ABSTRACT
Salmonellae are well-known pathogens, highly adaptive and potentially pathogenic for humans and/or animals. Salmonellae are capable of producing serious infections that are often food borne and present as gastroenteritis. The main reservoirs for non-typhoidal Salmonella are animals such as poultry, livestock, pets and reptiles. Salmonella typhi and Salmonella paratyphi colonize only in humans, so they can be acquired only from close contact with a person who has typhoid fever, from a chronic carrier, or from water or food contaminated by human feces. Determine the virulence of the Salmonella serovars obtained from human and animal sources by investigating the presence of chromosomal virulence gene, invA gene as it triggers the internalization of the organism required for invasion of deeper tissue. A total 480 clinical samples: 120 milk samples were collected from faculty of agriculture farm and Markets, 115 eggs were received from different farms and markets, 125 fresh slaughtered chicken and 120 stool sample were collected from Assiut Children University Hospital. Invasion gene operon, invA was detected in all 50 clinical isolates representing multiple serotypes from different sources. Identification of S. enterica and screening of invA gene through PCR based procedures can have major benefit in public health specifically for rapid diagnosis, epidemiological investigations, ideal vaccine, development of treatment, and prophylactic strategies for salmonellosis
ABSTRACT
Non typhoidal Salmonella [NTS] are important food-borne pathogens. Infection with NTS may not lead to fatal disease, hut it may remain localized in the gastrointestinal tract resulting in gastroenteritis or may take a septicemic form that can affect several organs systems causing gastroenteritis, bacteremia and subsequent focal infection. To compare PCR with different conventional methods for identification of non-typhoidal Salmonella species, and to determine the virulence of the Salmonella serovars obtained from human and animal sources by investigating the presence of virulence gene, InvA in the chromosomal DNA. A total of 480 clinical samples were collected. These included: 120 milk, 115 eggs and 125 fresh slaughtered chicken from farms, slaughterhouses, markets, in addition to 120 stool samples from Assiut Children University Hospital. They were subjected to conventional methods for bacteriological and biochemical examination. Conventional cultural examination, API 20 E system and PCR amplification assay of virulence gene invA were investigated in animal and human isolates. By comparing the results of PCR using SI 39 and SI 41 primers and those of culture examination, it was found that PCR had similar results to culture examination. PCR could detect 50 positive cultures of Salmonella species, while API 20 E could detect only 47 of these positive cultures.: PCR amplification assay has the ability to detect a wide range of Salmonella species depending on the design of primers targeted to invasion gene operon [InvA gene] of salmonella. PCR technique may provide a valuable, rapid, specific and sensitive laboratory diagnostic test for detection of salmonella DNA in cultures
ABSTRACT
This study divided 30 adult male albino rats into five groups: Group I [n =10] served as control, groups II and III [n = 5/each group] were exposed to 30ppm of HCHO vapor during six hours/day, five days/week for successive four andeight weeks, respectively, and Groups IV and V [n = 5/each group] were leftunder similar experimental conditions without any exposure for the same time-interval after being exposed to the above mentioned concentration andduration. Histological, histochemical and ultrastructural studies were alldone on lung tissue using both light as well as electron microscopes. Manymorphological alterations were observed in the lung tissue of rats exposed toformaldehyde spray. These changes were more evident with the electronmicroscopic examination and more apparent in animals exposed for prolongedperiods of time. In addition, many of these changes were irreversible aftercessation of exposure to formaldehyde
Subject(s)
Animals, Laboratory , Male , Administration, Inhalation , Lung/pathology , Microscopy, Electron , HistocytochemistryABSTRACT
The effect of chronic exposure to lead on neutrophil phagocytosis and its cytochemistry was studied. This study included 60 male persons varying in age from 20 to 40 years who were divided into two groups. Group I exposed to lead through the environment and according to the blood lead was further subdivided into subgroup Ia including 13 persons with normal blood level and subgroup Ib including 17 persons with a blood lead level higher than normal. Group II included 30 persons exposed to lead through their work as printers and painters. Blood samples were taken for estimation of blood lead level and determining the neutrophil phagocytic capacity. Blood films were spread and fixed for cytochemical demonstration of neutrophil alkaline phosphatase and myeloperoxidase enzymes activity, glycogen content and total lipids content. The results showed a significant inverse correlation between phagocytic capacity and blood lead level when it is higher than normal. Concerning enzymes activity, it showed a significant decrease with increased blood lead level higher than normal and neutrophil glycogen content. On the contrary to glycogen, neutrophil lipids showed a significant direct correlation to the increase in blood lead concentration. It was concluded that lead caused toxic effects to asymptomatic people and workers at levels of exposure that previously were considered harmless. Furthermore, neutrophils may provide a sensitive functional indicator of heavy metal contaminants present in the environment especially lead which is considered nowadays an even more serious health hazard