Immunological detection of human and camel cystic echinococcosis using different antigens of hydatid cyst fluid, protoscoleces, and germinal layers.

BACKGROUND AND AIM: Cystic echinococcosis (CE)/hydatidosis is one of the most prevalent neglected zoonotic diseases. It is initially asymptomatic and does not produce any clinical signs until the cyst becomes enlarged, causing localized pressure on internal organs and tissues. Therefore, the detection of Echinococcus granulosus antibodies is highly essential. This study evaluated the antigens of hydatid cyst fluid, protoscoleces, and germinal layers for efficient immunological diagnosis of CE in humans and camels. MATERIALS AND METHODS: Hydatid cyst fluid (FLc), protoscoleces (Psc), and the germinal layer (GLc) antigens were prepared from camel-lung hydatid cysts. In the same way, hydatid cyst fluid (FLh) and protoscoleces (Psh) antigens from human-liver cyst aspirate were produced. The comparative immunodiagnostic efficacy of the prepared antigens was verified using indirect enzyme-linked immunosorbent assay (ELISA), SDS-PAGE, and immunoblotting. RESULTS: ELISA proves that FLc and GLc antigens were higher than FLh and Psh antigens. This shows that binding reactivity in naturally infected human sera, camel sera, and Psc is the most potent, exhibiting 100% sensitivity with 78.26% and 76.47% specificity in camel and human sera, respectively. The CE prevalence using diagnostic Psc was 54.79% and 61.32% in tested human and camel sera, respectively. The electrophoretic profiles of all shared antigens showed similarities at 52, 41, and 22 kDa. Immunoblotting demonstrated common immune-reactive bands in all antigen types at 52 and 41 kDa against positive human and camel sera. CONCLUSION: This immunological study introduces camel hydatid cyst Psc as a potent diagnostic antigen and new immune-reactive fractions of 52 and 41 kDa for diagnosing hydatidosis in humans and camels.

Evaluation of primitive ground water supplies as a risk factor for the development of major waterborne zoonosis in Egyptian children living in rural areas.

BACKGROUND: Endemic waterborne zoonosis frequently occurs in both developed and less developed countries. Thus, bio-surveillance of waterborne zoonosis is a "necessity" for the implementation of effective preventive public health measures in Egyptian rural areas. The primitive individual water supplies created by the rural agriculture population, primarily from ground water, usually maximize the customers' exposure to impurity pathogens via diffused humans and animal excreta or wastages. The current study aimed to evaluate the frequency of zoonotic pathogens within the infiltrated untreated ground water supplies with an assessment of the impact of such biohazards on children living in the studied Egyptian rural areas. METHODS: A total of 796 stool samples were collected from children under 10 years of age from the Abulnomorous (401) and Shabramant (395) villages in Giza, Egypt, and two hundred forty five ground water samples were collected from various individual home water supplies (ground pumps) within two rural Egyptian localities, namely, the Abulnomorous (128) and Shabramant (117) villages. All the samples were examined for the identification of bacterial, fungal and parasitic zoonosis. RESULTS: The isolation of Campylobacter jejuni, Escherichia coli, Salmonella typhi and Shigella spp. was documented in the following frequencies in the water and stool samples of symptomatic children (11.4% and 5.2%), (6.9% and 2.9%), (13.9% and 6.4%) and (4.5% and 2.3%), respectively. Candida albicans and Cryptococcus neoformans were detected in the examined water and morbid stool samples at (7.8% and 2.9%) and (1.6% and 0%), respectively. Additionally, the existence of parasites, including Entamoeba histolytica (5.7% and 4%), Giardia lamblia (9% and 1.7%) and Cryptosporidium oocysts (15.1% and 3.5%), was determined. Regarding Toxoplasma gondii, sporulated oocysts were detected in the ground water (2.9%). The prevalence of diarrhea among the examined children in Abulnomorous was higher (24.7%) than those living in Shabramant (18.7%), which might be attributable to the higher presentation of associated social and environmental risk factors in Abulnomorous than in Shabramant with significant differences P≤0.05. Additionally, the ground water analysis showed that the water samples collected from Abulnomorous (83.0%) were more polluted than those from Shabramant (74.3%). CONCLUSIONS: The results confirm human biohazards through rural individual water supplies and reflect the need for public health education regarding the correct use of drinking ground water only after effective treatment through filtration and/or boiling.

Occurrence of virulent and antibiotic-resistant Shiga toxin-producing Escherichia coli in some food products and human stool in Egypt.

AIM: Shiga toxin-producing Escherichia coli (STEC) represent a severe public health issue worldwide, causing life-threatening diseases in the human gastrointestinal tract. This study aimed to determine the occurrence of virulent and antibiotic-resistant STEC in retail meat and milk products and human stool samples and to characterize the genes encoding for virulence and antibiotic resistance among the identified STEC isolates. MATERIALS AND METHODS: A total of 260 food samples were randomly collected from retail markets in different localities of El Giza Governorate, Egypt. 50 stool specimens were obtained from children that had diarrhea at Embaba Fever Hospital. All collected samples were initially subjected to bacteriological examination and serotyping, and then subsequently, the isolates were exposed to polymerase chain reaction application and sequencing for the identification of the virulence-related genes. Finally, the virulent STEC isolates were tested for antibiotic susceptibility. RESULTS: Serotyping of the 76 biochemically identified isolates showed that 18 were STEC with a predominance of non-O157 (16) while 2 O157:K-serotype was detected only in one food and one human isolate. Molecular identification of the virulence genes illustrated that the minced meat showed the highest prevalence of STEC (8%) as compared to the other food products. In the humans, the O157 was the only serotype that expresses the Shiga toxin-associated gene (eaeA). Antibiotic susceptibility test displayed that 13 of the 17 food and human isolates (76.47%) were resistant to cephalothin (KF30). 9 of the 13 cephalothin-resistant isolates harbor the ß lactamase (blaTEM )-resistant gene. All isolates were sensitive to chloramphenicol, ciprofloxacin, amikacin, and gentamicin. DNA sequencing and phylogenetic analysis of the stx2-positive minced meat isolate revealed a high genetic relatedness with beef minced meat from the USA and Australia. CONCLUSION: This study showed the predominance of non-O157 among the identified isolates. Minced meat showed the highest prevalence of STEC as compared to the other food products, and this work illustrates the necessity to consider the food products as a potential source of the non-O157 STEC serotypes. DNA sequencing and phylogenetic analysis revealed a high genetic relatedness with beef minced meat from the USA and Australia. This highlights the high probability of worldwide spread of such serotypes, signifying the importance of the one world concept.

Prevalence and phylogenetic characterization of Listeria monocytogenes isolated from processed meat marketed in Egypt.

Because of its high case fatality rate, listeriosis locates among the most frequent causes of death due to food-borne illness. In this study, a total of 150 processed meat samples were collected from Giza Governorate, Egypt. Phenotypic and genotypic identification of Listeria monocytogenes was performed using PCR incorporating listeriolysin O virulence gene hlyA followed by DNA sequence analysis. L. monocytogenes was confirmed in 4% of each of beef burger, minced meat, and luncheon samples. Phylogenetic analysis showed that all the six Egyptian isolates have high homology with Colombian isolate (EF030606), except one Egyptian isolate which showed high homology with Indian isolate (EU840690). The public health significance of these pathogens as well as recommended sanitary measures were discussed.

Comparative study between serological and molecular methods for diagnosis of toxoplasmosis in women and small ruminants in Egypt.

Routine serological diagnosis of toxoplasmosis provides high sensitivity, but specificity varies depending on the test used; false-positive results (IgM) have been reported. Blood samples were collected from 88 women (59 pregnant and 29 nonpregnant) and 86 contact animals (62 sheep and 24 goats) at El Fayoum Governorate during the period from October 2005 to December 2006. All collected samples were tested for Toxoplasma gondii infection by serological tests (ELISA IgM & IgG and Sabin-Feldman dye test) and polymerase chain reaction (PCR). Results revealed specific IgG in 45.8% and 41.4%, IgM in 30.5% and 24.2%, and positive Sabin-Feldman dye test in 23.7% and 17.2% in pregnant and nonpregnant women, respectively. Positive PCR products were detected in 32.2% and 27.6% in pregnant and nonpregnant women, respectively. Regarding animals, positive ELISA IgG and PCR were detected in 98.4% and 67.7% of sheep and 41.7% and 25.0% of goats, respectively. It was concluded that serological tests can detect higher rate of toxoplasmosis than PCR, so ELISA combined with the PCR technique is a recommended tool for accurate diagnosis of toxoplasmosis.

Evaluation of snail derived antigens of Fasciola gigantica for serodiagnosis of human fasciolosis.

Serum samples collected from a total number of twenty parasitologically confirmed cases of human fasciolosis were used to evaluate the diagnostic sensitivity and specificity of snail derived antigens; non infected snail (SA), infected snail (ISA), redia (RA), cercaria (CA) and encysted metacercaria (EMCA) of F. gigantica using the enzyme linked immunosorbent assay (ELISA) and enzyme linked immunotransfer blot (EITB). ELISA results showed that the highest level of sensitivity (100%) was with the CA as compared with ISA, RA and EMCA which displayed lower sensitivity levels of 30, 60 and 90%, respectively. All fasciolosis patients were seronegative with SA. Sodium dodecyle sulfate polyacrylamide gel electrophoresis and EITB (with rabbit antiserum raised against F. gigantica somatic antigen) of the snail derived antigens were carried out to characterize their protein profiles and detect cross-reactive polypeptide bands between them. The immunoblot profile of SA displayed cross-reactive bands at 61 and 30 kDa with ISA, RA, CA and EMCA; CA at 61, 34 and 30 kDa with ISA; 96, 61, 34, 30 and 23 kDa with RA and 61, 34, 23 and 19 kDa with EMCA. Cross reactive antigens may be important as possible candidates for vaccine and diagnosis of fasciolosis. Immunoblot of sera from fasciolosis patients using fractionated cercarial antigen on nitrocellulose strips showed that all sera recognized common reactive band at 32.5 kDa molecular weight from cercarial antigen. We suggest that the 32.5 kDa component of Fasciola cercarial antigen may be the most sensitive and specific for the diagnosis of human fasciolosis.

Identification of immunoreactive proteins of Trichinella spiralis adult and adult excretory/secretory (E/S) antigens in sera of human and animals.

Trichinella spiralis adult and adult excretory/secretory antigens were evaluated by ELISA and Western blot techniques for the serological diagnosis of trichinellosis in naturally infected human, swine and experimentally infected rats. Blood samples were collected from 16 symptomatic patients at hospital and 12 asymptomatic individuals working at the swine slaughter-house. Blood samples were also obtained from 75 pigs at two abattoirs and experimentally infected rats (day 25 PI). There was no great difference in the seroprevalence of trichinellosis between symptomatic (56%) and asymptomatic (50%) individuals. ELISA results recorded that 13% of swine was seropositive, while 44% were suspected to be infected with T. spiralis. Immunoblotting profiles of T. spiralis adult antigen against human, swine and rat sera showed common reactive bands at 95.00 and 64.466 KDa (human and swine), and 35.554 KDa (human and rat), while the blotting patterns of adult E/S products against human, swine and rat antibodies recognized two trichinellosis-specific determinants between human and swine (87.619 & 74.136 KDa) and between human and rat (98.00 & 16.535 KDa). It can be suggested that a 45.00, 75.355 & 25.389, and a 57.989 KDa polypeptides of adult antigen were diagnostic for human, swine and rat trichinellosis, respectively. While a 26.00, 24.00, and 46.994 KDa proteins of adult E/S products were diagnostic for human, swine and rat trichinellosis, respectively.