Prevalence and antimicrobial drug resistance of Staphylococcus aureus isolated from cow milk samples

Research (Published online: 21-12-2020)

19. Prevalence and antimicrobial drug resistance of Staphylococcus aureus isolated from cow milk samples

Matlale Phriskey Mphahlele, James Wabwire Oguttu, Inge-Marie Petzer and Daniel Nenene Qekwana

Veterinary World, 13(12): 2736-2742

ABSTRACT

Background and Aim: Staphylococcus aureus infections and antimicrobial resistance (AMR) in mastitis cases are both of clinical and economic importance. This study investigated the prevalence and AMR patterns of S. aureus isolated from composite milk samples of dairy cows submitted to the Onderstepoort Milk Laboratory for routine diagnosis.

Materials and Methods: A total of 2862 cow milk samples randomly selected from submitted samples were tested for the presence of S. aureus using microbiological and biochemical tests. Confirmation of isolates was done using the analytical profile index. Antimicrobial susceptibility of S. aureus isolates against 12 antimicrobial agents was determined using the disk diffusion method.

Results: S. aureus was isolated from 1.7% (50/2862) of the samples tested. All (100%) S. aureus isolates were resistant to at least one antimicrobial, while 62% (31/50) were resistant to three or more categories of antimicrobials (multidrug-resistant [MDR]). Most S. aureus isolates were resistant to erythromycin (62%; 31/50) and ampicillin (62%; 31/50). Almost half of S. aureus isolates were resistant to oxacillin (46%; 23/50) and only 8% (4/50) were resistant to cefoxitin.

Conclusion: Although the prevalence of S. aureus among mastitis cases in this study was low, isolates exhibited high resistance to aminoglycosides, macrolides, and penicillins, all of which are important drugs in human medicine. The high prevalence of MDR S. aureus and the presence of methicillin resistance among S. aureus observed in this study are of both clinical and public health concerns.

Keywords: antimicrobial resistance, bovine mastitis, multidrug resistance, public health, Staphylococcus aureus.

A novel ex vivo porcine model of acid-induced esophageal damage for preliminary functional evaluations of anti-gastroesophageal reflux disease medical devices

Research (Published online: 21-12-2020)

18. A novel ex vivo porcine model of acid-induced esophageal damage for preliminary functional evaluations of anti-gastroesophageal reflux disease medical devices

Domenico Ventrella, Roberta Salaroli, Alberto Elmi, Giacomo Carnevali, Monica Forni, Fabio Baldi and Maria Laura Bacci

Veterinary World, 13(12): 2728-2735

ABSTRACT

Aim: The aim of the study was to set up a porcine ex vivo model of acid-induced damage and to evaluate its performance by means of multichannel intraluminal impedance and pH (MII-pH) live recording, histology, and Evans blue (EB) permeability assay.

Materials and Methods: Thirteen esophagi, collected at a slaughterhouse, were ablated of their sphincters, pinned upright on a support, and placed in a thermostatic hood at 37°C with two infusion tubes and an MII-pH probe inserted in the top end. Three esophagi (histology controls) were only left in the hood for 3.5 h before sampling, while the remaining organs underwent the experimental protocol including saline infusion and recovery recording, and acid solution infusion and recovery recording.

Results: MII-pH analysis highlighted a significantly stronger decrease during acid infusion when compared to saline, but a better post-infusion recovery for saline solution. At the end of the protocol, MII was still statistically lower than baseline. The acid-damaged esophagi significantly absorbed more EB dye, and histology revealed strong mucosal exfoliation.

Conclusion: The proposed model of esophageal acid damage seems to be repeatable, reliable, and achievable using organs collected at the slaughterhouse. MII recording proved to have good sensitivity in detecting mucosal alterations also in ex vivo trials.

Keywords: esophagus ex vivo model, Evans blue permeability assay, gastroesophageal reflux disease, multichannel intraluminal impedance, pig.

Antimicrobial resistance situation in animal health of Bangladesh

Review (Published online: 19-12-2020)

17. Antimicrobial resistance situation in animal health of Bangladesh

Md. Al Amin, M. Nazmul Hoque, Amam Zonaed Siddiki, Sukumar Saha and Md. Mostofa Kamal

Veterinary World, 13(12): 2713-2727

ABSTRACT

Antimicrobial resistance (AMR) is a crucial multifactorial and complex global problem and Bangladesh poses a regional and global threat with a high degree of antibiotic resistance. Although the routine application of antimicrobials in the livestock industry has largely contributed to the health and productivity, it correspondingly plays a significant role in the evolution of different pathogenic bacterial strains having multidrug resistance (MDR) properties. Bangladesh is implementing the National Action Plan (NAP) for containing AMR in human, animal, and environment sectors through "One Health" approach where the Department of Livestock Services (DLS) is the mandated body to implement NAP strategies in the animal health sector of the country. This review presents a "snapshot" of the predisposing factors, and current situations of AMR along with the weakness and strength of DLS to contain the problem in animal farming practices in Bangladesh. In the present review, resistance monitoring data and risk assessment identified several direct and/or indirect predisposing factors to be potentially associated with AMR development in the animal health sector of Bangladesh. The predisposing factors are inadequate veterinary healthcare, monitoring and regulatory services, intervention of excessive informal animal health service providers, and farmers' knowledge gap on drugs, and AMR which have resulted in the misuse and overuse of antibiotics, ultimate in the evolution of antibiotic-resistant bacteria and genes in all types of animal farming settings of Bangladesh. MDR bacteria with extreme resistance against antibiotics recommended to use in both animals and humans have been reported and been being a potential public health hazard in Bangladesh. Execution of extensive AMR surveillance in veterinary practices and awareness-building programs for stakeholders along with the strengthening of the capacity of DLS are recommended for effective containment of AMR emergence and dissemination in the animal health sector of Bangladesh.

Keywords: animal health, antibiotic-resistant, antimicrobial resistance, bacteria, veterinary.

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.