Phenotypic and genotypic detection of virulence factors of Staphylococcus aureus isolated from clinical and subclinical mastitis in cattle and water buffaloes from different farms of Sadat City in Egypt

Mohamed Sabry Elsayed, Abd Elrahman Mahmoud El-Bagoury and Mai Abdallah Dawoud

Veterinary World, 8(9): 1051-1058

   doi: 10.14202/vetworld.2015.1051-1058

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Abstract

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Aim: To characterize Staphylococcus aureus from clinical and subclinical mastitis and identify virulence factors.

Materials and Methods: Two hundred and two milk samples were collected, 143 from mastitic cattle and buffaloes 94 and 49, respectively, and 59 from apparently healthy cattle and buffaloes 35 and 24, respectively.

Results: California mastitis test was applied and positive prevalence were 91.48% and 75.51% for cattle and buffalo with clinical mastitis and 37.14% and 45.83% for cattle and buffalo with subclinical mastitis. S. aureus was isolated from clinically mastitic cattle and buffaloes were 39.29% and 50%, respectively. While, from subclinical mastitic cattle and buffaloes were 80% and 72.73%, respectively. Hemolytic activity was assessed for S. aureus isolated from clinically and subclinical mastitic cases with prevalences of 100% and 56.25%, respectively. Thermo nuclease production from clinically and subclinical mastitic cases was 25% and 56.25%, respectively. Simplex polymerase chain reaction (PCR) conducted on S. aureus using 16S rRNA, clumping factor A, Panton valentine leukocidin, coagulase (Coa), alphahemolysin and beta-hemolysin those proved existence in 100%, 46.9%, 65.6%, 100%, 34.4%, and 43.75% of the isolates, respectively. While, multiplex PCR is utilized for detection of enterotoxins and proved that 12.5% was positive for enterotoxine Type D.

Conclusions: It is concluded that simplex and multiplex PCR assays can be used as rapid and sensitive diagnostic tools to detect the presence of S. aureus and characterize its virulence factors that help in detection of severity of infection, distribution and stating preventive and control strategies.

Keywords: clinical and subclinical mastitis, enterotoxins, identification, Staphylococcus aureus, polymerase chain reaction, virulence factors.

Analysis of reproductive traits of broiler rabbits reared in sub-temperate climate of Kodai hills, Tamil Nadu, India

Research (Published online: 08-09-2015)

3.  Analysis of reproductive traits of broiler rabbits reared in sub-temperate climate of Kodai hills, Tamil Nadu, India - S. Rajapandi, N. Ramanathan, R. Pourouchottamane, A. K. Thiruvenkadan, V. Ramesh Saravana Kumar, P. K. Pankaj and A.S. Rajendiran

Veterinary World, 8(9): 1045-1050

   doi: 10.14202/vetworld.2015.1045-1050

Abstract

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Aim: The present study was carried out at Institute Rabbit Farm of Southern Regional Research Centre, Mannavanur, Kodaikanal, Tamil Nadu, India having sub-temperate climate with winter temperature during night hours going below 0°C with an objective of finding the influence of different factors such as breed, year, season and parity on different reproductive traits of broiler rabbits in order to come out with the best strategies for improving the productivity.

Materials and Methods: A total of 1793 records (946 White Giant and 847 Soviet Chinchilla) for weight at mating (WM), weight at kindling (WK), gestation length (GL), litter size at birth (LSB) and litter size at weaning (LSW), litter weight at birth (LWB), and litter weight at weaning (LWW) were collected in the period between 2000 and 2009 and the data was analyzed using general linear model option of SAS 9.2.

Results: The overall mean GL, WM, WK, LSB, LSW, LWB, and LWW were 31.68±0.04 days, 3.65±0.01 kg, 3.84±0.01 kg, 6.91±0.08, 5.49±0.09, 387.62±4.07 g, and 4.66±0.07 kg, respectively. The breed has significantly influenced GL, WK, LSW, LWB, and LWW. The LSB, LSW, LWB, and LWW were 7.05±0.11, 5.76±0.13, 399.55±5.88 g, and 4.87±0.10 kg, respectively in White Giant and corresponding values for Soviet Chinchilla were 6.78±0.11, 5.22±0.12, 375.91±5.64 g, and 4.46±0.09 kg, respectively. The year of kindling had significantly affected all the reproductive traits under study and is varying over different years. The parity significantly influenced the WM, WK, and LWW. The LWW increased from first (4.16±0.21 kg) to second parity (4.86±0.19 kg) and remained in the same range from third parity onward. WM was significantly higher in spring season (3.72±0.02) than the animals in rainy (3.59±0.02) and winter season (3.65±0.02). Better reproductive performance in terms of higher LSB, LSW, LWB, and LWW as observed in the present study might be due to conducive environmental conditions prevailing in the region.

Conclusion: The significant effects of the non-genetic factors like year of kindling on all reproductive traits, season, and parity on some of the traits in rabbit breeds are indications that any future production enhancement strategy must take into consideration the environment by providing additional care, feed supplementation and better shelter management to the rabbits, so that the full genetic potential can be realized.

Keywords: litter traits, parity, rabbit, reproductive performance, season, sub-temperate.

Experimental infection of Aphanomyces invadans and susceptibility in seven species of tropical fish

Research (Published online: 08-09-2015)

2.  Experimental infection of Aphanomyces invadans and susceptibility in seven species of tropical fish - Seyedeh F. Afzali, Hassan Hj. Mohd Daud, Issa Sharifpour, Mohammad Afsharnasab and Shiv Shankar

Veterinary World, 8(9): 1038-1044

   doi: 10.14202/vetworld.2015.1038-1044

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Abstract

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Aim: Epizootic ulcerative syndrome (EUS) causes by aquatic oomycete fungus, Aphanomyces invadans is a dangerous fish disease of a wide range of fresh and brackish water, wild and farmed fish throughout the world. The objective of the present study was to determine the susceptibility of a number of tropical fish species to the EUS and compare the severity of infection between experimental groups.

Materials and Methods: Snakehead, Channa striata (Bloch, 1793); snakeskin gourami, Trichopodus pectoralis (Regan, 1910); koi carp,Cyprinus carpio (Linnaeus, 1758); broadhead catfish, Clarias macrocephalus (Günther, 1864); goldfish, Carassius auratus (Linnaeus, 1758); climbing perch, Anabas testudineus (Bloch, 1792); and Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) were challenged by intramuscular injection using zoospores of Aphanomyces invadans (NJM9701). The infected fish skins and muscles were examined for EUS histopathological characteristics, and the results on the severity of lesions and mortality were analyzed using SPSS program.

Results: All zoospore-injected fish were shown to be susceptible to the EUS infection except Nile tilapia. Although, the general histopathological pattern was similar in the zoospore-injected group, but there were some variation in granulomatous reaction, that is the presence or absence of giant cells, and time of mortality were detected. The result of statistical analysis showed that there was a significant difference between species, (c2=145.11 and p<0.01).

Conclusion: Gourami, koi carp, and catfish were demonstrated to be highly susceptible while goldfish and climbing perch were found to be moderately susceptible to the EUS infection. These findings suggested that the cellular response of fish to mycotic infection and granulomatous reaction varied in different fish species, which could not be an indicator of susceptibility or resistant to the EUS itself, although it was shown that the granulation rate and the level of maturity or solidification (consolidation of granulomas) were higher in resistant fish.

Keywords: Aphanomyces invadans, epizootic ulcerative syndrome, freshwater fish, histopathology.

Genetic analysis of reproductive performance of Frieswal cattle at Military Farm, Ambala

Research (Published online: 08-09-2015)

1.  Genetic analysis of reproductive performance of Frieswal cattle at Military Farm, Ambala - Jagdeep Kumar, Y. P. Singh, Sushil Kumar, Rajbir Singh, Ravinder Kumar and Pradeep Kumar

Veterinary World, 8(9): 1032-1037

   doi: 10.14202/vetworld.2015.1032-1037

Abstract

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Aim: This study was carried out to investigate the genetic analysis of reproductive performance of Frieswal cattle at Military Farm, Ambala.

Materials and Methods: A total number of 3005 lactation records of 1147 Frieswal cows over a period of 15 years extending from 1993 to 2007 were used to study at Military Dairy Farm, Ambala. The study period was divided into 5 period of 3 years each. The average performances of reproduction traits, effect of genetic and non-genetic factors were analyzed, and estimation of genetic and phenotypic parameters of reproduction traits was undertaken.

Results: The age at first calving (AFC) differed significantly across the periods of calving. The AFC was lowest during the third period (1999-2001) and longest in the first period (1993-95). The effect of season and period of calving, lactation order and regression of AFC on dry period, calving interval and service period was highly significant. The effect of sire was non-significant. The heritability estimates were low for almost all the traits under study. The service period had a high genetic correlation with dry period and calving interval. The dry period also found to have a low genetic correlation with calving interval in Frieswal cows. Service period had a high phenotypic correlation with dry period and very high with a calving interval. The phenotypic correlation between the dry period and calving interval was recognized high.

Conclusions: Low heritability estimate for the reproduction traits indicates that there is a very little additive genetic variance in these traits, and individual selection will not be helpful for improving them. Improvement may be brought through better feeding and management of cows by reducing the environmental variability.

Keywords: Frieswal cattle, non-genetics factors, age at first calving, service period.

Effect of glutamine supplementation and replacement of tris-egg yolk based extender with defatted cow milk on spermatozoa quality after equilibration and thawing

Research (Published online: 26-08-2015)

14.  Effect of glutamine supplementation and replacement of tris-egg yolk based extender with defatted cow milk on spermatozoa quality after equilibration and thawing - Vasundhara Dawra, Brijesh Yadav and Sarvajeet Yadav

Veterinary World, 8(8): 1027-1031

   doi: 10.14202/vetworld.2015.1027-1031

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Abstract

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Aim: The present study was designed to evaluate the effect of supplementation of glutamine and replacement of Tris-egg yolk (TE) based buffer with defatted cow milk on the spermatozoa quality after equilibration and thawing.

Materials and Methods: Semen was collected from five Bhadawari bulls biweekly, and a total of 30 ejaculates were taken. The semen ejaculates were pooled and divided into three equal parts. The pooled semen was diluted by TE based extender (control), TE + glutamine (8 mM) (T1) and 50% TE + 50% deffated cow milk + glutamine (8 mM) (T2). At two stages viz. after equilibration and after 12 h of cryopreservation (thawed samples), progressive motility, percent live, and percent acrosomal damage of the spermatozoa was assessed.

Results: Supplementation of glutamine improved (p<0.05) the spermatozoa quality with respect to the progressive motility, percent live and acrosomal damage both post-equilibration and post-thaw. T2 improved (p<0.05) the spermatozoa quality as compared to control, however; it was less (p<0.05) effective as compared T1 both post-equilibration and post-thaw.

Conclusion: From the results of present study it can be concluded that glutamine supplementation was effective in maintaining post-equilibration and post-thaw spermatozoa quality whereas defatted cow milk was not as effective as TE based buffer in the extender in improving the spermatozoa quality.

Keywords: Bhadawari bull, defatted milk, glutamine, post-thaw spermatozoa quality.

Effect of replacing oat fodder with fresh and chopped oak leaves on in vitro rumen fermentation, digestibility and metabolizable energy

Research (Published online: 26-08-2015)

13.  Effect of replacing oat fodder with fresh and chopped oak leaves on in vitro rumen fermentation, digestibility and metabolizable energy - K. Rajkumar, R. Bhar, A. Kannan, R.V. Jadhav, Birbal Singh and G. Mal

Veterinary World, 8(8): 1021-1026

   doi: 10.14202/vetworld.2015.1021-1026

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Abstract

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Aim: A study was conducted to evaluate the effect of replacing oat fodder (OF) with fresh oak leaves (FOL) or chopped oak leaves (COL) on rumen fermentation and digestibility through in vitro gas production technique (IVGPT).

Materials and Methods: Nine different diets were prepared by mixing OF with oak leaves (either FOL or COL) in different ratios (100:0, 75:25, 50:50, 25:75, and 0:100). The rations were evaluated through Hohenheim IVGPT with 200 mg substrate and 30 ml of buffered rumen liquor. All the syringes were incubated at 39°C for 24 h in buffered rumen liquor of cattle. After 24 h, the total gas production was recorded, and the contents were analyzed for in vitro methane production, protozoa no. and ammonia-N.

Results: Chopping (p<0.01) reduced the tannin fractions as well as non-tannin phenol. Increase in levels of oak decreased total gas production, methane, organic matter (OM) digestibility, and metabolizable energy (ME) values. The polyphenol content of the substrate did not show any significant difference on the protozoal count.

Conclusion: In vitro studies revealed that the addition of oak leaves reduced the methane production and ammonia nitrogen levels; however, it also decreased the OM digestibility and ME values linearly as the level of the oak leaves increased in the diet. Chopping was effective only at lower inclusion levels. Further studies, especially in vivo studies, are needed to explore the safe inclusion levels of oak leaves in the diet of ruminants.

Keywords: chopping, in-vitro, methane, oak leaves, oat fodder.

Pathomorphological and microbiological studies in sheep with special emphasis on gastrointestinal tract disorders

Research (Published online: 26-08-2015)

12.  Pathomorphological and microbiological studies in sheep with special emphasis on gastrointestinal tract disorders - Sarvan Kumar, K. K. Jakhar, Vikas Nehra and Madan Pal

Veterinary World, 8(8): 1015-1020

   doi: 10.14202/vetworld.2015.1015-1020

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Abstract

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Aim: The present study was envisaged to elucidate the pathomorphological and microbiological aspects of gastrointestinal tract (GIT) disorders of sheep/lambs.

Materials and Methods: Samples for research were collected from 12 sheep died with a history of GIT disorders which were brought for post-mortem examination to the Department of Veterinary Pathology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, for pathomorphological and microbiological examination.

Results: Gross pathological changes in various organs noticed were abomasitis, congestion and hemorrhages in intestine; necrotic foci on liver surface; enlarged, hard, and indurated mesenteric lymph nodes, hydropericardium, congestion, hemorrhages and consolidation of lungs and congestion and soft kidneys as the major change. On histopathological examination, there were abomasitis with leukocyte infiltration, enteritis with desquamation of mucosal epithelium and goblet cell hyperplasia, lymphadenitis with depletion of lymphocytes in the germinal center of lymphoid follicle, and splenitis with depletion of lymphocytes in the white pulp. In the liver congestion, degenerative changes in hepatocytes including cloudy swelling, fatty changes, congestion in sinusoids, and dilatation of sinusoids leading to atrophy of hepatocytes. Lungs evidenced edema, congestion, emphysema, serous inflammation, thickening of interlobular septa, fibrinous pleuritis, and peribronchiolar lymphoid follicle formation. Heart revealed sarcocystosis, fibrinous pericarditis, and hyalinization of the myocardium. In kidneys, congestion, focal interstitial nephritis, hyaline degeneration, and coagulative necrosis were seen. For microbiological aspects; cultural isolation was done from samples of liver, abomasum, mesenteric lymph nodes, spleen, heart blood, lungs, and kidneys from the carcasses of sheep/lambs. Escherichia coli was the only bacterium isolated during present studies. E. coliisolates from different tissues of carcasses of sheep/lambs were subjected to in-vitro drug sensitivity testing. Ciprofloxacin, cefixime, polymyxin B, amoxicillin + sulbactam, and amoxicillin + clavulanic acid were the most sensitive drugs followed by amikacin, ofloxacin, ampicillin, co-trimoxazole, and amoxicillin.

Conclusions: From the present study, it is reasonable to conclude that the major etiopathological cause of GIT disorders in sheep was E. coli infection, which causes a pathomorphological effect on various cadaver organs viz. abomasum, intestine, liver, mesenteric lymph nodes, lungs, spleen, kidneys, and heart followed by parasitic infection of Haemonchus contortus.

Keywords: gastrointestinal tract disorders, in-vitro chemotherapeutic sensitivity, microbiology, pathomorphology, sheep.

Histology and scanning electron microscopy of the tubal tonsil of goats

Research (Published online: 25-08-2015)

11.  Histology and scanning electron microscopy of the tubal tonsil of goats - V. R. Indu, K. M. Lucy, J. J. Chungath, N. Ashok and S. Maya

Veterinary World, 8(8): 1011-1014

   doi: 10.14202/vetworld.2015.1011-1014

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Abstract

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Aim: To observe the light and scanning electron microscopy (SEM) of the caprine tubal tonsil.

Materials and Methods: The study was conducted on six crossbred male goats of 6 months of age. From the median sections of the head, tissue pieces from the nasopharynx around the auditory tube were collected and fixed for histology and SEM.

Results: Tonsillar lymphoid tissue was located in the nasopharynx ventral to the auditory tube opening in the lateral wall of the pharynx. The height of the surface epithelium of the tubal tonsil measured 80.17±1.08 μm and was a pseudostratified ciliated columnar type with basal, supporting, and goblet cells. Above the dome of lymphoid nodules, the epithelium was modified into a follicle associated epithelium (FAE), also called lympho-epithelium or reticular epithelium and was characterized by the absence of goblet cells and cilia, reduced number of cell layers, and a large number of lymphoid cells due to interrupted basement membrane. The height of FAE was smaller than that of the surface epithelium and measured 34.33±0.92 μm. The surface of tubal tonsil showed folds and invaginations, which formed crypts. The lamina propria-submucosa underneath the epithelium was formed by the meshwork of reticular and, thin and loose collagen fibers with dome-like accumulation of lymphoid nodules. In the secondary lymphoid nodules, a corona, parafollicular area, and interfnodular area were observed. The average number of lymphoid nodules counted per field under low power magnification of microscope was 1.17±0.17, and the internodular distance was 34.00±4.37 μm. The mean diameter of lymphoid nodules was 566.67±11.45 μm and the lymphocyte count per nodule was 14741.67±174.36. The number of plasma cells counted per field under low power was 44.38±2.90 below the surface epithelium. The tubal tonsil was not encapsulated. In SEM, the surface epithelium of the tubal tonsils presented ciliated cells, microvillus (MV) cells, and goblet cells. The region of FAE possessed Type-I and Type-II MV cells and microfold (M) cells in between.

Conclusion: It was concluded that the tubal tonsils were well developed in goats, which might serve as a means of protection against the spread of infection to the middle ear cavity.

Keywords: goats, histology, tubal tonsil.

Evaluation of recombinant outer membrane protein C based indirect enzyme-linked immunoassay for the detection of Salmonellaantibodies in poultry

Research (Published online: 25-08-2015)

10.  Evaluation of recombinant outer membrane protein C based indirect enzyme-linked immunoassay for the detection of Salmonellaantibodies in poultry - Jinu Manoj, Rajesh K. Agarwal, Blessa Sailo, Mudasir Ahmed Wani and Manoj Kumar Singh

Veterinary World, 8(8): 1006-1010

   doi: 10.14202/vetworld.2015.1006-1010

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Abstract

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Aim: To evaluate the efficacy of recombinant outer membrane proteinC (rOmpC) based enzyme-linked immunoassay (ELISA) for the diagnosis of salmonellosis in poultry.

Materials and Methods: Three antigens were prepared, and the indirect ELISA was standardized using the antigens and the antiserum raised in chicken against Omp and rOmpC. Sera were collected from a total of 255 apparently healthy field chickens and screened for the presence of Salmonella antibodies by this ELISA.

Results: The sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of Omp revealed major polypeptides at 36, 42 and 52 kDa, and the rOmpC was evident by a single protein band of 43 kDa. The Omp and rOmpC antigen revealed an optimum concentration of 78 and 156 ng, respectively, in the assay, while the whole cell antigen gave an optimum reaction at a concentration of 106organisms/ml. The test was found to be specific as it did not react with any of the antisera of seven other organisms. The developed ELISA detected Salmonella antibodies from 22 (8.62%) samples with rOmpC antigen, while 24 (9.41%) samples gave a positive reaction with both Omp and whole cell antigens.

Conclusion: We suggest rOmpC based indirect ELISA as a suitable screening tool for serological monitoring of poultry flocks.

Keywords: antibody, antigen, outer membrane protein, poultry, Salmonella.

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