Evaluation of delaying effects of different short-term dosage regimens of topical ciprofloxacin on corneal ulcer healing in an avian model.

BACKGROUND: Knowledge on possible delaying effects of topical ciprofloxacin on corneal ulcer healing is scarce in avian patients. OBJECTIVES: The study evaluates effects of different dosage regimens of topical ciprofloxacin on healing of corneal ulcer in an avian model. METHODS: One hundred and fifty adult layers were randomly allocated into two equal categories each consisted of 5 groups (n = 15): 1, negative control (NC, normal cornea); 2, positive control (PC) (birds with experimental corneal ulcer); and 3, 4 and 5, birds with corneal injury that received ciprofloxacin 0.3% topically q6h, q8h and q12h, respectively for 3 (category 1) or 5 days (category 2). Corneas were excised for histopathological evaluation and determination of MMP-9 expression. RESULTS: While no significant difference was observed in daily-measured fluorescein-stained ulcer size among ciprofloxacin-treated birds and PC group in category 1, birds in PC group of category 2 had significantly smaller ulcers as compared to antibiotic-treated birds at the end of experiment (p < 0.01 for all cases). Histopathological evaluations at the end of the experiment showed no significant difference among PC and ciprofloxacin-treated birds of both categories for almost all of the assayed parameters. Over expression of MMP-9 mRNA was observed in PC group after 3 and 5 days of ulcer induction compared to NC groups. Its expression in ciprofloxacin-treated birds of both categories remained close to PC groups. CONCLUSIONS: While ciprofloxacin administration for 3 days does not affect ulcer healing, it delays healing process at the end of 5 days of treatments in an avian model of corneal ulcer injury. This delaying effect is not associated with a drastic change in MMP-9 expression.

Deterioration of wound healing and intense suppression of MMP-9 mRNA expression after short-term administration of different topical glucocorticoids or NSAIDs in an avian model of corneal lesions.

BACKGROUND: Corneal lesions are considered among important ophthalmic conditions in avian patients. Short-term outcome of using anti-inflammatory agents in corneal lesions of birds are not well-described. AIMS: The study evaluates effects of different anti-inflammatory agents on healing of alkali burn-induced corneal lesions in layer hens as an avian model. METHODS: Adult layers were randomly allocated into 7 groups (n=15) as follows: 1. Negative (normal) control (NC), and 2. Positive control (PC) with an experimentally induced-corneal lesion, 3-7. Birds with corneal lesions that were treated with dexamethasone, fluorometholone, prednisolone, ketorolac, or diclofenac eye-drops every 6 hours (QID) for 5 consecutive days. RESULTS: At the end of the experiment, proper healing was observed in PC group based on lesion area, while treated groups showed statistically larger lesion sizes as compared to PC birds (P<0.05). Although no significant difference was observed among groups, birds treated with ketorolac, diclofenac or fluorometholone had higher histopathological scores for most of the assayed parameters than other groups. Levels of tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) in corneal tissue of different groups were statistically the same. The mRNA expression of matrix metalloproteinase-9 (MMP-9) was increased 2.5 folds in PC group as compared to NC birds. However, birds treated with anti-inflammatory agents showed no detectable expression of MMP-9 mRNA. CONCLUSION: Five days of topical administration of non-steroidal anti-inflammatory agents (NSAIDs) or glucocorticoids (GCs) is associated with suppression of MMP-9 mRNA expression in corneal tissue and detrimental effects on wound healing in layers with alkali burn-induced corneal ulcers.

Assessment of type I interferons, clinical signs and virus shedding in broiler chickens with pre and post challenge Newcastle disease vaccination.

BACKGROUND: Newcastle disease (ND) causes devastating economic losses in poultry industry. AIMS: This study evaluates the plausible effect of prior or post challenge vaccination with a live commercial vaccine on some pathogenic aspects of velogenic Newcastle disease virus (vNDV) infection in broilers with an emphasis on elucidating type I interferons (IFNs) response trends. METHODS: Chicks (n=250) were randomly allocated into 5 equal groups including negative control (NC), positive control (PC) (challenged with vNDV), and treatment (T1-T3) groups: (T1) only received Villegas-Glisson/University of Georgia (VG/GA) strain of NDV vaccine, (T2) vaccinated 24 h prior to vNDV challenge, and (T3) vaccinated 24 h post vNDV challenge. Samples from trachea, cloacal content, and serum were collected at different time points to evaluate virus shedding or IFNs levels. RESULTS: Although clinical signs and lesions were not completely blocked by administration of vaccine prior to or post vNDV inoculation, the disease severity diminished as demonstrated by an increase in bird's survival rate and median survival days (MSDs). Moreover, prior to or post challenge VG/GA live vaccine administration, modified viral shedding patterns by decreasing the vNDV shedding period especially from the gastrointestinal (GI) system. Strong early type I IFNs response was observed in the trachea and sera of chickens vaccinated prior to or post-infection (pi) as compared to birds that received vaccine or vNDV alone. In trachea, IFN-α response was more pronounced than IFN-ß, while both IFNs showed a considerable change in serum. CONCLUSION: It seems that vaccination after challenge with vNDV can improve bird's health similar to prior administration and reduces virus shedding which may be due to type I IFNs production.

A primary occurrence of inclusion body hepatitis in absence of predisposing agents in commercial broilers in Iran: a case report.

BACKGROUND: Fowl adenoviruses (FAdVs) associated with certain clinical diseases including inclusion body hepatitis (IBH) have become of considerable importance in the poultry industry. Currently, an increasing number of IBH outbreaks in different parts of Iranian poultry industries is a growing concern. Infectious bursal disease virus (IBDV) or chicken infectious anemia virus (CIAV) have historically been incriminated as predisposing factors for FAdVs to cause IBH. Furthermore, some have speculated whether IBDV vaccine strains impact on IBH clinical manifestation. The present report assesses the potential predisposing role of IBDV, CIAV, and infectious bursal disease) IBD( vaccine strains for FAdVs in the course of an IBH occurrence in the field. CASE DESCRIPTION: 90000 day-old broiler chickens with the same parent source were housed, at 4 day-interval, in two commercial farms in Shiraz, Iran. Increased mortality with lesions of hepatitis, suggestive of IBH, started in the primitive farm right after blind prescription of IBD vaccine at the age of 12-days-old. Consequently, IBD vaccination was postponed for the apparently healthy chickens of the other farm in which chickens were monitored for the occurrence of IBH afterwards. Laboratory examination was followed by histopathology and polymerase chain reaction (PCR) on liver, cloacal bursa, and thymus samples to determine the involvement of FAdV, IBDV, and CIAV in the occurrence of the disease. FINDINGS/TREATMENT AND OUTCOME: No evidence was found to support the predisposing role of neither IBD vaccination nor IBDV/CIAV infection in this IBH occurrence. The results also demonstrated a primary role of the FAdV-11 as a causal agent of the IBH occurrence. CONCLUSION: The findings suggest that certain FAdVs are pathogenic enough to primarily induce IBH in young broilers.

Zataria multiflora, broiler health and performance: a review.

Zataria multiflora Boiss. (ZM) from Lamiaceae family, is an herb native to Iran, Pakistan, and Afghanistan with a history of use both as a condiment and a traditional medicine. The herb and/or its preparations have also shown promising effects in modern pharmacological studies. With regard to the importance of reducing synthetic drug administration both as growth promoters and therapeutic agents in poultry industry, this review is a short account of current knowledge about the beneficial effects of this herb on broiler health and performance parameters based on published materials in different databases such as Google Scholar, PubMed, ScienceDirect, Scientific Information Database, Scopus, etc. It seems that ZM, possibly due to the presence of thymol and carvacrol as its main constituents, can affect broiler's health especially with regard to its antioxidant effects, immunomodulatory properties and proper effects on gut bacterial pathogens and/or microbiota. It should be kept in mind that although major constituents of ZM essential oil (as the most studied preparation of the herb) are relatively similar, their relative content may show a broad range that can subsequently affect the outcome of ZM essential oil administration to broilers. Overall, ZM is a pluripotent herb and its effect on broilers should be more clarified in future studies.

Evaluation of the timing of the Escherichia coli co-infection on pathogenecity of H9N2 avian influenza virus in broiler chickens.

Bacterial co-infections can probably influence the pathogenicity of H9N2 low pathogenic avian influenza virus (AIV). This study aimed to evaluate the effect of exposure time to Escherichia coli (O:2) on the pathogenicity of H9N2 AIV in broiler chickens. Three hundred and sixty broiler chickens were randomly allocated to six equal groups. At the age of 26 days, all chicks except groups 5 and 6 were inoculated intra-nasally with H9N2 virus. At the same time, the birds in groups 1 and 5 were infected with E. coli via spray route. Birds in groups 3 and 2 were infected with E. coli three days prior to and three days post AI challenge, respectively. Mortality rates, clinical signs, gross and microscopic lesions, excretion and duration of virus shedding in faecal and tracheal samples and seroconversion to H9N2 virus were assessed in the challenged groups. The highest mortality rate was observed in chickens inoculated with H9N2 followed by E. coli. The most severe clinical signs, gross lesions, mortality rate and virus detection were observed at day 6 post challenge (PC) in birds of group 2, while the duration of virus shedding was longer in group 3 (E. coli followed by H9N2) than other groups. In conclusion, E. coli infection prior to, after or concurrently with H9N2 virus infection could exacerbate the adverse effects of the virus. Our results indicate that E. coli and H9N2 together can mutually exacerbate the condition of either disease in broiler chicks as compared to single infected birds.

Efficacy of thermostable I-2 Newcastle disease vaccine compared to B1 commercial vaccine in broiler chicken.

Frequent vaccination failures have occurred in the broiler farms in Eurasian countries during Newcastle disease outbreaks. The disease is enzootic in many countries of the region, especially in southwest Asia. I-2 vaccine has been used successfully in village chickens in many Asian and African countries. Our preliminary study showed good efficacy of the vaccine in broiler chickens. Therefore the current experimental study was conducted to compare viral shedding period of heat resistance I-2 vaccine with B1 commercial vaccine following challenge with Herts'33. For this purpose three hundred commercial broilers were randomly allocated into four groups; 1) Thermostable I-2 vaccine, 2) Hitchner B1 vaccine, 3) Challenge group with no vaccine, and 4) Negative control group. Experimental chicks were vaccinated on days 19 and 26 by the eye drop route and then the birds were challenged via intra ocular route on day 40 with a suspension containing 106 EID50/ml challenge virus. Experimental chickens were monitored by collecting buccal and cloacal swabs at different times. Collected swabs were submitted to PCR test. The results showed that vaccination can protect the birds against mortality and also decrease virus shedding; also there was not a significant difference between vaccination with I-2 and B1 vaccines.

Comparative evaluation of therapeutic efficacy of sulfadiazine-trimethoprim, oxytetracycline, enrofloxacin and florfenicol on Staphylococcus aureus-induced arthritis in broilers.

Staphylococcus aureus is an important human and veterinary pathogen that causes economic loss in the poultry industry. This study aimed to compare therapeutic efficacy of 4 commonly used antibiotics in poultry on S. aureus-induced arthritis in broilers. Sixty broilers, 8 weeks of age, were assigned at random into 7 groups as follows: (1) negative control (n = 5); (2) vehicle control (n = 5); (3) sulfadiazine-trimethoprim, 250 ml/1000 l drinking water (n = 10); (4) oxytetracycline 20%, 1 mg/l drinking water (n = 10); (5) florfenicol 10%, 1/1000 v/v in drinking water (n = 10); (6) enrofloxacin 10%, 1/1000 v/v in drinking water (n = 10) and (7) positive control (n = 10). Birds in group 2 were injected with 1 ml of sterile TSB medium into the right tibiotarsal joint on d 0 while other birds (except group 1) were challenged with 1 ml of 1.2 × 10(10) CFU/ml suspension of S. aureus bacteria. Antibiotic therapy was started from d 4 post challenge and continued for 5 d. At the end, birds were weighed and clinical severity of arthritis was determined. After blood collection, birds were slaughtered and tibiotarsal and hip joints were evaluated grossly. The content of inflammatory exudates of tibiotarsal joint and the degree of femoral head necrosis were recorded. Mucin clot test and histopathological evaluation were performed on right tibiotarsal joint. Serum interleukin 6 was also assayed. Sulfadiazine-trimethoprim had higher therapeutic efficiency with regard to most of the assayed criteria, whereas none of the antibiotics significantly affected femoral head necrosis and body weight. These data will help clinicians to have better antibiotic choice in field conditions.

Effects of Lactobacillus acidophilus and inulin on faecal viral shedding and immunization against H9 N2 Avian influenza virus.

AIMS: The aims of this investigation were to compare the effects of Lactobacillus acidophilus addition as simple or microencapsulated (ME) probiotic and inulin as prebiotic to the broiler diet on the faecal viral shedding and immunization against avian influenza virus (AIV) with or without H9 N2 vaccination. METHODS AND RESULTS: Simple or ME forms of Lact. acidophilus, inulin and combination of them as synbiotic were analysed for their ability to enhance immunity against H9 N2 AIV and to decrease faecal viral shedding in Cobb-500 broiler chicks. Our results indicated that probiotic as ME form can decrease haemagglutination inhibition (HI) titre significantly on days 34 in vaccinated trial (P < 0·05). Also, the effects of ME form of probiotic are more remarkable on reduction of viral faecal shedding detected by RT-PCR. CONCLUSIONS: The study shows the significant role of microencapsulation on probiotic effects against H9 N2 AIV. SIGNIFICANCE AND IMPACT OF THE STUDY: The application of probiotics especially in the ME form could have the potential for stimulating the immune system, preventing influenza infection and consequently reduce faecal viral shedding of H9 N2 AIV.