Akabane virus (AKAV) has been detected in a variety of host species in China, but there are only limited records of its occurrence in goats. However, more attention needs to be paid to understanding the diversity of viruses in this species. The aim of the study was to explore the genotype characteristics and variation trend of AKAV and their relationship with virulence in Yunnan, China.

In recent years, Shewanella putrefaciens, commonly known as a halophilic bacteria, has been associated with serious health disorders in freshwater fish. Therefore, it has been described as a new aetiological agent of the disease, named shewanellosis. S. putrefaciens is a heterogeneous group of microorganisms, belonging to the Alteromonadaceae family. Based on different criteria, three biovars and biogroups as well as four genomic groups have been distinguished. The first infections of S. putrefaciens in fish were reported in rabbitfish (Siganus rivulatus) and European sea bass (Dicentrarchus labrax L.). Outbreaks in farmed fish were reported in Poland for the first time in 2004. The disease causes skin disorders and haemorrhages in internal organs. It should be noted that S. putrefaciens could also be associated with different infections in humans, such as skin and tissue infections, bacteraemia, otitis. Investigations on pathogenic mechanisms of S. putrefaciens infections are very limited. Enzymatic activity, cytotoxin secretion, adhesion ability, lipopolysaccharide (LPS), and the presence of siderophores are potential virulence factors of S. putrefaciens. Antimicrobial resistance of S. putrefaciens is different and depends on the isolates. In general, these bacteria are sensitive to antimicrobial drugs commonly used in aquaculture.

Ornithobacterium rhinotracheale (ORT), is a bacterium that cause respiratory tract infection, has led to significant problems in the intensive poultry production. The current study aimed to isolate and identify ORT from broiler chickens, to detect antibacterial sensitivity and resistance of ORT isolates, and to test experimental infection of ORT in broiler chickens. One hundred eighty samples including tracheas, lungs and air sacs were subjected to isolation and phenotypic identification. Twelve suspected ORT isolates were used for molecular identification. Agar gel precipitation test was used to determine serotype of ORT isolates. Antibacterial sensitivity and resistance of ORT isolates were tested against 14 antibacterial drugs using standard disk diffusion technique. Pathogenicity of ORT was tested by experimental infection in broiler chickens. Results revealed that the incidence of ORT infection in broiler chickens in Assiut Governorate is 17.77% using isolation and phenotypic methods of identification, while it is 3.33% using molecular identification. Serological identification of ORT isolates indicated that all tested isolates, were belonged to serotype A. All ORT isolates were resistant to gentamycin, amoxycillin and cephradine with 100% incidence, where, 100% isolates were sensitive to colistin and doxycycline, 50% of isolates were sensitive to ampicillin and streptomycin, and 16.67% of isolates were sensitive to neomycin and trimethoprim. Living Newcastle attenuated vaccine, Lasota vaccine, exaggerates the clinical signs and lesions of ORT experimental infection.

The pathogenic effect of representative local isolates of Aeromonas organisms was studied on 1٠0 native breed chickens. At 2 weeks of age, one hundred chicks were grouped into four equal groups (1-4); 25 birds each; after collection of fecal from all groups, examined and proved to be free from Aeromonas species. All groups were subcutaneously (s.c) inoculated with 0.5 ml containing 9×105 cfu /bird. Group 1 of chickens was infected by A. hydrophila; while group 2 was infected with A. caviae. The third group was infected with A. sobria; while, chicks of Group 4 were kept as non infected control. Results were showed mild clinical signs in some birds in theform of alternative diarrhea. Post mortem lesions showed general congestion of all carcasses. In severely emaciated cases the lesions were confined to the intestine, which filled with watery fluid and distended with gas. Results of Aeromonas reisolation revealed that all collected weekly fecal swabs were positive. While, percentage of A. hydrophila and A. caviae was 100% out of all testedorgans, while isolation of A. sobria was 100%, 100% and 80% from liver, intestine and heart; respectively. Histopathological examination of infected chicken organs showing focal coaggulative necrosis in liver with mononuclear cells infiltration that varied in severity between groups as less severe in A. hydrophila (Gr.1) than A. caviae (Gr. 2), while A. sobria (Gr. 3) was markedly affected showing severe degenerated and dissociated hepatocytes. Intestinal changes were severe in group 3 than 2 while group 1 showing the mildest comparatively the changes was consist of necrosed mucosa, gland with leucocytic infiltration in lamina propria. Under thecondition of our study we can conclude that the used Aeromonas isolates from field diseased chickens were of mild pathogenicity to s.c. inoculated 12 days old Fayoumi chicks with long course affection.

A disease characterized by papules, nodules, vesicles, pustules and ulcers on teats and udder as well as drastic drop in milk production was seen among a cattle farm in Fayoum Governorate, Egypt. A virus was isolated by inoculation of vesicle and scrap homogenate pool from infected cattle into the chorioallantoic membrane of specific pathogen free embryonated chicken eggs. The virus was identified by presence of pock lesions, intracytoplasmic inclusion bodies on the chorioallantoic membrane, polymerase chain reaction and immunohistochemistry of the inoculated membrane. A novel pathogenicity model was developed via ear pinna inoculation of Swiss mice. The virus produced vesicular and ulcerative lesions at the site of inoculation in inoculated mice. The virus identity was confirmed by the presence of intracytoplasmic viral antigens by immunohistochemistry

This study was carried out to investigate the prevalence, molecular characterization and pathogenicity of field infectious bursal disease virus (IBDV) isolates. Nine isolates of IBDV were isolated from 13 naturally infected broiler flocks. Detection of IBDV antigen was carried out by agar gel precipitation test (AGPT), followed by virus isolation in specific pathogen free (SPF) embryonated chicken eggs (ECE) and finally molecularly characterized and identified using reverse transcriptase polymerase chain reaction (RT-PCR). The obtained nine strains of IBDV by RT-PCR were further classified by using restriction fragment length polymorphism (RFLP) technique into (4) classical, (3) variant and (2) very virulent (vv) IBDV serotype (I). The pathogenicity of the isolated IBDV strains was detected by three passages in SPF ECEs and by experimental infection of one hundred 14 days old maternally immune layer chicks. The results showed that the mortality rate of the embryos was increased by increase the number of passages till the third passage where it reached 100% for all IBDV strains and the embryos showed typical lesions of IBDV. Chicks inoculated with variant IBDV strains showed morbidity rates of 60-80 %, without mortalities. Sacrificed birds showed atrophied bursae and thymus glands and enlarged thickened proventriculus. Groups infected with classical IBDV strains showed morbidity rates 40- 60,% with mortality 0-20%. The detectable lesions were muscular hemorrhages with variable bursal lesions. Inoculated chicks with vvIBDV strains showed 50-70% morbidity and mortality of rate was 30% with lesions of muscular hemorrhages, severe nephrosis with ureates in the ureters, hemorrhagic bursitis and pin point hemorrhages on the proventricular glands. Control negative non-infected group showed neither clinical signs nor mortalities along the observation period. The histopathological effect (lesion score) of IBDV strains on the bursa, spleen and thymus glands confirmed the previously mentioned results and revealed that the highest severity (score) for these organs were induced by vv IBDV strains.

Objective: Salmonella is a widely-reported zoonotic bacterial pathogen and human infection is mostly attributed through direct or indirect contact with chickens. Salmonella Kentucky (S. Kentucky) is one of the motile serovars which has recently been identified from both poultry and human samples in Bangladesh. This study was conducted to assess its pathogenic potentials and shedding probability in backyard chicken. Materials and methods: We infected 22 backyard chickens orally, each with 106 cfu of Salmonella Kentuckey, which were then observed for 23 days to enlist clinical signs, gross and histo-pathological changes. Polymerase chain reaction (PCR) for Salmonella was applied on some representative samples to identify the presence of Salmonella. Results: Four chickens were sacrificed and the internal organs were examined to observe gross and microscopic tissue changes. Some reactive changes were seen in spleen during prolonged course of infection. The probability of S. Kentucky shedding was 77% (95%; CI 54-90%) on DPI 2, 41% (95%; CI 21-60%) on DPI 12 and 13% (95%; CI 3-31%) on DPI 21. The survival probability of the infected chickens was 50% (95%; CI 28-68%) on DPI 6, 32% (95%; CI 14-51%) on DPI 15 and 14% (95%; CI 3-31%) on DPI 23. Conclusion: Zoonotic S. Kentucky strain of human non-typhoidal clinical cases of gastroenteritis has potentials to produce clinical signs such as reduced feed uptake, watery or pasty fecal droppings and lesions, such as catarrhal enteritis and typhlitis. [J Adv Vet Anim Res 2018; 5(2.000): 196-203]

Objective: This study was conceived to investigate the pathogenicity of relapsed (Diminazene aceturate-resistant), field (original) and mixed (relapsed and field) isolates of Trypanosoma brucei brucei in rats.Materials and methods: Twenty eight healthy adult albino rats of both sexes weighing between 149-177 gm were used to compare the pathogenicity of relapsed, field and the mixed isolates of T. brucei brucei infections. The rats were separated into four groups (A-D); where, group A was kept as uninfected control, and group B was infected with 1x103 trypanosomes of the field isolate and 1x103 trypanosomes of the diminazene aceturate resistant isolate. The rats of groups C and D were infected with 1x106 trypanosomes of the diminazene aceturate-resistant isolate and 1x106 trypanosomes of the field isolate, respectively. Results: The infected rats became parasitemic within 4 to 8 days post-infection. The mean pre-patent periods (PP) were 4.1&plusmn;1.1, 6.0&plusmn;2.0 and 9.1&plusmn;1.1 days in groups B, C and D respectively, while the mean survival time (ST) in groups B, C and D were 21.4&plusmn;10.1, 27.1&plusmn;13.2 and 34.0 &plusmn;12.8 days, respectively. The PP and ST were shortest (P<0.05) in group B (mixed infections), and level of parasitemia was higher (P<0.05) in group B (mixed infections) as compared to groups C and D. The level of anemia was comparable (P>0.05) in groups C and D and more severe (P<0.05) in group B. Conclusion: Mixed infections exhibit shortest PP, ST, higher level of parasitemia and more severe anemia, and appear to be more pathogenic. [J Adv Vet Anim Res 2017; 4(1.000): 97-103]

Objective: Present research aims to isolate, identify, and determine the virulence of the Streptococcus agalactiae (group B Streptococcus; GBS), isolated from popped eye disease affected Tilapia and Vietnamese Koi (V. Koi) fishes. Materials and Methods: A total of 330 fish samples were collected, of which Tilapia (n = 180) and V. Koi (n = 150), were collected from 35 affected ponds of four selected districts of Bangladesh. Isolation of the bacterium was done using different culture media (Nutrient broth, Plate count agar, Tryptic Soy Agar, and Blood agar), and identification by using various biochemical tests (con¬ventional and using API 20 Strep kit) and polymerase chain reaction (PCR) using primers against 16S rRNA gene of S. agalactiae. Antibiotic susceptibility of the bacteria was performed using seven different antibiotics disc (Tetracycline, Oxytetracycline, Chlortetracycline, Streptomycin, Ciprofloxacin, Gentamicin, and Neomycin). Virulence of the isolated S. agalactiae was determined by infecting healthy Tilapia and V. Koi fishes through experimental infection. Results: Isolated bacteria were found Gram-positive paired and chained cocci, &#946;-hemolytic and non-motile. Findings of biochemical and serological tests indicate that the isolated bacterium belongs to Group B Streptococcus of Lancefield classification. PCR result also confirmed that the bacteria were S. agalactiae. The bacterial isolates possessed resistance property against all the seven antibiotics used in this study. The isolated GBS was found highly virulent and showed 80%90% mortality for Tilapia and V. Koi fishes in experimental infection within 16 days of post-infection. Conclusion: From the findings of this study, it may be concluded that isolated GBS from the Tilapia and V. Koi fishes were highly virulent and possessed multidrug-resistance properties. [J Adv Vet Anim Res 2021; 8(1.000): 14-23]

Objective: This study was carried out to assess the pathogenicity of local isolates of Mycoplasma ovipneumoniae and M. arginini in West African dwarf goats (kids) in Nigeria. Materials and methods: A total of 22 goats aged less than 1-year were purchased from markets. The goats were divided into six groups comprising of four experimental groups (EG; 4 in each) and two control groups (CG; 3 in each). The goats were fed ad libitum with standard diets and safe water. Groups EG1 and EG2 were infected with M. ovipneumoniae through trans-tracheal (TT) and intravenous (IV) routes, respectively, while those in groups EG3 and EG4 were infected with M. arginini through the same routes. Goats in groups CG1 and CG2 were inoculated with sterile Mycoplasma broth through TT and IV routes, respectively. In all cases, the amount of bacteria inoculated was 1.5x108 cells/mL. After the onset of the disease in goats, re-isolation of Mycoplasma was performed by culturing on mycoplasma agar supplemented with mycoplasma supplement G. The goats were monitored for 14 days post-infection (PI) to observe respiratory signs and mortality. Post-mortem (PM) examination was performed on each animal that died, while one surviving goat from each of the groups was sacrificed at 14 days PI for PM. After PM, histopathology was performed to observe the changes in tissues. Results: Cough and nasal discharges were observed in all the experimentally infected goats seven days PI. Mortalities were recorded in goats in EG1 (two goats), EG2 (one goats), EG3 (two goats) and EG4 (one goat). At PM, pneumonic lesions were observed in the lungs of all the experimentally infected goats. Conclusion: This study provides evidence that the local isolates of M. ovipneumoniae and M. arginini strains are pathogenic for goats in Nigeria. [J Adv Vet Anim Res 2016; 3(3.000): 242-251]