O₂ than the wild-type strain, during the fermentation process. The mutation on strain AB1 has an important positive effect on ICP production. This procedure shows that ICP production could be increased during fermentation by increasing the respiration capacity of Bacillus thuringiensis. Correspondence to: A. Bravo