Detection of Residual Antibiotics and Their Differential Distribution in Broiler Chicken Tissues Using Enzyme-Linked Immunosorbent Assay.

The aim of this study was to estimate the residue levels of five commonly used antibiotics in poultry tissue samples using enzyme linked immunosorbent assay (ELISA). A total of 200 samples that comprised breast and liver (100 each) were collected from five poultry farms randomly selected from Muscat regions. The samples were analyzed for enrofloxacin (ENR), gentamicin (GEN), oxytetracycline (OTC), sulfamethazine (SMZ), and tylosin (TYL) residue concentrations. Comparisons of antibiotic residues between breast and liver of chickens under investigations showed a significant difference of ENR, GEN, OTC, SMZ, and TYL residue concentrations (p < 0.05). The highest antibiotic residue concentrations reported in the chicken liver were TYL, GEN, OTC, SMZ, and ENR, respectively. The lowest residual antibiotic concentrations observed in the chicken breast were TYL, GEN, OTC, SMZ, and ENR, respectively. Furthermore, the Kruskal-Wallis statistical test revealed a significant difference between the five antibiotic concentrations in both breast (H (4) = 54.69, p < 0.05) and liver (H (4) = 44.36, p < 0.05). A follow up of this finding by Bonferroni correction for both breast and liver samples revealed a significant difference for the breast sample between the concentration of ENR residue, and the concentration of residues for of both OTC and TYL (p < 0.05). These data show that not all tissues incorporate antibiotics at the same concentration. The results of this study could support regulatory bodies in adopting, monitoring, and enforcing guidelines pertinent to safety levels of different antibiotic residue concentrations in poultry meat when antibiotics are used for different indications.

Diversity of Intestinal Bacterial Microbiota of Indigenous and Commercial Strains of Chickens Using 16S rDNA-Based Analysis.

The objective of this study was to assess the relative abundance of bacteria microflora in different segments of the gastrointestinal tract (duodenum, jejunum, ilium, and cecum) of indigenous (local Omani) and commercial (Cobb 500) chicken strains. Birds were raised under an intensive management system fed a nonmedicated corn-soybean meal diet from Day 0-35 days of age. Using 16S rDNA-based analysis the study showed that in both breeds of birds Bacilli were the most abundant class of bacteria in the duodenum, jejunum, and ileum. Local Omani chickens had significantly higher numbers of Clostridia at most time periods. Actinobacteria were found in higher numbers and reached 54.9% of the bacteria in the jejunum at Day 35 in Cobb 500 versus only 5.42% in the Omani chickens. The bacterial microbiota relative abundance differed significantly (p < 0.05) across different intestinal segments of the two strains, suggesting that each region developed its own bacterial community and the relative abundances of these were quite different.

Middle East respiratory syndrome coronavirus neutralising serum antibodies in dromedary camels: a comparative serological study.

BACKGROUND: A new betacoronavirus-Middle East respiratory syndrome coronavirus (MERS-CoV)-has been identified in patients with severe acute respiratory infection. Although related viruses infect bats, molecular clock analyses have been unable to identify direct ancestors of MERS-CoV. Anecdotal exposure histories suggest that patients had been in contact with dromedary camels or goats. We investigated possible animal reservoirs of MERS-CoV by assessing specific serum antibodies in livestock. METHODS: We took sera from animals in the Middle East (Oman) and from elsewhere (Spain, Netherlands, Chile). Cattle (n=80), sheep (n=40), goats (n=40), dromedary camels (n=155), and various other camelid species (n=34) were tested for specific serum IgG by protein microarray using the receptor-binding S1 subunits of spike proteins of MERS-CoV, severe acute respiratory syndrome coronavirus, and human coronavirus OC43. Results were confirmed by virus neutralisation tests for MERS-CoV and bovine coronavirus. FINDINGS: 50 of 50 (100%) sera from Omani camels and 15 of 105 (14%) from Spanish camels had protein-specific antibodies against MERS-CoV spike. Sera from European sheep, goats, cattle, and other camelids had no such antibodies. MERS-CoV neutralising antibody titres varied between 1/320 and 1/2560 for the Omani camel sera and between 1/20 and 1/320 for the Spanish camel sera. There was no evidence for cross-neutralisation by bovine coronavirus antibodies. INTERPRETATION: MERS-CoV or a related virus has infected camel populations. Both titres and seroprevalences in sera from different locations in Oman suggest widespread infection. FUNDING: European Union, European Centre For Disease Prevention and Control, Deutsche Forschungsgemeinschaft.

Expression, purification and crystallization of a collagen-binding fragment of Yersinia adhesin YadA.

A recombinant form of a collagen-binding fragment of Yersinia enterocolitica serotype O:3 adhesin YadA with an N-terminal polyhistidine affinity tag has been produced in Escherichia coli, purified and crystallized using the sitting-drop vapour-diffusion technique. Crystals belong to the trigonal space group R3, with unit-cell parameters a = b = 67.05, c = 221.95 A, and diffract to 1.55 A resolution on a synchrotron-radiation source.