Cryptococcus neoformans and Other Opportunistic Cryptococcus Species in Pigeon Dropping in Saudi Arabia: Identification and Characterization by DNA Sequencing

The prevalent variants of Cryptococcus neoformans, and other Cryptococcus species in pigeon excreta in Western Region of Saudi Arabia were studied. Ninety pigeon dropping samples were plated directly on Niger seed agar, and suspected colonies were sequenced using Illumina MiSeq. Species identification was determined using sequence read mapping to reference genomes of the two C. neoformans variants. In addition, sequence reads were identified using the KmerFinder tool. internal transcribed spacer 2 in the rDNA was also used for fungal barcoding of none of the C. neoformans species using two fungal identification databases. Phylogeny was studied using CSI Phylogeny (Center for Genomic Epidemiology, Denmark). The C. neoformans var. grubii mitochondrion and chromosome 1 reference sequences (accession numbers NC_004336.1 and CP022321.1, respectively) were used for sequence comparison and variant calling. Fifteen Cryptococcus isolates were isolated, 11 were identified as C. neoformans var. grubii, and 4 were found to be other opportunistic Cryptococcus species. Phylogeny analysis of C. neoformans var. grubii isolates showed a high degree of similarity between the C. neoformans isolates especially at the mitochondrial genome level. This study supports the fact that pathogenic and opportunistic Cryptococcus species are prevalent in domestic bird excreta which is an easy source of infection in the susceptible population.

Quantifying the Impact of a Pigeon Dropping on the Output Power of a 10W PV Module

The output power from a stationary PV module tends to fluctuate throughout a day. This may be due to shading caused by clouds, contrails, trees, buildings and birds. The purpose of this paper is to quantify the impact of one pigeon dropping on the output power of a 10 W PV module that is located in a semi-arid region of South Africa. Data used in this experimental quantitative study was obtained from a LabVIEW software program that was designed to monitor and record the output power of a number of identical PV modules. Observations from this data enabled photographs to be taken of the PV modules that highlight the pigeon dropping. Results indicate that the instantaneous output power of these 10 W PV modules may be reduced by up to 5%, depending on the location of the single dropping. If the dropping is not removed, then a 1.5% power reduction can be realized for an entire day. A recommendation is to regularly clean these modules in areas that are well inhabited by pigeons, as every accumulated loss of power may lead to system downtime or even component failure over a period of time.

Screening and Selection of Cryptococcus Neoformans Using Urease Activity and Temperature Range

Pigeon dropping has been known to be a reservoir for Cryptococcus neoformans. In this research, attempt has been made to screen and select for this life threatening organism using temperature (thermotolerance) and urease test sequentially. Fourteen (14) samples from pigeon droppings were collected from three markets in Benin City. Isolates obtained from these samples were subjected to urease and temperature test. The results showed that 10 isolates that were positive for temperature were equally positive for the urease tests, with highest growth rate 37°C recorded for samples obtained from New Benin (NB3). This experiment demonstrates the possibility of isolating C. neoformans at minimum temperature of 37°C thermotolerance and urease activity tests. Pathogenicity studies are recommended to further understand host – pathogen relationships. Keywords: Cryptococcus neoformans, Pathogenic, Urease, Thermotolerance, Isolates

Cryptococcus neoformans strains isolated from church towers in Rio de Janeiro City, RJ, Brazil

Cryptococcosis has been a significant cause of morbidity and mortality in patients with Aids. Many reservoirs of the agent Cryptococcus neoformans have been reported, but the ecology of this yeast must be elucidated in order to establish surveillance programs and to prevent infections. The objective of this study was to evaluate the presence of C. neoformans in Rio de Janeiro City, RJ, Brazil. Ten churches were selected for sampling and detection of the yeast collecting pigeon dropping, air samples from church towers and neighboring areas during one year. The data demonstrated that C. neoformans has been present in every church selected and was present in 37.8% of 219 pigeon dropping samples. As well as, the yeast was isolated from soil, insects, eggs, pigeon nests and feathers. Fifteen air samples (4.9%) were positive. The growth on C.G.B. medium showed that all strains belonged to C. neoformans var. neoformans, with 98.8% of the strains belonging to serotype A.

Characterization of Cryptococcus neoformans isolated from urban environmental sources in Goiânia, Goiás State, Brazil

Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningoencephalitis as the most frequent clinical presentation in immunocompromised patients, mainly in people infected by HIV. This fungus is an environmental encapsulated yeast, commonly found in soil enriched with avian droppings and plant material. A total of 290 samples of pigeon and the other avian droppings, soil, ornamental trees and vegetable material associated with Eucalyptus trees were collected to study environmental sources of Cryptococcus species in Goiânia, Goiás State. The determination of varieties, serotypes and the susceptibility in vitro to fluconazole, itraconazole and amphotericin B of C. neoformans isolates were performed. C. neoformans var. grubii (serotype A) was found in 20.3% (36/177) of pigeon dropping samples and in 14.3% (5/35) of samples of Eucalyptus. None of the environmental isolates of C. neoformans showed in vitro resistance to three antifungal agents. The knowledge of major route for human cryptococcal infection (inhalation of infectious particles from saprophytic sources) and a total of 60 C. neoformans isolates obtained from AIDS patients with cryptococcal meningitis between October 2001 and April 2002 justify the study of the habitats of these yeasts as probable sources of cryptococcosis in this city.