Salmonellosis in layer chickens: pathological features and isolation of bacteria from ovaries and inner content of laid eggs

We isolated and identified Salmonella organisms from ovaries of dead layer birds and from inner content of laid eggs of different poultry farms. The thirty eight ovarian swabs for bacteriology, visceral organs (liver, lung, spleen, egg follicles and intestine) of 38 dead birds for pathological study from 15 layer farms and 45 laid eggs (5 eggs/farm) from reported 9 Salmonella infected farms constituted samples of the study. Samples were subjected to isolation and identification of the causal agent followed by gross and histopathological study of the affected visceral organs. Seventeen of 38 ovarian swabs (44.7%) were Salmonella positive. The percentage of Salmonella Gallinarum, Salmonella Pullorum and paratyphoid causing Salmonella were 70.6%, 17.6% & 11.8%, respectively. About 53% livers of Salmonella affected birds were enlarged, congested, friable and bronze coloured with white necrotic foci. About 59% egg follicles were congested, hemorrhagic, discoloured with stalk formation and 70.6% intestines showed hemorrhagic to catarrhal enteritis. At histopathology, 76.5% livers were congested with formation of multifocal nodules and 82.4% egg follicles were congested with huge leukocytic infiltration. Infiltration of heterophils in intestinal mucosa was found in 47.1% cases. Four Salmonella isolates were found from 9 laid egg samples (5 eggs content comprised as 1 sample) and isolation rate was 44.4% reporting transovarian transmission in poultry Salmonellosis. DOI: http://dx.doi.org/10.3329/jbau.v10i1.12095 J. Bangladesh Agril. Univ. 10(1): 61–67, 2012

Distribution of yolk polypeptides in the follicle cells during the differentiation of the follicular epithelium in Sarcophaga bullata egg follicles

In S. bullata, the ovaries contribute to the synthesis of yolk polypeptides. A specific antiserum for yolk polypeptides was used to visualize the presence of yolk polypeptides in the follicle cells during their differentiation. After vitellogenesis has started, all follicle cells contain yolk polypeptides. The squamous follicle cells covering the nurse cells and the border cells lose yolk polypeptides before mid-vitellogenesis, whereas the follicle cells over the oocyte contain yolk polypeptides until after late vitellogenesis. All follicle cells are immunonegative afterwards. In vitro translation of poly(A)+ RNA demonstrated that the presence of yolk polypeptide mRNA correlates well with follicle cell immunopositivity for yolk polypeptides. This suggests that the follicle cells synthesize the ovarian yolk polypeptides. Differences in cellular and nuclear morphology, total and poly(A)+ RNA synthesis and the rate of yolk polypeptide synthesis were shown to be correlated with the presence or absence of yolk polypeptides in the differentiating follicular epithelium. The possible relationship between these different aspects of follicle cell differentiation, follicle cell polyploidy and the extracellular current pattern around follicles are discussed.

Feeding and associated behaviour of the adult cabbage root fly Erioischia brassicae (Bch.) (Dipt, Anthomyiidae) under laboratory conditions

Adults of the cabbage root fly (Erioischia brassicae (Bch.)) reared in culture were inactive on the day of emergence but they fed on carbohydrate (sucrose) and protein (Yeastrel) on day 2. Without food, the egg follicles increased to approximately one-third of their maximum size and were then resorbed. When food was available, females ingested sucrose on days 2 and 3 to mature the first batch of eggs, without any stimulus from mating. Without either a mate or a suitable oviposition site, females retained most of their eggs. Females obtained sufficient food for egg maturation by day 4, when their egg follicles were 400 μm, approximately half the size of the mature eggs. Only females mating on day 4 laid eggs at the expected time 6±0·3 days after emergence. With a suitable oviposition site, these females laid 299±48 eggs, approximately twice as many as any other females, and ten times as many viable eggs. When males were not allowed to mate, peak ingestion was delayed from days 8–12 to days 14–18. Mated females provided with an oviposition site laid most eggs on days 5 and 6 and fed again on day 7. This second peak of feeding was delayed until day 9 when mated females were denied, or unmated females were given, an oviposition site. Similar volumes of sucrose were imbibed by females whether they laid or retained their eggs. Females denied both a mate and a suitable oviposition site laid less than 1% of the expected eggs.

Seroprevalence and pathology of naturally infected Salmonellosis in poultry with isolation and identification of causal agents

The present study was conducted to determine the seroprevalence of Salmonella infections in poultry. This study covered cultural prevalence with isolation and identification of the causal agent and pathological lesions in different organs produced by Salmonella in layer farms of Mymensingh district during July-December 2007. The materials were blood samples, liver and cloacal swabs from live and dead birds. The used methods were whole blood agglutination test by commercially available Salmonella antigen kit, culture in different media, Gram's staining, motility test, basic 5 sugar fermentation test and histopathology. The overall seroprevalence was 45.9% in live bird and the rate of seroprevalence decreased with advancement of age of birds. The cultural prevalence in seropositive group was 71% and in seronegative group was 59%. In dead bird, the cultural prevalence in liver was 64% and from cloaca 57%. A total 160 isolates were characterized, among them 64.2% were Salmonella Pullorum, 22.3% were Salmonella Gallinarum and 13.5% were Paratyphoid group of Salmonellae. Pathologically friable, bronze color liver with focal necrosis, various grades of enteritis, and hemorrhagic and congested egg follicles with stalk formation were found. Microscopically, focal necrosis and degeneration with leukocytic infiltration in liver, inflammatory cells in the mucosa and submucosa of intestine were found. In egg follicles, congestion and hemorrhages with leukocytic infiltration were found. The isolated Salmonella organisms may be used for further research such as serotyping, vaccine production and antibiotic sensitivity test. Keywords: Salmonellosis; Seroprevalence; Agglutination test; Histopathology; Poultry DOI: 10.3329/jbau.v6i2.4830 J. Bangladesh Agril. Univ. 6(2): 327-334, 2008

Prevalence of Salmonella infection in naturally infected layer of birds in Bangladesh

The seroprevalence, cultural prevalence and pathological study of Salmonella infections in chickens of selected layer farms of Birgonj Upazila (Sub-district), Dinajpur were determined. A total of 175 blood samples were tested randomly by locally prepared Salmonella coloured antigen for seroprevalence study. Out of 96 cloacal swabs, 80 samples from live birds (36 from seropositive and 44 from seronegative) and 16 samples from dead birds were collected to determine the cultural prevalence of Salmonella organisms. Postmortem examination was done in 16 dead birds. Using whole blood agglutination test (WBA) with locally prepared Salmonella Pullorum coloured antigen, the overall seropositive prevalence was 46.2%. The seroprevalence decreased with age of birds. The cultural prevalence in seropositive was 33.3% and in seronegative 22.7%. In dead birds, the cultural prevalence using cloacal swab was 25%. A total 26 Salmonella were isolated, 27% Salmonella Pullorum, 58% Salmonella Gallinarum and 15% paratyphoid group of Salmonella. Isolation rate of Salmonella from cloacal swabs was significantly higher in seropositive than seronegative group. Grossly, the livers were friable, with bronze discolouration and necrotic foci, there was severe congestion in the lung, congested haemorrhagic egg follicles with stalk formation and enlarged discoloured spleen. Microscopically, there was focal necrosis and degeneration with leukocytic infiltration in liver, congestion and pneumonic lesions in the lung and various degrees of catarrhal to haemorrhagic enteritis in the intestine. In the egg follicles, congestion and haemorrhage with leukocytic infiltration and enlarged spleen with white necrotic foci were detected. In future, isolated Salmonella organisms may be used for vaccine production, serotyping and antibiotic sensitivity test. DOI: http://dx.doi.org/10.3329/bvet.v28i1.8809 Bangl. vet. 2011. Vol. 28, No. 1, 8-18