Evaluation of the Synergistic Effect of Amikacin with Cefotaxime against <em>Pseudomonas aeruginosa</em> and Its Biofilm Genes Expression

A total of 100 broiler chickens were examined for the presence of Pseudomonas aeruginosa by standard microbiological techniques. Susceptibility pattern for amikacin and cefotaxime was performed by Kirby-Bauer and microdilution assays. Then, checkerboard titration in trays was applied and FIC was measured to identify the type of interaction between the two antibiotics. The ability of isolates to form in vitro biofilm was detected by two methods, one qualitative (CRA) and the other quantitative (MTP), followed by investigating the effect of each antibiotic alone and in combination on the expression of biofilm genes. The overall isolation percentage of P. aeruginosa was 21%. Resistance to each antibiotic was more than 50%; the range of cefotaxime MIC was 8–512 μg/ml, while amikacin MIC range was 1–64 μg/ml. The FIC index established a synergistic association between tested two drugs in 17 (81%) of isolates and the remaining represent partially synergism. The qualitative technique showed that only 66.6% of the isolates were considered biofilm producers, while the quantitative technique showed that 90.4% of the isolates were biofilm producers. Further to RT-PCR investigation, significant repression against biofilm-forming genes (filC, pelA, and pslA) was observed for the combination of antibiotics when compared with monotherapy

Diagnostic efficacy of monoclonal antibody based sandwich enzyme linked immunosorbent assay (ELISA) for detection of Fasciola gigantica excretory/secretory antigens in both serum and stool

<p>Abstract</p> <p>Background</p> <p>This research was carried out to develop a reliable monoclonal antibody (MoAb)-based sandwich enzyme linked immunosorbent assay (ELISA) for the diagnosis of active <it>Fasciola gigantica </it>infection in both serum and stool for comparative purposes.</p> <p>Methods</p> <p>From a panel of MoAbs raised against <it>F. gigantica </it>excretory/secretory antigens (ES Ags), a pair (12B/11D/3F and 10A/9D/10G) was chosen due to its high reactivity and strict specificity to <it>F. gigantica </it>antigen by indirect ELISA.</p> <p>Results</p> <p>The two MoAbs were of the IgG₁and IgG_2asubclasses, respectively. Using SDS-PAGE and EITB, the selected MoAbs recognized 83, 64, 45 and 26 kDa bands of ES Ags. The lower detection limit of ELISA assay was 3 ng/ml. In stool, the sensitivity, specificity and diagnostic efficacy of ELISA was 96%, 98.2 and 97.1%; while in serum they were 94%, 94.6% and 94.3%, respectively. Moreover, a positive correlation was found between ova count in stool of <it>F. gigantica </it>infected patients and the OD readings of ELISA in both stool and serum samples (<it>r </it>= 0.730, p < 0.01 and r = 0.608; p < 0.01, respectively).</p> <p>Conclusions</p> <p>These data showed that the use of MoAb-based sandwich ELISA for the detection of <it>F. gigantica </it>coproantigens in stool specimens was superior to serum samples; it provides a highly efficient, non-invasive technique for the diagnosis of active <it>F. gigantica </it>infection.</p

Validity of Cooking in Microwave and Gamma-irradiation on Highly Virulent Aeromonas hydrophila Isolates in Basa Fish Fillet

The purpose of the study was to verify the existence and pathogenicity of Aeromonas hydrophila (A. hydrophila) in fish by validating the bactericidal effects of microwave and Gamma radiation on infected fish fillets. A total of 100 frozen Basa fish fillet samples were collected randomly from different markets in Zagazig, Sharkia Governorate, Egypt, and subjected to microbiological examination. The results revealed a 14% prevalence rate of A. hydrophila in fish fillets, which were tested for the presence of seven virulence genes: aerA, act, ast, alt, hyl, ahhR, and ahh1. All isolates exhibited traits related to virulence. The most predominated gene was ast (64.2%), followed by aerA, act, hyl, and ahhR (57.14% for each). Then, an experimental protocol for several treatments showed that Gamma radiation at a dose of 1 kGy decreased the count of A. hydrophila in fish fillets by 4.4 log10 CFU/g whereas doses of 2 and 3 kGy eradicated the pathogen. The same positive effect was recorded towards the microwave after cooking for 1, 2, and 3 minutes. Therefore, using microwave cooking and Gamma-irradiation alone and in combination with other decontamination methods may be more efficient in lowering the pathogen counts in fish meat.

Impact of Oral Administration of Chitosan–nanoparticles on Oxidative Stress Index and Gut Microbiota of Heat Stressed Broilers

The study investigated the effect of the administration of chitosan–nanoparticles (ChNP) on body performance, gut microbiota, some immunological parameters, expression of digestibility, and antioxidant-related genes in broilers. A total of 80 one-day-old Ross mixed-sex chicks were divided into two groups (40 birds each) in open door system: Chicks in group 1 were fed a basal diet as control, whereas chicks in group 2, were fed a basal diet, and drinking water supplemented with 50-mg ChNP/L. The experimental period lasted three weeks with a daily observation of body performance. Serum and tissue samples were collected for immunological evaluation, microbiota counts, and estimation of mRNA expression levels. ChNPs supplementation significantly increased beneficial microbiota and diminished coliforms, improved growth performance, kidney functions, total antioxidant capacity, and gene expressions of Glut, CAT1, CAT, SOD, and GPX1 in broilers. In conclusion, supplementation of ChNP led to an upregulation of body performance and antioxidant activity of broiler chicks phenotypically and genotypically

Thymoquinone blocks lung injury and fibrosis by attenuating bleomycin-induced oxidative stress and activation of nuclear factor Kappa-B in rats

Pulmonary fibrosis is one of the most common chronic interstitial lung diseases with high mortality rate after diagnosis and limited successful treatment. The present study was designed to assess the potential antifibrotic effect of thymoquinone (TQ) and whether TQ can attenuate the severity of oxidative stress and inflammatory response during bleomycin-induced pulmonary fibrosis. Male Wister rats were treated intraperitoneally with either bleomycin (15 mg/kg, 3 times a week for 4 weeks) and/or thymoquinone (5 mg/kg/day, 1 week before and until the end of the experiment). Bleomycin significantly increased lung weight and the levels of Lactate dehydrogenase, total leucocytic count, total protein and mucin in bronchoalveolar lavage and these effects were significantly ameliorated by TQ treatment. As markers of oxidative stress, bleomycin caused a significant increase in the levels of lipid peroxides and nitric oxide accompanied with a significant decrease in the antioxidant enzyme activity of superoxide dismutase and glutathione transferase. TQ treatment restored these markers toward normal values. TQ also coun- teracted emphysema in air alveoli, inflammatory cell infiltration, lymphoid hyperplastic cells activation surrounding the bronchioles and the over expression of activated form of nuclear factor kappa-B (NF-B) in lung tissue that was induced by bleomycin. Fibrosis was assessed by measuring hydroxyproline content, which increased markedly in the bleomycin group and significantly reduced by concurrent treatment with TQ. Furthermore, histopathological examination confirmed the antifibrotic effect of TQ. Collectively these findings indicate that TQ has potential antifibrotic effect beside its antioxidant activity that could be through NF- B inhibition

Hematological and Molecular Profiling of Some Blood Pathogens in Dog Breeding Farm in Egypt

Canine vector-borne diseases (CVBDs) are widespread arthropod-transmitted diseases that pose a significant threat to animal and human health. Despite their growing significance, little is known about the vector-born pathogen in Egypt. There is a substantial diagnostic challenge, especially when a dog is co-infected with more than one pathogen. Microscopic blood smear examination (n=49) followed by quantitative polymerase chain reaction (qPCR, n=6) using species-specific primers of Babesia and Mycoplasma was used to establish the prevalence of each infecting pathogen. Most of the examined dogs recorded macrocytic hypochromic anemia with marked thrombocytopenia. The dog ticks; Rhipicephalus sanguineus and Haemaphysalis elliptica were morphologically identified. Blood smear analysis showed that Babesia spp. was the most prevalent pathogen detected with an overall prevalence of 44.9% (22/49), 18.44% (9/49) for Mycoplasma spp, and co-infection was found in 8.2% (4/49) dogs. Quantitative PCR identified B. canis vogeli, B. gibsoni, and Mycoplasma haemocanis. Babesiosis infection in this study was significantly reliant on sex, season, and age. This is the first microscopical and molecular identification of M. haemocanis in dogs in Egypt. This study provides a foundation for future avenues of research investigating prevalent vector-borne pathogens in endemic areas and offers crucial knowledge for future diagnostic efforts.

Application of Bacteriophages for Biocontrol of Extensively Drug Resistant Salmonella Serovars Isolated from Poultry Farms

Salmonella is one of the most common foodborne pathogens causing diseases in humans and animals. Increased resistance to antibiotics necessitates the need for an alternative control strategy. This study aimed to screen, isolate and evaluate the bacteriophage characteristics for biocontrol of pathogenic Salmonella serovars. Twelve Salmonella isolates, including different Salmonella enterica serovars, were obtained from different sources of poultry farms. All isolates were screened for antibiotic sensitivity and showed multiple antibiotic resistance. Two lytic bacteriophages, vB_SalSph_WW1, and vB_SalM_WW2, were isolated from the sewage and characterized against Salmonella enterica serovar Enteritidis. Morphological analysis by transmission electron microscopy revealed that the vB_SalSph_WW1 phage belonged to the family Siphoviridae while the vB_SalM_WW2 phage belonged to the family Myoviridae. Both phages showed a broad host range within the Salmonella genus. Phages vB_SalSph_WW1 and vB_SalM_WW2 had a lytic effect on 3 (25%) and 4 (33.3%) of the 12 Salmonella isolates, respectively. The lytic cycle of each phage was determined by a one-step growth curve and both phages had the same short latent period (15 min). WW1 phage gave a burst size of 90 PFU/infected cell, while the vB_SalM_WW2 phage gave a higher burst size of 150 PFU/infected cell. The stability test revealed that vB_SalSph_WW1 and vB_SalM_WW2 phages were stable at pH 4–9 and pH 4–10, respectively. Both Phages exhibited high degrees of thermal tolerance with active titer as high as 42◦C. However, they lost their stability and the titers declined when heated at 50◦C for 30 min. This study revealed that vB_SalSph_WW1 and vB_SalM_WW2 phages have the potency to be used as an alternative strategy to control the infection of Salmonella in poultry farms and to prevent transmission of Salmonella infection to humans and spread of the pathogen into environment

Growth Hormone Ameliorates the Radiotherapy-Induced Ovarian Follicular Loss in Rats: Impact on Oxidative Stress, Apoptosis and IGF-1/IGF-1R Axis.

Radiotherapy is one of the standard cytotoxic therapies for cancer. However, it has a profound impact on ovarian function leading to premature ovarian failure and infertility. Since none of the currently available methods for fertility preservation guarantees future fertility, the need for an effective radioprotective agent is highly intensified. The present study investigated the mechanisms of the potential radioprotective effect of growth hormone (GH) on γ irradiation-induced ovarian failure and the impact of the insulin like growth factor 1 (IGF-1) in the underlying protection. Immature female Sprague-Dawley rats were either exposed to single whole body irradiation (3.2 Gy) and/or treated with GH (1 mg/kg s.c). Experimental γ-irradiation produced an array of ovarian dysfunction that was evident by assessment of hormonal changes, follicular development, proliferation marker (PCNA), oxidative stress as well as apoptotic markers. In addition, IGF-1/IGF-1R axis expression was assessed using real-time PCR and immunolocalization techniques. Furthermore, after full maturity, fertility assessment was performed. GH significantly enhanced follicular development and restored anti-Mullerian hormone serum level as compared with the irradiated group. In addition, GH significantly ameliorated the deleterious effects of irradiation on oxidative status, PCNA and apoptosis. Interestingly, GH was shown to enhance the ovarian IGF-1 at transcription and translation levels, a property that contributes significantly to its radioprotective effect. Finally, GH regained the fertility that was lost following irradiation. In conclusion, GH showed a radioprotective effect and rescued the ovarian reserve through increasing local IGF-1 level and counteracting the oxidative stress-mediated apoptosis

Mobile Colistin Resistance Determinants among Enterobacteriaceae Isolated from Different Poultry Species

Antimicrobial resistance (AMR) is a global threat that requires serious attention, particularly when it is developed against colistin, which is considered one of the ‘last resort’ antibiotics in the poultry industry. This study aimed to investigate the AMR profile of Enterobacteriaceae isolates from different poultry species, detect colistin resistance and investigate the existence of&nbsp;mcr&nbsp;genes in multi and extreme-resistant isolates. A total of 233 birds, chickens, ducks, turkeys, and quails, of various ages and breeds were collected from several localities of the Sharkia governorate and analyzed bacteriologically. The disc diffusion and E-test assays scrutinized the patterns of antibiotic, multidrug-resistant (MDR), and colistin resistance. The PCR assay was carried out to detect the&nbsp;mcr&nbsp;variants. Bacteriological examination revealed the incidence of 42.3% (99/233) of different Enterobacteriaceae members with a high predominance of&nbsp;E. coli,&nbsp;Salmonella,&nbsp;and Klebsiella species. Disc diffusion findings disclosed that 78.78% of isolates were resistant to colistin but E-test detected 19.19% only. Observed colistin resistance was strongly linked to the distribution of plasmid&nbsp;mcr-operons. The&nbsp;mcr&nbsp;1, 2, 3, 4, and 7.1 genes were detected in 42.1, 63.15, 57.89, 52.63, and 47.36% of the phenotypic resistant isolates, and about 36.84% harbored at least four&nbsp;mcr&nbsp;clusters. However, the&nbsp;mcr5&nbsp;gene was not discovered. The statistical assessment revealed a significant association between colistin resistance and MDR (p≤0.05). Moreover, there was a strong correlation between MCR-abundance and doxycycline, fosfomycin, beta-lactams, imipenem, and tobramycin resistances. In conclusion, this study highlights the alarming occurrence of colistin-resistant Enterobacteriaceae in various poultry aspects. An urgent strategy must be adopted to avert the spread of this phenomenon

Effect of Growth hormone (0.5, 1mg/kg s.c. once daily for 1 wk) on serum hormone levels in rats subjected to single dose whole-body irradiation (3.2 Gy).

<p>-Data expressed as Mean ± SEM (n = 6).</p><p>-a, b: Significantly different from control, radiation, respectively at p <0.05 using one-way ANOVA followed by Tukey–Kramer as a post-hoc test.</p><p>*AMH: Anti-mullerian hormone; FSH: follicle stimulating hormone; E2: estradiol.</p><p>Effect of Growth hormone (0.5, 1mg/kg s.c. once daily for 1 wk) on serum hormone levels in rats subjected to single dose whole-body irradiation (3.2 Gy).</p