Serum Plate Agglutination Test Research Articles

Seroprevalence and pathology of Mycoplasma gallisepticum infection in layer birds

Avian mycoplasmosis, caused by Mycoplasma gallisepticum (MG), imposes a significant threat to the poultry industry in Bangladesh, leading to considerable economic losses. This study aimed to determine the seroprevalence of MG and characterize the associated pathology in MG-infected layer birds from different geographical areas within the Nilphamari district. Our hypothesis suggested that the seroprevalence of MG infection in layer birds may vary based on geographical location within the Nilphamari district of Bangladesh, with higher prevalence expected in areas with colder temperatures, such as during the winter season, and in densely populated poultry farming regions. For the serum plate agglutination test, 400 random blood samples were collected, while tissue samples from suspected layer birds with respiratory distress were obtained from 40 commercial layer farms for histopathological analysis. The serum plate agglutination test revealed an overall seroprevalence of MG of 64.25%, with the highest prevalence occurring during the winter season (70%), particularly among layer birds aged 20-40 weeks. Moreover, the seroprevalence of MG was significantly higher in Kishoregonj upazila (68%) compared to Nilphamari sadar (62%). Gross examination of MG-infected layer birds unveiled characteristic features such as tracheal hemorrhages and mucous accumulation, pulmonary edema and hemorrhages, and air sac cloudiness. Histopathological observations included tracheal mucosal sloughing and increased goblet cell numbers, as well as lung edema, hemorrhages, and tissue destruction, alongside significant reactive cell infiltration and exudation in the air sacs. By shedding light on the current MG infection status in layer chickens within the Nilphamari district, this study provides valuable insights to aid poultry industry stakeholders in formulating preventive strategies and enhancing the overall health and welfare of poultry flocks. Asian J. Med. Biol. Res. 2024, 10(1), 58-66

Seroprevalence of Salmonella spp. infection in different types of poultry and biosecurity measures associated with Salmonellosis

Salmonella spp. infection is considered a crucial trouble of the poultry industry in Bangladesh. Hence, this study was aimed to estimate the seroprevalence of Salmonella spp. in poultry along with biosecurity practices that are associated with this Salmonella spp. infection. The study was conducted during the period from January to September, 2021 in Mymensingh and Gazipur district of Bangladesh. A total of 314 samples were considered to determine the seroprevalence. Seroprevalence was determined by performing the rapid serum plate agglutination test. The result revealed that the overall Salmonella spp. seroprevalence was 47.77% in the study area. The higher seroprevalence was in Mymensingh (51.59%) than Gazipur (45.21%) without significant (p>0.05) difference. The highest seroprevalence was in broiler (51.33%) where in layer and sonali was 32.67% and 16% respectively. Seroprevalence was significantly (p<0.05) higher in summer for layer (56.45%), broiler (60.64%) and sonali (51.22%) than the winter seasons. In layer farms, the flock size of >2000 to <2500 had significantly (p<0.05) higher (71.43%) seroprevalence. In broiler farms, 15 to 30 days old birds had significantly (p<0.01) higher (77.05%) seroprevalence than other age. Among the different categorical level of biosecurity practices, the poultry farms that used surface water (OR=0.182, 95% CI=0.106-0.314); disinfectant regularly (OR=0.296, 95% CI=0.171-0.511); having density of 8-10 birds/meter2 (OR=0.379, 95% CI=0.219-0.654); cleaned waterer and feeder regularly (OR=0.503, 95% CI=0.294-0.862); and having visitor restriction (OR=0.375, 95% CI=0.219-0.643) showed lower tendency (p<0.001) to seroprevalence. In brief, Strict farm hygienic practice and biosecurity measures are significantly linked to decrease the Salmonella spp. seroprevalence.

Seroprevalence, Identification, and Pathology of Salmonellosis in Selected Poultry Farms at Barishal District of Bangladesh

Salmonellosis is a critical challenge in commercial poultry farming. This study aimed to calculate seroprevalence, identify Salmonella spp., and its pathological investigation from January to December 2019. One hundred fifty (150) serum samples and fifty (50) cloacal swabs from apparently ill and healthy birds were collected in this study. Seroprevalence was observed by serum plate agglutination (SPA) tests. The tentative diagnosis of salmonellosis was made based on history, clinical signs and bacteriological studies. Salmonella spp. was further confirmed using an automated microbiological method (VITEK®2). Post mortem examination was done in apparently sick birds, and gross and microscopic pathological lesions were investigated and recorded in a datasheet. The overall seroprevalence of salmonellosis was 42.67% in commercial chickens. Age wise prevalence of avian salmonellosis showed significantly highest infection rate in adult layers (≥ 45 days old) 65.31%, then 40.74%up to 45 days. In case of broiler, the prevalence rate in 0-10 days, 11-20 days, and 21-35 days were 13.63%, 44.12%, and 16.67%, respectively. Seasonal influence showed significantly highest proportionate prevalence of salmonellosis during summer 66.15%in comparison to winter 25.00% and rainy 24.44% seasons respectively. In bacteriological study, 12 samples were positive for Salmonellae among 50 cloacal samples. Out of 12 positive samples 5 samples were selected for the automated microbiology system VITEK® 2, and only two samples were confirmed as Salmonella gallinarum. Gross pathology of representative organs revealed bronze-colored enlarged liver, hemorrhages in the spleen and lungs, and hemorrhages in the ovary with stalk development. Microscopically, multifocal nodule formation and infiltration of inflammatory cells in the liver parenchyma and marked congestion with inflammatory cells in the spleen, hemorrhage and congestion in the lungs and intestine.

Seroepidemiological Analysis of Brucellosis in Goat and Household Animal Keepers of District Swat

Brucellosis is a chronic bacterial infection that can infect a variety of animal species and humans. The disease has been studied in many parts of the world including Pakistan, however, caprine brucellosis has not been well reported and very few studies are published at the national level. This study was conducted to investigate the seroprevalence of brucellosis in goat and household animal keepers of district Swat Pakistan. A total of 235 blood samples were collected from goats and 53 blood samples from animal keepers following the standard protocols. All the serum samples were analyzed by the Rose Bengal Plate Test (RBPT) and Serum Plate Agglutination Test (SPAT) for the detection of anti-brucella antibodies. All the goat serum samples were also subjected to Enzyme-Linked Immunosorbent Assay (ELISA) for the comparison of two commonly used serological tests. The overall seroprevalence of brucellosis in the goat population of district Swat was recorded as 13.61% and 16.17% while in the human population it was recorded as 3.77% and 5.66% by RBPT and SPAT respectively. A significant correlation was found between abortion and seropositivity of brucellosis in goats with a p˂0.05. By comparing RBPT and SPAT considering ELISA as a gold standard, the SPAT test showed a greater sensitivity than RBPT recorded as 82% and 80 % by SPAT and RBPT respectively. It is concluded that brucellosis is prevailing in both the goat as well as in animal keepers of district Swat. Screening of animals and awareness of the general population through mass media is recommended.

Seroprevalence of Mycoplasma gallisepticum infection in layer chickens of Bangladesh

Mycoplasma gallisepticum causes major health hazards in poultry birds in Bangladesh which results in huge economic losses every year. This study was carried out to estimate and analyze the prevalence of Mycoplasma gallisepticum (MG) infection in commercial layer chickens at Kishoreganj district of Bangladesh during the period from November 2018 to October 2019. A total of 505 serum samples from 94 commercial layer farms of Kishoreganj Sadar Upazila and Pakundia Upazila of Kishoreganj district were collected. Serum plate agglutination (SPA) was performed to detect the antibody against MG. Prevalence was found 73% in the Kishoreganj district by SPA test. MG was significantly (P<0.01) more prevalent in Pakundia Upazila 82% than Kishoreganj Sadar Upazila 61.11%. In case of season, winter season had significantly higher (X^2=30.94, p=0.000) prevalence of MG infection. In relation to age, seroprevalence of MG infection was highest 78% in birds of 65 weeks’ age and lowest 71% in 6-25 weeks’ age birds. Any significant (P>0.05) association was not found between flock size and seroprevalence of MG. Seroprevalence was highest in flock containing above 2600 birds. MG infection is prevalent in the chicken population of Kishoreganj district, Bangladesh. Measures should be taken for successful prevention and control of this disease in Bangladesh.

Sero Survey of Salmonellosis in Broiler at Sylhet City of Bangladesh

The present study was undertaken to know the seroprevalence of Salmonella infection in broiler chickens in the Sylhet area, Northeastern Bangladesh. This investigation was conducted from 10 December 2018 through 20 January 2019. A total of 250 sera samples were collected from five live bird market of the Sylhet metropolitan area and subjected to rapid serum plate agglutination (RSPA) test using commercial salmonella antigen (LilliTest) to detect the presence of antibodies against salmonella infection. The overall prevalence of salmonella infection in the five live bird market visited in this investigation were recorded as 30.6%. The highest prevalence (46%) was reported from the samples of Lama bazar. And the lowest prevalence (20%) was reported from the samples of Mirabazar. It has been found that Salmonella infections are still significant disease problems in broiler farms in the Sylhet region. Keywords: Prevalence, Mirabajar, Antigen, Agglutination, Infection DOI: 10.7176/JNSR/12-20-01 Publication date: October 31 st 2021

Seroprevalence and pathological studies of Salmonella infection in commercial white layer birds

The present study was conducted to determine the seroprevalence and pathology of Salmonella infection in white commercial layer birds of District Faisalabad during June 2018 and June 2020. The current study aimed to determine the isolation, identification of Salmonella gallinarum (S. gallinarum), its cultural prevalence, antimicrobial resistance, molecular characterization, and pathological lesions produced in different organs of commercial layer birds. Initial screening of poultry flocks was done through serum plate agglutination test followed by culturing in different media, motility test, molecular confirmation, and histopathology. Based on the serum plate agglutination test, seroprevalence in the commercial white layer in dead and live flocks was 40.09%. The cultural prevalence of Salmonella in the seropositive group was 75.36% and in the seronegative was 31.84%. Cultural prevalence in the liver of dead birds was 62.06%, in spleen 58.62%, and in cloacal swabs was 67.24%. A total of 178 isolates were characterized through cultural characteristic and motility tests, among them 63.48% isolates were S. gallinarum, and 36.51% isolates were S. pullorum. The antibiogram study revealed that all the tested isolates were resistant to amoxicillin, gentamycin, kanamycin, doxycyclin, and tetracyclin. While tested isolates were sensitive to ciprofloxacin against S. gallinarum. Pathologically liver was friable, showing bonze discoloration with focal necrosis, enteritis of various grades, mottled white spleen, and enlarged kidneys were found. Microscopically, leukocytic infiltration with focal necrosis and degeneration, in mucosa and submucosa of intestinal inflammatory cells were observed. In conclusion, the seroprevalence, antibiogram, and molecular characterization of Salmonella help to control the disease in a better way through bacterin production of local isolates.

Investigation on Seroprevalence of Mycoplasma Gallisepticum Infection in Commercial Layer Farms in Rajshahi District Using Rapid Serum Plate Agglutination Test

Mycoplasma gallisepticum (MG) infection is very common in birds that cause respiratory infections in chickens, turkeys, and other avian species. It has brought about a considerable amount of financial losses to the poultry sector in Bangladesh. We conducted a study on the Seroprevalence of MG infection in two different geographical areas of Bangladesh under Rajshahi district, namely Paba and Bagmaraupazila. 800 sera samples were collected and tested with Rapid Serum Plate Agglutination Test (RSA) to identify the MG antibodies using commercial Mycoplasma gallisepticum antigen. The gross Seroprevalence of MG infection was 59.25% in the study area. The maximum rate (68.80%) of infection was found in the winter season, followed by the summer season (49.36%). The result further revealed that the condition was higher (69.01%) in larger-sized flocks than in small (53.63%). We noticed that younger birds having 10-20 weeks of age are more prone to be affected with avian mycoplamosis with an infection rate of 72% compared to their adult counterpart of 71+ weeks with 52% morbidity. Our study revealed that Mycoplasma gallisepticum infection is prevalent in Paba and Bagmaraupazila in Rajshahi. The farms should take strict bio-security measures to mitigate this infection in the mentioned areas. Proper medications for the affected birds and timely prophylactic measures for the healthy ones could be practical and preventive strategies against avian mycoplasmosis. Amid limitations, we conducted our experiments, and thus further research is warranted to substantially assess and validates our observations.

English

Mycoplasma gallisepticum (MG) is a pathogen of concern for poultry. Present study was conducted to determine the biological characteristics of a field isolate of MG, recovered from an MG-affected flock. This isolation was made through conventional method of MG cultivation, using modified Frey’s media after confirming the isolate by polymerase chain reaction (PCR). A total of 48 birds were segregated into experimental group (32 birds) and the control group (16 birds). To appraise primary site of infection, MG broth propagated culture containing 1x106 CFU/ml was inoculated intratracheally to each bird in the experimental group, whereas the control group was sham inoculated by uninoculated broth. The clinical signs and symptoms were recorded daily from day 1 to 21 post-infection (p.i.). Seroconversion monitoring was carried out, at day 5, 10, 15, 20 p.i. by Serum Plate Agglutination test (SPA) and Enzyme Linked Immunosorbent Assay (ELISA). To determine the dissemination pattern of MG, birds were sacrificed according to plan, swabbed from various organs and subjected to MG-specific PCR. Tracheal lesions and air sac lesions were scored after necropsy. Clinically, mild signs of respiratory discomfort were observed on day 5 p.i., which intensified on day 9 to 21 p.i. in the experimental group. PCR of tracheal swab samples was positive from day 7 to 21 p.i., and the swabs collected from lungs were positive for MG from day 9 to 21 p.i. The study concluded that, MG isolate from field showed limited dissemination pattern and is restricted to respiratory tract.

Development of an effective vaccination protocol to produce Salmonella-free layer fock

Salmonella infections are of prime importance in the layer chicken industry and pose a significant public health threat. Production of export quality poultry products requires Salmonella-free certification. We developed and applied a vaccination schedule based on a commercial live attenuated Salmonella enterica serovar Gallinarum biovar Gallinarum (S. Gallinarum) vaccine in a layer flock. A flock of 1000 ISA Brown chickens has vaccinated with a lyophilized fowl typhoid live vaccine at definite time intervals. Isolation of Salmonella spp. in cloacal swabs and detection of serum antibody responses were performed using serum plate agglutination (SPA) test and ELISA. At the time of vaccination (16 weeks (w) of age), 50% of the tested birds carried Salmonella spp. in feces. Following booster immunization at 18 w, 21 w, and then every 12 weeks interval, the shedding of Salmonella decreased significantly over time with 40% at 21 w, 10% at 30 w, and 5% each at 42 and 54 w, and no shedding was detected at 66 and 78 w. Biochemical analysis of 32 Salmonella isolates revealed 15.6% (n=5) Salmonella enterica serovar Gallinarum biovar Pullorum (S. Pullorum), 37.5% (n=12) Salmonella Gallinarum, and 46.9% (n=15) paratyphoid causing Salmonella. Of note, the Salmonella spp. detected after 21 w of age belonged to the paratyphoid group. The decreased shedding of bacteria paralleled with increased antibody responses. The antibody level at vaccination (20% positive rate at 16 w) increased over time with a 50% positive rate at 18 w, 80% at 42 w, 90% at 54 w, and 100% at 66 w and 78 w by serum plate agglutination (SPA) test. Similarly, the serum antibody levels of chickens were also measured using ELISA and were similar to the SPA test. In conclusion, the vaccine schedule developed in this study confirmed a high seroconversion and prevented Salmonella shedding in feces. Therefore, a three-month interval vaccination protocol from the pre-laying stage to the last stage of laying is recommended to prevent Salmonella infections in laying flocks.

Development of a Promising Agglutination Based Diagnostic Kit for Detection of Mycoplasma gallisepticum (MG) Infection in Chickens

Background: Mycoplasma gallisepticum (MG) an important respiratory tract pathogen is responsible for morbidity in poultry flocks. It affects poultry birds of various age groups of layers as well as broiler, especially in younger ones. The diagnosis of such ailment is highly sought for adopting suitable control measures. In this regard, classical procedure of culture and isolation of mycoplasmas is cumbersome, tedious and time-taking. In an earlier study, it was found that serology was more sensitive than bacteriology in MG infection. The serum plate agglutination test was used in many of the earlier sero-prevalence studies. It is recommended to use the serology based detection methods for screening the poultry flocks rather than testing individual poultry birds. For field based rapid diagnosis, agglutination based serology methods are best comparison to nucleic acid detection methods, more so in remote areas.In view of the difficulties in the diagnosis of MG infection in field condition, the study was undertaken to develop a user-friendly agglutination kit, which can be used as screening test for an early diagnosis of MG infection in the poultry flocks.Methods: Mycoplasma coloured antigen kit was developed and standardized using Mycoplasma gallisepticum F strain available at the Central University Laboratory. The prepared coloured antigen kit was stored at different temperatures such as 37°C, room temperature (22-28°C) and at 4-8°C at different period of time such as three months, six months and one year to know the shelf life of the kit.Result: The sensitivity of the coloured antigen kit was found to be 92.25% and specificity as 100%. The kit was found promising in the field condition for an early diagnosis of the ailment among the poultry flocks.

Zoonotic brucellosis: Seroprevalence and different serological tests comparison in ovine and caprine population in district Quetta, Balochistan

The present study was design to determine the seroprevalence of zoonotic brucellosis and different serological tests comparison in ovine and caprine population in district Quetta, Balochistan. A total of 500 blood samples, comprising of 250 each from sheep and goat were randomly collected from out skirts of District Quetta, Balochistan. Out of the 250 blood samples 125 were collected from each males and females. The serum samples were tested for the presence of anti-Brucella antibodies by Rose Bengal Plate Test (RBPT), Serum Plate Agglutination Test (SPAT) and Serum Tube Agglutination Test (STAT). The overall prevalence of brucellosis in sheep was recorded as 16.4%, 13.2% and 10.8% by RBPT, SPAT and STAT, respectively and in goat was found to be 11.6%, 8.8% and 6.8% by RBPT, SPAT and STAT, respectively. The sex-wise prevalence of brucellosis in Ram (male sheep) was recorded as 12.8%, 8.8% and 7.2% by RBPT, SPAT and STAT, respectively; while in Ewe (female sheep) it was 20.0%, 17.6% and 14.4% by RBPT, SPAT and STAT respectively. In Buck (male goat), the seroprevalence of brucellosis was recorded 8.0%, 5.6% and 3.2%, whereas in Dew (female goat) it was 15.2%, 12.0% and 10.4% by RBPT, SPAT and STAT, respectively. The prevalence of brucellosis was relatively higher in ovine (sheep) as compared to caprine (goat), irrespective of techniques used. It was also concluded that brucellosis was higher in females than in males in both sheep and goat. Among all the serological tests applied in the present study, RBPT was found to be more sensitive and showed higher prevalence of brucellosis in sheep as well as in goat population.

Prevalence of Human Brucellosis in a Suspected Population of District Swat

Background: Brucellosis is caused by a gram-negative, aerobic, non-spore forming, coccobacillus, transmitted by consumption ofcontaminated dairy products. Close contact with infected animals is also a risk factor. Diagnosis is difficult due to non-specificmanifestations like fever, back pain, arthralgia, muscle aches, and anemia, thereby diagnosis is based on laboratory tests.Although under rated, 50,000 new cases of human brucellosis worldwide are reported annually. In Pakistan, despite the diseasebeing endemic, data is limited. Moreover, the increased consumption of raw dairy products has posed an additional risk.Objective: To identify the prevalence of human brucellosis in the suspected population of District Swat.Material and Methods: This cross-sectional study was conducted at a tertiary-care hospital, of Swat from November 2017-October 2018. From the outpatient department, 150 participants were enrolled being suspected of having human brucellosis.Every participant was screened for Brucella antibodies by Serum Plate Agglutination Test (SPAT) and confirmed through Enzyme-Linked Immunosorbent Assay (ELISA) and Polymerase Chain Reaction (PCR).Results: The mean age of the participants was 29.65+11.27 years, 34% of which were 21-30 years of age. Most (62%, n=93) werefemales and a greater proportion of them consume fresh milk (45.3%), followed by fresh milk and milk pack both (30%). Around 119(79.3%) were positive on SPAT, 50.7% on ELISA, and 49.3% on PCR with a significantly higher proportion in females (p=0.001).Conclusion: Human brucellosis was found to be highly prevalent among suspected population exposed to raw dairy products witha definitive diagnosis found in almost half of the samples collected.

Comparison of Experimental Infection of Normal and Immunosuppressed Chickens with Mycoplasma gallisepticum

Four different models of infection of chickens with Mycoplasma gallisepticum (MG) were evaluated. Normal or immunosuppressed chicks (10 days old) were infected with the MG Rlow strain via eye and nasal drops or by direct air sac injection. Bacterial load in the lungs was quantified and air sac and tracheal lesion scores, tracheal mucosal thickness and humoral immune responses were assessed. Serum antibody responses were assessed by use of a serum plate agglutination test. Three days post infection (dpi), all immunosuppressed chicks had developed significant respiratory signs. Chicks infected via air sac injection had significant differences in serum antibody and gross lesion scores at 5 dpi. All chicks had developed pathological changes by 7 dpi. Air sac inoculation of immunosuppressed chicks produced more significant (P≤0.05) lesions, and these birds had the highest bacterial load in the lungs compared with other groups.

Molecular identification of Mycoplasma synoviae from breeder chicken flock showing arthritis in Egypt.

Aim:Arthritis is one of the most economic problems facing poultry industry worldwide. The study was done to detect possible causes of arthritis in breeder chicken flock with emphasis on molecular identification of Mycoplasma synoviae (MS).Materials and Methods:This study was carried on chicken from broiler breeder flock of 57 weeks’ age in Dakahlia, Egypt, suffered from arthritis with frequently 5-7% decrease in egg production, reduced fertility, and hatchability. Forty blood samples were randomly collected from individual birds in sterile tubes and used for serum separation. Serum samples were tested using serum plate agglutination (SPA) test against colored antigens for Mycoplasma gallisepticum (MG), MS, and Salmonella gallinarum-pullorum (SGP). On the other hand, 24 joint samples were collected. Of those 24 samples, 12 joint samples were subjected to bacteriological examination, while the other 12 were utilized for molecular diagnosis by polymerase chain reaction (PCR) for MS and avian reovirus (ARV).Results:SPA test results revealed the presence of antibodies against MG, MS, and SGP in tested sera in rates of 14/40 (35%), 35/40 (87.5%), and 9/40 (22.5%), respectively. Furthermore, 19 bacterial isolates were recognized from joint samples and identified as five Staphylococcus spp., nine Escherichia coli, three SGP, one Citrobacter, and one Proteus. The identified Staphylococcal isolates were three coagulase-positive staphylococci (two Staphylococcus aureus and one Staphylococcus hyicus) and two coagulase-negative staphylococci (one Staphylococcus epidermidis and one Staphylococcus lentus), while E. coli isolate serotypes were 1 O11, 2 O55, 3 O78, 1 O124, 1 O125, and 1 untyped. PCR proved that 12/12 (100%) samples were positive for MS variable lipoprotein hemagglutinin A (vlhA) gene, while ARV was not diagnosed in any of the examined samples. Four amplified vlhA gene of MS isolates (named MS-2018D1, MS-2018D2, MS-2018D3, and MS-2018D4) was successfully sequenced.Analysis of phylogenetic tree revealed the presence of 100% identity between each two sequenced isolates(isolates MS-2018D1 and MS-2018D4 and also isolates 2018D2 and MS-2018D3). However, the nucleotide similarity between four isolates was 88.6%. On the other hand, our field isolates MS-2018D1, MS-2018D4, MS-2018D2, and MS-2018D3 showed nucleotide identity with vaccine strain MS-H 98.4%, 98.4%, 88.1%, and 88.1%, respectively. Furthermore, the nucleotide similarities with field strains from Argentina ranged between 87.8% and 98.6%.Conclusion:Four field isolates of MS were identified in examined broiler breeder flock. A phylogenetic study of these isolates revealed the variation between isolated MS strains and vaccine strain. Therefore, further studies are required for evaluating the vaccine efficacy against the present field isolates of MS. In addition, application of MS immunization of breeder flocks is necessary for proper control of the disease.

Seroprevalence of Salmonella Infection in Commercial Layer Chickens in Cox’s Bazar District, Bangladesh

Salmonellosis is a zoonotic disease, usually transmitted from animal to human and vice versa and causes huge economic losses in poultry industry of Bangladesh. This study was aimed to estimate the seroprevalence of Salmonella infection in commercial layer farms of Cox’s Bazar district of Bangladesh, during the period from February to April, 2016. A total of 200 blood samples were collected from 20 farms of 4 randomly selected upazillas of Cox’s Bazar considering the age groups, and flock sizes. Rapid serum plate agglutination test was done and 42% chickens were found positive for Salmonella infection. With respect to age groups, the seroprevalence was higher (68%) in adults compared to young (20%) chickens. However, the seroprevalence of Salmonella infection was recorded remarkably (54.28%) in large flocks compared to small flocks. In conclusion, we can say that, Salmonella infection is prevalent in the commercial layer chickens of Cox’s Bazar district, Bangladesh. Appropriate measures and strategies should be taken for successful prevention and control of this disease in Bangladesh.

Molecular Identification and Sequencing of Mycoplasma gallisepticum Recovered from Broilers in Egypt.

Avian mycoplasmosis, particularly Mycoplasma gallisepticum (MG) is one of the infectious diseases associated with economic losses in Egyptian poultry industry. Thus, this study was aimed to determine the prevalence, serological identification, molecular characterization, sequencing and minimum inhibitory concentration of M. gallisepticum isolated from diseased broilers in Egypt. A total of 351 samples (227 tissue samples "tracheas and air sacs" and 124 tracheal swabs) and 71 sera were collected from diseased broilers. The conventional (isolation and biochemical) and molecular methods (PCR) were performed for detection of M. gallisepticum and virulence-associated gene (mgc2). The serum plate agglutination (SPA) test and enzyme-linked immunosorbent assay (ELISA) were applied on sera for determination of the presence of antibodies against M. gallisepticum. The minimal inhibitory concentration test (MIC) was used to determine the sensitivity of two sequenced M. gallisepticum strains to anti-mycoplasma agents. The total recovery rate of Mycoplasma from 351 samples from broilers was 45.29% (159) in which M. gallisepticum showed a prevalence of 62.89% (100/159). Serological identification of M. gallisepticum in 71 collected sera using SPA and ELISA were 54.9 and 40.8% with the highest geometric mean titer of ELISA for M. gallisepticum (699.08 and 495.92). Molecular characterization of Mycoplasma using PCR showed that 50% (3/6) of tested isolates were identified as M. gallisepticum based on 16SrRNA. Also, the mgc2 gene was detected in 50% (3/6) M. gallisepticum isolates. Two positive PCR mgc2 specific genes of M. gallisepticum isolates were subjected to gene target sequencing (GTS) to verify that these two isolates were M. gallisepticum. The minimal inhibitory concentration test (MIC) was applied to determine the sensitivity of these two sequenced M. gallisepticum strains to anti-mycoplasma agents. The first M. gallisepticum isolate was sensitive to tilmicosin, tiamulin and spiramycin. The second M. gallisepticum isolate showed sensitivity to tiamulin, spiramycin and tilmicosin. These results summarized the necessity of monitoring the Egyptian poultry farms for avian mycoplasmosis. Also, further studies are required for controlling of mycoplasma in all stages of the poultry industry production chain to avoid different losses in Egypt.

Efficacy of Tylosin and Tiamulin against Mycoplasmosis in poultry

Chronic respiratory disease (CRD) is one of the most important veterinary diseases in Bangladesh and all over the world. Mortality, reducing of weight gain and increasing of feed conversion ratio (FCR) are caused by CRD. Several drugs are used for prevention and control of Mycoplasmosis. It is caused by Mycoplasma gallisepticum (MG). Tylosin and Tiamulin are effective on M. gallisepticum. By considering generating resistance against antibiotics that is effective on MG, studying the effect of these drugs in the treatment and prevention of Mycoplasmosis in birds were the purpose of this research. In this study, 36 layer birds (MG positive) of 25 weeks aged divided in three similar groups (A, B and C) contain 12 birds in each group. In group A; Tylosin was administered after mixing with 2.5 gm in 1 L drinking water, for Group B; Tiamulin was administered after mixing with feed @ 0.45gm/kg feed and Group C; Control (No antibiotic was given, only common feeding). The Serum Plate Agglutination (SPA) test was conducted; in positive cases granules were formed slowly which could be seen during rocking. In the negative case, no such granules were formed. Overall 6 and 9 serums shown negative SPA test in Group A and Group B, respectively. Therefore, the efficacy of Tylosin was 50.00% and the Tiamulin was 75.00% which resemble statistically significant (P&lt;0.05). In control group, 5 birds were died during experiment. It can be concluded that usage of these antibiotics especially Tiamulin can be essential in the treatment and prevention of Mycoplasmosis in birds.Res. Agric. Livest. Fish.4(3): 187-191, December 2017

Comparative evaluation of Serum Plate Agglutination Test (SPAT) and Rose Bengal Plate Test (RBPT) for diagnosis of Brucella abortus in sera of cattle and human

Comparative evaluation of Serum Plate Agglutination Test (SPAT) and Rose Bengal Plate Test (RBPT) for diagnosis of Brucella abortus in sera of cattle and human

Development of Rapid Serum Plate Agglutination Test (RSPA) For Screening of Mycoplasma Synoviae Antibodies Using Namakkal Regional Isolate

The aim of the present study was to develop rapid serum plate agglutination test for detecting Mycoplasma synoviae antibodies using Namakkal regional isolates in commercial layer chicken. Mycoplasma synoviae colour antigen was prepared using 0.5 per cent basic fuchsine dye with the antigen concentration of 3x109 organisms/ml for rapid serum plate agglutination test (RSPA). To find out sensitivity and specificity of developed RSPA test in comparison with indirect ELISA 184 serum samples were collected from layer flock and tested by rapid serum plate agglutination test and indirect ELISA. Seropositivity of M. synoviae antibodies in RSPA and indirect ELISA was 51.08 and 54.34 per cent, respectively. The sensitivity and specificity of RSPA with reference to indirect ELISA was found to be 94 and 100 per cent respectively.