Potentially pathogenic yeasts from soil of children’s recreational areas in the city of Łódź (Poland)

Objectives: Yeasts may become potential human and animal pathogens, particularly for individuals with a depressed immune system. Their presence in the environment, especially in soil, may favour their spread into human ontocenoses. Materials and Methods: Eighty-four soil samples obtained from 21 children's recreational sites in Łódź in autumn 2010 and spring 2011 were evaluated. The yeasts were isolated by classical microbiological methods and identified on the basis of morphological and biochemical features. Results: The fungi were found in 73.8% and in 69.0% of the examined samples collected in autumn and spring, respectively. Among 97 isolates of yeasts, the species potentially pathogenic to humans and animals were Candida colliculosa, C. guilliermondii, C. humicola, C. inconspicua, C. lambica, C. lusitaniae, C. pelliculosa, C. tropicalis, Cryptococcus albidus, C. laurentii, C. neoformans, C. terreus, Kloeckera japonica, Geotrichum candidum, G. penicillatum, Rhodotorula mucilaginosa, R. glutinis, Saccharomyces cerevisiae, Sporobolomyces salmonicolor and Trichosporon cutaneum. The most frequently isolated fungi included the genus Cryptococcus (38 isolates) and two species: Rhodotorula glutinis (15), Trichosporon cutaneum (14). C. neoformans, an etiological factor of cryptococcal meningitis, was present in the sandpits of 3 kindergartens. The Candida species were identified from park playgrounds and school sports fields mainly in autumn 2010 (14 isolates), in spring 2011 - only 1 isolate. The concentration of fungal species in particular samples varied considerably, but in the majority of samples, fungi were present at concentration of up to 1×102 CFU/1 g of soil. Conclusions: Yeasts were present in the soil of parks, schools and kindergarten recreational areas; the fact may pose a health risk to humans, especially to children, and this type of biological pollution should be regarded as a potential public health concern

Using mycorrhiza helper microorganisms (MHM) to improve the mycorrhizal efficiency on plant growth

In the context of the “New Green Revolution,” innovative agricultural practices have to be identified to sustainably improve the traditional cultural approaches already used in the green revolution and to apply efficient technologies to solve actual agricultural problems (more particularly in the developing countries) but without the use of chemical pesticides and fertilizers. To reach this objective, soil microbes represent a largely unexplored resource to promote agricultural yield and productivity in the context of sustainable farming practices. Among these beneficial microorganisms, arbuscular mycorrhizal fungi (AMF) form symbiotic association with ~80% of vascular plant species. These efficient symbionts are considered as a key group of soil microorganisms able to improve P uptake by plants. In addition, AMF have the potential to improve plant defense against plant pathogens and to promote plant tolerance against abiotic stresses. AMF are primary biotic soil components which, when missing or impoverished, e.g., due to anthropic input, can lead to a less efficient ecosystem functioning. Many environmental factors can affect the impact of AMF inoculation on the plant growth including the fungal species compatibility with soil characteristics and the interactions between the fungal inoculant and other soil microorganisms. Some microorganisms, named mycorrhiza helper bacteria (MHB), can facilitate the establishment and the functioning of the AMF symbiosis by stimulating spore germination, mycelial growth, root colonization, or sporulation but also by reducing stresses that could impact AMF symbiosis. The aim of this chapter is to review mechanisms implemented by MHB to promote the AMF establishment and to enhance the efficiency of the mycorrhizal effect on the plant growth. Using Mycorrhiza Helper Microorganisms (MHM) to Improve the Mycorrhizal Efficiency on Plant Growth