Molecular identification, genotyping of virulence-associated genes, and pathogenicity of cellulitis-derived Escherichia coli

Research (Published online: 19-12-2020)

16. Molecular identification, genotyping of virulence-associated genes, and pathogenicity of cellulitis-derived Escherichia coli

Mohamed M. Amer, Hoda M. Mekky, Hanaa S. Fedawy, A. EL-Shemy, M. A. Bosila and Kh. M. Elbayoumi

Veterinary World, 13(12): 2703-2712

ABSTRACT

Background and Aim: Avian colibacillosis, which is caused by avian pathogenic Escherichia coli (APEC), is a major bacterial disease that affects birds of all ages worldwide, causing significant economic losses. APEC manifests in several clinical forms, including cellulitis, and its high pathogenicity is attributed to harboring numerous virulence-associated genes (VGs). This study evaluated the pathogenicity of the cellulitis-derived E. coli (O78) strain through molecular identification of genes coding for seven virulence factors and by conducting an in vivo assessment of capability for cellulitis induction in broiler chickens.

Materials and Methods: This study was performed using a previously isolated and identified cellulitis-derived E. coli (O78), which was screened for seven VGs using molecular detection and identification through polymerase chain reaction followed by nucleotide sequencing and phylogenetic analysis. Experimental infection by subcutaneous (SC) inoculation in broilers and its pathogenicity was confirmed in vivo by cellulitis induction. The impact of cellulitis on broiler performance was assessed.

Results: Molecular genotyping proved that the isolate harbored five virulence genes (iroN, iutA, tsh, iss, and papC) and was negative for stx1 and hly genes. The amplified products for iroN, iss, and iutA were subjected to sequencing and phylogenetic analysis, and the results indicate the highest similarity and matching with E. coli submitted to the National Center for Biotechnology Information GenBank. SC inoculation of bacteria in broiler chickens resulted in cellulitis, as indicated by thick red edematous skin with yellowish-white material in the SC tissue at the inoculation site, and the abdominal muscle showed redness and increased vacuolization. Histopathological examination revealed moderate-to-severe caseous inflammatory reaction with a marked accumulation of heterophils and mononuclear cells in the SC fatty tissue. The average feed intake, body weight gain (BWG), and feed conversion ratio (FCR) were lower in infected chickens in comparison with those of the control non-infected chickens.

Conclusion: This study proves that molecular techniques are accurate for pathogenicity determination in virulent bacteria, with the advantages of being rapid, time-saving, and economical. Cellulitis is associated with economic losses that are represented by a lower BWG and FCR.

Keywords: avian pathogenic Escherichia coli, cellulitis, colibacillosis, polymerase chain reaction, virulence-associated genes.

Impact of anthropogenic pressures on wild mammals of Northern Portugal

Research (Published online: 18-12-2020)

15. Impact of anthropogenic pressures on wild mammals of Northern Portugal

Andreia Garcês, Isabel Pires, Fernando Pacheco, Luís Sanches Fernandes, Vanessa Soeiro, Sara Lóio, Justina Prada, Rui Cortes and Felisbina Queiroga

Veterinary World, 13(12): 2691-2702

ABSTRACT

Background and Aim: Wild mammals are among the most threatened species of the world in large part due to human activity. In this work, we used the method of partial least squares-path modeling associated with a geographic information system to analyze the impact of anthropogenic pressures on the mortality of wild mammals.

Materials and Methods: We collected the data related to the cause of death of native wild mammals admitted to the Wildlife Rehabilitation Centre of Parque Biológico de Gaia in Northern Portugal, during 10 years (2008-2017).

Results: A total of 359 animals from 42 municipalities (rural and urban areas) were included in the study. The main cause of death was of traumatic origin. From the anthropogenic pressures included in the study, water reservoirs, small companies, and residential buildings were the ones that contributed the most to increase the mortality of traumatic and nontraumatic origin. This relation of cause-effect (mortality-anthropogenic pressures) was supported by the high coefficients of determination obtained (R2>0.8).

Conclusion: The present results allow a general view on the reality of mammal's mortality in Northern Portugal. Furthermore, it could also constitute a valuable tool for the conservation of wild mammals in those areas.

Keywords: anthropogenic factors, mortality, Northern of Portugal, partial least squares path modeling, wild mammals.

Inventory of biosecurity measures and antibiotics therapy practices on laying hen farms in Benin

Research (Published online: 17-12-2020)

14. Inventory of biosecurity measures and antibiotics therapy practices on laying hen farms in Benin

Oscar N. C. Aguidissou, Cyrille K. Boko, Camus M. Adoligbe, Clarisse H. Dete, Picole T. Capo-Chichi, Yao Akpo, Benoit G. Koutinhouin and Souaïbou Farougou

Veterinary World, 13(12): 2681-2690

ABSTRACT

Background and Aim: Laying hen breeding is on the rise in Benin; nevertheless, there are several sanitary constraints to its development, including bacterial diseases. Faced with this situation, breeders mainly resort to different means of treatment. The objective of this study was to assess the current state of hygiene measures, the bacterial diseases commonly encountered, and antibiotic therapy practices on laying hen farms in Benin.

Materials and Methods: A total of 200 laying hen farms were randomly selected from lists of laying hen farms obtained from veterinary offices, territorial agricultural development agencies, and the Benin National Union of Professional Aviculturists. Each visited farmer was subjected to a semi-structured questionnaire by direct interview. The results were compared using the bilateral Z-test.

Results: The results of this survey revealed that 99.5% of the surveyed farms had a health and medical prophylaxis program although only 88.5% of them reported strictly adhering to it (p<0.001). About 25.0% of them reported that the dominant bacterial diseases they commonly encountered on their farms were salmonellosis, colibacillosis, and chronic respiratory disease. Only 7.0% of farmers said that they confirmed their diagnosis outside of clinical signs through laboratory analysis. To control these pathologies, 14.5% of farmers used only oxytetracycline, while 39.0% used other antibiotics such as colistin, enrofloxacin, tylosin, tylodox, flumequine, and norfloxacin. In comparison, 13.5% used a trimethoprim-sulfadimethoxine and sulfadimidine combination, while 32.0% said that they used erythromycin, oxytetracycline, streptomycin, neomycin, and colistin (p<0.001) combination.

Conclusion: This study highlights the inadequacies of hygiene and antibiotic therapy practices implemented on Benin's laying hen farms.

Keywords: antibiotic therapy, bacterial diseases, biosecurity, laying hens.

Eucalyptus viminalis leaf extract alters the productivity and blood parameters of healthy broiler chickens

Research (Published online: 16-12-2020)

13. Eucalyptus viminalis leaf extract alters the productivity and blood parameters of healthy broiler chickens

G. K. Duskaev, O. V. Kvan and Sh. G. Rakhmatullin

Veterinary World, 13(12): 2673-2680

ABSTRACT

Background and Aim: As an alternative to natural and chemically synthesized direct-acting bactericides, there has been an increase in the use of plant extracts, which possess a set of phytochemicals with potential for microbial disease control; this is due to the spectrum of secondary metabolites present in extracts, which include phenolic compounds, quinones, flavonoids, alkaloids, terpenoids, and polyacetylenes. The biologically active substances within plant extracts, which perform protective functions for plant tissues, can have ambiguous effects on the animal body. Therefore, the aim of this study was to assess the ability of gamma-octalactone, isolated from Eucalyptus viminalis extract, to inhibit various LuxI/LuxR quorum-sensing (QS) systems in bacteria, and to evaluate its effect on broiler chickens.

Materials and Methods: Phytochemical analysis of E. viminalis extract was performed. The ability of gamma-octalactone to inhibit QS was evaluated using four different LuxI/LuxR bacterial test systems. In vivo assessments were performed on one hundred and twenty 7-day-old broiler chickens (Arbor Acres cross), split into four groups of 30 chickens: 1. Control group: Basic diet (BD); 2. experimental Group I: BD + gamma-octalactone at a dosage of 0.05 ml/kg live weight/day; 3. experimental Group II: BD + gamma-octalactone at a dosage of 0.1 ml/kg live weight/day; and 4. experimental Group III: BD + gamma-octalactone at a dosage of 0.2 ml/kg live weight/day. Hematological blood parameters were assessed using an automatic hematological analyzer (URIT-2900 Vet Plus, URIT Medial Electronic Co., China) and an automatic biochemical analyzer (CS-T240, Dirui Industrial Co., Ltd., China). Statistical analyses were performed using SPSS Statistics Version 20 (IBM); averages (M), standard deviations (σ), and standard deviation errors (m) were calculated. Results with p≤0.05 were considered significant.

Results: Based on the phytochemical analysis results, libraries of compounds with putative QS inhibitory properties were compiled. Gamma-octalactone exhibited a pronounced inhibitory effect on the LuxI/LuxR QS systems, characterized by EC50 values of 0.15-0.4 mM. In the in vivo portion of this study, broiler chicken live weights increased in all experimental groups, with the most significant increase in Group III (14.0%), in relation to the control group. Blood serum from the experimental group chickens had significantly higher levels of triglycerides and uric acid (p≤0.05), in comparison to the control group chickens. With respect to blood serum enzyme activity and antioxidant status indicators, the experimental group chickens had a higher level of gamma-glutamyl transferase, an enzyme associated with amino acid metabolism, than those in the control group; this increase was especially pronounced in Group III, with 37.0% increase (p≤0.05). Superoxide dismutase and catalase levels were higher in the experimental groups than the control group, corresponding to increases of 30.4-56.2% (p≤0.05), 33.3-83.3%, and 27.9-45.5% (p≤0.05) in Groups I, II, and III (p≤0.05), respectively. Morphological blood parameters did not display significant changes due to gamma-octalactone.

Conclusion: According to the results of this in vivo study in broiler chickens, gamma-octalactone, isolated from E. viminalis leaf extract and supplied at a dosage of 0.2 ml/kg live weight/day, led to an increase in the activity of blood plasma digestive enzymes, increased live weight, and had a positive effect on lipid metabolism and antioxidant status.

Keywords: broiler chickens, Eucalyptus viminalis leaf extract, gamma-octalactone, productivity, quorum sensing.

Bacillus subtilis and lactic acid bacteria improve the growth performance and blood parameters and reduce Salmonella infection in broilers

Research (Published online: 16-12-2020)

12. Bacillus subtilis and lactic acid bacteria improve the growth performance and blood parameters and reduce Salmonella infection in broilers

Nalisa Khochamit, Surasak Siripornadulsil, Peerapol Sukon and Wilailak Siripornadulsil

Veterinary World, 13(12): 2663-2672

ABSTRACT

Aim: The aim of the study was to determine the potentials and effects of Bacillus subtilis and lactic acid bacteria (LAB) as probiotics on broiler growth, health, and Salmonella infection.

Materials and Methods: To evaluate the inoculum size applicable for broilers, 1-day-old broilers were orally fed fresh cultures of single strains and a B. subtilis KKU213/Pediococcus pentosaceus NP6 mixture at 108 and 1012 colony-forming unit (CFUs)/mL/chick. The body weight gain (BWG), Salmonella contamination level and total Bacillus and LAB abundances in the crop and intestine were measured. Subsequently, 1-day-old broilers were orally fed of KKU213, CH403, and Pediococcus acidilactici SH8 at 1010 CFUs/mL, followed by inulin. After 35 days, the BWG, Bacillus and LAB abundances in the cecum, blood parameters, and KKU213 colonization were assessed.

Results: The broilers fed single strains or KKU213+NP6 exhibited a higher BWG and a higher crop LAB abundance than the controls (p<0.05). Probiotic feeding decreased the intestinal Salmonella abundance and correspondingly increased the LAB abundance. The broilers fed the mixed culture (KKU213+CH403+SH8) followed by prebiotics showed lower mortality, higher blood high-density lipoprotein levels, and lower blood uric acid levels than the controls (p<0.0004). Probiotic feeding significantly increased the Bacillus and LAB counts (p<0.05). A CE330 isolate obtained from the cecum after 35 days of KKU213 feeding was closely related to B. subtilis KKU213.

Conclusion: B. subtilis KKU213 is a potent probiotic strain that can survive, colonize and reduce Salmonella infection in broilers and improve their growth and health. This strain, combined with different LAB can act synergistically in the gut and promote broiler growth.

Keywords: broiler, Bacillus subtilis, lactic acid bacteria, probiotics.

Royal Jelly and Aliskiren mutually annul their protective effects against gentamicin-induced nephrotoxicity in rats

Research (Published online: 14-12-2020)

11. Royal Jelly and Aliskiren mutually annul their protective effects against gentamicin-induced nephrotoxicity in rats

Mohd Alaraj

Veterinary World, 13(12): 2658-2662

ABSTRACT

Background and Aim: Gentamicin (GM) is one of the most effective antibiotics for severe, life-threatening Gram-negative infections. Nevertheless, its clinical use has been restrained because of its nephrotoxic potential. Royal jelly (RJ) and aliskiren (ALK) can individually prevent such toxic effects. The aim of this study was to explore the protective effects of a combination treatment of RJ and ALK on GM-mediated nephrotoxicity.

Materials and Methods: Thirty-two adult female Wistar rats were divided equally into four groups: (I) Receiving normal saline; (II) GM (100 mg/kg, intraperitoneal [i.p.] injection); (III) GM (100 mg/kg, i.p. injection) plus ALK (50 mg/kg, i.p. injection); and (IV) GM (100 mg/kg, i.p. injection) plus ALK (50 mg/kg, i.p. injection) in combination with RJ (150 mg/ kg, orally). All treatments were administered daily for 10 days. The blood levels of creatinine, urea, uric acid, albumin, and total protein were measured. Then, the animals were sacrificed, and the kidneys were taken for histopathology.

Results: Compared to normal control rats, GM-injected rats showed significantly (p<0.001) higher serum concentrations of uric acid, urea, and creatinine as well as evidently (p<0.001) lower blood levels of albumin and total protein. Moreover, GM administration was associated with significant renal histopathological changes. All these alterations were considerably (p<0.05) improved in GM-injected rats receiving ALK compared to rats receiving GM alone. However, when RJ was given in combination with ALK to GM-injected rats, it lessened the beneficial nephroprotective effects of both agents.

Conclusion: The combination treatment of RJ and ALK is not desirable for GM-induced nephrotoxicity. Further studies are crucial to accurately explore the precise mechanism of RJ antagonistic interaction with ALK.

Keywords: aliskiren, gentamicin, nephrotoxicity, royal jelly.

Relationship of frozen-thawed semen quality with the fertility rate after being distributed in the Brahman Cross Breeding Program

Research (Published online: 14-12-2020)

10. Relationship of frozen-thawed semen quality with the fertility rate after being distributed in the Brahman Cross Breeding Program

Berlin Pandapotan Pardede, Muhammad Agil, Yudi Yudi and Iman Supriatna

Veterinary World, 13(12): 2649-2657

ABSTRACT

Background and Aim: Various factors can reduce the quality of semen used for artificial insemination and have an impact on fertility decline, such as poor handling during frozen semen distribution. This study was aimed at assessing the quality of frozen-thawed semen after distribution in the field and its importance in maintaining fertility.

Materials and Methods: The Brahman Cross (BX) breeding program of PT Lembu Jantan Perkasa, Indonesia, was used. This program was preferred due to its adherence to guidelines that limit the effects of extraneous factors that may affect semen quality. Frozen-thawed semen samples from eight bulls with the same production code were analyzed and compared between the production site (artificial insemination [AI] center) and the field (BX breeding program). Total and progressive motility (PM) of sperm were determined using computer-assisted semen analysis. Plasma membrane integrity (PMI) was assessed using hypoosmotic swelling test, sperm viability using Eosin-Nigrosin staining, acrosome integrity using trypan blue-Giemsa staining, morphological abnormalities using William staining, and DNA fragmentation using toluidine blue staining. The fertility rate was determined using the conception rate (%) derived from AI data based on 502 AI services and 478 cows in the BX breeding program. A t-test was used to compare the quality of frozen-thawed semen before and after distribution. The relationship between the qualities of frozen semen after distribution in the field with fertility was analyzed using Pearson correlation.

Results: There was no significant difference (p>0.05) in the quality of frozen-thawed semen (sperm motility, PMI, viability, acrosome integrity, abnormalities, and DNA fragmentation) between the production site (AI center) and after distribution in the field (BX breeding program). The semen met the minimum standards for AI programs. Total motility (r=0.986), PM (r=0.961), sperm viability (r=0.971), PMI (r=0.986), and acrosome integrity (r=0.992) were all positively correlated (p<0.05) with fertility rate; while sperm abnormalities (r=-0.996) and sperm DNA fragmentation (r=0.975) were negatively correlated (p<0.05) with fertility rate.

Conclusion: The study showed that to achieve the maximal and optimal fertility rate in bulls in an AI program, the overall quality of frozen-thawed semen in all aspects is critical. This can be achieved if the handling during distribution and storage, as well as the various factors that may affect the quality of semen in the field, can be controlled properly.

Keywords: artificial insemination, Brahman cross, distribution, fertility rate, frozen semen quality.