BACKGROUND: Extensive effort is focused on identifying genomic conserved antigens in development of effective vaccine against Enterotoxigenic Escherichia coli. Antigen 43 is one of the members of a large secreted protein family named autotransporters in the E.coli and other gram negative bacteria. Autotransporter proteins have a similar conserved structure. Some of them are recognized during both experimental and naturally occurring ETEC infections. Antigen 43 is represented as a potential target in vaccine development because of its virulence functions such as cell aggregation, biofilm formation and its presence in convalescent sera from human patients with ETEC diarrhea. OBJECTIVES: In this study, we carefully investigate antigenic structure and immunogenicity of the Antigen 43 protein of strain 510 E.coli isolated from calves by experimental methods and immunoinformatics tools. METHODS: Amino acid sequence, physico-chemical parameters, stability, secondary and tertiary protein structure, the ability of induction the B and T cell immune responses by having the effective epitopes and also the allergenicity assessment were analyzed. RESULTS: In this study, we identified 15 peptide sequences that can potentially induce B and T cell immune responses and finally, 9 of them were introduced as antigens. CONCLUSIONS: The results of in-silico analysis on this protein suggested that it can be used in bovine colibacillosis vaccine development.

BACKGROUND: The mechanism of pathogenesis and the role of virulence factors of avian pathogenic E. coli is still ill-defined. The ostrich industry is expanding, resulting in the interaction between poultry and ostrich. It is reported that the investigation of iss and bor virulence genes together, due to their structural and functional similarities, is valuable. Objectives: The investigation and comparison of presence of two genes involved in serum resistance, iss and bor, in E. coli isolated from apparently healthy ostriches and poultry with colibacillosis. Methods: As a cross-sectional study, E. coli was recovered from fecal samples of apparently healthy ostriches and poultry with colibacillosis, and iss and bor genes were screened and compared via PCR in E. coli isolates. Results: iss frequencies, with no statistical difference, were 50% and 64.4% in E. coli isolated from apparently healthy ostriches and poultry with colibacillosis, respectively (P>0.05). 31.8% and 15.6% of E. coli isolated from apparently healthy ostriches and poultry with colibacillosis were positive for bor, respectively, with no statistical difference (P>0.05). 11.1% of isolates from colibacillosis and 18.2% of isolates from apparently healthy ostriches feces, with no statistical difference, were positive for both genes (P>0.05). Conclusions: Equal statistical distribution of both genes, bor and iss, between apparently healthy ostriches and poultry with colibacillosis and the health level of studied ostriches indicated that E. coli isolated from ostrich, probably employs other virulence factors instead of bor and iss to establish a disease. This hypothesis needs to examine more virulence genes in ostrich-origin E. coli. In addition, the ostrich feces could be introduced as a source of iss and bor genes.

Colibacillosis is a disease caused by avian pathogenic E. coli (APEC) and is one of the principle cause of morbidity and mortality in poultry worldwide which is represented by a complex syndrome characterized by multiple organ lesions. This study was carried out to determine phylogenetic grouping and virulenceassociated genes contained by E. coli isolates which is related in causing disease in chicken. E. coli isolates obtained from clinical cases of Veterinary ResearchInstitute were re-identified by conventional methods. Phylogenetic grouping of the isolates was determined by triplex polymerase chain reaction (PCR), and the presence of eight virulence genes were identified by multiplex PCR. A total of 125 E. coli isolates were subjected toanalysis of phylogenetic background and virulence associated genes profiling. Phylogenetic analysis demonstrated that most of the E. coli isolated from chicken in this study belonged to group B1 (36.0%),group D (28.0%), group A (27.2%) and group B2 (8.8%). Multiplex PCR analysis demonstrated that 96 (78.6%) of the E. coli isolates harbored at least one virulencegene, while 29 (23.3%) did not contain any virulence genes tested. The most prevalent virulence genes identified were iss (51.2%), followed by iucD (36.0%),tsh (32.8%), vat (16.0%), astA (13.6%), irp2 (11.2%), papC (9.6%) and the least is cva/cvi gene (0%). None of the isolates harbored more than four virulence genes.Each of phylogenetic groups presented with different combinations of virulence genes, with no specific combinations of virulence genes found to correlate withE. coli phylogroups. None of the E. coli isolates harbored more than four virulence genes, suggesting that E. coli isolates from chicken in this study appear to bederived from commensal strains and may relate to environmental predispose factors especially stress factors in the host to establish infection.

Colibacillosis is animportant disease affecting the poultryindustry in many countries, caused bythe Avian Pathogenic E. coli (APEC):it manifests as various clinical signs. Itcontributes significantly to economicloss for poultry farmers as a result ofhigh mortality and morbidity in poultry.To overcome this, antibiotics have beenwidely used to eliminate E. coli infectionin poultry farms in recent years. Treatmentwith antibiotics has been considered as avital regimen to control E. coli infectionat the farm level for many years. However,high frequency of antibiotic resistance ofE. coli isolates from chicken has becomethe centre of attention due to public healthimportance. The aim of the present study isto determine the multidrug resistant profilesof E. coli strains isolated from chicken.E. coli isolates obtained from clinicalcases were re-identified and classified byconventional methods. Multidrug resistantprofiles against 13 different antibiotics of125 E. coli isolates were determined byusing disk diffusion method accordingto Clinical Laboratory Standard Institute(CLSI). Antibiogram revealed that 81.6%of the E. coli isolates showed multidrugresistant profiles to different antibiotics.Most of the E.coli isolates were highlyresistant to erythromycin (52.8%), followedwith tetracycline (52.0%), spectinomycin(39.2%), trimethoprim (38.4%) andflumequin (37.6%). Out of 125 isolatestested, 19.2% were resistant to more thaneight antibiotics, with one isolates found tobe multidrug resistant to most of antibioticsexcept polymyxin B. These findings alsodemonstrated that most of the isolateswere susceptible to antibiotics commonlyused for E.coli infections treatment inpoultry with lowest resistant score againstpolymyxin B (92.8%) and colistin (92.0%).Moderate resistant profiles were observedtowards amoxycilin (25.6%), apramycin(16%), kanamycin (8.8%) and streptomycin(8.0%). High percentage of multidrugresistance was found among the E. coliisolated from chicken as an indicator tomore serious problems in animal health.Therefore, continuous surveillance of antibiotic resistance profiles in chicken andother food animals is crucial to ensure foodchain safety

This study was conducted to investigate the high mortality of young lambs in two sheep farms in Pekan, Pahang over a period of 3 years. Samples from postmortem of 1,451 lambs below one year of age by a farm veterinarian were submitted for laboratory diagnosis at the Bacteriology Section of the Regional Veterinary Diagnostic Laboratory in Kuantan. Escherichia coli is the most commonly recorded bacteria with 161 lambs diagnosed in 2013. In 2014 and 2015, there was a decrease in occurrence of E. coli related deaths, with 120 and 75lambs respectively. A total of 25% of the cases showed Escherichia coli positive by culture on blood agar and MacConkey agar, and confirmed by biochemical tests. A total of 21% of the cases were positive for staphylococcus sp, 3% and 6% for Streptococcus sp and Klebsiella pneumonia, respectively. Other bacteria were isolated in 45% of the cases. It was further noted that a total of 285 lambs between the ages of one to four months of age followed by 58 lambs (20%) less than one month old had E.coli isolation. It is also noteworthy that there were 10 lambs with E.coli infection in one to fourteen day-old lambs during the 3-year period from January 2013 to December 2015. This information was collated as a result of routine diagnosis of field cases submitted and with the intention of highlighting the common pathogens causing high mortality in local small ruminant farms so that preventive action may be taken for future farming ventures. E. coli infections or Colibacillosis is an important finding and indicator of poor management including poor nutrition, hygiene and environmental contamination which can reduce animal immunity and render it susceptible to other infections.

Two experiments were carried out to evaluate the efficacy of the administration of active dry yeast and/or lactobacillus preparation (AVI-BAC), either before or after the infection with antibiotic resistant field strain of Escherichia coli O127 (E. coli O127) in controlling the severity of infection in quail chicks. The quail chicks of the different experimental groups were infected orally for two successive days with 3x107 CFU of E. coli O-127 as an individual dose. The used field strain proved to be highly pathogenic for quails. Probiotics were supplemented in the drinking water for the different treatment groups at a dose level of 0.5 gm/L. The results revealed that the inclusion of lactobacilli or active dry yeast before E. coli infection has been highly effective in reducing mortality rate, organ invasion and the number of E. coli positive quail chicks. In addition, it decreased the severity of macroscopic and microscopic lesions in different organs in the probiotic treated groups as compared to the infected controls. Lactobacilli preparations were more efficient in controlling the severity of the infection. On the other hand, the administration of yeast and /or lactobacilli after inducing E. coli infection reduced the mortality rate and the severity of lesion score in different organs but probiotics failed to protect quail chicks against the infection. It has been proved that the two probiotics have synergistic effect in controlling collibacillosis in quails.

Escherichia coli (E. coli) is a gram-negative bacterium that has economic and public health importance. E. coli strains have been classified into pathogenic and non-pathogenic strains. The pathogenic strains of E. coli can cause colibacillosis, which is a common bacterial disease in the poultry industry and the poultry farms in the region. The objective of the study was to investigate the prevalence of E. coli, its serotypes (O1, O2, O18 and O78) and their antimicrobial susceptibility in the colibacillosis cases in Sulaymaniyah province using culture, antimicrobial susceptibility and molecular approaches. A total of 86 broiler farms were investigated from November 2021 to June 2022. From each farm, samples (liver and heart) were taken from 3-5 broilers colibacillosis cases. The results showed that the colonies that had metallic-green sheen morphologies were positive for E. coli (62/86; 72.1%), in which only 23/62 (37.1%) of the isolates were positive for O2 (7/62; 11.3%), O18 (14/62; 22.6%), and O78 (2/62; 3.2%). While O1 was undetectable in the investigated colibacillosis cases. O18 was predominantly (7/86; 8.1%) detected among 20-30 days-old chickens and followed by O2 (4/86; 4.7%) in 10-20 days-old chickens. The results showed that the majorities of the detected E. coli in colibacillosis cases were isolated from the imported chick from Iran (30; 34.9%) and Netherlands (28; 32.6%). In conclusion, the results showed that the majorites of the colibacillosis cases in the region were caused by E. coli. The E. coli and its serotypes (O2, O18 and O78) had high prevalence in the region.

A total of 23,322 specimens collected between 2014 and 2017, froma total of 2,592 cases, were received in Veterinary Research Institute, Ipoh (VRI) from various states in Malaysia and testedfor common bacterial, viral, and parasitic diseases in pigs. The highest occurrence of isolated bacteria from 771 samples whichtested positive were Salmonella (47.38%) and Escherichia coli (15.68%), followed by Staphylococcus (6.62%), Streptococcus (5.57%), Klebsiella pneumonia (4.88%), Pseudomona (3.38%), Acinetobacter (3.14%), Aeromonas (2.79%), Enterobacter (2.44%), one each of Bacillus and Pasteurella multocida (1.74%), Enterococcus (1.39%) and Corynebacterium (1.05%). 1.74% of each bacteria detected were Moxarella, Aspergillus, Burkholderia andChromobacterium. Positive samples tested by ELISA was Japanese encephalitis virus (JEV) (9.15%), Aujezsky disease virus (ADV)(5.37%), porcine cirvo-virus-2 (PCV2) (5.09%) and porcine reproductive and respiratory syndrome virus (PRRSV) (4.52%). Positive amples tested by the molecular test wasPCV2 (1.62%), PRRSV (1.32%) and classical swine fever virus (CSFV) (0.4%). Serology tests were conducted on 11,305 samplesand reported positive for Brucella suis (15.32%), Brucella abortus (0.62%), Brucella melitensis (0.85%), and melioidosis (0.05%). Parasitology analyses on 99 samples. revealed presence of 10.1% coccidia and 1% each of helminths and Sarcocystis. Within the 4-year period, there were no positive samples for porcine parvovirus (PPV), Nipah virus, swine influenza virus (SIV), and bacteria of Johne’s disease and leptospirosis. Continuous assessment is required to establish a comprehensive baseline data of swine diseases in Malaysia.