Advanced molecular characterization of enteropathogenic Escherichia coli isolated from diarrheic camel neonates in Egypt

Research (Published online: 12-01-2021)

11. Advanced molecular characterization of enteropathogenic Escherichia coli isolated from diarrheic camel neonates in Egypt

Momtaz A. Shahein, Amany N. Dapgh, Essam Kamel, Samah F. Ali, Eman A. Khairy, Hussein A. Abuelhag and Ashraf S. Hakim

Veterinary World, 14(1): 85-91

ABSTRACT

Background and Aim: Camels are important livestock in Egypt on cultural and economic bases, but studies of etiological agents of camelid diseases are limited. The enteropathogen Escherichia coli is a cause of broad spectrum gastrointestinal infections among humans and animals, especially in developing countries. Severe infections can lead to death. The current study aimed to identify pathogenic E. coli strains that cause diarrhea in camel calves and characterize their virulence and drug resistance at a molecular level.

Materials and Methods: Seventy fecal samples were collected from diarrheic neonatal camel calves in Giza Governorate during 2018-2019. Samples were cultured on a selective medium for E. coli, and positive colonies were confirmed biochemically, serotyped, and tested for antibiotic susceptibility. E. coli isolates were further confirmed through detection of the housekeeping gene, yaiO, and examined for the presence of virulence genes; traT and fimH and for genes responsible for antibiotic resistance, ampC, aadB, and mphA. The isolates in the important isolated serotype, E. coli O26, were examined for toxigenic genes and sequenced.

Results: The bacteriological and biochemical examination identified 12 E. coli isolates from 70 fecal samples (17.1%). Serotyping of these isolates showed four types: O26, four isolates, 33.3%; O103, O111, three isolates each, 25%; and O45, two isolates, 16.7%. The isolates showed resistance to vancomycin (75%) and ampicillin (66.6%), but were highly susceptible to ciprofloxacin, norfloxacin, and tetracycline (100%). The structural gene, yaiO (115 bp), was amplified from all 12 E. coli isolates and traT and fimH genes were amplified from 10 and 8 isolates, respectively. Antibiotic resistance genes, ampC, mphA, and aadB, were harbored in 9 (75%), 8 (66.6%), and 5 (41.7%), respectively. Seven isolates (58.3%) were MDR. Real-time-polymerase chain reaction of the O26 isolates identified one isolate harboring vt1, two with vt2, and one isolate with neither gene. Sequencing of the isolates revealed similarities to E. coli O157 strains.

Conclusion: Camels and other livestock suffer various diseases, including diarrhea often caused by microbial pathogens. Enteropathogenic E. coli serotypes were isolated from diarrheic neonatal camel calves. These isolates exhibited virulence and multiple drug resistance genes.

Keywords: camel, multidrug-resistant Escherichia coli, real-time polymerase chain reaction, sequencing, virulence.

Effect of oxygen tension and antioxidants on the developmental competence of buffalo oocytes cultured in vitro

Research (Published online: 11-01-2021)

10. Effect of oxygen tension and antioxidants on the developmental competence of buffalo oocytes cultured in vitro

Amro M. El-Sanea, Ahmed Sabry S. Abdoon, Omaima M. Kandil, Nahed E. El-Toukhy, Amal M. Abo El-maaty and Hodallah H. Ahmed

Veterinary World, 14(1): 78-84

ABSTRACT

Aim: Oxidative stress (OS) is one of the major disruptors of oocyte developmental competence, which appears due to the imbalance between the production and neutralization of reactive oxygen species (ROS).

Materials and Methods: In Experiment 1, buffalo oocytes were in vitro matured, fertilized, and cultured at 38.5°C under 5% CO2 + 20% O2 in standard CO2 incubator (OS) or under 5% O2 + 5% CO2 + 90% N2 (Multi-gas incubator, low O2). In Experiment 2, buffalo cumulus oocytes complexes (COCs) were matured in Basic maturation medium (BMM) composed of TCM199+ 10% FCS+ 10 μg/ml FSH+ 50 μg/ml gentamicin (control group) or in BMM supplemented with 50 μM ascorbic acid (ascorbic acid group) or 3.0 mM glutathione (glutathione group) or 10-5 M melatonin (melatonin group) and cultured at 38.5°C under 20% O2 for 24 h. Matured buffalo oocytes in control, ascorbic acid, or melatonin groups were fertilized and zygotes were cultured for 8 days under the same conditions.

Results: In both experiments, maturation, cleavage, and blastocyst rates were recorded. Results showed that culture of buffalo oocytes under low O2 (5% O2) significantly increased maturation, cleavage, and blastocyst rates (p<0.05). Meanwhile, under 20% O2, addition of 10-5 M melatonin or 50 μM ascorbic acid to in vitro maturation (IVM) medium significantly improved cumulus cell expansion, nuclear maturation rates of buffalo oocytes (p<0.05), and increased cleavage and blastocyst rates (p<0.05).

Conclusion: About 5% O2 is the optimum condition for in vitro production of buffalo embryos, and addition of 10-5 M melatonin to IVM medium for oocytes cultured under 20% O2 could alleviate the adverse effect of high oxygen tension and increased embryo yield.

Keywords: antioxidants, buffalo oocytes, developmental competence, in vitro embryo production, O2 tension.

Comparison of two attenuated infectious bursal disease vaccine strains focused on safety and antibody response in commercial broilers

Research (Published online: 11-01-2021)

9. Comparison of two attenuated infectious bursal disease vaccine strains focused on safety and antibody response in commercial broilers

Thotsapol Thomrongsuwannakij, Nataya Charoenvisal and Niwat Chansiripornchai

Veterinary World, 14(1): 70-77

ABSTRACT

Background and Aim: Infectious bursal disease (IBD) or Gumboro disease is one of the most detrimental diseases in the poultry industry worldwide. Previous scientific studies have shown that live IBD vaccination might induce transient immunosuppression, leading to suboptimal vaccine responses, and therefore lack of protection against other infectious diseases; therefore, selecting an IBD vaccine in commercial farms is a concern. This study aims to compare two commercially attenuated IBD vaccines (intermediate and intermediate-plus strains) in terms of safety and antibody response to IBD and Newcastle disease viruses (NDV) in commercial broilers.

Materials and Methods: Overall, 216 Cobb broiler chickens were divided into three groups based on the IBD vaccine strain administered: V217 strain (Group 1), M.B. strain (Group 2), and an unvaccinated group (Group 3). Groups 1 and 2 were orally vaccinated with Hitchner B1 NDV vaccine strain 7 days after IBD vaccination. Blood samples were collected at IBD vaccination day (15 days of age) and at 7, 14, 21, and 28 days post-IBD vaccination. The immunosuppressive effects of the IBD vaccination were determined by NDV antibody response, the bursa:body weight (B:BW) ratio, and the histopathological lesion scores of the bursa of Fabricius. Phylogenetic analysis was also performed.

Results: Phylogenetic analysis revealed that the M.B. strain belonged to a very virulent IBD strain, whereas the V217 strain belonged to a classical IBD virus strain. NDV antibody titers of the two vaccinated groups increased after ND vaccination, reaching their maximum at 14 days post-ND vaccination and decreasing thereafter. The V217 group presented the highest NDV humoral response from 7 days post-vaccination (dpv) to the end of the study. The mean NDV antibody titer of the V217 group was significantly (p<0.05) higher than that of the M.B. group at 14 dpv. In addition, the V217 strain-induced lower bursal lesions post-IBD vaccination and a higher B:BW ratio at 7 and 21 dpv compared to the M.B. group. The higher B:BW ratio, lower bursal lesions, and higher ND antibody response present in the V217 group indicate that the V217 strain induces lower immunosuppressive effects compared to the M.B. strain.

Conclusion: The results of this study indicate that IBD vaccine selection merits consideration, as avoiding the immunosuppressive effects induced by live IBD vaccination and the consequent impact on response to other vaccines is important.

Keywords: broilers, immunosuppressive effects, infectious bursal disease, vaccination.

Changes in hematological, biochemical, and blood gases parameters in response to progressive inclusion of nitrate in the diet of Holstein calves

Research (Published online: 09-01-2021)

8. Changes in hematological, biochemical, and blood gases parameters in response to progressive inclusion of nitrate in the diet of Holstein calves

Abimael Ortiz-Chura, Gisela Marcoppido, José Gere, Gustavo Depetris, Francisco Stefañuk, Marcos D. Trangoni, Silvio L. Cravero, Claudia Faverín, Angel Cataldi and María E. Cerón-Cucchi

Veterinary World, 14(1): 61-69

ABSTRACT

Background and Aim: Nitrate (NO3–) reduces enteric methane emissions and could be a source of non-protein nitrogen in ruminant feeds. Nonetheless, it has a potential toxic effect that could compromise animal health and production. The purpose of this study was to determine the effects of progressive inclusion of NO3– in the diet on the hematological, biochemical, and blood gases parameters, in turn, the effects on feed intake and live weight gain (LWG) in Holstein calves.

Materials and Methods: Eighteen Holstein heifers and steers (nine animals/treatment) were maintained in individual pens for 45 days. Animals were randomly allocated to either a control or nitrate diet (ND) (containing 15 g of NO3–/kg of dry matter [DM]). The biochemical parameters and blood gases were analyzed only in the NO3– group on days: -1, 1, 7, 13, 19, and 25 corresponding to 0, 20, 40, 60, 80, and 100% of the total inclusion of NO3– in the diet, respectively. In addition, DM intake (DMI) and LWG were evaluated among dietary treatments.

Results: Feeding the ND did not influence DMI or LWG (p>0.05). Methemoglobin (MetHb) and deoxyhemoglobin increased according to the NO3– concentrations in the diet (p<0.05), while an opposite effect was observed for oxyhemoglobin and carboxyhemoglobin (p<0.05). Hematocrit levels decreased (p<0.05), while albumin, alanine aminotransferase, and gamma-glutamyl transpeptidase concentrations were not modified (p>0.05). However, glucose, urea, aspartate aminotransferase (AST), and retinol concentrations increased (p<0.05) according to the NO3– concentrations in the diet.

Conclusion: This study confirmed that the progressive inclusion of 123 g of NO3–/animal/day in the diet could be safe without affecting DMI and LWG of Holstein calves. In turn, a dose-response effect of the MetHb, glucose, urea, AST, and retinol was observed, but these values did not exceed reference values. These results highlighted the importance of using a scheme of progressive inclusion of NO3– in the diet of calves to reduce the risks of NO3– toxicity.

Keywords: dry matter intake, liver function, methemoglobin, nitrate toxicity.

Sequence analysis of the Hex A gene in Jacob sheep from Bulgaria

Research (Published online: 08-01-2021)

7. Sequence analysis of the Hex A gene in Jacob sheep from Bulgaria

Boyko Neov, Jivko Krastanov, Teodora Angelova, Nadezhda Palova, Stayka Laleva and Peter Hristov

Veterinary World, 14(1): 56-60

ABSTRACT

Background and Aim: Jacob sheep are a rare ancient breed of sheep believed to have originated from the Mediterranean area but which are now kept throughout the world. These sheep have recently attracted medical interest due to the observation of a genetic disorder in the breed that can be used as an animal model of Tay–Sachs disease (TSD). This study aims to detect mutations in the Hexosaminidase A gene in Jacob sheep based on sequence analysis of the 284-bp fragment situated between exon 11 and intron 11 of the gene, a target sequence for site-specific mutation. This is the first study that has investigated Jacob sheep in Bulgaria for gene-specific mutations.

Materials and Methods: A total of 20 blood samples were collected from Jacob sheep from the Rhodope Mountains. DNA was isolated from these samples, and a specific 284-bp fragment was amplified. The amplified products were purified using a polymerase chain reaction purification kit and sequenced in both directions.

Results: Target sequences were successfully amplified from all 20 investigated sheep. Sequence analysis did not show the homozygous, recessive, missense (G-to-C transition) mutation at nucleotide position 1330 (G1330→C) in exon 11, demonstrating that all of these sheep were a normal genotype (wild-type).

Conclusion: Jacob sheep are considered a potentially useful animal model in advancing the understanding of pathogenesis and developing potential therapies for orphan diseases, such as those characterized by mutant GM2 gangliosides. The clinical and biochemical features of the Jacob sheep model of TSD represent well the human classical late-infantile form of this disorder, indicating that the model can serve as a possible new research tool for further study of the pathogenesis and treatment of TSD.

Keywords: GM2 gangliosides, Hexosaminidase A gene, human replacement therapy, Jacob sheep, Tay–Sachs disease.

Demographic and clinical characteristics of dogs with centroblastic lymphoma

Research (Published online: 07-01-2021)

6. Demographic and clinical characteristics of dogs with centroblastic lymphoma

Katarzyna Kliczkowska-Klarowicz, Dariusz Jagielski, Michał Czopowicz and Rafał A. Sapierzyński

Veterinary World, 14(1): 49-55

ABSTRACT

Background and Aim: Centroblastic lymphoma (CBL) is the most common morphological type of lymphoma found in dogs; it is usually identified through cytology in veterinary clinical practice. This study aimed to identify the demographic and clinical characteristics of dogs with CBL that was diagnosed with cytology and immunocytochemistry.

Materials and Methods: Dogs with a suspicion of lymphoma were diagnosed by cytology supported by immunocytochemistry with the use of the updated Kiel classification adapted for dogs. During the analyzed time period, 336 lymphomas were diagnosed in dogs, including 171 cases of CBL. Epidemiological and clinical data from the dogs with CBL were provisionally collected.

Results: The epidemiology analysis revealed an increased risk of CBL in Rottweilers, golden retrievers, and Bernese mountain dogs. At admission, most of the dogs displayed generalized lymphadenopathy with spleen and liver enlargement. The most common hematological abnormality was leukocytosis due to neutrophilia. The most common biochemical abnormality was elevated alanine aminotransferase and alkaline phosphatase activities and selective hypoproteinemia due to hypoalbuminemia.

Conclusion: Rottweilers, Bernese mountain dogs, and golden retrievers appear to be overrepresented among dogs with CBL. CBL is usually diagnosed at an advanced clinical stage according to the World Health Organization; however, it is usually accompanied by only minor hematological and biochemical abnormalities.

Keywords: Bernese mountain dogs, clinical stage, cytology, epidemiology, fine-needle biopsy, Golden Retrievers, immunophenotype, lymphoma, Rottweilers.

Role of microorganisms isolated from cows with mastitis in Moscow region in biofilm formation

Research (Published online: 07-01-2021)

5. Role of microorganisms isolated from cows with mastitis in Moscow region in biofilm formation

Pavel Rudenko, Nadezhda Sachivkina, Yury Vatnikov, Sergey Shabunin, Sergey Engashev, Svetlana Kontsevaya, Arfenia Karamyan, Dmitry Bokov, Olga Kuznetsova and Elena Vasilieva

Veterinary World, 14(1): 40-48

ABSTRACT

Background and Aim: Mastitis is one of the most important diseases of cows and the most expensive pathology for the dairy industry. Therefore, this study was conducted to explore the role of microorganisms isolated from cows with mastitis in the formation of biofilms under the conditions of farm biogeocenosis in the Moscow region.

Materials and Methods: Periodic visits to 12 farms in the Moscow region were conducted to explore the microbial profile of the udder of cows with mastitis. During the visits, 103 milk samples from sick animals were collected and examined. Through microbiological analyses, 486 cultures of microorganisms were identified, which are assigned to 11 genera. Mastitis in cows is caused not only by a single pathogen but also by microbial associations, which included two to seven microbial isolates.

Results: It was observed that 309 isolates (63.6%) from the total number of isolated microorganisms could form a biofilm. The ability to form biofilms was most frequently observed in Staphylococcus aureus (18.8%), Escherichia coli (11.9%), and Staphylococcus uberis (11.7%) cultures from the total number of biofilm-forming microbial cultures. Low biofilm-forming ability among the isolated microorganisms was found in lactobacilli, wherein only 20 (22.5%) Lactobacillus strains had the ability to form biofilms. The isolated microorganisms exhibited different sensitivities to antimicrobial agents, which cause difficulty in selecting an antimicrobial agent that would act on all aspects of the parasitocenosis.

Conclusion: A high proportion of microorganisms isolated from cows with mastitis have the ability to form biofilms. The isolated microorganisms exhibited different and highly heterogeneous sensitivity to the action of antimicrobial drugs. This causes difficulty in using these tools for the effective control of mastitis in cows, which is frequently caused by pathogenic associations of microbial biofilms. Therefore, it is important to explore novel and more effective methods to combat this disease.

Keywords: bacterial communities, biofilms, biogeocenosis, cows, mastitis, sensitivity to antibiotics.