Antimicrobial profile of essential oils extracted from wild versus cultivated Origanum ehrenberjii against enteric bacteria

INTRODUCTION

The role of Origanum ehrenberjii against bacteria that cause enteric diseases is well known. Salmonella and Enterococcus cause high rates of enteric infections around the world. The aim of this study was to extract essential oils from cultivated and naturally growing O. ehrenberjii, compare the chemical profiles of the extracts and estimate their antimicrobial efficacy against enteric pathogens.

METHODOLOGY

Sixteen compounds were recovered consistently from essential oils extracted from O. ehrenberjii of wild and cultivated origin. The chemical profiles were determined using GC-MS. Safety of the essential oils was determined by observing mortality of chicks after intramuscular administration of the oils. The antimicrobial efficacy of the oils against the enteric pathogens was determined by the Kirby-Bauer Single Disk Diffusion assay.

RESULTS

The levels of thymol, carvacrol, para cymene and γ-terpinene were significantly different in the two oils. A significant difference in in vitro antimicrobial activity of the two oils against Salmonella enterica serovar Typhimurium was observed. Intramuscular administration of the two oils in one day-old chicks resulted in significant differences in mortality of 60% vs. 5% (p < 0.05) for wild and cultivated herbs respectively, reflecting the higher safety of the cultivated herb due to the differences in the levels of certain active ingredients.

CONCLUSIONS

The chemical profile of essential oil of wild vs. cultivated O. ehrenberjii differ significantly at compound level, suggesting the reason for their significant difference in efficacy against Salmonella enterica serovar Typhimurium, and also significant differences in the toxicity of the two oils.

Passaging impact of H9N2 avian influenza virus in hamsters on its pathogenicity and genetic variability

Introduction: Avian influenza viruses of the H9N2 subtype have been reported to cause human infections. This study demonstrates the impact of nasal viral passaging of avian H9N2 in hamsters on its cross species-pathogenic adaptability and variability of amino acid sequences of the hemagglutinin (HA) and neuraminidase (NA) stalk. Methodology: Three intranasal passagings of avian H9N2 in hamsters P1, P2, and P3 were accomplished. Morbidity signs and lesions were observed three days post viral inoculation. The HA test was used for presumptive detection of H9N2 virus in the trachea and lungs of the hamsters challenged with the differently passaged viruses. Different primers were used for PCR amplification of the HA1 and NA stalk regions of the differently passaged H9N2 viruses, followed by sequence alignment. Results: The morbidity signs indicated low pathogenicity of the differently passaged H9N2 viruses in hamsters. The frequency of gross and microscopic lesions in the tracheas and lungs were insignificantly different among hamsters challenged with the differently passaged H9N2 viruses (p > 0.05). There was 100% similarity in the amino acid sequence of the HA gene of most passaged viruses. The amino acid sequence of the neuraminidase in the third passaged H9N2 virus recovered from lungs showed a R46P mutation that might have a role in the pathogenic adaptability of P3 viruses in hamsters’ lungs. Conclusions: The apparent adaptation of avian H9N2 virus to mammalian cells is in agreement with the World Health Organization’s alertness for a possible public health threat by this adaptable virus.

Comparison of phenotypic and virulence genes characteristics in human and chicken isolates of Proteus mirabilis

The objective of this work is to compare the phenotypic and virulence genes characteristics in human and chicken isolates of Proteus mirabilis. The bacterial examination of 50 livers of individual broilers, marketed by four major outlets, revealed a high recovery of P. mirabilis (66%), and a low recovery frequency of Salmonella spp. (4%), Serratia odorifera (2%), Citrobacter brakii (2%), and Providencia stuartii (2%). The phenotypic biochemical characterization of the recovered 33 chicken isolates of P. mirabilis were compared to 30 human isolates (23 urinary and six respiratory isolates). The comparison revealed significant differences in the presence of gelatinase enzyme (100% presence in chicken isolates versus 91.3 and 83.3% presence in human urinary and respiratory isolates, respectively, P,0.05). The H(2)S production occurred in 100% of chicken isolates versus 95.6 and 66.7% presence in human urinary and respiratory isolates, respectively, P,0.05). The other 17 biochemical characteristics did not differ significantly among the three groups of isolates (P.0.05). Two virulence genes, the mrpA and FliL, were having a typical 100% presence in randomly selected isolates of P. mirabilis recovered from chicken livers (N510) versus isolates recovered from urinary (N55) and respiratory specimens of humans (N55) (P.0.05). The average percentage similarity of mrpA gene nucleotide sequence of poultry isolates to human urinary and respiratory isolates was 93.2 and 97.5-%, respectively. The high similarity in phenotypic characteristics, associated with typical frequency of presence of two virulence genes, and high similarity in sequences of mrpA gene among poultry versus human P. mirabilis isolates justifies future investigations targeting the evaluation of adaptable pathogenicity of avian Proteus mirabilis isolates to mammalian hosts.

A mini review of qRT-rtPCR technology application in uncovering the mechanism of food allergy and in the search for novel interventions

This mini review targets the inclusion of recent selected citations, between the year 2006 and 2012, that implement the qRT-rtPCR technology in their experimental designs, targeting the uncovering of the mechanism of food allergy. In addition, this same technology was implemented in specific experimental designs, aiming at finding novel nutritional, herbal medicine, and tolerance interventions against food allergy. The approach of using qRT-rtPCR technology helped in studying the dynamics of transcription of cytokines and chemokines in intestinal dendritic cells of the experimental animals during the allergic reaction to food. The suppression of transcription of specific cytokines or chemokines by nutritional, herbal medicine, and tolerance interventions was instrumental in the search for finding novel remedies for this health condition, that was traditionally managed by avoidance of offending foods in the diet.

Optimization of Saanen sperm genes amplification: evaluation of standardized protocols in genetically uncharacterized rural goats reared under a subtropical environment

The purpose of this research is to optimize quantitatively the amplification of specific sperm genes in reference genomically characterized Saanen goat and to evaluate the standardized protocols applicability on sperms of uncharacterized genome of rural goats reared under subtropical environment for inclusion in future selection programs. The optimization of the protocols in Saanen sperms included three production genes (growth hormone (GH) exons 2, 3, and 4, αS1-casein (CSN1S1), and α-lactalbumin) and two health genes (MHC class II DRB and prion (PrP)). The optimization was based on varying the primers concentrations and the inclusion of a PCR cosolvent (Triton X). The impact of the studied variables on statistically significant increase in the yield of amplicons was noticed in four out of five (80%) optimized protocols, namely in those related to GH, CSN1S1, α-lactalbumin, and PrP genes (P < 0.05). There was no significant difference in the yield of amplicons related to MHC class II DRB gene, regardless of the variables used (P > 0.05). The applicability of the optimized protocols of Saanen sperm genes on amplification of uncharacterized rural goat sperms revealed a 100% success in tested individuals for amplification of GH, CSN1S1, α-lactalbumin, and MHC class II DRB genes and a 75% success for the PrP gene. The significant success in applicability of the Saanen quantitatively optimized protocols to other uncharacterized genome of rural goats allows for their inclusion in future selection, targeting the sustainability of this farming system in a subtropical environment and the improvement of the farmers livelihood.

Evidence of infection with H4 and H11 avian influenza viruses among Lebanese chicken growers

Human infections with H5, H7, and H9 avian influenza viruses are well documented. Exposure to poultry is the most important risk factor for humans becoming infected with these viruses. Data on human infection with other low pathogenicity avian influenza viruses is sparse but suggests that such infections may occur. Lebanon is a Mediterranean country lying under two major migratory birds flyways and is home to many wild and domestic bird species. Previous reports from this country demonstrated that low pathogenicity avian influenza viruses are in circulation but highly pathogenic H5N1 viruses were not reported. In order to study the extent of human infection with avian influenza viruses in Lebanon, we carried out a seroprevalence cross-sectional study into which 200 poultry-exposed individuals and 50 non-exposed controls were enrolled. We obtained their sera and tested it for the presence of antibodies against avian influenza viruses types H4 through H16 and used a questionnaire to collect exposure data. Our microneutralization assay results suggested that backyard poultry growers may have been previously infected with H4 and H11 avian influenza viruses. We confirmed these results by using a horse red blood cells hemagglutination inhibition assay. Our data also showed that farmers with antibodies against each virus type clustered in a small geographic area suggesting that unrecognized outbreaks among birds may have led to these human infections. In conclusion, this study suggests that occupational exposure to chicken is a risk factor for infection with avian influenza especially among backyard growers and that H4 and H11 influenza viruses may possess the ability to cross the species barrier to infect humans.

Impact of competitive non-protective antigens in a booster killed vaccine on seroconversions to protective antigens of Newcastle disease virus in chickens

This study was designed to examine the impact of competitive non-protective antigens in a bivalent killed vaccine of Newcastle disease virus and infectious bronchitis (IB) virus on seroconversions against protective fusion protein of Newcastle disease (ND) virus (NDV), in free-range layers primed by live ND-clone 30 and IB-H120 vaccines. The experimental design included two free-range layer farms in which sera of randomly chosen layers were collected on two occasions from each of the two farms namely: at the time of administration of the killed booster vaccine (23 weeks of age) and three weeks later. The Western immunoblotting technique was used to react the individual pooled sera collected at different times from each farm with antigens used in priming, namely those of the ND-clone 30 virus and the IB-H120 virus. The optical density bands formed by reactions were compared statistically between seroconverted antibodies at 23 weeks with those of layers aged 26 weeks. The killed booster vaccine offered a significant seroconversion on both farms to the non-protective L-protein (248.0 kDa) of NDV and on one of the two farms to the non-protective NDV-matrix protein (40.0 kDa) (p<0.05). However, seroconversion to the protective fusion protein of NDV (60 kDa) failed on both farms (p<0.05). In addition, on one farm, a statistical significance was revealed by the killed booster vaccine seroconversion to non-protective IBV-nucleocapsid protein (510 kDa) and, on the other farm, to another non-protective IBV-glycoprotein (28.0 kDa) (p<0.05). The impact of competitive seroconversions to non-protective antigens and seroconversion failures to low molecular weights of NDV protective fusion protein is discussed.

Preliminary comparison of different immune and production components in local and imported Saanen goats reared under a sub-tropical environment

Three objectives were included in this research work. The first objective compared different immune components in healthy mature males, mature females, and female kids of local and imported Saanen goats, reared under a sub-tropical environment. The significantly differing immune components were the blood monocyte percent, blood CD8 count, and the total white blood cell count. The second objective compared the performance of Saanen versus local does. The means of the milk yield and prolificacy of the imported Saanen does were significantly higher than those of the local does (p<0.05). The third objective compared the immune responses (hemagglutination-HA titers) and complement fixation (CF) titers in mature does of the two breeds to chicken red blood cells (c-RBC). The HA titers showed a significant seroconversion only in imported Saanen (p<0.05) but not in local does; however, the CF titers increased significantly at 4 weeks following priming with c-RBC in local (p<0.05) but not in the imported Saanen does. The impact of the differences in blood immune components and responses to antigens in the compared goats on protection potential against prevalent diseases in the sub-tropical zone of the eastern Mediterranean countries is discussed.

Impact of embryonic passaging of H9N2 virus on pathogenicity and stability of HA1- amino acid sequence cleavage site

BACKGROUND

Highly virulent Avian Influenza viruses might arise from avirulent strains following viral passaging. This work aims at studying the impact of embryonic passaging of H9N2 on the stability of the HA1 amino acid sequence and its relatedness to pathogenicity.

MATERIAL/METHODS

The original H9N2 virus was propagated for 3 consecutive passages in embryonated chicken eggs. Pathogenicity and amino acids sequences at the HA1 gene level of the original (P0), and the once (P1), twice (P2), and three times (P3) passaged viruses were compared.

RESULTS

The percent mortality significantly increased in embryos inoculated with P2 (86.7%) and P3 of H9N2 (100%) in comparison to P0 (0.0%) and P1 of H9N2 (46.1%) (P<0.05), while the density of propagated H9N2 declined with passaging. The R-S-S-R motif was stable at the HA1 cleavage site of P0, P1, P2, and P3 viruses. The similarity in the HA1 sequences among the differently passaged viruses ranged between 93.2 to 100%.

CONCLUSIONS

The pathogenicity increased significantly upon passaging in chicken embryos in spite of the presence of the same motif at the HA1 cleavage site. Further investigations will target the study of changes in the whole HA protein and of Neuraminidases that could be responsible for a higher pathogenicity.

Koch's postulate of Arcanobacterium pyogenes and its immunogenicity in local and imported Saanen goats

The aim of this survey was to study Koch's postulate of Arcanobacterium pyogenes recovered from the necrotic lung of a kid and to compare the immunogenicity of this isolate in local and imported Saanen goats. The disease was successfully reproduced in intrathoracically challenged hamsters which showed lung congestion and liver abscesses, while hamsters that were intraperitoneally challenged showed only the formation of intestinal abscesses. The percentage of histopathologic legions in 12 observed microscopic fields per lung of three groups of hamsters (unchallenged controls, challenged intrathoracically and challenged intraperitoneally) showed a significant increase in lung necrosis of the intrathoracically challenged group, followed by intraperitoneally challenged hamsters, in comparison to unchallenged controls (p<0.05). In addition, the frequency of mucus accumulation in alveolar ducts followed the same respective pattern (p>0.05), while there was no significant difference in the frequency of neutrophil infiltration (p>0.05). The isolate was successfully recovered from the lungs and livers of hamsters challenged by both routes. Saanen does showed significant seroconversion using the indirect haemagglutination (HA) test and slide agglutination test (SAT) and at three weeks following priming and boosting with A. pyogenes antigens (p<0.05); however, only SAT showed significant seroconversion in local does at three weeks post booster (p<0.05). The possible causes and impact of the greater immunogenicity to A. pyogenes antigens in Saanen goats compared to local does are discussed.

Regression of the level of different heavy metals to size of marine organisms harvested from the "Jiyeh" oil spill zone of the eastern Mediterranean Sea

This study aimed to establish a baseline data on regression of the levels of Lead (Pb), Nickel (Ni) and Vanadium (V) to specific size dimensions of selected marine organisms harvested from an oil spill zone of the Eastern Mediterranean Sea. Twenty samples of each of Siganus rivulatus, Mullets and oysters were collected from each of six harvest sites. A total of 1, 3, and 3 respective significant regression equations (p < 0.01) were established between Pb, Ni, V and specific size dimensions of the selected marine organisms. The significant correlation associated with the highest R (2) value was obtained between the Pb (y) level and the width (x) of the Siganus rivulatus (y = -86.833x + 417.72). The other six statistically significant correlations were associated with lower values of R (2) ranging between 0.338 and 0.380. This baseline data will be used in the future to evaluate the self-purification process of pollutants in different sizes of indicator-marine organisms in this part of the Mediterranean Sea.

Comparison of the level of organic contaminants in bile and muscle of Mugil spp. following a major oil spill in the eastern Mediterranean Sea

The total polyaromatic hydrocarbons (TPAH) and the total polychlorinated biphenyls (TPCB) that originate from oil spills in sea and ocean waters are toxic to fish and their offspring. The authors compare the levels of organic contaminants (TPAH and TPCB) recovered from the bile versus the dorsal muscles of 120 individual Mugil spp. that were harvested from six sites in the eastern Mediterranean following a significant heavy oil spill. Results showed an insignificant difference between the mean of means of TPAH and TPCB (six means of individual Mugil spp. from six respective sites) in bile versus dorsal muscle. In addition, the correlation equation between the level of bile TPAH and the level of bile carcinogenic polyaromatic hydrocarbons (cPAH) was established. This data suggests the possibility of substituting the analysis of organic contaminants in muscles by using the liquid bile of Mugil spp., thus eliminating the time-consuming steps of lyophilisation and homogenisation of muscle. In addition, the bile cPAH could be predicted from the bile TPAH by a regression relationship.

Standardisation of a new model of H9N2/Escherichia coli challenge in broilers in the Lebanon

Primary infection by low pathogenic avian influenza (LPAI) predisposes for secondary infection by Escherichia coli in poultry, leading to significant economic losses. Future research in control of this ailment requires the establishment of a successful controlled challenge by avian influenza virus (AIV)/E. coli. Six groups of broilers (6 birds/group) were included for the standardisation of the controlled challenge by AIV/E. coli. Birds in groups 1, 2, 3, 4 and 5 received an intra-tracheal challenge of 0.5 ml of two haemagglutinating units of H9N2 virus at 20 days of age. At the age of 23 days, birds in group 1 received an intra-thoracic (right air sac)-E. coli challenge equivalent to 1.6 x 10 colony-forming units (cfu)/0.5 ml/bird, while birds in groups 2, 3, 4 and 5 received E. coli by the same route and in the following respective decreasing order of viable cells: 1.6 x 10(6), 1.6 x 10(5), 1.6 x 10(4) and 1.6 x 10(3); cfu. Birds in control group 6 were deprived of H9N2 and E. coli challenge. Results showed significant early mortality in group 1 that was challenged with the highest number of E. coli, in comparison to groups 2-6 (p<0.05); however, the average weight at 28 days of age was similar in surviving birds of groups 2-6 (p>0.05). The frequencies of four signs at 2 days and at 5 days post E. coli challenge (conjunctivitis, diarrhoea, ocular exudates and rales) in the surviving birds of groups 2-5 were most often higher than those observed in control group 6 (p<0.05). These four signs and five gross lesions (abdominal airsacculitis, left thoracic airsacculitis, pericarditis, right thoracic airsacculitis and tracheitis) had a decreasing pattern of frequency related to a decrease in the E. coli count used in the challenge.

Preliminary study on the efficacy and safety of eight individual and blended disinfectants against poultry and dairy indicator organisms

Eight individual and blended chemical disinfectants were screened for preliminary evaluation of safety, bactericidal and virucidal effectiveness against poultry and dairy organisms. The test organisms were Escherichia coli, Salmonella Enteritidis, Staphylococcus aureus, Streptococcus spp. and Clostridium perfringens, in addition to avian influenza virus (AIV) and Newcastle disease virus (NDV). Viable counts of surviving bacteria were determined after 30 min contact with each disinfectant and in the presence or absence of skimmed milk, to simulate the interference of organic matter. The haemagglutination test was used to assess the survival of the test viruses in the presence of the different disinfectants after propagation in 10-day-old chick embryos. In the presence of skimmed milk, a higher concentration of most of the disinfectants examined was required to exert antimicrobial effectiveness. When used individually, quaternary ammonium showed no virucidal activity against NDV and AIV; peracetic acid was not effective against Streptococcus spp., S. Enteritidis and NDV, while iodophors showed low bactericidal and inconsistent virucidal activity. The single and blended disinfectants with high microbicidal activities included phenols (high bactericidal and virucidal activity), blends of quaternary ammonium compounds (high bactericidal activity) and blends of cresols and organic acids (high virucidal activity). This suggests the use of blends of compatible compounds for disinfection operations in poultry and dairy industries since they will target a wider range of micro-organisms. None of the disinfectants had a negative effect on the development of the different organs of chicken embryos and the iodine-based disinfectant, developed for dairy-teat dipping, also showed no adverse reactions in experimental cows.

Holistic efficacy of specific nutrient synergy against avian flu virus: pathology and immunomodulation

The authors evaluated the holistic efficacy of nine specific nutrient synergy (NS) against avian influenza virus (AIV) strain Lebanon 1 (H9N2). The study included two segments; the first was designed to determine the minimum dose among four doses (1X, 2X, 3X and 4X in which X = 24.4 mg/ml/bird) of NS, administered intraoesophageally, once per day between 7 and 14 days of age, resulting in an improvement of chicken performance without any toxic side-effects; the second aimed at reducing pathological effects and inducing immunomodulation by the determined safe dose of NS in chickens exposed to AIV. The first segment showed that the daily oral administration of the NS to birds between 7 to 14 days of age at the 2X dose-level (320 mg/kg body weight or 48.8 mg/ml/bird) resulted in a consistent and significant improvement in the feed conversion (P<0.05) at 10 and 14 days of age, associated with a significant (P<0.05) increase in the liver weight index. In addition, the administration of NS at 2X level resulted in complete absence of toxicity signs (swollen infraorbital sinuses, ocular exudate, nasal discharge, thick oral saliva, diarrhoea, lameness and huddling) and complete absence of toxicity lesions (airsacculitis, hydropericardium signs, pericarditis, perihepatitis, splenomegaly and tracheitis). The four groups of birds that received levels 1X to 4X levels had significantly higher frequency of birds with gaseous caeca compared to the control group deprived of NS (P<0.05), a sign of higher fermentation activity in this organ. Data from the second segment of this research showed that the daily administration of NS at a level of 48.8 mg/ml/bird, between 7 to 14 days of age, to H9N2-challenged birds reduced specific pathological effects at 14 days of age namely: absence of rales at 3 days post H9N2 challenge and gross lesions (absence of tracheitis and enteritis at 7 days post challenge). Such reductions in signs and gross lesions were associated with a 63.4% reduction in immune responses to the hemagglutinin protein of the AIV, an indication that NS has a reducing effect on the viral infectivity in chickens.

Reverse transcriptase-polymerase chain reaction-based surveillance of type A influenza viruses in wild and domestic birds of the Lebanon

A total of 1 330 oropharyngeal swabs collected from wild and domestic birds in Lebanon were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) for type A avian influenza virus (AIV) during the migratory season between the autumn of 2005 and winter of 2006. Twenty-five species of birds were included in the study. There are 14 species of migratory wild birds, 4 species of resident wild birds, 3 species of pet birds and 4 species of farm birds. The number and percentage of positive type A avian influenza viruses in collected oropharyngeal swabs was 190 positive out of 1 330 samples tested (14.3%). The 190 oropharyngeal samples positive for AIV were further tested by specific RT-PCR for H5 and H7 subtypes. The 190 AIV-positive samples were all negative for H5, while 13 of the 190 (6.8%) were positive for H7. The H7-positive samples were confined to sparrows (resident wild bird species) and to backyard chicken in the south province, located 10-20 km from the Israeli-Lebanese border.