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.

Avian pathogenic E. coli (APEC) is the causative agent of colibacillosis in broiler chicken and various antibacterials used to control the infection may lead to the development of multidrug-resistant (MDR) and pan drug-resistant bacteria. Further, antibacterial resistant bacteria also emerge as a result of inappropriate use of antibacterials in chicken, reducing the efficacy of antibacterials used for medical purposes. Keeping this in view, this study was conducted to evaluate the in vitro antibacterial property of vitamin C against resistant bacteria when used along with enrofloxacin. A total of 60 liver swabs collected from the field were used in this study. E. coli were isolated using selective media and were genotypically confirmed by amplification of Adk gene. The resistant genes (qnrA, qnrB and qnrS) were detected through PCR. E. coli isolates were subjected to antimicrobial screening against enrofloxacin and vitamin C (L- ascorbic acid) both by qualitative method and quantitative method. Kirby-Bauer disc diffusion revealed enrofloxacin resistance in 83.33 percent of samples. The MIC of enrofloxacin against resistant isolates was 90.25 μg/ml, but when vitamin C was administered, the MIC was non-significantly lowered to 86.16 μg/ml in the macro broth dilution method. It was also found that vitamin C alone exhibited antibacterial activity at a concentration of ≥ 5 mg/ml. Hence, it is likely that vitamin C may improve antibacterial effects of enrofloxacin in poultry.

Coligranuloma is an economically important bacterial disease caused by Escherichia coli and is characterized by nodular granulomas in liver, mesentery and walls of intestine. Three adult white leghorn layer birds of 24-week-old were brought for necropsy examination from Jeelakarragudem village of West Godavari district. Upon necropsy, the birds revealed typically hard, yellow, nodular granulomas in the mesentery and on the wall of the intestines with few tiny nodular lesions on the liver. Impression smears of the nodules showed large number of gram-negative rod-shaped organisms. The inoculums from the nodular lesions when streaked on to MacConkey agar and EMB agar resulted in characteristic rose-pink and metallic sheen colonies respectively. PCR targeting the E. coli 16S ribosomal DNA resulted in an amplicon of 585 bp. Based on the necropsy lesions, staining and cultural characteristics and PCR, the disease was confirmed as Coligranuloma.

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.

Fascioliasis is an importantparasitic disease caused by the liver flukeFasciola gigantica in Malaysia. Theinfestation of liver fluke in ruminants;cattle, sheep, goats and buffaloes can resultin economic losses to the country mainlydue to the drop in livestock production,reduction in growth rate, condemnationof liver, reduction in draught power andhigh usage of anthelmintics. This paperdescribes a case of liver fluke infestationin a two year old male buffalo that waseventually slaughtered. The buffalowas reported to be emaciated and wasreared in an oil palm plantation for useas draught power in buffalo-drawn cartsloaded with oil palm bunches; alongwith 18 other buffaloes of various ages.Previously, there were two cases of buffalodeaths from the same herd. The organand faecal samples were sent to KuantanRegional Veterinary Laboratory (RVL)for diagnostic work up. The receivedsamples were then sent to parasitology,histopathology and bacteriology sectionsfor laboratory analysis and confirmationon the pathogens. The bacteriology resultshowed Escherichia coli isolated in allinternal organs. Presence of adult flukes(Fasciola gigantica) were observed inthe bile duct of the liver through grossexamination and also histopathologicalevaluation and supported by the positiveresult of Fasciola ova via sedimentationtest conducted from the faecal sample, thusjustifying the final diagnosis as severe liverfluke infestation leading to emaciation andsimultaneously having colibacillosis.

Colibacillosis, a disease caused by avian pathogenic Escherichia coli (APEC), is one of the main causes of economic losses in the poultry industry worldwide. This study was carried out in order to determine the APEC-associated virulence genes contained by E. coli isolates causing colibacillosis in chickens. A total of 45 E. coli isolates were obtained from the diagnostics and research branch of the Central Veterinary Laboratories, Bulawayo, Zimbabwe. These isolates were obtained from chickens with confirmed cases of colibacillosis after postmortem examination. The presence of the iutA, hlyF, ompT, frz, sitD, fimH, kpsM, sitA, sopB, uvrY, pstB and vat genes were investigated by multiplex polymerase chain reaction (PCR) assay. Of the 45 isolates, 93% were positive for the presence of at least one virulence gene. The three most prevalent virulence genes were iutA (80%), fimH (33.3%) and hlyF (24.4%). The kpsM, pstB and ompT genes had the lowest prevalence, having been detected in only 2.2% of the isolates. All 12 virulence genes studied were detected in the 45 APEC isolates. Virulence gene profiles were constructed for each APEC isolate from the multiplex data. The APEC isolates were profiled as 62.2% fitting profile A, 31.1% profile B and 6.7% profile C. None of the isolates had more than seven virulence genes. Virulence profiles of Zimbabwean APEC isolates are different from those previously reported. Zimbabwean APEC isolates appear to be less pathogenic and may rely on environmental factors and stress in hosts to establish infection.