Detection of InvA Gene in Non typhoidal salmonellae isolated from food products and clinical cases

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

Detection of non typhoidal salmonella isolated from food products and clinical cases by PCR and conventional methods: a comparative study

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

Selective IgA deficiency among children with recurrent infection

Aim of the study: to evaluate the incidence of IgA deficiency among children suffering from recurrent infections that were suspected to have a primary immunodeficiency disorder from the Assiut Pediatrics University Hospitals, in a hope that this would be the first step to establish a wider epidemiological study including the whole suspected primary immunodeficiency [PID] patients in the country

Methods: This study included 80 cases suffering from recurrent infections that were suspected to have a PID disorder from the Assiut Pediatrics University Hospitals. And eight apparently normal infants and children, age and sex matched that were enrolled as control in the period from July 2011 to May 2012. All children included in the study were subjected to the initial evaluation of immunocompetence which includes a clinical history and physical examination, and investigated for complete blood picture, ESR, Plain chest X-ray when indicated, Screening for serum level of IgA by Enzyme Linked Immuno-sorbent Assay [ELISA] and Radial Immuno-Diffusion [RID]. Patients with proved IgA deficiency were assayed for IgG and IgM

Results: Out of the 80 patients studied, 4 [5%] patients [group I] had laboratory evidence of IgA deficiency; three of them had IgG and IgM within normal level so they were diagnosed as selective IgA deficiency and one [25%] patient had low IgG and normal IgM level so that was diagnosed as common variable immunodeficiency disorder [CVID]. The mean values of age at onset of symptoms, age at diagnosis and the diagnosis lag were 10, 37.25 and 27.25 respectively

The diagnosis delay ranges from 2 months to 7 years. Parents' consanguinity was evident in our study, since 3/4 [75%] patients of group I were the products of consanguineous parents while the ratio was lesser in group II18/76 [23.7%] patients. The current study showed that patients with severe infections had significantly lower IgA levels, younger age and had earlier onset of recurrent infections than patients with less severe infections. There was no specific sex predilection in patients with IgA deficiency. There were no significant differences in both the total leucocytic, absolute lymphocyte and neutrophil counts or hemoglobin level in patients with selective IgA deficiency when compared to patients with normal IgA levels. The duration of infections was significantly longer in patients with selective IgA deficiency [mean: 11.5 days] when compared to patients with normal IgA levels [mean: 9.18 days]

Benign covuIsions with acute gastroenteritis in infants and young children

Seizures in diarrheic children may be due to several etiologies. However seizures may occur in the absence of an obvious cause which is called benign convulsions with gastroenteritis [BCWG]. The aim of this study is to describe the frequency, clinical characters and outcome of benign seizures with gastroenteritis in children attending Assiut University Children Hospital and its possible relationship to some pathogenic organisms. 62 patients with acute gastroenteritis and convulsions were recruited for the study and 35 children with acute gastroenteritis without convulsions were included as a control group They were 34 male and 28 female. The clinical data and electroencephalogram were recorded. Stool specimens from patients and controls were tested for Shigella spp, E. coil 0157. Stool radioimmunoassay for rotavirus was done. Follow up was done after recovery from seizure for one year in pediatric neurology outpatient clinic. The number of patients presented with seizures was 62 patients [34 boys and 28 girls]. Causes of convulsions could be detected in 29[46.8%] of the cases. in 33 cases [53.2%] of all studied patients no obvious causes for convulsions could be detected so they were considered as having BCWG. They were 11 girls and 22 boys. Rotavirus particles were present in 15 [45.5%] of BCWG cases and these cases had younger age, associated with more frequent motions, watery diarrhea, vomiting, thirst, more frequent seizures, earlier onset of seizures to onset of diarrhea and more frequent focal seizures. None of these patients showed recurrence of afebrile seizures later on and their developmental milestones remained normal during the one year follow up period. Benign convulsions with gastroenteritis are frequently associated with rotavirus infection, usually carry excellent prognosis and no need for prolonged antiepileptic therapy