Exposure to high thermal conditions for a long time induces apoptosis and decreases total RNA concentration in peripheral blood mononuclear cells among Indian Zebu–Jersey crossbreds

Research (Published online: 15-09-2022)

10. Exposure to high thermal conditions for a long time induces apoptosis and decreases total RNA concentration in peripheral blood mononuclear cells among Indian Zebu–Jersey crossbreds

Gbolabo Olaitan Onasanya, George M. Msalya, Aranganoor K. Thiruvenkadan, Nagarajan Murali, Ramasamy Saravanan, Angamuthu Raja, Moses Okpeku, Mani Jeyakumar, and Christian O. Ikeobi

Veterinary World, 15(9): 2192-2201

ABSTRACT

Background and Aim: Global warming has grave consequences on livestock production systems and profound negative effects on animal production. This study aimed to carry out an in vitro thermal stress stimulation (TSS) of bovine peripheral blood mononuclear cells (PBMCs) using different thermal assault conditions (TACs), including normal to extreme temperatures and varying durations of thermal exposure (DTE) to understand how PBMCs of Indian Zebu–Jersey crossbreds respond to various levels and durations of heat shock.

Materials and Methods: Ten milliliters of blood were collected from 70 Indian Zebu–Jersey crossbreds under aseptic conditions and were sampled for isolating PBMCs. Peripheral blood mononuclear cells were divided into seven groups, each comprising 10 PBMC samples isolated from 10 different animals. Aliquots of 500 μL of PBMCs were stressed by exposure to different TACs (37, 40, and 45°C) for DTEs of 3 or 6 h. Subsequently, the cells were harvested. The control unstressed samples (500 μL aliquots of PBMCs) were exposed to no TAC (0°C) and zero DTE (0 h). Total RNA from all the treatment groups of PBMCs were isolated and quantitated.

Results: We found a very strong association between TACs and RNA levels. In addition, PBMCs viability was negatively affected by heat shock. This led to an exponential reduction in PBMC count as TACs toughened. Only 3.59 × 105 ± 0.34 cells/mL were viable after exposure to 45°C for a 6 h DTE. This cell viability was lower than that measured in controls subjected to no stress and zero time DTE (2.56 × 107 ± 0.22 cells/mL). We also observed a reduction in the concentration of RNA isolated from thermally stressed PBMCs.

Conclusion: In vitro TSS of PBMCs provided biological information on the response of cellular systems to heat shock after exposure to TACs. This will help to mitigate and manage the effects of thermal stress in bovine species. The association between the reduction in PBMC count after in vitro TSS and the expression of heat shock protein 70 gene will be investigated in the future to further understand how Indian Zebu–Jersey crossbreds respond to in vitro thermal conditions. This will be used to determine the in vivo response of Indian Jersey crossbreds to different environmental thermal conditions and will further enable the in vivo understanding of thermotolerance potentials of bovine species for better adaptation, survival, and production performance.

Keywords: bovine, cell survival, climate change, peripheral blood mononuclear cells, RNA synthesis, thermal stress.

Genotypic characterization of mecA gene and antibiogram profile of coagulase-negative staphylococci in subclinical mastitic cows

Research (Published online: 15-09-2022)

9. Genotypic characterization of mecA gene and antibiogram profile of coagulase-negative staphylococci in subclinical mastitic cows

Eman S. Ibrahim, Sohad M. Dorgham, Asmaa S. Mansour, Abeer M. Abdalhamed, and Doaa D. Khalaf

Veterinary World, 15(9): 2186-2191

ABSTRACT

Background and Aim: Coagulase-negative staphylococci (CNS) are becoming the major cause of clinical and subclinical bovine mastitis around the world. This study aims to estimate the prevalence, antibiogram, and frequency of the methicillin-resistant (MR) (mecA) gene in CNS collected from cows with subclinical mastitis.

Materials and Methods: Thirty-four milk samples were collected from 20 cows. Fifteen subclinical mastitis samples (∼44.12%) were identified as CNS isolates. The Vitek2 compact system method was employed for the identification of the species. Furthermore, antibiotic sensitivity tests were performed against 10 different antibiotics for CNS strains. The mecA gene from isolated CNS was detected by conventional polymerase chain reaction (PCR).

Results: Staphylococcus haemolyticus was the most predominant isolated species with an incidence of 33.3% (5/15 isolates), followed by 26.7% for Staphylococcus sciuri and Staphylococcus vitamins (4/15 isolates), and 13.3% for Staphylococcus vitulinus (2/15 isolates), respectively. The highest resistance rates were determined to be 40% (6/15 isolates) against penicillin and oxacillin (OX), 33.3% (5/15 isolates) against clindamycin, 13% (2/15 isolates) against chloramphenicol, amoxicillin, and erythromycin, and 5% (1/15 isolates) against ciprofloxacin, respectively. The results revealed that the isolates were resistant to one or more antimicrobial agents, with five isolates displaying multiple antimicrobial resistance. Furthermore, the results exhibit that all CNS isolates had the mecA gene at 310 bp with a 100% frequency. Moreover, for detecting MR isolates, there are significant discrepancies between phenotypic and genotypic approaches, and only 6/15 CNS isolates phenotypically demonstrated OX resistance.

Conclusion: The results emphasize the necessity of frequent monitoring of phenotypic and genotypic profiles of CNS isolates to ensure effective control measures and the prevention of multidrug resistance strain evolution.

Keywords: coagulase-negative staphylococci, cows, mecA gene, polymerase chain reaction, subclinical mastitis.

Seroprevalence and risk assessment of Toxoplasma gondii infection in sheep and goats in North and Beqaa governorates of Lebanon

Research (Published online: 13-09-2022)

8. Seroprevalence and risk assessment of Toxoplasma gondii infection in sheep and goats in North and Beqaa governorates of Lebanon

Sara Khalife, Sara Moubayed, Rosy Mitri, Regina Geitani, and Dima El Safadi

Veterinary World, 15(9): 2180-2185

ABSTRACT

Background and Aim: Toxoplasmosis is a disease caused by the protozoan parasite Toxoplasma gondii that affects both humans and animals, leading to abortions and significant clinical manifestations in pregnant and immunocompromised hosts, in addition to massive economic losses in animal industries. Data from Lebanon are scarce regarding the seroprevalence of T. gondii infection in livestock. This study aimed to estimate the seroprevalence and assess the associated risk factors of T. gondii infection in sheep and goats in Lebanon.

Materials and Methods: A cross-sectional study was carried out from May 2020 to April 2021. Blood samples from 150 sheep and 145 goats (total 295) destined for human consumption were obtained from 20 Lebanese farms located in the North and Beqaa governorates. The anti-T. gondii immunoglobulin G antibodies were assayed through means of a modified agglutination test with a cutoff titer of 20.

Results: An overall seroprevalence of 48.5% (143/295) was reported: About 56.6% seroprevalence was found in sheep (85/150) and 40% (58/145) in goats. Adult age, female gender, and the wet season were significantly associated with an increased seropositivity rate of T. gondii infection (p < 0.001, p = 0.001, and p = 0.043, respectively).

Conclusion: These results confirm the spread of T. gondii in sheep and goats destined for human consumption in various geographical regions in Lebanon. Therefore, continuous monitoring of T. gondii infection in livestock is warranted to control the spread of the infection and limit its potential transmission to humans through the consumption of raw or undercooked meat.

Keywords: goats, Lebanon, risk factors, seroprevalence, sheep, Toxoplasma gondii.

A review: Virulence factors of Klebsiella pneumonia as emerging infection on the food chain

Review (Published online: 12-09-2022)

7. A review: Virulence factors of Klebsiella pneumonia as emerging infection on the food chain

Katty Hendriana Priscilia Riwu, Mustofa Helmi Effendi, Fedik Abdul Rantam, Aswin Rafif Khairullah, and Agus Widodo

Veterinary World, 15(9): 2172-2179

ABSTRACT

Health problems can be caused by consuming foods that have been processed in unsanitary conditions; hence, the study of the impact of contamination on food and its prevention has become critical. The disease caused by Klebsiella pneumoniae in food is increasing significantly every year across the world. The main factors that are essential for the virulence of K. pneumoniae are lipopolysaccharide and polysaccharide capsules. Furthermore, K. pneumoniae is capable of forming biofilms. Capsule polysaccharides, fimbriae types 1 and 3, are crucial virulence factors contributing to biofilm formation in K. pneumoniae. The food contamination by K. pneumoniae may not directly pose a public health risk; however, the presence of K. pneumoniae refers to unhygienic practices in food handling. This article aims to demonstrate that K. pneumoniae should be considered as a potential pathogen that spreads through the food chain and that necessary precautions should be taken in the future.

Keywords: biofilm, food chain, Klebsiella pneumonia, public health, virulence.

Distinctive location of piscine intestinal coccidiosis in Asian seabass fingerlings

Research (Published online: 09-09-2022)

6. Distinctive location of piscine intestinal coccidiosis in Asian seabass fingerlings

Watcharapol Suyapoh, Peerapon Sornying, Chanoknun Thanomsub, Khemjira Kraonual, Korsin Jantana, and Sirikachorn Tangkawattana

Veterinary World, 15(9): 2164-2171

ABSTRACT

Background and Aim: Coccidian infection (coccidiosis) is one of the most important causes of illness and death in the fish population, including Asian sea bass. The fingerling developmental stage is sensitive to various infectious agents. Economic losses are sustained by the sea bass aquaculture industry due to coccidiosis annually. However, the related pathological changes in the Asian sea bass fingerlings' three-part intestine remain unknown. This study aimed to investigate the Asian sea bass fingerlings' infection rate, infection location and site, and specific pathological lesions in the small intestinal tissues in a marine cage farming operation.

Materials and Methods: A cross-sectional study was conducted on 44 fingerling fishes. Major coccidia proportions were identified morphologically at both the macroscopic and microscopic levels. The infection number was determined based on coccidia presence at various intestinal locations and sites. All areas were assessed for pathological lesions using semi-quantitative grading. Analysis of variance was used to perform all data analyses using the SPSS software. Data were expressed as means ± standard deviation. p < 0.05 was considered statistically significant.

Results: All Asian sea bass fingerlings studied were infected with coccidia. Enteritis and mucosal necrosis were distinct lesions found in the anterior intestine, which had the highest infection rate (49.94%), followed by the mid intestine (35.63%), and the posterior intestine (22.43%). The most common coccidian infection site was extracellular (subepithelial), followed by intracytoplasmic, and epicellular sites. Histopathological lesion determination revealed that intestinal tissue inflammation and epithelial injuries were predominantly seen in the anterior gut (p < 0.05).

Conclusion: There was a high coccidian infection rate in Asian sea bass fingerlings from marine cage farming operations. Infection and intestinal damage at the anterior intestine, a major site, led to fingerling death. Disease prevention in the nursery should be intensive from the fingerling period to decrease the fatality rate caused by coccidia.

Keywords: Asian seabass, coccidian, fingerling, histopathology, Lates calcarifer, small intestine.

Accuracy of molecular diagnostic methods for the detection of bovine brucellosis: A systematic review and meta-analysis

Research (Published online: 08-09-2022)

5. Accuracy of molecular diagnostic methods for the detection of bovine brucellosis: A systematic review and meta-analysis

Lerato Mabe, ThankGod E. Onyiche, Oriel Thekisoe, and Essa Suleman

Veterinary World, 15(9): 2151-2163

ABSTRACT

Background and Aim: Bovine brucellosis is a disease of global socio-economic importance caused by Brucella abortus. Diagnosis is mainly based on bacterial culture and serology. However, these methods often lack sensitivity and specificity. A range of molecular diagnostic methods has been developed to address these challenges. Therefore, this study aims to investigate the diagnostic accuracy of molecular tools, in comparison to gold standard bacterial isolation and serological assays for the diagnosis of bovine brucellosis.

Materials and Methods: The systematic review and meta-analysis were conducted based on analyses of peer-reviewed journal articles published between January 1, 1990, and June 6, 2020, in the PubMed, Science Direct, Scopus, and Springer Link databases. Data were extracted from studies reporting the use of molecular diagnostic methods for the detection of B. abortus infections in animals according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The quality of included journal articles was assessed using the quality assessment of diagnostic-accuracy studies assessment tool and meta-analysis was carried out using Review Manager.

Results: From a total of 177 studies, only 26 articles met the inclusion criteria based on PRISMA guidelines. Data from 35 complete studies were included in the meta-analysis and used to construct 2 × 2 contingency tables. Improved diagnostic performance was observed when tissue (sensitivity 92.7% [95% confidence interval (CI) 82.0–98.0%]) and serum samples (sensitivity 91.3% [95% CI 86.0–95.0%]) were used, while the BruAb2_0168 locus was the gene of preference for optimal assay performance (sensitivity 92.3% [95% CI 87.0–96.0%] and specificity 99.3% [95% CI 98.0–100.0%]). Loop-mediated isothermal amplification (LAMP) had a higher diagnostic accuracy than polymerase chain reaction (PCR) and real-time quantitative PCR with sensitivity of 92.0% (95% CI 78.0–98.0%) and specificity of 100.0% (95% CI 97.0–100.0%).

Conclusion: The findings of this study assign superior diagnostic performance in the detection of B. abortus to LAMP. However, due to limitations associated with decreased specificity and a limited number of published articles on LAMP, the alternative use of PCR-based assays including those reported in literature is recommended while the use of LAMP for the detection of bovine brucellosis gains traction and should be evaluated more comprehensively in future.

Keywords: bovine brucellosis, Brucella abortus, meta-analysis, molecular diagnosis, systematic review.

Effect of leptin on the growth and expression of STAT3 in yak mammary epithelial cells

Research (Published online: 07-09-2022)

4. Effect of leptin on the growth and expression of STAT3 in yak mammary epithelial cells

Baoxia Dong, Sidra Mehran, Yuying Yang, Haixia Jing, Lin Liang, Xiaoyu Guo, and Qinwen Zhang

Veterinary World, 15(9): 2141-2150

ABSTRACT

Background and Aim: Leptin (LEP) is an autocrine and paracrine factor produced by the fat pad and acinar epithelial cells of the breast. This study aimed to investigate the effects of LEP on yak mammary epithelial cells (YMECs) and the expression of STAT3. In addition, we evaluated the possible effects of prolactin (PRL) on the function of LEP.

Materials and Methods: The YMECs were treated with 0, 50, 100, 200, 400, and 800 ng/mL LEP for 48 h in the absence of PRL and the presence of 500 ng/mL PRL. The growth activity of YMECs was measured using the cell counting kit-8 assay. The changes in the lactation signaling pathway-related factor STAT3 were detected at the mRNA, protein, and protein phosphorylation levels using the reverse transcriptase-quantitative polymerase chain reaction and Western blotting. To explore whether LEP affects the activation of STAT3 through JAK2/JAK3 in YMECs, the JAK2/3 signaling pathway inhibitor AG490 was used at a fixed concentration of LEP.

Results: Each concentration of LEP significantly promoted the expression of STAT3 mRNA (p < 0.05) in YMECs in the presence of PRL. In the absence of PRL, all concentrations of LEP were found to inhibit the expression of the STAT3 protein (p < 0.05). The expression of the STAT3 protein in YMECs was found to first increase followed by a decrease with an increase in the concentration of LEP. In addition, the phosphorylation level of STAT3 increased in all groups, except the 100 ng/mL concentration group. The STAT3 phosphorylation trend and protein expression were different, such that the level of protein phosphorylation was higher than that of the STAT3 protein (p < 0.05). The addition of AG490 reduced the expression of the STAT3 mRNA, STAT3 protein, and STAT3 phosphorylation in the LEP and LEP + PRL groups.

Conclusion: Altogether, the results indicated that different concentrations of LEP exerted varying effects on the growth of YMECs and the expression of STAT3, and the activity of STAT3 was primarily activated by JAK2. The addition of LEP can effectively inhibit the downregulation of the JAK2/STAT3 signal pathway by AG490, mitigate its inhibitory effect on the proliferation of YMECs, and reduce apoptosis. We believe that these findings will provide a theoretical and experimental basis for future research in this field.

Keywords: JAK2, leptin, mammary epithelial cells, STAT3, yak.