Dermatophytosis of pigs by Trichophyton mentagrophytes

We describe the isolation of Trichophyton mentagrophytes in two family-operated farms where the animals were suffering skin ailments characterized by a swelling and a reddening of the back and flanks.This condition affected 2 and 5% respectively of the animals on the farms, the younger ones being more frequently affected.     

3例不同临床表现的石膏样小孢子菌感染

报道3例由石膏样小孢子菌感染引起的、临床表现不同的皮肤癣病.例1表现为阴囊红色斑片,上覆白色斑点状痂屑,刮去痂屑后见湿润的基底面,患者父亲有同样病变,父子穿用同一件内裤,其父与家猫有密切接触.例2患儿左面部擦伤后局部出现钱币大小红斑,中央为白色痂皮,边缘有渗出伴痒.例3患儿右面部出现钱币大小、边界清楚的红斑,表面有散在的丘疹及少许鳞屑伴痒,偶有家猫接触.3例患者均平素体健.取皮损表面组织直接镜检均发现大量菌丝;真菌培养及鉴定为石膏样小孢子菌.诊断为石膏样小孢子菌所致皮肤感染.3例患者经抗真菌治疗1～2周后痊愈,取得很好疗效.     

Variability of biochemical characteristics in strains of Trichophyton mentagrophytes

The characteristics of 23 strains of Trichophyton mentagrophytes isolated from clinical samples, were studied. Sabouraud agar was the most adequate medium to inhance at their utmost the different taxonomical features. Variability of enzymatic reactions in strains of T. mentagrophytes was observed.     

An outbreak of dermatophytosis in pigs caused byMicrosporum canis

An outbreak of dermatophytosis caused byMicrosporum canis in a porcine farm is described. The morbidity was 100% among sows, 95% among new-borns and 75% among feedlot animals.Microsporum canis was also isolated from walls and environmental air.     

Studies on the macroconidia of Microsporum canis

The characteristics of an in vitro polyuridylic acid dependent amino acid incorporating system prepared from germinating macroconidia of Microsporum canis are described. The incorporation of ¹⁴C-phenylalanine into polyphenylalanine is dependent on S-30 extract, adenosine triphosphate, magnesium ions and polyuridylic acid. Incorporation is slightly enhanced by yeast transfer ribonucleic acid and pyruvate kinase. The system is highly sensitive to ribonuclease, puromycin and miconazole (an antifungal agent), moderately sensitive to sodium fluoride and much less sensitive to phenethylalcohol, cycloheximide, chloramphenicol and deoxyribonuclease. Cell-free extract from ungerminated conidia has less capacity to synthesize the protein and during germination a marked increase in the protein synthetic activity is observed. The results from experiments wherein ribosomes and S-100 fraction from germinated and ungerminated spores are interchanged, revealed that the defect in the extract from the ungerminated spore is in the ribosomes.Abbreviations Poly(U) polyuridylic acid - tRNA transfer ribonucleic acid - ATP adenosine triphosphate - GTP guanosine triphosphate - BSA bovine serum albumin - RNase ribonuclease - DNase deoxyribonuclease - POPOP 1,4-bis-2(5-phenyl oxazolyl)benzene - PPO 2,5-diphenyl oxazole - TCA trichloracetic acid     

Effect of visible light on carotenogenesis in arthroconidiating Trichophyton mentagrophytes

The effect of visible light on carotenoid content in the dermatophyte Trichophyton mentagrophytes ATCC 26323 was investigated. The fungus T. mentagrophytes accumulated several carotenoids when arthroconidiated on Sabouraud glucose agar at 37°C. When this fungus was irradiated with moderate fluence rates of white light, the resultant arthroconidia contained considerably less carotenoids in comparison with dark controls although growth and arthroconidiation of this fungus were not at all affected by visible light. The reduction of carotenoid content in arthroconidia was due primarily to blue light, although red light caused a slight decrease in pigmentation. The suppressive effect of visible light on pigmentation was fluence rate dependent. Carotenoid accumulation in arthroconidia was inversely and exponentially related to the fluence rate of light. Carotenoid formation in arthroconidiating T. mentagrophytes was neither photoinducible nor photostimulative. An analysis of isolated carotenoids revealed that visible light caused a quantitative reduction in pigmentation, and no single carotenoid was selectively decreased.Non-standard abbreviations PI pigmentation index - r coefficient of correlation     

Preliminary report on the isolation of a dysgonic variety ofMicrosporum canis together with the normal variety from a cattery

The isolation of a dysgonic variety ofMicrosporum canis from a large number of cats and kittens in a cattery is described. The normal variety of this fungus was isolated at the same time from the same animals. Dysgonic varieties are thought to be mutants of normal strains, but this isolation of both forms together suggests that the relationship may be more complex.     

Disseminated dermatophytosis caused by Microsporum gypseum in two patients with the acquired immunodeficiency syndrome

Microsporum gypseum is not a common agent of human dermatophytosis. To the best of our knowledge, this fungus has not been described in human immunodeficiency virus (HIV)-infected patients. We report a tinea corporis infection with atypical presentation caused by M. gypseum in two patients with the acquired immunodeficiency syndrome (AIDS) studied at the São Paulo Hospital (São Paulo, Brazil).This revised version was published online in October 2005 with corrections to the Cover Date.     

Fluconazole downregulates metallothionein expression and increases copper cytotoxicity in Microsporum canis

Azole antifungals are widely used to treat infections with dermatophyte fungi. Whereas it is well established that this class of drugs interferes with fungal ergosterol synthesis, little is known about its potential other biological effects. Here we report the isolation and structural organization of Microsporum canis metallothionein gene and demonstrate that fluconazole is able to downregulate the baseline as well as copper-induced expression of this gene. Since this effect occurred within 30 min after exposure of the fungus to fluconazole, it is unlikely that it is due to impaired ergosterol synthesis. Our additional demonstration that fluconazole enhances copper toxicity for M. canis suggests that inhibition of metallothionein expression by fluconazole is biologically relevant and may represent an important additional mode of the antifungal action of this drug. Therefore our data indicate that antifungal effects of azole derivatives might not only be due to interference with cell wall synthesis but may also affect other biological circuits within the fungal cells.     

须癣毛癣菌致儿童脓癣1例

报道由须癣毛癣菌引起的儿童头部脓癣1例.患儿为4岁幼女,因头皮部丘疹1个月,脓肿4d就诊.内服青霉素V钾无效.取断发镜检查见发外真菌孢子,培养鉴定为须癣毛癣菌,细菌培养为棒状杆菌.经内服和外用特比萘芬抗真菌,静脉输入头孢噻肟钠联合克林霉素及万古霉素抗细菌治疗,12d后脓肿减轻,细菌培养阴转,但真菌培养仍阳性,继续抗真菌治疗2个月后皮损消退,真菌检查阴性.     

Dermatophytes isolated from symptomatic dogs and cats in Tuscany,Italy during a 15-year-period

Between January, 1, 1986 and December, 31, 2000, dermatological specimens from 10.678 animals (7.650 cats and 3.028 dogs) were examined for dermatophytes. All the animals presented clinical signs of ringworm. Two thousand-four hundred fifty-six of the 10.678 (23%) examined animals scored positive for dermatophytes, 566 out of 3.028 canine (18.7%) and 1890 out of 7.650 feline specimens (24.7%). Microsporum canis constituted 83% and 97% of the isolated dermatophytes respectively in dogs and cats, M. gypseum represented 13% and 2.6% and T. mentagrophytes 5.5% and 0.2%. A sexual predisposition for mycotic infections was not observed. The animals with less than 1 year of age were more frequently infected. Canine toy breeds showed a significantly higher (P < 0.001) prevalence of infections by M. canis. Microsporum gypseum was mostly recorded from sporting (hunting) breeds [such as T. mentagrophytes (6.7%)]. Microsporum canis was isolated from long-haired cats with a ratio of 2:1 versus short-haired cats, while M. gypseum and T. mentagrophytes were never recovered from Persian cats. The annual distribution of the infections in dogs showed a significantly higher incidence for M. gypseum in summer versus winter and spring, while the recovery rate of M. canis from cats was very significantly higher in fall and winter than in summer and spring. Trichophyton mentagrophytes did not show a similar seasonal distribution.This revised version was published online in October 2005 with corrections to the Cover Date.     

Outbreak ofTinea capitis caused by Microsporum ferrugineum in Thailand

There was an outbreak ofTinea capitis at the Pak-kred Home for Mentally and Physically Handicapped Babies, Bangkok, Thailand in 1993. One hundred and thirty-eight cases were diagnosed as tinea capitis based on clinical signs and positive laboratory investigations. The results of Wood's light examination, KOH preparation and fungal culture were positive in 89.9, 75.9 and 27.4% respectively. The non-inflammatory form had a higher rate of positive KOH and culture than in the inflammatory form.Microsporum ferrugineum was the major pathogen (66.7%) and most of its infections (80.4%) caused a non-inflammatory type of tinea capitis. Griseofulvin, in a dosage of 10–15 mg/kg/day and selenium sulfide shampoos, yielded an 84.8% cure rate within 14.9 weeks. No recurrence or obvious adverse reactions were observed.     

High rate of Microsporum canis feline and canine dermatophytoses in Northeast Brazil: Epidemiological and diagnostic features

Over a one year period (November 2000-December 2001), clinical specimens from 189 dogs and 38 cats, from the city of Fortaleza, Ceará, Brazil, were examined at the Specialized Medical Mycology Center at the Federal University of Ceará to detect animals with dermatophytoses. The mycological analyses were conducted by direct microscopy and by fungal culture on Sabouraud agar, Sabouraud chloramphenicol agar and Mycosel agar. Dermatophytes were isolated from 27 of the 189 (14.3%) canine specimens and 14 of the 38 (36.8%) feline specimens. The identified dermatophytes were Microsporum canis (95%), M. gypseum (2.5%) and Trichophyton mentagrophytes var. mentagrophytes (2.5%). Microsporum canis was the most common species isolated (92.6% and 100%, for dogs and cats respectively). The percentage of positive direct microscopic examinations of clinical specimens and positive cultures was 61%. There was a high proportion of positive cultures from cats less than 1 year of age, but in dogs no significant differences were detected. There were no significant differences between the sexes. Dermatophytes were more frequently isolated in March, April and May, but no significant differences were detected in the seasonal distribution of canine and feline dermatophytoses.     

Epidemiology of dermatophytoses in a rural community in Eastern Nigeria and review of literature from Africa

A total of 4,287 primary school children, comprising 1,740 males and 2,547 females in Arochukwu local government area of Abia state Nigeria were examined for clinical signs of dermatophytoses. About 873 (20.4%), consisting of 505 males and 368 females had lesions consistent with dermatophytoses. The disease was more prevalent in males (29%) than females (14.4%) in a ratio of approximately 2:1 (P < 0.05). The infection rate increased from 16.8% in the 4–6 year age group to a peak of 28.1% in the 10–12 year age bracket and dropped sharply to 5.6% in the 16–18 year group. The highest prevalence (39%) was observed among males aged 10–12 years while females 16–18 years had the lowest prevalence (2.5%). Tinea capitis was the predominant clinical type of dermatophytoses, and occurred in 13.7% of the total population studied and 67% of lesion positive cases. Trichophyton soudanense and Trichophyton tonsurans the predominant aetiological agents of dermatophytoses with a prevalence of 26.2% and 21.6%, respectively. Others include Trichophyton mentagrophytes (18.8%), Epidermophyton floccosum (8.3%), Microsporum audouinii (6.4%), Microsporum gypseum (6.0%), Trichophyton rubrum (5.5%) and Microsporum ferrugineum (7.3%), which was isolated for the first time in Nigeria.     

Mitosis in the dermatophyteMicrosporum canis as revealed by freeze substitution electron microscopy

Summary Mitosis in the dermatophyteMicrosporum canis was studied by freeze substitution and electron microscopy, and analyzed by three dimensional reconstruction from serial sections of the mitotic nuclei. The interphase nucleus has associated nucleus-associated organelle (NAO) on a portion of the outer surface of the nuclear envelope, subjacent to which there was dense intranuclear material. The NAO divided and separated on the envelope, and a spindle was formed. The spindle was composed mostly of microtubules extended between opposite NAOs. Pairing of kinetochores was observed in the spindle from an early stage of development, when chromosomes were not so condensed, and remained unchanged while chromosome condensation proceeded until metaphase. Before the completion of nuclear division, daughter nuclei were connected by a narrow spindle channel, and then the nucleolus, whose structure underwent minimal change during mitosis, was eliminated into the cytoplasm.     

Extracellular enzymatic activity ofMicrosporum canis isolates

The enzymatic activity of 70 feline and canineMicrosporum canis isolates was determined by the Api-Zym^® test. The liquid phase of cultures, inoculated into Tryptic Soy Broth, was used to examine 19 enzymes. Considerable differences were observed among the extracellular enzymatic patterns. All the isolates produced alkaline phosphatase and beta-glucosidase, while lipase (C14), trypsin, chymotrypsin, beta-glucuronidase, and alpha-fucosidase activity was never revealed. Esterase (C4) activity was present in 57 samples (81%), esterase lipase (C8) in 31 (44%), leucine arylamidase in 35 (50%), valine arylamidase and cystine arylamidase in 7 (10%), acid phosphatase in 64 (91%), naphthol-AS-BI-phosphohydrolase in 60 (86%), alpha-galactosidase in 5 (7%), beta-galactosidase in 6 (8%), alpha-glucosidase in 25 (36%), N-acetyl-beta-glucosaminidase in 41 (58%), and alpha-mannosidase in 51 (73%). The beta-galactosidase activity ofM. canis has not been reported previously. Remarkable variations of intensity for each enzymatic activity were also detected. It is believed that these results could provide basic data for further investigations on the pathogenic role of enzymes secreted byM. canis.     

Preformed messengers inMicrosporum canis macroconidia

Macroconidia ofMicrosporum canis, when placed in a nutrient medium produce germ tubes within 4–6 h. Precursor incorporation studies showed that protein synthesis occurred prior to RNA synthesis. Sucrose density gradient analysis of wet and dry spore extracts revealed the presence of 16 % and 11 % polysomes respectively. The polysomal content increased to about 50% within 15 min of germination. Synthesis of RNA occurred only after 2 h of germination. Pool equilibration of the radioactive precursors was not limiting to these measurements. Polyadenylated RNA was isolated from macroconidia and was found to comprise 2–2.5 % of the total RNA. The poly(A)⁺ RNAs were heterodisperse and translatable in a wheat germ cell free translating system. It was concluded that macroconidia ofMicrosporum canis contain pre-formed mRNA which is translated early in germination     

Internal Transcribed Spacer (ITS) of rDNA of appendaged and non-appendaged strains of Microsporum gypseum reveals Microsporum appendiculatum as its synonym

Recently a new taxon of geophilic dermatophytes was established as Microsporum appendiculatum Bhat and Mariam, based on the presence of appendaged macroconidia. However, such appendages are already known in the related species Microsporum gypseum. We conducted a survey of soil in central India as a part of a microbial biodiversity project and obtained two strains of M. gypseum with appendaged macroconidia. Using phenotypical characterization in combination with sequencing and restriction fragment length polymorphism (RFLP) of the Internal Transcribed Spacer (ITS) region of rDNA, we found that all strains of appendaged species are identical. Therefore M. appendiculatum is regarded as a synonym of M. gypseum.     

Prolactin evokes lactational transmission of larvae in mice infected with Toxocara canis

We investigated the trans-lactational maternal–neonatal transmission of Toxocara canis larvae in mice, with particular interest in the role of prolactin in their migration to the mammary gland. Two female mice were infected with 300 T. canis eggs soon after delivery of 27 offspring. After 1 week of breast-feeding, seven larvae were recovered from 4 of 13 offspring. After 2 weeks of lactation, 101 larvae were recovered from all the remaining offspring. Daily prolactin administration (5 μg) was performed 2 weeks before T. canis infection and continued until 2 weeks after infection in six non-pregnant female mice, which resulted in larval accumulation in the mammary gland. Furthermore, prolactin administration in female mice that had been infected with T. canis 4 weeks prior to prolactin treatment induced migration of larvae into the mammary gland. These findings suggest that prolactin is a promoting factor contributing to lactational transmission of T. canis larvae in mice.     

Etude sur la contamination par les champignons dermatophytes d'une population de petits mammiferes sauvages en Alsace

Résumé Des 3782 petits mammifères sauvages capturés au cours d'une enquête poursuivie pendant plus de 4 ans, 15,78% sont contaminés par des dermatophytes.Les espèces de dermatophytes ou champignons, apparentés qui sont rencontrées ne sont que 6;Microsporum persicolor etTrichophyton mentagrophytes sont les espèces dominantes. Les campagnols roussâtres sont, de façon significative, plus contaminés parM. persicolor (11,63%) que parT. mentagrophytes (4,36%). Au contraire, les mulots sont plus contaminés parT. mentagrophytes: 13,95% contre 3,50% contaminés parM. persicolor. Les campagnols roussâtres mâles (13,33%) sont plus contaminés que les femelles (9,45%) parM. persicolor et les mulots mâles (17,09%) plus contaminés que les femelles (9,95%) parT. mentagrophytes. La présence deM. persicolor est notée pour la première fois chez le grand hamster. L'étude histologique de certains animaux permet de remarquer l'existence de lésions dermatophytiques. A l'isolement deT. mentagrophytes correspond une attaque pilaire de type endo-ectothrix; à l'isolement deM. persicolor correspond une attaque limitée à l'épiderme.

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3782 small wild mammals trapped during a 4 year survey have been examined in relation to a possible contamination by dermatophytes. 15.78% of the animals were contaminated.The prevailing species wereMicrosporum persicolor andTrichophyton mentagrophytes. The bank voles were significantly more contaminated byM. persicolor (11.63%) than byT. mentagrophytes (4.36%). On the contrary the wood mice were more contaminated byT. mentagrophytes: 13.95% as against 3.50% contaminated byM. persicolor. The male bank voles (13.33%) were more contaminated than the females (9.45%) byM. persicolor and the male wood mice (17.09%) more contaminated than the females (9.95%) byT. mentagrophytes. The occurrence ofM. persicolor in common hamster is noted for the first time. The existence of a pathological lesion in relation to the fungal contamination was noted in the small group of rodents examined histologically: WhenT. mentagrophytes was isolated the hairs were invaded in the endo-ectothrix type pattern; whenM. persicolor was cultivated, hairs are not attacked but only the epidermis.