African Journal of Virology Research

African Journal of Virology Research ISSN 3421-7347 Vol. 3 (2), pp. 001-007, February, 2009. © International Scholars Journals

Full Length Research Paper

Litter mycology and the impacts of litter type and preslaughter feed withdrawal on crop bacterial community in broiler chicken

Heshmatollah Khosravinia¹*, Mohammad H. Gharoni² and Mostafa Darvishnia¹

¹Agriculture Faculty, Lorestan University, P.O. 465, Khoramabad- 68135, Lorestan, Iran.

²Veterinary School, Lorestan University, P.O. 465, Khoramabad- 68135,Lorestan, Iran.

Accepted 21 September, 2007

Abstract

An experiment consisting of two trials was conducted to compare the frequency of occurrence for 8 fungi in six broiler litter materials and to evaluate the impact of litter type and preslaughter feed withdrawal (PFW) on crop bactrioflora of broiler chicken at processing plant. Litter types including rice husk (RH), shredded paper (SP), barley stalks (BS), cow dung (CD), wood shaving (WS) and a mixture of all five litters (MIX) were subjected to microbial decontamination prior to trials using 1 L formaldehyde (20% solution) per each 2 cubic feet and were kept in plastic bags for a period of one week. During the study (8-weeks), a total of 273 samples were taken from various litters at biweekly intervals and examined to monitor the presence of eight fungi species in various litters. At 56d, feeders have been removed form the pens at 0, 2, 4 and 6 h prior to slaughtered birds. Various litters showed significant difference concerning total fungal contamination (P < 0.05). The general frequency of eight fungi species studied was significantly differed for litters of concern (P < 0.01). The maximum and minimum frequencies were observed for Aspergillus sp. and Fusarium sp., respectively. The crop bacterioflora was significantly affected by duration of preslaughter feed withdrawal. The crop bacterioflora of the birds was the normal flora up to 4 h of PFW but afterward E. coli was appeared and started to colonize the crop. It was concluded that various litters have significant differences regarding their potential to host different fungal community and count. Shredded paper has the potential for enhancing a fungal community rich with Aspergillus, a common hazardous fungus. To prevent the crop of broiler from colonization by feed-borne hazardous bacteria prior to reach at processing plant, the PFW must not exceed 4 h.

Key words: Broiler chicken, crop bacterioflora, litter, fungi, preslaugther feed withdrawal.

African Journal of Virology Research ISSN 3421-7347 Vol. 2 (2), pp. 135-141, February, 2008. © International Scholars Journals

Full Length Research Paper

A study of polymerase chain reaction-computer database for species determination of human pathogenic microsporidia

Scot E. Dowd¹* and Jeanette A. Thurston-Enriquez²

¹USDA-ARS, Livestock Issues Research Unit, Lubbock, TX, Texas.

² USDA-ARS, Soil and Water Conservation Research Unit, Lincoln, NE 68583, Texas.

*Corresponding author. E-mail: [email protected]. Tel: 806-746-5356 ext 122 office. Fax: 806-744-5028.

Accepted 11 January, 2008

Abstract

The potential for waterborne disease and zoonotic transmission of at least two species of human pathogenic microsporidia has heightened interest in clinical and environmental detection methods for these organisms. Detection using the polymerase chain reaction (PCR) followed by computer database homology comparison (CDHC) (PCR-CDHC) was reported previously by this research group. As a result, PCR-CDHC has been employed by many research groups around the world for species determination of human pathogenic microsporidia. To validate the CDHC speciation approach, a phylogenetic tree was generated using the small subunit ribosomal DNA sequences (SSU-rDNA) of a large number of microsporidia. An index of similarity was created and used as part of an assessment of CDHCs ability to differentiate between closely related species. Polymerase chain reaction followed by dye termination PCR sequencing and subsequent CDHC of the sequences was performed on 8 species of microsporidia including four human pathogenic strains. The four non-human pathogenic microsporidia tested by this approach were those shown by the phylogenetic analyses to be very closely related to the other human pathogenic species as determined by branch length. In all cases the CDHC approach was able to correctly identify the eight species of microsporidia evaluated. To provide an example of PCR-CDHC, a “universal” and two previously published pathogen-specific microsporidia PCR protocols followed by PCR-CDHC was conducted to assess their ability to detect naturally occurring microsporidia species in swine wastewater. Only one primer set resulted in a PCR-CDHC analysis where presumptive human pathogenic microsporidia was detected. Subsequent CDHC showed these presumptive positive PCR results were actually false positives. With the appropriate primer set, PCR-CDHC proves to be a reliable method that can be used for specific species determination of human pathogenic microsporidia in samples where non-pathogenic species may be present.

Key words: Microsporidia, Sequencing, BLAST, PCR, detection.

Key words: AIDS, precautions, awareness, Pakistan.

African Journal of Virology Research ISSN 3421-7347 Vol. 1 (7), pp. 103-111, July, 2007. © International Scholars Journals

Review

Comparison of antigenic variation in pathogenic microorganisms

*Morris Gerard and Steve Crawley

Department of Microbiology, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield, South Yorkshire, England. E-mail: [email protected].

Accepted 22 April, 2007

Abstract

Antigenic variation is a process by which pathogenic micro-organisms escape the immune response of their mammalian hosts. By convergent evolution, protozoal, fungal and bacterial pathogens have developed similar genetic mechanisms for true antigenic variation. In this review article, the biology, the surface antigens and their encoding genes, and the molecular mechanisms of antigenic variation of the protozoa Trypanosoma brucei, Plasmodium falciparum, Babesia bovis, Giardia lamblia, the fungus Pneumocystis carinii, and the bacteria Borrelia hermsii, Anaplasma marginale, Neisseria gonorrhoeae, Mycoplasma bovis and Campylobacter fetus are compared.

Key words: Antigenic variation, pathogens, micro-organisms, molecular mechanisms, immune evasion.

African Journal of Virology Research ISSN 3421-7347 Vol. 1 (8), pp. 116-119, August, 2007. © International Scholars Journals

Full Length Research Paper

A study of the resistance of Trichosporon cutaneum against toxic chemicals

*Boshnakov Radev¹, Dimitar Chavdar² and Yanev Djankov²

¹Department of Microbiology, Faculty of Medical Sciences, Burgas Free University, Burgas, Bulgaria.

²Department of Biomedical Sciences, New Bulgarian University, Sofia, Bulgaria.

*Corresponding author. E-mail: [email protected]

Accepted 03 March, 2007

Abstract

Conditioning of cultures involves growing cells in the presence of increasing amounts of a toxic chemical. In order to investigate how conditioning affects a culture’s ability to resist new challenges, the resistance of Trichosporon cutaneum to various toxic chemicals, before and after conditioning to growth on phenol, was investigated by measuring the capacitance of cell suspensions at 0.4 MHz following a toxic challenge. The results show that cells grown on phenol are more resistant to the influence of polar aromatic toxic chemicals such as phenol (log P_ow = 1.48) and benzylalcohol (log P_ow = 1.1), but less resistant against less polar non-aromatic compounds such as n-octanol (log P_ow = 2.9). In reverse, cells grown on glucose were found to be more resistant against n-octanol, but less so against phenol and benzylalcohol. The results indicate that cells, adapted to be more resistant to one type of substance, may become more susceptible to other compounds.

Key words: conditioning, adaptation, membrane, Trichosporon cutaneum, capacitance.