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

Immune-regulation in chronic hepatitis B virus infected patients

To assess the percentage of regulatory T cells in peripheral blood of chronic hepatits B [CHB] virus infected patients in comparison with that in healthy controls and to evaluate their suppressive activity on gamma-IFN production by T cells. The percentages of CD4+CD25+ and CD4+CD25+Foxp3+ regulatory T [Treg] cells were quantified in the peripheral blood of 59 chronic hepatitis B patients in comparison with that of 32 controls. And to assess Treg suppressive activity, the percentage of CD4+CD25+Foxp3+Tregs secreting interleukin-10 [IL-10] were evaluated together with the percentage of gamma interferon [gamma-IFN] secreting T cells. This study showed that the percentage of CD4+CD25+Tcells was significantly higher in CHB patients in comparison with healthy controls [mean, 11 +/- 1.7 vs. 36 +/- 4.0 P= 0.007]. A weak positive correlation was observed only between the percentage of CD4+CD25+Foxp3+T cells and serum alanine aminotransferase [ALT] levels [r=0.3, P=0.02]. These findings suggest that Tregs are capable of inhibiting the HBV immune response, which could contribute to persistence of HBV infection. Manipulating these regulatory cells represent an important objective in order to develop new anti-microbial immunotherapies, particularly for chronic infections

Prevalence of hepatitic C virus antibodies in chronic liver disease, hepatitis, hepatocellular carcinoma and rheumatoid arthritis

The prevalence of antibodies to hepatitis C virus [Anti-HCV] has been measured using HCV EIA 2 second generation test in 97 patients with chronic liver disease [CLD], hepatitis, hepatocellular carcinoma [HCC] and rheumatoid arthritis [RA]. 45 normal subjects served as control. 46.15% of 39 patients with CLD were positive for anti-HCV, while 64.7% of 17 patients with hepatitis showed positive antibodies to HCV. In HCC, 60% of 15 patients were positive to anti-HCV. Interestingly, 36.4% of 26 patients with RA having positive rheumatoid factor showed positive antibodies to HCV and 11.1% of normal controls were positive to anti-HCV. HBsAg was positive in 20.5% in CLD and in 47% in hepatitis group, while 40% of HCC patients showed positive HBsAg. Low prevalence of HBsAg was found in RA and controls [3.8% and 4.4% respectively]. Our study revealed that HCV has a role in causation of hepatitis, hepatocellular carcinoma and chronic liver disease in our locality. Also, cross-reactivity between antibodies to HCV and other antibodies [rheumatoid factors] may occur

Chlamydia trachomatis and lower respiratory tract infection during infancy in Assiut

The study included 330 cases with lower acute respiratory tract infection [LARI] as well as 100 controls. Their ages ranged from 0 to 12 months [median 5 -months]. The cases were subjected to full clinical and radiological examination. The cases and controls were subjected to laboratory investigations which included determination of antichlamydial antibodies of IgG fraction in the serum, as well as gastric aspirate direct smear for determination of polymorphonuclear leucocytic proportion in relation to other cells and for bacterial and fungal detection. Cultures from gastric aspirate were done for bacterial and fungal isolation. The frequency of chlamydia trachomatis LARI was present in 15.2% of our cases. 29% of our cases with LARI between 1-6 months of age were due to chlamydia infection. The commonest presenting clinical picture of chlamydia LARI was that of bronchiolitis. The frequency of chlamydia bronchiolitis in our cases with LARI was significantly higher in low socio-economic state than the rest of the cases, in rural than urban cases, among artificially fed infants than breast fed ones and during spring and summer than autumn and winter. The frequencies of both acute otitis media and gastroenteritis were significantly higher among chlamydia LARI than other causes of LARI. The prognosis of chlamydia bronchiolitis was good except when associated with other bacterial infection. Gastric aspirate study proved to be as the sensitivity for direct gastric aspirate smear in detecting pathogenic micro-organisms In relation to culture was 84.6% for Candida, 81.3% for single bacterial infection and 69.7% for mixed bacterial infection useful tool in the diagnosis bacterial and fungal LARI in infancy, Chlamydial LARI should be considered in infants below 6 months of age with bronchiolitis

Prevalence of campylobacter spp in infant and children with acute diarrhoea in Assiut

150 infants and children with acute diarrhoea were studied to detect the frequency of Campylobacter jejuni as a cause of diarrhoea in the age group from one month to 8 years old. The stools of the patients and that of 50 controls were cultured for C.jejuni. The organism was isolated in 6.6% of the patients and it was not isolated from controls. It was found that the age up to one year old showing the highest incidence of campylobacter enteritis [70%] Male to Female ratio among the infected group was 3 : 2. It is concluded that C.jejuni was proved to be a significant cause of diarrheal morbidity in infants in Assiut, therefore trails should be made to isolate campylobacter organism from patients suffering from diarrhoea especially infants