ABSTRACT
We aimed to explore the population dynamics of snail in 3 sites of the White Nile in Sudan. More specifically, we aimed to investigate the annual patterns of snail populations that act as intermediate hosts of schistosomes and monthly snail infection rates and ecological characteristics presumably related to snail populations. We collected snails for 1 year monthly at 3 different shore sites in the vicinity of El Shajara along the White Nile river in Khartoum State, Sudan. In addition, we measured air and water temperatures, water turbidities, vegetation coverages, and water depths and current speeds. Most of the collected snails were Biomphalaria pfeifferi and Bulinus truncatus. The population densities of snails and their infection rates varied across survey sites. The collected snails liberated S. mansoni and S. haematobium cercariae as well as Amphistome and Echinostome cercariae. Infected snails were found during March-June. The ecological characteristics found to be associated with the absence of snails population were: high turbidity, deep water, low vegetation coverage (near absence of vegetation), high water temperature, and high current speed. To our knowledge, this is the first longitudinal study of the snail population and ecological characteristics in the main basin of the White Nile river.
ABSTRACT
We aimed to explore the population dynamics of snail in 3 sites of the White Nile in Sudan. More specifically, we aimed to investigate the annual patterns of snail populations that act as intermediate hosts of schistosomes and monthly snail infection rates and ecological characteristics presumably related to snail populations. We collected snails for 1 year monthly at 3 different shore sites in the vicinity of El Shajara along the White Nile river in Khartoum State, Sudan. In addition, we measured air and water temperatures, water turbidities, vegetation coverages, and water depths and current speeds. Most of the collected snails were Biomphalaria pfeifferi and Bulinus truncatus. The population densities of snails and their infection rates varied across survey sites. The collected snails liberated S. mansoni and S. haematobium cercariae as well as Amphistome and Echinostome cercariae. Infected snails were found during March-June. The ecological characteristics found to be associated with the absence of snails population were: high turbidity, deep water, low vegetation coverage (near absence of vegetation), high water temperature, and high current speed. To our knowledge, this is the first longitudinal study of the snail population and ecological characteristics in the main basin of the White Nile river.
ABSTRACT
A total number of 75 samples including 25 samples each of luncheon, minced frozen beef and sausage were collected from Assiut city [Upper Egypt] and examined bacteriologically for the presence of E. sakazakii and other Enterobacteriaceae genera and species by using the FDA enrichment procedure. In addition, a polymerase chain reaction [PCR] method for the rapid detection of E. sakazakii was adapted by using a set of primers designed from a region of the 16S ribosomal RNA gene. E. sakazakii was detected in 7 [28%] of sausage, but none of the luncheon and minced frozen beef samples were positive for E. sakazakii. Moreover, one false positive isolate was observed with FDA method. In contrast, PCR was highly sensitive and specific to E. sakazakii. E. cloacae were isolated from all samples, while E. agglomerans was detected only in luncheon samples. Also, 43 isolates related to family Enterobacteriaceae could be isolated including Citrobacter freundii, Escherichia coli, Hafnia alvei, Klebsiella pneumoniae, K. oxytoca, Kozaenae, K. planticola and Serratia marcescens. The public health importance of E. sakazakii and suggested control measures were discussed