Assessment of biodegradability of PVC containing cellulose by white rot fungus

Aims: Polyvinyl chloride (PVC) is the most widely used and environmentally damaging plastic. Processing, production and disposal of PVC cause release of toxic chlorine based compounds into environment. The objective of the present study was to assess the biodegradability of cellulose blended PVC by white rot fungi i.e. Phanerochaete chrysosporium. Methodology and results: Biodegradability of the strain for the polymer was tested on plate assay, sturm test, soil burial and shake flask experiments. The biodegradability of the polymer was determined by visual changes, plate assay and carbon dioxide production. Morphological changes in the polymer such as pits, extensive spotting, clear surface erosion, fungal attachment, roughening and deterioration of some parts were observed using scanning electron microscopy. Chemical changes like appearance and shortening of peaks using fourier transform infrared spectroscopy also confirmed the biodegradability of the polymer. Conclusion, significance and impact of study: The present study confirmed that mixing of small amount of cellulose increases the hydrophilicity of the polymer and lead to its microbial degradation and Phanerochaete chrysosporium has great potential for the treatment of solid waste containing plastics.

Natural infection of the sand fly Phlebotomus kazeruni by Trypanosoma species in Pakistan.

The natural infection of phlebotomine sand flies by Leishmania parasites was surveyed in a desert area of Pakistan where cutaneous leishmaniasis is endemic. Out of 220 female sand flies dissected, one sand fly, Phlebotomus kazeruni, was positive for flagellates in the hindgut. Analyses of cytochrome b (cyt b), glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) and small subunit ribosomal RNA (SSU rRNA) gene sequences identified the parasite as a Trypanosoma species of probably a reptile or amphibian. This is the first report of phlebotomine sand flies naturally infected with a Trypanosoma species in Pakistan. The possible infection of sand flies with Trypanosoma species should be taken into consideration in epidemiological studies of vector species in areas where leishmaniasis is endemic.

Polymorphisms of cytochrome b gene in Leishmania parasites and their relation to types of cutaneous leishmaniasis lesions in Pakistan.

The exact species and/or strains of Leishmania parasites involved strongly influence the clinical and epidemiological features of leishmaniasis, and current knowledge of those influences and relationships is inadequate. We report that cytochrome b (cyt b) gene sequencing identified causal Leishmania parasites of 69 cutaneous leishmaniasis cases in Pakistan over a 3-year period. Of 21 cases in highland areas (Quetta city, Balochistan province), 16 (76.2%) were identified as Leishmania (L.) tropica and five (23.8%) as Leishmania (L.) major. Of 48 cases from lowland areas, cities/villages in Indus valley in Sindh and Balochistan provinces, 47 (97.9%) were identified as L. (L.) major and one (2.1%) as L. (L.) tropica. Statistical analysis (Fisher's exact test) revealed a significant difference (P < 0.0001) in the distribution of the two species by altitude; L. (L.) major is predominant in lowland and L. (L.) tropica at highland areas. The present result enriched our earlier finding, based on the first year's cultured parasite data, that only L. (L.) tropica was found in highland areas and only L. (L.) major in lowland areas. Among Leishmania samples analyzed, three types of cyt b polymorphism of L. (L.) major were found, including 45 (86.5%) cases of type I, six (11.5%) of type II and one (2%) of type III. We report for the first time on the presence of polymorphisms in L. (L.) major (types I, II and III) based on species identification using cyt b gene sequencing from clinical samples. Moreover, we found no correlation between clinical presentation (wet-, dry- and/or mixed-types of cutaneous lesions) and causal Leishmania parasites.

Multilocus enzyme electrophoresis and cytochrome B gene sequencing-based identification of Leishmania isolates from different foci of cutaneous leishmaniasis in Pakistan.

Seventeen Leishmania stocks isolated from cutaneous lesions of Pakistani patients were studied by multilocus enzyme electrophoresis and by polymerase chain reaction amplification and sequencing of the cytochrome b (Cyt b) gene. Eleven stocks that expressed nine zymodemes were assigned to L. (Leishmania) major. All of them were isolated from patients in the lowlands of Larkana district and Sibi city in Sindh and Balochistan provinces, respectively. The remaining six, distributed in two zymodemes (five and one), isolated from the highland of Quetta city, Balochistan, were identified as L. (L.) tropica. The same result at species level was obtained by the Cyt b sequencing for all the stocks examined. No clear-cut association between the clinical features (wet or dry type lesions) and the Leishmania species involved was found. Leishmania (L.) major was highly polymorphic compared with L. (L.) tropica. This difference may be explained by the fact that humans may act as a sole reservoir of L. (L.) tropica in anthroponotic cycles; however, many wild mammals can be reservoirs of L. (L.) major in zoonotic cycles.

Histochemical localization of phosphomonoesterases in Avitellina lahorea Woodland, 1927 (Cestoda: Anoplocephalida).

Non-specific and specific phosphatases have been histochemically localized in the tissues of Avitellina lahorea, an intestinal parasite of sheep and goats. Large quantities of acid phosphatase, alkaline phosphatase and adenosine triphosphatase were observed in almost all organs except the parenchyma where there were moderate amounts of acid phosphatase and no alkaline phosphatase; the reproductive ducts contained moderate amounts of alkaline phosphatase. 5-nucleotidase was observed only in the uterus, egg pouches and eggs and glucose-6-phosphatase activity was restricted to the tegument. The probable functions of these moieties at different sites are discussed.

Histochemical localization of esterases in Avitellina lahorea Woodland, 1927 (Cestoda: Anoplocephalida).

Specific and non-specific esterases have been localized in sections and whole mounts of Avitellina lahorea, an intestinal parasite of sheep and goats. Non-specific esterases (NSE) were found in the sucker muscles, post-acetabular ganglia, nerve trunks, tegument, excretory canals, cirrus sac, vagina, uterus and the inner membrane of the embryophore. Acetylcholinesterase (AChE) was observed in all the above organs, including vas deferens and sperm ducts, but was absent from excretory canals and eggs. Tests with acetylthiocholine iodide (AThChI) revealed the nervous system, vas deferens, sperm ducts, uterus, cirrus sac and the vagina. The intensity of activity of AChE and AThChI was weak compared to NSE.