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Volume 6 (4); December 25, 2016


Research Paper

Identification and Characterization of Virulence-Associated Genes from Pathogenic Aeromonas Hydrophila Strains.

Alaa El-Dein Omar A, Moustafa Moustafa E and Mamdouh Zayed M.

World's Vet. J. 6(4): 185-192, 2016; pii: S232245681600025-6

DOI: http://dx.doi.org/10.5455/wvj.20161084

ABSTRACT

Aeromonas hydrophila is a freshwater, Gram-negative, non-spore-forming, rod-shaped, facultatively anaerobic bacterium that exists frequently in aquatic environments producing disease, not only to fish but also to human causing gastroenteritis. The present study aims to isolate, identify and characterize A. hydrophila isolated from Oreochromis niloticus fish in Kafr El-Sheikh governorate, Egypt using selective differential cultural medium (Rimler Shotts agar), morphological and biochemical tests (oxidase, catalase, methyl red, voges proskauer, indole, citrate utilization, gelatin hydrolysis, glucose, triple sugar iron, urease, starch hydrolysis, lactose and trehalose tests). Besides, to search for the presence of the virulence genes in the pathogenic A. hydrophila isolates. In the present study we screened the presence of five virulence-associated genes of A. hydrophila isolated from diseased cultured fish. The detection of virulence factors of A. hydrophila is a key component in determining potential pathogenicity because these factors act multifunctionally and multifactorially. Pathogenesis of A. hydrophila was checked by experimental infection to Oreochromis niloticus fish together with screening of the five virulence genes which are heat-stable enterotoxin (ast), cytotoxic enterotoxin, hemolysin and aerolysin and heat-labile enterotoxin (alt). The obtained results revealed that the five screened virulence genes were positively correlated with A. hydrophila pathogenicity and the presence of virulence genes in pathogenic A. hydrophila strains may help in disease diagnosis, prevention and control.
Key words:
Aeromonas hydrophila, Identification, Characterization, Oreochromis niloticus,
Virulence genes

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Research Paper

Molecular Detection of Streptococcus species Isolated from Cows with Mastitis.

Elsayed Eldesouky I, Allah Abd Elnaby Refae M, Saad Nada H and Ragab Hassb Elnaby G.

World's Vet. J. 6(4): 193-202, 2016; pii: S232245681600026-6

DOI: http://dx.doi.org/10.5455/wvj.20161085

ABSTRACT

Streptococcal mastitis is considered as one of the most common infectious diseases in the dairy cattle, which threatens the dairy industry all over the world. The aim of this study was to determine the prevalence of Streptococcus species in mastitic cows with molecular investigation to detect the presence of some virulence genes of the recovered isolates by PCR. A total of 150 milk samples were collected from dairy cattle with clinical and subclinical mastitis from different areas in El- Gharbia governorate, Egypt. Streptococcus species were isolated with an incidence of 38%. S. agalactiae, S. dysgalactiae, S. uberis, S. pyogenes, S. pneumoniae and S. faecalis were isolated from the milk samples of the examined cows with the percentage of 14.7%, 6%, 9.3%, 4.7%, 1.3% and 2%, respectively. Molecular investigation of virulence associated genes revealed that sip, cfb and bca genes of S. agalactiae were found with the percentage of 77.7%, 88.8% and 33.3%, respectively. The mig gene of S. dysgalactiae was found with an incidence of 77.8%. Of the examined S. uberis isolates, 55.5%, 22.2% and 33.3% were carrying the cfu, oppF and has A genes, respectively. The present study revealed the prevalence of Streptococci and distribution of virulence associated genes among the isolates. The high frequency of virulence genes in the isolates suggests an important role of these virulence genes in the pathogenesis of Streptococci in cattle mastitis.
Key words
: Mastitis, Cows, Streptococci, Virulence genes

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Research Paper

Constraints of Small-Scale Commercial Poultry Farms Analyzed by Garett’s Ranking Technique in and around Debre Markos, Amhara Region, Ethiopia.

Bezabih Yitbarek M, Tamir Mersso B and Mengistu Wosen A.

World Vet. J. 6(4): 203-209, 2016; pii: S232245681600027-6

DOI: http://dx.doi.org/10.5455/wvj.20161086

ABSTRACT

This study was carried out to assess constraints of small scale commercial poultry farms in and around Debre Markos, Amhara region, Ethiopia. Cross sectional study was involved on the assessment of socio demographic characteristics, flock size and constraints faced by employing structured questionnaire for personal interviews. The socio demographic and flock size data were analyzed by χ2 and one way analysis of variance, respectively. The constraints faced were ranked by the respondents and the factors were analyzed by Garrett’s ranking technique. The result showed that sex, age, marital status, religion, occupation, family size, experience years, educational level had statistically significant effect (p< 0.05) on the operation of small scale poultry farms. The mean flock size was 844.3 chicks. Flock size was influenced (P< 0.05) by sex of birds rather than breed. The flock size of female chicks were significantly (P< 0.05) higher than male chicks. Among the constraints; high cost of feed, unavailability of feed and feed ingredients, unavailability of land , lack of market linkage and promotion, high cost of birds for starting business, lack of finance, lack of extension service and lack of training were listed as 1-10 ranks sequentially. Therefore, for successful poultry production and further expansion in the study area; there is a need to improve market linkage and promotion, provide training on poultry husbandry practice, provision of land and fulfilling the financial needs through facilitating credit services are among the imperatives for improving the current status of small scale commercial poultry production
Key words:
Constraints, Flock size, Personal interview, Questionnaire

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