Bacterial Diseases In Poultry Research Articles

Effectiveness of probiotics in growing broiler chicken

Antibacterial preparations are used to prevent bacterial diseases in poultry when raising broilers but given the negative factor of their residual accumulation in meat and the acquisition of resistance by pathogens, it became necessary to find alternative means. The purpose of this study was to determine the effectiveness of various concentrations of Bacillus coagulans on the growth and development of broiler chickens. Methods employed: microbiological; physiological to determine the state of health and safety of chickens; zootechnical; pathological; statistical. The chickens in the experiment had a higher live weight at Day 35: in Group 1 – by 11%, in Group 2 – by 15.4%, and in Group 3 – by 18.4%, as opposed to the control. The average daily body weight gain of chickens in groups with B. coagulans was higher, in Group 1–by 10.8%, in Group 2–by 15%, and in Group 3–by 18.3%. The preservation rate in all experimental groups, regardless of the probiotic concentration, was 100%, while in the control group – 80%. There was an increase in live weight in the following groups: Group 1–by 11%, Group 2 – by 15.5%, Group 3 – by 19%. Feed conversion was lower in Group 1 by 5.3%, in Group 2 – by 3.4%, and in Group 3 – by 2%, compared to the control. At the end of the study, the level of Lactobacillus sp. in the intestines of chickens in Group 1 was 33.78% higher, in Group 2 – by 50%, in Group 3 – by 78.37%; a decrease in the content of Enterobacteriaceae sp. in Group 1–by 51.48%, in Group 2 – by 65.11%, in Group 3–by 90.67%; Staphylococcus sp. in Group 1–by 15.04%, in Group 2–by 35.44%, in Group 3–by 51.47% (p≤0.05), in contrast to the control. The average bursal weight in Group 1 was 4.82% higher, in Group 2–30% higher, in Group 3–37.53% higher, and the bursal index was 15%, 25%, and 30% higher, respectively, compared to the control

Bacterial and Viral Rodent-borne Infections on Poultry Farms. An Attempt at a Systematic Review.

Rodents are quite common at livestock production sites. Their adaptability, high reproductive capacity and omnivorousness make them apt to become a source of disease transmission to humans and animals. Rodents can serve as mechanical vectors or active shedders of many bacteria and viruses, and their transmission can occur through direct contact, or indirectly through contaminated food and water or by the arthropods which parasitise infected rodents. This review paper summarises how rodents spread infectious diseases in poultry production. The aim of this review was to use PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) principles to meta-analyse the available data on this topic. Three databases - PubMed, Web of Science and Scopus - and grey literature were searched for papers published from inception to July 2022 using the established keywords. An initial search identified 2,999 articles that met the criteria established by the keywords. This number remained after removing 597 articles that were repeated in some databases. The articles were searched for any mention of specific bacterial and viral pathogens. The importance of rodents in the spread of bacterial diseases in poultry has been established, and the vast majority of such diseases involved Salmonella, Campylobacter, Escherichia coli, Staphylococcus (MRSA), Pasteurella, Erysipelothrix or Yersinia infections. Rodents also play a role in the transmission of viruses such as avian influenza virus, avian paramyxovirus 1, avian gammacoronavirus or infectious bursal disease virus, but knowledge of these pathogens is very limited and requires further research to expand it.

A Comprehensive Review on Bacterial Vaccines Combating Antimicrobial Resistance in Poultry.

Bacterial vaccines have become a crucial tool in combating antimicrobial resistance (AMR) in poultry. The overuse and misuse of antibiotics in poultry farming have led to the development of AMR, which is a growing public health concern. Bacterial vaccines are alternative methods for controlling bacterial diseases in poultry, reducing the need for antibiotics and improving animal welfare. These vaccines come in different forms including live attenuated, killed, and recombinant vaccines, and they work by stimulating the immune system to produce a specific response to the target bacteria. There are many advantages to using bacterial vaccines in poultry, including reduced use of antibiotics, improved animal welfare, and increased profitability. However, there are also limitations such as vaccine efficacy and availability. The use of bacterial vaccines in poultry is regulated by various governmental bodies and there are economic considerations to be taken into account, including costs and return on investment. The future prospects for bacterial vaccines in poultry are promising, with advancements in genetic engineering and vaccine formulation, and they have the potential to improve the sustainability of the poultry industry. In conclusion, bacterial vaccines are essential in combating AMR in poultry and represent a crucial step towards a more sustainable and responsible approach to poultry farming.

Retrospective analysis of the spread of bacterial poultry diseases on the territory of Ukraine for the period 2012–2020

One of the most important livestock industries in the world is poultry breeding, which meets human needs for high-quality protein products (poultry meat, eggs) and is characterized by rapid return on investment. Bacterial infectious diseases of poultry are a major problem for the poultry industry and its strategic future. Given the relevance of bacterial diseases of poultry in the world and in Ukraine in particular, the authors conducted a retrospective analysis of the spread of these diseases in Ukraine for the period 2012–2020 by analyzing and systematizing the results of bacteriological investigations. In order to analyze the spread of bacterial diseases of poultry in terms of regions in Ukraine, we analyzed data on 20 diseases of poultry, namely: hemophilosis, infectious enterotoxemia, yersiniosis, campylobacteriosis, colibacteriosis, coligranulomatosis, klebsiella, listeriosis, mycoplasmosis, neisseriosis, pasteurellosis, pathogenic proteus, pneumococcosis, pseudomonosis, pullorosis, erysipelas septicemia, salmonellosis, staphylococcosis, streptococcosis and tuberculosis. According to the results of research, it is found that bacterial diseases of poultry are significantly common in Ukraine, the average infection of poultry with bacterial diseases for the period from 2012 to 2020 was 0.8%. The leading role in the etiological structure of pathogens of bacterial diseases of poultry was played by colibacillosis – 56.9% of the total number of all positive samples. Also, the dominant bacterial diseases of poultry in Ukraine during the analyzed period are: salmonellosis (13.5%), staphylococcosis (7.8%), pasteurellosis (7.0%), pseudomonosis (6.8%), pullorosis (3.6%) and streptococcus (2.6%). Significantly fewer positive samples were registered in the bacteriological investigations of other diseases: pneumococcosis 0.5%, tuberculosis 0.4%, infectious enterotoxemia 0.3%, pathogenic proteus 0.2%, erysipelas septicemia 0.1%, klebsiellosis 0.1%, listeriosis 0.1%, neisseriosis 0.08%, coligranulomatosis 0.05% and hemophilosis 0.02%. According to the results of bacteriological research of poultry for such diseases as yersiniosis, campylobacteriosis and mycoplasmosis – no positive test was found for the entire analyzed period. According to the results of ecological and geographical analysis, the heterogeneity of the nosological profile of bacterial diseases of poultry in different regions of Ukraine was established.

A retrospective analysis of antimicrobial resistance in pathogenic Escherichia coli and Salmonella spp. isolates from poultry in Uganda

ABSTRACT There are increasing reports of antimicrobial treatment failures for bacterial diseases of poultry in Uganda. The paucity of data on antimicrobial resistance (AMR) of pathogenic bacteria in Uganda is a major setback to AMR control. This study investigated the occurrence of fowl typhoid, colibacillosis, and AMR in associated pathogens from 2012 to 2018. Laboratory records from the Central Diagnostic Laboratory (CDL), a National Veterinary Diagnostic Facility located at Makerere University, were reviewed. Archived isolates of the causative bacteria for the two diseases were also evaluated for AMR. The frequencies of the two disease conditions, their clinical and necropsy presentations and the demographic data of the diagnostic samples were summarized from the records. Archived bacterial isolates were revived before antimicrobial susceptibility testing. This was done on Mueller Hinton agar using the disk diffusion method, against 16 antimicrobials of medical and veterinary importance according to the Clinical Laboratory Standards Institute guidelines. A total of 697 poultry cases were presented for bacteriological investigations in the review period. Colibacillosis and salmonellosis had prevalence rates of 39.7% (277/697) and 16.2% (113/697), respectively. A total of 63 and 92 isolates of Escherichia coli and Salmonella spp., respectively, were archived but 43 (68.3%) E. coli and 47 (51.1%) Salmonella spp. isolates were recovered and evaluated for AMR. Multidrug resistance was more frequent in E. coli (38; 88.4%) than salmonellae (25; 53.2%), (p < 0.001). The high prevalence of colibacillosis, salmonellosis and the AMR of associated pathogens warrants immediate institution of appropriate disease control measures.

Study of the properties of nanoparticles of Ag and Zn citrates

The use of nanomaterials has become especially relevant as components of new drugs, adjuvants and new ingredients in feed additives. The very combination of inorganic components (metals) with natural minerals (сeolites, clenoptolites) made it possible to create fundamentally new chemical compounds that differ significantly in the mechanism of action and their physicochemical characteristics from traditionally used drugs for the treatment of bacterial diseases of poultry. The practical application of the composition involves the use of small sizes of nanoparticles that are in the “nanoscale” from 1 to 100 nm. Our article contains the results of studies of Ag and Zn nanomaterials in combination with citrate in the form of powder and dispersed solutions. As a result of scanning electron microscopy, it was found that the studied sample of Ag and Zn nanoparticles is a gray powder of monocrystalline particles of irregular shape, the size of which varies from 160 to 350 nm. Particles of three sizes were most often found among Ag and Zn citrates, namely: 160 nm – 45 %, 210 nm – 35 %, 350 nm – 20 %. Studying the bactericidal properties of dispersed solutions of Ag and Zn citrates on microbial suspensions of test cultures of Escherichia coli (ser.O2), Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus epidermidis, we found that Ag citrate showed better bactericidal properties in relation to all experimental test cultures of Escherichia coli (ser.O2), Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus epidermidis, in contrast to the citrate solution Zn, which was only effective against Escherichia coli (ser.O2), and Staphylococcus epidermidis.

The Simultaneous Administration of a Probiotic or Prebiotic with Live Salmonella Vaccine Improves Growth Performance and Reduces Fecal Shedding of the Bacterium in Salmonella-Challenged Broilers.

Simple SummaryThe current study was performed to study the efficacy of live Salmonella Enteritidis (SE) vaccine alone and with simultaneous administration of probiotic or prebiotic on broiler chickens. The using of probiotic or prebiotic products administered via drinking water enhanced the growth performance of broiler chickens experimentally challenged with SE at the 28th day of age. The use of probiotic or prebiotic simultaneously with the live Salmonella vaccine can diminish the negative effect of live vaccines in terms of the growth performance, mortality rate, fecal shedding and organ re-isolation of SE. It is therefore a good strategy to relieve the negative effect of the harmful bacterium and improve the growth performance of broilers.Salmonellosis is one of the most important bacterial diseases in poultry, causing heavy economic losses, increased mortality and reduced production. The aim of this study was the comparative efficacy of a commercial probiotic and/or prebiotic with a live attenuated Salmonella Enteritidis (SE) vaccine on the protection of broiler chickens from SE challenge. The efficacy of probiotic or prebiotic products, as well as a live Salmonella Enteritidis (SE) vaccine at the 7th day of age, administered via drinking water, were evaluated for clinical protection and effects on growth performance of broiler chickens experimentally challenged with SE at the 28th day of age. The use of probiotic or prebiotic simultaneously with the live Salmonella vaccine can diminish the negative effect of live vaccine growth performance, reducing mortality rate, fecal shedding, and re-isolation of SE from liver, spleen, heart and cecum. The use of probiotic or prebiotic simultaneously with the application of the live Salmonella vaccine is a good practice to diminish the negative effect of the harmful bacteria and improve the growth performance of broilers. Thus, further studies may be carried out with layers and breeders.

Survey of veterinary prescribing for poultry disease.

To enable better antimicrobial stewardship, it is important to know what the patterns of prescribing behaviour are and what diseases or reasons antibiotics are being prescribed. A prescribing guideline (i.e. recommended best practice for writing prescriptions) developed by the Australian poultry veterinarians exists. However, it is not a prescribing guideline detailing treatments for the commonly observed bacterial diseases in commercial poultry. An online survey was deployed to all registered veterinarians and members of the Australian Veterinary Poultry Association to identify prescribing behaviours for the most frequently observed bacterial diseases of poultry. A total of 39 survey responses were received. Most surveys were started but not completed; 13 (33%) were completed with 18 (46%) containing some information on prescribing. The most frequent treatment responses were for Escherichia coli in both layers and broilers, chronic respiratory disease (CRD), fowl cholera and spotty liver in layers and necrotic enteritis in broilers. Treatments described were for products registered for poultry use, within the recommended label dose and duration of treatment (Tables 1, 2). Unsurprisingly, tetracyclines and amoxycillin, followed by lincomycin and trimethoprim sulfonamide products were the most frequently reported treatment options. Inappropriate treatments were reported for salmonellosis and one veterinarian recommended the use of enrofloxacin for the treatment of fowl cholera. Information provided by respondents will enable the initial development of prescribing guidelines for both commercial and small poultry flocks. Importantly, it identified less than optimal prescribing behaviour for some diseases, a reliance on one class of antibiotic more than others and a failure to utilise all antimicrobial classes potentially available for treatment. Critically, the survey identified a lack of treatment options for bacterial disease in poultry. The most important bacterial diseases of poultry remain the same; effective alternatives for antibiotic treatment are required and old diseases, thought once gone, are reinventing themselves as problems for the future. Surveys of prescribing behaviours are essential for identifying diseases of high priority, changes in treatments and response to treatment and to identify areas for targeted antimicrobial stewardship, and research needs.

Occurrence of Multidrug Resistant Salmonella spp. in Poultry and Approach for Its Indigenous Bio-control

A significant limitation to flourish poultry industry in Bangladesh is the emergence of multidrug resistance pathogenic bacteria like Salmonella spp. due to uncontrolled use of antibiotics for disease treatment. An alternative to antibiotics could be the application of probiotics. About 120 cloacal-swabs from poultry birds were investigated, seventy two (72) isolates of Salmonella spp. and twenty two (22) isolates of lactic acid bacteria (out of 50)were identified respectively by cultural, morphological and biochemical tests presumptively. Antibiotic sensitivity test of Salmonella spp. was performed, followed by Kirby-Bauer disc-diffusion assay with six antibiotic groups. All those isolates of Salmonella spp. were found to be highly resistant to â-lactam, cephalosporin, tetracycline and macrolide, highly sensitive to carbapenem and moderately sensitive to aminoglycosides. Then Salmonella spp. were used as a target for the prospective probiotic bacteria which were screened based on antimicrobial activity against those multidrug resistance Salmonella spp. In antagonism assay such as disc diffusion and one-streak method, it was revealed that five lactic acid bacteria showed antimicrobial activity against Salmonella spp. Further, lactic acid bacteria were characterized based on their tolerance ability to pH and NaCl, antibiotic susceptibility test. The tolerance range of Lactic acid bacteria was about pH (3.5-9.5), NaCl (4-8) % and also resistant to antibiotics groups like B lactam, aminoglycosides, and quinolone. Then 16S rDNA gene sequence analysis was performed for molecular identification of potential probiotic bacteria. One representative isolate was identified as phylogenetically closed relative to Pediococcus acidilactici. This study was able to demonstrate that Pediococcus acidilactici as anindigenous probiotic candidate to inhibit the growth of isolated multidrug resistant Salmonella spp. in poultry. The potent probiotic candidate Pediococcus sp. could be used to counter bacterial diseases in poultry, thereby it could ensure food safety in the poultry industries of Bangladesh.&#x0D; Bangladesh J Microbiol, Volume 34 Number 2 December 2017, pp 83-90

CLINICAL AND LABORATORY DIAGNOSES OF COMMON BACTERIAL DISEASES OF BROILER AND LAYER CHICKENS

The study was undertaken with a view to compare clinical and laboratory diagnoses of various bacterial diseases of poultry during the period from March 2009 to February 2010 in the laboratory of the Dept. of Microbiology and Hygiene, Bangladesh Agricultural University (BAU), Mymensingh. A total of 135 sick and dead chickens (47 broilers and 88 layers) were collected from 12 different poultry farms (4 broilers and 8 layers) of Mymensingh and Gazipur districts which were subjected for clinical followed by laboratory diagnosis. Clinical diagnosis was made on the basis of clinical history, clinical signs and postmortem findings of the affected birds whereas; confirmatory diagnosis was made by using cultural examination, Gram’s staining and different biochemical tests. In this study, out of 47 broilers, 16 (34%) chickens were clinically diagnosed as colibacillosis, 11 (23.40%) as salmonellosis and 2 (4.25%) as fowl cholera. In the same way, out of 88 layer chickens, 28 (31.82%) were diagnosed as colibacillosis, 16 (18.18%) as salmonellosis and 11 (12.50%) as fowl cholera. In laboratory, out of 47 suspected broiler chickens, 12 (25.53%) chickens were diagnosed as colibacillosis, 7 (14.89%) as salmonellosis and 0 (0%) as fowl cholera. Correspondingly of the 88 layer chickens 22 (25%) were diagnosed as colibacillosis, 11 (13.64%) as salmonellosis and 8 (9.09%) as fowl cholera. So the findings concluded that clinical diagnosis is not always accurate like laboratory diagnosis because in most cases clinical history, clinical signs and post-mortem lesions of different bacterial diseases including mixed infections are almost similar to other related diseases and it is recommended to confirm laboratory diagnosis before treatment of the diseases.DOI = http://dx.doi.org/10.3329/bjvm.v8i2.11188 Bangl. J. Vet. Med. (2010). 8 (2) : 107-115

Prevalence and characterization ofSalmonella Gallinarum in the chicken in Korea during 2000 to 2008

Salmonella enterica serovar Gallinarum (Salmonella Gallinarum) is the causative agent of fowl typhoid (FT), a severe systemic disease of chickens that results in high mortality. Since 1992, FT has become one of the most serious bacterial diseases in poultry in Korea. The purpose of this study was to investigate the prevalence of FT during 2000 to 2008 and characterize the phenotype and genetic diversity of Salmonella Gallinarum isolates before and after adopting national-wide vaccination with a live attenuated strain (SG 9R) in 2001. For 9 yr, a total of 983 farms were affected with FT outbreaks, and after reaching a peak in 2002 (206 farms affected), the prevalence of the disease gradually declined, whereas magnitude sales of the vaccine increased every year. According to the analysis based on the chicken breeds (n=521 farms), the incidence of FT in commercial broilers, Baeksemi (a mixed breed of male meat-type breeder and female commercial layer), commercial layers, native chickens, and broiler breeders was 47.7, 28.4, 17.2, 5.1, and 1.3%, respectively. Of the affected broilers, over 90% birds were under 2 wk of age, indicating it was possible that they were infected with Salmonella Gallinarum via vertical transmission. In the phenotypic analysis, Salmonella Gallinarum strains (n=142) isolated during 2001 to 2007 showed the same pattern in the majority of the biochemical tests such as carbohydrate fermentation and amino acid decarboxylation. Interestingly, all of the strains could not ferment rhamnose, but SG 9R could, making rhamnose a potential biomarker to distinguish the vaccine strain. In analyzing the genetic diversity by the pulsed field gel electrophoresis method with XbaI digestion, we examined a total 68 isolates of Salmonella Gallinarum obtained in 5 provinces in Korea (2001 to 2007). The pulsed field gel electrophoresis profiling produced 7 different patterns, but isolates within the same group did not show clear geographic or breed relationships. In conclusion, there were close epidemiological linkages between prevalence of FT and the sales volume of the live FT vaccine in Korea. In addition, a low phenotypic and genetic heterogeneity was observed among Korean Salmonella Gallinarum isolates and the live vaccine strain (SG 9R).

The role of probiotics in the poultry industry.

The increase of productivity in the poultry industry has been accompanied by various impacts, including emergence of a large variety of pathogens and bacterial resistance. These impacts are in part due to the indiscriminate use of chemotherapeutic agents as a result of management practices in rearing cycles. This review provides a summary of the use of probiotics for prevention of bacterial diseases in poultry, as well as demonstrating the potential role of probiotics in the growth performance and immune response of poultry, safety and wholesomeness of dressed poultry meat evidencing consumer’s protection, with a critical evaluation of results obtained to date.

Tetrameres fissispina Infection in Local Chickens in Taraba State, Nigeria, Case Report

A severe and fatal outbreak of Tetrameres fissispina in four flocks of local chickens in Nigeria is being described. The outbreak was characterized by sudden and massive death and pathology mimicking avian influenza. Convention tests for major viral and bacterial diseases of poultry in Nigeria were all negative. T. fissispina was isolated from most carcasses submitted for post mortem examination. A pathogenic T. fissispina in local chicken is being reported

The avian lung-associated immune system: a review

The lung is a major target organ for numerous viral and bacterial diseases of poultry. To control this constant threat birds have developed a highly organized lung-associated immune system. In this review the basic features of this system are described and their functional properties discussed. Most prominent in the avian lung is the bronchus-associated lymphoid tissue (BALT) which is located at the junctions between the primary bronchus and the caudal secondary bronchi. BALT nodules are absent in newly hatched birds, but gradually developed into the mature structures found from 6-8 weeks onwards. They are organized into distinct B and T cell areas, frequently comprise germinal centres and are covered by a characteristic follicle-associated epithelium. The interstitial tissue of the parabronchial walls harbours large numbers of tissue macrophages and lymphocytes which are scattered throughout tissue. A striking feature of the avian lung is the low number of macrophages on the respiratory surface under non-inflammatory conditions. Stimulation of the lung by live bacteria but not by a variety of bacterial products elicits a significant efflux of activated macrophages and, depending on the pathogen, of heterophils. In addition to the cellular components humoral defence mechanisms are found on the lung surface including secretory IgA. The compartmentalisation of the immune system in the avian lung into BALT and non BALT-regions should be taken into account in studies on the host-pathogen interaction since these structures may have distinct functional properties during an immune response.

Functional responses of neonatal chicken and turkey heterophils following stimulation by inflammatory agonists

Abstract Objective To determine functional responses of neonatal chicken and turkey heterophils to various inflammatory agonists. Animals 100 one-day-old chickens and turkeys. Procedure Blood heterophils were isolated and stimulated for 30 minutes at 39 C with ionomycin, phorbol myristate acetate (PMA), opsonized zymosan (OZ), or formyl-methionyl-leucyl-phenylalanine (FMLP). Functional responses (shape change, adherence, phagocytosis, influx of intracellular calcium, and oxidative burst) of stimulated heterophils were measured and compared with responses of unstimulated (control) heterophils. Results Turkey and chicken heterophils did not respond to FMLP stimulation. Stimulation of chicken and turkey heterophils with ionomycin resulted in significant increases in adherence, percentage of cells with a shape change, phagocytosis, intracellular calcium concentration, and oxidative burst. Turkey heterophils did not respond to PMA stimulation, whereas stimulation of chicken heterophils with PMA resulted in significant increases in adherence, percentage of cells with a shape change, phagocytosis, and oxidative burst but not intracellular calcium concentration. Stimulation of chicken and turkey heterophils with OZ resulted in significant increases in oxidative burst. Conclusions Mechanisms regulating initiation of heterophil activation in neonatal chicken and turkey heterophils are consistent with those described for heterophils isolated from mature birds. The biochemical and cytoskeletal systems of neonatal avian heterophils undergo functional alterations following stimulation with inflammatory agonists. Clinical Relevance Understanding heterophil activation and regulation should eventually lead to methods for controlling bacterial diseases in poultry. (Am J Vet Res 1998;59:1404–1408)

Isolation of Pasteurella multocida from broiler chickens

Pasteurella multocida, the etiological agent of fowl cholera, was isolated from five, 32 days oldbroilerchickens in the late of 1992. The chickens were from a farm located in Bogor area, raised in cages and each flock consisted of 1,550 broilers . Therewere 230 birds, aging from 28-31 days old, died with clinical signs of lameness and difficulty in breathing. Serological test of the isolate revealed serotype Aof Carter classification . To prove its virulences, the isolate was then inoculated into 3 mice subcutaneously. The mice died less then 24 hours postinoculation and P. multocida can be reisolated . The sensitivity test to antibiotics and sulfa preparations showed that the isolate was sensitive to ampicillin, doxycyclin, erythromycin, gentamycin, sulfamethoxazol-trimethoprim and baytril, but resistance to tetracyclin, kanamycin and oxytetracyclin. This is the first report of P. multocida isolation in broiler chickens in Indonesia, and it is intended to add information on bacterial diseases in poultry in Indonesia. Keywords : Pasteurella multocida, isolation, broiler chickens, antibiotics

&lt;i&gt;In vitro&lt;/i&gt; antibiotic sensitivity and therapeutic efficacy of experimental salmonellosis, colibacillosis and pasteurellosis in broiler chickens

Avian salmonellosis (AS), avian colibacillosis (AC) and avian pasteurellosis (AP) have been recognized as important bacterial diseases in poultry associated with morbidity and mortality in Bangladesh. The causative agents of these three diseases were isolated (5 isolates / disease) from dead chickens submitted for diagnosis at the BRAC Poultry Disease Diagnostic Centre, Gazipur during the period from January to December 2002. Five isolates of each of the Salmonella pullorum, Escherichia coli and Pasteurella multocida were evaluated against eight antibiotic containing disc which included ciprofloxacin, gentamicin, ampicillin, chloramphenicol, erythromycin, tetracycline, cephradine and penicillin G. Erythromycin in S. pullorum and Ciprofloxacin both in the E. coli and P. multocida were found highest sensitive, gentamicin, chloramphenicol, cephradine were found moderately sensitive to S. pullorum, gentamicin, tetracycline, erythromycin and ampicillin were found moderately sensitive to E. coli, and gentamicin ampicillin, cephradine and penicillin G were moderately sensitive to P. multocida. Therapeutic trials against experimentally produced S. pullorum, E. coli and P. multocida infection in three groups of broiler chickens showed that cephradine against S. pullorum and ciprofloxacin against both in E. coli and P. multocida were found highly effective both in vitro and in vivo studies, therefore, cephradine against salmonellosis and ciprofloxacin against colibacillosis and pasteurellosis are effective drugs of choice which could be used to control morbidity and mortality in poultry caused by these diseases.Key words: antibiotic sensitivity; salmonellosis; colibacillosis; pasteurellosis, broiler chickensdoi: 10.3329/bjvm.v2i2.2538Bangl. J. Vet. Med. (2004). 2 (2): 99-102