Incidence of aflatoxin producing strains and aflatoxin contamination in dry fruit slices of quinces (Cydonia oblonga Mill.) from the Indian State of Jammu and Kashmir

An investigation was undertaken to obtain data on the occurrence of aflatoxins and the aflatoxin producing potential of Aspergillus flavus strains isolated from dry fruit slices of quinces produced in jammu and Kashmir, India. A total of 147 A. flavus isolates recovered from dr fruit slices were grown in liquid rice flour medium and screened for the production of various aflatoxins by thin layer chromatography. The results showed that 23.14% of the tested isolates were aflatoxigenic, producing aflatoxins B₁and B₂ in varying amounts. Aflatoxins G₁ and G₂ were not detected. All 25 of the investigated market samples were also found to be aflatoxin B₁ positive and the level of contamination ranged from 96 to 8164 g/kg of the dry fruit which is quite high in comparison to the permissible level of 30 ppb. As per these results biochemical composition of dry fruit slices of quinces, along with climatic conditions seem to be very favourable for aflatoxin production by the toxigenic A. flavus strains. Therefore,monitoring of aflatoxins in dry fruit slices of quincesis recommended for this region.This revised version was published online in October 2005 with corrections to the Cover Date.     

Keratinolysis by poultry farm soil fungi

Two hundred and eleven dogs (including strictly house and stray dogs) and 170 cattle in and around the city of Madras, India were screened for the presence of dermatophytosis. 106 strains of dermatophytes (89 strains from dogs and 17 strains from bovines) were isolated. 57/106 strains were Trichophyton mentagrophytes var. mentagrophytes and 42/106 strains were of the Microsporum gypseum complex. 5 strains of T. rubrum and 2 strains of T. simii were also obtained in culture. A predominance of M. gypseum complex isolates was recorded in stray dogs and cattle and T. mentagrophytes var. mentagrophytes and T. rubrum in strictly house dogs. The family history of the owners of the most of the dogs had clear records of dermatophytosis. Further, the owners of the 11 dogs that yielded T. mentagrophytes var. mentagrophytes had either tinea corporis or tinea pedis. The etiological agent of all the 11 human cases was T. mentagrophytes var. interdigitale. Similarly the owners of 4 of the 5 dogs that yielded T. rubrum were known T. rubrum patients. All these patients responded to oral griseofulvin or ketaconozole, but the recurrence of lesions was noted with the cessation of treatment. None of the patients had onychomycosis and the family history of all the patients revealed no reports of T. rubrum infections. The pet dogs were presumed to be the source of re-infection. Reversed transmission of dermatophytes from humans to animals may be the reason for the selective predominance of these organisms in strictly house dogs. They also may act as sources of reinfection. Most of the animals had small, occult, scattered lesions. These lesions may either go unnoticed or are ignored by the owners of the animals. The taxonomic status of T. mentagrophytes var. mentagrophytes and T. mentagrophytes var. interdigitale was aligned to their teleomorph Arthroderma vanbreuseghemii. Our study suggests that the periodic screening and medication of all live-stock are essential for the prevention and management of the public health problem caused by dermatophytes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Production of extracellular keratinases by keratinophilic fungal species inhabiting feathers of living poultry birds (Gallus domesticus): A comparison

Fourteen species of keratinophilic fungi belonging to ten genera (Chrysoporium, Malbranchea, Chaetomium,Sepedonium, Microascus, Scopulariopsis, Curvularia, Fusarium, Aspergillus, Penicillium) were isolated from feathers of about one hundred living poultry birds. The isolated fungi were compared for their keratinase activity after growing them on two different media: (1) basal salts solution containing natural keratin (human hair) as the only source of carbon and nitrogen; (2) the medium was supplemented with a minor amount of readily assimilable source of carbon along with natural keratin. All the test fungi could grow on keratinous material, degrading it and releasing sulphydryl containing compounds detected as cysteine, total proteins and extracellular keratinase. Maximum enzyme release by these fungi occurred in the broth supplemented with glucose and vitamins, thereby indicating a correlation between the mycelial biomass and production of proteolytic keratinases. This revised version was published online in June 2006 with corrections to the Cover Date.     

Impact of some ecological factors on the occurrence of poultry soil-inhabiting keratinophiles

Investigations were conducted to assess the ecological factors governing distribution and survival of keratinophilic fungi in poultry farm soils. All the poultry farm soils were rich in humus and the keratinophilic fungi were generally found to be proportional to the soil organic matter. These soils were nearly neutral to weakly alkaline and organically rich with a high content of organic carbon, nitrogen, phosphorus, potassium, magnesium, calcium and iron. This revised version was published online in June 2006 with corrections to the Cover Date.     

Incidence of aflatoxin producing strains and aflatoxin contamination in dry fruit slices of quinces (Cydonia oblonga Mill.) from the Indian state of Jammu and Kashmir

An investigation was undertaken to obtain data on the occurrence of aflatoxins and the aflatoxin producing potential of Aspergillus flavus strains isolated from dry fruit slices of quinces produced in jammu and Kashmir, India. A total of 147 A. flavus isolates recovered from dr fruit slices were grown in liquid rice flour medium and screened for the production of various aflatoxins by thin layer chromatography. The results showed that 23.14% of the tested isolates were aflatoxigenic, producing aflatoxins B1 and B2 in varying amounts. Aflatoxins G1 and G2 were not detected. All 25 of the investigated market samples were also found to be aflatoxin B1 positive and the level of contamination ranged from 96 to 8164 micrograms/kg of the dry fruit which is quite high in comparison to the permissible level of 30 ppb. As per these results biochemical composition of dry fruit slices of quinces, along with climatic conditions seem to be very favourable for aflatoxin production by the toxigenic A. flavus strains. Therefore, monitoring of aflatoxins in dry fruit slices of quinces is recommended for this region.     

Co-occurrence of aflatoxin B<Subscript>1</Subscript> and cyclopiazonic acid in sour lime (<Emphasis Type="Italic">Citrus aurantifolia Swingle</Emphasis>) during post-harvest pathogenesis by <Emphasis Type="Italic">Aspergillus flavus</Emphasis>

During hot and humid seasons, extensive rot of sour lime was observed to be caused by Aspergillus flavus. In view of this, investigations were undertaken to obtain data on the production of various toxins by A. flavus during post harvest pathogenesis of sour lime. Sixty percent of the pathogenic A. flavus isolates were detected to be aflatoxin B₁ producers in sour lime tissue. It was also noted that thirty three percent of aflatoxigenic A. flavus isolates had the potential to coproduce cyclopiazonic acid (CPA). Such aflatoxigenic isolates produced quantitatively more CPA (ranging from 250.0 to 2501.3 g/kg) than aflatoxin B₁ (ranging from 141.3 to 811.7 g/kg) in the affected sour lime. This study demonstrates for the first time that sour lime are a favourable substrate for aflatoxin B₁ and cyclopiazonic acid production by A. flavus isolates. This is of great concern to the health of consumers.