BACKGROUND: Nowadays due to the extensive use of antibiotics, antimicrobial resistance is recognized as a global concern for the health of animals and humans. The consequences of antimicrobial resistance are resistance of zoonotic pathogenic factors and reductions in the effectiveness of treatment for many diseases. OBJECTIVES: The aims of this study are the monitoring and prevalence of antimicrobial residues of the poultry carcasses in Kerman poultry abattoirs. METHODS: A cross sectional study was conducted from June 2015 to October 2016. A total of 474 samples were collected from Kerman province poultry abattoirs and tested with four plate test (FPT) method. Data were analyzed  using Descriptive statistics for qualitative data with 95 % confidence interval. RESULTS: A total of 38 samples were positive (8/02 %), Antibiotics isolates included: Fluoroquinolone, Macrolide, Cephalosporin, β-lactam, Tetracycline, Sulfonamide and Amino glycoside. The highest rate of antibiotics isolated in positive samples was Fluoroquinolone (36/1 %) and the lowest rate was cephalosporin (4/1 %). Half of the samples were positive for one type of antibiotic (Fluoroquinolone), 28/9 % for two types of antibiotics, 13/1 % for three types of antibiotics, 5/2%  for five kinds of antibiotics and 2/6 % for six kinds of antibiotics. CONCLUSIONS: The results of the study showed that about 10 percent of the meat consumed in this province has antimicrobial residues. Therefore, it can be suggested that proper management strategies for controlling the veterinary drug usage in poultry farms be implemented.

BACKGROUND: Infectious diseases widely occur through bacteria such as Salmonella spp. in different hosts such as domestic animals and human. OBJECTIVES: The aim of this study was to isolate Salmonella Typhimurium bacteria from poultry feces and in vitro assessment of antimicrobial effects of 9 species of Zagros native medicinal plants. METHODS: Ethanol extracts of jooshir, shallots, Iranian eremurus, artichokes, sheng, amaranth, sorrel, oregano and harmel were extracted through rotary vacuum system. Furthermore, 12 strains of Salmonella Typhimurium were isolated from poultry feces in Sistan region. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of plant extracts were determined through micro dilution method. Sensitivity of different strains to antibiotics was tested through standard Kirby-Bauer diffusion disk methods. RESULTS: Salmonella Typhimurium strains are resistant to Penicillin (100%), Ampicillin (100%), Tetracycline (16.6%), Amikacin (8.3%) and Oxacillin (75.0%). Results of the antimicrobial assay have shown that extracts of amaranth, jooshir and artichokes had the highest MIC against Salmonella Typhimurium. CONCLUSIONS: Results of the current study showed that according to the antibiotic resistance of Salmonella Typhimurium isolated from poultry, antibiotic treatment, in particular with penicillin, ampicillin and oxacillin with the bacterium resistance of 75 to 100% would not be effective. In contrast, using plant ethanol extracts especially jooshir, amaranth and artichokes could be recommended as an alternative to conventional antibiotic treatments.

BACKGROUND: Virulent Newcastle disease virus (vNDV) imposes significant economic losses to the commercial poultry industry in our country and worldwide. However, in Iran scattered and relatively few studies have been done in order to characterize NDV isolates.   OBJECTIVES: The aim of the present study was to characterize two vNDV isolates obtained from commercial poultry farms in Isfahan province in 1999 through Haemagglutinin-Neuraminidase (HN) gene complete sequencing. METHODS: Haemagglutinin-Neuraminidase (HN) gene of each NDV isolate was amplified and sequenced using specific primers and then phylogenetically analyzed. RESULTS: Based on complete coding sequence of HN gene analysis, studied isolates showed close relationship with genotype XIII and subgenotype XIIIa NDV strains. Analysis of both complete HN gene and partial F gene lead to identical results and same classification of studied viruses. CONCLUSIONS: Results of present study are useful  for a better understanding of molecular epidemiology of indigenous NDV strains and determining important molecular differences between field and commonly used vaccinal strains related to main immunogenic proteins.

Phenotypic characteristics of 12 paired, Salmonella serotypes isolated from healthy and ill chickens were compared. Variables compared included antibiotic resistance profiles, production of colicins and siderophores, mannose-sensitive hemagglutination of erythrocytes, resistance to serum complement, carbon source utilization, presence and transmissibility of R plasmids, and invasiveness in primary chicken kidney cell culture. Differences were found between pairs for utilization of carbon sources, mannose-sensitive hemagglutination of erythrocytes, and invasiveness in cell culture.

When Salmonella typhimurium and Clostridium perfringens were tested in conventional chickens, larger numbers of S typhimurium and C perfringens adhered to Eimeria tenella-infected ceca than to uninfected ceca. In germ-free chickens, S typhimurium and C perfringens adhered to the E tenella-infected cecal mucosa more than to the uninfected cecal mucosa, but fewer Bacteroides vulgatus and Bifidobacterium thermophilum adhered to the E tenella-infected ceca than to the uninfected ceca. Many bacteria adhered to the lesions caused by E tenella as observed by scanning electron microscopy. On the basis of our findings, we suggest that infection with E tenella upsets the balance of competitive adherence of bacteria, allowing more colonization of S typhimurium and C perfringens.

Atracurium besylate, a nondepolarizing neuromuscular blocking agent, was administered to 24 isoflurane-anesthetized domestic chickens. Birds were randomly assigned to 4 groups, and atracurium was administered at dosage of 0.15, 0.25, 0.35 or 0.45 mg/kg of body weight. The time of onset of twitch depression, the amount of maximal twitch depression, and the duration of muscular relaxation were recorded. After return to control twitch height, atracurium was further administered to achieve > 75% twitch depression. When twitch depression reached 75% during noninduced recovery, 0.5 mg of edrophonium/kg was administered to reverse the muscle relaxation. Throughout the experimental period, cardiovascular, arterial blood gas, and acid-base variables were monitored. The effective dosage of atracurium to result in 95% twitch depression in 50% of birds, (ED95/9595) was calculated, using probit analysis, to be 0.25 mg/kg, whereas the ED95/95 the dosage of atracurium to result in 95% twitch depression in 95% of birds, was calculated by probit analysis to be 0.46 mg/kg. The total duration of action at dosage of 0.25 mg/kg was 34.5 +/- 5.8 minutes; at the highest dosage (0.45 mg/kg), total duration increased to 47.8 +/- 10.3 minutes. The return to control twitch height was greatly hastened by administration of edrophonium. Small, but statistically significant changes in heart rate and systolic blood pressure, were associated with administration of atracurium and edrophonium. These changes would not be clinically relevant. In this study, atracurium was found to be safe and reliable for induction of muscle relaxation in isoflurane anesthetized chickens.

Carvacrol is an essential oil extracted from oregano which can be used as a natural additive in poultry litter and could have a positive impact not only on production rates but also on the quality of poultry meat. The aim of this study was to evaluate the effect of the addition of carvacrol to litter on weight gain and the occurrence of residues in chicken tissues.