Génotypes d'échovirus 6 circulant dans la région de Monastir

OBJECTIVE OF THE WORK: Echoviruses of serotype 6 were reported to be endemic in Tunisia and even in other country over the world. they are associated with many outbreak meningitis. The Objective of this study was to genetically characterize echovirus 6 fields isolates. It gives a first approach on the molecular epidemiology of this serotype.

MATERIAL AND METHODS

Phylogenetic analysis of partial sequence in the 3'half of the VP1 region (2874-3529) from 25 strains of echovirus 6.

RESULTS

9 genotypes of echovirus 6 were individualized. Study area was Monastir, a touristic tunisian city. Strains were isolated from wastewater during one year, may correspond to three genotypes.

CONCLUSION

Many genotype could circulating during the same time and in the same region. This phenomena was reported to be atypic in the case of poliovirus.

Microbial characterization during composting of municipal solid waste

This study investigates the prevailing physico-chemical conditions and microbial community; mesophilic bacteria, yeasts and filamentous fungi, bacterial spores, Salmonella and Shigella as well as faecal indicator bacteria: total coliforms, faecal coliforms and faecal Streptococci, present in a compost of municipal solid waste. Investigations were conducted in a semi-industrial pilot plant using a moderate aeration during the composting process. Our results showed that: (i) auto-sterilization induced by relatively high temperatures (60-55 degrees C) caused a significant change in bacterial communities. For instance, Escherichia coli and faecal Streptococci populations decreased, respectively, from 2 x 10(7) to 3.1 x 10(3) and 10(7) to 1.5 x 10(3) cells/g waste dry weight (WDW); yeasts and filamentous fungi decreased from 4.5 x 10(6) to 2.6 x 10(3) cells/g WDW and mesophilic bacteria were reduced from 5.8 x 10(9) to 1.8 x 10(7) bacteria/g WDW. On the other hand, the number of bacterial spores increased at the beginning of the composting process, but after the third week their number decreased notably; (ii) Salmonella disappeared completely from compost by the 25th day as soon as the temperature reached 60 degrees C; and (iii) the bacterial population increased gradually during the cooling phase. While Staphylococci seemed to be the dominant bacteria during the mesophilic phase and at the beginning of the thermophilic phase, bacilli predominated during the remainder of the composting cycle. The appearance of gram-negative rods (opportunistic pathogens) during the cooling phase may represent a serious risk for the sanitary quality of the finished product intended for agronomic reuse. Compost sonication for about 3 min induced the inactivation of delicate bacteria, in particular gram-negatives. By contrast, gram-positive bacteria, especially micrococcus, spores of bacilli, and fungal propagules survived, and reached high concentrations in the compost.