E. coli infections in avian species are an economic threat to the poultry industry worldwide. The spread of MDR bacteria has been recognized as an increasing problem in the veterinary and medical fields. The current study aimed to investigate the phenotypic and genotypic antimicrobial patterns of avian Pathogenic E. coli isolated from broiler chickens. Results of in-vitro antimicrobial susceptibility testing showed that E. coli isolates were more sensitive to imipenem only (72.4%). On the other hand, they were highly resistant to most of used antimicrobials including ciprofloxacin (95.9%), amikacin (94.9%), cefotaxime sodium (92.9%), gentamicin (89.9%), cefotriaxone (89.9%), topramycin (87.8%), sulphamethoxazole/trimethoprime (85.7%), ceftazidim (84.7%). Also, they were resistant to cefoprazone (79.9%), doxycycline (72.4%) and amoxycillin/clavulinic acid (69.4%). All the tested isolates of E. coli (100%) were multi drug resistant (MDR). PCR was applied on 15 MDR E. coli isolates to determine 4 genes responsible for antibiotic resistance included ampC, blaCTX, blaSHV and tetA (A). The results revealed that that ampC and blaCTX genes were the most prevalent found in all isolates (100%) while tetA (A) and blaSHV genes were harbored in 14 isolates (93.3%).

Marek’s disease (MD) is a tumourous disease caused by Marek’s disease virus (MDV) and most commonly described in poultry. The aim of the study was to determine the occurrence of Marek’s disease virus infections in Poland and analyse clinical cases in the years 2015–2018. The birds for diagnostic examination originated from 71 poultry flocks of various types of production. Birds were subjected to anatomopathological examination post mortem, during which liver and spleen sections and other pathologically changed internal organs were taken. These sections were homogenised with generally accepted methods, then total DNA was isolated and amplified with a real-time PCR. A pair of primers complementary to the MDV genome region encoding the meq gene were used. MDV infection was found predominantly in broiler chicken flocks (69.01%), and also in layer breeder (9.85%) and commercial layer flocks (7.04% each). The results of research conducted in the years 2015–2018 clearly indicate that the problem of MDV infections is still current.

A significant threat to public health is presented by antibiotic-resistant strains of bacteria, selective pressure on which results from antibiotic use. Colistin is an antibiotic commonly used in veterinary medicine, but also one of last resort in human medicine. Since the 2015 discovery in China of the mcr-1 gene encoding colistin resistance in Enterobacteriaceae, other countries have noted its presence. This study was to find the mcr-1 gene prevalence in E. coli isolated from poultry slaughtered in Poland. Cloacal swabs were taken from December 2017 to October 2018 from broiler chickens in three regions. The samples (n = 158) were grouped as flocks treated with colistin sulphate (n = 87) and those not treated (n = 71). Resistance to antimicrobials commonly used in poultry was evaluated by minimum inhibitory concentration. The presence of the mcr-1 gene was confirmed by PCR. Isolates containing the mcr-1 gene were yielded by 11.27% of the samples from not treated flocks and 19.54% of those from treated flocks, but no statistically significant difference in the prevalence of the gene was seen between the groups. The results clearly preclude intensification of selective pressure for colistin resistance due to colistin sulphate treatment because they show that the avian gastrointestinal tract was already inhabited by colistin-resistant E. coli by the time the chickens came to the poultry house.

Introduction: The study sought to characterise antimicrobial resistance among coagulase-negative Staphylococcus (CNS) species recovered from broiler chickens and turkeys in Poland including the presence of 12 antimicrobial resistance genes and five classical genes of staphylococcal enterotoxins. Material and Methods: A panel of 11 antimicrobial disks evaluated the phenotypic sensitivity of the tested strains to antibiotics. Five multiplex PCR assays were performed using primer pairs for specific detection of antibiotic resistance genes and staphylococcal enterotoxin A to E genes. Results: Selected antimicrobial agent susceptibility testing revealed 100% of such in in vitro conditions to cefoxitin among strains of Staphylococcus sciuri and S. chromogenes. The blaZ (for ß-lactam) and mecA (for methicillin resistance) genes were in 58.3% and 27.5% of strains, respectively. Among genes resistant to tetracyclines, tetK was most frequent. Fewer (CNS) strains showed genes resistant to macrolides, lincosamides, and florfenicol/chloramphenicol. Multiplex PCR for classical enterotoxins (A-E) detected the see gene in two S. hominis strains, while the seb gene producing enterotoxin B was found in one strain of S. epidermidis. Conclusion: CNS strains of Staphylococcus isolated from poultry were either phenotypically or genotypically multidrug resistant. Testing for the presence of the five classical enterotoxin genes showed that CNS strains, as in the case of S. aureus strains, can be a source of food intoxications.

Introduction: Avian reovirus (ARV) infections in poultry populations are reported worldwide. The reovirus belongs to the genus Orthoreovirus, family Reoviridae. The aim of the study was to evaluate the incidence of ARV infections in the poultry population based on diagnostic tests performed in 2010–2017. Material and Methods: Samples of the liver and spleen were collected from sick birds suspected of ARV infection and sent for diagnostics. Isolation was performed in 5–7-day-old SPF chicken embryos infected into the yolk sac with homogenates of internal organs of sick birds. Four primer pairs were used to detect the σNS, σC, σA, and µA ARV RNA gene fragments. A nested PCR was used for the detection of the σNS and σC genes. Results: In 2010–2017, ARV infection was found in birds from 81 flocks of broiler chickens and/or layers, 8 flocks of slaughter turkeys, and in 4 hatchery embryos at 17–20 days of incubation. The primers used in RT-PCR and nested PCR did not allow effective detection of ARV RNA in all virus-positive samples. Conclusion: The problem of ARV infections in the poultry population in Poland still persist. The primers used for various ARV segments in RT-PCR and nested PCR did not allow effective detection of RNA in the visceral organs of sick birds. The presented results confirm the necessity of using classical diagnostic methods (isolation in chicken embryos, AGID).

Introduction: Despite the advancements in the field, there is a lack of data when it comes to co-infections in poultry. Therefore, this study was designed to address this issue. Material and Methods: Broiler birds were experimentally infected with E. coli (O78) and low pathogenic avian influenza (LPAI) strain, alone or in combination. The experimental groups were negative control. Results: The infected birds showed most severe clinical signs in E. coli+LPAI group along with a significant decrease in weight and enhanced macroscopic and microscopic pathological lesions. The survival rate was 60%, 84%, and 100% in birds inoculated with E. coli+LPAI, E. coli, and LPAI virus alone, respectively. The results showed that experimental co-infection with E. coli and H9N2 strain of LPAI virus increased the severity of clinical signs, mortality rate, and gross lesions. The HI titre against LPAI virus infection in the co-infected group was significantly higher than the HI titre of LPAI group, which may indicate that E. coli may promote propagation of H9N2 LPAI virus by alteration of immune response. Conclusion: The present study revealed that co-infection with E. coli and H9N2 LPAI virus caused more serious synergistic pathogenic effects and indicates the role of both pathogens as complicating factors in poultry infections.

A total of 180 samples were taken from diseased and freshly dead broiler chickens of various ages from various farms in El-Minya and Beni-Suef governorates and transferred to the lab for bacterial isolation and further molecular examination targeting E. coli. The results showed that 91 of 180 samples (50.6%) tested positive for E. coli. The   prevalence of some in vitro virulence markers of avian pathogenic E. coli was Congo red binding (CRB) (95.6% positivity) and moderate to strong biofilm production (92%). On 5% sheep blood agar, (67%) of examined isolates showed alpha hemolysis, while (27%) showed gamma hemolysis  and (5.5%) showed beta hemolysis. All the tested isolates exhibited a multidrug resistance (MDR) pattern. E. coli isolates demonstrated various degrees of resistance against, amoxicillin–sulbactam (82%) followed by streptomycin (76%), cefotaxime and trimethoprim/sulphamethoxazole (73%), tetracycline and ciprofloxacin (68%), chloramphenicol (66%), cefaclor (65%), cefixime (62%) respectively. Five MDR selected isolates were examined using PCR. The intended virulence genes were iss, tsh, fimH, and iroN genes. The genes iss and fimH were detected in all of the isolates investigated, whereas iroN was present in four isolates but tsh was found in only one isolate.

This study was planned to evaluate the extracts of Aloe vera (AV) at three different pH as a growth promoter, immunostimulant and coccidiostat agent in broiler production. This experiment was undertaken for a period of 35 days in the Institute of Animal Sciences, Faculty of Animal Husbandry, University of Agriculture Faisalabad, Pakistan. A total of 150 dayold broiler birds (Cobb) were randomly assigned to 5 treatments with 3 replicates of 10 chicks each. Birds were offered commercial broiler starter and finisher diets supplemented with 100 mg/kg enramycin (ANT), 50 ml/liter AV of pH 3 (AV1), 50 ml/liter AV of pH 7 (AV2), 50 ml/liter AV of pH 12 (AV3) and only fresh clean water (CON).

Poultry has been identified as a reservoir of foodborne enteric pathogens and antimicrobial resistant bacteria. The objective of this study was to describe and compare antimicrobial resistant isolates from an Ontario broiler chicken farm-level baseline project (2003 to 2004) to the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) Ontario abattoir and retail surveillance data from 2003, and to the most recent (2015) CIPARS Ontario chicken surveillance data in order to assess the impact of an industry-wide policy change in antimicrobial use. Ceftiofur resistance (TIO-R) prevalence in Salmonella decreased by 7% on farm between 2003 and 2004 and 2015. During the same timeframe, TIO-R E. coli prevalence decreased significantly by 16%, 11%, and 8% in farm, abattoir, and retail samples, respectively. Gentamicin resistant (GEN-R) E. coli, however, increased by 10% in farm and 15% in retail-derived isolates, and trimethoprim-sulfamethoxazole resistant (TMSm-R) E. coli increased significantly by 20%, 18%, and 5% in farm, abattoir, and retail isolates, respectively. Similarly, ciprofloxacin-resistant (CIP-R) Campylobacter spp. significantly increased in retail isolates by 11% and increased in farm (33%) and abattoir isolates (7%). The decrease in TIO-R Salmonella/E. coli in recent years is consistent with the timing of an industry-led intervention eliminating the preventive use of ceftiofur, a third generation cephalosporin and class of antimicrobials deemed critically important to human medicine. The rise in GEN-R and TMSm-R prevalence is indicative of recent shifts in antimicrobial use. Our study highlights the importance of integrated surveillance in detecting emerging trends and determining the efficacy of interventions to improve food safety.

The microbial community is known to have a key role during the rearing period of broilers. In this study, gut microbial composition and diversity were examined to evaluate the relationships between these factors and broiler growth performance. By applying 454-pyrosequencing of the V1-V3 regions of bacterial 16S rRNA genes, six fecal samples from four- and 28-day-old chickens from three broiler farms and 24 intestinal samples of broilers with heavy and light body weights were analyzed. Microbial composition assessment revealed Firmicutes to be the most prevalent phylum at farm A, while Proteobacteria were predominant at farms B and C. Fecal microbial richness and diversity indices gradually increased from four to 28 days at all three farms. Microbial diversity assessment revealed that small intestine microbial diversity was lower in heavy birds than in light birds. In light birds, the Firmicutes proportion was lower than that in heavy birds. In conclusion, each broiler farm revealed a specific microbial profile which varied with the age of the birds. The microbial communities appeared to affect growth performance; therefore, gut microbial profiles can be utilized to monitor growth performance at broiler farms.