Effect of oxygen injection in a reclaimed wastewater pipeline on the microbiological quality of water.

In this work the influence of oxygen injection on the inactivation of microbiological indicators during reclaimed wastewater transportation was studied. Experiments were carried out in a completely filled gravity pipe (62 km long), at two different periods of the year and with three different oxygen doses (7, 15 and 30 mg L(-1)). Microbiological parameters studied were faecal coliforms, Escherichia coli, enterococci and somatic coliphages. As a consequence of the oxygen injection, a significant inactivation of the microbiological parameters was observed during the aerobic stretch of the pipe. Later, once the oxygen had been consumed, inactivation stopped and even a slight regrowth of the microbial population took place. Inactivations were within the range of 0.6-1.0 log10 units, in most cases. No significant differences between inactivations for the different microbiological parameters were found, except for the somatic coliphages. A relationship between the inactivation degree and oxygen dose and organic matter content was observed. The biofilm played an important role in the inactivation process. The injection of oxygen contributes to improving the microbiological quality of reclaimed wastewater during its transport by pipelines, helping to diminish the subsequent on-site disinfection requirements.

Identification of genotypes of Giardia intestinalis of human isolates in Egypt.

In Egypt, the genotyping study of Giardia intestinalis in human is limited. To determine the prevalence of G. intestinalis, faecal samples were collected from Egypt. Samples were concentrated using density gradient centrifugation. The samples were subjected to PCR and DNA sequence analysis for TPI gene. Prevalence of Giardia infection was 34.6% of 52 examined. DNA sequence showed that the Assemblage B was the most prevalent (80%) genotype, the 15% of the positive samples belonged to Assemblage E, and the 5% of them belonged to Assemblage A. Certainly, both genotypes A and B are highly common in human worldwide. However, up to now, Assemblage E had not been known to be infectious for humans. Therefore, this is the first time that Assemblage E is reported in human. However, further analyses of a second locus are required to confirm this result. The extent to which Giardia-infected cattle in Egypt might pose a risk of human infection is unknown.

Raillietiella morenoi sp. n. (Pentastomida) from Gallotia atlantica (Peters and Doria, 1882) (Lacertidae) in the Canary Islands.

Raillietiella morenoi sp. n., a new cephalobaenid pentastomid found in the lungs of Gallotia atlantica collected in the Canary Islands, is described. The new species belongs to the sharp-tipped posterior-hook type. The annulus number, morphology, and dimensions of copulatory spicules and the dimensions of anterior and posterior hooks separate Raillietiella sp. n. from the other raillietiedid sharp-tipped posterior-hook species of small lizard parasites in Africa. The host character of endemic protected species of G. atlantica in Alegranza Island posed great difficulty in obtaining more parasite materials. However, more studies are required to state the variability of this species and its possible distribution in other species in the Canary Islands, as well as in other Gallotia spp.