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Biomedical subjects

M Refai

Publications and source records attributed to M Refai.

At least 19 recordsLinked to original sources
PubMed2005

Diagnosis of Ornithobacterium rhinotracheale infection in chickens by ELISA.

Specific Ornithobacterium rhinotracheale (ORT) antibodies were determined in serum samples of 24 clinically infected broiler flocks of different ages (1-42 d) and 11 broiler-breeding flocks (at ages between 26-56 w) by ELISA. Two commercially available kits were separately assessed. The BioCheck ELISA kit was used for testing 363 serum samples representing 12 broiler flocks, where 74 samples (20.3 %) were found to be positive and 49 (13.5 %) were suspected. The IDEXX ELISA kit was used for testing 148 serum samples representing different 12 broiler flocks, where 115 samples (77.7 %) were positive. Testing of additional 70 serum samples from 5 broiler- breeder flocks, associated with drop in egg production (1-4.5 %) at different ages, by BioCheck ELISA kit revealed that 78.5 % of the samples were positive and 21.4% were suspected. On the other hand, 338 serum samples representing 6 broiler-breeder flocks, associated also with egg drop, showed a 84.6 % rate of positive reaction, when tested by IDEXX ELISA kit. Positive serology correlated well with the clinical manifestations and isolation of the organism, which substantiates the reliability of the used kits in diagnosis of the disease.

Animals↗
PubMed1989

[Aeromonas hydrophila-related septicemia in the Nile tilapia Oreochromis niloticus].

From diseased wild and cultured Oreochromis niloticus in Lower Egypt, 17 Aeromonas hydrophila isolates were recovered. The mortality was between 10% and 70% in among cultured fish. The course of the disease ran in an acute manner. For cultured fish, the disease outbreaks were found mainly in winter and for the wild Nile fish, mortalities were observed in late spring and summer. Additionally wild fish were affected with ectoparasites. The LD50 values of the isolates ranged between 10(3) and 10(7). Isolates of high virulence were resistant to 1 hr boiling and to the bactericidal effect of fresh normal guinea pig serum. Moreover, they did not agglutinate in acriflavin. Only the virulent isolates could agglutinate tilapia erythrocytes. The above effects were reversed for avirulent isolates while moderately virulent isolates showed no consistency in their reactions. Tube agglutination test using O and WC antisera prepared against 6 isolates versus O and WC antigens of 17 isolates indicated an antigenic heterogenicity of different isolates. While some isolates were identical, 4 antigens out of 17 did not react with any of the sera.

Aeromonas↗
PubMed1989

Studies on the efficiency of absorbed bovine PPD in tuberculin and serological tests.

The passive haemagglutination, enzyme-linked immunosorbent assay and indirect fluorescent antibody tests were applied to study the non-specific reactions in experimentally infected guinea pigs and tuberculin positive bovines. These cross-reactions were greatly decreased after absorption of either sera with avian PPD or bovine PPD antigen with anti-avian PPD serum. The use of both absorbed sera and antigen raised the specificity of PHA and ELISA to 100%. The use of absorbed sera rendered the IFA specific in 95%. The absorption has reduced the sensitivity of ELISA, IFA and PHA by 14, 27 and 29%, respectively.

Animals↗
PubMed1983

Isolation of Cryptococcus neoformans, Candida albicans and other yeasts from pigeon droppings in Egypt.

Two hundred pigeon droppings, unmixed with soil, and collected from various provinces in lower Egypt (Delta) were cultured to detect yeasts. Yeasts were isolated from 53.5% of the samples; Cryptococcus neoformans was recovered from 30 samples and Candida albicans from 19 samples. Other Cryptococcus and Candida species as well as species of Torulopsis and Rhodotorula were also encountered. Aspergillus fumigatus was isolated on 13 occasions.

Animals↗
PubMed1979

Outbreak of botulism in Kenyan nomads.

During disease surveillance in Kenya, a series of deaths were investigated among a group of nomadic Gabra in Marsabit. The cause was identified as botulism (Clostridium botulinum Type A), contracted from sour milk prepared traditionally in a gourd. Reported outbreaks of botulism in Africa would appear to be extremely rare.

Adult↗
PubMed1979

Spectrum of Escherichia coli agglutinins in dam's sera, colostrum and calf's sera in Fresian cows and buffaloes in Egypt.

Sera collected from 18 pregnant buffaloes and Fresian cows during the last two weeks before parturition and from the newborn calves during the first two weeks after birth. All the samples together with the colostral whey of the first three days were examined for the presence of E. coli agglutinins using the tube agglutination and passive hemagglutination tests. The latter test was more sensitive and demonstrated higher titres in all cases, and consequently more O groups. Agglutinins to various E. coli O groups were detected in all samples. It is worthy to note that agglutinins to all E. coli O groups used as antigens were detected in 13 dam's sera, 17 colostrum and in one buffaloe calf. The titres were higher in colostrum than in dam's or calf's sera. The highest titre was 1:640. The O groups 101, 115, 117, and 26 were the most common among Fresian cows whereby the O groups 101 and 115 showed the highest titres. In buffaloes the O groups 101, 115, 8 and 26 were the most common with the O8 having the highest titre.

Agglutination Tests↗