First study on capsular serotypes and virulence factors of Pasteurella multocida isolates from Phan Rang sheep in Vietnam

Research (Published online: 14-02-2023)

6. First study on capsular serotypes and virulence factors of Pasteurella multocida isolates from Phan Rang sheep in Vietnam

Phu Van Nguyen, Cong Tuan Le, Xuan Huy Nguyen, Tuan Manh Nguyen, and Kim Cuc Thi Nguyen

Veterinary World, 16(2): 281-290

ABSTRACT

Background and Aim: Pasteurella multocida is considered as a main factor mediating pneumonic pasteurellosis in ruminants, including sheep. It is also a current threat to Phan Rang sheep in Vietnam. This study aimed to characterize P. multocida isolated from Phan Rang sheep, their antibiotic resistance profile, and the prevalence of some virulence-associated genes of these strains.

Materials and Methods: Bacteria were isolated on brain heart infusion, 10% sheep blood agar plates, and screened by biochemical tests. The polymerase chain reaction technique was used with specific primers to identify P. multocida, the presence of virulence-associated genes, and serotypes of isolates. Antimicrobial susceptibility and biofilm formation of isolates were examined using the disk diffusion method and crystal violet-based method, respectively.

Results: A total of 41 P. multocida strains were isolated from 485 samples from clinically sick and healthy sheep. Of the isolates, 58.53% were serotype A, 9.75% were serotype B, and 31.71% were serotype D. Healthy animals were infected with serotype D only. All 15 virulence genes were identified in all strains isolated from clinically sick sheep, while strains isolated from healthy sheep carried 11/15 virulence genes tested. Among virulence-associated genes exbB, exbD, tonB, ompA, oma87, fimA, hgbA, and nanB were detected in over 90% of isolates, whereas hgbB, nanH, tbpA and pfhA were less frequent. Interestingly, pmHAS and tadD were highly prevalent in capsular type A strains, whereas the toxA gene was detected in capsular type D strains only. All of the isolated strains were fully susceptible to enrofloxacin, ciprofloxacin, neomycin, and ofloxacin. About 92.68% were susceptible to chloramphenicol and 90.24% to amikacin, but there was high resistance to erythromycin, tetracycline, and amoxicillin. Our results reveal that 53.65% of 41 isolates could produce biofilm, whereas 46.34% could not.

Conclusion: Pasteurella multocida from Phan Rang sheep possess many virulence genes and resistance to several common antibiotics such as erythromycin, tetracycline, and amoxicillin. The results are an important warning regarding antibiotic resistance of P. multocida.

Keywords: antimicrobial resistance, biofilm formation, capsular type, Pasteurella multocida, Phan Rang sheep.

Whole-genome sequencing of Histophilus somni strains isolated in Russia

Research (Published online: 14-02-2023)

5. Whole-genome sequencing of Histophilus somni strains isolated in Russia

Svetlana Yatsentyuk, Julia Pobolelova, Veronika Gordeeva, and Irina Timofeeva

Veterinary World, 16(2): 272-280

ABSTRACT

Background and Aim: Histophilus somni is a Gram-negative bacterium belonging to the Pasteurellaceae family that can cause bovine histophilosis. Histophilus may act as a commensal or opportunistic bacterial cattle pathogen. Comparing genomes of the pathogenic strain 2336 with the non-pathogenic preputial 129Pt isolate revealed some putative virulence factors. The study of the complete genomes of H. somni strains circulating in Russia has never been conducted before. This study aimed to identify genetic features of the H. somni strains isolated in Russia and evaluate the possibility of using strains for vaccine development.

Materials and Methods: Three strains of H. somni were isolated from different sources. Strain 188-VIEV was isolated from a vaginal swab sample of cattle with endometritis. 532-VIEV and 551-VIEV were cultured from the cryopreserved bull semen samples imported from Canada. Histophilus somni strain ATCC 700025 provided by ATCC (American Type Culture Collection) was also used in the study. DNA extraction was performed using QIAamp DNA Mini Kit (QIAGEN, USA). The whole-genome sequencing of the four strains was performed using Illumina Miseq. The comparison of the resulting sequences with the complete genomes of H. somni 2336 and 129Pt, and detection of the resistance genes and virulence factors, was performed using the ResFinder and Virulence Factor Database web services.

Results: The genome size of the samples varied from 1.9 to 2.3 Mb. The number of coding sequences varied from 1795 to 2256. The average sequence density was 90%. The total guanine-cytosine (GC) content was 36.8%–37.2%, which coincided with data previously obtained for H. somni. Three out of four studied strains encoded putative virulence factors such as filamentous hemagglutinin homologs, lipooligosaccharide biosynthesis proteins, and proteins involved in iron transport and utilization. The Ser83Ile substitution was identified in the DNA topoisomerase II (gyrA) in H. somni strains 532-VIEV and 551-VIEV cultured from bull semen which led to resistance to fluoroquinolones. The gene (AAC-6-Ia + APH-2”) encoding a bifunctional aminoglycoside modification enzyme was detected in strain 551-VIEV.

Conclusion: Strains with virulence genes identified could be candidates for designing vaccines and potentially represent antigen sources. The results show that antibiotic-resistant H. somni can be spread with semen used for artificial insemination.

Keywords: antibiotic resistance genes, Histophilus somni, next-generation sequencing, virulence factors.

Antimicrobial susceptibility test and antimicrobial resistance gene detection of extracellular enzyme bacteria isolated from tilapia (Oreochromis niloticus) for probiotic candidates

Research (Published online: 11-02-2023)

4. Antimicrobial susceptibility test and antimicrobial resistance gene detection of extracellular enzyme bacteria isolated from tilapia (Oreochromis niloticus) for probiotic candidates

Mira Mawardi, Agustin Indrawati, I. Wayan Teguh Wibawan, and Angela Mariana Lusiastuti

Veterinary World, 16(2): 264-271

ABSTRACT

Background and Aim: Antimicrobial resistance (AMR) is a global problem that can increase mortality and morbidity rates and adversely affect health. Therefore, AMR control must be carried out in various sectors, including the fisheries sector, using probiotics. Bacteria can become resistant to antibiotics, including bacteria used for probiotics. This study aimed to isolate bacteria as potential producers of extracellular enzymes, phenotypic characterization, and antibiotic-resistant gene patterns.

Materials and Methods: In this study, 459 bacterial isolates were isolated from the stomach of tilapia in Indonesia. Tilapia was obtained from Sukabumi, Ciamis, Serang, Banjarnegara, Jayapura, Sorong, Manokwari Selatan, Takalar, Lampung, Batam, and Mandiangin. Enzymatic bacteria were identified. An antimicrobial susceptibility test was conducted by agar disk diffusion, and genotypic detection of encoding genes was performed using a molecular method.

Results: This study obtained 137 isolates (29.84%) that can produce extracellular enzymes. The highest number of E-sensitive isolates was found, including 130 isolates (94.89%). Six isolates (6/137) can produce four enzymes (amylase, protease, cellulose, and lipase), and they were sensitive to antibiotics. A total of 99 isolates can produce extracellular enzymes, and they were sensitive to antibiotics. Such isolates serve as a consortium of probiotic candidates. The isolates that are resistant to oxytetracycline (OT), erythromycin (E), tetracycline (TE), and enrofloxacin (ENR) included 15 isolates (10.95%), seven isolates (5.11%), three isolates (2.19%), and one isolate (0.73%), respectively. In addition, four isolates (2.92%) were detected as multidrug-resistant. The tet(A) gene obtained the highest result of detection of resistance genes in isolates that were intermediate and resistant to TE and OT. Isolates that serve as ENR intermediates have a high qnr(S) resistance gene.

Conclusion: The data in this study provide the latest update that bacteria can serve as a consortium of potential probiotics with antibiotic-resistant genes for the treatment of fish. Bacteria that are intermediate to antibiotics may contain resistance genes. The results of this study will improve the policy of probiotic standards in Indonesia.

Keywords: antibiotic, antimicrobial resistance, enzymatic bacteria, Oreochromis niloticus, probiotic.

Effect of claw blocks on the healing duration and lesion severities of claw lesions in lame cows in Western Thailand

Research (Published online: 11-02-2023)

3. Effect of claw blocks on the healing duration and lesion severities of claw lesions in lame cows in Western Thailand

Pipat Arunvipas, Teerachad Setkit, Jaturong Wongsanit, Theera Rukkwamsuk, Nitipong Homwong, and Anawat Sangmalee

Veterinary World, 16(2): 258-263

ABSTRACT

Background and Aim: Lameness is a major complication in dairy cattle affecting health and milk production. Several factors are found to contribute to this condition and specific treatments are required, including the process of claw trimming. The elevation of the claw, such as with the application of a claw block, was reported to be beneficial in the more severe cases. This study aimed to determine the efficiency of a claw block on claw lesions of lame cows in dairy farms in Western Thailand.

Materials and Methods: Locomotion scores of 376 dairy cows were determined by a veterinarian using a scale of 1–5 (1 = normal; 5 = severely lame) at the time of the visit. Cows with a score of 3 or greater were defined as clinically lame. In total, 134 clinically lame cows from 11 dairy farms in the Kanchanaburi and Ratchaburi provinces were included in the analysis. Claw lesions included a white line abscess, bruised sole, sole ulcer, sole abscess, white line separate, and double soles. Wooden or rubber claw blocks were applied to the unaffected claw of the same hoof as the injured claw of 116 cows, which were classified as the treatment cases, and 18 cows were left untreated and classified as the control cases. Each cow was checked on every week of the healing process for 2 months unless the cow was culled earlier. Survival analysis was based on the Kaplan–Meier estimator and Cox Proportional Hazard regression.

Results: The median healing time for lame cows with and without claw blocks was 21 and 36 days, respectively. After adjusting for the lesion severity and type, the lame cows with and without a claw block had hazard ratios of 2.16 and 3.08, respectively. The healing times between the four lesion types in cows with a claw block were not significantly different. The healing time was longer in lame cows, with a severity score of 4.

Conclusion: The results from this study reveal that the treatment of lame cows with claw blocks promoted the healing capacity of claw lesions after claw trimming.

Keywords: claw block, claw lesion, dairy cows, lameness.

Aeromonas hydrophila induction method in adult zebrafish (Danio rerio) as animal infection models

Research (Published online: 09-02-2023)

2. Aeromonas hydrophila induction method in adult zebrafish (Danio rerio) as animal infection models

Dahliatul Qosimah, Sanarto Santoso, Maftuch Maftuch, Husnul Khotimah, Loeki Enggar Fitri, Aulanni'am Aulanni'am, and Lucia Tri Suwanti

Veterinary World, 16(2): 250-257

ABSTRACT

Background and Aim: Zebrafish are frequently used as model organisms in scientific research as their genes mirror those of humans. Aeromonas hydrophila bacteria can infect humans and animals, mainly fish. This study aimed to identify the concentration and route of A. hydrophila infection in adult zebrafish. Zebrafish had been used as a challenge test by analyzing their hematological profiles, blood glucose levels, and survival rates.

Materials and Methods: Induction of cell supernatant free (CSF) from A. hydrophila bacteria in adult zebrafish was carried out via bath immersion (BI), intraperitoneal injection (IPI), intramuscular injection (IMI), and healthy zebrafish as a control (C). The bacterial concentrations were 107, 109, and 1011 colony-forming units (CFU)/mL. At 24 h post-infection, the outcomes of infection were evaluated based on survival rates, hematological profiles, and blood glucose levels. A one-way analysis of variance with a confidence level of 95% was employed to examine the data.

Results: In the BI, IPI, and IMI treatment groups, the survival rate of the fish reached a peak of 100%, 22%–100%, and 16%–63%, respectively, compared with the injection technique. In the IMI2 group, a 109 CFU/mL bacterial concentration was determined to correspond to the lethal dosage 50. All infection groups had lower erythrocyte and hemoglobin counts but higher leukocyte counts than the control group. The blood sugar levels of the healthy and infected groups were not significantly different.

Conclusion: The route of A. hydrophila infection through Intramuscular injection with a concentration of 109 CFU/mL indicated a high performance compared to other techniques. This method could be developed as a reproducible challenge test.

Keywords: Aeromonas hydrophila, animal model, hematological profile, survival rate, zebrafish.

Veterinary World reviewer acknowledgment 2022

Reviewer Acknowledgment 2022 (Published online: 08-02-2023)

1. Veterinary World reviewer acknowledgment 2022

A. V. Sherasiya and Nazir

Veterinary World, 16(2): 246-249

Contributing reviewers 

Veterinary World editorial team would sincerely like to thank all of our reviewers who contributed to peer review for the journal in 2022.

Methicillin-resistant Staphylococcus aureus isolates derived from humans and animals in Yogyakarta, Indonesia

Research (Published online: 31-01-2023)

29. Methicillin-resistant Staphylococcus aureus isolates derived from humans and animals in Yogyakarta, Indonesia

Mulya Fitranda, Siti Isrina Oktavia Salasia, Osman Sianipar, Dion Adiriesta Dewananda, Adika Zhulhi Arjana, Fatkhanuddin Aziz, Madarina Wasissa, Fajar Budi Lestari, and Christin Marganingsih Santosa

Veterinary World, 16(1): 239-245

ABSTRACT

Background and Aim: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) as a highly pathogenic strain in veterinary and human medicine is a growing global problem. This study aimed to evaluate MRSA isolates of human and animal origin against various antibiotics in Yogyakarta, Indonesia.

Materials and Methods: The susceptibility test was carried out by the disk diffusion method using Mueller-Hinton agar against nine antibiotic disks. Methicillin-resistant S. aureus strains were genetically confirmed through mecA gene detection encoding for methicillin resistance by polymerase chain reaction.

Results: All 240 S. aureus strains isolated from animals and humans were resistant to penicillin G (P) (100% and 99%, respectively), followed by ampicillin (AMP), amoxicillin (AML), oxacillin (OX), erythromycin (E), clindamycin (DA), tetracycline (TE), gentamicin (GEN), and ciprofloxacin (CIP). Eighty-three MRSA strains were resistant to OX (100%), P (100%), AMP (99.27%), AML (95.52%), E (87.77%), TE (71.33%), DA (63.24%), GEN (38.81%), and CIP (26.87%).

Conclusion: The antimicrobial resistance pattern of S. aureus human isolates was similar to their animal counterpart, with 77.20% of MRSA strains classified as multidrug-resistant (MDR) bacteria. These findings indicate an increase in MDR S. aureus strains of animal origin in Yogyakarta, thus raising public health concerns about MRSA zoonotic spread.

Keywords: antimicrobial resistance, methicillin-resistant Staphylococcus aureus, multi-drug resistance, Staphylococcus aureus.