Shigella flexneri vaccine development: Oral administration of peptides derived from the 49.8 kDa pili protein subunit activates the intestinal immune response in mice

Research (Published online: 11-02-2022)

7. Shigella flexneri vaccine development: Oral administration of peptides derived from the 49.8 kDa pili protein subunit activates the intestinal immune response in mice

Khoirul Anam, Agustina Tri Endharti, Sri Poeranto, Hidayat Sujuti, Dwi Yuni Nur Hidayati and Sumarno Reto Prawiro

Veterinary World, 15(2): 281-287

ABSTRACT

Background and Aim: The morbidity and mortality of Shigella infections remain a global challenge. Epitope-based vaccine development is an emerging strategy to prevent bacterial invasion. This study aimed to identify the ability of the 49.8 kDa pili subunit adhesin protein epitope of Shigella flexneri to induce an intestinal immune response in mice.

Materials and Methods: Thirty adult male Balb/c mice were divided into a control group, cholera toxin B subunit (CTB) group, CTB+QSSTGTNSQSDLDS (pep_1) group, CTB+DTTITKAETKTVTKNQVVDTPVTTDAAK (pep_2) group, and CTB+ ATLGATLNRLDFNVNNK (pep_3). We performed immunization by orally administering 50 μg of antigen and 50 μl of adjuvant once a week over 4 weeks. We assessed the cellular immune response by quantifying T helper 2 (Th2) and Th17 using flow cytometry. In addition, we assessed the humoral immune response by quantifying interleukin (IL-4), IL-17, secretory immunoglobulin A (sIgA), and β-defensin using enzyme-linked immunoassay. Statistical analysis was performed using one-way analysis of variance and Kruskal–Wallis test.

Results: Peptide oral immunization increases the cellular immune response as reflected by the increase of Th2 (p=0.019) and Th17 (p=0.004) cell counts, particularly in the CTB_pep_1 group. Humoral immune response activation was demonstrated by increased IL-4 levels, especially in the CTB+pep_3 group (p=0.000). The IL-17 level was increased significantly in the CTB+pep_1 group (p=0.042). The mucosal immune response was demonstrated by the sIgA levels increase in the CTB+pep_3 group (p=0.042) and the β-defensin protein levels (p=0.000).

Conclusion: All selected peptides activated the cellular and humoral immune responses in the intestine of mice. Further studies are necessary to optimize antigen delivery and evaluate whether the neutralizing properties of these peptides allow them to prevent bacterial infection.

Keywords: epitope, immune response, oral, Shigella flexneri, shigellosis.

Phagocytosis and intracellular killing of Pasteurella multocida B:2 by macrophages: A comparative study between buffalo and cattle

Research (Published online: 10-02-2022)

6. Phagocytosis and intracellular killing of Pasteurella multocida B:2 by macrophages: A comparative study between buffalo and cattle

Qistina Hasnan, Yulianna Puspitasari, Sarah Othman, Mohd Zamri-Saad and Annas Salleh

Veterinary World, 15(2): 275-280

ABSTRACT

Background and Aim: Pasteurella multocida B:2 is the causative agent of hemorrhagic septicemia (HS) in buffalo and cattle. Buffaloes are known to be more susceptible to HS than cattle, but the reason for this remains unknown. This study aimed to compare the in vitro efficiency with which buffalo and cattle macrophages can kill P. multocida B:2.

Materials and Methods: Monocyte-derived macrophages of buffalo and cattle were used in this study. They were exposed to 1×106 colony-forming unit/mL of live P. multocida B:2 before the cells were harvested at 0, 30, 60, and 120 min post-exposure and viewed under a fluorescence microscope to count viable and non-viable macrophages and the macrophages with phagocytosing P. multocida B:2 cells. The phagocytosis, intracellular bacterial killing, and macrophage death rates were calculated and compared between the two species and sampling points.

Results: In general, the rates of phagocytosis, intracellular killing, and macrophage death increased with time of exposure for both animal species. No significant (p>0.05) differences were noted between the phagocytosis rates by the macrophages of buffalo and cattle throughout the experiment. However, the rates of intracellular killing were significantly (p<0.05) higher in cattle macrophages at 30 min and 120 min post-exposure than those of buffalo. The death rates of buffalo macrophages were significantly (p<0.05) higher than those of cattle at 60 min and 120 min post-exposure.

Conclusion: With higher bacteria killing ability and lower macrophage death, cattle appeared to be more efficient at handling P. multocida B:2 infection than buffalo.

Keywords: buffalo, cattle, in vitro efficiency, macrophages, Pasteurella multocida B:2.

Validation method for determining enrofloxacin and tylosin levels in broiler liver, kidney, and muscle using high-performance liquid chromatography

Research (Published online: 08-02-2022)

5. Validation method for determining enrofloxacin and tylosin levels in broiler liver, kidney, and muscle using high-performance liquid chromatography

Agustina Dwi Wijayanti, Rahmad Dwi Ardiansyah, Anggi Muhtar Pratama, Aris Haryanto and Ida Fitriana

Veterinary World, 15(2): 268-274

ABSTRACT

Background and Aim: Enrofloxacin and tylosin can be combined into an antibiotic formulation which is expected to have a broader range of antibacterial activity against various infections in broilers. Validation method analysis of the levels of these two active compounds needs to be done for future use in pharmacokinetic or residual studies. The present study aims to determine a suitable validation method of isocratic high-performance liquid chromatography (HPLC) to measure the concentration of antibiotic combinations in the broiler liver, kidney, and muscles.

Materials and Methods: The combination of enrofloxacin and tylosin in the liver, kidney, and muscle was validated by HPLC method to find the procedures, processes, equipment, and systems used, consistently provides the appropriate results. The chromatography system consisted of an Octadecyl-silica column of 5 μm in diameter and 150 mm in length with a mobile phase of a mixture of 0.05 M monobasic sodium phosphate (pH 2.5) and acetonitrile (65:35 v/v). The solution was detected at a wavelength of 280 nm, 30°C, a flow rate of 1 mL/min, and an injection volume of 20 μL. The combination antibiotics powder was produced from PT Tekad Mandiri Citra, Bandung, Indonesia, and broiler tissues obtained from day-old chick broilers maintained for 30 days with free antibiotic feed.

Results: Validation of a combination solution of enrofloxacin and tylosin shows the linearity values of enrofloxacin and tylosin in the liver, kidney, and muscles as r2=0.9988, r2=0.9999, r2=0.9997, r2=0.9989, r2=0.9978, and r2=0.9962. The accuracy and precision values of enrofloxacin in the liver, kidney, and muscles were 5.53, 6.23, and 6.93, respectively. The values of accuracy and precision of tylosin in the liver, kidney, and muscles were 10.43, 4.63, and 7.16%, respectively. The retention times for enrofloxacin and tylosin were 1.945-2.000 min and 4.175-4.342 min. The limit of detection (LOD) and limit of quantity (LOQ) values for enrofloxacin were 3.03 and 10.1 μg/g, respectively. In contrast, the LOD and LOQ values for tylosin were 9.05 and 30.17 μg/g, respectively.

Conclusion: The value of linearity, accuracy, precision, specificity, and sensitivity of the combined solution of enrofloxacin and tylosin showed promising results.

Keywords: enrofloxacin-tylosin combination, high-performance liquid chromatography, validation method.

The first study on seroprevalence and risk factors for zoonotic transmission of ovine and caprine brucellosis in the Province of Bam, Burkina Faso

Research (Published online: 05-02-2022)

4. The first study on seroprevalence and risk factors for zoonotic transmission of ovine and caprine brucellosis in the Province of Bam, Burkina Faso

Dieudonné Tialla

Veterinary World, 15(2): 262-267

ABSTRACT

Background and Aim: Brucellosis is a bacterial disease notorious for its ability to infect a wide range of domestic and wildlife animals, as well as humans. This study aimed to determine the seroprevalence of ovine and caprine brucellosis and the associated risk factors in the Province of Bam in Burkina Faso.

Materials and Methods: The individual serological status of 300 unvaccinated sheep and 300 unvaccinated goats was determined by Rose Bengal and indirect enzyme-linked immunosorbent assay (iELISA) serological tests used in parallel. The frequency of behaviors conferring risk of developing this zoonotic disease was determined through two epidemiological questionnaires, which identified known risk factors for the transmission of brucellosis between animals and humans.

Results: Individual seroprevalence was estimated at 6.0% (18/300) in sheep and 4.3% (13/300) in goats. The "herd" prevalence of brucellosis was estimated at 60% in sheep while 40% in goats. Positivity in the iELISA serological test was significantly associated with age, sex, and husbandry system in sheep and goats.

Conclusion: These results indicate that Brucella melitensis circulates in sheep and goat farms in the Province of Bam in Burkina Faso. As B. melitensis is highly pathogenic to humans, adequate measures must be taken to protect the population against this zoonotic disease.

Keywords: brucellosis ovine and caprine, Burkina Faso, Province of Bam, seroprevalence, zoonosis.

Synchronization of rumen degradable protein with non-fiber carbohydrate on microbial protein synthesis and dairy ration digestibility

Research (Published online: 05-02-2022)

3. Synchronization of rumen degradable protein with non-fiber carbohydrate on microbial protein synthesis and dairy ration digestibility

Annisa Rosmalia, Idat Galih Permana and Despal Despal

Veterinary World, 15(2): 252-261

ABSTRACT

Background and Aim: Dairy ration formulations should consider the synchronization of the rumen degradable protein (RDP) to rumen undegradable protein (RUP) ratio (RDPR) with non-fiber carbohydrate (NFC) to achieve optimum microbial protein synthesis (MPS), reduce feed costs, and reduce N excretion to the environment. This study aimed to investigate the effect of RDPR and NFC synchronization on in vitro digestibility, fermentability, and MPS.

Materials and Methods: The experiment used a 3×3 factorial randomized block design with four replications. The first factor was RDPR (RDPR1=50:50; RDPR2=55:45; RDPR3=60:40) and the second factor was NFC levels (NFC1=30%, NFC2=35%, NFC3=40%). The experimental diets were evaluated using a two-stage in vitro method. The examined parameters included rumen pH, NH3 concentration, total volatile fatty acid (VFA) concentration, the molar proportion of VFAs, rumen microbes (protozoa and total bacteria population), and MPS. Data were analyzed using ANOVA, followed by the Duncan test.

Results: The results show that neither RDPR nor NFC affected rumen pH, NH3, total VFA, and the rumen microbe population. The interaction between RDPR and NFC affected the molar proportion of acetate, iso-butyrate, and n-valerate. The combination of RDPR1 and NFC1 produced a lower molar proportion of acetate (49.73%) than the other treatment combinations (>54%). The acetate to propionate ratio was influenced by the NFC levels, in which NFC2 and NFC3 produced the highest ratio (p<0.05). MPS was affected by RDPR and NFC, but not by their interaction. Treatments NFC2 and RDPR3 produced the highest MPS. NFC affected the dry matter and organic matter digestibility (DMD and OMD), with treatment NFC3 resulting in the highest DMD and OMD.

Conclusion: The combination of a 60:40 RDPR with 35% NFC resulted in the best synchronization of protein and energy available for MPS and digestion activity in the rumen.

Keywords: dairy ration digestibility, microbial protein synthesis, rumen degradable protein, rumen undegradable protein, synchronization.

Most common inappropriate drug usage factors in anthelmintic treatment on sheep farms in Latvia

Research (Published online: 04-02-2022)

2. Most common inappropriate drug usage factors in anthelmintic treatment on sheep farms in Latvia

Līga Kovaļčuka, Dace Keidāne, Alīna Kļaviņa, Marta Barbara Grasberga and Armands Vekšins

Veterinary World, 15(2): 244-251

ABSTRACT

Background and Aim: There is little understanding about antiparasitic drug prescription trends and implementation to reduce possible drug overuse or misuse worldwide. This study aimed to review sheep parasite control strategies and antiparasitic drug use habits in Latvia. To the best of the author's knowledge, this is the first study in the world that describes how antiparasitic drugs are used and what are the most common drug usage errors in a sheep farm.

Materials and Methods: A semi-structured questionnaire was designed to collect relevant information from face-to-face interviews to assess 22 sheep farmers' knowledge and management procedures in farms. We collected information about animal feeding, herding, parasite diagnostics, and antiparasitic drug usage. The questionnaire summary included information on pasture use, parasite control management, and anthelmintic drug choice/use.

Results: Only 36% of farms regularly managed parasite control by analyzing fecal samples for parasites, but prophylactic deworming was employed in all farms. Ivermectin, albendazole, levamisole, and monepantel were used on the farms and most of the farms were multidrug users; 77.3% of the farms used albendazole and 72.7% used ivermectin.

Conclusion: The results indicated a lack of parasitological examination and parasite control of the flock, mostly empiric drug selection, incorrect dosing, inaccurate drug administration, drug storage, and use errors. A proactive approach to herd health planning, regular parasitic control, and prophylactic measures may benefit farmers and veterinarians.

Keywords: anthelmintics, drug resistance, drug usage errors, sheep.

Molecular prevalence of Dirofilaria immitis and Wolbachia infections in pet and semi-domesticated cats in Bangkok, Thailand

Research (Published online: 03-02-2022)

1. Molecular prevalence of Dirofilaria immitis and Wolbachia infections in pet and semi-domesticated cats in Bangkok, Thailand

Naris Thengchaisri, Tawin Inpankaew, Surapong Arthitwong, Jörg M. Steiner and Panpicha Sattasathuchana

Veterinary World, 15(2): 239-243

ABSTRACT

Background and Aim: Although cats are not natural hosts for heartworm infections (Dirofilaria immitis), evidence suggests that feline heartworm disease can be detrimental because of a severe inflammatory response. Recent studies have found that infection with bacteria of the genus Wolbachia is the principal cause of acute inflammatory filaria disease; nonetheless, the prevalence of cats naturally infected with heartworms and Wolbachia remains unclear. This study aimed to estimate the prevalence and current distribution of feline heartworm disease and its association with Wolbachia infection in pet and semi-domesticated cats in Bangkok, Thailand.

Materials and Methods: A total of 260 cats (130 pet cats and 130 semi-domesticated cats) were enrolled in this study. Blood samples were placed into ethylenediaminetetraacetic acid tubes for hematological analysis and DNA extraction. A polymerase chain reaction (PCR) was performed to analyze samples for the presence of D. immitis and Wolbachia infections.

Results: The prevalence (95% confidence interval [CI]) of D. immitis infection in pet, semi-domesticated, and all cats were 3.9% (1.3-8.8%), 27.7% (20.2-36.2%), and 19.6% (15.0-25.0%), respectively. The prevalence (95% CI) of Wolbachia infection in pet, semi-domesticated, and all cats were 18.5% (12.2-26.2%), 31.5% (23.7-40.3%), and 25.0% (19.9-30.7%), respectively. The prevalence of D. immitis and Wolbachia infections in semi-domesticated cats was significantly higher than in pet cats (p=0.002 and p=0.022, respectively). There was a significant association between D. immitis and Wolbachia infections (p<0.001). There was also a significant association between D. immitis infection and the presence of eosinophilia (p<0.045).

Conclusion: From the PCR analysis, it can be concluded that semi-domesticated cats were at higher risk for D. immitis infection than pet cats. There was a significant association between positive D. immitis infection and positive Wolbachia infection. Combinations of anthelmintic and antimicrobial therapy should be considered in heartworm-positive cats.

Keywords: cat, heartworm, prevalence, Wolbachia.