Identification of Acanthamoeba spp. from water and soil of public parks in the north of Iran

Acanthamoeba, a free-living and opportunistic protozoan parasite, is a causative agent of severe human infections of the cornea and brain. The present study evaluated the distribution and genotyping of Acanthamoeba spp. in water and soil of recreational places in various areas in Guilan province in northern Iran. Eighty water and 20 soil samples were collected from the study area. Water samples were vacuum filtered through a 0.45 μm pore-size membrane filter. Soil samples were washed with sterile distilled water, and washings were similarly filtered, as mentioned for water samples. The filtered material was cultured on non-nutrient agar plates seeded with heat-killed Escherichia coli. Molecular analysis was performed by PCR and sequencing using specific primers for Acanthamoeba. Finally, 26 isolates were successfully sequenced. According to culture and PCR methods, 54% of water and 100% of soil samples were contaminated with Acanthamoeba. Based on the sequencing data, genotypes T4 (47%), T5 (35.29%), T3 (11.76%), and T11 (5.88%) were identified in water samples. Genotypes T4 (66.6%), T5 (22.2%) and T15 (11.1%) were identified in water samples. Most isolates might present a potential health hazard for humans in this region. To the best of our knowledge, this is the first comprehensive survey of water and soil of recreational areas in northern Iran and the first report on identifying genotype T15 from soil sources.

An efficient method for collecting the full-length adults, fragments, and eggs of Trichobilharzia spp. from the liver of definitive hosts

Precise identification of avian schistosomes in the genus Trichobilharzia at the species level is difficult and requires both traditional morphological and molecular techniques. To obtain satisfactory results by traditional methods, the characteristics of the intact adults or large fragments of male and females are necessary. The present study aimed to introduce a more efficient method for collecting eggs and both fragments and intact worms for morphological identification of visceral Trichobilharzia spp. Thirty-eight domestic ducks (twenty-eight fresh and ten frozen) were studied. For fresh samples, warm saline (40-45 °C) was injected into the portal vein or liver tissue, followed by slicing of the liver to small pieces in a large Petri dish. All materials were then transferred into the laboratory sieves arranged from the largest to the smallest mesh size and while crushed with the hand, washed, and filtered using a trigger water sprayer. The collected materials were studied under a stereomicroscope for parasite eggs, fragments, and full-length worms. Out of 28 freshly killed ducks, 19 (67.9%) and of 10 frozen ducks 6 (60%) were positive for visceral Trichobilharzia spp. The full-length worms and large fragments of male worms were mostly recovered with the mesh no. 150 (diameter of 106 μm) and small fragments, especially of females, and eggs with the mesh no. 270 (diameter of 53 μm). In addition to large numbers of fragments, 15 full-length adults were obtained from fresh and 2 from frozen ducks. The number of collected full-length adults was related to the worm burden. Since morphological description of different species of the genus Trichobilharzia is primarily based on the availability of adult worms, the application of methods that provide a higher number of intact males and females will result in better characterization of the species and deposition of appropriate voucher specimens. These results show the present method as a suitable tool for the collection of quality adults of visceral Trichobilharzia spp. in ducks.

Development of sensitive detection of cryptosporidium and giardia from surface water in iran

BACKGROUND

The protozoan parasites Cryptosporidium spp. and Giardia are known to occur widely in both raw and drinking waters. They are two of the causative agents of waterborne outbreaks of gastroenteritis throughout the world. In the present study, a PCR assay and FA were developed for detection of Cryptosporidium oocysts and Giardia cyst in environmental samples.

METHODS

We have detected Cryptosporidium spp. oocysts and Giardia cysts in seeded and unseeded environmental water samples by PCR method. Water samples were spiked with oocysts (50, 100,300,500) and filtrated with a 1.2-µm pore size cellulose nitrate and follow by DNA extraction and purification by QIAamp DNA mini kit. Nested-PCR assay amplified an 850 bp fragment of 18s rRNA gene specific for Cryptosporidium and 435 bp fragment of glutamate dehydrogenase (GDH) target gene for Giardia. Also many river water from north of Iran, be checked by these methods.

RESULTS

Cryptosporidium and Giardia DNAs were detected in seeded water sample and Giardia was detected in all 5 water samples from river in north of Iran by nested- PCR and FA. Also in one river water sample, Cryptosporidium was detected.

CONCLUSION

This protocol is effective for detection of these waterborne parasites in treated and untreated water samples. This study can also serve as a platform for further investigations and research water source in Iran.

Neglected human fascioliasis case in a visceral leishmaniasis endemic area, north-Western iran

Ardabil Province, northwestern Iran, is endemic for visceral leishmaniasis of Mediterranean type from many years ago. This situation might cause to underestimate other important diseases, which occur sporadically within the same area. In this case, a 6-year-old male patient in this area was treated as infected with visceral leishmaniasis initially with seropositive result for visceral leishmaniasis. Afterwards, histopathological study of crashed material and tissue sections surprisingly revealed numerous liver fasciolid fluke eggs. This case demonstrates that in an area endemic for a given parasitoses, other important infectious diseases must be considered as well.

Strongyloides stercoralis: The Most Prevalent Parasitic Cause of Eosinophilia in Gilan Province, Northern Iran

BACKGROUND

Eosinophilia occurs in a wide variety of situations such as parasitic infections, allergic disorders, and malignancies. Most cases of eosinophilia of parasitic origin, especially those with a tissue migration life cycles consists of human infections by helminth parasites. The aim of present study was to determine the parasitic causes of eosinophilia in patients in a major endemic area of human fascioliasis in Gilan Province, northern part of Iran.

METHODS

One hundred and fifty patients presenting with an elevated eosinophilia attending infectious disease clinics with or without clinical symptoms, were examined. After clinical history evaluation and physical examination, coprological examinations were performed using the formalin-ether and the Kato-Katz techniques for detection of Fasciola sp. and intestinal parasites.

RESULTS

Forty two percent of patients were infected with S. stercoralis, nine (6%) were found to be infected with Fasciola sp. while only a single patient (0.7%) were infected by Ttrichostrongylus sp.

CONCLUSION

Local clinicians in Gilan may consider eosinophilia as a suggestive indication for diagnosis of human fascioliasis, especially when microscopic stool and/or serological tests are negative. Based on the results, local physicians should consider S. stercoralis as the potential causes of eosinophilia in patients with elevated eosinophilia.

Human Subcutaneous Dirofilariasis due to Dirofilaria (Nochtiella) repens: Clinically Suspected as Cutaneous Fascioliasis

BACKGROUND

The significant increase in the number of human subcutaneous dirofilariasis in recent years, suggests the appearance of a new health problem in the old world with most cases reported from Mediterranean countries. Besides the present case, eleven cases of human subcutaneous dirofilariasis have been detected in Iran, three of which belong to Gilan Province, northern Iran.

METHODS

We present an autochthonous case of subcutaneous Dirofilaria repens infection in a 39-year-old woman from Kouchesfahan district of Gilan Province, manifest as an itching and highly erythmatous subcutaneous tender nodule on her right thigh. The nodule was excised by a dermatologist as a suspected case of cutaneous fascioliasis.

RESULTS

Microscopic examination of the excised nodule revealed the presence of D. repens.

CONCLUSION

Since Gilan Province is the endemic region for human fascioliasis and several cases of cutaneous fascioliasis have been detected in the province during last two decades, we propose the physicians and pathologists to take in to account subcutaneous dirofilariasis as an emergent zoonosis causing dermal and visceral lesions which may sometimes misdiagnose as malignant tumors, and also as differential diagnosis of cutaneous fascioliasis.

Phenotypic analysis of adults of Fasciola hepatica, Fasciola gigantica and intermediate forms from the endemic region of Gilan, Iran

Fascioliasis is an important human and animal disease caused by Fasciola hepatica and Fasciola gigantica. In Iran, the distribution of these two species overlaps in most areas, including the northern human endemic province of Gilan where both fasciolids are simultaneously found in individual cattle and buffaloes. A phenotypic study of fasciolid adult flukes from naturally infected bovines from Gilan was carried out by means of an exhaustive morphometric analysis using traditional microscopic measurements and an allometric model. The Iranian fasciolids were compared to F. hepatica and F. gigantica standard populations, i.e. from geographical areas where both species do not co-exist (Bolivia and Burkina Faso, respectively). Although morphometric values somewhat overlapped, there were clear differences in allometric growth. The allometric function was adjusted to 25 pairs of variables. Results obtained revealed that Iranian F. hepatica-like specimens are larger than the F. hepatica standard and Iranian F. gigantica-like specimens are longer and narrower than the F. gigantica standard, but with smaller body area. Measurements which permit a specific differentiation in allopatric populations (distance between ventral sucker and posterior end of the body; ratio between body length and body width) overlap in the specimens from Gilan, thus proving the presence of intermediate forms. When compared to the standard populations, the different Iranian fasciolid morphs show greater differences in F. gigantica-like specimens than in F. hepatica-like specimens. This study shows that simple, traditional microscopic measurements may be sufficient for the morphometric characterisation of fasciolids, even in areas where intermediate forms are present.

Helminth parasites of the wild boar, Sus scrofa, in Luristan province, western Iran and their public health significance

Seven helminth species were obtained from 12 wild boars (Sus scrofa) during a survey from 2000 to 2001 in Luristan province, western Iran. These species include the cestode larvae Cysticercus tenuicollis (25%), C. cellulosae (8.3%), the nematodes Metastrongylus apri (41.6%), M. pudendotectus (16.6%), M. salmi (8.3%), Trichuris suis (8.3%) and the acanthocephalan Macracanthorhynchus hirudinaceus (41.6%). No trematodes were found. Seven wild boars (58.3%) were identified as having at least one helminth species. A single infection was detected in 16.6% of cases, but a three species infection covered the highest rank (25%). All these helminths have been reported from other areas of Iran including the north, northeast and southwest, but not in Luristan. Among seven helminths identified, at least three species are transmissible to humans. The public health significance of these helminths is discussed.

Sip2p and its partner snf1p kinase affect aging in S. cerevisiae

For a number of organisms, the ability to withstand periods of nutrient deprivation correlates directly with lifespan. However, the underlying molecular mechanisms are poorly understood. We show that deletion of the N-myristoylprotein, Sip2p, reduces resistance to nutrient deprivation and shortens lifespan in Saccharomyces cerevisiae. This reduced lifespan is due to accelerated aging, as defined by loss of silencing from telomeres and mating loci, nucleolar fragmentation, and accumulation of extrachromosomal rDNA. Genetic studies indicate that sip2Delta produces its effect on aging by increasing the activity of Snf1p, a serine/threonine kinase involved in regulating global cellular responses to glucose starvation. Biochemical analyses reveal that as yeast age, hexokinase activity increases as does cellular ATP and NAD(+) content. The change in glucose metabolism represents a new correlate of aging in yeast and occurs to a greater degree, and at earlier generational ages in sip2Delta cells. Sip2p and Snf1p provide new molecular links between the regulation of cellular energy utilization and aging.

Passage through stationary phase advances replicative aging in Saccharomyces cerevisiae

Saccharomyces cerevisiae mother cells undergo an aging program that includes morphologic changes, sterility, redistribution of the Sir transcriptional silencing complex from HM loci and telomeres to the nucleolus, alterations in nucleolar architecture, and accumulation of extrachromosomal ribosomal DNA circles (ERCs). We report here that cells starved for nutrients during prolonged periods in stationary phase show a decrease in generational lifespan when they reenter the cell cycle. This shortened lifespan is not transmitted to progeny cells, indicating that it is not due to irreversible genetic damage. The decrease in the lifespan is accompanied by all of the changes of accelerated aging with the notable exception that ERC accumulation is not augmented compared with generation-matched, nonstarved cells. These results suggest a number of models, including one in which starvation reveals a component of aging that works in parallel with the accumulation of ERCs. Stationary-phase yeast cells may be a useful system for identifying factors that affect aging in other nondividing eukaryotic cells.

A role for Saccharomyces cerevisiae fatty acid activation protein 4 in regulating protein N-myristoylation during entry into stationary phase

Saccharomyces cerevisiae contains four known acyl-CoA synthetases (fatty acid activation proteins, Faaps). Faa1p and Faa4p activate exogenously derived fatty acids. Acyl-CoA metabolism plays a critical role in regulating protein N-myristoylation by the essential enzyme, myristoyl-CoA:protein N-myristoyltransferase (Nmt1p). In this report, we have examined whether Faa1p and Faa4p have distinct roles in affecting protein N-myristoylation as cells transition from growth in rich media to a growth-arrested state during nutrient deprivation (stationary phase). The colony-forming potential of 10 isogenic strains was defined as a function of time spent in stationary phase. These strains contained either a wild type or mutant NMT1 allele, and wild type or null alleles of each FAA. Only the combination of the Nmt mutant (nmt451Dp; reduced affinity for myristoyl-CoA) and loss of Faa4p produced a dramatic loss of colony-forming units (CFU). The progressive millionfold reduction in CFU was associated with a deficiency in protein N-myristoylation that first appeared during logarithmic growth, worsened through the post-diauxic phase, and became extreme in stationary phase. Northern and Western blot analyses plus N-myristoyltransferase assays showed that Nmt is normally present only during the log and diauxic/post-diauxic periods, indicating that N-myristoylproteins present in stationary phase are "inherited" from these earlier phases. Moreover, FAA4 is the only FAA induced during the critical diauxic/early post-diauxic transition. Although substitution of nmt1-451D for NMT1 results in deficiencies in protein N-myristoylation, these deficiencies are modest and limited by compensatory responses that include augmented expression of nmt1-451D and precocious induction of FAA4 in log phase. Loss of Faa4p from nmt1-451D cells severely compromises their capacity to adequately myristoylate Nmt substrates prior to entry into stationary phase since none of the other Faaps are able to functionally compensate for its absence. To identify Nmt1p substrates that may affect maintenance of proliferative potential during stationary phase, we searched the yeast genome for known and putative N-myristoylproteins. Of the 64 genes found, 48 were successfully deleted in NMT1 cells. Removal of any one of the following nine substrates produced a loss of CFU similar to that observed in nmt1-451Dfaa4Delta cells: Arf1p, Arf2p, Sip2p, Van1p, Ptc2p, YBL049W (homology to Snf7p), YJR114W, YKR007W, and YMR077C. These proteins provide opportunities to further define the molecular mechanisms that regulate survival during stationary phase.